Hydraulic cylinder for actuating a friction clutch in a motor vehicle

Abstract

Hydraulic cylinder for actuating a friction clutch in a motor vehicle with a cylinder housing (2) in which a movable piston is mounted, wherein a sensor housing (8) is attached to the cylinder housing (2) in which a sensor detecting the position of the piston is arranged, wherein the sensor housing (8) is connected to the cylinder housing (2) via at least one rivet connection (6, 10; 13, 15), characterized in that the rivet connection (6, 10; 13, 15) projects beyond the cylinder housing (2) transversely to its longitudinal extent and that the rivet connection (6, 10;13, 15) consists of a cylinder housing rivet connection (6a, 6b, 6c, 6d) having a first opening (7a, 7b, 7c, 7d) and a sensor housing rivet connection (10a, 10b) having a second opening (11a, 11b), wherein, with an identical orientation of the first (7a, 7b, 7c, 7d) and the second opening (11a, 11b) of the cylinder housing rivet connection (6a, 6b, 6c, 6d) and the sensor housing rivet connection (10a, 10b), a rivet (16) is guided through the first (7a, 7b, 7c, 7d) and the second opening (11a, 11b).

Description

[0001] The invention relates to a hydraulic cylinder for actuating a friction clutch in a motor vehicle with a cylinder housing in which a movable piston is mounted, wherein a sensor housing is attached to the cylinder housing in which a sensor detecting the position of the piston is arranged.

[0002] To enable early detection of the driver's intent when engaging a vehicle clutch, a sensor is mounted on a master cylinder (designed as a hydraulic cylinder) used to actuate a friction clutch in the vehicle. This sensor detects a change in the position of a piston located within the cylinder housing of the hydraulic cylinder, triggered by the driver pressing the clutch pedal. The sensor is housed in a sensor casing attached to the cylinder housing of the hydraulic cylinder. Typically, the sensor casing is clipped, glued, or screwed onto the cylinder housing. Alternatively, pockets are integrated into the hydraulic cylinder to accommodate the sensor casing. Due to these different mounting methods, the sensor casing is always attached to the cylinder housing in a predetermined position.These fixed positions of the sensor housing necessitate the design of a new mounting arrangement for the sensor housing on the cylinder housing for each coupling type, taking into account its specific installation space requirements. A device for mounting a sensor housing to a cylinder housing is known from DE 10 2008 062 337 A1.

[0003] The invention is therefore based on the objective of providing a hydraulic cylinder which, with only one fastening arrangement, enables variable fastening of the sensor housing to the hydraulic cylinder, taking into account the respective installation space of the coupling.

[0004] According to the invention, the problem is solved by connecting the sensor housing to the cylinder housing via at least one rivet connection, wherein the rivet connection projects beyond the cylinder housing transversely to its longitudinal extent. Such a rivet connection allows for various degrees of freedom in attaching the sensor housing to the cylinder housing. This enables the selection of the degree of freedom corresponding to the available installation space for each coupling type when attaching the sensor housing to the hydraulic cylinder. Using such a standardized attachment, variable connection of the sensor housing to the hydraulic cylinder is possible without requiring any modifications to the cylinder housing or the sensor housing. This reduces manufacturing costs.

[0005] The rivet connection consists of a cylinder housing rivet connection with a first opening and a sensor housing rivet connection with a second opening. When the first and second openings of the cylinder housing rivet connection and the sensor housing rivet connection are aligned, a rivet passes through both openings. Since the cylinder housing rivet connection and the sensor housing rivet connection can be aligned in different positions, the sensor can be attached to the cylinder housing in various orientations by rotating or tilting the sensor housing, taking into account the available installation space. The sensor housing can be attached to the respective cylinder housing rivet connection from below or from above. Furthermore, the same rivet connection allows the sensor housing to be attached to the left or right side of the cylinder housing.

[0006] In one embodiment, the cylinder housing rivet connection has a guide pocket for the sensor housing. This facilitates the insertion and holding of the sensor housing, and thus the covering of the first opening of the cylinder housing rivet connection and the second opening of the sensor housing rivet connection during manufacturing, which is why the assembly of the cylinder housing and sensor housing can also be carried out in a fully automated process.

