DE102005004465A1 - Automotive electro-hydraulic brake system back-pressure dampening module has hydraulic line and screen with bleed hole outside hydraulic control unit - Google Patents

Abstract

An automotive electro-hydraulic brake system has an electronic control unit (ECU), a hydraulic control unit (HCU) and a drive for a pump that is integrated within the HCU, The system further has valves and brake pipes. A hydraulic line and a screen (41) with bleed hole are positioned between the pressure side of the pump and the main brake cylinder (1) outside the hydraulic control unit.

Description

The The invention relates to an electrohydraulic vehicle brake system, comprising an electronic control unit (ECU), a hydraulic control unit (HCU) with electromagnetically controllable, hydraulic input and output Exhaust valves for wheel brakes, and with a drive for a pump integrated into the hydraulic control unit (HCU) is provided, as well as valve means and channels, which is a switching the suction and delivery routes the pump especially for adaptation to ABS, ASR / ESP (driving stability control interventions) or cruise control rule interventions (ICC).

One generic vehicle brake system is sufficient known. The pump of the vehicle brake system fulfills different in the mentioned applications Functions. In ABS control interventions, a rapid pressure reduction in allows the wheel brakes, by filling a low-pressure accumulator. The pump is used for blank promotion the low - pressure accumulator, by - against the brake pressure of Driver - one Pressure increase within piston-loaded pressure chambers of the master cylinder made so that a brake pedal, which indirectly or directly on the master cylinder piston acts, even in the pressure reduction processes in the wheel brakes in one currently set brake actuation position remains (return principle).

For the pump become mainly check valve controlled displacement pumps used by the piston type. The ventilation of the piston pump is with an abrupt opening and closing behavior the check valves coupled. Sharing the pressure surges to the driver by brake pedal vibrations or in two-wheeled vehicles as Bremshebelvibrieren with what is generally considered to be capable of improvement.

To solve this problem, so-called pulsation dampers on the pressure side of the pump have been frequently proposed and also used. These are exemplary of DE 43 36 464 A1 or the DE 199 48 444 A1 refer to. The pulsation dampers provide a cushioning of the pressure surges, so that pressure surges are less noticeable to the driver. The effect of a damper chamber is dependent on its absorption volume and an increase in volume is inherently associated with greater effectiveness. On the other hand, the volume of a hydraulic control unit is limited by the limited space in a vehicle installation space and even more so in two-wheeled vehicles.

A Another object of the pump is to provide a fast pressure increase the energy required to carry out a driver-independent triggered driving stability control intervention to deliver. In this context, additional volumes and elasticities - as defined by known pulsation dampers originate - in principle undesirable, because it involves a certain loss of effect. Consequently, let the known pulsation dampers in their impact characteristics alone by modifying constructive conditions optimize for a single particular operating condition.

It is an object of the present invention, the disadvantages mentioned and to provide funds and an operating procedure, about the brake application characteristic a hydraulic brake system better on the control function - be it an ABS control intervention on the one hand, or an ESP control intervention on the other - adapt. It is especially about pressure pulsations more comfortable than previously dismantle, without the volume of a hydraulic control unit increase.

These The object is achieved according to the invention by outside the hydraulic control unit (HCU) between a pressure side the pump and a pressure chamber of a master cylinder damping means comprising at least one hydraulic line and a diaphragm provided which are a pressure propagation from the pressure chamber in the direction Wheel brake does not hinder, and a pressure propagation due to return promotion of pressure medium in the direction of pressure chamber dampen. With the invention are the following advantages. In the ABS return operation mode are pump pressure surges through the glare effect restricted. In the opposite direction, the flow is not hindered, the glare is ineffective and therefore does not hinder ESP control intervention.

According to embodiments a first embodiment The invention is a switching or analogized controllable valve provided for the purpose of dimming a hydraulic line part. Preferably is the switching or analog valve as electromagnetically actuated Forming control panel or adjustable aperture. This allows a targeted controllable or at least switchable glare and on This way, an improved adaptation of a brake system to the respective operating state. The vote of the glare effect is simplified and there is also the possibility of glare to be actively involved in electronic regulatory processes.

de facto will with the damping means in a basic position an unrestrained fluid passage, and in a Switching allows an inhibited fluid passage in the pressure chamber.

