Flow control valve

Abstract

To provide a flow control valve which enables fine control of the flow rate.SOLUTION: A flow control valve controls a flow rate of a fluid flowing between a first port 1a and a second port 1b and includes: a check valve part 20 which is provided in a first passage 11 connecting the first port and the second port with each other and blocks flow flowing from the second port 1b to the first port 1a while allowing flow flowing from the first port 1a to the second port 1b; and a throttle valve part 30 which is provided in a second passage 12 connecting the first port 1a and the second port 1b with each other and arranged parallel to the first passage 11 and reduces a flow rate of flow in both directions. The throttle valve part 30 has: a shaft body 31 in which a columnar spool 32 is provided at its tip; moving means 33 which moves the shaft body 31 in an axial direction; and a sleeve 34 into which the spool 32 is inserted. The spool 32 has a groove 32c which is open on its side surface 32a and an apical surface 32b and has a constant width.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flow control valve for controlling the flow rate of a fluid. [Background technology]

[0002] In hydraulic devices that operate by hydraulic pressure, flow control valves are used to control the flow rate of hydraulic oil in order to control the operation of actuators. Among these, a type of flow control valve known as a one-way throttle valve is known, which allows free flow in one direction and restricts flow in the reverse direction.

[0003] A conventional flow control valve has a check valve and a throttle valve arranged in parallel, the valve element of the throttle valve is a poppet, and the flow rate is controlled by changing the amount of gap between the valve seat (see Patent Document 1, Figure 9). The conventional flow control valve disclosed in Patent Document 1 has a problem in that a gap is formed all around the poppet, making it difficult to control minute flow rates.

[0004] In addition, the conventional flow control valve disclosed in Patent Document 1 has a poppet movement axis that is perpendicular to the straight line connecting the inlet port and the outlet port. When attaching the flow control valve to the end of a pipe, the flow control valve itself needs to be rotated, but rotating a conventional T-shaped flow control valve requires clearance around it. This makes it necessary to space the pipes sufficiently apart, which prevents free piping. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 62-258270 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above problems, an object of the present invention is to provide a flow control valve capable of precisely controlling the flow rate.

[0007] Another object of the present invention is to provide a flow control valve which requires a small clearance when piping. [Means for solving the problem]

[0008] A flow control valve according to the present invention is a flow control valve that controls the flow rate of a fluid flowing between a first port and a second port, and comprises: a check valve section that is provided in a first flow path connecting the first port and the second port and that blocks a flow from the second port to the first port while allowing a flow from the first port to the second port; and a throttle valve section that is provided in a second flow path that connects the first port and the second port and is parallel to the first flow path and that throttles the flow rate of the flow in both directions, wherein the throttle valve section has a shaft having a cylindrical spool at its tip, moving means for moving the shaft in its axial direction, and a sleeve into which the spool is inserted, and the spool has grooves of a constant width that open on its side and tip face.

[0009] According to this invention, the flow rate can be precisely controlled by precisely adjusting the size of the orifice formed by the groove in the spool.

[0010] Another flow control valve according to the present invention is characterized in that, in a vertical cross-sectional view of the spool, a bottom portion of the groove has a linear shape.

[0011] In another flow control valve according to the present invention, the bottom of the groove has an arc shape in a vertical cross section of the spool.

[0012] Another flow control valve according to the present invention is characterized in that the length of an opening of the groove on the side surface is longer than the length of an opening of the groove on the tip surface.

[0013] Another flow control valve according to the present invention is characterized in that the first port and the second port are arranged opposite each other, and the axial direction of the shaft is inclined by 15° to 75° with respect to a line connecting the first port and the second port.

