JPH06241338A - Manufacture of rotor core for motor-operated valve, rotor feed screw and rotor - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a rotor core in which the thread-cut leading end of a female thread part is precisely aligned with the position of a valve closing limit stopper. CONSTITUTION:A recess 34 for molding a valve closing limit stopper 9d and a pin attaching hole 35 opened to the center part of a cavity 34 are formed in a lower die 31 of a die device 30, and a set pin 36 screwed and secured in the pin attaching hole 35 is positioned through the engagement of a key ridge 35a with a key groove 36a so that the thread-cut leading end part 19b of a bushing male thread 19a is positionally aligned with the stopper molding recess 34. Further, it is attached between a pin stepped part 36b against which the lower end part of the bushing 19 abuts the lower end of the bushing, and the inner bottom surface of the stopper molding recess 34a with being held at a height 2h which is integer times as high as the pitches of the bushing male thread. After the set pin 36 incorporating the bushing is set, the die device 30 is closed, and molten resin is cast into the cavity 34 so as to form a rotor core integrally incorporated with the bushing 19 and a molded sleeve 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor central body, a rotor feed screw, and a method for manufacturing a rotor used as a component of an electric valve for controlling the flow rate of a fluid such as a refrigerant.

[0002]

2. Description of the Related Art FIG. 5 is a longitudinal sectional view showing a conventional motor-operated valve for controlling the flow rate of a refrigerant.
Having a first flow path Pa and a second flow path Pb communicating with
A valve body E provided with a valve seat 2 in a valve chamber communication portion of a flow path, a long rod-shaped needle valve 4 that comes in contact with and separates from a seat valve seat 3 of the valve body E, and a second valve of the valve body E. It has a cylindrical hermetically sealed case 6 fixed to the outer side opposite to the flow path Pb, and a stator coil 18 arranged outside the case, and is rotated inside the case 6 by energizing and exciting the stator coil 18. Rotor 11 which can move its position in the valve opening / closing direction
And a male screw tube 8 for opening and closing the needle valve 4 by a screw feed action by the rotation of the rotor of the stepping motor M, and the lower lid 7 of the case 6 has a valve body. It is welded and fixed to E.

The rotor 11 has a cylindrical sleeve 9'having an internal thread 9a as shown in FIG. 6 on its inner periphery, and a cylindrical permanent member fixed to the outside of this sleeve 9'with a retaining ring 16 as shown in FIG. The inner peripheral female screw 9a of the sleeve 9'is screwed onto the outer peripheral male screw 8a of the male screw tube 8 (which is fitted and fixed to the valve housing protruding port 17 of the valve body E). The needle valve 4 inserted inside the male screw tube 8 is fixed so that its upper end shaft portion is inserted into the central hole of the upper partition wall of the sleeve 9'and is moved integrally with the rotor 11 by the shaft stopper 14. When the rotor 11 is rotated by interposing a washer 13 and a valve closing buffer spring 12 for urging the needle valve 4 in the valve closing direction at the lower part of the center hole, the rotor 11 screw-feeds the male screw tube 8. It is possible to control the fluid flow rate corresponding to the pulse signal given to the stator coil 18 by moving the needle valve 4 in the opening / closing direction by the rotational movement of the rotor 11 while rotating by the action. There is.

Reference numeral 15 shown in FIGS. 5 and 6 is a valve closing pin which is press-fitted and fixed in a pin mounting hole 9c provided in the lower end portion of the sleeve 9'for adjusting the amount of protrusion, and FIG. Reference numeral 5 shown in FIG. 7 is a fully closed stopper pin that is press-fitted and fixed in a pin mounting hole Ea provided at the upper end of the valve body E, and when the needle valve 4 is closed, the valve closing pin 15 is a fully closed stopper pin. As shown in FIG. 5, the outer peripheral surface of the rotor 5 is brought into contact with the outer peripheral surface of the rotor 5 to regulate the valve closing limit of the rotor 11.

[0005]

In order to regulate the valve closing lower limit of the rotor 11, the thread cutting start end portion 9b of the inner peripheral female screw 9a of the sleeve 9'and the pin mounting for inserting the valve closing regulating pin 15 are attached. It is necessary to align the position of the hole 9c on the same center line with respect to the sleeve diametrical direction as shown in FIG. 6, and it is necessary to adjust the protrusion amount h2 of the valve closing restriction pin 15 and press-fit it into the pin mounting hole 9c. It was

Similarly, in the male screw tube 8 fixed to the valve body E, the position of the threading start end 8b of the male screw 8a and the position of the pin mounting hole Ea provided in the valve body E are on the same center line as shown in FIG. In addition, it is necessary to fix it to the valve housing protruding port 17, and in order to adjust the h1 dimension after press-fitting and fixing the full-closed stopper pin 5 into the pin mounting hole Ea, press the full-closed stopper pin 5 onto the pin and press it. It was necessary to cut the end face.

