JPH0442555Y2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention relates to a gas compressor, and particularly to a gas compressor with variable compression chamber capacity suitable for car coolers.

<Prior Art> Conventionally, this type of gas compressor has been equipped with a control plate between the side block and the compression chamber, and by rotating this control plate, in order to vary the capacity of the compression chamber. The structure is such that the opening position of a bypass passage formed on the control plate surface that bypasses the compression chamber and the suction chamber to the compression chamber changes to adjust the amount of compression of the compressed gas.

This control plate is driven by a mechanism as shown in FIG.

In the figure, an opening 30 having an inner cylindrical shape is bored in the front head 12, and a drive shaft 31 is slidably fitted into this opening 30.
The tip 31a faces the inside of the suction chamber 23 and is always urged toward the rearward side by the spring pressure of the pressing spring 32.

On the other hand, the rear end 31b of the drive shaft 31 is connected to the space 33.
Lubricating oil is supplied inside, and the hydraulic pressure of this lubricating oil pushes the drive shaft 31 in the opposite direction to the spring pressure of the pressing spring 32.
is energized. Lubricating oil separated from the compressed gas on the discharge side of the compressed gas is supplied to the space 33 from a hydraulic pressure supply path 35 through a communication hole 36 . This communication hole 36 has a constriction part (not shown) formed in the middle, which prevents sudden pressure fluctuations on the discharge side.
It is arranged so that the light does not directly reach the space 33.

Further, the relationship between the drive shaft 31 and the control plate 19 is such that a drive pin (not shown) is formed protruding from the side surface of the control plate 19 facing the front head 12, and this drive pin is connected to the front side block 1.
The tip 37a of the pin passes through an arcuate guide hole (not shown) formed in the drive shaft 31 and faces into the suction chamber 23, and the tip 37a of the pin is engaged in a recess 39 formed in the drive shaft 31. There is.

Therefore, the total pressure of the spring pressure of the pressing spring 32 and the suction pressure in the suction chamber 23 is applied to the tip 31a of the drive shaft 31. On the other hand, the hydraulic pressure of the lubricating oil supplied into the space 33 is applied to the rear end 31b of the drive shaft 31, and the drive shaft 31 moves forward and backward within the opening 30 due to the differential pressure between the total pressure and the hydraulic pressure. Then, the control plate 19 is rotated within a predetermined angle via the drive pin.

Furthermore, between the suction chamber 23 and the space 33,
A hydraulic control valve 40 is provided for regulating hydraulic pressure. This hydraulic control valve 40 has a chamber 42 formed in the middle of a passage 41 that communicates with the space 33, and a bellows 43 disposed within the chamber 42.
When the bellows 43 is inflated, the tip of the rod 44 protruding from the movable end presses the ball 45 loosely fitted in the passage 41 against the spring 46, thereby opening the passage 41 and filling the space. 33 is configured to release the hydraulic pressure of 33 to the suction chamber 23 on the low pressure side.

When a gas compressor equipped with the control plate 19 having such a configuration is used, for example, in a car cooler, it is normally connected to the output shaft of the engine and driven, so when the engine speed becomes high, the engine speed increases per unit time. The amount of refrigerant compressed increases, the pressure on the discharge side of the gas compressor increases, and at the same time the pressure on the suction chamber 23 side decreases. Then, the hydraulic pressure control valve 40 is operated in accordance with the fluctuation in the pressure in the suction chamber 23, the hydraulic pressure in the space 33 is released to the suction chamber 23 side, and the hydraulic pressure in the space 33 is reduced. As a result, the drive shaft 31 is retracted and the control plate is rotated, so that the capacity of the compression chamber is automatically adjusted to an appropriate value, and the amount of refrigerant to be compressed is adjusted to an appropriate amount.

<<Problem to be solved by the invention>> However, in the above hydraulic control valve 40, the passage 41 is blocked by the ball 45 and the oil pressure from the space 33 is applied to the ball 45. To open the bellows 43, the bellows 43 required a pushing force sufficient to overcome the hydraulic pressure. Therefore, the force acting on the ball 45 changes due to a change in the pressure in the space 33 due to the opening/closing operation of the hydraulic control valve 40, making it difficult to precisely adjust the amount of refrigerant compression.

This idea was made to solve these problems, and aims to make the hydraulic control valve for adjusting the compression amount in a gas compressor smaller and to achieve precise compression amount adjustment. .

