JPH0313006Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is an electronically controlled expansion valve used during the refrigeration cycle of room air conditioners, car air conditioners, etc.
Alternatively, it relates to an electric valve used in combination with a microcomputer in the general industrial field as a so-called proportional control valve, and is characterized by extremely low noise caused by rattling of the rotor.

[Conventional technology]

One example is a pulse motor valve that combines a pulse motor and a valve and is controlled by a microcomputer.
A device having a configuration as shown in FIG. 2 has been put into practical use. Its configuration will be explained below.

The valve stem has a needle valve and a male thread formed from the tip, and a rotor made of a cylindrical permanent magnet with multi-pole magnetization on the outer periphery and a resin rotor sleeve are injection molded on the valve stem. integrated by
The male thread is fixed to the valve body and is screwed into a propulsion bearing having a female thread cut in the center.

The outer periphery of the rotor of the motor is covered with a thin cylindrical case, and a stator coil of the motor is fixed to the outside of this case at a position corresponding to the rotor of the motor.

The lower end of the case is hermetically integrated with a valve body having a fluid inlet/outlet and a valve seat by plasma welding or the like, and the upper end of the case is also sealed with a lid.

A stopper bolt with high screw efficiency is fixed to the center of the inner surface of the lid, and a stopper nut having a symmetrical through-hole with a central female thread is screwed into this stopper bolt, and a plate is attached to the tip of the stopper bolt. is fixed, and a pin fixed to the bottom surface of the central recess of the rotor sleeve is inserted into the through hole of the stopper nut. Next, I will explain the operation.

When the stator coil is energized to rotate by a certain amount in the valve closing direction, the rotor of the motor and the valve shaft rotate together, and the valve shaft moves forward due to the action of the propulsion screw. On the other hand, the stopper nut fitted into the stopper bolt fixed to the lid is rotated by a pin that rotates integrally with the rotor, so that it moves forward in the same way as the valve shaft.

Motor-operated valves are adjusted in advance so that when the valve stem rotates a predetermined amount in the valve-closing direction, the needle-shaped valve seats on the valve seat and the stopper nut hits the backing plate just before the valve closes completely. The straight movement of the stopper nut is stopped by hitting the plate. Therefore, the rotation and linear movement of the valve stem are also stopped. This valve closed state is shown in FIG.

Subsequently, when the stator coil is energized in the valve opening direction, the stopper nut separates from the backing plate surface, rotates and moves straight backward together with the valve shaft, and after a predetermined rotation, hits the inner surface of the lid. The rotation and linear movement of the valve stem also stops in the same way as when the valve is closed and stopped.

[Problem that the invention attempts to solve]

In conventional products configured as described above, the motor rotor, which is a permanent magnet made of ferrite, may When rotating or moving in a straight line, it comes into contact with the inner surface of a case made of a non-magnetic material such as stainless steel, resulting in a problem of metallic scraping or hitting noises.

This invention was made to solve the above problems, and the rotor of the motor rotates and
To provide an electric valve that can be operated quietly without generating any noise even if it comes into contact with the inner surface of a case when moving in a straight line.

[Means for solving problems]

In the present invention, a resin layer having excellent chemical resistance against fluids is closely provided on the inner surface of a thin cylindrical case made of a non-magnetic material or on the outer peripheral surface of the rotor.

[Effect]

In the present invention, the resin layer is in close contact with the inner surface of the thin cylindrical case or the outer circumferential surface of the motor rotor, so even if the motor rotor swings and hits the case, it will not rub against the resin surface. Because of this, it is possible to provide an electric valve with extremely low rotor contact and hitting noise.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIG.

The basic structure is the same as the conventional product, but the resin layer of the present invention uses a resin material with excellent chemical resistance to fluids, and is thick enough to fit inside the inner surface of the thin cylindrical case. A 0.1mm sheet is rolled into a cylindrical shape and inserted and fixed. That is, the sheet spreads out so as to come into close contact with the inner surface of the case due to its elastic force, so no adhesive is required.

The resin layer may be formed by coating the inner surface of the cylindrical case or the outer peripheral surface of the rotor with Teflon resin, or may be formed by coating the rotor of the motor with a tube-shaped layer.
When this electric valve is used in a refrigerant, the sheet material may be a Nitoflon coated product.
No.970-4 (trade name, manufactured by NEC Corporation) is suitable.

The device configured as described above operates in the same way as the conventional product, but a resin layer is added to either of the motor rotors, which are permanent magnets made of ferrite, to avoid direct contact with the stainless steel case. Since this is provided, it becomes an electric valve that can prevent metallic contact and hitting noises that occur when the rotor of the motor rotates or moves in a straight line.

[Effects of this invention]

As explained above, the present invention has a resin layer with excellent chemical resistance against fluids on the inner surface of the thin cylindrical case or on the outer circumferential surface of the motor rotor. Furthermore, even if the rotor of the motor rattles, it is possible to provide an electrically operated valve that operates quietly, and has a high practical effect.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention in a valve closed state, and FIG. 2 is a vertical cross-sectional view showing a conventional valve closed state. is the valve stem, is the valve seat, is the needle valve, is the male thread, is the motor rotor, is the valve body, is the female thread, is the propulsion bearing, is the case, is the motor stator coil, is the entrance/exit, is the lid , is the propulsion screw, is the rotor sleeve, is the cover plate, is the stopper bolt, is the through hole of the stopper nut, is the stopper nut, is the pin, is the rotor part.

Claims (1)

[Scope of utility model registration request] The rotor and stator coil of the motor part of the electric valve are separated into the inside and outside of the case through a thin cylindrical case made of non-magnetic material, and the rotor is separated from the valve shaft by a resin layer. In an electric valve that is integrally provided on the outer periphery of a rotor sleeve integrally formed by injection molding, a resin layer with excellent chemical resistance against fluid is provided on the inner surface of the thin-walled cylindrical case or on the outer periphery of the rotor. A low-noise structure for an electric valve characterized by the provision of.