JP2550912Y2 - Master cylinder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master cylinder which is used, for example, in a vehicle brake or clutch device and is called a center valve type.

[0002]

2. Description of the Related Art A master cylinder of this type includes an actual open cylinder 1.
There is one disclosed in JP-A-130867. this is,
A cylinder body having a cylinder hole formed therein, and a piston movably inserted into the cylinder hole to define a hydraulic chamber;
A through hole that radially penetrates a shaft portion of the piston that extends outward from the cylinder body, a valve hole formed in the piston by connecting the through hole to the hydraulic chamber, A valve body disposed so as to close the opening to the hydraulic chamber and a stem extending from the valve body through the valve hole to the through hole are fitted into the through hole so as to be able to contact the stem. A pin member movable in the through-hole in the axial direction of the piston, and an annular member formed with a built-in hole into which the pin member is inserted to support an end thereof and movable along the outer periphery of the shaft portion of the piston A cover fitted to the outer periphery of the annular member to prevent the pin member from being removed, and a valve attached to the cylinder body via the pin member and the stem by engagement with the annular member. A stopper for moving in a direction away from the opening; In which a spring urges said annular member on the stopper is provided.

[0003]

In this conventional master cylinder, it is possible to visually check whether or not the pin member is incorporated in a cover fitted to the outer periphery of the annular member to prevent the pin member from coming off. Although there is a hole, the cover
Is designed so that the annular member is fitted to the outer periphery of the piston, the pin member is inserted into the mounting hole and the through hole, and then fitted to the outer periphery of the annular member.

[0004] Therefore, if the pin member is displaced in the radial direction during assembly, the cover must be fitted while correcting the deviation, and the assemblability of the pin member to the annular member is poor. was there.

The present invention has been made to solve this problem, and provides a master cylinder capable of confirming whether or not a pin member has been incorporated from the outside of a cover and improving assemblability. The purpose is to:

[0006]

In order to achieve the above-mentioned object, a master cylinder according to the present invention is characterized in that the cover has a hole large enough to allow the pin member to be inserted therein, and the cover has a hole formed in the annular member. On the other hand, when positioned in the axial direction, the support hole is formed so as to be deviated from the mounting hole while leaving an opening in which the inside of the support hole can be viewed.

The mounting holes are formed in pairs in the radial direction of the annular member, and a plurality of the holes are provided so that the pin member does not penetrate the cover. It is characterized by having.

Further, the cover is positioned with respect to the annular member by receiving the urging force of the spring.

[0009]

In the master cylinder of the present invention described above, when the cover is fitted to the annular member so that the hole aligns with the assembly hole during assembly, the pin member is assembled from outside the cover through the hole. It can be fitted into the through hole and the through hole of the piston. After that, when the cover is deviated to the same position as the used state with respect to the annular member and positioned, the cover functions as a retaining member for the pin member, but does not cover the entire opening of the mounting hole. Can be visually confirmed through a hole in the cover.

Even if a pair of mounting holes are provided in the annular member, the cover and the annular member are provided by providing a plurality of holes for the cover so that the pin member does not penetrate the cover. While making it easy to perform circumferential alignment with
When the pin member is inserted, it can be prevented that the pin member penetrates the cover and shifts in the radial direction.

Further, since the cover is positioned with respect to the annular member by receiving the biasing force of the spring, the cover can be assembled after the pin member is assembled into the annular member without providing a separate positioning member. The above-mentioned deviation of the hole of the cover with respect to the mounting hole of the annular member can be maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a center valve type master cylinder embodying the present invention, showing a main part in cross section. In FIG. 1, reference numeral 1 denotes a cylinder body, in which a bottomed cylinder hole 2 having one end opened is formed,
On the outer peripheral portion, two connecting portions 51 of the hydraulic fluid reservoir 50 are provided.
Bosses 3A and 3B respectively connected to A and 51B are formed to protrude in the radial direction.

The cylinder hole 2 is a stepped hole whose opening 4 is formed to have a diameter larger than that of the other portion 5. Inside the cylinder hole 2, a sub piston 6 is formed at the bottom side (not shown) of the cylinder hole 2. A cup seal 7 is fitted to the end of the portion 4 side, and a head 8A of a main piston 8 is fitted with a cup seal 9 to the opening 4 side, and both are slidably inserted. The shaft 8B of the main piston 8 is fitted with the sealing device 10 fitted in the opening 4.
Slidably penetrates and protrudes out of the cylinder hole 2.

