JPH0617009Y2 - Variable capacity compressor pressure control valve - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a pressure regulating valve of a variable displacement compressor for controlling a discharge flow rate of a refrigerant of a compressor such as a car cooler.

[Conventional technology]

Conventionally, this type of pressure adjusting valve is disclosed in Japanese Patent Publication No. 62-40555.

That is, the conventional pressure adjusting valve will be described with reference to FIG. 2. The pressure adjusting valve has a control point set by the compressor suction pressure through the hole 1a in the bellows chamber 1 when the discharge pressure of the compressor is constant. Below, the bellows 2 expands due to the elastic force of the spring 3 in the bellows 2, and the second valve body 5 on the suction pressure side is closed via the first actuation rod 4, and
The second valve rod 5 integrated with the second valve body 5 opens the first valve body 7 on the discharge pressure side.

Since the chambers D and D'of the valve body 10 communicate with the control chamber of the compressor via the passages 8 and 9, respectively, when the first valve body 7 is open, the control chamber and the suction pressure are The differential pressure increases,
The inclination angle of the wobble plate of the compressor is reduced, the stroke amount of the piston is reduced, the discharge flow rate of the compressor is reduced, and the suction pressure is controlled to approach the control point pressure.

Further, when the suction pressure is equal to or higher than the set control point, the first valve body 7 is closed and the second valve body 5 is opened contrary to the above, so that the pressure difference between the control chamber pressure and the suction pressure is increased. Is reduced, and the discharge flow rate of the compressor is increased by the action opposite to the above to control the suction pressure to approach the control point pressure.

[Problems to be solved by the device]

However, in the conventional pressure regulating valve, since the passages 8 and 9 communicating with the compressor control chamber have a large diameter and are short, the differential pressure between the control chamber pressure and the suction pressure is changed when the discharge pressure or the suction pressure fluctuates. Change abruptly and cause hunting. Further, when the first valve body 7 or the second valve body 5 is opened, it is difficult to regulate the maximum flow rate, and thus there is a problem that the discharge flow rate of the compressor cannot be smoothly controlled.

Further, in the pressure regulating valve as described above, each valve body 5,
In order to assemble 7 and the functional parts such as the actuating rods 4, 6 and the bellows 2 at predetermined positions, the valve body 10 has a three-part structure of the first valve body 10a, the second valve body 10b and the bellows cover 1. Since it is necessary to integrate them by press fitting or caulking, it is very difficult to accurately manufacture the interval size of each valve seat and the concentricity of the valve body 10, etc. There was a drawback of this.

Further, in the above-mentioned conventional one, since the sharp upper end of the first actuating rod 4 and the valve pin pocket of the second valve body 5 are fitted, the bellows 2 is inclined with respect to the valve operating direction. However, in the case of lateral displacement, a force component different from that in the valve operating direction is applied to the valve portion from the bellows portion, and there is a problem in that responsiveness to control deteriorates.

[Means for Solving the Problems]

The present invention has been devised to solve the above-mentioned problems, and includes a first valve chamber 18 communicating with the discharge chamber 15 of the compressor 11, a first valve chamber 18 and a flow passage 20. The second valve chamber 19 communicating with the suction chamber 14 of the compressor 11 and the hole 44.
An integral valve body 17 having a bellows chamber 30 communicating therewith, and a small-diameter elongated passage 21 opening to the flow passage 20 and communicating with the control chamber 16 of the compressor 11 is provided in the valve body 17. , A first valve body 22 that is spring-biased toward the flow path 20 side is incorporated in the first valve chamber 18, and the second valve chamber 1
The second valve element 9 is spring-biased to the bellows chamber 30 side.
5, the bellows chamber 30 is provided with a bellows 31 that extends together with the spring 35 on the second valve body 25 side, and a communication hole 29 that connects the second valve chamber 19 and the bellows chamber 30 is provided. Then, the second valve body 25 slides in the valve body 17 in the axial direction, and the protruding portion A at one end thereof has the first valve body 22.
And the other end abuts on a receiver 33 provided on the bellows 31, and the receiver 33 is movable relative to the second valve body 25 in the valve body operating direction and a direction orthogonal to the operating direction. It is characterized by

[Action]

Since the present invention has the above-mentioned means, it responds to both the discharge pressure Pd and the suction pressure Ps, and the operation of the bellows 31 causes the discharge pressure side valve element and the suction pressure side valve element, that is, the first valve element. The second valve bodies 22 and 25 open and close the flow path 20.

