JPS62131981A - Capacity control valve in capacity variable compressor - Google Patents

Abstract

PURPOSE:To externally control a set pressure with a compressor being kept installed by providing a set pressure introducing passage separately from the suction and discharge pressure feeding passages of a cooling medium, and making the pressure receiving part of a capacity control valve sense said set pressure, as an externally balanceable type. CONSTITUTION:A valve body 26 and a valve body 28 which are brought into contact with and separated from valve seats v1, v2 provided in a suction pressure feeding passage s''' and a discharge pressure feeding passage d''' which are connected to a set pressure in a crankcase 1 from the suction sides and discharge sides of piston cylinders 3, 3', are provided in a capacity control valve B. And, one valve body is driven to be opened when the other valve body is closed based on the action of a diaphragm 16 in the valve B, and an externally adjustable adjusting spring 22 is provided on the outside of the diaphragm 16. And, a set pressure introducing passage (c) from the inside of the crankcase 1 is connected to a pressure receiving chamber inside the diaphragm 16. Thereby, a set pressure for one side of the diaphragm 16 can be introduced from the inside of the case 1 through the passage (c), enabling accurate control of the set pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a capacity control valve in a variable capacity compressor.

[Conventional technology]

In Katara, the compressor is installed in conjunction with the car engine, so the rotation speed of the compressor varies widely between when the car is driving on a city road and when driving on a highway. The suction volume becomes excessive and the low-pressure pressure decreases, especially in the intermediate period, and the compressor opens and closes frequently because the capacity exceeds what is necessary, and the blowout temperature becomes too low, creating a feeling of draft and wasting power. There are disadvantages such as using

As a countermeasure to this problem, as shown in Japanese Patent Publication No. 58-158382, a variable-capacity compressor with a variable-angle wobble temporary type detects the suction pressure and controls the pressure inside the compressor to vary the capacity. It is intended to maintain pressure (temperature).

By the way, in the above-mentioned known technology, the pressure receiving part of the control valve is located in the flow path of the refrigerant to be sensed and is of the so-called inward type, so when the control valve opens, the suction pressure to be sensed is set at an intermediate setting. Since it changes under the influence of pressure, the true suction pressure cannot be detected, and it does not have an external adjustment function, so it is impossible to adjust the set pressure according to differences in compressor quality. Ta.

[Problem that the invention seeks to solve]

The present invention has been made with attention to the above points, and is an outward type in which a circuit separate from the refrigerant flow path is provided so that the set pressure is sensed by the pressure receiving part of the capacity control valve. The set pressure can be easily adjusted from the outside while the device is attached.

[Means for solving problems]

In order to achieve the above object, the present invention provides a valve seat that approaches and separates from a valve seat interposed in a suction pressure supply passage and a discharge pressure supply passage that communicate from the suction side and discharge side of the piston cylinder to the set pressure in the crankcase. The first valve body and the second valve body are driven so that when one valve body closes, the other valve body opens based on the operation of the pressure responsive member, and the adjustment is freely adjustable on the outside of the pressure responsive member. A configuration is adopted in which a spring is provided and a pressure receiving chamber inside the spring is communicated with the set pressure introduction passage from inside the crankcase.

[For production]

In the above configuration, the set pressure inside the crankcase is set by an adjustment spring that is opposed to each other on one side of the pressure-responsive member, and when the set pressure is about to rise, the valve of the suction pressure supply passage is opened to increase the suction pressure inside the crankcase. When the set pressure is about to drop, the valve of the discharge pressure supply passage is opened and the discharge pressure is introduced, thereby keeping the set pressure constant.

〔Example〕

In FIG. 1, A is a compressor, and B is a capacity control valve fixed in a mounting recess H on one side of the compressor A.

