JPS6157957B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capacity adjustment device for a rotary compressor.

Rotary compressors such as screw compressors and vane compressors are directly connected to and driven by a prime mover such as a diesel engine, but when air consumption decreases, the passage area on the suction side of the rotary compressor must be reduced. Therefore, a capacity adjustment device is provided to reduce the amount of air discharged from the rotary compressor and reduce the power consumption of the prime mover. This conventional capacity adjustment device has a structure in which a diaphragm is reciprocated in response to an increase or decrease in air consumption, and a piston fixed to the diaphragm opens and closes a valve provided in a passage on the suction side of the rotary compressor. In this conventional capacity adjusting device, the diaphragm was damaged due to its reciprocating motion, and the piston and valve shafts were worn out, making it impossible to provide a durable capacity adjusting device.

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacity adjustment device for a rotary compressor that is highly durable, compact, and low cost. First, a conventional capacity adjusting device for a rotary compressor will be explained in detail based on the drawings.

FIG. 1 shows a vane compressor equipped with a conventional capacity adjustment device. In FIG. The chamber 19 is a discharge chamber provided at the lower part of the cylinder 20. 23 is a rotor provided eccentrically with respect to the center of the cylinder 20; 22 is a groove provided radially in the rotor;
21 is a vane slidably inserted into the groove 22. 24 is a compression chamber formed by the inner periphery of the cylinder 20, two adjacent vanes, the outer periphery of the rotor 23, and end plates provided at both ends of the rotor 23 in the axial direction; 81 is the compression chamber 24; This is an oil injection port provided to inject oil for cooling, lubricating, and sealing the compression chamber. 1 is an unloader body provided on the suction chamber 8 side of the cylinder 20, 2 and 3 are a valve seat and a valve bearing provided in the unloader body 1, and 5 is a valve 4 that is slidably inserted into the bearing 3. This is the shaft. 6 is a suction port provided at the top of the unloader body 1, and 7 is an opening provided at the bottom of the unloader body 1, and the suction port 6 communicates with the outlet of an intake air cleaner (not shown) of the rotary compressor. , the opening 7 communicates with the suction chamber 8 .
9 is a diaphragm body provided on the side of the unloader body 1; 11 is a diaphragm to which the piston 10 is fixed; the diaphragm 11 is fixed to the diaphragm body 9 by a cover 12;
6, 27 and a pressure reducing valve 14 to a receiver tank (not shown), and the chamber 15 on the right side of the diaphragm communicates via a conduit 28 to a second diaphragm chamber 33 of the regulator 16. The first diaphragm chamber 31 of the regulator 16 communicates with the receiver tank via a conduit 29. 37 is the compressor 18
A lever 38 of the governor 37 is connected to a lever 35 of the regulator via a rod 36.

When the engine is started and the compressor 18 connected directly to the engine is rotated, the air is cleaned of dust by an air cleaner, reaches the intake port 6, and enters the intake chamber 8 through the opening between the valve seat 2 and the valve 4. , is compressed in the compression chamber 24. The compressed air is discharged from the discharge port 25 through the discharge chamber 19 to the receiver tank.

When the air consumption decreases and the pressure inside the receiver tank exceeds the set pressure, the first diaphragm 30 that fixed the needle valve 17 of the regulator 16 is pushed by the pressure and moves to the right, and the needle valve 1
7 leaves the seat, compressed air flows from the first diaphragm chamber 31 to the second diaphragm chamber 33 surrounded by the second diaphragm 32, and the internal pressure of the second diaphragm chamber 33 also increases, overcoming the tension of the spring 34 and closing the lever. Move 35 to the left.

On the other hand, the pressure in the second diaphragm chamber 33 is
The air is sent to the chamber 15 on the right side of the diaphragm 11 of the unloader, overcomes the internal pressure of the chamber 13, pushes the piston 10 to the left, moves in the direction of closing the valve 4, and blocks the intake air.

As the lever 35 of the regulator 16 moves, the lever 38 of the engine governor 37 is moved to the left via the rod 36 to reduce the engine speed.

