JPS61180077A - Motor-driven control valve - Google Patents

Abstract

PURPOSE:To prevent a valve from cutting into the valve opening by providing a partition between the primary opening and the secondary opening with a valve opening which has an edge shaped into a three-dimension curve. CONSTITUTION:A valve opening 2a is established on a partition 2 between the primary opening 1a and the secondary opening 1b in a valve body 1, and a needle valve 3 goes in and out through said valve opening 2a. The valve opening 2a intersects with a circular lateral opening 1a at right angles, and in this case such a valve seat as finished by boring or the like is not required, and accordingly the edge (2a1) of the valve opening 2a is formed by lines which intersect with a lateral opening and a longitudinal opening shaped into a circular form each other so that the edge is shaped into a three-dimension curve. The needle valve 3 has a conical surface section 3c for the flow control which is formed by cutting off the top edge of the needle valve and also has an upright sliding unit 3d which has a size almost agreeing with the bore of the valve opening 2a. When the valve is in a closed state, the upright sliding unit 3d penetrates deep into the valve opening 2a so that leakage from the valve can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric control valve used as an electric expansion valve or the like in a refrigeration system.

Conventional technology This type of control valve in the past was developed in 1982.
As shown in Japanese Patent No. 92263, the flow path is controlled by bringing the conical circumferential surface of the needle valve into contact with and separating from the valve seat, and the flow characteristics are changed by changing the shape of the conical circumferential surface. ing.

Problems to be Solved by the Invention In the above conventional technology, it is necessary to perform precision machining on the valve seat on which the needle valve approaches and separates, and the torque of the stamping motor as an electric device is small. It was necessary to take special measures to prevent the needle valve body from biting into the valve seat when the valve is closed.

The present invention has been made with attention to the above-mentioned points, and is designed to prevent the valve body from biting into the valve port, and to set the flow rate characteristics by the shape of the valve port. be.

Means for Solving the Problems In order to achieve the above object, in the present invention, in an electric control valve in which a valve body is actuated by a motor, a circular horizontal hole is provided at right angles to the partition wall between the primary port and the secondary port. formed to form a valve port having a three-dimensional curved end;
An electric control pulp according to the present invention employs a configuration in which a needle valve is provided with a sliding portion directly above the conical peripheral surface portion for control and having an outer diameter that substantially matches the valve port. and a stepping motor part M.

In the pulp part V, the opening 1a of the valve body 1 and the secondary roller l
A valve port 2a is provided in the partition wall 2 between B and a needle valve 3 moves forward and backward with respect to the valve port 2a. Screw tube 4
It is slidably supported in the axial direction within the shaft.

A lower lid 5 is provided on the upper part of the valve body 1 with the male screw tube 4 in the center, and a closed case 6 of a part M of the stepping motor is fixed onto the lower lid 5. Case 6
A stator 8 having a built-in coil 7 is provided on the outer periphery of the stator 8 . A rotor 9 is rotatably supported within the case 6 by the male threaded tube 4. The rotor 9 is the support tube 1
A cylindrical permanent magnet 11 is fitted to the outer circumferential portion of the magnet 0, and then the upper edge 10a is expanded over the permanent magnet 11 to integrate the two. A male threaded tube 12 which is fitted and fixed is attached to the male threaded tube 4 with an end metal, and is provided so as to be rotatable and movable in the axial direction.

A connecting wall 10b is formed in the axially intermediate portion of the support cylinder 10, and the small diameter portion 3a of the needle valve 3 is inserted into the hole 10c of the connecting wall 10b and fixed thereto with an E ring 13. A compression coil spring 14 is stirred in the small diameter portion 3a of the needle valve 3 between the step portion 3b and the connecting wall 10b.

A shaft 15 fixed to the case 6 at the upper part of the rotor 9
A helical guide ring 16 is attached to the helical guide ring 16, and a slider 17 is engaged with the helical guide ring 16 so as to be able to rotate and move up and down. It is engaged with the rod 18. When the coil 7 of the stator 8 is energized, the rotor 9 rotates, and the slider 17 moves up and down along the spiral guide ring 16 in accordance with the rotation of the rotor 9. 9 and the movement of the needle valve 3 are stopped.

The needle valve 3 has a conical peripheral surface portion 3C for flow rate control with a cut-off tip at its end, and a straight sliding portion 3d whose outer diameter substantially matches the diameter of the valve port 2a. ing. When the needle valve 3 is closed, as shown in FIG. 1, the straight sliding portion 3d deeply enters the valve port 2a, thereby reducing valve leakage.

A pressure equalizing hole 3e is formed in the center of the needle valve 3, extending in the axial direction from the end and opening in the sliding hole IC of the valve body 1. The force exerted on the needle valve 3 by the differential pressure at is reduced.

The valve port 2a is formed as a circular vertical hole that is perpendicular to the circular horizontal hole 1d that forms the second vent lb, and the end of the valve port 2a is not processed by boring or the like to form a valve seat. Therefore, the end 2at of the valve port 2a is composed of the intersection of a circular horizontal hole and a vertical hole, forming a three-dimensional curve (port 9 in Fig. 2), so that the flow rate characteristics are as shown in Fig. 3. Changes slowly.

Conventionally, as shown in FIG.
Whereas it was necessary to perform a boring process 2C' to form a circular valve seat 2b' at the end of the valve port 2a' perpendicular to the valve opening 2a', this step can be omitted in the present invention.

As described above, the present invention provides an electric control pulp in which a valve body is actuated by a motor; Since the needle valve is provided with a conical peripheral surface portion for control and a linear sliding portion having an outer diameter that substantially matches the valve port, the needle valve body This does not cause jamming, and it is possible to obtain flow characteristics that change slowly.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of an embodiment of the present invention, Fig. 2 (a) is a cross-sectional view of the connecting portion between the horizontal hole and the vertical hole forming the valve port, and Fig. 2 (b) is the same as above. 3 is a flow rate characteristic diagram of the present invention, and FIG. 4 is a sectional view of a conventional valve port. DESCRIPTION OF SYMBOLS 1... Valve body, 1a... Primary port, 1b... Secondary port, 1d... Circular horizontal hole, 2... Partition wall, 2a... Valve port, 2at... End part, 3 ...Needle valve, 3C...
Conical peripheral surface part for control, 3d... straight sliding part,

Claims (1)

[Claims] In an electric control valve whose valve body is actuated by a motor, a valve port is formed perpendicularly to a circular horizontal hole in the partition wall between the primary port and the secondary port, and has a three-dimensional curved end, and is 1. An electric control valve characterized in that a linear sliding portion having an outer diameter substantially matching the valve port is provided following the conical peripheral surface portion for control.