JPH0894211A - Step type pilot solenoid valve - Google Patents

Abstract

PURPOSE: To variably control the time of maintaining the valve opening condition that only a small flow rate of a refrigerant flowing through a pilot passage is allowed, and suppress a great impact noise and vibration to be generated at the time of the opening of the valve of a main valve body. CONSTITUTION: Construction is made so that pressure in a back pressure chamber 10 into which an upstream side pressure is introduced through a throttled passage 12 acts on a closed valve side due to a first pressure receiving area and, on the other hand, the upstream side pressure acts on an opened valve side due to a second pressure receiving area smaller than the first pressure receiving area while a downstream side pressure acts on the opened valve side due to a third pressure receiving area. A main valve body 7 is provided, which is selectively seated on or separated from a main valve seat part 4 by the differences of pressure received to open and close a main fluid passage 5. Further, a solenoid pilot valve 16 is provided, which operates stepwise in three steps of fully closing, half opening and fully opening a pilot fluid passage 14 for allowing the back pressure chamber 10 to connectively communicate to the main fluid passage 5 on the downstream side of the main valve seat part 4. In the case where the pilot fluid passage 14 is in a half open state, the pilot valve is put into an open condition for a small flow rate while keeping the closing of the valve of the main valve body 7 and, only in the case where the pilot fluid passage 14 is in a fully open state, the main valve body 7 is separated from the main valve seat part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step type pilot electromagnetic on-off valve, and more particularly to a step type pilot electromagnetic on-off valve used as an on-off valve for opening and closing a refrigerant passage in a refrigeration cycle.

[0002]

2. Description of the Related Art In a heat pump type multi-air conditioner, a plurality of indoor heat exchangers are connected in parallel to each other in a refrigerating cycle and used as an indoor heat exchanger in a room that needs heating during heating to reduce heat loss. It has been conventionally practiced to selectively supply only the refrigerant.

In this case, the opening and closing of the refrigerant passage is individually performed for each indoor heat exchanger by the electromagnetic opening / closing valve provided on the upstream side of the indoor heat exchanger when viewed from the flow of the refrigerant during heating.
In the multi-air conditioner as described above, a high differential pressure is generated before and after the electromagnetic on-off valve in the closed state.Under this condition, the electromagnetic on-off valve is opened in order to start heating of a new room. Then, the pressure difference causes the refrigerant to rapidly flow, which causes a loud fluid noise and vibration of the pipe.

In order to avoid this, two electromagnetic on-off valves are provided in parallel for each indoor heat exchanger, and one of these electromagnetic on-off valves is connected in series with a throttle passage means such as a capillary. However, at the time of starting heating of a new room, first, the electromagnetic on-off valve connected to the throttle passage means is opened to flow the refrigerant with a small flow rate to reduce the differential pressure before and after the electromagnetic on-off valve. One of the solenoid on-off valves is being opened.

Further, as an electromagnetic on-off valve proposed to avoid the above-mentioned inconvenience, as disclosed in Japanese Patent Laid-Open No. 3-175243, a pilot valve is electromagnetically driven to open the main valve body by a pilot. By opening the passage, refrigerant flows through the pilot passage to the downstream side of the on-off valve before opening the main valve body, thereby reducing the pressure difference between the upstream side and the downstream side of the on-off valve, in other words, the pilot. A pilot electromagnetic on-off valve configured to open the main valve body after increasing the pressure on the downstream side by the refrigerant flowing in the passage has already been proposed.

[0006]

The two electromagnetic on-off valves and the throttle passage means achieve the intended purpose, but two electromagnetic on-off valves and throttle passage means are provided for each indoor heat exchanger. Since it is necessary to provide them, there is a drawback that the number of piping parts and the number of piping man-hours increase and the cost increases.

On the other hand, the solenoid on-off valve disclosed in Japanese Patent Laid-Open No. 3-175243 does not have such a drawback, but due to its structure, the main valve body is opened from the time when the pilot passage is opened. The time to delay the valve opening depends on the rising speed of the valve downstream side pressure introduced into the pressure chamber (low pressure chamber) of the pressure equalizing valve that controls guiding the valve upstream side pressure to the back pressure chamber of the main valve body, This is uniquely determined by the flow rate of the refrigerant flowing through the pilot passage, and the valve opening delay time of the main valve body cannot be variably controlled.

For this reason, it may not be possible to variably control the maintenance time of the small flow rate valve open state only by the flow rate of the refrigerant flowing through the pilot passage, and it may not be possible to sufficiently suppress the generation of large fluid noise and vibration. The present invention has been made in view of the above-mentioned problems, and it is possible to variably control the maintenance time of the small flow rate open state of only the flow rate of the refrigerant flowing through the pilot passage, and the number of piping parts and the number of piping steps. Without increasing
An object of the present invention is to provide a step-type pilot electromagnetic on-off valve capable of sufficiently suppressing the generation of loud fluid noise and vibration when the valve is opened.

