HPB Hydraulic Power Braking System

Transcription

1 HPB Hydraulic Power Braking System 4 th Edition This publication is not subject to any update service. New versions are available in INFORM at Copyright WABCO 2007 Vehicle Control Systems An American Standard Company The right of amendment is reserved Version 004/01.07(en)

2 Table of Contents 1. General Comments Diagrams of HPB Systems single - circuit dual - circuit dual - circuit with auxiliary braking system dual - circut with relay valves Description of Components Spring Brake Actuator Pressure Switch Hydraulic Accumulator Brake Valve Hand Brake Valve Double Check Valve Shut-Off Valve Check Valve Relay Valve General Comments...45 Information for Installation Capacity of Accumulators Legal Requirements ECE Regulation 13 - Annex 7C (Excerpt)

3 1. General Comments HPB Hydraulic Power Braking System At present the majority of specialpurpose vehicles, particularly construction vehicles up to a dead weight of approx. 7 tonnes, are equipped with hydraulic muscular power braking systems. Vehicles with a higher dead weight usualy have compressed-air braking systems. Since wet inboard disk brakes are being increasingly used in European construction vehicles, WABCO has developed a Hydraulic Power Braking System (HPB) which takes into account the special requirements for construction vehicles. The components of the hydraulic braking system are suitable for fluids on the basis of mineral oils and some bio-fluids which means that the fluids present in the construction vehicle's hydraulics can be used as the energy transmitter for the braking system. The cross-sections of the components have been designed to account for the higher viscosity of such fluids rather than conventional brake fluid. The components are particularly robust to ensure that they are capable of withstanding the tough conditions of everyday operation. The legal requirements for the HPB with regard to the size of its energy accumulators, the performance of its energy source and the properties of the alarm devices are defined in ECE - Regulation No. 13, Annex 7c. (Please refer to our manual "Legal Requirements", 2004 Edition, or page 50 to this brochure). The HPB system is not really suitable for operating a trailer braking system. This requires a system for supplying compressed air with a hydraulically operated Trailer Control Valve ( ) to be installed. The hand brake facility for the trailer can then be operated, for instance, via a hydro pressure switch, a solenoid valve and a relay valve (pneumatic). In order to take into account the trend towards dual circuit service braking systems, we recommend that vehicles > 25 k.p.h. are fitted with a dual circuit HPB system. Although according to the German Motor Vehicle Construction and Use Regulation construction vehicles merely require a single circuit system. IMPORTANT! If the brake volume is greater than 75 cm³, at least the first (top circuit) of the pedal brake valve must be equipped with a relay valve. The response and threshold times must be checked in all cases. If necessary, both circuits of the service brake system must be equipped with relay valves. 6

4 2. HPB - Diagram single - circuit all pipes of brake line NW 10 Port connections: 0 Suction 1 Energy supply 2 Energy delivery 5 Return connection No. Qty. Description Part Number 1 1 Pump 2 1 Pressure Filter 3 1 Shut-Off Valve Brake Valve Tank 9 Wheel brake cylinder 10 No. Qty. Description Part Number 11 1 Pressure Switch Pressure Switch Test connection Accumulator

5 HPB - Diagram dual - circuit 2. all pipes of brake line NW 10 Port connections: 0 Suction 24, 25 Hydraulic accumulator for Brake Valve: 1 Energy supply 26, 27 Hydraulic accumulator 24 Test connection (manometric switch) 11 Energy supply Circuit 1 28 Pressure switch 25 Test connection (manometric switch) 12 Energy supply Circuit 2 2 Energy delivery 4 Pilot connection 21 Energy delivery Circuit 1 5 Return connection 22 Energy delivery Circuit 2 51 Return connection Circuit 1 23 Energy delivery Circuit 3 52 Return connection Circuit 2 No. Qty. Description Part Number 1 1 Pump 2 1 Pressure Filter 3 1 Shut-Off Valve Brake Valve Tank 9 Wheel brake cylinder 10 No. Qty. Description Part Number 11 1 Pressure Switch Pressure Switch Test connection Accumulator Accumulator

6 2. HPB - Diagram dual - circuit with auxiliary braking system all pipes of brake line NW 10 Port connections: 0 Suction 24, 25 Hydraulic accumulator for Brake Valve: 1 Energy supply 26, 27 Hydraulic accumulator 24 Test connection (manometric switch) 11 Energy supply Circuit 1 28 Pressure switch 25 Test connection (manometric switch) 12 Energy supply Circuit 2 2 Energy delivery 4 Pilot connection 21 Energy delivery Circuit 1 5 Return connection 22 Energy delivery Circuit 2 51 Return connection Circuit 1 23 Energy delivery Circuit 3 52 Return connection Circuit 2 No. Qty. Description Part Number 1 1 Pump 2 1 Pressure Filter 3 1 Shut-Off Valve Brake Valve Hand Brake Valve Tank 9 Wheel brake cylinder 10 1 Spring Brake Actuator No. Qty. Description Part Number 11 1 Pressure Switch Pressure Switch Pressure Switch Test connection 15 1 Accumulator Accumulator Accumulator Accumulator

7 HPB - Diagram dual-circut with relay valves 2. all pipes of brake line NW 10 Port connections: 0 Suction 24, 25 Hydraulic accumulator for Brake Valve: 1 Energy supply 26, 27 Hydraulic accumulator 24 Test connection (manometric switch) 11 Energy supply Circuit 1 28 Pressure switch 25 Test connection (manometric switch) 12 Energy supply Circuit 2 2 Energy delivery 4 Pilot connection 21 Energy delivery Circuit 1 5 Return connection 22 Energy delivery Circuit 2 51 Return connection Circuit 1 23 Energy delivery Circuit 3 52 Return connection Circuit 2 No. Qty. Description Part Number 1 1 Pump 2 1 Pressure Filter 3 1 Shut-Off Valve Brake Valve Hand Brake Valve Relay Valve Tank 9 Wheel brake cylinder 10 1 Spring Brake Actuator No. Qty. Description Part Number 11 1 Pressure Switch Pressure Switch Pressure Switch Test connection 15 1 Accumulator Accumulator Accumulator Accumulator Accumulator Accumulator