[0014] According to this invention, since the length protruding from the line connecting the first port and the second port is short, the clearance required during piping can be made small. Effect of the Invention

[0015] According to the present invention, it is possible to provide a flow control valve capable of precisely controlling the flow rate. [Brief description of the drawings]

[0016] [Figure 1] 1 is a side cross-sectional view showing a flow control valve according to a first embodiment of the present invention. [Diagram 2] 5A and 5B are enlarged cross-sectional side views showing a check valve portion of the flow control valve according to the first embodiment of the present invention, where (a) is a view showing a state in which the pressure on the second port side is high, and (b) is a view showing a state in which the pressure on the first port side is high. [Diagram 3] 1A and 1B are enlarged cross-sectional side views showing a throttle valve portion of a flow control valve according to a first embodiment of the present invention, in which (a) shows a state in which a shaft body has moved toward its tip end, and (b) shows a state in which the shaft body has moved toward its base end. [Figure 4] 1A and 1B are partially enlarged views of the vicinity of the tip of the shaft of a flow control valve according to a first embodiment of the present invention, in which (a) is a side view, (b) is an arrow view taken along the line AA in (a), and (c) is a cross-sectional view showing the line BB in (a). [Diagram 5] 1A and 1B are enlarged cross-sectional side views showing the vicinity of a sleeve in a flow control valve according to a first embodiment of the present invention, in which (a) shows a state in which a shaft has moved toward its tip end, and (b) shows a state in which the shaft has moved toward its base end. [Figure 6]3A and 3B are explanatory diagrams illustrating a spool in the flow control valve according to the first embodiment of the present invention, and explaining the relationship between the position of the edge of the sleeve and the size of the orifice. [Figure 7] 1A is a longitudinal cross-sectional view illustrating modified examples of a spool of a flow control valve according to a first embodiment of the present invention, in which (a) the shape of the bottom of the groove is an arc that is concave toward the opening, (b) the shape of the bottom of the groove is an arc that is convex toward the opening, and (c) the shape of the bottom of the groove is a curved shape with a non-constant curvature. [Figure 8] 1A and 1B are partially enlarged views of the vicinity of the tip of a shaft of a flow control valve according to a second embodiment of the present invention, where (a) is a side view, (b) is an arrow view taken along the CC arrow in (a), and (c) is a cross-sectional view showing the DD section of (a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Next, an embodiment of a flow control valve to which the present invention is applied will be described with reference to the drawings. Note that the embodiment described below is a preferred embodiment of the present invention, and therefore various technically preferable limitations are attached, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is limited.

[0018] First Embodiment A flow control valve according to a first embodiment of the present invention will be described with reference to Figs. 1 to 7. Fig. 1 is a side cross-sectional view showing a flow control valve according to a first embodiment of the present invention. Fig. 2 is a side cross-sectional view showing an enlarged check valve portion of the flow control valve according to the first embodiment of the present invention, (a) showing a state in which the pressure on the second port side is high, and (b) showing a state in which the pressure on the first port side is high. Fig. 3 is a side cross-sectional view showing an enlarged throttle valve portion of the flow control valve according to the first embodiment of the present invention, (a) showing a state in which the shaft body has moved toward its tip end, and (b) showing a state in which the shaft body has moved toward its base end. Fig. 4 is a partially enlarged view showing the vicinity of the tip end of the shaft body of the flow control valve according to the first embodiment of the present invention, (a) being a side view, (b) being an arrow view showing the view as viewed from the AA arrow in (a), and (c) being a cross-sectional view showing the BB cross section in (a). Fig. 5 is a side cross-sectional view showing an enlarged view of the vicinity of the sleeve in the flow control valve according to the first embodiment of the present invention, (a) showing a state in which the shaft body has moved toward its tip end, and (b) showing a state in which the shaft body has moved toward its base end. Fig. 6 is an explanatory diagram showing a spool in the flow control valve according to the first embodiment of the present invention, and explaining the relationship between the position of the edge of the sleeve and the size of the orifice. Fig. 7 is a vertical cross-sectional view showing modified examples of the spool in the flow control valve according to the first embodiment of the present invention, in which (a) the bottom of the groove has a concave arc shape toward the opening, (b) the bottom of the groove has a convex arc shape toward the opening, and (c) the bottom of the groove has a curved shape with a non-constant curvature.

[0019] The flow control valve 1 according to this embodiment has a valve box 10 as shown in Fig. 1. The valve box 10 is formed with a first port 1a and a second port 1b through which a fluid flows in and out, and the first port 1a and the second port 1b are arranged opposite each other. The valve box 10 is also formed with a first flow path 11 and a second flow path 12 that connect the first port 1a and the second port 1b.

