JPS6287689A - Vane type variable displacement compressor - Google Patents

Abstract

PURPOSE:To permit a working chamber to be easily sealed, by holding the space, formed between a cylinder and a housing, to a low pressure, in the case of a variable displacement vane compressor turning the cylinder. CONSTITUTION:A cylinder 12 of a variable displacement vane compressor is turnably arranged in a housing 13, and its one part arranges a pressing means 41 for turning the cylinder 12. While space between the housing 13 and the cylinder 12 is formed into a low pressure chamber 24 communicating with a suction hole 18 through a passage 23. Consequently, the compressor, generating a small differential pressure acting on a sealed part of a pressure chamber formed by a rotor 11, cylinder 12 and vanes 16, enables construction of a seal device of said pressure chamber to be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a vane type variable capacity compressor, and particularly to a variable capacity compressor suitable as a compressor for a car cooler or an air conditioner.

``Prior Art and its Problems'' Vane compressors are small, high-speed, high-efficiency co-compressors that have already been put to practical use in car air conditioners. However, the capacity of a car air conditioner compressor is set to exhibit a certain level of capacity in a low speed range, such as when the engine is idling, so the capacity becomes excessive in the mid-to-high speed range of the engine. For this reason, a variable capacity compressor is desired in which the capacity of the compressor is gradually reduced in the medium to high speed rotation range. Such variable capacity compressors have been put into practical use as reciprocating type or plate type compressors, but not as vane type compressors.

Of course, as a vane type oil pump, a pump whose capacity is variable by changing the amount of eccentricity between a rotor and a cylinder is known. However, this conventional vane type variable displacement pump system could not be used as is for compressors that require high discharge pressure. The reason for this is that if the amount of eccentricity between the rotor and cylinder is made variable, it becomes difficult to seal the pressure chamber, making it impossible to obtain the necessary discharge pressure, or there are problems with durability.

Furthermore, as current vehicles become more sophisticated, various devices are installed in the engine compartment, and there is not enough space, so air conditioner compressors are also required to be downsized. Vane type compressors meet this demand because they are characterized by their small size; however, when a variable capacity type is used, a conventional variable capacity vane pump becomes large. In other words, conventional variable-capacity vane pumps do not take into account miniaturization, and even if they satisfy high-pressure characteristics suitable for car coolers, it is difficult to install them in vehicles.

``Object of the Invention'' From this technical background, the present invention aims to provide a vane-type variable volume dipping bomb that can withstand high pressure and can be used as a compressor for car air conditioners. Another object of the present invention is to obtain a highly compact vane type variable capacity compressor suitable for use in car air conditioners.

"Summary of the Invention" The uninvented Vane Gamachi variable displacement compressor is based on the idea that by locating the high pressure chamber formed inside the cylinder within the low pressure chamber, the high pressure chamber can be easily sealed and high pressure can be achieved. It is characterized by a housing in which a cylinder is pivotally connected to make the amount of eccentricity with respect to the rotor variable, and a closed space between the cylinders as a low-pressure chamber that communicates with the suction hole. . In other words, the gas pressure on the suction side where the suction holes communicate has a positive pressure of about 2 to 5 kg/am'', so the pressure difference with the high pressure chamber inside the cylinder is the same as when the space between the cylinder and the housing is set to atmospheric pressure. The smaller the cylinder, the easier it is to seal.The invention further includes a biasing means for biasing the cylinder in a direction that increases the amount of eccentricity, and a resistor for resisting the biasing means, in order to achieve miniaturization and smooth operation. Improvements have been made to the pressing means that moves the cylinder, the pivoting position of the cylinder to the housing, etc.

These features will be explained in the description of the embodiments.

"Embodiments of the Invention" The present invention will be described below with reference to illustrated embodiments. In FIGS. 1 and 2, 11 is a rotor, 12 is a cylinder, and 13 is a cylinder.
is housing. The housing Y13 includes a center housing 13a that is approximately annular and houses the rotor 11 and cylinder 12 therein, and a side housing 13b that closes both end faces of the center housing 13a and is attached to the side surfaces of the rotor 11 and cylinder 12. , 13c or β) is configured. - of side housings 13b, 13c
In some cases, it can be sunk together with the center/Uji leg 13a.

The shafts ILa and Ilb on both sides of the rotor 11 are rotatably supported by side housings 13b and 13e, respectively. That is, the rotor 11 rotates at the )i1 position. For example, the driving force generated by the IJ of the vehicle is applied to the shaft 11b. 14 is a mechanical seal that prevents gas leakage from the gap between the car 11b and the side housing 13C.

