JP2017223263A - Solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve having small difference of flow rate in a minimum valve opening state and having high energy conservation.SOLUTION: A solenoid valve is configured to convert rotation movement of a rotor into linear movement with screwing of a male screw member and a female screw member, and move a valve element 5, stored in the valve body, in an axial direction based on the linear movement. The valve element includes an insensitive part 52 that when inserted into a valve port 21, is formed with a minute clearance 23 between the valve element and the inner peripheral surface of the valve port. A height H of the insensitive part inserted into the valve port is formed higher than a height of a backlash h portion in screwing.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electric valve used for a refrigeration cycle or the like.

  Conventionally, an electric valve used for a package air conditioner, a room air conditioner, a refrigerator, and the like is known (for example, Patent Document 1). In this motor-operated valve, as shown in FIG. 7, when the stepping motor is driven and the rotor 103 rotates, the valve body 114 is cylindrically guided through the moving shaft 102 by the screw feeding action of the female screw 131a and the male screw 121a. It moves along the axis L direction along 113. Thereby, adjustment which opens and closes the valve body 114 is made, and the flow rate of the refrigerant flowing in from the pipe joint 111 and flowing out from the pipe joint 112 is controlled.

  In this motor-operated valve, a slight gap 123 is formed between the valve port 121 and the valve body 114 even when the valve body 114 is moved to the maximum in the valve closing direction. It is designed to be in a state. For this reason, even in the minimum valve open state, the fluid is allowed to flow slightly through the gap 123 (see FIG. 8), and the flow rate following the low frequency operation of the compressor can be ensured. Further, since the refrigerant can always circulate in the refrigeration cycle, the compressor can be prevented from being burned out.

JP 2007-205565 A

  By the way, at present, improvement in energy saving performance is actively studied for air conditioners and refrigerators, and the same performance is also required for motor-operated valves used in refrigeration circuits. Here, the performance required for improving the energy saving performance includes suppression of forward / reverse difference in the flow path direction, reduction of variation in flow rate and valve opening point, and the like. In particular, the motor-operated valve used in the air conditioner needs to be controlled in consideration of the above-described performance, so that control for realizing energy-saving operation has become very difficult.

  In the motor-operated valve described in Patent Document 1 described above, the flow rate characteristics are different between when the fluid is passed in the forward direction and when the fluid is passed in the reverse direction, and the flow rate is increased by the screw backlash h (see FIG. 2). There is a difference. Specifically, as shown in FIG. 8 (a), compared to the case where fluid flows in the forward direction in the minimum valve open state, the reverse direction in the minimum valve open state as shown in FIG. 8 (b). When the fluid flows through the valve body 114, the position of the valve body 114 is increased by the amount of the screw backlash h, and the gap 123 is widened.

  Here, FIG. 9 is a graph showing the relationship between the flow rate change and the pulse application amount. In FIG. 9, the horizontal axis of the graph represents the amount of pulses applied to the stepping motor to move the valve body 114, and the vertical axis of the graph represents the flow rate. The origin of the graph represents the minimum valve open state. According to FIG. 9, it can be seen that the flow rate when the fluid is passed in the reverse direction is increased by the screw backlash h in the minimum valve open state than when the fluid is passed in the forward direction.

As described above, in the conventional motor-operated valve, when the fluid is allowed to pass in the opposite direction, the flow rate in the minimum valve open state increases.
An object of the present invention is to provide an electric valve with a small difference in flow rate in a minimum valve open state and high energy saving performance.

To achieve the above object, the motor-operated valve of the present invention is
This is an electric valve that converts the rotational motion of the rotor into a linear motion by screwing the male screw member and the female screw member, and moves the valve element accommodated in the valve body in the axial direction based on this linear motion. And
When the valve body is inserted into a valve port, the valve body includes an insensitive portion that forms a minute clearance with the inner peripheral surface of the valve port,
A height of the insensitive portion inserted into the valve port is formed to be higher than a height of a screw play at the time of the screwing.

