JPH0623755Y2 - Compressor capacity control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a compressor capacity control device for detecting the pressure in a receiver tank and appropriately adjusting the capacity of an engine-driven compressor based on the detected pressure. .

[Problems to be Solved by Prior Art and Invention] Rotary compressors such as screw compressors and vane compressors are
It can be directly connected to a prime mover such as a diesel engine or gasoline engine and driven, but when the air consumption decreases, it detects the internal pressure of the receiver tank that stores compressed air and reduces the passage area on the suction side of the rotary compressor. The capacity control device is provided to reduce the discharge air amount of the rotary compressor and reduce the power consumption of the prime mover by reducing the engine speed as well as reducing the engine speed.

A capacity control device disclosed in Japanese Utility Model Laid-Open No. 59-81749 is known as a control method for increasing / decreasing the passage area and increasing / decreasing the rotational speed of a prime mover. As shown in FIG. 5, this device stores an unloader 3 that controls the amount of intake gas by opening and closing a butterfly valve 2 provided at a suction port 1 of a compressor and a compressed air that communicates with a discharge port of the compressor. A regulator 7 having a receiver tank 4 for operating the compressor and an engine 5 directly connected to the compressor for driving the compressor, and having a valve mechanism 6 into which the internal pressure of the receiver tank 4 is introduced and which operates in accordance with the internal pressure. The governor lever 9 for increasing / decreasing the rotation speed of the engine 5 is connected to the lever 8 of FIG. 1 through the first rod 10, and the lever 8 is connected to the second rod 10a.
The butterfly valve 2 is connected to the butterfly valve 2 via a valve to convert the fluctuation of the internal pressure of the receiver tank 4 into the rotational movement of the lever 8 of the regulator 7, and the rotational movement operates the butterfly valve 2 and the governor lever 9.

However, in such a control system, the butterfly valve 2 has a seat portion at the entire outer periphery thereof, and the ventilation resistance is small until just before closing, and the butterfly valve 2 is not operated at the time of starting.
And the governor lever 9 are always interlocked, the governor lever 9 changes from the high speed position to the low speed position, and the butterfly valve 2 also changes from the fully open position to the fully closed position. The operation characteristics of both are as shown in B of FIG. 4 (B) described later. Therefore, the amount of intake gas sucked into the compressor is large, and therefore, the drive torque becomes large immediately after the compressor is started. In addition, a larger load is applied to the engine 5 in a state where the engine oil has a high viscosity and a large sliding resistance, and as a result, it is difficult to start the engine, especially at low temperatures. Also, immediately after startup, when the inside of the receiver tank reaches a predetermined internal pressure and the butterfly valve 2 closes rapidly, the governor lever 9 also rapidly returns to the low speed side at the same time, but the butterfly valve 2 has a small ventilation resistance until just before closing. However, there is a problem that an engine stall is likely to occur because the amount of suction gas sucked into the compressor is large.

In addition, the same problem as described above occurs when the receiver tank 4 reaches a predetermined internal pressure and shifts from full load to no load during continuous operation, that is, when the compressor is under no load. Even when the load shifts from the normal load to the normal full load, the load due to the compression action of the compressor is abruptly applied in parallel with the increase in the rotation speed of the engine from the low speed, and thus there is the same problem as described above.

Another control method is disclosed in Japanese Patent Application Laid-Open No. 57-173591. As shown in FIG. 6, this control device is provided with a valve seat 14 and a valve bearing 15 on an unloader body 13 provided on the suction chamber 12 side of a cylinder 11, and a shaft portion 17 of a valve 16 is slidable on the bearing 15. insert. Diaphragm body 13a provided on the side of the unloader body 13
A diaphragm 19 to which a piston 18 is fixed is provided in the first chamber 20 on the left side of the diaphragm 19 communicates with a receiver tank (not shown) via a pressure reducing valve 20a, while a second chamber 21 on the right side of the diaphragm 19 is provided. Communicates with the second diaphragm chamber 23 of the regulator 22. Further, it communicates with the receiver tank via the first diaphragm chamber 24 of the regulator 22.
A lever 28 of the regulator 22 is connected to a lever 27 of a governor 26 of an engine (not shown) that drives the compressor 25 via a rod 28a.

