CN113494619B

CN113494619B - Electric valve

Info

Publication number: CN113494619B
Application number: CN202110648153.7A
Authority: CN
Inventors: 中川大树; 传田宏树
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2016-06-14
Filing date: 2017-04-21
Publication date: 2023-07-25
Anticipated expiration: 2037-04-21
Also published as: WO2017217114A1; CN109219716B; JP2017223263A; JP6359593B2; CN113494619A; CN109219716A

Abstract

The invention provides an electric valve with small flow difference and high energy saving performance in a minimum valve opening state. The electric valve converts rotational movement of a rotor into linear movement by rotational movement of a male screw member and a female screw member, and moves a valve body accommodated in a valve body in an axial direction based on the linear movement, wherein the valve body includes a failure state portion that forms a minute gap with the inner peripheral surface of the valve port when the valve port is inserted, and a height of the failure state portion inserted into the valve port is formed to be higher than a height of a thread gap amount when the threads are coupled.

Description

Electric valve

The application is a divisional application; the application number of the parent case is 2017800331720, and the invention name is an electric valve.

Technical Field

The present invention relates to an electrically operated valve used in a refrigeration cycle or the like.

Background

Conventionally, an electrically operated valve for an external air conditioner, an indoor air conditioner, a refrigerator, or the like has been known (for example, patent document 1). In this motor-operated valve, as shown in fig. 7, when the rotor 103 is rotated by driving the stepping motor, the valve body 114 is moved in the direction of the axis L by the screw feed action of the female screw 131a and the male screw 121a via the moving shaft 102. Thereby, the on-off valve body 114 is adjusted to control the flow rate of the refrigerant flowing in from the joint pipe 111 and flowing out from the joint pipe 112.

In this motor-operated valve, even if the valve body 114 is moved to the maximum in the valve closing direction, as shown in fig. 8, a small gap 123 is formed between the valve port 121 and the valve body 114, and the motor-operated valve is designed so as to be in the minimum valve-open state at this time. Therefore, even in the minimum valve opening state, the fluid is allowed to flow slightly through the gap 123, and the flow rate following the low-frequency operation of the compressor can be ensured. In addition, since the refrigerant can always circulate in the refrigeration cycle, the burning of the compressor can be prevented.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2007-205565

Disclosure of Invention

Problems to be solved by the invention

However, in the air conditioner and the refrigerator, improvement of energy saving performance has been actively studied, and similar performance is required even in an electric valve used in a refrigeration circuit. Here, as the performance required for improving the energy saving performance, suppression of positive contrast in the flow path direction, reduction of the flow rate, variation of the valve opening point, and the like are illustrated. In particular, since the electric valve used in the air conditioner needs to be controlled in consideration of the above performance, it is very difficult to control the electric valve to realize the energy-saving operation.

In the motor-operated valve described in patent document 1, when the fluid is passed in the forward direction, the flow rate characteristics are different from those when the fluid is passed in the reverse direction, and the flow rate varies by the amount of the thread clearance h (see fig. 2). Specifically, compared to the case where the fluid flows in the forward direction (lateral flow→downstream) in the minimum valve opening state as shown in fig. 8 (a), the position of the valve body 114 increases by the screw clearance h and the clearance 123 increases in the case where the fluid flows in the reverse direction (downward→lateral flow) in the minimum valve opening state as shown in fig. 8 (b).

Here, fig. 9 is a graph showing a change relation of the flow rate with respect to the applied amount of the pulse. In fig. 9, the horizontal axis of the graph indicates the amount of pulse applied to the stepper motor to move the valve body 114, and the vertical axis of the graph indicates the flow rate. In addition, the origin of the graph represents the minimum valve opening state. As can be understood from fig. 9, the flow rate in the minimum valve-open state increases by the thread clearance h amount when the fluid is passed in the reverse direction as compared with when the fluid is passed in the forward direction.

As described above, in the conventional solenoid valve, when the fluid is passed in the opposite direction, the flow rate in the minimum valve-opening state increases, and therefore there is a problem in that energy saving is greatly reduced due to the increase in the flow rate.

