KR20010032090A - Hydraulic Aggregate for Slip-Controlled Braking Systems - Google Patents

Abstract

The housing 4 of the hydraulic device has an accumulator accommodation bore 1 oriented parallel to the axis of the engine accommodation bore 3 and the valve accommodation bores 2, 2 ^{I of the} two valve rows X, Y. The accumulator motor receiving bore 1 and the valve receiving bores 2, 2 ^{I of} the first and second valve rows X, Y are side by side facing the first end face of the housing 4.

Description

Hydraulic Aggregate for Slip-Controlled Braking Systems

The invention discloses a hydraulic device of a slip-controlled brake system according to the preamble of claim 1.

Patent application DE 40 13 160 A1 already discloses a hydraulic system of a slip control brake system in which several valve receiving bores of inlet and outlet valves are arranged in the first and second valve rows. The pump bore is provided outside the two valve rows in the block shaped housing, the pump bore being oriented across the direction in which the valve receiving bore is towards the housing. In addition, a motor receiving bore oriented perpendicular to the pump bore is provided outside the two valve rows in the housing. An additional location bore for the accumulator element and the damping chamber is located perpendicular to the axis of the valve receiving bore and separated from the valve row through the pump bore. Each of the two valve rows has an inlet and outlet valve, and the outlet valve is always positioned between the valve receiving bore of the inlet valve, so that the accumulator element, which functions in conjunction with the outlet valve, is in a straight line with the pair of outlet valves in the housing. Each is arranged. The receiving bore of the accumulator element is defined at both sides by a noise damping chamber hydraulically connected to both the injection valves of both valve rows and the compression side of the pump.

Due to the bore of the accumulator element and the damping chamber extending to the side portion at right angles to the axis of the pump receiving bore, much space is required to integrate all the receiving bores into the housing. Thus, the resulting external dimensions of the block shaped housing make the required space for the hydraulic device in the vehicle large. Another disadvantage is that the proposed arrangement of the bore in the housing lacks free space for placing additional receiving bores as long as the external dimensions of the block shaped housing remain the same, so that the hydraulic device cannot be functionally expanded in a given dimension. In addition, since the inlet and outlet valves are arranged in both valve rows, the compressed fluid accessories leading to the wheel brakes are distributed on both sides of the housing, which provide additional space on both sides of the housing as well as for guiding connection lines outside the housing. Makes this necessary.

Therefore, it is an object of the present invention that, even if the dimensions of the housing are kept as small as possible, all the receiving bores are optimally arranged in the housing, and such an arrangement is a simple means to include other functions when the position concept has a uniform design. It is to improve the hydraulic system of the type described above in such a way that it can be expanded by means of.

According to the invention, this object is solved by a hydraulic device of the type described above by means of the features of claims 1 to 15.

Other features and advantages of the present invention will be described next by taking the shape of the hydraulic device shown in some figures as an example.

1 is a top view of the bottom of a hydraulic apparatus in which a valve and accumulator receiving bore are disposed.

FIG. 2 is a three dimensional view of the housing shown in FIG. 1 for clarifying all receiving bores and compressed fluid channels. FIG.

FIG. 3 is a view rotated around the longitudinal axis and the vertical axis of the housing in order to detail the details shown in FIGS. 1 and 2.

FIG. 4 is a three dimensional view of a modified housing compared to FIGS. 1-3, which housing has a damping chamber incorporated in the pump receiving bore.

5-7 show accumulator bores employed in other low pressure accumulator designs.

8 and 9 illustrate another embodiment of a damping chamber design in a housing.

