JPH02107880A - Flow control valve - Google Patents

Abstract

PURPOSE:To prevent the occurrence of noise and the abrasion of a valve body and a valve seat by exciting an operating coil with AC, generating an induction current in a coil-shaped operating body made of a shape memory alloy for self-heating, and opening or closing the valve body with its recovery force and the exciting force of a spring. CONSTITUTION:When an operating coil 39 is excited with AC, an induction current is generated in a coil-shaped operating body 26 made of a shape memory alloy via a magnetic circuit containing a valve seat 11 and a valve body 17, it is self-heated to the transformation temperature or above, the operating body 26 is extended and recovered against the exciting force of a spring 35, the needle section 18 of the valve body 17 is separated from the valve seat 11 to allow the flow of a fluid, when excitation is stopped, the valve seat 11 is closed to block the flow of the fluid. These valve opening/closing actions are repeated, and the flow of the fluid is controlled by changing the ratio between the opened time and the closed time. No noise occurs, and the abrasion of the valve body and the valve seat is reduced. The movement of the valve body 17 is detected by the change of the impedance of a coil 44 for detection.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention is directed to a flow rate control valve that controls the flow rate of refrigerant, etc. in a refrigeration cycle by 1J.

(Prior Art) A conventional flow rate control valve used to control the flow rate of refrigerant in a refrigeration cycle is, for example, one that drives the coil a of a solenoid valve of Kanzo using a pulse width modulation method, as shown in FIG. Similar to a general solenoid valve, when the coil a is energized, the fixed iron core made of 1ifl bamboo leaves the valve body C made of magnetic material with the spring d.
, and pulls the valve body C away from the valve seat C, and opens the inlet f.
When the refrigerant is made to flow through the outlet q and the coil a is de-energized, the valve body C is pressed against the valve seat C by the spring d.
The flow of refrigerant is stopped, and by driving coil a with a pulse current, the opening and closing operations are continuously repeated.1! The flow rate is controlled by changing the sum of υ1 of the energization time and the town energization time using a pulse width modulation method.

(Problem to be Solved by the Invention) By the way, in the conventional flow control valve described above, the moving speed of the valve body C is fast and the valve body C collides violently with the fixed iron core and the valve seat e, so that the Ig In addition, the pulse width modulation method requires a direct current power source, and the electric circuit for changing the pulse width is complicated.

The present invention has been developed in view of the above points, and therefore provides a FII11 control valve that generates no noise, has less wear on the valve body and valve seat, and can be operated with an AC power source.

[Structure of the invention]

(Means for Solving the Problems) A flow control valve according to claim 1 of the present invention includes a cylindrical main body 1 made of a non-magnetic material and provided with an inlet 3 and an outlet 6 at both ends in the longitudinal direction; A valve seat 11 made of a magnetic material is provided near one end inside the main body 1 and makes the inflow port 3 and the outflow port 6 communicate with each other. The valve seat 11 is provided so as to be freely movable in the direction of the axis 1 of 1.
a valve body 17 made of a magnetic material, which has a small-diameter needle part 18 for opening and closing the valve seat 11 at one end thereof, and a large-diameter locking part 19 at the other end of the needle part 18;
A spring 35 is provided inside the main body 1 with respect to the valve body 171C and biases the valve body 17 toward the valve seat 11 at one end;
It is located between the locking part 19 of the valve body 17 and the valve seat 11, and is provided on the outside of the needle part 18 of the valve body 17. A coil-shaped actuating body 26 made of a shape memory alloy that is compressively deformed and then expanded and restored against the biasing force of the spring 35 below the transformation temperature to bias the valve body 17 toward the other end; and an outer side of the main body 1. The actuating coil 39 is excited with alternating current, and the valve seat 11 and the valve body 1 are
An induced current is generated in the coil-shaped actuating body 26 made of the shape memory alloy through a magnetic circuit including 7, and the induced current causes the actuating body 26 to self-heat.

The flow control valve of claim 2 is defined as 1 f9 of claim 1.
1. II In the tllll valve, the valve body 1 is placed on the outside of the main body 1.
A detection coil 44 for detecting the movement of 7 is provided.