As the air consumption increases and the pressure in the receiver tank decreases, the volume regulator operates in exactly the opposite manner as described above, valve 4 is fully opened and lever 38 is moved to the right to increase engine speed.

Furthermore, when the engine is stopped and the rotation of the compressor is stopped, the compressed air remaining in the compression chamber 24 flows back into the suction chamber 8 due to the pressure difference between high and low levels, and the valve 4 is closed due to this back flow pressure. This prevents the air remaining in the compression chamber from flowing back to the suction port 6.
There will be no clogging of the air cleaner or contamination of equipment with oil.

Such a conventional capacity adjustment device has a complicated structure and high cost, and also requires a valve 4 and a valve seat 2 to completely seal the intake air when the intake is blocked.
This requires a lot of time for assembly. Furthermore, due to the reciprocating movement of the diaphragm 11, the diaphragm 11 may be damaged or the piston 1 may be damaged.
0. Wear occurs on the sliding part of the shaft part 5 of the valve 4,
It was not possible to create a sufficiently durable capacity adjusting device.

The present invention eliminates these drawbacks and provides a compact, durable, and low cost capacity adjusting device with fewer components.

The present invention will be explained in detail below based on the drawings.
2 to 6 show an embodiment of the capacity adjustment device of the present invention, FIG. 2 is a perspective view of the capacity adjustment device of the present invention, and FIG. 3 is a top view of the capacity adjustment device of FIG. FIG. 4 is a diagram in which the capacity adjustment device of FIG. 2 is attached to a vane compressor. 5 and 6 are diagrams showing the operation of the disc valve 43 of the capacity adjusting device of FIG. 2, FIG. 5 is a diagram showing the disc valve 43 in a closed state, and FIG. FIG. 4 is a diagram showing a state in which the valve 43 is open. In addition, Figures 2 to 6
In the figure, the same parts as in FIG. 1 are given the same numbers.

In FIGS. 2 to 6, 54 is a body provided with a circular intake opening 56 in the center;
Reference numeral 3 denotes a disc valve fitted into the intake opening 56 of the body 54 so as to have a minimum clearance (first clearance) 55 necessary for rotation between the body and the disc valve. A center shaft 60 on which the plate valve 43 rotates is provided eccentrically from the center of the disk valve. 57 and 58 are bosses provided on the body 54, and the central axis 60
is supported by bearings 59 inserted into the bosses 57 and 58. Sealing between the center shaft 60 and the receiving shaft 59 is achieved by an O-ring 61.

64 is a body 54 with a disc valve 43 connected to an intake opening 56
A disc valve 4 provided so as to come into contact with the disc valve when it is in one extreme position where it is fitted with the disc valve and blocks the intake air.
3, and 65 and 66 are the stoppers of disc valve 4.
3 is a shielding plate made of a semicircular thin plate fixed to the outer surface of the disc valve in the opening direction with a bolt 67, and the disc valve rotates counterclockwise in the figure, and one end thereof abuts the stopper 64. , when the outer periphery of the disc valve is in one extreme position where the outer periphery of the disc valve fits into the suction opening and blocks intake air, the shielding plate communicates with the first gap 55 between the body 54; and the first gap 5
5 (see FIG. 5). Further, the center shaft 60 is provided with a small gap (second gap) 68 in a direction substantially perpendicular to the center shaft 60 (see FIG. 5). A spring 70 and a coupling fitting 44 are provided to apply a load to close the disk valve when the plate valve is in the other extreme state of being fully open, and the coupling fitting 44 is fixed to the central shaft 60 with a taper pin 71. The spring 70 has one end fixed to the body 54 with a pin 72 and the other end fixed to the coupling fitting 44 with a pin 73. The tension of the spring is set to the position where the disc valve opens the intake opening to the maximum due to the negative pressure in the suction chamber 8 caused by the rotation of the compressor, that is, the other extreme position where the passage area on the suction side of the compressor is maximized. Set it so that it can rotate up to. The coupling fitting 44 is provided with an opening groove 45 having an open end 80 on the side surface of the coupling fitting on the side of the regulator 16 and extending in the direction of rotation of the area disc valve.
One end of the link rod 46 is freely inserted into the opening groove 45 through the opening end 80, and when the link rod 46 moves to the left in FIG. When the link rod 46 is moved to the right, the tip of the link rod 46 is separated from the bottom of the opening groove 45, and the negative pressure in the suction chamber 8 or The disc valve 43 is configured to be able to freely rotate relative to the link rod 46 by the dynamic pressure of the compressed air flowing back into the suction chamber 8 when the compressor is stopped.

