JP2007032675A - Motor operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the rotational contact between a valve element and a valve seat of a motor operated valve without rotating the valve element but only by allowing movement in the axial direction. <P>SOLUTION: The motor operated valve 1 drives a rotor assembly 100 in a can 40 by a stator unit 80. A female screw member 130 of the rotor assembly 100 is rotatably supported in a guide member 60. A valve stem 70 having a male screw 76 screwed to the female screw member 130 has a projection 74 engaged with a longitudinal groove 62 of the guide member 60, and moves only in the axial direction without the rotational movement. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric valve that is installed in a refrigeration system and used as a refrigerant flow control valve.

An electric valve equipped in a refrigeration system is driven by a stator having a coil attached to the outside of a can, which is rotatably supported in a pressure vessel called a can, as disclosed in Patent Document 1, for example. The lift amount of the valve is controlled by converting the rotation of the rotor into an axial movement by a screw mechanism.
When the valve is in the valve-closed position and the fully-open position with respect to the orifice, a stopper device that restricts the rotation of the rotor is required.
JP 2001-50415 A

In the motor-operated valve described above, the valve shaft having the needle-like valve element is lifted with respect to the orifice while rotating. Therefore, when the valve body comes into contact with the orifice, friction due to rotation is generated, which may cause problems such as valve leakage.
An object of the present invention is to provide a motor-operated valve that prevents wear between a valve body and an orifice by lifting the orifice with respect to the orifice by only a linear motion without giving a rotational motion to a valve shaft integrated with the valve body. To do.

  In order to achieve the above object, an electric valve according to the present invention includes a female screw member connected to a rotor, a guide member that is a fixing member that slidably guides the female screw member, and a male screw portion that is screwed into the female screw member. A valve shaft having a valve body at the tip and a rotation stop mechanism for the valve shaft. The rotation preventing mechanism for the valve shaft is composed of a longitudinal groove provided in the inner diameter portion of the guide member and a protrusion provided in the outer diameter portion of the valve shaft and engaged with the longitudinal groove of the guide member.

  The motor-operated valve of the present invention is provided with the above-described means, so that the valve shaft having the valve body at the tip is brought into contact with and separated from the orifice of the orifice member only by a linear motion without rotating. That is, there is no rotational sliding between the valve body and the valve seat, and therefore no wear is generated, and no foreign matter due to wear is generated, and stable valve leakage is maintained over a long period of time. be able to.

FIG. 1 is a cross-sectional view showing the overall configuration of the motor-operated valve of the present invention.
The motor-operated valve denoted as a whole by reference numeral 1 has a cylindrical valve body 10 made by press working or the like. An orifice member 20 is fixed to the valve body 10 and pipes 30 and 32 communicating with the valve chamber are attached.

The orifice member 20 has an orifice 22 and controls the flow rate of the refrigerant flowing between the pipes 30 and 32 with a valve portion 72 described later. The open end of the valve body 10, the can 40 is fixed by welding means W _1. A synthetic resin guide member 60 integrated with a disk-shaped metal flange 50 is fixed between the valve body 10 and the can 40. The flange 50 is integrated with the guide member 60 by insert molding.

The flange 50 has a pressure equalizing hole 52, and the guide member 60 has a pair of longitudinal grooves 62.
The stator unit 80 detachably fitted on the outer periphery of the can 40 has a coil 82 and drives the rotor assembly 100 in the can 40.

  The rotor assembly 100 includes a permanent magnet rotor 110 formed by integrally molding a magnetic material and a resin, and a female screw member 130 that is integrally connected to the rotor 110 via a connecting member 120. A valve shaft 70 having a male screw portion 76 that is screwed into a female screw portion 132 of the female screw member 130 includes a synthetic resin guide body 71 having a protrusion 74 that engages with a longitudinal groove 62 of a synthetic resin guide member 60. The tip of the shaft 70 is formed in a needle-like valve portion 72.

  A coil spring 140 and a cap 150 are disposed between the female screw member 130 and the top of the can 40, and thrust to the rotor assembly 100 toward the valve chamber 12 is given.

FIG. 1 shows a state in which the motor-operated valve 1 is in a fully closed state. When the rotor assembly 100 is driven to rotate in the valve opening direction from this state, the female screw member 130 tries to rotate together with the valve shaft 70. Since the protrusion 74 of the valve shaft 70 is engaged with the longitudinal groove 62 of the guide member 60, the rotation is restricted and the valve shaft 70 is pulled up in the axial direction corresponding to the pitch of the threaded portion to be screwed.
By this action, the valve portion 72 of the valve shaft 70 is lifted by a predetermined distance from the orifice 22, and the valve opening degree is controlled.

The rotor assembly 100 is always applied toward the valve chamber 12 by a coil spring 140 and a cap 150. In response to this thrust, the male screw portion 76 and the female screw portion 132 are always held in screw engagement, and backlash is eliminated. Therefore, the rotation amount of the rotor assembly 100 and the valve lift are always proportional, and the valve opening degree is controlled with high accuracy.
While the rotor assembly 100 rotates six times, the valve body is lifted from the fully closed position to the fully closed position. A stopper device 200 that restricts the rotation of the rotor assembly 100 at both end positions is provided.