[0020] The first flow path 11 has a flow path 11a close to the first port 1a and a flow path 11b close to the second port 1b, which are aligned in a straight line. The first flow path 11 is provided with a check valve section 20, which is configured to allow a flow from the first port 1a to the second port 1b, while blocking a flow from the second port 1b to the first port 1a.

[0021] The second flow path 12 has a flow path 12a branching off from the flow path 11a and a flow path 12b branching off from the flow path 11b. The second flow path 12 is parallel to the first flow path 11. The second flow path 12 is provided with a throttle valve section 30, which is configured to throttle the flow rate of the second flow path 12 in both directions.

[0022] Next, the configuration of the check valve portion 20 will be described with reference to Fig. 2. The check valve portion 20 has a poppet 21 that is housed in the flow path 11b and is movable left and right in the figure, a spring 22 that elastically presses the poppet 21 toward the right in the figure, a spring seat 23 that fixes the end of the spring 22 to the valve box 10, and a valve seat 24 provided at the boundary between the flow paths 11a and 11b.

[0023] Next, the operation of the check valve portion 20 will be described. When a fluid tries to flow from the second port 1b toward the first port 1a, that is, when the pressure of the second port 1b is higher than the pressure of the first port 1a, the poppet 21 is pressed to the right in the figure by the spring 22 and the pressure of the fluid, and comes into close contact with the valve seat 24. This blocks communication between the flow paths 11b and 11a (see FIG. 2(a)). In other words, the flow from the second port 1b toward the first port 1a is blocked. Note that, since the poppet 21 has holes at appropriate positions, communication between the flow paths 11b and 12b is maintained.

[0024] When the fluid tries to flow from the first port 1a to the second port 1b, that is, when the pressure at the first port 1a is higher than the pressure at the second port 1b, the poppet 21 is pressed to the left in the figure by the fluid pressure and moves to the left against the elastic force of the spring 22, releasing the close contact with the valve seat 24. This causes the fluid to flow from the flow path 11a to the flow path 11b (see FIG. 2(b)). In other words, the flow from the first port 1a to the second port 1b is permitted.

[0025] Next, the configuration of the throttle valve portion 30 will be described with reference to FIG. 3. The throttle valve portion 30 has a shaft body 31 formed symmetrically about the entire axis. The shaft body 31 is accommodated in a receiving hole 13 formed in the valve box 10. The receiving hole 13 and the shaft body 31 are inclined at about 45° with respect to a line connecting the first port 1a and the second port 1b, i.e., with respect to the first flow passage 11 (see FIG. 1). An intermediate portion 31a between the tip and base end of the shaft body 31 is accommodated in an expanded diameter portion 13a formed in the receiving hole 13 with a large hole diameter. The expanded diameter portion 13a communicates with the flow passage 12b. The shaft body 31 is provided with an O-ring 31c that seals the gap between the shaft body 31 and the receiving hole 13.

[0026] A male thread 31b is formed near the base end of the shaft body 31, and is fitted into a female thread 13b formed in the receiving hole 13. A knob 33 is coupled to the base end of the shaft body 31, and when the knob 33 is turned, the male thread 31b and the female thread 13b act to cause the shaft body 31 to move smoothly in its axial direction while rotating. In other words, the knob 33 is a moving means for the shaft body 31. Figure 3(a) shows the shaft body 31 moved toward its tip end, and Figure 3(b) shows the shaft body 31 moved toward its base end.

[0027] A cylindrical spool 32 having a smaller diameter than the intermediate portion 31a is provided at the tip of the shaft 31. A sleeve 34 into which the spool 32 is inserted without any gap is provided in the valve box 10, adjacent to the enlarged diameter portion 13a of the receiving hole 13. When the shaft 31 is moved by turning the knob 33, the spool 32 moves while rotating within the sleeve 34 (see FIGS. 3(a) and (b)). The sleeve 34 is connected to the flow path 12a.

[0028] Next, the spool 32 will be described in detail with reference to FIG. 4. The spool 32 has a cylindrical side surface 32a and a flat tip surface 32b at the tip. The spool 32 also has a groove 32c, which opens to the side surface 32a and the tip surface 32b. Specifically, in this embodiment, the groove 32c opens to extend in the axial direction along the generatrix on the side surface 32a as shown in FIG. 4(a), and opens to extend in the radial direction through the center on the tip surface 32b as shown in FIG. 4(b). The groove 32c has a certain width, which is sufficiently narrower than the flow paths 12a and 12b. The length of the opening of the groove 32c on the side surface 32a is longer than the length of the opening on the tip surface 32b.

