JPH0424221Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flow rate pressure control valve using a poppet valve.

[Conventional technology]

As a flow rate pressure control valve using a poppet valve, the applicant of the present invention filed an application and published the application in 1983.
There is one shown in Publication No. 150380.

This conventional flow pressure control valve is constructed as shown in FIG.
A poppet 2 is fitted to control the pressure oil flowing out from the next port ₁₁ to the secondary port ₁₂ . Of the ports 1 ₁ and 1 ₂ above, the primary port 1 ₁ is located at a position facing the pressure receiving surface provided on the outer periphery of the poppet 2, and the secondary port 1 ₂ is located toward the tip of the poppet 2. The poppet 2 is biased toward the secondary port 12 by a compression spring 4 housed in the spring chamber 1b, and the valve formed between the primary port ₁₁ and the secondary port ₁₂ is biased toward the secondary port ₁₂ . A tapered surface 2a is pressed against the seat 1c. There is also a pin hole 2 inside the poppet 2.
b is formed, and one end of the metering pin 3 is loosely inserted into this pin hole 2b. The other end of the metering pin 3 is a small diameter part 3a, and a stepped part 3d having a notch 3c is formed between it and the large diameter part 3b, and the tip of the small diameter part 3a is a spring chamber. It protrudes toward the end plate 13 that liquid-tightly closes the opening end surface of 1b, and its hemispherical tip abuts against the inner surface of the end plate 13 whose position is adjusted by the shim 14. Furthermore, a spring receiver 3e is formed on the tip side of the small diameter portion 3a, and one end of the compression spring 4 is supported by this spring receiver 3e.

Note that the portion between the small diameter portion 3a and the large diameter portion 3b of the metering pin 3 may be a tapered portion.

On the other hand, around the large diameter part 3b of the metering pin 3 inserted into the poppet 2, there is an annular port ₂₁ that communicates with the primary side port ₁₁ through a passage 2c, and on the end surface side of the metering pin 3, , a pressure chamber is provided which communicates with the primary port ₁₁ through a passage 2d, and the pressure introduced into the port ₂₁ flows into the spring chamber 1b through the narrow gap between the poppet 2 and the metering pin 3. In addition to being introduced into the spring chamber 1
The pressure in b and the pressure in the secondary port ₁₂ are transferred to the control port 5 formed in the main body 5a of the pilot valve 5 attached to the valve main body 1 through passages 1d and 1e formed in the valve main body 1. ₁ and spring chamber 5
e, 5g.

Two mutually parallel valve holes 5b and 5c are formed in the valve body 5a, and these valve holes 5
Among b and 5c, the valve hole 5b located on the valve body 1 side
A pressure compensation piston 7 is movably housed in the valve hole 5c, and a pilot piston 8 and a pilot poppet 9 are movably housed in the valve hole 5c. The pilot piston 8 is connected to the chamber 5 via the pilot port ₅₂ .
Operated by pilot pressure Pi introduced into d,
A pilot poppet 9 whose one end abuts against the pilot piston 8 is adapted to open and close.
The pilot poppet 9 is biased in the valve closing direction by a compression spring 10 housed in the spring chamber 5e. Further, in the pressure compensating piston 7, one of the ports 5 ₃ and 5 ₄ provided around the valve hole 5 b is communicated with the control port 5 ₁ , and the other port _{5 4 is} opened and closed by the pilot poppet 9 . _Five
The pressure compensating piston 7 is urged in the same direction as the pilot poppet 9 by a compression spring 11 housed in a spring chamber 5g. Further, a passage 7b communicating between the pressure chamber _5h and the port ₅₄ is provided in the large diameter portion 7a that opens and closes between the ports 53 and ₅₄ , and is designed to perform pressure compensation as described later. At the same time, the spring chambers 5e and 5g are communicated with the secondary port ₁₂ via the passage 1e.

Next, to explain the operation when flow rate is controlled by a meter-in circuit in which an actuator (not shown) is connected to the primary side port ₁₁ of the valve body 1, when the poppet 2 is in the closed state shown in FIG.
₁ and the inside of the spring chamber 1b communicate in a constricted state through a narrow gap between the large diameter portion 3b of the metering pin 3, which is loosely fitted into the valve hole 2b in the poppet 2, and the valve hole 2b. has been done.

