Electric valve

Abstract

To suppress wear of a fitting groove, and prevent uneven wear of the fitting groove.SOLUTION: A motor valve comprises: a valve body 12 including a valve chamber 13 communicating with a first flow path 14 and a second flow path 15; a valve element 18 that moves toward and away from a valve seat 16 formed in the valve chamber; an electric motor 31 that drives the valve element; a speed reduction mechanism 21 that reduces the rotational speed of the electric motor; an output shaft 22 that outputs the rotation reduced by the speed reduction mechanism; and a transmission mechanism 23 that converts the rotational motion of the output shaft into linear motion and transmits it to the valve element. The transmission mechanism is an electric valve that has a feed screw member 25 having a plate-shaped part 25c that is fitted into a slit-shaped fitting groove 22a formed in the output shaft in a vertically movable manner and a male screw part 25a formed on an outer surface, and a bearing member 24 having a female screw part 24a screwed to the male screw part, and a relief part 22b that communicates with the fitting groove and can receive a tip part of the plate-shaped part in a non-contact manner is provided at the back part of the fitting groove.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric valve, and particularly to the structure of a power transmission part of a gear-type electric valve.

Background Art

[0002] An electric valve that adjusts the opening degree of a valve using an electric motor such as a stepping motor and controls the flow rate of a refrigerant has been conventionally used in a refrigeration cycle device provided with a refrigerant circuit such as an air conditioner or a refrigerating / freezing device.

[0003] Further, as such an electric valve, there is a gear-type electric valve. FIGS. 5 to 7 show an example of a gear-type electric valve. As shown in these figures, the electric valve 41 includes a valve body 12 having a valve chamber 13 communicating with a first flow path pipe 14 and a second flow path pipe 15 inside, a valve element 18 that moves forward and backward with respect to a valve seat 16 formed in the valve chamber 13, an electric motor 31 that drives the valve element 18, a speed reduction mechanism (a mysterious planetary gear speed reduction mechanism) 21 that reduces the rotation of the electric motor 31, an output shaft 22 that outputs the rotation reduced by the speed reduction mechanism 21, and a transmission mechanism 23 that converts the rotational motion of the output shaft 22 into a linear motion and transmits it to the valve element 18.

[0004] The transmission mechanism 23 includes a feed screw member 25 having a plate-shaped portion 25c that is vertically movably fitted into a slit-shaped fitting groove 22a formed in the output shaft 22, and a female screw portion 24a formed on the lower inner surface of the central hole of the bearing member 24. The feed screw member 25 has a male screw portion 25a on its outer peripheral surface that is screwed into the female screw portion 24a of the bearing member 24, and these male screw portion 25a and female screw portion 24a constitute a feed screw. Therefore, when the rotation of the output shaft 22 is transmitted to the feed screw member 25 through the fitting groove 22a and the plate-shaped portion 25c, the feed screw member 25 moves in the vertical direction while rotating. Then, the vertical movement of the feed screw member 25 is transmitted to the valve element 18 through the ball joint 26.

[0005] Further, the following Patent Document 1 is a document that discloses such an electric valve.

Prior Art Document

[0006] [Patent Document 1] Japanese Patent Publication No. 2017-9025 [Overview of the project] [Problems that the invention aims to solve]

[0007] By the way, in conventional electric valves 41, as the valve body 18 moves up and down, the plate-shaped portion 25c of the lead screw member 25 slides vertically within the fitting groove (hereinafter sometimes simply referred to as "groove") 22a of the output shaft 22, which can cause wear on the fitting groove 22a due to prolonged use.

[0008] Here, the lower part (entrance) of the fitting groove 22a is always in contact with the plate-shaped part 25c, while the upper part (inner part) of the fitting groove 22a is only in contact with the plate-shaped part 25c when the plate-shaped part 25c rises. As a result, the lower part of the groove is worn down deeply, while the upper part is worn down relatively less, causing uneven wear of the fitting groove 22a. Consequently, in the past, this could lead to looseness between the output shaft 22 and the feed screw member 25 (plate-shaped part 25c) or a decrease in the coaxiality between the output shaft 22 and the feed screw member 25.

[0009] Furthermore, the portion of the plate-shaped part 25c that comes into contact with the tip (upper end) corner 25d is prone to being scraped and worn down by the corner 25d as it pushes upward within the fitting groove 22a when the feed screw member 25 rises.

