JP6087397B2 - Motorized valve - Google Patents

Description

  The present invention relates to a motor-operated valve that controls the flow rate of a refrigerant such as a heat pump refrigeration cycle.

  Conventionally, as an electric valve, there exist some which were disclosed by Unexamined-Japanese-Patent No. 2004-197800 (patent document 1) and Unexamined-Japanese-Patent No. 2002-39417 (patent document 2), for example. In Patent Document 1, a male screw is formed on the rotor shaft side of the electric motor, a female screw through which the rotor shaft passes is disposed, and a valve body is provided at the lower end of the rotor shaft. Moreover, the thing of patent document 2 has a female screw formed in the rotor side of an electric motor, the male screw which penetrates the center of this rotor is arrange | positioned, and is equipped with the valve body in the lower end part of the operating shaft. Then, the rotational movement of the rotor of the electric motor is converted into a linear movement of the operating shaft by a screw feed mechanism of a female screw and a male screw, and the valve body is moved with respect to the valve seat to open and close the valve. These motor-operated valves are used in a refrigeration cycle (refrigerant piping system) of a cooling device as disclosed in, for example, Japanese Patent Laid-Open No. 5-45027 (Patent Document 3).

Japanese Patent Laid-Open No. 2004-197800 JP 2002-39417 A JP-A-5-45027

  In the hot gas bypass path of the refrigeration cycle as in Patent Document 3, the temperature of the refrigerant rises to about 120 ° C. For this reason, when the conventional motor-operated valve is used for the hot gas bypass passage, the vertical and horizontal engagement portions (screw portions) of the female screw and the male screw are different due to the difference in linear expansion coefficient between the member constituting the female screw and the member constituting the male screw. There is a problem that the play is reduced and the operability of the screw feed mechanism is deteriorated. In addition, wear powder generated by repetitive operations and other sliding parts accumulate, and the actual clearance of the screw part becomes smaller than the prescribed clearance. Furthermore, since the motor torque decreases because the magnet demagnetization and the coil electrical resistance increase at high temperatures, it is important to secure an appropriate clearance. In addition, since the strength of the material generally decreases at high temperatures, in the motorized valve used for the hot gas bypass passage, it is necessary to increase the engagement length of the screws, so the influence of the pitch deviation between the screws becomes large. These problems prevent desired operability from being obtained.

  The present invention has been made to solve the above-described problems, and even when used in a high temperature environment, the backlash of the screw portion in the screw feed mechanism of the electric valve is ensured, and stable operability is ensured. This is the issue.

In the motor-driven valve according to claim 1, the rotational axis of the rotor of the electric motor is linearized by a screw feed mechanism of a female screw formed on the rotor side and a male screw arranged coaxially with the female screw at the center of the rotor. In the motor-operated valve that converts the movement into a valve seat that is opened and closed by moving the valve element disposed on the operating shaft with respect to the valve seat, the member constituting the female screw and the member constituting the male screw are the female screw. axial perpendicular direction of the linear expansion rate, together are formed of a material such as greater than perpendicular linear expansion coefficient in the axial direction of the male screw, the axial coefficient of linear expansion of the internal thread A member constituting the female screw and a member constituting the male screw are respectively formed of a material having a linear expansion coefficient in the axial direction of the male screw .

The motor-driven valve according to claim 2 is configured such that the rotational axis of the rotor of the electric motor is linearized by a screw feed mechanism of a female screw formed on the rotor side and a male screw disposed coaxially with the female screw at the center of the rotor. In the motor-operated valve that converts the movement into a valve seat that is opened and closed by moving the valve element disposed on the operating shaft with respect to the valve seat, the member constituting the female screw and the member constituting the male screw are the female screw. The linear expansion coefficient in the direction perpendicular to the axial direction of the male screw is made of a material that is larger than the linear expansion coefficient in the direction perpendicular to the axial direction of the male screw, and the member constituting the female screw is made of a resin material. A fibrous filler is mixed in the resin material as a base material so as to be in the same direction as the axial direction of the female screw.

According to the motor-operated valve of claim 1 or 2 , the male screw member is such that the linear expansion coefficient in the direction perpendicular to the axial direction of the female screw member is larger than the linear expansion coefficient in the direction perpendicular to the axial direction of the male screw member. Since the female screw member expands more outward than the male screw member in a high temperature environment, the play between the male screw member and the female screw member can be secured, and the screw feed mechanism operates stably. Sex can be secured.