In the representation according to FIG. 1, the top view of the block-shaped housing 4 is greatly enlarged. The bottom of the housing 4 has eight valve receiving bores 2, 2 ^I in both the first and second valve rows X and Y, and electromagnetically actuated inlet and outlet valves are inserted into the receiving bore. do. On the outside, which is the side of the two valve rows (X, Y), there is a pump receiving bore, which is covered by two parallel accumulator receiving bores 1 in the figure. The accumulator receiving bore 1 is parallel not only to the axis of the valve receiving bore 2,2 ^I but also to the sides of the two valve rows X, Y, while the pump receiving bore 5 is a valve row (X, Y). Extend parallel to In the middle between the two accumulator receiving bores 1 is a motor receiving bore 3 extending into the pump receiving bore 5 parallel to the axis of the accumulator receiving bore 1. The motor receiving bore 3 oriented vertically towards the pump bore 5 not only supports the flange of the electric motor used to drive the pump stuck to the pump receiving bore 5, but also the eccentricity or crank required for the pump. Provide drive. In view of the above-mentioned receiving bore, a high integration density of the individual functional elements on the minimum bottom surface of the valve housing 4 is required. This aligns the accumulator receiving bore (1), the valve receiving bore (2, 2 ^I ) and the motor receiving bore (3) parallel to their axes and possibly accumulate the accumulator receiving bore (1) and the valve receiving on a single surface of the housing. Based on the idea of the present invention for distributing the bores 2, 2 ^I side by side, and as can be seen in the three-dimensional drawing, the bore depth in the housing 4 is defined as short as possible. The second valve train Y located next to the pump receiving bore 5 and the accumulator receiving bore 1 supports only the discharge valves necessary to reduce the brake pressure in the wheel brakes. Thus, a very short connection for the pressurized fluid is required from the discharge valve to the connection on the inlet side of the pump bore 5 via the accumulator receiving bore 1, where a piston accumulator or diaphragm accumulator is responsible for discharging the compressed fluid from the outlet valve. It is provided for temporary storage. The injection valve is located in the valve receiving bore 2 ^I of the first valve row X separated from the accumulator receiving bore 1 and the pump receiving bore 5 by the second valve row Y. By placing the injection valve in the first valve row X, the brake pressure transducer attachments B1 and B2 facing the housing 4 near the first valve row X and the attachments R1, leading to the wheel brakes, R2, R3, R4 can be arranged as close as possible to each other, so that the connection pattern of the brake lines on the side of the housing 4 becomes uniform. FIG. 1 also shows a third valve train Z which faces away from the first and second valve trains X, Y towards the housing surface of the housing 4. Thus, the third valve train Z arranged in close proximity to the two accumulator receiving bores 1 ensures a simple functional expansion of the hydraulic system designed to control the blocking pressure for traction or vehicle dynamic control. For this purpose, electromagnetic valves are used for the two outer valve receiving bores ( ^II ), which are designed as electrical conversion valves sealed in their initial positions. The electromagnetic valve, which is open at the initial position, is arranged between the two valve receiving bores 2 ^III of the valve row Z.

2 and 3 show how the compressed fluid channel required for the functioning of the desired hydraulic system should be connected to the above described receiving bore. In connection with FIG. 1, in spite of the very dense arrangement of the above-described bores for supporting the individual functional elements, the space remaining between the two valve rows (X, Y) is driven by the electric motor in the motor receiving bore 3. It can be used to support the through opening that can be used to supply In the fact that the inner valve receiving bores are respectively offset in the direction of the motor receiving bore 3 with respect to the outer valve receiving bore of each valve row X, Y, Z, the first valve row X and the third valve row. Outside (Z) there is free space that can be used to arrange the penetrated or threaded holes 14, 15 for securing the cover on the bottom surface, which cover can be part of an integrated electronic controller. In the same way, the flange of the electric motor mounted to the motor receiving bore 3 is connected to the through-holes 14, 15 on the end face of the housing 4 away from the valve row (X, Y, Z) by screwing. Can stick. Finally, a leak bore 16 may be provided for such an arrangement and design of the motor accommodating bore 3 if necessary for discharging all fluid that may accumulate. However, due to the fact that it can support a large amount of fluid, the proposed motor receiving bore 3 can store a certain amount of leaking fluid, so the leaking bore shown may not be necessary.

