JPH0811700A - Master cylinder - Google Patents

Abstract

PURPOSE:To provide a master cylinder capable of facilitating assembly, simplifying the construction of a retainer and holder, and eliminating a stopper positioning member. CONSTITUTION:A master cylinder is provided with a second piston 22 inserted closely into a hole of a cylinder body, a valve 3 opened and closed between a pressure chamber and a supplement chamber, a holder 6 fixed to an inner hole, a return spring 82 installed between a second piston 22 and a holder 6, and a rod 4 of which one end is connected to the valve 3. Also the rod 4 is inserted into an inserting hole 51 of a retainer 5 and a through-hole 61 of the holder 6, provided with a tapered surface at the top of it and a stopper extraction preventing flange part, and also provided with a stopper 7 by cam action. Then the through-hole 51 of the retainer 5 and the through-hole 61 of the holder 6 have a diameter capable of inserting the rod 4 and arranged on the same axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master cylinder used for a vehicle hydraulic brake device, a hydraulic clutch device, etc., and more particularly, it is provided with a valve for opening and closing a pressure chamber and a replenishing chamber. The present invention relates to a portless master cylinder.

[0002]

2. Description of the Related Art As a master cylinder used in a hydraulic brake device or a hydraulic clutch device, there is a portless type master cylinder (for example, Japanese Utility Model Laid-Open No. 3-47856).
This portless master cylinder is characterized by having a valve that opens and closes between the pressure chamber and the supply chamber. An example of a conventional portless master cylinder is shown in FIGS.
Will be explained.

As shown in FIG. 5, the master cylinder 90
Has a first piston 21 and a second piston 22 in the inner hole 12 of the cylinder body 11. With these two pistons 21 and 22, the inside of the inner hole 12 of the cylinder body 11 is divided into four chambers of a first replenishing chamber R1, a first pressure chamber R2, a second replenishing chamber R3, and a second pressure chamber R4. Has been done.

The second pressure chamber R4 communicates with the hydraulic line 18. Further, the second piston is provided with a communication hole 25 which communicates the second supply chamber R3 and the second pressure chamber R4, and the valve 3 which opens and closes the communication hole 25 is provided on the second pressure chamber R4 side.
Are provided (FIGS. 5 and 6).

At the front end of the second pressure chamber R4 (on the left side in FIG. 5),
The holder 60 is fixed. The valve 3 is connected to one end of a rod 40 provided between the holder 60 and the second piston 22, as shown in FIGS. And one end 42 of the rod to which the valve 3 is connected
0 is slidably supported by a retainer 50 in the second piston 22 via a spring 55.

A stopper portion 410 is provided at the tip of the rod 40. The stopper portion 410
Is inserted into the holder 60 and is in contact with the contact portion 650 (FIG. 7) of the holder 60. Further, a positioning member 70 for positioning the stopper portion 410 is fitted in the holder 60. This positioning member 70
Is the valve 3 inserted in the valve hole 23 of the second piston 22.
The rod 40 and the stopper portion 410 are provided to hold the valve hole 23, the retainer 50, and the holder 60 on the same axis.

Reference numerals 81 and 82 are return springs for urging the first and second pistons 21 and 22 to the non-actuated position (rightward in FIG. 5). Return spring 82
Has a slightly larger spring force than the return spring 81. Further, reference numerals 201, 203, 204 and 205 are piston cups for sealing. Other structures and effects are the same as those of the actual Kaihei 3-47856.

[0008]

However, the above-mentioned conventional master cylinder has the following problems. That is, the rod 40 has an integral structure in which the stopper portion 410 provided at the tip portion thereof is integrally fixed to the rod body. Therefore, the tip of the rod 40 is attached to the holder 60.
As shown in FIG. 7, the holder 6 is
No. 0 is provided with an assembly hole 620 having a hole diameter larger than the diameter 410a of the stopper portion 410. Also, in order to exert the stopper function after assembly, in the holder 60,
The contact portion 650 is provided below the assembly hole 620 (FIGS. 6 and 7).