Further, according to the electric valve according to claim 1, the expansion in the axial L direction becomes equal between the male screw member and the female screw member, the pitch change in the pitch change and axial internal thread of the axial external thread and is equal, the pitch It is possible to prevent a reduction in axial play of the entire screw due to the change.

Further , according to the electric valve of claim 2 , since the direction and strength of the filler can be arbitrarily selected, the linear expansion coefficient in the axial direction of the female screw and the linear expansion coefficient in the axial direction of the male screw can be made equal, and The linear expansion coefficient in the direction perpendicular to the axial direction can be made larger than the linear expansion coefficient in the direction perpendicular to the axial direction of the male screw. Further, since a resin material is used as the base material, the manufacturing becomes easy.

It is a longitudinal cross-sectional view of the motor operated valve of 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the motor operated valve of 2nd Embodiment of this invention. It is a figure which shows the example which forms the external thread member and internal thread member in embodiment with the resin material which mixed the fibrous filler.

  Next, an embodiment of the motor-operated valve of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a motor-operated valve according to the first 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 motor-operated valve of this embodiment has a valve housing 1. The valve housing 1 includes a valve chamber 1a, an inlet port 1b opened on one inner peripheral surface of the valve chamber 1a, and an axis L direction of the valve chamber 1a. An outlet port 1c opened at one end, a valve port 1d communicating with the outlet port 1c and the valve chamber 1a, and a cylindrical guide fitting hole 1e penetrating the valve chamber 1a are formed. An end of the valve port 1d on the valve chamber 1a side constitutes a valve seat 1d1. The inlet port 1b is formed as a horizontal hole, and a joint pipe 11 connected to the hot gas bypass is fixed to the inlet port 1b by brazing. The outlet port 1c is formed as a pilot hole, and a joint pipe 12 connected to the hot gas bypass path is fixed to the outlet port 1c by brazing.

  A cylindrical guide 13 is fitted in the guide fitting hole 1e in the upper part of the valve chamber 1a, and the guide 13 is fixed to the valve housing 1 by caulking the upper part of the valve housing 1. A cylindrical valve body 14 and a piston 15 are inserted into the guide 13, and the valve body 14 is attached to the lower end of the operating shaft 2 via a bearing 17. A buffering coil spring 14 a is disposed in the valve body 14. A male screw receiving portion 13a is formed at the upper end of the guide 13, and the operating shaft 2 can be slid in the direction of the axis L by the male screw receiving portion 13a, and the upper portion of the operating shaft 2 faces the stepping motor 10 described later. It is extended. A male screw member 21 having a male screw 21a is fixed to the outer periphery of the operation shaft 2 in the stepping motor 10.

  A dish-like lid case 16 is airtightly fixed to the upper portion of the valve housing 1 by brazing, and a stepping motor 10 as an electric motor is attached to the lid case 16. A cylindrical rotor case 10 a of the stepping motor 10 is airtightly fixed to the lid case 16. The rotor 3 is rotatably disposed inside the rotor case 10a. The rotor 3 includes a female screw member 31, a female screw holder 32, a coupling fitting 33, and a magnet 34 in order from the inside. The connection fitting 33 connects the female screw holder 32 and the magnet 34. An internal thread 31 a is formed inside the internal thread member 31. The male screw 31 a is screwed to the male screw 21 a on the outer peripheral surface of the male screw member 21. A stator unit 10b is disposed on the outer periphery of the rotor case 10a, and the stepping motor 10 rotates the rotor 3 according to the number of pulses when a pulse signal is given to the stator coil of the stator unit 10b. Let

  A stopper holding rod 41 is suspended and fixed inside the rotor case 10a. A spiral guide 42 is attached to the stopper holding rod 41, and a movable stopper 43 is engaged with the spiral guide 42. The movable stopper 43 is moved up and down while being swung by being guided by the spiral guide 42 as the rotor 3 rotates by being kicked around by the pin 33 a attached to the connection fitting 33 of the rotor 3. The movable stopper 43 is in contact with the stopper portion 42a at the lower end of the spiral guide 42 or the stopper portion 42b at the upper end, thereby restricting the rotation of the rotor 3 in the valve closing direction or the valve opening direction.