The invention aims to provide an electric valve with small flow difference and high energy saving performance in a minimum valve opening state.

Means for solving the problems

In order to achieve the above object, an electrically operated valve according to the present invention converts a rotational motion of a rotor into a linear motion by a screw coupling of a male screw member and a female screw member, moves a valve body accommodated in a valve body in an axial direction based on the linear motion,

the valve body includes a failure state portion forming a minute gap with the inner peripheral surface of the valve port when the valve port is inserted,

the height of the failure state portion inserted into the valve port is formed to be higher than the height of the thread clearance amount at the time of the bolt coupling.

This can suppress a difference in flow rate between when the fluid is passed in the forward direction and when the fluid is passed in the reverse direction in the minimum valve-opening state. Therefore, the energy saving problem that the minimum valve opening state flow rate increases and the energy saving performance decreases when the fluid is passed in the opposite direction can be improved.

In the electric valve according to the present invention, the outer peripheral surface of the failure state portion is parallel to the inner peripheral surface of the valve port.

This can further reduce the difference in flow rate between when the fluid is passed in the forward direction and when the fluid is passed in the reverse direction in the minimum valve-opening state, and can greatly improve the energy saving problem.

This can eliminate a difference in flow rate between when the fluid is passed in the forward direction and when the fluid is passed in the reverse direction in the minimum valve-opening state, and can solve the problem of energy saving.

Effects of the invention

According to the present invention, an electrically operated valve having a small flow rate difference in a minimum valve-opening state and high energy saving performance can be provided.

Drawings

Fig. 1 is a schematic cross-sectional view of an electrically operated valve according to an embodiment.

Fig. 2 is a diagram showing a state of screw engagement between a male screw and a female screw of the electric valve according to the embodiment.

Fig. 3 is an enlarged view of a main part of the motor-operated valve according to the embodiment.

Fig. 4 is a graph showing the results of comparing flow rate characteristics of the electric valve according to the embodiment.

Fig. 5 is an enlarged view of a main part of an electrically operated valve according to another embodiment.

Fig. 6 is a graph showing the result of comparing flow rate characteristics of the motor-operated valve according to the other embodiment.

Fig. 7 is a schematic cross-sectional view of a conventional electrically operated valve disclosed in japanese patent application laid-open No. 2007-205565.

Fig. 8 is an enlarged view of a main part of a conventional electrically operated valve.

Fig. 9 is a graph showing the result of comparing flow rate characteristics of a conventional electrically operated valve.

Detailed Description

Hereinafter, an electrically operated valve according to an embodiment will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing an electrically operated valve according to an embodiment. In the present specification, "up" and "down" refer to the up-down direction in the state shown in fig. 1. In the present specification, the term "forward direction" refers to a direction in which fluid passes from the joint pipe 11 to the joint pipe 12, and the term "reverse direction" refers to a direction in which fluid passes from the joint pipe 12 to the joint pipe 11.

The electrically operated valve 100 of this embodiment has a cylindrical valve body 1, and a cylindrical valve chamber 1A is formed in the valve body 1. Further, a joint pipe 11 communicating with the valve chamber 1A is attached to the valve body 1 from the side surface side, and a joint pipe 12 is attached to one end portion of the valve chamber 1A in the axial direction L. The valve body 1 is provided with a valve seat member 2 on the valve chamber 1A side of the joint pipe 12. The valve seat member 2 is formed of stainless steel, brass, or the like, and has a valve port 21 having a circular cross-sectional shape for communicating the valve chamber 1A with the joint pipe 12, and a secondary port 22 having a diameter larger than that of the valve port 21.

The support member 3 is mounted so that the lower end of the valve body 1 is coupled to the valve seat member 2 from the upper portion of the valve chamber 1A. The support member 3 is fixed to the valve body 1 by a mounting jig 3a provided in an upper opening of the valve body 1. A fixed lower end stopper SD protruding upward is formed at the upper end of the support member 3, and a fixed upper end stopper SU protruding radially is formed at the outer periphery of the upper end of the support member 3. Further, a female screw 31 coaxial with the axis L of the valve port 21 and a screw hole thereof are formed in the center of the support member 3, and a cylindrical guide hole 32 having a diameter larger than the diameter of the outer periphery of the screw hole of the female screw 31 is formed. A cylindrical male screw shaft 4 as a valve body holding portion is disposed in the screw hole of the female screw 31 and the guide hole 32. The support member 3 is formed with an insertion hole 34 through which a valve body 5 to be described later is inserted.

