JPH0557444B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flow control valve, and in particular, the present invention relates to a flow rate control valve, and in particular, the present invention relates to a flow rate control valve, and in particular, to
The present invention relates to a flow rate control valve that can be optimally adopted as a main valve of various devices related to (Japanese Patent Application No. 61-31699, Japanese Patent Application No. 61-31700).

[Technology of prior application]

The applicant of this application has filed the above-mentioned earlier application, for example, Japanese Patent Application No. 61
In No.-11709, we proposed the device illustrated in FIG.

The device shown in FIG. 4 is a flow control device composed of a main valve 10, a first pilot valve 20, and a second pilot valve 30. The main components are a valve body 12 that is slidably inserted in the vertical direction (axial direction), and a spring 13 that biases the valve body 12 downward. The valve body 11 has a stepped inner hole in which small diameter holes 11b and 11c of the same diameter are coaxially provided on both upper and lower sides of a large diameter hole 11a, and a valve seat 11d is formed in a lower continuous step. It also has an annular groove 11e with which the inflow passage P1 communicates and an annular groove 11f with which the outflow passage P2 communicates.

The valve body 12 is slidably inserted into the large-diameter hole 11a in a pressure-balanced state (a state in which the pressure in the inflow path P1 acting on both the upper and lower ends is always canceled out) and is inserted into the tapered surface 12a1. a poppet valve portion 12a that seats on or leaves the valve seat 11d to cut off communication between the inflow path P1 and the outflow path P2, and the poppet valve portion 1
A connecting portion 12b is provided on the lower side of the connecting portion 2a and forms an oil chamber R1 that extends into the lower small diameter hole 11b and has an outflow passage P2 communicating with the small diameter hole 11b at all times. A lower small diameter hole 11 is provided.
It is integrally provided with a piston portion 12c that is slidably inserted into the small diameter hole 11b and forms an oil chamber R2 at the end of the small diameter hole 11b, and is provided above the poppet valve portion 12a and is slidable into the upper small diameter hole 11c. A small-diameter cylindrical portion 1 that is fitted into the small-diameter hole 11c and forms an oil chamber R3 at the end of the small-diameter hole 11c.
2d is integrally provided. However, oil chamber R2
is connected to the first pilot valve 20 and to the first switching valve 31 of the second pilot valve 30, and the oil chamber R3 is connected to the inlet passage P1 via the throttle 14.
It is connected to the second switching valve 32 of the second pilot valve 30.

The first pilot valve 20 is a pressure reducing valve 21 that reduces the pressure of the pressure oil introduced through the supply path P3 to a predetermined value.
The pressure reducing valve 21 passes through the throttle 22 to the oil chamber R.
The current control relief valve 23 proportionally controls the pilot pressure applied to the valve 2 in accordance with the current applied value. The second pilot valve 30 includes a first switching valve 31 whose operation is controlled by the pilot pressure applied to the oil chamber R2, and a second switching valve 32 whose operation is controlled by the first switching valve 31. It is structured as follows. When the pilot pressure applied from the oil chamber R2 through the passage P4 is less than the set value, the first switching valve 31 is in an inoperable state as shown in the figure and disconnects the supply path P3 from the second switching valve 32. When the pilot pressure is equal to or higher than the set value, it is activated and connects the supply path P3 to the second switching valve 32. The second switching valve 32 operates when connected to the supply path P3 by the first switching valve 31, and connects the passage P5 communicating with the oil chamber R3 and the return path P6 communicating with the reservoir T. When the switching valve 31 disconnects the supply path P3 and connects it to the return path P6, it becomes inactive as shown in the figure, cutting off communication between the path P5 communicating with the oil chamber R3 and the return path P6. .

In the flow control device configured as described above, the poppet valve portion 1 of the valve body 12 of the main valve 10
2a so that the pressure inside the inflow path P1 always cancels out, and the poppet valve part 12a and the piston part 12c act so that the pressure inside the outflow path P2 always cancels out, so the inflow path The valve body 12 of the main valve 10 is not pushed in the axial direction due to fluctuations in the pressure inside P1 or the pressure inside the outflow path P2.

Also, if the value of the current applied to the relief valve 23 in the first pilot valve 20 is less than the set value, the oil chamber R
If the pilot pressure applied to the second pilot valve 30 is less than the set value, the second pilot valve 30
The first switching valve 31 is in an inoperable state and disconnects the supply path P3 from the second switching valve 32;
The second switching valve 32 is in a non-operating state, cutting off communication between the oil chamber R3 and the return path P6. Therefore, the valve body 12 of the main valve 10 seats the poppet valve portion 12a on the valve seat 11d by the action of the spring 13 and the hydraulic pressure applied to the oil chamber R3 from the inflow path P1 through the throttle 14. Communication of the outflow path P2 is appropriately blocked.