  Thereby, 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 open state can be suppressed. Therefore, when the fluid is passed in the reverse direction, it is possible to improve the problem of energy saving that the flow rate in the minimum valve open state increases and the energy saving performance decreases.

Moreover, the motor operated valve of the present invention is
The outer peripheral surface of the insensitive portion and the inner peripheral surface of the valve port are substantially parallel.

  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 open state, greatly improving the problem of energy saving. Can do.

Moreover, the motor operated valve of the present invention is
The outer peripheral surface of the insensitive portion and the inner peripheral surface of the valve port are parallel to each other.

  As a result, 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 open state can be eliminated, and the problem of energy saving can be solved.

  According to the invention of the present invention, it is possible to provide an electric valve with a small difference in flow rate in the minimum valve open state and high energy saving performance.

It is sectional drawing of the motor operated valve which concerns on embodiment. It is a figure which shows the screwing state of the external thread and internal thread in the motor operated valve which concerns on embodiment. It is a principal part expanded sectional view of the motor operated valve concerning an embodiment. It is a graph which shows the result of having compared the flow characteristics of the motor operated valve concerning an embodiment. It is a principal part expanded sectional view of the motor operated valve concerning other embodiments. It is a graph which shows the result of having compared the flow characteristic of the motor operated valve concerning other embodiments. It is sectional drawing of the conventional motor operated valve currently disclosed by Unexamined-Japanese-Patent No. 2007-205565. It is a principal part expanded sectional view of the conventional motor operated valve. It is a graph which shows the result of having compared the flow characteristics of the conventional motor operated valve.

  Hereinafter, an electric valve according to an embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an electric valve according to an embodiment. Note that “upper” and “lower” described in the present specification mean the up and down directions in the state shown in FIG. In addition, the “forward direction” described in the present specification means a direction when the fluid is passed from the joint pipe 11 toward the joint pipe 12, and the “reverse direction” means that the fluid is passed through the joint pipe. It means the direction when passing from the pipe 12 toward the joint pipe 11.

  The motor-operated valve 100 of this embodiment has a cylindrical valve main body 1, and a cylindrical cylinder-shaped valve chamber 1 </ b> A is formed in the valve main body 1. In addition, a joint pipe 11 communicating with the valve chamber 1A from the side surface side is attached to the valve body 1, and a joint pipe 12 is attached to one end portion in the axis L direction of the valve chamber 1A. Further, 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 that communicates the valve chamber 1A and the joint pipe 12 and a subport 22 having a diameter larger than that of the valve port 21.

  A support member 3 is attached from the upper part of the valve body 1 to the valve chamber 1A so that the lower end is coupled to the valve seat member 2. The support member 3 is fixed to the valve body 1 by a mounting bracket 3 a provided in the 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 in the radial direction is formed at the outer peripheral edge of the upper end of the support member 3. A female screw 31 coaxial with the axis L of the valve port 21 and its screw hole are formed at the center of the support member 3 and a cylindrical guide hole having a diameter larger than the outer periphery of the screw hole of the female screw 31. 32 is formed. A male screw shaft 4 as a cylindrical 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 later-described valve body 5 is inserted.

  The male screw shaft 4 has a large diameter portion 41 aligned with the guide hole 32 and a small diameter portion 42 having a diameter smaller than that of the large diameter portion 41. A cylindrical spring accommodating portion 41 a is formed in the large diameter portion 41, and a slide hole 42 a is formed in the center of the small diameter portion 42. And the valve body 5 is inserted and inserted from the spring accommodating part 41a to the slide hole 42a. Further, a spring receiver 43 and a coil spring 44 are disposed in the spring accommodating portion 41a, and the coil spring 44 is arranged in a compressed state by welding a spring bracket 45 to the upper end of the spring accommodating portion 41a. It is installed. Further, a male screw 42 b is formed on the outer periphery of the small passage portion 42, and the male screw 42 b is screwed to the female screw 31 of the support member 3. In addition, when the male screw 42b and the female screw 31 are screwed together, as shown in FIG. 2, a screw play h is generated in the gap between the screw thread of the male screw 42b and the screw thread of the female screw 31. This screw play will be described in detail later. Further, 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 41b. A movable lower end stopper MD is formed on the lower surface of the flange portion 41b.

