JPH047415Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention Industrial application field The present invention relates to a pressure compensation structure in a flow rate regulating valve.

Conventional technology and its problems Conventional pressure-compensated flow regulating valves have separate pressure compensation mechanisms and check mechanisms, and the pressure compensation mechanisms are mounted by screwing, press-fitting, or welding. Therefore, it is difficult to process and assemble, and the shape of the spool is complicated, making it difficult to obtain precision.

The first purpose of this invention is to solve the above problems, and by integrating the pressure compensation mechanism and the check mechanism, and by making these mechanisms cylindrical in shape, they can be fitted into one type to improve accuracy. The aim is to simplify processing and assembly.

The second purpose of the present invention is that when the aperture hole approaches full closure due to movement of the spool, the degree of opening changes rapidly, causing the spool to oscillate.
The aim is to eliminate the drawbacks such as the tendency for the fluid jet force just before closing to act on the spool and cause errors in pressure regulation.The spool's throttle structure has been improved to prevent oscillations and to improve the control characteristics of pressure regulation. This is what we are trying to secure.

B. Structure of the invention and its function The structure of the invention is such that a cylindrical spool that can slide on the inner protrusion of the cylindrical ferrule is provided in the cylindrical ring, and a check spring chamber is formed by a partition wall inside the cylindrical spool. The spring chamber for pressure compensation is partitioned,
The cylindrical ring is provided with an inlet that communicates with the flow rate setting throttle valve and an outlet that communicates with the outlet during control, and the cylindrical spool has an inlet/outlet hole that corresponds to the inlet and an outlet that communicates with the outlet during control. The gist of the present invention is a pressure compensation structure for a flow rate regulating valve, characterized in that a throttle hole corresponding to the outlet is opened, and as an improved embodiment, this throttle is provided near the throttle hole of the cylindrical spool. They devised a device with a small hole that opened in a fully closed position, or that overlapped the hole.

FIG. 1 is a sectional view of one embodiment of the present invention, showing the case of controlled flow.

As shown in this figure, a cylindrical ferrule 1 is fitted into the valve body A with a valve cover 2, and a cylindrical spool 3 that can slide on the inner protrusion of the cylindrical ferrule 1 is incorporated.

This cylindrical spool 3 has a partition wall 4,
A check spring chamber 6 having a check spring 5 and a pressure compensating spring chamber 8 having a pressure compensating spring 7 are separated by the partition wall 4.

In other words, the spool 3 is mounted with balance between the check spring 5 and the pressure compensating spring 7.

The valve body A also includes a port 10 communicating with the check spring chamber 6 and the flow rate setting throttle valve 9, a port 11 communicating with the pressure compensation spring chamber 8 and the outlet for control flow, and a port 11 communicating with the pressure compensation spring chamber 8 and the outlet for control flow. Three flow paths are provided, including a port 12 that communicates with the spring chamber 8.

Further, the cylindrical ferrule 1 is provided with a plurality of inflow ports 13 communicating with the ports 12 and a plurality of outlet ports 14 communicating with the ports 11 on its circumference.

Further, in the cylindrical spool 3, a plurality of inlet/outlet holes 15 corresponding to the inlet 13 and a plurality of throttle holes 16 corresponding to the outlet 14 are opened at respective circumferential positions.

In addition, it goes without saying that the valve cover 2 in FIG. 1 may be constructed of a joint.

To explain the case of controlled flow with reference to FIG. 1, fluid flowing into the port 10 passes through the flow rate setting throttle valve 9 and flows from the port 12 to the inlet 1 of the ferrule 1.
3 and enters the pressure compensating spring chamber 8 through the inlet/outlet hole 15 of the spool 3, and further this fluid flows from the throttle hole 16 of the spool 3, through the outlet 14 of the ferrule 1, to the port 11, and flows out from the outlet. That's what I do.

At this time, P ₁ - before and after the flow rate setting throttle valve 9.
A pressure difference of P ₂ results. This pressure difference is naturally the pressure difference between the front and back of the spool 3, that is, the check spring chamber 6 and the pressure compensation spring chamber 8, and this pressure difference causes the spool 3 to move to the right in FIG. 16 is constricted to reduce the flow, P ₁
The pressure difference between -P ₂ becomes smaller, and the spool 3 stops when the force on the right side of the spool 3 and the reaction force of the pressure compensating spring 7 are balanced. The pressure difference across the flow rate setting throttle valve 9 is determined by the force of the spring 7 at that time, and this state is maintained.

When this pressure difference increases and the flow rate tries to increase, the spool 3 moves to the right, and conversely, when the pressure difference decreases and the flow rate tries to decrease, the spool 3 moves to the left, keeping the flow rate constant. be.

In this way, during controlled flow, even if a force acts to change the determined pressure difference due to some factor, the position of the spool 3 is adjusted so as to keep the pressure difference constant. In other words, ports 10 and 11
Even if pressure fluctuations occur, the pressure difference remains constant.

Note that if it is desired to change the flow rate, it is done by changing the opening degree of the throttle valve 9, and it goes without saying that the flow rate changes in proportion to the opening area.

FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 when used in free flow.

When the present invention is used for free flow as shown in this figure, the flow direction is opposite to the above-mentioned controlled flow, and the port 11 side is the inlet and the port 10 side is the outlet. The fluid enters from the outlet 14 of the ferrule 1 and enters the throttle hole 1 of the spool 3.
6 and flows into the pressure compensation spring chamber 8 from the opening between the right side of the spool 3 and the ferrule 1, flows to the left in the figure due to fluid pressure, and directly enters the check spring chamber 6 from the entrance/exit hole 15 of the spool 3. and exits through port 10.

Note that the spool 3 moves to the left and begins to flow from the inlet/outlet hole 15, and its cracking pressure is determined by the check spring 5.

Furthermore, when there is no flow, the inlet/outlet hole 15 is closed due to the balance between the springs 5 and 7.

By the way, in the above structure, if there is a large change in the opening area of the throttle hole 16 of the spool 3 when it closes during controlled flow, the spool 3 will not stop at a balanced position due to the inertia of the spool itself and the inertia of the fluid, and will close. The phenomenon of opening too much and then opening too much due to the reaction is repeated, and the spool 3 becomes susceptible to oscillation.

In order to eliminate the above oscillation, the present inventors further investigated and devised the following embodiment.

FIG. 3 is a side view of a cylindrical spool in an embodiment of the present invention.

As shown in this figure, the throttle hole 16 of the cylindrical spool 3
By providing a small hole 17 that opens near the fully closed position of the aperture hole 16 or at a position that overlaps with this, the change in area at the moment when the aperture hole 16 is fully closed becomes gradual. This means that the spool 3 no longer oscillates.

Moreover, this small hole 17 also exhibits the following effects.

4 is a cross-sectional view of the cylindrical spool of FIG. 3; FIG.

As shown in this figure, when the opening of the throttle hole 16 is narrowed to a small degree, the fluid coming out from here is jetted out diagonally as shown by arrow A, and the component force of the jetting action is applied in the sliding direction of the spool 3. However, since it acts in the direction of closing the aperture as shown by arrow B in the figure, it has a negative effect on the control characteristics, but by providing the small hole 17, the aperture hole 1
When the spool 6 is narrowed by a small opening, most of the flow is ejected from the small hole 17, and the ejecting direction is either perpendicular to the spool 3, as shown in C in the figure, or from the small hole 17. If the angle is slightly narrowed, the angle is close to a right angle, and the adverse effect on the control characteristics of the spool 3 is extremely reduced.

C. Effects of the invention The invention is as described above, and its effects are listed below.

(a) The spool has a simple cylindrical shape, making it easy to process and has a highly accurate structure.

(b) Since the inner surface of the ferrule is cylindrical with both ends open, processing accuracy such as internal grinding is high, and the spool has excellent sliding performance.

(c) The outer surface of the ferrule is also cylindrical and can be mounted by pressing it with a lid or joint, so it can be screwed in or
Press-fitting, welding, etc. are unnecessary, and assembly is considerably simplified.

(d) The pressure compensation function and the check function are integrated, so that controlled flow and free flow can be used as desired, and the number of parts is reduced and the system is compact.

(e) By providing a small hole in the spool, the change in the area of the aperture hole becomes gradual, preventing oscillation and at the same time ensuring the control characteristics of the spool.

(f) It is a device whose basic elements are a ferrule, a spool, a pressure compensation spring, and a check spring, and it is a unit type that can be attached with a lid or joint, so it can be used with various flow rate adjustment devices. It is also reusable and very convenient.

As described above, the present invention has various excellent effects, and its usefulness is enormous.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, showing the case of controlled flow. FIG. 2 is a cross-sectional view of the embodiment of FIG. 1 when used in free flow.
FIG. 3 is a side view of the cylindrical spool in an embodiment of the present invention. 4 is a cross-sectional view of the cylindrical spool of FIG. 3; FIG. A... Valve body, 1... Cylindrical ring, 2... Valve lid, 3... Cylindrical spool, 4... Partition wall, 5...
...Check spring, 6...Check spring chamber, 7
...Pressure compensation spring, 8...Pressure compensation spring chamber,
9... Throttle valve for flow rate setting, 10, 11, 12...
Port, 13... Inlet, 14... Outlet, 15
...Entry/exit hole, 16...Aperture hole, 17...Small hole.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A cylindrical spool that can slide on the inner surface protrusion of the cylindrical ring is provided, and a check spring chamber and a pressure compensation spring are separated by a partition wall inside the cylindrical spool. The chamber is partitioned, and the cylindrical ring is provided with an inlet that communicates with the flow rate setting throttle valve and an outlet that communicates with the outlet during control, and the cylindrical spool is A pressure compensation structure for a flow rate regulating valve, characterized in that an inlet/outlet hole corresponding to the inlet and a throttle hole corresponding to the outlet are open. 2. The pressure compensation structure for a flow rate regulating valve according to claim 1, wherein the cylindrical spool has a small hole that opens at the fully closed position of the throttle hole or at a position that overlaps the throttle hole.