JP2016125554A - Process of manufacture of electric valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a variation of a valve opening point and assure a fine controlling characteristic without being influenced by assembly accuracy or an accuracy in applied component elements in an electric valve.SOLUTION: A supporting member 2 is press fitted and fixed to a valve housing 1 at "a valve rod reference point setting step" in Fig.2[A] under a non-installed state of a stator coil 63 and a case 61. The valve rod 3 having a biasing spring 4 installed therein is inserted into the supporting member 2, a needle part 31 of the valve rod 3 is set at a valve port 13 to set "the valve rod reference point". At the stage in Fig.2[B], a magnet roller 62 is installed at the supporting member 2. At "the rotation reference point setting step" in Fig.2[C], the magnet rotor 62 is rotated in a clockwise direction to have "rotation reference point" where a movable lower end stopper MD is abutted against a fixed lower end stopper SD. At the fourth step in Fig.2[D], the magnet rotor 62 is rotated from "the rotation reference point" by a predetermined set amount [predetermined rotating amount] only. The state is held and a fixing member 5 is fixed to the valve rod 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing an electric valve that controls the flow rate of a fluid such as a refrigerant such as an expansion valve of a refrigeration circuit such as an air conditioner or a refrigerator.

  2. Description of the Related Art Conventionally, as an electric valve used in a refrigeration circuit such as an air conditioner or a refrigerator, there is a flow control valve disclosed in, for example, Japanese Patent Laid-Open No. 2013-204613 (Patent Document 1). This flow control valve (electric valve) has a magnet rotor disposed in a case of a stepping motor (electric motor), and has a needle part (valve element part) in the lower part at the center of a male screw shaft fixed to the magnet rotor. The valve body is inserted. The male screw shaft forms a screw feed mechanism together with the female screw of the support member on the valve body side.

  And it is comprised so that a magnet rotor may be rotated and a valve port may be opened and closed by a needle part with a screw feed mechanism. Further, the rotation range of the magnet rotor is regulated by a fixed lower end stopper at the upper end of the support member and a movable lower end stopper on the magnet rotor side.

JP 2013-204613 A

  In recent years, improvement in energy saving performance has been actively studied for air conditioners and refrigerators, and the same performance is required for motor-operated valves used in the refrigeration circuit. Examples of the performance required for the motor-operated valve include an improvement in controllability in a minute flow rate range and a reduction in flow rate variation.

  In particular, in a large air conditioner (PAC, building multi, etc.), there are applications in which the motor-operated valve must be closed. In this case, the motor-operated valve must be opened with a predetermined pulse (valve-opening point) from the valve-closed state. However, the valve-opening point may vary greatly depending on the assembly accuracy of the motor-operated valve and the accuracy of parts used. When an air conditioner is operated for the purpose of improving energy saving, there is no choice but to deal with this variation by controlling the compressor and the fan. When the valve opening points vary greatly, the flow rate at the specified valve opening also varies greatly, and it is considered that fine controllability is impaired. Eliminating such variations is a very important issue particularly when performing control in a minute flow rate range in an air conditioner, and is also a major issue for an electric valve used in an air conditioner.

  It is an object of the present invention to ensure fine controllability in a motor-operated valve, for example, by reducing variations in valve opening points without being affected by assembly accuracy and accuracy of parts used.

