JPH11287358A - Valve and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform fine passage control by making variable the passage resistance, steplessly as long as practicable, and perform fine temp. control in cooling and heating, or an energy-saving operation. SOLUTION: The invention comprises a piston 1 provided at the surface with a pair of grooves 1a and 1b, a pair of cylinders 2a and 2b in which two parts of the piston 1 at least including the grooves are inserted, and the second passage which is formed from the inner surfaces of the cylinders 2a and 2b and the grooves 1a and 1b and where the fluid flowing in the first passage 7a flows in and out. The piston 1 is moved within the cylinders 2a and 2b, and thereby the resistance of the second passage is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a flow path resistance of a passage (flow path) through which a fluid such as liquid or gas flows.
The present invention relates to a valve for adjusting a flow rate of a fluid flowing through the flow path, and particularly to a valve used for adjusting a flow rate of a fluid such as a refrigerant in a refrigeration cycle of a room air conditioner, a car air conditioner, or the like.

[0002]

2. Description of the Related Art Conventionally, when a fluid such as a liquid or a gas flows through a flow path, various valves have been used to adjust the flow rate.

For example, Japanese Patent Application Laid-Open No. 4-208374 discloses a valve having a spiral flow path formed on the inner surface of a pipe, which is used as an alternative to a capillary tube. Valve "is disclosed. In the throttle valve disclosed in this publication, the flow path resistance that determines the flow rate of the fluid flowing in the pipe is fixed to the flow path resistance determined by the shape for a specific flow rate. ing.

[0004] Conventionally, there is a solenoid (electromagnetic valve) as an electric / electronic control type valve. This solenoid valve
A plunger is installed on a valve body (piston), and the plunger is stroked by turning on / off the energization of an electromagnetic coil, so that the valve body is separated from and seated on a valve seat.

For example, in an "electromagnetic valve" disclosed in Japanese Patent Application Laid-Open No. Hei 8-193670, as a means for moving a valve body and a plunger, the attraction force of a solenoid and the elastic force of a spring are used. That is, the solenoid is turned on
To open or close the valve,
When the solenoid is turned off, the spring is pulled back or pushed back to return to the closed state or the open state.

Therefore, the "electromagnetic valve" disclosed in the above publication is used for switching between opening and closing, and is used for a check valve, a two-way valve, a four-way valve, etc., or an operation control of an automobile. It is often used as a valve for devices and the like.

As another valve, for example, Japanese Patent Application Laid-Open No. Hei 7-310844 discloses an "electrically operated valve" in which a stepping motor and a valve body are combined.

[0008] The "motorized valve" disclosed in the above publication is
The position of the valve body is controlled by rotating a plunger having a valve body at the tip by a stepping motor. This makes it possible to finely control the flow path resistance, which is important in controlling the flow rate of the fluid.

In addition to the various valves described above, see, for example,
JP-A-79409 discloses a "control valve" in which a motor-operated valve having the function of a throttle valve and a four-way switching valve are combined. As shown in FIGS. 41 and 42, the "control valve" is provided with a pressure equalizing hole 656 at the center of the valve portion 655, so that when the rotor 605 is rotated to move up and down, a chamber 662 and an opening 620 are formed. The operating resistance generated by the pressure difference between the vicinity and the operating resistance (in the case where the valve body 651 is moved in the movable axis direction using the rotor 605,
Rotational force applied to the rotor 605 in the opposite direction to the rotational force) is eliminated, so that the flow rate of a large flow rate refrigerant can be controlled with a small driving force.

In the above publication, the starting surface (the surface forming the cut end of the cut slit 664) is located in the vicinity of the distal end of the valve body 651 in the direction of the valve axis, that is, in the direction of the movable axis of the valve body 651. An example having a vertically formed slit 664 is also disclosed.

On the other hand, in a conventional refrigeration cycle of an air conditioner or the like, the flow rate adjustment range of the fluid is greatly different between during heating and during defrosting. Switching and responding. For example, in the refrigeration cycle shown in FIG. 34, at the time of heating, a refrigerant as a fluid flows from the indoor heat exchanger 502 of the indoor unit 501 to the outdoor heat exchanger 505 via the expansion valve 504 of the outdoor unit 503.
On the other hand, at the time of defrosting, the compressor 506 of the outdoor unit 503 is not used.
From the output side of the outdoor heat exchanger 50 via the solenoid valve 507
The high-temperature fluid (refrigerant) from the compressor 506 was flown to the outdoor heat exchanger 505 by using the bypass 508 formed toward the fifth heat exchanger 505.

[0012]

Generally, in a refrigerating cycle of a room air conditioner, a car air conditioner, or the like, the flow resistance of the refrigerant is made variable, and moreover, the flow rate is changed as steplessly as possible. It is desired to perform fine flow control, perform fine temperature control during cooling and heating, or perform energy saving operation.

However, in the "throttle valve" disclosed in Japanese Patent Application Laid-Open No. 4-208374, since a pin forming a helical flow path is fixed to the inner surface of the pipe, the flow path resistance has a certain flow rate. In contrast, its shape, that is, the flow path cross-sectional area,
It is fixed at a value determined by the flow path length and the like.

Therefore, in the "throttle valve" disclosed in the above publication, since the flow path resistance is fixed,
Fine flow control is not possible, and as a result, even if this "throttle valve" is used for a refrigeration cycle such as a room air conditioner, fine temperature control during cooling and heating or energy saving operation cannot be performed. Occurs.

The "solenoid valve" disclosed in Japanese Patent Application Laid-Open No. Hei 8-193670 is a solenoid valve of the type that energizes an electromagnetic coil and causes the plunger to stroke to open or close the valve. It is very difficult to stop in the middle of a stroke.

Therefore, in the "electromagnetic valve" disclosed in the above publication, it is difficult to control the opening / closing degree of the electromagnetic valve at the position of the plunger to adjust the flow rate. As a result, fine flow path control is performed. However, even if this "solenoid valve" is used in a refrigeration cycle of a room air conditioner or the like, there arises a problem that fine temperature control during cooling and heating or energy saving operation cannot be performed.

An "electrically operated valve" in which a stepping motor and a valve body disclosed in Japanese Patent Application Laid-Open No. 7-310844 are combined.
Since the position of the plunger can be changed according to the rotational position of the stepping motor, the degree of opening and closing of the valve can be digitally controlled.

[0018] Therefore, in the above-mentioned “electrically operated valve”,
Compared with the solenoid valve disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 8-193670, the position of the plunger can be changed digitally but variable, so that a somewhat finer flow path control is performed and the passing flow rate is reduced. Can be adjusted.

However, it is necessary to seal the high-pressure refrigerant inside the valve, and it is difficult to seal the high-pressure refrigerant simply by attaching a general-purpose stepping motor from the outside.

Therefore, in the above disclosed example, the entire stepping motor is covered with a cylindrical case made of metal or the like, or a cap-shaped case is arranged between the coil and the rotor inside the stepping motor. This is done by sealing.

However, since the stepping motor having a diameter of about 50 mm protrudes in the direction in which the plunger is stroked, there is a problem that the overall size of the "electrically operated valve" becomes large. In particular, in the latter case, there is a problem that the distance between the coil and the rotor becomes longer, and the power consumption for rotating the rotor increases.
Further, the use of such a special stepping motor results in a problem that the stepping motor itself becomes expensive and the cost of the entire valve increases.

In general, the drive circuit for controlling the rotation of the stepping motor itself has a considerably large configuration. Therefore, when the valve portion and the drive circuit portion are considered together, the overall size is further increased. There is a problem that the cost increases.

Japanese Patent Application Laid-Open No. 9-79409 discloses a "control valve" in which a motor-operated valve having the function of a throttle valve and a four-way switching valve are combined, as shown in FIGS. 41 and 42.
By the pressure equalizing hole 656 provided in the center of the valve portion 655,
The opening 620 formed below the valve port 608 and the chamber 6
62 communicates with each other, so that the pressure of the refrigerant becomes equal before and after the pressure equalizing hole 656.

However, the route through which the refrigerant flows is (1) the opening 620 → the valve portion 655 → the opening 618 or the opposite direction (2) the opening 618 → the valve portion 655 → the opening 620. In the vicinity of 656 and the chamber 662, the circulation of the refrigerant stops, and the refrigerant stagnates. For example, in the case of (1), the refrigerant that has stagnated due to lack of circulation is condensed by transferring heat with the surroundings, and in the case of (2),
The temperature of the refrigerant which has been throttled by the valve portion 655 and has become low temperature rises again. For these reasons, the "control valve" has a problem that heat loss occurs in the refrigeration cycle.

Moreover, in this "control valve", the valve portion 655
The distance from the chamber to the chamber 662 is very long, and is assumed to be about 30 to 40 mm in comparison with the size of the stepping motor including the rotor 605 and the stator coil 602. 66
The heat loss in the vicinity of 2 is particularly large.

On the other hand, as shown in FIG.
05 and fixed to the opening 618 by vertical movement.
In the case of the disclosure example in which the slit 664 is formed near the tip of the valve body 651 which is a columnar body that functions as a valve that adjusts the flow rate of the refrigerant in the opening 620, the starting surface of the slit 664 is in the valve axis direction, that is, the valve body 651. Are formed substantially vertically toward the movable axis direction of the valve body 651 when the rotor is moved up and down by the rotor 605. For this reason, the gap between the piston (valve portion 655) and the cylinder (valve port 608) suddenly largely changes, and as shown in FIG.
For a stroke of 51, the flow rate change becomes steep (the gradient of the flow rate characteristic is about 38 to 40 (L / min) / mm),
There is a problem that control becomes difficult.

In the case of an on-off valve that only performs opening and closing, it is preferable that the flow rate change is rather steep. However,
The "control valve" of the above disclosed example cannot be fully closed because the refrigerant always leaks from the clearance between the valve portion 655 and the valve port 608, and cannot be used as an on-off valve. On the other hand, when the “control valve” of the above-described disclosed example is used as a throttle valve, there is a problem that the shape of the slit 664 causes a sharp change in the flow rate as described above, which is inappropriate.

Further, in the conventional valve, the flow control range is limited, so that the bypass 508 is used to switch the flow path of the fluid between heating and defrosting, as in the refrigeration cycle shown in FIG. Since it is necessary to provide a valve (electromagnetic valve 507) for each of them, there is a problem that the configuration of the refrigeration cycle is complicated.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to make the flow path resistance variable, and to make it variable as steplessly as possible. By controlling the flow path, it is possible to perform fine temperature control at the time of cooling and heating, or to perform energy saving operation.Moreover, when used in a refrigeration cycle with a wide flow rate adjustment range, one valve can adjust the flow rate over a wide range. An object of the present invention is to provide a valve that can be covered and can simplify the configuration of a refrigeration cycle, and a control method thereof.

[0030]

According to a first aspect of the present invention, there is provided a valve including a piston and a cylinder into which the piston is inserted, and a flow path provided between the piston and the cylinder. The flow path resistance of the fluid passing through the flow path is adjusted by changing the relative position of the piston and the cylinder.

According to the above configuration, the flow path resistance for a certain flow rate is determined by parameters such as the length of the portion where the piston is inserted into the cylinder, the clearance between the piston diameter and the cylinder diameter, and so on. Can change the flow resistance of the flow path formed between the piston and the cylinder.

Thus, the flow rate of the fluid flowing through the flow path can be changed almost steplessly, so that the flow rate can be finely adjusted. Further, the fluid can be depressurized according to the change in the flow path resistance.

Further, by providing a driving means for driving the piston as in the valve of the second aspect,
Automatic control is possible.

According to a second aspect of the present invention, there is provided a valve having a piston, a cylinder into which the piston is inserted, and driving means for changing a relative position between the piston and the cylinder. It is characterized in that a flow path is provided between the cylinder and the piston, and the relative position between the piston and the cylinder is changed by the driving means, whereby the flow path resistance of the fluid passing through the flow path is adjusted. .

According to the above configuration, the flow path resistance for a certain flow rate is determined by parameters such as the length of the part where the piston is inserted into the cylinder, the clearance between the piston diameter and the cylinder diameter, and so on. Can change the flow resistance of the flow path formed between the piston and the cylinder.

Thus, since the flow rate of the fluid flowing through the flow path can be changed almost steplessly, fine flow rate adjustment can be performed.

In addition, since the driving means for driving the piston is provided, it is possible to easily perform variable drive control between the piston and the cylinder.

According to a third aspect of the present invention, in order to solve the above-described problem, in addition to the configuration of the first or second aspect, the length of a portion where the cylinder is inserted into the piston is made variable. It is characterized in that the flow path resistance of the fluid passing through the flow path is adjusted.

According to the above construction, in addition to the function of the first or second aspect, the flow path resistance for a certain flow rate is determined by the length of the portion where the piston is inserted into the cylinder. By making the length of the portion that is variable, the flow resistance of the flow path formed between the piston and the cylinder can be changed.

According to a fourth aspect of the present invention, in order to solve the above-described problem, in addition to the configuration of the first, second or third aspect, a groove is formed on at least one of the piston surface and the cylinder inner surface. And

According to the above construction, in addition to the function of the first, second or third aspect, the flow path resistance for a certain flow rate is determined by the length, width and depth of the groove in the portion where the piston is inserted into the cylinder. , The number, the clearance, etc., are generally determined, so that the relative position of the piston and the cylinder having the above-mentioned groove can be varied, so that the flow path resistance can be varied according to the groove inserted into the cylinder. It becomes possible.

As a result, the flow rate that can be flowed is greater than when no grooves are formed on either the piston surface or the cylinder inner surface, and the flow rate adjustment range can be expanded or set to a desired range.

In particular, if the groove cross section is formed uniformly, the flow path resistance can be linearly varied with respect to the position of the piston.

According to a fifth aspect of the present invention, there is provided a valve in addition to any one of the first to fourth aspects.
It is characterized in that the piston and the cylinder are formed as a pair.

According to the above construction, in addition to the function of any one of the first to fourth aspects, the piston and the cylinder are formed as a pair, so that the flow between the piston and the cylinder is formed. The tracts are also formed in pairs. Therefore, the fluid that has entered from outside the valve flows separately into the paired flow paths. Since the paired flow paths are formed so that the flow path resistance of the portion where the piston is inserted into the cylinder is the same, the high-pressure fluid flowing from outside the valve passes through each paired flow path. Similarly, it is decompressed and expanded to a low pressure state and flows out to the outlet of the flow channel.