1 and 2 show the spatial arrangement of the receiving fluid and the compressed fluid channel of the hydraulic system leading to a uniform arrangement of the bores in the block. The three-dimensional view of the housing 4 shows that the motor receiving bore 3 faces the housing surface opposite the housing surface with the valve rows X, Y, Z and the accumulator receiving bore 1. Thus, the end face of the housing supporting the electric motor provides many places for the motor housing, the vertical through opening 17 provided in the housing 4 for powering the motor if desired or necessary, and the flange of the electric motor. Through holes 14 and 15 for fixing them can be used. Despite the small dimensions of the housing 4, the end face of the housing 4 of the motor side can, for example, accommodate wheel brake accessories R1, R2 leading to the rear wheel. These attachments reach the outer valve receiving bore 2 ^{I in} the first valve row X via a relatively short compressed fluid channel and thus through the injection valve opening at the initial position in which the brake pressure transducer B1, The attachment of B2). In addition, the accessories of the brake pressure transducers B1 and B2 are connected to two valve receiving bores 2 ^I located in the valve row X via a compressed fluid branch not shown in the figure. Two valves in which the wheel brake accessories R3, R4 (named the front wheel brakes in the illustrated embodiment) are provided in the valve row X, provided with the attachments of the brake pressure transducers B1, B2 on the connection side. It is also connected to the receiving bore 2 ^I. All of the first and second valve rows (X, Y), so that the brake fluid supplied by the brake pressure transducer can be discharged to the wheel brake in the direction of the accumulator receiving bore (1) through the first valve row (X). There is a short horizontal compressed fluid connection 19 between the opposing valve receiving bores 2, 2 ^I , whereby the first actuated discharge valve in the second valve row Y is opened. The compressed fluid collected in the corresponding valve receiving bore 2 ^I of the valve row X flows into a horizontal compressed fluid channel 6 designed as a collecting channel, which collects downward in the direction of the housing surface shown in FIG. It reaches the accumulator receiving bore 1 via the inclined collection channel 7. According to the figure, the accumulator receiving bore 1 is provided with a return flow channel 8 extending obliquely upwardly in an opposite direction, the return flow channel 8 being a horizontal compressed fluid channel facing the pump receiving bore 5. Up to. The compressed fluid channel 9 is connected to a pulsation damper 20. Between the accumulator receiving bore 1 and the return flow channel 8 is provided a return valve 23 which is closed in the direction of the accumulator receiving bore 1. The receiving bore for the pulsation damper 20 extends concentrically with the outer valve receiving bore 2 ^{II in} the third valve row Z coming from the direction of the end face of the housing 4 on the motor side, so that the pump is injected. A joint compressed fluid connection to the horizontal compressed fluid channel 9 leading to the side is ensured by the outer valve receiving bore 2 ^II . In addition, a compressed fluid channel 13 extending horizontally between the pump receiving bore 5 and the vertical accumulator receiving bore 1 and below the compressed fluid channel 9 supports an electromagnetic valve that is closed in its initial position. Oriented vertical valve receiving bore (2 ^II ). This compressed fluid channel is connected to one of the two attachments B1, B2 of the brake pressure transducer, respectively. These compressed fluid channels 13 each reach a valve receiving bore 2 ^III provided in the valve row Z next to the valve receiving bore 2 ^II supporting the electric conversion valve. The electromagnetic valve, which is opened in the initial position and inserted into the valve receiving bore 2 ^III , has a first valve row X from the compressed fluid channel 11 which extends above the pump receiving bore 5 in the housing 4. Up to the valve receiving bore (2 ^I ) in the valve), thus allowing access to the wheel brake attachment (R1, R3 or R2, R4) of one of the two brake circuits. At approximately intermediate positions of the valve receiving bores 2 ^II , 2 ^III , the noise damping chambers 10 are respectively located above the third valve row Z, and the pressure connection portion extending from the pump receiving bore 5 toward it ( 21) is open to each brake circuit. The connection to the horizontal compressed fluid channel 11 is provided to the outlet of the noise damping chamber 10 via the orifice plate 22. The longitudinal axis of the illustrated noise damping chamber 10 of all the brake circuits is oriented towards the side of the housing 4 and thus extends across the third valve row Z. Further space is saved when the noise chamber 10 is designed as a ring-shaped space that is allocated concentrically directly to the pump receiving bore 5 concentrically with the compression side of the pump by undercutting the pump receiving bore 5, for example. do. In this connection, the pressure connection 21 of the pump can be connected to the pressurized fluid channel 11 leading to the first valve row X without significant change in the bore. A corresponding embodiment will be described later with reference to FIG. 4.

The placement of the receiving bore and the path of the compressed fluid channel are defined by the two wheel brake accessories R1, R3 of the brake circuit in FIG. The mirror inverted arrangement as well as the same function are present in the bore of the housing 4 representing the second brake circuit but are not described in detail as they are similar in structure.