The other end of the link rod 46 is connected to the regulator 1.
6, and the lever 35 is connected via a rod 36 to a lever 38 of a governor 37 of the engine.

Next, the operation of the capacity adjusting device of the present invention will be explained in detail.

When the engine (not shown) is started and the compressor 18 directly connected to the engine is rotated in the direction of arrow B,
As the link rod 46 has moved to the right as shown in FIG. Upon receiving negative pressure, it rotates overcoming the tension of the spring 70 to the other extreme position where the suction side passage area is maximized. Dust is removed from the air by an air cleaner (not shown), and the air is sucked into the compressor as shown by the dotted arrow C through the intake opening 56 of the body 54, compressed in the compression chamber 24, and the compressed air is sent to the discharge port 25. , and is discharged into a receiver tank (not shown) through the discharge chamber 19.

When the air consumption decreases and the pressure inside the receiver tank rises and exceeds the set pressure, the air pressure in the tank fills the first diaphragm chamber 31 of the regulator 16 through the conduit 49, overcomes the spring 39, and closes the needle valve 17. is released from the seat, pressure air is introduced into the second diaphragm chamber 33, the second diaphragm 32 is pushed and the lever 35 is moved until it hits the stop pass screw 40, and the movement of the lever 35 causes the coupling fitting 44 to be moved to the left via the rod 46. direction and rotate until the disc valve 43 comes into contact with the stopper 64, that is, to one extreme position where it fits into the intake opening and blocks the intake (see Figure 5).
At this time, the first gap 55 between the disc valve 43 and the body 54 becomes the minimum, the first gap 55 is blocked by the shielding plates 65 and 66, and the passage bends into the second gap 68. By doing so, the amount of gas that leaks and enters through the gap 55 can be reduced, so that the pressure in the receiver tank does not increase when there is no load.

On the other hand, the movement of the lever 35 of the regulator 16 moves the governor lever 38 to the left via the rod 36, thereby reducing the rotation of the engine. Therefore, the compressor performs no-load operation.

When the air consumption increases and the tank pressure decreases, the pressure in the first diaphragm chamber 31 of the regulator 16 decreases, and the tension of the spring 39 causes the needle valve 17 to contact the seat and open the flow to the second diaphragm chamber 33. The residual air in the second diaphragm chamber 33 passes through the relief hole orifice 50, passes through the conduit 51, and is discharged from the intake side opening 53 of the unloader. The lever 35 of the regulator 16 is moved to the right by the tension of the spring 34, the engine governor lever 38 is moved to the speed increasing side to increase the engine rotation, and the rod 46 is moved to the right.
Its tip moves along the opening groove 45 of the coupling fitting 44. As the speed of the engine increases, the rotation of the compressor 18 increases, and the negative pressure in the suction chamber 8 causes the disc valve 43 to overcome the tension of the spring 70 and automatically rotate, opening the intake opening 56 of the suction passage (the sixth (see figure), suction air is introduced into the compressor 18.

When the compressor is stopped, the residual pressure in the compression chamber 24 flows backwards due to the difference between high and low pressures, and air and oil are drawn into the suction chamber 8.
The disk valve 43 receives the dynamic pressure. At this time, since the lever 35 of the regulator is rotated to the right and the link rod 46 is moved to the right, the areas receiving this dynamic pressure of the disc valve are different on both sides of the central shaft 60, and the spring 70
The disc valve 43 automatically rotates in the direction of closing in a well-timed manner to add tension to the stopper 64.
to close the intake opening 56.

At this time, as in the case of no load, the gap 55 between the disc valve 43 and the opening 56 of the body 54 is shielded by the shielding plates 65 and 66, and the passage bends into the gap 68, so that the disc valve 43 is closed. Since the flow rate of gas flowing through the gap when closed can be reduced, backflow fluid can be prevented from entering the upper part of the disc valve.