The respective valve is either in the hydraulic control unit or arranged on the master cylinder. When the valve on the Master cylinder is arranged, there is the advantage that the line volume - from Pressure outlet of the pump to the valve - the damper volume is added. This results in the effect of a somewhat artificially enlarged in volume damper chamber, without this additional volume in the hydraulic control unit hold to have to. This will with improved damping effect achieved a further miniaturization of the hydraulic control unit.

on the other hand it is conceivable, completely on a damper chamber, which provided integrated in the hydraulic control unit is to renounce.

One Operating procedure for An electrohydraulic vehicle braking system relies on the fact that the Valve exclusively for pressure reduction during ABS control is used to dampen the effect of pressure pulsations.

A Embodiment of a second embodiment The invention is based on the fact that the damping means in a damping module are provided, which between the master cylinder and the Pump inserted is, and a check valve includes that check valve hydraulically parallel to the hydraulic line between the master cylinder and the hydraulic control unit is connected, and wherein the check valve a pressure propagation from the pressure chamber through the bypass in the direction Wheel brake is not obstructed, and a pressure propagation from the pump blocked by the bypass in the direction of the pressure chamber. The abstract of damping agents in a separate module a cost-effective modular system with different comfortable brake systems. If a simple one Braking system with low comfort requirements is sufficient, easy on the damping module be omitted, without structural changes to the hydraulic control unit to have to provide. Furthermore allows This is a flexible-decentralized utilization of the damping module in the vehicle.

In Further embodiment of the second embodiment, the damping module a hydraulically switchable separating valve with a closing body, wherein the isolation valve is hydraulically parallel to the hydraulic line Switched between master cylinder and hydraulic control unit is, and an open position and a closed position having, wherein the closing body at pressure balanced state is in an open position, and at master cylinder side actuated actuation in a closed position arrives. The hydraulically switchable isolation valve is tuned that it is during brake application closes quickly, and the repressed Pressure medium over the check valve and the panel gets in the direction of the wheel brake. After releasing the brake allows the opened separating valve with its additional opening cross-section an advantageous very fast pressure equalization between the master cylinder and wheel brake. This accelerated pressure equalization mediates lag-free, agile and sportive brake feel. One Impression of Bremsnachwirkungen despite dissolved brake operation is avoided.

It is advantageous in terms of the packaging of the components when the closing body as stepped stepped piston is formed, and that the valve seat for the hydraulically switchable isolation valve and the valve seat for the check valve are formed on a common component.

Of the Stepped piston is acted upon by a prestressed return spring, in a room in a housing of the damping module is received, and wherein the space has ventilation means to this with the ambient atmosphere connect to. Through these measures This avoids that the stepped piston when moving an air volume has to compress.

If the damping module Filter has, each in an input, and in an output of the damping module are provided, a component damage due to chips, wear products, Valve leakage and more prevented.

If the damping module continue with elastic brake hoses to the master cylinder, and connected to the hydraulic control unit (HCU), this allows a further improvement of the damping effect.

Especially for use with two-wheeled vehicles, it makes sense if the damping module on the one hand directly to or in a departure of the master cylinder is screwed, and forms a structural unit with this.

Further Details of the invention will become apparent from the description and the drawings concerning two embodiments out. In the drawing shows:

1 a known electrohydraulic vehicle brake system ( DE 10204567 A1 )

2 a first embodiment of the invention with reduced, in the hydraulic control unit with integrated damping chambers,

3 An embodiment of the first embodiment without integrated damping chambers,

4 1 is a schematic circuit diagram relating to a first embodiment of a second embodiment with a damping module,

5 a schematic circuit diagram relating to a second embodiment of the second embodiment with a damping module,

6 an enlarged section through the damping module in the basic position according to 5 .

7 a strong cut-out enlargement of a valve area in 6 .

8th the damping module according to 6 with driver-initiated brake actuation,

9 the damping module according to 6 in ABS return cycles, and

10 a strong cut-out enlargement of the valve area in 9 ,

An electro-hydraulic vehicle brake system has a pressure source in the form of a master cylinder 1 of tandem type with a pressure medium reservoir 2 which is usually from a brake pedal 3 via a vacuum brake booster 4 is pressed. The brake booster 4 is designed for example as an active brake booster. This means that the brake booster is externally controllable, and also without operating the brake pedal 3 is able, by electrical control, the actuating piston of the master cylinder 1 to shift and build up a pressure in the brake system. From the master cylinder 1 or the pressure source run two brake lines 5 and 6 via a hydraulic control unit (HCU) to wheel brake. In detail, only the brake circuit I is shown, wherein the brake circuit II can be constructed either identical or, for example, in a brake system with traction control (ASR) and front-axle rear brake circuit distribution can only be provided with a anti-lock device (ABS).

