JP3839908B2 - Motorized valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor-operated valve used for flow control of a fluid such as a refrigerant used in a refrigeration cycle.
[0002]
[Prior art]
The motor-operated valve used in the refrigeration cycle has a configuration in which, for example, a rotary motion of a stepping motor is converted into a linear motion of a valve body by a screw mechanism and a flow path area between the valve body and an orifice of the valve body is controlled.
Specifically, a bush having a female thread portion is attached to the valve body, a male screw portion is provided on a valve body that supports a valve body or a valve body integral with a rotor of a stepping motor, and both screw portions are screwed together.
[0003]
[Problems to be solved by the invention]
In this type of motor-operated valve, the valve element rotates with the rotor while the tip of the valve element contacts the orifice. This contact closes the motor-operated valve, but the valve element receives the axial force of the screw and is pressed against the orifice. However, when the needle-like valve body is pressed against the orifice, the valve body may come into close contact with the orifice, which may cause a problem of poor valve opening, which makes it difficult to open the valve.
Therefore, in the conventional motor-operated valve, the stopper portion is provided, and simultaneously with the valve closing, the rotation of the rotor is stopped by the stopper portion.
However, it is difficult to accurately manage the synchronization between the rotation stop due to the contact of the stopper portion and the valve closing due to the variation in the assembly dimensions of the parts such as the rotor and the valve body. In order to solve this problem, a hollow portion is provided in the valve holder, and the valve body is slidable via the coil spring. The coil spring is rotated by the rotor that further rotates and lowers after the valve body contacts the orifice by the axial force of the screw. There is a structure in which a valve body is pressed against an orifice by compressing and generating a predetermined spring load. However, after the contact of the valve body with the orifice, the rotor further rotates in the valve closing direction until it comes into contact with the stopper portion. As a result, when the frictional force repeatedly due to the contact of the valve body with the orifice increases, wear of the orifice surface occurs, which may cause problems such as fluctuations in flow rate characteristics.
In view of this point, an object of the present invention is to provide a motor-operated valve that can prevent orifice wear and suppress fluctuations in flow rate characteristics.
[0004]
[Means for Solving the Problems]
Electric valve of the present invention includes a valve body having a valve chamber and an orifice, and the can that is kicked with Ri taken to the valve body, a stator member arranged outside of the can, is disposed inside of the can and the rotor member that includes a cylindrical valve holder having a threaded portion on an outer peripheral portion integral with said rotor member, a valve body slidably inserted into the hollow portion of the valve holder to open and close said orifice, said valve body A bush having a threaded portion fixed to the inner peripheral portion and threadedly engaged with a threaded portion of the valve holder, and disposed between one end of the valve holder and the valve body with the valve body facing the orifice. A coil spring that is urged to be biased, and is arranged on the axis of the valve holder, one end of which is press-fitted into one end of the valve holder and protrudes into the valve holder, and the other end is axially connected to a bearing member integral with the can Loosely fitted in The valve holder is moved in the axial direction by rotating the rotor member, the valve body is in contact with and separated from the orifice, and the coil spring is in contact with the orifice in the state where the valve body is in contact with the orifice. An electric valve configured to press a valve body against the orifice with a predetermined pressure, wherein one end of the shaft is formed in an arc shape when viewed from a side surface protruding toward the valve body, and the one end of the shaft A disc-shaped washer is provided between one end of the coil spring, the washer has a recess that is rotatably fitted to one end of the shaft, and the valve body is in contact with the orifice. Is stationary, and rotational sliding is generated between the washer and the shaft . Furthermore, in the motor-operated valve of the present invention, the washer has the recess on both sides . Furthermore, the motor-operated valve of the present invention has a smaller contact area between the shaft and the washer by making the curvature radius of one end of the shaft different from the curvature radius of the recess of the washer. Furthermore, the motor-operated valve of the present invention is formed by forming a plating coating layer made of a material containing nickel in polytetrafluoroethylene