JPH0541097Y2 - - Google Patents

Description

[Detailed Description of the Invention] a. Industrial Application Field The present invention relates to a tandem type master cylinder.

b. Prior Art FIG. 6 shows a conventionally employed master cylinder.

In this master cylinder 1, a cylinder housing 2 is composed of a body main body 3 and a cap 4. The body main body 3 has an opening 3a at one end.
A female thread 3b is formed on the inner peripheral surface of the opening 3a. On the other hand, a male screw 4a is formed on the outer peripheral surface of one end of the cap 4, and the male screw 4a is connected to the body 3 of the cap 4.
It is attached to the body main body 3 by screwing it into the female screw 3b of the body.

A piston guide 5 and packings 6 and 7 are disposed within the main body 3 of the cylinder housing 2, and a secondary piston 8 is inserted through the piston guide 5. The piston 8, piston guide 5, and gaskets 6 and 7 define two pressure chambers 9 and 10 within the cylinder housing 2.

Also, the cap 4 of this cylinder housing 2
Inside there are a piston guide 11 and a packing 1.
2 and 13 are disposed, and a sleeve 14 is disposed extending between the cap 4 and the main body 3. A primary piston 15 is inserted through the piston guide 11 and the sleeve 14.

The pressure chambers 9, 10 have two parts 16a,
16b and 17a, 17b are slidably coupled to each other in a non-separable manner, and a biasing means includes telescopic retainers 16, 17, and return springs 18, 19 disposed on these retainers 16, 17. These biasing means cause the pistons 8 and 15 to move into the pressure chambers 9 and 15, respectively.
10 is biased in the direction of expanding the volume.

In this master cylinder 1, in the non-operating state, the pressure chamber 9 has a passage 8a formed in the piston 8,
The pressure chamber 10 is connected to an oil reservoir 20 through a passage 5a bored in the piston guide 5 and a passage 2a bored in the cylinder housing 2, and a pressure chamber 10 is connected to a passage 15a bored in the piston 15 and a passage 2a bored in the piston guide 11. It communicates with an oil reservoir 20 through a passage 11a, a passage 21 formed between the cap 4 and the sleeve 14, and a passage 2b bored in the cylinder housing 2.

In such a master cylinder 1, in FIG. 6, when the primary piston 15 is moved to the left,
The communication between the pressure chamber 10 and the oil reservoir 20 is cut off, and then the pressure inside the pressure chamber 10 is increased, whereby the secondary piston 8 is also moved to the left, and the communication between the pressure chamber 9 and the oil reservoir 20 is cut off. Subsequently, the pressure within the pressure chamber 9 is increased. Therefore, the oil in the pressure chambers 10 and 9 is transferred to the port 10.
a, 9a to each wheel cylinder (not shown).

c Problems to be solved by the invention By the way, in such a master cylinder 1,
In order to take out the internal parts for maintenance etc., first remove the cap 4 from the main body 3, then take out the seal 13, piston guide 11, seal 12 and piston 15 together with the cap 4, and then remove the spring 19 together with the retainer 17. Then, the sleeve 14 is removed. Furthermore, in order to take out the internal parts, the gasket 7, piston guide 5, and gasket 6 are taken out together with the piston 8, and finally the spring 18 is taken out together with the retainer 16.

In addition, in order to replace or reassemble the internal parts, first assemble the packing 13, piston guide 11, packing 12, and sleeve 14 to the primary piston 15, attach them to the cap 4, and then attach the retainer 17. with spring 1
9 is loaded into the piston 4. On the other hand, the secondary piston 8 is equipped with a gasket 6, a piston guide 5, and a gasket 7, and the piston 8 is also loaded with a spring 18 together with a retainer 16. Then, this secondary piston 8 is loaded into the sleeve 14 attached to the cap 4, and then the cap 4 is inserted into the body body 3 together with the primary piston 15, and the cap 4 is screwed onto the body body 3 to complete the assembly work. complete.

As described above, in the conventional tandem type master cylinder 1, the disassembly and assembly work for maintenance etc. is extremely complicated.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tandem master cylinder whose internal parts can be easily disassembled and assembled.

d Means for Solving the Problems The tandem type master cylinder of the present invention has a tandem type master cylinder in which a primary piston and a secondary piston are connected in series with a telescoping type retainer with a biasing means provided with a spring. In the cylinder, one end of the retainer is fixed to the primary piston, a claw is formed at the other end of the retainer, a recess is formed at an end of the secondary piston, and the claw is engaged with the recess, A tandem type master cylinder, characterized in that the primary piston and the secondary piston are connected to each other.

e Function In the tandem master cylinder of the present invention, when disassembling the primary piston, the secondary pistons and their biasing means can be taken out at the same time, and when reassembling them, they can be assembled at the same time. .

f Embodiment FIG. 1 shows a tandem type master cylinder according to the present invention.