  A case 61 of a stepping motor (not shown) is airtightly fixed to the upper end of the valve body 1 by welding or the like. In the case 61, a magnet rotor 62 whose outer peripheral portion is magnetized in multiple poles is rotatably provided. A stator coil (not shown) is disposed on the outer periphery of the case 61, and the stepping motor rotates the magnet rotor 62 according to the number of pulses when a pulse signal is given to the stator coil. The magnet rotor 62 has a fitting hole 62a and a rotation stopper (not shown). Then, the fitting hole 62a is fitted to 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 bracket 45 is further enlarged. The magnet rotor 62 is fixed to the male screw shaft 4 by being press-fitted into and welded to the end portion of the diameter portion 41.

  The valve body 5 is made of stainless steel, brass, or the like, and has a tip 51 at the lower end, an insensitive portion 52, and a rod portion 54 having a cylindrical rod shape. The tip 51 and the insensitive part 52 will be described in detail later. In the motor-operated valve 100 of the present invention, the rotation of the magnet rotor 62 is restricted by the movable lower end stopper MD and the fixed lower end stopper SD coming into contact with each other, so that the valve body 5 is moved to the maximum in the valve closing direction. Even in this state, a slight clearance 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 via a spring receiver 43. The valve body 5 has a rod portion 54 extending to the valve seat member 2 through the insertion hole 34 of the support member 3. Thereby, the valve body 5 is held by the male screw shaft 4 in a state of being biased in the valve seat direction. Further, the valve body 5 can be displaced relative to the male screw shaft 4 in the direction of the axis L against the urging force of the coil spring 44. This relatively displaceable range is such that the upper end of the rod portion 54 contacts the bottom of the spring accommodating portion 41a and the coil spring 44 extends, and the upper end of the rod portion 54 extends upward from the bottom of the spring accommodating portion 41a. This is a range up to a slightly separated position.

  With the above configuration, the male screw shaft 4 is rotated together with the magnet rotor 62 by the rotation of the magnet rotor 62, and the male screw shaft 4 is axially moved by the screw feeding action of the male screw 42 b of the male screw shaft 4 and the female screw 31 of the support member 3. The tip part 51 and the insensitive part 52 of the valve body 5 move forward and backward 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 motor-operated valve 100, the valve port 21 is not completely blocked by the valve body 5, and when the insensitive portion 52 is located in the valve port 21 of the valve seat member 2, the insensitive portion The valve is in the minimum valve open state in which a slight clearance is generated between the valve port 21 and the valve port 21. For this reason, even when the valve body 5 is moved to the maximum in the valve closing direction, the fluid is allowed to flow slightly through the clearance.

  Next, the principal part of the motor operated valve 100 in the embodiment will be described. FIG. 3 is an enlarged cross-sectional view of a main part 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. In addition, an insensitive portion 52 having an outer peripheral surface parallel to the inner peripheral surface of the valve port 21 is formed continuously above the distal end portion 51. In addition, the height of the insensitive state part 52 is formed so as to be higher than the height of the screw play h at the time of screwing shown in FIG.

  Here, Fig.3 (a) is a figure which shows the case where the fluid is allowed to pass in the forward direction in the minimum valve open state. On the other hand, FIG.3 (b) is a figure which shows the case where the fluid is made to pass in a reverse direction in the minimum valve open state. As shown in FIG. 3A, when the fluid is passed in the forward direction, the valve body 5 is pushed downward by a force due to 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 valve body 5 is moved more than when the fluid is passed in the forward direction. The position becomes higher by the screw play h.