8 3. Description of Components 13

9 Spring Brake Actuator with quick-release facility without quick-release facility Purpose: The spring brake actuator serves to generate the braking force for the wheel brake in secondary and parking braking systems. Operation: Ready Position In the driving condition, the pressure from the hand brake valve is acting directly on Port 1 of the Spring Brake Actuator. The secondary or parking brake is released. Braking position When the hand brake valve is actuated, the hydraulic pressure is reduced as a function of the angular position of the hand brake lever. As the pressure in the hydraulic portion (A) of the Spring Brake Actuator is reduced, the force of the releasing Compression Spring (B) makes Piston Rod (C) retract in the direction of the Actuator's axis, thus actuating the wheel brake. The Spring Brake Actuator's maximum brake force is reached when the pressure falls to zero. Quick Release Facility: Some variants are available with a quickrelease facility. This permits, in the event of the pressure in the hydraulic portion (A) failing, the wheel brake to be released by applying a blow in the direction of the arrow (F), using a hammer, thus severing the frictional connection established between Compression Spring (B) and Piston Rod (C) and actuating the quick-release facility (D). As the pressure in the hydraulic portion (A) builds up again, the connection between Compression Spring (B) and Piston Rod (C) is established once more and the Spring Brake Actuator is fully operative again. Emergency Release Facility If Spring Brake Actuators without a quickrelease facility are used, the parking brake can still be released should the hydraulic pressure fail. To do so, the Hexagon Nut (6) on Piston Rod (K) is taken off Yoke (C1). An open-jawed spanner (jaw size 13) is applied to Section (L) on Piston Rod (K). Piston Rod (K) is then turned in such a way that Yoke (C1) is displaced towards the brake lever. 14

10 Spring Brake Actuator Technical Data: Part Number Operating pressure 150 bar max. Stroke 80 ± 3 mm Release pressure 87 ± 4 bar 60-4 bar 40 ± 4bar bar 60-4 bar Operating temperature range 30 C to +80 C Medium mineral oil 10 to 2000 mm 2 /s Output force at 0 mm stroke 2.75 kn 2.3 kn 1.5 kn 3.0 kn 2.3 kn Output force at 80 mm stroke 4.32 kn 3.25 kn 2.2 kn 5.0 kn 3.25 kn Piston rod deflection 3 on all sides Emergency release facility NO NO NO YES YES Yoke NO YES YES YES YES Bellows YES YES YES YES YES Weight 6.5 kg 6.8 kg 8.0 kg Repair Kits: Repair kit Variant of Actuator For safety reasons the whole of the Spring Brake Actuator must be replaced if parts other than those listed above are damaged. Attention! The enclosed portion of the actuator is spring-loaded! Replacing the Bellows Remove clamps (2; 3 or H) from the bellows, replace as necessary when fitting the new bellows. Pull off the faulty bellows (1), push on new bellows and fasten with clamps (2; 3 or H). Replacing the Yoke When replacing the Yoke (5) on actuators without a quick-release facility, immobilize the piston rod (K) by applying a spanner (jaw size 13). Remove Hexagon Nut (6) and unscrew Yoke (5) from the piston rod. The new Yoke (5) is screwed into the piston rod up to the point where the original piston rod length is once again achieved (see outline drawing: distance from centre yoke hole to end face of Port 1). Secure piston rod by means of hexagon nut. 15

11 Spring Brake Actuator Installation dimensions: showing: quick release facility: actuation by applying a blow to the flange Thread of pipe connections: M16 x deep Variant 002 showing:

12 Spring Brake Actuator Installation Requirements: The connecting lines must be installed in such a way as to permit proper bleeding. The actuator should be mounted at a slight angle, its piston rod pointing downwards. Maintenance: No special maintenance beyond the legal requirements is necessary. When using high-pressure cleaners on the vehicle, please make sure that the water jet is not aimed directly at the Spring Brake Actuator (to prevent damaging the bellows) Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! 17

13 Pressure Switch Purpose: The Pressure Switches are used to visually or audibly warn the driver of the pressure within the system. Operation: Make Contact / Circuit Closer The Pressure Switch can be fitted in the braking system or directly on one of its components. The system pressure acts on an absorption area within the switch, making an electrical contact as the pressure on that area is increased. The resulting current is used to activatea warning facility, for instance. breaking an electrical contact as the pressure on that area is increased. The current is now broken, e.g. to deactivate a warning facility. Installation Requirements: No special measures need to be taken. Maintenance: No special maintenance beyond the legal requirements is necessary. When using high-pressure cleaners on the vehicle, please make sure that the water jet is not directed at the Pressure Switch. (corrosion of contacts). Break Contact Make Contact Break Contact / Circuit Breaker The Pressure Switch can be fitted in the braking system or directly on one of its components. The system pressure acts on an absorption area within the switch, Technical Data: Part Number Medium G H 1 (mm) H 2 (mm) Adjusting range in bar Actuating pressure in bar Break Contact mineral oil M12x ± mineral oil M12x ± mineral oil M12x ± mineral oil M12x ± mineral oil M10x1 tapered mineral oil M12x ± 0,5 42 Make Contact mineral oil M12x1 tapered mineral oil M12x ± mineral oil M12x mineral oil M10x1 tapered mineral oil M12x ± 0,5 42 Voltage in V Breaking capacity of all pressure switches 100 Voltampere resistive load Boot for Pressure Switch: Part Number

14 Pressure Switch Installation dimensions: Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the Pressure Switch needs to be replaced as a whole if damaged. Adjusting and testing the Pressure Switch: Adjusting screw The adjusting screw located between the two contact plugs can be set to the desired value within a certain range. For adjusting range, please refer to the table "Technical Data" on the previous page. After making the adjustment, the adjusting screw should be secured using wax or a similar material. 19

