JP2546122Y2 - Air modulator - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a technology that is effective when applied to a vehicle or the like equipped with an air over hydraulic brake system.

[Conventional technology]

The prior art of this type of air modulator includes
The one shown in the figure is known.

In the figure, the air modulator 51 includes a large-diameter air cylinder 52 formed of a bottomed cylindrical body, and a small-diameter hydraulic cylinder 53 mounted on the opening side of the air cylinder 52. I have. Inside the air cylinder 52, there is provided an air piston 54 slidable in the axial direction, and a piston rod 55 movable in the axial direction in conjunction with the air piston 54.

The inside of the air cylinder 52 is separated into a pneumatic chamber 56 and a back pressure chamber 57 by the air piston 54.
In a normal state, the rear end of the back pressure chamber 57 is urged toward the pneumatic chamber 56 by the tip of a return spring 58 locked by the hydraulic cylinder 53.

In this state, when predetermined compressed air is supplied from the port 60 of the air cylinder 52 into the pneumatic chamber 56, the internal pressure in the pneumatic chamber 56 is increased, and the air piston 54 is opposed to the return spring 58 by the piston rod. 55 is urged toward the hydraulic cylinder 53. By such an operation, the hydraulic piston 61 connected to the end of the piston rod 55 on the hydraulic cylinder side is moved to the hydraulic cylinder 53
The brake fluid inside is compressed to supply brake fluid pressure to the wheel cylinder W / C.

[Problems to be solved by the invention]

By the way, in the air modulator having the above function, an air breather for supplying air to a back pressure chamber 57 of the air cylinder 52 is provided together with an inlet 62 for supplying brake fluid to a hydraulic cylinder 53. 63 had to be provided.

This air breather 63 is a hydraulic cylinder
A hole 64 for communicating the outside and the back pressure chamber 57 is formed in the stepped portion of 53, a breather base 65 is attached so as to cover the hole 64, and around the air passage 66 of the breather base 65. The filter material 67 in which fine wire-shaped steel materials were assembled was filled, and this was fixed by the locking cap 68.

Such a filter material 67 captures foreign matter such as dust in the atmosphere and supplies only clean air into the back pressure chamber 57.

However, the structure of the air breather 63 has the following disadvantages.

First, the air breather structure has a large number of components and occupies a large proportion in the entire air modulator, and thus is disadvantageous for an air modulator having a limited mounting space on a vehicle.

Secondly, at the time of maintenance such as vehicle inspection, a predetermined water pressure is applied to each part of the air modulator 51 to perform a cleaning process. In the air breather 63 having the above structure, a filter material is used.
Water pressure is directly applied to 67, and moisture may enter the back pressure chamber 57 of the air cylinder 52, which may degrade the performance of the air modulator 51.

The present invention has been made in view of the above problems,
An object of the present invention is to provide an air modulator which has a small number of parts, is small in size, and is easy to maintain by housing an air breather in a hydraulic cylinder.

[Means for solving the problem]

In order to solve the above problem, the present invention divides the inside of a cylinder into a pneumatic chamber into which high pressure is introduced, and a back pressure chamber connected to the atmosphere, and provides an air modulator having a piston that slides in the cylinder. The configuration was as follows.

That is, a filter housing hole provided in the cylinder, a cylindrical filter breather housed in the filter housing hole and opened to the back pressure chamber, and a peripheral surface of the filter breather and the filter housing hole. An annular space provided therebetween, and an air passage connecting the annular space to the atmosphere, wherein when the atmosphere flows between the back pressure chamber and the air passage, a periphery of the filter breather is provided. It was structured to circulate through the surface and the annular space.

[Action]

According to the above-described means, a filter housing hole opened in the direction of the back pressure chamber in the cylinder is provided, and a filter breather is housed in the housing hole. Thus, the outer shape of the air modulator can be greatly reduced.

Moreover, an annular space is provided on the peripheral surface of the filter breather,
Since this is configured to be connected to the atmosphere through the air passage, sufficient air can be supplied to the back pressure chamber, and the operation response of the piston can be enhanced.

