JP7489874B2 - Check valve with release mechanism - Google Patents

Description

The present invention relates to a check valve with a release mechanism that prevents backflow.

A check valve allows fluid to flow in a specified direction and prevents flow in the opposite direction (i.e., backflow). A pilot-operated check valve can forcibly open the valve passage to allow backflow. An example of such a pilot-operated check valve is the pilot-operated check valve described in Patent Document 1 (see pilot-operated check valve 50 in Figure 3 of Patent Document 1). In the pilot-operated check valve described in Patent Document 1, a rod receives pilot pressure and operates. The rod then pushes the valve body away from the valve seat. This forcibly opens the valve passage.

JP 2007-298183 A

In the pilot-operated check valve of Patent Document 1, it is necessary to operate the rod to forcibly open the valve passage. And pilot pressure is required to operate the rod. Therefore, a pump, piping, etc. are required to supply the pilot pressure. Pumps, piping, etc. are not necessarily provided in all configurations of small hydraulic drive devices. Therefore, if a pilot-operated check valve such as that of Patent Document 1 is provided in a small hydraulic device, the hydraulic device will become larger. This makes it difficult to reduce the size of the hydraulic device.

The present invention aims to provide a check valve with a release mechanism that can be made smaller.

The check valve with release mechanism of the present invention comprises a housing in which a valve passage is formed, a valve body that moves between a closed position that closes the valve passage and an open position that opens the valve passage, and at least one piezoelectric element that moves the valve body in an opening direction from the closed position toward the open position, the piezoelectric element having an operating surface that is displaced by a drive signal, the operating surface being disposed to the side of the valve body.

According to the present invention, the valve body is forcibly moved to the open position by operating the piezoelectric element, allowing backflow. This makes it possible to miniaturize the check valve with release mechanism.

The present invention allows for miniaturization.

1 is a cross-sectional view showing a check valve with a release mechanism according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of the release mechanism-equipped check valve of FIG. 1 . FIG. 2 is a cross-sectional view showing a state in which the valve passage in the release mechanism-equipped check valve of FIG. 1 is open. FIG. FIG. 6 is a cross-sectional view showing a check valve with a release mechanism according to a second embodiment of the present invention.

The check valves with release mechanism 1, 1A according to the first and second embodiments of the present invention will be described below with reference to the drawings. Note that the concept of direction used in the following description is used for convenience in the description and does not limit the orientation of the configuration of the invention to that direction. Furthermore, the check valve with release mechanism 1 described below is merely one embodiment of the present invention. Therefore, the present invention is not limited to the embodiment, and additions, deletions, and modifications are possible within the scope of the spirit of the invention.

First Embodiment
The check valve with a release mechanism 1 shown in Fig. 1 allows fluid to flow in a forward direction and prevents fluid from flowing in a reverse direction (i.e., backflow). That is, the check valve with a release mechanism 1 closes the valve passage 2 to prevent backflow of pressure liquid. Furthermore, when a drive signal is input thereto, the check valve with a release mechanism 1 opens the valve passage 2 to allow backflow. The check valve with a release mechanism 1 having such a function includes a housing 3, a valve body 4, a plate member 5, and a plurality of piezoelectric elements 6.

The housing 3 has a valve passage 2 for flowing pressurized liquid. The valve passage 2 has an inlet passage 11, a valve chamber 12, and an outlet passage 13. In more detail, the inlet passage 11, the valve chamber 12, and the outlet passage 13 are arranged in that order in the valve passage 2 and are connected to each other. In this embodiment, the inlet passage 11, the valve chamber 12, and the outlet passage 13 are formed along a predetermined axis L1. That is, the valve chamber 12 is connected to the inlet passage 11 on one side in the axial direction, and is connected to the outlet passage 13 on the other side in the axial direction. The inlet passage 11 has a valve port 11a in a portion connected to the valve chamber 12. Furthermore, the valve chamber 12 has a valve seat 14 formed to surround the valve port 11a. In this embodiment, the valve seat 14 is formed in a tapered shape. That is, the valve seat 14 expands in diameter as it moves away from the valve port 11a. The shape of the valve seat 14 does not have to be formed in a tapered shape. The valve seat 14 may be, for example, a circular protrusion, and may have any shape as long as the valve body 4, which will be described later, can be seated thereon to block the valve passage 2. In this embodiment, the outflow passage 13 is formed to have approximately the same diameter as the valve chamber 12. The outflow passage 13 is also not limited to the shape described above, and may be formed to have a smaller diameter than the valve chamber 12.