(Function) The flow control valve according to claim 1 of the present invention has a coil 39 for operation.
When excited with alternating current, an induced current is generated in the coil-shaped actuating body 26 made of a shape memory alloy through a magnetic circuit including the valve seat 11 and the valve body 17, and this induced current causes the actuating body 2 to
6 self-heats and reaches a temperature higher than the transformation temperature, the actuating body 26 stretches and restores its original state against the biasing force of the spring 35, and the needle portion 18 of the valve body 17 is arched away from the valve seat 11, thereby separating the valve seat 11. , when the flow of fluid is allowed and the excitation of the coil 39 for rotation is stopped, the electromotive force disappears, the actuating body 26 no longer generates heat, and the actuating body 2G is cooled by the fluid, causing a change! Aff
, below degrees.

The spring 35 compresses and deforms the actuating body 26 while deforming the valve body 1.
The needle part 18 of 7 is pressed against the valve seat 11 to close the valve 11 and prevent the flow of fluid.This valve opening operation and the valve r
I Repeated fishing operation, valve opening time and valve f! The fluid flow section is controlled by changing the ratio of f1 time.

The flow control valve according to a second aspect of the invention is the flow control valve according to the first aspect, in which movement of the valve body 17 is detected by a change in impedance of the detection coil 44.

(Embodiment) An embodiment of the flow 1 control valve of the present invention will be described with reference to FIG.

1 is a cylindrical main body, and this main body 1 is made of a non-magnetic material,
At one end (the right end in the figure), a locking part 2 with a large outer diameter and an inlet 3 with a small inner diameter are formed, and an introduction pipe 4 is connected airtightly to the inlet 3. A lid 5 made of a non-magnetic material and forming a part of the main body 1 is airtightly fitted to the end (left end in the figure), and an outlet 6 is formed in the lid 5. A lead-out pipe 7 is connected in an airtight manner.

Note that the lid 5 includes a valve seat 11 and a coil-shaped actuating body 2, which will be described later.
6, coiled shorting wire 31, conductive washer 27, valve body 1
7 and the compression spring 35, etc., are installed in the main body 1, and then inserted into the main body 1.

Reference numeral 11 denotes a valve seat. This valve seat 11 is made of a magnetic material, has a communication hole 12 in the center, and has a surrounding wall part 13 with a larger inner diameter formed at the other end. It is press-fitted and fixed near one end of the main body 1.

Reference numeral 17 denotes a valve body, and the valve body 17 is made of a magnetic material, and has a small diameter needle portion 18 with a sharp tip on one end side relative to the valve seat 11, and a large diameter locking Y519 is integrally attached to the other end of the small diameter needle portion 18. A notch 20 is formed along the length direction on one side of the distal end of the needle 18, and an insulating layer is formed on the outer periphery of the needle 'vA1B on the locking part 19 side. 21 is formed, and furthermore, a through hole 22 is formed from one side of the needle portion 18 near the locking portion 19 to the other side of the locking portion 19. It is inserted into the other end side of the inside of the main body 1 so as to be movable in the axial direction of the main body 1.

The length of the large-diameter locking portion 19 at the other end of the valve body 17 is approximately equal to the length of the surrounding wall portion 13 of the valve seat 11 into which the needle portion 18 at one end of the valve body 17 enters.

Reference numeral 26 denotes an actuating body. This actuating body 26 is coil-shaped and made of a shape memory alloy, and is wound around the outer periphery of the insulating layer 21 of the needle portion 18 of the valve body 17. Both ends of the actuating body 26 are provided with conductive washers 27. The other end surface of the surrounding wall portion 13 of the valve seat 11 and one end portion of the locking portion 19 of the valve body 17 are in contact with each other via the valve seat 11 .

Note that the coil-shaped actuating body 26 made of this shape memory alloy
has a transformation temperature higher than the temperature of the fluid to be used, that is, the refrigerant of the refrigeration cycle, and has the property of restoring to its original shape when the temperature increases from below the transformation temperature to above the transformation temperature. The state shown in the figure is a state in which the material is compressed and deformed at a temperature below the transformation temperature.

31 is a conductive wire, and this conductive wire rA31 is connected to the actuating body 26.
It has a reversely wound coil shape and is located outside the actuating body 26, and similarly to the actuating body 26, the surrounding wall part 13 of the valve seat 11 and the locking part of the valve body 11 are connected via the conductive washer 27. The conductive wire 31 and the actuating body 26 form an m@ path via a conductive washer 27.