[0009]

In order to achieve the above-mentioned object, the step-type pilot electromagnetic on-off valve according to the present invention has the pressure of the back pressure chamber having a first pressure-receiving area on the valve closing side, and the valve housing. The fluid pressure upstream of the main valve seat portion formed on the valve is exerted on the valve opening side with a second pressure receiving area smaller than the first pressure receiving area, and the fluid pressure downstream of the main valve seat portion is set to the third. A main valve body having a pressure-receiving area of .about. And a throttle passage that connects the main fluid passage to the back pressure chamber and guides fluid pressure upstream of the main valve seat portion to the back pressure chamber, and the back pressure chamber downstream of the main valve seat portion. A pilot fluid passage communicatively connected to the main fluid passage of A fully closed position for cutting off the communication of the pilot fluid passage, an intermediate opening position for bringing the pilot fluid passage into communication with a first valve opening, and a pilot fluid passage larger than the first valve opening. A step operation type electromagnetic pilot valve that opens and closes in three steps between the second valve opening degree and the fully open position where the pilot fluid passage is blocked or is dependent on the first valve opening degree. In the communicating state, the main valve body is seated on the main valve seat portion due to the pressure difference and closes the main fluid passage, and the pilot fluid passage is in the communicating state by the second valve opening degree. In some cases, the first valve opening and the second valve opening of the pilot fluid passage open the main fluid passage by separating the main valve body from the main valve seat portion due to the pressure difference. And the first of the main valve body ~ It is characterized in that it is set to the pressure receiving area of the three.

In the step-type pilot solenoid on-off valve according to the present invention, the solenoid pilot valve moves in the axial direction to cooperate with the pilot valve seat portion provided in the pilot fluid passage to control the flow rate. The pilot valve to be performed, and the pilot valve is arranged so as to be movable between a first position and a second position in the moving direction of the pilot valve, and moves from the first position to the second position. A first plunger for engaging the body to drive the pilot valve body from the fully closed position to the intermediate opening position;
The first plunger and the pilot valve body are arranged in series in the moving direction of the pilot valve body so as to be movable between a third position and a fourth position in the moving direction of the pilot valve body. A second plunger that engages with the pilot valve element by moving to the fourth position to drive the pilot valve element from the intermediate opening position to the fully open position, and the second plunger of the first plunger. A suction element fixedly arranged to face the end face on the position side, a yoke having one end connected to the suction element, the first plunger located at the second position, and the second plunger Permanently latching the second plunger at the fourth position by forming a magnetic closed loop with the first plunger, the second plunger, the attractor and the yoke by being located at the fourth position. magnet , By energizing in the first direction, the yoke is excited in a first magnetic pole direction opposite to the magnetic pole direction of the permanent magnet to drive the first plunger to the second position, An electromagnetic coil that drives the second plunger to the fourth position by exciting the yoke in a second magnetic pole direction that is the same as the magnetic pole direction of the permanent magnet by energizing in a second direction opposite to the direction. It may be a detailed feature to have and.

In the above step type pilot solenoid on-off valve, the pilot fluid passage is provided in the main valve body, and the pilot valve body cooperates with the parrot valve seat portion formed in the main valve body. It may be configured to control the flow rate. Further, in the step-type pilot electromagnetic on-off valve according to the present invention, the pilot valve body is a first pilot valve body driven by the first plunger and a second pilot having a hollow structure driven by the second plunger. With a double structure including a valve body, the first pilot valve body performs flow rate control in cooperation with a first pilot valve seat portion formed on the second pilot valve body,
The second pilot valve body may have a detailed characteristic that it cooperates with a second pilot valve seat portion formed on the valve casing side to control the flow rate.

Further, in the step type pilot solenoid on-off valve according to the present invention, the main valve body and the pilot valve body of the electromagnetic pilot valve are opened and closed by moving in the axial direction, respectively, and Another detailed feature may be that the moving direction of the pilot valve element of the electromagnetic pilot valve is the same axis direction.

[0013]

According to the above-mentioned structure, when the pilot valve body is located at the fully closed position, the main valve body is also located at the closed position. In this case, the pilot fluid passage is also located at the main fluid passage. Communication is also cut off, and the step-type pilot solenoid on-off valve is fully closed.

When the pilot valve body is driven to the intermediate opening position, the pilot fluid passage is brought into communication with the first valve opening, and while the pilot valve body is located at the intermediate opening position, , The main valve body is kept closed, that is, the state where the communication of the main fluid passage is cut off is maintained, and the small flow rate open state of only the flow rate according to the first valve opening degree is maintained.

When the pilot valve body is driven to the fully open position and the pilot fluid passage is brought into communication with the second valve opening degree, the main valve body is opened only for the first time so that the main fluid passage is brought into communication with the step valve. The pilot solenoid on-off valve is fully open. When the pilot valve body of the electromagnetic pilot valve is driven to open and close by a combination of two plungers, a permanent magnet, and an electromagnetic coil, the pilot valve is driven by the spring force of the return spring in the normal state where the electromagnetic coil is not energized. The body is located at the fully closed position, the electromagnetic coil is energized in the first direction, the pilot valve body is located at the intermediate opening position, and the electromagnetic coil is placed in the second direction in the direction opposite to the first direction. The pilot valve body is positioned at the fully open position by the energization in the direction.

At the fully open position, the pilot valve body is kept in the fully open position by the magnetic force of the permanent magnet even when the energization of the electromagnetic coil is stopped. When the pilot valve body has a double structure of the first pilot valve body and the second pilot valve body, the opening and closing of the first pilot valve body surely determines the first valve opening degree. The opening and closing of the second pilot valve element reliably determines the second valve opening.

[0017]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of a step-type pilot solenoid on-off valve according to the present invention.