[0010] Therefore, the object of the present invention is to suppress wear of the fitting groove 22a and to prevent uneven wear of the fitting groove 22a. [Means for solving the problem]

[0011] To solve the aforementioned problems and achieve the objective, the electric valve according to the present invention comprises a valve body having a valve chamber inside that communicates with a first flow path and a second flow path, a valve body that moves back and forth relative to a valve seat formed in the valve chamber, an electric motor that drives the valve body, a reduction mechanism that reduces the rotation of the electric motor, an output shaft that outputs the rotation reduced by the reduction mechanism, and a transmission mechanism that converts the rotational motion of the output shaft into linear motion and transmits it to the valve body, wherein the transmission mechanism comprises a feed screw member having a plate-shaped portion and a male threaded portion formed on its outer circumference that is fitted vertically movably into a slit-shaped fitting groove formed on the output shaft, and a bearing member having a female threaded portion that screws into the male threaded portion, The output shaft is located inside it. A relief section that can receive the tip of the plate-shaped part in a non-contact manner. The relief portion is open at its lower end, allowing it to communicate with the fitting groove at the upper end of the fitting groove, while its upper end is closed. .

[0012] In this application, the direction from the valve seat towards the valve body is defined as "up," and the direction from the valve body towards the valve seat is defined as "down." Based on these concepts of "up" and "down," terms related to up and down, such as "upper," "downward," "upper part," "lower part," "upper side," and "lower side," are used. However, since the electric valve of the present invention (and the embodiments described later) can be used in various orientations, "down" is not necessarily the direction of gravity and "up" is not necessarily the opposite direction of gravity.

[0013] The electric valve of the present invention is a gear-type flow control valve that controls the flow rate of a fluid such as a refrigerant. Similar to the conventional electric valve, it has a lead screw member and a bearing member as a transmission mechanism for transmitting the driving force of the electric motor to the valve body. When the rotation of the output shaft is transmitted to the lead screw member via the fitting groove and plate-shaped portion, the lead screw member moves up and down due to the action of the lead screw, which is formed by a male threaded portion formed on the outer circumferential surface of the lead screw member and a female threaded portion provided on the bearing member. The up and down movement of the lead screw member is then transmitted to the valve body, causing the valve body to move in the vertical direction. This changes the distance between the valve body and the valve seat, thereby changing the flow rate of the fluid.

[0014] On the other hand, in the electric valve according to the present invention, a relief portion is provided at the back (upper part) of the fitting groove of the output shaft. More specifically, the fitting groove is on the lower side and the relief portion is on the upper side, and the fitting groove and the relief portion are formed on the output shaft so that they communicate with each other and are aligned in the vertical direction.

[0015] The relief portion described above prevents the tip (upper end) corner of the plate-shaped portion from contacting (or moving up and down while in contact with) the inner surface of the fitting groove, and also prevents the contact state between the fitting groove and the plate-shaped portion in the vertical direction from changing (or from changing significantly) with the opening and closing operation of the valve (i.e., the up and down movement of the feed screw member), thereby preventing uneven wear of the fitting groove in the vertical direction.

[0016] More specifically, by providing a relief portion at the top of the fitting groove, the portion of the fitting groove that the plate-shaped part may or may not contact with is reduced as the plate-shaped part moves up and down, thereby improving the degree of uneven wear in the fitting groove. In particular, this development In the Ming Dynasty This configuration ensures that when the valve is closed (i.e., when the plate-shaped part is in its lowest position), the tip (upper end or upper surface) of the plate-shaped part is positioned inside the relief section. With this configuration, the fitting groove is always in contact with the plate-shaped part over its entire length in the vertical direction, and the contact state between the fitting groove and the plate-shaped part in the vertical direction does not change with the opening and closing operation of the valve (up and down movement of the feed screw member). As a result, the fitting groove does not wear unevenly in the vertical direction. Furthermore, with this configuration, the tip corner of the plate-shaped part, which is prone to wear on the fitting groove, is always located inside the relief section and does not come into contact with the fitting groove, thus suppressing wear on the fitting groove.

