JPH0337670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow control valve connected to a refrigerant circuit of an air conditioner, a refrigerator-freezer, etc., and used to control the flow rate of refrigerant.

[Conventional technology]

In recent years, compressors in the refrigerant circuits of room air conditioners, electric refrigerators, etc. are driven by inverter motors, and the rotational speed of the compressor is varied widely to achieve optimal operation depending on the situation. .

In order to achieve even more efficient operation, a pulse motor type flow control valve is used as an expansion valve to control the flow rate of refrigerant according to the capacity of the compressor.

By the way, the above-mentioned pulse motor type flow control valve has a structure as shown in FIG. 4, filed by the applicant of the present invention in Japanese Utility Model Application No. 124384/1984.

However, when the motor 6 is energized, the rotor 3, which is integrally formed with a valve shaft 23 having a male thread 22 housed in a cylinder 4, is rotated, and this rotation is converted into a linear motion of the valve shaft 23 by a bearing 24. Convert and rotatably caulk the ball 25 to the tip of the valve stem 23,
In addition, a needle valve 27 that controls the degree of opening with respect to the valve seat 26 is located on the opposite side of the ball 25 at the tip of the valve shaft 23 with respect to the valve seat 26, and the rear part of the needle valve 27 is connected via a spring 28. By pressing and fixing with the adjustment nut 29, and by the rotational linear movement of the valve shaft 23,
The ball 25 at the tip of the valve shaft 23 pushes the tip of the needle valve 27 to control the degree of opening with respect to the valve seat 26.

Since this pulse motor type flow control valve controls the flow rate by rotating the male thread 22 of the valve stem 23 about 5 times, a highly durable and expensive material must be used for the thread connection part. There was a drawback that it did not work. Furthermore, since the valve shaft 23 is moved a considerable amount in the axial direction, the product size increases in the height direction.

Furthermore, in the closed type shown in this drawing, a needle valve 27, a spring 28, and an adjusting nut 29 are required, resulting in a problem that the structure becomes more complicated and the size becomes larger.

[Means for solving problems]

The flow control valve of the present invention has an outer cylinder 1 forming a valve seat.
A valve port 17 is provided on the bottom surface 19 of the outer cylinder at a position with a radius r from the axis of the inner shaft 2, and a flow rate to the valve port 17 is provided on a concentric circle with a radius r from the center of the inner shaft 2, corresponding to the valve port 17. A protrusion 18 of an appropriate shape is formed to continuously change the refrigerant flow rate within a range of one revolution of the rotor 3.

That is, the valve port 17 and the inlet port 15 leading to the outside.
A thin-walled cylinder 4 is provided on the top of the outer cylinder 1, and a stator 7 is disposed outside this cylinder 4.
A flow rate control valve is provided with an inner shaft 2 rotatably integrated with a rotor 3 inside, and the flow rate passing through the valve port 17 is controlled by the rotation of the inner shaft 2, and the center of the outer cylinder bottom surface 19 A recess 12a is formed in the axial center, and a valve port 17 is provided at a position of radius r from the axis of the motor. A concave portion 12b is formed at the center of the lower surface of the shaft 2, and approximately 3/3 of the concentric circle with radius r from the center of the inner shaft 2 is formed.
4, the protrusion 18 with a constant width is formed so that the gap h with the bottom surface of the outer cylinder gradually increases from approximately 0, or the width w of the protrusion 18 is formed with the gap h with the bottom surface of the outer cylinder constant. The diameter of the valve port 17 is gradually reduced, and the recess 12a on the bottom surface of the outer cylinder and the recess 1 on the lower surface of the inner shaft are formed.
2b, a steel ball 14 was inserted into the hole 21 on the upper surface of the inner shaft via a compression coil spring 13, and the upper part of the steel ball 14 was fixed to the upper part of the thin cylinder 4. The inner shaft 2 is supported between the inner shaft 2 and the outer cylinder 1 by pressure contact with the conical recess 14a on the lower surface of the upper lid 5, and the inflow resistance to the valve port 17 is continuously changed within a range of one revolution of the rotor 3. It is characterized by being able to control the flow rate of the refrigerant. Further, a coil spring 8 having locking portions 8a and 8b bent inwardly and outwardly, respectively, is disposed on the outer peripheral portion below the inner shaft 2, and one locking portion 8a is fitted onto the inner shaft 2. The other locking portion 8b abuts against a locking pin 9 attached to the outer cylinder 1 to determine the rotational angle of the inner shaft 2.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 3, based on the drawings. A closed type flow control valve will be described below. A valve port 17 is provided on the bottom surface 19 of the outer cylinder at a position with a radius r from the axis. It is being A hole 2 is provided on the bottom surface of the inner shaft 2 above the valve port in a manner corresponding to the valve port 17.
0 is provided in the hole 20, and a steel ball valve closing element 10 is inserted into the hole 20 via a spring 11 so as to be pressed against the valve opening 17 below.