At this time, a pressure difference occurs before and after the flow path, but the pair of flow paths are formed so that the fluid flows out in the positive and negative directions of the relative movement of the piston and the cylinder, respectively. As a result, the differential pressure in the positive and negative directions is eliminated, the force acting on the piston is canceled by the pressure difference, and the force burdening the movement of the piston can be reduced. Can be greatly reduced. Therefore, the energy required for driving the driving means, such as electric power, can be significantly reduced.

According to a sixth aspect of the present invention, in order to solve the above-mentioned problem, in addition to the configuration of the fifth aspect, a groove is formed in at least one of a piston surface and a cylinder inner surface of at least one of a pair of a piston and a cylinder. Is formed.

According to the above construction, in addition to the function of the fifth aspect, of the two sets constituting the pair of flow paths, the grooves are not formed in one set of flow paths, so that the overall flow rate can be substantially reduced. Can be reduced by half. Thus, the flow rate when the flow rate is reduced to the maximum (hereinafter, referred to as the minimum flow rate) can be reduced, and the throttle effect of the throttle valve increases. In addition, although a groove is not formed, a small amount of fluid flows in the clearance between the piston and the cylinder, so that the pressure before and after the piston can be made substantially the same.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problem, in addition to the configuration of the fifth or sixth aspect, one of the piston and the cylinder formed in a pair is formed. It is characterized in that the diameter is different from the diameter of the other pistons and cylinders.

According to the above construction, in addition to the function of the fifth or sixth aspect, the diameter of at least one set of the two sets of pistons and cylinders forming one pair of flow paths is changed to the other set. When the diameter is smaller, the clearance between the piston and the cylinder can be reduced when manufacturing with the same processing accuracy when the diameter is smaller than when the diameter is larger.

As a result, the flow rate at the minimum flow rate can be kept small, and the throttle effect of the throttle valve increases.

In order to solve the above-mentioned problem, the valve according to claim 8 has, in addition to the configuration according to any one of claims 4 to 7,
The groove is formed in a spiral shape with respect to the direction of the movable axis of the piston.

According to the above construction, in addition to the function of any of claims 4 to 7, the groove is formed spirally in the direction of the movable axis of the piston, so that the length of the groove is reduced. On the other hand, the length of the groove forming portion of the piston can be shortened, and the size of the entire valve can be reduced.

According to a ninth aspect of the present invention, in order to solve the above-mentioned problem, in addition to the configuration of the eighth aspect, at least one of the piston surface and the cylinder surface of at least one of the piston and the cylinder formed in pairs. Wherein the spiral grooves formed in the same direction are formed in the same direction.

According to the above configuration, in addition to the function of the eighth aspect, it is possible to prevent the piston formed in a substantially cylindrical shape from rotating due to the force of the fluid passing through the groove.

According to a tenth aspect of the present invention, in order to solve the above-described problems, in addition to the configuration of the fourth aspect, the groove is at least partially different in width and depth. I have.

According to the above configuration, in addition to the functions of the fourth to ninth aspects, since the flow path resistance due to the groove is partially different, depending on the amount of insertion of the piston into the cylinder,
In addition to a change in the flow path resistance, a change in the flow path resistance due to a change in the shape of the groove is added. Therefore, in addition to the effect of any of claims 4 to 9, the flow rate adjustment range can be expanded without changing the dimensions of the entire valve.

This makes it possible to use a single valve in place where two valves having significantly different flow rate adjustment ranges are used. For example, in an air conditioner, the range of flow adjustment is significantly different between heating and defrosting, so separate flow paths are provided, and valves having an appropriate flow adjustment range are used for each. According to the mold valve, the flow rate adjustment range can be widened by one valve, so that the flow paths for heating and defrosting can be integrated in one valve.

Therefore, the refrigeration cycle of the air conditioner can be reduced in size and simplified, so that the number of manufacturing steps can be reduced and the cost can be reduced.

According to an eleventh aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of any of the fourth to ninth aspects, the valve is characterized in that the groove has a uniform cross section.

According to the above construction, in addition to the function of any one of the fourth to ninth aspects, since the cross section of the groove is formed uniformly, the piston is moved in the cylinder to extend the length of the flow path. When adjusting the length, the flow path length with respect to the piston position,
That is, the flow path resistance can be linearly varied.

A twelfth aspect of the invention is characterized in that, in order to solve the above problem, in addition to any one of the fourth to eleventh aspects, the groove is formed in multiple rows.

According to the above arrangement, claims 4 to 11
In addition to the above-mentioned operation, even when a part of the groove is clogged by the contaminants present inside the refrigeration cycle, the fluid can flow through another groove. In addition, depending on the formation form of the groove, the flow path resistance can be set stepwise.

According to a thirteenth aspect of the present invention, in order to solve the above-mentioned problems, in addition to any one of the first to twelfth aspects, the opening at one end of the cylinder is formed smaller than the diameter of the piston. It is characterized by:

According to the above construction, claims 1 to 12
In addition to the above operation, the front end surface of the piston hits the inner surface of the opening portion of the cylinder formed smaller than the diameter of the piston, so that the fluid is sandwiched between the front end surface of the piston and the inner surface of the cylinder opening. Through the small gap, thereby further reducing the minimum flow rate.

According to a fourteenth aspect of the present invention, in order to solve the above-mentioned problem, in addition to any one of the first to twelfth aspects, the piston and the cylinder have tapered ends. And

According to the above arrangement, claims 1 to 12
In addition to any one of the above, the taper surfaces formed at the tip of the piston and the cylinder come into contact with each other,
The fluid passes through a small gap between the tapered surfaces, thereby further reducing the minimum flow rate.

According to a fifteenth aspect of the present invention, in order to solve the above-mentioned problem, in addition to any one of the first to fourteenth aspects, the piston and the cylinder are made of a material having substantially the same linear expansion coefficient. It is characterized by.

According to the above construction, claims 1 to 14
In addition to any of the above operations, a change in the clearance between the piston and the cylinder due to a change in the refrigerant temperature can be suppressed as much as possible, and a valve as a throttle valve that obtains a stable throttle effect even when the refrigerant temperature changes can be obtained. be able to.

According to a sixteenth aspect of the present invention, in order to solve the above-mentioned problem, in addition to the configuration of any of the second to fifteenth aspects, the driving means comprises a magnetic member provided at the upper end of the movable shaft of the piston. Or a plunger made of a magnetic material or formed of a permanent magnet, a solenoid provided on or near the movable axis of the piston for attracting or repelling the plunger, and attracting or repelling the solenoid. It is characterized by comprising an urging means for urging the piston in a direction opposite to the generation force so as to balance the repulsion generation force.

According to the above arrangement, claims 2 to 15
In addition to any of the above operations, the piston can be moved or held by sucking or repelling a plunger provided on the movable axis of the piston with a solenoid.
In addition, when the excitation of the solenoid is stopped, the piston returns to the predetermined position by the urging means.

Therefore, by changing the force generated in the solenoid in accordance with the injection current, the piston is moved in accordance with the balance position of the force determined by the attraction force of the solenoid and the urging force of the urging means. Or can be held at a predetermined position. This eliminates the need to use a special stepping motor having a sealed inside to move the piston, thereby reducing the size of the entire valve.

According to a seventeenth aspect of the present invention, in order to solve the above-mentioned problem, in addition to any one of the second to fifteenth aspects, the driving means is made of a magnetic material or coated with a magnetic material. Or a piston composed of a permanent magnet, provided on or near the movable axis of the piston, a solenoid for attracting or repelling the piston, And an urging means for urging the piston in a direction opposite to the generated force.

According to the above arrangement, claims 2 to 15 are provided.
In addition to any of the above functions, the piston itself also functions as a plunger by forming the piston itself with a magnetic substance or a magnetic material coated or a permanent magnet. This eliminates the need to provide a plunger in addition to the piston as in claim 15, so that the number of parts constituting the valve can be reduced, and the cost of the valve can be reduced. In addition, since the driving portion can be lighter in weight than the configuration in which the plunger is provided on the piston, the energy for driving the piston can be reduced.

In order to solve the above-mentioned problem, the valve of claim 18 is characterized in that, in addition to the constitution of claim 16 or 17, the urging means is arranged inside the solenoid.

According to the above construction, claim 16 or 1
In addition to the operation of 7, the urging means is disposed inside the solenoid, so that an empty space for the movement of the plunger can be effectively used. Thus, the size of the entire valve can be reduced. When a compression spring is used as the biasing means, it is only necessary to insert the spring during assembly,
A means for installing a spring such as a tap, such as a tension spring, is not required, and the number of steps for the mounting operation can be reduced.

According to a nineteenth aspect of the present invention, in order to solve the above-mentioned problem, in addition to the configuration of any one of the sixteenth to eighteenth aspects, a collision buffering means is disposed between a piston or a plunger and the solenoid. It is characterized by having.

According to the above arrangement, the present invention is characterized in that:
In addition to the operation of any one of the above items 8, the collision damping means is disposed between the piston or the plunger and the solenoid, so that the piston or the plunger moves even if the piston moves suddenly beyond the maximum balance point. Collision with the solenoid can be prevented. This can prevent wear of the piston or plunger and the solenoid, and generation of vibration and noise at the time of collision.

According to a twentieth aspect of the present invention, in order to solve the above-described problems, in addition to any one of the sixteenth to eighteenth aspects, a projection is provided on any one of a piston or a plunger and a solenoid. In addition, a guide groove for guiding the protrusion is formed in a part of the solenoid, the piston or the plunger.

According to the above-mentioned structure, claims 16 to 1
8, in addition to the fact that a projection is provided on a part of the solenoid and that the piston or plunger is provided with a guide groove for guiding the projection of the solenoid in the movable axis direction of the piston, or A projection is provided on a part of the piston or the plunger, and a guide groove for guiding the projection in the direction of the movable axis of the piston is provided on the solenoid, whereby rotation of the plunger can be prevented. This prevents the piston from rotating in the cylinder. Therefore,
When the position of the piston is the same, it is possible to prevent the flow path length in the cylinder from slightly changing due to the rotation of the piston, thereby preventing the flow path resistance from fluctuating.

According to a twenty-first aspect of the present invention, in order to solve the above-mentioned problems, the power generated in the solenoid is reduced by varying the injection current to the solenoid of the valve according to the sixteenth to twentieth aspects. The piston is held or moved at a predetermined position in accordance with the balance position determined by the generated force and the urging force of the urging means.

According to the above configuration, the suction force generated in the solenoid is changed by changing the injection current, and the piston is held in accordance with the balance position determined by the suction force and the urging force of the urging means. , By moving
Opening and closing of a valve using a solenoid can be performed steplessly.

According to a twenty-second aspect of the present invention, in order to solve the above-mentioned problem, in addition to the structure of the twenty-first aspect, the injection current is a pulse current, and the amplitude of the pulsed current is made variable. Thus, the position of the piston is controlled.

According to the above construction, in addition to the function of claim 21, the injection current is a pulse current, and the position of the piston is controlled by making the amplitude of the pulsed current variable. The dead zone and the hysteresis are not generated at the time of the movement, and the movement can be performed smoothly, and the stepless control can be performed.

According to a twenty-third aspect of the present invention, in order to solve the above-mentioned problem, in addition to the structure of the twenty-second aspect, the position of the piston is controlled by changing the duty of the pulse of the pulse current. It is characterized by.

According to the above construction, in addition to the function of claim 22, the injection current is a pulse current, and the position of the piston is controlled by varying the duty of the pulse, whereby the attraction force received by the plunger Can be kept uniform, and the generation of extra frictional force between the piston and the cylinder can be prevented.

Further, according to the above configuration, it is possible to inject an average current having the same effect even with a power supply voltage lower than that of claim 22, thereby reducing power consumption.

According to a twenty-fourth aspect of the present invention, in order to solve the above problem, in addition to the structure of the twenty-second aspect, the position of the piston is controlled by changing the frequency of the pulse of the pulse current. It is characterized by.

According to the above construction, in addition to the function of claim 22, the injection current is a pulse current, and the position of the piston is controlled by varying the frequency of the pulse, whereby the plunger receives a suction force. Can be kept uniform, and the generation of extra frictional force between the piston and the cylinder can be prevented.

Further, according to the above configuration, it is possible to inject an average current having the same effect even with a power supply voltage lower than that of claim 22, thereby reducing power consumption.

In order to solve the above-mentioned problem, the valve according to claim 25 has, in addition to the configuration according to claim 5, a pair of flow paths formed by the piston and the cylinder inside the piston. It is characterized in that a communication hole for communication is provided.

According to the above construction, in addition to the function of the fifth aspect, two flows of the refrigerant, which are decompressed and expanded in the respective flow paths forming a pair and brought into a low pressure state, are provided, for example, inside the piston. They can be joined by the communication hole. This eliminates the need to separately provide a merging flow path (a split flow path in the case of input / output reverse) where the refrigerant flowing through the paired flow paths merges again, so that the valve shape can be reduced in size.
Further, since the respective flow paths forming the pair communicate with each other through the communication hole, there is no difference in pressure of the refrigerant before and after the piston, for example, in the movable axis direction. Therefore, the driving force of the piston can be further greatly reduced.

Further, according to the above configuration, since the communication hole can always place the refrigerant in a circulating state, the refrigerant does not condense in the vicinity of the communication hole, and exchanges heat between the stagnant refrigerant and the outside. The effect that no heat loss occurs due to the above is obtained.

According to a twenty-sixth aspect of the present invention, in order to solve the above-mentioned problem, in addition to the structure of the fifth aspect, the pressure in the movable axis direction of the piston is balanced to adjust the flow path resistance. It is characterized by doing.

According to the above construction, in addition to the function of the fifth aspect, there is no pressure difference between the fluids flowing through the pair of flow paths before and after in the direction of the movable axis of the piston, so that the driving force of the piston is reduced. This makes it possible to provide an excellent valve as a throttle valve for adjusting the flow rate of the fluid.

According to a twenty-seventh aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of the tenth aspect, the groove is a groove that gradually changes a gap between the piston and the cylinder or a width of the groove. It is characterized by:

According to the above construction, in addition to the function of the tenth aspect, the gap between the piston and the cylinder or the width of the groove, or both, simultaneously increase gradually, so that the flow rate of the fluid flowing therethrough gradually increases. And the flow rate does not change steeply with respect to the movement amount (stroke) of the piston.

According to a twenty-eighth aspect of the present invention, in order to solve the above-mentioned problems, in addition to the configuration of the twenty-seventh aspect, the groove has a tapered surface that gradually changes a gap between the piston and the cylinder or a width of the groove. Alternatively, it is a groove having a curved surface.