Then, as shown in FIG. 7, in order to support only the rod 40 after the rod is inserted, the stopper portion 4
A central hole 610 having a hole diameter smaller than the diameter of 10 and slightly larger than the shaft diameter of the rod 40 is provided. This center hole 610 is
It is below the assembling hole 620.

On the other hand, as shown in FIGS. 6 and 8, in the same manner as the holder 60, the retainer 50 has a central hole 510 for supporting the rod 40 and a large-diameter assembly hole 520 in which the center is shifted upward. Is provided. The diameter of the assembly hole 520 is larger than the diameter 410a of the stopper portion 410 of the rod 40. The diameter of the center hole 510 is smaller than the diameter of the one end portion 420 of the rod 40.

When the rod 40 and the retainer 50 are assembled, as shown in FIGS.
The stopper 410 and the rod 40 are inserted by aligning the shaft center C1 with the center C2 (FIG. 8) of the assembly hole 520 of the retainer 50. Next, as shown in FIGS. 6 and 7, the axial center C1 of the rod 40 and the axial center C3 of the assembly hole 620 of the holder 60 are aligned, and the stopper portion 410 and the rod 40 are aligned.
Through. After that, the axial center C1 of the rod 40 and the axial centers C4, C5 of the central holes 510, 610 are aligned, and the rod 4
0 is supported in the central holes 510 and 610.

However, as described above, when the rod 40 is assembled to the retainer 50 and the holder 60, since the diameter of the stopper portion 410 is large, as shown in FIG.
A core shift process is required. Therefore, the assemblability is poor. Further, it is necessary to provide the retainer 50 and the holder 60 with the assembling holes and the center holes 510 and 610 for supporting, which complicates the structure. Further, by adopting such an assembling method, the axial displacement of the rod 40 after the assembling is prevented, and the stopper portion and the abutting portion of the holder are surely brought into contact with each other as shown in FIGS. As shown, a stopper positioning member 70 is required.

The present invention has been made in view of the above conventional problems, and a master cylinder that can be easily assembled, has a simple structure of a retainer and a holder, and does not require a stopper positioning member is provided. It is the one we are trying to provide.

[0014]

A master cylinder of the present invention is a piston that is fluid-tightly and axially slidably inserted into an inner hole of a cylinder body that contains hydraulic fluid through a piston cup. A valve that opens and closes between a pressure chamber that is always connected to the hydraulic line and a replenishment chamber that is always connected to the reservoir, a holder fixed to the rear part in the inner hole, A return spring is provided to urge the piston toward a non-operating position, and a rod is provided between the piston and the holder, one end of which is connected to the valve, and a tip of which is inserted into the holder. The rod is inserted into the through hole of the retainer provided on the piston side, and the tip thereof is inserted into the through hole of the holder, and the tip has a diameter larger than that of the through hole. The stopper is detachably attached, and the insertion hole of the retainer and the through hole of the holder have a hole diameter through which the rod can be inserted, and the insertion hole and the through hole are provided on the same axis. The master cylinder is characterized by being

What is most noticeable in the present invention is that the rod has a stopper removably attached to the tip thereof, and the through hole of the retainer and the through hole of the holder are holes through which the rod can be inserted. It has a diameter and the through hole and the through hole are provided on the same axis.

The rod is manufactured separately from a stopper which is detachably attached to the tip of the rod, and the valve is connected to one end of the stopper. Further, as the stopper, for example, a split ring type circular ring as shown in the embodiment, which can be extended and detached in the circumferential direction of the ring, may be used. Further, a bulged tip portion for preventing stopper coming off is provided at the tip portion of the rod.