In the compressor A, a plurality of cylinders 3゜3'...
A piston 4 is slidably provided in each cylinder 3, 3', . . . . crank case l
A drive shaft 5 is rotatably provided from the head portion 2 to the head portion 2, and the drive shaft 5 is driven by an engine (not shown) via a belt 7 via a boot 1J6 provided at the outer end. Drive shaft 5
is provided with a variable angle wobble plate 8 as is well known, and the wobble plate 8 and the piston 4 are connected to an annular groove 8a and a socket 4a.
When the wobble plate 8 is rotated in an inclined state by the drive shaft 5, the piston rod 9 through the piston 4 reciprocate, and the crankcase 1 Set pressure Pc inside and suction pressure P inside cylinders 3, 3'...
The mounting angle of the wobble plate 8 is automatically adjusted according to the differential pressure between the wobble plate 8 and the wobble plate 8, and the stroke amount of the piston 4 changes as the angle of the wobble plate 8 changes.

There are suction ports S at both ends of each cylinder 3, 3'...
and a discharge port are provided, and each suction port S communicates with each other through an internal passage S, and each discharge port communicates with each other through an internal conduit d. An evaporator 10 and a condenser 11 forming a refrigeration cycle are connected to one cylinder 3 through passages s' and d', and a capacity control valve B is connected to the other cylinder 3' through passages S'' and d''. connected to. Piston 4 is installed in the intake port S.
A valve body 12 that opens during the suction stroke of the piston 4 and closes during the discharge stroke is provided, and a valve body 13 that opens during the discharge stroke of the piston 4 and closes during the suction stroke is provided at the discharge port.
is provided.

In the capacity adjustment valve B, a pressure responsive part M is provided on one side of the main body 14.
is provided. The pressure responsive part M has an upper lid 17 with a diaphragm 16 sandwiched between a lower lid 15 fixed to the main body 14, and a spring box 18 is fixed to the upper lid 17.
Adjusting screw 19 screwed into spring box 18 and diaphragm 1
An adjustment spring 22 is provided between the upper stopper 20 of No. 6 and a spring receiver 21 that comes into contact with it.

On the other side of the diaphragm 16 is a stop 24 of the first interlocking rod 23.
A spring 25 is provided between the corresponding metal 24 and the main body 14, and is opposed to the adjustment spring 22. The bolt 24 and the spring 25 are located in the pressure receiving chamber R1, and the pressure P to be controlled from the crankcase 1 is applied to the pressure receiving chamber R+.
A set pressure introduction port 14a is formed which communicates with the passage C through which the pressure is introduced.

The first interlocking rod 23 passes through the sliding hole 14b of the main body and reaches the first valve chamber R2, and the first valve element 26 fixed to its tip opens and closes the valve seat v1. A suction pressure introduction port 14C communicating with the suction pressure passage S'' is provided on the secondary side of the first valve chamber R2, and a suction pressure supply port 14C communicating with the suction pressure supply passage S'' to the crankcase l is provided on the secondary side. A mouth 14d is formed.

On the axial extension line of the first interlocking rod 23, the second valve chamber R is passed from the suction pressure introduction port 14C through the sliding hole 14e.
A second interlocking rod 27 extending up to 3 is provided at one end so as to be able to freely approach and separate from the first valve body 26.

A second valve body 28 is provided at the other end of the second interlocking rod 27 so as to be movable toward and away from the valve seat v2 to open and close the valve seat v2. A spring 30 is provided between the second valve body 28 and the spring receiver 29 for biasing the second valve body 28 in the closing direction of the valve seat v2 and the second interlocking rod 27 in the direction of contacting the first valve body 26. .

A discharge pressure inlet 14f communicating with the discharge pressure passage d'' is provided on the primary side of the second valve chamber R3, and a discharge pressure inlet 14f communicating with the discharge pressure supply passage d'' to the crankcase l is provided on the secondary side. A supply port 14g is formed. Note that 31 is a seal ring.

In the above configuration, the crank chamber pressure Pc in the crankcase 1 is introduced into the pressure receiving chamber R+ from the passage C through the set pressure introduction port 14a, and opposes the adjustment spring 22 via the diaphragm 16.

