JP2013203121A - Cylinder device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder device that can prevent a cup seal from being bitten and improve a supplying ability when an operation is canceled.SOLUTION: A first cup seal 7 includes an outer circumferential liquid passing groove formed from a base end face of a base portion 7a to an outer circumferential face on a cylinder bore opening side of an outer circumferential lip part 7c, and an inner circumferential liquid passing groove 7f formed on a cylinder bore bottom side of an inner circumferential lip part 7b. The inner circumferential liquid passing groove 7f and the outer circumferential liquid passing groove are formed with equal intervals therebetween in a circumferential direction and in positions corresponding to each other in radial directions, and a sectional area in the outer circumferential liquid passing groove where hydraulic fluid flows is formed to be larger than a sectional area in the inner circumferential liquid passing groove 7f where the hydraulic fluid flows.

Description

  The present invention relates to a cylinder device, and more particularly to a cylinder device in which a plunger is movably inserted into a cylinder hole via a cup seal.

  As a cylinder device, an annular seal groove is formed in a cylinder hole in which a plunger is movably inserted, and a cup seal that slidably seals between the cylinder hole and the plunger is fitted in the seal groove. Widely done. Generally, the seal groove has a circumferential seal groove bottom surface, a cylinder hole bottom side surface, a cylinder hole opening side surface, and a seal groove opening opened to the plunger side, and the cup seal is a seal groove The base end surface is disposed on the cylinder hole opening side, the base end surface is in contact with the side surface of the cylinder hole opening portion, and extends from the inner peripheral side of the base portion toward the bottom of the cylinder hole, and the inner peripheral surface is the outer peripheral surface of the plunger. And an outer peripheral lip portion that extends from the outer peripheral side of the base portion toward the bottom of the cylinder hole, and the outer peripheral surface abuts against the bottom surface of the seal groove. Further, some cup seals have liquid passage grooves formed on the outer peripheral surface of the base portion and the distal end surface of the inner peripheral lip portion as a passage through which the working fluid flows when the plunger returns when the operation is released (for example, (See Patent Document 1).

Japanese Patent No. 4388838

  However, since the above-described cup seal has the liquid passage groove provided in the base portion formed in the entire radial direction of the base portion, the amount of deformation when the plunger returns when releasing the operation increases, and the inner peripheral side of the base portion is The so-called biting that bites between the plunger and the cylinder hole was easy to occur. The replenishability of the hydraulic fluid when the plunger returns when the operation is released depends on the relationship between the cross-sectional area through which the hydraulic fluid in the base fluid passage groove passes and the cross-sectional area through which the hydraulic fluid in the inner lip portion passes. Because of the great difference, it was necessary to properly set the cross-sectional area through which both hydraulic fluids pass.

  Then, this invention aims at providing the cylinder apparatus which can aim at prevention of the bite of a cup seal, and the improvement of the replenishment property at the time of an operation | movement cancellation | release.

  In order to achieve the above object, a cylinder device according to the present invention includes a bottomed cylinder hole formed in a cylinder body, an annular seal groove provided in the cylinder hole, and a cup seal fitted in the seal groove. A plunger slidably inserted into the cylinder hole through the cup seal, and the seal groove includes a circumferential seal groove bottom surface, a cylinder hole bottom side surface, a cylinder hole opening side surface, A seal groove opening that opens to the plunger side, and the cup seal is disposed on the cylinder hole opening side of the seal groove, and a base portion whose base end surface is in contact with a side surface of the cylinder hole opening portion; An inner peripheral lip portion that extends from the peripheral side toward the cylinder hole bottom portion so that the inner peripheral surface contacts the outer peripheral surface of the plunger in a slidable manner, and extends from the outer peripheral side of the base portion toward the cylinder hole bottom portion. Outer peripheral surface In the cylinder device including the outer peripheral lip portion that contacts the bottom surface of the seal groove, the cup seal is formed on the outer peripheral side extending from the base end surface of the base portion to the outer peripheral surface of the outer peripheral lip portion on the cylinder hole opening side. A liquid passage groove, and an inner peripheral side liquid passage groove formed on a cylinder hole bottom side of the inner peripheral lip portion, wherein the inner peripheral side liquid passage groove and the outer peripheral side liquid passage groove are the inner peripheral lip. Are formed in positions corresponding to the radial direction in the circumferential direction of the outer peripheral lip portion and the cross-sectional area through which the hydraulic fluid in the outer peripheral side fluid passage groove passes, the hydraulic fluid in the inner peripheral side fluid passage groove is It is characterized by being formed larger than the cross-sectional area passing through.