The h1 dimension shown in FIG. 7 is set by an integral multiple of the pitch of the male screw 8a + pitch / 2, and h2 shown in FIG.
The dimension is set to be an integral multiple of the pitch of the female screw 9a, so that the valve-closing restriction pin 15 is adjusted so that the full-closed stopper pin 5 has a pitch / 2 contact amount. Since the screwing position of the valve actuating mechanism is regulated as described above, there is a problem that not only the number of parts is large, but also the number of assembling steps is large and the workability is difficult and expensive.

The present invention has been made in order to solve the above-mentioned conventional problems. A first object of the present invention is to adjust the positions of the thread cutting start end portion of the female screw and the valve closing restriction stopper without the conventional adjustment work. It is an object of the present invention to provide a method capable of manufacturing an accurately matched rotor central body.

A second object of the present invention is to provide a method for manufacturing a rotor feed screw in which the positions of the thread cutting start end of the male screw and the fully closed stopper are accurately matched without the conventional adjustment work. Especially.

Further, a third object of the present invention is to provide a method capable of manufacturing a rotor in which the positions of the thread cutting start end portion of the female screw and the valve closing restriction stopper are accurately matched without the conventional adjustment work. It is in.

[0011]

A first invention for achieving the above first object is to provide a cylindrical sleeve 9 having a valve closing stopper 9a and molded entirely of synthetic resin, and an internal thread on the inner circumference. A method for manufacturing a rotor central body for a motor-operated valve, which comprises a metal bush 19 integrally formed and fixed to an inner peripheral portion of the sleeve 9 by defining a molding cavity 34 of the sleeve 9. A mold device 30 that can be opened and closed, and a lower mold 31 of the mold device, which has a molding concave portion 34a of the valve closing stopper 9d and a key protrusion 35a on the inner periphery opening to the center of the cavity 34 A mounting hole 35 is provided, and the bush 19 is inserted into the pin mounting hole 35 of the lower mold 31.
Of the bushing female screw 19a with the threading start end 19b of the bushing female screw 19a
key protrusion 35a and key groove 36a so as to correspond to the position a.
A predetermined height dimension h that is an integral multiple of the bush female screw pitch between the pin step portion 36b with which the bush lower end portion abuts and the inner bottom surface of the stopper molding recess 34a.
2 Hold and install the bush with the set pin 36
Of the mold device 30 after the lower mold 31 is set
Is closed, and molten resin is injected and injected into the cavity 34 to manufacture a rotor central body in which the bush 19 and the molding sleeve 9 are integrated.

A second invention for achieving the above second object is as follows.
On the outer periphery of the base end mounting portion 8c of the male screw pipe 8 having a male screw 8a on the outer periphery and having a mounting portion 8c for the valve body E at the base end and having a valve full-close stopper 5a. Synthetic resin base end flange body 20 integrally plastically fixed
A method of manufacturing a rotor feed screw for a motor-operated valve, comprising: an upper mold 42 and a lower mold 41 which define a molding cavity 44 of the flange body 20 and which can be opened and closed.
0, and a fully closed stopper 5a is provided on the lower mold 41 of this mold device.
Bush mounting hole 4 having a key projection 45a at the inner bottom opening to the molding recess 44a and the center of the cavity 44
5 and a bottomed cylindrical set bush 46 in which the male screw tube 8 is screwed and fixed in the bush mounting hole 45 of the lower die 41, and a thread cutting start end portion 8b of the male screw 8a is provided.
Is set by the engagement of the key protrusion 45a and the key groove 46a so as to correspond to the stopper molding recess 44a, and the base end mounting portion 8c of the male screw tube 8 is mounted so as to project onto the lower mold 41, and this set is set. With the bush 46 set in the lower mold 41, the upper mold 42 having the cavity center recess 42a that fits into the base end mounting portion 8c of the male screw tube 8 is closed, and the molten resin is injected and injected into the cavity 44. It is characterized in that a rotor feed screw in which the male screw tube 8 and the molding flange body 20 are integrated is manufactured.