[0017] Furthermore, in the conventional electric valve described above, the contact area with the fitting groove increases as the feed screw member rises, resulting in increased sliding resistance, whereas the above This invention According to this, the contact area of ​​the plate-shaped part with respect to the fitting groove does not change depending on the vertical position of the lead screw member, making it possible to maintain a constant sliding resistance of the lead screw member. [Effects of the Invention]

[0018] According to the present invention, it is possible to suppress wear of the fitting groove and prevent the fitting groove from wearing unevenly.

[0019] Other objects, features, and advantages of the present invention will be clarified by the following description of the embodiments of the present invention based on the drawings. In each figure, the same reference numerals indicate the same or corresponding parts.

Brief Description of the Drawings

[0020] [Figure 1] FIG. 1 is a longitudinal sectional view showing an electric valve (closed valve state) according to an embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal sectional view showing the electric valve (fully open state) according to the above embodiment. [Figure 3] FIG. 3 is a longitudinal sectional view showing the output shaft and the feed screw member in the closed valve state of the electric valve according to the above embodiment. [Figure 4] FIG. 4 is a longitudinal sectional view showing the output shaft and the feed screw member in the open valve (fully open) state of the electric valve according to the above embodiment. [Figure 5] FIG. 5 is a longitudinal sectional view showing an example of a conventional electric valve (closed valve state). [Figure 6] FIG. 6 is a longitudinal sectional view showing the output shaft and the feed screw member in the closed valve state of the above conventional electric valve. [Figure 7] FIG. 7 is a longitudinal sectional view showing the output shaft and the feed screw member in the open valve (fully open) state of the above conventional electric valve.

Embodiments for Carrying Out the Invention

[0021] An electric valve according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. In each figure, two-dimensional coordinates orthogonal to each other representing the vertical direction and the horizontal direction are appropriately displayed, and the following description is made based on these directions. Also, the terms "vertical" and "horizontal" may be used, where the vertical direction coincides with the up-down direction, and the direction orthogonal to the vertical direction is the horizontal direction including the left-right direction.

[0022] As shown in Figures 1 to 4, an electric valve 11 according to one embodiment of the present invention is an electric valve suitable for use in a refrigeration cycle device such as a heat pump type heating and cooling system to adjust the flow rate of a refrigerant, and comprises a valve body 12 having a valve chamber 13 and a valve seat 16 inside, a valve element 18 that is provided so as to be able to move forward and backward (up and down) relative to the valve seat 16, an electric motor 31 that drives the valve element 18, a reduction mechanism 21 that reduces the rotation of the electric motor 31 (rotor 33 described later), a transmission mechanism 23 that converts the rotation reduced by the reduction mechanism 21 into linear motion and transmits it to the valve element 18, and a can (sealed container) 20 that forms a sealed space at the top of the valve body 12.

[0023] The valve body 12 has a main body portion 12a that forms a valve chamber 13, and a cylindrical connecting portion 12b that extends upward from the upper end of the main body portion 12a and allows connection of the electric motor 31 (can 20). The valve seat 16 is formed at the upper end of an orifice 17 that penetrates the bottom surface of the main body portion 12a in the vertical direction. A first flow path pipe 14 (corresponding to the first flow path of the present invention) is connected to the bottom surface of the main body portion 12a so as to communicate with the valve chamber 13 via the orifice 17. A second flow path pipe 15 (corresponding to the second flow path of the present invention) is connected to the side surface of the main body portion 12a so as to communicate with the valve chamber 13. In this embodiment, the first flow path pipe 14 is used as the inlet passage for the refrigerant and the second flow path pipe 15 is used as the outlet passage for the refrigerant, but it is also possible to use the second flow path pipe 15 as the inlet passage and the first flow path pipe 14 as the outlet passage.

[0024] The connecting portion 12b has a smaller outer diameter than the main body portion 12a. Therefore, a stepped portion 12c is formed at the boundary between the main body portion 12a and the connecting portion 12b on the outer circumferential surface of the valve body 12. The lower end of the can 20 is joined (welded) to this stepped portion 12c via a ring-shaped base plate 19, thereby integrating the can 20 and the valve body 12. The can 20 is a cylindrical member with a bottomless lid (open bottom and closed top) formed by press-forming a metal plate (for example, a stainless steel plate).

[0025] In this embodiment, the electric motor 31 that drives the valve body 18 is configured as a stepping motor. This stepping motor 31 consists of a stator 32 installed on the outside (outer circumference) of the can 20 and a rotor 33 rotatably installed on the inside (inner circumference) of the can 20.