Note that this l electric wire 31 and the actuating body 26 are not electrically connected directly due to their long winding diameters, but are electrically connected through the conductive washer 27. Each is set such that there is a spacing between adjacent windings even in the compressed state as shown.

Reference numeral 35 denotes a coiled compression spring, which is inserted into the main body 1 following the valve body 17, and when the lid 5 is attached to the other end of the main body 1, each 5 and one engaging part of the valve body 17, and in this state, the valve body 17 is urged toward one end, and when the actuating body 26 is below the transformation temperature, the actuating body 26 and the conductive wire 31 is compressed and deformed to move the valve body 17 toward the valve seat 11, and the tip of the needle portion 18 of the valve body 17 is inserted into the communication hole 12IP of the valve seat 11.
By pressing, the communication hole 11 is emptied, and when the actuating body 26 is below the transformation temperature, the actuating body 26 is compressed by the restoring force of expansion Q, and the valve body 11 is allowed to separate from the valve 811. The communication hole 12 is opened.

Reference numeral 39 denotes an actuation coil, and this coil 9 is disposed around the outer periphery of the main body 1, and extends from the valve seat 11 to the locking portion 19 of the valve body 17, and has coils at both ends thereof. is fitted with a yoke 40 made of a magnetic material, and this pair of yokes 40
are interposed between both ends of the coil 39 and the locking portions 19 of the valve seat 11 and the valve body 17.

Reference numeral 44 denotes a detection coil, which is disposed on the outer periphery of the main body 1 adjacent to the left end of the actuation coil 39. A locking portion 19 of the holder is configured to move in and out.

In addition, this detection coil 44 and the above-mentioned actuation coil 3
9 is held between a holding member 48 attached to the outside of the other end of the main body 1 and a locking portion 2 at one end of the main body 1.

Next, the operation will be explained.

The flow 8 control valve of this embodiment is connected to the refrigerant flow path of the refrigeration cycle via the inlet pipe 4 and the outlet pipe 7, and is connected to the refrigerant flow path of the refrigeration cycle through the inlet pipe 4 and the outlet pipe
1. In the illustrated state, the actuating coil 39 is not energized, and the coil-shaped actuating body 26 made of a shape memory alloy is below the transformation temperature due to the temperature of the refrigerant, and is not compressed. The spring 35 compresses and deforms the operating body 26 and the conductive wire 31 via the valve body 11, moves the valve body 17 toward the valve seat 11, and moves the tip of the needle portion 18 of the valve body 17 into the valve seat 11. The rTi is pressed against the communication hole 12 to block the communication hole 12 and prevent the flow of the refrigerant.

In this state, when the coil 39 for operation is energized with alternating current based on the commercial power supply and the coil 39 is excited with alternating current, one end of the coil 39, one yoke 40, the surrounding wall part 13 of the valve seat 11, The needle part 18 of the valve body 11, the locking of the valve body 11, '1119, and the coil 39 via the other yoke 40.
A magnetic flux passes through the magnetic circuit leading to the other end, and the coil-shaped actuating body 26 and the conductive $1 flow along the needle portion 18 of the valve body 17.
Since the alternating current magnetic flux passes through the center of 131, conductive washer 2
An operating body 26 and a conductive wire 31 forming an n circuit via 7
An induced current is generated, and this induced current causes the actuating body 26 made of a shape memory alloy to self-heat and reach a temperature higher than its transformation temperature, causing the coiled actuating body 26 to stretch and restore its original state against the biasing force of the compression spring 35. , the needle portion 18 of the valve body 17 is dispensed from the valve seat 11 to allow the refrigerant to flow, and the refrigerant flows from the inlet 3 of the main body 1 to the communication hole 12 of the valve seat 11, and the valve seat 11. It flows to the outlet 6 of M5 through the notch 20 of the needle portion of the body 17, the outside of the needle portion 18, and the through hole 22 of the locking portion 19 of the valve body 11.

In addition, at this time, the magnetic flux is applied to the valve body 17,
It goes in and out of the needle part 18 at the end and the locking part 19 at the end (l!!). Since magnetic flux enters and exits from the yoke 40 around it and does not enter and exit in the axial direction, the valve body 17 is not subjected to axial force due to magnetic force, and therefore,
The valve body 17 operates stably only by the relationship between the restoring force of the operating body 26 and the biasing force of the compression spring 35.

