JPS6319406A - Flow control valve - Google Patents

Abstract

PURPOSE:To reduce the influence of flow force by constituting a variable throttle part by the opening provided on the outer circumference at the lower end of a spool part, the inner wall of a large diameter hole, and a ring-shaped groove. CONSTITUTION:On the outer circumference at the lower end of the spool part 42b of a valve body 42, an opening 42b1 is formed, and by the opening 42b1, the inner wall 41a1 of a large diameter hole, and a ring-shaped groove 41e, a variable throttle part A whose flow passage area is always smaller than that formed between the taper surface 42c1 of a poppet valve part 42c and its valve seat 41d is constituted. Thus, since the flow force caused by the pressure oil flowing in the flow passage formed between the taper surface 42c1 of the poppet valve part 42c and its valve seat 41d can be almost eliminated, the influence of flow force can be reduced. Further, since the shape of the opening 42b1 provided on the spool part 42b can be suitably determined without being restricted by the others, the setting of the flow passage area at the variable throttle part can be facilitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a flow rate control valve, and in particular, the present invention relates to a flow control valve, and in particular, the present invention relates to a flow control valve.
Japanese Patent Application No. 61-11709, Japanese Patent Application No. 11710, Japanese Patent Application No. 61-31699, Japanese Patent Application No. 61-3170
The present invention relates to a flow control valve that can be optimally adopted as the main valve of each device related to No. 0).

[Technology of prior application]

The applicant of this application has filed the above-mentioned earlier application, for example, Japanese Patent Application No. 1986-11.
In No. 709, a device illustrated in FIG. 4 was proposed.

The device shown in FIG. 4 includes a main valve 10. First pilot valve 20
The main valve 10 includes a valve body 11 and a valve fitted into the valve body 11 so as to be slidable vertically (axially). The main components are a body 12 and a spring 13 that biases the valve body 12 downward. The valve body 11 has a large diameter hole 11a.
The small diameter hole 11b and IIC of the same diameter are provided coaxially on both the upper and lower sides of the annular pipe, which has a stepped inner hole with a valve seat lid formed in the lower continuous step part, and has an annular shape with which the inflow passage P1 communicates. An annular groove 11f through which the groove 11e and the outflow path P2 communicate.
have.

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 Pl acting on both the upper and lower ends is always canceled out), and is inserted into the tapered surface 12a.
1, a poppet valve part 12a seats on and leaves the valve seat 11d to block communication between the inflow passage P1 and the outflow passage 22; and a lower small diameter hole 11 provided on the lower side of the poppet valve part 12a.
a connecting portion 12b that extends into the small diameter hole 11b and forms an oil chamber R1 between which the outflow passage P2 is always in communication;
A piston part 12C is provided on the lower side of the poppet valve part 12b, and is integrally provided with a piston part 12C that is slidably inserted into the lower small diameter hole 11b and forms an oil chamber R2 at the end of the small diameter hole 11b. It is integrally provided with a small diameter cylindrical portion 12d that is slidably inserted into the upper small diameter hole 11C and forms an oil chamber R3 at the end of the small diameter hole 11C. However, oil chamber R
2 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 inflow passage P1 via the throttle 14, and 30 second switching valves 32.

The first pilot valve 20 includes a pressure reducing valve 21 that reduces the pressure of the pressure oil introduced through the supply path P"3 to a predetermined value, and a pilot pressure applied from the pressure reducing valve 21 to the oil chamber R2 through the throttle 22 to a current applied value. The second pilot valve 30 includes a first switching valve 31 whose operation is controlled by pilot pressure applied to the oil chamber R2, and a current control relief valve 23 that performs proportional control according to the pressure applied to the oil chamber R2. It is constituted by a second switching valve 32 whose operation is controlled by a valve 31.The first switching valve 31 is set to a non-operating state as shown in the figure when the pilot pressure applied from the oil chamber R2 through the passage P4 is less than a set value. When in the operating state, the connection between the supply passage P3 and the second switching valve 32 is cut off, and when the pilot pressure is equal to or higher than the set value, it becomes the operating state and connects the supply passage P3 to the second switching valve 32.

The second switching valve 32 is connected to the supply path P3 by the first switching valve 31.
A passage P5 that operates when connected to the oil chamber R3 and communicates with the oil chamber R3.
When the first switching valve 31 disconnects the supply path P3 and connects it to the return path P6, the oil chamber R3 becomes inactive as shown in the figure. 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 main valve 1
The inflow path P1 is connected to the poppet valve portion 12a of the valve body 12 of No.
The internal pressure always acts to cancel each other out, and the pressure inside the outflow path P2 acts on the poppet valve portion 12a and the piston portion 12C so as to always cancel each other out, so that the pressure inside the inflow path P1 and the outflow The valve body 12 of the main valve 10 is not pushed in the axial direction due to fluctuations in the pressure inside the passage P2.