The male screw shaft 4 includes a large diameter portion 41 corresponding to the guide hole 32 and a small diameter portion 42 smaller in diameter than the large diameter portion 41. A cylindrical spring housing portion 41a is formed in the large diameter portion 41, and a slide hole 42a is formed in the center of the small diameter portion 42. The valve body 5 is fitted and inserted from the spring housing portion 41a to the slide hole 42a. Further, a spring holder 43 and a coil spring 44 are disposed in the spring housing portion 41a, and the coil spring 44 is disposed in a compressed state by welding a spring holder metal tool 45 to the upper end of the spring housing portion 41 a. Further, a male screw 42b is formed on the outer periphery of the small diameter portion 42, and the male screw 42b is screwed into the female screw 31 of the support member 3. When the male screw 42b is screwed with the female screw 31, as shown in fig. 2, a thread clearance h is generated between the thread of the male screw 42b and the thread of the female screw 31. The thread clearance will be described in detail later. A flange portion 41b is formed in the large diameter portion 41 of the male screw shaft 4, and a notch portion (not shown) cut in the radial direction is formed in a part of the flange portion 41 b. Further, a movable lower end stopper MD is formed below the flange 41 b.

A casing 61 of a stepping motor, not shown, is hermetically fixed to the upper end of the valve body 1 by welding or the like. A magnet rotor 62 magnetized to the outer periphery is rotatably provided in the housing 61 at a plurality of poles. A stator coil, not shown, is disposed on the outer periphery of the housing 61, and the stepping motor rotates the magnet rotor 62 according to the number of pulses by applying a pulse signal to the stator coil. The magnet rotor 62 has a fitting hole 62a and a rotation stopper (not shown). The fitting hole 62a is fitted into the large diameter portion 41 of the male screw shaft 4, the rotation stopper is engaged with the notch portion of the flange portion 41b of the male screw shaft 4, and the spring holder metal tool 45 is press-fitted into the end portion of the large diameter portion 41, thereby fixing the magnet rotor 62 to the male screw shaft 4.

The valve body 5 is formed of stainless steel, brass, or the like, and has a lower end portion 51, a failure state portion 52, and a rod portion 54 having a cylindrical rod shape, and the front end portion 51 and the failure state portion 52 will be described in detail later. In the motor-operated valve 100 of the present invention, the movable lower end stopper MD abuts against the fixed lower end stopper SD to regulate the rotation of the magnet rotor 62, so that even in a state where the valve body 5 is maximally moved in the valve closing direction, a small gap is formed between the valve body 5 and the valve port 21.

The valve body 5 is always urged downward by a coil spring 44 through a spring holder 43. In addition, the stem 54 of the valve body 5 is extended to the valve seat member 2 through the insertion hole 34 of the support member 3. Thus, the valve body 5 is held by the male screw shaft 4 in a state of being biased in the valve seat direction. The valve body 5 is relatively displaceable in the direction of the axis L with respect to the externally threaded shaft 4 against the urging force of the coil spring 44. The range of the relative displacement is a range from a position where the upper end of the lever 54 contacts the bottom of the spring housing 41a and the coil spring 44 extends to a position where the upper end of the lever 54 is slightly apart upward from the bottom of the spring housing 41 a.