Also, at this time, since the locking portion 19 of the valve body 17 moves relative to the detection coil 44, the detection coil 44
The impedance changes, and the movement of the valve body 11 can be detected by this change in impedance, and the position of the valve body 11 can be detected by the impedance of the detection coil 44.

Then, when the excitation of the operating coil 39 is stopped, the electromotive force disappears and the operating body 26 no longer generates heat.
6 is cooled down to below the transformation temperature by the refrigerant flowing around it, and the compression spring 35 compresses and deforms the actuating body 26 and the conductive wire 31 via the valve body 17 to move the valve body 17 toward the valve seat 11. , and presses the tip of the needle portion 18 of the valve body 17 against the communication hole 12 of the valve seat 11 to close the communication hole 12 and prevent the flow of refrigerant.

When controlling the flow rate of the refrigerant, the valve opening operation by energizing the operating coil 39 and the valve ri1 operation by de-energizing are repeated, and the ratio of the valve opening time 11'1 and the valve m time is changed. , the flow rate of the fluid can be controlled 211v, and at this time, the movement position of the valve body 17 is detected by the detection coil 44, and this is fed back to the energization timing and current value of the actuation coil 39. Then, valve body 1
7 can be moved accurately to precisely control the flow ω. For example, the time from the start of energization to the opening of the valve, and the time from the stop of energization to the valve closing φ11, vary depending on the temperature of the refrigerant. However, this is used for detection] Ile 44 to J knee)
You can know this by using the coil 39 for fl.
When feedback is given to the energization timing and current value,
Valve opening and closing operations can be performed accurately,
In particular, if the working body 26 is excessively cooled by the refrigerant,
Although it is difficult to open the valve, even in such a state, if a large current is passed through the actuating valve 39, the amount of heat generated by the actuating body 26 will increase, so make sure to open the valve body 17 properly! , IJ can be done.

(Effects of the Invention) As described above, according to the present invention, the restoring force of the shape memory alloy and the biasing force of the spring are used alternately to open and close the valve body, so that the valve body can be opened and closed unlike an electromagnetic type. There is no noticeable collision with other parts, no noise is generated, and there is less wear on the valve body and valve seat.Also, the valve opening operation is performed by exciting an operating coil outside the main body with alternating current. This is done indirectly by causing the coil-shaped actuating body made of a shape memory alloy inside the main body to generate self-heating using an induced current, and the valve closing operation is done by cooling the actuating body with fluid, so the closed structure is achieved. is easy to obtain, and moreover, an AC power source can be used as the power source.

If a detection coil is provided as in claim 2, movement of the valve body can be detected, so accurate operation can be performed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the flow control valve of the present invention;
FIG. 2 is a sectional view showing a conventional flow control valve. 1. Main body, 3. Inlet, 6. Outlet, 11. Valve seat, 17. Valve body, 18. Needle part, 19. Locking part, 26. Operating body, 35.・Spring, 39... Coil for operation, 44... Coil for detection. October 17, 1986

Claims (2)

[Claims] (1) A cylindrical body made of a non-magnetic material with an inlet and an outlet provided at both lengthwise ends, and a magnetic body provided near one end inside the body to communicate the inlet and outlet. a valve seat consisting of a body; a small-diameter needle portion provided at the other end of the interior of the main body with respect to the valve seat so as to be movable in the axial direction of the main body, and at one end with respect to the valve seat for opening and closing the valve seat; A valve body made of a magnetic material having a large-diameter locking portion at the other end of the needle portion, and a spring provided inside the main body to bias the valve body toward the valve seat at one end. It is located between the locking part of the valve body and the valve seat and is provided on the outside of the needle part of the valve body, and is compressed and deformed through the valve body by the biasing force of the spring at a temperature below the transformation temperature. As described above, there is provided a coil-shaped actuating body made of a shape memory alloy that expands and restores itself against the urging force of the spring to urge the valve body toward the other end, and an actuating coil provided outside the main body. The actuating coil is excited with alternating current, and an induced current is generated in the coiled actuating body made of the shape memory alloy through a magnetic circuit including the valve seat and the valve body, and this induced current causes A flow control valve characterized by self-heating of the actuating body. (2) The flow control valve according to claim 1, characterized in that a detection coil for detecting movement of the valve body is disposed outside the main body.