CN112424499A

CN112424499A - Slave cylinder with pressure medium channel and clutch operating device

Info

Publication number: CN112424499A
Application number: CN201980048047.6A
Authority: CN
Inventors: 米歇尔·雅基; 朱利安·奥斯特
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-07-17
Filing date: 2019-07-02
Publication date: 2021-02-26
Also published as: DE112019003604A5; WO2020015782A1; DE102018120704A1

Abstract

The invention relates to a slave cylinder (1) for a clutch actuating device of a motor vehicle, comprising a housing (3) extending concentrically about a longitudinal axis (2) and at least one piston (5a, 5b) which is accommodated displaceably in the housing (3) and delimits a pressure chamber (4a, 4b) together with the housing (3), wherein the housing (3) is provided with at least one pressure medium channel (7a, 7b), the at least one pressure medium channel opens into a receiving chamber (6a, 6b) of the housing (3) which is designed as a pressure chamber (4a, 4b), the housing (3) has a first housing part (8) made of a synthetic material, which directly forms at least one pressure medium channel (7a, 7b), and a second housing part (9) which is connected to the first housing part (8) and is made of a metallic material. The invention also relates to a clutch actuating device having a slave cylinder (1).

Description

Slave cylinder with pressure medium channel and clutch operating device

Technical Field

The invention relates to a slave cylinder for a clutch actuating device of a motor vehicle, such as a passenger car, a lorry, a bus or another commercial vehicle, having a housing which extends concentrically about a longitudinal axis and having at least one piston which is accommodated displaceably in the housing and which is separated from the housing by a pressure chamber, wherein the housing is provided with at least one pressure medium channel which opens into a receiving chamber of the housing which forms the pressure chamber. Thus, the Slave Cylinder is implemented as a Concentric Slave Cylinder (CSC/"Concentric Slave Cylinder"). The invention also relates to a clutch actuating device and a master cylinder having such a slave cylinder.

Background

The applicant of the prior art already knows a generic slave cylinder in different designs. This situation is illustrated with reference to fig. 4 and 5, which illustrate the prior art. It is known from this design to introduce the pressure medium channel 7 ' in the metal housing 3 ' of the slave cylinder 1 ' by cutting through a plurality of bores.

Therefore, the past designs have the disadvantage that the pressure medium duct is produced by cutting through a relatively large number of steps. In addition to the relatively high manufacturing costs, a cleaning process for removing the metal chips is also indispensable. Another disadvantage is that the design achieved is relatively bulky and correspondingly heavy.

Disclosure of Invention

The object of the present invention is therefore to overcome the disadvantages of the prior art and to provide a lightweight slave cylinder which can be produced in as few steps as possible.

According to the invention, the above-mentioned problem is solved by a housing having a first housing part made of a synthetic material, which directly (and preferably completely) forms at least one pressure medium channel, and having a second housing part which is connected to the first housing part and is made of a metallic material.

On the one hand, the slave cylinder is thus realized in a particularly lightweight manner, and on the other hand, the introduction of the pressure medium channel into the first housing part is significantly simplified.

Further advantageous embodiments are claimed in the dependent claims and are explained in detail below.

It is therefore also advantageous if the first channel section of the at least one pressure medium channel is formed directly with the first housing part (without tools) in a molding process (of the first housing part), preferably during casting/by means of a casting technique (injection molding).

It should be noted here that a plurality of channel sections, and preferably all channel sections, of the at least one pressure medium channel are preferably designed in this way. Thereby significantly reducing manufacturing costs.

If the channel section extends in the housing in the radial direction of the longitudinal axis, this can be simply shaped in the casting process. The first channel section is further preferably a channel section which extends in the radial direction from the second channel section of the at least one pressure medium channel, which channel section flows into the receiving chamber, outwards to a third channel section which exits from the housing. As a result, a large part of the pressure medium channel can be machined as free of machining as possible.

The first channel section expands radially outward in its diameter, which can be achieved particularly easily with the aid of slides or the like in casting technology.