A third invention for achieving the third object is as follows:
A cylindrical rotor body 11a which has a valve closing stopper 9d and is entirely molded of a resin material mixed with magnet powder, and an internal thread 19a on the inner circumference, which is integrally fixed to the inner circumference of the rotor body 11a by plastic molding. A method for manufacturing a rotor for a motor-operated valve, comprising:
A mold device 30 that defines a molding cavity 34 'of a is provided, and a lower mold 31 of the mold device is provided with a molding concave portion 34a of the valve closing restriction stopper 9d and an inner periphery that is open at the center of the cavity 34. A pin mounting hole 35 having a key protrusion 35a is provided, and a set pin 36 in which the bush 19 is screwed and fixed in the pin mounting hole 35 of the lower die 31 is used. Is positioned by the engagement of the key protrusion 35a and the key groove 36a so as to correspond to the position, and an integer multiple of the bush female screw pitch is provided between the pin step portion 36b with which the bush lower end portion abuts and the inner bottom surface of the stopper molding recess 34a. After mounting the bushing set pin 36 to the lower mold 31, the mold device 30 is closed. And, the cavity 34 'of the molten resin of the magnet powder mixed with injection injected into, characterized by manufacturing the rotor forming the rotor body 11a and the bushing 19 are integrated.

[0014]

According to the manufacturing method of the first invention, the female screw 19
It is possible to manufacture a rotor central body in which the thread cutting start end portion 19b of a and the valve closing restriction stopper 9d are accurately aligned by injection molding with good workability.

According to the manufacturing method of the second aspect of the present invention, the rotor feed screw in which the thread cutting start end portion 8b of the male screw 8a and the position of the fully closed stopper 5a are accurately aligned can be manufactured by injection molding with good workability.

According to the manufacturing method of the third invention, the threading start end portion 19b of the female screw 19a and the valve closing stopper 9d.
It is possible to manufacture a rotor whose position is accurately matched by injection molding with good workability.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIG.

In the first embodiment, the valve closing restriction stopper 9 is used.
Cylindrical sleeve 9 having d and being entirely molded of synthetic resin
And a bush 19 made of metal, which has an internal thread 19a on the inner circumference and is integrally plastically fixed to the inner circumference of the sleeve 9, and is a method for manufacturing a rotor central body for a motor-operated valve. The mold device 30 (composed of a lower mold 31, an upper mold 32, and a split mold 33 arranged between the upper and lower molds) that defines a molding cavity 34 of the mold mold 30 is provided. The lower mold 31 is provided with a molding concave portion 34a of the valve closing restriction stopper 9d and a pin mounting hole 35 having a key protrusion 35a on the inner circumference opening to the center of the cavity 34,
The set pin 36 in which the bush 19 is screwed and fixed into the pin mounting hole 35 of the lower die 31 is attached to the bush female screw 19
The threaded starting end portion 19b of a is positioned so as to correspond to the molding recess 34a of the valve closing stopper 9 as shown in FIG. ) And the stopper step concave portion 3 which is positioned by the engagement of
1A by holding a predetermined height dimension h2 which is an integral multiple of the pitch of the bush female screw 19a between the inner bottom surface of 4a and FIG.
After setting the bushing set pin 36 to the lower mold 31, the mold device 30 is closed and a molten resin (not shown) is injected into the cavity 34 to form the bush 19 and the molding. The rotor central body as shown in FIG. 1 (B) in which the sleeve 9 is integrated is manufactured.

Reference numeral 36c shown in FIG. 1A indicates a male screw portion of the set pin 36 to which the bush 19 is screwed.
36d is a pin upper end projecting portion which forms the center hole 9e of the sleeve upper end partition, and this pin upper end projecting portion 36d is the mold device 3
When the 0 mold is closed, the boss center hole 32a of the upper mold 32 is shown in FIG.
It is adapted to be fitted as shown in (A). FIG. 2 shows a second embodiment of the present invention.

