JPH0218856Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pilot type relief valve that controls the relief pressure of pressurized fluid supplied to fluid equipment.

<Prior Art> Generally, in various valve devices, a filter is incorporated inside to remove foreign matter from the pressure fluid to prevent malfunction of the valve device.

However, in the conventional valve device described above, the filter assembly structure is poor, and assembly and replacement of the filter is troublesome. Particularly in those such as pilot type relief valves that constantly flow a pilot flow rate, they are prone to clogging due to foreign objects, etc.
Therefore, the filter must be replaced frequently,
There was a drawback that time was wasted in replacing the filter.

<Purpose of the invention> The present invention was made in order to eliminate such drawbacks of the conventional method, and its purpose is to provide a pilot type relief valve that allows easy assembly and replacement of the filter. It is.

<Structure of the invention> The present invention has been made to achieve the above object. A cap is fitted to one end of the valve hole into which the main spool is slidably fitted, and the cap is used to separate foreign substances in the fluid. The present invention relates to a pilot type relief valve characterized in that it holds a filter to be removed.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. 1 and 2, reference numeral 10 indicates a valve body of the pilot type relief valve of the present invention, and this valve body 10 is composed of a body member 10a made of a non-magnetic material and a body member 10b made of a magnetic material. A balance valve 50 and a safety valve 70 are incorporated into the main body member 10a, and the main body member 10b is
A pilot valve 11 is incorporated in the.

First, the structure of the pilot valve 11 is such that a valve hole 12 is formed in the main body member 10b.
A control spool 13 made of a magnetic material is slidably inserted into the spool. Further, a valve sleeve 14 is fixed to the lower end of the main body member 10b. The outer periphery of the valve sleeve 14 is fitted and supported by the main body member 10a, and a valve seat member 15 is screwed into the inner hole so that its position can be adjusted. A relief passage 16 into which pressure fluid is introduced via a communication passage 40 is opened in the valve seat member 15, and a valve seat is formed at the opening end of the relief passage 16 to which a ball valve 17 abuts. Discharge path 3
A ball seat 18 that abuts the ball valve 17 is installed in a chamber 82 that communicates with the tank via the control spool 1.
A spring 19 for setting relief pressure is inserted between the spring 1 and the spring 3. However, due to the repulsive force of the lever spring 19, the ball valve 17 is moved to the valve seat member 15.
The control spool 13 is urged upward while making contact with the valve seat of the valve seat.

A sleeve 21 made of a non-magnetic material is fixed to the outer periphery of the main body member 10b of the valve body 10 by brazing or the like, and a sleeve-shaped yoke 22 made of a magnetic material is attached to the inner periphery of the sleeve 21. It is fitted and fixed at a position where it is joined to the upper surface of the main body member 10b via a spacer ring 23 made of a non-magnetic material. A mounting screw 24 is formed on the inner periphery of the yoke 22, and a yoke plug 25 made of a magnetic material that is screwed onto the mounting screw 24 is fitted and fixed to the yoke 22. A set screw 26 is screwed into the yoke plug 25 so that its position can be adjusted, and a balance spring 27 is interposed between the set screw 26 and the control spool 13. A solenoid 29 wound around a bobbin 28 made of a non-magnetic material is attached to the outer periphery of the sleeve 21.
A cover 30 surrounding the yoke plug 9 and having a lower end joined to the main body member 10b is fixed to the upper end of the yoke plug 25 with a nut 31.

Next, the structure of the balance valve 50 will be described. As shown in FIG. A pressure port 54 communicating with the pump and a discharge port 55 communicating with the tank are opened and spaced apart in the axial direction. Valve hole 5
A main spool 56 is slidably inserted into the main spool 56, and a through hole 58 with a throttle 57 is formed in the main spool 56.The first and second valve chambers 61, 62 on both sides of the main spool 56 They communicate with each other via 57. Main spool 56
A spring 59 is inserted between the main spool 56 and the cap 51, and the repulsive force of the spring 59 holds the main spool 56 at the sliding end that normally contacts the cap 52. In this state, the pressure port 54 and Communication with the discharge port 55 is cut off. However, the main spool 56 is the spring 5.
When the pressure port 54 and the discharge port 55 are slid against the repulsive force 9, the pressure port 54 and the discharge port 55 are brought into communication with each other.

The cap 51 is removably attached to one end of the valve hole 53 with a circlip 65, and has a bottomed cylindrical shape with a center hole 51a, and a spring 59 is seated on the bottom wall. This cap 51 has a large number of through holes 51b that penetrate from the center hole 51a toward the outer periphery.
The second valve chamber 62 and the communication passage 40 are communicated with each other via. Further, this cap 51 has an annular groove 51c formed on its outer periphery, and a cylindrical filter 66 is inserted into the through hole 51c.
It is attached so that b is closed. The filter 66 has a laminated structure in which the outside of a fine wire mesh is reinforced with a coarse wire mesh, and both ends of the filter 66 are soldered to the cap 51.