  The base end surface of the base is formed with the outer peripheral side fluid passage groove on the outer peripheral side, and on the inner peripheral side, a conical surface inclined in a direction gradually separating from the cylinder hole opening side surface is formed toward the plunger. In addition, it is preferable that a seal point that contacts and seals the plunger when the plunger is actuated is provided at the inner peripheral side end of the conical surface. Furthermore, it is preferable that the inner end portion of the outer peripheral side liquid passage groove is disposed at an intermediate portion of the conical surface, and a meat portion is left on the inner peripheral side of the inner end portion of the conical surface. is there.

  In addition, a replenishing groove that communicates with the seal groove is formed on an inner peripheral surface of the cylinder hole at a side surface of the bottom of the cylinder hole of the seal groove. It is preferable to increase the cross-sectional area through which the hydraulic fluid in the circumferential side fluid passage groove passes.

  According to the cylinder device of the present invention, by forming the cross-sectional area through which the hydraulic fluid in the outer peripheral side fluid passage groove passes larger than the cross-sectional area through which the hydraulic fluid in the inner peripheral side fluid passage groove passes, When the plunger returns via the inner circumferential side fluid passage groove, the working fluid can be circulated favorably, the plunger can be satisfactorily returned, and the rigidity of the inner peripheral lip is ensured. be able to.

  Further, the base end surface of the base portion of the cup seal is formed with an outer peripheral side fluid passage groove on the outer peripheral side, and a conical surface inclined in a direction gradually moving away from the cylinder hole opening side surface toward the plunger on the inner peripheral side. In addition, a meat portion is left without forming an outer peripheral side fluid passage groove on the inner peripheral side of the base portion, and an inner end portion of the outer peripheral side fluid passage groove is disposed at an intermediate portion of the conical surface. Since the meat portion is left on the inner peripheral side of the inner end portion of the conical surface, it is possible to suppress deformation of the cup seal when the plunger returns when the operation is released. Furthermore, by providing a seal point at the inner peripheral side end of the conical surface that contacts and seals the plunger when the plunger is operated, the inner peripheral side of the base is returned to the plunger and cylinder hole when the plunger returns when the operation is released. Occurrence of biting between and can be suppressed. Further, by providing the seal point as described above, the stroke of the plunger from when the plunger starts to operate until the hydraulic fluid starts to increase in pressure can be set short, and the invalid stroke can be reduced.

  Further, a replenishing groove is formed on the inner peripheral surface of the cylinder hole at the bottom surface of the cylinder hole, and communicates with the seal groove. By making the cross-sectional area through which the hydraulic fluid passes through the groove large, the hydraulic fluid flows well on the inner peripheral lip portion side when the operation is released, so that the replenishment oil property can be improved and the plunger can be returned smoothly.

It is principal part sectional drawing of the hydraulic master cylinder apparatus which shows one example of this invention. It is a perspective view of the front side of the cup seal similarly used for a hydraulic master cylinder device. It is III-III sectional drawing of FIG. It is IV-IV sectional drawing of FIG. It is a front view of the cup seal which shows one example of the present invention. It is a rear view of a cup seal similarly. It is a perspective view of the back side of a cup seal similarly. It is a sectional view of a hydraulic master cylinder device similarly.

  1 to 8 show an embodiment in which the cylinder device of the present invention is applied to a plunger type hydraulic master cylinder device for a vehicle. As shown in FIG. 8, the hydraulic master cylinder device 1 has a cylinder body 2 having a bottomed cylinder hole 2a, and a union boss 2b protruding from the bottom of the cylinder hole 2a. A union hole 2c is formed in the portion 2b. A boss portion 2e having a liquid passage hole 2d communicating with the cylinder hole 2a protrudes from the upper portion of the cylinder body 2, and is connected to a reservoir (not shown) via a seal member 3 at the boss portion 2e. A connector 4 is attached. Further, mounting brackets 2f, 2f for mounting the vehicle body project from the lower portion of the cylinder body 2, and a large-diameter hole 2g into which the distal end side of the push rod 5 is inserted is provided on the cylinder hole opening side. A diameter tube portion 2h is provided continuously.