The brake circuit I extends from the master cylinder 1 over the brake line 5 , a separating valve 7 and two brake branch lines 8th and 9 each with an inlet valve 10 respectively. 11 to the wheel brakes 12 and 13 , From the wheel brakes 12 and 13 each leads a return branch 14 respectively. 15 each with an outlet valve 16 respectively. 17 to a return line 18 , which are connected to a low-pressure accumulator 19 connected. The low pressure accumulator 19 is via a first suction line 20 with the suction side of a self-priming return pump 21 connected.

The pump 21 is preferably of the piston type, is powered by an electric motor 28 driven and includes a pressure valve 26 and a suction valve 27 , these valves 26 . 27 in a housing of the pump 21 are integrated. There are both the pressure valve 26 as well as the suction valve 27 Usually designed in the form of check valves, each with a ball as a closing body, a spring and a sealing seat purely mechanical.

The pump 21 points in front of the suction valve 27 furthermore a second suction line 22 in which an electromagnetically operated switching valve 24 is inserted. The second suction line 22 is to the brake line 5 between master cylinder 1 and isolation valve 7 connected. A pressure line 25 connects the pressure side of the return pump 21 or the pressure valve 26 with the brake line 5 between isolation valve 7 and the intake valves 10 and 11 ,

In a normal braking, so in a pedal-operated braking without critical slip values or other critical driving dynamics factors all valves remain in their illustrated position. The pressure build-up in the wheel brakes 12 and 13 via the brake line 5 and the brake branches 8th and 9 , A release of pressure when the brake is released takes place in the opposite way.

In an anti-lock control (ABS), the brake system operates on the return flow principle, which is known per se. The electromagnetic switching valve 24 remains closed and the isolation valve 7 stays open. Only the intake valves 10 and 11 and the exhaust valves 16 and 17 be in a known manner for pressure control in the wheel brakes 12 and 13 connected. The return pump 21 spends that in the low pressure accumulator 19 located pressure medium via the pressure line 25 back into the brake line 5 between isolation valve 7 and the intake valves 10 and 11 , In an active braking, such as a traction control (ASR) or an active brake intervention (ESP) for the purpose of yaw moment control, the isolation valve 7 closed and the solenoid operated switching valve 24 open. Then brake pressure is built up independently of the driver, which is the result of the pump 21 or a so-called active brake booster can take place. For this purpose, the brake booster 4 the master cylinder 1 Press, so that through the brake line 5 a pressure medium pressure on the solenoid-operated switching valve 24 in the second suction line 22 to the pump 21 propagates.

The 2 and 3 agree in large parts with the 1 match. Matching features are identified with corresponding reference numerals, and repetition of the description is omitted. One However, the main difference is that outside the hydraulic control unit (HCU) between the pressure side of the pump 21 and a pressure chamber of the master cylinder 1 Damping means comprising at least one hydraulic line and a diaphragm 41 are provided, the pressure propagation from the pressure chamber in the direction of the wheel brake 12 . 13 do not obstruct, and dampen a pressure propagation due to return of pressure fluid in the direction of the pressure chamber. In the simplest case, according to the invention, it is a direction-dependent diaphragm 41 within the hydraulic line.

According to 2 However, it is an additional electromagnetic switching valve 29 . 30 between pressure side of the pump 21 and the master cylinder 1 intended. Furthermore, both circles of a dual-circuit brake system are shown. By switching to one, the hydraulic line in the direction of the master cylinder 1 dimming switch position is the entire pipe volume - starting from the pressure port of the pump 21 to the valve 29 . 30 provided as damper chamber volume. By the dimming of inevitably required hydraulic lines (brake lines 5 . 6 ) Thus, a much larger damper chamber volume is realized, as in known vehicle brake systems with a damper chamber, which is provided integrated in the hydraulic control unit HCU. The volume of inevitably required piping is thereby used as an external damper chamber volume. As a result, the internal damper chamber volume is greatly reduced ( 2 ) or completely eliminable ( 3 ). Furthermore, the damping effect by switching to the other switching position can be switched off or at least reduced.

