JP2005255020A - Hydraulic master cylinder for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic master cylinder for a vehicle with a simple structure capable of confirming whether or not a lid member is securely installed on a cylinder body. <P>SOLUTION: In the hydraulic master cylinder for the vehicle, the lid member 5 is constituted by a cylindrical sleeve 3 with a bottom and a plug for removal-stopping the sleeve 3. The sleeve 3 has an inner diameter insertable with a secondary piston 8 and is inserted into a cylinder body 2 while an opening side is directed to the inside of the cylinder body 2 through seal rings 18, 18. In the plug 4, a circular disc part 4b provided with a male screw part 4a on an outer periphery is continuously formed on a sleeve 3 side and a hexagonal projection part 4c is continuously formed on one end opening side of the cylinder body 2 respectively. A positioning pin 20 projecting into the cylinder body 2 is detachably provided on one end opening side of the cylinder body 2 and a distal end of the positioning pin 20 is positioned at an outer surface side of the circular disc part 4b in the state where the male screw part 4a is threaded to the cylinder body 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydraulic master cylinder for a vehicle in which brakes and clutches of automobiles, motorcycles and three-wheeled vehicles are operated with hydraulic pressure, and more specifically, one end opening portion of a cylinder body opened at both ends is closed with a lid member. The present invention relates to a hydraulic master cylinder that forms a cylinder hole.

2. Description of the Related Art Conventionally, some plunger-type hydraulic master cylinders or the like form a cylinder hole by attaching a lid member to one end opening of a cylinder body that is open at both ends. The lid member is formed by integrally forming a cylindrical portion inserted into the cylinder body and a flange portion covering one end portion of the cylinder body. Screws are respectively provided on the outer peripheral tip side of the cylindrical portion and the inner periphery of the cylinder body. Is provided. A seal ring is fitted to the front end of the cylindrical portion and the vicinity of the flange portion, and the lid member is attached to the cylinder main body by screwing the front end side of the cylindrical portion into the cylinder main body (see, for example, Patent Document 1). ).
Japanese Utility Model Publication No. 8-2002

  However, in the above-mentioned, since the hydraulic pressure is generated at the bottom of the cylinder hole, when the lid member is attached to the cylinder body, the sealing performance of the lid member is deteriorated unless the lid member is securely screwed into the cylinder body. There was a fear.

  Therefore, an object of the present invention is to provide a hydraulic master cylinder for a vehicle that can confirm whether or not the lid member is securely attached to the cylinder body with a simple structure.

  In order to achieve the above object, according to the first aspect of the present invention, in the first aspect of the invention, a lid member is attached to one end opening of the cylinder body having both ends open to form a bottomed cylinder hole, and a piston is inserted into the cylinder hole. In the hydraulic master cylinder for a vehicle, which is inserted and defines a hydraulic chamber between the piston and the lid member, the lid member has a disk portion having a threaded portion on the outer periphery, and an outer surface of the cylinder body. The cylinder body is screwed so as to be located inside the one end opening, and a positioning pin protruding into the cylinder body is detachably provided on the one end opening side of the cylinder body, and the lid member is screwed to the cylinder body. In this state, the tip of the positioning pin is positioned on the outer surface side of the disc portion.

  In the second invention, the lid member is constituted by a bottomed cylindrical sleeve and a plug for preventing the sleeve from coming off, and the sleeve has an inner diameter into which the piston can enter, and is sealed to the cylinder body. The opening side is inserted through the ring toward the inside of the cylinder body, and the plug includes the disk portion.

  In the third invention, the positioning pin is provided at a position facing the bottom wall of the reservoir attached to the top of the hydraulic master cylinder, and the leg extends to the vicinity of the outer end of the positioning pin at the bottom of the reservoir. It is characterized by providing a piece.

  In the first invention, when the screw amount of the lid member is not sufficient, the lid member comes into contact with the disk portion of the lid member and the positioning pin cannot be inserted into the cylinder body in a predetermined state. It is possible to easily check whether or not the cover member is attached to the cover member, and there is no possibility that the sealing performance of the lid member is lowered. Further, the positioning pin can prevent the lid member from coming off.

  In the second invention, when the insertion position of the sleeve into the cylinder body is attached to the opening side of one end from the set position or the amount of screwing of the plug is not sufficient, the positioning pin is the disk portion of the plug. It is possible to confirm that the sleeve and the plug are not mounted at the set positions because the sleeve and the plug cannot be inserted into the cylinder body. As a result, there is no risk that the sealing performance of the sleeve will deteriorate, and the sleeve will not be twisted when the cylinder body is mounted, so that the sealing member mounted on the sleeve will not be damaged and the sealing performance of the lid member will be ensured. Can do.