The step type pilot solenoid on-off valve has a valve casing 1, which has an inlet port 2
An outlet port 3 and a main fluid passage 5 having a main valve seat portion 4 in the middle. A stepped piston-shaped main valve body 7 is fitted in a valve chamber 6 of the valve casing 1 at a large diameter portion 8 so as to be movable in the left-right direction in the drawing. The main valve body 7 has a small diameter portion 9
Is selectively seated and separated from the main valve seat portion 4 at the main fluid passage 5
Open and close.

The main valve body 7 defines a back pressure chamber 10 on the large diameter portion 8 side, and the pressure Pb of the back pressure chamber 10 has a pressure receiving area (first pressure receiving area) S1 of the large diameter portion 8. Valve closing force Pb ・ S1
And the spring force F of the spring 11 is exerted as a valve closing force, and the pressure on the inlet port 2 side of the main valve seat portion 4, that is, the upstream pressure Pi, is smaller than the pressure receiving area S1 of the large diameter portion 8 With the pressure receiving area (second pressure receiving area) S1 -S2 from which the pressure receiving area S2 of 9 is subtracted, the valve opening force Pi (S1 -S2)
2) and the pressure on the outlet port 3 side of the main valve seat 4, that is, the pressure Po on the downstream side, has a pressure receiving area S3 approximately equal to the pressure receiving area S2 of the small diameter portion 9,
It is exerted as S3 and is opened / closed by the equilibrium relation of the valve closing force Pb.S1 + spring force F and the valve opening force Pi (S1-S2) + Po.S3.

Here, the main valve body 7 is Pb.S1 + F> P
If i (S1 −S2) + Po · S3, the main valve seat 4 is seated and the communication of the main fluid passage 5 is cut off.
If S1 + F <Pi (S1−S2) + Po · S3, the communication with the main fluid passage 5 is established apart from the main valve seat 4.

The back pressure chamber 10 includes a main valve body 7 and a valve housing 1.
Between the main valve seat portion 4 and the valve chamber 6 on the inlet port 2 side, and the upstream side pressure Pi is introduced. . A pilot fluid passage 14 is formed in the valve casing 1 to connect the back pressure chamber 10 to a main fluid passage 5 downstream of the main valve seat portion 4. A pilot valve seat portion 15 is formed in the middle of the pilot fluid passage 14, and the pilot valve seat portion 15 is opened and closed by a pilot valve body 17 of an electromagnetic pilot valve 16.

The pilot valve element 17 has a flow rate setting section 18 at the tip end thereof which is a step for cooperating with the pilot valve seat section 15 to control the flow rate, as shown in FIGS. 1 and 4 (a). And a fully closed position where the pilot fluid passage 14 is cut off, and an intermediate open position for bringing the pilot passage 14 into the open state with the first valve opening as shown in FIGS. 2 and 4B. 3 and 4 (c), the pilot passage 14 is reciprocated between a fully open position in which the pilot passage 14 is in a communicating state with a second valve opening larger than the first valve opening. Moving.

In this case, if the pilot fluid passage 14 is blocked or is in a communication state due to the first valve opening, Pb.S1 + F> Pi (S1 -S2) + Po.S
The relationship of 3 is established, the main valve body 7 is seated on the main valve seat portion 4 due to this pressure difference and the main fluid passage 5 is closed, and the pilot fluid passage 14 is in the communicating state by the second valve opening degree. In some cases, Pb · S1 + F <Pi (S1−S2) + Po · S3
Is established and the main valve body 7 is separated from the main valve seat portion 4 by this pressure difference and opens the main fluid passage 5, so that the first valve opening and the second valve of the pilot fluid passage 14 are opened. The opening degree and each pressure receiving area S1, S2, S3 of the main valve body 7 are set.

A plunger holding tube 19 is fixedly mounted on the valve housing 1 in the same axial direction as the pilot valve body 17, and a stem portion 20 of the pilot valve body 17 extends in the center of the plunger holding tube 19. are doing. An upper plunger (first plunger) 21 and a lower plunger (second plunger) 22 having a hollow structure are fitted and loaded into the plunger holding tube 7 so as to be movable in series in the moving direction of the pilot valve body 17. There is. A suction element 23 is fixedly mounted on the upper end of the plunger holding tube 19, and the lower bottom surface of the suction element 23 faces the upper end surface of the upper plunger 21 at a predetermined interval.

A return spring 24, which is a compression coil spring, is provided between the suction element 23 and the pilot valve body 17, and the return spring 24 directs the pilot valve body 17 downward in FIG. Are urging. The upper plunger 21 is movable between a descending position (first position) shown in FIG. 1 and an ascending position (second position) in contact with the suction element 23 as shown in FIG. Yes, lower plunger 22 is in the lowered position (third position) shown in FIG.
As shown in FIG. 3, it is movable to the raised position (fourth position) where it abuts the upper plunger 21 located in the raised position. An intermediate spring 29 is provided between the upper plunger 21 and the lower plunger 22 so as to urge them in a direction in which they are axially separated from each other.

Upper plunger 21 and lower plunger 22
The stem 20 of the pilot valve body 17 is fitted in each of the hollow portions so as to be relatively displaceable in the axial direction.
A flange portion 26 that engages with a step portion 25 formed on the upper plunger 21 and a step portion 28 that engages with a step portion 27 formed on the lower plunger 22 are formed on the side.

The upper plunger 21 is moved from the lowered position to the raised position, whereby the step portion 25 and the flange portion 26 are moved.
The pilot valve body 17 by the engagement with the return spring 24
The lower plunger 22 is moved from the fully closed position to the intermediate opening position against the spring force of, and the lower plunger 22 is moved from the lowered position to the raised position by the engagement of the step portions 27 and 28.
The pilot valve body 17 is moved from the intermediate opening position to the fully open position against the spring force of the return spring 24.