<Means for Solving the Problems> This invention was made to achieve the above object, and consists of a cylinder block whose inner circumference is approximately elliptical, and front and rear side blocks attached to both sides of the cylinder block. , horizontally suspended rotatably within a cylinder chamber constituted by the cylinder block and both side blocks,
The rotor has multiple vanes that can move forward and backward in the radial direction, and on the inner surface of the front side block,
A substantially disk-shaped control plate that can rotate within a predetermined angle, a drive shaft that is connected to rotate this control plate and is arranged so that its tip faces into the suction chamber, and a drive shaft that is retracted. A pressing means that urges the direction, an oil reservoir on the compression chamber side where lubricating oil is stored, and a space on the rear end side of the drive shaft communicate with each other, and the pressure in the compression chamber is transmitted to the space on the rear end side of the drive shaft. and a hydraulic control valve that is provided in a communication passage that communicates between the rear end side space of the drive shaft and the suction chamber, and that controls opening and closing of the communication passage in accordance with an increase or decrease in pressure in the suction chamber. In a gas compressor, there is a chamber that is open to the suction chamber side, an extender that is provided in the chamber and expands and contracts due to external pressure, and a middle part of the extender that is protruded from the movable end of the extender and has a uniform diameter. a spool-shaped valve body with a small diameter step;
A housing part in which a guide hole into which the valve body is slidably fitted is formed, and a guide hole formed in the housing part at the position of the small diameter stepped part when the valve body fitted in the guide hole is projected. An oil passage that intersects with the chamber and connects one end to the chamber and the other end to a communication passage connected to the rear end side space of the drive shaft, and one end opening on the distal end side of the valve body and in which lubricating oil is stored. The hydraulic control valve is characterized by comprising a hydraulic communication passage whose other end is open on the oil reservoir side on the compression chamber side.

<<Operation>> When the pressure in the suction chamber decreases due to an increase in the rotational speed of the rotor or a decrease in the cooling load, etc., the expandable element in the chamber expands, and the valve body at the tip of the expandable element expands. By sliding through the hole, the small diameter step part of the valve body reaches the oil passage formed in the housing part, and the hydraulic pressure in the space on the rear end side of the drive shaft is released to the suction chamber side through the chamber. , the drive shaft is retracted and the control plate is rotated in a direction that reduces the amount of compression.

When the pressure in the suction chamber increases, the expandable element in the chamber contracts and the valve body slides in the return direction, closing the oil passage formed in the housing and reducing the hydraulic pressure in the space on the rear end of the drive shaft. From the rise of
The drive shaft moves forward and the control plate rotates in a direction that increases the amount of compression.

When these valve bodies slide, hydraulic pressure from the hydraulic communication passage is constantly applied to the tip of the valve body, allowing for delicate pressure adjustment, and the pressure in the space does not act on the valve body. , precise compression adjustment can be obtained.

<<Example>> Next, an example of the gas compressor according to this invention will be described based on the drawings.

FIG. 1 is a sectional view taken along the line shown in FIG. 2, showing the main parts of the gas compressor according to this invention, and FIG. 2 is a longitudinal sectional view showing the overall structure of the gas compressor according to this invention.

In FIGS. 1 and 2, this gas compressor includes a compressor main body 10, a casing 11 with an open end that encloses the main body 10 in a airtight manner, and a front head 12 attached to the open end surface of the casing 11. It is equipped with

The compressor main body 10 includes a cylinder block 13 having a substantially elliptical inner circumference, and front side blocks 1 attached to both sides of the cylinder block 13.
4, and a rear side block 15, and a substantially elliptical cylinder chamber 2 formed by these.
A solid cylindrical rotor 18, which is integral with the rotor shaft 16 and has five vanes 17 mounted around the rotor shaft 16 that can be freely retracted in the radial direction, is horizontally suspended in the rotor 4 so as to be freely rotatable.

Further, a substantially disk-shaped control plate 19 is rotatably fitted into a boss portion 14a protruding from the inner surface of the front side block 14 via a thrust bearing 26. This boss portion 14a
An O-ring 51 is installed in a groove 19a formed in the inner circumferential surface of the control plate 19 that fits into the groove 19a.
Regarding the structure and operation of the mechanism that drives the control plate 19, the explanation of the common parts already explained in the above-mentioned prior art will be omitted, and the explanation between the suction chamber 23 and the space 33, which is a feature of this invention, will be omitted. The hydraulic control valve 50 provided in the will be explained.