The valve body 4 is accommodated in the valve chamber 12. The valve body 4 moves between a closed position that closes the valve passage 2 and an open position that opens the valve passage 2. In more detail, the valve body 4 is formed in a spherical shape. The valve body 4 seats on the valve seat 14 to block the flow of pressurized liquid from the valve port 11a. That is, when the valve body 4 is located in the closed position where it sits on the valve seat 14, the valve passage 2 is closed by the valve body 4. When the pressure liquid flows in the forward direction, the valve body 4 is pushed by the pressure liquid guided to the inflow passage 11. As a result, the valve body 4 leaves the valve seat 14 and the pressure liquid flows from the valve port 11a to the valve chamber 12. That is, when the valve body 4 is pushed by the pressure liquid and moves from the closed position to the open position, the valve passage 2 is opened. As a result, the inflow passage 11 and the outflow passage 13 are connected. Also, when the pressure liquid tries to flow backward, the valve body 4 is pushed toward the valve seat 14 by the pressure liquid. Then, the valve body 4 eventually seats on the valve seat 14. As a result, the valve body 4 is pushed by the pressure fluid and moves from the open position to the closed position. The valve passage 2 is then closed, and communication between the inflow passage 11 and the outflow passage 13 is blocked.

The plate member 5 prevents the valve body 4 from coming off the valve chamber 12. More specifically, the plate member 5 is formed in a roughly plate-like shape. The plate member 5 is interposed between the valve chamber 12 and the outflow passage 13. For example, the plate member 5 is sandwiched between two parts that are configured to be separable in the housing 3. As a result, the plate member 5 is disposed between the valve chamber 12 and the outflow passage 13. In addition, the plate member 5 is formed with a plurality of holes or a plurality of grooves, etc. As a result, the pressure liquid guided to the valve chamber 12 can be guided to the outflow passage 13. The shape and the method of attachment of the plate member 5 are not limited to the above-mentioned method. In addition, if the outflow passage 13 has a smaller diameter than the valve chamber 12 and the valve body 4, the plate member 5 does not need to be provided.

The multiple piezoelectric elements 6, also shown in FIG. 2, deform, i.e., expand and contract repeatedly in response to a drive signal input from a control device (not shown). The multiple piezoelectric elements 6 vibrate by repeatedly expanding and contracting. The multiple piezoelectric elements 6 bounce the valve body 4 by vibrating. In this way, the multiple piezoelectric elements 6 move the valve body 4 in the opening direction (reference line direction along the reference line (axis L1) described later) from the closed position toward the open position by bouncing the valve body 4. To explain in more detail, the multiple piezoelectric elements 6 are arranged on the side of the valve body 4 in the opening direction. The multiple piezoelectric elements 6 have an action surface 6a. The multiple piezoelectric elements 6 are arranged with the action surfaces 6a facing each other and facing the valve body 4. The action surface 6a is displaced by the deformation of the multiple piezoelectric elements 6. In this embodiment, the action surface 6a is adapted to come into contact with the valve body 4 when displaced. The action surface 6a applies a force including an opening direction component to the valve body 4 when it comes into contact with the valve body 4. In this embodiment, the action surface 6a is arranged at an angle θ1 (for example, 5°<θ1≦85°, more preferably 20°<θ1≦70°) with respect to a reference line (axis L1 in this embodiment) extending in the opening direction. Furthermore, the action surface 6a is arranged so as to abut on the valve orifice 11a side of the great circle 4a that passes through the center of the ball of the valve body 4 on which it is seated and is perpendicular to L1 (for example, see contact point T in FIG. 1). As a result, when the action surface 6a abuts, a force including an opening direction component is applied from the action surface 6a to the valve body 4. As a result, the valve body 4 is lifted in the opening direction.

