JPH0557441B2 - - 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 step. Inflow path P1
It has an annular groove 11e with which it communicates and an annular groove 11f with which the outflow path 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.
The spool portion 12c is integrally provided with a spool 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 on the upper side of the poppet valve portion 12a and slides into the upper small diameter hole 11c. It is integrally provided with a small diameter cylindrical portion 12d which is freely fitted and inserted and forms an oil chamber R3 at the end of the small diameter hole 11c. Thus, the oil chamber R2 is connected to the first pilot valve 20 and the first switching valve 31 of the second pilot valve 30, and the oil chamber R3 is connected to the inlet passage P through the throttle 14.
1 and the second pilot valve 30
The second switching valve 32 is connected to the second switching valve 32 .

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 a non-operating state as shown in the figure, and disconnects the supply path P3 from the second switching valve 32. Further, when the pilot pressure is equal to or higher than the set value, the valve 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 the oil chamber R3 is activated.
The passage P5 communicating with the reservoir T and the return passage P6 communicating with the reservoir T are made to communicate with each other, and when the first switching valve 31 disconnects the supply passage P3 and connects it to the return passage P6, the When activated, oil chamber R3
The communication between the passage P5 communicating with the return passage P6 is cut off.

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 passage P1 always cancels out, and the poppet valve part 12a and the spool part 12c always act on the poppet valve part 12a and the spool part 12c so that the pressure inside the outflow passage P2 always cancels out. 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 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 poppet valve Tapered surface 1 of portion 12a
The flow path area of the variable throttle section formed between 2a1 and the valve seat 11d can be adjusted.
You can adjust the flow rate.

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 term angle θ of the tapered surface 12a1 in the poppet valve portion 12a of the valve body 12 is set to 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. A valve seat is formed in a step between the large diameter hole and the large diameter hole, and a first inflow/outflow passage is connected to the large diameter hole side of the valve seat, and a second inflow/outflow passage is communicated with an intermediate portion of one of the small diameter holes. A valve body formed with an annular groove formed in the large diameter hole is inserted into the large diameter hole in such a manner that the pressures received from the first inflow and outflow passage are always canceled out, and the valve seat is seated and removed on a tapered surface. a poppet valve part that cuts off communication between the two inflow and outflow passages, 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 the valve seat is provided at an end of the small diameter hole on the large diameter hole side. a connecting portion that forms a first oil chamber that communicates with the first inflow and outflow passage through the connecting portion; and a connecting portion that is provided on one side of the connecting portion and is slidably inserted into the one small diameter hole, and a pilot pressure is provided at the end of the small diameter hole. A second oil chamber is formed in the annular groove portion, and a third oil chamber is formed in the annular groove portion, and communicates with the first oil chamber through a communication passage in the intermediate portion, and is connected to the small diameter hole inner wall and the annular groove. Integrally includes a spool portion having an opening 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;
The poppet valve is provided on the other side of the poppet valve part, and is slidably inserted into the other small diameter hole, and is always connected to the inflow channel of the two inflow and outflow channels at the end of the small diameter hole through a throttle. The present invention is configured to include a valve body that integrally includes a small diameter portion that forms a fourth oil chamber that is selectively connected to the return path, and a spring that urges the valve body toward the second oil chamber.

[Action/effect of the invention]

In the flow control valve according to the present invention, by applying pilot pressure to the second 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 tapered surface of the poppet valve portion and the valve body. It communicates with the tapered surface of the poppet valve part through a variable throttle part formed by a channel formed in the seat, a first oil chamber, a communication passage, an opening provided in the spool part, an inner wall of the small diameter hole, and an annular groove. The flow path formed between the valve seats 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 at the variable throttle section with the smallest flow path area. stipulated.

Therefore, the shape of the opening provided in the spool part can be set as appropriate without being restricted by other things, and the rate of change in the flow path area of the variable throttle part with respect to the axial stroke of the valve body can be set as appropriate. Can be made smaller. 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 part and the valve seat functions as a mere passage, and is composed of the opening provided in the spool part, the inner wall of the small diameter hole, and the annular groove. Since the fluid is throttled at the variable throttle section, it is possible to almost eliminate the flow force generated by the pressure oil flowing through the flow path formed between the tapered surface of the pocket valve section and the valve seat. The flow force generated by the flowing pressure oil can be made 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 variable orifice can be set to a desired value. The area of the flow path can be made so that it is not so affected by the flow force. In addition,
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 at the end of the large diameter hole near the valve seat 41d and communicating with the inflow passage P11, and an annular groove 41f formed in the middle part of the lower small diameter hole 41b and communicating with the outflow passage P12. are doing.