This hydraulic control valve 50 has a chamber 52 formed in the middle of a communication path 51 that communicates with the space 33, a bellows 53 whose one end is fixed within the chamber 52, and expands and contracts with external pressure, and a movable end of the bellows 53. A housing portion 57 includes a spool-shaped valve body 55 that protrudes from the spool and has a small-diameter stepped portion 54 formed in the middle portion of a uniform diameter, and a guide hole 56 into which the valve body 55 is slidably fitted. When the valve body 55 fitted in the guide hole 56 is projected, it intersects with the housing part 57 at the position of the small diameter stepped part 54, and has one end connected to the chamber 52 and the other end connected to the rear end side space of the drive shaft 31. Oil passage 58 connected to communication passage 51 connected to 33
One end is opened at the tip side of the valve body 55, that is, the inner end of the guide hole 56, and the other end is connected to the hydraulic pressure supply path 35,
That is, an oil reservoir 34 on the compression chamber side where lubricating oil is stored.
The hydraulic communication passage 59 is opened on the side.

Next, the operation of this hydraulic control valve 50 will be explained.

When the rotation speed of the rotor 18 increases or the cooling load etc. decreases and the pressure in the suction chamber 23 decreases, the bellows 53 inside the chamber 52 expands.
The valve body 55 at the tip slides through the guide hole 56 formed in the housing part 57, and the small diameter stepped portion 5 of the valve body 55
4 reaches the oil passage 58 formed in the housing portion 57, and the hydraulic pressure in the rear end side space 33 of the drive shaft 31 is released to the suction chamber 23 side via the chamber 52, so that the drive shaft 31 The control plate 19 rotates in a direction that reduces the amount of compression.

Also, when the pressure in the suction chamber increases, the chamber 5
As the bellows 53 in 2 shrinks, the valve body 5
5 slides in the return direction, closes the oil passage 58 formed in the housing part 57, and the oil pressure in the rear end side space 33 of the drive shaft 31 increases, so that the drive shaft 31
moves forward, and the control plate 19 rotates in a direction that increases the amount of compression.

That is, this hydraulic control valve 50
The operating pressure of the bellows 53 in the suction chamber 2 is adjusted in advance.
By setting the pressure to the pressure in the steady operating state in step 3, if the pressure in the suction chamber 23 fluctuates due to a change in the cooling load or the drive speed, the fluctuation value is fed back and the suction chamber 23 is maintained at a predetermined pressure. In addition, with this gas compressor,
Discharge pressure acts on the tip of the valve body via the hydraulic communication path, so for example in the summer when the cooling load increases and the discharge pressure increases due to external heating, the discharge pressure at the tip of the valve body increases. As a result, the valve body becomes difficult to slide along the guide path at the set operating pressure of the expander.In other words, in the summer, the control plate rotates in a direction that reduces the amount of compression with a delay compared to the winter.
During the delay, the compression amount is maintained large and cooling can be achieved well, so the compression amount can be adjusted with high precision according to the cooling load.

Next, the adjustment of the amount of compression performed in connection with the operation of this hydraulic control valve 50 will be explained.

When the pressure in the space 33 changes due to the opening and closing of the hydraulic control valve 50, the drive shaft 31 moves forward and backward, and the control plate 19, which is engaged with the drive shaft 31 by a drive pin (not shown), moves to a predetermined position. Rotates clockwise or counterclockwise within an angle.

Bypass holes 20 are provided on the peripheral edge of the control plate 19, facing each other by 180°, and the bypass holes 20 are formed in the front side block 14 shown in FIG. 2 by rotation of the control plate 19. It is configured to selectively communicate with the suction port 21 and the bypass hole 22. As a result, when the load increases or during low-speed operation, the pressure in the suction chamber 23 increases, and when the control plate 19 is rotated,
The bypass hole 20 of the control plate 19 and the intake port 21 of the front side block 14 almost coincide with each other,
A large amount of refrigerant gas is supplied from the suction chamber 23 to the cylinder chamber 24 through the suction port 21 and the bypass hole 20, increasing the capacity of the compression work chamber.

On the other hand, when the load is reduced or when operating at high speed,
When the pressure in the suction chamber 23 decreases and the control plate 19 is rotated in the opposite direction, the bypass hole 20 of the plate 19 and the bypass hole 22 formed in the front side block 14 align, and these bypass holes 20, 22 By bypassing the compressed gas in the cylinder chamber 24 into the suction chamber 23 through the cylinder chamber 24, the capacity of the compression working chamber is reduced and an optimum compression amount is maintained.

