JP2507228Y2 - Flow control valve capable of pressure compensation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a flow rate control valve having a pressure compensation function.

[Prior Art] A conventional flow rate adjusting valve with pressure compensation has a system in which the pressure before and after the throttle for flow rate setting is transmitted by each pilot port to move the spool. The spool for use is moved only by the influence of the pressure difference generated in the throttle for flow rate setting.

Therefore, even if the differential pressure between the inlet and the outlet of the valve becomes high and the throttle portion for pressure compensation is close to the fully closed state, the force acting on the spool is only the pressure difference of the flow rate setting throttle portion. The flow rate is stable without changing the pressure difference.

[Problems to be Solved by the Invention] As described above, the conventional flow control valve with pressure compensation can obtain a stable flow rate, but this control valve requires a plurality of long pilot ports in addition to the main port. Moreover, its structure is very complicated as seen in the flow control valve with pressure compensation in JIS-B8357, and it requires a lot of labor for port hole processing, etc., and it takes a lot of labor and cost to manufacture. .

In addition, it is necessary to prevent the spool from being affected by the outlet pressure. For example, a device proposed by the applicant of the present invention in February 1987 for "pressure compensating structure of flow rate adjusting valve" (Practical application Sho 62-0)
No. 25137; Japanese Utility Model Laid-Open No. 63-133670), a cylindrical ferrule for eliminating the influence of the outlet pressure is incorporated on the outer circumference of the spool.

As described above, the conventional flow rate adjusting valve of this type has a great cost problem due to its complicated structure.

By the way, even though it is a flow rate adjusting valve, there are many things that may have a slight change in flow rate depending on the application, that is,
Surprisingly, there are many applications in which changes in the flow rate within a certain allowable range do not pose a problem, and it is judged that the expensive adjustment valve with the accurate flow rate stability as described above is not necessary for such applications. Therefore, there is a demand for an inexpensive flow control valve suitable for this type of application.

The adjusting valve of the present invention was developed for the purpose of solving this problem, and it has a very simple structure to exert a pressure compensating function and adjust the flow rate within a certain allowable range. It is intended to provide a possible flow control valve.

[Means for Solving the Problems] As a result of various studies to achieve the above object, as a result of providing a throttle hole outlet in the spring chamber and moving the spool toward the outlet side, the spool end throttles the throttle hole outlet. If configured, the pressure difference between the inlet side and the outlet side acts on the area of the outlet of the throttle hole to generate a force in the direction of the outlet side, and this force affects the pressure difference of the flow rate setting throttle portion. However, they have found that the structure has a very simple structure and a pressure compensation function, and the flow rate can be adjusted within an appropriate allowable range.

That is, according to the present invention, a spool for pressure compensation is slidably provided in a valve body, and a spring chamber having a throttle hole outlet and an inlet side are partitioned by the spool. When the spool moves into the spring chamber through a section and is discharged through the throttle hole outlet, and the spool moves toward the outlet side against a spring provided in the spring chamber,
A flow control valve capable of pressure compensation, characterized in that a spool end portion is adapted to throttle the outlet of the throttle hole.

The present invention will be described with reference to the drawings by taking one embodiment.

 FIG. 1 is a sectional view showing an essential part of the regulating valve of the present invention.

As shown in this figure, in the present invention, the spool (2) is provided in the valve body (1) and the spring chamber (4) is provided through the partition wall (3) of the spool (2). is there.

A spring (5) is provided in the spring chamber (4) and abuts against the partition wall (3) of the spool (2) to press the spool (2). Also this spring chamber (4)
The outlet is a throttle hole outlet (6), and the outlet area of the throttle hole outlet (6) can be throttled by the spool end (7).

That is, the spool (2) slidably moves due to the pressure difference and the balance of the spring (5) to expand / contract the spring chamber (4), and at the same time, the spool end (7) expands / contracts the area of the throttle hole outlet (6). It is structured so that it can be done.

The inlet side (8) of the valve body (1) and the spring chamber (4) communicate with each other through, for example, a through hole (9) formed in the spool (2) and a port (10) communicating therewith, A flow rate setting throttle portion (11) is interposed in the middle of the port (10), and the flow rate can be set by the flow rate setting throttle valve (12).

That is, in the embodiment of FIG. 1, the fluid enters the spool (2) from the inlet side (8), passes through the through hole (9) of the spool (2) and the port (10), and then the flow rate setting throttle portion ( 11) into the spring chamber (4) and the throttle hole outlet (6)
Is discharged from.

In the drawing, the flow rate setting throttle (11) is shown as port (1
It is shown that the flow rate setting throttle (11) is provided in the partition wall (3) of the spool (2).
It may be provided in the.

Further, in the drawing, the spool (2) is provided with the through hole (9) so that the fluid can pass through the through hole (9), but the present invention is not limited to this, and for example, the spool (2). It is also possible to make the length short and provide a gap so that the fluid communicates with the port (10).

[Operation] The regulating valve of the present invention has the above-mentioned structure, and the operation principle thereof will be described below.

First, the fluid flowing in from the inlet side (8) generates a differential pressure in the flow rate setting throttle portion (11), and generates a thrust force that moves the spool (2) to the outlet side (13). When this thrust becomes larger than the drag force of the spring (5), the spool (2) moves toward the outlet side (13).

By this movement of the spool (2), the spool end (7)
Compresses the throttle hole outlet (6) of the spring chamber (4) to generate a pressure in the fluid flowing out, and the pressure in the spring chamber (4) rises. As a result, the movement of the spool (2) stops.