[0007] In one variant, the rivet connection has two cylinder housing rivet connections arranged one above the other, spaced apart from each other, and extending in the same direction transversely to the longitudinal dimension of the cylinder housing. The sensor housing rivet connection is inserted between these connections. Alternatively, it consists of two spaced-apart sensor housing rivet connections formed one above the other on one side of the sensor housing, with the cylinder housing rivet connection inserted between them. The two gaps that arise between the cylinder housing rivet connection and the sensor housing rivet connection in this configuration allow for improved force distribution, for example, when inserting the sensor housing into the cylinder housing, thus largely preventing damage to the cylinder housing rivet connections or the sensor housing rivet connections.

[0008] In one embodiment, the opening of the cylinder housing rivet connection extends transversely to the longitudinal extent of the cylinder housing. In particular, each opening extends approximately perpendicular to the longitudinal extent of the respective cylinder housing rivet connection. This design allows for various degrees of freedom when attaching the sensor housing via the sensor housing rivet connections, which is why the sensor arrangement can be easily adapted to the available installation space in the coupling.

[0009] In a further development, two rivet connections are formed on the cylinder housing, positioned opposite each other along the longitudinal direction of the cylinder housing and spaced apart to accommodate the sensor housing. At least one rivet connection of each connection is aligned with the corresponding rivet connection of the sensor housing, perfectly aligned with the rivet's position. This spacing of the two rivet connections allows for the insertion of any sensor housing. The sensor housing itself can have different dimensions, and the lengths of the rivet connections can be adjusted to facilitate its attachment to the cylinder housing rivet connections.

[0010] In one variant, the distance between the two rivet connections corresponds approximately to the dimensions of the sensor housing. This embodiment allows for a backlash-free arrangement of the sensor housing on the cylinder housing.

[0011] Advantageously, a sensor holder extending along the longitudinal dimension of the cylinder housing is arranged between two cylinder housing rivet connections pointing away from the sensor holder. This sensor holder, which is centrally located on the cylinder housing, aligns the sensor position during the manufacturing process and holds it in place until riveting, thus simplifying the manufacturing process. The position of the rivet connections also advantageously allows the sensor housing to be attached in at least two positions.

[0012] In one embodiment, two cylindrical housing rivet connections are formed near each end of the sensor mount, pointing away from the sensor mount and arranged symmetrically to the sensor mount. The cylindrical housing rivet connections are positioned to minimize the installation space while simultaneously allowing for four different sensor housing positions. During manufacturing, the sensor housing is fixed centrally between the cylindrical housing rivet connections, simplifying the insertion of the rivets into both the cylindrical housing rivet connections and the sensor housing rivet connections.

[0013] In a particularly convenient and cost-effective embodiment, the cylinder housing and the cylinder housing rivet connections, as well as preferably the sensor holder, are made in one piece, in particular from a plastic or from a metallic material, preferably aluminium.

[0014] Particularly low space requirements are achieved when the sensor housing is designed at right angles, with two sensor housing rivet connections being designed symmetrically to an angle element of the sensor housing.

[0015] The invention allows for numerous embodiments. One of these will be explained in more detail with reference to the figures shown in the drawing.

[0016] It shows: Fig. 1: A first embodiment for attaching a sensor housing to a hydraulic cylinder, Fig. 2: Variants of the arrangement of the sensor housing on the hydraulic cylinder according to Fig. 1, Fig. 3: a second embodiment for attaching the sensor housing to the hydraulic cylinder, Fig. 4: A third embodiment for attaching the sensor housing to the hydraulic cylinder. Fig. 5: an embodiment similar to Fig. 2, with crushed ribs.

[0017] Identical features are marked with the same reference symbol.

