JP7190199B2 - electric valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to a motor-operated valve, and more particularly to a valve body structure of a motor-operated valve having a valve body having an inverted conical needle portion at its tip.

2. Description of the Related Art Motor-operated valves that control the degree of opening of valves using electric motors such as stepping motors have been conventionally used in refrigeration cycle devices including refrigerant circuits, such as air conditioners, refrigerators, and freezers.

As one of such motor-operated valves, a valve body is provided with a needle portion that is sharpened in the shape of an inverted cone or an inverted truncated cone at the tip, and the needle portion is advanced and retracted so as to be inserted into and removed from the valve opening to open the valve. There is a motor-operated valve that adjusts the temperature and controls the flow rate of a fluid (refrigerant, etc.) (see, for example, Patent Document 1 below).

JP 2012-197849 A

By the way, in recent years, along with the improvement in the performance of each device constituting the refrigerant circuit and the improvement in the performance of the refrigerant itself, there is a demand for control when the flow rate of the refrigerant is low.

Here, as one method of performing high-precision control at a low flow rate in an electric valve provided with a needle portion, the angle of the needle portion, that is, the opposing generatrices of the inverted conical or inverted truncated conical needle portion (opposing The angle (hereinafter referred to as the "valve angle") formed by the adjacent peripheral surfaces) may be made an acute angle.

However, if the valve angle is set to an acute angle, the valve disc may bite into the valve seat when the valve is closed, and a phenomenon may occur in which the valve cannot be opened smoothly. More specifically, when the valve angle is made smaller than 45°, the valve disc cannot be removed from the valve seat after seating and is locked due to the so-called wedge principle (the needle portion sticks into the valve opening like a wedge and cannot be pulled out). A phenomenon that the valve cannot be opened occurs.

In addition, as the valve angle becomes smaller, foreign matter is more likely to be caught between the valve seat and the valve body, and the foreign matter may get caught and damage the valve body and the valve seat, which may lead to an increase in the amount of valve leakage.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to enable highly accurate flow rate control when the flow rate is low and to prevent an increase in valve leakage caused by foreign matter.

In order to solve the above-mentioned problems and achieve the object, a first electrically operated valve according to the present invention includes a valve main body having a valve chamber and a valve opening with a valve seat, and a valve body that advances and retreats relative to the valve seat without rotating. a valve body for controlling the amount of fluid passing through the valve body, a first flow path port communicating with the valve chamber via the valve port, a second flow path port communicating with the valve chamber, and an electric drive section for driving the valve body. , the valve body includes a seat portion having an inverted cone shape or an inverted truncated cone shape whose diameter gradually decreases toward the valve seat, and the seat portion is inserted into the valve opening when the valve is closed when seated on the valve seat. A motor-operated valve having a needle portion capable of closing a valve port, wherein an angle between opposing generatrices of the seating portion is set to 26° or more and less than 45°, and either one of the seating portion and the valve seat is provided. Alternatively, both surfaces were provided with a coating layer containing a fluororesin.

In order to improve the controllability at low flow rates, it is necessary to reduce the valve angle, that is, the angle formed by the facing generatrices of the needle portion (especially the seating portion that abuts the valve seat). It has already been mentioned that if the valve angle is less than 45°, the needle sticks into the valve opening like a wedge, causing the valve body to bite into the valve seat and prevent the valve from opening smoothly. Just like that.

Therefore, in the present invention, a coating layer containing a fluororesin is formed on the surface of one or both of the needle portion (seating portion) and the valve seat. If a coating layer containing fluororesin is formed on the surface, it is possible to reduce the frictional resistance of the needle portion that is inserted into and removed from the valve seat (valve port). ) The valve disc can be easily removed from the valve opening, and the valve disc can be prevented from biting into the valve seat.

The lower limit of the valve angle is set to 26°, the reason for which will be described in detail later in the embodiment.

A second motor-operated valve according to the present invention includes a valve body having a valve chamber and a valve opening with a valve seat, and a valve body that moves forward and backward while rotating with respect to the valve seat to control the amount of fluid passing through. a first channel port communicating with the valve chamber via the valve port; a second channel port communicating with the valve chamber; It includes a seat portion having an inverted cone shape or an inverted truncated cone shape with a gradually decreasing diameter, and a needle portion that can be inserted into the valve opening to close the valve opening when the seat portion is seated on the valve seat and the valve is closed. wherein the angle formed by the facing generatrices of the seating portion is set to 26° or more and less than 60°, and the surfaces of one or both of the seating portion and the valve seat contain fluororesin. provided with a cover layer.