According to the above configuration, in addition to the effect of the configuration according to the twenty-seventh aspect that the flow rate adjustment range is widened, in the groove having the tapered surface, the flow rate change with respect to the amount of movement of the piston becomes linear, and In the groove with
The change in the flow rate is gradual, and a non-linear flow rate characteristic can be obtained. For this reason, the flow rate change with respect to the movement amount of the piston does not change abruptly, so that the flow rate resolution per stroke is improved, and the controllability of the valve can be improved.

[0100]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a valve according to the present embodiment comprises a piston 1 having a pair of grooves 1a and 1b formed on a surface thereof, and a cylinder body 2 into which a groove-shaped portion of the piston 1 is inserted. And a valve housing 3 for covering the piston 1 and the cylinder body 2, and a solenoid 4 as driving means for moving the piston 1 within the cylinder body 2.

The cylinder body 2 is a pair of cylinders 2
a and 2b are integrally formed and attached to the valve housing 3 by caulking or the like. The cylinders 2a and 2b
Are formed integrally because coaxiality during cylinder processing is easily obtained. However, the cylinder 2a
-2b may be provided separately.

The valve housing 3 is provided with at least two inlets and outlets 5 and 6.
6 are connected to pipes 8a and 8b through which fluid flows. Thereby, the inflow / outlet 5.6 and the pipe 8a
8b form first flow paths 7a and 7b through which the fluid to be subjected to flow rate adjustment flows.

The cylinder body 2 comprises a pair of cylinders 2a and 2b corresponding to the grooves 1a and 1b of the piston 1 forming a pair. The grooves 1a and 1b of the piston 1 are inserted into the cylinders 2a and 2b, respectively. The cylinder 2a
The flow path formed by the inner surface of the piston 2b and the grooves 1a and 1b of the piston 1 is a second flow path. The second flow path branches in a direction symmetrical to the first flow paths 7a and 7b. By making the flow resistance in the second flow path variable, the flow rate of the fluid flowing in the first flow path is adjusted.

As described above, the piston 1 and the cylinder 2
Are formed in pairs. Here, being formed as a pair means that the fluid separates and flows into each of the paired portions, and the flow path resistance between the piston 1 and the cylinder 2 in each of the paired portions becomes the same. , The fluid flowing into each of the paired parts is
And the cylinder 2 relative to the positive and negative directions.

In the valve having the above structure, the pipe 8a
From the first flow path 7a near the inflow / outlet 5
Divide in the vicinity, the grooves 1a and 1b of the piston 1 and the cylinder 2
After passing through the second flow path constituted by the inner surfaces a and 2b, it merges again near the first flow path 7b near the inflow / outflow port 6, and flows out to the pipe 8b.

The high-pressure fluid that has flowed in from the outside of the valve is similarly decompressed and expanded in each pair of flow paths, becomes a low-pressure state, and flows out to the flow path outlet.

At this time, a pressure difference occurs before and after the flow path, but the second flow path forming the pair has fluid in symmetric directions of relative movement of the piston and the cylinder, for example, positive and negative directions. So that the positive,
The differential pressure in the negative direction is eliminated, and the force acting on the piston is canceled by the pressure difference, so that the force that is burdensome on the movement of the piston can be reduced, and the driving force of the piston can be greatly reduced. Therefore, there is an effect that energy required for driving the driving means, for example, electric power can be significantly reduced.

In the above valve, the piston 1 is connected to the cylinder 2
The length of the second flow path can be changed by moving it within a.2b. Thereby, the flow resistance in the second flow path can be changed, so that the amount of the fluid flowing through the second flow path can be adjusted. As a result, the fluid flowing through the valve having the above-described configuration can be adjusted. That is, the first flow paths 7a and 7
The flow rate of the fluid flowing between b can be adjusted.

That is, when the fluid flows from the first flow path 7a toward the second flow path, the fluid flowing from the inflow / outflow port 5 often has a high pressure, and the grooves 1a and 1b of the piston 1 and the cylinder 2a 2b, the fluid is decompressed and expanded into a low-pressure fluid due to flow path resistance when passing through the second flow path formed by
It flows out of the valve from the first flow path 7b.

A substantially cylindrical plunger 9 made of a magnetic material is provided on one end surface 12 of the piston 1 in the longitudinal direction. On the other hand, a tension spring 10 as an urging means is provided on the other end surface 13 in the longitudinal direction of the piston 1.

The plunger 9 can be easily moved in and out of the valve housing 3 through a through hole 3a formed in the valve housing 3. Outside the through hole 3a of the valve housing 3, the plunger 9 and the piston 1
Is provided with a solenoid 4 which can be inserted.

The solenoid 4 includes a coil 14, a coil winding bobbin (hereinafter referred to as a bobbin) 15, a core 16 made of a magnetic material, and yokes 17 and 18. The solenoid 4 sucks the plunger 9 made of a magnetic material by a suction force generated according to the injection current.
As a result, the piston 1 is moved toward the solenoid 4 by the solenoid 4.

In order to prevent leakage of fluid in the valve, an O-ring (not shown) for sealing is provided between the yoke 17 and the valve housing 3 in the valve, or welding is performed. A sealing portion 19 is formed. Also, between the bobbin 15 and the yoke 18, and between the core 16 and the yoke 17, a joining portion 20 is formed by caulking or welding so that fluid does not leak to the coil 14 side. 21 are formed.

The other end surface 13 of the piston 1 in the longitudinal direction
Is fixed to the wall surface of the valve housing 3. The tension spring 10 is held in a state where the stopper 11 and the end face 13 of the piston 1 are pressed against each other in a state where the tension spring 10 is slightly stretched to generate tension. The reason why the stopper 11 and the end face 13 of the piston 1 are held in pressure contact with each other in a state where the tension spring 10 is slightly stretched to generate tension is that the injection current of the solenoid 4 is O
When it becomes FF, make sure that the piston 1
It is to return to.

Here, the piston 1 shown in FIG.
This will be described below with reference to (a) to (c) and FIG.

As shown in FIGS. 2A to 2C, the piston 1 has a substantially cylindrical shape, and a pair of grooves 1a.
1b is formed. The grooves 1 a and 1 b are formed spirally in the direction of the movable axis of the piston 1.

The grooves 1a and 1 near the center of the piston 1
The region 22 where b is not formed has a substantially cylindrical shape having a smaller diameter than the portion where the grooves 1a and 1b are formed so as to reduce the weight and not to hinder the fluid.

As shown in FIG. 2 (b),
An installation portion 23 formed of a tap used for arranging the extension spring 10 is formed. This installation part 2
Reference numeral 3 denotes a tap in the present embodiment, but the tap is not limited to this. Further, the installation portion 23 is formed in a carved portion 24 formed substantially at the center of the end face 13 in order to reduce the space.

The piston 1 is provided with grooves 1c and 1d which are wider and deeper than the grooves 1a and 1b.
1b. This groove 1c
1d is formed for flowing a large amount of fluid. For example, in the case of an air conditioner, 1d is used for flowing a large amount of fluid for defrosting.

Further, as the material of the piston 1, a metal excellent in abrasion resistance, pressure resistance and the like, a resin lightweight and excellent in workability are used.

In this embodiment, the total length of the grooves 1a and 1c is 160 mm, and the diameter of the piston 1 is 8 mm or 10 mm. Also, the grooves 1a and 1 of the piston 1
As shown in FIG. 3, the cross-sectional shape of “b” has a rectangular shape, a groove width of 0.4 mm, a depth of 0.4 mm, and a formation pitch of 1 mm.
mm. The depth, width and pitch of the grooves are set according to the flow rate of the target fluid.

Here, the operation of the valve having the above configuration will be described below.

First, before describing the operation of the valve, the relationship between the flow rate Q of the fluid and the pressure drop ΔP will be described.

In general, the relationship between the flow rate Q of a fluid and the pressure drop ΔP is expressed by the following equation (1), assuming that the fluid passes through a cylindrical flow path.

ΔP = 8λ · l / d ⁵ · ρ / π ² · Q ² (1) where l: length of circular pipe, d: diameter of circular pipe, λ: pipe Coefficient of friction, ρ; density of fluid.

From the above equation (1), it can be seen that the pressure drop ΔP increases as the flow path resistance increases. Therefore, it can be seen that by controlling the length 1 and the diameter d of the circular channel, the channel resistance of the circular channel changes, and the pressure drop ΔP, that is, the degree of pressure reduction, can be more finely controlled. At this time,
to r _h = d / hydraulic radius given by 4, a · b / 2
A flow path having a rectangular cross-section with sides a and b having a relationship of / (a + b) = r _h may be a flow path having the same effect as a circular pipe having the above d as an equivalent diameter. it can.

Next, the mechanism of decompression and expansion of the fluid by the valve having the above configuration will be described below with reference to FIGS. 4 (a) to 4 (d).

The pressure drop of the fluid due to the decompression and expansion in the valve having the above structure is obtained in the second flow path formed by the cylinders 2a and 2b and the grooves 1a and 1b of the piston 1.
Note that, in the drawing, arrows indicate fluid, and indicate a state in which the fluid is diverted and flows into a pair of second flow paths, and a solenoid for driving the piston 1, a tension spring,
The valve housing is omitted.

The state of FIG. 4A is a state in which the stopper 11 of FIG. 1 and the piston 1 are held so as to be pressed against each other, as described above. That is, there is no displacement of the piston 1,
The flow path resistance is in the maximum state. At this time, the maximum decompression and expansion can be performed for a certain flow rate. In this case, the position is suitable for a case where it is desired to operate the air conditioner with a reduced cooling / heating capacity such as a minimum capacity (energy saving) operation.

The state shown in FIG. 4B is a state in which the piston 1 is displaced slightly to the right in the drawing (the solenoid 4 in FIG. 1), and among the grooves 1a and 1b, the cylinders 2a and 2a of the cylinder body 2 are displaced.
It is in a state of being decompressed and expanded by the portion (second flow path) inserted into 2b. In this case, this is a region suitable for a case where it is desired to operate with a wide range of cooling / heating capacity such as the rated operation of an air conditioner or the like and before and after the rated operation.

In the state shown in FIG. 4C, the piston 1 is
The state is further displaced to the same side from the state of (b), in which the spiral second flow path portion contributing to the reduced pressure expansion is out of the cylinder, and the pressure drop due to the reduced pressure expansion is the least. State.

The state shown in FIG. 4D shows a case where grooves 1c and 1d designed to have a width and a depth that do not cause a pressure drop other than a negligible pressure loss are used. In this case, such as a defrosting operation in an air conditioner, when a large flow rate is used, the flow rate capacity is used in a region where the flow capacity is significantly different.

In the present invention, the above-mentioned FIGS.
State can be controlled steplessly by varying the injection current,
It is a valve that enables fine flow control required in refrigeration cycles such as room air conditioners and car air conditioners.

Here, the advantages when the valve of the present invention is used in a refrigeration cycle of an air conditioner or the like will be described.

FIG. 5 shows a simplified cycle diagram when the valve of the present invention is used. Generally, a defrosting operation in an air conditioner or the like is required when frost adheres to a heat exchanger of an outdoor unit during a heating operation in winter. In FIG. 5, the flows of the refrigerant during defrosting and during heating are indicated by solid and dotted arrows, respectively.

In the refrigeration cycle shown in FIG.
From the indoor heat exchanger 102 of the indoor unit 101 to the outdoor unit 103
Outdoor heat exchanger 105 via the valve 104 of the present invention.
The refrigerant, which is a fluid, flows through the fluid. On the other hand, even during defrosting,
From the output side of the compressor 106 of the outdoor unit 103, the four-way valve 107, the indoor heat exchanger 102, and the outdoor heat exchanger 105 via the valve 104 are connected to the indoor heat exchanger 102.
High-temperature fluid (refrigerant) is flowing.

Therefore, in the defrosting operation, the position of the piston of the valve is merely moved from FIG. 4 (c) to FIG. 4 (d), and the high-temperature fluid is discharged from the indoor heat exchanger 102 shown in FIG. Since a large amount flows toward the outdoor heat exchanger 105, frost attached to the outdoor heat exchanger 105 can be removed.

As described above, since the valve of the present invention also has a defrosting flow path, the piping of the defrosting bypass 508 can be provided as in the conventional refrigeration cycle shown in FIG. It can be seen that a valve such as an electromagnetic valve 507 for switching defrost, which is required to be installed at 508, is not required, and a part of the cycle can be simplified, and the size and cost can be reduced.

In the valve having the above structure, as shown in FIG. 1, the cylinder body 2 and the valve housing 3 are formed as separate members, and the tension spring 10 and the solenoid 4 are arranged on the opposite side via the piston 1. Although provided, the present invention is not limited to this. For example, a valve having a configuration as shown in FIGS. 6 and 7 may be used.

The valve shown in FIG.
The cylinder body 32 made of 2b is formed integrally with the valve housing 33. In general, as shown in FIG. 1, when the cylinder body 2 and the valve housing 3 are separate members, the cylinder body 2 must be attached to the valve housing 3 with high accuracy. By integrally configuring the cylinder body 32 and the valve housing 33, the process can be omitted. The cylinders 32a and 32b are
It is manufactured by a method such as drilling from the side of the through hole 33a provided in.

The valve shown in FIG. 6 is a valve in which a compression spring 34 is provided inside the solenoid 4 as urging means. That is, since the movable space of the plunger 9 is effectively used, the space for installing the tension spring 10 of the valve shown in FIG. 1 can be omitted, and the overall shape of the valve can be further reduced by the width W. Further, at the time of assembling, it is only necessary to insert the spring into the inside of the solenoid 4, so that there is no need for a spring installation means such as a tap as in the tension spring 10, and it is possible to save man-hours such as hooking the spring.

The suction force of the solenoid 4 and the compression spring 34
The position of the piston 1 is controlled according to the balance position determined by the repulsive force of the piston. This principle is the same as when the extension spring 10 is used as in the valve shown in FIG.

The valve shown in FIG. 7 is, like the valve shown in FIG. 6, a cylinder body 3 composed of cylinders 32a and 32b.
6 is formed integrally with the valve housing 33, and is different from the valve shown in FIG. 6 in that a bobbin for winding the coil 14 of the solenoid 4 has a non-magnetic flange 36a.
This is characterized in that the cap 36 is provided with a cap (hereinafter, referred to as a flanged cap).