Therefore, when the value of current applied to the relief valve 23 in the first pilot valve 20 is made equal to or more than the set value and the pilot pressure given to the oil chamber R2 is made equal to or more than the set value, the first switching valve 31 in the second pilot valve 30 becomes more than the set value. The second switching valve 32 operates to connect the supply path P3 to the second switching valve 32, and the second switching valve 32 operates to connect the supply path P3 to the second switching valve 32.
3 is communicated with the return path P6. For this reason, oil chamber R
3 becomes almost zero, and the valve body 12 of the main valve 10
is maintained at a position where the pressing force due to the pilot pressure in the oil chamber R2 (set to a certain value higher than the set value by the first pilot valve 20) and the acting force of the spring 13 are balanced, and the inflow path P1 Outflow path P2
The flow rate flowing to is specified. Therefore, by changing the value of current applied to the relief valve 23 in the first pilot valve 20 and changing the pilot pressure applied to the oil chamber R2, the position of the valve body 12 of the main valve 10 can be adjusted, and the inflow path The flow rate flowing from P1 to outflow path P2 can be adjusted.

As is clear from the above description, the main valve 10 of the flow rate control device described above has the function of a poppet valve, that is, the function of appropriately blocking communication between the inflow path P1 and the outflow path P2 (blocking without leakage). However, it has the advantage that the flow rate flowing from the inflow path P1 to the outflow path P2 can be easily and accurately adjusted in accordance with the pilot pressure applied to the oil chamber R2.

[Problem that the invention seeks to solve]

By the way, in the main valve 10 of the flow control device described above, the apex angle θ of the tapered surface 12a1 in the poppet valve portion 12a of the valve body 12 is set at a predetermined angle ( usually
40 to 60 degrees), the poppet valve part 12
There is a problem in that the rate of change in the flow path area (opening area that defines the flow rate of the valve) of the variable restrictor with respect to the axial stroke of a is large, and it is difficult to set the flow path area to a desired value.

Further, the tapered surface 12a1 of the poppet valve portion 12a
A large flow force may be generated by the pressure oil flowing through the variable restrictor formed between the valve seat 11d and the valve seat 11d, and the valve body 12 may be pushed in the axial direction. Sometimes.

[Means for solving problems]

In order to solve the above-described problems, the present invention provides a flow control valve that can be adopted as the main valve 10 described above, in which a large-diameter hole and small-diameter holes of the same diameter are coaxially provided on both sides of the large-diameter hole, and one small-diameter hole is provided. and a valve seat is formed in a step between the large diameter hole, a first inflow/outflow path is connected to an intermediate portion of the large diameter hole, and a second inflow/output path is connected to an intermediate portion of one of the small diameter holes. a spool portion that is slidably inserted into the large diameter hole and forms a first oil chamber and a second oil chamber that communicate with each other at both ends of the large diameter hole; a poppet valve portion provided on the first oil chamber side and seated on or detached from the valve seat with a tapered surface to interrupt communication between the first oil chamber and the one small diameter hole; a connecting portion that is provided on the side, extends into the one small diameter hole, and forms a third oil chamber that communicates with the first oil chamber through the valve seat and communicates with the second inflow/output passage between the small diameter hole; and integrally includes a piston part that is provided on one side of the connecting part and that forms a fourth oil chamber that is slidably inserted into the one small diameter hole and applies pilot pressure to the end of the small diameter hole. At the same time, the spool portion is provided on the second oil chamber side, and is slidably inserted into the other small diameter hole, and a flow path serving as an inflow path of the two inflow and outflow paths is provided with a throttle at the end of the small diameter hole. a small-diameter portion forming a fifth oil chamber that is always connected to the spool portion and selectively connected to the return path; a valve body constituting a variable throttle portion whose flow path area is always smaller than the flow path area formed between the tapered surface of the poppet valve portion and the valve seat by axial movement toward the fifth oil chamber; The structure includes a spring that urges the body toward the fourth oil chamber.