A cylinder housing 31 of this master cylinder 30 is composed of a main body 32 and a cap 33. The main body 32 has an opening 32a at one end. And this opening 32a
A female thread 32b is formed on the inner circumferential surface, and a cylinder portion 32c is formed further inward. On the other hand, a male thread 33 is formed on the outer circumferential surface of the cap 33, and the outer diameter of the tip portion 33b of the male thread 33a is slightly smaller than the inner diameter of the cylinder portion 32c of the body main body 32.

And, this cap 33 has its tip 33
By fitting the O-ring 34 to b, screwing the male screw 33a into the female screw 32b of the body main body 32, and screwing the cap 33, the body main body 3
It is attached to 2. Then, the O-ring 34 comes into contact with the cylinder portion 32c of the body main body 32, slides on the cylinder portion 32c as the cap 33 spirals, and guides the cap 33.

Furthermore, as shown in FIGS. 3 and 4, this cap 33 has six grooves 33c formed at equal intervals in the axial direction on its inner peripheral surface, and with a center angle θ. A circumferential annular groove 33d is formed at the tip.

On the other hand, the sleeve 3 installed inside the cap 33
5 is made of synthetic resin and is obtained by molding in which the mold is cut in the axial direction. This sleeve 35, as shown in FIGS. 2 and 3,
It has seven protrusions 35a on the outer periphery of the intermediate portion. Five of the seven protrusions 35a are arranged at equal intervals with the same center angle θ as the groove 33c of the cap 33, and the other two have a different center angle θ/2.
It is located with. The protrusion 35a is formed by undercut molding.
This molding is done while the synthetic resin is not fully cured.
The mold is cut by bending the protrusion 35a.

This sleeve 35 has seven protrusions 35.
Five of the caps a are aligned with the grooved line 33c of the cap 33, and are pushed inward along the grooved line 33c. Then, the other protrusion 35a of the sleeve 35 is
It is press-fitted into the inner circumferential surface of the cap 33 and is formed into an annular groove 33d.
, and is loosely fitted into the groove 33d.

Note that the sleeve 35 has an annular recess 35b on the outer periphery of the tip thereof for accommodating the O-ring 36. As shown in FIG. 3, the recesses 35b are formed by protrusions 35c formed at approximately equal intervals in the circumferential direction.
and a flange portion 35d.
The protrusion 35c is also formed by undercut molding similarly to the protrusion 35a.

Further, a biasing means 38 is assembled to the primary piston 37. The biasing means 38 is composed of a return spring 39 and a retainer 40, and the retainer 40 is composed of a bolt 41 and a cylindrical body 42.
It consists of. The bolt 41 and the cylindrical body 42 are connected in a telescopic manner, that is, in a manner that they cannot be separated from each other and are slidable.
is screwed onto the piston 37. A flange 42a is formed at the free end of the cylinder 42, and the spring 39 is disposed between the flange 42a and the piston 37. Further, at the base of the flange 42a of the cylindrical body 42, as shown in FIG. 2, claws 42b are formed at three locations in the circumferential direction to protrude inwardly by cutting and raising them. On the other hand, a boss 43a is formed on the end surface of the secondary piston 43 on the side of the primary piston 37, and an annular recess 43b is formed on the circumferential surface of the boss 43a. Then, the claw 42b of the cylindrical body 42 is engaged with the recess 43b,
Thereby, the cylinder body 42 and the secondary piston 43
are integrated.

Further, a biasing means 44 is also assembled to the secondary piston 43. This biasing means 44 also
It is composed of a return spring 45 and a retainer 46, and the retainer 46 is composed of a bolt 47 and a cylindrical body 48. And this bolt 47
The cylinder body 48 and the cylinder body 48 are connected in a telescopic manner, and a bolt 47 is screwed into the piston 43.
A flange 48a is formed at the free end of the cylinder 48, and this flange 48a and the piston 4
The spring 45 is arranged between the three.

Therefore, the primary piston 37, the secondary piston 43, and the biasing means 38, 44 are
be integrated.