  A plunger 6 is slidably inserted into the cylinder hole 2a via a first cup seal 7 shown in FIG. 1A and a second cup seal 8 shown in FIG. Is formed in the first seal groove 9 formed on the inner peripheral surface of the cylinder hole 2a on the cylinder hole bottom side of the liquid passage hole 2d, and the second cup seal 8 is disposed on the cylinder hole opening side of the liquid passage hole 2d. A hydraulic pressure chamber 11 is defined between the bottom of the cylinder hole 2 a and the first cup seal 7, and is fitted into a second seal groove 10 formed on the inner peripheral surface of the cylinder hole 2 a.

  The first seal groove 9 and the second seal groove 10 are opened in the circumferential direction in the seal groove bottom surfaces 9a and 10a, cylinder hole bottom side surfaces 9b and 10b, cylinder hole opening side surfaces 9c and 10c, and the plunger side. Each has seal groove openings 9d and 10d. Further, a replenishment oil chamber 2i continuous with the liquid passage hole 2d is formed on the inner peripheral surface of the cylinder hole 2a between the first seal groove 9 and the second seal groove 10, and the first seal groove 9 A replenishing groove 2k communicating with the first seal groove 9 is formed on the inner peripheral surface of the cylinder hole 2a on the cylinder hole bottom side. Further, the inner peripheral side of the cylinder hole opening side surface 9c of the first seal groove 9 is formed so as to be gradually inclined toward the cylinder hole opening side, and a communication portion communicating with the replenishing oil chamber 2i at the inner peripheral end portion. 9e is formed.

  The union boss 2b is formed with a union hole 2c that opens to the bottom side of the cylinder hole, and a banjo for fixing the banjo 14 fixed to the tip of the flexible hydraulic pipe 13 to the union hole 2c. A female screw portion 2m to which the bolt 12 is screwed is formed. The banjo 14 includes a fixed tube 14a that is fixed by caulking to the end of the hydraulic pipe 13, a ring body 14b that is fixed to the union boss portion 2b by the banjo bolt 12, and a small-diameter neck tube 14c that connects them. A first through hole 14d that is continuous with the hydraulic pipe 13 is formed across the neck tube 14c and the ring body 14b. The banjo bolt 12 has a male threaded portion 12b formed on the outer periphery on the tip side of the shaft portion protruding from the hexagonal head portion 12a. Inside the shaft portion, there are a hydraulic chamber 11 and a first through hole 14d of the ring body 14b. The hydraulic passage 11 communicates with the hydraulic pipe 13 through the union hole 2c, the second through-hole 12c of the banjo bolt 12, and the first through-hole 14d of the banjo 14. ing.

  The plunger 6 is formed in a bottomed cylindrical shape having a recess 6a that opens to the bottom side of the cylinder hole. The peripheral wall on the recess opening side penetrates through the inside and outside of the peripheral wall, and at the initial position in a non-operating state, A plurality of small-diameter communication ports 6b that communicate between the fuel tank 11 and the replenishing oil chamber 2i are formed in the circumferential direction. A spherical recess 6c is formed on the outer surface of the plunger 6 on the cylinder hole opening side so that the tip of the push rod 5 that pushes the plunger 6 contacts.

  In the push rod 5, a hemispherical large-diameter head portion 5a that contacts the spherical recess 6c is inserted into the cylinder hole 2a from the large-diameter hole 2g, and a retaining ring 15 and a retainer 16 that are engaged with the large-diameter hole 2g. And is prevented from coming off.

  Between the bottom surface 6d of the concave portion 6a of the plunger 6 and the bottom surface 2n of the cylinder hole 2a, one end is seated on the bottom surface 6d of the plunger 6 and the other end is seated on the bottom surface 2n of the cylinder hole 2a. A return spring 17 is disposed for returning 6 to a predetermined initial position.

