JPS6291672A - Variable delivery compressor - Google Patents

Abstract

PURPOSE:To convert to a smaller delivery easily, by converting a pressure adjusting device forcibly through a form variation device when the coolant temperature rises abnormally, in a compressor where reciprocating strokes of a piston can be operated by the signal pressure adjusted at the pressure adjusting device. CONSTITUTION:When a shaft 104 is rotated through an electromagnetic clutch 107, and a wabble plate 108 is swayed to reciprocate a piston 110, the coolant from an intake chamber 302 is compressed in a compression chamber 305, and exhausted to an exhaust chamber 303. In this case, a high pressure coolant and a low pressure coolant from the said chambers 305 and 302 are introduced to a high pressure chamber and a low pressure chamber 401 and 402 of a pressure adjusting device 400 respectively, and the both coolants are mixed at a mixing chamber 403 to make a signal pressure, which is introduced to a signal pressure chamber 101 through a passage 500. And, the pressure adjusting device 400 is composed to release a high pressure side valve 405 by an increased plus- power of a spring 412 of a form memory alloy, when the coolant temperature in a high pressure side linking route 404 rises over a specific value.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a variable capacity compressor, and is particularly effective for use as a refrigerant compressor for an automobile air conditioner.

[Conventional technology]

Conventionally, this type of so-called wobble plate type compressor has been known to be equipped with variable capacity means. (
(For example, US Pat. No. 4,428,718) In this method, a signal pressure chamber is formed on the back surface of the piston, and the reciprocating stroke of the piston is varied by adjusting the pressure within the signal pressure chamber. As a means for adjusting the pressure in the signal pressure chamber, adjusting the pressure in the compressor suction chamber and the pressure in the compressor discharge chamber has been used.

[Problem that the invention seeks to solve]

The pressure regulating means determines the discharge capacity required of the compressor by sensing the pressure within the suction chamber. However, with this conventional means, it has not been possible to satisfactorily reduce the capacity of the compressor when an abnormality occurs in the refrigeration cycle in which the compressor is used.

The present invention was devised in view of the above points, and it is possible to basically use the conventional pressure regulating means as is, and to reduce the capacity appropriately when the compressor is operated under abnormal conditions. The purpose is to make it possible.

[Means and operations for solving the problem] In order to achieve the above object, the present invention includes a shape changing means that changes its shape when the temperature exceeds a predetermined temperature in a portion of the pressure regulating means that can sense the temperature of the fluid in the pressure chamber. We will adopt a configuration in which That is, it is known that when the refrigeration cycle is operated with an insufficient amount of refrigerant circulation, the temperature of the discharged refrigerant becomes abnormally high. Therefore, when such an abnormality occurs, the shape changing means senses the temperature and forcibly switches the pressure adjusting means. Thereby, the pressure regulating means introduces the high pressure within the pressure chamber into the signal pressure chamber, and forcibly reduces the stroke of the piston.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 1, 100 is a front housing that has a signal pressure chamber 101 inside, and 102 is a cylinder 1 that has five cylinders inside.
03, both housings 10
0,102 are securely connected via the 0 ring. 104 is a housing 100.102 bearing 105,1
An electromagnetic clutch 107 is fixed to the tip of the shaft 104. Through this electromagnetic clutch, the shaft 104 receives the driving force of an automobile engine (not shown) and rotates. do.

A wobble plate 108 is swingably connected to the shaft 104, and is connected to the piston 110 via a connector 109.
It is connected with. That is, the piston receives the rocking motion of the wobble plate via the connector 109, and
Move back and forth within 3. 111 is wobble plate 108
The wobble plate 108 is connected to the wobble plate 108 via a spherical connecting portion 112.

Reference numeral 200 denotes a shaft sealing device for keeping the interior of the signal pressure chamber 101 confidential, and is disposed between the shaft 104 and the housing 100. Incidentally, the housings 100 and 102 are attached to an automobile engine through brackets 201 and 202.

A cover housing 300 is disposed behind the rear housing 102 via a side plate 301, and has a suction chamber 302 and a discharge chamber 303 inside. The suction chamber introduces low-pressure refrigerant from the evaporator of the refrigeration cycle through a suction-side refrigerant passage (not shown). The low-pressure refrigerant enters the pressure chamber 30 formed by the piston 110 and the cylinder 103 through the suction hole 304.
5 will be introduced. Although not shown, a suction valve is provided between the suction hole 304 and the pressure chamber 305.

The high-pressure refrigerant compressed in the compression chamber 305 is discharged into the discharge chamber 303 through a discharge hole 306 and a discharge valve (not shown). The discharged high-pressure refrigerant is discharged from the discharge chamber 303 to the condenser of the refrigeration cycle via a discharge-side refrigerant passage (not shown).

