JPH09310777A - Flow control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow control valve, in which a bite with a valve seat is not generated at the time of full-closing a valve, by providing an inside rotor to be driven by an outside rotor and a cylindrical sealing case for sealing between the outside rotor and the inside rotor. SOLUTION: A cylindrical sealing case 18 made of stainless steel or the like is arranged between an outside rotor 20 and an inside rotor 30. As a result, the inside rotor 30 is arranged with a valve element 4 in a space, which is communicated with a coolant flow passage 2 and which is sealed in relation to outside, and the outside rotor 20 are arranged with a driving coil 12 in a space communicated with the outside. Since the outside rotor 20 is not mechanically connected to the valve element 4 and the only inside rotor 30 is connected to the valve element 4, inertia moment of a member to be rotated with the valve element 4 is small. Consequently, at the time of full-closing the valve, when electrifying to the driving coil 12 is stopped, bite of the valve element 4 with a throttle hole 3 is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate control valve for controlling the flow rate of a fluid such as a refrigerant used in a refrigeration cycle in a closed case by driving a stepping motor.

[0002]

2. Description of the Related Art A flow rate control valve for controlling a flow rate of a fluid by driving a stepping motor is generally arranged such that a rotor is connected to a valve body for flow rate adjustment supported by a spiral engagement and the rotor is surrounded. The rotor is rotationally driven by passing a current through the driving electromagnetic coil to displace the flow rate adjusting valve element in the axial direction to adjust the flow rate of the fluid.

However, since it is necessary to configure the fluid so that the fluid does not leak to the outside, a hermetic case is arranged between the rotor and the drive coil so that the electromagnetic force of the drive coil reaches the rotor through the partition wall of the hermetic case. I have to.

[0004]

As described above, the rotor of the stepping motor is wholly arranged in the hermetically sealed case, but most of it is a permanent magnet, so that it is very heavy and has a large moment of inertia. .

Therefore, when the energization of the drive coil is stopped when the valve is fully closed, the rotation of the rotor does not stop and the valve element bites into the valve seat, and then the valve element does not move in the opening direction. was there.

Further, since the hermetically sealed case is arranged so as to surround the thick rotor, it is necessary to give a thickness corresponding to the diameter thereof. Therefore, the gap (magnetic gap) between the drive coil and the rotor is large, resulting in loss of driving force.

Therefore, an object of the present invention is to provide a flow control valve which does not bite into the valve seat when the valve is fully closed and which has a high energy drive efficiency.

[0008]

In order to achieve the above object, the flow control valve of the present invention is an outer rotor which is driven to rotate by an electromagnetic coil, and an outer rotor which is connected to a valve body for flow control. An inner rotor arranged inside the outer rotor so as to form a magnetic coupling between the inner rotor and the inner rotor driven by the outer rotor, and a cylinder arranged to seal between the outer rotor and the inner rotor. It is characterized in that it is provided with a closed case.

Permanent magnets may be arranged on the outer rotor and the inner rotor so as to face each other with the hermetically-sealed case sandwiched therebetween and to change their polarities in the circumferential direction. You may make it displace in an axial direction by being supported and rotationally driven.

Further, permanent magnets may be arranged on the outer rotor and the inner rotor so as to face each other with the hermetic case sandwiched therebetween and to change their polarities in the axial direction. You may make it displace in an axial direction by being supported and rotationally driven.

Further, permanent magnets are arranged on the outer rotor and the inner rotor so as to face each other with the hermetically sealed case interposed therebetween, and the permanent magnets are arranged so that their polarities are changed in the circumferential direction and the axial direction, respectively. May be.

[0012]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a first embodiment in which the present invention is applied to an expansion valve of a refrigeration cycle, and a refrigerant passage 2 through which a refrigerant for sending to an evaporator (not shown) passes is provided in a main body 1. It is bent at a right angle.

A throttle hole 3 having a narrowed flow passage area is formed in the middle of the refrigerant passage 2, and a conical tip portion of a valve body 4 for adjusting the flow rate of the refrigerant is opposed to the throttle hole 3. Are arranged.