  However, since the insensitive 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 backlash h, the lowermost end of the insensitive portion 52 and the upper surface of the valve port 21 are provided. By inserting the valve body 5 into the valve port 21 (see FIG. 3A) to a depth at which the distance H between the two and the screw h becomes greater than the screw backlash h (H> h), the fluid flows in the forward direction in the minimum valve open state. It is possible to prevent the interval of the clearance 23 from being changed between when it is passed through and when it is passed in the opposite direction. Therefore, the flow rate of the fluid passing through the clearance 23 in the minimum valve open state can be made constant.

  FIG. 4 is a graph showing the relationship of the change in flow rate with respect to the pulse application amount. In FIG. 4, the horizontal axis of the graph represents the amount of pulses applied to the stepping motor to move the valve body 5, and the vertical axis of the graph represents the flow rate. The origin of the graph represents the minimum valve open state.

  When the valve body 5 is inserted into the valve port 21 to a depth where the distance H between the lowermost end of the insensitive portion 52 and the upper surface of the valve port 21 is larger than the screw backlash h (H> h) in the minimum valve open state. As shown in the circle in FIG. 4, the flow rate of the fluid passing through the clearance 23 in the minimum valve open state is the same when the fluid is passed in the forward direction and when the fluid is passed in the opposite direction. Become.

  According to the motor-operated valve 100 according to this embodiment, the fluid is allowed to pass in the forward direction in the minimum valve open state by forming the height of the insensitive portion 52 higher than the height of the screw play h at the time of screwing. It is possible to suppress a difference in flow rate between when the fluid is passed and when the fluid is passed in the opposite direction. Such a difference in flow rate can be eliminated by forming the outer peripheral surface of the insensitive portion 52 so as to be parallel to the inner peripheral surface of the valve port 21. Thereby, when the fluid is passed in the reverse direction, the problem of energy saving that the energy saving performance is greatly reduced by increasing the flow rate in the minimum valve open state can be solved.

  Next, an electric valve according to another embodiment will be described. In the motor-driven valve according to another embodiment, the outer peripheral surface of the insensitive portion 52 has a slight taper in the embodiment. Therefore, in other embodiments, portions different from the embodiments will be described in detail, and descriptions of overlapping portions will be omitted.

  FIG. 5A is an enlarged cross-sectional view of the main part of the motor-operated valve in the minimum valve open state when the fluid is passed in the forward direction, and FIG. It is sectional drawing to which the principal part of the motor operated valve of the minimum valve open state was expanded. As shown in FIGS. 5A and 5B, the inclination angle β of the outer peripheral surface of the insensitive portion 52 ′ is formed to be smaller than the inclination angle α of the outer peripheral surface of the tip 51 (β <Α).

  In this case, it is possible to prevent the clearance 23 from changing greatly between 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, a change in the flow rate of the fluid passing through the clearance 23 in the minimum valve open state can be suppressed.

  FIG. 6 is a graph showing the relationship of the change in flow rate with respect to the pulse application amount when the motor-operated valve according to another embodiment is used. When the valve body 5 is inserted into the valve port 21 so that the distance between the lowermost end of the insensitive portion 52 ′ and the upper surface of the valve port 21 is larger than the screw backlash h in the minimum valve open state (FIG. 5A 6), as shown in FIG. 6, the difference in the flow rate of the fluid passing through the clearance 23 in the minimum valve open state caused when the fluid is passed in the forward direction and when the fluid is passed in the opposite direction. Can be suppressed.

  According to the motor-operated valve according to this embodiment, the fluid is allowed to pass in the forward direction in the minimum valve open state by forming the height of the insensitive portion 52 ′ higher than the height of the screw play h at the time of screwing. It is possible to suppress a difference in flow rate between when the fluid is passed and when the fluid is passed in the opposite direction. This difference in flow rate can be further reduced by forming the outer peripheral surface of the insensitive portion 52 ′ so as to be substantially parallel to the inner peripheral surface of the valve port 21. Thereby, when the fluid is passed in the opposite direction, the energy saving problem that the energy saving performance is greatly reduced by increasing the flow rate in the minimum valve open state can be greatly improved.