A plurality of vane grooves 15 are formed in this rotor 11 and are inclined forward in the direction of rotation shown by arrows.
An outwardly projecting vane 16 is slidably fitted in 5 .

On the other hand, the cylinder 12, on which the vane 16 slides on its inner peripheral surface, is pivotally connected to the housing 13 (side housing 13b) by means of a fulcrum pin 17, so that it can swing. Therefore, the eccentricity Me between the cylinder 12 and the rotor 11 is changed by swinging the cylinder 12.

The cylinder 12 has a suction hole 18 and a discharge hole 1 on its outer peripheral surface.
9 is drilled. On the other hand, the lid body 2o constituting a part of the center housing 13a has a
A suction port 21 is provided to communicate the inside and outside of the
The suction port 21 and the suction hole 18 communicate with each other via a suction pipe 22 that is fixed to the cylinder 12 side.

In order to allow the cylinder 12 to swing, the suction pipe 22 has a certain clearance C between it and the lid 20, and between the upper end surface and the side surface of the pipe 22, this clearance C, and a communication hole bored in the cylinder 12. A closed space 24 between the cylinder 12 and the housing 13 is communicated with the suction port 21 by 23 . The present invention provides cylinder 1
This space between 2 and the housing 13 is used as a low pressure chamber 24 and 17.
Its biggest feature is that.

The cylinder 12 is further provided with a discharge chamber 26 communicating with the discharge hole 19 , and between the discharge chamber 26 and the discharge hole 19 . An on-off valve 27 is provided.

This on-off valve 27 has one end of a leaf spring 28 located on the -L side of the discharge hole 19 fixed with a pin 29, and the rotor 11
, the pressure chamber surrounded by the cylinder 12 and the vane 16 opens when the gas pressure reaches a certain value or more, and the high-pressure gas is introduced into the discharge chamber 26. The discharge chamber 26 communicates with a high pressure surge tank 31 formed integrally with the side housing 13b via an axis-h direction passage 30.
A discharge port 32 is open at 1. 33 is an oil separator that separates oil from the pressure-sensitive gas. cylinder 1
An O-ring 35 surrounding the outer circumference of the rotor 11 and an O-ring 36 surrounding the outer circumference of the axial passage 30 are sandwiched between the contact surfaces of the rotor 11 and the side housing 13I). The O-rings 35 and 36 swing around the fulcrum pin 17 of the cylinder 12, and the side housing 13b (13c)
slide against.

In this vane type compressor, when the rotor 11 rotates, low-pressure gas is sucked into the cylinder 12 through the suction port 21, suction pipe 22, and suction hole 18, and as the rotor 11 rotates, low-pressure gas is sucked into the cylinder 12 and compressed as the rotor 11 rotates. , the on-off valve 27, the discharge chamber 26, the axial passage 30, the high pressure surge tank 31, and the discharge port 32, and is discharged as high pressure gas. The discharge amount and discharge pressure of this high-pressure gas increase as the eccentricity e between the rotor 11 and the cylinder 12 increases, so by swinging the cylinder 12 around the fulcrum pin 17 to adjust the eccentricity e, The discharge amount and discharge pressure can be changed.

In the process of compressing this gas, the inside of the cylinder 12 becomes high pressure, so sealing it becomes a problem. However, in the present invention, by arranging the entire cylinder 12 within the low pressure chamber 24,
Lightens the burden on the seal. That is, cylinder 12
When the outer periphery of the cylinder 12 is at atmospheric pressure, the seal member such as the O-ring 35 that seals between the side surface of the cylinder 12 and the side housings 13b and 13c must be designed to be able to handle the absolute pressure on the high pressure side. However, as in the present invention, the cylinder 12 is connected to the suction port 21 in the low pressure chamber 2.
4, it is sufficient if it can withstand the differential pressure with the high pressure side, and the sealing burden is therefore reduced.

In other words, inside the cylinder 12 there is a primary seal with the low pressure chamber 24 and secondary seals 38a, 38b, 38c, 38 for sealing the low pressure chamber 24 from the outside air.
d+7) Since it is sealed by a two-stage seal, the sealing effect becomes higher accordingly. Note that the pressure in the low pressure chamber 24 is approximately the same as the pressure of the fluid sucked into the suction hole 18.

