JP2014122646A - Cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder device which can improve operability while saving a seal property.SOLUTION: A cylinder device comprises: housings 32 and 33 having a cylinder chamber 47; a piston 40 which is contained in the cylinder chamber 47 and reciprocating motion is possible inside the cylinder chamber 47; a cup seal 46 mounted to the piston 40 and having lip units 46b and 46c contacting with the wall surface of the cylinder chamber 47 slidably; and a liquid chamber 35 surrounded by the housings 32 and 33 and the cup seal 46 in the cylinder chamber 47, and filled with hydraulic fluid. The housings 32 and 33 have slant sliding surface units 32c and 33c in at least the part on the wall surface of the cylinder chamber 47, which slidably contact with the lip units 46b and 46c.

Description

  The present invention relates to a cylinder device.

  The hydraulic brake device and clutch release device have a cylinder device. Some cylinder devices are configured such that the piston slides in the cylinder, and in order to seal the oil in the hydraulic chamber surrounded by the cylinder and the piston, the piston is provided with a cup seal having a lip portion ( For example, see Patent Documents 1 and 2).

  For example, Patent Document 1 discloses a hydraulic clutch release device in which a seal is secured by insert molding a cup seal on an annular protrusion formed at the tip of the annular piston on the hydraulic pressure chamber side.

  Further, in Patent Document 2, a cup seal is attached to an annular groove formed in a piston, a contact width between the cup seal and the cylinder body is set small, and the seal surface pressure between the cup seal and the cylinder body has a peak. Thus, a cylinder device is disclosed in which an oil film is easily cut during sliding to ensure a sealing force.

JP 2011-179666 A Japanese Patent Laid-Open No. 11-82750

  The following analysis is given by the inventor.

  However, in the hydraulic clutch release device described in Patent Document 1, when the clutch pedal is operated, the cup seal and the cylinder wall surface (the wall surface of the inner case, the wall surface of the outer case) become closer to the back of the stroke position of the annular piston. There is a concern that the sliding resistance increases. That is, as the stroke position of the annular piston goes deeper, the pressure force of the cup seal (the pressure of the cup seal against the cylinder wall surface) increases due to the influence of the oil pressure of the cup seal, and the contact width between the cup seal and the cylinder wall surface increases. There is a concern that the sliding resistance between the cup seal and the cylinder wall surface is increased, and the operability is deteriorated.

  Further, in the cylinder device described in Patent Document 2, there is a concern about oil leakage in a state where the brake pedal is not operated (an initial stroke where the applied pressure is extremely low). In other words, even if the contact width between the cup seal and the cylinder body is set to be small, the deformation amount of the cup seal increases during pressure reception, resulting in an increase in the contact width between the cup seal and the cylinder body. There is concern that the sliding resistance with the cylinder body will increase and the operability will deteriorate, and if the contact width between the cup seal and the cylinder body is increased, the amount of deformation during pressure reception can be suppressed, but the surface pressure peak Since it becomes difficult to come out, there exists a possibility that sealing performance may deteriorate.

  Further, in the cylinder device described in Patent Literature 2, when the cup seal is worn, there is a concern about oil leakage due to a decrease in the tightening allowance of the cup seal. That is, when the free length of the cup seal is reduced due to wear of the cup seal, the surface pressure peak becomes difficult to occur due to a decrease in the tightening allowance of the cup seal, and the sealing performance may be deteriorated.

  The main subject of this invention is providing the cylinder apparatus which can improve operativity, ensuring a sealing performance.

  In a first aspect of the present invention, in a cylinder device, a housing having a cylinder chamber communicating with a liquid path, and the cylinder chamber is wholly or partially housed, and reciprocates in a predetermined direction inside the cylinder chamber. A movable piston, a cup seal attached to the piston and having a lip portion slidably in contact with a wall surface of the cylinder chamber, and surrounded by the housing and the piston or the cup seal in the cylinder chamber A liquid chamber filled with hydraulic fluid, and the housing is at least a portion of the wall surface of the cylinder chamber slidable with the lip portion, and the liquid chamber in the predetermined direction in the cylinder chamber From the central axis of the piston in the predetermined direction as it moves away from the end in the predetermined direction. Characterized in that it has an inclined sliding surface portion which is inclined away towards the corner.

  In the cylinder device according to the present invention, the housing includes a combination of a cylindrical first housing and a cylindrical second housing arranged at a predetermined interval on the inner periphery of the first housing. The cylinder chamber is an annular space between the first housing and the second housing, the piston is configured in an annular shape, and the cup seal is used as the lip portion. An outer lip portion that is slidably in contact with one housing; and an inner lip portion that is in slidable contact with the second housing, wherein the inclined sliding surface portion includes the first housing and the second housing. It is preferably formed on one or both of the housings.

  In the cylinder device according to the present invention, the cylinder device is a concentric slave cylinder that operates the diaphragm spring of the clutch cover assembly by operating the diaphragm spring of the clutch cover assembly by the hydraulic oil pressure generated in the clutch master cylinder. Preferably, the piston is urged toward the liquid chamber by the diaphragm spring via a predetermined member.

  In the cylinder device according to the present invention, the housing is configured in a cylindrical shape, and the piston has a groove that is recessed radially inward in the circumferential direction on the outer peripheral surface, and the cup seal is The lip portion includes an outer lip portion that is slidably in contact with the housing, and an inner lip portion that is attached to the groove portion, and the inclined sliding surface portion is an inner peripheral surface or an outer peripheral surface of the housing. It is preferable to be formed.

  In the cylinder device of the present invention, the cylinder device is configured to connect and disconnect the clutch disk by operating the diaphragm spring of the clutch cover assembly via the release fork and the release bearing by the hydraulic pressure of the hydraulic oil generated in the clutch master cylinder. The piston is preferably urged toward the liquid chamber by the diaphragm spring via the release fork and the release bearing.

  In a second aspect of the present invention, in the cylinder device, a housing having a cylinder chamber that communicates with a liquid passage, and the cylinder chamber is wholly or partially housed, and reciprocates in a predetermined direction inside the cylinder chamber. A movable piston, a cup seal attached to the housing and having a lip portion slidably contacting the wall surface of the piston, and the cylinder chamber surrounded by the housing and the piston or the cup seal And a fluid chamber filled with a working fluid, wherein the piston is separated from the fluid chamber in the predetermined direction at least in a portion slidable with the lip portion, and the predetermined of the piston. It has an inclined sliding surface portion inclined so as to approach the central axis of the direction.

  In the cylinder device according to the present invention, it is preferable that the cylinder device is a master cylinder that generates hydraulic pressure of hydraulic fluid in response to an operation of the pedal, and the piston receives an operation force acting on the pedal.

  According to the present invention, the inclined sliding surface portion is formed in the slidable portion with the lip portion of the cup seal, so that when the liquid pressure in the liquid chamber is changed from a low state to a high state, the sliding slip from the lip portion is performed. It is possible to suppress or prevent a change in the pressing force to the moving surface portion, and as a result, it is possible to ensure the sealing performance between the lip portion and the inclined sliding surface portion, and to improve the operability.

It is the schematic diagram which showed the structure of the clutch system containing the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention. It is sectional drawing which showed typically the structure of the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention. It is sectional drawing for demonstrating the state of the cup seal in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention. It is sectional drawing for demonstrating the change of the cup seal in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention, (A) is a figure at the time of an oil chamber being low pressure, (B) is an oil chamber. It is a figure at the time of high pressure. It is sectional drawing for demonstrating the change of the cup seal in the cylinder apparatus (concentric slave cylinder) which concerns on a comparative example, (A) is a figure when an oil chamber is low pressure, (B) is a figure when an oil chamber is high pressure. It is. It is the figure which contrasted with the comparative example and showed typically the relationship between the contact width of a cup seal in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention, and a hydraulic pressure. It is the figure which showed typically the relationship between the direct pressure of a cup seal in a cylinder apparatus (concentric slave cylinder), and oil_pressure | hydraulic, (A) is a figure in the case of Example 1, (B) is in the case of a comparative example. FIG. It is the figure which showed typically the relationship between the direct pressure of a cup seal, clearance, and stroke in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention. It is the figure which showed typically the relationship between the sliding resistance and hydraulic pressure in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention by contrasting with a comparative example. It is a figure including the time of the outward path | route and the time of a return path | route which showed typically the relationship between the sliding resistance and oil_pressure | hydraulic in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention in contrast with the comparative example. It is the figure which showed typically the relationship between the operation load and hydraulic pressure in a cylinder apparatus (concentric slave cylinder). It is the enlarged view of the area | region R of FIG. 11 which showed typically the relationship between the operation load and oil_pressure | hydraulic in a cylinder apparatus (concentric slave cylinder). It is the figure which showed typically the relationship between the sliding resistance and hydraulic pressure in a cylinder apparatus (concentric slave cylinder), and the relationship between A and B of FIG. It is sectional drawing which showed typically the change (change by abrasion of the friction material of a clutch disc) of the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention, (A) is the figure at the time of shipment, B) is a diagram after wear. It is sectional drawing which showed typically the change (change by abrasion of the friction material of a clutch disc) of the cylinder apparatus (concentric slave cylinder) which concerns on a comparative example, (A) is a figure at the time of shipment, (B) is wear. FIG. It is the figure which contrasted with the comparative example and showed typically the relationship between the tightening allowance of the cup seal in the cylinder apparatus (concentric slave cylinder) which concerns on Example 1 of this invention, and hydraulic pressure. It is the schematic diagram which showed the structure of the clutch system containing the cylinder apparatus (clutch release cylinder) which concerns on Example 2 of this invention. It is sectional drawing which showed typically the structure of the cylinder apparatus (clutch release cylinder) which concerns on Example 2 of this invention. It is sectional drawing which showed typically the structure of the cylinder apparatus (clutch master cylinder) which concerns on Example 3 of this invention.