It is therefore likewise expedient if the at least one pressure medium duct is closed off by a plug radially on the outside of the housing, preferably in the radial extension of the first duct section. This further simplifies the casting-technical design of the pressure medium channel.

The plug is preferably made of a synthetic material and is welded to the first housing part. This further simplifies the mounting of the slave cylinder.

The robustness of the housing is increased if a prestressing plate is attached to the housing, which reinforces the first housing part in the region of the outlet of the pressure medium channel. The outlets are in principle those (axial) openings of the pressure medium channel which extend radially outside the pressure chamber to the housing circumference. The prestressed plate is made of an aluminum plate or a steel plate.

Furthermore, it is expedient to accommodate/pre-fix the prestressed plate in the accommodation of the first housing part in a form-fitting and/or force-fitting manner. Thereby further simplifying installation.

It has proven particularly advantageous if the prestressed plate has (first) through-holes for receiving fasteners, such as bolts or rivets. The first housing part is preferably provided with further (second) through-holes, which are aligned/arranged in a row with the first through-holes. In the fixed state of the slave cylinder on the gearbox or clutch housing, the housing is preferably fixed to the first housing part by means of a clamping prestress plate with fasteners.

Furthermore, it is advantageous for the bearing of the prestressed plate that it has a metal inlay which is provided and dimensioned for the (indirect) bearing of the prestressed plate relative to the second housing part. The second housing part likewise preferably has a third through-opening aligned with the first and second through-openings and is supported on the metal insert on the side facing away from the (axial) prestress plate. A particularly robust construction of the housing is thereby achieved.

Furthermore, it is advantageous for the second housing part to be pre-fixed/mounted on the first housing part by means of a snap-in/locking link (positively and/or non-positively). Thereby further simplifying installation.

It is also advantageous to design the slave cylinders as so-called twin slave cylinders, in which pressure chambers which can be controlled independently of one another are provided in the housings and the (respective) pressure medium channels open out into the receiving chamber of each housing which forms a pressure chamber. This also makes it possible to control the double clutch particularly effectively via the slave cylinder.

The invention also relates to a clutch actuating device (for a motor vehicle drive train) having a slave cylinder according to at least one of the above-described embodiments of the invention and a master cylinder connected or connectable thereto.

In other words, according to the invention, the CSC (slave cylinder) is therefore equipped with a prestressed plate on the pressure oil port (pressure medium channel). According to the invention, in the CSC, the pressure oil supply line (pressure medium channel) is integrated into the plastic component (first housing part) via the plastic pressure chamber (first housing part) and the steel base part (second housing part). The complicated subsequent drilling into the metal housing as is carried out in the prior art is thus avoided. Furthermore, the two pressure oil supply lines are provided with prestressed plates which connect the two ports (pressure medium channel/outlet of pressure medium channel) and are screwed in order to position the ports.

Drawings

The present invention will be described in detail below with reference to the accompanying drawings.

Fig. 1 shows a longitudinal section through a slave cylinder according to a preferred embodiment of the invention, wherein the section is chosen such that a first pressure medium channel leading into a first pressure chamber of the housing of the slave cylinder can be seen,

fig. 2 is a perspective view of the slave cylinder according to fig. 1 in full view, wherein the position of the two pressure medium channels of the housing coming out from the periphery of the slave cylinder can be seen,

fig. 3 is a sectional view of the slave cylinder according to fig. 1 and 2 in the region of the two outlets of the pressure medium channel, in which region a prestressed plate is installed, in order to stiffen the housing,

FIG. 4 is a longitudinal cross-sectional view of a slave cylinder according to the prior art and

figure 5 is a perspective view of the complete slave cylinder of figure 4.

Detailed Description

The drawings are merely schematic in nature and are provided to aid in understanding the present invention. Like elements are provided with like reference numerals.