Note that the cylinder 12 is provided with an oil return passage 37 that communicates between the low pressure chamber 24 and the communication hole 23. This oil return passage 37 passes through the clearance C2 between the suction pipe 22 and the lid 20 and the communication hole 23, and then passes through the low pressure chamber 2.
This is for returning oil that flows into the suction hole 18 and accumulates therein to the suction hole 18.

That is, since the flow rate of the suction gas is high in the suction hole 18 portion, the oil contained in the gas that accumulates at the bottom of the low pressure chamber 24 flows through the oil return passage 37 and the communication hole 23 due to this flow rate.
is returned to the suction hole 18 via. This oil return mechanism allows effective oil circulation within the single condenser. Note that in order to increase the gas flow rate in the communication hole 23 portion and further ensure oil return, a venturi portion 38 having a narrower inner diameter may be provided in the suction hole 18, as shown in FIG.

Furthermore, according to this embodiment, suction into and discharge from the cylinder 12 are performed from the outer peripheral surface of the cylinder 12, so that the suction and discharge portions can be easily sealed. In a conventional general vane pump, the side housing 13b or 1
Drill elastic suction holes and discharge holes in cylinder 12.
Inhalation and exhalation were performed from the sides. However, if a variable displacement pump follows this suction/discharge mechanism, the cylinder 12 swings relative to the side housing L3a or 13c, so sealing must be performed at the movable part. Problems arise in sealing performance or durability. On the other hand, if suction and discharge are performed from the outer peripheral surface of the cylinder 12, there is almost no need for sealing in the movable part, and the O
It is only necessary to seal using the rings 35 and 36. Therefore, as a whole, compared to a conventional vane type variable displacement pump, sealing is easier and higher pressure can be achieved. This O-ring 35
．． 36 may be constructed from other slidable seal members.

Next, the urging means 40 that swings and urges the cylinder 12 in a direction in which the eccentricity e increases, and the pressing means 41 that swings the cylinder 12 against the urging means 40 will be explained.

The urging means 40 and the pressing means 41 are made of wood,
This contributes to miniaturization of the entire system and smooth operation.

The biasing means 40 includes a plurality of disc springs 42 fitted around the outer periphery of the suction vibrator 22 in alternating directions. That is, the suction vibrator 22 has a spring seat 2 on the cylinder 12 side.
2a, and a spring seat 43 is provided on the inner surface of the lid body 20, and a disc spring 42 is inserted between the spring seat 22a and the spring seat 43 to urge the cylinder 12 to swing.

On the other hand, the pressing means 41 includes a pressing piston 44 that is positioned substantially on the same axis as the suction vibrator 22 and supported by the center housing 13a on the opposite side of the suction vibrator 22, and a press piston 44 that is connected to the outer surface of the cylinder 12. It is composed of a pole 45 interposed therebetween. Pressing piston 44
The cylinder 12 is formed with a spherical recess 44a into which a part of the pole 45 fits, and a spherical four part 12a. 46
is a compression spring that urges the pressing piston 44 toward the cylinder 12 and brings the pawl 45 into constant contact with the spherical recess 44a and the spherical recess 12a. Therefore, the pressing piston 44
When high pressure is introduced into the pressure chamber 47 formed between the back surface and the attachment body 48, the pressing piston 44 advances t)17, and the cylinder 12 is swung in the direction of decreasing the eccentricity e. Therefore, by appropriately controlling the pressure introduced into the pressure chamber 47, the magnitude of the eccentricity e can be controlled, and the discharge pressure and discharge amount can be controlled.

The pawl 45 may be provided integrally with the pressing piston 44 or the cylinder 12. In this way, the pressing force of the pressing piston 44 is applied to the cylinder 1 through at least one spherical surface.
2, the movement of the pressing piston 44 can be smoothly transmitted to the cylinder 12.

Further, the urging means 40 and the pressing means 41 are connected to the fulcrum pin 17.
In order to increase the arm length of the rotational moment of the cylinder 12 that scrapes the center and operate it with a small force, it is desirable to provide it at a position as far away from the fulcrum pin 17 as possible, as in the embodiment. , the pressing means 41 is pressed against the urging means 4.
It is not always safe to place the pressing means 41 on the same axis as the fulcrum pin 17 in order to reduce the operating force.
It is desirable to install it away from the

Further, the position of the fulcrum pin 17 is in a direction A that is perpendicular to the eccentric direction of the rotor 11 and cylinder 12 passing through the axis O of the cylinder.
If the cylinder 12 is provided at a position inclined by an angle α from the cylinder 12, the cylinder 12 can be rotated with an even smaller force. As shown in Figure 3 now.

