Master cylinder, assembly including this master cylinder and a body-mountable support structure; actuating device and clutch system

Abstract

Master cylinder (1) for a clutch actuation device of a motor vehicle, comprising a housing (2) and a piston (3) slidably received in the housing (2), wherein the housing (2) has a flange area (6) extending transversely to a displacement axis (4) of the piston (3) and designed for support on a body-fixed mounting structure (5) of the motor vehicle, characterized in that the flange area (6) is provided on its side (7) provided for support on the mounting structure (5) with a multi-layer sealing and damping element (8) consisting of at least one foamed material, wherein the sealing and damping element (8) has a first layer (9) which consists of a different foamed material or of the same material with a different foam structure than a second layer (10) of the sealing and damping element (8).

Description

The invention relates to a master cylinder for a clutch actuation device of a motor vehicle, such as a passenger car, truck, bus, or other commercial vehicle, comprising a housing and a piston slidably mounted in the housing, wherein the housing has a flange area extending transversely to a displacement axis of the piston and designed for support against a body-mounted mounting structure of the motor vehicle. The invention further relates to a clutch actuation arrangement consisting of this master cylinder and a body-mounted mounting structure. The invention also relates to an actuation device for a clutch of a motor vehicle, comprising this master cylinder. Finally, the invention relates to a clutch system for a drivetrain of a motor vehicle, comprising a clutch and this actuation device. Various arrangements of master cylinders on body-mounted support structures are already known from the prior art. For example, DE 10 2015 212 479 A1 discloses a hydraulic cylinder unit with a flexible connection. However, in previously known designs, it has been found that the connection points between the master cylinder and the mounting structure often cause or amplify unwanted vibrations. The fluid-tight connection points thus frequently have the disadvantage that undesirable noises, perceptible to the driver, can occur during vehicle operation. A master cylinder according to the preamble of claim 1 is known from CN 2 05 226 145 U. Further prior art is disclosed in DE 10 2012 211 276 A1. It is therefore the object of the present invention to eliminate the disadvantages known from the prior art and in particular to provide a master cylinder which, on the one hand, ensures a reliable fluid seal on the part of a body-mounted support structure, and on the other hand, provides significant vibration damping on the part of the support structure. This is solved according to the invention by providing the flange area on its side intended for support on the holding structure (directly) with a multi-layered sealing and damping element consisting of at least one foamed material. The use of multiple different layers significantly improves damping performance. This helps to avoid unwanted noise during vehicle operation. Further advantageous embodiments are claimed in the dependent claims and are explained in more detail below. According to the invention, the sealing and damping element has a first layer consisting of a different foamed material or of the same (foamed) material with a different foam structure than a second layer of the sealing and damping element. This further optimizes the damping effect for the specific application. Furthermore, it is advantageous if the first layer is attached directly to the flange area, i.e., in direct contact with the flange area. Adhesive bonding has proven to be the preferred method for attaching the first layer to the flange area. This makes mounting the sealing and damping element to the flange area particularly easy. If the first layer is thinner than the second layer, the sealing and damping element can be integrated particularly compactly into existing installation space. The various layers of the sealing and damping element are preferably bonded (directly) together. This makes the sealing and damping element particularly cost-effective to manufacture. It has proven particularly advantageous if different layers of the sealing and damping element consist of different foamed plastic materials. This further simplifies the manufacturing process. Furthermore, it is advantageous if the second layer has a smaller extent than the first layer when viewed in a radial direction along the displacement axis. This makes it particularly easy to insert the second layer into the corresponding recess of the holding structure. Furthermore, the invention relates to an arrangement for clutch actuation, comprising a master cylinder according to the invention, designed according to at least one of the embodiments described above, and a mounting structure that can be attached to the body, wherein the mounting structure has a plate-shaped receiving section with a through-hole and the housing projects through the through-hole in such a way that the flange area is supported on the receiving section via the sealing and damping element, forming a fluid seal. In this context, it is also advantageous if a damping coating, preferably made of a foamed material, is attached to the retaining structure on one side of the receiving section facing the flange area, and the sealing and damping element rests at least partially (preferably with its first layer) on this damping coating (preferably across its entire surface). This keeps the connection particularly simple. The first layer preferably rests directly against the damping coating, forming the liquid