JPH0115965Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is an electronically controlled expansion valve used during the refrigeration cycle of room air conditioners, car air conditioners, etc.
The present invention also relates to a proportional control valve used in combination with a microcomputer in the general industrial field, and particularly to a proportional control valve using a stopper that is inexpensive and has a simple structure.

[Prior Art] A valve seat 2 is provided in a part of the valve body 1 as shown in FIG. 1, and the flow rate is controlled by changing the gap formed between the valve seat 2 and the needle valve 3. In a conventional proportional control valve, a needle valve 3, a valve stem 4, a motor rotor 6, and a male thread 7 are integrated, and the central part of the valve stem 4 is supported by a bearing metal 8, and is fitted into the male thread 7. The screws 9 are fitted together, the female screw retainer 10 is press-fitted into the case 11 made of a non-magnetic material, and the female screw 9 is positioned inside the female screw retainer 10 with a gap that allows the female screw 9 to perform a slight centering action, The case 11 is hermetically integrated with the main body 1 by a method such as brazing, and a fixed coil 1 of the motor is placed outside the case 11 at a position corresponding to the rotor 6 of the motor.
2 were provided, and the liquid inlets and outlets 13 and 14 were configured to serve as fluid inlets and outlets. Outer diameter shape of female thread 9 and female thread presser 10
The inner diameter shape is non-circular such as hexagonal,
They are designed so that they do not rotate relative to each other.

Therefore, when the fixed coil 12 of the motor is energized, the rotor 6 rotates, and due to the screw action of the male screw 7 and female screw 9, the valve shaft 4 and the rotor 6 of the motor rotate and move in the axial direction. Along with this, the gap formed between the valve seat 2 and the needle valve 3 changes, and the amount of fluid flowing between the inlets and outlets 13 and 14 is controlled.

[Problem to be solved by the invention] In such a configuration, when the needle valve 3 comes into close contact with the valve seat 2 and is in the closed state, the needle valve 3 is rotated by the rotor 6 of the motor. Since the valve seat 2 is pressed against the valve seat 2 while being rotated, an extremely strong screwing friction force is exerted, resulting in a phenomenon in which the valve does not open easily even when an attempt is made to reverse the rotor 6 of the motor in the valve opening direction.

When the valve is fully open, either the tip of the male screw 7 hits the case 11 or the end of the motor rotor 6 comes into contact with the female screw retainer 10, causing the valve stem 4 to open. Although the motor can be moved, the inventor also noted that there is a phenomenon in which the rotor 6 of the motor does not rotate easily even if an attempt is made to rotate it in the valve-closing direction due to the extremely strong screw friction force acting in any case. have experienced. One reason why such a phenomenon occurs can be said to be that a conventional motor such as the one illustrated in FIG. 1 has a characteristic that the starting torque is considerably smaller than the maximum rotational torque. This is because a special motor whose starting torque is larger than the maximum torque during rotation is extremely expensive, so it was necessary to eliminate the above problem by changing the structure of the valve itself.

[Means for Solving the Problems] The present invention eliminates these drawbacks by providing a valve seat 2 in a part of the valve body 1, and a needle valve 3 with a compression spring 15 at the tip of the valve shaft 4. The rotor 6 of the motor and the male screw 7 are integrally formed at the rear of the valve stem 4 and housed in the valve body 1, and the center part of the valve stem The bearing metal 8
In a proportional control valve, the female thread 9 is fitted onto the male thread 7, and a fixed coil of the motor is provided at a position corresponding to the rotor outside the case 11. The bipin 16 is fixed by press-fitting or the like, and as a stopper for restricting the rotational and linear movement of the pin 16, the stopper body 18 is formed by pressing a thin plate spring material into a cylindrical shape that matches the inner diameter of the valve body 1. At the same time, the movement stroke (l-
m) Claw 1 cut and bent in the inner diameter direction at separate positions
7 and 17, and is configured such that when the pin 16 reaches the fully open/closed position, the pin 16 and the rear pawl 17 or the pin 16 and the front pawl 17 come into contact in the rotational direction. .

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 2 to 4.

FIG. 2 is a longitudinal sectional side view of the proportional control valve according to the present invention.