Reference numeral 400 denotes pressure regulating means provided within the cover housing 300, and this means 400 has the following configuration. High pressure chamber 401 into which high pressure refrigerant is introduced from discharge chamber 303, suction chamber 3
A low-pressure chamber 402 introduces low-pressure refrigerant from the 02 side, and a mixing chamber 403 mixes the high-pressure refrigerant in the high-pressure chamber 401 and the low-pressure refrigerant in the low-pressure chamber 402.The high-pressure chamber 401 and the mixing chamber 403 communicate through a high-pressure side communication passage 404. The opening area of this communication path is controlled by the high pressure side control valve 405.

The mixing chamber 403 and the low pressure chamber 402 are communicated through a low pressure side communication passage 406, and a low pressure side control valve 40 is connected to this communication passage.
7 is arranged, thereby controlling the opening area of the communication path 406. In addition, the high pressure side and low pressure side control valves 405, 40
7 are connected by a connecting rod 408, and the recontrol valve 40
5.407, the expansion and contraction of the bellows 410 is transmitted via the connecting rod 409.

The bellows 410 is disposed within the low pressure chamber 402 and has a predetermined pressure inside thereof, so that it expands and contracts in accordance with the pressure of the low pressure chamber 402. That is, when the pressure in the low pressure chamber 402 is low, the bellows 410 expands, and conversely, when the pressure in the low pressure chamber increases, the bellows 410 contracts.

411 and 412 are springs, and the bellows 410
and assists the movement of the control valves 405, 407. The spring 412 is disposed within the high pressure side communication passage 404 and biases the high pressure side control valve 405 in the passage opening direction. Spring 411 is disposed within bellows 410,
The bellows 415 is biased in the direction of its extension.

The spring 412 is made of shape memory alloy.
It is set to expand rapidly when the temperature reaches a predetermined temperature, for example, 150° C. or higher. That is, when the temperature in the high pressure chamber 401 reaches a predetermined temperature or higher, the biasing force of the spring 412 increases rapidly, pushing the high pressure side control valve 405 in the direction of opening the passage with a large force.

Next, the operation of the compressor configured as described above will be described. Electromagnetic clutch 1
07, the shaft 104 rotates, and this shaft 1
The rotation of 04 causes the wobble plate 168 to swing. The swinging motion of the wobble plate 108 is transmitted to the piston 110 via the connector 109, thereby causing the piston 1
10 reciprocates within the cylinder 103. The volume of the compression chamber 305 changes with this reciprocating motion, and refrigerant is sucked from the suction chamber 302 when the volume expands. When the volume decreases, the refrigerant is compressed inside the compression chamber 305 and the high-pressure refrigerant is discharged 3
Discharge to 03.

The high-pressure refrigerant in the discharge 303 and the low-pressure refrigerant in the suction chamber 302 are introduced into the high-pressure chamber 401 and the low-pressure chamber 402, respectively. Both refrigerants flow into the mixing chamber 403 via the high-pressure side communication passage 404 and the low-pressure side communication passage 406, respectively, where a predetermined pressure signal is mixed. This pressure signal is transmitted through the passage 50
0 to the signal pressure chamber, thereby controlling the pressure within the signal pressure chamber.

When the pressure in the signal pressure chamber is high, the differential pressure across the piston 110 becomes relatively small. Therefore, the width of the reciprocating movement of the piston 110 becomes smaller. As a result, the overall discharge capacity of the compressor decreases.

When the pressure in the signal pressure chamber is low, the differential pressure across the piston 110 becomes relatively large.

Therefore, the width of the reciprocating movement of the piston 110 increases,
The overall discharge capacity of the compressor also increases.

When the pressure in the low pressure chamber 410 is low, the bellows 110 expands, thereby causing the low pressure side control valve 407 to close to the low pressure side communication path 4.
06 and the high pressure side control valve 4.
05 increases the opening area of the high pressure side communication path 404. As a result, the refrigerant introduced into the mixing chamber 403 is
The high-pressure refrigerant from No. 3 increases, so the signal pressure becomes high.

This high signal pressure increases the pressure inside the signal pressure chamber,
As a result, the capacity of the compressor becomes smaller. That is, in state B where the cooling load is small (state where the low-pressure side refrigerant pressure is low), the discharge capacity of the compressor automatically becomes small.

Conversely, when the cooling load is high (low-pressure side refrigerant pressure is high), the bellows 410 contracts. Therefore, the low pressure side control valve 407 increases the opening area of the low pressure side communication passage 406, and the high pressure side control valve 405 decreases the opening area of the high pressure side communication passage 404. As a result, the pressure within the mixing chamber becomes low, and the pressure within the signal pressure chamber 101 also becomes low. Thereby, the discharge capacity of the compressor increases.

When the amount of refrigerant in the entire refrigeration cycle decreases, the temperature of the refrigerant on the discharge side becomes abnormally high. In this case, the high temperature is transmitted to the spring 412 facing the high pressure chamber 401, and the set load of the spring 412 increases rapidly. Therefore, in this state, the high pressure side control valve 405 is forcibly pushed upward in the figure, increasing the opening area of the high pressure side communication passage 404.