[Action/effect of the invention]

In the flow control valve according to the present invention, by applying pilot pressure to the fourth oil chamber and moving the valve body in the axial direction against the spring, the inflow passage and the outflow passage are connected to the spool portion of the valve body and the valve body. A first oil chamber, a flow path formed between the tapered surface of the poppet valve section and the valve seat, and a third oil chamber formed between the variable throttle section, the first oil chamber, and the third oil chamber are formed between the tapered surface of the poppet valve section and the valve seat. The flow path functions as a simple passage whose flow path area is always larger than the flow path area of the variable throttle section, and the flow rate flowing from the inflow path to the outflow path is defined by the variable throttle section having the smallest flow path area.

Therefore, the shape of the opening of the variable throttle part provided in the spool part or the valve body can be set as appropriate without being restricted by other things, and the flow path of the variable throttle part can be adjusted according to the axial stroke of the valve body. The rate of change in area can be appropriately reduced. Therefore, it is possible to easily set the flow path area of the variable throttle portion to a desired value.

In addition, in the flow control valve according to the present invention, the flow path formed between the tapered surface of the poppet valve portion and the valve seat functions as a mere passage, and the variable throttle portion is configured by the spool portion of the valve body and the valve body. Since the fluid is throttled at the valve seat, the flow force generated by the pressure oil flowing through the flow path formed between the tapered surface of the poppet valve part and the valve seat can be almost eliminated, and the flow force generated by the pressure oil flowing through the variable throttle part can be almost eliminated. It is possible to make the flow force smaller than that shown in Fig. 4, and the axial movement of the valve body due to the flow force can be reduced, and the flow path of the variable throttle section can be set to a desired value. The area can be made less influenced by the flow force. According to the experimental results of the present inventor, it has been found that the flow force acting on the valve body in the flow control valve according to the present invention is approximately half of the flow force acting on the valve body shown in FIG.

〔Example〕

An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a flow control valve according to the present invention, and the flow control valve 40 includes a first member 41A, a second member 41A, and a second member 41A.
Valve body 4 consisting of member 41B and third member 41C
1, a valve body 42 that is slidably inserted into the valve body 41 in the vertical direction (axial direction), and a spring 43 that urges the valve body 42 downward. The valve body 41 has a stepped inner hole in which small diameter holes 41b and 41c of the same diameter are coaxially provided on both upper and lower sides of a large diameter hole 41a, and a valve seat 41d is formed in the lower step. It has an annular groove 41e formed in the middle part of the large diameter hole 41a and communicated with the inflow passage P11, and an annular groove 41f formed in the middle part of the lower small diameter hole 41b and communicated with the outflow passage P12.

The valve body 42 is slidably inserted into the large diameter hole 41a, and has communication holes 42a (as shown by phantom lines in FIG. 3) provided in the valve body 41 at both ends of the large diameter hole 41a. A spool portion 42b forming a first oil chamber R11 and a second oil chamber R12 that communicate with each other through
A poppet valve portion is provided on the lower side of b (on the first oil chamber R11 side) and seats on and leaves the valve seat 41d at the tapered surface 42c1 to interrupt communication between the first oil chamber R11 and the lower small diameter hole 41b. 42c, and a connecting portion 42d that is provided below the poppet valve portion 42c, extends into the lower small diameter hole 41b, and forms a third oil chamber R13 that communicates with the outflow path P12 between the small diameter hole 41b and the small diameter hole 41b.
and a small diameter hole 4 provided on the lower side of the connecting portion 42d.
A piston part 42e is integrally provided to form a fourth oil chamber R14 which is slidably inserted into the poppet valve 42e and to which pilot pressure is applied to the end of the small diameter hole. Hole 41
A fifth oil chamber R is slidably inserted into the small diameter hole 41c and is always connected to the annular groove 41e via the throttle 44 at the end of the small diameter hole 41c, and is selectively connected to the return path P6.
15 (see FIG. 3) is integrally provided with a small diameter cylindrical portion 42f. Further, the outer periphery of the lower end of the spool portion 42b of the valve body 42 has a large diameter hole inner wall 41a1 and an annular groove 41e. An opening 42b1 constituting a variable throttle section A whose flow path area is always smaller than the flow path area formed between the seats 41d is provided. Note that the opening 42
One of the shapes shown in FIG. 2 is adopted as the shape of b1.

The flow control valve configured as described above has the fourth oil chamber R14 connected to the first pilot valve 20 and the first switching valve 31 of the second pilot valve 30, as illustrated in FIG. , and the fifth oil chamber R
15 is connected to the second switching valve 32 of the second pilot valve 30, it is used as the main valve of the flow rate control device. The configurations of the first pilot valve 20 and the second pilot valve 30 are exactly the same as those shown in FIG. 4.