The sealing device 10 includes a guide member 13 disposed between an annular stopper 11 that engages with the step of the opening 4 and a retaining ring 12 that is fitted to the end on the opening 4 side. , An outer seal material 14 for sealing between the guide member 13 and the opening 4 and an inner seal material 15 (cup seal) for sealing between the guide member 13 and the shaft portion 8B of the main piston 8. The inner peripheral seal member 15 is fitted in an annular groove formed by the inner peripheral surface of the concave portion 13A formed in the guide member 13 and the shaft portion 8B. Material 15 and stopper 1
A retaining ring 16 is interposed between the inner seal member 15 and the inner seal member 15 to prevent the inner peripheral seal material 15 from coming out of the annular groove.

The slave piston 6 is urged toward the main piston 8 by a return spring (not shown) interposed between the bottom of the cylinder hole 2 and the slave piston 6 so as to be in contact with the bottom of the cylinder hole 2. A secondary hydraulic chamber (not shown) is defined therebetween, and a primary hydraulic chamber A is defined between the secondary hydraulic chamber and the main piston 8.

As shown in FIG. 2, the main piston 8 has a through hole 2 which penetrates in the radial direction near the head 8A of the shaft portion 8B.
0, and the cross-sectional shape of the through hole 20 is the shaft portion 8Bn.
o The head 8A is formed so as to be elongated when viewed in the axial direction.
Opens into the liquid supply chamber B defined between the stopper 11 and the liquid supply chamber B. The main piston 8 further includes a concave portion 21 formed in a head portion 8A opening to the main hydraulic pressure chamber A, and a bottom 21a of the concave portion 21.
The valve body 23 has a valve hole 22 having one end open to the other end and the other end opening to the through hole 20, and a valve body 23 capable of closing the opening of the valve hole 22 on the main hydraulic pressure chamber A side in the recess 21. It is urged by the spring 24 toward the through hole 20 and housed. From this valve body 23, an axial stem 25 that fits loosely into the valve hole 22 and projects into the through hole 20.
The end of the stem 25 on the side of the through hole 20 is
6 is in abutment engagement with the peripheral surface. The pin member 26 is a shaft member that is inserted into the through hole 20 while allowing a predetermined amount of movement in the axial direction of the shaft portion 8B, and both ends of the pin member 26 are slidably fitted to the main piston 8. Assembly hole 27 of annular member 27
a, 27b, and is held undetachably by the cover 28. A spring 29 is interposed between the cover 28 and the head 8A of the main piston 8, and the annular member 27, together with the cover 28, is sealed by the spring force of the spring 29.
The ring member 27 is urged toward the zero side, and the end surface of the annular member 27 on the sealing device 10 side is engaged with the stopper 11.

Between the sub piston 6 and the main piston 8,
The return spring 30 and the bolt 32 of the main piston 8 are housed. The return spring 30 has one end engaged with a flange 6 </ b> A provided at an end of the slave piston 6 on the opening 4 side, and a spring receiver 31 fitted to the tip of the head 8 </ b> A of the main piston 8.
The other end is engaged. The bolt 32 includes a head portion 32A having one end engaged with a side surface of the spring receiver 31 on the main piston 8 side, and a shaft member 32B extending through the center hole of the spring receiver 31 and extending to the slave piston 6 side. , This shaft member 32B
Is screwed into the sub piston 6, thereby connecting the sub piston 6 and the main piston 8. As a result, the slave piston 6 and the main piston 8 are urged in a direction to be separated from each other by the spring force of the return spring 30, and the maximum separation distance is regulated by the bolt 32.

The secondary hydraulic chamber and the main hydraulic chamber A have discharge ports 52A and 52B, respectively.
Communicates with the inside of the boss 3A through a through hole 53 formed in the wall of the cylinder body 1.

Here, FIG. 2 and FIG.
Reference numeral 6 denotes a structure assembled to the main piston 8 by a cover 28, an annular member 27 and a spring 29, which will be described in detail below with reference to both drawings.

In both figures, the cover 28 has a cylindrical shape whose diameter gradually decreases in the axial direction, and has a large-diameter cylindrical portion 28A, a medium-diameter cylindrical portion 28B, and a small-diameter cylindrical portion 28C shorter than the entire length of the annular member 27. Are formed continuously, and the peripheral wall of the large-diameter cylindrical portion 28A is provided with three holes 28a through which a pin member 26 that opens radially at a predetermined angle can be inserted.

The annular member 27 has a pair of mounting holes 27a and 27b penetrating in the radial direction, and the mounting hole 27a is formed in the large-diameter cylindrical portion 28A of the cover 28 by one hole of the cover 28. 28a is fitted with its axis aligned. At this time,
A radially outer opening of the mounting hole 27b of the annular member 27 is provided with a cover.
28 and is closed.