In this second embodiment, a metallic male screw tube 8 having a male screw 8a on the outer circumference and a mounting portion 8c for the valve body E at the base end, and a valve full-close stopper 5a are provided. A method for manufacturing a rotor feed screw for a motor-operated valve, comprising a synthetic resin base end flange body 20 integrally plastically fixed to the outer periphery of a base end mounting portion 8c of a pipe 8, wherein the flange body 20 is formed. A mold device 40, which includes an upper mold 42 and a lower mold 41 that define a cavity 44, is openable and closable, and the lower mold 41 of the mold device has a molding recess 44a for the valve full-close stopper 5a.
And a bush mounting hole 45 having a key ridge 45a on the inner bottom surface opening to the center of the cavity 44, and the male screw tube 8 is screwed and fixed in the bush mounting hole 45 of the lower mold 41 with a bottom. The cylindrical set bush 46,
The male screw 8a is positioned by engaging the key projection 45a and the key groove 46a (provided at the lower end of the set bush 46) so that the thread cutting start end 8b of the male screw 8a corresponds to the stopper forming recess 44a. 2A in a state in which the base end mounting portion 8c of No. 8 projects above the lower mold 41, and is fitted to the base end mounting portion 8c of the male screw pipe 8 in the set state of the set bush 46 with respect to the lower mold 41. The upper mold 42 having the cavity center recess 42a to be fitted is closed,
A molten resin (not shown) is injected and injected into the cavity 44 to manufacture a rotor feed screw as shown in FIG. 2 (C) in which the male screw tube 8 and the molding flange body 20 are integrated.

Reference numeral 46b shown in FIG. 2 (A) is a female screw portion of the set bush 46 to which the male screw tube 8 is screwed, and h1 dimension shown in FIG. 2 (C) is the upper surface of the fully closed stopper 5a and the upper end of the male screw 8a. The height dimension between the parts is set to an integral multiple of the pitch of the male screw 8a + pitch / 2. It is a code.

FIG. 3 comprises a rotor central body manufactured by the method of the first embodiment (first invention) and a rotor feed screw manufactured by the method of the second embodiment (second invention). It is a sectional view of a motor-operated valve, and this motor-operated valve is constituted as follows.

That is, the motor-operated valve has a valve body E having a first flow passage Pa and a second flow passage Pb communicating with the valve chamber 1 and a valve seat 2 provided at a valve chamber communicating portion of the second flow passage. , This valve body E
A long rod-shaped needle valve 4 that comes into contact with and separates from the seat valve seat 3, a cylindrical hermetically sealed case 6 fixed to the outer side of the valve body E opposite to the second flow path Pb, and the case. The case 6 having a stator coil 18 arranged outside the
A pulse controllable stepping motor M provided with a rotor 11 that can be moved in the valve opening / closing direction by rotating the stator coil 18 by energizing the stator coil, and the needle valve by a screw feeding action by the rotation of the rotor of the stepping motor M. And a lower lid 7 of the case 6 is fixed to the valve body E by welding.

The rotor 11 has a cylindrical sleeve 9 made of synthetic resin, a metal bush 19 having an internal thread 19a on the inner circumference and integrally fixed to the inner circumference of the sleeve 9 by a metal bush 19. The sleeve 9 is composed of a cylindrical permanent magnet 10 fixed to the outside of the sleeve 9 with a retaining ring 16.
The inner peripheral female screw 19a is screwed into the outer peripheral male screw 8a of the male screw tube 8 (which is fitted and fixed in the valve housing recessed hole 17a of the valve body E). The rotor central body targeted by the first invention is composed of the sleeve 9 and the bush 19. The needle valve 4 provided inside the male screw tube 8 is inserted into the central hole of the upper partition wall of the sleeve 9 so that the needle valve 4 is moved integrally with the rotor 11 by the shaft stopper 14 as in the conventional one. When the rotor 11 is rotated by interposing a washer 13 and a valve closing buffer spring 12 for urging the needle valve 4 in the valve closing direction at the lower part of the center hole, the rotor 11 is rotated by the male screw tube 8 The rotor valve 11 moves in the axial direction while rotating by the screw feeding action, and the rotational movement of the rotor 11 moves the needle valve 4 in the opening / closing direction to control the fluid flow rate corresponding to the pulse signal given to the stator coil 18. It is like this.

When the needle valve 4 is closed, a valve closing stopper 9d integral with the resin molding sleeve 9 is brought into contact with the outer peripheral surface of the full closing stopper 5a integral with the resin molding flange body 20 as shown in FIG. The valve closing limit of the rotor 11 is regulated. FIG. 4 shows a third embodiment of the present invention.