The upper piece 32 of the yoke 31 is fixedly connected to the upper end of the suction element 23 by a bolt 30. The yoke 31 is arranged in a U-shaped lateral shape so as to cover one side of the plunger holding tube 19 and is located at a height position substantially corresponding to the lower end of the upper plunger 21 in the plunger holding tube 19. It has a section 33. Between the upper piece 32 and the lower piece 33 of the yoke 31, a DC electromagnetic coil 34 is fixedly arranged so as to surround the plunger holding tube 19.

A permanent magnet 35 is provided on the lower surface of the lower piece 33.
The permanent magnet 35 is connected and attached with a pole, and the pole piece 36 is connected and attached to the S pole of the permanent magnet 35. The permanent magnet 35 is
As shown in FIG. 3, since the upper plunger 21 and the lower plunger 22 are both located in the raised position, a magnetic closed loop formed by the upper plunger 21, the lower plunger 22, the suction element 23, and the yoke 31 (in the figure, (Indicated by the dashed arrow) to latch upper plunger 21 and lower plunger 22 in the raised position.

When the electromagnetic coil 34 is energized in the first direction (hereinafter referred to as the forward direction), the yoke 31 is in the direction opposite to the magnetic pole direction of the permanent magnet 35, and the first magnetic pole direction indicated by the solid arrow in FIG. Is excited to drive the upper plunger 21 to a raised position, and the yoke 31 is driven in the same direction as the magnetic pole direction of the permanent magnet 35 by energizing in a second direction (hereinafter, reverse direction) opposite to the first direction. Is excited in the second magnetic pole direction to drive the upper plunger 21 and the lower plunger 22 to the raised position.

A bear removing coil 37 forming a short-circuiting ring is fixedly attached to the lower bottom surface of the suction element 23. Next, the operation of the step-type pilot electromagnetic on-off valve having the above-mentioned configuration will be described.

When the electromagnetic coil 34 is not energized, as shown in FIG. 1, the pilot valve body 17 is positioned at the fully closed position, which is the most lowered position, due to the spring force of the return spring 24. There is. In this state, the communication of the pilot fluid passage 14 is blocked, and the upstream pressure Pi introduced into the back pressure chamber 10 by the orifice passage 12 results in the upstream pressure Pi = the back pressure chamber pressure Pb> the downstream pressure Po. As a result, Pb.S1 + F> Pi (S1 -S2) + Po.
The relationship of S3 is established, and the main valve body 7 is seated on the main valve seat portion 4 to shut off the communication of the main fluid passage 5, as shown in FIG. As a result, the step type pilot solenoid on-off valve is fully closed.

In the fully closed state described above, when the electromagnetic coil 34 is energized in the forward direction, the yoke 31 is excited in the first magnetic pole direction shown by the solid arrow in FIG. 2 and is shown by the solid arrow. The upper plunger 21 is moved upward and magnetically attracted to the suction element 23 to be positioned at the elevated position. Due to this movement, the pilot valve body 17 is lifted against the spring force of the return spring 24,
It is located at the intermediate opening position shown in FIG.

In this state, the pilot fluid passage 14 is brought into communication with the first valve opening degree, and the fluid is introduced from the inlet port 2 through the communication passage 13, the orifice passage 12 and the back passage with the flow rate according to the first valve opening degree. Flows to the outlet port 3 side through the pressure chamber 10 and the pilot fluid passage 14. Due to this flow, the back pressure chamber pressure Pb drops and the downstream pressure Po rises, but at the flow rate by the first valve opening degree, Pb.
The first valve opening of the pilot fluid passage 14 and the pressure receiving areas S1, S2, S3 of the main valve body 7 are set so that the relationship of S1 + F> Pi (S1-S2) + Po.S2 is maintained. Therefore, even at this time, Pb · S1 + F> Pi (S1
As shown in FIG. 2, the main valve body 7 is seated on the main valve seat portion 4 to block the communication of the main fluid passage 5 as shown in FIG. maintain.

As a result, the step-type pilot electromagnetic on-off valve is in a small flow rate open state in which only the flow rate according to the first valve opening of the pilot fluid passage 14 is reached. This small flow rate valve open state is stably maintained while the electromagnetic coil 34 is energized in the forward direction. By setting the maintenance time of this small flow rate valve open state to an optimum value, the differential pressure before and after the main valve body 7 becomes small, and the fluid passing noise and the fluid shock are generated when the main valve body is opened thereafter. Is suppressed.

In the above-mentioned small flow rate valve open state, the electromagnetic coil 34
When reverse current is applied to the yoke 31, the yoke 31 is excited in the second magnetic pole direction, and the magnetic circuit shown by the broken line arrow in FIG. 3 is formed. As a result, the upper plunger 21 is kept magnetically attracted to the suction element 23 by the magnetic holding action of the bear removing coil 37, and the lower plunger 22 is magnetically attracted to the upper plunger 21 against the spring force of the intermediate spring 29. 22 is also located in the raised position. Due to this movement, the pilot valve body 17 is further lifted against the spring force of the return spring 24 and is positioned at the fully open position shown in FIG.