[0026] The stator 32 includes a yoke 34, a coil 36 with windings wound on a bobbin 35, and a resin molded cover 37 that covers the yoke 34 and the coil 36.

[0027] Meanwhile, the rotor 33 is rotatably supported by a round rod-shaped support shaft member 38 that extends vertically through the center of the can 20 along the central axis A. The lower end of the support shaft member 38 is fitted to the upper part of the output shaft 22 (described later) that outputs the rotation of the rotor 33 so as to be able to rotate relative to it, and the upper end is supported by a support member 39 located in the upper part of the interior of the can 20.

[0028] Inside the rotor 33, the reduction mechanism 21 is equipped with a unique planetary gear mechanism that has a high reduction ratio and is advantageous for miniaturization. The rotation of the rotor 33 is reduced by the reduction mechanism 21 and transmitted to the output shaft 22 located at the center of the lower surface of the rotor 33, and output from the output shaft 22.

[0029] A cylindrical bearing member 24 is positioned at the lower part of the rotor 33, and this bearing member 24 rotatably supports the output shaft 22. The bearing member 24 is fitted and fixed within the connection portion 12b of the valve body 12.

[0030] An insertion hole 24b is formed in the center of the upper surface of the bearing member 24, and the output shaft 22 is rotatably inserted into this insertion hole 24b. On the other hand, a female threaded portion 24a is formed in the lower center of the bearing member 24, and a male threaded portion 25a formed on the outer circumferential surface of the lead screw member 25 is screwed into this female threaded portion 24a. These bearing member 24 (female threaded portion 24a) and lead screw member 25 (male threaded portion 25a) form a lead screw mechanism and constitute the transmission mechanism 23 that converts the rotational motion supplied from the stepping motor 31 via the reduction mechanism 21 into vertical linear motion and transmits it to the valve body 18.

[0031] In other words, the lead screw member 25 has a cylindrical portion 25b with the male thread portion 25a formed on its outer surface, and a flat screwdriver-shaped plate portion 25c that rises vertically upward from the upper surface of the cylindrical portion 25b. The plate portion 25c is fitted into a slit-shaped fitting groove 22a provided at the lower end of the output shaft 22 so as to be slidable in the vertical direction. Here, the rotor 33 and the output shaft 22 rotate without moving up and down at a fixed position in the vertical direction, and this rotational motion is transmitted to the lead screw member 25 side via the fitting groove 22a and the plate portion 25c. Therefore, as the plate portion 25c provided on the lead screw member 25 slides vertically within the fitting groove 22a of the output shaft 22, the lead screw member 25 moves linearly in the vertical direction by the lead screw mechanism even though the output shaft 22 does not move vertically when the rotor 33 rotates.

[0032] Furthermore, a relief portion 22b is provided at the upper end (inner part) of the fitting groove 22a, which communicates with the fitting groove 22a and receives the tip of the plate-shaped portion 25c in a non-contact state. This relief portion 22b is a cylindrical (circular cross-section) space that extends in the front-rear direction (direction perpendicular to the plane of the paper in Figures 1 to 4) so ​​as to communicate with the fitting groove 22a at the upper end of the fitting groove 22a, has a diameter larger than the groove width (width dimension in the left-right direction) of the fitting groove 22a, and passes horizontally through the output shaft 22. The relief portion 22b performs the function of maintaining a constant contact area between the plate-shaped portion 25c and the output shaft 22 (inner surface of the fitting groove 22a) as follows.

[0033] In the closed valve state, where the lead screw member 25 is at its lowest point (see Figures 1 and 3), the upper surface of the plate-shaped portion 25c is located inside (bottom surface of) the relief portion 22b. On the other hand, when the valve is opened, the lead screw member 25 rises and moves upward so that the upper part of the plate-shaped portion 25c is inserted into the relief portion 22b. Furthermore, the upper end of the plate-shaped portion 25c inserted into the relief portion 22b does not come into contact with any other members, including the output shaft 22 (fitting groove 22a). On the other hand, the fitting groove 22a is always in contact with the plate-shaped portion 25c over its entire length in the vertical direction, and the contact state between the fitting groove 22a and the plate-shaped portion 25c in the vertical direction does not change with the opening and closing operation of the electric valve 11 (up and down movement of the lead screw member 25). As a result, the fitting groove 22a does not wear unevenly in the vertical direction.