[0029] The depth of the groove 32c is determined by the distance between the bottom 32d of the groove 32c and the side surface 32a or the tip surface 32b. The shape of the bottom 32d can be set arbitrarily. As will be described later, the shape of the bottom 32d determines how the flow rate is restricted by the throttle valve portion 30. In the embodiment shown in Fig. 4(c), the shape of the bottom 32d is linear from the side surface 32a to the tip surface 32b in a vertical cross section.

[0030] Next, the action of throttling the flow rate by the throttle valve portion 30 will be described with reference to FIG. 5. As described above, since the spool 32 moves while rotating inside the sleeve 34, the opening of the groove 32c on the side surface 32a can actually face any radial direction, but for convenience of explanation, FIG. 5 shows the opening facing right in the figure. In the state shown in FIG. 5(a), the spool 32 is deeply inserted into the sleeve 34, and at this time, the opening of the groove 32c on the side surface 32a is mostly blocked by the sleeve 34, while a part of it is exposed to the expanded diameter portion 13a. On the other hand, the opening of the groove 32c on the tip surface 32b is exposed toward the flow path 12a. Therefore, the path through which the fluid flows is connected from the flow path 12b through the expanded diameter portion 13a and the groove 32c to the flow path 12a. That is, the groove 32c forms an orifice in the second flow path 12 having the flow paths 12a and 12b.

[0031] FIG. 5(b) shows a state in which the shaft 31 has moved toward the base end compared to the state shown in FIG. 5(a). In the state shown in FIG. 5(b), the spool 32 is shallowly inserted into the sleeve 34, and the opening of the groove 32c on the side surface 32a is partially blocked by the sleeve 34, but most of it is exposed to the expanded diameter portion 13a. Therefore, the groove 32c forms an orifice in the second flow passage 12, but the size of the orifice in the state shown in FIG. 5(b) is larger than that in the state shown in FIG. 5(a). That is, a larger flow rate flows in the state shown in FIG. 5(b) than in the state shown in FIG. 5(a). The size of the orifice is determined by the shortest distance between the area of ​​the opening on the side surface 32a of the groove 32c that is blocked by the sleeve 34 and the bottom 32d of the groove 32c. Therefore, when the knob 33 of the throttle valve portion 30 is turned to move the shaft 31 in the axial direction, the size of the orifice changes depending on the position. This makes it possible to restrict the flow rate through the second flow passage 12.

[0032] Next, the relationship between the relative positions of the spool 32 and the sleeve 34 and the size of the orifice will be described with reference to Fig. 6. When the edge 34a of the sleeve 34 is at position X shown in Fig. 6 on the spool 32, the area of ​​the opening in the side surface 32a of the groove 32c that is blocked by the sleeve 34 is the section from position X to position O. Because the bottom 32d is linear, the shortest distance between this section and the bottom 32d of the groove 32c is the perpendicular line X-X' extending from position X to the bottom 32d, and this length is L1. This portion becomes the orifice, and if the width of the groove 32c is W, then the area of ​​the orifice is W x L1.

[0033] When the knob 33 is turned and the shaft body 31 moves in the proximal direction, and when the edge 34a of the sleeve 34 is at the position Y shown in FIG. 6 on the spool 32, the region of the opening on the side surface 32a of the groove 32c blocked by the sleeve 34 is the section from the position Y to the position O. Since the bottom 32d of the groove 32c is linear, the shortest distance between this section and the bottom 32d of the groove 32c is the perpendicular line Y - Y' extended from the position Y to the bottom 32d, and this length is L2. This part becomes the orifice. If the width of the groove 32c is W, the area of the orifice is W×L2. When the knob 33 is further turned and the shaft body 31 moves in the proximal direction, and when the edge 34a of the sleeve 34 is at the position Z shown in FIG. 6 on the spool 32, the region of the opening on the side surface 32a of the groove 32c blocked by the sleeve 34 is the section from the position Z to the position O. Since the bottom 32d of the groove 32c is linear, the shortest distance between this section and the bottom 32d of the groove 32c is the perpendicular line Z - Z' extended from the position Z to the bottom 32d, and this length is L3. This part becomes the orifice. If the width of the groove 32c is W, the area of the orifice is W×L3. The shape of the bottom 32d shown in FIG. 6 is linear, and L1 < L2 < L3. Thus, by turning the knob 33 to move the shaft body 31, the area of the orifice can be changed, and the flow rate flowing through the orifice can be changed.