on the surface of the washer. The motor-operated valve of the present invention is provided with a valve body having a valve chamber and an orifice, a can attached to the valve body, a stator member arranged outside the can, and arranged inside the can. A rotor member; a cylindrical valve holder that is integral with the rotor member and has a threaded portion on the outer periphery; a valve body that is slidably inserted into a hollow portion of the valve holder; and that opens and closes the orifice; and A bush having a threaded portion that is fixed and screwed to the threaded portion of the valve holder on the inner periphery, and is disposed on the axis of the valve holder, and one end is loosely fitted to one end of the valve holder so as to be slidable in the axial direction. And a shaft projecting into the valve holder and having the other end loosely fitted in a bearing member integral with the can in the axial direction, and disposed between one end of the valve holder and one end of the shaft. Through the shaft A coil spring that urges the valve body toward the orifice, and when the rotor member rotates, the valve holder moves in the axial direction, and the valve body contacts and separates from the orifice. Is an electric valve in which the coil spring presses the valve body against the orifice with a predetermined pressure in a state where the coil spring is in contact with the orifice, and one end of the shaft is viewed from a side surface protruding toward the valve body. The top of the valve body is in contact with one end of the valve body, the valve body is swingable in the radial direction with respect to the valve holder, and the valve body is in contact with the orifice. The valve body is stationary in the state, and rotational sliding is generated between the shaft and the valve body.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing the overall configuration of the motor-operated valve according to the embodiment of the present invention, and FIG. 2 is an explanatory view showing the main part thereof.
The motor-operated valve denoted as a whole by reference numeral 1 has a cylindrical can 10 and a motor mold 20 fitted on the outer periphery of the can 10. The motor mold 20 is made of resin, and includes a stator yoke 21, a bobbin 24, and a magnet wire 22 wound around the bobbin 24. The magnet wire 22 is connected to a connector 34 inside the housing 30 attached to the motor mold 20 via a lead wire 23. The connector 34 is connected to the control device via a lead wire 36. The bobbin 30 is filled with an epoxy resin 32.
[0006]
The motor mold 20 is detachably fitted to the outer peripheral portion of the can 10 in the axial direction, and is fixed to the motor mold 20 by a stopper 28 attached by a screw 26. A recess 11 for receiving the stopper 28 is formed on the outer periphery of the can 10.
The lid member 12 is attached to the opening of the can 10 by means such as welding, and the valve body 40 is attached to the opening of the lid member 12. The valve body 40 is made of, for example, a copper alloy and has a valve chamber 42, an inlet 43, and an outlet 44. The outlet 44 forms an orifice that controls the flow rate of the valve.
[0007]
An inlet side pipe 50 communicates with the inlet 43 of the valve body 40, and an outlet side pipe 52 communicates with the outlet 44 which is an orifice.
A guide bush 90 is inserted into the inner diameter portion of the valve body 40. The guide bush 90 has a female threaded portion 92 at its inner diameter, and a valve holder 70 having a male threaded portion 74 that is screwed into the female threaded portion 92 is attached. The valve holder 70 has a cylindrical shape having a hollow portion 71, and a valve body 80 is slidably inserted in the lower portion. A disc-shaped washer 100 is provided at the bottom of the hollow portion 71 of the valve holder 70. The valve body 80 is always urged in a direction to be pushed outward by the coil spring 72 inserted into the hollow portion 71 through the washer 100, and the valve body 80 is pressed by the collar 82 that is press-fitted into the inlet portion of the valve holder. The protruding position is restricted.
[0008]
A shaft 64 is disposed on the valve holder 70. A plastic sleeve 60 is integrally formed on the outer periphery of the shaft 64 and the valve holder 70, and a bond magnet 62 is formed on the outer periphery of the plastic sleeve 60. The bonded magnet 62 functions as a motor rotor.
The upper end portion of the shaft 64 is supported by the bearing member 14 disposed on the back surface of the top portion of the can 10. When the lower end portion of the coil spring 66 provided on the outer peripheral surface of the shaft 64 is supported by the upper surface of the sleeve 60, the rotor rotates and rises together with the valve holder 70, and when the screw portion is unscrewed, This is for pressing the valve holder 70 toward the bush 90 side.
The stopper member 77 attached to the upper portion of the bush 90 regulates the lower end position of the rotor, is formed of a resin material, and comes into contact with the stopper portion 78 of the sleeve 60.