  In the third aspect of the present invention, the positioning pin can be prevented from coming off by the leg piece provided at the bottom of the reservoir, and the lid member can be securely attached to the cylinder body.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The hydraulic master cylinder 1 has a bottomed cylinder hole 6 formed by attaching a cover member 5 comprising a sleeve 3 and a plug 4 to one end opening of a cylinder body 2 having both ends open. The primary piston 7 and the secondary piston 8 are inserted, the first hydraulic chamber 9 is interposed between the primary piston 7 and the secondary piston 8, and the second hydraulic chamber 10 is interposed between the secondary piston 8 and the lid member 5. Each is defined.

  The cylinder body 2 is formed in a substantially cylindrical shape with both ends open, and in order from one end opening side that becomes the bottom of the cylinder hole, a large diameter female screw hole 2a for screwing the plug 4, a sleeve insertion hole 2b for inserting the sleeve 3, A piston insertion hole 2c for inserting the primary piston 7 and the secondary piston 8 and a small-diameter hole 2d for inserting the primary piston 7 are formed. The large-diameter female screw hole 2a has a female screw on the inner side of the opening at one end. Seal support members 11, 12 are mounted between the sleeve insertion hole 2 b and the piston insertion hole 2 c and on the other end opening side of the piston insertion hole 2 c, and the first cup seal 13 is attached to the seal support member 11. And the second cup seal 14, the third cup seal 15 is mounted on the seal support member 12, and the fourth cup seal 16 is fitted on the inner peripheral surface of the small diameter hole 2d at the tip. A piston guide 17 having a liquid passage 17a communicating with the discharge port P1 of the cylinder body 2 is mounted on the inner peripheral surface of the piston insertion hole 2c.

  As described above, the lid member 5 includes the bottomed cylindrical sleeve 3 and the plug 4 that prevents the sleeve 3 from coming off. The sleeve 3 has an inner diameter that allows the secondary piston 8 to enter. The sleeve 3 is inserted into the cylinder body 2 via seal rings 18 and 18 with the opening side facing the cylinder body 2. A piston guide 19 provided with 19a is mounted. The bottom wall of the sleeve 3 is formed with a cylindrical convex portion 3a projecting toward the one end opening side of the cylinder body 2 at the center, and the peripheral wall of the sleeve 3 communicates with the discharge port P2 of the cylinder body 2. A liquid passage 3b is formed. The plug 4 has a disc portion 4b having a male screw portion 4a on the outer periphery, and a hexagonal convex portion 4c protruding from the center of the outer surface of the disc portion 4b. Is formed with a housing recess 4 d of the protrusion 3 a formed in the sleeve 3. In the plug 4, the male screw portion 4 a is screwed into the large-diameter female screw hole 2 a of the cylinder body 2, and the disk portion 4 b is screwed inside the one end opening of the cylinder body 2. By this attachment, the convex portion 3a is accommodated in the accommodating concave portion 4d, the sleeve side end surface of the disc portion 4b and the bottom outer surface of the sleeve 3 come into contact with each other, and the sleeve 3 is prevented from coming off.

  An insertion hole 2e through which the positioning pin 20 is detachably inserted is formed in the cylinder radial direction on the one end opening side of the cylinder body 2 upper part. When the positioning pin 20 is inserted into the insertion hole 2e with the plug 4 screwed to the cylinder body 2 as described above, the tip of the positioning pin 20 protrudes into the cylinder body 2 and the disc portion 4b. It is arrange | positioned at the outer surface side. Thus, the cylinder hole 6 is formed in the cylinder body 2 by attaching the lid member 5 to the one end opening of the cylinder body 2.

  A primary piston 7 is disposed on the distal end side of the cylinder hole 6, and a secondary piston 8 is disposed on the bottom side. The primary piston 7 has a push rod receiving hole 7a on the tip side and a recess 7b on the bottom side of the cylinder hole, and the closing member 21 attached to the other end opening side of the cylinder body 2 and the third cup seal. 15 and the fourth cup seal 16 is liquid-tightly accommodated in the cylinder hole 6. In addition, a retainer 23 of a guide pin 22 that connects the primary piston 7 and the secondary piston 8 is accommodated in the recess 7b.

  The secondary piston 8 has a recess 8a on the bottom side of the cylinder hole and a recess 8b on the tip side. The secondary piston 8 is liquid-tightly received in the cylinder hole 6 via the first cup seal 13 and the second cup seal 14, and the recess 8b. The retainer 24 which fixed the front-end | tip head of the said guide pin 22 is attached to. A plurality of through holes 8c are formed in the peripheral wall on the cylinder hole bottom side of the secondary piston 8 provided with the recess 8b. The first hydraulic chamber 9 is defined between the concave portion 7 b of the primary piston 7 and the concave portion 8 b of the secondary piston 8, and the first return spring 25 is contracted between the retainers 23 and 24. . The second hydraulic chamber 10 is defined between the recess 8 a of the secondary piston 8 and the bottom wall of the sleeve 3, and the second return spring 26 is compressed between the recess 8 a and the bottom wall of the sleeve 3. Established.

