JPH0828746A - Pilot pressure actuating directional control valve - Google Patents

Abstract

PURPOSE:To change the flow of pressure oil by reducing the length of a spring box and the length of an entire body and sliding a spool under pilot pressure. CONSTITUTION:A spring box 40 attached to a housing 20 has a joint attaching hole 41 for a pipeline and a spring attaching hole 42 provided with an eccentric large diameter hole 50 and a small diameter hole 51 and is provided with a large diameter hole 55 and a small diameter hole 56 which are eccentric so that the attaching part 53 of a joint 52 for a pipeline is not rotated. Then, the attaching part 53 is fitted and attached to the joint attaching hole 41 for the pipeline so as to prevent its looseness by a presser plate 60, and can be sealed thereto even when its fitting margin is shortened, so that the length of the spring box 40 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot pressure operated directional control valve which slides a spool by pilot pressure to switch the flow of pressure oil.

[0002]

2. Description of the Related Art As a pilot pressure operated directional control valve, one disclosed in Japanese Patent Laid-Open No. 3-172602 is known. That is, as shown in FIG. 1, the spool 3 is fitted into the spool hole 2 of the housing 1, a pair of spring boxes 4 is attached to the left and right of the housing 1, and the spool 3 is neutralized by the springs 5 provided in the spring box 4. The spool 3 is biased to a position to supply pilot pressure to the pressure receiving chamber 6 in the spring box 4.
To the first position and the second position by sliding the shaft into the spring 5, and the pump port 7 and the first and second actuator ports 8 and 9
It is known that the first and second tank ports 10 and 11 are connected and disconnected.

[0003]

In such a pilot pressure actuated directional control valve, a pilot pressure intake port 12 is formed in the spring box 4 for supplying pilot pressure to the pressure receiving chamber 6, and the pilot pressure intake port is formed. A pipe joint such as an elbow is screwed into the pipe 12. For example, as shown in FIG. 2, the pilot pressure intake 12 of the spring box 4 is a screw hole, and the screw portion 14 of the pipe joint 13 is screwed.

With this structure, the pipe joint 13 is firmly attached to the spring box 4, and the pilot pressure intake port 12 of the pipe joint 13 and the spring box 4 is provided in order to prevent oil leakage from the screwed portion. The length of screwing with and becomes longer, and the pilot pressure intake port 12 of the spring box 4, that is, the pipe joint 1
Since the portion where 3 is screwed is long, the length of the spring box 4 is long. For this reason, the length of the entire directional control valve becomes large, and the area (field) of the mounting location becomes large.

Further, when the pipe connecting portion 15 of the pipe joint 13 is not L-shaped in line with the screw portion 14, it is difficult to orient the pipe connecting portion 15 in a predetermined direction.
That is, when a plurality of pilot pressure operated directional control valves are overlapped with each other, if the pipe connection portions 15 are oriented in the same direction, the pilot pipes can be connected easily. When the screws are attached by screwing, the orientations of the pipe connection portions 15 may be uneven.

Therefore, an object of the present invention is to provide a pilot pressure operated directional control valve which can solve the above-mentioned problems.

[0007]

In the first pilot pressure actuated directional control valve of the present invention, a spool 22 is slidably fitted in a spool hole 21 of a housing 20, and the spool 22 is connected to a spring 48 and a pressure receiving chamber. In the pilot pressure actuated directional control valve that slides with the pilot pressure, the spring box 40 is attached to the end face of the housing 20 in the longitudinal direction of the spool, and the spring box 40 is attached to a pipe joint mounting hole in which a pipe joint 52 is attached. 41 and a spring 48 are housed to form a pressure receiving chamber, and a spring mounting hole 42 is formed. The piping joint mounting hole 41 has a large diameter hole 50 and a small diameter hole 51 that are eccentric from each other. 52 is provided with a pipe connecting portion 54 in a mounting portion 53 composed of a large diameter portion 55 and a small diameter portion 56 which are eccentric to each other, and the mounting portion 53 is fitted into the pipe joint mounting hole 41. While, its fitting portion is provided a sealing member to seal the pipe joint 52 and retained by retainer plates 60 bolted to the spring box 40 spring box 4
It is attached to 0. The second pilot pressure operated directional control valve of the present invention is provided with a spool hole 21 of the housing 20.
The spool 22 is slidably inserted into the
In the pilot pressure actuated directional control valve for sliding the spring with the pilot pressure in the pressure receiving chamber, the housing 2
The spring box 40 is attached to the end face of the spool in the longitudinal direction of 0, and the spring box 40 is provided with the pipe joint mounting hole 41 in which the pipe joint 52 is mounted and the spring mounting hole 42 in which the spring 48 is housed to form the pressure receiving chamber. It is assumed that the pipe joint mounting hole 41 has a polygonal shape, the pipe joint 52 has a polygonal mounting portion 53 provided with a pipe connecting portion 54, and the mounting portion 53 is the pipe joint mounting hole 41. And the retaining plate 60 bolted to the spring box 40 to prevent the pipe from slipping off, and sealing the space between the bottom of the pipe joint mounting hole 41 and the end face of the mounting portion 53 with a sealing material to form the pipe joint 52. It is attached to the spring box 40.