When the set pressure Pc increases, the diaphragm 16 moves in the direction of compressing the displacement spring 22, and the first interlocking rod 23 responds to this movement and moves the first valve body 26 to the valve seat v1.
The suction pressure Ps from the passage S'' is sent into the crankcase 1 through the suction pressure supply passage S''' and lowered to the set pressure pc. In this case,
The second valve body 28 closes the valve seat v2 and blocks the flow of the discharge pressure Pd (FIG. 2).

Conversely, when the set pressure Pc becomes lower, the diaphragm 16 pushes the first interlocking rod 23 due to the expansion of the adjustment spring 22, and the first valve body 26 closes the valve seat v1 to cut off the flow of the suction pressure Ps. In the closed state, the body 26 separates the second valve body 28 from the valve seat v2 by driving the second interlocking rod 27, and supplies the discharge pressure Pd from the passage d'' to the crankcase 1 through the discharge pressure supply passage d''. The pressure is increased to the set pressure Pc (Fig. 3). Therefore,
The set pressure Pc in the crankcase 1 is kept constant,
Despite changes in engine rotation, when the cooling load is small, Ps decreases, so the value of (Pc-Ps) increases, and the compressor capacity is controlled.

In the embodiment shown in FIG. 4, another sealing structure for attaching the capacity control valve B' to the compressor A' is shown, and the structural parts corresponding to the capacity control valve B described above are given the same reference numerals! It is shown with .

The capacity control valve B' is fitted into a mounting recess H' on one side of the compressor A', and has an elastic seal ring 31' on the outer peripheral edge of the upper cover 17' around the spring box 18' of the pressure responsive part M'. A holder ring 32 having a T-shaped cross section is fitted into the mounting recess H' and fixed with a retaining ring 33, and the elastic seal ring 31' is pressed against the upper cover 17' and the peripheral wall 34 of the mounting recess H'. to seal it with the outside.

〔effect〕

As described above, the present invention includes a first valve body that approaches and separates from a valve seat provided in a suction pressure supply passage and a discharge pressure supply passage that communicate from the suction side and discharge side of a piston cylinder to a set pressure in the crankcase. The second valve body is driven so that when one valve body closes, the other valve body opens based on the operation of the pressure responsive member, and a freely adjustable adjustment spring is provided on the outside of the pressure responsive member. Since the set pressure introduction passage from inside the crankcase is connected to the pressure receiving chamber inside the crankcase, the set pressure for one side of the pressure responsive member in the capacity control valve is controlled independently from the fluid circulation passage. It can be introduced through a dedicated passage from inside the case, allowing accurate control of the set pressure, and since the adjustment spring can be adjusted from the outside, individual adjustments can be made easily.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the capacity control valve, and FIG. 3 is a diagram of the same operating state.
FIG. 4 is a sectional view of another embodiment. A...Compressor, B...Capacity control valve, 1...
Crank case, 3, 3'...Piston cylinder, 1
6... diaphragm (pressure responsive member), vl... first valve seat, v2... second valve seat, 26... first valve body, 2
8...Second valve body, 22...Adjustment spring, S'.
...Suction pressure supply passage, d'...Discharge pressure supply passage,
C...Set pressure introduction passage. Patent applicant Saginomiya Seisakusho Co., Ltd. Figure 2 4f

Claims (1)

[Claims] A first valve body and a second valve body that come into contact with and separate from valve seats interposed in a suction pressure supply passage and a discharge pressure supply passage that communicate from the suction side and discharge side of the piston cylinder to the set pressure in the crankcase are pressure-responsive. When one valve body closes based on the operation of the member, the other valve body is driven to open, and a freely adjustable adjustment spring is provided on the outside of the pressure responsive member, and the crank is installed in the pressure receiving chamber inside the spring. A capacity control valve for a variable capacity compressor, characterized in that it is formed by communicating a set pressure introduction passage from inside the case.