15 Hydraulic Accumulator Purpose: Fluids are practically incompressible and are thus incapable of accumulating pressure energy. In hydropneumatic accumulators, the compressibility of a gas is utilized to accumulate fluid. The compressible medium used in the accumulators is nitrogen. In braking systems, the purpose of the accumulators is to store the energy supplied by the hydrailc pump. They are also used as an energy reserve when the pump is not working, as a compensator for any losses through leakage, and as oscillation dampers. diaphragm (C) as a gas-tight dividing element. The fluid portion (A) is connected to the hydraulic circuit, causing the diaphragm accumulator to be filled and the gas volume to be compressed as the pressure rises. When the pressure falls, the compressed gas volume will expand, thus displacing the accumulated pressure fluid into the circuit. The diaphragm bottom contains a valve disk (D) which, if the diaphragm accumulator is completely empty, closes the hydraulic outlet, thus preventing damage to the diaphragm. Operation: The accumulator consists of a fluid portion (A) and a gas portion (B) with a Technical Data: Part Number Diameter 121 mm 136 mm Mounting height 146 mm 160 mm Nominal volume 0.75 dm³ 1.0 dm³ Priming pressure 50 bar Operating medium mineral oil Operating pressure 180 bar max. 200 bar max. Thread M18x1.5 M22x1.5 Operating temperature range 30 C to +80 C Mounting position optional Priming gas nitrogen 20

16 Hydraulic Accumulator Installation Requirements: The accumulators can be fitted in the hydraulic circuit, directly on a component or in blocks on suitable consoles. They should be fitted in as cool a location as possible. Installation can be in any position. Maintenance: No special maintenance beyond the legal requirements is necessary. The accumulator should be checked annually. It should be replaced if the initial gas pressure has fallen by more than 30% (please refer to "Performance testing and checking of the Accumulator"). Disposal of the Accumulator: Before the accumulator is scrapped, its gas filling pressure must be reduced. For this purpose, drill a hole through Gas Chamber (B) using a drill approx. 3 mm in diameter. The gas chamber is located on the side opposite the threaded port above the welding seam around the centre of the accumulator. Wear safety goggles when doing this job! Performance testing and checking of the Accumulator: A = ball valve for shutting off pump flow B = ball valve for reducing pressure S = safety valve: set to 180 bar max. M = pressure gauge H = hydraulic accumulator The accumulator is gradually pressurized via the test pump; until the initial gas pressure is reached, the hydraulic pressure in the accumulator will rise abruputly. This is apparent from gauge "M". If the initial gas pressure is more than 30% below the prescribed value, the accumulator needs to be replaced. If the measuring process needs to be repeated, wait for intervals of 3 minutes between the individual tests. Any accumulator whose initial gas pressure is insufficient must be scrapped following the instructions under "Disposal of the Accumulator". The amount of initial gas pressure can also be checked from the vehicle. Start the vehicle's engine. The pump will now supply oil to the accumulators. Until the initial gas pressure is reached, the hydraulic pressure in the accumulator will rise abruputly. This is apparent from the gauge in the cab. If the initial gas pressure is more than 30% below the prescribed value, that initial pressure lies outside the permissible range for at least one of the accumulators fitted in the vehicle. This accumulator can be traced only by using the method described above, i.e. all accumulators have to be individually tested. The accumulator whose initial gas pressure is insufficient must be replaced and scrapped following the instructions under "Disposal of the Accumulator". Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the Accumulators need to be replaced as a whole if damaged. 21

17 Brake Valve for single circuit braking system Purpose: The purpose of the Brake Valve is to sensitively increase and decrease the braking pressure when the brake pedal (or the actuating lever) is actuated. Operation: Ready Position When the braking system is ready for operation, its accumulator pressure acts directly on Port 1 of the Brake Valve. A connection is established between Ports 21 and 51 so that the wheel brake (Port 21) is pressureless via the return (Port 51). Partial Braking When the Brake Valve is actuated, an amount of hydraulic pressure is output as a ratio of the foot force applied. The Spring Assembly (A) beneath Base Plate (E) is designed in such a way that the braking pressure changes depending on the angle. In the lower braking pressure range, the vehicle can be slowed sensitively. When the braking process is commenced, Slide (C) is mechanically actuated via Spring Assembly (A). As Slide (C) moves downward, it will first close Return 51 via the control edge, thus establishing a connection between Accumulator Port 1 and Port 21 for the wheel brake cylinders. The foot force applied now determines the output braking pressure. Control Slide (C) is held in the control position by the force applied (spring assembly) and the hydraulic pressure below Slide (C) (balance of forces). After output of the braking pressure, Slide (C) is in a partial braking position, causing Ports 1 and 51 to close and holding the pressure in Port 21. Full Braking Position When Pedal (B) is fully actuated, an end position of the brakes is reached and a connection established between Accumulator Port 1 and Brake Cylinder Port 21. Return 51 is closed at this point. When the braking process is ended, a connection is once again established between Brake Cylinder Port 21 and Return Port 51, closing Accumulator Port 1. Limiting the Braking Pressure Pedal Restriction Screw (D) on Base Plate (E) below Pedal (B) is used to limit the braking pressure. This will cause the accumulator pressure building up in the braking system to be limited Leading edge 22

18 Brake Valve for single circuit braking system Technical Data: Part Number Pedal Angle Actuating path Brake pressure Actuating force Comments ± 10 mm 150 bar 360 N 1) ± 10 mm bar 280 N 1) ± 10 mm bar 240 N 1) ± 10 mm bar 240 N 1) Lever 150 bar 875 N 1) ± 5 mm bar 350 N 1) bar 280 N 1) bar 360 N 1) with pedal locking bar 300 N device 1) Operating temperature range for all variants 30 C to +80 C / Operating pressure: 150 bar 1) Pressure at the return port 51 < 5 bar Installation dimensions: showing: Thread of pipe connections: M 14x deep Port connections: 1 = Energy supply 21 = Energy delivery 51 = Return connection showing: Variant