The concentric slave cylinder 1 according to the invention can be seen in detail in fig. 1 with regard to its structure. The slave cylinder 1 is usually used in its operation in a clutch operating device of a clutch system in a drive train of a motor vehicle. Furthermore, the slave cylinder 1 cooperates hydraulically with the master cylinder in order to adjust the clutch of the clutch system between its engaged and disengaged positions.

The slave cylinder 1 is in this embodiment designed as a hydraulic slave cylinder 1 with two

cylinder subunits

22a, 22 b. The slave cylinder 1 is thus realized as a double slave cylinder. The two

cylinder subunits

22a, 22b are constructed essentially identically. The first cylinder subunit 22a is arranged radially outside (with respect to the central longitudinal axis 2) the second cylinder subunit 22 b. Each

cylinder subunit

22a, 22b has a

pressure chamber

4a, 4b spaced from the housing 3 and the

piston

5a, 5 b. Each

pressure chamber

4a, 4b is again formed by a receiving

chamber

6a, 6b of the housing 3. The housing 3, like the entire slave cylinder 1, extends annularly/concentrically around the longitudinal axis 2 due to its design as a concentric slave cylinder 1.

The first cylinder subunit 22a has a first piston 5a, which is accommodated in the housing 3, i.e. in a first receiving chamber 6a of the housing 3, so as to be displaceable along the longitudinal axis 2 of the slave cylinder 1. The first piston 5a typically has a seal 23 which, together with the first receiving chamber 6a, delimits the first pressure chamber 4a of the first cylinder subunit 22a and seals it against a first operating bearing 24 a. The first piston 5a is coupled immovably with a first operating bearing 24a, which is shown here only in sections for the sake of clarity. As can also be seen in fig. 1, the first receiving chamber 6a is formed entirely by the first housing part 8 of the housing 3.

A second receiving chamber 6b of a second cylinder subunit 22b, which likewise extends annularly about the longitudinal axis 2, is realized axially inside the first receiving chamber 6a, which extends annularly about the longitudinal axis 2. On the other hand, the second receiving chamber 6b is formed by the first housing part 8, in particular, with respect to the radial outer wall 25 and the front wall 26. The radially inner wall 27 of the second receiving chamber 6b, which is arranged radially within the outer wall 25, is formed by the second housing part 9. For this purpose, the second housing part 9 forms a jacket region 28 extending along the longitudinal axis 2, radially inside which the second piston 5b of the second cylinder subunit 22b forms a boundary of the second pressure chamber 4 b. In the housing 3, the second piston 5b is likewise displaceable along the longitudinal axis 2, that is to say is accommodated in the second receiving chamber 6 b. The second piston 5b is coupled immovably to a second actuating bearing 24b arranged radially in the first actuating bearing 24 a.

The two-part construction of the second housing part 9 of the housing 3 can be seen well in connection with fig. 2. The second housing part 9 is made of a metal material; the second housing part 9 is made of sheet metal. The flange region 29 of the second housing part 9, which adjoins the sleeve region 28 in the axial direction (i.e. along the longitudinal axis 2), is abutted by the end face of the first housing part 8. The first housing part 8 is therefore supported in the axial direction on the second housing part 9. The second housing part 9 is fixed to the first housing part 8 by a snap-in connection 30. The first housing part 8 is likewise made entirely of synthetic material. The first housing part 8 is pushed (radially from the outside) over the sleeve region 28. On the first housing part 8, a plurality of axial projections 31 forming the detent connection 30 are realized in the form of detent noses/detent hooks (material-integrated).

According to the invention, as can be seen from the observation of fig. 1 and 2, two

pressure medium channels

7a, 7b, which open out into the receiving

chambers

6a, 6b of the

cylinder subunits

22a, 22b, respectively, are realized directly and completely in the first housing part 8. The first pressure medium channel 7a opens with its radially inner end into the first receiving chamber 6a and with its radially outer end at a (first) outlet 15a, exits in the axial direction from the housing 3/first housing part 8 to the surroundings. Thus, the first outlet 15a is arranged radially outside the first receiving chamber 6 a. The first pressure medium channel 7a is naturally separated from the second pressure chamber 4 b/the second receiving chamber 6 b.