The first motor-operated valve has a structure in which the valve body advances and retreats without rotating with respect to the valve seat. The present invention can also be applied to a motor-operated valve having a "valve body rotation structure".

That is, in such a valve body rotation structure, friction is large because the valve body comes into contact with and separates from the valve material while rotating, and when the valve angle is about 60 degrees (below 60 degrees), the valve seat bites. phenomenon occurs. Therefore, in the second motor-operated valve according to the present invention, as described above, the angle between the facing generatrices of the seating portion is set to 26° or more and less than 60°, and the seating angle is set to 26° or more and less than 60° as in the case of the first motor-operated valve. A coating layer containing a fluororesin is provided on the surface of one or both of the portion and the valve seat.

Further, the fluororesin is, for example, one of PTFE, FEP, PFA, ETFE, and modified PTFE.

Further, in a preferred embodiment of the present invention, a base layer having a hardness higher than that of the base material is formed between the coating layer and the base material (the main body portion of the needle portion (valve body) and the main body portion of the valve seat). This is to prevent the valve body and the valve seat from being damaged by foreign matter. By providing a hard base layer, it is possible to minimize damage to the valve body and valve seat due to foreign matter getting caught, and to prevent valve leakage or an increase in the amount of valve leakage.

The underlying layer is, for example, a Ni—P plated layer. In addition, the thickness of the base layer should be 200 cm ³ per minute or less, which is the generally allowable valve leakage rate when the motor-operated valve is used in the refrigerant circuit. , 10 μm or more and 30 μm or less. This point will be described in more detail later in the embodiment.

Moreover, the thickness of the coating layer is preferably 5 μm or more and 30 μm or less. The reason for this will also be described in detail later in the embodiment.

According to the present invention, it is possible to control the flow rate with high accuracy when the flow rate is low, and to prevent an increase in the amount of valve leakage due to foreign matter getting caught.

Other objects, features and advantages of the present invention will become apparent from the following description of embodiments of the present invention based on the drawings. In addition, the same code|symbol shows the same or a corresponding part in each figure.

FIG. 1 is a longitudinal sectional view showing an electrically operated valve (closed state) according to one embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing the electric valve (valve open state) according to the embodiment. FIG. 3 is a longitudinal sectional view conceptually showing an enlarged needle portion and valve seat of the electric valve according to the embodiment. FIG. 4 is a graph showing the relationship between the valve opening degree and the flow rate of fluid passing through the valve when the valve angle is made small. FIG. 5 shows an electrically operated valve (conventional product) without a Ni-P plating layer, an electrically operated valve (comparative example) with a 5 μm thick Ni—P plating layer, and a 10 μm thick Ni—P plating layer. For the motor-operated valve (embodiment) and the motor-operated valve (embodiment) provided with a Ni—P plating layer with a thickness of 15 μm, the valve leakage amount was measured after piano wires with a diameter of 15 μm and a piano wire with a diameter of 130 μm were bitten. It is a diagram showing the result of the measurement.

〔overall structure〕
As shown in FIGS. 1 to 3, a motor-operated valve 1 according to one embodiment of the present invention is a motor-operated valve suitable for use in refrigerating cycle devices such as heat pump cooling and heating systems for adjusting the flow rate of refrigerant. A valve body 11 internally provided with a valve chamber 12, a valve port 18 opening to the valve chamber 12, and a valve seat 17; A can 34 that forms a space, a valve element 19 that controls the flow rate of fluid by moving back and forth (up and down) with respect to the valve seat 17, and a first flow passage port that communicates with the valve chamber 12 via the valve port 18. 13, a second flow path port 15 communicating with the valve chamber 12, a stepping motor (electrical drive unit) 41 for driving the valve body 19, and a reduction mechanism (magnitude planetary gear reduction mechanism) for reducing the rotation of the stepping motor 41. 54 and a transmission mechanism (screw feed mechanism) 30 that converts the reduced rotational motion into linear motion and transmits it to the valve body 19 .