The primary piston 37 is guided within the cylinder housing 32 by a piston guide 49 and a sleeve 35, and the secondary piston 43 is guided by a piston guide 50. Further, gaskets 51 and 52 are provided on both end surfaces of the piston guide 49, thereby achieving a seal between the piston guide 49 and the piston 37, and gaskets 53 and 54 are provided on both end surfaces of the piston guide 50. This provides a seal between the piston guide 50 and the piston 43. Then, by the piston guide 50,
The primary pressure chamber 5 is located inside the cylinder housing 32.
5 and a secondary pressure chamber 56.

In the tandem master cylinder 30 configured in this way, the primary pressure chamber 5 is in the non-operating state.
5 is communicated with the oil reservoir 57 via a passage 37a formed in the piston 37, a passage 49a formed in the piston guide 49, a groove 33c formed in the cap 33, and a passage 32d formed in the body main body 32, Further, the secondary pressure chamber 56 is connected to the passage 43a bored in the piston 43 and the piston guide 5.
It communicates with an oil reservoir 57 through a passage 50a bored in the body 32 and a passage 32e bored in the body main body 32.

In this master cylinder 30, when the primary piston 37 moves to the left in FIG. 1, communication between the pressure chamber 55 and the oil reservoir 57 is cut off, and the pressure inside the pressure chamber 55 is increased. Almost simultaneously, the secondary piston 43 is also moved to the left, and the communication between the pressure chamber 56 and the oil reservoir 57 is cut off.
The pressure inside increases. Therefore, the pressure chamber 5
The oil in 5 and 56 is fed under pressure to each wheel cylinder (not shown) via ports 55a and 56a.

To disassemble such a master cylinder 30 for maintenance or the like, the cap 33 may be removed from the main body 32. Then, the sleeve 35 is removed together with the cap 33, and along with this, the piston guide 49 and the packings 51, 52 interposed between the sleeve 35 and the cap 33 are removed, and the packings 51, 52 are in pressure contact with each other. The primary piston 37 is also taken out together with the secondary piston 43 and the biasing means 44. Furthermore, along with the secondary piston 43, there are also gaskets 53, 54 that are in pressure contact with the piston 43, and gaskets 53, 54 that are in pressure contact with the piston 43.
The piston guide 50 interposed therebetween is also taken out.

That is, in the tandem type master cylinder described above, when the cap 33 is removed from the main body 32, all the parts inside the cylinder housing 31 are removed together with the cap 33.

Further, in order to reassemble the cap 33 after parts have been replaced, etc., the cap 33 to which each component has been assembled in advance may be screwed onto the body main body 32. Then, the piston guide 50, sleeve 35, and piston guide 49 are held between the body main body 32 and the cap 33, and are positioned.

In the above embodiment, the protrusion 35a of the sleeve 35 is engaged with the annular groove 33d, and the cap 3 is closed.
Although the sleeve 35 is integrated with the cap 33, the sleeve 35 does not necessarily have to be integrated with the cap 33. This is because this sleeve 35 is removed together with the piston guide 50 which is removed together with the cap 33.

In addition, in the tandem type master cylinder 30 of the above embodiment, the cylindrical body 42 of the retainer 40 has a claw 42b.
This pawl 42b is connected to the secondary piston 4.
Although the retainer 40 and the secondary piston 43 are connected by engaging with the recess 43b of No. 3, they can also be connected by the structure shown in FIG.

Tandem type master cylinder 60 shown in FIG.
Here, one end 63 of the spring 63 is attached to the end of the secondary piston 61 on the primary piston 62 side.
A recess 61a is formed for accommodating the recess 6a.
An annular groove 61b is formed in the inner peripheral wall of the spring 64, a flange 64a is formed at one end of the retainer 64, and the coil diameter of one end 63a of the spring 63 is made larger than that of the other portion 63b.
The retainer 64 is connected to the secondary piston 61 by housing the flange 64a in the recess 61a of the secondary piston 61, and then fitting one end 63a of the spring 63 into the annular groove 61b of the secondary piston 61. Ru. That is, the flange 64a of the retainer 64 is held between one end 63a of the spring 63 and the bottom surface of the recess 61a of the secondary piston 61.

Furthermore, in the embodiment shown in FIG.
The retainer 40 is connected to the piston 37 by screwing the bolt 41 into the primary piston 37, and their connection is shown in FIG. This can also be done with a different structure.