Next, in this state, open chamber 5 from pilot port 5 ₂ .
When the pilot pressure Pi is introduced into the piston d, the pilot piston 8 operates against the compression spring 10 in response to this pilot pressure Pi, and the pilot poppet 9
to open. Since the pressure in the chamber 5h is reduced by opening the pilot poppet 9, the pressure compensating piston 7 moves toward the chamber 5h by the bias of the compression spring 11, and the ports 5 ₃ and 5 ₄ provided around the valve hole 5b are moved. communicate between. As a result, the pressure inside the spring chamber 1b
Since P ₂ flows through the pilot valve 5 to the secondary port 1 ₂ and decreases, the pressure Pi at the primary port 1 ₁ decreases.
A pressure difference sufficient to open the poppet ₂ is generated in the pressure P2 in the spring chamber 1b, and the poppet 2 is moved in the opening direction, causing pressure oil to flow from the primary port ₁₁ to the secondary port _12. leak. The degree of opening of the poppet 2 is determined by the amount of pressure _P2 inside the spring chamber 1b that escapes, and if the degree of opening of the poppet 2 becomes too large, the notch 3c of the metering pin 3 will cause a gap between the port ₂₁ and the spring chamber 1b. Since the primary side port ₁₁ and the spring chamber 1b are communicated with each other, there is no pressure difference between the two, and the poppet 2 is pushed back in the valve closing direction due to the pressure receiving area difference.

On the other hand, the pressure compensating piston 7 senses the pressure in the spring chamber 1b and adjusts the pressure oil flowing out from the port ₅₃ to the port ₅₅ by releasing the pilot poppet 9, so that the pressure P of the primary port ₁₁ is adjusted. Even if ₁ changes,
The flow rate flowing from the primary port 1 ₁ to the secondary port 1 ₂ can be compensated to be constant.

[Problem that the invention attempts to solve]

In the above conventional example, the variable throttle between the poppet 2 and the metering pin 3 was formed by a notch 3c cut on the outer periphery of the land portion of the metering pin 3, so that the metering pin 3 was fitted into the notch 3c. It is necessary to provide an annular port ₂₁ on the inner circumference of the poppet 2 that communicates with the primary port ₁₁ , but since this annular port 2 is machined on the inner surface of the small poppet 2, it is very difficult and costly to process. was expensive.

This idea was created in consideration of the above.
It is an object of the present invention to provide a flow rate pressure control valve in which the machining of a poppet and metering pin is facilitated and costs can be reduced.

[Means for solving problems]

In order to achieve the above object, the flow rate pressure control valve according to the present invention has a primary side port 1 connected to the load side on the inner peripheral surface and a secondary side port ₁ connected to the tank side at one end. ₂ , and a spring chamber 1b at the other end.
In the valve hole 1a of _the valve body ₁ having A poppet 20 is installed inside the poppet 20 with the spring 4 biased toward the secondary port 1 ₂ , and the poppet 20 has a pin hole 2 b opened toward the spring chamber 1 b facing the primary port 1 _{1 .} One end of the metering pin 30 supported on the spring chamber 1b side is fitted into this pin hole 2b with a slit in between, and the above-mentioned In the flow rate pressure control valve, the opening and closing of the poppet 20 is controlled by communicating the primary side port ₁₁ and the spring chamber 1b and controlling the pressure in the spring chamber 1b by the pilot valve 5.
The pin hole 2b of No. 0 and the primary port ₁₁ are communicated through a slit 21 provided in the axial direction in the poppet 20, and the land 31 of the metering pin 3 that fits into the poppet 20 is connected to the length of the slit 21. This land 31 is made shorter than the slit 2.
It is configured so that it faces 1.

[Effect]

In the above configuration, when the poppet 20 is in the closed state, the primary port ₁₁ and the spring chamber 1b are constricted by the slit 21 with a small flow path area regulated by the end of the land 31 of the metering pin 30. communicated in the state. By opening the pilot spool 5 in this state, a pressure difference sufficient to move the poppet 20 in the opening direction is created between the pressure _P1 of the primary side port ₁ and the pressure _P2 inside the spring chamber 1b, and the poppet 20 is opened. 20 in the opening direction, and pressure oil flows out from the primary port 1 ₁ to the secondary port 1 ₂ . At this time, as the poppet 20 moves in the opening direction, the opposing portion of the slit 21 and the land 31 moves toward the tip side of the poppet 20, so that the area of the slit 21 facing the spring chamber 1b becomes larger. , the cross-sectional area of the flow path communicating with the primary port ₁₁ and the spring chamber 1b becomes larger, thereby eliminating the pressure difference between the two, and the poppet valve 2 is pushed back in the valve closing direction to balance the forces. Pause in the ivy position.