That is, when the discharge pressure Pd is constant, the heat load decreases or the rotation speed of the compressor 21 increases, and when the suction pressure Ps becomes equal to or lower than the set control point, the bellows 31 expands to the second pressure.
The valve body 25 is closed, and the first valve body 22 is opened via the one end protruding portion A of the second valve body 25.

Therefore, the discharge chamber 15 and the control chamber 16 of the compressor 11 are provided in the flow passage 20 and the valve body 17 and have a small diameter and long passage 2.
1, the differential pressure between the control chamber pressure Pc and the suction pressure Ps becomes large, and the inclination angle of the wobble plate 12a is made small to reduce the discharge flow rate of the compressor 11 as described above.

On the contrary, when the suction pressure Ps becomes equal to or higher than the set control point, the bellows 31 contracts, the second valve body 25 opens downward by the elastic force of the second spring 28, and the first valve body 22 opens. The spring 23 of No. 1 closes the valve downward. Therefore, the bellows chamber 30 has a hole 44 provided in the valve body 17 and a second valve body 2
5 communicates with the control chamber 16 via the communication hole 29 provided in 5, the flow passage 20 provided in the valve body 17 and the small-diameter elongated passage 21, and the differential pressure between the control chamber pressure Pc and the suction pressure Ps becomes small, The wobble plate 12a is increased in inclination angle to increase the discharge flow rate of the compressor 11.

At this time, since the length of the protruding portion A of the second valve body 25 can be appropriately selected by design, the second valve body 25 can be opened before the first valve body 22 is closed, and Depending on the purpose, the length of the protruding portion A can be selected so that it has an appropriate pressure characteristic.

Further, the small-diameter elongated passage 21 that communicates the flow path 20 with the control chamber 16 has a fluid throttling action, and abrupt fluctuation of the differential pressure between the control chamber pressure Pc and the suction pressure Ps is suppressed, so that the variable displacement compression is performed. The machine 11 can be stably controlled.

Further, since the valve body 17 is integrated, workability and assemblability are improved, and accuracy can be improved.

Furthermore, according to the present invention, since the second valve body 25 and the receiver 33 of the bellows 31 are in contact with each other so as to be movable relative to each other in the direction perpendicular to the valve operating direction, the bellows 31 can be moved relative to the valve operating direction. When displaced in the lateral direction, the valve body 25 and the receiver 3
3, the contact position with 3 moves, and a force is applied from the bellows 31 to the valve body 25 only in the valve operating direction, and the bellows 31 is inclined at the sliding portion between the second valve body 25 and the valve body 17. The responsiveness can be improved without causing friction due to the lateral displacement.

〔Example〕

An embodiment of the present invention will be specifically described below with reference to FIG.

In the figure, 11 is a variable displacement compressor, which has a wobble plate 12a, a drive hub 12b, a piston 13, a suction chamber 14, a discharge chamber 15, and a control chamber 16, and when the drive hub 12b rotates, the piston 13 reciprocates. The refrigerant discharged from the discharge chamber 15 is supplied to a condenser and an evaporator (not shown) to perform predetermined cooling and return to the suction chamber 14.

Reference numeral 17 denotes a main body of a pressure regulating valve according to the present invention, which is installed in a valve housing (not shown) of the compressor 11, and the valve main body 17 is a first valve chamber 1 communicating with a discharge chamber 15 of the compressor 11.
8 and a second valve chamber 18 that communicates with the first valve chamber 18 via a flow path 20.
Valve chamber 19, a bellows chamber 30 that communicates with the suction chamber 14 of the compressor 11 through a hole 44, and a small-diameter elongated passage 21 that opens to the flow passage 20 and communicates with the control chamber 16 of the compressor 11. In one example, it is composed of an integral metal part having a narrow passage having a diameter of about 0.8 mm which acts as a throttling action of fluid.