19 Brake Valve for single circuit braking system Installation dimensions: showing: Thread of pipe connections: Variant 1, 21 and M 14x deep M 12x , 102, 108, 128 M 14x deep 124 M 16x deep M 12x M 16x deep M 10x1 Port connections: 1 = Energy supply 21 = Energy delivery 24 = Test port 51 = Return connection Installation Requirements: Return Line 51 must be connected directly to the tank. The connecting lines must be installed in such a way as to permit proper bleeding. Maintenance of the Brake Valve No special maintenance beyond the legal requirements is necessary. When using high-pressure cleaners on the vehicle, please make sure that the water jet is not aimed directly at the Brake Valve. (to prevent damaging the bellows) Replacing the Pedal Cover Pedal Cover (1) is simply pulled off by hand. The new pedal cover is pushed over Pedal (B) and tightened manually. Fasten the bellows with the strap retainers. Replacing the complete Actuating Mechanism Carefully clamp the unit vertically in a fixture. The actuating mechanism can be removed by taking out the four Screws (H) below Base Plate (E). Make sure that Spring Assembly (A) does not fall out. When installing the new actuating mechanism, make sure that Spring Assembly (A) is fitted in the right order. Tighten the four Screws (H). 24

20 Brake Valve for single circuit braking system Replacing the Bellows To change Bellows (3) it is advisable to remove Pedal (B). For this purpose, loosen Retaining Ring (L) and knock out Bolt (M) using a mandril. When knocking out the bolt, make sure that the mandril is applied to the side of the bolt without a knurl. Remove Pedal (B) and Bellows (3). Now fit the new Bellows (3) and proceed in reverse order as described above. The upper portion of Bellows (3) is fastened to Piston (N), its lower portion to Base Plate (E). Replacing the Grooved Ring Carefully clamp the unit vertically in a fixture. Unscrew Screw Plug (P) and pull Slide (C) out downwards. Check the slide for damage. If they are found to be damaged, the whole Brake Valve needs to be replaced. (Pairs of slides and housings are matched in manufacturing.) If the slide is not damaged in any way, remove the whole actuating mechanism as described above. Remove Spring Assembly (A) and Grooved Ring (4) and put in a new greased grooved ring with its lips pointing downwards. Install both the spring assembly as shown in the drawing, and the pedal. Carefully reinsert Slide (C) into the housing from below, turning it slightly. Put in Spring (R) and close the unit with Screw Plug (P). Check Return Port 51 to see if there is a gap of approx. 2 mm between the lower edge of the hole and the control edge of Slide (C). If this is not the case, change the setting by removing or adding distance washers (5) in the upper spring plate of the spring assembly. Check the distance between the lower edge of the hole and the control edge of Slide (C) again. Spare parts: Description No. Part Number Variant of Brake Valve complete , 102, 103 Actuating Mechanism , 124 Bellows , 121, 124 Repair kit Variant of Brake Valve For safety reasons the whole of the Brake Valve must be replaced if parts other than those listed above are damaged. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! 25

21 Brake Valve for dual circuit braking system Purpose: The purpose of the Brake Valve is to sensitively increase and decrease the braking pressure when the brake pedal (or the actuating lever) is actuated. Operation: Ready Position When the braking system is ready for operation, its accumulator pressure acts directly on Port 1.1/1.2 of the Brake Valve. A connection is established between Ports 2.1/2.2 and Ports 5.1/5.2 so that the wheel brakes (Ports 2..) are pressureless via the returns (Ports 5..). Partial Braking When the Brake Valve is actuated, an amount of hydraulic pressure is output as a ratio of the foot force applied. The Spring Assembly (A) beneath Base Plate (E) is designed in such a way that the braking pressure changes depending on the angle. In the lower braking pressure range, the vehicle can be slowed sensitively. When the braking process is commenced, the upper Slide (C1) is mechanically actuated via Spring Assembly (A), and the lower Slide (C2) is actuated hydraulically by Slide (C1). As Slides (C1 and C2) move downward, they will first close Returns 5.1/5.2 via the control edges, thus establishing a connection between Accumulator Ports 1.1/1.2 and Ports 2.1/2.2 for the wheel brake cylinders. The foot force applied now determines the output braking pressure. The Control Slides (C1 and C2)) are held in the control position by the force applied (spring assembly) above the slides and the hydraulic pressure below the slides (balance of forces). After output of the braking pressure, Slides (C1 and C2) are in a partial braking position, causing Ports 1.1/1.2 and 5.1/5.2 to close and holding the pressure in Ports 2.1/2.2. Full Braking Position When Pedal (B) is fully actuated, an end position of the brakes is reached and a connection established between Accumulator Ports 1.1/1.2 and Brake Cylinder Ports 2.1/2.2. Returns 5.1/5.2 are closed at this point. When the braking process is ended, a connection is once again established between Brake Cylinder Ports 2.1/2.2 and Return Ports 5.1/5.2, closing Accumulator Ports 1.1/1.2. The arrangement of slides in the valve ensures that even if one braking circuit fails the other remains fully operational. This is achieved by means of the mechanical actuation of both slides and requires slightly more pedal travel. Limiting the Braking Pressure Pedal Restriction Screw (D) on Base Plate (E) below Pedal (B) is used to limit the braking pressure. Failure of a Circuit In the event of the lower circuit failing, the upper circuit will remain operational. Spring Assembly (A) will mechanically actuate Slide (C1). In the event of the upper circuit failing, the lower circuit will remain operational since the lower Slide (C2) is mechanically actuated by Spring Assembly (A) and Slice (C1). Leading edge 26