The valve body 42 is slidably inserted into the large-diameter hole 41a in a pressure-balanced state (a state in which the pressure in the inflow path P11 acting on both the upper and lower ends is always canceled out) and is inserted into the tapered surface 42a1. A poppet valve portion 42a that seats on or leaves the valve seat 41d to cut off communication between the inflow path P11 and the outflow path P12, and a small diameter hole 41 provided below the poppet valve portion 42a.
A connecting portion 42b that extends into the small diameter hole 41b and forms a first oil chamber R11 that communicates with the inflow passage P11 through the valve seat 41d, and a lower small diameter hole provided below the connecting portion 42b. 41b to form a second oil chamber R12 that is slidably inserted into the small diameter hole 41b and applies pilot pressure to the end of the small diameter hole 41b.
A spool portion 42c that forms a third oil chamber R13 is integrally provided in the 1f portion, and a spool portion 42c that is provided above the poppet valve portion 42a is slidably inserted into the upper small diameter hole 41c and is inserted into the upper small diameter hole 41c at the end of the small diameter hole 41c. Aperture 44
A fourth oil chamber R14 is always connected to the annular groove 41e and selectively connected to the return path P6.
(See FIG. 3) is integrally provided with a small diameter cylindrical portion 42d.

Therefore, in the intermediate portion of the spool portion 42c described above, an inner hole (closed by a plug 42e) provided in the axial direction at the axes of the spool portion 42c and the connecting portion 42b, and an inner hole provided in the connecting portion 42b. The first oil chamber R11 is connected to the first oil chamber R11 through a communication path P20 consisting of a radial hole.
An opening 42c1 is formed which communicates with the small diameter hole inner wall 41b1 and the annular groove 41.
f, the valve body 42 moves upward, so that the tapered surface 42a1 of the poppet valve portion 42a and the valve seat 41
A variable constriction section A is configured, the flow path area of which is always smaller than the flow path area formed between d. Note that one of the shapes illustrated in FIG. 2 is adopted as the shape of the opening 42c1.

The flow control valve configured as described above has the second oil chamber R12 connected to the first pilot valve 20 and connected to the first switching valve 31 of the second pilot valve 30, as illustrated in FIG. , and the fourth oil chamber R
By connecting 14 to the second switching valve 32 of the second pilot valve 30, it can be used as the main valve of the flow control device. Note that the configurations of the first pilot valve 20 and the second pilot valve 30 are exactly the same as those shown in FIG.

By the way, in the flow rate control valve configured as described above, in any state, the outflow path P12
The internal pressure does not exert any axial force on the valve body 42, and the poppet valve portion 4 of the valve body 42
2a so that the internal pressure of the inflow passage P11 always cancels out, and the poppet valve part 42a and the spool part 42c act so that the internal pressure of the first oil chamber R11 always cancels out. The valve body 42 is not pushed in the axial direction due to fluctuations in the pressure inside the inflow path or the pressure inside the outflow path.

Further, the pressing force due to the pilot pressure applied to the second oil chamber R12 is small, and the pressure applied to the fourth oil chamber R14 is small.
If the communication with the return path P6 is cut off, the valve body 42 moves the poppet valve portion 42a to the valve seat 41d by the action of the hydraulic pressure applied to the fourth oil chamber R14 from the inflow path P11 through the throttle 44 and the spring 43. The patient is seated, and communication between the inflow path P11 and the outflow path P12 is appropriately interrupted.

Furthermore, if the pressing force due to the pilot pressure applied to the second oil sac R12 is greater than the mounting load of the spring 43, and the fourth oil sac R14 is connected and communicated with the return path P6, the fourth oil sac R14 The oil pressure inside is approximately zero, and the valve body 42 is in the second oil chamber R12.
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 are a flow path formed between the tapered surface 42a1 of the poppet valve portion 42a and the valve seat 41d, the first oil chamber R11, and the communication path P2.
0, the opening 42c1 provided in the spool part 42c, the small diameter hole inner wall 41b1, and the annular groove 41e communicate through the variable throttle part A, and the tapered surface 42a1 of the poppet valve part 42a and the valve seat 41d
The flow path formed between them functions as a simple passage whose flow path area is always larger than the flow path area of the variable throttle section A, and the flow rate flowing from the inflow path P11 to the outflow path P12 is directed to the variable throttle section A with the smallest flow area. stipulated. Therefore, by changing the pilot pressure applied to the second oil chamber R12, 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.

Therefore, the shape of the opening 42c1 provided in the spool portion 42c of the valve body 42 can be set as appropriate without being restricted by other things, and
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 42a1 of the poppet valve portion 42a and the valve seat 41d
The flow path formed between them functions as a mere passage,
In addition, since the fluid is throttled at the variable throttle section A formed by the opening 42c1 provided in the spool section 42c, the small diameter hole inner wall 41b1, and the annular groove 41e, the tapered surface 42a1 of the poppet valve section 42a
The flow force generated by the pressure oil flowing through the flow path formed between the valve seat 41d and the valve seat 41d can be almost eliminated, and the flow force generated by the pressure oil flowing through the variable throttle part A can be reduced compared to that shown in FIG. The valve body 4 can be made small.
Variable aperture part A that can reduce the axial movement due to the flow force of 2 and is set to a desired value.
The area of the flow path can be made less affected 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 42 is approximately half of the flow force acting on the valve body 12 shown in FIG.