[0034] Furthermore, the upper corner portion 25d of the plate-shaped portion 25c, which is prone to wear on the fitting groove 22a, is always located inside the relief portion 22b and does not come into contact with the fitting groove 22a. Therefore, wear on the fitting groove 22a can be suppressed compared to conventional designs. Moreover, since the contact area of ​​the plate-shaped portion 25c with respect to the fitting groove 22a does not change depending on the vertical position of the feed screw member 25, the sliding resistance of the feed screw member 25 can be kept constant, making it possible to achieve stable opening and closing operation of the electric valve 11 (up and down movement of the feed screw member 25).

[0035] Furthermore, grease is generally applied between the fitting groove 22a and the plate-shaped portion 25c to reduce sliding resistance, and the relief portion 22b can also function as a grease reservoir to hold the grease. In addition, wear particles may be generated due to the sliding of the plate-shaped portion 25c over time, but by accumulating and holding these particles inside the relief portion 22b, the possibility of wear particles getting stuck between the male threaded portion 25a and the female threaded portion 24a or between the valve body 18 and the valve seat 16, thereby reducing the possibility of adverse effects on their operation or valve leakage, can be reduced by providing the relief portion 22b.

[0036] The linear motion of the lead screw member 25 in the vertical direction, as described above, is transmitted to the valve body 18 via a ball-shaped joint 26 consisting of a ball 26a and a ball seat 26b. By interposing the ball-shaped joint 26 in this way, only the linear motion in the vertical direction is transmitted from the lead screw member 25 to the valve body 18, without transmitting the rotational motion of the lead screw member 25.

[0037] The valve body 18 is a cylindrical member having a needle-shaped (inverted cone-shaped) tip at its lower end that moves toward and away from the valve seat 16, and has a flange portion 18a that protrudes horizontally outward at its upper end. A fitting hole 18b is formed on the upper surface of the valve body 18, and the ball seat 26b is fitted into this fitting hole 18b.

[0038] Furthermore, the valve chamber 13 is equipped with a stepped cylindrical valve body guide member 27. This valve body guide member 27 consists of a guide portion 27a with a small diameter (inner and outer diameter) formed at its lower end, a ring-shaped flange portion 27c that extends horizontally outward from its upper end, and a large-diameter portion 27b with a large diameter (inner and outer diameter) formed in the middle portion (between the guide portion 27a and the flange portion 27c). The guide portion 27a supports the valve body 18 so that it can slide up and down. The flange portion 27c is positioned to rest on a stepped portion 12d formed at the lower end of the inner circumferential surface of the connection portion 12b of the valve body 12, and is sandwiched between the stepped portion 12d and the bearing member 24, thereby preventing vertical displacement of the valve body guide member 27. In addition, a stepped portion 27d is formed on the inner circumferential surface of the valve body guide member 27 between the large-diameter portion 27b and the guide portion 27a.

[0039] Furthermore, a compression coil spring 28 is provided inside the large-diameter portion 27b, more specifically, in the gap between the outer circumferential surface of the valve body 18 and the inner circumferential surface of the large-diameter portion 27b. This compression coil spring 28 is installed in a compressed state between the flange portion 18a of the valve body 18 and the stepped portion 27d of the valve body guide member 27, thereby biasing the valve body 18 upward (in the opening direction). By pressing the valve body 18 against the lead screw member 25 via the flange portion 18a of the valve body 18 and the ball-shaped joint 26, the valve body 18, the ball-shaped joint 26, and the lead screw member 25 are held together in the vertical direction. Additionally, during the opening operation, the biasing force of the compression coil spring 28 is applied to the valve body 18 in addition to the driving force of the electric motor 31, thereby ensuring a more reliable opening operation.

[0040] In this embodiment, the central axis A of the valve body 12 (body portion 12a and connecting portion 12b), valve seat 16, orifice 17, valve element 18, ball joint 26, bearing member 24, can 20, and support shaft member 38, as well as the central axis (rotation axis) A of the rotor 33, output shaft 22, and lead screw member 25, coincide with each other.

[0041] The operation of the electric valve 11 according to this embodiment is as follows.

