JPH0557442B2 - - 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.
A spool portion 12c is integrally provided which 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 so as to be 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 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 the valve seat 21a1 and the valve seat 11d can be adjusted, and the flow path area can be adjusted from the inflow path P1 to the outflow path P.
2 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. A valve seat is formed in a stepped portion between 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 connected to an intermediate portion of one of the small diameter holes. a valve body that is fitted into the large-diameter hole in such a manner that pressures received from the first inflow and outflow passages are always canceled out, and seated on the valve seat on a tapered surface, and separated from the valve seat so that both the inflow and outflow passages are connected to each other; a poppet valve section that cuts off communication between the outlet passages; and a poppet valve section that is provided on one side of the poppet valve section, extends into the one small diameter hole, and passes through the valve seat to the large diameter hole side end of the small diameter hole to allow the first inflow to pass through the valve seat. a connecting portion forming a first oil chamber communicating with the outlet passage; and a small diameter hole of the second inlet/outlet passage in the valve body, which is provided on one side of the connecting portion and is slidably inserted into the one small diameter hole. A spool portion that constitutes 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 the opening formed at the side end portion, and a spool portion on one side of the spool portion. a second connecting portion provided on one side of the second connecting portion to form a second oil chamber always communicating with the first oil chamber in the one small diameter hole; It is integrally provided with a piston portion that forms a third oil chamber that is slidably inserted and applies pilot pressure to the end of the small diameter hole, and is provided on the other side of the poppet valve portion and is connected to the other small diameter hole. A fourth hole is slidably inserted into the small-diameter hole and is always connected to the inflow path of the two inflow and outflow paths through a throttle, and selectively connected to the return path.
The valve body is configured to include a valve body that integrally includes a small diameter portion that forms an oil chamber, and a spring that urges the valve body toward the third oil chamber.

[Action/effect of the invention]

In the flow control valve according to the present invention, pilot pressure is applied to the third oil chamber and the valve body moves in the axial direction against the spring, so that the inflow passage and the outflow passage are connected to the tapered surface of the poppet valve portion and the valve body. The poppet valve communicates with the flow path formed between the seats, the first oil chamber, the second oil chamber, the spool section, and the variable throttle section formed by the opening formed at the end of the small diameter hole of the second inflow/outflow path. The flow path formed between the tapered surface of the section and the valve seat 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 has the smallest flow path area. Defined by the variable aperture section.

Therefore, the shape of the opening formed at the end of the second inlet/outlet passage on the small diameter hole side can be set as appropriate without being restricted by other things, and the variable throttle part can be adjusted to the axial stroke of the valve body. The rate of change in flow path area can be appropriately reduced. Therefore,
The flow path area of the variable throttle section can be easily set to a desired value.

Further, 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 flow path formed at the end of the spool portion and the small diameter hole side of the second inflow and outflow path functions as a mere passage. Since the liquid is throttled by the variable throttle section formed by the opening, 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 poppet valve section and the valve seat.
The flow force generated by the pressure oil flowing through the variable restrictor 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, thereby achieving the desired value. It is possible to prevent the flow path area of the variable throttle section set to be affected by the flow force to a large extent. 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.
Member 41B, third member 41C, and fourth member 41D
(This member is a sleeve that is fitted and fixed in the inner hole at the lower end of the first member 41A.
1A); a valve body 42 fitted into the valve body 41 so as to be slidable in the vertical direction (axial direction);
The main component is a spring 43 that urges the valve body 42 downward. The valve body 41 has a large diameter hole 41a.
Small diameter holes 41b and 41c of the same diameter are provided coaxially on both the upper and lower sides of the valve seat 41.
d, and an annular groove 41e formed at the large diameter hole end on the side close to the valve seat 41d and communicating with the inflow passage P11, and an intermediate part of the lower small diameter hole 41b. It has an annular groove 41f formed correspondingly and communicating with the outflow path P12.

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 and is slidably inserted into the opening 41g formed in the fourth member 41D (the shape of this opening is one of those illustrated in FIG. 2), so that the valve body 42 moves upward. Therefore, the tapered surface 42a of the poppet valve portion 42a
1 and the valve seat 41d, and a spool portion 42c forming a variable throttle portion A whose flow path area is always smaller than the flow path area formed between the valve seat 41d and the valve seat 41d; The second oil chamber R1 always communicates with the first oil chamber R11 through the communication passage P20.
2, and a third connecting portion 42d that is provided below the second connecting portion 42d and is slidably inserted into the lower small diameter hole 41b, and a pilot pressure is applied to the end of the small diameter hole. A piston part 42e forming an oil chamber R13 is integrally provided, and a throttle 44 is provided on the upper side of the poppet valve part 42a and is slidably inserted into an upper small diameter hole 41c.
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 42f.

