JP2001295957A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost expansion valve that can miniaturize a coil by allowing the driving force of a motor to be converted into high torque. SOLUTION: In this expansion valve 20, a current is applied to stator coils 10A-10H fixed to the outer periphery of a cylindrical case 9. A planetary gear 1 thereby rolls abutting on the inner peripheral surface of the cylindrical case 9, so that a valve stem 4 is rotated, and a needle valve 4a controls the opening degree of an orifice 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve, and more particularly, to an expansion valve for controlling a flow rate of a refrigerant in an air conditioner or the like.

[0002]

2. Description of the Related Art In recent years, the capacity of an air conditioner that has been used can be greatly varied by utilizing inverter control.
Accordingly, a refrigerant flow control mechanism is the most important factor for maintaining an appropriate refrigeration cycle under various conditions.

If this is to be realized by a conventional capillary tube or a temperature-type expansion valve, the refrigerant circuit is inevitably complicated. For this reason, a refrigerant flow control valve called an electronically controlled expansion valve is generally used for the purpose of controlling the refrigerant by systemization with a microcomputer.

FIG. 4 is a schematic sectional view showing the structure of a general electronically controlled expansion valve disclosed in Japanese Patent Laid-Open Publication No. 3-260482. With reference to FIG. 4, the expansion valve 120 is
04, a propulsion bearing 105, a valve seat 106, a cylindrical case 109, a stator coil 110, and a rotor 111.

[0005] A stator coil 110 is fixed to the outer periphery of a cylindrical case 109 made of a non-magnetic material, and a rotatable rotor 111 is arranged in the cylindrical case 109. The stator coil 110 and the rotor 111 constitute a stepping motor. Rotor 111
, A valve shaft 104 is attached.

The valve shaft 104 is provided with a male screw 104b, which is screwed with a female screw of the propulsion bearing 105. A needle-shaped valve 104a is provided at the tip of the valve shaft 104, and the needle-shaped valve 104a is arranged so that the opening degree of the valve port 106a of the valve seat 106 can be controlled. The valve port 106a is located between the refrigerant inlet / outlet portions 107 and 108.

[0007] Regarding the operation of controlling the flow rate of refrigerant in the expansion valve 120, first, the rotor 111 of the motor is rotated by energizing the stator coil 110. The valve shaft 104 rotates together with the rotor 111, and this rotation is
Is converted into a linear motion of the valve shaft 104. Due to this linear motion, the needle valve 104a at the tip of the valve shaft 104 is
6a, the opening degree of the valve port 106a is controlled. Thus, the flow rate of the refrigerant flowing between the entrances 107 and 108 is controlled.

[0008]

In the conventional expansion valve 120, since the stator coil 110 and the rotor 111 are not in contact with each other, an air gap is required between them and the cylindrical case 109 is not provided. It is sandwiched. For this reason, the interval between the inner diameter of the stator coil 110 and the outer diameter of the rotor 111 must be increased, and the rotor 111 and the stator coil 110 need to be large in order to obtain the necessary rotational force for the rotor 111. Need to be Thereby, the expansion valve 1
20 is expensive, and the power consumption of the stator 110 is increased.

In order to reduce the gap between the outer periphery of the rotor 111 and the inner periphery of the cylindrical case 109 while preventing the inner periphery thereof from coming into contact with the outer periphery of the rotor 111, the dimensional tolerance of the outer diameter is reduced.
In addition, the rotor 1 is set so that the amount of eccentricity with respect to the center axis is reduced.
11 must be manufactured with high accuracy as a whole. In addition, since the rotor 111 performs the same operation as the pulse motor together with the stator 110, it is necessary that the rotor 111 is a permanent magnet that is multipolarly magnetized with high accuracy. As described above, there is a problem that the conventional expansion valve 120 is expensive in terms of processing accuracy and magnetization accuracy.

It is therefore an object of the present invention to provide an inexpensive expansion valve which can convert the driving force of a motor into a high torque, thereby making it possible to reduce the size of the coil.