[Outline of Embodiment]
In the cylinder device according to Embodiment 1 of the present invention, a housing (32, 33 in FIG. 2) having a cylinder chamber (47 in FIG. 2, 60d in FIG. 18) communicating with a liquid passage (4 in FIG. 1, 4 in FIG. 17). 18) in FIG. 18, and a piston (40 in FIG. 2, 61 in FIG. 18) that is entirely or partially housed in the cylinder chamber and that can reciprocate in a predetermined direction inside the cylinder chamber. A cup seal (46 in FIG. 2 and 65 in FIG. 18) having a lip portion (46b, 46c in FIG. 2, 65a in FIG. 18) that is attached to the piston and slidably contacts the wall surface of the cylinder chamber. ), And a fluid chamber (35 in FIG. 2 and 67 in FIG. 18) that is surrounded by the housing and the piston or the cup seal in the cylinder chamber, and is filled with hydraulic fluid, Shi The predetermined direction of the piston as it moves away from the end of the cylinder chamber in the predetermined direction on the liquid chamber side at least in a portion slidable with the lip portion on the wall surface of the chamber. 2c and 32c in FIG. 2 (c) in FIG.

  In the cylinder device according to Embodiment 2 of the present invention, a housing having a cylinder chamber (70b in FIG. 19) communicating with a liquid passage (corresponding to 4 in FIG. 1 and 4 in FIG. 17), and the cylinder chamber in whole or in part And a piston (71 in FIG. 19) that can reciprocate in a predetermined direction inside the cylinder chamber, and a lip that is attached to the housing and slidably contacts the wall surface of the piston 19 (72b in FIG. 19) and a liquid chamber (74 in FIG. 19) that is surrounded by the housing and the piston or the cup seal in the cylinder chamber and filled with hydraulic fluid. ), And the piston is separated from the liquid chamber in the predetermined direction at least in a portion slidable with the lip portion. It has an inclined sliding surface portion which is inclined so as to approach the center axis of the predetermined direction (71a in FIG. 19).

  Note that, in the present application, where reference numerals are attached to the drawings, these are only for the purpose of helping understanding, and are not intended to be limited to the illustrated embodiments. Hereinafter, embodiments will be described with reference to the drawings.

  A cylinder device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a configuration of a clutch system including a cylinder device (a concentric slave cylinder) according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing the configuration of the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention. FIG. 3 is a cross-sectional view for explaining the state of the cup seal in the cylinder device (concentric slave cylinder) according to Embodiment 1 of the present invention. The concentric slave cylinder 3 in FIG. 1 schematically shows the concentric slave cylinder 3 in FIG.

  The cylinder device according to the first embodiment is applied to the concentric slave cylinder 3. Referring to FIG. 1, the clutch system including the concentric slave cylinder 3 is configured to cut off the rotational power from the crankshaft 11 in the power transmission path between the crankshaft 11 of the engine (not shown) and the transmission input shaft 31. It is a system that makes contact. The clutch system includes a clutch cover assembly 1, a clutch disk 2, a concentric slave cylinder 3, an oil passage 4, a clutch master cylinder 5, and a clutch pedal 6. The crankshaft 11 has a flywheel 12 attached thereto by a plurality of bolts 13 and rotates integrally with the flywheel 12.

  The clutch cover assembly 1 is an assembly assembled by a clutch cover 14, bolts 15, fulcrum members 16, 17, a diaphragm spring 18, and a pressure plate 19 (see FIG. 1). The clutch cover assembly 1 receives the operation of the concentric slave cylinder 3 to frictionally engage and release the clutch disk 2 with the flywheel 12.

  The clutch cover 14 is an annular member formed so as to cover the outer peripheral portion of the clutch disk 2 (see FIG. 1). The clutch cover 14 is attached and fixed to the flywheel 12 by bolts 15 at the outer peripheral portion, and rotates integrally with the flywheel 12. The clutch cover 14 is separated from the flywheel 12 at the inner peripheral portion, and covers the outer peripheral portion of the clutch disk 2 and the pressure plate 19. The clutch cover 14 has a caulking portion 14 a that supports two fulcrum members 16 and 17 arranged so as to sandwich both sides of the intermediate portion of the diaphragm spring 18 at the inner peripheral end portion. The caulking portion 14 a supports the two fulcrum members 16 and 17 by caulking at a plurality of spaces between the lever portions of the diaphragm spring 18. The caulking portion 14a supports the diaphragm spring 18 so as to be swingable with the fulcrum members 16 and 17 as fulcrums.

  The fulcrum members 16 and 17 are annular members that serve as fulcrums for swinging the lever portion of the diaphragm spring 18 (see FIG. 1). The fulcrum members 16 and 17 are disposed on both sides of an intermediate portion of the diaphragm spring 18 and are supported by being caulked by caulking portions 14 a of the clutch cover 14 in a plurality of spaces between lever portions of the diaphragm spring 18.

  The diaphragm spring 18 is an elastic member in which a plurality of lever portions extend radially inward from an annular disc spring portion, and is a constituent part of a pressing load adjusting mechanism (see FIG. 1). The diaphragm spring 18 is sandwiched between the two fulcrum members 16 and 17 supported by the caulking portion 14a of the clutch cover 14 at an intermediate portion. The diaphragm spring 18 is a lever member having the fulcrum members 16 and 17 as fulcrums. The diaphragm spring 18 is in contact with the pressure plate 19 so as to be able to contact and separate on the surface on the engine side (right side in FIG. 1) of the outer peripheral portion of the disc spring portion. The diaphragm spring 18 is in contact with the release bearing 36 of the concentric slave cylinder 3 on the surface of the inner peripheral portion of the lever portion on the transmission side (left side in FIG. 1). In the diaphragm spring 18, the disc spring portion biases the pressure plate 19 toward the flywheel 12 by tilting the fulcrum members 16 and 17 to the fulcrum, and the lever portion pushes the release bearing 36 on the transmission side (the left side in FIG. 1). ). The diaphragm spring 18 urges the pressure plate 19 to press the portions of the friction materials 20 and 21 of the clutch disk 2 against the flywheel 12. The diaphragm spring 18 is displaced so that the disc spring portion is separated from the flywheel 12 by pressing the lever portion toward the flywheel 12 by the concentric slave cylinder 3, and the pressure plate 19 is biased toward the flywheel 12 side. Is released.

  The pressure plate 19 is an annular plate that presses the friction sliding portion of the clutch disc 2 against the flywheel 12 (see FIG. 1). The pressure plate 19 has a surface on the engine side (the right side in FIG. 1) that frictionally slides with the friction material 21 of the clutch disk 2. The pressure plate 19 is in contact with the disc spring portion of the diaphragm spring 18 at a protrusion protruding from the surface on the transmission side (left side in FIG. 1).

  The clutch disc 2 is a circular disc-like assembly disposed between the flywheel 12 and the pressure plate 19 (see FIG. 1). The clutch disk 2 has a friction sliding portion in which friction materials 20 and 21 are attached and fixed (for example, rivet caulking, adhesion, etc.) to both surfaces of the lining plate 22 at the outer peripheral portion. It is sandwiched between the flywheel 12 and the pressure plate 19. The clutch disk 2 is attached and fixed to the side plates 23 and 24 by a plurality of rivets 25 at the inner peripheral portion of the lining plate 22, and a hub member 28 is disposed between the side plates 23 and 24. , 24 and the hub member 28 are provided with a damper portion for buffering (absorbing) the torsion (torque fluctuation) by the elastic force of the elastic member 27. In the clutch disk 2, a thrust member 29 is disposed between the side plate 23 and the hub member 28, and a thrust member 30 is disposed between the side plate 24 and the hub member 28. The clutch disk 2 is spline-engaged with the transmission input shaft 31 at the inner periphery of the hub member 28 so as not to rotate but to move in the axial direction. The transmission input shaft 31 is arranged coaxially on the crankshaft 11 and the rotating shaft 8.