  According to a first aspect of the present invention, there is provided a method of manufacturing an electric valve, comprising: a magnet rotor constituting an electric motor; and a valve chamber having a valve port disposed on the opposite side of the valve port and the magnet rotor via a screw feed mechanism. A support member that is supported coaxially with the axis of the valve port, a valve body portion is provided at an end portion on the valve port side, and an end portion on the opposite side to the valve body portion is penetrated through the center of the magnet rotor. A valve member, a fixing member fixed to the end of the valve rod and coming into contact with the magnet rotor, and a biasing spring that biases the valve rod in a direction in which the valve body portion is separated from the magnet rotor. A stopper mechanism that regulates at least a lower end position of the magnet rotor on the valve port side, and rotates the magnet rotor by the stator coil to apply the screw by a screw feed mechanism. The magnet rotor is moved in the axial direction, and the valve body portion of the valve stem is advanced and retracted with respect to the valve port in a state where the fixing member is in contact with the magnet rotor by the urging force of the urging spring. A method of manufacturing an electric valve that controls a flow rate of a fluid passing through a valve port, the valve main body having the support member and the lower end stopper, or a support member equivalent to the support member and the lower end stopper, A valve body jig having an equivalent lower end stopper, and setting a valve stem reference point that is a predetermined position of the valve stem in the axial direction of the valve body portion with respect to the support member A valve stem reference point setting step, a rotation reference point setting step for setting a rotation reference point of the magnet rotor, which is a point where the magnet rotor has reached the lower end position, and the fixing member An adhering step for adhering to the valve stem, and in the adhering step, the biasing spring is disposed between the valve stem and the magnet rotor, and the valve stem is set in the valve stem reference point setting step. The rotation angle of the magnet rotor with respect to the rotation reference point is set to a predetermined amount for the valve rod set as the rod reference point and the magnet rotor set as the rotation reference point in the rotation reference point setting step. The fixing member is fixed to the valve stem set as the valve stem reference point in a state where the predetermined set amount is maintained.

2. The method for manufacturing an electric valve according to claim 1, wherein the valve main body is used, and the valve stem reference point set in the valve stem reference point setting step is the valve stem reference point. The body part is a point where the valve port reaches a closed state from an open state.

  The method for manufacturing an electric valve according to claim 3 is the method for manufacturing the electric valve according to claim 1, wherein the valve body jig is used, wherein the valve rod reference point set in the valve rod reference point setting step is The valve body portion is a point shifted by an adjustment width in the axial direction from a point where the valve port reaches the closed state from the open state.

  According to the method for manufacturing an electric valve according to claim 1, a predetermined set amount that is a rotation angle of the magnet rotor that sets the rotation reference point is set, and the fixing member is fixed to the valve rod that sets the valve rod reference point. As a result, the distance between the magnet rotor and the valve body portion in a state in which the fixing member is in contact with the magnet rotor can be set by the biasing force of the biasing spring, and, for example, variation in valve opening points can be reduced. Can do.

  According to the method for manufacturing a motor-operated valve of claim 2, a motor-operated valve is manufactured using the valve body, and for example, variation in valve opening points can be reduced as in claim 1, and the valve stem reference point is Since the valve body portion is the point where the valve port reaches the closed state from the open state, the valve body portion can be set to a closed specification valve in which the valve port is closed and the biasing spring is further compressed.

  According to the method for manufacturing a motor-operated valve of claim 3, the motor-operated valve is manufactured using the valve body jig, and the same effect as that of claim 1 can be obtained. Moreover, since the position which determines the said valve stem reference | standard point of a valve main body jig | tool can be set arbitrarily, an open specification valve can also be set.

It is a longitudinal cross-sectional view of the motor operated valve manufactured by the manufacturing method of one Embodiment of this invention. It is a figure which shows the former stage of the manufacturing method and assembly process of the motor operated valve of 1st Example. It is a figure which shows the manufacturing method of the motor operated valve of 1st Example, and the back | latter stage of an assembly process. It is a figure which shows the former stage of the manufacturing method and assembly process of the motor operated valve of 2nd Example. It is a figure which shows the manufacturing method of the motor operated valve of 2nd Example, and the back | latter stage of an assembly process.

  Next, an embodiment of a method for manufacturing an electric valve according to the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of an electric valve manufactured by the manufacturing method of the embodiment. Note that the concept of “upper and lower” in the following description corresponds to the upper and lower sides in the drawing of FIG. The expressions “clockwise (clockwise)” and “counterclockwise (counterclockwise)” indicate the direction of rotation when the motor-operated valve is viewed from above.