Then, when the air consumption decreases and the pressure inside the receiver tank exceeds the set pressure, the needle valve of the regulator 22
The first diaphragm 22b with the fixed 22a is pushed and moved to the right, the needle valve 22a is separated from the seat, compressed air flows from the first diaphragm chamber 24 to the second diaphragm chamber 23, and the internal pressure of the second diaphragm chamber 23 is increased. Is lifted to overcome the tension of the spring 22c and move the lever 28 to the left.
The lever 27 of the governor 26 is interlocked with the lever 28 to reduce the engine speed. On the other hand, the second diaphragm chamber
The pressure of 23 is sent to the chamber 21 on the right side of the diaphragm 19 to overcome the internal pressure of the chamber 20, push the piston 18 to the left, and move the valve 16 in the closing direction. As described above, in this device, the valve 16 provided at the intake port is controlled by the pressure difference between the first and second chambers 20 and 21, while the lever 27 of the governor 26 controls the regulator 22.
It is designed to work with.

However, in such an apparatus, the valve seat 14 is provided on the unloader body 13 and the valve seat 14
Since the valve 16 that can be brought into contact with is provided, there is a problem that the structure is complicated, the mounting space becomes large, and the weight increases. Further, since the combination of the valve seat 14 and the valve 16 causes a large suction resistance, there is a problem that the valve itself has to be necessarily large.

In order to solve such a problem, the combination of the valve seat 14 and the valve 16 shown in FIG. 6 can be replaced with a lightweight valve, and a butterfly valve having a small suction resistance is adopted. However, as described above, since the butterfly valve 2 has the seat portion on the entire outer periphery thereof, it has a feature that the ventilation resistance is small until just before closing, as compared with the diaphragm type unloader, but as described above, the opening degree is small. However, when it is opened, a large amount of intake air flows into the compressor, which results in further promoting engine stalling when transitioning from the unloaded state to the loaded state at the time of starting the compressor or during continuous operation.

The present invention is an engine-driven compressor that has a butterfly valve for controlling the amount of intake gas at the intake port and a governor control device for increasing or decreasing the engine speed, and is used when starting with low engine torque or in a continuous state. It is an object of the present invention to improve the control characteristics of the butterfly valve and the governor in order to prevent engine stalling during the transition from the unloaded state to the loaded state.

[Means for Solving the Problems] The present invention is provided with a receiver tank 40 that communicates with a discharge port 33a of an engine 54 driven compressor 31 and stores compressed air.
A bellows type regulator 52 that operates according to the internal pressure of the receiver tank 40 is provided, and a butterfly valve 38 that controls the intake air amount in conjunction with the operation of the bellows type regulator 52 is provided at the suction port 32a of the compressor 31. ,
A diaphragm type regulator 55 that operates according to the internal pressure of the receiver tank 40 and has a slower response speed than the bellows type regulator 52 is provided, and the rotation speed of the engine 54 is increased / decreased in conjunction with the diaphragm type regulator 55. Then, the above-mentioned bellofram type regulator 52
Introduces the internal pressure of the receiver tank 40 into the first chamber 59a provided on one side of the bellows 59 through the air passage 53 having the manually operated valve 53a, and the piston 60 is provided on the other side of the bellows 59 with the bellows 59. A spring 61b that is held by 59 and presses the piston 60 is provided, and the piston 60 has an operation shaft for operating the butterfly valve 38.
61 is connected to the diaphragm type regulator.
55 is a first chamber for introducing the internal pressure of the receiver tank 40
63 is provided, and a second chamber 65 is provided in the first chamber 63.
A first diaphragm 67 facing the passage 64 in the first chamber 63, and a needle valve 66 for opening and closing the passage 64, which is integrated with the first diaphragm 67. The control lever 70 for controlling the engine 54 rotational speed is rotatably provided in contact with the other of the second diaphragm 68 provided in the second chamber 65, and the control lever 70 is rotated by a spring 73. The first chamber of the bellows type regulator 52 is configured to be pressed.
59a side and the suction port 32a of the compressor 31 are connected via a return air passage 78, and a throttle is provided in the middle of the return air passage 78.
77a is provided, and the diaphragm type regulator 55 is further provided.
A return air passage 77 having one end connected to the second chamber 65 is connected between the return air passage 78 between the first chamber 59a side and the throttle 77a to control the opening / closing of the butterfly valve 38 and the engine 54.
It is a capacity control device for a compressor, which independently controls the increase and decrease control of the rotation speed.