Further, when the current applied to the relief valve 23 in the first pilot valve 20 is less than the set value and the pilot pressure applied to the oil chamber R2 is less than the set value, as shown in the figure, the second pilot valve 30 The first switching valve 31 is in an inoperative state, cutting off the connection between the supply path P3 and the second switching valve 32, and the second switching valve 32 is in an inactive state, and the oil chamber R3 and the return path P6 are communicated with each other. is blocking. For this reason, the valve body 12 of the main valve 10 seats the poppet valve portion 12a on the valve seat lid by the action of the oil pressure and the spring 13 applied to the oil chamber R3 from the inflow path P1 through the proof 14, and the inflow path P1 The communication between the outflow path P2 and the outflow path P2 is clearly blocked.

Therefore, the relief valve 2 in the first pilot valve 20
When the pilot pressure applied to the oil chamber R2 is equal to or higher than the set value by setting the value of current applied to P3 to the set value or more, the first switching valve 31 in the second pilot valve 30 is activated to switch the supply path P3.
Since the oil chamber R3 is connected to the second switching valve 32, the second switching valve 32 is operated to communicate the oil chamber R3 with the return path P6. For this reason,
The oil pressure in the oil chamber R3 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 value equal to or higher than the set value by the first pilot valve 20) and the acting force of the spring 13 are balanced, and the flow from the inflow path P1 to the outflow path is maintained. The flow rate flowing to P2 is defined. Therefore, by changing the value of current applied to the relief valve 23 in the first pilot valve 20 and changing the pyropressure applied to the oil chamber R2, the valve body 1 of the main valve 10
2 can be adjusted, and the flow rate flowing from the inflow path P1 to the outflow path P2 can be adjusted eight times.

As is clear from the above description, the main valve 10 of the above-described flow rate control device functions as a poppet valve, that is, appropriately blocks communication between the inflow path P1 and the outflow path 22 (prevents leakage). While having this function, 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 force applied to the oil chamber R2.

[Problem that the invention seeks to solve]

By the way, in the main valve 10 of the flow rate control device described above, the tapered surface 12 of the poppet valve portion 12a of the valve body 12
Since the apex angle θ of a1 is limited to a predetermined angle (usually 40 to 60 degrees) due to the need to ensure proper seating on the valve seats 1 and 1d, a variable throttle for the axial stroke of the poppet valve portion 12a is used. 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 valve is large, and it is difficult to set the flow path area to a desired value.

In addition, the tapered surface 12a1 of the poppet valve portion 12a and the valve seat l
Since a large flow force may be generated by the pressure oil flowing through the variable restrictor formed between the id and push the valve body 12 in the axial direction, the above-mentioned flow path area which has been carefully set may be affected. be.

[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 forming a valve seat in the stepped portion between the large diameter hole,
a valve body having a first inflow/outflow passage connected to an intermediate portion of the large diameter hole and a second inflow/output passage connected to an intermediate portion of one of the small diameter holes, and a valve body that is slidably inserted into the large diameter hole; a spool portion forming 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 that shuts off communication between the first oil chamber and the one small diameter hole when seated or separated; and a poppet valve portion provided on one side of the poppet valve portion and disposed within the one small diameter hole. and the first valve seat through the valve seat between the small diameter hole and the small diameter hole.
a connecting portion forming a third oil chamber that communicates with the oil chamber and the second inflow/outlet passage; 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 has the same small diameter. A piston part is integrally provided at the hole end to form a fourth oil chamber to which pilot pressure is applied, and is provided on the second oil chamber side of the spool part and is slidably fitted into the other small diameter hole. A small diameter portion is integrally inserted into the small diameter hole end to form a fifth oil chamber that is always connected to the inflow channel of the two inflow and outflow channels via a throttle and selectively connected to the return channel. In preparation for this, a flow is formed between the tapered surface of the poppet valve portion and the valve seat by the axial movement of the spool portion toward the fifth oil chamber side by the valve body at the end portion of the spool portion on the first oil chamber side. The present invention is configured to include a valve body constituting a variable throttle portion whose flow path area is always smaller than the flow path area, and a spring that urges the valve body toward the fourth oil chamber.