The first valve chamber 18 has a spherical first valve body 22.
And a first spring 23 for urging the valve body 22 so as to close the one end opening of the flow passage 20, and the second spring
Second valve chamber 19 has a conical valve portion and a protruding portion A.
Valve body 25 is incorporated.

The second valve body 25 includes the partition wall B and the valve body 17 which are orthogonal to each other.
Has a cylindrical sliding portion C that slides on the inner wall of the
And a second spring 28 incorporated between the second valve chamber 19 and the upper wall of the second valve chamber 19.
Is urged toward the bellows chamber 30 (downward in the figure).

A communication hole 29 that communicates the second valve chamber 19 and the bellows chamber 30 is formed in the partition wall B of the valve body 25.

A bellows 31 is provided in the bellows chamber 30, a stopper 32 having a T-shaped cross section is provided at the center of the bellows 31, and a dish-shaped receiver 33 is provided above the stopper 32.
And the upper edge of the bellows 31 is sandwiched and fixed between the receiver 33 and the stopper 32.

Reference numeral 34 is an adjusting screw screwed into the valve body 17, and a third spring 35, which is a compression spring, is interposed between the adjusting screw 34 and the stopper 32. Reference numeral 36 is an O-ring for sealing which is fitted in the outer peripheral groove of the adjusting screw 34.

The valve body 25 has one end protruding portion A protruding into the flow path 20.
In the figure, the bottom surface is in contact with the upper surface of the receiver 33. Reference numeral 45 is a filter wire mesh provided in the first valve chamber 18.

In the above-described embodiment, the valve body 25 is provided with the communication hole 29 in the partition wall B, but the peripheral wall portion of the valve body 17 may be provided with a communication hole for communicating the second valve chamber 19 and the bellows chamber 30. . Also,
Although the lower end surface of the valve body 25 (the end surface that abuts on the receiver 33) is a flat surface, it may be a spherical surface.

Since the pressure control valve of the present invention is configured as described above, when the suction pressure Ps becomes lower than the control point when the discharge pressure Pd is constant, the bellows 31 expands together with the elasticity of the third spring 35, and In the figure, the second valve body 25 is raised through the stopper 32 and the receiver 33, and the first valve body 22 is also raised against the elasticity of the first spring 23.
The valve chamber 18 and the flow path 20 communicate with each other. At this time, the lower end opening valve seat portion of the flow path 20 is closed due to the rise of the valve body 25.

As described above, the discharge chamber 15 and the control chamber 16 of the variable displacement compressor 11, the first valve chamber 18, the flow passage 20 and the elongated passage 21 are provided.
The pressure difference between the suction pressure Ps and the control chamber pressure Pc increases, the inclination angle of the wobble plate 12a of the compressor 11 decreases, the stroke amount of the piston 13 decreases, and the discharge of the compressor increases. The flow rate is reduced and the suction pressure is controlled to approach the control point pressure.

On the contrary, when the suction pressure Ps becomes equal to or higher than the control point, the pressure causes the bellows 31 to move to the third spring 35.
It contracts against the elasticity of. Due to the contraction of the bellows 35, the second valve body 25 is opened downward by the elastic force of the second spring 28, and the first valve body 22 is downwardly closed by the elastic force of the first spring 23.

Therefore, the elongated passage 21 of the valve body 17 communicates with the bellows chamber 30 through the passage 20 and the communication hole 29 of the second valve chamber 19 and the second valve body 25, and further through the hole 44 to the compressor suction. Since it communicates with the chamber 14, the control chamber pressure Pc and the suction pressure Ps
The pressure difference between the wobble plate 12a and the wobble plate 12a decreases.
The inclination angle of is increased, and the discharge flow rate of the compressor 11 is controlled to be increased.

Thus, according to the present invention, when the discharge pressure Pd is constant,
By increasing or decreasing the suction pressure Ps, the discharge flow rate can be increased or decreased correspondingly.

At this time, if the dimension of the protruding portion A of the second valve body 25 is appropriately selected by design, when the suction pressure Ps is lowered, the first valve is inserted through the protruding portion A before closing the second valve body 25. The control valve has the characteristic of opening the body 22. Also, depending on the purpose, the protrusion A
Appropriate pressure characteristics can be obtained by selecting the length.