According to the above configuration, the male screw shaft 4 rotates together with the magnet rotor 62 by the rotation of the magnet rotor 62, and the male screw 42b of the male screw shaft 4 and the female screw 31 of the support member 3 are caused to move in the axial direction (up and down) by the screw feeding action of the male screw shaft 4, whereby the tip end portion 51 and the failure state portion 52 of the valve body 5 advance and retreat with respect to the valve port 21 of the valve seat member 2. Thereby, the opening degree of the valve port 21 is changed, and for example, the flow rate of the refrigerant flowing from the joint pipe 11 to the joint pipe 12 is controlled. In the present motor-operated valve 100, the valve port 21 is not completely blocked by the valve body 5, and when the failure state portion 52 is located in the valve port 21 of the valve seat member 2, the valve is in the minimum valve-open state in which a slight gap is generated between the failure state portion 52 and the valve port 21. Thus, even in a state where the valve body 5 is maximally moved in the valve closing direction, the fluid is allowed to slightly flow through the gap.

Next, the main parts of the motor-operated valve 100 according to the embodiment will be described. Fig. 3 is an enlarged view of a main portion of the motor-operated valve 100 according to the embodiment. As shown in fig. 3, a substantially conical tip 51 having a tapered outer peripheral surface that narrows downward is formed at the lower end of the valve body 5. Further, a failure state portion 52 having an outer peripheral surface parallel to the inner peripheral surface of the valve port 21 is formed continuously with the distal end portion 51 above the distal end portion 51. As shown in fig. 2, the height of the failure state portion 52 is higher than the height of the thread clearance h at the time of thread bonding.

Here, fig. 3 (a) is a diagram showing a case where the fluid is passed in the forward direction (lateral→downstream) in the minimum valve opening state. On the other hand, fig. 3 (b) is a diagram of the case where the fluid is passed in the opposite direction (downward cross flow) in the minimum valve opening state. As shown in fig. 3 (a), when the fluid is passed in the forward direction, the valve body 5 is pushed down by a force generated by the flow of the fluid and a pressure difference acting on the valve body 5. On the other hand, as shown in fig. 3 (b), when the fluid is passed in the reverse direction, the valve body 5 is lifted upward by the fluid, and the position of the valve body 5 is increased by the screw gap h compared to when the fluid is passed in the forward direction.

However, since the failure state portion 52 has an outer peripheral surface parallel to the inner peripheral surface of the valve port 21 and has a height higher than the screw clearance H, by inserting the valve body 5 into the valve port 21 until the distance H between the lowermost end of the failure state portion 52 and the upper surface of the valve port 21 is greater than the screw clearance H by a depth (H > H) (see fig. 3 (a)), the interval of the gap 23 can be kept unchanged when the fluid is caused to flow in the forward direction and when the fluid is caused to pass in the reverse direction in the minimum valve-opening state. Therefore, the fluid flow rate through the void 23 can be made constant in the minimum valve-opening state.

Fig. 4 is a graph showing a change in flow rate with respect to the amount of pulse applied. In fig. 4, the horizontal axis of the graph indicates the amount of pulse applied to the stepper motor to move the valve body 5, and the vertical axis of the graph indicates the flow rate. In addition, the origin of the graph represents the minimum valve opening state.

In the minimum valve opening state, when the valve body 5 is inserted into the valve port 21 until the depth (H > H) that is greater than the thread clearance H is set between the lowermost end of the failure state portion 52 and the upper surface of the valve port 21, as shown in the circle of fig. 4, the flow rate of the fluid passing through the gap 23 in the minimum valve opening state is the same flow rate when the fluid passes in the forward direction as when the fluid passes in the reverse direction.

According to the electrically operated valve 100 of this embodiment, the height of the failure state portion 52 is made higher than the height of the screw gap h in screw engagement, so that the difference in flow rate between when the fluid passes in the forward direction and when the fluid passes in the reverse direction in the minimum valve-opening state can be suppressed. This difference in flow rate can be eliminated by forming the outer peripheral surface of the failure state portion 52 parallel to the inner peripheral surface of the valve port 21. Thus, by increasing the flow rate in the minimum valve opening state when the fluid is made to flow in the opposite direction, the energy saving problem that the energy saving performance is greatly reduced can be solved.

Next, an electrically operated valve according to another embodiment will be described. In the electric valve of this other embodiment, the outer peripheral surface of the failure state portion 52 is a slightly angled tapered surface. Therefore, in other embodiments, portions different from those of the embodiments will be described in detail, and the description of the duplicated portions will be omitted.