22 Brake Valve for dual circuit braking system Technical Data: Part Number Pedal Angle Actuating path Operating Pressure Brake pressure 1) Pressure at the return port 5: 5 bar max. 2) Port 5.1 closed with plug Actuating force Comments ± 10 mm 150 bar bar 320 N 1) Lever 28 mm 150 bar 120 bar 800 N 1) mm 150 bar bar 300 N 1) ± 10 mm 150 bar bar 380 N 1) ± 2 mm 150 bar bar 200 N 1) ± 5 mm 150 bar bar 220 N 1) mm 150 bar 150 bar 320 N 1) mm 150 bar 150 bar 400 N 1) mm 150 bar 150 bar 400 N 1) Piston 12 mm 150 bar 150 bar 2700 N 1) Piston 13 mm 150 bar 150 bar 3000 N Flange valve, 1) bar 50 bar 250 N with pedal locking device, 1) ± 10 mm 150 bar bar 290 N 1) bar 40 bar 280 N with pedal locking device, 1) ± 10 mm 150 bar bar 300 N 1) ± 10 mm 150 bar bar 240 N 1), 2) bar 90 bar 350 N with pedal locking device, 1), 2) bar bar 340 N 1), 2) bar bar 200 N to bar bar 460 N with hydr. actuation (Port 3 M 12x1.5), 1) with electrical actuation of the retarder, 1) to bar bar 460 N for VOLVO with electrical actuation of to bar 167 ± 5 bar 420 N the retarder, 1) Operating temperature range for all Variants 30 C to +80 C Spare parts: Repair Kits: Description No. Part Number Variant of Brake Valve complete Actuating Mechanism Bellows , 216, 220, 227, 233, 235, 246, 401, 408, 411, 414, 508, 510 Repair kit Variant of Brake Valve , , ,

23 Brake Valve for dual circuit braking system Installation dimensions: showing: Port connections: 1.1, 1.2 = Hydraulic accumulator 2.1, 2.2 = Service brake 2.4, 2.5 = Test connection 5.1, 5.2 = Return connection Thread of pipe connections: Variant 1.1, 1.2, 2.1, 2.2, 5.1, , 216, 218, 219, 220, 227, M 16x , 234, 235, -12 deep 247, 508, 510, , 413, M 16x deep 202, 301, 309, M 16x , 408, deep 246 Flange valve 2.4, 2.5 M 10x1-8 deep M 12x1.5-8 deep M 12x deep Base plate panel opening showing:

24 Brake Valve for dual circuit braking system Installation dimensions: showing: Port connections: 1.1, 1.2 = Hydraulic accumulator 2.1, 2.2 = Service brake 2.4, 2.5 = Test connection 5.1, 5.2 = Return connection showing:

25 Brake Valve for dual circuit braking system Installation Requirements: Return Lines 5.1/5.2 must be connected directly to the tank. The connecting lines must be installed in such a way as to permit proper bleeding. Maintenance of the Brake Valve No special maintenance beyond the legal requirements is necessary. When using high-pressure cleaners on the vehicle, please make sure that the water jet is not aimed directly at the Brake Valve (to prevent damaging the bellows) Replacing the Pedal Cover Pedal Cover (1) is simply pulled off by hand. The new pedal cover is pushed over Pedal (B) and tightened manually. Fasten the bellows with the strap retainers. Replacing the complete Actuating Mechanism Carefully clamp the unit vertically in a fixture. The actuating mechanism can be removed by taking out the four Screws (H) below Base Plate (E). Make sure that Spring Assembly (A) does not fall out. When installing the new actuating mechanism, make sure that Spring Assembly (A) is fitted in the right order. Tighten the four Screws (H). Replacing the Bellows To change Bellows (3) it is advisable to remove Pedal (B). For this purpose, loosen Retaining Ring (L) and knock out Bolt (M) using a mandril. When knocking out the bolt, make sure that the mandril is applied to the side of the bolt without a knurl. Remove Pedal (B) and Bellows (3). Now fit the new Bellows (3) and proceed in reverse order as described above. The upper portion of Bellows (3) is fastened to Piston (N), its lower portion to Base Plate (E). Secure the bellows using clamps. Replacing the Grooved Ring Carefully clamp the unit vertically in a fixture. Unscrew Screw Plug (P) and pull Slides (C1 and C2) out downwards. Check the slides for damage. If they are found to be damaged, the whole Brake Valve needs to be replaced. (Pairs of slides and housings are matched in manufacturing.) If the slides are not damaged in any way, remove the whole actuating mechanism as described above. Remove Spring Assembly (A) and Grooved Ring (4) and put in a new greased grooved ring with its lips pointing downwards. Install both the spring assembly as shown in the drawing, and the pedal. Carefully re-insert Slide (C1) into the housing from below, turning it slightly. Put in Spring (R1), followed by Slide (C2), using a slight turning motion if possible. Insert Spring (R2) and close the unit with Screw Plug (P). Check Return Port 5.1 to see if there is a gap of approx. 2 mm between the lower edge of the hole and the control edge of Slide (C1). If this is not the case, change the setting by removing or adding Distance Washers (5) in the upper spring plate. Check the distance between the lower edge of the hole at Port 5.1 and the control edge of Slide (C1) again. For safety reasons the whole of the Brake Valve must be replaced if parts other than those listed above are damaged. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! 30