At the same time, the low pressure side control valve 407 reduces the opening area of the low pressure side communication passage 406. As a result, high-pressure refrigerant is introduced into the mixing chamber 403 regardless of the magnitude of the suction-side refrigerant pressure. As a result, the pressure within the signal pressure chamber 101 increases and the discharge capacity of the compressor decreases.

In addition, in the above example, the spring 41 is used as the shape changing means.
Although spring 412 is used, the effect of the present invention can of course be achieved with members other than spring 412.

FIG. 2 shows an example in which a connecting rod 408 is used as the shape changing means. A predetermined temperature (for example, 150
A joint 600 made of a shape memory alloy whose length expands rapidly at temperatures (°C) is provided. When the high-pressure side refrigerant temperature reaches a predetermined temperature or higher, the temperature is transmitted to the joint of the connecting rod 408. As a result, joint 60
0 expands and forces the high pressure side control valve 405 to open the high pressure side communication path 4.
Pull it away from 04. As a result, the high pressure refrigerant flows into the mixing chamber 403.
high pressure is transmitted to the signal pressure chamber as a signal pressure.

FIG. 3 is an example in which the shape changing means is used in the high pressure side control valve 405. The high pressure side control valve 405 is operated at a predetermined temperature (for example, 15
When the temperature is below 0° C., it forms a tight spiral as shown in FIG. 4, but when it exceeds a predetermined temperature, it becomes a rough spiral as shown in FIG.

Therefore, when the temperature is higher than a predetermined temperature, the high pressure side control valve
04 cannot be closed, the high-pressure refrigerant automatically enters mixing chamber 4.
Introduced in 2003. As a result, the pressure within the signal pressure chamber 101 increases.

FIG. 6 shows a configuration in which the position of the high-pressure side communication passage 404 is changed by a shape changing means.

That is, the high pressure side communication passage 404 (especially the high pressure side control valve 4
05) is slidably disposed within the cover housing 300, and its upper and lower ends are connected to springs 700.
．． 701.

One spring 700 is at a predetermined temperature (for example, 150°C)
If the temperature is higher than that, the shape memory alloy is made of a shape memory alloy whose shape changes rapidly, and the setting force increases rapidly after reaching a predetermined temperature.

When the temperature is below a predetermined temperature, the high pressure side communication passage 404 is arranged at the same position as shown in FIG. However, when the temperature exceeds a predetermined temperature, the setting force of the spring 700 increases rapidly, and the high-pressure side communication passage 404 is forcibly pushed downward in the figure. As a result, the opening area of the high-pressure side communication passage 404 is expanded, and high-pressure refrigerant is introduced into the mixing chamber 403. As a result, the pressure within the signal pressure chamber 101 also increases. Note that the spring 700 is a normal bias spring, and the spring 700 is a normal bias spring.
The same effect can be achieved even if 01 is a shape memory alloy spring.

〔Effect of the invention〕

As described above, the compressor of the present invention can vary its own discharge capacity according to the pressure on the suction side, and can forcibly reduce the capacity when the temperature on the high pressure side rises abnormally.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the compressor of the present invention, FIGS. 2, 3, and 6 are sectional views showing main parts of other embodiments of the compressor of the present invention, and FIG. 4 and FIG. 5 is a front view showing the operation of the high pressure side control valve shown in FIG. 3. 100, 102. 300--Housing, 1o1
...Signal pressure chamber, 104...Shaft, 108...
・Wobble plate, 109...Connector, 110・
...Piston, 400...Pressure adjustment means, 405,4
08゜412.700...High pressure side control valve, connecting rod, spring, 50o...passage, each forming a shape changing means. Representative Patent Attorney Takashi Okabe Figure 2 Figure 3

Claims (1)

[Claims] A housing having a plurality of cylinders and a signal pressure chamber on the back surface of the cylinders, a shaft rotatably disposed within the housing, and a wobble plate disposed within the signal pressure chamber and swingably attached to the shaft. and,
A piston slidably disposed within the cylinder, a connector disposed within the signal pressure chamber for connecting the wobble plate and the piston, and a compression chamber formed by the cylinder and the piston. a suction chamber for introducing the fluid, a discharge chamber for discharging fluid from the compression chamber, and introducing fluid pressure from the suction chamber and the pressure chamber as a signal pressure,
A pressure adjusting means for adjusting an output signal pressure and a passage for guiding the pressure outputted by the pressure adjusting means to the signal pressure chamber of the housing, and a predetermined portion of the pressure adjusting means for detecting the fluid temperature on the discharge chamber side. A variable capacity compressor configured to include a shape changing means that changes shape when the temperature exceeds a predetermined temperature, and forcibly guide the fluid in the compression chamber side to the pressure adjusting means when the temperature of the fluid reaches a predetermined temperature or higher. .