To explain in more detail, the check valve 1 with release mechanism is provided with two piezoelectric elements 6 in this embodiment. The two piezoelectric elements 6 are arranged so that the action surfaces 6a face each other. Therefore, when a drive signal is intermittently input to the two piezoelectric elements 6, the valve body 4 can be moved back and forth (i.e., vibrated) between the two opposing action surfaces 6a (see the two-dot chain line and arrow in FIG. 3). This causes the valve body 4 to move in the opening direction, that is, the valve body 4 moves away from the valve port 11a. More specifically, since the force that the valve body 4 receives from the action surfaces 6a includes an opening direction component, the valve body 4 moves in the opening direction while vibrating between the two action surfaces 6a. In this way, the valve passage 2 is forcibly opened by the valve body 4 moving away from the valve port 11a. Note that the two action surfaces 6a facing each other means that they are located in front of each other regardless of the angle θ1 of the action surfaces 6a. In other words, the two action surfaces 6a do not necessarily need to face each other in a state where they are upright and parallel to the axis L1.

As shown in FIG. 2, the working surface 6a of each piezoelectric element 6 has a gap d1 between it and the valve body 4 when the valve body 4 is seated on the valve seat 14. This allows the valve body 4 to be reliably seated on 14. On the other hand, the gap d1 of at least one of the working surfaces 6a of the two piezoelectric elements 6 is smaller than the maximum displacement of the working surface 6a, i.e., the maximum deformation of the piezoelectric element 6, in this embodiment. However, the gap d1 is not limited to this. This allows the working surface 6a to be reliably abutted against the valve body 4 when one of the two piezoelectric elements 6 is deformed. Therefore, the valve body 4 can be more reliably moved in the opening direction by operating the two piezoelectric elements 6.

In the check valve 1 with release mechanism thus configured, when the valve element 4 is pressed to cause the pressurized liquid to flow in a predetermined direction, the valve element 4 moves from the closed position to the open position. This opens the valve passage 2. Then, the pressurized liquid flows from the inlet passage 11 through the valve chamber 12 and the hole or groove in the plate member 5 to the outlet passage 13. In other words, flow from the inlet passage 11 to the outlet passage 13 is permitted. On the other hand, when the pressurized liquid tries to flow backwards, the valve element 4 is pressed against the valve seat 14 by the pressurized liquid. This closes the valve passage 2. Then, flow from the outlet passage 13 to the inlet passage 11 is prevented, that is, flow in the reverse direction is prevented.

When a drive signal is intermittently input to the piezoelectric element 6 from a control device (not shown) while backflow is prevented, the check valve with release mechanism 1 operates as follows. That is, the control device inputs a drive signal that changes continuously and repeatedly (e.g., a sine wave signal) or an intermittent drive signal (e.g., a PWM signal) to the two piezoelectric elements 6. This causes the working surface 6a of the piezoelectric element 6 to be intermittently displaced (i.e., vibrate). Then, when the valve body 4 abuts against each working surface 6a, the valve body 4 moves from the closed position to the open position, and the valve passage 2 is forcibly opened. That is, the valve passage 2 is forcibly opened to allow backflow.

In the check valve 1 with release mechanism configured in this manner, the piezoelectric element 6 forcibly moves the valve body 4 to the open position to allow backflow. Since the check valve 1 with release mechanism is configured with the piezoelectric element 6, the check valve 1 with release mechanism can be made smaller. In addition, since the action surface 6a is inclined at an angle θ1 with respect to the reference line, a force including an opening component can be applied to the valve body 4 by displacing the action surface 6a and abutting it against the valve body 4. In addition, since the piezoelectric element 6 does not also serve as the valve seat 14, the geometric precision and surface roughness required for the valve seat 14 are not required. Therefore, the piezoelectric element 6 is easy to manufacture. Therefore, the check valve 1 with release mechanism is easy to configure and costs can be kept low.