[0008]

[Operation] According to the first pilot pressure operated directional control valve, the fitting length between the piping joint mounting hole 41 of the spring box 40 and the mounting portion 53 of the piping joint 52 can be shortened to ensure reliable sealing. . Further, the pipe joint 52 can be prevented from coming off by the pressing plate 60, and the eccentric large diameter hole 50 and the small diameter hole 5
Since the large-diameter portion 55 and the small-diameter portion 56 that are eccentric to 1 are fitted to each other, the pipe joint 52 can be firmly attached without rotating the pipe joint 52. According to the second pilot pressure operated directional control valve, the fitting length between the pipe joint mounting hole 41 of the spring box 40 and the pipe joint 52 mounting portion 53 can be shortened to ensure reliable sealing. Further, the pipe joint 52 is pressed to hold the plate 60.
The polygonal mounting portion 53 is fitted into the polygonal pipe joint mounting hole 41, so that the pipe joint 52 does not rotate and the pipe joint 52 can be firmly mounted.

[0009]

[Example] As shown in FIG. 3, a spool 22 is fitted in a spool hole 21 of a housing 20, and a pump port 23, first and second load pressure detection ports 24 and 25, are inserted in the spool hole 21. First and second actuator port 2
6, 27, first and second tank ports 28, 29 are formed, and the spool 22 has first and second small diameter portions 30,
31 and the intermediate small diameter portion 32 are formed, and when the spool 22 is in the neutral position shown in FIG.
3 slides to the right in FIG. 3 to reach the first position, the pump port 23 communicates with the second load pressure detection port 25, the first load pressure detection port 24 communicates with the first actuator port 26, and The pressure oil flowing into the pump port 23 by connecting the actuator port 27 to the second tank port 29 is the first
The return oil from the actuator 33 flows into the actuator 33 through the actuator port 26, and the return oil from the actuator 33 flows out through the second actuator port 27 into the second tank port 29.

When the spool 22 is slid to the second position from the state of FIG. 3 to the second position, the pump port 23 communicates with the first load pressure detection port 24 and the second load pressure detection port 25 moves to the second actuator port. Pump port 2 communicating with 27
The pressure oil of No. 3 flows into the actuator 33, the first actuator port 26 communicates with the first tank port 28, and the return oil of the actuator 33 flows out to the first tank port 28. That is, the first load pressure detection port 24 and the second load pressure detection port 25 are in communication.

A first spring box 40 is attached to one end surface 20a of the housing 20 in the longitudinal direction of the spool, and the first spring box 40 has a pipe joint mounting hole 41 opened at one end surface 40a and the other end surface. Spring mounting hole 42 opened to 40b
And a hole 43 that communicates both the mounting holes, and a first spring receiver 44 and a second spring receiver 45 are provided in the spring mounting hole 42. The end surface 20a and the end surface of the spool 22 come into contact with each other, and
5 contacts the bottom wall 42a of the spring mounting hole 42 and the stepped portion 47 of the bolt 46 provided on the spool 22, and the first and second spring supports 4
A spring 48 is provided between 4 and 45 to hold the spool 22 in the neutral position, and the inside of the spring mounting hole 42 serves as a pressure receiving chamber 49.