  With the above configuration, when the stepping motor 10 is driven, the rotor 3 rotates within a range regulated by the movable stopper 43 and the stopper portions 42a and 42b. The rotation of the rotor 3 is converted into a linear motion of the operating shaft 2 by the screw feeding action of the female screw 31a and the male screw 21a on the rotor 3 side, and the valve body 14 moves in the direction of the axis L via the operating shaft 2. Thereby, the valve body 14 adjusts the opening degree of the valve port 1d, and the flow rate of the refrigerant flowing in from the joint pipe 11 and flowing out from the joint pipe 12 is controlled.

  FIG. 2 is a longitudinal sectional view of the motor-operated valve according to the second embodiment, and the same or corresponding elements as those in FIG. In the second embodiment, the valve body 14 is formed integrally with the operating shaft 2, and a valve port member 1 f is fitted between the outlet port 1 c and the valve chamber 1 a. A valve port 1g is formed in the valve port member 1f, and an end portion of the valve port member 1f constitutes a valve seat 1f1.

  Also in the second embodiment, when the rotor 3 is rotated by driving the stepping motor 10, the rotation of the rotor 3 is caused by the screw feeding action of the female screw 31a on the rotor 3 side and the male screw 21a on the working shaft 2 side. 2 is converted into a linear motion of 2 and the valve body 14 moves in the direction of the axis L via the operating shaft 2. Thereby, the valve body 14 adjusts the opening degree of the valve port 1g, and the flow rate of the refrigerant flowing in from the joint pipe 11 and flowing out from the joint pipe 12 is controlled.

  The material of the male screw member 21 and the female screw member 31 is selected in consideration of the linear expansion coefficient in the direction perpendicular to the axis L. In general, a resin material can be mixed with a reinforcing material (filler) such as carbon fiber or glass fiber, and properties such as linear expansion coefficient and thermal conductivity can be changed depending on the amount and strength of the filler to be mixed. Table 1 below shows examples of the materials of the male screw member 21 and the female screw member 31 and their linear expansion coefficients.

A combination of these materials satisfies the condition that “the linear expansion coefficient in the direction perpendicular to the axis L direction of the female screw member 31 is greater than the linear expansion coefficient in the direction perpendicular to the axis L direction of the male screw member 21”. Thus, the material of the male screw member 21 and the female screw member 31 is determined. In addition, PPS (polyphenylene sulfide) mixed with fibrous filler can give anisotropy to the linear expansion coefficient by changing the directionality of the fibrous filler, and in a direction perpendicular to the axial direction. Different linear expansion coefficients can be provided. For example, when carbon fiber is used as a filler, the linear expansion coefficient is 2.5 × 10 ^{−5 in} a certain direction, and the linear expansion coefficient in a direction perpendicular to this direction is 3.5 × 10 ^−5. it can. Depending on the amount and strength of the filler to be mixed, the linear expansion coefficient is 1.0 × 10 ^{−5 in a} certain direction, and the linear expansion coefficient in a direction perpendicular to this direction is 3.5 × 10 ^−5. is there. Therefore, the female screw member 31 is formed so that the direction in which the linear expansion coefficient is small is the axis L direction, and the direction in which the linear expansion coefficient is large is the direction perpendicular to the axis L direction. Then, the male screw member 21 is formed so that the linear expansion coefficient of the male screw member 21 in the direction perpendicular to the axis L direction is smaller than the linear expansion coefficient of the female screw member 31 in the direction perpendicular to the axis L direction. In the case where the male screw member 21 is made of stainless steel and the case where the male screw member 21 is made of brass, the materials that cannot be used for the female screw member 31 are described in the lower part of Table 1, but other than this, combine the material of the member 21 and the female screw member 31.

For example, the male screw member 21 is made of stainless steel and the female screw member 31 is made of brass. Alternatively, the male screw member 21 is made of stainless steel, and the female screw member 31 is made of PPS using carbon fiber as a filler so that the linear expansion coefficient in the direction perpendicular to the axis L direction is 3.5 × 10 ⁻⁵ . Alternatively, the male screw member 21 is made of brass, and the female screw member 31 is made of PPS or PEEK (polyether ether ketone) or PI (polyimide) or a linear expansion coefficient in the direction perpendicular to the axis L direction of 3.5 × 10 ⁻⁵ or PAI (polyamideimide) is used.

The male screw member 21 is made of ceramic (zirconia) having a linear expansion coefficient of 1.05 × 10 ⁻⁵ , and the female screw member 31 has a linear expansion coefficient of 3.5 × 10 ⁻⁵ in the direction perpendicular to the axis L direction and the axis L The PPS is made of carbon fiber filler so that the linear expansion coefficient in the direction is 1.0 × 10 ⁻⁵ . If it does in this way, the linear expansion coefficient of the axial L direction of the internal thread member 31 and the linear expansion coefficient of the external thread member in the axial L direction will become equivalent, satisfying the said conditions. As a result, the expansion in the axis L direction is equivalent between the male screw member 21 and the female screw member 31, the pitch change of the male screw 21a is equal to the pitch change of the female screw 31a, and the backlash of the entire screw in the axis L direction due to the pitch change is reduced. Can be prevented.

  Table 2 below shows an example in which the material of both the male screw member 21 and the female screw member 31 is PPS.

That is, the male screw member is made of PPS using carbon fiber as a filler so that the linear expansion coefficient in the direction of the axis L is 3.5 × 10 ⁻⁵ and the linear expansion coefficient in the direction perpendicular to the axis L is 2.5 × 10 ^−5. 21 is formed. The female screw member is made of PPS using carbon fiber as a filler so that the linear expansion coefficient in the axis L direction is 2.5 × 10 ⁻⁵ and the linear expansion coefficient in the direction perpendicular to the axis L is 3.5 × 10 ^−5. 31 is formed. Thus, the above condition is satisfied.

  FIG. 3 is a diagram illustrating an example in which the male screw member 21 and the female screw member 31 are formed of a resin material using carbon fiber as a filler. The male screw member 21 is formed by aligning and mixing a carbon fiber filler 21B in a direction perpendicular to the axis L with respect to a base material 21A made of a resin material. The female screw member 31 is formed by aligning and mixing a carbon fiber filler 31B in a direction parallel to the axis L with respect to a base material 31A made of a resin material.

  By doing so, in the male screw member 21, the linear expansion coefficient in the direction perpendicular to the axis L direction of the base material 21A is reduced by the strength of the carbon fiber filler 21A, and in the female screw member 31, the line in the axis L direction of the base material 31A. While the expansion coefficient is reduced by the strength of the carbon fiber filler 21A, the linear expansion coefficient in the direction perpendicular to the axis L direction is hardly affected by the carbon fiber filler 31B. Therefore, the above conditions can be satisfied. In addition, the orientation direction of this carbon fiber filler can be set by the position of the gate at the time of resin molding, for example.

  In this way, the male screw member 21 and the female screw member 31 are made so that the linear expansion coefficient in the direction perpendicular to the axis L of the female screw member 31 is larger than the linear expansion coefficient in the direction perpendicular to the axis L of the male screw member 21. Since it forms, even if it uses in a high temperature environment, the backlash of the external thread member 21 and the internal thread member 31 can be ensured, and the stable operativity of a screw feed mechanism can be ensured.

DESCRIPTION OF SYMBOLS 1 Valve housing 1d1 Valve seat 1f1 Valve seat 14 Valve body 2 Actuating shaft 21 Male screw member 21a Male screw 3 Rotor 31 Female screw member 31a Female screw 10 Stepping motor (electric motor)

Claims (2)

The operating shaft is converted into a linear motion by a screw feed mechanism of a female screw formed on the rotor side and a male screw arranged coaxially with the female screw at the center of the rotor. In the motor-operated valve that moves the valve body arranged on the valve seat to open and close the valve,
A member that constitutes the member and the external thread constituting the internal thread, the direction perpendicular to the linear expansion ratio in the axial direction of the internal thread, such that greater than perpendicular linear expansion coefficient in the axial direction of the external thread Material Are formed respectively by
A member constituting the female screw and a member constituting the male screw are respectively formed of a material in which the linear expansion coefficient in the axial direction of the female screw is equal to the linear expansion coefficient in the axial direction of the male screw. Motorized valve. The operating shaft is converted into a linear motion by a screw feed mechanism of a female screw formed on the rotor side and a male screw arranged coaxially with the female screw at the center of the rotor. In the motor-operated valve that moves the valve body arranged on the valve seat to open and close the valve,
A material in which the member constituting the female screw and the member constituting the male screw have a linear expansion coefficient in a direction perpendicular to the axial direction of the female screw larger than a linear expansion coefficient in the direction perpendicular to the axial direction of the male screw. Are formed respectively by
  The motor-operated valve according to claim 1, wherein the member constituting the female screw has a resin material as a base material and a fibrous filler is mixed in the resin material so as to be in the same direction as the axial direction of the female screw.

Images