  The first cup seal 7 is disposed on the cylinder hole opening side of the first seal groove 9, and has an annular base 7a that contacts the side surface 9c of the cylinder hole, and from the inner peripheral side of the base 7a toward the cylinder hole bottom. A cylindrical inner peripheral lip portion 7b that extends and contacts the outer peripheral surface of the plunger 6 so as to be slidable, and a bottom surface of the seal groove that extends from the outer peripheral side of the base portion 7a toward the bottom of the cylinder hole. And a cylindrical outer peripheral lip portion 7c in contact with 9a. Furthermore, outer peripheral side liquid passage grooves 7d are formed at equal intervals in the circumferential direction from the base end surface of the base portion 7a to the outer peripheral surface of the outer peripheral lip portion 7c on the cylinder hole opening side. Further, the inner peripheral lip portion 7b has a plurality of elastic protrusions 7e protruding from the front end of the outer peripheral side toward the bottom of the cylinder hole at equal intervals in the circumferential direction, and two adjacent elastic protrusions 7e. Between these, an inner circumferential side liquid passage groove 7f is formed. The inner circumferential side fluid passage groove 7f and the outer circumferential side fluid passage groove 7d are formed at equal intervals in the circumferential direction of the inner circumferential lip portion 7b and the outer circumferential lip portion 7c and at positions corresponding to the radial direction. The cross-sectional area through which the hydraulic fluid in the outer peripheral side fluid passage groove 7d passes is formed larger than the cross-sectional area through which the hydraulic fluid in the inner peripheral side fluid passage groove 7f passes. Further, the cross-sectional area through which the hydraulic fluid in the inner peripheral side fluid passage groove 7f passes is the cross-sectional area through which the hydraulic fluid in the replenishing groove 2k passes, that is, between the outer peripheral surface 6e of the plunger 6 and the outer peripheral surface 2p of the replenishing groove 2k. It is formed larger than the cross-sectional area.

  The base portion 7a is formed with an outer peripheral side liquid passage groove 7d extending from an intermediate portion of the base end surface to an intermediate portion of the outer side surface of the outer peripheral lip portion 7c. As it goes, a conical surface 7g that is inclined in a direction gradually separating from the cylinder hole opening side surface is formed. The inner end portion 7j of the outer peripheral side liquid passage groove 7d is disposed at an intermediate portion of the conical surface 7g, and the meat portion 7k is left on the inner peripheral side of the inner end portion 7j of the conical surface 7g. A seal point P1 that contacts the outer peripheral surface of the plunger 6 from the time when the plunger 6 is actuated and the hydraulic fluid starts to increase in pressure is provided at the inner peripheral side end. Furthermore, a plurality of circumferential grooves 7h formed in the circumferential direction are formed in the middle portion of the inner circumferential surface of the inner circumferential lip portion 7b, and an axial groove 7i formed in the cylinder axial direction is formed on the distal end side of the inner circumferential surface. Each is formed.

  The second cup seal 8 is a well-known cup seal, extends in the radial direction, and has an annular base 8a through which the plunger 6 slidably passes, and an inner peripheral side end of the base 8a. An annular inner peripheral lip portion 8b that extends toward the bottom of the cylinder hole and through which the plunger 6 slidably passes, and an outer peripheral surface that extends from the outer peripheral end of the base portion 8a toward the bottom of the cylinder hole Is provided with an outer peripheral lip portion 8c that comes into contact with the bottom surface 10a of the seal groove, and the length of the inner peripheral lip portion 8b in the cylinder axial direction is shorter than the length of the outer peripheral lip portion 8c in the cylinder axial direction. .

  In the vehicular hydraulic master cylinder device 1 formed as described above, the plunger 6 is provided at the position shown in FIG. 8 by the elastic force of the return spring 17 when not in operation. An inner peripheral side end of the conical surface 7g of the first cup seal 7 is disposed at a position on the cylinder hole bottom side of the communication port 6b, and the refilling oil chamber 2i, the first seal groove 9, and the communication port 6b communicate with each other. Between the connector 4 and the hydraulic chamber 11, the working fluid can flow.