In the same way as the first pressure medium channel 7a, but offset in the circumferential direction from the first pressure medium channel 7a, a second pressure medium channel 7b leading into the second receiving chamber 6b is likewise provided completely in the first housing part 8. The second pressure medium channel 7b therefore extends radially outward from its radially inner end, which opens into the second receiving chamber 6b, to the region that opens into the second pressure chamber 4b, and radially outward to its radially outer end. The second pressure medium channel 7b extends in the axial direction from the housing 3/first housing part 8 at the (second) outlet 15b into the surroundings. Thus, a second outlet 15b is provided radially outside the second receiving chamber 6 b. As seen in fig. 2, the second outlet 15b is arranged offset in the circumferential direction from the first outlet 15 a.

For the sake of brevity, further configurations of the two

pressure medium channels

7a, 7b are described by way of example for the first pressure medium channel 7a of the first cylinder subunit 22a, wherein the described embodiment is to be regarded as independent of the second pressure medium channel 7b of the second cylinder subunit 22 b. The main difference in the design of the two

pressure medium channels

7a, 7b is that the second pressure medium channel 7b is of a radially longer design due to the selected arrangement of the pressure medium channel 7a radially inside the second pressure chamber 4 b.

The first pressure medium channel 7a has a first channel section 10 extending straight in the radial direction. The first channel section 10 is preferably realized without tools. The first channel section 10 is formed directly in a molding process, here an injection molding process, by which the first housing part 8 is likewise molded. The first channel section 10 has an inner diameter which expands outward in the radial direction. Preferably, the first channel section 10 is manufactured using a corresponding slide in a casting tool. The first channel section 10 merges at its radially inner side into a second channel section 11 which extends in the axial direction and merges into the first receiving chamber 6 a. The second channel section 11 is likewise produced by a molding process. The first channel section 10 merges on its radially outer side into a third channel section 12 which forms a first outlet 15 a. The third channel section 12 likewise extends in the axial direction, i.e. substantially perpendicularly to the first channel section 10. Likewise, the third channel section 12 is formed during the molding process of the first housing part 8.

In the radial extension 32 of the first channel section 10, which is necessary for the molding process, a plug 14 made of synthetic material is used and welded in the bore 33 formed by the extension 32. The plug 14 is made of a plastic material, like the first housing part 8. The first channel section 10 is therefore limited by the plug 14 to the radial outside 13 of the housing 3.

As can also be seen from the summary of fig. 1 to 3, a prestressed plate 16 is mounted on the first housing part 8 in order to reinforce the first housing part 8. According to fig. 3, the prestressed plate 16 is in principle pre-fixed in the receptacle 17 on the gearbox/clutch housing side in the unfixed position of the slave cylinder 1. The prestressed plate 16 is held in the receptacle 17 in a form-fitting manner. The pre-stressed plate 16 has a first through hole 18. The first through-hole 18 is aligned in the axial direction with a second through-hole 19, which is arranged directly in the first housing part 8. It can further be seen in fig. 3 that the two first and second through-

openings

18, 19 are aligned with the further third through-opening 21 of the second housing part 9 (in the flange region 29). For the sake of clarity, in the fixed position of the slave cylinder 1 on the clutch box/gearbox, fasteners, not shown, pass through these through

holes

18, 19, 21 and form a secure connection of the prestressed plate 16 with the two

housing parts

8, 9. For the axial support of the prestressing plate 16 relative to the second housing part 9, a sleeve-like inlay 20(/ band) surrounding the fastening element is used in the first housing part 8. The inlay 20 thus functions in a typical manner as a support for the prestressed plate 16 relative to the second housing part 9.