  This electric valve has a valve housing 1 formed by cutting a metal member with stainless steel or the like, and the valve housing 1 has a valve chamber 1A inside thereof. A first joint pipe 11 connected to the valve chamber 1 </ b> A is connected to one outer peripheral side of the valve housing 1. A second joint pipe 12 is connected to the lower end of the valve housing 1, and a valve port 13 is formed on the inner bottom surface of the valve housing 1. The second joint pipe 12 is connected to the valve port 13 via the valve port 13. Conducted to chamber 1A. The first joint pipe 11 and the second joint pipe 12 are fixed to the valve housing 1 by brazing or the like. An attachment hole 14 that opens to the upper end is formed on the opposite side of the valve housing 1 from the valve port 13, and the support member 2 is attached to the attachment hole 14 by press-fitting.

  The support member 2 has a substantially cylindrical holder portion 21 and a flange portion 22 near the valve housing 1 of the holder portion 21, and the fixed end side stopper member 7 is fixedly attached to the flange portion 22. A fixed lower end stopper SD protruding upward is formed at one location on one side of the fixed end side stopper member 7. Further, a male screw portion 21a is formed on the outer periphery of the substantially intermediate portion of the holder portion 21 of the support member 2, and a cylindrical rotor for guiding a magnet rotor 62 described later is provided above the male screw portion 21a. A guide 21b is formed. Further, a valve guide hole 21c coaxial with the axis L of the valve port 13 is formed at the center of the support member 2, and the valve rod 3 is inserted into the guide hole 21c.

  The valve rod 3 is formed of SUS or the like, and has a needle portion 31 as a “valve body portion” at the lower end, a columnar portion 32 inserted through the guide hole 21 c of the support member 2, and a rod-shaped rod having a smaller diameter than the columnar portion 32. Part 33. A biasing spring 4 is disposed around the rod portion 33 between the step portion 32a of the cylindrical portion 32 and the magnet rotor 62 in a compressed state. Thereby, the valve stem 3 is always urged toward the valve port 13 with respect to the magnet rotor 62.

  A lid 15 is attached to the upper end of the valve housing 1, and a case 61 of a stepping motor 6 as an electric motor is airtightly fixed to the lid 15 by welding or the like. In the case 61, a magnet rotor 62 whose outer peripheral portion is magnetized in multiple poles is rotatably provided. A stator coil 63 is disposed on the outer periphery of the case 61. The stepping motor 6 rotates the magnet rotor 62 according to the number of pulses when a pulse signal is given to the stator coil 63.

  The magnet rotor 62 is composed of a rotor body 621 and a magnet 622 fixed to the outer periphery thereof. The rotor body 621 is made of a PPS resin to which an additive for improving slidability is added, but this may be a metal such as SUS or brass. The magnet 622 is molded by mixing magnetic powder into a base material made of PPS or the like. The magnet 622 may be a permanent magnet made of ferrite.

  A female screw portion 621a coaxial with the axis L of the valve port 13 and a screw hole thereof are formed below the center of the rotor main body 621, and at the center of the rotor main body 621 from the inner periphery of the screw hole of the female screw portion 621a. A cylindrical slide hole 621b having a small diameter is also formed. Further, a valve rod insertion hole 621c is formed at the upper center of the slide hole 621a. In addition, a movable lower end stopper MD that protrudes downward is formed at one lower portion of the magnet 622.

  The valve stem 3 is inserted into the guide hole 21 c of the support member 2, and the end 3 a of the valve stem 3 (the end of the rod portion 33) is inserted into the valve rod insertion hole 621 c of the rotor body 621. The magnet rotor 62 is inserted into the slide hole 621b through the rotor guide 21b of the support member 2, and the female screw portion 621a on the magnet rotor 62 side is screwed to the male screw portion 21a on the support member 2 side. The fixing member 5 is press-fitted into the end 3a of the valve stem 3, and is fixed integrally with the valve stem 3 by welding.

  The male screw portion 21a and the female screw portion 621a are screw feeding mechanisms. In this embodiment, the male screw portion 21a and the female screw portion 621a are right-hand screws. A compression spring 64 is provided between the case 61 and the magnet rotor 62 to urge the magnet rotor 62 in the valve closing direction. However, backlash between the male screw portion 21a and the female screw portion 621a occurs. By removing, it acts to reduce the operating sound of the magnet rotor 62.