26 Hand Brake Valve (Locked position = pressure reduc Purpose: The purpose of the Hand Brake Valve is to sensitively increase and decrease the braking pressure when the hand brake lever is actuated. Operation: Ready Position When the braking system is ready for operation, its accumulator pressure acts directly on Port 1 of the Hand Brake Valve. A connection is established between Ports 1 and 21 so that the vehicle's hand brake is released. Secondary Braking System When the Hand Brake Valve is actuated, the hydraulic release pressure is increased or decreased as a function of the hand brake lever's pivoting angle. Spring Assembly (A) below Cam Plate (B) permits a sensitive braking process for the vehicle. When the secondary braking process is commenced, Slide (C) is mechanically actuated via Spring Assembly (A). Slide (C) moves upwards, it first closes Accumulator Port 1 via the control edge and then establishes a connection between Brake Cylinder Port 2 and Return 5. The pivoting angle of the hand brake lever will now determine the pressure in the spring brake actuator (Port 2). Slide (C) is held in the control position by the force (spring assembly) above the slide and by the hydraulic pressure below the slide (balance of forces). Slide C is in a partial braking position, causing Ports 1 and 5 to close and to hold the pressure in Port 2. In the range of partial brake application, the hand lever will automatically return to the driving position when the braking process is ended. Parking Brake When the lever is fully actuated, an end position of the brake is reached and a connection is established between Return 5 and Brake Cylinder Port 2. Accumulator Port 1 is closed and the lever is locked in position. When the parking brake is released, a connection between Brake Cylinder Port 2 and Accumulator Port 1 is once more established, and Return Port 5 is closed. Once released from its locked position, the hand brake lever will automatically return to the driving position. Installation Requirements: Return Line 5 must be connected directly to the tank. The connecting lines must be installed in such a way as to permit proper bleeding. The Hand Brake Valve should be installed in a position where it cannot be accidentally actuated by the driver's foot. Maintenance of the Brake Valve No special maintenance beyond the legal requirements is necessary. When using high-pressure cleaners on the vehicle, please make sure that the water jet is not aimed directly at the Hand Brake Valve (to prevent damaging the bellows) Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! Replacing the Bellows To change Bellows (D), remove Actuating Button (E) from Lever (F). To do this, push out the two Retaining Pins (G). The Bellows (D) can now be pulled off and the new ones installed. Push Actuating Button (E) back onto Lever (F), securing it with Retaining Pins (G). 31

27 Hand Brake Valve Technical Data: Part Number Operating pressure Working pressure bar bar 125 bar *) 50 bar Permissible medium Operating temperature range in locked position mineral oil 40 C to +80 C pressure reducing *) ONLY FOR REPLACEMENT! Spare parts: Description Part Number Variant of Hand Brake Valve Bellows For all devices still in use For safety reasons the whole of the Hand Brake Valve must be replaced if parts other than the bellows are damaged. Installation dimensions: showing: Thread of pipe connections: 1,21, 5 = M16 x deep 25 = M 12 x deep Port connections: 1 = Energy supply 21 = Energy delivery 24 = Pressure switch connection 5 = Return connection 32

28 Double check valve NO LONGER AVAILABLE! ONLY FOR INFORMATION! Purpose: The purpose of the Double Check Valve is to permit alternate actuation of the braking circuits. It permits a hydraulic braking circuit to be actuated by two actuating valves. Operation: from Port 11 or 12, depending on the type of actuation of the valve, to Port 2. A ball seat valve arrangement ensures that as the foot brake valve is actuated, Port 12 remains pressureless when the pressure is increased at Port 11, and vice versa. The ball seat also prevents the control pressure being reduced through the part of the line which is not being utilized. When the control pressure is built up, the control pressure is passed unrestrictedly Technical data Part Number Operating pressure 200 bar max., 2 bar min. Permissible medium mineral oil 10 mm²/s to 1936 mm²/s brake fluid Operating temperature range 40 C to +80 C Rate of flow max. 12 dm³ / min Weight 0.42 kg Installation dimensions: Thread of pipe connections: M 14 x 1.5 DIN Port connections: 11, 12 = Energy supply 2 = Energy delivery Maintenance of the Double Check Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! 33

29 Shut-Off Valve for Single Circuit Systems Purpose: The purpose of the Shut-Off Valve is to control the pressure level in the accumulators. Operation: Ready Position When the braking system is ready for operation (i.e. the accumulators are charged) the pump stream is present at Port 1 of the Shut-Off Valve. A connection is established between Ports 1 and 5 so that the pump stream can, with a small difference in pressures, be returned directly to the reservoir or other consumers. The rear of Main Slide (A) is pressureless. The pressure within the braking system will hold Control Slide (B) in its locked position (E1) in which the rear of Main Slide (A) is directly connected to Return 5 via Hole (G). Check Valve (C) in the hole to Port 2 secures the accumulator pressures. Charging Process As the accumulator pressure falls to the preset value, Control Slide (B) will, through the force of Spring Assembly (D), overcome its locked position (E1) and move to another locked position (E2). Via Orifice (F) and through Connecting Hole (H), an oil stream flows to the rear of Main Slide (A). The pressure building up at the rear of Main Slide (A) and the pressure present below Main Slide (A) put Main Slide (A) in a floating position, permitting a partial stream to continue to reach Port 5 and the remaining stream to flow to Port 2 via Check Valve (C) until the pressure at Port 2 is approx. 150 bar. Control Slide (B) will then once again move to Locked Position (E1) in which a connection is established between Ports 1 and 5 and the whole of the pump stream once again flows to the reservoir. Check Valve (C) once again secures the accumulator pressures. Technical Data: Part Number Operating pressure 200 bar max. Pressure at port bar max. 200 bar max. 50 bar max. Cut-in pressure bar bar bar Cut-off pressure bar bar bar Flow rate max. 16 l /min from 1 2 = l /min from 1 5 = 45 l /min Permissible medium mineral oil: mm² /s Operating temperature 30 C to +80 C range Weight 2.4 kg from 1 2 = l /min from 1 5 = 45 l /min 34

30 Shut-Off Valve for Single Circuit Systems Installation dimensions: showing: Thread of pipe connections: 1, 5 = M 18 x deep (M = 50 ± 5 Nm) 2 = M 16 x deep (M = 40 ± 5 Nm) Port connections: 1 = Energy supply 2 = Service brake 5 = Return connection Installation Requirements: The connecting lines must be installed in such a way as to permit proper bleeding. Maintenance of the Shut-Off Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the whole of the Shut-off Valve must be replaced if damaged. 35