It is assumed that a rotational force P is applied to the cylinder 12 when the fulcrum pin 17 is located at the B position in the A direction.

On the other hand, the fulcrum bottle 17 is positioned at IC by α rotation from the direction A, and the biasing means 40 and the pressing means 41 are placed at positions substantially perpendicular to the line segment connecting the fulcrum bottle 17 and the center of the cylinder 12. If provided, the biasing means 40 and the pressing means 4
Since the force acting on the cylinder 12 is Ps in α, the cylinder 12 can be rotated with a force smaller than P.

FIG. 4 shows an embodiment of a control valve 50 for actuating the push piston 44. As shown in FIG. This control valve 50 controls the cylinder 1 so that the differential pressure between the discharge pressure and the suction pressure is approximately constant.
This controls the position of position 2. By controlling this differential pressure to be constant, it is possible to suppress overcapacity in the medium and high speed rotation range. This control valve 50 is provided, for example, at the bottom of the high-pressure surge tank 31.

This control valve 50 has a piston 52 fitted inside a valve cylinder 51 to form a low pressure chamber 53 and a high pressure chamber 54 before and after the piston 52.
．． It communicates with the suction port 21 and the high pressure surge tank 31 via 56. Further, in the front part of the low pressure chamber 53,
A high pressure chamber 57 is formed, and this high pressure chamber 57 is similarly connected to a conduit 58.
It is connected to a high pressure surge tank 31 through 1°. A pole 59 and a compression spring 6 are provided between the low pressure chamber 53 and the high pressure chamber 57.
A check valve 61 consisting of 0 is provided, and the pawl 59 is moved against the compression spring 60 by a pressing pin portion 52a at the tip of the piston 52. This is a compression spring that urges the valve 61 to move away from the valve 61. A pipe line 63 opens in a portion of the low pressure chamber 53 near the compression spring 60, and this pipe line 63 communicates with the pressure chamber 47.

According to this control valve 50, until the discharge pressure reaches a certain value, the pressure in the suction port 21 is guided to the pressure chamber 47 via the conduit 55, the low pressure chamber 53, and the conduit 63, so the pressing piston 44 is activated. do not.

In other words, the cylinder 12 is held at a position where the eccentricity me is maximum, and the discharge pressure and discharge amount increase in proportion to the increase in the rotational speed of the rotor 11.

When this discharge pressure exceeds a certain value, the high pressure surge tank 3
1 and channel 56 into the high pressure chamber 54 overcomes the force of the compression spring 62, so that the piston 52
moves forward and pushes the pole 59, opening the check valve 61. Then, the high pressure on the discharge side that is led to the high pressure chamber 57 via the pipe line 58 is guided into the pressure chamber 47 from the pipe line 63, so the pressing piston 44 receiving the pressure of the pressure chamber 47 moves forward and presses the cylinder. 12 is rotated in the direction in which the amount of eccentricity e becomes smaller.

Therefore, the discharge pressure decreases. When the discharge pressure falls below a certain value, the piston 52 returns to its original position due to the force of the compression spring 6z, and the check valve 61 closes, so that the pipe 63 returns to the low pressure side via the low pressure chamber 53 and the pipe 55. It will be communicated to. Therefore, the press piston 44 retreats and the discharge pressure increases again, and the same operation is repeated thereafter, so that an excessive increase in the discharge pressure is suppressed.

The control valve 50 to the north shows an example, and the present invention has the following features:
The movement of the pressing screw 44 may be controlled by another control valve.

In FIG. 2, reference numeral 64 is a well-known lubricating device, which operates according to the pressure difference between the high-pressure surge tank 31 and the cylinder 12.
The oil remaining at the bottom of the high-pressure surge tank 31 is supplied to the sliding surfaces between the rotor 11 and the side housings i3b and 13e through lubricating oil passages 65, 66, 67, and 68.