  With the above configuration, when the magnet rotor 62 rotates, the magnet rotor 62 moves in the direction of the axis L (up and down) by the screw feeding action of the female screw portion 621a and the male screw portion 21a. When the needle portion 31 is not seated on the valve port 13, the urging force of the urging spring 4 brings the fixing member 5 into contact with the magnet rotor 62, and the valve stem 3 moves together with the magnet rotor 62. The needle portion 31 advances and retreats with respect to the valve port 13. Thereby, the opening degree of the valve port 13 is changed, and the flow rate of the refrigerant flowing from the first joint pipe 11 to the second joint pipe 12 or the flow rate of the refrigerant flowing from the second joint pipe 12 to the first joint pipe 11 is controlled. The

  When the needle portion 31 is in the control range for controlling the flow rate and the magnet rotor 62 rotates and descends, the movable lower end stopper MD passes over the fixed lower end stopper SD. When it further rotates and descends, the movable lower end stopper MD engages with the fixed lower end stopper SD to restrict the rotation. That is, the movable lower end stopper MD constitutes a stopper mechanism in which the fixed lower end stopper SD regulates the lower end position of the magnet rotor 62. As described above, the rotation of the magnet rotor 62 is stopped by the stopper mechanism. That is, it cannot be rotated clockwise. The instantaneous position where the movable lower end stopper MD abuts on the fixed lower end stopper SD is referred to as a “rotation reference point”.

  Here, the electric valve of the embodiment can be set to the following two specifications. First, when the magnet rotor 62 rotates clockwise and the movable lower end stopper MD comes into contact with the fixed lower end stopper SD, that is, at the “rotation reference point”, the needle portion 31 closes the valve port 13 to further bias the spring 4. Is a compressed state, which is called a “closed specification valve”. Secondly, the specification in which the needle portion 31 does not close the valve port 13 at the “rotation reference point”, which is referred to as “open specification valve”. Of course, the valve can be closed just at the “rotation reference point”.

  In addition, the stepping motor 6 rotates the magnet rotor 62 by a rotation angle corresponding to the number of pulses when a pulse signal is given to the stator coil 63. The number of pulses from the “reference point” to the moment when the valve is opened counterclockwise is referred to as “valve opening pulse”.

  In the magnet rotor 62, the positional relationship between the magnetized pattern around the magnet 622 and the movable lower end stopper MD, the positional relationship between the position of the support member 2 (and the fixed lower end stopper SD) and the stator coil 63, and the magnetism in the stator coil 63. The positional relationship between the phases is determined respectively. Therefore, fine controllability is impaired unless the valve opening at the “valve opening pulse” of the “closed specification valve” and the “rotation reference point” of the “open specification valve” is set accurately. Therefore, as in the following first and second embodiments, the distance from the needle portion 31 to the fixing member 5, that is, the position of the fixing member 5 with respect to the valve stem 3 is set in the assembly process of the motor-operated valve.

  2 and 3 are views showing a method for manufacturing the motor-operated valve and an assembly process according to the first embodiment. 2, 3, 4, and 5, reference numerals are given only to main members, and reference numerals are omitted for other members. In addition, the hatched lines indicating the cross section are omitted, and the parts related to the operation in each process are indicated by hatched lines.

  The first embodiment is a manufacturing method using a “valve body” composed of a valve housing 1 and a support member 2. First, in a non-mounted state of the stator coil 63 and the case 61, the support member 2 is press-fitted and attached to the valve housing 1 in the first step as the “valve rod reference point setting step” in FIG. The valve rod 3 equipped with the biasing spring 4 is inserted into the support member 2 and attached to the valve housing 1, and the needle portion 31 of the valve rod 3 is seated on the valve port 13. That is, by this seating, a “valve stem reference point” that is a predetermined position of the valve stem 3 in the direction of the axis L of the needle portion 31 (valve body portion) with respect to the support member 2 is set. Next, the magnet rotor 62 is mounted on the support member 2 in the second step of FIG.