  The concentric slave cylinder 3 is a cylinder device that operates the diaphragm spring 18 of the clutch cover assembly 1 by the hydraulic pressure of the hydraulic oil generated in the clutch master cylinder 5 to operate the connection and disconnection of the clutch disk 2 (FIG. 1). reference). The concentric slave cylinder 3 is also referred to as a hydraulic clutch release device for operating the clutch connection / disconnection by hydraulic pressure. In the concentric slave cylinder 3, an oil chamber 35 is formed between the inner housing 32 and the outer housing 33 by the inner housing 32, the outer housing 33 and the cup seal 46, and the annular pistons 40, 39 are formed by the oil pressure in the oil chamber 35. Then, the plate member 37 and the release bearing 36 are moved in the direction of the rotary shaft 8 to operate the clutch cover assembly 1. The concentric slave cylinder 3 includes an inner housing 32, an outer housing 33, a seal 34, an oil chamber 35, a release bearing 36, a first annular piston 39, a second annular piston 40, a disc spring 41, A coil spring 42, a seat member 43, a cover member 44, a retaining ring 45, and a cup seal 46 are included (see FIG. 2).

  The inner housing 32 is a cylindrical (drum-shaped, annular) member (see FIGS. 1 and 2). The inner housing 32 includes a cylindrical portion 32a, a flange portion 32b, and an inclined sliding surface portion 32c. The cylindrical portion 32a is a portion surrounding the transmission input shaft (31 in FIG. 1). The cylindrical portion 32a has an inclined sliding surface portion 32c that slides with the inner lip portion 46c of the cup seal 46 on the outer peripheral surface. The inclined sliding surface portion 32c is a surface (outer conical surface) inclined outward in the radial direction as it goes to the engine side (right side in FIG. 2) in the axial direction. The inclined sliding surface part 32c can be, for example, 1 ° or more with respect to the rotation axis (8 in FIG. 1). The flange portion 32b is a portion extending in the outer peripheral direction from one end of the cylindrical portion 32a.

  The outer housing 33 is a cylindrical (drum-shaped, annular) member disposed so as to surround the inner housing 32 at a predetermined interval (see FIGS. 1 and 2). The outer housing 33 includes an oil port 33a, a mounting flange 33b, and an inclined sliding surface portion 33c. The oil port 33 a is a portion that serves as an oil passage for supplying hydraulic pressure of hydraulic oil supplied from the clutch master cylinder 5 through an oil passage (4 in FIG. 1) to the oil chamber 35. The mounting flange 33b is a flange-shaped portion for mounting to a clutch housing (not shown) or the like. The outer housing 33 has an inclined sliding surface portion 33c that slides with the outer lip portion 46b of the cup seal 46 on the inner peripheral surface. The inclined sliding surface portion 33c is moved away from the end of the cylinder chamber 47 in the sliding direction of the cup seal 46 on the oil chamber 35 side in the sliding direction, and as it goes to the axial engine side (right side in FIG. 2). The surface is inclined radially outward (inner conical surface). The inclined sliding surface portion 33c can be, for example, 1 ° or more with respect to the rotation axis (8 in FIG. 1).

  In the first embodiment, both the outer housing 33 and the inner housing 32 are provided with the inclined sliding surface portion 33c and the inclined sliding surface portion 32c. However, the inclined sliding surface portion is provided only on one of the outer housing 33 and the inner housing 32. You may make it provide.

  The seal 34 is an annular member made of an elastic material for sealing a joint surface between the flange portion 32b of the inner housing 32 and the outer housing 33 (see FIG. 2). The seal 34 is arranged in an annular groove formed in a portion on the outer peripheral side of the oil chamber 35 in the outer housing 33.

  The oil chamber 35 is an annular liquid chamber (a part of the cylinder chamber 47 between the inner housing 32 and the outer housing 33) surrounded by the inner housing 32, the outer housing 33, and the cup seal 46 (FIG. 1). FIG. 2). The oil chamber 35 is filled with hydraulic oil (hydraulic fluid). The oil chamber 35 is connected to the clutch master cylinder 5 via the oil port 33 a and the oil passage 4. In the oil chamber 35, the radial interval (clearance) between the inclined sliding surface portion 32c of the inner housing 32 and the inclined sliding surface portion 33c of the outer housing 33 changes according to the axial position (stroke position). As it approaches the side (the right side in FIG. 2), the radial interval becomes narrower.

  The release bearing 36 is a ball bearing for enabling a pressing operation of a rotating diaphragm spring (18 in FIG. 1) (see FIGS. 1 and 2). In the release bearing 36, a plurality of balls are arranged in the circumferential direction between the inner ring 36a and the outer ring 36b. The inner ring 36a is rotatably supported by the outer ring 36b via a ball, and is always in contact with the diaphragm spring (18 in FIG. 1) at the end on the engine side (right side in FIG. 2). Therefore, the inner ring 36a rotates integrally with the diaphragm spring (18 in FIG. 1). The outer ring 36 b is a non-rotating ring fixed to the plate member 37 by the holding member 38.

  The plate member 37 is an annular member that is attached by a disc spring 41 at the attachment portion 39a of the first annular piston 39 so as to be aligned (see FIGS. 1 and 2). The plate member 37 has an attachment portion 39 a inserted therethrough at a predetermined interval (clearance) on the inner periphery, and can be eccentric with respect to the first annular piston 39. The plate member 37 is pressed toward the main body of the first annular piston 39 by the disc spring 41 at the inner peripheral portion, and movement in the axial direction is restricted. The plate member 37 has a sheet member 43 mounted on the surface on the coil spring 42 side, and receives a biasing force of the coil spring 42 via the sheet member 43. The outer ring 36 b of the release bearing 36 is held by the holding member 38 at the outer peripheral portion of the plate member 37.

  The holding member 38 is an annular member for holding the outer ring 36b of the release bearing 36 on the plate member 37 (see FIG. 2).

  The first annular piston 39 is an annular (cylindrical) member capable of reciprocating in a predetermined direction within an annular space (cylinder chamber 47) between the inner housing 32 and the outer housing 33 (FIG. 1, (See FIG. 2). The first annular piston 39 operates to be slidable in the axial direction (left-right direction in FIG. 2) by sliding the second annular piston 40 in the cylinder chamber. The first annular piston 39 has an attachment portion 39 a for attaching the plate member 37 to a portion that is not accommodated in the outer housing 33. The attachment portion 39a is inserted through the inner periphery of the plate member 37 with a predetermined interval (clearance). The attachment portion 39a supports the inner peripheral end portion of the disc spring 41 so as to restrict movement of the disc spring 41 toward the engine side (right side in FIG. 2). The first annular piston 39 is in contact with the second annular piston 40 at the end on the oil chamber 35 side so as to be able to contact and separate.

  The second annular piston 40 is an annular (cylindrical) member capable of reciprocating in a predetermined direction within an annular space (cylinder chamber 47) between the inner housing 32 and the outer housing 33 (FIG. 1, (See FIGS. 2 and 3). The second annular piston 40 is slidable in the axial direction (left-right direction in FIG. 2) by the oil pressure of the oil chamber 35 in the cylinder chamber. The second annular piston 40 has a recess 40a for mounting the mounting portion 46a of the cup seal 46 at the end on the oil chamber 35 side. The second annular piston 40 is in contact with the first annular piston 39 at the end on the engine side (the right side in FIG. 2) so as to be able to contact and separate.

  The disc spring 41 is an annular member having spring elasticity for attaching the plate member 37 to the attachment portion 39a of the first annular piston 39 (see FIGS. 1 and 2). The disc spring 41 urges the plate member 37 toward the transmission side (left side in FIG. 2), and supports the plate member 37 so that the plate member 37 can be aligned in the radial direction.

  The coil spring 42 is an elastic member interposed between the sheet member 43 and the sheet portion 44a of the cover member 44 in the axial direction (left-right direction in FIG. 2) (see FIGS. 1 and 2). One end of the coil spring 42 is supported by the outer housing 33 via the seat portion 44a of the cover member 44, and the other end of the coil spring 42 connects the release bearing 36 via the seat member 43 and the plate member 37 to the diaphragm spring (18 in FIG. 1). ) Side.

  The sheet member 43 is a member that receives the biasing force of the coil spring 42 and is attached to the holding member 38 (see FIG. 2).