In the above embodiment, an opening groove 45 is provided in the coupling fitting 44, and one end of the link rod 46 is freely inserted into the opening groove 45, thereby reducing the negative pressure in the suction chamber 8 or the suction chamber when the compressor is stopped. Although the disc valve 43 is constructed so as to be able to be rotated by the dynamic pressure of the compressor air flowing back into the valve 8, it goes without saying that the opening groove 45 may be provided in the lever of the regulator.

As explained in detail above, the present invention is a capacity adjustment device that increases or decreases the amount of air discharged from a rotary compressor by increasing or decreasing the passage area on the suction side of the rotary compressor. and a disc valve that rotates from one extreme position that fits into the intake opening to the other extreme position that maximizes the passage area on the intake side, and is provided eccentrically with respect to the center of the disc valve. In the capacity adjustment device for a rotary compressor, the capacity adjustment device is configured to be rotatably supported by a central shaft, and to increase or decrease the area of the intake opening by rotation of the central shaft, One end of the central shaft protrudes outside the body, and a coupling fitting fixed to the shaft end protruding outside the body and a lever of the regulator are connected by a link rod, and either of the coupling fitting or the regulator lever is connected. An opening groove extending in the rotating direction of the disc valve is provided on one side, and one end of the link rod is freely fitted into the opening groove, so that the link rod closes the intake opening. During start-up or load operation, the negative pressure in the suction chamber caused by the rotation of the compressor allows the disc valve to be rotated to the ultimate position that maximizes the passage area on the suction side of the compressor. The capacity adjustment device can close the disc valve at low cost and have high durability. Also,
A spring is provided between the body and the coupling fitting to bias the disc valve in the closing direction via the central shaft that supports the disc valve, so that the disc valve can be quickly and reliably closed when the compressor is stopped. Can be closed. Also,
Since the body is provided with a stopper that comes into contact with the disc valve when the disc valve is fitted into the intake opening, the disc valve can be reliably stopped at the position where it fits into the intake opening. Since the gap between the valve and the body can be kept small, the flow rate of gas flowing into the suction chamber can be reduced during non-negative operation. Similarly, when the compressor is stopped,
It is possible to reliably block the backflow of compressed air flowing back into the suction chamber toward the air cleaner side.

[Brief explanation of the drawing]

FIG. 1 shows a vane compressor with a conventional capacity adjustment device. 2 to 6 show an embodiment of the capacity adjustment device of the present invention, FIG. 2 is a perspective view of the capacity adjustment device of the present invention, and FIG. 3 is a top view of the capacity adjustment device of FIG. FIG. 4 is a diagram in which the capacity adjustment device of FIG. 2 is attached to a vane compressor. 5 and 6 are diagrams showing the operation of the disc valve 43 of the capacity adjusting device of FIG. 2, FIG. 5 is a diagram showing the disc valve 43 in a closed state, and FIG. FIG. 4 is a diagram showing a state in which the valve 43 is open. 43...disc valve, 44...coupling fitting, 45...
Opening groove, 54...Body, 56...Intake opening, 6
0...Central axis, 64...Stopper, 70...Spring.

Claims (1)

[Claims] 1. A disc valve that fits into an intake opening provided at the center of the body is rotatably supported by a central shaft provided eccentrically with respect to the center of the disc valve. In a capacity adjusting device for a rotary compressor configured to increase or decrease the intake opening area by rotation, one end of the rotating central shaft of the disc valve is made to protrude outside the body, A coupling fitting fixed to the protruding shaft end and a lever of the regulator are connected by a link rod, and either the coupling fitting or the regulator lever is provided with an opening groove extending in the rotating direction of the disc valve. A rotary compressor, characterized in that one end of the link rod is freely fitted into the opening groove, and the disk valve closes the intake opening when the link rod is extended to the maximum. Capacity adjustment device. 2. The capacity adjusting device for a rotary compressor according to claim 1, wherein a spring is provided on the central shaft that supports the disc valve in a direction to close the disc valve. .