The flow rate control valve configured as described above has the third oil chamber R13 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. 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, 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, and the spool part 42c and Since the pressure inside the second oil chamber R12 acts on the piston portion 42e so as to always cancel it out, the valve body 42 is pushed in the axial direction by fluctuations in the pressure inside the inflow path and the pressure inside the outflow path under any conditions. It never happens.

Further, the pressing force due to the pilot pressure applied to the third oil chamber R13 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 resists the pressing force due to the pilot pressure described above due to the hydraulic pressure applied to the fourth oil chamber R14 from the inflow path P11 through the throttle 44 and the action of the spring 43. The poppet valve portion 42a is seated on the valve seat 41d, 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 third oil sac R13 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 third oil chamber R13.
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 second oil chamber R12, the spool portion 42c and the opening 41g formed in the fourth member 41D communicate through the variable throttle portion A, and the tapered surface 42a1 of the poppet valve portion 42a and the valve seat 41d communicate with each other. The formed flow path 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 at the variable throttle section A with the smallest flow path area. stipulated.
Therefore, by changing the pilot pressure applied to the third oil chamber R13, 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 opening 4 formed in the fourth member 41D
1g, the shape 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 axial stroke of the valve body 42 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 by the variable throttle section A formed by the spool section 42c and the opening 41g formed in the fourth member 41D, a variable throttle section A is formed between the tapered surface 42a1 of the poppet valve section 42a and the valve seat 41d. The flow force generated by the pressure oil flowing through the flow path can be almost eliminated, and the flow force generated by the pressure oil flowing through the variable restrictor A can be made smaller than that shown in FIG. The axial movement of the valve body 42 due to the flow force can be reduced, and the flow path area of the variable restrictor A, which is set to a desired value, 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 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 figure, the second member 41B and the fourth member 41D of the valve body 41 are integrally connected. The valve body 42 and the spring 43 are assembled in the first member 41A, and the valve body 42 and the spring 43 are assembled in the second member 41B and the fourth member 41D. Therefore, this flow control valve has the advantage of being easy to assemble and that the mounting load of the spring 43 can be adjusted in advance. Note that the other configurations are exactly the same as the configuration 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 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, an 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 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. An overall configuration diagram showing an example of a flow rate control device configured with a flow rate control valve as a main valve, Figure 4 is based on Japanese Patent Application No. 61-11709
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. 6 is a diagram showing an example of the flow control valve according to the present invention. FIG. 3 is an overall configuration diagram showing a flow rate control device in which a modification is configured as a main valve. 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, 41g...Opening, 42...Valve body, 42a...Poppet valve portion, 4
2a1...Tapered surface, 42b...Connecting portion, 42c
...Spool part, 42d...Second connection part, 42e
...Piston part, 42f...Small diameter part, 43...Spring, 44...Aperture, A...Variable aperture part, P11...
...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...Third oil chamber Chamber, R14...4th oil chamber.

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 the large diameter hole side of the seat and a second inflow/outflow passage connected to an intermediate portion of one of the small diameter holes; a poppet valve portion that is inserted into the valve seat in a state where the pressures received are always canceled out and seats on the valve seat with a tapered surface, and separates from the valve seat to cut off communication between the two inflow and outflow passages, and one side of the poppet valve portion. a connecting portion that is provided and extends into the one small diameter hole and forms a first oil chamber that communicates with the first inflow/output passage through the valve seat at an end of the small diameter hole on the large diameter hole side; An opening provided on one side and slidably inserted into the one small diameter hole, and formed at the small diameter hole side end of the second inflow/output passage in the valve body, is formed between the tapered surface of the poppet valve portion and the valve seat. a spool portion constituting a variable throttle portion whose flow path area is always smaller than the flow path area formed in the spool portion; a second connecting portion forming a second oil chamber; and a second connecting portion provided on one side of the second connecting portion and slidably inserted into the one small diameter hole and applying pilot pressure to the end of the small diameter hole. 3. A piston part that forms an oil chamber is integrally provided, and the piston part is provided on the other side of the poppet valve seat and is slidably inserted into the other small diameter hole, and a piston part that forms one of the two inflow and outflow passages is provided at the end of the small diameter hole. A fourth channel is always connected to the inflow channel via a throttle and is selectively connected to the return channel.
A flow control valve comprising: a valve body integrally provided with a small diameter portion forming an oil chamber; and a spring urging the valve body toward the third oil chamber.