By forming the bobbin portion with the cap 36 having a flange made of a non-magnetic material as described above, the sealing performance of the valve can be improved, which is particularly effective in controlling the flow rate of a high-pressure fluid. Fluid leakage to the coil 14 or the like can be prevented. Also, caulking or welding work between the core 16 and the yoke 17 can be omitted.

Such a flanged cap 36 is
Manufactured by deep drawing, side drawing or other deep drawing. Aluminum, stainless steel or the like is used as the material.

Further, the point different from the valve and the like shown in FIG. 6 is that a taper portion 38 is formed at the tip of the plunger 37. The flanged cap 36 has a certain amount of R portion 39 inside in manufacturing. At this time, in a tip shape having an edge like the plunger 9 in FIG.
Depending on the size of the portion 39, when the plunger is completely sucked, the R portion 39 may be stuck. By having the tapered portion 38 at the tip, it is possible to prevent the plunger from getting into the R portion 39. Further, with such a tapered shape, it is possible to reduce the difficulty of movement of the plunger due to the viscous resistance when the viscosity of the fluid is high.

Here, examples of the piston used in the valve of the present invention will be described below with reference to FIGS.

In the following example, the piston 1 shown in FIG.
The width, the depth, the formation pitch, the cross-sectional shape, the number, the form, and the like of the grooves 1a and 1b formed in FIG. Therefore, the same effect can be added even if the shapes of the grooves 1a and 1b of the piston 1 are changed.

In the piston shown in FIG. 8, a simple spiral groove 40 having a constant width, depth, and formation pitch is formed as a pair. The piston length can be made shorter than in the example shown in FIG. 2, and the valve shape can be reduced in size. It is used in a refrigeration cycle or the like in which a flow path for flowing a large amount of fluid is constituted by a separate pipe.

In the piston shown in FIG. 9, the pitch formed in the region 41a near the center of the pair of grooves 41 is coarser than the pitch formed in the regions 41b on both ends. As will be described later, the relationship between the injection current to the solenoid 4 and the displacement of the piston or plunger (the graph of FIG. 20) is not a linear relationship, and the displacement tends to greatly change with a constant current change near the center of the displacement stroke. It is in. Therefore, by roughening the pitch of the flow path portion of the piston corresponding to the area, that is, the area 41a near the center of the groove 41, the flow path resistance can be maintained even if the displacement greatly changes for a constant current change. It is possible to change uniformly. For example, the area 41a near the center is the area 4 on both ends.
The formation pitch is about 2.5 times that of 1b.
The pitch at which the grooves are formed in the region 41a near the center and the regions 41b on both ends is set according to the relationship between the injection current in the solenoid and the displacement of the piston or plunger at that time.

The piston shown in FIG. 10 has a plurality of simple linear grooves 42 formed therein. This is effective in applications where a small pressure drop is required, and a case where a pressure drop similar to that of a spiral flow path can be obtained by reducing the width and depth of the groove. At the end of the flow path, a portion 42 with an increased groove width
a so that the fluid easily flows out and in. The number of pairs of grooves need not necessarily be plural, and may be one in some cases.

The piston shown in FIG.
Are formed at both ends thereof with a channel 43a having a large width and a large depth, and they form a pair. This has the effect of reducing the variation in the ease with which the fluid flows into and out of each groove 43.

The piston 44 shown in FIGS.
Is formed in a substantially quadrangular prism shape, and a substantially spiral pair of grooves 45a and 45b is formed on the surface thereof.
At the end of 45b, grooves 45c and 45d are formed which are wider and deeper than the grooves 45a and 45b, respectively. A relatively large R portion 46 is provided on the ridge of the quadrangular prism in order to reduce the resistance of the piston 44 when it moves. In this case, the shape of the cylinder (not shown) has a substantially rectangular cylindrical shape in accordance with the shape of the piston 44.

As described above, since the piston 44 is a quadrangular prism, it is possible to prevent the piston 44 from rotating in the cylinder. Therefore, even if the piston 44 is kept at the same position, the rotation may slightly change the flow path length inside the cylinder. This can prevent the flow path resistance from fluctuating.

As shown in FIG. 12 (b), the surface 44a of the piston 44 has an installation portion 23 formed on the engraved portion 24 for mounting the tension spring 10. Same as the valve shown in FIG.

FIG. 13 shows a case where the cross section of the groove 47 has a curved shape. Thereby, it is possible to reduce a pressure loss other than a necessary pressure drop due to a fluid passing through a flow path formed by a cylinder (not shown) and the groove 47,
The load on the compressor can be reduced.

The piston 48 shown in FIG. 14 shows a case where there is no constriction near the center. Such a piston 4
8 can be manufactured simply by forming a groove on the surface by using a standardized drawn material or extruded material as it is, so that the manufacturing process can be simplified, the number of steps can be reduced, and the cost can be reduced. Groove 4
9a and 49b can be easily formed by end milling or rolling.

The pistons and cylinders may be changed as necessary.
As wear resistant material on the surface, TiC, TiN, and _{Cr 3 C 2, MoSi 2,} B, A
l, Si, Ti, Zr, V, Nb, Ta, carbides w such as nitrides, an oxide, Au as a low-wear additives, Ag, Pb, MoSi _2, Teflon, even when used in coatings of PbO is there.

FIG. 15 shows an example of a case where the surface of the piston is coated with the above-mentioned wear-resistant material, low-wear material, or the like. FIG.
The film 51a is formed on the surface of the piston 1 by sputtering, ion plating, CVD, plating, or the like.

Further, the above-mentioned sputtering is performed on the piston 1
Is performed while rotating about the axis to cover the entire curved surface.
Therefore, not only the frictional force between the piston 1 and the piston 1 when the piston 1 moves due to the unique properties of the wear-resistant material, the low-wear material, etc., but also the coating portion 51b formed on the shoulder of the groove 1a, 1b cross-section By having a rounded shape, there is an effect that, due to its shape effect, it is not rubbed and damaged when moving. Further, the slidability of the piston can be further improved.

The groove provided in the piston is not necessarily provided on the piston surface, but may be provided on the inner surface of the cylinder, for example.

Here, the driving means of each of the above-described valves will be described below with reference to FIGS. 1, 4 and 16.

First, the displacement of the piston 1 will be described with reference to the graph of FIG. However, in the graph of FIG. 16, the displacement X of the plunger 9 of the piston 1 is plotted on the horizontal axis, the suction force of the solenoid is Fsol, and the tension of the spring is Fk, on the vertical axis. Hereinafter, regarding the displacement X, the position where the piston 1 is pressed against the stopper 11, that is, the position where the plunger 9 is farthest from the core 16 is the displacement 0, and the position where the plunger 9 is attracted to the core 16 is the right position shown in FIG. It is a dotted line.

Fsol shows a hyperbolic characteristic with respect to the displacement X. For example, Fsol has characteristics such as curves 51, 52 and 53 according to the injection currents I1, I2 and I3. Fk is a linear straight line with respect to the displacement. Therefore, when a spring having a characteristic represented by a straight line 54 is used for a solenoid having the above characteristics, the intersections are the contacts 51a, 52a, and 53a, and the intersections are the positions of the X coordinates 51b, 52b, and 53b of the contacts. Thus, Fsol and Fk are balanced. Therefore, if the injection current is varied, the position of the balance changes accordingly,
The position of the piston 1 can be controlled.

The piston 1 shown in FIGS. 4 (a) to 4 (d)
Is executed by controlling the balance position within the range of 0 ≦ X ≦ coordinate position 53b. X = coordinate position 53
b is the maximum balancing position. At this time, X> coordinate position 53
At b, Fsol becomes much larger than the tension Fk of the spring, and the plunger 9 is rapidly attracted to the core 16.

The range of the X> coordinate position 53b is shown in FIG.
In other words, it is a region where there is no balance position and cannot be controlled due to current variation. Therefore, the range in which the position can be controlled by varying the current is 0 ≦ X ≦ coordinate position 5
3b is the piston movement shown in FIGS.
It is assigned to a movement range where the flow path resistance is desired to be changed steplessly, and it is not necessary to change steplessly for the movement from (c) to (d) in FIG. X> The range of the coordinate position 53b is shown in FIG.
Assign to piston movement to (d). Thereby,
Since the plunger 9 is rapidly attracted to the core 16, the movement from (c) to (d) in FIG. 4 can be achieved immediately. Further, by returning the injection current value to I3 or less, the injection current value is pulled back by the tension spring 10, and control at 0 ≦ X ≦ coordinate position 53b can be performed. Thus, the portion of X> coordinate position 53b does not become a useless space, and the valve can be miniaturized.

Next, another control method will be described with reference to FIG. 1 and FIGS.

In the graph of FIG. 17, white circles indicate the movement of the piston in the positive direction, and black circles indicate the movement in the negative direction. The dashed line exceeds the stated maximum equilibrium position and indicates that the piston is rapidly attracted to the core.

When the frictional force between the piston 1 and the cylinders 2a and 2b is large, or when the fluid has a large viscosity and the resistance to the movement of the piston 1 is large, the characteristic of the injection current versus the displacement is May have hysteresis in the positive and negative directions of movement.

In such a case, even if the injection current increases or decreases, a phenomenon in which the piston 1 stops at a specific position and jumps when moving is likely to occur. That is, there is a dead zone against the increase in the injection current, and the movement of the piston 1 is discrete. this is,
It is considered to occur for the following reasons. When the piston moves in the positive direction (toward the solenoid 4 in FIG. 1), Fso1 needs to act on more than the sum of Fk and the resistance f1 acting in the negative direction, that is, the frictional force or the resistance due to viscosity. That is, it is represented by the following equation.

| Fk | + | f1 | ≦ | Fso1 | When the piston 1 moves in the negative direction, Fso1
May be equal to or less than the difference between Fk and the resistance f2 acting in the positive direction, that is, the resistance due to friction or viscosity. That is, it is represented by the following equation.

| Fk | − | f2 | ≧ | Fso1 | That is, in order for the piston 1 to make a positive displacement, a suction force greater than the tension of the spring is required at a certain displacement, and the piston 1 makes a negative displacement. In order to achieve this, it is necessary that the suction force be smaller than the tension of the spring at a certain displacement.

Next, pulse driving in the solenoid will be described. When the solenoid 4 is pulse-driven at a frequency higher than the mechanical time constant of the mechanical system in the valve shown in FIG. 1, the time during which Fso1 is acting, Fk
The time during which is acting alone appears alternately according to the frequency. The electric time constant is extremely smaller than the mechanical time constant and can be ignored.

During the time when Fso1 is acting, f1 is negative, and when the time when Fk is acting alone, f2 is f2.
Acts in the positive direction. At this time, since the frequency of the pulse is much faster than the mechanical time constant, that is, Fso1 and Fk and f1 and f2 are alternated much faster than the mechanical time constant, from the viewpoint of the response performance of the mechanical system, When the movement starts, it is considered that the left and right resistances f1 and f2 are generated at the same time, and the phenomenon of offset is occurring.

Therefore, a state in which there is virtually no resistance is exhibited. This eliminates hysteresis and dead zone in piston movement, smooth piston movement, and enables stepless control, regardless of friction conditions between the piston and cylinder, resistance due to fluid viscosity, etc. Becomes

FIG. 18 shows an example of a simplified pulse drive circuit. The basis is a constant current circuit, which mainly monitors a current amount as a potential and feeds back a feedback portion 60 and an amplifying portion 6.
1, monitor resistor 62, output resistor 6 of feedback section 60
3 and a solenoid 64. A diode 65a, a capacitor 65b, and the like for preventing a decrease in injection current due to a back electromotive force when the solenoid 64 is turned on,
It may be installed alone or in parallel with the solenoid 64.

When the control pulse signal 66 is inputted, a pulse current amplified in synchronization with the frequency is supplied to the solenoid 64.
Is injected into. The injection current can be varied by varying the amplitude of the control pulse signal 66. The injection current can be monitored at the potential at point A, and its waveform is indicated generally by 67.

In the case of pulse control, Fso1 is turned ON / OFF in accordance with the frequency, and Fk operates irrespective of time.
_AVE. And Fk are determined by a displacement that balances. FIG.
Indicates a control signal and a drive current waveform, and the drive current changes according to the amplitude of the control pulse signal, whereby the attraction force of the solenoid can be changed.

FIG. 20 is a graph showing characteristic data of displacement versus injection current due to pulse driving. Hysteresis and dead zone are eliminated, and the curve 70 of the graph overlaps in the positive and negative directions. Here, the piston can be controlled steplessly by changing the pulse current amplitude steplessly under the condition of a frequency of 250 Hz and a duty of 50%. Note that the frequency also takes into account the inductance of the solenoid, and
A band of several hundred Hz can be used.

Further, another method relating to the pulse control will be described below with reference to FIG.

The duty variable control for varying the injection current by varying the duty of the control pulse signal is shown in FIG. 21A, and the frequency variable control for varying the injection current by varying the frequency of the control pulse signal. Is shown in FIG.

In the variable duty control, the average current can be varied while keeping the pulse amplitude constant, so that the power supply voltage + Vcc can be set lower than in the variable amplitude control method, the drive circuit can be simplified, and the cost can be reduced. Is also cheaper.
By changing the duty steplessly to about 30 to 90% under the condition of a frequency of 250 Hz and a fixed current amplitude,
The piston can be controlled steplessly.

As shown in FIG. 18, the current flowing through the solenoid is determined by the time constant determined by the inductance L of the solenoid, the internal resistance rL, the monitor resistance 62, the internal resistance of the amplifier 61 (in this case, a transistor), etc. The waveform 67 has a blunt rising shape. Assuming that the drive circuit does not include the diode 65a and the capacitor 65b and the internal resistance of the amplifying unit 61 can be ignored, the drive current waveform I of the solenoid is expressed by the following equation (2) as a function of time t. Is done.

I = E / R · (1−exp (−R / L · t)) (2) where R is generally the internal resistance rL of the solenoid, and E
Is + Vcc.

In addition, the induced current in the reverse direction flowing by the back electromotive force generated in the solenoid promotes dulling of the waveform. The reason why the falling waveform is not dull depends on the polarity of the amplifier 61 (transistor). It is considered that the actual injection current waveform of the solenoid is dull even at the fall.

For the reasons described above, by utilizing the characteristic that the waveform of the current flowing through the solenoid is dull,
By varying the frequency, the time average value of the suction force can be changed. That is, if the frequency is varied in a frequency band having a period shorter than the time constant determined by the above equation (2), the peak of the pulse current can be varied as shown in FIG. In this description, the electric time constant of the solenoid (63.2% of the peak) is about 1.7 ms.
ec, the frequency is changed from 1.6 kHz to 200 k under the condition that the duty is 50% and the current amplitude is fixed.
By continuously changing the frequency in the range of about Hz, the piston 1
Can be controlled steplessly.