[0018] In Fig. Figure 1 shows various views of a hydraulic cylinder 1, which is arranged as a master cylinder in a hydraulic clutch actuation device of a motor vehicle. The hydraulic cylinder 1 has a cylindrical cylinder housing 2 in which a piston (not shown) is movably mounted. The piston is moved in its position by the driver via a clutch pedal or by control electronics, thereby actuating the clutch. Fig. In Figure 1a, the cylinder housing 2 has a collar 3 by means of which the hydraulic cylinder 1 is positioned between the vehicle interior and the engine compartment. A mounting device for a sensor is shown below the collar 3. The mounting device consists of a guide rail 4, which extends along the longitudinal dimension of the hydraulic cylinder 1. At each end of the guide rail 4, a receptacle 5a, 5b, designed as a groove, is formed for a sensor housing 8, which will be shown later. On both sides of the receptacles 5a, 5b, a cylinder housing rivet connection 6a, 6b; 6c, 6d extends. These cylinder housing rivet connections 6a, 6b; 6c, 6d are located transversely to the longitudinal dimension of the cylinder housing 2. They project beyond the diameter of the cylinder housing 2.Each of the cylinder housing rivet connections 6a, 6b; 6c, 6d has an opening 7a, 7b; 7c, 7d for guiding a rivet (not shown), which is inserted after the sensor housing 8, containing the sensor, has been inserted into the receptacles 5a, 5b of the guide rail 4. The cylinder housing rivet connections 6a, 6b; 6c, 6d are positioned such that they project beyond the cross-section of the cylinder housing, yet occupy as little installation space as possible. A top view of the hydraulic cylinder 1 with the described rivet connection is shown in . Fig. 1b shown while Fig. Figure 1c shows a side view of the corresponding hydraulic cylinder 1.

[0019] In Fig. Figure 2 shows four variants for the arrangement of the sensor housing 8 on the cylinder housing 2. The sensor housing 8 is designed at right angles, with a sensor housing rivet connection 10a, 10b on each side of an angled element 9 of the sensor housing 8. The sensor housing rivet connections 10a and 10b also each have an opening 11a, 11b, into which the rivet 16 engages when installed. Fig. 2a The openings 11a, 11b are aligned with the first opening 7a and the opening 7c (not shown) of the cylinder housing rivet connections 6a and 6c, respectively. The angle element 9 was previously inserted into the receptacles 5a, 5b of the guide rail 4. Due to the mounting of the sensor housing 8 by means of the guide rail 4, the sensor housing 8 is positioned on the hydraulic cylinder 1 so that the rivet 16 can be pushed through the superimposed cylinder housing rivet connections 6a, 6c and the sensor housing rivet connections 10a, 10b and the sensor housing 8 is riveted to the cylinder housing 2. Fig. Figure 2a shows the connection of the sensor housing 8 to the right of the cylinder housing 2, with the sensor housing 8 pointing away from the cylinder housing 2. In contrast, in Fig. Figure 2b shows the fastening of the sensor housing 8 to the left of the cylinder housing 2. The sensor housing rivet connections 10b and 10a are connected to the cylinder housing rivet connections 6b and 6d.

[0020] Another position of the arrangement of the sensor housing 8, in which the sensor housing 8 points towards the cylinder housing 2, is shown in the Fig. 2c and Fig. 2D representation. Fig. In 2c, the sensor housing rivet connection 10b aligns with the cylinder housing rivet connection 6a, while the sensor housing rivet connection 10a is connected to the cylinder housing rivet connection 6c, which is not visible. Even in this position of the sensor housing 8, which is inclined towards the cylinder housing 2, there is a left and a right possible arrangement of the sensor housing 8. Fig. Figure 2c shows the right-hand arrangement, while in Fig. Figure 2d shows the left-hand arrangement, in which the sensor housing rivet arrangement 10a is connected to the cylinder housing rivet arrangement 6b, while the sensor housing rivet arrangement 10b is aligned with the cylinder housing rivet arrangement 6d (not shown). Due to this design, the sensor can assume four positions without requiring any changes to the rivet connections.