The male screw 6 formed on the outer periphery of the valve body 4 on the base side is screwed with the female screw 7 formed on the main body 1 to form the valve body 4
Are supported on the main body 1 by spiral engagement. Therefore, the valve body 4 is displaced in the axial direction by rotating it about the axis, whereby the flow passage area of the throttle hole 3 is changed and the refrigerant flow rate is changed.

A stepping motor portion 10 for rotating the valve body 4 is connected to an end portion of the main body 1. The stepping motor unit 10 is surrounded by a hollow disk-shaped yoke 11, and a drive electromagnetic coil 12 (hereinafter referred to as “drive coil 12”) is arranged on the outer edge side of the yoke 11. 13 is a reel around which a coil wire is wound, 14 is a power supply socket, and 15 is a retaining ring.

Inside the drive coil 12, the drive coil 1
An annular outer rotor 20 driven to rotate by 2 is arranged rotatably around an axis. Outer rotor 20
Is the upper and lower receivers 16, so as to prevent displacement other than rotation.
Movement is regulated by 17.

As shown in FIG. 2, which is a plan sectional view, an annular rotor magnet 21 (permanent magnet) facing the drive coil 12 is arranged around the outer peripheral portion of the outer rotor 20. Since there is no partition between the drive coil 12 and the like, the distance between the drive coil 12 and the drive coil 12 is, for example, 0.5 m.
It is possible to obtain high driving efficiency by narrowing the width to about m.

An outer permanent magnet 22 for forming a magnetic coupling with an inner permanent magnet 32 of an inner rotor 30, which will be described later, is formed on the inner peripheral portion of the outer rotor 20 by changing the polarity in the circumferential direction. And is integrally fixed (or integrally molded) to the synthetic resin cylinder 23 together with the rotor magnet 21.

Inside the outer rotor 20, an inner rotor 30 that rotates together with the valve body 4 is arranged coaxially with the valve body 4. However, between the outer rotor 20 and the inner rotor 30, a cylindrical hermetic case 18 made of, for example, stainless steel is disposed to hermetically seal the two.

As a result, the inner rotor 30 is in a space that communicates with the valve body 4 in the refrigerant flow path 2 and is sealed from the outside, and the outer rotor 20 is in a space that communicates with the drive coil 12 in the outside. As shown in FIG. 2, an inner permanent magnet 32 for forming a magnetic coupling with the permanent magnet 22 (outer permanent magnet) of the outer rotor 20 is provided on the outer surface portion of the inner rotor 30 in a hermetically sealed case. The polarities are changed in the circumferential direction so as to face the outer permanent magnet 22 with the pole 18 sandwiched therebetween, and they are arranged on the entire circumference, and are integrally formed with the synthetic resin shaft 31.

Then, one end of the synthetic resin shaft 31 is rotatably received by a bearing fixed in the sealed case 18, and the other end side of the synthetic resin shaft 31 is connected to the valve body 4 by an angular shaft 31a. Therefore, the rotation of the inner rotor 30 is mechanically directly transmitted to the valve body 4.

In the apparatus of the embodiment configured as described above, the drive coil 12 is energized and the outer rotor 20 is rotated.
Is rotated by a predetermined angle, the outer rotor 20 and the inner rotor 30 forming a magnetic coupling are driven to rotate by the same angle, and the valve body 4 is displaced in the axial direction to change the flow rate of the refrigerant.

Since the outer rotor 20 is not mechanically connected to the valve body 4 and only the inner rotor 30 is connected to the valve body 4, the moment of inertia of the member rotating with the valve body 4 is small. Therefore, when energizing the drive coil 12 is stopped when the valve is fully closed, the valve body 4 does not bite into the throttle hole 3.

FIG. 3 shows a second embodiment of the present invention, in which the structure of the stepping motor section 10 does not seem to be the same as that of the first embodiment, but first, as shown in FIG. The difference is that the permanent magnet 22 and the inner permanent magnet 32 are arranged so as to face each other with the hermetically sealed case 18 sandwiched therebetween and to change their polarities many times in the axial direction.

Further, the female screw 36 formed on the synthetic resin cylinder 23 and the male screw 37 formed on the closed case 18 are screwed together, and the outer rotor 20 is supported by the closed case 18 by spiral engagement. And the outer rotor 20 is the drive coil 1
It is different in that it is displaced in the axial direction by being rotationally driven by 2.