In principle, it is conceivable every valve 29 . 30 analogized form controllable, so that even a regulation can be achieved regarding the glare.

For the spatial arrangement of the switching valve or analog valve 29 . 30 two rankings are preferred. On the one hand in direct arrangement on or in the master cylinder 1 , or in the hydraulic control unit (HCU).

An operating method for the electrohydraulic vehicle brake system relies on the valve 29 . 30 only in pressure reduction operations during ABS control operations, and when a return of brake fluid takes place in the direction of the master cylinder is switched to the dimming position to attenuate the said pulsations.

The 4 to 10 describe another embodiment of the invention, in particular for use in a two-wheeled vehicle without pneumatic brake booster and each having a simple master cylinder 1 each brake circuit.

Based on the basic hydraulic interconnection between master cylinder 1 (THZ), hydraulic control unit (HCU) and wheel brake 12 is between master cylinder 1 and hydraulic control unit HCU a damping module 40 intended. In a basic configuration has the damping module 40 over a panel 41 , which is inserted in the hydraulic line, and further via a check valve 42 which is in a bypass 43 is provided to the hydraulic line, and a pressure propagation from the pressure chamber in the direction of the wheel brake 12 not hindered, and a pressure propagation from the arranged in the hydraulic control unit (HCU) pump 21 blocked in the direction of the pressure chamber.

A specially designed solution according to 5 is based on the embodiment of 4 and also has a hydraulically switchable isolation valve 44 which is parallel to the hydraulic line and parallel to the bypass 43 between master cylinder 1 and HCU is connected, and has an open position and a closed position. Again 5 can be seen, there is the isolation valve 44 when the brake is released in an open position. A brake actuated by the driver via the master cylinder, which causes a system pressure, leads to the immediate closing of the hydraulically switchable isolating valve 44 , with the consequence that the main flow through the bypass 43 with the open check valve 42 and a smaller flow through the hydraulic line with the orifice 41 he follows.

An embodiment of the construction of the schematic damping module 40 to 5 is the 6 removable. Generally, the damping module reminds 40 removed from so-called screw-in regulators used in brake systems before electronic brake control systems became standard.

A housing 45 has a continuous stepped bore 46 for recording aperture 41 , Check valve 42 and isolation valve 44 , The check valve 42 is HCU-sided within the stepped bore 46 provided, in other words furthest into the stepped bore 46 inserted. This check valve assembly includes a spring cup 47 with through holes 48 , Return spring 49 and closing body 50 who is against a valve seat 51 on a valve seat carrier 52 is pressed. The support of the closing body 50 on the valve seat 51 closes a through hole 53 through the valve seat carrier 52 , Off center is the valve seat carrier 52 with as far as possible passages 54 provided to prevent the flow. The check valve 42 opposite has the valve seat carrier 52 via another valve seat 55 for the separating valve 44 , In other words, the valve seat carrier 52 multifunctional and has a dual function.

The isolation valve 44 has an axially movable closing body 56 formed as a stepped piston, and axially within a cartridge 57 is displaceable. The bullet 57 is in the case 45 arranged. The stepped piston is in the direction of the valve seat 55 formed tapered, and ends with a piece of pipe 58 , which with a sealing element 59 relative to the cartridge 57 is sealed. Another sealing element 60 is provided at the THZ side end of the stepped piston. The stepped piston is at least partially funnel-shaped and preferably produced by extrusion or sheet metal forming. A preloaded return spring 61 relies on the one hand on the cartridge 57 and on the other hand on the stepped piston, so that the stepped piston permanently aspires to an open position. The return spring 61 is in a room 62 from the case 45 taken, which by means of deaerating - such as a channel 63 and a sealing element 64 - connectable to the atmosphere.

In the illustrated embodiment, the return spring is supported 61 about the cartridge 57 , an interposed disc 65 and the valve seat carrier 52 ultimately on the case 45 from. In this regard it is noted that between cartridge 57 and valve seat carrier 52 a conical centering seat may be provided so that the disc 65 can be omitted in principle. Furthermore, the pipe section 58 of the stepped piston pass through a funnel-shaped body, the meaning and purpose of which will be explained below.