  In operation, when the push rod 5 pushes the plunger 6 toward the bottom of the cylinder hole, the plunger 6 moves forward in the cylinder hole 2a while compressing the return spring 17 in the hydraulic chamber 11, and the communication port 6b The hydraulic pressure begins to be generated in the hydraulic pressure chamber 11 from the time when the fluid pressure chamber 11 and the replenishment oil chamber 2i are disconnected from each other after passing through the seal point P1 of the first cup seal 7, and the pressurized hydraulic fluid is a union. It is supplied to the brake system through the hole 2c.

  At this time, by providing a seal point P1 that seals against the outer peripheral surface of the plunger 6 on the inner end of the meat portion 7k left on the inner peripheral side of the conical surface 7g of the first cup seal 7, The stroke of the plunger 6 from when the plunger 6 starts to operate until the hydraulic fluid starts to increase in pressure can be set short, and the invalid stroke can be reduced. Furthermore, since the hydraulic fluid does not leak from the inner peripheral side of the conical surface 7g, it is possible to stabilize the pressurization performance from when the plunger 6 starts to operate until the hydraulic fluid starts to increase in pressure. A plurality of circumferential grooves 7h formed in the circumferential direction are formed in the middle portion of the inner circumferential lip portion 7b of the first cup seal 7, and are formed in the cylinder axial direction on the distal end side of the inner circumferential surface. Since the axial grooves 7i are formed, the sliding resistance with the plunger 6 can be reduced, and the plunger 6 can be moved well.

  Further, when the operation is released, the plunger 6 returns to the initial position by the elastic force of the return spring 17. When the plunger 6 moves to the cylinder hole opening side, the hydraulic fluid flows from the connector 4 into the first seal groove 9 via the replenishing oil chamber 2i and the communication portion 9e, and flexes the first cup seal 7. Then, the fluid flows into the hydraulic chamber 11 through the outer peripheral side liquid passage groove 7d and the inner peripheral side liquid passage groove 7f of the first cup seal 7. Furthermore, hydraulic fluid can flow between the connector 4 and the hydraulic chamber 11 via the communication port 6b. At this time, the rigidity of the inner peripheral lip portion 7b is ensured by forming the cross-sectional area through which the hydraulic fluid in the outer peripheral side fluid passage groove 7d passes larger than the sectional area through which the hydraulic fluid in the inner peripheral side fluid passage groove 7f passes. However, the hydraulic fluid can be circulated satisfactorily through the liquid passage hole 2d, the replenishing oil chamber 2i, the communication portion 9e, the outer peripheral side liquid passage groove 7d, and the inner peripheral side liquid passage groove 7f, and the plunger 6 can be made good. Can be returned.

  Further, since the meat portion 7k is left on the inner peripheral side of the base end surface of the base portion 7a, it is possible to suppress deformation of the first cup seal 7 when the plunger 6 returns when the operation is released. Further, the base end surface of the base portion 7a is formed by the conical surface 7g, and the inner peripheral side of the cylinder seal opening side surface 9c of the first seal groove 9 is formed to be gradually inclined toward the cylinder hole opening portion side, thereby operating. When the plunger 6 is returned at the time of release, the inner peripheral side of the base portion 7a can be prevented from being bitten between the plunger 6 and the cylinder hole 2a. Further, a replenishment groove 2k that opens to the cylinder hole bottom side surface 9b of the first seal groove 9 is formed in the cylinder hole 2a. Since the hydraulic fluid flows smoothly on the inner peripheral lip portion when the operation is released, the supply oil property can be improved and the plunger 6 can be returned smoothly.

  In addition, this invention is not restricted to what provides a seal point in the inner peripheral side edge part of the conical surface provided in the base part of the 1st cup seal like the above-mentioned embodiment, Furthermore, a conical surface is provided in a base part. You may not have. Further, the cylinder hole may not include a supply groove that communicates with the first seal groove. Further, the present invention can be applied to a tandem hydraulic master cylinder.