Each figure shows mutually orthogonal two-dimensional coordinates representing vertical and horizontal directions, and the following description is based on these directions. 1 and 2 do not show a base layer and a coating layer (described later with reference to FIG. 3) formed on the surfaces of the valve body 19 and the valve seat 17. FIG.

A cylindrical can 34 with a lid (open bottom and closed top) is joined to the upper end of the valve body 11 via a ring-shaped base plate 25 . has a stator 42 and a rotor 47 is rotatably installed on the inner circumference (inner side) of the can 34 . The rotor 47 and stator 42 constitute the stepping motor 41 .

A stator 42 arranged outside the can 34 includes a yoke 43 , a bobbin 44 , a coil 45 and a resin mold cover 46 . The rotor 47 arranged inside the can 34 is constructed by integrally connecting a cylindrical rotor member 47a made of a magnetic material and a sun gear member 48 made of a resin material. A shaft 32 is inserted into the central portion of the sun gear member 48 and the upper portion of the shaft 32 is supported by a support member 33 arranged inside the top portion of the can 34 .

The sun gear 48 a of the sun gear member 48 meshes with a plurality of planetary gears 49 rotatably supported by a shaft 50 provided on a carrier 51 placed on the bottom surface of the output gear 53 . The upper part of the planetary gear 49 meshes with an annular ring gear (internal fixed gear) 55 attached to the upper part of the cylindrical member 35 fixed to the upper part of the valve body 11 , and the lower part of the planetary gear 49 meshes with the annular output gear 53 . It meshes with tooth gear 52 . The number of teeth of the ring gear 55 and the number of teeth of the internal gear 52 of the output gear 53 are slightly different. be. These gear mechanisms (sun gear 48a, planetary gear 49, ring gear 55, and output gear 53) constitute a reduction mechanism (paradox planetary gear reduction mechanism) 54 that reduces the rotation of the stepping motor 41 described above. .

A cylindrical bearing member 26 is inserted into the upper portion of the valve chamber 12 of the valve body 11 and is crimped and fixed to the valve body 11 . The output gear 53 is in sliding contact with the upper surface of the bearing member 26 . The upper portion of a stepped cylindrical output shaft 31 is press-fitted into the center of the bottom of the output gear 53, and the lower portion of the output shaft 31 is rotatably inserted into a fitting hole 26a formed in the upper surface of the central portion of the bearing member 26. do. A lower end portion of a shaft 32 is rotatably fitted to the upper portion of the output shaft 31 .

A female threaded portion 27 is formed in the lower center portion of the bearing member 26, and a male threaded portion 29 formed on the outer peripheral surface of a screw driving member 28 is screwed into the female threaded portion 27. As shown in FIG. The bearing member 26 (female threaded portion 27) and the screw driving member 28 (male threaded portion 29) vertically rotate the screw feed mechanism 30, that is, the rotational motion supplied from the stepping motor 41 via the reduction mechanism 54. It constitutes a transmission mechanism that converts the motion into linear motion and transmits it to the valve body 19 .

Here, the output gear 53 rotates at a fixed position in the vertical direction without moving up and down. A flat driver-shaped plate-like portion 28a provided at the upper end portion of the member 28 is inserted to transmit the rotational motion of the output gear 53 to the screw driving member 28 side. When the plate-shaped portion 28a provided on the screw driving member 28 slides vertically in the fitting groove 31a of the output shaft 31, the output gear 53 (rotor 47) rotates, thereby moving the output gear 53 vertically. Despite this, the screw driving member 28 is linearly moved vertically by the screw feed mechanism 30 .

The linear motion of the screw drive member 28 is applied to the valve body 19 via a ball joint 22 consisting of a ball 23 and a ball seat 24 fitted in a fitting hole 19b provided in the center of the upper surface of the valve body 19. transmitted. The valve body 19 is slidably inserted in (the lower part of) a stepped cylindrical spring case 20 fixed inside the valve body 11, and the valve body 19 is guided by the spring case 20 to move vertically. move to The screw driving member 28 and the valve body 19 on the driving part side rotate and slide about the central axis (the central axis of the present invention coincides with the rotation axis of the rotor 47) via the ball 23 (rotating sliding part). , the rotation of the screw drive member 28 is not transmitted to the valve body 19 . A compression coil spring 21 is provided between the upward step surface of the spring case 20 and the downward step surface of the upper portion of the valve body 19 to normally bias the valve body 19 in the valve opening direction (upward).