The above-described variable amplitude control, variable duty control, and variable frequency control may be performed alone or in combination of two or more as appropriate. In addition, since the resistances f1 and f2 are canceled by the pulse current control, and the state is such that there is no resistance at the time of starting the movement, the current value (time average value) required for driving the piston is DC. It is reduced compared to driving.

Further, since the waveform of the pulse current is a pulse such as a triangular wave, a sawtooth wave, a sine wave or the like whose rising is not steep, generation of a back electromotive force generated in the solenoid can be almost eliminated. Except for the determined and unavoidable blunting of the waveform, it can be prevented as much as possible, and the current consumption can be reduced.

In particular, when a sine wave is used, a sine wave current can be generated directly and easily from a commercial power supply (AC power supply) in accordance with the above-described effects, so that the drive circuit is simplified, and There is an advantage that the size can be reduced.

[Embodiment 2] Next, another embodiment of the present invention will be described below with reference to FIG. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
In the present embodiment, differences from the first embodiment will be mainly described.

In the present embodiment, the plunger 9 and the core 16
This embodiment is different from the first embodiment in that a compression spring 80 as a collision buffer is provided between the first and second embodiments. In the present embodiment, the compression spring 80 is mounted on the core 16. The compression spring 80 is preferably made of a non-magnetic material so as not to adversely affect the suction force and the stroke characteristics of the plunger 9. The compression spring 80 is configured such that the position of the distal end portion 81 due to its natural length in the installed state is the same as the distal end position of the plunger 9 in FIG. . That is, FIG.
The compression spring 80 at the portion exceeding the maximum balancing position 53b of FIG.
Works.

In the present embodiment, the compression spring 80 serving as the collision buffer may be attached to the tip of the plunger 9. According to the method described above, even if the piston suddenly moves beyond the maximum balancing position 53b shown in FIG. 16, it is possible to prevent the plunger 9 from colliding with the core 16. Thereby, the plunger 9 and the core 1
6 and the occurrence of vibration and noise at the time of collision can be prevented.

[Embodiment 3] Next, another embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, differences from Embodiments 1 and 2 will be mainly described.

In this embodiment, the plunger 9 and the core 1
6 is a composite spring 85 composed of a plurality of compression springs 82, 83, 84 having different lengths.
This embodiment is different from the first and second embodiments in that
Due to this composite spring 85, the relationship between the tension and the displacement is shown in FIG.
The result is shown by a polygonal line 86 in the graph shown in FIG.

By using the composite spring 85, compared with the coordinate position 53b when the maximum balance position is a single spring,
It will be extended to the coordinate position 53c. As a result, the suction force changes abruptly, and the area that is difficult to use can be effectively used, and the control range can be expanded. Therefore, the size of the valve can be reduced. This composite spring 85 may be mounted on the plunger 9. Further, it may be used in combination with the tension spring 10 used in FIG.

[Embodiment 4] Next, another embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals, and description thereof will be omitted.

FIGS. 25A and 25B are sectional views of the solenoid as viewed from the core 16 side. As shown in FIG. 25 (a), in the present embodiment, a guide projection 91 is provided on a bobbin 90 of a solenoid, and a plunger 93 having a guide groove 92 for guiding the projection 91 is provided. .

Thus, rotation of the plunger 93 can be prevented, and rotation of the piston in the cylinder can be prevented. Therefore, even if the position of the piston is the same, it is possible to prevent the flow path length inside the cylinder from slightly changing due to the rotation, thereby preventing the flow path resistance from fluctuating.

The guide projections 91 and the guide grooves 92
Is the center axis 93 of the plunger 93 as shown in FIG.
There may be a case where a plurality of sensors are provided symmetrically with respect to b. Thereby, the suction force acting on the plunger becomes substantially symmetrical with the movement axis of the piston, and it is possible to prevent the generation of an extra frictional force between the piston and the cylinder.

[Fifth Embodiment] Next, another embodiment of the present invention will be described below with reference to FIGS. In the present embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, the first to fourth embodiments are mainly described.
The difference from the above will be described.

In this embodiment, the plunger 9 and the core 16 are replaced by a conical plunger 94 and a core 95 as shown in FIG. It is different from 1.

Since the tips of the plunger 94 and the core 95 are conical, the curve of the suction force gradually increases as shown in the graph of FIG. 28, and the maximum balancing position 98 'extends to the balancing position 98. Thus, the control range can be expanded.

The plunger 96 shown in FIG. 27 (a) having a cylindrical shape at the tip but a reduced rear portion is shown in FIG.
A shape like the plunger 97 shown in FIG. 7B has the same effect.

In the valve of the present invention, a flow path is provided between the piston and the cylinder, and the effective length of the flow path (the length of the portion corresponding to the flow path) is changed to reduce the pressure and adjust the flow rate. The size of the valve itself is about 3
８8 mm, which is slightly larger. However, since the variation in machining finish hardly affects the length, width, depth, and clearance of the groove formed on the piston surface, there is almost no variation in the flow rate adjustment capability with respect to the movement (position) of the piston. Has advantages.

Although the size of the valve portion itself is slightly larger, about 3 to 8 mm, it is about 30% smaller than that of a conventional needle valve.

In the valve of the present invention, when the directions of the inflow and outflow of the fluid are reversed, for example, in the valve shown in FIG. 1, the fluid flows from the inflow / outflow port 6 of the valve housing 3 toward the inflow / outflow port 5. Even when flowing, it is possible to reliably balance the high-pressure fluid.

Therefore, it is suitable for use in a refrigeration cycle in which the upstream pressure is as high as 30 to 45 kg / cm ² , such as a refrigeration cycle of an air conditioner, in which fluid flows reversely during cooling and during heating. Can be

The valve of the present invention can be used not only for air conditioners but also for refrigeration cycles in refrigerators. Further, it is suitably used as a valve used for adjusting the flow rate of oil such as an oil fan heater.

As described above, according to the valve and the control method thereof of the present invention, the following effects can be obtained in addition to the effects described above.

That is, since the cross-sectional shape of the piston is substantially cylindrical, the resistance force when the piston moves in the cylinder is reduced, and the energy required for driving the piston can be reduced.

Also, by making the direction of formation of the pair of grooves formed in the piston the same, the substantially cylindrical piston is rotated by the force of the fluid flowing through the flow path formed by the groove and the inner surface of the cylinder. Can be prevented.

Also, by making the cross-sectional shape of the pair of grooves formed in the piston the same, the flow path resistance of the flow path formed by the groove and the inner surface of the cylinder can be made the same. The pressure drop of the fluid as it passes can be the same. As a result, there is no pressure difference in the positive and negative directions of the movement of the piston, so that a force that bears on the movement of the piston can be eliminated, and the driving force of the piston can be greatly reduced. Therefore, the energy required for driving the driving means, for example, electric power, can be significantly reduced, and the running cost can be reduced.

Further, by making the pitch of the pair of flow paths formed in the piston the same, the flow path resistance of the flow path formed by the pair of grooves and the inner surface of the cylinder with respect to the position of the piston is reduced. It can be the same and the pressure drop of the fluid as it passes through the flow path can be the same. As a result, there is no pressure difference in the positive and negative directions of the movement of the piston, so that a force that bears on the movement of the piston can be eliminated, and the driving force of the piston can be greatly reduced. Therefore, the energy required for driving the driving means, for example, electric power, can be significantly reduced, and the running cost can be reduced.

Further, since the cross section of the groove formed in the piston has a substantially curved shape, it is possible to reduce the pressure loss of the fluid other than the necessary pressure effect due to the passage of the flow passage, thereby reducing the load on the compressor. As a result, power consumption can be reduced and adverse effects on the life of the compressor can be reduced.

Further, by removing a part of the part of the groove of the piston where the flow path is not formed, the mass of the piston can be reduced, and the energy required for driving the piston can be reduced.

Further, by forming the plunger with a permanent magnet, the attraction force of the solenoid can be reduced, and the injection current can be reduced. That is, the energy required for driving can be reduced. On the return path, the direction of the magnetic field may be reversed by switching the direction of the current of the solenoid.

Further, by adopting a configuration in which the piston is coated with a magnetic material, the material of the piston itself does not necessarily need to be a magnetic material, and the range of material selection can be expanded.

Further, by forming the piston and the cylinder with materials having substantially equal linear expansion coefficients, it is possible to suppress a change in clearance due to a temperature change in the piston and the cylinder.

Further, since the waveform of the pulse current which is the injection current for driving the solenoid is a triangular wave or a sawtooth wave, the generation of the back electromotive force generated when the solenoid is turned on can be almost eliminated, and the solenoid is driven. The current can be prevented as much as possible except for the inevitable dulling of the waveform determined by the inductance and the resistance, and the current consumption can be reduced.

Further, since the waveform of the pulse current is a sine wave, not only the same effect as when the waveform of the pulse current is a triangular wave or a sawtooth wave can be obtained, but also the sine wave Since it can be generated directly and easily from a power supply (AC power supply), the drive circuit is simplified, and thereby the size can be reduced.

Further, by installing a capacitor in parallel with the solenoid, it is possible to substantially eliminate the generation of a back electromotive force that occurs when the solenoid is turned on. It is possible to prevent as much as possible other than such a dull waveform, so that the current consumption can be reduced.

Further, by installing a diode in parallel with the solenoid, the generation of back electromotive force generated when the solenoid is turned on can be almost eliminated. It is possible to prevent as much as possible other than such a dull waveform, so that the current consumption can be reduced. In addition, since the diode has a smaller shape than the capacitor, the drive circuit can be downsized.

[Embodiment 6] The following will describe still another embodiment of the present invention with reference to FIG.

As shown in FIG. 29, the valve according to the present embodiment comprises a piston 201, a cylinder 202 into which the piston 201 is inserted, and a driving device for moving the piston 201 in the cylinder 202. (Drive means) 204.

The cylinder 202 is provided with inflow / outflow ports 202a and 202b through which fluid flows in / out. Therefore, the cylinder 202 and the inflow / outflow ports 202a and 20a
2b together with the valve housing 203.

The piston 201 and the cylinder 20
A flow path 201a is formed between the two. That is,
In the valve, for example, the inflow / outflow port 20 of the cylinder 202 is used.
The fluid that has flowed in from 2a passes through the flow path 201a and flows out from the other inflow / outflow port 202b.

A shaft 205 is provided on one end surface of the piston 201 in the direction of the movable axis of the piston 201. This shaft 205 is a shaft 2 projecting from the driving device 204 in the direction of the movable axis of the piston 201.
06.

The driving device 204 is composed of, for example, a motor, and transmits the driving force of the motor to the shaft 205 provided on the piston 201 via the shaft 206. Specifically, by making a contact portion of the shaft 205 with the shaft 206 a screw forming portion 207, the rotational movement of the driving device 204 is controlled by the shaft 206.
Through the screw forming part 207 through the shaft 20
5 is moved in the direction of the movable axis of the piston 201, and the piston 201 is moved inside the cylinder 202.

The cylinder 202 is provided with the inflow / outlet 20
2a and a piston insertion portion, a chamber 212 is formed, and this chamber 212
The bearing member 213 is separated from the drive device 204 side, and furthermore, in the axial direction, the sealing member 21 is provided so as to cover the shaft.
4 are installed.

A sleeve 215 is provided between the seal member 214 and the driving device 204, and the shafts 205 and 206 are communicated with each other so that the above-described screw forming portion 207 comes inside the sleeve 215. .

The seal member 214 is pressed against the shaft 205 and the sleeve 215 by the internal pressure of the fluid.
Prevents fluid from leaking to the side.

The seal member 214 has a pressure resistance,
It is made of rubber, resin or the like which has excellent properties such as chemical resistance and little deterioration due to temperature change.

Further, the sleeve 215 and the valve housing 203
Is sealed with an O-ring 216 or the like.

Here, the operation of the valve having the above configuration will be described. The drive 201 causes the piston 201
Is moved in the direction of the movable axis, and the piston 201 is moved to the cylinder 2
02 has a variable length. Thereby, the flow path resistance of the flow path 201a changes.

As described above, by changing the flow path resistance of the flow path 201a, the flow rate of the fluid flowing through the flow path 201a can be adjusted.
-The flow rate of the fluid flowing between 202b can be adjusted.

In the valve having the above structure, the fluid inflow / outflow port 2
Fluid flowing from 02a is decompressed in the flow path 201a,
Outflow to the inflow / outflow port 202b. The flow path resistance at this time is
As shown in FIG. 29, when the piston 201 is completely buried in the cylinder 202,
01 is gradually reduced as it moves toward the driving device 204 side.

As a result, the flow path resistance can be varied steplessly only by moving the piston 201 relative to the cylinder 202, so that a linear flow rate adjustment can be performed.

If the driving device 204 is stopped while the piston 201 is in the middle of the stroke, the piston 201 is held at that position, so that a constant flow rate operation becomes possible.

In addition, since the driving device 204 is composed of a motor or the like, if the driving control of the motor is controlled by an electronic circuit or the like, the flow rate adjustment of the valve having the above configuration can be automatically controlled.

[Seventh Embodiment] The following will describe still another embodiment of the present invention with reference to FIG. Note that, in the present embodiment, a case where the diameter of one set of pistons and cylinders is smaller than the diameter of another set of two sets of pistons and cylinders forming a pair of valves described in the first embodiment. explain.
That is, in the present embodiment, portions different from the first embodiment will be described.

As shown in FIG. 30, the piston 221 of the valve according to the present embodiment has a flow path 22 including a spiral groove.
The first piston portion 221a formed with 0 and the second piston portion 221b having no groove and having a smaller diameter than the first piston portion 221a are integrally formed.

The first piston 221a is inserted into the cylinder 222a of the cylinder 222, and the second piston 221b is inserted into the cylinder 222b of the cylinder 222.

That is, the diameter of the insertion portion of the cylinder 222b into which the second piston portion 221b is inserted is formed smaller than the diameter of the insertion portion of the cylinder 222a into which the first piston portion 221a is inserted.

The cylinder body 222 is formed integrally with the valve housing 223, similarly to the valve shown in FIG. 6 of the first embodiment. The piston 221 is inserted from the opening 223 a of the valve housing 223 on the solenoid 4 side, and is stopped by the stopper 11.