seal. In addition to the lateral contact of the first layer with the damping coating, it is advantageous if the second layer rests radially from the inside against the damping coating, which is also recessed in the area of ​​the through-hole. This results in a particularly clever application of the second layer, so that it acts as a damping layer in addition to the first layer. For better vibration isolation, it is also advantageous if the master cylinder is attached to a pedal bracket of a clutch pedal. Furthermore, the invention relates to an actuating device for a clutch of a motor vehicle, comprising a master cylinder according to the invention in at least one of the previously described embodiments and a slave cylinder fluidically connected to the master cylinder. The invention also relates to a clutch system for a drive train of a motor vehicle, comprising a clutch and the actuating device that acts on this clutch during operation. In other words, waterproof and noise-dampening layers (first and second layers) are provided between a splash guard (support structure) and a pedal box (pedal stand). It is proposed to integrate the various layers of a foam for waterproofing and noise reduction between the splash guard and the pedal box. Preferably, one layer (damping coating) is supplemented by two further layers (first and second layers). The invention will now be explained in more detail below using figures. Figure 1 shows a longitudinal section of an arrangement of a master cylinder according to a preferred embodiment, incorporating a mounting structure of a motor vehicle that is further connected to the bodywork, in which a sealing and damping element acting between a housing of the master cylinder and the mounting structure is particularly clearly visible; Figure 2 shows a perspective view of the master cylinder used in Figure 1 from an oblique angle from the outside, in which an outer contour of the different layers of the sealing and damping element is clearly visible; Figure 3 shows a detailed view of the arrangement according to Figure 1, cut in the longitudinal direction, in the area of ​​the sealing and damping element; Figure 4 shows a perspective view of the master cylinder used in Figure 1, in which a side of a flange area of ​​the housing facing away from the sealing and damping element is visible.Fig. 5 shows a perspective view of the arrangement consisting of the master cylinder and the mounting structure according to Fig. 1, in which the further periphery of the master cylinder, such as a clutch pedal, as well as the further shaping of the mounting structure are clearly visible; Fig. 6 shows a perspective view of the arrangement according to Fig. 5 from a side facing away from the clutch pedal; and Fig. 7 shows a perspective exploded view of the components as they are used in the arrangement according to Fig. 5, so that the design of the clutch pedal, the master cylinder, a damping coating and the mounting structure are particularly clearly visible. The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference symbols. Figure 1 illustrates the detailed structure of a hydraulic master cylinder 1 according to the invention, implemented in a preferred embodiment. In operation, the master cylinder 1 is associated with a slave cylinder of a clutch actuating device and is hydraulically coupled to the slave cylinder. During operation of the clutch actuating device, the slave cylinder engages and disengages a corresponding clutch, such as a friction clutch. Consequently, in operation, the clutch actuating device is part of a clutch system, which also includes the corresponding clutch upon which the actuating device acts. The further coupling of the master cylinder 1 with a clutch pedal 15 is clearly visible in Figures 5, 6 to 7. The clutch pedal 15 itself is pivotably mounted on a pedal bracket 16. This pedal bracket 16 is firmly anchored to a support structure 5 of the vehicle, which is further connected to the body. The support structure 5 preferably forms an integral part of the body. Here, the support structure 5 is designed as a firewall. The master cylinder 1 is designed in a known manner and therefore has a housing 2 in which a piston 3 is slidably guided along its displacement axis 4 / longitudinal axis (Fig. 1). The clutch pedal 15 is coupled to the piston 3. A piston rod 17, which projects from the housing 2, serves to couple the movement of the piston to the clutch pedal 15 via its bearing eye 18. Fig. 1 further shows that the piston 3 and the housing 2 define a hydraulic pressure chamber 19. A sensor device 21 is provided for detecting the position of the piston 3 along its displacement axis 4. As can be clearly seen in Fig. 6, the master cylinder 1 protrudes through a through hole 12 provided in the holding structure 5 in such a way that the housing 2 together with the sensor device 21 is arranged on a side of the holding structure 5 facing away from the clutch pedal 15 (second side 22 of the receiving section 11). In Fig. 1, the mounting structure 5 is shown laterally to its plate-shaped receiving section 11. The receiving section 11 directly forms the through-hole 12, through which the master cylinder 1 partially projects along the displacement axis 4. On a (first) side 13 of the receiving section 11 facing the clutch pedal 15, a flange area 6 formed on the housing 2 is directly supported on the receiving section 11 / the mounting structure 5. The housing 2 is thus firmly mounted to the mounting structure 5. Furthermore, the housing 2 is held / positioned with the pedal bracket 16. As can be seen in Fig. 5, the flange area 6 is partially arranged between the mounting structure 5 and the pedal bracket 16. For noise-dampening and liquid-tight