In other words, the supply of pressure oil between the clutch housing and the

CSC pressure chambers

4a, 4b is carried out in a polymer housing (first housing part 8) having three channels (

channel sections

10, 11, 12) which have sealing plugs 14 and are realized tool-lessly in the polymer housing 8, which sealing plugs are welded into the polymer housing 8. The use of the prestressed plate 16 presses the low-pressure oil supply (pressure

medium channels

7a, 7b) by screwing the CSC 1 and thus prevents the CSC 1 from leaking due to solidification of the synthetic material or material fatigue. The main advantages are: weight (polymer housing 8) and cost (no machining).

Description of the reference numerals

1 slave cylinder

2 longitudinal axis

3 case

4a first pressure chamber

4b second pressure chamber

5a first piston

5b second piston

6a first receiving chamber

6b second receiving chamber

7a first pressure medium channel

7b second pressure medium channel

8 first housing part

9 second housing part

10 first channel section

11 second channel section

12 third channel section

13 outside

14 plug

15a first outlet

15b second outlet

16 prestressed plate

17 accommodating part

18 first through hole

19 second through hole

20 damascene

21 third through hole

22a first cylinder sub-unit

22b second cylinder subunit

23 seal

24a first operating bearing

24b second operating bearing

25 outer wall

26 front wall

27 inner wall

28 sleeve region

29 flange region

30 snap-lock connection

31 projection

32 extension part

33 holes

Claims

1. A slave cylinder (1) for a clutch actuating device of a motor vehicle, having a housing (3) extending concentrically about a longitudinal axis (2) and having at least one piston (5a, 5b) which is accommodated displaceably in the housing (3) and delimits a pressure chamber (4a, 4b) together with the housing (3), wherein the housing (3) is provided with at least one pressure medium channel (7a, 7b), the at least one pressure medium channel opens into a receiving chamber (6a, 6b) of the housing (3) which is designed as a pressure chamber (4a, 4b), the pressure medium channel is characterized in that the housing (3) has a first housing part (8) made of a synthetic material, which directly forms the at least one pressure medium channel (7a, 7b), and a second housing part (9) which is connected to the first housing part (8) and is made of a metallic material.

2. The slave cylinder (1) according to claim 1, characterized in that the first channel section (10) of the at least one pressure medium channel (7a, 7b) can be formed directly from the first housing component (8) in terms of casting technology.

3. The slave cylinder (1) according to claim 2, characterized in that the first channel section (10) extends in the radial direction of the longitudinal axis (2) from a second channel section (11) of the at least one pressure medium channel (7a, 7b) opening into the receiving chamber (6a, 6b) outwards as a third channel section (12) emerging from the housing (3).

4. The slave cylinder (1) according to claim 2 or 3, characterized in that the first channel section (10) expands radially outwards in diameter.

5. The slave cylinder (1) according to any one of claims 1 to 4, characterized in that the at least one pressure medium channel (7a, 7b) is closed off by a plug (14) on the radial outside (13) of the housing (3).

6. The slave cylinder (1) according to claim 5, characterized in that the plug (14) consists of a synthetic material and is welded to the first housing part (8).

7. The slave cylinder (1) according to one of claims 1 to 6, characterised in that a prestressing plate (16) is mounted on the housing (3) which reinforces the first housing part (8) in the region of the outlet (15a, 15b) of the at least one pressure medium channel (7a, 7 b).

8. The slave cylinder (1) according to claim 7, characterized in that the prestressed plate (16) is accommodated in a form-fitting and/or force-fitting manner in an accommodation (17) of the first housing part (8).

9. The slave cylinder (1) according to one of claims 1 to 8, characterised in that two pressure chambers (4a, 4b) which can be controlled independently of one another are formed in the housing (3), wherein a pressure medium channel (7a, 7b) opens into a receiving chamber (6a, 6b) of the housing (3) which each forms a pressure chamber (4a, 4 b).

10. Clutch operating device with a slave cylinder (1) according to one of claims 1 to 9 and a master cylinder coupled or couplable with the slave cylinder (1).