31 Shut-Off Valve for Dual Circuit Systems Purpose: The purpose of the Shut-Off Valve is to control the pressure level in the accumulators. Operation: Ready Position When the braking system is ready for operation (i.e. the accumulators are charged) the pump stream is present at Port 1 of the Shut-Off Valve. A connection is established between Ports 1 and 5 so that the pump stream is, with a small difference in pressures, returned directly to the reservoir. The rear of Main Slide (A) is pressureless. The pressure within the braking system will hold Control Slide (B ) in its locked position (E1) in which the rear of Main Slide (A) is directly connected to Return 5 via Hole (G). Check Valve (D) in the hole to Ports 21 and 23 secures the accumulator pressures. Shuttle Valve (H) causes the accumulator with the lowest pressure to operate the Shut-Off Valve whilst securing the circuit in the event of a broken pipe. Charging Process As the accumulator pressure falls to the preset value, Control Slide (B) will, through the force of Spring Assembly (C), overcome its locked position (E1) and move to another locked position (E2). Via Orifice (F) an oil stream flows to the rear of Main Slide (A). The pressure building up at the rear of Main Slide (A) and the pressure present below Main Slide (A) put Main Slide (A) in a floating position, permitting a partial stream to continue to reach Port 5 and the remaining stream to flow to Ports 21/23 via Check Valve (D) until the pressure within the braking system is approx. 150 bar. Control Slide (B) will then once again move to Locked Position (E1) in which a connection is established between Ports 1 and 5. The whole of the pump stream once again flows to the reservoir via Port 5. Check Valve (D) once again secures the accumulator pressures. Technical Data: Part Number Operating pressure 200 bar max. Pressure at port 5 temporary 200 bar Cut-in pressure bar Cut-off pressure bar Rate of flow max. 45 l /min Permissible medium mineral oil: 2000 to 10 mm² /s VAI 6 to 12 Operating range bar Operating temperature range 30 C to +80 C Weight 3.8 kg 36

32 Shut-Off Valve for Dual Circuit Systems Installation dimensions: x View X showing: Thread of pipe connections: 1, 5 = M18x deep (M = 50 ± 5 Nm) 21, 23, 27 = M16x deep (M = 40 ± 5 Nm) 28 = M12x deep (M = 28 ± 3 Nm) Port connections: 1 = Energy supply 21, 23 = Service brake 27 = Hydraulic accumulator 28 = Pressure switch 5 = Return connection Installation Requirements: The connecting lines must be installed in such a way as to permit proper bleeding. Maintenance of the Shut-Off Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the whole of the Shut-off Valve must be replaced if damaged. 37

33 Shut-Off Valve for Triple Circuit Systems Variant 007 Purpose: The purpose of the Shut-Off Valve is to control the pressure level in the accumulators. Operation: Ready Position When the braking system is ready for operation (i.e. the accumulators are charged) the pump stream is present at Port 1 of the Shut-Off Valve. A connection is established between Ports 1 and 5 so that the pump stream is, with a small difference in pressures, returned directly to the reservoir. The rear of Main Slide (A) is pressureless. The pressure within the braking system will hold Control Slide (B ) in its locked position (E1) in which the rear of Main Slide (A) is directly connected to Return 5 via Hole (G). Check Valve (D) in the hole to Port 27 secures the accumulator pressure of the operating accumulator. This is available as an additional braking volume for the braking system, preventing excessively frequent actuation of the Shut-Off Valve in the event of a leakage. Shuttle Valves (H) additionally secure each braking circuit against pressure losses in the event of a broken pipe. Charging Process As the accumulator pressure falls to the preset value, Control Slide (B) will, through the force of Spring Assembly (C), overcome its locked position (E1) and move to another locked position (E2). Via Orifice (F) an oil stream flows to the rear of Main Slide (A). The pressure building up at the rear of Main Slide (A) and the pressure present below Main Slide (A) put Main Slide (A) in a floating position, permitting a partial stream to continue to reach Port 5 and the remaining stream to flow to Ports 21//22/ 23 via Check Valve (D) until the pressure within the braking system is approx. 150 bar. Control Slide (B) will then once again move to Locked Position (E1) in which a connection is established between Ports 1 and 5. The whole of the pump stream once again flows to the reservoir via Port 5. Check Valve (D) again secures the accumulator pressures. Variant

34 Shut-Off Valve for Triple Circuit Systems Technical Data: Part Number Pressure at port 5 temporary 200 bar max. Pressure limiting bar without Cut-in pressure Cut-off pressure bar bar Flow rate max. 16 l /min 45 l /min Flow rate to braking circuit l /min l /min Permissible medium mineral oil mm² /s Installation dimensions: Operating temperature range Weight 30 C to +80 C 3.8 kg x showing: View X Thread of pipe connections: 1, 5 = M18x deep (M = 50 ± 5 Nm) 21, 22, 23, 27 = M16x deep (M = 40 ± 5 Nm) 28 = M12x deep (M = 28 ± 3 Nm) Port connections: 1 = Energy supply 21, 22, 23 = Service brake 27 = Hydraulic accumulator 28 = Pressure switch 5 = Return connection Installation Requirements: The connecting lines must be installed in such a way as to permit proper bleeding. Maintenance of the Shut-Off Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the whole of the Shut-off Valve must be replaced if damaged. 39

