JPH0449418Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is formed separately from the directional control valve,
This invention relates to a pressure control valve that is used by being attached to the main body of a directional control valve.

[Conventional technology]

A conventional pressure control valve of this type is shown in FIG. This pressure control valve 1 has a through hole 4 that communicates with a low pressure tank passage 3 formed in a main body 2 of the directional control valve and a load passage where high pressure acts, and a valve seat-like seat on the edge of the opening. form 5,
The front end of the valve seat body 6 is pressed into contact with the seat 5 in an oil-tight manner, and a valve hole 7 that opens into the through hole 4 is bored in the front end surface of the valve seat body 6. A main valve 10 is accommodated in a valve chamber 9 formed following the valve hole 7 so as to move forward and backward toward the valve seat 8.
The main valve 10 is pressed by a valve spring 11 from behind the main valve 10 and is seated on a valve seat 8, and a valve chamber 9 communicates with the tank passage 3 via a passage 12.
Then, in order to press the tip of the valve seat body 6 into oil-tight pressure contact with the seat 5, a screw hole 14 is bored through the wall 13 of the tank passage 3 facing the seat 5 from inside to outside.
A male screw 15 is formed on the outer periphery of the valve seat body 6 slightly rearward from the tip thereof, and is screwed into the screw hole 14 so that the valve seat bodies 6 are screwed together. Therefore, when the valve seat body 6 is screwed in, its tip portion is seated on the seat 5. In the figure, 16 is a lock nut, 17 is a main body, 18 is an adjustment screw, 19 is a nut, and 20 is a cap nut. The adjustment screw 18 is used to adjust the rear end support position of the valve spring 11 to adjust the spring force that presses the main valve 10. Note that 21 is a communicating hole.

In this pressure control valve 1, the hydraulic pressure in the load passage of the switching valve acts on the front surface of the main valve 10 through the valve hole 7.
When the hydraulic pressure in the load passage overcomes the pressing force by the valve spring 11, the main valve 10 opens and the pressure oil in the load passage is released to the tank passage 3 through the valve chamber 9 and the passage 12.

[The problem that the idea aims to solve]

A conventional pressure control valve 1 has a valve seat body 6 with respect to a seat 5.
A screw hole 14 is provided in order to bring the front end into oil-tight pressure contact.
The male screw 15 is screwed together with the male screw 15, and the thrust is used to obtain a pressing force. For this reason, if the screwing direction along the screw hole 14 and the positional relationship and angle of the seat 5 do not match accurately, the front end of the valve seat body 6 and the seat 5 may not come into close contact with each other around the entire circumference, but may contact partially. This causes oil to leak from the load passage, which is the high pressure side, to the tank, which is the low pressure side. The machining accuracy must be extremely high in order to ensure close contact around the entire circumference, and it is extremely difficult to prevent oil from leaking in this area.

The object of this invention is to provide a pressure control valve as described above, in which the front end of the valve seat body and the seat 5 are in close contact with each other so that no oil leaks from this portion.

[Means to solve the problem]

This idea involves opening a hole in the tank passage of the directional control valve that leads to the load passage, forming a valve-seat-like seat on the edge of the opening, and pressing the front end into oil-tight contact with the seat. A valve seat body having a valve hole opening into the through hole is provided, and a main valve pressed from behind by a valve spring is provided on the valve seat formed at the rear end of the valve hole, and the main valve is pressed from behind by a valve spring. In the pressure control valve configured to open and close between the through hole and the tank passage by opening and closing the hole, the pressure control valve is formed in a cylindrical shape and penetrates the tank passage wall from the outside toward the opening. A main body having a fixed tip is provided, and a pressing spring is provided in the front end of the main body to accommodate the valve seat body so as to be movable back and forth with a small gap between the valve seat body and the outer periphery thereof, and to press the entire seat body from behind, The present invention is characterized in that a lid is provided which is coupled to the rear end of the main body, supports the rear end of the pressure spring, and supports the rear end of the valve spring in an adjustable manner.

[Effect]

In order to press the front end surface of the valve seat body into contact with the seat,
Since the configuration uses the pressing force of the pressing spring and provides a small gap between the outer periphery of the valve seat body and the main body, it is possible to press the valve seat body from the rear with the front end surface partially in contact with the seat. If pressure is applied, the front end surface will be displaced within a small gap so that it comes into contact with the seat around the entire circumference. Therefore, if the shape of the seat and the front end surface are such that they are in close contact with each other around the entire circumference, this state of close contact is automatically obtained.

〔Example〕

One embodiment of this invention will be described with reference to FIG. In the figure, 30 is a pressure control valve, 31 is a main body, 32 is a valve seat body, 33 is a pressing spring, 34 is a main valve, 35 is a valve spring, and 36 is a lid.

The main body 31 is formed into a cylindrical shape, has a slightly small diameter at the front end, and has a male thread 40 on its outer periphery. A small-diameter inner hole portion 4 that is fixed together and has a stepped inner hole slightly rearward than the front end.
It is formed in 2.

The valve seat body 32 has a generally cylindrical shape, has an outer diameter such that it can be inserted into the small-diameter inner hole 42 with a small gap 43 in between, and has a flange-shaped portion 44 that expands outward at the rear end.
The front end surface 45 is formed into a steeply tapered shape, and is formed so as to abut all around a valve seat-shaped seat 46 formed at the opening edge of the through hole 4 that opens into the tank passage 3. ing. Front end surface 45 of valve seat body 32
At the center of the valve hole 47 is a valve hole 47 that opens into the through hole 4. A valve seat 48 is formed at the rear end of the valve hole 37, and an inner hole following the valve seat 48 is formed into an enlarged valve chamber 49.
A passage 50 communicating between the inside and outside is bored in the front end of the valve chamber 49. This passage 50 connects the valve chamber 49 to the main body 3.
It communicates with the tank passage 3 via the front end inner hole 51 of 1.