sealing of the flange area 6 to the mounting structure 5, a sealing and damping element 8 designed according to the invention is attached to the flange area 6. The structure of the sealing and damping element 8 is also clearly visible in conjunction with Figures 2, 3 to 4. According to the invention, the sealing and damping element 8 (Figure 3) is composed of two individual layers 9 and 10 (also referred to as layers). A first layer 9 of the sealing and damping element 8 is entirely plate-shaped. The first layer 9 rests directly against a (first) axial side 7 of the flange area 6 facing the receiving section 11. The first layer 9 is attached directly to the first side 7, namely by gluing.A (second) axial side 25 of the flange area 6 facing away from the receiving section 11 along the displacement axis 4 is uncovered by the sealing and damping element 8. The second layer 10 is formed separately from the first layer 9. The second layer 10 is attached to a side of the first layer 9 facing axially away from the flange region 6, namely by bonding. The second layer 10 is also essentially plate-shaped. The second layer 10 has a smaller radial extent with respect to the displacement axis 4 than the first layer 9. The second layer 10 has a greater thickness (axial extent) than the first layer 9. Although the second layer 10 also rests flat against the retaining structure 5 / the receiving section 11 in the axial direction (Fig. 3), it is additionally arranged radially within a further damping coating 14, which is attached to the retaining structure 5. The second layer 10 has essentially the same thickness as the damping coating 14. The second layer 10 preferably rests radially against this damping coating 14 from the inside.The second layer 10 has a shape (radial outer contour) complementary to an inner surface 23 of the damping coating 14 on its radial outer side. Thus, the second layer 10 preferably lies flat against the inner surface 23 of the damping coating 14 over a circumferential area along a circumferential direction. In the assembled position of the arrangement 20, the first layer 9 rests against the retaining structure 5, specifically against the damping coating 14, in such a way as to create a liquid seal, i.e., it prevents the passage of a liquid, such as water, from the side of the retaining structure 5 facing away from the clutch pedal 15 (second side 22 of the receiving section 11) to the side facing the clutch pedal 15 (first side 13 of the receiving section 11) of the retaining structure 5 through the through-hole 12. The first layer 9 is compressed / pressed together with an axial preload between the flange area 6 and the damping coating 14. In the assembled position of the arrangement 20, the second layer 10 rests against the retaining structure 5, specifically against the receiving section 11, and the first layer 9 in such a way that it also forms the fluid seal, i.e., it prevents the passage of a fluid, such as water, from the side of the retaining structure 5 facing away from the clutch pedal 15 to the side of the retaining structure 5 facing the clutch pedal 15 through the through-hole 12. Like the damping coating 14, the second layer 10 also contributes to vibration damping. The first layer 9 also has a damping effect on vibrations acting on the retaining structure 5 during operation. The second layer 10 is compressed / pressed together with an axial preload between the retaining structure 5 / receiving section 11 and the flange area 6. In the embodiment shown, the two layers 9 and 10 are made of different foamed plastic materials, i.e., different plastic foams. In other embodiments, it is also possible in principle to use the same materials, such as polyurethane, for both layers 9 and 10, but to design the foam structure of the two layers differently. In other words, according to the invention, a foam (sealing and damping element 8) with two layers 9, 10 is realized. The second layer 10 is used for water / liquid sealing between the instrument panel (support structure 5) and the first layer 9. The first layer 9 is used for liquid sealing between the second layer 10 and the housing plate (flange area 6) of the CMC (housing 2 of the master cylinder 1 ("clutch master cylinder")). The first layer 9 is also used for noise damping between the noise-dampening foam (damping coating 14) of the instrument panel 5 and the housing plate 6 of the CMC 2. The foam 8 according to the invention is thus manufactured in one piece from two layers 9, 10. The two layers 9, 10 are bonded together. The foam 8 is then attached to the CMC 2. A bellows 24 is also typically provided to seal the piston rod 17.The housing 2 is preferably attached to both the pedal box 16 and the instrument panel 5. Specifically, the CMC 2 is attached to the pedal box 16, and the pedal box 16 is further attached to the instrument panel 5. The damping coating 14 is applied to the instrument panel 5. The second layer 10 is pressed between the instrument panel 5 and the first layer 9 of the CMC 2. The first layer 9 is also pressed between the damping coating 14 and the housing plate 6 of the CMC 2. Furthermore, the first layer 9 is pressed between the second layer 10 and the housing plate 6 of the CMC 2. Reference symbol list 1 Master cylinder 2 Housing 3 Piston 4 Displacement shaft 5 Mounting structure 6 Flange area 7 First side of the flange area 8 Sealing and damping element 9 First layer 10 Second layer 11 Receiving section 12 Through hole 13 First side of the receiving section 14 Damping coating 15 Clutch pedal 16 Pedal bracket 17 Piston rod 18 Bearing eye 19 Pressure chamber 20 Arrangement 21 Sensor device 22 Second side of the receiving section 23 Inside 24 Bellows 25 Second side of the flange area