Incidentally, in a non-sealing type flow control valve, the valve closing element 10 can be omitted. Of course, in this case, the hole 20 and the spring 11 are also unnecessary.

As shown in FIGS. 2 and 3, from the end of the hole 20, a gap h with the outer cylinder bottom surface 19 is sequentially formed over about 3/4 of a concentric circle with radius r from the center of the inner shaft 2. A protrusion 18 with a constant width is formed so as to increase in size, and by rotating the inner shaft 2, the outer cylinder bottom surface 19 and the protrusion 18 are formed.
By changing the gap, the flow rate of refrigerant flowing from the inflow pipe 15 facing this gap to the outflow pipe 16 via the valve port 17 can be changed at a constant ratio. There is.

Incidentally, the width w of the protrusion 18 may be made smaller while keeping the gap h between the protrusion 18 and the bottom surface 19 of the outer cylinder constant, or a combination thereof may be used. Furthermore, the flow resistance of the refrigerant can be changed by forming an arcuate groove 18' at the top of the projection 18, as shown by the two-dot chain line in FIG.

The motor 6 consists of a rotor 3 and a stator 7, and the inner shaft 2 is integrally attached to the rotor 3 of the motor 6. Furthermore, a thin stainless steel cylinder 4 made of, for example, a non-magnetic material is interposed between the rotor 3 and the stator 7, and an outer cylinder 1 is provided at the lower end of the thin cylinder 4, and an upper lid 5 is provided at the upper end of the thin cylinder 4. They are each hermetically joined by a method such as welding, and the inside and outside of the cylinder 4 are completely separated.

The motor 6 is, for example, a pulse motor, and is rotated by an angle proportional to the pulse in response to a pulse instruction sent from a microcomputer (not shown).

The lower valve mechanism side of the flow control valve, that is, the bottom surface of the outer cylinder 1
9 and a conical recess 12 in the center of the lower surface of the inner shaft 2.
A, 12b are formed, and a steel ball 12 is interposed in the recessed part. Also, on the motor side above the flow control valve, a compression coil spring 13 is inserted into a hole 21 formed in the center upper surface of the inner shaft 2. The inner shaft 2 is supported at the center of the thin cylinder 4 by inserting the ball 14 and compressing the upper part of the steel ball 14 in a conical recess 14a formed on the lower surface of the upper lid 5. A compression coil spring 13 inserted in the inner shaft 2 is constantly pressed against the inner shaft 2 to prevent rattling in the axial direction.

A coil spring 8 having locking portions 8a and 8b bent inwardly and outwardly, respectively, is disposed on the lower outer circumference of the inner shaft 2, and one locking portion 8a is fitted into the inner shaft 2. fixed and the other locking part 8b
Rotation of the rotor 3 is stopped when a valve closing element 10, which is provided on the inner shaft 2 so as to come into contact with a stop pin 9 attached to the outer cylinder 1, reaches the position of the valve opening 17.

Note that the stop pin 9 is not necessarily fixed to the outer cylinder, but may be fixed to the thin cylinder 4. In the figure, 16
1 is an outflow pipe provided below the valve port 17 of the outer cylinder 1, and 15 is an inflow pipe provided on the side of the outer cylinder 1.

[Operation of the present invention]

FIG. 3 is a developed view of the valve mechanism at a position at a radius r from the axis, and shows the fully closed state.

Now, when a pulse in the opening direction is applied to the stator 7 of the motor 6 according to an instruction from the microcomputer, the inner shaft 2 rotates according to the number of pulses, and the third
In the figure, the protrusion 18 provided on the lower surface of the inner shaft 2 moves rightward. Along with this, the height h from the valve port 17 and the valve port to the protrusion 18 gradually increases, so if the primary pressure of the refrigerant remains the same, the amount of refrigerant passing through the outflow pipe 16 gradually increases, reaching point A. The maximum flow rate occurs when it passes by.

If the stator 7 is energized and the inner shaft 2 is rotated in the closing direction, the amount of refrigerant flowing out through the outflow pipe will gradually decrease, and the valve closing element 10 will close to the valve port 17 at the position shown in the figure.
is completely closed.