〔Example〕

 Hereinafter, the present invention will be described based on embodiments.

The air modulator 1 of the present invention is arranged in a vehicle brake system as shown in FIG.

That is, the air supply path 4 from the air tank 2 to the brake valve 3 is branched at an intermediate portion and connected to the antilock control valve 5. The antilock control valve 5 is connected to an air modulator 1a on the rear wheel side by an air supply path 6. On the other hand, the brake valve 3
The air supply path 7 is also connected to the air modulator 1a.

Further, the brake valve 3 is connected to the air modulator 1b on the front wheel side by another air supply path 8.

A speed sensor 10 is disposed on each of the front and rear wheels, detects rotation of each wheel, and outputs a detection signal to a central control unit.
Send to 11

The central control unit 11 controls the brake state of each wheel by operating the antilock control valve 5 and the air modulator 1 according to the state of the detection signal from the speed sensor 10, the brake valve 3, and the like.

The air modulator 1 used in this manner will be described in more detail with reference to FIGS.

FIG. 2 functionally shows the air modulator 1 of the present embodiment. That is, the air modulator 1 includes a housing 12, an air cylinder 13, and a hydraulic cylinder.
These components are integrally assembled by a long mounting bolt 15 as shown in FIG. That is, the air modulator 1 connects the air cylinder 13 to the housing 12 by fastening four mounting bolts 15 (only two bolts in the front direction are shown in FIG. 3).
And the hydraulic cylinder 14. More specifically, the housing 12 and the hydraulic cylinder 14
Bolt mounting flanges 16 and 17 are formed to project in the side direction of the mounting bolts.
Thus, the housing 12, the air cylinder 13, and the hydraulic cylinder 14 are integrally fixed.

Inside the housing 12, there are an inlet switching valve 18 for selectively introducing air from the air supply passages 6 and 7, a hold valve 20 composed of a normally open solenoid valve, and a normally closed solenoid valve. And a decay valve 21 configured. Each of these valves is communicated with a pneumatic chamber 22 of the air cylinder 13 by a passage 23. The decay valve 21 is
The inside of the pneumatic chamber 22 can be evacuated by communicating with an exhaust port 24 to the outside. In FIG. 1, only the sectional structure of the hold valve 20 is shown in the housing 12 portion.

The air cylinder 13 has an air piston 25 that can slide in the axial direction and a piston rod 26 that can move in the axial direction in conjunction with the air piston 25 inside the air cylinder 13.

In a normal state, the air piston 25 is urged in the housing direction by a return spring 27 whose one end is locked to the inner end surface of the hydraulic cylinder 14, and is formed between the air piston 25 and the housing surface. And acts to compress the compressed air chamber 22. Note that the air cylinder 13, the housing 12, and the hydraulic cylinder
A sealing material 28 such as an O-ring is interposed between the sealing member 14 and 14 to maintain an airtight state with the outside.

The hydraulic cylinder 14 has a hydraulic port 31 having a smaller diameter than the air cylinder 13, and a hydraulic piston 32 connected to an end of the piston rod 26 is provided in the hydraulic port 31. It is slidably mounted. An outlet 36 communicating with the wheel cylinder W / C is opened at the distal end side of the hydraulic port 31.

In addition, an inlet 37 is provided in the stepped portion of the hydraulic cylinder 14 to communicate with the hydraulic port 31 with an external reservoir (not shown). The brake fluid is supplied into the hydraulic port 31 through the inlet 37. A check valve 38 is fitted in the inlet 37 to prevent the backflow of the brake fluid from the hydraulic port 31 to the reservoir.

Next, the structure of the air breather which is a feature of the present embodiment will be described.

In this embodiment, the air breather has a filter breather 42 obtained by processing a foamed resin having a predetermined air permeability into a bottomed cylindrical shape as a main component, and the filter breather 42 has a filter housing hole of the hydraulic cylinder 14. Housed in 43. Here, the filter accommodation hole 43 is
The stepped portion of the hydraulic cylinder 14 is bored substantially in parallel with the piston rod 26, and is opened on the surface of the stepped portion on the side of the back pressure chamber 30.