[0021] In Fig. Figure 3 shows a second embodiment for attaching the sensor housing 8 to the hydraulic cylinder 1, in which a guide rail is omitted. This simplifies the attachment of the sensor housing 8 to the hydraulic cylinder 1, meaning that no extra slide is required for manufacturing the hydraulic cylinder 1 during injection molding of a plastic. The second mounting point is completely eliminated, and only one pair of cylinder housing rivet connections 13a, 13b is required. The cylinder housing rivet connections 13a, 13b are spaced apart and arranged one above the other along the longitudinal extent of the cylinder housing 2 ( Fig. 3a, Fig. 3c). These cylinder housing rivet connections 13a, 13b have guide pockets 14a, 14b into which the angle element 9 with the sensor housing rivet connections 10a, 10b is inserted. The guide pockets 14a, 14b, designed as crimp ribs and integrated into the cylinder housing rivet connections 13a, 13b, serve to align the sensor housing. The sensor housing rivet connections 10a, 10b are attached to the angle element 9 of the sensor housing 8 transversely to the longitudinal axis of the sensor housing 8 in order to be independent of the width of the sensor housing 8 during the riveting process. In this embodiment, four different positions of the sensor housing 8 on the cylinder housing 2 are also possible. A connecting line 12, which is not required for attaching the sensor housing 8, serves in particular for orientation, whereby in Fig. Figure 3b shows a front view of the cylinder housing 2 with the cylinder housing rivet connection 13b. Fig. Figure 3c shows a perspective view of the cylinder housing 2 with the sensor housing 8, while in the Fig. In 3D only the sensor housing 8 is shown. It is clearly evident that the sensor housing rivet connections 10a, 10b extend transversely to the longitudinal axis of the sensor housing 8 and symmetrically to the angled element 9.

[0022] A third embodiment for attaching the sensor housing 8 to the cylinder housing 2 is shown in Fig. 4 shown. Fig. Figure 4a shows a side view of hydraulic cylinder 1, while in Fig. Figure 4b shows a front view of the hydraulic cylinder 1. Fig. Figure 4c shows a perspective view of the hydraulic cylinder 1, illustrating a third possible way of attaching the sensor arrangement 8 to the hydraulic cylinder 1. In this arrangement, according to... Fig. 4d the sensor housing 8, in particular its angled element 9, has two sensor housing rivet connections 15a, 15b on each side, which are symmetrically opposite the sensor housing rivet connections 15c, 15d. As shown from Fig. As shown in Figure 4c, the cylinder housing rivet connection 13a, located on the cylinder housing 2, is inserted between the sensor housing rivet connections 15a and 15b, without the need for additional guide rails. The same procedure is followed with the cylinder housing rivet connection 13b, which is pressed between the opposing sensor housing rivet connections 15c and 15d. The sensor housing 8 thus has a double rivet connection 15a, 15b or 15c, 15d on each side. This rivet connection between the sensor housing 8 and the hydraulic cylinder 1 results in improved force distribution during the assembly of the sensor housing 8. At the same time, it provides not only a particularly simple but also a particularly stable fastening of the sensor housing 8. In this third version as well, the sensor housing 8 can be fastened to the cylinder housing 2 in four positions by means of the symmetrical arrangement of the sensor housing rivet connections 15a, 15b or 15c, 15d on the hydraulic cylinder 1.

[0023] Based on the above explanations, a standardized hydraulic cylinder can be easily connected to a standardized sensor housing 8, whereby the arrangement of the sensor housing 8 on the hydraulic cylinder 1 can be varied taking into account the available installation space.

[0024] In Fig. Figure 5 represents a further variant of a hydraulic cylinder 1 according to the invention. This hydraulic cylinder 1 is similar to the one described in Figure 5. Fig. 2. In the embodiment shown, a detailed description of the common features has been omitted. In contrast to the embodiment in Fig. 3 indicates the hydraulic cylinder 1 in the Fig. 5 support elements with crush ribs 17, which are arranged near the cylinder housing rivet connections 13a and 13b. During the assembly of the sensor housing (analogous to the Fig. 3) The crush ribs 17 are partially deformed and thus serve to compensate for tolerances, ensuring that the sensor housing is fixed to the hydraulic cylinder without play in all mounting positions.

[0025] Such crimp ribs can also be used in the embodiments according to Fig. 1, Fig. 2 and Fig. 4 or provided on the sensor housing. Reference symbol list 1 hydraulic cylinder 2 cylinder housings 3 collars 4 guide rail 5a recording 5b recording 6a Cylinder housing rivet connection 6b Cylinder housing rivet connection 6c Cylinder housing rivet connection 6d Cylinder housing rivet connection 7a Opening of a cylinder housing rivet connection 7b Opening a cylinder housing rivet connection 7c Opening of a cylinder housing rivet connection 7d Opening of a cylinder housing rivet connection 8 Sensor housings 9 Angle element of the sensor housing 10a Sensor housing rivet connection 10b Sensor housing rivet connection 11a Opening a sensor housing rivet connection 11b Opening a sensor housing rivet connection 12 Connection cable 13a Cylinder housing rivet connection 13b Cylinder housing rivet connection 14a Guide bag 14b Guide bag 15a Sensor housing rivet connection 15b Sensor housing rivet connection 15c Sensor housing rivet connection 15d Sensor housing rivet connection 16 rivets 17 squeeze ribs

