JP6584564B2 - Motorized valve - Google Patents

Description

  The present invention relates to, for example, an electric valve that controls the flow rate of refrigerant in an air conditioner.

Patent document 1 discloses the detailed structure of the motor operated valve according to the present applicant.
In this electric valve, a stator is disposed on the outer peripheral portion of a closed bottomed cylindrical member called a can, and this drives a rotor that is rotatably supported inside the can. The stator and rotor constitute a stepping motor.

  The rotation of the rotor is transmitted to the sun gear of the speed reducer using the planetary gear mechanism and output to the output gear. By using the planetary gear mechanism, a reduction ratio of the output gear to the sun gear can be as large as about 1/50, and fine flow rate control can be achieved. As the reduction ratio, a reduction ratio required in design can be obtained by appropriately selecting the number of teeth of each gear constituting the planetary gear mechanism.

  The rotation of the output gear is transmitted to a male screw member called a driver (screw shaft 52 in Patent Document 1). The male screw of the driver (the male screw portion 53 in Patent Document 1) is screwed into the female screw portion of the screw bearing (the cylindrical bearing 50 in Patent Document 1) fixed inside the can, and the driver rotates the output gear. The motion is converted into a linear motion by a screw mechanism. The linear motion of the driver is transmitted to the shaft-like valve body, and changes the flow path area between the valve body and the valve seat. With this action, the motor-operated valve can precisely control the flow rate of the refrigerant.

JP 2008-101765 A

  In the motor-operated valve described above, the output gear rotates at a fixed position in the axial direction, and a flat driver-shaped convex portion provided at the lower end of the output gear is inserted into a slit-shaped concave portion provided in the driver for output. The rotational movement of the gear is transmitted to the driver side. If the output gear rotates by sliding the convex portion of the output gear in the concave portion provided in the driver, the driver does not move in the direction of the rotational axis, but the driver is Can move linearly in the axial direction. As a result, the distance between the output gear and the driver changes.

In order to allow the driver to move linearly, a certain amount of clearance is required at the engaging portion between the convex portion and the concave portion. The output gear rotates in both directions and controls the position of the valve body in the axial direction via a driver. However, due to the presence of the gap described above, hysteresis occurs when the rotation direction changes between the rotation of the output gear and the rotation of the driver.
An object of the present invention is to provide a motor-operated valve that eliminates the hysteresis described above.

In order to achieve the above object, an electric valve according to the present invention includes a valve body having a valve chamber and a valve seat formed therein, a cylindrical can coupled to the valve body, and an outside of the can. a stator member to be mounted, a rotor to be mounted in the interior of the can, while reducing the rotational speed of the rotor, and a planetary gear reduction device for outputting the output gear to move in the vertical direction with respect to the rotor, the valve seat A valve body that moves in the contact and separation direction to control the amount of fluid to pass through, a screw bearing that is fixed to the valve body and has a female thread portion formed from the valve body side to a predetermined portion, and rotates together with the output gear A male screw portion that is screwed into the female screw portion of the screw bearing, and a driver that moves in the axial direction by rotating together with the output gear to drive the valve body; and the rotor that outputs the rotor in the axial direction. Contrary to gear Biased in direction, it is to the basic configuration that includes a spring means for regulating the axial position of the rotor.
With this configuration, there is no gap between the output gear and the screw driving member, and the hysteresis is reduced.

  By providing the above-described means, it is possible to reduce the hysteresis of the flow rate characteristic that occurs when the electric valve is opened and closed.

Sectional drawing of one Example of this invention (fully opened state). Sectional drawing of one Example of this invention (fully closed state).

  1 and 2 are sectional views of a motor-operated valve according to an embodiment of the present invention. FIG. 1 shows a state where the valve is fully opened, and FIG. 2 shows a state where the valve is fully closed.

The motor-operated valve according to an embodiment of the present invention, indicated as a whole by the reference numeral 1, has a valve body 10, and a valve chamber 14 and an orifice 16 communicating with the valve chamber 14 are formed in the valve body 10.
A pipe 12 a on the orifice 16 side and a pipe 12 b communicating with the opening on the side surface of the valve chamber 14 are connected to the valve body 10. A screw bearing 20 is inserted into the upper portion of the valve chamber 14 of the valve body 10 and is fixed to the valve body 10 by the caulking means K1.
A female screw portion 22 is formed at the center of the screw bearing 20. A base plate 28 is fixed to the upper part of the valve body 10, and a bottomed cylindrical can 30 is attached thereto.

  A stator member indicated as a whole by reference numeral 40 is fitted on the outer periphery of the can 30. The stator member 40 includes a bobbin 44 covered with a plastic 42 and a coil 46 wound around the bobbin 44, and the coil 46 is supplied with power via a lead wire 48. This stator member constitutes a stepping motor together with the rotor member 50 that is rotatably supported inside the can 30.

The rotor member 50 made of a magnetic material is integrally connected to a sun gear member 51 made of a plastic material, and these constitute a rotor. A shaft 62 is inserted in the center of the sun gear member 51. The upper part of the shaft 62 is supported by a support member 60 disposed inside the top of the can 30.
The carrier 53 is provided on a bottom surface of an output gear 70 described later, and includes a shaft 54 that rotatably supports a plurality of planetary gears 55.

The sun gear 52 of the sun gear member 51 meshes with a plurality of planetary gears 55 that are rotatably supported by the shaft 54. The planetary gear 55 is a gear that is long in the axial direction, and the upper half of the planetary gear 55 is an annular ring gear (internal fixed gear) 58 attached to the upper part of the cylindrical member 24 fixed to the upper part of the screw bearing 20 by a caulking part K2. I'm engaged.
The lower half of the planetary gear 55 meshes with the internal gear 71 of the annular output gear 70.