Of the 6 as well as the further enlargement in 7 can be clearly seen that the pipe section 58 of the stepped piston a radially passing through the wall aperture 41 having. The diameter of the aperture 41 determined in this context, the achieved glare. Now, if a funnel-shaped (distance) body is provided, this allows a reliable fit of a sealing ring 60 , It remains to be completed that the interior 66 the stepped piston is effective as an integrated damping chamber in which the pressure medium after passing through the aperture 41 relaxed.

As the 6 continues to show, is the case 45 with a lid 67 closed, with the housing 45 connected is. It is understood that in each case at the entrance and at the exit of the damping module 40 Filter may be provided to prevent damage to downstream valves.

The hydraulic connection of the damping module 40 to the master cylinder 1 and to the HCU using piping or flexible hoses. Even a direct screwed or screwed into the master cylinder 1 is conceivable.

The function and effect of the damping module 40 is as follows:
When the brake is released, the valves are located 42 . 44 of the damping module 40 in a position like out 6 and 7 seen. Braking immediately causes the isolation valve 44 and thereby the second bypass 39 closes. Under the prevailing pressure difference opens the check valve 42 and the pressure build-up in de5 wheel brake 12 starts according to 8th ,

Within blocking control cycles then finds a return of brake fluid in the direction of the master cylinder 1 instead of. The hydraulically switchable isolation valve 44 is closed under the applied pressure. The missing inflow (pressure difference) in the direction of the wheel brake leads to the closing of the check valve 42 with closed isolation valve 44 like out 9 and 10 seen. The from HCU direction in the master cylinder 1 aspiring flow only passes through the aperture 41 in the pressure chamber of the master cylinder 1 , Thus, pressure pulsations from the diaphragm 41 and between the damping module 40 and HCU liquid volume (hose) provided.

• 1. Die Baugröße der HCU wird durch Verkleinerung oder Eliminierung einer internen Dämpferkammer reduziert.
• 2. Die Dämpfwirkung ist abänderbar (schaltbar).
• 3. Die Zu-, Abschalt- oder Regulierung der Dämpfwirkung kann aktiv in den Regelalgorithmus einbezogen werden, um vielfältige Aufgaben zu erfüllen.
• 4. Die Anordnung des Dämpfungselementes kann flexibel erfolgen und ist nicht an die HCU gebunden.

In summary, the following advantages are achieved by the invention:

• 1. The size of the HCU is reduced by reducing or eliminating an internal damper chamber.
• 2. The damping effect is changeable (switchable).
• 3. The activation, shutdown or regulation of the damping effect can be actively included in the control algorithm to fulfill a variety of tasks.
• 4. The arrangement of the damping element can be flexible and is not bound to the HCU.

1

pressure source

2

Pressure fluid reservoir

3

brake pedal

4

Brake booster

5

brake line

6

brake line

7

isolation valve

8th

Brake branch line

9

Brake branch line

10

intake valve

11

intake valve

12

wheel brake

13

wheel brake

14

Return branch

15

Return branch

16

outlet valve

17

outlet valve

18

Return line

19

Low-pressure accumulator

20

suction

21

Return pump

22

suction

23

24

switching valve

25

pressure line

26

pressure valve

27

suction

28

electric motor

29

switching valve

30

switching valve

39

second bypass

40

damping module

41

cover

42

check valve

43

bypass

44

isolation valve

45

casing

46

stepped bore

47

spring cup

48

Through Hole

49

Return spring

50

closing body

51

valve seat

52

Valve seat carrier

53

Through Hole

54

passage

55

second valve seat

56

closing body

57

cartridge

58

pipe section

59

sealing element

60

Dichtelelement

61

Return spring

62

room

63

channel

64

sealing element

65

disc

66

Inner

67

cover

Claims (17)