Then, the spring 29, the cover 28, and the annular member 27 are fitted to the outer periphery of the shaft 8B of the main piston 8 in this order,
The cover 28 is moved toward the head 8A so that the mounting hole 27a of the annular member and the hole 28a of the cover 28 are concentric.
Then, the annular member 27 and the cover 28 are moved toward the head 8A, and the mounting hole 27a of the annular member and the hole 2 of the cover 28 are moved.
8a is aligned with the through hole 20 of the main piston 8 in the radial direction. At this time, the main piston 8
Spring 29 interposed between the head 8A and the cover 28
Has one end engaged with the head 8A of the main piston 8, the other end engaged with the outer peripheral step portion 28b of the medium-diameter cylindrical portion 28B of the cover 28, and the small-diameter cylindrical portion 28C of the cover 28. The inner circumference of
The main piston 8 is supported by the shaft portion 8B so as to be slidable in the axial direction.

Next, a shaft-shaped pin member 26 having substantially the same length as the outer diameter of the annular member 27 is inserted in the order of the hole 28a, the mounting hole 27a, and the mounting hole 27b from outside the radius of the cover 28. Then, the cover 28 is abutted against a cover 28 covering the mounting hole 27b and is erected in the through-hole 20. The cover 28 is attached to the inner peripheral step 28c of the large-diameter cylindrical portion 28A. Part 8A
Move until it engages the side end face. Thereby, the cover
28 is deviated from the concentric position with the mounting hole 27a of the annular member 27, and the peripheral wall of the large-diameter cylindrical portion 28A of the cover 28 covers a part of the mounting hole 27a. 20
Both ends of the pin member 26 located inside are restricted from moving in the radial direction by the peripheral wall of the cover 28, and the pin member 26
Of the main piston 8 into the through hole 20 is completed.

The main piston 8 to which the pin member 26 is assembled and the valve body 23, the valve spring 24 and the like are separately assembled is slidably inserted into the cylinder hole 2 together with the slave piston 6. When the sealing device 10 is fitted in the opening 4, the annular member 27 and the cover 28 6 to the pin member 26
The valve body 23 is opened through the stem 25 that abuts and engages the peripheral surface of the valve body 23. As a result, the cover 28 receives the spring force of the spring 29, and the inner peripheral step 28 c engages with the annular member 27, and the hole 28 a is inserted into the mounting hole 27 a of the annular member 27.
Will be positioned at a position where the deviation occurs.

The master cylinder according to the embodiment of the present invention is:
The operation of the master cylinder will be briefly described below.

FIGS. 1 and 2 show a non-operating state of the master cylinder.
, The hydraulic fluid reservoir 50 communicates with the main hydraulic pressure chamber A through the through hole 53, the liquid supply chamber B, the through hole 20, the valve hole 22, and the recess 21.

In this state, when a brake pedal (not shown) is depressed, the main piston 8 moves toward the slave piston 6 against the spring force of the return spring 30. When the main piston 8 is moved toward the slave piston 6, the annular member 27
As a result, the pin member 2 is brought into contact with the stopper 11.
6 does not move together with the main piston 8, so that the stem 25
The valve element 23 engaged with the pin member 26 through the main piston 8 is moved toward the sealing device 10 with respect to the main piston 8, and the main piston 8 is moved until the valve element 23 is seated on the bottom 21 a of the recess 21. Is moved, the main hydraulic pressure chamber A is shut off from the hydraulic fluid reservoir 50.

Further, when the main piston 8 is moved toward the sub piston 6, a hydraulic pressure is generated in the main hydraulic chamber A, and the generated hydraulic pressure is supplied from a discharge port 52A opened to the main hydraulic chamber A to a pipe. To a brake device (not shown).

Further, with the above movement of the main piston 8, the slave piston 6 also moves in the same direction. Similarly, the slave hydraulic chamber (not shown) is cut off from the hydraulic fluid reservoir 50 side, and A hydraulic pressure is generated in the chamber, and the generated hydraulic pressure is transmitted through a pipe from a discharge port 52 </ b> B that opens to the slave hydraulic chamber, and is not shown.
Sent to the device.

According to this embodiment, the cover 28
Is positioned relative to the annular member 27 such that one of the plurality of holes 28a is concentric with the mounting hole 27a, and these two are aligned with the main piston 8 by one of the holes 28a, the mounting hole 27a. If it is fitted to the position aligned with the through hole 20,
The pin member can be inserted from the outside of the cover 28 in the order of the hole 28a and the mounting hole 27a of the annular member 27, so that the pin member can be inserted into the through hole 20 of the main piston 8 and the mounting hole 27a.
Since the end of the pin member 26 fitted into the member b can be brought into contact with the cover 28, the pin member 26 can be easily incorporated into the annular member 27 without causing radial displacement. After the pin member 26 is mounted on the annular member 27, the cover 28 is moved in a direction opposite to the head 8 </ b> A side of the main piston 8 so as to cover a part of the mounting hole 27 a of the annular member 27. Since the hole 28a is displaced, whether or not the pin member 26 is incorporated in the annular member 27 is visually checked via the hole 28a and the installation hole 27a while preventing the pin member 26 from coming off. Can be confirmed.