  Next, in the third step as the “rotation reference point setting step” in FIG. 2C, the magnet rotor 62 is rotated clockwise, and the movable lower end stopper MD is brought into contact with the fixed lower end stopper SD. This is the “rotation reference point”. Next, in the fourth step of FIG. 2D, the magnet rotor 62 is rotated from the “rotation reference point” by a predetermined set amount (predetermined rotation amount). Next, in the fifth step of FIG. 3 (A), the fixed member 5 is moved in the state where the “valve stem reference point” (sitting state) of the valve stem 3 and the “predetermined set amount” of the magnet rotor 62 are held. Insert into bar 3. Next, in the sixth step of FIG. 3B, the fixing member 5 is welded and press-fitted to the valve stem while maintaining the “valve stem reference point” of the rod 3 and the “predetermined set amount” of the magnet rotor 62. It sticks with etc. Next, in the seventh step of FIG. 3C, the compression spring 64 is disposed, and the case 61 and the valve housing 1 are joined by welding or the like.

  4 and 5 are views showing a method for manufacturing the motor-operated valve and an assembling process of the second embodiment. The second embodiment is a manufacturing method using a valve body jig. First, in the first step of FIG. 4A, the support member 2 is press-fitted and attached to the valve housing 1 to obtain the valve body assembly 10. In addition, a valve body jig 20 equivalent to the valve body assembly 10 is prepared. The valve body jig 20 is provided with a support member 2 ′ equivalent to the support member 2 of the valve assembly 10. The valve body jig 20 is formed with a pseudo port 13 ′ having the same diameter as the valve port 13 of the valve body assembly 10. Then, a height difference in the direction of the axis L is provided between the seating portion of the pseudo port 13 ′ and the seating portion of the valve port 13. The difference in height is the “adjusted height”. When the “closed specification valve” is used, the seating portion of the pseudo port 13 ′ is set lower than the seating portion of the valve port 13 by a set amount. In the case of “open specification valve”, the seating portion of the pseudo port 13 ′ is set higher than the seating portion of the valve port 13 by a set amount. Note that the male screw portion 21a 'and the fixed lower end stopper SD' in the support member 2 'do not affect the setting accuracy, and may be similar to the support member 2.

  Next, in the second step of FIG. 4 (B), the valve rod 3 with the biasing spring 4 is inserted and attached to the support member 2 'of the valve body jig 20, and the needle portion 31 of the valve rod 3 is simulated. Seat on port 13 '. That is, by this seating, a “valve stem reference point” that is a predetermined position of the valve stem 3 in the direction of the axis L of the needle portion 31 (valve body portion) with respect to the support member 2 ′ is set. Then, the magnet rotor 62 is mounted on the support member 2 '.

  Next, in the third step as the “rotation reference point setting step” in FIG. 4C, the magnet rotor 62 is turned clockwise, and the movable lower end stopper MD is brought into contact with the fixed lower end stopper SD ′. “Rotation reference point”. Next, in the fourth step of FIG. 5A, the valve 5 is fixed with the “valve stem reference point” (sitting state) of the valve stem 3 and the “rotation reference point” of the magnet rotor 62 held. Insert into bar 3. Next, in the fifth step of FIG. 5B, the fixing member 5 is welded to the valve stem and press-fitted while the “valve stem reference point” of the rod 3 and the “rotation reference point” of the magnet rotor 62 are held. It sticks with etc. Then, the assembly of the magnet rotor 62 and the valve stem 3 is taken out from the valve body jig 20.

  Next, in the sixth step of FIG. 5C, the assembly of the magnet rotor 62 and the valve stem 3 obtained through the fifth step is mounted on the valve body assembly 10, and the seventh step of FIG. Then, the compression spring 64 is disposed, and the case 61 and the valve housing 1 are joined by welding or the like.