Electrohydraulic vehicle brake system, comprising an electronic control unit (ECU), a hydraulic control unit (HCU) with electromagnetically controllable, hydraulic intake and exhaust valves ( 10 . 11 . 16 . 17 ) for wheel brakes ( 12 . 13 ), and with a drive ( 28 ) for a pump ( 21 ), which is provided integrated in the hydraulic control unit (HCU), and preferably with further valve means ( 7 . 24 ) and channels ( 22 . 25 ), which switches the suction and delivery paths of the pump ( 21 ) in particular for the purpose of adapting to ABS, ASR / ESP (driving stability control interventions), ICC (cruise control control interventions) or for pre-crash control strategies, characterized in that outside the hydraulic control unit (HCU) between a pressure side of the pump ( 21 ) and a pressure chamber of a master cylinder ( 1 ) Damping means comprising at least one hydraulic line and a diaphragm ( 41 ) are provided, the pressure propagation from the pressure chamber in the direction of the wheel brake ( 12 . 13 ), and damp a pressure propagation due to return conveyance of pressure medium in the direction of the pressure chamber. Electrohydraulic vehicle brake system according to claim 1, characterized in that the damping means a switching valve ( 29 . 30 ) for the purpose of dimming a hydraulic line. Electrohydraulic vehicle brake system according to claim 1, characterized in that the damping means analogized have controllable valve for the purpose of dimming a hydraulic line. Electrohydraulic vehicle brake system according to claim 2 or 3, characterized in that the switching valve or the analogized controllable valve ( 29 . 30 ) is designed as a solenoid valve. Electrohydraulic vehicle brake system according to claim 1, characterized in that the damping means in a basic position an unrestrained fluid passage, and in a switching stage a allow inhibited fluid inlet into the pressure chamber. Electrohydraulic vehicle brake system according to claim 2 or 3, characterized in that the valve ( 29 . 30 ) is integrated in the hydraulic control unit (HCU). Electrohydraulic vehicle brake system according to claim 2 or 3, characterized in that the valve ( 29 . 30 ) on the master cylinder ( 1 ) is arranged. Electrohydraulic vehicle brake system according to one of claims 1 - 7, characterized in that the hydraulic control unit (HCU) without Pulsationsdämpfungskammer for the pump ( 21 ) is trained. Operating method for an electrohydraulic Vehicle brake system having the features according to claims 1 and 2 or 3, characterized in that the valve ( 29 . 30 ) is switched exclusively for depressurization operations during ABS control operations to dampen the effect of pressure pulsations. Electrohydraulic vehicle brake system according to claim 1, characterized in that the damping means in a damping module ( 40 ) are provided, which between the master cylinder ( 1 ) and the pump ( 21 ), and a check valve ( 42 ) that the check valve ( 42 ) hydraulically parallel to the hydraulic line between the master cylinder ( 1 ) and hydraulic control unit (HCU), and wherein the check valve ( 42 ) a pressure propagation from the pressure chamber through the bypass ( 43 ) in the direction of the wheel brake ( 12 ) and a pressure propagation from the pump ( 21 ) through the bypass ( 43 ) blocked in the direction of the pressure chamber. Electrohydraulic vehicle brake system according to claim 10, characterized in that the damping module ( 40 ) a hydraulically switchable, isolation valve ( 44 ) with a closing body ( 56 ), that the separating valve ( 44 ) hydraulically parallel to the hydraulic line between the master cylinder ( 1 ) and hydraulic control unit (HCU) is connected, and has an open position and a closed position, wherein the closing body ( 56 ). is in an open position in a depressurized state, and reaches a closed position when the master brake pressure is applied to the master cylinder. Electrohydraulic vehicle brake system according to claim 11, characterized in that the closing body ( 56 ) is formed as a stepped stepped piston, and that the valve seat ( 55 ) for the separating valve ( 44 ) and the valve seat ( 51 ) for the check valve ( 42 ) are formed on a common component. Electrohydraulic vehicle brake system according to claim 11, characterized in that the stepped piston by a prestressed return spring ( 61 ) in a room ( 62 ) in a housing ( 45 ) of the damping module ( 40 ) and that the room ( 62 ) Has ventilation means to connect to the ambient atmosphere. Electrohydraulic vehicle brake system according to claim 10, characterized in that the damping module ( 40 ) Has filters, each in an input, and in an output of the damping module ( 40 ) are provided. Electrohydraulic vehicle brake system according to claim 10, characterized in that the damping module ( 40 ) has an integrated damper chamber, Electrohydraulic vehicle brake system according to claim 10, characterized in that the damping module ( 40 ) with elastic brake hoses to the master cylinder ( 1 ), and connected to the hydraulic control unit (HCU). Electrohydraulic vehicle brake system according to claim 10, characterized in that the damping module ( 40 ) on the one hand directly to or into a departure of the master cylinder ( 1 ) is screwed, and forms a structural unit with this.