After the assembly of the main piston 8 to the master cylinder is completed, the annular member 27 and the cover 28 are moved by the spring force of the spring 29 interposed between the cover 28 and the main piston 8. Because it is urged toward the stopper 11, the cover
The cover 28 is attached to the mounting hole 27 of the annular member 27 without separately providing a member for positioning the annular member 28 with respect to the annular member 27.
The movement of the pin member 26 to be concentric with the hole 28a of the cover 28 is restricted, and the pin member 26 is prevented from coming out of the annular member 27 and the cover 28 to the radial outside.

Further, since the spring 29 is provided in series with the annular member 27 and the cover 28 in the axial direction, the spring 29 is provided in parallel with the outer periphery of the cover as in a conventional master cylinder. In order to prevent the spring 29 from contacting the inner wall of the cylinder hole 2,
It is not necessary to increase the diameter of the cylinder, which can contribute to downsizing of the master cylinder.

In this embodiment, the holes 28 of the cover 28 are provided.
The shape of a is not limited to this, but
When the eccentric member 8 is eccentric with respect to the mounting hole 27a of the annular member 27, a shape capable of covering a part of the mounting hole 27a of the annular member 27, for example, a long hole extending in the axial direction of the cover 28 It may be a long hole extending in the radial direction. The number of holes 28a provided in the cover 28 is not limited to three, but may be a single hole or a plurality of holes provided so as not to penetrate the mounting holes 27a and 27b of the annular member 27. There may be.

[0035]

As described in detail above, according to the master cylinder of the present invention, a hole through which a pin member can be inserted is
When the cover is positioned in the axial direction with respect to the annular member, the cover is formed so as to be deviated from the mounting hole except for an opening that allows the inside of the mounting hole to be seen. When fitting to the annular member so that the mounting holes are aligned,
When the pin member can be fitted into the mounting hole and the through hole of the piston through the hole from the outside of the cover, and after the pin member is assembled into the piston, the cover is displaced and positioned with respect to the annular member. The cover functions as a stopper for the pin member, and the presence or absence of the insertion of the pin member can be visually confirmed through the hole of the cover.

Further, even if a pair of mounting holes are provided in the annular member, the cover and the annular member can be formed by providing several holes for the cover so that the pin member does not penetrate the cover. It is possible to easily adjust the position of the pin member in the circumferential direction, and to prevent the pin member from penetrating the cover and displacing in the radial direction when the pin member is inserted. This makes it possible to improve the assemblability of the pin member into the through hole of the piston.

Further, the cover is positioned with respect to the annular member under the urging force of the spring, and after the pin member is assembled into the annular member, the cover hole is positioned with respect to the mounting hole of the annular member. Since the above deviation can be maintained, a cover is separately provided.
There is no need to provide a member for positioning, and an economical master cylinder with a simple structure can be obtained.

[Brief description of the drawings]

FIG. 1 is a partially sectional side view showing a mashita cylinder as one embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a main part in FIG.

FIG. 3 is a sectional view taken along line XX in FIG. 1;

[Description of Signs] 1 Cylinder main body 2 Cylinder hole 8 Main piston 8B Shaft 11 Stopper 20 Through hole 22 Valve hole 23 Valve body 25 Stem 26 Pin member 27 Annular member 27a, b Assembly hole 28 Cover 28a Hole 29 Spring

Claims (3)

(57) [Scope of request for utility model registration] A cylinder body having a cylinder hole;
A piston movably inserted into the cylinder hole to define a hydraulic chamber, a through hole radially passing through a shaft portion of the piston extending outwardly of the cylinder body, and a through hole extending through the hydraulic chamber. A valve hole formed in said piston in contact with
A valve body disposed so as to close the opening of the valve hole with respect to the hydraulic chamber, and a stem extending from the valve body to the through hole through the inside of the valve hole, are provided with the through hole so as to be able to contact the stem. A pin member fitted into the hole and movable in the axial direction of the piston in the through hole, and a built-in hole into which the pin member is inserted to support an end thereof is formed along the outer periphery of the shaft portion of the piston. A movable annular member, a cover fitted around the outer periphery of the annular member to prevent the pin member from being removed, and a cover attached to the cylinder body and engaged with the annular member through the pin member and the stem. A master cylinder having a stopper for moving the valve body in a direction away from the opening and a spring for urging the annular member toward the stopper. Hole of the The cover - is the set write hole leaving a visible opening formed so deviates from the set write holes formed by the master cylinder when positioned axially relative to the annular member. 2. The mounting hole is formed as a pair in the radial direction of the annular member, and a plurality of the holes are provided so that the pin member does not penetrate the cover. The master cylinder according to claim 1, wherein 3. The master cylinder according to claim 1, wherein the cover is positioned with respect to the annular member by receiving an urging force of the spring.