In this state, the pilot fluid passage 14 is brought into communication with the second valve opening, and the fluid is introduced from the inlet port 2 through the communication passage 13, the orifice passage 12, and the back passage at the flow rate of the second valve opening. By flowing to the outlet port 3 side through the pressure chamber 10 and the pilot fluid passage 14, the back pressure chamber pressure Pb further decreases and the downstream pressure Po further increases, and at this time, Pb · S1 + F <Pi (S1 -S
2) + Po · S2, the second valve opening of the pilot fluid passage 14 and the pressure receiving areas S1, S2, S3 of the main valve body 7 are set so that Pb · S1 at this time. The relationship of + F <Pi (S1 −S2) + Po · S2 is established, and the main valve body 7 is, as shown in FIG.
The main fluid passage 5 is brought into communication with the main valve seat portion 4 by being separated therefrom. As a result, the step type pilot solenoid on-off valve is fully opened.

In this state, the permanent magnet 35
3 forms a magnetic closed loop indicated by a dashed arrow in FIG. 3, and the upper plunger 21 and the lower plunger 22 are both latched in the raised position by the magnetic force of the permanent magnet 35.
Even if the reverse energization to the electromagnetic coil 25 is stopped, the pilot valve body 17 remains in the fully open position.

5 (a) and 5 (b) show the relationship between the flow rate characteristics in each state of the above-mentioned step type pilot electromagnetic on-off valve and the valve position of the pilot valve body 17 and the energization characteristics to the electromagnetic coil 34. It is shown. When the electromagnetic coil 34 is energized in the forward direction in the fully open state described above, the pilot valve body 17 returns to the intermediate opening position, and when energization to the electromagnetic coil 34 is stopped in this state, the pilot valve body 17 After moving to the fully closed position, the stepped pilot solenoid on-off valve returns to the fully closed state shown in FIG. Further, in the above fully opened state, the pilot valve body 17 is brought to the fully closed position by forward energization of the electromagnetic coil 34 with a low forward current such as to cancel the magnetic force of the permanent magnet 35 or with a short pulse. Return.

6 to 8 show a second embodiment of the step type pilot solenoid on-off valve according to the present invention. In the second embodiment, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. In this embodiment, the pilot valve seat portion 15 is formed in the valve housing 38 of the electromagnetic pilot valve 16, and the pilot valve body 17, the plunger holding tube 19 and the like are attached to the valve housing 38 to unitize the electromagnetic pilot valve 16. The electromagnetic pilot valve 16 is fixedly mounted on the valve housing 1 with the valve housing 38.

In this case, the electromagnetic pilot valve 16 is attached to the valve housing 1 so that the main valve body 7 and the pilot valve body 17 are arranged on the same axis, and the back pressure chamber 10 is connected to the main valve body 7. It is defined between the valve housing 38 and the valve housing 38. Except for the above-mentioned arrangement relationship, it is the same as the first embodiment, and this embodiment can also obtain the same operation as the above-mentioned first embodiment.

In this embodiment, the electromagnetic pilot valve 16 is unitized to improve the assembling property, and the pilot valve body 17 and the main valve body 7 of the electromagnetic pilot valve 16 are improved.
By arranging and on the same axis, the assembling directions are unified and the automatic assembling is improved.

9 to 11 show a third embodiment of the step type pilot solenoid on-off valve according to the present invention. In addition,
Also in the third embodiment, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. In this embodiment, the needle-shaped inner valve body (first pilot valve body) driven by the upper plunger 21.
17 and an outer valve body (second pilot valve body) 39 integrally formed at the end portion of the lower plunger 22 and driven by the lower plunger 22 are provided. The lower plunger 22 has a hollow structure as a whole including a portion of the outer valve body 39, and an inner valve seat portion (first valve seat portion) on which the inner valve body 17 is selectively seated near the lower end of the hollow portion. ) 40 is formed.

The inner valve body 17 is shown in FIGS. 9 and 12 (a).
As shown in FIG. 4, the communication passages 41 and 42 formed in the outer valve body 28 by being seated in the inner valve seat portion 40 are shown.
10 and 12 (b), the communication passages 41 and 42 are made to communicate with each other by separating from the inner valve seat portion 40, as shown in FIG. 10 and FIG. 12 (b).
4 is brought into a communication state with the first valve opening.

The outer valve body 39 is a pilot valve seat portion (second pilot valve seat portion) formed in the valve housing 1.
15 selectively seats / separates from the pilot valve seat portion 15 to allow the inner valve body 17 to seat on the inner valve seat portion 29, as shown in FIGS. 11 and 12C. The communication between the communication passages 41 and 42 is cut off to bring the pilot passage 14 into the communication state with the second valve opening.

In this embodiment, in the fully closed state shown in FIG. 9, the electromagnetic coil 34 is energized in the forward direction, and the upper plunger 21 magnetically attracts the attractor 23, as in the above-described embodiment. By being located in the raised position, as shown in FIG. 10, the inner valve body 17 is lifted and separated from the inner valve seat portion 40, whereby the communication passages 40 and 41 are provided.
And the pilot passage 14 is in communication with the first valve opening.

This first valve opening is surely determined in an on / off manner by opening / closing the inner valve body 17, and the flow rate by the first valve opening is uniquely determined by the effective diameter of the inner valve seat portion 40. Variation in flow rate due to the first valve opening is reduced,
The small flow rate open state of the step-type pilot solenoid on-off valve stabilizes with high accuracy.