In this way, the spool (2) operates so that the drag force of the spring (5) and the thrust due to the pressure difference between the front and rear of the spool (2) are balanced, and the pressure difference of the flow rate setting throttle (11) is made constant. Therefore, the flow rate is kept stable, and the adjusting valve of the present invention can be used as a flow rate adjusting valve having a pressure compensation function.

However, the above action is obtained when the pressure difference (ΔP) between the inlet side (8) and the outlet side (13) is within the predetermined range, and the flow rate increases as the pressure difference (ΔP) increases. Will change.

That is, when the pressure difference (ΔP) gradually increases in the state where the spool (2) is actuated and the throttle hole outlet (6) is throttled, it acts on the outlet area of the throttle hole outlet (6) and causes the spool (2) to exit. Generates a force that directs it to the side (13), and eventually
This force moves the spool (2) against the spring (5), so that the spool end (7) gradually reduces the throttle hole outlet (6) to reduce the flow rate, and further the pressure difference (Δ
When P) becomes large, the spool end (7) is finally pressed against the throttle hole outlet (6), the outlet is closed and the flow stops.

 This is shown in the graph of FIG.

That is, FIG. 2 is a graph showing the relationship between the pressure difference between the inlet and the outlet and the flow rate in the regulating valve of the present invention.

In the graph of FIG. 2, the vertical axis represents the flow rate (Q) and the horizontal axis represents the pressure difference (ΔP).

As shown in this graph, when a pressure difference (ΔP) occurs, the flow rate (Q) suddenly increases at first, and the predetermined pressure difference (ΔP)
Then, the flow rate (Q) is stabilized and operates as a flow rate adjusting valve having the pressure compensation function as described above.

And as the pressure difference (ΔP) further increases,
Gradually, the flow rate (Q) continuously changes and decreases, and finally when the pressure difference (ΔP) reaches point K in the graph, the throttle hole outlet (6) is closed and the flow rate (Q) disappears. .

That is, the allowable range (s) of the flow rate change shown in the graph
When using this regulator inside the pressure difference (Δ
If P) is within the working pressure difference range (t) shown in the graph, it functions as a flow rate adjusting valve.

In other words, the force of the spring (5), the diameter of the spool (2), the diameter of the throttle hole outlet (6), etc. should be set so that the flow rate variation is within the allowable range in the working pressure difference range (t). Thus, if the throttle hole outlet (6) is appropriately reduced in size, it can be used as a flow rate adjusting valve with pressure compensation after limiting the range of operating pressure difference.

On the contrary, the adjusting valve of the present invention can adjust the flow rate (Q) by the pressure difference (ΔP) by utilizing the characteristic that the flow rate (Q) decreases when the pressure difference (ΔP) increases, and the pressure difference (ΔP) can be adjusted. It can also be used as a special valve in which the flow will stop if it becomes extremely large.

As described above, the regulating valve of the present invention is provided with the throttle hole outlet (6) in the spring chamber (4), and the throttle hole outlet (6) can be expanded and contracted by the spool end (7) which moves together with the spool (2). This is the most characteristic feature of the above, and the pressure difference (ΔP) between the inlet side and the outlet side is this throttle hole outlet (6).
The pressure compensation function works in the range where the pressure difference (ΔP) is small, and the flow rate adjustment is achieved. When the pressure difference (ΔP) gradually increases, the flow rate (Q) decreases and the end The flow stops at.

[Effects of the Invention] The effects of the present invention are listed below.

(A) Since there is no pilot port in the valve body, the labor for port processing is drastically reduced, and the labor and cost required for manufacturing are greatly reduced.

(B) Furthermore, the number of parts that make up this regulating valve is small,
It is easy to process and assemble, has a large economic effect, and can further reduce the price.

(C) In addition, since a ferrule on the outer circumference of the spool is not required,
The spool diameter can be increased, the responsiveness and operability are improved, and the adjustment valve can have high sensitivity.

(D) Since the structure is simple, the overall size can be reduced, and the applications are increased.

As described above, the present invention exerts various excellent effects, and exhibits extremely high usefulness as a flow rate adjusting valve for applications in which there is no problem even if the flow rate changes within a certain allowable range.

[Brief description of drawings]

FIG. 1 is a sectional view showing an essential part of the regulating valve of the present invention. FIG. 2 is a graph showing the relationship between the pressure difference between the inlet and the outlet and the flow rate in the regulating valve of the present invention. (1) …… Valve body, (2) …… Spool, (3)…
… Partition wall, (4) …… spring chamber, (5) …… spring, (6)
…… Throttle hole outlet, (7) …… Spool end, (8) ……
Entrance side, (9) …… through hole, (10) …… port, (11)…
… Flow rate setting throttle, (12) …… Flow rate setting throttle valve,
(13) …… Outlet side, ΔP …… pressure difference between (8) and (13), Q …… flow rate,

Claims (1)

(57) [Scope of utility model registration request] 1. A spool for pressure compensation is slidably provided in a valve body, and a spring chamber having a throttle hole outlet and an inlet side are partitioned by the spool, and a fluid enters from the inlet side to restrict flow rate. When the spool moves into the spring chamber through the portion and is discharged through the throttle hole outlet, and the spool moves toward the outlet side against the spring provided in the spring chamber, the spool end portion has the throttle hole. A flow control valve capable of pressure compensation, characterized in that the outlet is throttled.