  A pair of boss portions 2f, 2g are projected from the upper portion of the cylinder body 2, and a reservoir 27 is provided on the boss portions 2f, 2g via a grommet seal. A fluid passage hole 2h communicating with the bottom wall of the boss portion 2g formed on the other end opening side of the cylinder body 2 is formed in the peripheral wall on the other end opening side of the cylinder body 2, and the seal support 12 includes A communication hole 12a communicating with the liquid passage hole 2h and the inside of the cylinder hole 6 is formed, and the first hydraulic pressure chamber 9 includes a through hole 7c formed in the primary piston 7, the communication hole 12a and the liquid passage hole. It communicates with the reservoir 27 via 2h. Further, a liquid passage hole 2i communicating with the bottom wall of the boss portion 2f formed on the one end opening side of the cylinder body 2 is formed in the peripheral wall on the one end opening side of the cylinder body 2, and the seal support member 11 includes A communication hole 11a communicating with the liquid passage hole 2i and the inside of the cylinder hole 6 is formed, and the second hydraulic pressure chamber 10 includes a passage hole 8c formed in the secondary piston 8, the communication hole 11a, and the liquid passage hole 2i. And communicated with the reservoir 27 via

  The reservoir 27 has a shape that protrudes to the bottom side of the cylinder body 2 because of its attachment to the vehicle body. The lower half body 27a and the upper half body 27b made of synthetic resin are heat-sealed, Is a storage chamber. Boss portions 27c and 27d are formed in the lower half body 27a, and the boss portions 27c and 27d are inserted into the boss portions 2f and 2g of the cylinder body 2, and are installed so as to project between the boss portions 2f and 2g. The cylinder body 2 and the interior of the reservoir 27 are communicated with each other by screwing a piece 2j and a mounting piece 27e protruding between the boss portions 27c and 27d. Further, a leg piece 27f is provided at the bottom of the lower half 27a so as to extend to the vicinity of the head 20a, which is the outer end of the positioning pin 20. The upper half body 27b has a shape projecting to the bottom side of the cylinder body 2, and a hydraulic fluid injection port 27g is provided in a deviated position on the bottom side of the reservoir main body 2. The reservoir cap is connected to the hydraulic fluid injection port 27g. 28 is attached.

  When the hydraulic master cylinder 1 formed as described above is not braked, the primary piston 7 and the secondary piston 8 are disposed at the positions shown in FIG. 3 by the resilient force of the return springs 25 and 26, The first hydraulic chamber 9 and the second hydraulic chamber 10 communicate with the reservoir 27, respectively. When the push rod pushes the primary piston 7 during operation, the primary piston 7 advances the cylinder hole 6 toward the bottom while compressing the first return spring 25 in the first hydraulic pressure chamber 9, and at the same time, the secondary piston 8 Starts to advance toward the bottom of the cylinder hole. When the through hole 8c of the secondary piston 8 is closed by the first cup seal 13, the communication between the second hydraulic pressure chamber 10 and the reservoir 27 is blocked, thereby generating a hydraulic pressure in the second hydraulic pressure chamber 10. . The pressurized hydraulic fluid passes through the fluid passage 3b of the sleeve 3 and is supplied to one brake system via the discharge port P2 of the cylinder body 2.

  With this advance, when the set load of the second return spring 26 and the pressure of the second hydraulic pressure chamber 10 exceed the set load of the first return spring 25, the first hydraulic pressure chamber 9 is compressed and the first fluid is compressed. The hydraulic fluid generated in the pressure chamber 9 is supplied to the other brake system through the fluid passage 17a of the piston guide 17 and the discharge port P1 of the cylinder body 2. When the braking is released, the primary piston 7 and the secondary piston 8 are returned to their initial positions by the return springs 25 and 26.