When the electromagnetic coil 34 is energized in the reverse direction with the small flow rate valve open, the upper plunger 21 is magnetically attracted to the suction element 23 by the magnetic holding action of the bear removing coil 37, as shown in FIG. The lower plunger 22 is magnetically attracted to the upper plunger 21 so as to be positioned at the raised position while keeping the attracted state, and the outer valve body 39 is separated from the pilot valve seat portion 15. By this, the inner valve body 1
7 is seated on the inner valve seat portion 29, the communication between the communication passages 41 and 42 is cut off, and the pilot passage 14 is brought into the communication state with the second valve opening degree.

This second valve opening is surely determined in an on / off manner by opening / closing the outer valve body 39, and the flow rate due to the second valve opening is uniquely determined by the effective diameter of the pilot valve seat portion 15. Variations in the flow rate due to the second valve opening are also reduced, and the fully open state of the step-type pilot electromagnetic on-off valve is stabilized with high accuracy.

13 to 15 show a fourth embodiment of the step type pilot solenoid on-off valve according to the present invention. In the fourth embodiment as well, the same parts as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. This embodiment is a modification of the second embodiment, in which the pilot passage 14 is formed through the main valve body 7, and the parrot valve seat portion 15 is formed in the main valve body 7.
The pilot valve element 17 is selectively seated on the parrot valve seat portion 15 and applies the force of the return spring 24 to the main valve element 7 as a valve closing force. Thereby, the spring 11 is omitted.

Other than the above, it is substantially the same as the second embodiment. Next, the operation of the step-type pilot electromagnetic on-off valve having the above-mentioned configuration will be described. When the electromagnetic coil 34 is not energized, as shown in FIG. 13, the pilot valve body 17 is seated on the pilot valve seat portion 15 by the spring force of the return spring 24 and is in the fully closed position. are doing. In this state, the communication of the pilot fluid passage 14 is cut off, and the back passage 10 is closed by the orifice passage 12.
The upstream pressure Pi introduced into the
The back pressure chamber pressure Pb> the downstream pressure Po. This allows
The relationship of Pb · S1 + F> Pi (S1−S2) + Po · S3 is established, and the main valve body 7 is seated on the main valve seat portion 4 as shown in FIGS. 13 and 16 (a). The main fluid passage 5 is disconnected. As a result, the step type pilot solenoid on-off valve is fully closed.

The spring force F in this case is the return spring 24.
Is a spring force applied to the main valve body 7 via the pilot valve body 17. When the electromagnetic coil 34 is energized in the forward direction in the above fully closed state, the upper plunger 21 is located at the raised position as in the case of the above-described embodiment, and the pilot valve body 17 is moved to the position shown in FIGS. It is located at the intermediate opening position shown in b).

In this state, the pilot fluid passage 14 is brought into communication with the first valve opening degree, and the fluid flows from the inlet port 2 through the communication passage 13, the orifice passage 12 and the back passage at the flow rate according to the first valve opening degree. Flows to the outlet port 3 side through the pressure chamber 10 and the pilot fluid passage 14. Due to this flow, the back pressure chamber pressure Pb drops and the downstream side pressure Po rises, but at the flow rate by the first valve opening degree, Pb.S1 + F> Pi (S1-S2) as in the above-described embodiment. + P
The relationship of o · S2 is maintained, and the main valve body 7 is
As shown in 6 (b), the state where the main valve seat portion 4 is seated and the communication of the main fluid passage 5 is blocked is maintained. At this time, since the pilot valve body 17 is separated from the pilot valve seat portion 15 of the main valve body 7, the spring force of the return spring 24 does not act on the main valve body 7, and the spring force F becomes zero.

In the above-mentioned small flow rate valve open state, the electromagnetic coil 34
When the reverse current is applied to the lower plunger 22, the lower plunger 22 also comes to the raised position as in the above-described embodiment, and the pilot valve body 17 is further lifted against the spring force of the return spring 24. 14, located in the fully open position shown in FIG. 16 (c).

In this state, the pilot fluid passage 14 is brought into communication with the second valve opening degree, and the fluid is introduced from the inlet port 2 through the communication passage 13, the orifice passage 12 and the back passage with the flow rate according to the second valve opening degree. By flowing to the outlet port 3 side through the pressure chamber 10 and the pilot fluid passage 14, the back pressure chamber pressure Pb further decreases and the downstream pressure Po further increases. As a result, Pb.S1 + F <Pi (S1 -S2) + Po.S2 as in the above-described embodiment.
As shown in FIG. 14 and FIG. 16 (c), the main valve body 7 is separated from the main valve seat portion 4 to bring the main fluid passage 5 into the communicating state. As a result, the step type pilot solenoid on-off valve is fully opened.

FIG. 17 shows an embodiment of a drive circuit for a step-type pilot electromagnetic on-off valve according to the present invention. In this drive circuit, four transistors Tr1, Tr2, Tr3, and Tr4 are bridge-connected as switching elements, and the direct current power source 43 is used as a single power source to control the energization direction of the electromagnetic coil 34, in other words, the polarity is inverted.

In this drive circuit, the transistor T
With r2 and Tr3 kept off, the transistor Tr1,
When an ON signal is input to each of the gate terminals a and d of Tr4 and the transistors Tr1 and Tr4 are turned on, a current flows in the direction of the broken arrow, and the electromagnetic coil 34 is energized in the forward direction.

On the other hand, in the direction, transistors Tr1 and T
When r4 is in the off state and an on signal is input to the gate terminals b and c of the transistors Tr2 and Tr3, respectively, and the transistors Tr2 and Tr3 are in the on state, respectively, a current flows in the direction of the solid arrow and the electromagnetic coil 34 is reversed. Directional energization is performed.