Further, the first flow passage port 13 is formed in the bottom portion of the valve chamber 12 (valve main body 11), and a pipe joint 14 is connected to the first flow passage port 13, and one side portion of the valve chamber 12 (valve main body 11) is formed with the second flow path port 15 and a pipe joint 16 is connected to the second flow path port 15 . Further, the first flow path port 13 communicates with the valve chamber 12 via a valve port (orifice) 18 which is composed of a cylindrical inner peripheral surface and a valve seat 17 which is the upper edge of the inner peripheral surface. One of the first flow path port 13 and the second flow path port 15 is used as an inlet through which the refrigerant flows into the valve chamber 12 , and the other is used as an outlet through which the refrigerant flows out from the valve chamber 12 .

[Structure of valve body needle and valve seat]
The valve body 19 has a substantially cylindrical overall shape, but has an inverted truncated cone shape (or an inverted cone shape) whose diameter gradually decreases toward the valve opening 18 so that it can be inserted into and removed from the valve opening 18 . is provided at the lower end. In the valve closed state (see FIGS. 1 and 3) in which the valve body 19 is displaced to the lowest position, the tapered side surface (seating surface (corresponding to the “seating portion” in the present invention)) of the needle portion 19a serves as the valve seat. 17 to block the valve opening 18 .

On the other hand, in the open state in which the valve body 19 is displaced upward from the closed state in FIG. A gap is formed between and through which the coolant flows. Also, the refrigerant flow rate can be adjusted by changing the amount of displacement of the valve body 19 in the vertical direction.

FIG. 3 is an enlarged cross-sectional view showing the needle portion 19a and the valve seat 17 portion (the valve port 18 portion at the center of the bottom portion of the valve body 11). As shown in this figure, the needle portion 19a is formed by forming an underlying layer 61 on the surface of a valve body portion 63 made of metal such as stainless steel, and further forming a coating layer 62 on the underlying layer 61 (on the surface). Consists of The valve seat 17 side, that is, the valve seat 17 and the bottom portion of the valve body 11 including the valve port 18 is formed by applying a base layer 61 to the surface of the body portion 64 of the valve body made of a metal such as brass, similar to the valve body 19 . is formed, and a coating layer 62 is further formed thereon.

3 emphasizes the thickness of the base layer 61 and the coating layer 62 for explanation, and the dimensional ratio of each part, that is, the outer diameter of the valve body portion 63 and the inner diameter of the valve port 18. It does not accurately represent the ratio of the thickness dimension of the underlying layer 61 and the thickness dimension of the covering layer 62 . It should be noted that the hardness of the underlying layer 61 is preferably higher than that of the foreign matter. Hardness is good. Also, the covering layer 62 is selected to have a hardness lower than that of the underlying layer 61 .

[Valve angle and covering layer]
In this embodiment, the valve angle θ (the angle formed by the opposed generatrices of the needle portion (seat portion) 19a/see FIG. 3) is set to 26°. The coating layer 62 (the coating layer 62 on the valve body 19 side and the coating layer 62 on the valve seat 17 side) is a PTFE layer formed by PTFE dispersion plating. The PTFE layer formed by PTFE dispersion plating is a composite plating film having a structure in which PTFE is dispersed in a Ni—P plating matrix and taken in in the form of particles. The Ni—P plating matrix portion has higher hardness than the foreign matter.

FIG. 4 shows the valve opening degree (lift amount (upward movement distance) of the valve body 19) and the valve 1 when the valve angle θ is 45° (broken line) and when the valve angle θ is 26° (solid line). As is clear from this diagram, when the valve angle θ is decreased, the increasing tendency of the flow rate with respect to the increase in the valve opening becomes moderate, and when the flow rate is low, Control with higher precision becomes possible. Therefore, in this embodiment, the valve angle θ is set to 26°, which is even smaller than the conventional lower limit (45°).

On the other hand, if the valve angle θ is reduced, the valve body 19 may bite into the valve seat 17 . Prepare. As a result, the frictional resistance between the valve body 19 and the valve seat 17 is reduced to prevent the biting phenomenon from occurring. Further, by forming the coating layer 62 by PTFE dispersion plating, the durability (corrosion resistance, wear resistance, etc.) of the coating layer 62 can be improved.