In this fully closed position, the retaining pin 9 of the outer cylinder 1 is set to come into contact with one end 8b of the coil spring 8, and the rotational energy of the inner shaft 2 is released by the spring force of the coil spring 8. Absorbed.
Therefore, the valve closing element 10 is prevented from coming off the valve port 17 even if a rotation pulse is applied in the closing direction further than in the fully closed state. Furthermore, the sound of contact between the locking portion 8b and the stop pin 9 that occurs when the inner shaft 2 stops can be minimized by the buffering effect of the coil spring 8.

[Effects of the present invention]

In the present invention, as is clear from the above description, a protrusion 18 of an appropriate shape is provided to continuously change the flow rate to the valve port 17 provided on the bottom surface 19 at a position of radius r from the axis of the outer cylinder 1. Since the refrigerant flow rate can be controlled within the range of one revolution of the rotor 3, the durability is significantly improved compared to the conventional one. In addition, in a sealed type flow control valve, a closing element can be provided in the inner shaft, making it possible to provide a flow control valve with a very simple and inexpensive structure. In the valve, a valve closing element can be completely eliminated.

Furthermore, since the present invention completely eliminates the need for axial movement of the valve shaft as in the prior art, one locking portion 8a of the coil spring 8 disposed on the lower outer periphery of the inner shaft 2 is connected to the inner shaft 2. It is possible to provide an extremely simple stopper structure in which the stopper is fitted into and fixed in place, and the other locking portion 8b abuts against a stop pin 9 attached to the outer cylinder 1, and the noise during operation of the stopper can be reduced. This is an extremely useful invention industrially.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of the flow control valve of the present invention, Fig.
FIG. 3 is a perspective view of the lower surface of the inner shaft according to the present invention, FIG. 3 is a vertical cross-sectional view of the valve mechanism developed at a radius r, and FIG. 4 is a vertical cross-sectional view of a conventional flow control valve. 1...Outer cylinder, 2...Inner shaft, 3...Rotor, 4...Cylinder,
5... Upper lid, 6... Motor, 7... Stator, 8... Coil spring, 9... Stopping pin, 10... Valve closing element, 12, 1
4...Steel ball, 11, 13...Spring, 15...Inflow pipe, 1
6...Outflow pipe, 17...Valve port, 18...Protrusion.

Claims (1)

[Claims] 1. A thin-walled cylinder 4 is provided at the top of an outer cylinder 1 equipped with a valve port 17 and an inflow port 15 communicating with the outside, and this cylinder 4
A flow control valve having a stator 7 disposed outside the valve and a rotatably provided inner shaft 2 integrated with a rotor 3 inside the valve, the flow rate passing through the valve port 17 being controlled by the rotation of the inner shaft 2. A recess 12a is formed at the center of the bottom surface 19 of the outer cylinder, and a valve port 17 is provided at a radius r from the axis. A hole 21 is provided at the center of the upper surface, and a recess 12b is formed at the center of the lower surface of the inner shaft 2. Approximately 3/3 of the concentric circle with radius r from the center of the inner shaft 2 is formed.
4, the protrusion 18 is formed with a constant width so that the gap h with the bottom surface of the outer cylinder gradually increases from approximately 0, or the width w of the protrusion 18 is formed with the gap h with the bottom surface of the outer cylinder constant. The diameter of the valve port 17 is gradually reduced, and the recess 12a on the bottom surface of the outer cylinder and the recess 1 on the lower surface of the inner shaft are formed.
2b, a steel ball 14 was inserted into the hole 21 on the upper surface of the inner shaft via a compression coil spring 13, and the upper part of the steel ball 14 was fixed to the upper part of the thin-walled cylinder 4. The inner shaft 2 is supported between the inner shaft 2 and the outer cylinder 1 by pressure contact with the conical recess 14a on the lower surface of the upper lid 5, and the inflow resistance to the valve port 17 is continuously changed within a range of one revolution of the rotor 3. A flow control valve characterized by being able to control the flow rate of refrigerant. 2. The flow control valve according to claim 1, wherein a coil spring 8 has locking portions 8a and 8b bent inwardly and outwardly, respectively, on a lower outer peripheral portion of the inner shaft 2.
At the same time, one locking part 8a is fitted into the inner shaft 2 and fixed, and the other locking part 8b is fixed to the outer cylinder 1.
A flow control valve characterized in that the stop position of the inner shaft 2 is determined by contacting a stop pin 9 attached to the inner shaft 2.