In addition, when the action surface 6a abuts against the valve element 4, it abuts on the valve orifice 11a side of the great circle 4a of the valve element 4 when the valve element 4 is seated on the valve seat 14. Therefore, no matter what position the valve element 4 moves to, the action surface 6a abuts on the valve orifice 11a side of the great circle 4a of the valve element 4. This makes it possible to prevent the piezoelectric element 6 from generating a force that presses the valve element 4 against the valve orifice 11a when the action surface 6a is displaced, no matter what position the valve element 4 moves to. In other words, the valve passage 2 can be reliably opened by operating the piezoelectric element 6.

Second Embodiment
The check valve with a release mechanism 1A of the second embodiment is similar in configuration to the check valve with a release mechanism 1 of the first embodiment. Therefore, the configuration of the check valve with a release mechanism 1A of the second embodiment will be described mainly with respect to the differences from the check valve with a release mechanism 1 of the first embodiment, and the same components will be denoted by the same reference numerals and description thereof will be omitted.

The check valve 1A with a release mechanism of the second embodiment shown in FIG. 4 has a housing 3A, a valve body 4A, a spring member 7, and a plurality of piezoelectric elements 6. The housing 3A has a valve passage 2A. The valve passage 2A has an inlet passage 11, a valve chamber 12, and an outlet passage 13A. In this embodiment, the inlet passage 11 and the valve chamber 12 are formed along the axis L1. On the other hand, the outlet passage 13 is formed perpendicular to the axis L1. That is, the outlet passage 13A is connected to the side of the valve chamber 12. The valve body 4A is a plunger type valve. The valve body 4A is accommodated in the valve chamber 12 so as to be slidable along the axis L1. The tip of the valve body 4A is seated on a valve seat 14A formed around the valve port 11a. When the valve body 4A is positioned in the closed position where it is seated on the valve seat 14A, the valve passage 2A is closed by the valve body 4A. On the other hand, when the valve body 4A moves to an open position away from the valve seat 14A, the valve passage 2A is opened.

The spring member 7, which is a biasing member, is housed in the spring chamber 12a of the valve chamber 12. The spring member 7 biases the valve body 4A toward the valve port 11a, that is, in the closing direction from the open position to the closed position. Therefore, in the check valve with release mechanism 1A, the pressure liquid introduced into the inflow passage 11 lifts the valve body 4A against the biasing force of the spring member 7, thereby allowing the flow of pressure liquid. In addition, the valve body 4A is formed with a communication passage 4b that connects the outflow passage 13A and the spring chamber 12a. Therefore, when pressure liquid is introduced into the outflow passage 13A, the pressure liquid is introduced into the spring chamber 12a through the communication passage 4b. As a result, the valve body 4A is pressed in the closing direction by the pressure liquid and the spring member 7. Then, the valve passage 2 is closed. This prevents backflow.

The outer peripheral surface of the base end side of the valve body 4 protrudes outward over the entire circumference. That is, the valve body 4 has a large diameter portion 4c on the base end side. The large diameter portion 4c is formed with its surface on the valve port 11a side, i.e., the inclined surface 4d, inclined at an angle θ2 (for example, 5°<θ2≦85°, more preferably 20°<θ2≦70°) with respect to the axis L1. A step portion 3a is formed in the housing 3A so as to correspond to the inclined surface 4d. A plurality of piezoelectric elements 6 are provided on the step portion 3a.

The multiple piezoelectric elements 6 are arranged at intervals on the step 3a. In this embodiment, two piezoelectric elements 6 are provided on the step 3a. The two piezoelectric elements 6 are arranged with their working surfaces 6a to the side of the valve body 4A in the opening direction. The working surfaces 6a of the piezoelectric elements 6 are also arranged at an incline corresponding to the inclined surface 4d. In this embodiment, the working surface 6a is inclined at an angle θ2 with respect to the axis L1, similar to the inclined surface 4d.