Furthermore, in the present invention, the lower limit of the valve angle θ is set to 26° for the following reasons. Conventionally, when the valve angle θ is sharpened to be less than 45°, the valve seat 17 is bitten, as already described. Using the formula, the slack rate F2/F1, which is the ratio of the valve opening load (force when pulling out the wedge) F2 and the seating load (force when driving in the wedge) F1, is calculated as the conventional structure (valve body 19 and valve seat 17 do not have the coating layer 62 and the valve angle θ is 45°, which is the lower limit value), and the valve angle θ having the same degree of slackness as this slackness rate is The structure (the structure of the present invention) is sought.

F1=2×R×(μ×cos θ+sin θ) (Formula 1)

F2=2×R×(μ×cos θ−sin θ) (Formula 2)

In the above equations, R represents surface pressure [kgf], μ represents friction coefficient, and θ/2 (half of valve angle θ) represents seating angle [°]. In addition, since the coefficient of friction when metals come into contact with each other is about 0.1 to 0.2, the median value of the range is taken to set the friction coefficient μ of the conventional structure to 0.15, and the friction of fluororesin Since the coefficient is about 0.07 to 0.1, the median value of the range is taken to set the friction coefficient μ of the structure of the present application to 0.085.

When the slackness rate F2/F1 of the conventional structure (valve angle 45°) is calculated, F2/F1=-0.4683.

Conversely, for the structure of the present application (valve angle θ), when the valve angle θ at which the slack rate of the conventional structure is F2/F1 = -0.4683 is obtained, F2/F1 = -0.4683 and , .mu.=0.085, .theta..apprxeq.26.degree.

F2/F1={2×R×(μ×cos θ−sin θ)}/{2×R×(μ×cos θ+sin θ)} (Formula 3)

−0.4683={2×R×(0.085×cos θ−sin θ)}/{2×R×(0.085×cos θ+sin θ)} (Formula 4)

Therefore, according to the structure of the present application, even if the valve angle θ is set to 26°, it is possible to achieve a slack rate equivalent to the lower limit of 45° for the valve angle θ of the conventional structure. be the lower limit of the angle θ.

In the above-described embodiment, the rotary sliding portion is interposed between the driving portion and the valve body, and when the valve body comes into contact with or separates from the valve seat, the rotational force of the driving portion is applied to the valve body. An example in which the present invention is applied to a motor-operated valve having a structure in which the vibration is not transmitted to the valve seat (that is, a structure in which the valve body advances and retreats without rotating with respect to the valve seat) was given. However, the present invention has a structure in which the valve body rotates according to the rotation of the rotor, and the valve body contacts and separates (abuts and separates) from the valve seat while rotating (that is, the valve body rotates with respect to the valve seat). It can also be applied to a structure that advances and retreats while moving).

A conventional structure in which the valve body moves up and down while rotating (rotating valve body structure) has, for example, a threaded portion (e.g., male thread) formed on the valve shaft of the valve body and a threaded portion (e.g., female thread) fixed to the valve body side. The rotor is fixed on the valve shaft side, and the valve shaft (valve body) moves up and down as the rotor rotates. In this type of valve body rotation structure, the valve body rotates to contact and separate from the valve seat, resulting in large friction. A biting phenomenon on the valve seat 17 occurs. However, if the present invention is applied to such a structure, the coefficient of friction μ will be about 0.085. Therefore, it will be possible to achieve the same degree of slackness as when the valve angle θ is 26° in the above embodiment. becomes possible. Therefore, the lower limit of the valve angle θ in the valve body rotation structure is set to 60°.

In the structure described above (the structure of the present application, the valve body rotating structure), the surfaces of both the valve body 19 and the valve seat 17 are covered with the coating layer 62, but either the valve body 19 or the valve seat 17 Even with the structure covered with the coating layer 62, the valve angle ?

In addition, the structure of the present application includes both the base layer 61 and the coating layer 62 as shown in FIG. The effect that can be reduced can be exhibited even in a configuration without the base layer 61, that is, in a configuration in which only the coating layer 62 is formed on the base material (the valve body portion 63 and the valve seat body portion 64). When only the coating layer 62 was formed on the base material, the effect was recognized when the thickness of the coating layer 62 was 5 μm or more.