Further, the insertion hole of the retainer is larger than the outer diameter of the rod so that the tip portion of the rod is inserted. The center of the insertion hole is located at the same position as the axial center position of the rod after assembly. Further, the through hole of the holder is larger than the outer diameter of the rod because the tip portion of the rod is inserted therethrough. The center of the through hole is located at the same position as the axial center position of the rod after assembly. Therefore, the axis of the through hole of the retainer and the axis of the through hole of the holder are provided on the same axis as the axis of the rod after being inserted through them.

[0018]

[Operation and effect] In the master cylinder of the present invention,
When assembling the piston to the holder, first attach the cup to the piston, then move the rod and retainer connecting the valve to the piston side on the same axis to install. Next, the return spring and holder are also moved to the piston side on the same axis and installed. Finally, attach a stopper to the tip of the rod inserted in the holder. This completes the assembly. In addition,
The above assembling order is an example, and the assembling order may be changed as long as the assembling direction and the positional relationship do not change.

As described above, according to the present invention, it is not necessary to change the axial center of each part during and after the assembling. Therefore, it can be assembled very easily.

Therefore, it is not necessary to adopt a complicated assembling method such as changing the axial center after assembling and after assembling as in the prior art. Further, unlike the conventional case, it is not necessary to separately provide an assembling hole and a supporting center hole, and the structure of the retainer and the holder is simple. Further, in the present invention, since the stopper having the outer diameter larger than the through hole of the holder is detachably provided, the stopper positioning member as in the conventional example is unnecessary. Further, since the stopper is provided detachably, it is easy to disassemble the rod and the retainer, the holder, the return spring, etc. during maintenance.

Therefore, according to the present invention, it is possible to provide a master cylinder which can be easily assembled, has a simple structure of a retainer and a holder, and does not require a stopper positioning member.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A master cylinder according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2, the master cylinder 10 of this example has a piston cup 2 inside an inner hole 12 of a cylinder body 11 for containing a hydraulic fluid.
It has a first piston 21 and a second piston 22 that are fitted in a liquid-tight manner and slidably in the axial direction via 01 to 205.

Further, a valve 3 provided in the second piston 22 for opening and closing between a pressure chamber R4 which is always in communication with the hydraulic pressure conduit 18 and a replenishment chamber R3 which is always in communication with a reservoir (not shown), A holder 6 fixed at the rear of the hole 12,
A return spring 82 is provided between the second piston 22 and the holder 6 to urge the piston 22 toward a non-operating position. Further, a rod 4 is provided between the second piston 22 and the holder 6, one end of which is connected to the valve 3 and the end of which is inserted into the holder 6.
Have.

The rod 4 is inserted into the through hole 51 of the retainer 5 provided on the second piston 22 side, and the tip thereof is inserted into the through hole 61 of the holder 6 so that the stopper 7 is attached to the tip. Is detachably attached.
Further, the insertion hole 51 of the retainer 5 and the through hole 61 of the holder 6 have a hole diameter through which the rod 4 can be inserted, and the insertion hole 51 and the through hole 61 are provided on the same axis. There is.

The rod 4 is manufactured at the tip thereof separately from the stopper 7 which is detachably mounted, and the valve 3 is connected to one end 42 thereof. Further, the stopper 7 is a split ring type as shown in FIG. 3, and has a fitting hole 71 for fitting the rod 40 in the center, and a slit communicating with the fitting hole 71 to the outside. It has a part 72.
The tip of the rod 4 is tapered and further provided with a bulging tip 41 having a stopper preventing flange.

Further, the second piston 22 is provided with a valve hole 23 for accommodating the valve 3 connected to the rod 4. The valve hole 23 communicates with the second replenishment chamber R3 through a communication hole 25 provided in the second piston 22. In addition, the valve 3 is inserted into the valve hole 23 through the communication hole 2
A spring 55 for urging 5 is stored,
The spring 55 is locked by the retainer 5.