Claims

Master cylinder (1) for a clutch actuation device of a motor vehicle, comprising a housing (2) and a piston (3) slidably received in the housing (2), wherein the housing (2) has a flange area (6) extending transversely to a displacement axis (4) of the piston (3) and designed for support on a body-fixed mounting structure (5) of the motor vehicle, characterized in that the flange area (6) is provided on its side (7) provided for support on the mounting structure (5) with a multi-layer sealing and damping element (8) consisting of at least one foamed material, wherein the sealing and damping element (8) has a first layer (9) which consists of a different foamed material or of the same material with a different foam structure than a second layer (10) of the sealing and damping element (8). Master cylinder (1) according to claim 1, characterized in that the first layer (9) is attached directly to the flange area (6). Master cylinder (1) according to claim 1 or 2, characterized in that the first layer (9) has a smaller thickness than the second layer (10). Master cylinder (1) according to one of claims 1 to 3, characterized in that the different layers (9, 10) of the sealing and damping element (8) are bonded together. Master cylinder (1) according to one of claims 1 to 4, characterized in that the different layers (9, 10) of the sealing and damping element (8) consist of different foamed plastic materials. Arrangement (20) for clutch confirmation, comprising a master cylinder (1) designed according to at least one of claims 1 to 5 and a body-fixed retaining structure (5), wherein the retaining structure (5) has a plate-shaped receiving section (11) with a through-hole (12) and the housing (2) projects through the through-hole (12) in such a way that the flange area (6) is supported on the receiving section (11) via the sealing and damping element (8), forming a fluid seal. Arrangement (20) according to claim 6, characterized in that a damping coating (14) preferably consisting of a foamed material is attached to the retaining structure (5) on a side (13) of the receiving section (11) facing the flange area (6) and the sealing and damping element (8) rests at least partially on this damping coating (14). Actuating device for a clutch of a motor vehicle, comprising a master cylinder (1) according to at least one of claims 1 to 5 and a slave cylinder fluidically connected to the master cylinder (1). Clutch system for a drive train of a motor vehicle, comprising a clutch and an actuating device according to claim 8.

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