The filter breather 42 is accommodated with the opening 42a arranged in a direction matching the opening of the filter accommodation hole 43, and the opening 42a is located behind the return spring 27 accommodated in the back pressure chamber 30. It is pressed at the end. Therefore, the filter breather 42 is urged toward the bottom of the filter housing hole 43 by the elasticity of the return spring 27, and is prevented from dropping to the back pressure chamber 30 side.

An annular space 40a is formed on the peripheral surface of the filter breather 42, and the annular space 40a is connected to an air passage 44 communicating with the atmosphere outside the cylinder.

A cap breather 45 is mounted at the tip of the air passage 44. As shown in FIG. 3, the cap breather 45 has a structure in which the distal end is closed and a plurality of intake ports 46 are provided on a peripheral surface thereof so that the air can be sucked through the intake ports 46. ing.

As described above, in this embodiment, since the filter breather 42 is housed in the filter housing hole 43 in the hydraulic cylinder 14, the outer shape of the air modulator 1 is smaller than that of the air breather 63 shown in FIG. Can be significantly reduced in size.

Moreover, an annular space 40 is formed on the peripheral surface of the filter breather 42.
Since a is configured so that the atmosphere communicates with the air passage 44 from the peripheral surface of the filter breather 42, the air circulation area can be increased between the filter breather 42 and the air passage 44, and a large amount of air flows to the back pressure chamber 30. Atmosphere can be supplied, and the operation response of the air piston 25 can be enhanced.

Further, in the present embodiment, only the four mounting bolts 15 are loosened for maintenance, and the housing 12, the air cylinder 1
3 and the hydraulic cylinder 14 can be separated, and the filter breather 42 can be easily replaced. Moreover, the presser of the filter breather 42 is
The filter breather is made using the elasticity of
No separate member is required to prevent the 42 from falling off, making maintenance easier.

Further, since the suction port 46 of the cap breather 45 is provided in a direction perpendicular to the air passage 44, even when the pressure of the washing water is applied to the cap breather 45 during maintenance, the washing water is supplied to the air passage 44. Filter breather 42 through 44
, And the intrusion of moisture into the back pressure chamber 30 is more reliably prevented.

[Effect of the invention]

According to the present invention, by housing the air breather in the hydraulic cylinder, it is possible to obtain an air modulator having a small number of parts and a small size, which is easy to maintain. In addition, an annular space is provided on the peripheral surface of the filter breather, and the atmosphere is communicated with the air passage from the peripheral surface of the filter breather. Can be supplied to the back pressure chamber, and the operation response of the air piston can be enhanced.

[Brief description of the drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a front sectional view showing an air modulator, FIG. 2 is a schematic diagram functionally showing the air modulator, and FIG. The figure is a front view of the air modulator, and FIG. 4 is a brake system diagram using the air modulator. FIG. 5 is a front sectional view showing a conventional air modulator. 1,1a, 1b …… Air modulator, 13 …… Air cylinder, 1
4 ... Hydraulic cylinder, 22 ... Pneumatic chamber, 25 ...
Air piston, 30 ... back pressure chamber, 40a ... annular space, 42 ...
… Filter breather, 43… filter housing hole, 44… air passage,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Takao Maki, inventor, 5-4-1, Higashi 5-chome, Hanyu City, Saitama Prefecture Akebono Brake Industry Co., Ltd. (56) References JP 61-101258 (JP, A) JP 639473 (JP, Y2) US Patent 3,976,536 (US, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A pneumatic chamber into which a high pressure is introduced in a cylinder;
In an air modulator having a piston which is divided into a back pressure chamber connected to the atmosphere and slides in a cylinder, a filter accommodation hole provided in the cylinder, and a filter accommodation hole accommodated in the filter accommodation hole, A cylindrical filter breather that is open to the outside, an annular space provided between the peripheral surface of the filter breather and the filter housing hole, and an air passage connecting the annular space to the atmosphere. An air modulator characterized in that when the atmosphere flows between the back pressure chamber and the air passage, the air flows through the peripheral surface of the filter breather and the annular space.