The pressure spring 33 is a relatively strong coil spring,
It has a coil diameter corresponding to the flange-like portion 44, and is accommodated in the inner hole of the main body 31, with its front end abutting the flange-like portion 44 and its rear end abutting the front end of the lid 36 in a compressed state.

The main valve 34 is accommodated in a valve chamber 49 of the valve seat body 32 so as to be able to move forward and backward, and has a tapered portion 5 formed at the front end.
2 is formed to open and close a valve hole 47 having a valve seat 48.

The valve spring 35 is a coil spring and is similar to the pressure spring 33.
The front end is in contact with the main valve 34, and the rear end is in contact with the lid 36 in a compressed state.

The lid 36 oil-tightly closes the rear end of the inner hole of the main body 31 and supports the rear ends of the pressure spring 33 and the valve spring 35 . It is equipped with a spring receiver 53, an adjustment screw 54, and a lock nut 55.

In the pressure control valve 30 configured in this manner, the valve seat body 32 is pressed from behind by the pressure spring 33, and the front end surface 45 is pressed into contact with the seat 46. A small gap 4 is formed between the small diameter inner hole 42 of the main body 31 and the small diameter inner hole 42 of the main body 31.
It is in a state where it is located through 3. Therefore, for example, when the male screw 40 is screwed into the screw hole 41 during assembly, the front end surface 45 of the valve seat body 32 will be brought into contact with the seat 46.
Even if the tip surface 45 and the seat 46 are in contact with each other in a part of the circumferential direction at this time,
When the main body 31 is further rotated and moved forward, the pressing force by the pressing spring 33 increases, so that the front end surface 45
The valve seat body 32 is displaced using the contact position of the seat 46 as a fulcrum, and the front end surface 45 and the seat 46 are about to come into contact with each other around the entire circumference. The displacement of the valve seat body 32 at this time is calculated by the small gap 4
3 allows, the front end surface 45 and the seat 46 come into contact with each other around the entire circumference.

FIG. 3 shows another embodiment, in which the small gap 43 in the first embodiment is made as small as possible to the extent that the necessary displacement of the valve seat body 32 can be obtained. For example, the small gap 43a has a diameter difference of about 0.1 mm. It is as follows. For this reason, an axial groove 60 is provided on the outer periphery of the valve seat body 32 so as to sufficiently communicate the spring chamber with the tank passage 3 side. The rest is the same as the first embodiment,
Equivalent parts are indicated by the same drawing symbols.

According to this configuration, the valve seat body 3 is provided in the small diameter inner hole portion 42.
The rear part of the valve seat body 32 is maintained almost coaxially, and the amount of displacement when the tip of the valve seat body 32 comes into contact with the seat 46 during assembly is small, so the seat 46 is less likely to be damaged. It is advantageous.

[Effect of idea]

According to this invention, the main body is fixed to the tank passage wall and the valve seat body is pressed by a pressure spring so that its front end face is pressed against the seat, and there is a small gap between the valve seat body and the inner hole of the main body. Because we accommodated them by separating them,
The front end surface of the valve seat body can be brought into reliable, oil-tight pressure contact with the seat on the opening edge of the high-pressure side opening on the tank passage side, thereby allowing the high-pressure oil in the load passage to contact the seat. It is possible to obtain a pressure control valve that does not leak from between the valve seat bodies, and there is no need to make manufacturing tolerances very strict in manufacturing the valve, and the effect is that it can be manufactured easily.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of this invention.
FIG. 2 is a longitudinal sectional view showing one example of a conventional pressure control valve, and FIG. 3 is a longitudinal sectional view showing another embodiment of this invention. 30...Pressure control valve, 31...Main body, 32...
Valve seat body, 33...Press spring, 34...Main valve, 35
... Valve spring, 36 ... Lid, 43, 43a ... Small gap, 45 ... Front end surface, 46 ... Seat, 47 ... Valve hole, 48 ... Valve seat, 49 ... Valve chamber, 50 ... Passage, 53... Spring holder, 54... Adjustment screw.

Claims (1)

[Scope of Claim for Utility Model Registration] A through hole communicating with the load passage is opened in the tank passage of the directional control valve, a seat shaped like a valve seat is formed on the edge of the opening, and the front end is pressed into contact with the seat in an oil-tight manner. A valve seat body having a valve hole opened in the through hole is provided on the front end surface of the main valve, and a main valve pressed from behind by a valve spring is provided on the valve seat formed at the rear end of the valve hole. A pressure control valve configured to open and close between the through hole and the tank passage by a main valve opening and closing the valve hole, wherein the pressure control valve is formed in a cylindrical shape and penetrates the tank passage wall from the outside toward the opening. A main body with a tip fixed to the wall thereof is provided, and the valve seat body is accommodated in the front end of the main body so as to be movable forward and backward with a small gap between it and the outer periphery, and the valve seat body is pressed from behind. A pressure spring is provided,
A pressure control valve characterized in that a lid is provided which is coupled to the rear end of the main body, supports the rear end of the pressure spring, and supports the rear end of the valve spring in an adjustable manner.