JPH0249421Y2 - - 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, the present invention relates to an electric valve used in combination with a microcomputer in the general industrial field, and is used as a so-called proportional control valve.

[Conventional technology]

An example of a pulse motor valve that combines a pulse motor and a valve and is controlled by a microcomputer has been put into practical use as shown in FIG. 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 patch plate is attached to the tip of the stopper nut. On the other hand, 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, the operation will be explained.

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 propelling screw. On the other hand, the stopper nut fitted into the stopper bolt fixed to the lid,
Since it is rotated by a pin that rotates together with the rotor, 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,
After a predetermined rotation, it hits the inner surface of the lid, and the rotation and linear movement of the valve stem also stops, similar to when the valve is closed and stopped.

[Problem that the invention attempts to solve]

In the conventional product constructed as described above, a permanent magnet made of ferrite is used in the rotor of the motor, so the weight of the rotary moving part is heavy and the efficiency is poor. In addition, the rotor was integrated by injection molding a rotor sleeve between the rotor and the valve stem, but depending on the injection molding conditions, there was a problem that the rotor could break or crack. , which was a factor in increasing costs.

The present invention was devised to solve the above-mentioned problems, and aims to reduce the weight of the rotary moving part, improve efficiency, and provide an inexpensive electric valve.

[Means for solving problems]

In this invention, the rotor part, which consists of two parts of the conventional motor rotor and rotor sleeve, is made by injection molding using a composite material of ferrite powder material and a resin material that can adapt to the chemical characteristics of the fluid. A rotor portion is formed, and the rotor portion and the valve shaft are integrated.

[Effect]

The rotor part of the motor in the present invention is lighter in weight and less prone to cracks and cracks during injection molding because the conventional rotor and rotor sleeve are made of a composite material of ferrite powder material and resin material. This makes it possible to provide an inexpensive electric valve with good rotational efficiency.

[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 rotor part of the present invention replaces the conventional rotor and rotor sleeve with a composite material of ferrite powder material and a resin material that can adapt to the chemical characteristics of the fluid. It is formed by injection molding, and is integrally molded with the valve stem. As the composite material, KPM-2A (trade name, manufactured by Hitachi Metals, Ltd.) was used.

The device configured as described above operates in the same way as the conventional product, but since the rotor part of the motor is made of a composite material of ferrite powder and resin material and is integrally formed with the valve shaft, The weight of the rotating part is approx.
30% lighter and has less angular momentum during operation,
Improves rotational efficiency. In addition, there are no cracks or cracks during injection molding that occur with conventional ferrite rotors, resulting in an inexpensive motorized valve.

[Effects of this invention]

As explained above, in the present invention, the rotor and rotor sleeve of a conventional motor are made of a composite material made of a mixture of ferrite powder material and resin material to form the rotor part, and the rotation efficiency is high. , which has a high practical effect in that it can provide an inexpensive electric valve.

[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 stop screw,
is the pin, and 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 integrated with the valve stem through a rotor sleeve formed by injection molding, the conventional rotor and rotor sleeve are replaced with a composite material of ferrite powder material and a resin material that can adapt to the chemical characteristics of the fluid. A rotor structure for an electric valve, characterized in that a rotor part is formed by injection molding, and the rotor part and a valve shaft are integrated.