[0009]
The valve chamber 42 of the valve main body 40 communicates with the inside of the can 10 through the passage 46, and the inside of the can 10 and the hollow portion of the valve holder communicate with each other through the hole 73. Accordingly, the valve chamber 42, the inside of the can 10 and the hollow portion of the valve holder are always pressure-equalized, so that the refrigerant flowing into the valve chamber 42 is filled into the can 10, and the internal threaded portion 92 of the bush 90 and the valve holder 70 are filled. The refrigerant also flows into the threaded portion of the male screw portion 74 and between the coil spring 72 and the washer 100.
The refrigerant has a strong cleaning action, and therefore, the lubricating component of the sliding portion is easily removed.
[0010]
Between the washer 100 and the coil spring 72, rotational sliding occurs when the valve body 80 is seated on the orifice 44 and stops rotating.
In order to press the valve body against the orifice with a predetermined force, even after the valve body 80 contacts the orifice 44, the rotor is rotated by a predetermined rotation angle to compress the coil spring 72 to generate a spring force.
Because of this action, the washer 100 and the coil spring 72 rotate and slide while receiving thrust from the spring.
[0011]
Since the disk-shaped washer 100 is inserted in the present invention, the washer 100 can achieve the function of a thrust bearing and achieve smooth rotational sliding. The washer 100 is made of a material such as stainless steel. By making the washer 100 into a disk shape, the washer can be accurately disposed at the bottom of the hollow portion of the valve holder, for example, by tweezers utilizing vacuum during assembly.
[0012]
Furthermore, in the present invention, lubrication can be improved and the function as a thrust bearing can be improved by applying (NI + PTFE) plating in which nickel is added to polytetrafluoroethylene on both sides of the washer 100.
The washer 100 may be disposed between the spring 72 and the valve body 80 instead of being disposed between the bottom of the hollow portion 71 of the valve holder 70 and the spring 72.
[0013]
The plating means is the same as general electroless nickel plating.
This plated plating layer of NI + PTFE has high hardness, excellent slipperiness, and high wear resistance. Therefore, by forming this plating coating layer on the washer disposed between the valve holder and the spring, the valve holder can be used even in an electric valve that controls a refrigerant body having high cleaning properties and low lubricity. The valve body always functions normally and can exhibit a predetermined performance.
[0014]
In the above-described embodiment, the washer 100 is constituted by a flat disk and is in contact with the mating member. For example, a protrusion is provided in the central portion of the washer to provide a contact with the mating member. You may make it point-contact with.
[0015]
FIG. 3 is a cross-sectional view of a motor-operated valve showing another embodiment of the present invention, FIG. 4 is a cross-sectional view of a main part, and the same reference numerals as those in FIGS. 1 and 2 indicate the same or equivalent parts.
In the present embodiment, the top of the valve holder 70 has a configuration protruding from the upper surface of the plastic sleeve 60. The shaft 200 press-fitted into the central portion of the valve holder 70 is supported by a bearing member 14 whose upper end is disposed on the back surface of the top of the can 10. The lower end portion of the coil spring 66 disposed on the outer peripheral portion of the shaft 200 is supported by the upper surface of the valve holder 70.
The lower end portion of the shaft 200 protrudes into the hollow portion 71 of the valve holder 70. The lower end 202 of the shaft 200 has an arc at the tip and abuts against the upper surface of the washer 220.
[0016]
The lower surface of the washer 220 is brought into contact with the upper surface of a coil spring 72 disposed between the washer 220 and the coil spring 72 always urges the valve body 80 in a direction to push it outward. The valve holder 70 is screwed into a bush 90 fixed to the valve body 40, rotates together with the plastic sleeve 60 and the bond magnet 62 formed on the outside thereof, and moves in the axial direction by the action of the screw portion. Other configurations are also the same as those in the above-described embodiment, and thus description thereof is omitted.