The safety valve 70 has a structure in which a valve hole 71 is formed in the main body member 10b, and a seat member 72 is screwed into the valve hole 71 so that its position can be adjusted. This sheet member 72 has an introduction path 73.
A through hole 74 is opened through which the pressure fluid of the second valve chamber 62 is introduced, and a ball valve 75 is installed at the open end of the through hole 74 .
A valve seat is formed that abuts the valve. A poppet valve 78 that abuts the ball valve 75 is installed inside the valve hole 71 that communicates with the tank via the discharge passage 77, and a spring inserted between the poppet valve 78 and the bottom wall of the valve hole 71 79 brings the ball valve 75 into contact with the valve seat of the seat member 72.

In the leaf valve configured as described above, the pressure port 54
The pressure fluid supplied to the main spool 56 is introduced into the relief passage 16 of the valve seat member 15 via the throttle 57 in the main spool 56, the second valve chamber 62, and the communication passage 40. At this time, a constant current is applied to the solenoid 29, and as a result, the cover 30 and the main body member 1
0b, a magnetic flux is formed through the control spool 13, the yoke 22, the yoke plug 25, and the cover 30, and an upward absorption force is applied to the control spool 13 in accordance with the applied current. Therefore, control spool 1
3 is the suction force of the yoke 22 and the spring 1
9. The spring 27 is located in a balanced position, and the ball valve 17 is pushed upward by the fluid pressure of the pressure fluid introduced into the relief passage 16, and a certain minute distance is created between it and the valve seat of the valve seat member 15. A clearance is ensured so that a small amount of pressure fluid flows out of this clearance via the cap 51 into the tank. Therefore, a slight pressure difference occurs between the valve chambers 61 and 62 at both ends of the main spool 56, and the main spool 56 maintains the opening degrees of the pressure port 54 and the discharge port 55 at a constant level by the repulsive force of the spring 59.

After that, when the pressure in the first valve chamber 61 increases, the second valve chamber 62 and the relief passage 16
The internal pressure also increases. When this pressure rises above the relief pressure set by the spring 19, the ball valve 17 is opened wider against the spring 19, and the pressure fluid is discharged from the chamber 82 to the discharge passage 34.
It escapes to the tank side through. This relief effect causes a pressure drop in the pressure fluid passing through the throttle 57, which causes the first and second valve chambers 61,
62, resulting in the main spool 56 sliding against the spring 59;
The pressure port 54 and the discharge port 55 are communicated with each other, and a large amount of pressure fluid is discharged from the discharge port 55. By discharging this pressure fluid, the pressure in the first valve chamber 61 decreases, the pressures in the first and second valve chambers 61 and 62 are balanced, and the main spool 56 moves to its original position and returns to the first valve chamber. 61 and the discharge port 55 are cut off.

In the relief action of such a relief valve, a certain amount of fluid is always supplied to the valve portion of the pilot valve 11, but since the filter 66 is inserted in the supply passage, the pressure fluid in the pressure fluid is Foreign matter is completely removed by this filter 66,
There is no malfunction of the pilot valve 11 due to the intrusion of foreign matter.

Further, if the filter 66 becomes clogged due to long-term use, the filter 66 can be easily replaced by removing the filter 66 together with the cap 51 from the valve hole 53 and inserting a new filter 66.

In addition, even if you forget to replace the filter 66, the internal pressure in the second valve chamber 62 will rise above the set pressure set by the safety valve 70, and the ball valve 75 of this safety valve 70 will close to the seat member 72. As a result, the pressure fluid in the second valve chamber 62 flows through the inlet passage 73, the through hole 74, the valve hole 71, and the discharge passage 77.
The second valve chamber 62
Main spool 5 due to increase in internal pressure or associated
6 malfunction can be prevented.

<Effects of the invention> As described above, in the present invention, a cap is fitted to one end of the valve hole into which the main spool is slidably fitted, and a filter is held in this cap to separate and remove foreign matter in the fluid. Because the configuration is
This has the advantage that the filter can be easily assembled and replaced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view of the pilot type relief valve of the present invention, and FIG.
The figure is a sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view of Figure 2.
It is a sectional view taken along the line - in the figure. 10... Valve body, 13... Control spool, 15
... Valve seat member, 16 ... Relief passage, 17 ...
Ball valve, 19... Spring, 22... Yoke, 27... Spring, 29... Solenoid,
50...Balance valve, 51...Cap, 53...
... Valve hole, 54 ... Pressure port, 55 ... Discharge port, 56 ... Main spool, 66 ... Filter.

Claims (1)

[Scope of utility model registration request] A pilot type valve that controls the primary pressure by displacing the main spool within a valve hole formed in the valve body according to the pressure balance between the primary pressure from the pump and the pilot pressure controlled by the pilot valve. In the relief valve, a cap forming a valve chamber for introducing pilot pressure between the main spool and the main spool is removably attached to one end of the valve hole,
A pilot type relief valve characterized in that the cap holds a filter for removing foreign matter in the fluid flowing from the valve chamber to the pilot valve.