By the way, in the flow control valve configured as described above, the pressing force due to the pilot pressure applied to the fourth oil chamber R14 is small, and furthermore, the pressing force applied to the fourth oil chamber R14 is small.
5 is cut off from communication with the return path P6, the valve body 42 passes from the inflow path P11 through the throttle 44 to the fifth
The poppet valve portion 42c is seated on the valve seat 41d against the pressing force of the pilot pressure described above due to the hydraulic pressure applied to the oil chamber R15 and the action of the spring 43, and proper communication between the inflow path P11 and the outflow path P12 is established. It's definitely blocked. At this time, the pressure inside the inflow passage P11 only acts on a part of the outer periphery of the spool portion 42b of the valve body 42 and does not act as a force to push the valve body 42 in the axial direction, and Since the pressure inside the outflow path P12 applied to R13 acts on the poppet valve part 42c and the piston part 42e so as to always cancel each other out, the valve body 42 moves in the axial direction due to fluctuations in the pressure inside the inflow path and the pressure inside the outflow path. You will not be pushed to.

Further, if the pressing force due to the pilot pressure applied to the fourth oil chamber R14 is greater than the mounting load of the spring 43, and the fourth oil chamber R14 is connected and communicated with the return path P6, the fifth oil chamber R15 The oil pressure inside is approximately zero, and the valve body 42 is in the fourth oil chamber R14.
It is pushed to a position where the pressing force by the pilot pressure inside and the acting force of the spring 43 are balanced. Therefore, the inflow path P11 and the outflow path P12 communicate through the variable throttle section A, the first oil chamber R11, the flow path formed between the tapered surface 42c1 of the poppet valve section 42c and the valve seat 41d, and the third oil chamber R13. The tapered surface 42a1 of the poppet valve portion 42a and the valve seat 41d
The flow path formed therebetween functions as a simple passage whose flow area is always larger than that of the variable throttle section A, and the flow rate flowing from the inflow path P11 to the outflow path P12 is the variable throttle section A with the smallest flow path area. stipulated by. Therefore, by changing the pilot pressure applied to the fourth oil chamber R14, the position of the valve body 42 can be adjusted, and the amount of throttling at the variable throttle section A can be adjusted, and the fluid flows from the inflow path P11 to the outflow path P12. Flow rate can be adjusted. At this time, the pressure inside the inflow path P11 acts only on a part of the outer periphery of the spool portion 42b of the valve body 42, and the valve body 4
2 in the axial direction, and the pressure inside the first to third oil chambers R11 to R13 flows through the outflow path P.
12 internal pressure, and each of the first to third
The pressure inside the oil chambers R11 to R13 is the spool portion 42b,
Since the valve body 42 acts on the poppet valve portion 42c and the piston portion 42e in such a way that they always cancel each other out, the valve body 42 is not pushed in the axial direction due to fluctuations in the pressure in the inlet passage or the pressure in the outlet passage.

By the way, the shape of the opening 42b1 provided in the spool portion 42b of the valve body 42 can be set as appropriate without being restricted by other things.
The rate of change in the flow path area of the variable restrictor A with respect to the second axial stroke can be appropriately reduced. Therefore, the flow path area of the variable throttle section A can be easily set to a desired value.

In addition, in the flow control valve of this embodiment, the tapered surface 42c1 of the poppet valve portion 42c and the valve seat 41d
The flow path formed between them functions as a mere passage,
and the opening 42b1 provided in the spool portion 42b, the large diameter hole inner wall 41a1 of the valve body 41, and the annular groove 41e.
Since the fluid is throttled in the variable throttle section A constituted by the above, the flow force generated by the pressure oil flowing through the flow path formed between the tapered surface 42c1 of the poppet valve section 42c and the valve seat 41d can be almost eliminated. In addition, the flow force generated by the pressure oil flowing through the variable restrictor A can be made smaller than that shown in FIG. 4, and the axial movement of the valve body 42 due to the flow force can be reduced. This makes it possible to prevent the flow path area of the variable throttle section A, which is set to a desired value, from being affected by the flow force. According to the inventor's experimental results, the flow force acting on the valve body 42 is the same as that of the valve body 12 shown in FIG.
It was found that the flow force acting on the