The piezoelectric element 6 thus positioned can apply a force that includes a component in the opening direction to the valve body 4A when the working surface 6a is brought into contact with the inclined surface 4d. In other words, the piezoelectric element 6 can apply a force that includes a component that resists the biasing force of the spring member 7 to the valve body 4A via the working surface 6a. This allows the valve body 4A to be forcibly moved to the open position by the piezoelectric element 6, even in cases where a biasing force acts on the valve body 4A.

Furthermore, the action surface 6a is disposed with a gap d2 from the inclined surface 4d. This allows the valve body 4A to be reliably seated on the valve seat 14A. On the other hand, in this embodiment, the gap d2 is smaller than the maximum displacement of the action surface 6a, i.e., the maximum deformation of the piezoelectric element 6. However, the gap d2 is not limited to this. This allows the action surface 6a to be reliably abutted against the valve body 4A when either of the two piezoelectric elements 6 is deformed. Therefore, the valve body 4A can be moved in the opening direction by operating the two piezoelectric elements 6.

In addition, the check valve with release mechanism 1A of the second embodiment has the same effects as the check valve with release mechanism 1 of the first embodiment.

<Other embodiments>
In the check valves with release mechanisms 1, 1A of the first and second embodiments, two piezoelectric elements 6 are provided, but the number of piezoelectric elements 6 does not necessarily have to be two. For example, the number of piezoelectric elements 6 may be one, or may be three or more. Furthermore, the multiple piezoelectric elements 6 do not necessarily have to be arranged so that their working surfaces 6a face each other. The multiple piezoelectric elements 6 may be arranged offset along the circumferential direction. Moreover, the working surface 6a may also be arranged to the side of the valve body 4, 4A, and its shape and position are not limited to those described above.

In the check valves with release mechanisms 1 and 1A of the first and second embodiments, the piezoelectric element 6 may be positioned so that the operating surface 6a abuts against the valve body 4 before displacement.

1, 1A Check valve with release mechanism 2, 2A Valve passage 3, 3A Housing 4, 4A Valve body 4a Large circle 6 Piezoelectric element 6a Working surface 7 Spring member (biasing member)
11a Valve port 14, 14A Valve seat d1, d2 Gap

Claims (6)

a housing in which a valve passage is formed;
a valve body that moves between a closed position that closes the valve passage and an open position that opens the valve passage;
at least one piezoelectric element that moves the valve body in an opening direction from a closed position toward an open position;
The piezoelectric element has an operating surface that is displaced by a drive signal,
The operating surface is disposed to the side of the valve body. The check valve with release mechanism according to claim 1, wherein the operating surface is arranged at an angle with respect to a reference line extending in the opening direction. The valve passage has a valve port,
The housing has a valve seat around the valve port,
The valve body is seated on the valve seat in a closed position,
The action surface is disposed with a gap from the valve body when the valve body is seated on the valve seat,
3. The check valve with a release mechanism according to claim 1, wherein the gap is set to be equal to or smaller than a maximum displacement of the operating surface. At least two piezoelectric elements are included,
4. The check valve with a release mechanism according to claim 1, wherein the two piezoelectric elements are arranged with their respective operating surfaces facing each other. The valve passage has a valve port,
The housing has a valve seat around the valve port,
The valve body is formed in a spherical shape and is seated on the valve seat in a closed position.
5. The check valve with a release mechanism according to claim 1, wherein the operating surface is disposed so as to abut on the valve orifice side of a great circle that passes through a center of the valve body and is perpendicular to a reference line extending in an opening direction. The valve body further includes a biasing member that biases the valve body in a closing direction from an open position toward a closed position,
5. The check valve with a release mechanism according to claim 1, wherein the acting surface of said piezoelectric element applies to said valve body a force including a component resisting the biasing force of said biasing member.

Images