100 Motorized valve 1 Valve body 1A Valve chamber 2 Valve seat member 3 Support member 3a Mounting bracket 4 Male screw shaft 5 Valve body 21 Valve port 23 Clearance 31 Female screw 42b Male screw 51 Tip 52 Insensitive part 54 Rod part 62 Magnet rotor h Screw backlash H Distance between bottom end of dead zone and top surface of valve port L-axis

Conventionally, an electric valve used for a package air conditioner, a room air conditioner, a refrigerator, and the like is known (for example, Patent Document 1). In this electric valve, as shown in FIG. 7, when the stepping motor is driven and the rotor 103 rotates, the valve element 114 is moved in the axis L direction via the moving shaft 102 by the screw feeding action of the female screw 131a and the male screw 121a. Moving. Thereby, adjustment which opens and closes the valve body 114 is made, and the flow rate of the refrigerant flowing in from the pipe joint 111 and flowing out from the pipe joint 112 is controlled.

In this motor-operated valve, a slight gap 123 is formed between the valve port 121 and the valve body 114 as shown in FIG. 8 even when the valve body 114 is moved to the maximum in the valve closing direction . At this time, the valve is designed to be in the minimum valve open state. Therefore, even at the minimum valve open state, is allowed fluid to flow slightly through the gap 123, it is possible to ensure the flow rate to follow the low frequency operation of the compressor. Further, since the refrigerant can always circulate in the refrigeration cycle, the compressor can be prevented from being burned out.

To achieve the above object, the motor-operated valve of the present invention is
This is an electric valve that converts the rotational motion of the rotor into a linear motion by screwing the male screw member and the female screw member, and moves the valve element accommodated in the valve body in the axial direction based on this linear motion. And
An insensitive portion that forms a minute clearance with the inner peripheral surface of the valve port when the valve body is inserted into the valve port ;
A tip portion having a tapered outer peripheral surface formed continuously with the insensitive portion, and
A height of the insensitive portion inserted into the valve port is formed to be higher than a height of a screw play at the time of the screwing.

As a result, 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 open state can be eliminated, and the problem of energy saving can be solved.
Moreover, the motor operated valve of the present invention is
The valve body is made of stainless steel or brass.
Moreover, the motor operated valve of the present invention is
A support member fixed to the valve body and functioning as the female screw member;
A male screw shaft fixed to the rotor and functioning as the male screw member;
With
The valve body is held by the male screw shaft in a state of being biased in the direction of a valve seat member disposed in the valve body.

A case 61 of a stepping motor (not shown) is airtightly fixed to the upper end of the valve body 1 by welding or the like. In the case 61, a magnet rotor 62 whose outer peripheral portion is magnetized in multiple poles is rotatably provided. A stator coil (not shown) is disposed on the outer periphery of the case 61, and the stepping motor rotates the magnet rotor 62 according to the number of pulses when a pulse signal is given to the stator coil. The magnet rotor 62 has a fitting hole 62a and a rotation stopper (not shown). Then, 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 bracket 45 is further made large-diameter. The magnet rotor 62 is fixed to the male screw shaft 4 by being press-fitted into the end of the portion 41 and welded.

Claims (3)

This is an electric valve that converts the rotational motion of the rotor into a linear motion by screwing the male screw member and the female screw member, and moves the valve element accommodated in the valve body in the axial direction based on this linear motion. And
The valve body includes an insensitive portion that forms a minute clearance with the inner peripheral surface of the valve port when inserted into the valve port,
The motor-operated valve, wherein a height of the insensitive portion inserted into the valve port is formed to be higher than a height corresponding to a screw play at the time of screwing.   The motor-operated valve according to claim 1, wherein the outer peripheral surface of the insensitive portion and the inner peripheral surface of the valve port are substantially parallel.   The motor-operated valve according to claim 2, wherein the outer peripheral surface of the insensitive portion and the inner peripheral surface of the valve port are parallel to each other.

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