In the third embodiment, the valve closing stopper 9
a cylindrical rotor body 11a which has a d and is entirely molded from a resin material containing magnet powder; and a metal body which has an internal thread 19a on its inner periphery and is integrally plastically fixed to the inner periphery of the rotor body 11a. A method for manufacturing a rotor for a motor-operated valve including the bush 19 of FIG. 1 and a mold device 30 (a lower mold 31 and an upper mold 3 that can be opened and closed to define a molding cavity 34 ′ of the main body 11 a
2 and a split mold 33 arranged between the upper and lower molds), and the lower mold 31 of the mold device 30 has a molding recess 34a of the valve closing restriction stopper 9d and the cavity 34 '.
A pin mounting hole 35 having a key protrusion 35a is provided on the inner periphery opening to the center of the set pin 36 in which the bush 19 is screwed and fixed into the pin mounting hole 35 of the lower mold 31.
The key protrusion 3 so that the thread cutting start end 19b of the bush female screw 19a and the stopper molding recess 34a are in position.
5a and the key groove 36a (provided on the outer periphery of the lower end of the set pin 36), and the bush female screw is provided between the pin stepped portion 36b with which the bush lower end contacts and the inner bottom surface of the stopper molding recess 34a. The lower die 31 of the bushing set pin 36 is mounted while holding a predetermined height dimension h2 which is an integral multiple of the pitch of 19a, as shown in FIG.
After the mold is set, the mold device 30 is closed, a molten resin (not shown) mixed with magnet powder is injected and injected into the cavity 34 ', and the bush 19 and the molding rotor body 11a are integrated. The rotor shown in FIG. 4 (B) is manufactured.

Reference numeral 36c shown in FIG. 4 (A) is a male screw portion of the set pin 36 to which the bush 19 is screwed,
36d is a pin upper end projecting portion which forms the center hole 9e of the sleeve upper end partition, and this pin upper end projecting portion 36d is the mold device 3
When the 0 mold is closed, the boss center hole 32a of the upper mold 32 is shown in FIG.
It is adapted to be fitted as shown in (A).

[0028]

According to the manufacturing method of the first invention shown in FIG. 1, the rotor central body in which the positions of the thread cutting start end portion 19b of the female screw 19a and the valve closing restriction stopper 9d are accurately aligned as shown in FIG. It can be manufactured with good workability by injection molding as shown in FIG. In addition, the second shown in FIG.
According to the manufacturing method of the invention, a rotor feed screw in which the position of the thread cutting start end portion 8b of the male screw 8a and the position of the fully closed stopper 5a are exactly aligned as shown in FIG. 2 (B) is formed by injection molding as shown in FIG. 2 (A). It can be manufactured with good workability. Furthermore,
According to the manufacturing method of the third invention shown in FIG.
A rotor in which the positions of the thread cutting start end portion 19b and the valve closing restriction stopper 9d are accurately aligned as shown in FIG. 4C can be manufactured with good workability by injection molding as shown in FIG. 4A.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of manufacturing a rotor central body according to a first embodiment of the present invention, in which FIG. 1 (A) is a sectional view of an essential part with a bushing set pin set in a molding die device;
FIG. 6B is a central longitudinal sectional view of the rotor central body manufactured by the method of the first embodiment, and FIG. 6C is a bottom view of the rotor central body as seen from below.

FIG. 2 is an explanatory view showing a method for manufacturing a rotor feed screw according to a second embodiment of the present invention, in which FIG. 2 (A) is a cross-sectional view of essential parts in a state where a male screw tube and a set bush are set in a molding die device. The same figure (B) is a top view of the rotor feed screw manufactured by the method of the second embodiment, and the same figure (C) is a central longitudinal sectional view of the state where this feed screw is attached to the valve body.

FIG. 3 is a cross-sectional view of a motorized valve including a rotor central body manufactured by the method of the first embodiment and a rotor feed screw manufactured by the method of the second embodiment.

FIG. 4 is an explanatory view showing a method of manufacturing a motor-operated valve rotor according to a third embodiment of the present invention, in which FIG. 4 (A) is a cross-sectional view of an essential part in a state where a bushing set pin is set in a molding die device;
The figure (B) is a central longitudinal sectional view of the rotor manufactured by the method of the third embodiment, and the figure (C) is a bottom view of the rotor as seen from below.

FIG. 5 is a bottom view showing a conventional electric valve.

FIG. 6 is a central longitudinal sectional view showing a rotor sleeve in a conventional electric valve.

FIG. 7 is a central longitudinal cross-sectional view showing a state where a rotor feed screw (male thread pipe) in a conventional electric valve is attached to a valve body.