[0034] In addition, as shown in FIG. 6, when the bottom 32d is linear, the relationship between the movement amount of the shaft body 31 and the area of the orifice is linear. Regarding the shape of the bottom 32d, in addition to being linear, for example, as shown in FIG. 7(a), it can be an arc shape concave toward the opening, and as shown in FIG. 7(b), it can be an arc shape convex toward the opening. Also, as shown in FIG. 7(c), it can be a curved shape with a non-constant curvature. In the cases of FIGS. 7(a), (b), and (c), the relationship between the movement amount of the shaft body 31 and the area of the orifice is different from that in FIG. 6. The shape of the bottom 32d can be set according to the relationship between the desired movement amount of the shaft body 31 and the flow rate.

[0035] In addition, the shape of the groove 32c shown in Figures 6 and 7 is such that the length of the opening on the side surface 32a is longer than the length of the opening on the tip surface 32b. This allows the change in the area of ​​the orifice relative to the amount of movement of the shaft 31 to be gradual. In other words, it is possible to finely control the flow rate. Of course, the relationship between the length of the opening on the side surface 32a and the length of the opening on the tip surface 32b for the shape of the groove 32c can be freely set. Note that the shaft 31 can move further in the base end direction than the state shown in Figure 5(b), and when the spool 32 is released from the sleeve 34, the area of ​​the orifice between the flow passages 12a and 12b suddenly expands, and the flow rate also increases rapidly.

[0036] Next, the flow control of the entire flow control valve 1 according to this embodiment will be described with reference to Fig. 1. When a fluid tries to flow from the second port 1b to the first port 1a, that is, when the pressure of the second port 1b is higher than the pressure of the first port 1a, the check valve section 20 operates as described above to block communication between the flow paths 11b and 11a. Therefore, the fluid from the flow path 11b flows toward the flow path 12b.

[0037] As described above, the flow rate of the fluid from the flow passage 12b is throttled by the throttle valve unit 30, and the fluid passes through the flow passages 12a and 11a and reaches the first port 1a. The flow rate of the fluid flowing from the flow passage 12b to the flow passage 12a is set by rotating the knob 33 of the throttle valve unit 30.

[0038] When a fluid tries to flow from the first port 1a to the second port 1b, that is, when the pressure at the first port 1a is higher than the pressure at the second port 1b, the check valve section 20 does not block the first flow path 11, and the fluid flows from the flow path 11a to the flow path 11b. At this time, a part of the fluid flows from the flow path 12a to the flow path 12b via the throttle valve section 30 at a flow rate set by the knob 33 of the throttle valve section 30. In other words, most of the fluid flowing from the first port 1a to the second port 1b passes through the first flow path 11, and only a small part passes through the second flow path 12.

[0039] Next, the relationship between the flow control valve 1 according to this embodiment and piping will be described with reference to FIG. 1. The first port 1a and the second port 1b of the flow control valve 1 are configured to be connected to the pipe by inserting them into the end of the pipe and twisting them. Therefore, the fluid control valve 1 itself may be rotated during installation. As shown in FIG. 1, the flow control valve 1 according to this embodiment has the first port 1a and the second port 1b arranged opposite each other, and the shaft 31 of the throttle valve portion 30 is arranged so as to be inclined at about 45° with respect to the line connecting the first port 1a and the second port 1b (i.e., the first flow path 11). The distance from the line connecting the first port 1a and the second port 1b to the knob 33 of the throttle valve portion 30 is short, i.e., the protruding length is short, so that the clearance required for piping is small.