The needle valve 3 is attached to the tip of the valve stem 4 by caulking via a compression spring 15, so that when the needle valve 3 is brought into close contact with the valve seat 2, strong screwing frictional force does not act. There is. Further, the valve shaft 4 is provided with a pin 16 in a direction perpendicular to the axial direction near its tip, and a motor rotor 6 and a male screw 7 are integrally provided at the rear of the valve shaft 4. There is. And the center part of the valve stem is a bearing metal 8
The rear end portion is screwed into a female thread 9.

FIG. 4 is a perspective view of the stopper body 18 for restricting the rotational and linear movement of the pin 16. This stopper main body 18 is formed into a cylindrical shape by pressing a thin plate spring material, and is located at a position on its circumference axially apart by the stroke of the valve, that is, the movement stroke of the pin 16 =
A claw 17 cut and bent in the inner diameter direction at the l-m position,
17 is formed.

Note that 19 is a projection that engages with the groove 20 of the main body and prevents the stopper main body 18 itself from rotating, but this is not necessarily necessary.
8 can also be press-fitted into the valve body and fixed.

[Operation of the invention] Since the invention is constructed in this way, for example, when the valve shaft 4 rotates and moves in the valve opening direction, the tip of the male thread 7 may come into contact with the case 11, or
Alternatively, before the motor rotor 6 contacts the female screw retainer 10, the pin 16 collides with the rear pawl 17 of the stopper body and is prevented from rotating, so that no screwing friction force is generated. Therefore, when the rotor 6 is rotated in the valve closing direction, it can be rotated without any resistance.

Further, when the valve shaft 4 rotates and moves in the valve closing direction, the needle valve 3 contacts the valve seat 2 and closes, and when the compression spring 15 is slightly compressed, the pin 16 The needle valve 3 collides with the front pawl 17 and is prevented from rotating.
Due to the co-aligning action of the compression spring 15 and the mutual rotation action of the needle valve 3 and the valve shaft 4, no screwing friction force is generated between the needle valve 3 and the valve seat 2.

Therefore, when the rotor 6 is reversed in the valve opening direction, the valve can be opened with little resistance and with a small rotational torque.

[Effect] In this way, in the present invention, the contact between the pin 16 and the claws 17, 17 that function as stoppers both act as a "force to prevent rotation" in the rotational direction of the shaft 4, and the shaft 4 is rotated. Since it does not act as a directional movement inhibiting force, no screwing friction force is generated, and even an inexpensive motor with a small starting torque can be driven satisfactorily.

Furthermore, the stopper structure of the present invention is made up of a cylindrical stopper body 18 and a pin 16 formed by pressing a sheet of thin plate spring material, so the structure is extremely simple and can be produced at low cost. be able to.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view of a conventional proportional control valve. Second
The figure is a longitudinal side view of the present invention. Figure 3 is A- in Figure 2.
A enlarged sectional view. FIG. 4 is a perspective view of the stopper body. 1... Valve body, 2... Valve seat, 3... Needle valve, 4
...Valve stem, 6...Motor rotor, 7...Male thread, 8...Bearing metal, 9...Female thread, 10...
Female thread presser, 11...Case, 12...Motor fixed coil, 13, 14...Fluid inlet/outlet, 1
5...Compression spring, 16...Pin, 17...Stopper.

Claims (1)

[Scope of utility model registration request] A valve seat 2 is provided in a part of the valve body 1, and a needle valve 3 is movably crimped onto the tip of a valve shaft 4 via a compression spring 15 to position it. The valve body 6 and the male thread 7 are integrally formed and housed in the valve body 1, the central part of the valve shaft is supported by the bearing metal 8, and the female thread 9 is fitted into the male thread 7.
In a proportional control valve in which a fixed coil of a motor is provided at a position corresponding to the rotor outside the case 11,
A pin 16 is fixed to a part of the valve shaft 4 on the needle valve side by press fitting, etc., and a stopper body 18 is made of a thin plate spring material by pressing as a stopper for restricting the rotational and linear movement of the pin 16. Pawls 17, 17 are machined into a cylindrical shape that matches the inner diameter of the valve body 1, and are cut and bent in the inner diameter direction at positions on the circumference and separated by the movement stroke (l-m) of the pin 16.
, and when the pin 16 reaches the fully open/closed position, the pin 16 and the rear pawl 17 or the pin 16 and the front pawl 17 come into contact in the rotational direction. .