Further, the retainer 5 is provided with an insertion hole 51 having a diameter larger than the outer diameter of the bulging tip 41 of the rod 4 and smaller than the outer diameter of the one end 42 to which the valve 3 is connected. There is. The center of the insertion hole 51 is located at the same position as the axial center position of the rod 4 after assembly. Further, as shown in FIG. 4, the holder 6 is provided with a through hole 61 having a diameter larger than the outer diameter of the bulging tip 41 of the rod 4 and smaller than the outer diameter of the stopper 7. The center 611 of the through hole 61 is located at the same position as the axial center position of the rod after assembly. Therefore, the insertion hole 51 of the retainer 5 and the through hole 61 of the holder 6 are provided on the same axis.
Others are the same as the above-mentioned conventional example.

Next, the function and effect of this example will be described. In the master cylinder 10 of this example, when assembling the second piston 22 to the holder 6 as shown in FIG.
As shown in FIG. 1, first, the second piston 22, the piston cup 205, the rod 4 connecting the valve 3, the spring 5
5, the retainer 5, the return spring 82, and the holder 6 are arranged in the order of assembly.

Then, the second piston 22 is assembled in sequence. That is, first, the piston cup 205 is attached to the second piston 22, and then the rod 4, the spring 55, and the retainer 5 to which the valve 3 is connected are moved to the piston side on the same axis and incorporated. Then, the return spring 82 and the holder 6 are also moved to the piston side on the same axis and assembled. Finally, with respect to the rod 4 inserted in the holder 6, in front of the bulging tip portion 41, by the cam action of the fitting hole 71 and the slit portion 72 of the stopper 7 and the bulging tip portion 41, Stopper 7
Mating. This completes the assembly.

Therefore, according to this example, it is not necessary to change the axial center of each component at the time of assembling and after the assembling as in the conventional example. Therefore, the assemblability can be facilitated. Further, in this example, the stopper 7 having an outer diameter larger than the through hole 61 of the holder 6 is attached to the rod 41.
The stopper positioning member unlike the conventional example is unnecessary because it is mounted after the insertion. Also, retainer 5 and holder 6
Have an insertion hole 51 for inserting a rod and a through hole 61, respectively, and do not require a separate center hole for rod support as in the conventional example. Therefore, the structure is simple.

[Brief description of drawings]

FIG. 1 is a development explanatory view of an assembly component of a master cylinder according to an embodiment.

FIG. 2 is a sectional view of a master cylinder according to an embodiment.

FIG. 3 is a front view of a stopper in the master cylinder according to the embodiment.

FIG. 4 is an explanatory diagram of a through hole of a holder in the master cylinder according to the embodiment.

FIG. 5 is a sectional view of a master cylinder according to a conventional example.

FIG. 6 is a development explanatory view of an assembly component of a master cylinder according to a conventional example.

FIG. 7 is an explanatory view of a holder mounting hole in a master cylinder according to a conventional example.

FIG. 8 is an explanatory diagram of retainer mounting holes in a master cylinder according to a conventional example.

[Explanation of symbols]

 10. . . Master cylinder, 11. . . Cylinder body, 22. . . Second piston, 3. . . Valve, 4. . . Rod, 5. . . Retainer, 6. . . Holder, 7. . . Stopper, 81, 82. . . Return spring,

Claims (1)

[Claims] 1. A piston, which is fluid-tightly and axially slidably fitted into an inner hole of a cylinder body containing a hydraulic fluid, through a piston cup, and is constantly provided in a hydraulic pressure pipe line provided in the piston. A valve that opens and closes between the pressure chamber that communicates with the replenishment chamber that always communicates with the reservoir, a holder fixed to the rear portion of the inner hole, and the piston that is provided between the piston and the holder. And a return spring that is biased toward the valve, a rod that is provided between the piston and the holder, has one end connected to the valve, and a tip that is inserted into the holder.
It is inserted into a through hole of a retainer provided on the piston side and its tip is inserted into the through hole of the holder, and a stopper having a diameter larger than the through hole is detachably attached to the tip, and A master cylinder characterized in that the through hole of the retainer and the through hole of the holder have a hole diameter through which the rod can be inserted, and the through hole and the through hole are provided on the same axis.