  The cover member 44 is a cylindrical member that covers the outer periphery of the coil spring 42 (see FIG. 2). The cover member 44 is set so as not to interfere with the release bearing 36 even when the annular pistons 40 and 39 slide to the oil chamber 35 side. The cover member 44 has a seat portion 44a extending to the inner peripheral side at the end portion on the transmission side (left side in FIG. 2). The seat portion 44 a supports one end of the coil spring 42 and is in contact with the outer housing 33.

  The retaining ring 45 is an annular member that restricts sliding of the annular pistons 40 and 39 to the engine side (right side in FIG. 2) (see FIG. 2). The retaining ring 45 is attached to a groove formed in the vicinity of the engine side (right side in FIG. 2) end portion of the outer peripheral surface of the inner housing 32.

  The cup seal 46 is made of an elastic material and is an annular seal member that seals the oil chamber 35 (see FIGS. 1, 2, and 3). The cup seal 46 is disposed in a cylinder chamber 47 between the inner housing 32 and the outer housing 33. The cup seal 46 has a mounting portion 46 a that is mounted in the concave portion 40 a of the second annular piston 40. The cup seal 46 has an outer lip portion 46b and an inner lip portion 46c at a portion on the oil chamber 35 side. The outer lip portion 46b is a portion that protrudes toward the oil chamber 35 over the entire circumference on the outer side in the radial direction than the inner lip portion 46c. The outer peripheral surface of the outer lip portion 46b is slidably in contact with the inclined sliding surface portion 33c of the outer housing 33 with a tightening margin (outer diameter tightening margin), a contact width, and a direct pressure as shown in FIG. The inner lip portion 46c is a portion that protrudes toward the oil chamber 35 over the entire circumference radially inward of the outer lip portion 46b. The inner peripheral surface of the inner lip portion 46c is slidably in contact with the inclined sliding surface portion 32c of the inner housing 32 with a tightening margin (inner diameter tightening margin), a contact width, and a direct pressure as shown in FIG.

  Here, the tightening allowance of the cup seal 46 is the sum of the outer diameter tightening allowance and the inner diameter tightening allowance. The outer diameter tightening allowance is expressed by a half of the difference between the outer diameter (free outer diameter) of the cup seal 46 in the free state and the inner diameter (outer inner diameter) of the outer housing 33 (see Formula 1). The inner diameter fastening allowance is expressed by a half of the difference between the outer diameter (inner outer diameter) of the inner housing 32 and the inner diameter (free inner diameter) of the cup seal 46 in a free state (see Formula 1).

[Formula 1]
Outer diameter tightening margin = (Free outer diameter-Outer inner diameter) / 2
Inner diameter allowance = (Inner outer diameter-Free inner diameter) / 2

  The oil path 4 is a liquid path that transmits the hydraulic pressure of the hydraulic oil of the clutch master cylinder 5 to the oil chamber 35 of the concentric slave cylinder 3 (see FIG. 1). One end of the oil passage 4 is connected to the oil port (corresponding to 70 a in FIG. 19) of the clutch master cylinder 5, and the other end is connected to the oil port 33 a of the outer housing 33.

  The clutch master cylinder 5 is a cylinder device that generates hydraulic oil pressure corresponding to the amount of depression (operation amount) in response to the operation (depression operation) of the clutch pedal 6 (see FIG. 1). The hydraulic oil pressure generated in the clutch master cylinder 5 is transmitted to the oil chamber 35 of the concentric slave cylinder 3 through the oil passage 4.

  The clutch pedal 6 is a pedal that is operated (depressed) by the driver to switch the operating state of the clutch system (see FIG. 1). The clutch pedal 6 operates the clutch master cylinder 5 in response to an operation (depression operation).

  Next, operation | movement of the cylinder apparatus which concerns on Example 1 of this invention is demonstrated, contrasting with a comparative example. FIG. 4 is a cross-sectional view for explaining the change of the cup seal in the cylinder device (concentric slave cylinder) according to Embodiment 1 of the present invention, (A) is a view when the oil chamber is at a low pressure, and (B). These are figures when the oil chamber is at high pressure. FIG. 5 is a cross-sectional view for explaining the change of the cup seal in the cylinder device (concentric slave cylinder) according to the comparative example, in which (A) is a diagram when the oil chamber is at a low pressure, and (B) is the oil chamber. It is a figure at the time of high pressure. FIG. 6 is a diagram schematically illustrating the relationship between the contact width of the cup seal and the hydraulic pressure in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention in comparison with the comparative example.

  First, the configuration of the cylinder device according to the comparative example will be described. In the comparative example, instead of the inclined sliding surface portion (32c in FIG. 2) and the inclined sliding surface portion (33c in FIG. 2) of Example 1, a flat sliding surface portion (32d in FIG. 5) and a flat sliding surface portion (FIG. 5) are used. 33d). The flat sliding surface portion 32d is a sliding surface that slides with the inner lip portion 46c of the cup seal 46 on the outer peripheral surface of the cylindrical portion (32a in FIG. 2) of the inner housing (corresponding to 32 in FIG. 2). The flat sliding surface portion 33 d is a sliding surface that slides with the outer lip portion 46 b of the cup seal 46 on the inner peripheral surface of the outer housing 33. The flat sliding surface portion 32d and the flat sliding surface portion 33d are cylindrical surfaces that are flat in the axial direction (inner cylindrical surface sliding portions). The radial distance (clearance) between the flat sliding surface portion 32d and the flat sliding surface portion 33d is constant even at the axial position (stroke position). Other configurations are the same as those of the first embodiment.

  In the operation of the cylinder device according to the comparative example, when the hydraulic pressure of the hydraulic oil in the oil chamber 35 changes from the low pressure (see FIG. 5A) to the high pressure (see FIG. 5B), the contact width becomes small from the large state. Change to state. That is, when the hydraulic pressure of the hydraulic oil in the oil chamber 35 changes from low pressure (see FIG. 5A) to high pressure (see FIG. 5B) (when the second annular piston 40 moves to the right in FIG. 5). However, the direct pressure (see FIG. 3) due to the tightening allowance of the cup seal 46 does not change with the stroke of the second annular piston 40 and does not affect the contact width, but the direct pressure due to hydraulic pressure (see FIG. 3) increases and comes into contact. As a result, the contact width of the cup seal 46 increases (see FIG. 6).

  On the other hand, in the operation of the cylinder device according to the first embodiment, even if the hydraulic pressure of the hydraulic oil in the oil chamber 35 is changed from a low pressure (see FIG. 4A) to a high pressure (see FIG. 4B), the contact width is increased. Remain small. That is, when the hydraulic pressure of the hydraulic oil in the oil chamber 35 changes from low pressure (see FIG. 4A) to high pressure (see FIG. 4B) (when the second annular piston 40 moves to the right side of FIG. 4). ) Is similar to the comparative example in that the direct pressure by hydraulic pressure (see FIG. 3) is increased and the contact width is increased, but the cup seal is moved together with the axial movement (stroke) of the second annular piston 40. Since the direct pressure (see FIG. 3) due to the tightening allowance of 46 acts to reduce the contact width, an increase in the contact width of the cup seal 46 is suppressed (prevented) as compared with the comparative example (see FIG. 6). ).

  Next, the influence of the hydraulic pressure of the hydraulic oil in the oil chamber in the cylinder device according to Embodiment 1 of the present invention will be described in comparison with a comparative example. FIG. 7 is a diagram schematically showing the relationship between the direct pressure of the cup seal and the hydraulic pressure in the cylinder device (concentric slave cylinder), (A) is a diagram in the case of Example 1, and (B) is a comparison. It is a figure in the case of an example. FIG. 8 is a diagram schematically illustrating the relationship between the direct pressure of the cup seal, the clearance, and the stroke in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention.

Here, in the concentric slave cylinder 3, when hydraulic oil pressure is input to the oil chamber 35, the sliding resistance due to the movement of the cup seal 46 is lost, and the pressing force obtained by subtracting the sliding resistance from the input is the cup seal. 46 to the release bearing 36. That is, it can be expressed as “input = sliding resistance + output”. The sliding resistance F is expressed by the sum of the dynamic frictional resistance μP and the viscous damping force CV as shown in Equation 2. The dynamic friction resistance μP is represented by the product of the dynamic friction resistance coefficient μ of the sliding surface of the cup seal 46 and the direct pressure P. The direct pressure P is represented by the sum of the direct pressure PS due to the tightening allowance of the cup seal 46 and the direct pressure PP due to the hydraulic pressure of the hydraulic oil in the oil chamber 35. The viscous damping force CV is represented by the product of the damping coefficient C related to the cup seal 46 and the square V ² of the moving speed of the cup seal 46.