As a result, the inner rotor 30 forming a magnetic coupling with the outer rotor 20 is displaced in the axial direction following the displacement of the outer rotor 20 in the axial direction while rotating, and does not rotate.

Further, in this embodiment, the valve body 4
A divergent shape is used as the rotator and is fixed to the synthetic resin shaft 31 of the inner rotor 30. In order to cancel the pressure difference between the both ends of the valve body 4, the valve body 4 has an axial position. A through hole is formed.

In the apparatus of the embodiment configured as described above, the drive coil 12 is energized and the outer rotor 20 is rotated.
When the rotor is driven to rotate by a predetermined angle, the outer rotor 20 is displaced in the axial direction, and the valve element 4 connected to the inner rotor 30 forming a magnetic coupling with the outer rotor 20 is displaced in the axial direction to cause the refrigerant to flow. Flow rate changes.

For the valve body 4, the outer rotor 2
Since 0 is not mechanically connected and only the inner rotor 30 is connected to the valve body 4, the moment of inertia of the member integrally displaced with the valve body 4 is small. Therefore, when energizing the drive coil 12 is stopped when the valve is fully closed, the valve body 4 does not bite into the throttle hole 3.

As in the first embodiment, the gap (magnetic gap) between the drive coil 12 and the rotor magnet 21 of the outer rotor 20 is small, the energy loss is small, and the drive efficiency is good.

The present invention is not limited to the above-described embodiment. For example, in the configuration of FIG. 3, the polarities of the outer permanent magnet 22 and the inner permanent magnet 32 are set in the circumferential direction and the axial direction, respectively. You may change and arrange in order.
By doing so, the inner rotor 30 is replaced by the outer rotor 20.
The magnetic coupling action of and allows simultaneous driving in both directions of rotation and axial movement.

[0032]

According to the present invention, the rotor rotatably driven by the drive coil is divided into the outer rotor and the inner rotor forming the magnetic coupling.
Since only the inner rotor is connected to the valve body and the moment of inertia thereof can be made very small, the valve can be operated accurately without being cut into the valve seat when the valve is fully closed.

Further, since the outer rotor and the inner rotor are partitioned by the cylindrical hermetic case, the gap between the drive coil and the rotor can be narrowed and the magnetic gap can be reduced. High driving efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a plan sectional view of the first embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view of a second embodiment of the present invention.

FIG. 4 is a partially enlarged view of a vertical cross section of a second embodiment of the present invention.

[Explanation of symbols]

 3 Throttle Hole 4 Valve Body 10 Stepping Motor Section 12 Driving Electromagnetic Coil 18 Sealed Case 20 Outer Rotor 21 Rotor Magnet 22 Outer Permanent Magnet 30 Inner Rotor 32 Inner Permanent Magnet

Claims (6)

[Claims] 1. An annular outer rotor, which is rotationally driven by an electromagnetic coil, and a flow rate adjusting valve body, and is arranged inside the outer rotor so as to form a magnetic coupling between the outer rotor and the outer rotor. A flow control valve, comprising: an inner rotor driven by the outer rotor; and a cylindrical hermetic case arranged to hermetically seal between the outer rotor and the inner rotor. 2. The flow control valve according to claim 1, wherein permanent magnets are arranged on the outer rotor and the inner rotor so as to face each other with the hermetically-sealed case sandwiched therebetween and to change their polarities in the circumferential direction. 3. The flow control valve according to claim 2, wherein the valve body is supported by a spiral engagement and is displaced in the axial direction by being rotationally driven. 4. The flow control valve according to claim 1, wherein permanent magnets are arranged on the outer rotor and the inner rotor so as to face each other with the hermetically sealed case in between and to have polarities changed in the axial direction. 5. The flow control valve according to claim 4, wherein the outer rotor is supported by a spiral engagement and is displaced in the axial direction by being rotationally driven. 6. A permanent magnet is disposed on the outer rotor and the inner rotor so as to face each other with the hermetic case interposed therebetween, and the permanent magnets are disposed so that their polarities are changed in the circumferential direction and the axial direction, respectively. The flow control valve according to claim 1, wherein: