JP2005172020A - Motor operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify and miniaturize a valve body drive by lessening driving force necessary for operation of a valve body so that refrigerant pressure at a high pressure side is applied to a back of the valve body as back pressure. <P>SOLUTION: A motor-operated valve comprises the valve body 10, a high pressure fluid lead-in pipe 11a arranged on the valve body, a low pressure fluid lead-out pipe 13a arranged on and communicated with the valve body via a valve chamber 12 from the high pressure fluid lead-in pipe, a valve body driving section 20 arranged on the valve body, a guide bush 15 mounted on the valve body, a rotor 31 rotatably driven by the valve body driving section, an operating bar holder 35 supporting on the guide bush 15 integrated with the rotor in a screwed state, and a valve body 40 capable of opening and shutting by an operating bar 30 retained on the operating bar holder 35 in the valve chamber. High pressure fluid pressure of the high pressure fluid lead-in pipe is operated on the valve body from both sides of an opening and shutting direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric valve used in a refrigeration cycle such as an air conditioner or a refrigeration apparatus.

Conventionally, an electric valve used by being incorporated in this type of air conditioner, refrigerator, etc. is a device that adjusts the flow rate of a fluid such as a refrigerant, and usually includes a valve body having a valve chamber and a valve seat, A cylindrical can with a bottom fixed to the upper part of the valve body via a hook-shaped portion, and a rotor is built inside the can, and an insertion hole is formed in the center of the can outside. The stator which has is externally fitted.
A conventionally known motor-operated valve is disclosed in Patent Document 1 below.
JP 2001-50415 A

  This known motor-operated valve will be described as follows. FIG. 2 is a longitudinal sectional view of the conventional motor-operated valve 1. The valve body 2 includes a valve chamber 2c, a guide bush fixing portion 2d, and a can fixing portion 2e. The valve chamber 2c has a refrigerant or the like. A fluid outflow pipe 2a and a fluid inflow pipe 2b through which fluid flows in and out are provided, and a valve seat 2f to which a needle valve, which is a valve body 3a formed at the tip of the valve shaft 3, contacts and separates is disposed. ing.

  The guide bush fixing portion 2d is located above the valve chamber 2c, and the valve main body 2 and the guide bush 4 are fixed thereto. A female screw portion 4a is formed on the inner periphery of the guide bush 4, and a male screw portion 5a formed on the outer periphery of the operating rod holder 5 is screwed into the female screw portion 4a. A feed mechanism is configured. In the operating rod holder 5, a valve shaft 3 having a valve body 3 a formed at the lower end is slidably fitted. The valve shaft 3 is fitted in the operating rod holder 5. It is always urged downward by the compression coil spring 3b.

The can fixing portion 2e is located at the upper end of the valve body 2 and is composed of a ring-shaped metal plate whose inner peripheral surface is fixed by caulking and whose lower end surface is joined by welding. The can 6 is fixed to the valve body 2 by welding to the valve body. The valve shaft 3 and the rotor 7 are coupled by externally fitting a sleeve 5a formed integrally with the operating rod holder 5 to the valve shaft 3 and by internally fitting the sleeve 5a to the rotor 7 with a permanent magnet. . A push nut 3 c is press-fitted and fixed to the upper end of the valve shaft 3, and its flange portion is coupled to the rotor 7 while allowing the valve shaft 3 to move slightly up and down.
Further, the upper limit of the upward movement of the valve shaft 3 and the rotor 7 is defined by the contact between the spring 7 b provided on the upper portion of the rotor 7 and the inner surface of the can 6. The lower stopper 4b fixed to the operating rod holder 5 and the upper stopper 5b formed on the sleeve 5a constitute a stopper mechanism.

  A rotor 7 is built in the can 6, and a stator 8 is fitted on the outside of the can 6. A stator coil 8 a and a yoke 8 b are stored in the stator 8 in the vertical direction, and the stator coil 8 a is energized through a lead wire 8 c and a connector 8 d provided on the outer periphery of the stator 8. The yoke 8b is excited by energizing the stator coil 8a to rotate the rotor 7, and the operating rod holder 5 and the valve shaft 3 are slid by a screw feed mechanism to open and close the valve body 3a to adjust the flow rate of the refrigerant. It is carried out. A connector cover 8 e is bonded to the stator 8.

  A metal ring-shaped mounting plate 9 is fixed below the stator 8, and an anti-rotation piece 9 a formed integrally with the mounting plate 9 is engaged with a fluid outflow pipe 2 a that protrudes horizontally from the valve body 2. The engagement hole 9b is engaged with one side of the ring-shaped welded portion between the valve body 2 and the can 6 and a pressing piece 9c formed integrally with the mounting plate 9 is pressed on the other side of the ring-shaped welded portion. Thus, the stator 8 is fixed.

  By the way, in the said motor operated valve 1, since the difference of the refrigerant | coolant pressure of a high pressure fluid introduction pipe | tube and the refrigerant | coolant pressure of a low pressure fluid derivation | leading pipe is large, when driving a valve body to an opening direction or a closing direction, a big driving force is required. Therefore, it is necessary to enlarge the valve body driving part by that amount.

  The present invention has been invented to solve such a problem, and the object of the present invention is to introduce the driving force necessary for the operation of the valve body by introducing the high-pressure side refrigerant pressure as the back pressure into the back portion of the valve body. The aim is to reduce the drive motor part and simplify and reduce the size.

In order to achieve the above object, the present invention employs the following means.
The motor-driven valve according to claim 1 is a valve main body, a high-pressure fluid introduction hole provided in the valve main body, a low-pressure fluid outlet hole provided in the valve main body through the valve chamber, and a valve main body. A valve body driving portion provided in the valve body, a guide bush mounted on the valve body, a rotor driven to rotate by the valve body driving portion, an operating rod holder integrated with the rotor and supported in a screwed state on the guide bush, And a valve body that opens and closes by an operating rod held by the operating rod holder, and the pressure of the high-pressure fluid in the high-pressure fluid introduction hole acts on the valve body from both the opening and closing directions.

The motor-operated valve according to claim 2 is the motor-operated valve according to claim 1, wherein a back-pressure chamber for introducing a high-pressure fluid is provided in the valve body, and the valve body is operated in the closing direction in the back-pressure chamber. And
The motor-operated valve according to claim 3 is the motor-operated valve according to claim 1 or 2, wherein one end of the operating rod and one end of the valve body are faced to the back pressure chamber, and a buffer spring is compressed between both ends. It is characterized by arranging.

  The motor-operated valve according to claim 4 is the motor-operated valve according to claim 2 or 3, wherein the pressure of the high-pressure fluid is applied to the valve body from the high-pressure fluid introduction hole to the open side, and the back pressure chamber is closed to the close side. It is made to act on.

  According to the above means, since the pressure of the high-pressure fluid in the opening direction and the pressure of the high-pressure fluid in the closing direction are applied to the valve body in both directions, the influence of the fluid pressure on the valve body is reduced. Since the driving force is small, the valve body driving unit may be a smaller device than the conventional one, and the entire valve unit is simplified.

  Hereinafter, embodiments of an expansion valve according to 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 present invention. In FIG. 1, the same components as those shown in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 1, the motor-operated valve D according to the present embodiment includes a valve body 10 and a valve body driving unit 20 attached to the upper part of the valve body 10. A high-pressure fluid introduction hole 11 is formed in the lower part of the valve body 10 in the lateral direction, and a low-pressure fluid lead-out hole 13 communicated from the high-pressure fluid introduction hole 11 through the orifice 18 and the valve chamber 12 in the upper part. Formed in the direction. A back pressure chamber 16 is formed between the upper portion of the valve body 10 and a guide bush 15 (described later), and the back pressure chamber 16 is introduced into the high pressure fluid via a high pressure introduction passage 16 a formed in the valve body 10. It communicates with the hole 11.

  The valve body 10 between the valve chamber 12 and the back pressure chamber 16 is fitted with a valve rod support member 17 in an airtight manner to separate the valve chamber 12 and the back pressure chamber 16 from each other. The valve body support member 17 is formed with a hole 17a through which a valve body 40 described later is inserted so as to be movable up and down. The inner diameter of the hole 17a is smaller than the inner diameter of the orifice 18 in this embodiment.

  The high-pressure fluid introduction hole 11 is fitted with a high-pressure fluid introduction pipe 11 a, the low-pressure fluid lead-out hole 13 is fitted with a low-pressure fluid lead-out pipe 13 a, and the valve body 40 can slide on the valve body support member 17. It is fitted in the state. The valve body 40 is composed of a large-diameter valve head 40a and a small-diameter valve rod portion 40b, but between one end (upper end) 42 of the valve rod portion 40b and one end (lower end) 32 of an operation rod 30 described later. The buffer springs 33 are arranged in a compressed state via spring receivers 33a and 33b, respectively.

  Next, the valve drive unit 20 mounted on the upper part of the valve body 10 will be described. The upper end of the valve body 10 is formed in a cylindrical shape so as to form the back pressure chamber 16, and a cylindrical guide bush 15 having a different diameter is fitted to the upper part of the inner periphery of the valve body 10, and a canister is formed on the outer periphery thereof. 14 is welded. A back pressure chamber 16 is formed between the valve body 10 and the guide bush 15. In addition, a lower stopper 15a is screwed on the outer periphery of the lower diameter large portion of the guide bush 15.

The rotor 31 disposed in the can 14 is coupled to the operation rod holder 35 via a support ring 34, and the support ring 34 is configured by a brass metal ring inserted when the rotor 31 is formed. Further, the upper protrusion of the operating rod holder 35 is fitted into the inner peripheral hole portion of the support ring 34, and the outer periphery of the protrusion is fixed by caulking so that the rotor 31, the support ring 34, and the operating rod holder 35 are coupled.
A valve body drive unit 20 is mounted on the outer periphery of the can 14 provided on the upper part of the valve body 10. A return spring 19 formed of a cylindrical compression coil spring is attached to the outer periphery of a push nut 19a that is press-fitted and fixed to the upper end of the operating rod 30 on the upper portion of the operating rod holder 35, and a male screw 15b of the guide bush 15 and When the threaded engagement with the female thread 35b of the operating rod holder 35 is released, the return spring 35 abuts on the inner surface of the can 14 and urges the threaded engagement between the fixed screw portion and the moving screw portion. Further, in the back pressure chamber 16, a buffer spring 33 is disposed between one end (lower end) 32 of the operating rod 30 and the valve body 40.

  In the electric valve D configured as described above, the high-pressure refrigerant flows into the high-pressure fluid introduction hole 11 from the high-pressure fluid introduction pipe 11a, and flows out from the low-pressure fluid lead-out pipe 13a through the orifice 18, the valve chamber 12, and the low-pressure fluid lead-out hole 13. It is configured as follows. At this time, the valve body 40 is opened and closed by the vertical movement and fluid pressure of the operating rod 30 driven by the valve body driving unit 20, and the flow rate of the valve body 40 is controlled.

  An upward high pressure refrigerant pressure proportional to the cross-sectional area of the orifice 18 acts from the lower orifice 18 to the valve head 40a of the valve body 40 (pressure receiving portion 41), and from the upper back pressure chamber 16, Since a downward high pressure refrigerant pressure proportional to the cross-sectional area of the valve stem 40b acts, in the case of the embodiment, the difference between the cross-sectional area of the orifice 18 and the cross-sectional area of one end (upper end) 42 of the valve stem 40b. Such pressure acts upward.

  Therefore, when the valve body 40 is moved up and down in the valve body driving unit 20, the influence of the high-pressure refrigerant can be further reduced by bringing the cross-sectional area of the orifice 18 close to the cross-sectional area of the valve rod portion 40 b. In the above embodiment, the high pressure refrigerant differential pressure is applied to the valve body 40 in the opening direction. However, by disposing the valve body below the orifice 18 (upstream side), the high pressure refrigerant differential pressure is increased. It may be applied in the closing direction.

The longitudinal cross-sectional view of the motor operated valve which concerns on this invention. The longitudinal cross-sectional view of the motor operated valve which concerns on a prior art.

Explanation of symbols

1 .... (conventional) motorized valve 2 .... valve body 2a ... fluid outflow pipe 2b ... fluid inflow pipe 2c ... valve chamber 2d ... guide bush fixing part 2e ... can fixing part 2f ... valve seat 3 · · Valve shaft 3a · · Valve body 3b · · Compression coil spring 3c · · Push nut 4 · · Guide bush 4a · · Female screw portion 4b · · Lower stopper 5 · · Actuator holder 5a · · Male screw portion 5a · · Sleeve 5b · · Upper stopper 6 · · · Can 7 · · · rotor 7b · · spring 8 · · stator 8a · · stator coil 8b · · yoke 8c · · lead wire 8d · · connector 8e · · cover 9 · · mounting plate 9a ·・ Non-rotating piece 9b ・ ・ Engagement hole 9c ・ ・ Pressing piece

D .. Motorized valve (the present invention) 10. Valve body 11. High pressure fluid introduction hole 11a. High pressure fluid introduction pipe 12. Valve chamber 13. Low pressure fluid outlet hole 13a. Low pressure fluid outlet pipe 14. Can 15 ·· Guide bush 15a ·· Lower stopper 15b ·· Male screw 16 ·· Back pressure chamber 16a ·· High pressure introduction path 17 ·· Valve support member 17a ·· Hole 18 ·· Orifice 19 · Reset spring 19a ·· Push nut 20 ..Valve drive unit 30 ..Operating rod 31 ..Rotor 32 ..One end (of actuating rod 30) 33..Buffer springs 33a, 33b..Spring support 34..Support ring 35..Operating rod Holder 35a ··· Upper stopper 35b · · Female screw 40 · · Valve body 40a · · Valve head portion 40b · · Valve stem portion 41 · · Pressure receiving portion 42 · · · (One end of valve stem portion 40b)

Claims (4)

  A valve body, a high-pressure fluid introduction hole provided in the valve body, a low-pressure fluid lead-out hole provided in communication with the valve body from the high-pressure fluid introduction hole via the valve chamber, a valve body drive unit provided in the valve body, A guide bush mounted on the valve body, a rotor driven to rotate by the valve body drive unit, an operating rod holder integrated with the rotor and supported by screwing to the guide bush, and an operation held by the operating rod holder And a valve body that opens and closes by a rod, wherein the pressure of the high-pressure fluid in the high-pressure fluid introduction hole acts on the valve body from both the opening and closing directions.   The motor-operated valve according to claim 1, wherein a back pressure chamber for introducing a high-pressure fluid is provided in the valve body, and the valve body is caused to act in a closing direction in the back pressure chamber.   The motor-operated valve according to claim 1 or 2, wherein one end of the operating rod and one end of the valve body are faced to the back pressure chamber, and a shock absorbing spring is disposed between both ends.   4. The motor-operated valve according to claim 2, wherein the pressure of the high-pressure fluid acts on the valve body from the high-pressure fluid introduction hole to the open side, and acts from the back pressure chamber to the close side.

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