FIG. 5 shows another embodiment of the present invention, and in the flow control valve shown in the same figure, a communication passage that communicates an opening 42c2 provided in the spool portion 42c of the valve body 42 with the first oil chamber R11 is used. A communication passage P21 provided in the valve body 41 is used as the valve body. Also opening 4
One of the shapes illustrated in FIG. 6 is adopted as the shape of 2c2. The rest of the structure is exactly the same as that of the flow control valve shown in FIG. Also,
The operations and effects of the embodiment shown in FIG. 5 are substantially the same as those of the embodiments shown in FIGS. 1 to 3 described above, and therefore the explanation thereof will be omitted.

In addition, in the above-described embodiment, the fourth oil chamber R
14 is communicated with the annular groove 41e via the throttle 44, and the flow path connected to the annular groove 41e is connected to the inflow path P1.
1 and the flow path connected to the annular groove 41f was defined as the outflow path P12, but the fourth oil chamber R14 was made to communicate with the annular groove 41f via the throttle 44, and the flow path connected to the annular groove 41f was defined as the outflow path P12. Even if the flow path connected to the annular groove 41e is used as the inflow path and the flow path connected to the annular groove 41e is used as the outflow path, the same functions and effects as in the above embodiment can be expected. Further, in the above embodiment, the annular groove 41e is formed at the lower end of the large diameter hole 41a of the valve body 41, and the inflow passage P11 is communicated with the annular groove 41e. Then, the large diameter hole 41a is enlarged to the diameter of the annular groove 41e.
Even if the inflow path P11 is communicated with the inflow path P11, the same actions 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 the 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. 3 is the same as shown in 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 essential parts showing another embodiment of the flow control valve according to the present invention, and FIG.
FIG. 7 is an end view showing an example of the shape of the opening shown in the figure, and FIG. 7 is an overall configuration diagram showing a flow rate control device configured as a main valve of a modified example of the flow rate control valve according to the present invention. Explanation of symbols, 40... Main valve, 41... Valve body,
41a...Large diameter hole, 41b, 41c...Small diameter hole,
41b1...Inner wall of small diameter hole, 41d...Valve seat, 41
f...Annular groove, 42...Valve body, 42a...Poppet valve part, 42a1...Tapered surface, 42b...Connection part, 42c...Spool part, 41c1, 41c2
...Opening, 42d...Small diameter part, 43...Spring, 4
4... Throttle, A... Variable throttle section, P11... Inflow path (first inflow/output path), P12... Outflow path (second inflow/output path), P6... Return path, P20, P21...
Communication path, R11...first oil sac, R12...second oil sac, R13...third oil sac, R14...fourth oil sac.

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 formed by forming an annular groove in which a first inflow/outflow passage is connected to the large diameter hole side of the seat and a second inflow/outflow passage communicates with an intermediate portion of one of the small diameter holes; a poppet valve part that is inserted and inserted in a state where the pressures received from the first inflow and outflow passages are always canceled out, and seats on the valve seat on a tapered surface and separates from the valve seat to cut off communication between the two inflow and outflow passages; a connecting part that is provided on one side of the part and extends into the one small-diameter hole, and forms a first oil chamber that communicates with the first inflow and outflow passage through the valve seat at an end of the small-diameter hole on the side of the large-diameter hole; , a second oil chamber is provided on one side of the connecting portion and is slidably inserted into the one small diameter hole, and a pilot pressure is applied to the end of the small diameter hole, and a third oil chamber is formed in the annular groove portion. A flow path is formed by forming an oil chamber and communicating with the first oil chamber through a communication passage in the intermediate portion, and a flow path formed between the tapered surface of the poppet valve portion and the valve seat by the inner wall of the small diameter hole and the annular groove. In addition to integrally comprising a spool portion having an opening constituting a variable aperture portion whose area is always small,
The poppet valve is provided on the other side of the poppet valve part, and is slidably inserted into the other small diameter hole, and is always connected to the inflow channel of the two inflow and outflow channels at the end of the small diameter hole through a throttle. a valve body that integrally includes a small diameter portion forming a fourth oil chamber that is selectively connected to the return path; and a spring that biases the valve body toward the second oil chamber. control valve. 2. The flow control valve according to claim 1, wherein the communication passage is a communication hole provided in the valve body. 3. The flow control valve according to claim 1, wherein the communication passage is a communication hole provided in the valve body.