  Also in the second embodiment, the magnet rotor 62 may be rotated by a predetermined rotation amount by the “rotation reference point setting step” which is the third step of the first embodiment. In this case, the set amount is determined according to the predetermined rotation amount and the “adjustment height”. The second embodiment corresponds to the case where the rotation amount is set to 0 degree in the “rotation reference point setting step”.

  By using the valve body jig 20 having the pseudo port 13 ′ in which the seating portion is lower than the seating portion of the valve port 13 as in the second embodiment described above, it can be set as a “closed specification valve”. When the “valve stem reference point” of the valve stem 3 is set using the valve body jig, the needle portion 31 is seated on the seat portion of the pseudo valve port 13 ′ in the second embodiment. However, another portion such as the lower end of the cylindrical portion 32 of the valve stem may be received at a predetermined position of the valve body jig.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention.

DESCRIPTION OF SYMBOLS 1 Valve housing 1A Valve chamber 11 1st joint pipe 12 2nd joint pipe 13 Valve port 2 Support member 21 Holder part 21a Drive male screw part 3 Valve rod 31 Needle part (valve body part)
32 cylindrical portion 33 rod portion 4 urging spring 5 fixing member 6 stepping motor (electric motor)
61 Case 62 Magnet rotor 621a Drive female screw part 63 Stator coil SD Fixed lower end stopper (stopper mechanism)
MD Movable lower end stopper (stopper mechanism)
10 Body assembly 20 Body jig L Axis

Claims (3)

A magnet rotor constituting an electric motor, and a support disposed on the opposite side of the valve port with respect to the valve chamber having the valve port and supporting the magnet rotor coaxially with the axis of the valve port via a screw feed mechanism A valve body having a valve body portion provided at an end on the valve port side, a valve rod having an end opposite to the valve body portion penetrating through the center of the magnet rotor, and the end of the valve rod A fixing member fixed to a portion and abutting on the magnet rotor, and a biasing spring for biasing the valve rod in a direction in which the valve body portion is separated from the magnet rotor,
A stopper mechanism for restricting at least the lower end position of the magnet rotor on the valve port side, and rotating the magnet rotor by the stator coil and moving the magnet rotor in the axial direction by the screw feed mechanism, The flow rate of the fluid passing through the valve port is controlled by advancing and retracting the valve body portion of the valve rod with respect to the valve port in a state where the fixing member is in contact with the magnet rotor by the biasing force of the biasing spring. A method for manufacturing a motor-operated valve,
A step of performing using a valve body having the support member and the lower end stopper, or a valve body jig having a support member equivalent to the support member and a lower end stopper equivalent to the lower end stopper,
A valve stem reference point setting step for setting a valve stem reference point that is a predetermined position of the valve stem in the axial direction of the valve body portion with respect to the support member;
A rotation reference point setting step for setting a rotation reference point of the magnet rotor, which is the point at which the magnet rotor has reached the lower end position;
A fixing step of fixing the fixing member to the valve stem;
With
In the fixing step,
The biasing spring is disposed between the valve stem and the magnet rotor, the valve stem set as the valve stem reference point in the valve stem reference point setting step, and the rotation reference point setting step With respect to the magnet rotor set as the rotation reference point, the rotation angle of the magnet rotor with respect to the rotation reference point is set to a predetermined set amount, and the valve rod reference point is maintained while the predetermined set amount is maintained. The fixing member is fixed to the valve stem set to
The manufacturing method of the motor operated valve characterized by the above-mentioned. The method for manufacturing an electric valve according to claim 1, wherein the valve body is used.
The method for manufacturing an electric valve, wherein the valve stem reference point set in the valve stem reference point setting step is a point where the valve body portion reaches the valve port from an open state to a closed state. The method for manufacturing an electric valve according to claim 1, wherein the valve body jig is used.
The valve stem reference point set in the valve stem reference point setting step is a point where the valve body part is shifted by an adjustment width in the axial direction from the point where the valve port reaches the valve port from the open state to the closed state.
The manufacturing method of the motor operated valve characterized by the above-mentioned.

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