35 Check Valve Purpose: The purpose of the Check Valve is to secure the pressure in the intact braking circuits of a triple circuit braking system in the event of one circuit failing. Operation: Filling Position After Check Valves (A) have opened, the oil stream from Port 1 will reach the downstream accumulators of the brake valves via Ports 21 and 22 and flows via Port 23 to the accumulator for the hand brake valve. Pressure gauges or manometric switches can be connected at Ports 24, 25 and 26 to check the braking pressure. Ready Position When the pressure at Port 1 is reduced, return flow of the oil is prevented by closing of Check Valves (A), thus securing the pressure in the hydraulic accumulators. As the pressure is increased, Check Valves (A) are opened once again, permitting the pressures in the cirucits to be balanced. Pressure Limiting Facility A Pressure Limiting Valve (B) integrated in the Check Valve limits the output pressure to a maximum of 180 bar. Technical Data: Part Number Operating pressure 160 bar max. Pressure limiting bar Permissible medium mineral oil: 1940 to 10 mm² /s Operating temperature range 40 C to +80 C Flow rate 0.7 to 16 l /min Nominal diameter 8 mm 40

36 Check Valve Installation dimensions: Thread of pipe connections: 1, 5, 21 22, 23 = M14x1.5 DIN , = M14x deep Port connections: 1 = Energy supply = Energy delivery 5 = Return connection Installation Requirements: The connecting lines must be installed in such a way as to permit proper bleeding. The Check Valve can be mounted in any position. Maintenance of the Check Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the whole of the Check Valve must be replaced if damaged. 41

37 Relay Valve Purpose: The purpose of the Relay Valve is to rapidly transfer large volumes to the wheel brake. It offers the benefit of being able to operate with a small actuating volume. Operation: Ready Position When the braking system is ready for operation, the accumulator pressure is present at Port 1 of the Relay Valve. A connection is established between Ports 2 and 5 so that the wheel brake cylinders of the vehicle are released. Braking position When the foot brake valve is actuated, a hydraulic braking pressure builds up at Port 2 as a function of the input pressure at Port 4. When the braking process is commenced, Slide (A) is actuated via Control Port 4 and moves into the braking position against the force of Spring (B). The slide will first close Return Port 5 via the control edge and then, via another control edge, connect Accumulator Port 1 with Port 2. Via a hole, the oil stream now flows from Port 1 to Port 2 through Hollow Slide (A), moving it to its final braking position. In this process, the output braking pressure at Port 2 is equal to the control pressure of the foot brake valve at Port 4. Release position As the control pressure at Port 4 is reduced, Hollow Slide (A) returns to its initial position. The connection between Ports 1 and 2 is closed once again by the control edges. The second control edge will then open the connection between Port 1 and Return Port 5. Technical Data: Part Number Operating pressure Control volume Pressure at port bar max. 1.3 cm³ < 3 bar Permissible medium mineral oil: 2000 to 10 mm² /s Operating temperature range 40 C to +80 C Transmission ratio 1 : 1 42

38 Relay Valve Installation dimensions: Installation Requirements: The return line must be connected directly to the tank. The connecting lines must be installed in such a way as to permit proper bleeding. The Relay Valve should be mounted in the vicinity of the wheel brake. Maintenance of the Relay Valve No special maintenance beyond the legal requirements is necessary. Repair Work: When working on the braking system, always make sure that there is absolutely no pressure in the system. Even when the engine is switched off there will be some residual pressure in the system! When doing repair work, make sure your environment is very clean. Immediately close all open ports on the components and on pipes using plugs! For safety reasons the whole of the Relay Valve must be replaced if damaged. 43

39 Information for Installation 4. General Comments a) All pipes in the braking system must have a nominal width of at least 10 mm. b) The pipes should be installed in such a way as to permit proper bleeding, i.e. so that no air cushions can develop. If you detect noises when commencing the braking process, this is an indication of poor bleeding. c) When fitting the pipes, make sure that there are no areas of friction. d) The return lines of the individual components of the braking system must not be combined in one return line to the tank. e) Do not use a pipe for the return lines of the dual circuit brake valve to combine them in one return line. (This is possible only if Ports 5.1 and 5.2 are connected by means of hoses and combined to form one return line.) f) Look for visible leaks in lines and pipes. Leaks are an indication that the system is not properly sealed. Check the level of the brake fluid. Stop leakage. g) When using high-pressure cleaners, do not aim the nozzle directly at the bellows. (This may cause damage to the bellows.) h) When working on the braking system, always make the sure that the system is completely pressureless! i) Make sure that everything is spotlessly clean! j) Immediately close all open ports on the components and on pipes using plug! IMPORTANT! Even when the engine is switched off or the pump is not running, the system pressure will be maintained! 47

40 4. Information for Installation Information for Installation It is particularly important that the components all have their separate return lines since otherwise the return pressure can be present in the wheel brake in the form of residual pressure. This leads to unnecessary wear of the brake linings and excessive temperatures at the wheel brake and can thus result in hardening of the linings, and in a failure of the seals on the wheel brake cylinders. When combining the returns of the dual circuit foot brake valve, please make sure that hoses are used for connecting the return ports. Using a pipe to connect the two circuits can cause functional defects through distortions in installation. For very long vehicles with large cylinder volumes, the installation of relay valves can be very helpful, reducing response and pressure build-up times to a minimum. The relay valve should be fitted as close to the wheel brake cylinders as possible. Thus the lengths of the lines from the accumulator to the wheel brake cylinders are reduced since the foot brake valve only actuates the relay valves. The input volume of the relay valves is approx. 1 cm³. If shut-off valves with an integrated check valve are used, an additional accumulator of 0.7 litres needs to be screwed into the component. That additional accumulator is primarily used to monitor the actual pressure of the other three accumulators and to report them to the shut-off valve. The accumulators can be emptied when the brakes are operated, without being recharged since all circuits are secured from each other by the check valves. The additional accumulator will also prevent activation of the shut-off valve as a consequence of small leakages and thus a fall in pressure in the connection established between the check valves even though the pressure in the accumulators of the braking circuit is still higher than 120 bar. Capacity of Accumulators The capacity of the hydraulic accumulators must be designed according to the legal provisions for the HPB with regard to the size of energy accumulators. For this purpose we require the following information from you: We support our customers, free of charge, in designing the accumulators. 48