[Action/effect of the invention]

In the flow rate 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 variable throttle section constituted by the main 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
The flow path that communicates through the oil chamber and is formed between the tapered surface of the poppet valve portion and the valve seat functions as a mere passage whose flow path area is always larger than the flow path area of the variable throttle portion, and flows from the inflow path to the outflow path. The flow rate is defined by the variable throttle section with 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.

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 variable throttle portion is configured by the spool portion of the valve body and the valve body. Since the fluid is throttled at , 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 part and the valve seat, and the flow force generated by the pressure oil flowing through the variable throttle part can be reduced. The flow force generated can be made smaller than that shown in Fig. 4, the axial movement of the valve body due to the flow force can be reduced, and the variable throttle section 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. 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 rate control valve according to the present invention, and the flow rate control valve 40 includes a valve body 41 consisting of a first member 41A, a second member 41B, and a third member 41C, and a valve body 41 having upper and lower parts inside the valve body 41. The main components are a valve body 42 that is slidably inserted in the direction (axial direction) and a spring 43 that biases 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 communicating with the inflow passage pH, and an annular groove 141f formed in the middle part of the lower small diameter hole 41b and communicating 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. first oil chambers R1 that communicate with each other through
The spool part 42b that forms the first oil chamber R12 and the second oil chamber R12 is provided on the lower side (the first oil chamber R11 side) of the spool part 42b, and the tapered surface 42C1 seats on the valve seat 41d and separates from the valve seat 41d. 1. A poppet valve portion 42c that communicates and connects the oil chamber R11 and the lower small diameter hole 41b, and a poppet valve portion 42c that is provided below the poppet valve portion 42c and extends into the lower small diameter hole 41b.
1b, which forms a third oil chamber R13 that communicates with the outflow path P12, and a connecting portion 42d that is provided on the lower side of the connecting portion 42d and is slidably fitted into the small diameter hole 41b, and an end of the small diameter hole. It is integrally provided with a piston portion 42e forming a fourth oil chamber R14 to which pilot pressure is applied, and is slidably inserted into an upper small diameter hole 41C provided above the poppet valve portion 42a. A small diameter cylindrical portion 42f that forms a fifth oil chamber R15 (see Fig. 3) that is always connected to the annular groove 41e through the throttle 44 and selectively connected to the return path P6 is integrally formed at the end of the hole 41c. We are prepared. Also, the valve body 42
A large diameter hole inner wall 41a is provided on the outer periphery of the lower end of the spool portion 42b.
1 and the annular m41e, the tapered surface 42c of the poppet valve portion 42c is moved in the axial direction toward the fifth oil chamber R15.
An opening 42b1 constituting 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 is provided. Note that the shape of the opening 42b1 is one of those shown in FIG. 2.

The flow rate control valve configured as described above, as illustrated in FIG. 3, connects the fourth oil chamber R14 to the first pilot valve 20 and also connects to the first +JJ exchange valve 31 of the second pilot valve 30, Furthermore, by connecting the fifth oil chamber R15 to the second switching valve 32 of the second pilot valve 30, it can be 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, if the pressing force due to the pilot pressure applied to the fourth oil chamber R14 is small and the fifth oil chamber R15 is cut off from communicating with the return path P6, , the valve body 42 resists the pressing force due to the pilot pressure described above by the action of the hydraulic pressure applied to the fifth oil chamber R15 through the throttle 44 from the inflow path pH and the action of the spring 43, and seats the poppet valve portion 42C on the valve seat 41d. Therefore, communication between the inflow path pH and the outflow path P12 is appropriately blocked. At this time, the inflow channel pH pressure 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. Since the pressure inside the outflow path P12 applied to R13 always acts on the poppet valve portion 42C and the piston portion 42e to cancel each other out, the valve body 42 is pushed in the axial direction due to fluctuations in the pressure inside the inflow path and the pressure inside the outflow path. It will not be moved.

In addition, 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 if the fourth oil chamber R14 is connected and communicated with the return path P6, the fifth oil chamber R14 The oil pressure in the chamber R15 is approximately zero, and the valve body 42
is pushed to a position where the pressing force due to the pilot pressure in the fourth oil chamber R14 and the acting force of the spring 43 are balanced.

Therefore, the inflow path pH and the outflow path P12 are
.