  DESCRIPTION OF SYMBOLS 1 ... Fluid pressure master cylinder apparatus, 2 ... Cylinder main body, 2a ... Cylinder hole, 2b ... Union boss | hub part, 2c ... Union hole, 2d ... Liquid through-hole, 2e ... Boss part, 2f ... Mounting bracket, 2g ... Large-diameter hole 2h: Large diameter cylindrical portion, 2i: Replenishing oil chamber, 2k ... Replenishing groove, 2m ... Female thread portion, 2n ... Bottom surface, 3 ... Seal member, 4 ... Connector, 5 ... Push rod, 5a ... Large diameter head, 6 ... plunger, 6a ... recess, 6b ... communication port, 6c ... spherical recess, 6d ... bottom surface, 7 ... first cup seal, 7a ... base, 7b ... inner lip, 7c ... outer lip, 7d ... outer liquid Through groove, 7e ... elastic protrusion, 7f ... inner periphery side fluid passage groove, 7g ... conical surface, 7h ... circumferential groove, 7i ... axial groove, 7j ... inner end, 7k ... meat part, 8 ... second Cup seal, 9 ... first seal groove, 9a ... bottom surface of seal groove, 9b ... bottom hole side , 9c ... cylinder hole opening side surface, 9d ... seal groove opening, 9e ... communication portion, 10 ... second seal groove, 10a ... seal groove bottom surface, 10b ... cylinder hole bottom side surface, 10c ... cylinder hole opening side surface, 10d ... Seal groove opening, 11 ... Hydraulic chamber, 12 ... Banjo bolt, 12a ... Hex head, 12b ... Male thread, 12c ... Second through hole, 13 ... Hydraulic pipe, 14 ... Banjo, 14a ... Fixed pipe, 14b ... Ring body, 14c ... cervical tube, 14d ... first through hole, 15 ... retaining ring, 16 ... retainer, 17 ... return spring

Claims (4)

A bottomed cylinder hole formed in the cylinder body, an annular seal groove provided in the cylinder hole, a cup seal fitted in the seal groove, and slidable in the cylinder hole via the cup seal And the seal groove has a circumferential seal groove bottom surface, a cylinder hole bottom side surface, a cylinder hole opening side surface, and a seal groove opening opened to the plunger side, The cup seal is disposed on the cylinder hole opening side of the seal groove, and has a base portion whose base end surface is in contact with the side surface of the cylinder hole opening portion and extends from the inner peripheral side of the base portion toward the bottom of the cylinder hole. An inner peripheral lip portion whose peripheral surface is in slidable contact with the outer peripheral surface of the plunger, and an outer peripheral lip portion that extends from the outer peripheral side of the base portion toward the bottom of the cylinder hole and whose outer peripheral surface contacts the bottom surface of the seal groove And with In the cylinder device, the cup seal includes an outer peripheral side liquid passage groove formed from a base end surface of the base portion to an outer peripheral surface on the cylinder hole opening side of the outer peripheral lip portion, and a cylinder hole bottom portion of the inner peripheral lip portion. An inner peripheral side liquid passage groove formed on the side, and the inner peripheral side liquid passage groove and the outer peripheral side liquid passage groove are respectively radial in the circumferential direction of the inner peripheral lip portion and the outer peripheral lip portion. The cross-sectional area through which the hydraulic fluid in the outer peripheral side fluid passage groove passes is formed larger than the cross-sectional area through which the hydraulic fluid in the inner peripheral side fluid passage groove passes. Cylinder device. The base end surface of the base portion is formed with the outer peripheral side liquid passage groove on the outer peripheral side, and on the inner peripheral side, a conical surface is formed that is inclined in a direction gradually moving away from the cylinder hole opening side surface toward the plunger. The cylinder device according to claim 1, wherein a seal point is provided at an inner peripheral side end portion of the conical surface so as to contact and seal the plunger when the plunger is operated. An inner end portion of the outer peripheral side liquid passage groove is disposed at an intermediate portion of the conical surface, and a meat portion is left on an inner peripheral side of the inner end portion of the conical surface. The cylinder device according to claim 2. A replenishing groove is formed on the inner peripheral surface of the cylinder hole at a bottom side surface of the cylinder groove and communicates with the seal groove. The cylinder device according to any one of claims 1 to 3, wherein a cross-sectional area through which hydraulic fluid in the liquid passage groove passes is formed to be large.

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