A recess 222 is formed on the upper surface of the washer 220 and is fitted to the lower end 202 of the shaft 200. It should be noted that the washer may be formed with the same concave portion on both sides, so that either side can come into contact with the shaft to improve the assemblability. With this configuration, even when the valve body 80 abuts against the orifice 44 and the rotation is stopped, and the washer 220 rotates together with the coil spring 72, the valve body 80 rotates and slides with the lower end 202 of the shaft 200. Does not occur. In addition, the concave portion 222 formed on the upper surface of the washer 220 has a curved surface, and by changing the radius of curvature, the upper surface of the washer 220 and the lower end portion of the shaft 200 can be in any form of surface, line, or point. It becomes.
By forming a plating layer with high lubricity on the upper surface of the washer 220 and further forming a nitride film on the surface of the tip of the shaft, smoother sliding and wear resistance can be obtained.
[0017]
FIG. 5 is a cross-sectional view of a main part showing still another embodiment of the present invention, and other configurations are the same as those in FIG. 1 or FIG.
Even in this apparatus, a valve holder 170 formed integrally with a plastic sleeve (not shown) is provided, and the valve holder 170 is connected to a bush (not shown) fixed to the valve body side via a screw portion 174. The rotor is moved up and down together with the plastic sleeve.
A lower end portion of the shaft 300 is inserted into the internal space 171 of the valve holder 170 via a coil spring 172. The upper end 305 of the shaft 300 is supported by the bearing member 14 attached to the top of the can. At this time, a large clearance is provided between the upper end portion 305 of the shaft 300 and the bearing member 14, and the shaft 300 that moves up and down integrally with the valve holder 170 is not restrained.
[0018]
A lower end portion 310 of the shaft 300 is formed in a head portion having an arc at the tip, and is in contact with an end portion of the coil spring 172. The top portion 312 of the lower end portion 310 is brought into contact with the top portion of the valve body 80 by an arc surface.
A collar 82 is press-fitted into the opening 171 of the hollow portion 171 of the valve holder 170 so as to prevent the valve body 80 from coming off. An appropriate clearance is provided between the collar 82 and the valve body 80 to allow the valve body 80 to swing. With this configuration, the valve body 80 is prevented from being restricted due to the orifice 44 and malfunctioning.
[0019]
Since this device is configured to press the valve body directly by the shaft having the arc at the tip as described above, the degree of freedom of swinging of the valve body is increased and the valve body is restrained with respect to the orifice. It can prevent more reliably.
[0020]
【The invention's effect】
As described above, the present invention is an electric valve of an air conditioner that has a strong detergency and needs to operate in a state where it is exposed to a refrigerant having low lubricity, and is integrated with a rotor of a stepping motor. A hollow portion is provided in a valve holder that performs a linear motion together with a rotational motion by a screw action, and a valve body is slidably inserted into the hollow portion. Then, one end of a shaft arranged on the axis of the valve holder is press-fitted into one end of the valve holder and protruded into the valve holder, and one end of the shaft is formed in an arc shape when viewed from the side surface protruding toward the valve body. It is.
[0021]
Then, the inserting a coil spring between the shaft and the valve body, it is interposed washers between the coil spring and the shaft, since the washer is provided with a recess to be fitted rotatably to one end of the shaft The washer functions as a thrust bearing and can smoothly rotate and slide between the shaft and the washer even after the valve body is restrained by the orifice. Accordingly, the valve body in contact with the orifice to maintain the stationary state can prevent wear of the orifice, it is possible to suppress the variation of the flow amount characteristic. Thereby, according to this invention, the reliability of a motor operated valve can be improved .
[0022]
Moreover, even if one end of the shaft is formed in an arc shape when viewed from the side surface protruding toward the valve body, and the top portion thereof is brought into contact with the valve body, rotational sliding occurs between the shaft and the valve body. Therefore, it is possible to prevent wear by maintaining the stationary state of the valve body in contact with the orifice. Further, since the valve body is swingable in the radial direction with respect to the valve holder , the valve body is forcibly inserted into the orifice and restrained due to the misalignment between the valve body and the orifice. The problem is solved. Furthermore, the function as a thrust bearing can be further improved by forming a plating layer with high lubricity on the washer and forming a nitride film on the surface of the shaft. Therefore, it is effective for an electric valve of an air conditioner that handles a refrigerant having low lubricity, such as an alternative refrigerant.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of a motor-operated valve to which the present invention is applied.