Further, in the present invention, in order to connect the flow path 20 and the control chamber 16 to each other, the elongated passage 21 having a small diameter and a length corresponding to the volume of the control chamber 16 is provided in the valve body 17, so that the heat load and the compressor 11 When the discharge pressure Pd or the suction pressure Ps fluctuates due to a change in the number of revolutions, the fluid flows from the discharge chamber 15 side to the control chamber 16 or from the control chamber 16 to the suction chamber 14, and the difference between the control chamber pressure Pc and the suction pressure Ps. When the pressure changes, since there is a throttling action of the fluid, not only the fluctuation of the discharge flow rate of the compressor 11 becomes gentle but also the maximum flow rate is easily limited,
The control of the compressor 11 can be stably performed.

Further, according to the present invention, since the valve body 17 is integrally formed,
The workability and the assemblability are good, and the accuracy can be improved.

Moreover, since the valve portion and the bellows portion are in contact with each other by the valve element 25 and the receiver 33 so as to be relatively movable in the direction orthogonal to the valve operating direction, the bellows 31 is displaced laterally with respect to the valve operating direction. Even when the contact position between the valve body 25 and the receiver 33 moves, a force is applied from the bellows 31 to the valve body 25 only in the valve operating direction, and sliding between the valve body 25 and the valve body 17 occurs. There is no friction due to the inclination of the bellows 31 or the lateral displacement of the bellows 31, and the response is good.

[Effect of device]

Since the pressure regulating valve of the present invention has the above-mentioned structure, it can stably control the variable displacement compressor, obtain the pressure characteristic according to the purpose, and the workability and assemblability. It is possible to provide a pressure regulating valve having good responsiveness and improved accuracy as well as good responsiveness.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the relationship between the pressure regulating valve of the present invention and a variable displacement compressor, and FIG. 2 is a schematic vertical sectional view of a conventional pressure regulating valve. 11 ... Variable capacity compressor, 13 ... Piston, 14 ... Suction chamber, 15 ... Discharge chamber, 16 ... Control chamber, 17 ... Valve body, 18
... first valve chamber, 19 ... second valve chamber, 20 ... flow path, 21 ...
Elongated passage, 22 ... first valve body, 23 ... first spring, 2
5 ... 2nd valve body, A ... 1st protrusion part of 2nd valve body, C ... 2nd
Sliding part of valve body, 28 ... Second spring, 29 ... Communication hole, 30
... Bellows chamber, 31 ... Bellows, 32 ... Stopper, 33
... receiver, 35 ... third spring, 44 ... hole.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hitoshi Umezawa 7-1724 Todoroki, Setagaya-ku, Tokyo Inside Fuji Koki Co., Ltd. (72) Inventor Jiro Oka 7-17 Todoroki, Setagaya-ku, Tokyo No. 24 Incorporated company Fujikoki Co., Ltd. (56) References Japanese Patent Publication No. 62-40555 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A first valve chamber (18) communicating with a discharge chamber (15) of a compressor (11) and a second valve chamber communicating with this first valve chamber via a flow path (20). Chamber (19), suction chamber (14) and hole (44) of compressor (11)
An integral valve body (17) having a bellows chamber (30) communicating with each other is provided, and the valve body (17) is opened to the flow path (20) and the control chamber of the compressor (11) ( 16) is provided with a small and slender passageway (21) communicating with the first valve chamber (18) and a first valve body (22) which is spring-biased toward the flow passage (20) is incorporated into the first valve chamber (18). 2 valve chambers (1
9) has a second valve body (2
5) is incorporated, and the bellows chamber (30) is provided with a bellows (31) extending along with the spring (35) on the side of the second valve body (25). It has a communication hole (29) for communicating the bellows chamber (30), the second valve body (25) slides in the valve body (17) in the axial direction, and its one end protruding portion (A) is the above-mentioned. First valve body
(22), and the other end (3) of the bellows (31)
A variable capacity, which is in contact with 3), and in which the receiver (33) can move relative to the second valve body (25) in a valve body operating direction and a direction orthogonal to the operating direction. Type pressure regulator valve.