In addition, in the structure of the present application, an inverted truncated cone-shaped valve body has been described as an example. can be selected in various ways. In this case, the valve angle θ is the angle of the inverted truncated cone of the seating surface, and when the flow rate is low immediately after the valve is opened, the increasing tendency of the flow rate with respect to the increase in the valve opening degree becomes moderate, enabling highly accurate control.

[Underlayer and its thickness]
The underlying layer 61 (the underlying layer 61 on the valve body 19 side and the underlying layer 61 on the valve seat 17 side) is a Ni—P plated layer by Ni—P plating (electroless nickel plating). Higher hardness than the base material (valve body portion 63 made of metal such as stainless steel and valve seat body portion 64 made of metal such as brass, both of which are lower in hardness than the Ni—P plating layer) This is because the provision of the hard base layer 61 minimizes damage to the valve element 19 and the valve seat 17 due to foreign matter getting caught, and prevents an increase in valve leakage. In addition, by providing such a hard base layer 61, it is possible to prevent or suppress a decrease in the accuracy of flow rate control due to variations in the flow rate caused by scars caused by foreign matter.

Further, the thickness of the underlying layer 61 is set to 10 μm or more in this embodiment for the following reasons.

FIG. 5 shows the results of measuring the amount of valve leakage after piano wires with diameters of 15 μm and 130 μm were bitten in when the thickness of the Ni—P plating layer (base layer) was 5 μm, 10 μm, and 15 μm. It is.

From these test results, the thicker the base layer 61 ^, the smaller the valve leakage. It can be seen that the thickness of the underlying layer 61 should be 10 μm or more in order to satisfy the conditions. Therefore, in this embodiment, the thickness of the underlying layer 61 is set to 10 μm or more. Considering the cost (processing time) of plating, the thickness of the underlying layer 61 is preferably 30 μm or less.

The test shown in FIG. 5 was conducted with a motor-operated valve in which only the base layer 61 was formed on the base material and the coating layer 62 was not formed. Observation of the cross-sectional structure of the scar caused by the 130 μm piano wire biting after the test in FIG. As the thickness of the underlying layer 61 became thicker, the recesses became smaller.

In addition, the condition of forming the coating layer 62 with various thicknesses on the base layer 61 was added, and as a result of conducting a bite test (additional test) of the piano wire (130 μm) in FIG. 5, the thickness of the coating layer 62 was A significant reduction in valve leakage was observed at a thickness of 5 μm or more, and the leakage was further reduced when the thickness of the coating layer 62 was increased.

[Coating layer and its thickness]
First, the thickness of the coating layer 62 for alleviating the biting phenomenon will be described. In order to reduce the valve angle θ at which the biting phenomenon occurs (26° in this application), it is sufficient that the fluorine resin is exposed on the surfaces of the valve body 19 and the valve seat 17 even without the underlying layer 61. In a test in which the thickness of the coating layer 62 was 1 μm, the valve angle θ could be set to 26°. If the thickness of the coating layer 62 exceeds 30 μm, the processing time will be long and the cost will be high. That is, the thickness of the coating layer 62 is 1 μm or more and 30 μm or less in order to suppress the biting phenomenon.

Next, the thickness of the coating layer 62 for alleviating the adverse effects of foreign matter will be described. It is said that when a foreign object is caught between the valve body 19 and the valve seat 17, the plastic deformation of the base material of the valve body 19 and the valve seat 17 can be prevented by temporarily deforming the coating layer 62. Conceivable. In addition, it is considered that the influence of the scars can be alleviated by filling the scars generated in the base material of the valve body 19 and the valve seat 17 and the underlying layer 61 due to the deformation of the covering layer 62 when the valve is closed. In order to exhibit these effects, the thickness of the coating layer 62 should be 5 μm or more as described above. In other words, the thickness of the coating layer 62 that mitigates the adverse effects of foreign matter on the base material and the underlying layer 61 and allows for the processing cost is 5 μm or more and 30 μm or less.

As described above, if the thickness of the base layer 61 is set to 10 μm or more and 30 μm or less and the thickness of the coating layer 62 is set to 5 μm or more and 30 μm or less, both the biting phenomenon and the adverse effects of the foreign matter can be alleviated.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to these, and that various modifications can be made within the scope of the claims. .