In particular, taking into account the arrangement according to FIG. 2, the arrangement of the receiving bore and the compressed fluid channel on several parallel horizontal reference planes A1, A2, A3 of the housing will be described based on FIG. 3. According to the figure, the bottom reference plane A1 (indicated by the dashed line) of the housing is located in the region of the accumulator accommodating bore 1 and the valve accommodating bores 2 ^I , 2 ^II , 2 ^III . It is located in the level. The other reference plane A2 of the housing, located in the middle of the housing 4, extends along the compressed fluid channel 6 and clearly shows the inclined angle of the connecting channel 7 in the direction of the accumulator receiving bore 1. . The compressed fluid channel 9 is located in the reference plane A3 above the reference plane A2 of the housing. The return flow channel 8, which extends inclined from the direction of the reference plane A2 of the housing and faces the reference plane A3 of the housing, is oriented towards the compressed fluid channel 9. A compression fluid branch 18 for attachments B1 and B2 of the brake pressure transducer extending horizontally to the levels A1 to A3 of the housing and a horizontal channel 11 for the noise damping chamber 10 are located above the housing reference plane A3. do. The reference planes A1 to A3 of the housing show the planned distribution of the compression fluid channel and the receiving bore, making the integration density of all functional elements as large as possible.

Of particular importance here is the compression fluid channel 6, the connecting channel 7, the return flow channel 8 and the compressed fluid channel 9 between the valve receiving bore 2 of the second valve row Y. It is important that the hydraulic connection between the accumulator receiving bore 1 and the pump receiving bore 5 be kept as short as possible. Such a connection, in all brake systems equipped with an anti-block system, may be referred to as a secondary circuit and needs to be ventilated and represents an undesired dead space in the housing, using a fluid volume.

In the case of the same design, the above-mentioned hydraulic device is not limited to the anti-blocking function, and not only drives the dynamic control, but also obtains the third anti-slip for the purpose of obtaining anti-slip. Since the dead space separated from the main brake circuit by the discharge valve can be extended by a very simple mechanical production method to accommodate the valve row (Z), the valve receiving bore (2 ^II ) is normally closed by an electromagnetic valve. Is not greatly expanded by directly connecting the compressed fluid channel 9 to the inlet side of the pump. Another advantage of the present invention is the free space located between the accumulator receiving bore 1 and the pump receiving bore 5, which allows the pulsation damper 20 to connect directly to the return flow channel 8. Instead of the arrangement shown in the figures, a pulsation damper 20 is provided at the side of the housing 4 at the level at which the return flow line 8 is connected to the accumulator receiving bore 1. This is because it can be arranged parallel to the axis.

As another example of the arrangement shown in FIGS. 1-3, FIG. 4 shows a coaxial arrangement of the noise damping chamber 10 with respect to the pump receiving bore, which arrangement is to be obtained by undercutting the pump receiving bore 5. Can be. In this embodiment, the compressed fluid channel 21 on the compression side of the pump continues in the direction of the noise damping chamber 10 shown in Figs. By moving the noise attenuation chamber 10 to the region of the pump receiving bore 5, an extension of the compressed fluid channel 21 on the compression side of the pump is provided with a blind plug in the housing 4. Thus, the compressed fluid channel 21 directly reaches the compressed fluid channel 11 of each brake circuit via the compressed fluid branch 12 already shown in FIGS. 2 and 3. It can be seen that all other features shown in FIG. 4 correspond to the detailed description already described in FIGS.

5, 6 and 7 show an advantageous embodiment showing the design of the low pressure accumulator 24 and other accessories which seal the accumulator receiving bore 1.

5 shows a low pressure accumulator 24 designed as a piston type accumulator, wherein the housing 25 is made of a metal part made by deep drawing, preferably the piston 26 pressed from the sheet metal part is O-. It is sealed by the ring 27 and guided to the housing 25. A peripheral collar 28 of the housing 25, like the piston head, is attached to the end face of the relatively flat accumulator receiving bore 1 and secured to the housing 4 by a caulking tool.

FIG. 6, which differs from FIG. 5 but is attached to its description, shows a cylindrical projection 29 in an accumulator receiving bore 1 which supports an O-ring in a ring groove to seal the accumulator housing 25. To show.

In contrast to the details of FIGS. 5 and 6, silver 7 has an accumulator housing 25 consisting of a rigid corner with a flange supporting an O-ring on the outside for sealing the accumulator receiving bore 1. Is suggested.

In all the above-described embodiments according to FIGS. 5, 6 and 7, the low pressure accumulator 24 includes the accumulator housing 25 before the piston 26 and its compression spring 30 are inserted into the accumulator receiving bore 1. ) Is a subassembly that can always be pre-assembled in the module and thus can be manipulated independently.