[Formula 2]
F = μP + CV ²
F: sliding resistance μ: dynamic friction resistance coefficient P: direct pressure (P = PS + PP)
PS: Direct pressure due to tightening allowance PP: Direct pressure due to hydraulic pressure C: Damping coefficient V: Speed

  In the comparative example (see FIG. 5), since the radial distance (clearance) between the flat sliding surface portion 32d and the flat sliding surface portion 33d is constant, the cup seal 46 is independent of the hydraulic pressure of the hydraulic oil in the oil chamber 35. The direct pressure PS due to the tightening margin is constant, but as the hydraulic pressure of the hydraulic oil in the oil chamber 35 is higher, the direct pressure PP due to the hydraulic pressure increases and the total direct pressure P increases (see FIG. 7B).

  On the other hand, in Example 1 (see FIG. 4), the radial distance (clearance) between the inclined sliding surface portion 32c and the inclined sliding surface portion 33c increases the hydraulic pressure of the hydraulic oil in the oil chamber 35, and the cup seal 46 is Since it becomes wider as it moves to the two annular piston 40 side, the direct pressure total P is obtained by the interaction (offset) of the direct pressure PP due to the hydraulic pressure and the direct pressure PS due to the interference with respect to the change in hydraulic pressure of the hydraulic oil in the oil chamber 35. (= PS + PP) is stabilized (see FIG. 7A). That is, when the hydraulic pressure of the hydraulic oil in the oil chamber 35 increases, the direct pressure PP due to the hydraulic pressure increases, the clearance increases as the stroke increases, and the direct pressure PS due to the tightening margin decreases. That is, the increase in the direct pressure PP due to the hydraulic pressure cancels out the decrease in the direct pressure PS due to the tightening allowance. Therefore, in Example 1, the direct pressure total P is constant or changes are small.

  In the first embodiment, the clearance (the diameter between the inclined sliding surface portion 32c and the inclined sliding surface portion 33c is determined so that the total direct pressure P is constant from the hydraulic characteristics of the cup seal 46 (change rate of PP). It is preferable to determine the gradient (inclination angle with respect to the rotation axis) of the direction interval (see FIG. 8). By doing so, the operation feeling of the clutch pedal 6 can be optimized for each vehicle type.

  Next, a change in sliding resistance (sliding hysteresis torque) in the cylinder device according to the first embodiment of the present invention will be described in comparison with a comparative example. FIG. 9 is a diagram schematically showing the relationship between the sliding hysteresis torque and the hydraulic pressure in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention in comparison with the comparative example. FIG. 10 is a diagram including the time of the forward path and the time of the return path schematically showing the relationship between the sliding resistance and the hydraulic pressure in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention in comparison with the comparative example. is there. FIG. 11 is a diagram schematically showing the relationship between the operation load and the hydraulic pressure in the cylinder device (concentric slave cylinder). FIG. 12 is an enlarged view of a region R in FIG. 11 schematically showing the relationship between the operation load and the hydraulic pressure in the cylinder device (concentric slave cylinder). FIG. 13 is a diagram schematically showing the relationship between the sliding resistance and the hydraulic pressure in the cylinder device (concentric slave cylinder) and the relationship between A and B in FIG.

  In the comparative example (see FIG. 5), as shown in FIG. 7 (B), the direct pressure total P increases in the outward path where the hydraulic pressure of the hydraulic oil in the oil chamber 35 increases from a low pressure to a high pressure. Increase (see FIG. 8 and FIG. 9). In the return path in which the hydraulic pressure of the hydraulic oil in the oil chamber 35 is changed from high pressure to low pressure, the hydraulic pressure is reduced from a hydraulic pressure that is significantly lower than the maximum value of the sliding resistance of the forward path, and the sliding resistance is opposite to the forward path. Will decrease.

  On the other hand, in Example 1 (see FIG. 4), as shown in FIG. 7A, the direct pressure total P is constant or small as the hydraulic pressure of the hydraulic oil in the oil chamber 35 changes from low pressure to high pressure. The sliding resistance is lower than that of the comparative example, and the constant or change is small (see FIGS. 8 and 9). In the return path where the hydraulic pressure of the hydraulic oil in the oil chamber 35 decreases from high pressure to low pressure, the hydraulic pressure decreases from a lower hydraulic pressure than the maximum value of the sliding resistance of the forward path, and the sliding resistance is opposite to the forward path. Thus, it is constant or small in a state lower than the comparative example. From this, it can be seen that Example 1 has better responsiveness when the clutch pedal (6 in FIG. 1) is returned in the return path than the comparative example.

  In addition, the sliding resistance with respect to the hydraulic pressure of the hydraulic oil in the oil chamber 35 is calculated from the load efficiency diagram of FIG. The measured value in FIG. 11 is the stepping load measured with the clutch pedal (6 in FIG. 1). The calculated value (efficiency 100%) in FIG. 11 is a stepping load when it is assumed that there is no sliding resistance (input = output). Referring to FIG. 12, which is an enlarged view of region R in FIG. 11, the sliding resistance A in the forward path is a value obtained by subtracting the measured value in the forward path from the calculated value (efficiency 100%), and the sliding resistance B in the backward path is a calculated value. This is a value obtained by subtracting the return path measurement value from (efficiency 100%). The figure of FIG. 13 is obtained by calculating and plotting the sliding resistances A and B for each hydraulic pressure.

  Next, the influence of cup seal wear in the cylinder device according to the first embodiment of the present invention will be described in comparison with a comparative example. FIG. 14 is a cross-sectional view schematically showing changes in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention (changes due to wear of the friction material of the clutch disk). The figure of (B) is a figure after abrasion. FIG. 15 is a cross-sectional view schematically showing changes in the cylinder device (concentric slave cylinder) according to the comparative example (changes due to wear of the friction material of the clutch disc), (A) is a diagram at the time of shipment; B) is a diagram after wear. FIG. 16 is a diagram schematically illustrating the relationship between the cup seal tightening allowance and the hydraulic pressure in the cylinder device (concentric slave cylinder) according to the first embodiment of the present invention in comparison with the comparative example.

  When the friction material 20, 21 of the clutch disk 2 is worn and thinned from the state of the concentric slave cylinder 3 at the time of shipment (see FIGS. 14A and 15A; when new), the diaphragm spring 18 rises ( The inner peripheral end of the diaphragm spring 18 is displaced to the transmission side (left side in FIGS. 14 and 15), the outer peripheral end is displaced to the engine side (right side in FIGS. 14 and 15)), and the cup seal 46 is shifted. Move to the machine side (left side of FIGS. 14 and 15) (see FIGS. 14B and 15B). In addition, the sliding surface of the cup seal 46 is worn in parallel with the wear of the friction materials 20 and 21.

  In the comparative example, when the cup seal 46 is moved to the transmission side (left side in FIG. 15) while the sliding surface of the cup seal 46 is worn, the radial distance between the flat sliding surface portion 32d and the flat sliding surface portion 33d. Since the (clearance) is constant, the tightening allowance of the cup seal 46 is lower than when shipping (when new), and oil leakage is likely to occur (see FIG. 16).

  On the other hand, in Example 1, when the cup seal 46 moves to the transmission side (left side in FIG. 14) in a state where the sliding surface of the cup seal 46 is worn, the diameters of the inclined sliding surface portion 32c and the inclined sliding surface portion 33c. Since the direction interval (clearance) becomes narrow, the tightening allowance of the cup seal 46 can be made the same as that at the time of shipment (new time), the possibility of oil leakage can be reduced, and the durability is improved. (See FIG. 16). From this, in Example 1, even if the sliding surface of the cup seal 46 is worn, it is possible to suppress a reduction in the tightening allowance of the cup seal 46 as compared with the comparative example. The moving surface portion 33 c acts as a wear compensation mechanism for the cup seal 46.

  According to the first embodiment, the operation can be made lighter than before from the early stage to the late stage of the stroke (depression) of the clutch pedal 6. That is, by setting a larger radial distance (clearance) between the inclined sliding surface portion 32c and the inclined sliding surface portion 33c in the later stage than the initial stroke, the inclined sliding surface portion 32c from the cup seal 46 at high pressure is set. In addition, the sliding resistance can be reduced by suppressing the change in the pressing force to the inclined sliding surface portion 33c, and as a result, the operation of the clutch pedal 6 becomes light.

  Further, according to the first embodiment, the operability of the half clutch is improved (half clutch operation is facilitated). That is, the operation in the latter half of the stroke of the clutch pedal 6 at a high pressure is lightened, the difference in the sliding resistance between the depression and return of the clutch pedal 6 is reduced (see FIG. 10), and the width of the clutch disengagement and contact can be narrowed. .

  Further, according to the first embodiment, the inclination of the inclined sliding surface portion 32c and the inclined sliding surface portion 33c with respect to the rotation axis (gradient) can improve the rigidity of the inner housing 32 and the outer housing 33 itself. Thus, the hydraulic pressure rising characteristic can be improved, and the loss stroke of the clutch pedal 6 can be reduced.