As shown in FIGS. 3 and 4, the spring mounting hole 42 comprises a large diameter hole 50 and a small diameter hole 51.
0 and the small diameter hole 51 are eccentric, the large diameter hole 50 is opened to the one end face 40a of the first spring box 40, and the bottom portion of the small diameter hole 51 is opened to the spring mounting hole 42 by the hole 43.

As shown in FIG. 5, the pipe joint 52 has an L-shaped mounting portion 53 and a pipe connecting portion 54, and the mounting portion 5
3 comprises a large diameter portion 55 and a small diameter portion 56, and the large diameter portion 55
An annular groove 57 is formed on the outer peripheral surface of the small diameter portion 56 and is eccentric with respect to the large diameter portion 55.

As shown in FIGS. 3 and 4, the pipe joint 52 has a large diameter portion 55 and a small diameter portion 56 fitted into the large diameter hole 50 and the small diameter hole 51 of the first spring box 40, respectively. The O-ring 58, which is fitted to the spring box 40 so as not to rotate and is attached to the annular groove 57 of the large-diameter portion 55, crimps and seals the large-diameter hole 50. It is prevented from coming off by a holding plate 60 attached to the bolt 59.

Because of this, the fitting portion of the pipe joint 52 and the first spring box 40 is sealed by the O-ring 58, and the pipe joint 52 is prevented from coming off by the presser plate 60, so that a large eccentricity occurs. The pipe joint 52 is fixed so as not to rotate by the large diameter portion 55 and the small diameter portion 56 that are eccentric with the diameter hole 50 and the small diameter hole 51, and the orientation of the pipe connection portion 54 of the piping joint 52 is always constant.

A second spring box 61 is attached to the other end surface 20b of the housing 20 in the longitudinal direction of the spool, and this second spring box 61 has a pipe joint mounting hole 41 as well as the first spring box 40. The spring mounting hole 42 is provided, and the small diameter hole 51 of the pipe joint mounting hole 41 is directly opened to the spring mounting hole 42. No spring is provided in the spring mounting hole 42. That is, the spool 22 is held in the neutral position by the spring 48 provided in the first spring box 40, and the spool 22 slides leftward and rightward against the spring 48, so that the second spring box 61 is moved.
There is no spring inside. In addition, in the pipe joint mounting hole 41 of the second spring box 61, a pipe joint 52 is formed as described above.
Is installed.

Because of this, the length of the second spring box 61 is reduced by the spring storage space. The second
The first spring box 40 may be attached instead of the first spring box 61.

As shown in FIGS. 6 and 7, the pipe joint 52 may have a mounting portion 53 and a pipe connecting portion 54 aligned with each other.

As shown in FIGS. 8 and 9, the pipe joint mounting holes 41 of the first and second spring boxes 40, 61 may be polygonal, and the pipe joint 52 mounting portion 53 may be polygonal. . In this case, an O-ring 58 is mounted between the bottom of the pipe joint mounting hole 41 and the end surface of the mounting portion 53.

With this configuration, the direction of the pipe connecting portion 54 of the pipe joint 52 can be changed according to the polygonal shape. In this case, it is necessary to tighten the holding plate 60 with a strong force to crush the O-ring 58,
The bolt 59 for tightening the holding plate 60 does not protrude from the pipe joint 52, so there is no problem.

[0021]

According to the first aspect of the present invention, the fitting length between the piping joint mounting hole 41 of the spring box 40 and the mounting portion 53 of the piping joint 52 can be shortened for reliable sealing. Further, the pipe joint 52 can be prevented from coming off by the pressing plate 60, and since the large diameter portion 55 and the small diameter portion 56, which are eccentric to the eccentric large diameter hole 50 and the small diameter hole 51, are fitted, the piping joint 52 rotates. The pipe joint 52 can be firmly attached without doing so. Therefore, since the pipe joint mounting hole 41 of the spring box 40 can be made short, the length of the spring box 40 can be made short, and the length of the entire pilot pressure operated directional control valve can be made small to reduce the space. , The direction of the pipe connecting portion 54 of the L-shaped pipe joint 52 is always constant. According to claim 2, the spring box 40
Piping joint mounting hole 41 and mounting portion 53 of piping joint 52
The fitting length with and can be shortened for reliable sealing. Also,
The pipe joint 52 can be prevented from coming off by the pressing plate 60, and since the polygonal mounting portion 53 is fitted in the polygonal pipe joint mounting hole 41, the pipe joint 52 does not rotate and the pipe joint 52 does not rotate. Can be firmly attached. Therefore,
Since the piping joint mounting hole 41 of the spring box 40 can be made short, the length of the spring box 40 can be made short, the length of the pilot pressure operated directional control valve as a whole can be made small, and the space can be made small. The direction of the pipe connecting portion 54 of the V-shaped pipe joint 52 is always constant, and the direction can be changed.