[Explanation of symbols]

5a ... Valve fully closed stopper, 8 ... Male screw tube, 8a ... Male screw tube outer peripheral male screw, 8b ... Screw cutting start end portion of male screw, 8c ... Male screw pipe base end mounting portion, 9 ... Sleeve (molding sleeve), 9
d ... Valve closing restriction stopper, 11 ... Motor valve rotor, 11a
... rotor body, 19 ... bush, 19a ... bush inner peripheral female screw, 19b ... thread cutting start end of female screw, 20 ... base end flange body, 30 ... molding die device, 31 ... lower die, 32 ...
Upper mold, 33 ... Split mold, 34 ... Sleeve molding cavity, 34 '... Rotor body molding cavity, 34a ...
Valve closing stopper stopper recess, 35 ... Pin mounting hole, 35a
… Key ridges, 36… Set pins, 36a… Keyways, 40
Molding die device, 41 lower mold, 42 upper mold, 42a cavity center recess, 44 flange molding cavity, 44a fully closed stopper molding recess, 45 bush mounting hole, 45a key protrusion , 46 ... Set bush, 46
a ... Keyway.

Claims (3)

[Claims] 1. A tubular sleeve which has a valve closing stopper and is entirely molded of synthetic resin, and a metal sleeve which has an internal thread on its inner circumference and is integrally plastically fixed to the inner circumference of the sleeve. A method of manufacturing a rotor central body for a motor-operated valve comprising a bush, comprising a mold device capable of opening and closing, which defines a molding cavity of the sleeve, and a molding recess of a valve closing stopper provided in a lower mold of the mold device. And a pin mounting hole having a key protrusion on the inner periphery opening in the center of the cavity, and a set pin in which the bush is screwed and fixed in the pin mounting hole of the lower mold, the thread cutting starting end of the bush female screw is Positioned by the engagement of the key projection and the key groove so as to correspond to the stopper molding recess, and between the pin step portion with which the lower end of the bush abuts and the inner bottom surface of the stopper molding recess are an integral multiple of the bush female thread pitch. Mounting while maintaining the predetermined height,
After the set pin with the bush is set in the lower mold, the mold device is closed, and the molten resin is injected and injected into the cavity to manufacture a rotor central body in which the bush and the molding sleeve are integrated. A method for manufacturing a rotor central body for a motor-operated valve. 2. A male threaded pipe made of metal having a male thread on the outer periphery and a mounting portion for the valve body at the base end portion, and a valve full-closed stopper integrated with the outer periphery of the base end mounting portion of the male threaded pipe. A method for manufacturing a rotor feed screw for a motor-operated valve, which comprises a base flange body made of synthetic resin, which is plastically fixed to a metal mold, comprising an upper mold and a lower mold which define a molding cavity of the flange body and which can be opened and closed. The lower mold of the mold device is provided with a molding recess of the valve full-close stopper and a bush mounting hole having a key ridge on the inner bottom opening to the center of the cavity. A bottomed cylindrical set bush in which the male screw tube is screwed and fixed in the mounting hole is positioned by engagement of the key protrusion and the key groove so that the thread cutting start end of the male screw corresponds to the stopper molding recess. Base end mounting of the male screw tube Installed with the part protruding above the lower mold, and with this set bush set to the lower mold, close the upper mold that has a cavity center concave part that fits into the base end mounting part of the male screw tube, and melt into the cavity. A method for manufacturing a rotor feed screw for a motor-operated valve, which comprises injecting a resin to produce a rotor feed screw in which a male screw tube and a molded flange body are integrated. 3. A cylindrical rotor body having a valve closing stopper and entirely molded of a resin material mixed with magnet powder; and an internal thread on the inner periphery of the rotor body, which is integrally molded on the inner peripheral portion of the rotor body. A method for manufacturing a rotor for a motor-operated valve, which comprises a fixed metal bush, comprising a mold device capable of defining a molding cavity of the rotor body, wherein a valve closing valve is provided in a lower mold of the mold device. A set pin, in which the bush is screwed and fixed into the pin mounting hole of the lower mold, is provided with a molding recess of the restriction stopper and a pin mounting hole having a key protrusion on the inner periphery opening to the center of the cavity. The bush female thread pin is positioned between the pin stepped portion, which is in contact with the lower end of the bush, and the inner bottom surface of the stopper molding recess by positioning the key protrusion and the key groove so that the thread cutting start end of the stopper corresponds to the stopper molding recess. After mounting the bushing set pin to the lower mold, the mold device is closed and the molten resin mixed with magnet powder is injected and injected into the cavity. Then, a rotor for a motor-operated valve is manufactured by manufacturing the rotor in which the bush and the molded rotor body are integrated.