[0011]

The expansion valve of the present invention includes a case, a stator coil, a planetary gear, a valve shaft, and a valve seat. The stator coil is fixed to the outer periphery of the case. The planetary gear rolls along the inner peripheral surface of the case when the stator coil is energized. The valve shaft is arranged so as to rotate by being given a rotational force by the rolling of the planetary gears and to be able to move straight by the rotation. The valve seat has a hole whose opening is controlled by the valve body at the tip of the valve shaft by the linear movement of the valve shaft.

In the expansion valve of the present invention, since the planetary gear rolls in contact with the inner peripheral surface of the case, the planetary gear is decelerated at the contact portion to generate a high torque. Since high torque can be obtained without increasing the size of the stator coil, the expansion valve can be reduced in size. In addition, to generate high torque with small power consumption,
The power consumption of the stator coil can be suppressed.

[0013] The expansion valve preferably further includes an external gear fixed to the valve shaft. The planetary gear has a ring shape, and the external teeth provided on the outer circumference of the ring mesh with the internal teeth provided on the inner peripheral surface of the case, and the internal teeth provided on the inner circumference of the ring form the outer gear. Mesh with external teeth.

[0014] The meshing of the gears makes it possible to transmit the driving force from the planetary gears to the valve shaft.

Preferably, in the above-mentioned expansion valve, an eccentricity adjusting member made of a flexible material capable of preventing eccentricity of the valve shaft due to rolling of the planetary gear is further provided between the valve shaft and the external gear. I have.

As a result, the eccentricity of the valve shaft due to the rolling of the planetary gear can be suppressed, so that a higher processing accuracy than in the past is not required.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view schematically showing a configuration of an expansion valve according to one embodiment of the present invention, and FIG.
It is a figure which follows the 0-50 line.

Referring to FIGS. 1 and 2, an expansion valve 20 according to the present embodiment includes a planetary gear 1, an external gear 2, an eccentricity adjusting member 3, a valve shaft 4, a propulsion bearing 5, It mainly has a valve seat 6, a case 9, and stator coils 10A to 10H.

The stator coils 10A to 10H are fixed so as to surround the outer periphery of a cylindrical case 9 made of a non-magnetic material. Internal teeth 9 a are provided on the inner peripheral surface of the cylindrical case 9. A ring-shaped planetary gear 1 is provided in the case 9.
And an external gear 2 having external teeth 2a. The planetary gear 1 has external teeth 1a meshing with the internal teeth 9a of the case 9 on the annular outer peripheral surface, and has the external gear 2 on the annular inner peripheral surface.
Has internal teeth 1b that mesh with the external teeth 2a.

As described above, the driving force is applied to the valve shaft 4 by the so-called rolling motor in which the planetary gear 1 rolls along the inner peripheral surface of the cylindrical case 9.

The valve shaft 4 is fixed to the external gear 2 with the eccentricity adjusting member 3 interposed. The eccentricity adjusting member 3 is formed of a flexible material that can prevent the valve shaft 4 from being eccentric due to the rolling of the planetary gear 1. A male screw 4 b is provided on the valve shaft 4, and the male screw 4 b is screwed with a female screw of the propulsion bearing 5. The needle-shaped valve 4a located at the tip of the valve shaft 4 is arranged so that the opening degree of the orifice 6a provided in the valve seat 6 can be controlled. The orifice 6a is located between the inlet and outlet portions 7 and 8 of the refrigerant.

Next, the operation of controlling the flow rate of the refrigerant in the expansion valve of the present embodiment will be described. Referring to FIGS. 1 and 2, first, each of a plurality of stator coils 10A to 10H is sequentially energized as shown in FIG. This allows
When the external teeth 1a of the planetary gear 1 are attracted and mesh with the internal teeth 9a of the cylindrical case 9, the planetary gear 1 rotates at a reduced speed along the inner peripheral surface of the cylindrical case 9. Further, the internal gear 1b of the planetary gear 1 meshes with the external gear 2a of the external gear 2, and the external gear 2 is further rotated at a reduced speed.