When all the transistors Tr1 to Tr4 are off, the electromagnetic coil 34 is not energized. In this drive circuit, the DC power supply 43 is used as a single power supply and the electromagnetic coil 34 is simply turned on and off.
The reversal control of the energization direction to the electromagnetic coil 34 can be performed stably at a higher speed than in the case of using the relay switch, and without causing a contact failure or the like over a long period of time.

The switching element in this drive circuit may be a MOSFET or the like instead of the transistor. FIG. 18 shows a usage example in which the step type pilot solenoid on-off valve according to the present invention is incorporated in a heat pump type multi-air conditioner.

In FIG. 18, 50 is a compressor, 5
Reference numeral 1 is an outdoor heat exchanger, 52 is an accumulator, 53 is a four-way valve, and 54 is an indoor heat exchanger. A plurality of indoor heat exchangers 54 are provided and are arranged in parallel with each other, and are individually arranged in each room, for example.

The electric expansion valve 5 is provided for each indoor heat exchanger 54.
5 and a solenoid on-off valve 56 are provided, and the solenoid on-off valve 5
6 is a step-type pilot solenoid on-off valve according to the present invention. In addition, in FIG. 18, the solid line indicates the flow of the refrigerant during cooling, and the broken line indicates the flow of the refrigerant during heating.

In the above embodiment, the throttle passage is provided by the orifice passage 12 formed in the main valve body, but this may be provided in the valve casing 1.
Further, this may be provided by a gap existing between the sliding surfaces of the inner peripheral surface of the valve chamber 6 (the inner peripheral surface of the cylinder bore) and the outer peripheral surface of the main valve body 7.

[0064]

As can be understood from the above description, according to the step type pilot electromagnetic on-off valve of the present invention, the electromagnetic pilot valve is operated in three steps of fully closed, medium open and fully open, and the electromagnetic pilot valve When the pilot valve body is driven to the intermediate opening position, the pilot fluid passage is in communication with the first valve opening, and the main valve is open while the pilot valve body is located at the intermediate opening position. Since the main valve is kept closed by closing the valve to maintain the small flow rate open state with only the flow rate of the first valve opening, the maintenance time can be set by energizing the solenoid pilot valve. The optimum control of the maintenance time reduces the differential pressure across the main valve disc, and sufficiently suppresses the generation of large impact noise and vibration due to the fluid flow when the main valve disc is opened. So as to.

When the pilot valve body of the electromagnetic pilot valve is driven to open and close by a combination of two plungers, a permanent magnet and an electromagnetic coil, the electromagnetic pilot valve is fully closed only by reversing the energizing direction of the electromagnetic coil. It is possible to surely perform the step operation in three stages of middle open and full open, and it is possible to reduce power consumption without continuously energizing the electromagnetic coil to maintain the fully closed state and the fully open state.

When the pilot valve body has a double structure consisting of the first pilot valve body and the second pilot valve body, the opening and closing of the first pilot valve body ensures the first valve opening degree. The opening and closing of the second pilot valve element reliably determines the second valve opening, and the small flow rate open state and full open state of the step-type pilot solenoid open / close valve are stable with high accuracy, and the step-type pilot electromagnetic open / close The operational reliability of the valve is improved.

By disposing the pilot valve body and the main valve body of the electromagnetic pilot valve on the same axis, the assembling direction of the valve device is unified and the automatic assembling property is improved. When the pilot fluid passage is provided in the main valve body and the pilot valve body cooperates with the parrot valve seat portion formed in the main valve body to control the flow rate, the valve structure is simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of a step-type pilot electromagnetic on-off valve according to the present invention in a fully closed state.

FIG. 2 is a cross-sectional view showing a first embodiment of a step type pilot solenoid on-off valve according to the present invention in a small flow rate open state.

FIG. 3 is a sectional view showing a first embodiment of a step-type pilot electromagnetic on-off valve according to the present invention in a fully opened state.

4 (a), (b) and (c) are partially enlarged cross-sectional views showing in detail the open / closed state of the electromagnetic pilot valve in the first embodiment.

5 (a) and 5 (b) show the relationship between the flow rate characteristics and the valve position of the pilot valve body in each state of the step type pilot electromagnetic on-off valve in the first embodiment, and the relationship with the energization characteristics for the electromagnetic coil. It is a graph shown.

FIG. 6 is a cross-sectional view showing a second embodiment of a step-type pilot electromagnetic on-off valve according to the present invention in a fully closed state.

FIG. 7 is a sectional view showing a second embodiment of the step-type pilot solenoid on-off valve according to the present invention in a small flow rate valve opened state.

FIG. 8 is a sectional view showing a second embodiment of a step-type pilot solenoid on-off valve according to the present invention in a fully opened state.

FIG. 9 is a sectional view showing a third embodiment of a step-type pilot solenoid on-off valve according to the present invention in a fully closed state.

FIG. 10 is a sectional view showing a third embodiment of the step-type pilot electromagnetic on-off valve according to the present invention in a small flow rate valve opened state.

FIG. 11 is a sectional view showing a third embodiment of a step-type pilot solenoid on-off valve according to the present invention in a fully opened state.

12 (a), (b) and (c) are partially enlarged sectional views showing in detail the open / closed state of the electromagnetic pilot valve in the third embodiment.