For example, the material forming the coating layer 62 is PTFE in the present embodiment, but may be other fluororesins such as FEP, PFA, ETFE, modified PTFE, or the like. Further, the object of the present invention can be achieved if the base layer 61 and the coating layer 62 on the valve body 19 and valve seat 17 sides are formed at the portions where the two (the valve body 19 and the valve seat 17) contact each other. Therefore, it is not necessary to provide the base layer 61 and the coating layer 62 over the entire outer surface of the valve body 19 or the entire inner surface of the valve body 11 .

In addition, the motor-operated valve according to the present invention can typically be preferably used in a refrigeration cycle device having a refrigerant circuit, such as an air conditioner (air conditioner), a freezer, or a refrigerator. It is possible to use the electrically operated valve according to the present invention in various applications. Therefore, the "fluid" referred to in the present invention includes heat carriers (refrigerants and heat carriers) as well as various liquids and gases (gases).

Reference Signs List 1 electric valve 11 valve body 12 valve chamber 13 first channel port 14, 16 pipe joint 15 second channel port 17 valve seat 18 valve port 19 valve body 19a needle portion (seating portion)
19b Fitting hole 20 Spring case 21 Compression coil spring 22 Ball-shaped joint 23 Ball 24 Ball receiving seat 25 Base plate 26 Bearing member 26a Insertion hole 27 Female screw part 28 Screw driving member 28a Plate-like part 29 Male screw part 30 Screw feeding mechanism 31 Output Shaft 31a Fitting groove 32 Shaft 33 Supporting member 34 Can 35 Cylindrical member 41 Stepping motor 42 Stator 43 Yoke 44 Bobbin 45 Coil 46 Resin mold cover 47 Rotor 48 Sun gear member 48a Sun gear 49 Planetary gear 50 Shaft 51 Carrier 52 Internal gear 53 Output gear 54 Mechanical paradox planetary gear reduction mechanism 55 Ring gear 61 Base layer 62 Coating layer 63 Main body portion (base material) of valve body
64 Body portion of valve seat (base material)

Claims (7)

a valve body provided with a valve chamber and a valve port with a valve seat;
a valve body that controls the amount of passage of fluid by moving back and forth without rotating with respect to the valve seat;
a first channel port communicating with the valve chamber via the valve port;
a second channel port communicating with the valve chamber;
an electric drive unit that drives the valve body,
The valve port comprises a cylindrical inner peripheral surface and the valve seat that is the upper edge of the cylindrical inner peripheral surface,
The valve body
The valve includes a seat portion having an inverted cone shape or an inverted truncated cone shape whose diameter gradually decreases toward the valve seat, and is inserted into the valve opening when the valve is closed when the seat portion is seated on the valve seat. A motor-operated valve having a needle part capable of closing a mouth,
setting the angle formed by the opposing generatrices of the seating portion to 26° or more and less than 45°;
A motor-operated valve, comprising a coating layer containing a fluororesin on the surface of one or both of the seat portion and the valve seat. a valve body provided with a valve chamber and a valve port with a valve seat;
a valve body that controls the flow rate of fluid by moving forward and backward while rotating with respect to the valve seat;
a first channel port communicating with the valve chamber via the valve port;
a second channel port communicating with the valve chamber;
an electric drive unit that drives the valve body,
The valve port comprises a cylindrical inner peripheral surface and the valve seat that is the upper edge of the cylindrical inner peripheral surface,
The valve body
The valve includes a seat portion having an inverted cone shape or an inverted truncated cone shape whose diameter gradually decreases toward the valve seat, and is inserted into the valve opening when the valve is closed when the seat portion is seated on the valve seat. A motor-operated valve having a needle part capable of closing a mouth,
setting the angle formed by the opposing generatrices of the seating portion to 26° or more and less than 60°;
A motor-operated valve, comprising a coating layer containing a fluororesin on the surface of one or both of the seat portion and the valve seat. The motor operated valve according to claim 1 or 2, wherein the fluororesin is any one of PTFE, FEP, PFA, ETFE, and modified PTFE. 4. The electrically operated valve according to any one of claims 1 to 3, further comprising an underlying layer having hardness higher than that of the base material between the coating layer and the base material. The electric valve according to claim 4, wherein the base layer is a Ni—P plating layer. The electric valve according to claim 5, wherein the base layer has a thickness of 10 µm or more and 30 µm or less. The motor operated valve according to any one of claims 4 to 6, wherein the coating layer has a thickness of 5 µm or more and 30 µm or less.

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