1st oil chamber R11, tapered surface 42C of poppet valve part 42c
1 and the flow path formed between the valve seat 41d and the third oil chamber R13
The flow path formed between the tapered surface 42a1 of the poppet valve portion 42a and the valve seat 41d functions as a simple passage whose flow path area is always larger than the flow path area of the variable throttle portion A, and the inflow path pH The flow rate flowing from the outlet to the outflow path P12 is defined by the variable throttle section A having the smallest flow path area. 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 in the variable throttle part A can be adjusted, and the pH of the inlet passage can be changed to the pH of the outlet passage P.
The flow rate flowing to i2 can be adjusted. However,
At this time, the inflow channel pH pressure 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.
The pressure inside the oil chambers R11 to R13 is approximately equal to the pressure inside the outflow path P12, and the pressure inside each of the first to third oil chambers R11 to R13 is always offset by the spool portion 42b, the poppet valve portion 42c, and the piston portion 42e. Therefore, 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, and the flow path of the variable throttle portion A with respect to the axial stroke of the valve body 42 can be set appropriately. The rate of change in area can be appropriately reduced.

Therefore, the flow path area of the variable throttle section A can be easily set to a desired value.

Further, in the flow control valve of this embodiment, the flow path formed between the tapered surface 42c1 of the poppet valve portion 42C and the valve seat 41d functions as a skewer passage, and the spool portion 42b
The opening 42b1 provided in the valve body 41 and the large diameter hole inner wall 41a of the valve body 41
1 and the annular groove 41e.
The flow force generated by the pressure oil flowing through the flow path formed between the tapered surface 42c1 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 is shown in FIG. It can be made smaller than the one shown, and the axial movement of the valve body 42 due to the blow force can be reduced, and the flow path area of the variable throttle section A set to a desired value can be adjusted to the flow force. can be made so that it is not affected as much. 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. 4.

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 member 41
A valve seat 41d is formed at D. 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, the second member 41 of the valve body 41
In the state where B and the fourth member 41D are integrally connected, the first
The valve body 42 and the spring 43 are assembled in the member 41A, and the valve body 42 and the spring 43 are assembled in the second member 41B and the fourth member 41D in advance. Therefore, this flow control valve has the advantage that it is easy to assemble and that the mounting load of the spring 43 can be adjusted in advance. Further, in this flow rate control valve, the variable throttle part A is connected to an opening 41 formed in the lower end outer peripheral wall 42b2 of the spool part 42b and the fourth member 41D.
g. 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. In addition, the effect of the embodiment shown in FIG.
Since the effects are substantially the same as those of the embodiment shown in FIGS. 1 to 3 described above, a description thereof will be omitted.

In the above embodiment, as shown in FIG. 3, the fifth oil chamber R15 is connected to the annular groove 41e through the throttle 44.
The flow path connected to the annular groove 41e was set as the inflow path pH, and the flow path connected to the annular groove 41f was set as the outflow path P12. Even if the flow path connected to the annular groove 41f is used as an inflow path and the flow path connected to the annular groove 141e is used as an outflow path, the same functions 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. FIG. 4 is an overall configuration diagram showing an example of a flow rate control device configured with a flow rate control valve as the main valve. FIG. 6 is an enlarged cross-sectional view of a main part showing another embodiment of the flow control valve according to the present invention, and FIG. 6 is an end view showing an example of the shape of the opening shown in FIG. 5. Explanation of symbols 40...Flow rate control valve (main valve), 41...Valve body, 4
1a...-Large diameter hole, 41b, 41cm 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 throttle part, pH...Inflow path (first inflow and outflow path) R
12... Outflow path (second inflow/output path), P6... Return path, R11... First oil chamber, R12... Second oil chamber, R1
3...Third oil chamber, R14...Fourth oil chamber, R15...
・No. 5 oil room. Figure 3

Claims (1)

[Scope of Claims] 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 main body having a first inlet/outlet passage connected to the middle part of the hole and a second inflow/outlet passage connected to the middle part of one of the small diameter holes, and a valve body having the same size and slidably inserted into the large diameter hole. A spool portion forming a first oil chamber and a second oil chamber communicating with each other at both ends of the 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 is separated 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 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 forms a fourth oil chamber that is freely inserted into the small diameter hole and applies pilot pressure to the end of the small diameter hole, and is provided on the second oil chamber side of the spool part and has a second small diameter hole. A fifth oil chamber is slidably inserted into the hole and at the end of the small diameter hole is always connected to the inflow path of the two inflow and outflow paths via a throttle and selectively connected to the return path. The tapered surface of the poppet valve portion is integrally provided with a small diameter portion to form a small diameter portion, and the spool 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 flow control valve comprising: a valve body that constitutes a variable throttle portion whose flow path area is always smaller than the flow path area formed between the valve seats; and a spring that biases the valve body toward the fourth oil chamber. .