FIG. 5 shows another embodiment of the present invention, and in the flow control valve shown in the same figure, the valve body 41 is constituted by first to fourth members 41A to 41D, and the fourth A valve seat 41d is formed on the member 41D. Therefore, the durability of the valve seat 41d can be improved by using iron as the material of the fourth member 41D, for example. Further, in a state where the second member 41B and the fourth member 41D of the valve body 41 are integrally connected, the first
It is assembled into the member 41A, and the second member 41
A valve body 42 and a spring 43 are installed in advance in B and the fourth member 41D. For this reason, this flow control valve has the advantages of easy assembly and the spring 43
The advantage is that the mounting load can be adjusted in advance. In addition, in this flow control valve,
The variable throttle part A is the lower end outer peripheral wall 4 of the spool part 42b.
2b2 and an opening 41g formed in the fourth member 41D. Note that one of the shapes shown in FIG. 6 is adopted as the shape of the opening 41g. The rest of the structure is substantially the same as that of the flow control valve shown in FIG. Further, since the operations and effects of the embodiment shown in FIG. 5 are substantially the same as those of the embodiment shown in FIGS. 1 to 3 described above, the explanation thereof will be omitted.

In the above embodiment, as shown in FIG. 3, the fifth oil chamber R15 is communicated with the annular groove 41e through the throttle 44, and the flow path connected to the annular groove 41e is connected to the inflow path. P11 and the flow path connected to the annular groove 41f was defined as the outflow path P12, but the fifth oil chamber R15 is connected to the annular groove 4 through the throttle 44.
1f and the flow path connected to the annular groove 41f is used as the inflow path, and the flow path connected to the annular groove 41e is used as the outflow path, the same effects and effects as in the above embodiment can be expected.

[Brief explanation of the drawing]

FIG. 1 is an enlarged cross-sectional view of essential parts showing one embodiment of a flow control valve according to the present invention, FIG. 2 is an end view showing an example of the shape of the opening shown in FIG. 1, and FIG. Figure 4 is an overall configuration diagram showing an example of a flow rate control device configured with a flow rate control valve as a main valve.
11709, FIG. 5 is an enlarged cross-sectional view of main parts showing another embodiment of the flow control valve according to the present invention, and FIG.
FIG. 3 is an end view showing an example of the shape of the opening shown in the figure. Explanation of symbols, 40...Flow rate control valve (main valve), 4
1...Valve body, 41a...Large diameter hole, 41b, 41
c...Small diameter hole, 41d...Valve seat, 42...Valve body,
42b...Spool part, 42c...Poppet valve part, 42c1...Tapered surface, 42d...Connection part,
42e...Piston part, 42f...Small diameter part, 43
...Spring, 44...Aperture, A...Variable aperture section, P
11... Inflow path (first inflow/output path), P12... Outflow path (second inflow/output path), P6... Return path, R11
...First oil chamber, R12...Second oil chamber, R13...
3rd oil chamber, R14...4th oil chamber, R15...5th oil chamber
Oil room.

Claims (1)

[Scope of Claims] 1 Small diameter holes of the same diameter are coaxially provided on both sides of a large diameter hole, and a valve seat is formed in the step between one of the small diameter holes and the large diameter hole, and A valve body having a first inflow/outflow passage connected to an intermediate portion of a diameter hole and a second inflow/output passage connected to an intermediate portion of one of the small diameter holes; A spool portion forming a first oil chamber and a second oil chamber communicating with each other at both ends of the large diameter hole, and a spool portion provided on the first oil chamber side of the spool portion and seated on the valve seat with a tapered surface. a poppet valve part that separates from the first oil chamber and blocks communication between the first oil chamber and the one small diameter hole, and a poppet valve part that is provided on one side of the poppet valve part and extends into the one small diameter hole and between the same small diameter hole. a connecting portion forming a third oil chamber that communicates with the first oil chamber through the valve seat and also communicating with the second inflow/outlet passage; and a connecting portion that is provided on one side of the connecting portion and slides into the one small diameter hole. It is integrally provided with a piston part that is movably inserted and forms a fourth oil chamber in which pilot pressure is applied to the end of the small diameter hole, and is provided on the second oil chamber side of the spool part and is connected to the second oil chamber. a fifth oil chamber that is slidably inserted into the small diameter hole and is always connected to the inflow channel of the two inflow and outflow channels via a throttle and selectively connected to the return channel at the end of the small diameter hole; The poppet valve portion is integrally provided with a small diameter portion forming a small diameter portion, and the poppet valve portion is axially moved toward the fifth oil chamber side by the valve body at the end portion of the spool portion on the first oil chamber side. A valve body that constitutes a variable throttle portion whose flow path area is always smaller than the flow path area formed between the tapered surface and the valve seat, and a spring that biases the valve body toward the fourth oil chamber. Flow control valve.