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 and 2. In the description of this embodiment, members having the same functions as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

Poppet 2 fitted into valve hole 1a of valve body 1
0 is provided with an axial slit 21 that communicates the pin hole 2b provided in the poppet 20 with the primary port ₁₁ of the valve body 1. On the other hand, a metering pin 30 that fits into the pin hole 2b is provided with a land 31 that faces the slit 21.

The length of this land 31 is the length of the above slit 2.
It is shorter than the length of 1.

The axial positional relationship between the slit 21 and the land 31 is such that when the poppet 20 is pressed against the valve seat 1c by the spring 4, the end of the land 31 is slightly inserted into the slit 21 side, and the land 31 is inserted through the slit 21. The primary side port ₁₁ and the spring chamber 1b communicate with each other through a small cross-sectional area of the flow path, and the poppet 20 connects the spring 4 with the spring chamber 1b.
As the land 31 moves away from the valve seat 1c against the force, the land 31 moves toward the tip of the poppet 20, and the cross-sectional area of the flow path formed by the slit 21 increases. Also metering pin 3
Pressure chamber 2 ₂ in poppet 20 where the tips of 0 and 0 face each other
is constantly communicated with the primary port ₁₁ through the slit 21.

The slit 21 is formed by wire electrical discharge machining, laser, or other means. 2
3 is the hole at the starting end of the hole.

In the above configuration, when the poppet 20 is in the closed state, the primary port ₁₁ and the spring chamber 1b are constricted by the slit 21 with a small flow path area regulated by the end of the land 31 of the metering pin 30. It is connected in a state where it is connected. By opening the pilot spool 5 in this state, a pressure difference sufficient to move the poppet 20 in the opening direction is created between the pressure _P1 in the primary port ₁₁ and the pressure _P2 in the spring chamber 1b. The poppet 20 moves in the opening direction, and pressure oil flows out from the primary port 1 ₁ to the secondary port 1 ₂ , producing the same effect as in the conventional example described above.

At this time, as the poppet 20 moves in the opening direction, the opposing portion of the slit 21 and the land 31 moves toward the tip side of the poppet 20, so that the slit 2
The area facing the spring chamber 1b side of the poppet valve 2 becomes larger, and the cross-sectional area of the flow path communicating with the primary port ₁₁ and the spring chamber 1b becomes larger, thereby eliminating the pressure difference between the two. is pushed back in the valve closing direction and comes to rest at a position where the forces are balanced.

[Effect of idea]

According to the present invention, machining of the poppet 20 and metering pin 30 is facilitated, and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a plan view showing a poppet, and FIG. 3 is a sectional view showing a conventional example. 1 is the valve body, 1b is the spring chamber, 1 ₁ is the primary side port, 1 ₂ is the secondary side port, 20 is the poppet, 21
is the slit, 30 is the metering pin, and 31 is the land.

Claims (1)

[Scope of utility model registration request] Primary side port ₁ connected to the load side on the inner peripheral surface
The secondary port ₁₂ connected to the tank side is connected to the tank side at one end, and the outer pressure receiving surface is inserted into the valve hole 1a of the valve body 1 having the spring chamber 1b at the other end. The poppet 20 is installed internally so as to face the secondary port 1 ₂ and with its tip facing the secondary port 1 ₂ and biased toward the secondary port 1 ₂ by a spring 4 interposed in the spring chamber 1 b. This poppet 20 is provided with a pin hole 2b that is open to the spring chamber 1b side and communicates with the portion facing the primary side port ₁₁ , and a meter supported on the spring chamber 1b side is inserted into the pin hole 2b. One end side of the ring pin 30 is fitted with a slit left in place, and the primary side port ₁₁ and the spring chamber 1b are communicated through the slit created by the slit to pilot the pressure inside the spring chamber 1b. In the flow rate pressure control valve which controls the opening and closing of the poppet 20 by controlling the valve 5, the pin hole 2 of the poppet 20 is
b and the primary side port ₁₁ are communicated through a slit 21 provided in the axial direction in the poppet 20, and the land 3 of the metering pin 3 that fits into the poppet 20
1 is shorter than the length of the slit 21, and the land 31 is opposed to the slit 21.