[0040] Furthermore, in the flow control valve 1 according to this embodiment, the shaft 31 is disposed at an angle to the first flow passage 11, so the total amount of movement of the shaft 31 can be made larger than when the shaft 31 is disposed perpendicular to the first flow passage 11. This makes it possible to use the throttle valve portion 30 to throttle the flow rate more finely.

[0041] Second Embodiment Next, a flow control valve according to a second embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a partially enlarged view of the vicinity of the tip of the shaft of the flow control valve according to the second embodiment of the present invention, in which (a) is a side view, (b) is a view seen from the arrow CC in (a), and (c) is a cross-sectional view showing the DD cross section of (a).

[0042] The difference between this embodiment and the first embodiment is the shape of the spool 32 of the throttle valve portion 30. As shown in Fig. 8(a), the spool 32 according to this embodiment has a groove 32c like the first embodiment, but has an extension portion 32e in which the width of the opening at the tip end surface 32b is further expanded. The extension portion 32e has a crescent-shaped opening at the side surface 32a.

[0043] When the spool 32 according to this embodiment is applied, when the shaft 31 is moved in the base end direction and the opening in the side surface 32a of the expansion portion 32e approaches the edge 34a of the sleeve 34, the area of ​​the orifice formed suddenly expands and the flow rate also increases rapidly. In other words, when the sleeve 34 shown in Fig. 8 is applied, it is possible to provide a throttle valve portion 30 in which, when the knob 33 is turned, the increase in flow rate is gentle up to a certain point, but then the increase becomes large from that point on. The shape and size of the expansion portion 32e can be set according to the desired characteristics of the throttle valve portion 30.

[0044] <Other Modifications> In the flow control valve 1 according to the embodiment described above, the shaft 31 of the throttle valve portion 30 is disposed so as to be inclined at about 45° with respect to the line connecting the first port 1a and the second port 1b, but the inclination angle can be set appropriately. This angle is preferably 15° to 75°, and more preferably 30° to 60°. Furthermore, in the flow control valve 1 according to the embodiment described above, the first port 1a and the second port 1b are disposed so as to face each other, but this is not limited to this arrangement, and they can be disposed arbitrarily. [Explanation of symbols]

[0045] 1 Flow Control Valve 1a First port 1b Second port 10 Valve box 11 First flow path 11a Flow path 11b Flow path 12 Second flow path 12a Flow path 12b Flow path 13. Storage hole 13a Expanded diameter part 13b Female thread 20 Check valve section 21 Poppet 22 Spring 23 Spring seat 24 Valve seat 30 Throttle valve section 31 Axial body 31a middle part 31b Male thread 31c O-ring 32 Spool 32a side 32b Tip surface 32c groove 32d bottom 32e Extension 33 Knob (Means of Transportation) 34 Sleeve 34a Edge

Claims

1. A flow control valve that controls a flow rate of a fluid flowing between a first port and a second port, a check valve portion provided in a first flow path connecting the first port and the second port, the check valve portion allowing a flow from the first port to the second port while blocking a flow from the second port to the first port; a throttle valve portion that is provided in a second flow passage that connects the first port and the second port and is parallel to the first flow passage and that throttles a flow rate in both directions, the throttle valve portion includes a shaft body having a cylindrical spool at its tip, a moving means for moving the shaft body in its axial direction, and a sleeve into which the spool is inserted, The spool has a groove of a constant width that opens on its side surface and tip surface. A flow control valve comprising:

2. In a vertical cross-sectional view of the spool, the shape of the bottom of the groove is linear.

2. The flow control valve according to claim 1.

3. In a vertical cross-sectional view of the spool, the bottom of the groove has an arc shape.

2. The flow control valve according to claim 1.

4. The length of the opening of the groove at the side surface is longer than the length of the opening of the groove at the tip surface.

4. The flow control valve according to claim 1, wherein the flow control valve is a valve that is connected to the flow control valve.

5. The first port and the second port are disposed opposite to each other, The axial direction of the shaft is inclined at an angle of 15° to 75° with respect to a line connecting the first port and the second port.

4. The flow control valve according to claim 1, wherein the flow control valve is a valve that is connected to the flow control valve.

6. The first port and the second port are disposed opposite to each other, The axial direction of the shaft is inclined at an angle of 15° to 75° with respect to a line connecting the first port and the second port.

5. The flow control valve according to claim 4.

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