In this way, the refrigerant gas introduced into the suction chamber 23 from the intake port 25 of the futon head 12 is
The gas is introduced into the cylinder chamber 24 through the suction port 21, and is adjusted to the optimum compression amount depending on the operating conditions, even if the load on the compression amount of the refrigerant gas or the driving rotation speed of the rotor shaft 16 fluctuates. maintained. moreover,
The compressed high pressure gas is transferred to the rear side block 15.
The oil is supplied to the oil separator 28 located at the back of the rear side block 15 through a communication hole 27 provided in the rear side block 15.
After the lubricating oil contained in the compressed gas is separated, it is discharged to the outside from the rear space of the casing 11 through the discharge port 29, as shown by the broken line arrow.

As is clear from the above description, the gas compressor according to the invention has a spool-shaped valve body 55 in the hydraulic control valve 50 for adjusting the capacity of the compression work chamber in response to changes in load and rotation speed. By using this, it is possible to eliminate the influence of the primary pressure in the communication path 51, that is, the pressure in the space 33, on the opening/closing operation. As a result, the opening/closing operation of the valve is obtained that is approximately proportional to the secondary pressure in the communication passage 51, that is, the pressure in the suction chamber 23, and the amount of compression can be controlled with high precision.

In the above embodiment, the bellows 53 is used to generate the driving force for opening and closing the valve, but it can also be replaced with a diaphragm, a piston, or the like.

<Effects of the invention> As mentioned above, the gas compressor according to this invention has the following effects:
By configuring the hydraulic control valve controlled by the suction chamber pressure to adjust the compression amount using a spool-shaped valve body, the influence of the primary side pressure in the flow path on the opening/closing operation is eliminated. As a result, the opening/closing operation of the valve is obtained that is substantially proportional to the secondary pressure in the flow path, and the amount of compression can be controlled with high precision.

Moreover, according to this gas compressor, the discharge pressure acts on the tip of the valve body via the hydraulic communication path, so
For example, in the summer when the cooling load increases and the discharge pressure increases due to external heating, the tip of the valve body is pressed extra by the increased discharge pressure, and the valve body is guided at the set operating pressure of the expander. It becomes difficult to slide on the road. In other words, in the summer, the control plate rotates in a direction that reduces the amount of compression with a delay compared to the winter, and during this delay, the amount of compression remains large, allowing for good cooling, so the amount of compression is reduced according to the cooling load. can also be adjusted with high precision.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the gas compressor according to this invention, FIG. 2 is a sectional view taken along the line shown in FIG. 1,
FIG. 3 is a sectional view showing a conventional example. 10...Compressor main body, 13...Cylinder block, 14...Front side block, 15...
Rear side block, 17... Vane, 18...
Rotor, 19... Control plate, 23... Suction chamber, 24... Cylinder chamber, 34... Oil reservoir, 5
0...Hydraulic control valve, 51...Communication path, 52...Chamber, 53...Bellows, 54...Small diameter stepped portion,
55... Spool-shaped valve body, 56... Guide hole, 5
7...Housing part, 58...Oil passage, 59...Hydraulic communication passage.

Claims (1)

[Claims for Utility Model Registration] A cylinder block with a substantially elliptical inner circumference, front and rear side blocks attached to both sides of this cylinder block, and a rotating cylinder inside a cylinder chamber constituted by the cylinder block and both side blocks. A rotor that is freely suspended horizontally and has a plurality of vanes that can move forward and backward in the radial direction, a substantially disk-shaped control plate that can be rotated within a predetermined angle on the inner surface of the front side block, and this control plate can be rotated. A drive shaft that is connected so that it can move and is arranged so that its tip faces into the suction chamber, a pressing means that urges the drive shaft in the backward direction, and an oil reservoir on the compression chamber side in which lubricating oil is stored. and a hydraulic pressure supply path that communicates the rear end side space of the drive shaft and transmits the pressure of the compression chamber to the high end side space of the drive shaft, and communicates between the rear end side space of the drive shaft and the suction chamber. A gas compressor equipped with a hydraulic control valve provided in a communication passage and controlling opening/closing of the communication passage according to an increase/decrease in pressure in the suction chamber, a chamber opened to the suction chamber side, and a chamber provided within the chamber. A telescoping element that expands and contracts in response to external pressure, a spool-shaped valve body that protrudes from the movable end of the telescoping element and forms a small-diameter step in the middle, and a guide hole into which the valve element is slidably fitted. The formed housing part intersects with the guide hole formed in the housing part at the position of the small diameter stepped part when the valve body fitted into this guide hole is projected, and one end is connected to the chamber and the other end is connected to the above drive. An oil passage connected to a communication passage connected to the space on the rear end side of the shaft, and a hydraulic pressure having one end opened on the tip side of the valve body and the other end opened on the oil reservoir side on the compression chamber side where lubricating oil is stored. A gas compressor characterized in that the hydraulic control valve is configured by a communication passage and the like.