The connection structure between the retainer 64 and the primary piston 62 shown in FIG. 5 is almost the same as the connection structure between the retainer 64 and the secondary piston 61 shown in the same figure.

In the case of this master cylinder 60, the recess 62a formed in the primary piston 62 for accommodating the other end 63c of the spring 63 is deep.
A taper is attached to guide the other end 63c. The annular groove 62b has a concave portion 6
It is formed in contact with the bottom surface of 2a.

In this connection structure between the retainer 64 and the primary piston 62, the flange 64b formed at the other end of the retainer 64 is accommodated in the recess 62a of the primary piston 62, and then the large diameter portion of the other end 63c of the spring 63 is shaped into an annular shape. The retainer 64 is connected to the primary piston 62 by fitting into the groove 62b. That is, the flange 64b of the retainer 64 is held between the other end 63c of the spring 63 and the bottom surface of the recess 62a of the primary piston 62.

g Effect of the invention As mentioned above, in the tandem type master cylinder according to the invention, by removing the cap,
Most of the parts inside the cylinder housing can be taken out together, thus making disassembly work extremely easy.

In addition, in the master cylinder according to the present invention, since most of the parts are assembled into the cap in advance when reassembling the parts, it is easy to check the parts, and therefore it is possible to prevent incorrect assembly or omission of parts. This can be prevented, and assembly is also extremely easy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a tandem master cylinder according to the present invention, and FIG. 2 is a perspective view showing a portion of the primary retainer and secondary piston.
Fig. 3 is a partially sectional perspective view showing a part of the sleeve and cap, Fig. 4 is a cross-sectional view of the sleeve and a front view of the cap, and Fig. 5 is a diagram showing the tandem type master cylinder according to the present invention. FIG. 6 is a longitudinal sectional view showing another embodiment, and FIG. 6 is a longitudinal sectional view showing a conventional master cylinder. 30... Tandem type master cylinder, 31...
Cylinder housing, 32...Body main body, 32
a...Opening, 32b...Female thread, 33...Cap, 33a...Male thread, 35...Sleeve, 37
...Primary piston, 38...Biasing means, 3
9... Return spring, 40... Retainer,
41...Bolt, 42...Cylindrical body, 42a...Flange, 42b...Claw, 43...Secondary piston, 43a...Boss, 43b...Recess, 44...
...Biasing means, 45...Return spring, 46
... Retainer, 47 ... Bolt, 48 ... Cylindrical body, 48a ... Flange, 49, 50 ... Piston guide, 51, 52, 53, 54 ... Packing, 55, 56 ... Pressure chamber, 60 ... Tandem type master cylinder, 61...Secondary piston,
61a... recess, 61b... annular groove, 62... primary piston, 62a... recess, 62b...
Annular groove, 63... Spring, 63a... One end, 63c... Other end, 64... Retainer, 64
a, 64b...flange.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a tandem master cylinder in which a primary piston and a secondary piston are connected to each other with a telescopic retainer interposed with a biasing means equipped with a spring, One end is fixed to the primary piston, a claw is formed at the other end of the retainer, a recess is formed at the end of the secondary piston, and the claw is engaged with the recess to connect the primary piston and the secondary piston. A tandem type master cylinder characterized by having a piston connected to each other. (2) In a tandem master cylinder in which a primary piston and a secondary piston are connected to each other with a biasing means having a spring disposed in a telescopic retainer, an end portion of the secondary piston on the primary piston side , forming a recess for accommodating an end of the spring on the secondary piston side, and forming an annular groove on the inner circumferential wall of the recess, and forming a flange on the end of the retainer on the secondary piston side; The coil diameter of the secondary piston side end of the spring is made larger than other parts, the secondary piston side end of the spring is fitted into the annular groove of the secondary piston, and the secondary piston side flange of the retainer is fitted into the secondary piston side flange of the retainer. A tandem type master cylinder characterized in that it is sandwiched between a spring and the secondary piston. (3) A recess is formed in the primary piston to accommodate the primary end of the spring, an annular groove is formed in the inner peripheral wall of the recess, and a flange is formed in the primary piston end of the retainer. Further, the coil diameter of the primary piston side end of the spring is made larger than other parts, and the primary piston side end of the spring is fitted into the annular groove of the primary piston, so that the primary piston side end of the spring is fitted into the annular groove of the primary piston. The tandem type master cylinder according to claim 1 or 2, wherein the piston side flange is sandwiched between the spring and the primary piston.