  Further, according to the first embodiment, it is possible to suppress (prevent) the change in the sliding resistance from the new article to the lifetime, and to stabilize the operation feeling of the clutch pedal 6. In other words, even when the friction members 20 and 21 of the clutch disk 2 are worn, even if the diaphragm spring 18 rises and the position of the cup seal 46 moves to the transmission side (left side in FIG. 14), the inclined sliding surface portion 32c and the inclined sliding surface portion 32c are inclined. Since the radial distance (clearance) with respect to the sliding surface portion 33c is narrower than when it is new, the allowance for the cup seal 46 is secured, and the change in sliding resistance can be suppressed (prevented).

  Further, according to the first embodiment, oil leakage can be prevented when the clutch pedal 6 is released (the clutch is in contact). In other words, even when the friction members 20 and 21 of the clutch disk 2 are worn, even if the diaphragm spring 18 rises and the position of the cup seal 46 moves to the transmission side (left side in FIG. 14), the inclined sliding surface portion 32c and the inclined sliding surface portion 32c are inclined. Since the radial distance (clearance) with respect to the sliding surface portion 33c is narrower than when new, the allowance for tightening the cup seal 46 is ensured, and oil leakage can be prevented.

  Further, according to the first embodiment, wear of the cup seal 46 itself can be reduced, and durability can be improved. In other words, by setting the radial interval (clearance) between the inclined sliding surface portion 32c and the inclined sliding surface portion 33c larger in the later period than the initial stroke, the direct pressure of the cup seal 46 can be suppressed at high pressure. The sliding resistance is reduced, and the wear amount of the cup seal 46 can be reduced.

  Further, according to the first embodiment, the cup seal 46 moves to the lower pressure side by providing the inclined sliding surface portion 32c and the inclined sliding surface portion 33c with an inclination (gradient) with respect to the rotation axis. The effect is promoted.

  A cylinder device according to a second embodiment of the present invention will be described with reference to the drawings. FIG. 17 is a schematic diagram illustrating a configuration of a clutch system including a cylinder device (clutch release cylinder) according to Embodiment 2 of the present invention. FIG. 18 is a cross-sectional view schematically showing a configuration of a cylinder device (clutch release cylinder) according to Embodiment 2 of the present invention. The clutch release cylinder 7 shown in FIG. 18 schematically shows the clutch release cylinder 7 shown in FIG.

  The cylinder device according to the second embodiment relates to the clutch release cylinder 7. Referring to FIG. 17, in the clutch system including the clutch release cylinder 7, the clutch release cylinder 7, the release bearing 50, and the release fork 51 are used instead of the concentric slave cylinder (3 in FIG. 1) of the first embodiment. ing. Other configurations are the same as those of the first embodiment.

  The clutch release cylinder 7 connects and disconnects the clutch disk 2 by operating the diaphragm spring 18 of the clutch cover assembly 1 via the release fork 51 and the release bearing 50 by the hydraulic oil pressure generated in the clutch master cylinder 5. The cylinder device is operated (see FIG. 17). The clutch release cylinder 7 is also referred to as a hydraulic clutch release device for operating the clutch connection / disconnection by hydraulic pressure. The clutch release cylinder 7 forms an oil chamber 67 in the housing 60, and the piston 61, the cup seals 64 and 65, and the push rod 62 are moved in the axial direction (extension direction of the push rod 62) by the oil pressure in the oil chamber 67. Move and actuate the release fork 51. The clutch release cylinder 7 includes a housing 60, a piston 61, a push rod 62, a boot 63, a cup seal 64, a cup seal 65, a spring 66, an oil chamber 67, and a bleeder plug 68 ( (See FIG. 18).

  The housing 60 is a cylindrical member (see FIG. 18). The housing 60 has a cylinder chamber 60d in which the piston 61 is slidably inserted. The cylinder chamber 60d is open on the push rod 62 side in the extending direction of the push rod 62, and has a bottom on the oil port 60a side. The cylinder chamber 60d has a cylindrical inclined sliding surface portion 60c that slides with the outer lip portions 64a and 65a of the cup seals 64 and 65. The inclined sliding surface portion 60c is a surface (outer conical surface) that is inclined radially outward as it goes toward the push rod 62 in the axial direction. The inclined sliding surface portion 60c can be set to, for example, 1 ° or more with respect to the extending direction of the push rod 62. The housing 60 has an oil port 60a for supplying hydraulic pressure of hydraulic oil supplied from the clutch master cylinder (5 in FIG. 17) through the oil passage (4 in FIG. 17) to the oil chamber 67. The housing 60 has a hole 60 b that communicates with the oil chamber 67. The hole 60 b is an oil hole for exchanging the hydraulic oil and bleeding the air in the oil chamber 67. The hole 60b is screwed with the bleeder plug 68 from the outside. The housing 60 has a mounting portion 60e on the outer peripheral surface near the opening of the cylinder chamber 60d. The mounting portion 60e is a groove portion that is continuous in the circumferential direction, and the mounting portion 63b of the boot 63 is mounted thereon. The housing 60 has attachment portions 60f and 60g for attaching to a clutch housing (not shown) or the like on the outer peripheral surface.

  The piston 61 is a columnar member that can reciprocate in a predetermined direction inside the cylinder chamber 60d of the housing 60 (see FIG. 18). The piston 61 has groove portions 61a and 61b on the outer peripheral surface. The groove portion 61a is a groove portion that is formed closer to the push rod 62 than the groove portion 61b and is recessed inward in the radial direction continuously in the circumferential direction. A cup seal 64 is attached to the groove 61 a and is in close contact with the inner lip 64 b of the cup seal 64. The groove portion 61b is a groove portion that is formed closer to the oil chamber 67 than the groove portion 61a and is recessed inward in the radial direction continuously in the circumferential direction. A cup seal 65 is attached to the groove portion 61 b and is in close contact with the inner lip portion 65 b of the cup seal 65. The piston 61 has a recess 61 c that is recessed in the extending direction of the push rod 62 on the end surface on the push rod 62 side. The recessed portion 61c supports the end portion of the push rod 62 so as to be swingable. The piston 61 is urged toward the push rod 62 by a spring 66 at the end surface on the oil chamber 67 side.

  The push rod 62 is a rod-shaped member for pressing the power point of the release fork 51 (see FIG. 18). The push rod 62 is inserted into the cylinder chamber 60 d from the opening of the cylinder chamber 60 d of the housing 60. The end portion of the push rod 62 is inserted into the recess 61c of the piston 61 and is supported by the recess 61c so as to be swingable. The push rod 62 has a mounting portion 62a at a portion of the housing 60 that protrudes from the cylinder chamber 60d. The mounting portion 62a is a groove portion continuous in the circumferential direction, and the mounting portion 63a of the boot 63 is mounted. The tip of the push rod 62 protrudes outside the boot 63 and is supported by the force point of the release fork 51 so as to be swingable. The push rod 62 is movable in the extending direction of the push rod 62 under the pressing force of the piston 61.

  The boot 63 is a cylindrical and flexible member that covers the gap between the push rod 62 and the cylinder chamber 60d of the housing 60 so that the push rod 62 can move in the extending direction (see FIG. 18). The boot 63 is formed in a bellows shape in which a mountain fold and a valley fold are repeated at an intermediate portion, and is deformed when the push rod 62 moves in the extending direction. The boot 63 has a mounting portion 63b that is mounted on the mounting portion 60e of the housing 60 at one end in the extending direction of the push rod 62, and a mounting portion 63a that is mounted on the mounting portion 62a of the push rod 62 at the other end. . The boot 63 seals a gap between the push rod 62 and the cylinder chamber 60 d of the housing 60.

  The cup seal 64 is made of an elastic material and is an annular seal member that seals the oil chamber 67 (see FIG. 18). The cup seal 64 is attached to the groove 61 a of the piston 61. The cup seal 64 has an outer lip portion 64a and an inner lip portion 64b at a portion on the oil chamber 67 side. The outer lip portion 64a is a portion that protrudes toward the oil chamber 67 over the entire circumference on the outer side in the radial direction than the inner lip portion 64b. The outer peripheral surface of the outer lip portion 64a is slidably in contact with the inclined sliding surface portion 60c of the housing 60 with a tightening margin, a contact width, and a direct pressure. The inner lip portion 64b is a portion that protrudes toward the oil chamber 67 over the entire circumference on the radially inner side of the outer lip portion 64a. The inner peripheral surface of the inner lip portion 64 b is in close contact with the groove portion 61 a of the piston 61.