8 and 9 show one possible embodiment of a noise damping chamber that can be sealed against compressed fluid by a tubular sealing element 31 having a different design and fluid support capability. The tubular sealing element 31 is preferably made of one piece or two pieces of sheet metal. For example, the tubular sealing element is attached to the noise attenuation chamber 10 by a locking wire 32. The thin metal part designed as a cover lock is sealed by an O-ring.

In conclusion, the present invention discloses the idea of arranging the bores in the housing 4, which in turn provides another function of the hydraulic system in order to ensure versatility of the housing 4 without significantly deforming the housing 4. The possibility of using the same arrangement of receiving bores for leads to the idea of uniform channels. At the same time the above described receiving bore and compressed fluid channel are arranged in such a way as to save as much space as possible so that the dimensions of the housing 4 are kept to a minimum. Therefore, the hydraulic device proposed by the present invention is uniformly clamped regardless of whether the hydraulic device for use in the anti-lock system of the brake system or the extended hydraulic device is used for driving dynamic control. , By drilling and milling operations. By arranging the accumulator accommodating bore 1 on the side of the valve accommodating bores 2, 2 ^Ⅰ , 2 ^II , 2 ^III , the low pressure accumulator 24 provides the valve accommodating bores 2, 2 ^Ⅰ , 2 ^II , 2 ^III . It can be located in a special protected place in the sealing cover, the depth of the accumulator receiving bore 1 in the housing 4 is limited to the depth necessary to fix the low pressure accumulator 24, and the necessary actuation of the low pressure accumulator 24 The volume is converted into the covered housing 25.

In addition, the present invention requires that the compressed fluid be over a very short distance in the region of the primary brake circuit and the secondary brake circuit. Since the accumulator accommodating bore (1) as well as the valve accommodating bore (2) for the discharge valve are arranged as close as possible to the pump accommodating bore (5), the resulting dead space volume of the secondary brake circuit is minimized. And filling.

Reference list

1: Accumulator accommodation bore

2, 2 ^Ⅰ : Valve accommodation bore

2 ^Ⅱ , 2 ^Ⅲ : Valve Accommodating Bore

3: motor accommodating bore

4: housing

5: pump bore

6: compressed fluid channel

7: connecting channel

8: return flow channel

9: compressed fluid channel

10: noise attenuation chamber

11: compressed fluid channel

12: compressed fluid channel

13: compressed fluid channel

14: through hole

15: through hole

16: leak bore

17: through opening

18: compressed fluid branch

19: compressed fluid connection

20: pulsation attenuator

21: compression attachment

22: orifice plate

23: return valve

24: low pressure accumulator

25: housing

26: piston

27: O-ring

28 color

29: projection

30: compression spring

31: tubular sealing element

32: lock wire

A1, A2: reference level of the housing

A3, A4: reference level of the housing

R1, R2: Wheel Brake Attachment

R3, R4: Wheel Brake Attachment

B1, B2: Brake Pressure Transducer Attachment

X, Y, Z: Valve row

Claims (16)

