JP3330832B2 - Electric valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor-operated expansion valve used for an air conditioner or the like and a motor-operated valve used as a proportional control valve used in combination with a microcomputer in general industrial fields.

[0002]

2. Description of the Related Art Conventionally, as air conditioners have become smaller,
The miniaturization of the motor-operated valve for controlling the flow rate of the refrigerant incorporated therein has been promoted. Further, when miniaturizing this type of can-seal type motor-operated valve, in order to minimize the gap between the rotor of the motor and the case, special attention is paid to the prevention of the run-out of the rotor.

FIG. 3 is a longitudinal sectional side view showing a structure of a conventional electric control valve for preventing the rotor from swaying disclosed in Japanese Patent Publication No. 1-182680. The electric control valve includes a valve portion V and a stepping motor portion M. In the valve portion V, a valve seat 3 is provided on a partition wall 2 between a primary port 1a and a secondary port 1b of the valve body 1.
Is provided so that the needle valve 4 comes in contact with and separates from the valve seat 3.

On the valve body 1, a sealed case 5 in a stepping motor section M is fixed.
A fixed support member 6 is provided to hang down from the upper end in the direction of the valve body 1. The fixed support member 6 is provided with a cylindrical guide portion 6a and a male screw portion 6b connected in the axial direction.

The rotor 7 has a cylindrical permanent magnet 9 fitted on the outer peripheral portion of the support cylinder 8 and then the upper edge 8a is expanded on the permanent magnet 9 to integrally crimp the two. Things,
Engagement tube 10 fitted and fixed to intermediate connecting portion 8b of support cylinder 8
An external thread portion 6b of the fixed support member 6 is screwed into the female thread portion 10a, and the sliding tube portion 10b is connected to the guide portion 6a.
Is engaged.

A connecting tube 11 is further fixed to the connecting portion 8b of the support tube 8, and a hole 11 in a bottom wall 11a of the connecting tube 11 is fixed.
b, the small diameter portion 4a of the needle valve 4 penetrates and the stopper 4b is configured to engage with the bottom wall 11a, and a compression coil spring is provided between the bottom wall 11a and the step portion 4c of the needle valve 4. The coil spring 12 constantly urges the needle valve 4 in the valve closing direction.

A coil 13 is provided on the outer periphery of the closed case 5.
A built-in stator 14 is provided. Reference numeral 15 denotes an engagement piece provided on the rotor 7, and reference numeral 16 denotes a stopper, both of which are engaged during the final rotation of the rotor 7 when the valve is closed.

Accordingly, in the electric control valve configured as described above, the rotor 7 rotates while the female thread portion 1 is rotated.
0a and the male screw portion 6b move vertically.
The sliding tube portion 10b moves on the cylindrical guide portion 6a. However, when the coil 13 is energized sequentially, the rotor 7
Attempts to make uneven movement in the axial direction and in the radial direction, but due to the engagement of the sliding tube portion 10b and the guide portion 6b, the above movement is distributed and received by the screw portion. The wear can be reduced and rattling of the threaded portion during operation can be reduced.

[0009]

However, the electric control valve configured as described above has the following problems. Since the center in the longitudinal direction of the rotor 7 does not match the center in the longitudinal direction of the sliding tube portion 10b and the screw, the lower end of the rotor 7 may swing, and the rotor may hit the case. Since the fixed support member 6 serving as a guide for the rotor is made to hang down from the upper surface of the case, it is difficult to form the rotor at the center of the case and vertically in processing, and the rotor 7 may come into contact with the inclined case. Since the needle 4 is located away from the engagement between the sliding tube portion 10b and the guide portion 6b and the screwing position of the screw portion, the needle may be squeezed into the valve body. Although there are motors miniaturized with a rotor made of a rare-earth magnet having a strong magnetic force, the rare-earth magnet is not only very expensive, but also needs to be coated and plated because it is easily rusted. For this reason, the cost was further increased.

[0010]

SUMMARY OF THE INVENTION The present invention provides a rotor shaft,
That is, when supporting the valve shaft 28 with the propulsion bearing 35, the vertical center position of the rotor 24 and the vertical center position of the propulsion bearing 35 are matched to reduce the runout of the rotor . Try to offer
It is.

That is , the motor- operated valve of the present invention converts the valve shaft 28 into a linear motion by a male screw of a valve shaft 28 integral with the rotor 24 of the motor and a female screw of a propulsion bearing 35 provided on the valve body 32. A motor-operated valve for controlling the degree of opening of a valve seat 33 in a valve body 32. A cylindrical guide portion 28a, a male screw 28b, and a vertical hole 28c are formed in the center of a rotor 24 formed in an inverted cup shape. The valve shaft 28 is fixed in a hanging manner, and a ball 29 is inserted into the vertical hole 28c of the valve shaft 28.
And a needle 31 is fixed by caulking via a compression coil spring 30 so as to be slidable up and down, and a cylindrical propulsion bearing support 34 is integrally formed above the valve body 32 so as to face the internal space of the rotor 24. The propulsion bearing support 3
A propulsion bearing 35 formed with a sliding portion 35a for sliding the guide portion 28a of the valve shaft and an internal thread 35b is fixed to the upper opening of the rotor 24 from above the inner surface.
The longitudinal center position of the propulsion bearing 35 is matched with the vertical center position of the propulsion bearing 35 to reduce the runout of the rotor.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of a motor-operated valve according to the present invention. The motor-operated valve has a case 2 made of a non-magnetic material.
The rotor 24 of the motor is rotated by energizing the stator coil 23 of the motor fixed to the outer peripheral portion of the motor 1.
2, a propulsion bearing 35 provided via a propulsion bearing support 34
The opening degree of the valve seat 34 in the valve body 32 is controlled by converting the valve shaft 28 into a linear motion by a female screw.