Therefore, in the valve having the above-described structure, the plunger 9 is sucked by the suction force generated by the solenoid 4, similarly to the valve of FIG. The portion 221a moves to the solenoid 4 side from the state shown in FIG. This allows
The flow rate is adjusted by utilizing the fact that the flow path resistance in the flow path 220 formed by the surface of the first piston portion 221a and the cylinder 222a changes.

At this time, the point that no groove is formed in the second piston portion 221b and the second piston portion 221b
Also, in the case of manufacturing with the same machining accuracy because the diameter of the insertion portion of the cylinder 222b is small, the clearance between the piston and the cylinder can be reduced.

As described above, at the minimum flow rate, that is, when the flow rate is reduced to the maximum, the flow rate can be suppressed to a small value.
The throttle effect of the valve as the throttle valve increases.

[Eighth Embodiment] The following will describe still another embodiment of the present invention with reference to FIGS. 31 and 32. In this embodiment, the basic structure is the same as that of the valve described in the sixth embodiment.
The flow path constituted by the piston and the cylinder is different.

The valve according to the present embodiment differs from the valve shown in FIG. 29 of the sixth embodiment in that a spiral groove 230 is formed in the piston 201 as shown in FIG. It is. That is, in the portion where the piston 201 is inserted into the cylinder 202, in the valve shown in FIG. 29, a flow path is formed between the piston 201 and the inner surface of the cylinder 202, but in the valve of the present embodiment, A flow path is formed by the groove 230 and the inner surface of the cylinder 202.

Here, the operation of the valve having the above configuration will be described. The drive 201 causes the piston 201
Is moved in the direction of the movable axis, so that the piston 20
The length of the portion where 1 is inserted into the cylinder 202 is variable. Thereby, the flow path resistance of the flow path formed by the groove 230 and the inner surface of the cylinder 202 changes.

As described above, by changing the flow path resistance of the flow path, the flow rate of the fluid flowing through the flow path can be adjusted.
As a result, the flow rate of the fluid flowing between the inflow / outflow ports 202a and 202b of the valve can be adjusted.

In the valve having the above structure, the fluid inflow / outflow port 2
02a flows from the groove 230 and the cylinder 202
The pressure is reduced in the flow path formed by the inner surface and the inflow / outflow port 202 b
Leaks to At this time, the flow path resistance is largest when the piston 201 is completely buried in the cylinder 202 as shown in FIG.
It is configured to gradually decrease as it moves to the 04 side.

Thus, the flow resistance of the flow path formed by the groove 230 and the inner surface of the cylinder 202 can be varied steplessly only by moving the piston 201 relative to the cylinder 202. Linear flow adjustment can be performed.

Further, since the groove 230 is spirally formed on the surface of the piston 201, when the same flow path length is to be obtained, it can be smaller than a valve having no groove as shown in FIG. Therefore, the size of the entire valve can be reduced.

Further, the driving device 204 for the cylinder 202
The diameter of the opening 202c at the opposite end to the piston 2
It is formed so as to be smaller than the diameter of 01.

As a result, the end surface 201b of the piston 201, that is, the end surface opposite to the end surface on which the shaft 205 is disposed, comes into contact with the inner surface of the opening 202c of the cylinder 202. Therefore, the fluid passes through the gap between the distal end surface 201b of the piston 201 and the inner surface of the opening 202c of the cylinder 202. As a result, the minimum flow rate can be further reduced.

In order to further reduce the minimum flow rate of the valve, as shown in FIG.
02c and the piston 20 abutting on the opening 202c.
A valve in which the one end portion 201d is formed in a tapered shape is conceivable.

According to the valve having the above structure, the tip 201d of the piston 201 and the opening 2
The tapered surfaces 02c are in contact with each other, and the fluid passes through the gap between the tapered surfaces, whereby the minimum flow rate can be further reduced.

[Embodiment 9] The following will describe still another embodiment of the present invention with reference to FIG.

As shown in FIG. 33, the valve according to the present embodiment comprises two pairs of a piston 251 and a cylinder 252, and a pair of the piston 251 and the cylinder 252.
And a driving device (driving means) 204 for moving the object inside.

The cylinder 252 is provided with inflow / outflow ports 252a and 252b through which fluid flows in / out. Therefore, the cylinder 252 and the inflow / outflow ports 252a / 25
2b together with the valve housing 253.

A spiral groove (hereinafter, referred to as a spiral groove) 251a is formed on each surface of the piston 251.
251b is formed, and a flow path is formed by the spiral grooves 251a and 251b on the surface of the piston 251 and the inner surface of the cylinder 252.

That is, in the valve, for example, the cylinder 2
The fluid that has flowed in from the inflow / outflow port 252a passes through the spiral groove 251a and flows out from the other inflow / outflow port 252b.

A shaft 255 is provided on one end surface of the piston 251 in the direction of the movable axis of the piston 251. The shaft 255 protrudes from the driving device 204 in the direction of the movable axis of the piston 251.
It is linked to 56.

The piston 251 by the driving device 204
Is the same as that of the sixth embodiment.

That is, the driving device 204 is composed of, for example, a motor, and transmits the driving force of this motor to the shaft 255 provided on the piston 251 via the shaft 256. Specifically, by making the contact portion of the shaft 255 with the shaft 256 a screw forming portion 257, the rotational movement of the driving device 204 is controlled by the shaft 25.
6 and converted by the screw forming portion 257 to form the shaft 2
55 is moved in the direction of the movable axis of the piston 251, and the piston 251 is moved inside the cylinder 252.

The cylinder 252 has an inflow / outflow port 25
A chamber 262 is formed between 2a and the piston insertion portion.

The driving device 20 for the shaft 255
A bearing part 263 for receiving the shaft 255 is provided on the fourth side.
Further, a seal member 264 is provided in the axial direction so as to cover the shaft 255.

[0270] A sleeve 215 is provided between the seal member 264 and the driving device 204, and the shafts 255 and 256 communicate with each other so that the above-mentioned screw forming portion 257 comes inside the sleeve 215. .

The seal member 264 is pressed against the shaft 255 and the sleeve 215 by the internal pressure of the fluid.
Prevents fluid from leaking to the side.

Further, the sealing member 264 has pressure resistance,
It is made of rubber, resin or the like which has excellent properties such as chemical resistance and little deterioration due to temperature change.

The sleeve 215 and the valve housing 253
Is sealed by an O-ring 266 or the like.

Here, the operation of the valve having the above configuration will be described. The driving device 204 allows the piston 251 to be driven.
Is moved in the direction of the movable axis, and the piston 251 is moved to the cylinder 2
The length of the part inserted in 52 is changed. As a result, the flow path resistance of the flow path formed by the spiral grooves 251 a and 251 b and the inner surface of the cylinder 252 changes.

As described above, by changing the flow resistance of the flow path, the flow rate of the fluid flowing through the flow path can be adjusted.
As a result, the flow rate of the fluid flowing between the inflow / outflow ports 252a and 252b of the valve can be adjusted.

In the valve having the above structure, the fluid inflow / outflow port 2
The fluid that has flowed in from 52a is decompressed by the spiral groove 251a and flows out to the inflow / outflow port 252b. At this time, as shown in FIG. 33, the flow path resistance is largest when the piston 251 is completely buried in the cylinder 252, and gradually decreases as the piston 251 moves toward the driving device 204. It is configured.

Thus, by merely moving the piston 251 relative to the cylinder 252, the flow path resistance can be varied steplessly, so that a linear flow rate adjustment can be performed.

If the driving device 204 is stopped in a state where the piston 251 is in the middle of the stroke, the piston 251 is held at that position, so that a constant flow rate operation becomes possible.

Further, since the driving device 204 is composed of a motor or the like, if the driving control of this motor is controlled by an electronic circuit or the like, the flow rate adjustment of the valve having the above configuration can be automatically controlled.

Further, when the valve having the above configuration is used in a refrigeration cycle of an air conditioner or the like, the flow resistance of the flow path formed by the spiral grooves 251a and 251b and the inner surface of the cylinder 252 changes, so that the passing refrigerant is reduced in pressure. Has an effect.

Further, as described in Embodiment 1,
Since the pressure is offset in the positive and negative directions of the movement of the piston 251, the force required to drive the piston 251 can be reduced.

Thus, the driving device 204 having a small driving force (eg, torque) can be used.

[Embodiment 10] Still another embodiment of the present invention will be described with reference to FIGS.
It is as follows. In the present embodiment, the same components as those in the first to ninth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 35, the piston 301 of the valve according to the present embodiment has a pair of grooves 30 formed on the surface thereof.
1a / 301b, cylinder body 302, cylinder 302a
-302b, solenoid 304, plunger 309,
Each corresponds to the piston 1, the grooves 1a and 1b forming a pair on the surface thereof, the cylinder body 2, the cylinders 2a and 2b, the solenoid 4, and the plunger 9 of the valve according to the first embodiment shown in FIG.

The solenoid 304 is of the same type as the driving means and the solenoid 4 described in FIG. 6 in the first embodiment, is constituted by a solenoid, and has a compression spring as an urging means inside. The solenoid 304 is mounted on the cylinder 302b by caulking or welding.

In the valve according to the present embodiment, as shown in FIG. 36 (a), the pressure loss is reduced near the center of the piston 301 and the fluid easily flows through the grooves 301a and 301b. A small diameter portion 301e is provided.

In the valve according to the present embodiment, as shown in FIGS. 35, 36 (a) and (b), a communication hole 330 penetrating substantially in the movable axis direction of the piston 301 is formed inside the piston 301 and the plunger 309. Provided. Piston 3
01 and the plunger 309 are screwed together with a screw portion 309a.

The valve of the present embodiment has at least two
Two inflow / outflow ports 306a and 306b are provided. The inflow / outflow ports 306a and 306b form first flow paths 307a and 307b through which a fluid having a symmetric flow rate adjustment flows. The inlet / outlet 306a is provided near the center of the piston 301 formed in a pair. The inflow / outflow port 306b is provided, for example, near the end of the cylinder 302a on the side opposite to the solenoid 304 side.

The fluid flowing from the inflow / outflow port 306a is divided near the first flow path 307a in the vicinity of the inflow / outflow port 306a, and the groove 301a
1b and a pair of flow paths formed by the inner surfaces of the cylinders 302a and 302b, while passing through each pair while being decompressed.

Here, of the pair of flow paths, the groove 30
1a, passing through the flow path formed by the groove 301a and the inner surface of the cylinder 302a,
The flow path flowing out to is referred to as a second flow path 301c. On the other hand, toward the groove 301b of the pair of flow paths, the groove 3
01b and the inner surface of the cylinder 302b, the plunger 309 and the cylinder 302b
Is referred to as a second flow path 301d. The flow path follows a flow path that passes through a clearance portion of the solenoid 304 and flows into a void portion (cavity 332) inside the solenoid 304.

[0291] One end of the communication hole 330 is open to the inflow / outlet port 306b, and the other end is open to the cavity 332. Thereby, the second flow paths 301c and 30
1d is configured to communicate with each other through the communication hole 330. That is, the communication hole 330 is connected to the second flow path 301c.
The grooves 301a and 301b and the cylinder 302a that make a pair on the surface of the piston 301 by communicating the 301d
Communicating with a pair of flow paths formed by the inner surface of 302b;

In the above configuration, the second flow path 3
Of the fluids 01c and 301d, the fluid that has flowed into the second flow path 301d passes through the communication hole 330, then merges with the second flow path 301c near the first flow path 307b, and flows out from the inflow / outflow port 306b. I do.

At this time, the second flow paths 301c and 301d
Are communicated with each other through the communication hole 330,
There is almost no pressure difference at c · 301d. As a result, there is substantially no pressure difference before and after the piston 301 in the movable axis direction, and the force for driving the piston 301 in the movable axis direction can be reduced. Further, the inflow and outflow are in the opposite directions, that is, the fluid flows in from the inflow / outlet 306b, and the inflow / outflow 30
In the case of flowing out from 6a, it passes through the reverse route. Also in that case, the second flow paths 301c and 301d
Are communicated through the communication hole 330, so that almost no pressure difference occurs between the two flow paths.

Further, the valve according to the present embodiment has a flow path portion where fluid flowing through a pair of flow paths merges again as described in Embodiment 1 (when the input and output are reversed). Is a flow channel portion for diverting), for example, the first channel in FIG.
Since it is not necessary to separately provide the flow path 7b and the like, it is possible to reduce the size of the valve.

The pair of second flow paths 301c and 30c
Since there is no need to provide a flow path for guiding 1d to the flow path portion where the flow path 1d joins, for example, FIG.
Can be omitted. For this reason, the cylinder body 302 can also serve as a valve housing, and the size of the valve can be significantly reduced.

In these cases, the piston 301 and the cylinder body 302 formed as a pair may have asymmetric shapes. Further, there may be a difference between the flow rates passing through the pair of second flow paths 301c and 301d. Further, instead of providing the small diameter portion 301e provided near the center of the piston 301, the shape of the piston 301 having a straight outer shape may be employed.

The valve driving means according to the present embodiment may be a stepping motor similar to that described in the ninth embodiment as shown in FIG. in this case,
At the connection portion 331a, the piston 301 and the shaft 255 are connected by caulking or screwing. For this reason, the communication hole 330 is inserted into the communication hole 330 so that the shaft 255 does not hinder the flow of the fluid passing through the communication hole 330 as shown in FIG.
7. A wide portion 331 is provided as shown in FIG. The connecting portion 331a having the wide portion 331 is
It is formed integrally with the piston 301.

In the case of the valve shown in FIG. 37, since the communication hole 330 communicates the second flow paths 301c and 301d, a flow path portion where both flow paths merge (when the input and output are reversed) Does not need to separately provide a flow path for guiding the fluid to the flow dividing portion. For this reason, as shown in a valve housing 253 shown in FIG.
Since there is no need to provide a gap between the valve 3 and the valve 3, the size of the valve can be reduced. In addition, the merging flow path portion (when the input and output are reversed, the flow channel portion that diverges)
Since the piston 301 is located near one end on the side opposite to the drive means 204 side, there is no need to separately provide a structure like the inflow / outlet 252b shown in FIG. 33 in the valve housing 303, and the valve can be further reduced in size.

[0299] The piston 301 is connected to the inflow / outflow port 306b.
Since the end surface of the inflow / outlet 306b on the piston 301 side is in contact with the end surface of the piston 301 in the state of moving to the maximum side, there is no need to further provide the stopper 11 shown in FIG.