[Brief description of drawings]

FIG. 1 is a sectional view of a conventional pilot pressure operated directional control valve.

FIG. 2 is a sectional view of a mounting portion of a conventional piping joint.

FIG. 3 is a sectional view of a pilot pressure operated directional control valve according to a first embodiment of the present invention.

FIG. 4 is a left side view of FIG.

FIG. 5 is a front view of a pipe joint.

FIG. 6 is a sectional view of a pilot pressure operated directional control valve showing a second embodiment of the present invention.

FIG. 7 is a front view of a pipe joint.

FIG. 8 is a sectional view of a pilot pressure operated directional control valve showing a third embodiment of the present invention.

9 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

20 ... Housing, 21 ... Spool hole, 22 ... Spool, 23 ... Pump port, 24 ... First load pressure detection port, 25 ... Second load pressure detection port, 26 ... First actuator port, 27 ... Second actuator port, 28
... 1st tank port, 29 ... 2nd tank port, 40 ...
1st spring box, 41 ... Piping joint mounting hole, 42 ... Spring mounting hole, 48 ... Spring, 50 ... Large diameter hole, 51 ... Small diameter hole, 52
... Piping joint, 53 ... Mounting part, 54 ... Piping mounting part, 55
… Large diameter part, 56… small diameter part.

Claims (2)

[Claims] 1. A pilot pressure operated directional control valve in which a spool 22 is slidably inserted in a spool hole 21 of a housing 20 and the spool 22 is slid by a pilot pressure in a spring 48 and a pressure receiving chamber. A spring box 40 is attached to the end face of the spool in the longitudinal direction of the spool, and the spring box 40 has a pipe joint mounting hole 41 in which a pipe joint 52 is mounted and a spring mounting hole 42 in which the spring 48 is housed to form a pressure receiving chamber. A large diameter hole 50 in which the pipe joint mounting holes 41 are eccentric to each other.
And a small diameter hole 51, a pipe joint 52, and a pipe connecting portion 54 provided on a mounting portion 53 composed of a large diameter portion 55 and a small diameter portion 56 that are eccentric to each other, and the mounting portion 53 is for piping. The spring box 4 is fitted into the joint mounting hole 41, and a sealing material is provided at the fitting portion for sealing.
A pilot pressure actuated directional control valve characterized in that a pipe joint 52 is attached to a spring box 40 with a retaining plate 60 bolted to 0 to prevent it from coming off. 2. A pilot pressure operated directional control valve in which a spool 22 is slidably fitted in a spool hole 21 of a housing 20 and the spool 22 is slid with a spring 48 and pilot pressure in a pressure receiving chamber. A spring box 40 is attached to the end face of the spool in the longitudinal direction of the spool, and the spring box 40 has a pipe joint mounting hole 41 in which a pipe joint 52 is mounted and a spring mounting hole 42 in which the spring 48 is housed to form a pressure receiving chamber. The pipe joint mounting hole 41 has a polygonal shape, the pipe joint 52 has a polygonal mounting portion 53 provided with a pipe connecting portion 54, and the mounting portion 53 is provided in the pipe joint mounting hole 41. The retainer plate 60 is fitted to the spring box 40 to prevent it from coming off, and a sealing material is provided between the bottom of the pipe joint mounting hole 41 and the end face of the mounting portion 53. Pilot pressure operated directional control valve, characterized in that the pipe joint 52 by Lumpur attached to the spring box 40.