In FIG. 1, reference numeral 22 denotes a lid which covers the upper part of the case 21, and the lid 22 is hermetically integrated by welding or the like. A stopper shaft 2 is provided at the center of the lid 22.
The stopper shaft 25 has a coil-shaped stopper guide 26 and an engagement piece 27 fitted on the stopper shaft 25.

The rotor 24 may be a plastic magnet made of ferrite powder. However, in order to reduce the size, it is desirable that the rotor be a plastic magnet formed by mixing a rare earth magnetic powder and a resin material. Plastic magnets using this rare-earth magnetic powder are not only less expensive than rotors using existing rare-earth magnets, but also have a skin layer formed on the surface, so coating and plating to prevent rust as in the past. Is unnecessary.

The valve body 32 is provided with a fluid outlet 37 downward.
And a fluid inlet 38 on the side. A fluid inlet chamber 39 communicating with the fluid inlet 38 and a fluid outlet 3
7, a valve seat 33 is formed. The propulsion bearing support 34 is integrally provided on an upper portion of the main body 23. The propulsion bearing support 34 is formed in a cylindrical shape so as to face the inside of the rotor 24, and has a propulsion bearing 35 at its upper opening. Are fixed by press fitting, and a through hole 36 is provided in the wall surface. In the figure, reference numeral 40 denotes a propulsion screw chamber formed between the propulsion bearing support 34 and the case 21.

The valve shaft 28 is integrally fixed in a hanging manner to the center of a rotor 24 formed in an inverted cup shape.
The valve shaft 28 is provided with a cylindrical guide portion 28a, a male screw 28b, and a vertical hole 28c at a lower end portion. A ball 29 and a compression coil spring 3 are provided in the vertical hole 28c of the valve shaft.
After 0 is inserted, the needle 31 is fixed so as to be able to slide up and down by caulking.

The propulsion bearing 35 is fixed to the upper opening of the propulsion bearing support 34 by press fitting or the like. The propulsion bearing 35 slides the guide portion 28a of the valve shaft from above the inner surface. A sliding portion 35a and an internal thread 35b for movement are provided. And the rotor 2
4 and the vertical center position of the propulsion bearing 25 are matched.

Therefore, the propulsion bearing 25 provided in alignment with the longitudinal center of the rotor 24, the sliding portion 25a and the female screw 2
Since the guide portion 28a of the valve shaft 28 and the male screw 28b are engaged with the 5b, the runout of the rotor 24 is reduced as much as possible, and the rotor 24 does not touch the case 21, so that noise due to contact does not occur. .

[0019]

The motor-operated valve of the present invention has a structure in which the rotor shaft, that is, the valve shaft 28 is supported by the propulsion bearing 35.
By matching the vertical center position of 4 with the vertical center position of the propulsion bearing 25, the rotor does not oscillate, so that the gap between the rotor and the case is reduced and the size of the motor-operated valve can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a motor-operated valve according to the present invention.

FIG. 2 is a longitudinal sectional view showing an example of a conventional motor-operated valve.

[Explanation of symbols]

V Valve section M Stepping motor section 1 Valve body 1a Primary port 1
b Secondary port 2 Partition wall 3 Valve seat 4
Needle valve 4a Small diameter part 4b Stopper 4
c End 5 Sealed case 6 Fixed support member 6
a Guide part 6b Male thread part 7 Rotor 8
Support tube 8a Upper and lower edges 8b Connecting portion 9
Permanent magnet 10 Engagement tube 10a Female thread 10
b Sliding tube portion 11 Connecting tube 11a Bottom wall 11
b hole 12 compression coil spring 13 coil 14
Stator 15 Engagement piece 16 Stopper 21 Case 22 Lid 23
Stator coil 24 Rotor 25 Stopper shaft 26
Stopper guide 27 Engagement piece 28 Valve shaft 28
a Guide part 28b Male screw 28c Vertical hole 29
Ball 30 Compression coil spring 31 Needle 32
Valve body 33 Valve seat 34 Propulsion bearing support 35
Propulsion bearing 35a Sliding part 35b Female thread 36
Through hole 37 Fluid outlet 38 Fluid inlet 38
Fluid inlet chamber 40 Propulsion screw chamber

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-105562 (JP, A) JP-A-5-122900 (JP, A) JP-A 1-275977 (JP, A) JP-A-4- 109852 (JP, A) JP-A-6-174129 (JP, A) JP-A-61-186072 (JP, U) JP-A 62-185470 (JP, U) JP-A 61-117589 (JP, U) JP 3-26303 (JP, B2) JP 5-61508 (JP, B2) JP 3-11491 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 31/00-31/05 F25B 41/06

Claims (1)

(57) [Claims] (1) Valve shaft 28 integral with rotor 24 of the motor
Male thread and the female thread of the propulsion bearing 35 provided on the valve body 32
The valve shaft 28 is converted into a linear motion by the
A motor-operated valve for controlling the degree of opening of the valve seat 33, The center of the rotor 24 formed in an inverted cup shape has a cylindrical shape.
Formed with a guide portion 28a, a male screw 28b, and a vertical hole 28c.
The valve shaft 28 is fixed in a drooping manner.
A ball 29 and a compression coil spring
The needle 31 can be slid up and down by caulking through 30
Fixed to Above the valve body 32, the internal space of the rotor 24
And a cylindrical propulsion bearing support 34
Ke The upper opening of the propulsion bearing support 34 has
The sliding portion 35 for sliding the guide portion 28a of the valve shaft
a and the propulsion bearing 35 formed with the female screw 35b is fixed.
Wear The vertical center position of the rotor 24 and the propulsion bearing 35
By matching the vertical position of the rotor
Motorized, characterized in that the run-out is reduced.
valve.