Claims

[1] Hydraulic cylinder for actuating a friction clutch in a motor vehicle, comprising a cylinder housing (2) in which a movable piston is mounted, wherein a sensor housing (8) is fastened to the cylinder housing (2), in which a sensor detecting the position of the piston is arranged, characterized in that the sensor housing (8) is connected to the cylinder housing (2) via at least one rivet connection (6, 10; 13, 15), characterized bythat the riveted connection (6, 10; 13, 15) projects beyond the cylinder housing (2) transversely to its longitudinal extent and that the riveted connection (6, 10; 13, 15) consists of a cylinder housing rivet connection (6a, 6b, 6c, 6d) having a first opening (7a, 7b, 7c, 7d) and a sensor housing rivet connection (10a, 10b) having a second opening (11a, 11b), wherein with a congruent alignment of the first (7a, 7b, 7c, 7d) and the second opening (11a, 11b) of the cylinder housing rivet connection (6a, 6b, 6c, 6d) and the sensor housing rivet connection (10a, 10b), a rivet (16) through the first (7a, 7b, 7c, 7d) and the second opening (11a, 11b). [2] Hydraulic cylinder according to claim 1, characterized by that the cylinder housing rivet connection (13a, 13b) has a guide pocket (14a, 14b) for the sensor housing (8). [3] Hydraulic cylinder according to claim 1 or 2, characterized bythat the rivet connection (13, 15) has two cylinder housing rivet connections (13a, 13b) arranged one above the other, spaced from one another and extending transversely to the longitudinal extent of the cylinder housing (2) in the same direction, between which the sensor housing rivet connection (10a, 10b) is inserted or consists of two spaced sensor housing rivet connections (10a, 10b) formed one above the other on one side of the sensor housing (8), between which the cylinder housing rivet connection (13a, 13b) is pushed. [4] Hydraulic cylinder according to at least one of claims 1, 2 or 3, characterized by that the opening (7a, 7b, 7c, 7d) of the cylinder housing rivet connection (6, 13) extends transversely to the longitudinal extent of the cylinder housing (2). [5] Hydraulic cylinder according to at least one of the preceding claims, characterized byin that two rivet connections (13a, 10b; 13b, 10a) are formed on the cylinder housing (2), which are spaced apart from one another in the longitudinal direction of the cylinder housing (2) to accommodate the sensor housing (8), wherein the at least one cylinder housing rivet connection (13a, 13b) of each rivet connection (13a, 10b; 13b, 10a) is aligned congruently with the sensor housing rivet connection (10a, 10b) to accommodate the rivet (16). [6] Hydraulic cylinder according to claim 5, characterized by that the distance between the two riveted joints (13a, 10b; 13b, 10a) approximately corresponds to the extension of the sensor housing (8). [7] Hydraulic cylinder according to claim 1, characterized by that a sensor holder (4) extending along the longitudinal extent of the cylinder housing (2) is arranged between two cylinder housing rivet connections pointing away from the sensor holder (4). [8] Hydraulic cylinder according to claim 7, characterized bythat near the ends of the sensor holder, two cylinder housing rivet connections (6a, 6b, 6c, 6d) are formed, each pointing away from the sensor holder and arranged symmetrically to the sensor holder. [9] Hydraulic cylinder according to at least one of the preceding claims, characterized by that the cylinder housing (2) and the cylinder housing rivet connections (6, 13) as well as the sensor holder (4) are made in one piece, in particular from a plastic or from a metallic material, preferably aluminum. [10] Hydraulic cylinder according to one of the preceding claims, characterized by that crush ribs are arranged in the area of ​​the cylinder housing rivet connections (6a, 6b, 6c, 6d, 13a, 13b) or in the area of ​​the sensor housing rivet connections (10a, 10b).

Images