"Effects of the Invention" As described above, the vane type variable capacity compressor of the present invention is configured by the rotor, cylinder, and vanes because the cylinder with the rotor inside is located in the low pressure chamber communicating with the suction port. This makes it easier to seal pressure chambers. Therefore, a higher pressure vane compressor can be obtained. Also, the suction and discharge to the cylinder,
By performing sealing from the outer circumferential surface of the cylinder, sealing at the suction and discharge portions is also facilitated since there is no need to use movable parts, and this is suitable for achieving high pressure. Furthermore, if the biasing means for rotating and biasing the cylinder in a direction that increases the amount of eccentricity with respect to the rotor, and the pressing means for moving the cylinder against this biasing means are configured as in the embodiment, it can be operated in a small size. A reliable vane type variable capacity acid compressor can be obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view taken along line I-1 in Fig. 2 showing an embodiment of the vane type variable capacity compressor of the present invention, Fig. 2 is a longitudinal sectional view thereof, and Fig. 3 is a rotation fulcrum of the cylinder. FIG. 4 is a vertical sectional view showing an example of a control valve of a pressing piston that operates a cylinder. FIG. 5 is a diagram showing another embodiment of the present invention. FIG. DESCRIPTION OF SYMBOLS 11... Rotor, 12... Cylinder, 13... Housing, 13a... Center housing, 13b, 1
3C...Side housing, 16...Vane, 17
...Fullin pin, 18...Suction hole, 19...Discharge hole, 21...Suction port, 22...Suction vibe, 24
・-・Low pressure chamber, 26...Discharge chamber, 27...Opening/closing valve,
28... Leaf spring, 31... High pressure surge tank, 32
...Discharge port, 37...Oil return passage, 40.
... Murasecho 7th stage, 41... Pressing means, 42... Book spring, 44... Pressing piston, 45... Pole, 47
...Pressure chamber, 50...Control valve.

Claims (13)

[Claims] (1) A rotor that is rotationally driven; a vane that is slidably supported outward on this rotor; a cylinder that the tip of this vane slides into; a housing that houses this cylinder and the rotor; Pivot means for pivotally connecting the cylinder to the housing with variable eccentricity; urging means for moving and urging the cylinder in a direction in which the eccentricity increases; pressing means for moving the cylinder against the urging means; and the cylinder. 1. A vane type variable capacity compressor comprising a suction hole and a discharge hole that are opened to the air, wherein a space between the housing and the cylinder is a low pressure chamber that communicates with the suction hole. (2) In claim 1, the housing is
A vane type variable capacity compressor consists of a center housing located around the outer periphery of the cylinder and rotor, and side housings that contact and seal both sides of the cylinder and rotor. (3) The vane type variable capacity compressor according to claim 2, wherein a slidable seal member surrounding the outer periphery of the rotor is sandwiched between the contact surfaces of the side housing and the cylinder. (4) The vane type variable capacity compressor according to claim 2, wherein the suction hole of the cylinder communicates with a suction port provided in the housing, and the discharge hole communicates with a discharge port provided in the housing. (5) In claim 3 or 4, the suction port of the housing is opened on the outer peripheral surface of the center housing of the housing, and the suction port and the suction hole bored in the outer peripheral surface of the cylinder are connected to each other. A vane type variable capacity compressor that communicates through a pipe. (6) The vane type variable capacity compressor according to claim 5, wherein the biasing means is a spring means fitted concentrically around the outer circumference of the suction pipe. (7) A vane type variable capacity compressor according to claim 6, wherein the spring means is a laminated disc spring. (8) In any one of claims 4 to 7, the cylinder is formed with a discharge hole bored in the outer peripheral surface of the cylinder and a discharge chamber with which the discharge hole communicates,
The side housing is integrally provided with a high pressure surge tank that communicates with the discharge chamber through the axial passage of the side housing and the cylinder, and the vane type variable capacity compressor has a discharge port opening into the high pressure surge tank. . (9) The vane type variable capacity compressor according to claim 8, wherein a slidable seal member surrounding the axial passage is sandwiched between the contact surfaces of the side housing and the cylinder. (10) In claim 1, the pressing means:
A vane type variable displacement compressor supported by the center housing on the opposite side of the biasing direction of the biasing means. (11) A vane type variable capacity compressor according to claim 10, in which the pressing force of the pressing means is transmitted to the cylinder via at least one spherical surface. (12) The vane type variable capacity compressor according to claim 10 or 11, wherein the pressing piston is controlled by a control valve receiving suction pressure and discharge pressure so that the differential pressure therebetween is constant. (13) The vane type variable capacity compressor according to claim 1, wherein the cylinder is provided with an oil return passage that communicates the bottom of the low pressure chamber with the suction hole.