  In the hydraulic master cylinder 1 of this embodiment, the cover member 5 is formed by the sleeve 3 and the plug 4, the sleeve 3 with the seal ring 18 attached is inserted into the cylinder body 2, and then the plug 4 is screwed into the cylinder body 2. Since the sleeve 3 is attached to prevent the sleeve 3 from coming off, the seal ring 18 can be prevented from being twisted and damaged when the lid member 5 is mounted. In addition, when the insertion position of the sleeve 3 into the cylinder body 2 is attached to one end opening side than the set position, or when the amount of screwing of the plug 4 is not sufficient, the tip of the positioning pin 20 is the disk portion. 4b, and cannot be inserted into the cylinder body 2. Therefore, it can be easily confirmed whether the sleeve 3 and the plug 4 are securely attached to the set position of the cylinder body 2. Sealing performance does not deteriorate. Further, the tip of the positioning pin 20 protrudes to the outer surface side of the disc portion 4b of the plug 4, so that the plug 4 can be prevented from coming off.

  Furthermore, by providing a leg piece 27f that extends to the vicinity of the head 20a of the positioning pin 20 at the bottom of the reservoir 27, the leg piece 27f can prevent the positioning pin 20 from coming off, and the plug 4 can be further tightened. The cylinder body 2 can be securely attached. In addition, the reservoir 27 has a shape protruding to the bottom side of the cylinder body 2, but when a load is applied to the hydraulic fluid inlet 27 g side of the reservoir 27, the leg piece 27 f is the head 20 a of the positioning pin 20. And the reservoir 27 can be supported.

  If the length of the positioning pin is set to a length where the lower end comes into contact with the hexagonal convex portion when the positioning pin is inserted into the insertion hole of the cylinder body, the head is attached to the outer end as in the above-described embodiment. Need not be provided.

  Further, the present invention is not limited to being applied to a plunger-type hydraulic master cylinder as in the above-described embodiment, but can be applied to any type of hydraulic master cylinder. Further, the lid member of the present invention is not particularly limited to one constituted by a sleeve and a plug, and any member may be used as long as it has a disk portion provided with a screw portion.

It is a principal part expanded sectional view of the hydraulic master cylinder for vehicles which shows the example of 1 form of this invention. It is II-II sectional drawing of FIG. It is a cross-sectional front view of the hydraulic master cylinder for vehicles similarly.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hydraulic master cylinder, 2 ... Cylinder main body, 2a ... Large diameter female screw hole, 2b ... Sleeve insertion hole, 2c ... Piston insertion hole, 2d ... Small end diameter hole, 2e ... Insertion hole, 2f, 2g ... Boss part, 2h , 2i ... liquid passage hole, 2j, 27e ... mounting piece, 3 ... sleeve, 3a ... convex part, 3b ... liquid passage, 4 ... plug, 4a ... male screw part, 4b ... disc part, 4c ... hexagonal convex part, 4d ... accommodating recess, 5 ... lid member, 6 ... cylinder hole, 7 ... primary piston, 7a ... accommodating hole, 7b, 8a, 8b ... recess, 7c, 8c ... through hole, 9 ... first hydraulic chamber, 10 ... first 2 fluid pressure chambers, 11, 12 ... seal support members, 11a, 12a ... communication holes, 13 ... first cup seal, 14 ... second cup seal, 15 ... third cup seal, 16 ... fourth cup seal, 17 ... Piston guide, 17a ... liquid passage, 18 ... seal ring, 19 Piston guide, 19a ... liquid passage, 20 ... positioning pin, 20a ... head, 21 ... closing member, 22 ... guide pin, 23, 24 ... retainer, 25 ... first return spring, 26 ... second return spring, 27 ... Reservoir, 27a ... lower half, 27b ... upper half, 27c, 27d ... boss, 27f ... leg piece, 27g ... hydraulic fluid inlet, 28 ... reservoir cap

Claims (3)

A lid member is attached to one end opening of the cylinder body with both ends open to form a bottomed cylinder hole, a piston is inserted into the cylinder hole, and a hydraulic chamber is defined between the piston and the lid member. In the vehicle hydraulic master cylinder formed, the lid member is screwed on a disk portion having a threaded portion on the outer periphery so that the outer surface is located inside the one end opening of the cylinder body, A positioning pin that protrudes into the cylinder body is detachably provided at one end opening side of the cylinder body, and the tip of the positioning pin is connected to the outer surface side of the disk part with the lid member screwed to the cylinder body. The hydraulic master cylinder for vehicles characterized by being located in. The lid member is composed of a cylindrical sleeve with a bottom and a plug that prevents the sleeve from coming off, and the sleeve has an inner diameter into which the piston can enter, and is open to the cylinder body via a seal ring. 2. The vehicle hydraulic master cylinder according to claim 1, wherein the plug is provided with the disc portion. The positioning pin is provided at a position facing a bottom wall of a reservoir attached to the top of the hydraulic master cylinder, and a leg piece extending to the vicinity of the outer end of the positioning pin is provided at the bottom of the reservoir. The hydraulic master cylinder for a vehicle according to claim 1, wherein the hydraulic master cylinder is for a vehicle.

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