  The cup seal 65 is made of an elastic material and is an annular seal member that seals the oil chamber 67 (see FIG. 18). The cup seal 65 is disposed closer to the oil chamber 67 than the cup seal 64. The cup seal 65 is attached to the groove 61 b of the piston 61. The cup seal 65 has an outer lip portion 65a and an inner lip portion 65b at a portion on the oil chamber 67 side. The outer lip portion 65a is a portion that protrudes toward the oil chamber 67 over the entire circumference at a radially outer side than the inner lip portion 65b. The outer peripheral surface of the outer lip portion 65a is slidably in contact with the inclined sliding surface portion 60c of the housing 60 with a tightening margin, a contact width, and a direct pressure. The inner lip portion 65b is a portion that protrudes toward the oil chamber 67 over the entire circumference on the radially inner side of the outer lip portion 65a. The inner peripheral surface of the inner lip portion 65 b is in close contact with the groove portion 61 b of the piston 61.

  The spring 66 is an elastic member that biases the piston 61 toward the push rod 62 (see FIG. 18). The spring 66 is disposed in the oil chamber 67, one end is supported on the bottom surface of the cylinder chamber 60 d of the housing 60, and the other end biases the piston 61 toward the push rod 62.

  The oil chamber 67 is a liquid chamber surrounded by the housing 60, the piston 61, and the cup seal 65 (see FIG. 18). The oil chamber 67 is filled with hydraulic oil (hydraulic fluid). The oil chamber 67 is connected to a clutch master cylinder (5 in FIG. 17) via an oil port 60a and an oil passage (4 in FIG. 17). In the oil chamber 67, the radial interval (clearance) of the inclined sliding surface portion 60c of the cylinder chamber 60d of the housing 60 changes according to the axial position (stroke position), and the radial direction as it approaches the push rod 62 side. The interval of becomes wider.

  The bleeder plug 68 is a member that is detachably screwed into the hole 60 b from the outside of the hole 60 b of the housing 60.

  The release bearing 50 is a ball bearing that enables the rotating diaphragm spring 18 to be pressed (see FIG. 17). The release bearing 50 is arranged on the outer periphery of the transmission input shaft 31 so as to be movable in the axial direction. In the release bearing 50, a plurality of balls are arranged in a circumferential direction between an annular rotating wheel and a non-rotating wheel. The rotating wheel of the release bearing 50 is always in contact with the diaphragm spring 18 and rotates integrally with the diaphragm spring 18. The non-rotating wheel of the release bearing 50 is slidably in contact with the operating point of the release fork 51 and receives a pressing operation of the release fork 51.

  The release fork 51 is a lever rod that moves the release bearing 50 in the axial direction by operating the clutch release cylinder 7 (see FIG. 17). The release fork 51 is a push rod (62 in FIG. 18) of the clutch release cylinder 7 at the power point. It is in contact with the tip of the swayable. The release fork 51 has a fulcrum portion 51a supported at a fulcrum by a pivot (not shown) fixed to a clutch housing (not shown) or the like. The release fork 51 is slidably in contact with the non-rotating wheel of the release bearing 50 at an operating point.

  With the above configuration, when the hydraulic pressure of the hydraulic oil in the oil chamber 67 changes from low pressure to high pressure (when the piston 61 moves to the left side of FIG. 18 with respect to the housing 60), the hydraulic cup seal 65, The direct pressure of 64 (the pressure of the outer lip portions 65a and 64a of the cup seals 65 and 64 with respect to the inclined sliding surface portion 60c) is increased and the contact width (the contact width of the outer lip portions 65a and 64a) is increased. As a result, the direct pressure (the pressure of the outer lip portions 65a and 64a of the cup seals 65 and 64 against the inclined sliding surface portion 60c) by the tightening allowance of the cup seals 65 and 64 is reduced and the contact width is reduced. Therefore, an increase in the contact width of the cup seals 65 and 64 is suppressed (prevented), and the outer lip portions 65a and 64a slide in an inclined manner. Less constant or vary sliding resistance is low generated between the parts 60c. Further, when the cup seals 65, 64 move to the oil chamber 67 side in a state where the sliding surfaces of the cup seals 65, 64 are worn, the radial interval (clearance) of the inclined sliding surface portion 60c becomes narrow. The tightening allowances of 65 and 64 can be made comparable to those at the time of shipment (when new), the possibility of oil leakage can be reduced, and the durability can be improved.

  According to the second embodiment, the same effect as the first embodiment is obtained.

  A cylinder device according to a third embodiment of the present invention will be described with reference to the drawings. FIG. 19 is a cross-sectional view schematically showing a configuration of a cylinder device (clutch master cylinder) according to Embodiment 3 of the present invention.

  The cylinder device according to the third embodiment relates to a clutch master cylinder (corresponding to 5 in FIGS. 1 and 17). The clutch master cylinder 5 is a cylinder device that generates hydraulic pressure of hydraulic oil in response to an operation (depression operation) of a clutch pedal (corresponding to 6 in FIGS. 1 and 17) (see FIG. 19). The clutch master cylinder 5 converts the pedal force acting on the clutch pedal (corresponding to 6 in FIGS. 1 and 17) into hydraulic pressure, and the converted hydraulic pressure is converted into a concentric slave through an oil passage (corresponding to 4 in FIGS. 1 and 17). Output to other cylinder devices such as a cylinder (corresponding to 3 in FIG. 1) and a clutch release cylinder (corresponding to 17 in FIG. 1). The clutch master cylinder 5 includes a housing 70, a piston 71, cup seals 72 and 73, and an oil chamber 74.

  The housing 70 is a cylindrical member (see FIG. 19). The housing 70 has a cylinder chamber 70b in which the piston 71 is slidably inserted. The cylinder chamber 70b has an opening on the rod 71b side of the piston 71 in the extending direction of the piston 71 and a bottom on the opposite side. The cylinder chamber 70b is surrounded by a cylindrical inner wall surface portion 70e. The housing 70 supplies hydraulic pressure of hydraulic oil generated in the oil chamber 74 through an oil passage (corresponding to 4 in FIGS. 1 and 17), a concentric slave cylinder (corresponding to 3 in FIG. 1), a clutch release cylinder (corresponding to FIG. 17). And an oil port 70a for supplying to another cylinder device. The housing 70 has groove portions 70c and 70d at the inner wall surface portion 70e. The groove part 70c is a groove part that is formed closer to the oil chamber 74 than the groove part 70d and is recessed in the radial direction continuously in the circumferential direction. A cup seal 72 is attached to the groove portion 70 c and is in close contact with the outer lip portion 72 a of the cup seal 72. The groove part 70d is a groove part that is formed closer to the rod part 71b of the piston 71 than the groove part 70c, and is recessed in the radial direction continuously in the circumferential direction. A cup seal 73 is attached to the groove portion 70 d and is in close contact with the outer lip portion 73 a of the cup seal 73. The housing 70 is fixed to the vehicle body or the like. The housing 70 has an integral configuration in FIG. 19, but may have a configuration in which a plurality of parts are combined.

  The piston 71 is a cylindrical member that can reciprocate in a predetermined direction inside the cylinder chamber 70b of the housing 70 (see FIG. 19). The piston 71 has a rod portion 71b extending outward from the opening of the cylinder chamber 70b. The rod portion 71b receives a pedaling force (operation force) acting on a clutch pedal (corresponding to 6 in FIGS. 1 and 17). The piston 71 has a cylindrical inclined sliding surface portion 71 a that slides with the inner lip portions 72 b and 73 b of the cup seals 72 and 73. The inclined sliding surface portion 71a is a surface (outer conical surface) inclined inward in the radial direction as it goes to the rod portion 71b side in the axial direction. The inclined sliding surface portion 71a can be, for example, 1 ° or more with respect to the extending direction of the rod portion 71b.

  The cup seal 72 is an annular sealing member made of an elastic material and sealing the oil chamber 74 (see FIG. 19). The cup seal 72 is disposed closer to the oil chamber 74 than the cup seal 73. The cup seal 72 is attached to the groove portion 70 c of the housing 70. The cup seal 72 has an outer lip portion 72a and an inner lip portion 72b at a portion on the oil chamber 74 side. The outer lip portion 72a is a portion that protrudes toward the oil chamber 74 over the entire circumference on the outer side in the radial direction than the inner lip portion 72b. The outer peripheral surface of the outer lip portion 72 a is in close contact with the groove portion 70 c of the housing 70. The inner lip portion 72b is a portion that protrudes toward the oil chamber 74 over the entire circumference radially inward of the outer lip portion 72a. The inner peripheral surface of the inner lip portion 72b is slidably in contact with the inclined sliding surface portion 71a of the piston 71 with a tightening margin, a contact width, and a direct pressure.