2 to 5 show details of main components of the motor-operated valve of the present invention.
FIG. 2 shows details of the flange 50 and guide member 60 assembly. The flange 50 has a pressure equalizing hole 52, and the guide member 60 has an inner diameter portion 66 that guides the outer diameter portion of the female screw member of the rotor assembly and a pair of longitudinal grooves 62. The round hole 61 of the guide member 60 guides the valve shaft slidably.
The outer diameter part of the upper end of the guide member 60 is formed in the thin diameter part 63, and the convex part 64 for stoppers is provided.

FIG. 3 shows details of the valve stem 70.
The valve shaft 70 has a needle-like valve portion 72 at the tip. On the diameter of the guide body 71 guided by the inner diameter portion 61 of the guide member 60, a pair of protrusions 74 extending in the axial direction are formed. A male screw portion 76 is provided at the end of the valve shaft 70 opposite to the valve portion 72. The guide body 71 is integrated with the valve shaft 70 by insert molding.

FIG. 4 shows details of the rotor assembly 100.
The rotor assembly 100 includes a permanent magnet rotor 110 formed by molding a resin mixed with a magnetic material, a ring-shaped metal connecting member 120 integrally formed by insert molding, and a metal supported by the connecting member 120. A female screw member 130 is provided.
An internal thread portion 132 is formed in the internal diameter portion of the internal thread member 130, and the large-diameter outer diameter portion 134 is slidably contacted with the internal diameter portion 66 of the guide member 60. A stopper device, which will be described later, is fitted into the small-diameter outer diameter portion 136.
At the upper end of the inner diameter portion 112 of the rotor 110, a convex portion 114 that contacts the stopper device is provided.

FIG. 5 shows details of a stopper device that restricts rotation of the rotor assembly at the fully open position and the fully closed position of the valve.
The stopper device 200 is composed of a plurality of synthetic resin rotating disks. In the embodiment shown in the figure, five rotating disks 210, 220, 230, 240, 250 are provided. The first rotating disk 210 has a through hole 214 that is loosely fitted into the small-diameter outer diameter portion 136 of the female screw member 130 of the rotor assembly, and a convex portion 212 that protrudes from the outer diameter portion.
The second rotating disk 220 and subsequent units have the same configuration.
The five rotating disks 210, 220, 230, 240, 250 are mounted on the outer diameter portion 136 of the female screw member 130 in a stacked state.

Next, the operation of this stopper device will be described.
In the assembled state, one surface 114a of the convex portion 114 inside the rotor 110 of the rotor assembly 100 is in contact with one surface 212a of the convex portion 212 of the first rotating disk 210 of the stopper device 200. And

When the rotor assembly 100 rotates in an arrow _{R 1} direction, the convex portion 114 of the rotor 110 of the rotor assembly 100, apart from the convex portion 212 of the first rotary disk 210 rotates approximately 1, the convex portion 114 is first It hits against the other surface of the convex portion 212 of one rotating disk 210.
When the rotor assembly 100 further rotates, the first rotating disk 210 also rotates together. When the rotor assembly 100 rotates approximately once, the convex part 212 of the first rotating disk 210 hits the convex part 222 of the second rotating disk 220.

When the above operation is repeated and the fifth rotating disk 250 makes approximately one rotation, the convex portion 252 hits the convex portion 64 of the fixed-side guide member 60 and the rotation of the rotor assembly 100 stops. At the rotational position of the rotor assembly 100, the lift of the valve shaft 70 is maximized and the valve is fully opened.
When the rotor assembly 100 rotates in the opposite direction and the valve shaft 70 moves in the valve closing direction, each rotating disk of the stopper device 200 also rotates in the opposite direction and stops the rotation of the rotor assembly 100 at the final position. .

  In the above-described embodiment, the rotor assembly 100 is restricted within a rotation range within six rotations. An arbitrary rotation area can be set by changing the number of rotating disks and the width of the convex portion.

Sectional drawing which shows the whole motor-driven valve structure of this invention. Explanatory drawing of a guide member. Explanatory drawing of a valve stem. Explanatory drawing of a rotor assembly. Explanatory drawing of a stopper apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorized valve 10 Valve body 20 Orifice member 22 Orifice 40 Can 60 Guide member 62 Vertical groove 70 Valve shaft 71 Guide body 72 Valve part 74 Protrusion 80 Stator unit 100 Rotor assembly 110 Rotor 130 Female screw member 200 Stopper device

Claims (3)

A valve body having an orifice member; a rotor of a motor housed inside a can fixed to the valve body;
A stator including an excitation coil disposed outside the can; and a motorized valve for controlling the valve opening by converting the rotational motion of the rotor into a forward / backward motion by a screw mechanism and transmitting it to the valve body,
A female screw member connected to the rotor; a guide member that is a fixed member that slidably guides the female screw member; a male screw portion that is screwed into the female screw member; A motorized valve with an anti-rotation mechanism.   2. The electric motor according to claim 1, wherein the rotation preventing mechanism for the valve shaft is constituted by a longitudinal groove provided in an inner diameter portion of the guide member and a protrusion provided in an outer diameter portion of the valve shaft and engaged with the longitudinal groove of the guide member. valve. The motor-operated valve according to claim 1 or 2, wherein the guide member and the protrusion are formed by resin molding.

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