A housing having an inlet valve and an outlet valve in several valve receiving bores in the first and second valve rows, A pump bore disposed outside the two valve rows within the housing, the pump bore intersecting a direction in which the valve receiving bore is in the housing; A motor receiving bore disposed outside the two valve rows within the housing and aligned perpendicular to the pump bore, Accumulator receiving bore facing the housing outside the two valve rows, In the hydraulic system of a slip control brake system having several compressed fluid channels connecting a valve, a pump receiving bore and an accumulator receiving bore and establishing a hydraulic connection between one brake pressure transducer and several wheel brakes, The accumulator accommodating bore 1 is arranged parallel to the axis of the valve accommodating bores 2, 2 ^I of the two valve trains X and Y and the motor accommodating bore 3, wherein the first and second valve trains are arranged. (X, Y) of the apparatus, characterized in that toward the first end surface of the valve accommodating bores (2,2 ^ⅰ) and the accumulator accommodating bore (1) alongside the housing (4). 2. The valve receiving bore (2) for the discharge valve (1) according to claim 1, characterized in that it is arranged in the second valve row (Y) located next to the pump bore (5) and the accumulator receiving bore (1). Device. 2. The valve of the first valve row (X) according to claim 1, wherein the injection valve is spatially separated from the pump bore (5) and the accumulator accommodation bore (1) by the second valve row (Y). The device characterized in that it is arranged in the receiving bore (2 ^I ). The housing (4) according to claim 1 or 2, wherein several valve receiving bores (2 ^II , 2 ^III ) of the third valve row (Z) are separated from the first and second valve rows (X, Y). Device, characterized in that the third valve row (Z) is located next to the accumulator receiving bore (1). 3. The valve receiving bore 2 of the second valve row Y extends to a second reference level A2 of the housing, the valve receiving bore pairs 2 being the second of the housing. Characterized in that it is respectively connected to one compressed fluid channel 6 facing the connecting channel 7 extending to the accumulator receiving bore 1 at an angle inclined from the reference level A2 to the first reference level A1. Device. 3. The accumulator receiving bore (1) is provided with a return flow channel (8) extending at an angle inclined to the compressed fluid channel (9) facing the pump receiving bore (5). The channel (9) is characterized in that it is arranged at a third reference level (A3) outside of the first and second reference levels (A1, A2) of the housing. 7. The pump receiving bore (5) according to claim 5 or 6, wherein the pump receiving bore (5) is bounded by an inclined connection channel (7) and a return flow channel (8), and the second reference level and the third reference of the housing. Device arranged between levels (A2, A3). 2. The injection according to claim 1, wherein the injection in the valve receiving bores (2, 2 ^I ) of the first and second valve rows (X, Y) for controlling the anti-blocking pressure in the wheel brake and Wherein only the discharge valve is electromagnetically actuated. 5. The valve receiving bore of claim 3, wherein the electromagnetic valve opened in the initial position is between the brake pressure transducer attachments B1, B2 and the injection valve of the first valve row X. And (2 ^III ) each arranged to interrupt the pressurized fluid connection. 10. The third valve row (Z) according to claim 9, wherein the electromagnetic valve closed in the initial position is a direct hydraulic connection between the accessory of the pump receiving bore (5) on the injection side and the brake pressure transducer accessories (B1, B2). Device provided in the valve receiving bore ( ^II ). The discharge section of the pump receiving bore (5) on the compression side is a noise attenuation chamber (10) arranged outside the first and second reference levels (A1, A2) of the housing (4). Device characterized in that it is facing. 12. The noise damping chamber (10) according to claim 11, wherein the noise attenuation chamber (10) is designed in a ring-shaped space that is coaxially aligned towards the pump receiving bore (5) and at the channel level of the pump receiving bore (5) on the compression side. Device, characterized in that the arrangement. 12. The device according to claim 11, wherein the noise damping chamber (10) is disposed between the valve receiving bore (2 ^II ) and the compressed fluid accessory of the third valve row (Z). The noise attenuation chamber 10 is connected to a compressed fluid channel 11 located away from the first, second and third reference levels A1, A2 and A3 of the housing and is compressed. The fluid branch 12 is characterized in that it reaches the valve receiving bore 2 ^II of the electromagnetic valve which is connected to the compressed fluid channel 11 and located in the third valve row Z and opened in an initial position. Device. A housing having inlet and outlet valves in the first and second valve rows, A pump bore disposed outside the two valve rows in the housing, the pump bore being oriented intersecting with the direction in which the valve receiving bore is towards the housing, A motor receiving bore oriented perpendicular to the pump bore and disposed outside two valve rows in the housing, An accumulator receiving bore facing the housing outside the two valve rows; In the hydraulic system of a slip control brake system comprising a valve, a pump receiving bore and an accumulator receiving bore, and several compressed fluid channels for establishing a compression connection between one brake pressure transducer and several wheel brakes, The compressed fluid channels 9, 11, 13 are provided with the first and second valve rows X, Y for the purpose of obtaining a multifunctional and uniform arrangement of the bores in which the third valve row Z is in the block. Wheel brake fittings and attachments B1, B2 of the brake pressure transducers facing the housing 4 in such a way that they are selectively located on the first end face and can be connected to the compressed fluid channels 9, 11, 13. The third valve train Z extends in the opposite direction from the apparatus R1 to R4, and the third valve train Z is caused by the accumulator receiving bore 1 located on the first and second end faces. X, Y). 16. The apparatus according to claim 15, wherein the accumulator receiving bore (1) supports a low pressure accumulator (24) forming a subassembly that can be operated independently.