[Embodiment 11] Still another embodiment of the present invention will be described with reference to FIGS.

In this embodiment, the same components as those in the first to tenth embodiments are denoted by the same reference numerals, and description thereof will be omitted.

The valve according to the present embodiment is provided with a piston 301 as shown in FIG. This piston 301 is characterized in that it has a plurality of grooves 335 each formed of a tapered surface whose width gradually changes on a part of the side surface. The tapering direction of the tapered surface is the same direction for each groove 335, and all of them are provided so as to taper from the inflow / outlet 306b side shown in FIG. FIG. 40 shows a flow characteristic of the valve according to the present embodiment in which the piston 301 having such a groove 335 is mounted on the valve according to the tenth embodiment. Note that the valve element stroke (mm) shown in FIG. 40 means the amount of movement when the piston 301 moves in the direction from the inflow / outflow port 306b toward the driving means 204.

According to the above configuration, the tapered portion of the groove 335 is gradually removed from the inner surface of the adjacent cylinder body 302 as the piston 301 moves, so that the groove width of the groove 335 gradually increases. Produces the same effect. Therefore, since the flow rate of the fluid flowing with respect to the movement amount (stroke) of the piston 301 also gradually increases, the change in the flow rate does not become steep with respect to the stroke of the piston 301 as shown in FIG. In this case, the ratio of the flow rate change to the stroke of the piston 301 is about 3.5 (L / m
in) / mm. This is described in Japanese Patent Application Laid-Open No. 9-79409.
Of the piston having a slit whose starting surface is substantially vertical in the "control valve" disclosed in Japanese Unexamined Patent Publication (Kokai) No. H11 (1995), that is, the ratio of flow rate change to stroke, that is, about 38 to 40 (L / mi)
Compared with n) / mm, it is understood that it is 1/10 or less. Therefore, it can be seen that the valve according to the present embodiment has a higher flow rate resolution per stroke and is easier to control than the "control valve".

Incidentally, the groove 335 may have a structure in which the gap between the piston 301 and the cylinder body 302 gradually changes according to the required flow characteristics. Also, the groove 33
The change of the groove width of 5 and the gap may be linear or curved. That is, the above-described tapered surface may be a curved surface that gradually changes the width of the groove 335. Further, the groove width or the length of the groove 335 may be changed.
Further, the number of the grooves 335 may be one or plural. Further, one groove may be provided on any one side of the piston 301 having a paired structure.

[0305]

As described above, the valve according to the first aspect of the present invention has a piston and a cylinder into which the piston is inserted, a flow path is provided between the piston and the cylinder, and the piston and the cylinder are connected to each other. The flow path resistance of the fluid passing through the flow path is adjusted by changing the relative position of the flow path.

Therefore, since the flow path resistance for a certain flow rate is determined by parameters such as the length of the portion where the piston is inserted into the cylinder, the clearance between the piston diameter and the cylinder diameter, the relative resistance between the piston and the cylinder is determined. By changing the position, the flow path resistance of the flow path formed between the piston and the cylinder can be changed.

Thus, since the flow rate of the fluid flowing through the flow path can be changed almost steplessly, there is an effect that the flow rate can be adjusted very finely.

As described above, the valve according to the second aspect of the present invention includes the piston, the cylinder into which the piston is inserted, and the driving means for changing the relative positions of the piston and the cylinder. And the flow path resistance of the fluid passing through the flow path is adjusted by changing the relative position between the piston and the cylinder by the driving means.

Therefore, the flow path resistance for a certain flow rate is determined by parameters such as the length of the portion where the piston is inserted into the cylinder, the clearance between the piston diameter and the cylinder diameter, etc. By changing the position, the flow path resistance of the flow path formed between the piston and the cylinder can be changed.

Thus, the flow rate of the fluid flowing through the flow path can be changed almost steplessly, so that the flow rate can be adjusted very finely.

[0311] Further, since the driving means for driving the piston is provided, it is possible to easily perform the variable drive control between the piston and the cylinder.

According to the third aspect of the present invention, as described above, in addition to the configuration of the first or second aspect, the length of a portion where the cylinder is inserted into the piston can be varied to thereby provide the valve. This is a configuration for adjusting the flow path resistance of the fluid passing through the flow path.

Therefore, in addition to the effect of the first or second aspect, the flow path resistance for a certain flow rate is determined by the length of the portion where the piston is inserted into the cylinder. By making the length variable, the flow resistance of the flow path formed between the piston and the cylinder can be changed.

As described above, the valve according to the fourth aspect of the invention has a configuration in which a groove is formed on at least one of the piston surface and the cylinder inner surface in addition to the configuration of the first, second or third aspect.

Therefore, in addition to the effects of the first, second, and third aspects, the flowable flow rate becomes larger than when no grooves are formed on either the piston surface or the cylinder inner surface, and the flow rate adjustment range can be expanded. This has the effect.

As described above, the valve according to the fifth aspect of the present invention has a configuration in which a piston and a cylinder are formed as a pair in addition to the configuration of any one of the first to fourth aspects.

Therefore, in addition to the effect of any one of the first to fourth aspects, the piston and the cylinder are formed as a pair, so that the fluid entering from the outside of the valve forms a pair. The fluid flows separately into the flow path between the cylinder and the piston. Since the paired flow paths are formed so that the flow path resistance of the portion where the piston is inserted into the cylinder is the same, the high-pressure fluid flowing from outside the valve passes through each paired flow path. Similarly, it is decompressed and expanded to a low pressure state and flows out to the outlet of the flow channel.

At this time, a pressure difference occurs before and after the flow path, but the flow path forming the pair is formed so that the fluid flows out in the positive and negative directions of the relative movement of the piston and the cylinder, respectively. As a result, the differential pressure in the positive and negative directions is eliminated, the force acting on the piston is canceled by the pressure difference, and the force burdening the movement of the piston can be reduced. Can be greatly reduced. Therefore, there is an effect that energy required for driving the driving means, for example, electric power can be significantly reduced.

As described above, in the valve according to the sixth aspect of the present invention, in addition to the structure of the fifth aspect, a groove is formed on at least one of the piston surface and the cylinder inner surface of at least one of the pair of the piston and the cylinder. Configuration.

[0320] Therefore, in addition to the effect of the structure of claim 5, of the two sets constituting the pair of flow paths, the grooves are not formed in one set of flow paths, so that the entire flow rate is reduced to approximately half. Can be suppressed. Thus, the flow rate when the flow rate is reduced to the maximum (hereinafter, referred to as the minimum flow rate) can be reduced, and the throttle effect of the throttle valve increases. In addition, although a groove is not formed, a small amount of fluid flows through the clearance between the piston and the cylinder, so that the pressure before and after the piston can be made substantially the same.

[0321] As described above, in the valve according to the seventh aspect of the present invention, in addition to the configuration of the fifth or sixth aspect, the diameter of either one of the piston and the cylinder formed as a pair is formed. , The configuration is different from the diameters of the other pistons and cylinders.

Therefore, in addition to the effect of the constitution of claim 5 or 6, at least one of the two sets of pistons and cylinders forming a pair of flow passages has the diameter of the other set of pistons and cylinders changed. By making the diameter smaller, the clearance between the piston and the cylinder can be reduced when manufacturing with the same processing accuracy when the diameter is smaller than when the diameter is larger. As a result, the flow rate at the minimum flow rate can be reduced, and the effect of restricting the throttle valve can be increased.

As described above, according to the valve of the eighth aspect, in addition to the configuration of any of the fourth to seventh aspects, the groove has
This is a configuration that is spirally formed in the direction of the movable axis of the piston.

Therefore, in addition to the effect of any one of claims 4 to 7, the groove is formed spirally in the direction of the movable axis of the piston. The length of the groove forming portion of the piston can be shortened, and the size of the entire valve can be reduced.

According to the ninth aspect of the present invention, as described above, in addition to the configuration of the eighth aspect, the valve formed on at least one of the piston surface and the cylinder inner surface of at least one of the piston and the cylinder formed in pairs. The above-mentioned spiral groove is formed in the same direction.

Therefore, in addition to the effect of the constitution of claim 8, there is an effect that rotation of the piston formed in a substantially cylindrical shape by the force of the fluid passing through the groove can be prevented.

According to the tenth aspect of the present invention, as described above, in addition to the configuration of any of the fourth to ninth aspects, the groove is formed by:
At least the width and the depth are partially different.

Therefore, in addition to the effect of any one of the fourth to ninth aspects, without changing the dimensions of the entire valve,
The flow rate adjustment range can be expanded.

Thus, a single valve can cope with a place where two valves having significantly different flow rate adjustment ranges are used. For example, in an air conditioner, the range of flow adjustment is significantly different between heating and defrosting, so separate flow paths are provided, and valves having an appropriate flow adjustment range are used for each. According to the mold valve, the flow rate adjustment range can be widened by one valve, so that the flow paths for heating and defrosting can be integrated in one valve.

Therefore, the size and simplification of the refrigeration cycle of the air conditioner can be reduced, so that the number of manufacturing steps can be reduced and the cost can be reduced.

[0331] The valve of the eleventh aspect of the present invention has a configuration in which the cross section of the groove is formed uniformly in addition to the configuration of any of the fourth to ninth aspects.

Therefore, in addition to the effect of any one of claims 4 to 9, the uniform cross section of the groove allows the piston to move within the cylinder to reduce the length of the flow path. When adjusting, the flow path length with respect to the piston position,
That is, there is an effect that the flow path resistance can be linearly varied.

[0333] As described above, the valve of the twelfth aspect of the present invention has a configuration in which grooves are formed in multiple rows in addition to the configuration of any of the fourth to eleventh aspects.

Therefore, in addition to the effect of any one of claims 4 to 11, even when a part of the groove is clogged by the contaminants present inside the refrigeration cycle, the fluid is caused to flow through another groove. Can be.

Further, depending on the formation form of the groove, there is an effect that the flow path resistance can be set stepwise.

The valve according to the thirteenth aspect of the present invention has a structure in which the opening at one end of the cylinder is formed smaller than the diameter of the piston in addition to the structure of any one of the first to twelfth aspects. is there.

Therefore, in addition to the effect of any one of the first to twelfth aspects, the distal end surface of the piston hits the inner surface of the opening portion of the cylinder formed to be smaller than the diameter of the piston. Passes through a small gap portion between the distal end surface of the piston and the inner surface of the cylinder opening, thereby providing an effect that the minimum flow rate can be further reduced.

As described above, the valve according to the fourteenth aspect of the present invention has a configuration in which the ends of the piston and the cylinder are formed in a tapered shape, in addition to the configuration of any one of the first to twelfth aspects.

Therefore, in addition to the effect of any one of the first to twelfth aspects, the piston and the tapered surface formed at the tip of the cylinder are brought into contact with each other.
The fluid passes through a small gap portion sandwiched between the tapered surfaces, thereby providing an effect that the minimum flow rate can be further reduced.

As described above, in the valve according to the fifteenth aspect, in addition to the configuration according to any one of the first to fourteenth aspects, the piston and the cylinder are made of a material having substantially the same linear expansion coefficient. .

Therefore, in addition to the effect of any one of the first to fourteenth aspects, a change in the clearance between the piston and the cylinder due to a change in the refrigerant temperature can be suppressed as much as possible. There is an effect that a valve as a throttle valve for obtaining a stable throttle effect can be obtained.

According to a sixteenth aspect of the present invention, as described above, in addition to any one of the second to fifteenth aspects, the drive means is made of a magnetic material provided at the upper end of the movable shaft of the piston. Or a plunger coated with a magnetic material or made of a permanent magnet, a solenoid provided on or near the movable axis of the piston for attracting or repelling the plunger, and a solenoid for attracting or repelling the solenoid. An urging means for urging the piston in a direction opposite to the generated force so as to balance the generated force.

Therefore, in addition to the effect of any of the second to fifteenth aspects, the piston can be moved or held by sucking or repelling the plunger provided on the movable axis of the piston with the solenoid. it can.
In addition, when the excitation of the solenoid is stopped, the piston returns to the predetermined position by the urging means.

Therefore, by changing the force generated in the solenoid according to the injection current, the piston is moved in accordance with the balance position of the force determined by the attraction force of the solenoid and the urging force of the urging means. Or can be held at a predetermined position. Accordingly, it is not necessary to use a special stepping motor having a sealed structure to move the piston, so that the size of the entire valve can be reduced.

According to the seventeenth aspect of the present invention, as described above, in addition to any one of the second to fifteenth aspects, the driving means is made of a magnetic material or coated with a magnetic material, or A piston made of a permanent magnet, a solenoid provided on or near the movable axis of the piston to attract or repel the piston,
An urging means for urging the piston in a direction opposite to the force so as to balance the force of the attraction or repulsion of the solenoid.

Therefore, in addition to the effect of any one of the second to fifteenth aspects, the piston also functions as a plunger by forming the piston itself with a magnetic material or a magnetic material coated or a permanent magnet. Will be. This eliminates the need to provide a plunger in addition to the piston as in claim 15, so that the number of parts constituting the valve can be reduced, and the cost of the valve can be reduced. In addition, since the driving portion can be lighter in weight than the configuration in which the plunger is provided on the piston, the effect of reducing the energy required for driving the piston can be obtained.

[0347] As described above, the valve of the eighteenth aspect of the invention is configured such that the biasing means is disposed inside the solenoid, in addition to the configuration of the sixteenth or seventeenth aspect.

Therefore, in addition to the effect of the configuration of claim 16 or 17, in addition to the arrangement of the biasing means inside the solenoid, an empty space for moving the plunger can be effectively used. This produces an effect that the size of the entire valve can be reduced.

In the valve according to the nineteenth aspect of the present invention, as described above, in addition to the configuration according to any one of the sixteenth to eighteenth aspects, the collision buffer means is disposed between the piston or the plunger and the solenoid. Configuration.

Therefore, in addition to the effect of any one of the sixteenth to eighteenth aspects, the provision of the shock absorbing means between the piston or the plunger and the solenoid allows the piston to move beyond the maximum balance point. Even if it moves suddenly, it is possible to prevent the piston or the plunger from colliding with the solenoid. This has the effect of preventing wear of the piston or plunger and the solenoid, and generation of vibration and noise at the time of collision.

According to a twentieth aspect of the invention, as described above, in addition to any one of the sixteenth to eighteenth aspects, the piston or the plunger and the solenoid are provided with projections on any part thereof. A guide groove for guiding the protrusion is formed in one of the solenoid and the piston or the plunger.

Therefore, in addition to the effect of any one of the sixteenth to eighteenth aspects, a projection is provided on a part of the solenoid, and the projection of the solenoid is guided to the piston or plunger in the direction of the movable axis of the piston. By providing a guide groove, or by providing a projection on a part of the piston or plunger and providing a guide groove for guiding the projection in the movable axis direction of the piston on the solenoid, Can be prevented from rotating. This prevents the piston from rotating in the cylinder. Therefore,
When the position of the piston is the same, there is an effect that the flow path length in the cylinder due to the rotation of the piston is slightly changed and the flow path resistance can be prevented from fluctuating.

The valve control method according to the twenty-first aspect of the present invention
As described above, by varying the injection current to the solenoid of the valve according to claim 16 to 20, the generated force generated in the solenoid is changed, and determined by the generated force and the biasing force of the biasing means. The configuration is such that the piston is held or moved at a predetermined position in accordance with the balancing position to be set.

Therefore, by changing the injection current, the suction force generated in the solenoid is changed, and the piston is held or moved according to the balance position determined by the suction force and the urging force of the urging means. By doing so, there is an effect that the valve can be opened and closed steplessly using the solenoid.

The valve control method according to the twenty-second aspect of the present invention
As described above, in addition to the configuration of the twenty-first aspect, the injection current is a pulse current, and the position of the piston is controlled by changing the amplitude of the pulse-injected current.

Therefore, in addition to the effect of the twenty-first aspect, the injection current is a pulse current, and the position of the piston is controlled by making the amplitude of the pulsed current variable so as to move the piston. In this case, the dead zone and the hysteresis do not occur, and a smooth movement can be performed, so that stepless control can be performed.

The control method of the valve according to the twenty-third aspect is as follows.
As described above, in addition to the structure of claim 22, the position of the piston is controlled by changing the duty of the pulse of the pulse current.

Therefore, in addition to the effect of the structure of claim 22, the injection current is a pulse current, and by controlling the position of the piston by varying the duty of the pulse, the suction force received by the plunger can be equalized. , And the generation of extra frictional force between the piston and the cylinder can be prevented.

Further, according to the above configuration, it is possible to inject an average current having the same effect even with a power supply voltage lower than that of the twenty-second aspect, and to reduce power consumption.

The control method for a valve according to the twenty-fourth aspect is as follows.
As described above, in addition to the structure of claim 22, the position of the piston is controlled by changing the frequency of the pulse of the pulse current.

Therefore, in addition to the effect of the structure of claim 22, the injection current is a pulse current, and by controlling the position of the piston by changing the frequency of the pulse, the suction force received by the plunger is made uniform. , And the generation of extra frictional force between the piston and the cylinder can be prevented.

Further, according to the above configuration, an average current having the same effect can be injected even with a power supply voltage lower than that of the twenty-second aspect, so that power consumption can be reduced.

According to the twenty-fifth aspect of the present invention, as described above, in addition to the configuration of the fifth aspect, a pair of flow paths formed by the piston and the cylinder communicate with the inside of the piston. In this configuration, a communication hole is provided.

Therefore, in addition to the effect of the constitution of claim 5, two flows of the refrigerant which have been decompressed and expanded in the respective flow paths forming a pair and brought into a low pressure state are communicated with, for example, a communication hole provided inside the piston. Can be combined. This eliminates the need to separately provide a merging flow path (a split flow path in the case of input / output reverse) where the refrigerant flowing through the paired flow paths merges again, so that the valve shape can be reduced in size.
Further, since the respective flow paths forming the pair communicate with each other through the communication hole, there is no difference in pressure of the refrigerant before and after the piston, for example, in the movable axis direction. Therefore, the driving force of the piston can be further greatly reduced.

Further, since the communication hole can always place the refrigerant in a circulating state, the refrigerant does not condense in the vicinity of the communication hole, and heat loss occurs due to transfer of heat between the stagnant refrigerant and the outside. There is an effect that there is no.

According to the twenty-sixth aspect of the present invention, as described above, in addition to the configuration of the fifth aspect, the pressure in the movable axis direction of the piston is balanced to adjust the flow path resistance. It is.

Therefore, in addition to the effect of the structure of claim 5, since the pressure difference of the fluid flowing through the pair of flow passages before and after in the movable axis direction of the piston is eliminated, the driving force of the piston can be reduced. This makes it possible to provide an excellent valve as a throttle valve for adjusting the flow rate of the fluid.

The valve according to the twenty-seventh aspect of the present invention has a structure in which the groove is a groove that gradually changes the gap between the piston and the cylinder or the width of the groove in addition to the structure of the tenth aspect. is there.

Therefore, in addition to the effect of the configuration of claim 10, since the gap between the piston and the cylinder or the width of the groove or both of them is gradually increased at the same time, the flow rate of the fluid flowing therethrough is also gradually increased. This has the effect that the flow rate does not change steeply with respect to the movement amount (stroke) of the piston.

[0370] As described above, in the valve according to the twenty-eighth aspect, in addition to the configuration of the twenty-seventh aspect, the groove may be such that the gap between the piston and the cylinder or the width of the groove gradually changes. It is a structure which is a groove which has.

Therefore, in addition to the effect of the constitution of claim 27, the flow rate adjustment range is widened. In addition, in the groove having the tapered surface, the flow rate change with respect to the amount of movement of the piston is linear, and in the groove having the curved surface. Thus, it is possible to obtain a non-linear flow characteristic in which the flow rate change is gradual. For this reason, since the change in the flow rate with respect to the movement amount of the piston does not change abruptly, the flow rate resolution per stroke is improved, and the controllability of the valve can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a valve according to an embodiment of the present invention.

FIGS. 2A and 2B are three views showing a piston constituting the valve shown in FIG. 1, wherein FIG. 2A is a plan view, FIG. 2B is a front view, and FIG.

FIG. 3 is a schematic sectional view of a shape of a groove of a piston shown in FIGS. 2 (a) to 2 (c).

4 (a) to 4 (d) are explanatory diagrams showing the pressure reduction in the valve shown in FIG. 1. FIG.

FIG. 5 is a schematic block diagram of a refrigeration cycle using the valve shown in FIG. 1;

FIG. 6 is a schematic configuration diagram of a valve according to another embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 8 is an explanatory view showing another example of the piston used for the valve of the present invention.

FIG. 9 is an explanatory view showing still another example of a piston used for the valve of the present invention.

FIG. 10 is an explanatory view showing still another example of the piston used in the valve of the present invention.

FIG. 11 is an explanatory view showing still another example of the piston used for the valve of the present invention.

FIGS. 12A and 12B show still another example of the piston used in the valve of the present invention, wherein FIG. 12A is a plan view and FIG.
Is a front view, and (c) is a side view.

FIG. 13 is an explanatory view showing still another example of a piston used for the valve of the present invention.

FIG. 14 is an explanatory view showing still another example of a piston used for the valve of the present invention.

FIG. 15 is an explanatory view showing a method for coating a piston with a protective film according to the present invention.

FIG. 16 is a graph showing a relationship between a suction force of a solenoid and a tension of a spring and a displacement of a piston in the valve of the present invention.

FIG. 17 is a graph showing a relationship between an injection current to a solenoid and a displacement of a piston in the valve of the present invention.

FIG. 18 is a circuit diagram for pulse driving in a solenoid.

19 is a waveform chart showing control signals and drive current waveforms in the circuit shown in FIG.

FIG. 20 is a graph showing a relationship between a current injected into a solenoid by pulse driving and displacement of a piston.

21A and 21B show waveforms of a control pulse signal and a drive current in pulse control, where FIG. 21A is a waveform diagram for variable duty control, and FIG. 21B is a waveform diagram for variable frequency control.

FIG. 22 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 23 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 24 is a graph showing a relationship between a suction force of a solenoid and a tension of a spring and a displacement of a piston in the valve shown in FIGS.

FIGS. 25A and 25B are front views showing a relationship between a plunger or a piston and a solenoid in the valve of the present invention.

FIG. 26 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIGS. 27 (a) and 27 (b) are explanatory views showing other plunger shapes of the valve of the present invention.

FIG. 28 is a graph showing the relationship between the attraction force of the solenoid and the tension of the spring and the displacement of the piston in the valve shown in FIGS.

FIG. 29 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 30 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 31 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 32 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 33 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

FIG. 34 is a schematic block diagram showing a conventional refrigeration cycle.

FIG. 35 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

36 (a) is a side view of a piston constituting the valve shown in FIG. 35, and FIG. 36 (b) is a front view of the piston.

FIG. 37 is a schematic configuration diagram of a valve according to still another embodiment of the present invention.

38 is a sectional view taken along the line AA of FIG. 37.

FIG. 39 is an explanatory view showing still another example of the piston used in the valve of the present invention.

FIG. 40 is a graph showing flow characteristics of a valve according to still another embodiment of the present invention.

FIG. 41 is a longitudinal sectional view showing an example of a conventional valve.

FIG. 42 is an enlarged view showing a valve portion provided with a slit of the valve of FIG. 41.

FIG. 43 is a graph showing flow characteristics of the valve of FIG. 41.

[Explanation of symbols]

 Reference Signs List 1 piston 1a to 1d groove 2 cylinder body 2a 2b cylinder 3 valve housing 4 solenoid (drive means) 7a 7b first flow path 9 plunger (drive means) 10 tension spring (biasing means) 16 core 32 cylinder body 32a / 32b cylinder 33 valve housing 34 compression spring (biasing means) 37 plunger (drive means) 40 groove 41 groove 42/43 groove 45a-45d groove 47 groove 49a / 49b groove 80 compression spring (collision buffering means) 85 composite Spring (collision buffering means) 91 Projection for projection (projection) 92 Guide groove 93/94 Plunger 95 Core 96/97 Plunger 201 Piston 201a Flow path 202 Cylinder 204 Drive unit (Drive means) 220 Flow path 221 Piston 221a First piston Part 221b second piston part 222 cylinder body 222a cylinder 222b cylinder 230 groove 251 piston 251a groove 251b groove 252 cylinder 301 piston 301a groove 301b groove 301c flow path 301d flow path 302 cylinder body 306a inflow / outflow 306b inflow / outflow port 330 communication hole 335 groove

Continued on front page (72) Inventor Hiroyuki Hanato 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation

Claims (28)

[Claims] A piston and a cylinder into which the piston is inserted, a flow path provided between the piston and the cylinder, and passing through the flow path by changing a relative position between the piston and the cylinder. A valve for adjusting a flow path resistance of a fluid. A piston, a cylinder into which the piston is inserted, and driving means for changing a relative position between the piston and the cylinder; a flow path provided between the piston and the cylinder; A valve that adjusts the flow path resistance of the fluid passing through the flow path by changing the relative position between the piston and the cylinder. 3. A flow path resistance of a fluid passing through said flow path is adjusted by changing a length of a portion where said cylinder is inserted into said piston. A valve according to claim 1. 4. The valve according to claim 1, wherein a groove is formed on at least one of the piston surface and the cylinder inner surface. 5. The valve according to claim 1, wherein the piston and the cylinder are formed as a pair. 6. The valve according to claim 5, wherein a groove is formed on at least one of the piston surface and the cylinder inner surface of at least one of the pair of the piston and the cylinder. 7. A valve according to claim 5, wherein the diameter of one of the pair of pistons and cylinders is different from the diameter of the other piston and cylinder. . 8. The apparatus according to claim 4, wherein said groove is formed helically with respect to the direction of the movable axis of the piston.
8. The valve according to any one of claims 7 to 7. 9. The helical groove formed on at least one of a piston surface and a cylinder surface of at least one of a piston and a cylinder formed in a pair is formed in the same direction. Item 8. The valve according to Item 8. 10. The valve according to claim 4, wherein the groove has at least a partial difference in width and depth. 11. The valve according to claim 4, wherein a cross section of the groove is formed uniformly. 12. The valve according to claim 4, wherein said groove is formed in multiple rows. 13. The valve according to claim 1, wherein an opening at one end of the cylinder is formed to be smaller than a diameter of the piston. 14. A valve according to claim 1, wherein said piston and said cylinder have tapered ends. 15. The valve according to claim 1, wherein the piston and the cylinder are made of a material having substantially the same linear expansion coefficient. 16. The drive means is made of a magnetic material provided at an upper end of a movable shaft of a piston.
Or a plunger coated with a magnetic material or made of a permanent magnet; a solenoid provided on or near the movable axis of the piston for attracting or repelling the plunger; and a generating force of the solenoid The valve according to any one of claims 2 to 15, further comprising an urging means for urging the piston in a direction opposite to the generated force. 17. The driving means, comprising: a piston made of a magnetic material, or coated with a magnetic material, or made of a permanent magnet; provided on or near a movable axis of the piston; 3. A solenoid for causing attraction or repulsion, and an urging means for urging the piston in a direction opposite to the generated force so as to balance the generated force of the solenoid. 16. The valve according to any one of claims 15 to 15. 18. The apparatus according to claim 16, wherein said biasing means is disposed inside said solenoid.
The described valve. 19. The valve according to claim 16, wherein a collision buffer is disposed between said piston or plunger and said solenoid. 20. A projection is provided on one part of the piston or plunger and the solenoid, and a guide groove for guiding the projection is provided on one part of the solenoid and the piston or plunger. 19. The valve according to claim 16, wherein the valve is formed. 21. A generator according to claim 16, wherein a current generated in said solenoid is varied by varying an injection current to said solenoid, and determined by the generated force and the biasing force of said biasing means. A method for controlling a valve, comprising: holding or moving a piston at a predetermined position according to a balanced position to be adjusted. 22. The valve control method according to claim 21, wherein the injection current is a pulse current, and the position of the piston is controlled by changing the amplitude of the pulse-injected current. 23. The valve control method according to claim 22, wherein the position of the piston is controlled by changing the duty of the pulse of the pulse current. 24. The method according to claim 22, wherein the position of the piston is controlled by changing the frequency of the pulse of the pulse current. 25. The valve according to claim 5, wherein a communication hole is provided in the piston to communicate a pair of flow paths formed by the piston and the cylinder. 26. The valve according to claim 5, wherein the pressure is equalized before and after the piston in the direction of the movable axis. 27. The valve according to claim 10, wherein said groove is a groove for gradually changing a gap between said piston and said cylinder or a width of said groove. 28. The valve according to claim 27, wherein the groove is a groove having a tapered surface or a curved surface that gradually changes a gap between the piston and the cylinder or a width of the groove.