  The above-described gear configuration constitutes a so-called planetary gear mechanism, and in the reduction device (planetary gear reduction device) using this planetary gear mechanism, the number of teeth of the ring gear 58 and the teeth of the internal gear 71 of the output gear 70 are as follows. By making the number slightly different, the number of rotations of the sun gear 52 can be reduced with a large reduction ratio and transmitted to the output gear 70.

The output gear 70 is integrally connected to the driver 72.
The output gear 70 can be raised and lowered as will be described later, and the male screw portion 74 of the driver 72 is screwed into the female screw portion 22 of the screw bearing 20, so that the output gear 70 and the driver 72 are rotated. And move in the axial direction. The amount of movement of the driver 72 in the axial direction is transmitted to the shaft-shaped valve body 80 via a ball-shaped joint 76. The valve body 80 is guided by a pipe-like spring case 90 fixed inside the valve body 10 and moves in the axial direction. A coil spring 92 is disposed between the spring case 90 and the valve body 80, and always biases the valve body 80 in the valve opening direction.

As described above, in the motor-driven valve of the present invention, the output gear 70 and the driver 72 are integrally rotated and moved in the axial direction. Because of this structure, the joint structure between the output gear and the driver existing in the conventional motor-operated valve can be omitted, and the occurrence of hysteresis can be reduced.
That is, in the conventional motor-operated valve as shown in Patent Document 1, the output gear of the planetary gear mechanism does not move up and down, while the driver performs the lifting operation, the output gear and the driver are separated, In addition, the connection structure by engaging the convex portion and the concave portion is adopted so that the driver can move up and down with respect to the output gear. However, in one embodiment of the present invention, the output gear 70 can be raised and lowered as described above. In addition, since the output gear 70 and the driver 72 are integrated, the gap existing between the output gear 70 and the driver 72 can be omitted, and the occurrence of hysteresis can be reduced.

In this embodiment, since the carrier 53 is placed on the bottom surface of the output gear 70, the carrier 53 and the planetary gear 55 also move up and down as the output gear 70 moves up and down. That is, the meshing surface of the upper part of the planetary gear 55 with respect to the ring gear 58 is displaced in the direction of the central axis of the rotor member 50 as the output gear 70 moves up and down.
In this case, for example, when the lower end of the sun gear 52 provided in the rotor 50 is placed on the carrier 53, the rotor member 50 also moves up and down together with the output gear 70, and the rotor member 50 and the stator The position in the axial direction between the member 40 changes, and a torque drop as a stepping motor occurs.

  In order to prevent this phenomenon, in this embodiment, a disc spring 100 is provided between the ring gear 58 that is a fixing member and the sun gear member 51. The disc spring 100 is supported by the ring gear 58, which is a fixed member, so that the sun gear member 51 is always pushed up toward the support member 60 side of the shaft 62 and is brought into contact with the support member 60, so that the output gear 70 is lowered. Even so, the rotor member 50 does not descend, and torque does not decrease.

  In the above description, the entire unit composed of the carrier 53, the shaft 54, and the planetary gear 55 is moved up and down in accordance with the lifting and lowering of the output gear 70. If a spring means for pushing up the carrier 53 is provided between them and the unit is brought into contact with, for example, the sun gear member 51, when the output gear 70 is raised or lowered, only the output gear 70 is raised or lowered. It is also possible not to change the positions of the carrier 53 and the planetary gear 55 in the axial direction. In this case, as the output gear 70 moves up and down, the meshing surface of the output gear 70 with the lower planetary gear 55 is displaced in the direction of the central axis of the rotor member 50.

FIG. 1 shows a fully open state in which the valve body 80 is raised to the maximum position, and shows a state in which the valve lift L1 between the needle portion 82 at the tip of the valve body 80 and the valve seat 18 is maximum.
FIG. 2 shows a fully closed state in which the needle portion 82 of the valve body 80 is seated on the valve seat 18. Since the structure and operation of each member are the same as those in FIG. 1, the same reference numerals are given and detailed description thereof is omitted.

DESCRIPTION OF SYMBOLS 10 Valve main body 12a, 12b Pipe 14 Valve chamber 16 Orifice 18 Valve seat 20 Screw bearing 22 Female thread part 24 Cylindrical member 28 Base plate 30 Can 40 Stator member 42 Plastic 44 Bobbin 46 Coil 48 Lead wire 50 Rotor member 51 Solar gear member 52 Solar gear 53 Carrier 54 Shaft 55 Planetary Gear 58 Ring Gear 60 Support Member 62 Shaft 70 Output Gear 71 Internal Gear 72 Driver 74 Male Screw Portion 80 Valve Body 82 Needle Portion 90 Spring Case 92 Coil Spring 100 Disc Spring

Claims (2)

A valve body having a valve chamber and a valve seat formed therein;
A cylindrical can coupled to the valve body;
A stator member mounted outside the can;
A rotor equipped inside the can;
By reducing the rotational speed of the rotor, and a planetary gear reduction device for outputting the output gear to move in the vertical direction with respect to said rotor,
A valve body that moves in the direction of contact with and away from the valve seat and controls the amount of fluid passing;
A screw bearing fixed to the valve body and having a female thread portion formed from the valve body side to a predetermined portion ;
External thread portion is provided to be screwed into the internal thread portion of the front Symbol bush, a driver moves in the axial direction by rotating together with the output gear for driving said valve body,
Biases in the axial direction of the rotor in the opposite direction to the said output gear, comprising a spring means for regulating the axial position of the rotor,
An electrically operated valve characterized by that. The driver moves in the axial direction in a state of being rotatably supported by the inner peripheral surface on the rotor side of the screw bearing rather than the female screw portion.
The motor-operated valve according to claim 1.

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