Fig. 5 (a) is an enlarged view of a main part of the electric valve in the minimum valve opening state when the fluid is passed in the forward direction (lateral flow→downstream), and fig. 5 (b) is an enlarged view of a main part of the electric valve in the minimum valve opening state when the fluid is passed in the reverse direction (downward cross flow). As shown in fig. 5 (a) and (b), the inclination angle β of the outer peripheral surface of the failure state portion 52' is formed smaller than the inclination angle α of the outer peripheral surface of the distal end portion 51 (β < α).

In this case, the interval between the voids 23 does not become large when the fluid is passed in the forward direction in the minimum valve-open state and when the fluid is passed in the reverse direction in the minimum valve-open state. Therefore, in the minimum valve-open state, the flow rate change of the fluid passing through the void 23 can be suppressed.

Fig. 6 is a graph showing a change in flow rate with respect to the amount of pulse applied in the case of using the electric valve according to the other embodiment. In the minimum valve opening state, when the valve body 5 is inserted into the valve port 21 so that the distance between the lowermost end of the failure state portion 52' and the upper surface of the valve port 21 is larger than the screw clearance h (see fig. 5 (a)), as shown in fig. 6, it is possible to suppress a difference in the flow rate of the fluid passing through the void 23, which occurs when the fluid passes in the forward direction and when the fluid passes in the reverse direction in the minimum valve opening state.

According to the electric valve of this embodiment, the height of the failure state portion 52' is formed higher than the height of the thread clearance h at the time of thread bonding, so that the difference in flow rate between when the fluid passes in the forward direction and when the fluid passes in the reverse direction in the minimum valve-opening state can be suppressed. This flow rate difference can be further reduced by forming the outer peripheral surface of the failure state portion 52' substantially parallel to the inner peripheral surface of the valve port 21. Thus, by increasing the flow rate in the minimum valve opening state when the fluid is passed in the opposite direction, the energy saving problem of greatly reducing the energy saving can be significantly improved.

Symbol description

100-electric valve, 1-valve body, 1A-valve chamber, 2-valve seat member, 3-support member, 3 a-mounting metal tool, 4-externally threaded shaft, 5-valve body, 21-valve port, 23-clearance, 31-female thread, 42 b-male thread, 51-front end portion, 52-fail status portion, 54-stem portion, 62-magnet rotor, H-thread clearance, H-distance between the lowest end of fail status portion and upper face of valve port, L-shaft.

Claims

1. An electric valve which converts a rotational motion of a rotor into a linear motion by a screw engagement of a male screw member and a female screw member, and moves a valve body accommodated in a valve body in an axial direction based on the linear motion, the electric valve being characterized in that,

the valve body includes: a cylindrical rod-shaped rod portion; a failure state portion that forms a minute gap with an inner peripheral surface of the valve port when the valve port is inserted, and has an outer peripheral surface parallel to an axis of the valve port; and a tip portion having a tapered outer peripheral surface formed continuously with the failure state portion,

the diameter of the stem is larger than the failure state portion and the valve port, the failure state portion is formed between the stem and the tip portion, the stem and the failure state portion are connected via a connecting portion having a tapered outer peripheral surface,

the tapered outer peripheral surface of the connecting portion has an axial length longer than the clearance, the valve port has an inner peripheral surface parallel to the outer peripheral surface of the failure state portion, and when the valve body is moved to the maximum extent in a direction opposite to the rotor, at least a part of the failure state portion is located in the valve port, and a height of the failure state portion inserted into the valve port is formed to be higher than a height of a thread clearance amount at the time of the thread bonding.

2. The electrically operated valve as set forth in claim 1, wherein,

the valve body is formed of stainless steel or brass.

3. An electrically operated valve as claimed in claim 1 or 2, characterized in that,

the device is provided with:

a support member fixed to the valve body and functioning as the female screw member; and

a male screw shaft adhesively fixed to the rotor and functioning as the male screw member,

the valve body is held by the male screw shaft in a state of being biased in a direction of a valve seat member disposed on the valve body.