The rotation of the external gear 2 causes the valve shaft 4 to rotate,
The rotational motion is converted by the propulsion bearing 5 into a linear motion of the valve shaft 4. The needle valve 4a of the valve shaft 4 has an orifice 6a.
, The opening degree of the orifice 6a is controlled by the needle valve 4a, and the flow rate of the refrigerant flowing between the entrances 7 and 8 is controlled.

In the present embodiment, since the planetary gear 1 rolls while meshing with the internal teeth 9a of the cylindrical case 9, high torque is generated while being decelerated. Since high torque is obtained with such small stator coils 10A to 10H, the expansion valve 20 main body can be downsized. Also, since high torque can be obtained with small power consumption, the stator coils 10A to 10A
Power consumption at 10H can be suppressed.

In this embodiment, the valve shaft 4 and the external gear 2
The eccentricity adjusting member 3 is provided between the two. Since the eccentricity adjusting member 3 is made of a material that is flexible enough to prevent the valve shaft 4 from being eccentric due to the rolling of the planetary gear 1, the eccentricity of the valve shaft 4 can be prevented. Therefore,
The planetary gear 1, the cylindrical case 9, and the external gear 2 do not require as high a processing accuracy as the conventional example to prevent the eccentricity of the valve shaft 4.

The eccentricity adjusting member 3 is, for example, chloroprene rubber (CR) or hydrogenated nitrile rubber (H) in order to prevent eccentricity of the valve shaft 4 due to rolling of the planetary gear 1.
NBR) or the like, and preferably has a hardness of, for example, 60 to 70 degrees.

The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0029]

As described above, in the expansion valve of the present invention, since the planetary gear rolls in contact with the inner peripheral surface of the case, the planetary gear is decelerated at the contact portion to generate a high torque. Because high torque can be obtained without increasing the size of the stator coil,
The size of the expansion valve can be reduced. Further, since high torque is generated with small power consumption, power consumption in the stator coil can be suppressed.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a configuration of an expansion valve according to an embodiment of the present invention.

FIG. 2 is a schematic view taken along the line 50-50 in FIG. 1;

FIG. 3 is a diagram for explaining a state of energizing a stator coil of the expansion valve according to the embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a configuration of a conventional expansion valve.

[Explanation of symbols]

Reference Signs List 1 planetary gear, 2 external gear, 3 eccentricity adjusting member, 4 valve shaft, 4a needle valve, 4b male screw, 5 propulsion bearing, 6
Valve seat, 6a orifice, 7, 8 doorway, 9 cylindrical case, 10A to 10H stator coil.

Continued on the front page F term (reference) 3H062 AA02 AA15 BB30 CC01 DD01 EE08 FF41 HH04 HH08 5H641 BB09 BB19 GG02 GG04 GG08 GG12 HH06 JA01 JA08 JA19

Claims (3)

[Claims] A case, a stator coil fixed to an outer periphery of the case, a planetary gear that rolls along an inner peripheral surface of the case by energizing the stator coil, and a rolling of the planetary gear. Is given a rotational force to rotate,
And a valve shaft arranged so as to be capable of linear movement by the rotation thereof, and a valve seat having a hole whose opening is controlled by a valve body at the tip of the valve shaft by the linear movement of the valve shaft. valve. An outer gear fixed to the valve shaft, wherein the planetary gear has a ring shape, and external teeth provided on an outer periphery of the ring shape are provided on an inner peripheral surface of the case. The expansion valve according to claim 1, wherein the internal teeth mesh with the internal teeth and the internal teeth provided on the inner periphery of the ring shape mesh with the external teeth of the external gear. 3. An eccentricity adjustment member made of a flexible material that can prevent eccentricity of the valve shaft due to rolling of the planetary gear is further provided between the valve shaft and the external gear.
The expansion valve according to claim 2.