FIG. 2 is an enlarged view of a main part of FIG.
FIG. 3 is an explanatory view showing another embodiment of the present invention.
4 is a cross-sectional view of the main part of FIG. 3;
FIG. 5 is a cross-sectional view of a main part showing another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motorized valve 10 Can 12 Cover member 14 Bearing member 20 Motor mold 21 Stator yoke 24 Bobbin 30 Housing 40 Valve main body 42 Valve chamber 44 Orifice 60 Plastic sleeve 62 Bond magnet 70 Valve holder 71 Hollow part 72 Coil spring 74 Male thread part 80 Valve body 90 Bush 92 Female thread part 100 Washer 170 Valve holder 172 Coil spring 200 Shaft 220 Washer 300 Shaft

Claims (6)

A valve body having a valve chamber and an orifice, and the can that is kicked with Ri taken to the valve body, a stator member arranged outside of the can, a rotor member disposed inside of the can, the rotor a cylindrical valve holder having a threaded portion on an outer peripheral portion of a member integral with a valve body slidably inserted into the hollow portion of the valve holder to open and close the orifice, within the peripheral portion is fixed to the valve body a bushing having a threaded portion to be screwed with the threaded portion of the valve holder, a coil spring for biasing the valve body is arranged between the inner end of the valve holder and the valve body to said orifice Arranged on the axis of the valve holder, one end is press-fitted into one end of the valve holder and protrudes into the valve holder, and the other end is loosely fitted in a bearing member integral with the can so as to be slidable in the axial direction. And a shaft When the rotor member rotates, the valve holder moves in the axial direction, the valve body contacts and separates from the orifice, and the coil spring contacts the orifice with the valve body in contact with the orifice. An electric valve that is pressed at a predetermined pressure,
One end of the shaft is formed in an arc shape when viewed from a side surface projecting toward the valve body, a disc-shaped washer is provided between one end of the shaft and one end of the coil spring, and the washer is connected to the shaft. It has a recess that is rotatably fitted to one end, so that the valve body is stationary while the valve body is in contact with the orifice, and rotational sliding occurs between the washer and the shaft. ,
An electrically operated valve characterized by that . The motor operated valve according to claim 1, wherein the washer has the concave portion on both surfaces. The motor-operated valve according to claim 1 or 2, wherein a contact area between the shaft and the washer is reduced by making a curvature radius of one end of the shaft different from a curvature radius of the recess of the washer . On the surface of the washer, electric valve according to any one of claims 1 to 3 obtained by forming a plated-coating layer made of a material containing polytetrafluoroethylene nickel. A valve body having a valve chamber and an orifice, and the can that is kicked with Ri taken to the valve body, a stator member arranged outside of the can, a rotor member disposed inside of the can, the rotor a cylindrical valve holder having a threaded portion on an outer peripheral portion of a member integral with a valve body slidably inserted into the hollow portion of the valve holder to open and close the orifice, within the peripheral portion is fixed to the valve body a bushing having a threaded portion to be screwed with the threaded portion of the valve holder is placed on the axis of the valve holder, the inside of the valve holder with one end slidably loosely fitted in the axial direction at one end of the valve holder The other end of the valve holder is slidably fitted in a bearing member integral with the can, and is disposed between one end of the valve holder and one end of the shaft. The valve body is And a coil spring for urging the, said valve body together with the rotor member wherein the valve holder moves axially by rotating into contact or away from the said orifice, said valve body is in contact with the orifice An electric valve in which the coil spring presses the valve body against the orifice with a predetermined pressure in a state,
One end of the shaft is formed in an arc shape when viewed from a side surface projecting toward the valve body, and a top portion thereof is in contact with one end of the valve body, and the valve body is in a radial direction with respect to the valve holder. The valve body is stationary in a state where the valve body is in contact with the orifice, and rotational sliding occurs between the shaft and the valve body.
An electrically operated valve characterized by that . The motor-operated valve according to any one of claims 1, 2, 3, and 5, wherein a nitride film is formed on a surface of the shaft by a tuftride method.

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