[0042] When current is supplied to the stator 32 (coil 36) so that the rotor 33 rotates in one direction from the closed valve state shown in Figure 1, the rotation of the rotor 33 is reduced by the reduction mechanism 21, then converted into linear motion by the transmission mechanism 23, and the lead screw member 25 is pulled upward. Accordingly, the valve body 18, which is pressed against the lower surface of the lead screw member 25 via the ball joint 26 by the biasing force of the compression coil spring 28, is pulled upward and the valve body 18 separates from the valve seat 16, resulting in an open valve state where the refrigerant that has flowed in through the first flow path pipe 14 flows out through the valve chamber 13 and out from the second flow path pipe 15 (see arrow F in Figure 2). The amount of refrigerant that passes through in this open valve state (refrigerant flow rate) can be adjusted by the amount of rotation of the rotor 33 (distance between the valve body 18 and the valve seat 16).

[0043] On the other hand, when current is supplied to the stator 32 (coil 36) so that the rotor 33 rotates in the opposite direction to the one direction described above from the open valve state, the rotation of the rotor 33 is converted into linear motion by the transmission mechanism 23, and the lead screw member 25 moves downward. Along with this downward movement, the valve body 18 moves downward, and when the valve body 18 seats on the valve seat 16, the flow path between the first flow path pipe 14 and the second flow path pipe 15 is blocked, resulting in a closed valve state (see Figure 1).

[0044] Although embodiments of the present invention have been described above, it will be apparent to those skilled in the art that the present invention is not limited thereto and that various modifications can be made within the scope of the claims.

[0045] For example, although the relief portion 22b in the above embodiment has a circular cross-sectional shape, it may have any cross-sectional shape as long as it can accommodate the upper end of the plate-shaped portion 25c in a non-contact state (without contacting the upper end of the plate-shaped portion 25c). Also, although the reduction mechanism 21 in the above embodiment is equipped with a mysterious planetary gear mechanism, it is also possible to use a planetary gear mechanism other than the mysterious planetary gear mechanism or other reduction mechanisms. [Explanation of Symbols]

[0046] A. Central axis (axis of rotation) F Refrigerant flow 11,41 Electric valve 12 Valve body 12a Main body 12b Connection section 12c Stepped portion on the outer surface of the valve body 12d Step section 13 valve chambers 14. First flow channel tube 15. Second flow channel 16 valve seats 17 Orifice 18 Valve body 18a Flange portion of the valve body 18b Fitting hole 19 Base Plate 20 cans (airtight containers) 21. Reduction mechanism (mysterious planetary gear mechanism) 22 Output shaft 22a Fitting groove 22b Escape Department 23. Transmission mechanism (feed screw mechanism) 24 Bearing Member 24a Female thread section 24b Insertion hole 25 Lead screw member 25a Male threaded portion 25b Cylindrical section 25c Plate-shaped part 25d Upper end (tip) corner of the plate-like part 26 Ball joint 26a Ball 26b Ball seat 27 Valve body guide member 27a Guide section 27b Large diameter section 27c Flange portion of valve body guide member 27d Step portion of valve body guide member 28 Compression coil spring 31. Electric motor (stepping motor) 32 stata 33 Rotors 34 York 35 bobbins 36 coils 37 Resin molded cover 38 Support shaft member 39 Support member

Claims

[Claim 1] A valve body having a valve chamber inside that communicates with a first flow path and a second flow path, A valve body that moves back and forth relative to a valve seat formed in the valve chamber, The electric motor that drives the valve body, A reduction mechanism for reducing the rotation of the aforementioned electric motor, An output shaft that outputs rotation reduced by the reduction mechanism, A transmission mechanism that converts the rotational motion of the output shaft into linear motion and transmits it to the valve body, Equipped with, The aforementioned transmission mechanism is A feed screw member having a plate-shaped portion that is fitted vertically into a slit-shaped fitting groove formed on the output shaft, and a male threaded portion formed on its outer surface, A bearing member having a female threaded portion that screws into the male threaded portion, has It is an electric valve, The output shaft has a relief portion inside that can receive the tip of the plate-shaped portion in a non-contact manner, The relief portion is open at its lower end, thereby communicating with the fitting groove at the upper end of the fitting groove, and its upper end is closed. The tip of the plate-shaped portion is positioned inside the relief portion when the valve is closed. An electric valve characterized by the following features.

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