FIG. 13 is a sectional view showing a third embodiment of the step-type pilot solenoid on-off valve according to the present invention in a fully closed state.

FIG. 14 is a cross-sectional view showing a third embodiment of the step type pilot solenoid on-off valve according to the present invention in a small flow rate open state.

FIG. 15 is a sectional view showing a third embodiment of a step-type pilot solenoid on-off valve according to the present invention in a fully opened state.

16 (a), (b) and (c) are partially enlarged cross-sectional views showing in detail the open / closed state of the electromagnetic pilot valve in the third embodiment.

FIG. 17 is an electric circuit diagram showing an embodiment of a drive circuit for a step-type pilot electromagnetic on-off valve according to the present invention.

FIG. 18 is a block diagram showing a usage example in which the step type pilot solenoid on-off valve according to the present invention is incorporated in a heat pump type multi-air conditioner.

[Explanation of symbols]

 1 Valve Casing 2 Inlet Port 3 Outlet Port 4 Main Valve Seat 5 Main Fluid Passage 7 Main Valve Body 10 Back Pressure Chamber 12 Orifice Passage 14 Pilot Fluid Passage 15 Pilot Valve Seat 17 Pilot Valve (Inner Valve) 21 Top Plunger 22 Lower plunger 23 Suction element 24 Return spring 31 Yoke 34 Electromagnetic coil 35 Permanent magnet 38 Valve housing 39 Outer valve body 40 Inner valve seat portion

Claims (5)

[Claims] 1. A first pressure receiving area, wherein a pressure of a back pressure chamber is applied to a valve closing side, and a fluid pressure upstream of a main valve seat portion formed in a valve housing is smaller than the first pressure receiving area. The second pressure receiving area is applied to the valve opening side, and the fluid pressure downstream of the main valve seat is applied to the valve opening side with the third pressure receiving area. A main valve body that is seated / separated to open / close the main fluid passage, and the main fluid passage upstream of the main valve seat portion is connected to the back pressure chamber, and the main valve seat is connected to the back pressure chamber. Section for guiding the fluid pressure upstream of the portion, a pilot fluid passage for connecting the back pressure chamber to the main fluid passage downstream of the main valve seat portion, and a cutoff for communication of the pilot fluid passage The fully closed position and the pilot fluid passage to the first valve opening A three-stage opening / closing operation between an intermediate opening position in which the pilot fluid passage is in a communicating state and a fully open position in which the pilot fluid passage is in a communicating state with a second valve opening greater than the first valve opening. An operation type electromagnetic pilot valve, and when the pilot fluid passage is shut off or is in a communication state by the first valve opening degree, the main valve body moves to the main valve seat portion due to the pressure difference. When the main fluid passage is seated and the main fluid passage is closed and the pilot fluid passage is in a communication state by the second valve opening degree, the main valve body is separated from the main valve seat portion by the pressure receiving difference. A first valve opening and a second valve opening of the pilot fluid passage and first to third pressure receiving areas of the main valve body are set so as to open the main fluid passage. Characteristic step type pilot solenoid on-off valve. 2. The pilot valve body, wherein the electromagnetic pilot valve moves in an axial direction to control a flow rate in cooperation with a pilot valve seat portion provided in the pilot fluid passage, and the pilot valve body. Is arranged movably between a first position and a second position in the moving direction of the pilot valve body by engaging the pilot valve body by moving from the first position to the second position. A first plunger for driving from the fully closed position to the intermediate opening position, in series in the moving direction of the first plunger and the pilot valve body, and a third position in the moving direction of the pilot valve body. It is movably arranged between the fourth position and the third position to move from the fourth position to engage with the pilot valve body to move the pilot valve body from the intermediate opening position. Fully open position A second plunger to be driven; a suction element fixedly arranged facing the end surface of the first plunger on the second position side; a yoke having one end connected to the suction element; The plunger is located at the second position, and the second plunger is located at the fourth position to form a magnetic closed loop by the first plunger, the second plunger, the attractor, and the yoke. A permanent magnet for latching the second plunger at the fourth position, and exciting the yoke in a first magnetic pole direction opposite to the magnetic pole direction of the permanent magnet by energizing in the first direction. The first plunger is driven to the second position, and the yoke is moved to the second magnetic pole direction which is the same as the magnetic pole direction of the permanent magnet by energizing in the second direction opposite to the first direction. Excite the second Step Pilot solenoid valve according to claim 1, characterized in that it has an electromagnetic coil, a for driving the plunger into the fourth position. 3. The pilot fluid passage is provided in the main valve body, and the pilot valve body is configured to cooperate with a parrot valve seat portion formed in the main valve body to control the flow rate. The step type pilot solenoid on-off valve according to claim 2, wherein. 4. A dual structure in which the pilot valve element comprises a first pilot valve element driven by the first plunger and a hollow second pilot valve element driven by the second plunger. The first pilot valve body cooperates with the first pilot valve seat portion formed on the second pilot valve body to control the flow rate, and the second pilot valve body is formed on the valve casing side. The step-type pilot solenoid on-off valve according to claim 2, wherein the flow rate control is performed in cooperation with the second pilot valve seat portion that is formed. 5. The main valve body and the pilot valve body of the electromagnetic pilot valve are opened and closed by moving in the axial direction, and the moving direction of the main valve body and the moving direction of the pilot valve body of the electromagnetic pilot valve. 5. The step type pilot solenoid on-off valve according to claim 1, wherein and are in the same axial direction.