  The cup seal 73 is made of an elastic material and is an annular seal member that seals the oil chamber 74 (see FIG. 19). The cup seal 73 is attached to the groove portion 70 d of the housing 70. The cup seal 73 has an outer lip portion 73a and an inner lip portion 73b at a portion on the oil chamber 74 side. The outer lip portion 73a is a portion that protrudes toward the oil chamber 74 over the entire circumference on the outer side in the radial direction than the inner lip portion 73b. The outer peripheral surface of the outer lip 73 a is in close contact with the groove 70 d of the housing 70. The inner lip portion 73b is a portion that protrudes toward the oil chamber 74 over the entire circumference radially inward of the outer lip portion 73a. The inner peripheral surface of the inner lip portion 73b is slidably in contact with the inclined sliding surface portion 71a of the piston 71 with a tightening margin, a contact width, and a direct pressure.

  The oil chamber 74 is a liquid chamber surrounded by the housing 70, the piston 71, and the cup seal 72 (see FIG. 19). The oil chamber 74 is filled with hydraulic oil (hydraulic fluid). The oil chamber 74 has a concentric slave cylinder (corresponding to 3 in FIG. 1), a clutch release cylinder (corresponding to 7 in FIG. 17), etc. through an oil port 70a and an oil passage (corresponding to 4 in FIGS. 1 and 17). It is connected to the cylinder device.

  In the configuration as described above, when the hydraulic pressure of the hydraulic oil in the oil chamber 74 changes from low pressure to high pressure (when the piston 71 moves to the left side of FIG. 19 with respect to the housing 70), the hydraulic cup seal 72, The direct pressure of 73 (the pressure of the inner lip portions 72b and 73b of the cup seals 72 and 73 against the inclined sliding surface portion 71a) increases and the contact width (the contact width of the inner lip portions 72b and 73b) increases. Along with the movement (stroke) of the piston 71 in the axial direction, the direct pressure (pressure of the inner lip portions 72b and 73b of the cup seals 72 and 73 with respect to the inclined sliding surface portion 71a) by the tightening allowance of the cup seals 72 and 73 is reduced and the contact width is increased. Since it acts so that it becomes smaller, an increase in the contact width of the cup seals 72 and 73 is suppressed (prevented), and the inner lip portions 72b and 73b are inclined and slid. Less constant or vary sliding resistance is low generated between the parts 71a. In addition, when the piston 71 moves to the rod portion 71b side while the sliding surfaces of the cup seals 72 and 73 are worn, the radial interval (clearance) of the inclined sliding surface portion 71a is narrowed. The tightening allowance can be made comparable to that at the time of shipment (when new), the possibility of oil leakage can be reduced, and the durability can be improved.

  According to the third embodiment, the same effect as the first embodiment is obtained.

  In the first to third embodiments, the cylinder device in the clutch system has been described as an example. However, the present invention may be applied to a device having a cylinder device such as another brake device.

  It should be noted that the embodiments and examples may be changed and adjusted within the scope of the entire disclosure (including claims and drawings) of the present invention and based on the basic technical concept. Various combinations or selections of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are included within the scope of the claims of the present invention. Is possible. That is, the present invention naturally includes various variations and modifications that could be made by those skilled in the art according to the entire disclosure including the claims and the drawings, and the technical idea.

1 Clutch cover assembly 2 Clutch disc 3 Concentric slave cylinder (cylinder device)
4 Oil passage (liquid passage)
5 Clutch master cylinder (cylinder unit)
6 Clutch pedal 7 Clutch release cylinder (cylinder unit)
DESCRIPTION OF SYMBOLS 8 Rotating shaft 11 Crankshaft 12 Flywheel 13 Bolt 14 Clutch cover 14a Caulking part 15 Bolt 16, 17 Supporting member 18 Diaphragm spring 19 Pressure plate 20, 21 Friction material 22 Lining plate 23, 24 Side plate 25 Rivet 27 Elastic member 28 Hub Member 29, 30 Thrust member 31 Transmission input shaft 32 Inner housing (housing, second housing)
32a Tubular part 32b Flange part 32c Inclined sliding surface part (outer conical surface sliding part)
32d Flat sliding surface part 33 Outer housing (housing, first housing)
33a Oil port 33b Mounting flange 33c Inclined sliding surface part (inner conical surface sliding part)
33d Flat sliding surface 34 Seal 35 Oil chamber (liquid chamber)
36 Release bearing 36a Inner ring 36b Outer ring 37 Plate member 38 Holding member 39 First annular piston 39a Mounting portion 40 Second annular piston 40a Recessed portion 41 Disc spring 42 Coil spring 43 Seat member 44 Cover member 44a Seat portion 45 Retaining ring 46 Cup seal 46a Mounting part 46b Outer lip part (lip part)
46c Inner lip part (lip part)
47 cylinder chamber 50 release bearing 51 release fork 51a fulcrum 60 housing 60a oil port 60b hole 60c inclined sliding surface (inner conical surface sliding)
60d Cylinder chamber 60e Mounting portion 60f, 60g Mounting portion 61 Piston 61a, 61b Groove portion 61c Recessed portion 62 Push rod 62a Mounting portion 63 Boot 63a, 63b Mounting portion 64, 65 Cup seal 64a, 65a Outer lip portion (lip portion)
64b, 65b Inner lip 66 Spring 67 Oil chamber (liquid chamber)
68 Bleeder plug 70 Housing 70a Oil port 70b Cylinder chamber 70c, 70d Groove 70e Inner wall surface 71 Piston 71a Inclined sliding surface (outer conical surface sliding)
71b Rod part 72, 73 Cup seal 72a, 73a Outer lip part 72b, 73b Inner lip part (lip part)
74 Oil chamber (liquid chamber)

Claims (7)

A housing having a cylinder chamber communicating with the liquid path;
A piston that is entirely or partially housed in the cylinder chamber and that can reciprocate in a predetermined direction inside the cylinder chamber;
A cup seal attached to the piston and having a lip portion slidably contacting the wall surface of the cylinder chamber;
A liquid chamber surrounded by the housing and the piston or the cup seal in the cylinder chamber and filled with a working fluid;
With
The housing is separated from the end of the cylinder chamber in the predetermined direction in the predetermined direction in the predetermined direction, at least in a portion slidable with the lip portion in the cylinder chamber. A cylinder device comprising an inclined sliding surface portion inclined so as to be separated from a central axis in a predetermined direction in a direction perpendicular to the central axis. The housing has a configuration in which a cylindrical first housing and a cylindrical second housing arranged at a predetermined interval on the inner periphery of the first housing are combined,
The cylinder chamber is an annular space between the first housing and the second housing,
The piston is configured in an annular shape,
The cup seal includes, as the lip portion, an outer lip portion that is slidably in contact with the first housing, and an inner lip portion that is slidably in contact with the second housing,
The cylinder device according to claim 1, wherein the inclined sliding surface portion is formed on one or both of the first housing and the second housing. The cylinder device is a concentric slave cylinder that operates connection / disconnection of a clutch disk by operating a diaphragm spring of a clutch cover assembly by hydraulic pressure of hydraulic oil generated in a clutch master cylinder,
The cylinder device according to claim 2, wherein the piston is urged toward the liquid chamber by the diaphragm spring via a predetermined member. The housing is configured in a cylindrical shape,
The piston has a groove portion recessed radially inward continuously in the circumferential direction on the outer peripheral surface,
The cup seal has, as the lip portion, an outer lip portion that is slidably in contact with the housing, and an inner lip portion that is attached to the groove portion,
The cylinder device according to claim 1, wherein the inclined sliding surface portion is formed on an inner peripheral surface or an outer peripheral surface of the housing. The cylinder device is a clutch release cylinder that operates connection / disconnection of a clutch disk by operating a diaphragm spring of a clutch cover assembly via a release fork and a release bearing by hydraulic oil pressure generated in a clutch master cylinder. ,
5. The cylinder device according to claim 4, wherein the piston is urged toward the liquid chamber by the diaphragm spring via the release fork and the release bearing. A housing having a cylinder chamber communicating with the liquid path;
A piston that is entirely or partially housed in the cylinder chamber and that can reciprocate in a predetermined direction inside the cylinder chamber;
A cup seal attached to the housing and having a lip portion slidably contacting the wall surface of the piston;
A liquid chamber surrounded by the housing and the piston or the cup seal in the cylinder chamber and filled with a working fluid;
With
The piston has an inclined sliding surface portion that is inclined so as to approach the central axis of the piston in the predetermined direction as it moves away from the liquid chamber in the predetermined direction at least in a portion slidable with the lip portion. A cylinder device comprising: The cylinder device is a master cylinder that generates hydraulic pressure of hydraulic fluid in response to an operation of a pedal,
The cylinder device according to claim 6, wherein the piston receives an operating force acting on the pedal.

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