[Operation] At the time of starting the compressor, the lever 76 of the engine governor 75 is in the high speed position by the diaphragm type regulator 55,
The bellows-type regulator 52 causes the butterfly valve 38 to be in the fully open position. The internal pressure of the receiver tank 40 gradually rises as the number of revolutions of the engine 54 rises, so that the belofram regulator 52 operates to close the butterfly valve 38 to control the intake gas amount of the compressor 31. At the same time, the lever 76 of the engine governor 75 is a diaphragm type regulator.
55 operates and returns to low speed side L. Also, when the compressor 31 shifts from full load to no load after shifting to normal operation, the lever 76 of the engine governor 75 returns to the low speed side L in response to the operation of the diaphragm type regulator 55, and the bellofram type regulator 55 is returned. 52 operates to close the butterfly valve 38. Also, when shifting from no load to full load, the engine governor responds to the operation of the diaphragm regulator 55.
The lever 76 of 75 moves to the high speed side H, and the bellows-type regulator 52 operates to open the butterfly valve 38. Since the response speed of the bellows type regulator 52 is faster than that of the diaphragm type regulator 55, the butterfly valve 38 is closed immediately at the time of starting, the intake gas amount is controlled, and the driving torque of the engine is small. In addition, since the butterfly valve 38 is closed and the lever 76 of the engine governor 75 is set to the low speed side L at the time of starting and shifting from full load to no load, a large load is not applied to the engine. When shifting from no load to full load, the lever 76 of the engine governor 75 moves from the low speed side L, the engine speed increases, and then the butterfly valve 38 opens. Therefore, the startability is improved and there is no engine stalling.

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, a compressor 31 includes a male rotor 35 in a cylinder 34 having a suction chamber 32 having a suction port 32a at the upper portion and a discharge chamber 33 having a discharge port 33a at the lower portion. The female rotor 36 is built in, and the working chamber 37 compresses the air flowing in from the suction chamber 32 and flows out to the discharge chamber 33 together with the lubricating oil. A butterfly valve 38 is mounted on the suction port 32a side of the suction chamber 32 provided with an air cleaner (not shown), and a check valve 39 toward the suction chamber 32 is mounted on the secondary side of the butterfly valve 38. To do.

On the other hand, a check valve (not shown) is built in the discharge chamber 33, and a discharge pipe 42 communicating with a receiver tank 40 having a separator 41 is connected to the discharge port 33a of the discharge chamber 33. Further, the receiver tank 40 is provided with a first lubricating oil passage 44 leading to the oil cooler 43, and the oil cooler 43 is provided with a second lubricating oil passage 45 leading to the compressor 31. Further, an oil filter 46 is attached to the compressor 31 side of the second lubricating oil passage 45. A bypass lubricating oil passage 47 is provided between the first and second lubricating oil passages 44, 45, and a bypass valve 48 for keeping the lubricating oil temperature at an appropriate temperature by opening and closing by a temperature sensing element (not shown) is provided at one end thereof. .

On the other hand, the receiver tank 40 is provided with an auto-relief valve 49 that opens a valve (not shown) to automatically release the pressure in the separator 41 when the compressor 31 stops. A second air passage 53 connected to the drain tank 50 and connected to a manual opening / closing valve 53a described later is connected to the passage 51.
And the third air passage 56 leading to the diaphragm regulator 55
Connect. 57 is the suction chamber 32 and the auto relief valve
A fourth air path connecting between 49, and when the compressor 31 is stopped, the internal air pressure of the separator 41 is released to the atmosphere by operating the valve in the auto relief valve 49 by the backflow air to the suction port 32a. . Reference numeral 53a is a manual opening / closing valve for the starting unloader, which manually opens the second air passage 53 when the compressor 31 is started at a low temperature such as in a cold region and closes it after the start.

As shown in FIG. 2, the bellows type regulator 52 divides the inside of the casing 58 into two first and second chambers 59a, 59b by a bellows drum 59 formed of a substantially cylindrical rubber body.
The second air passage 53 is connected to the first chamber 59a, while the second chamber 59a
On the b side, a piston 60 held by a bellows 59 and an operating shaft that is connected to the piston 60 and projects from the casing 58.
61 and a spring 61b interposed between the side of the casing 58 and the piston 60. Therefore, the first by compressed air
The bellows 59 moves to a position where the total pressure on the chamber 59a side and the tension of the spring 61b are balanced, and this movement causes the operation shaft 61 to move.
Goes back and forth. The operating rod 38a of the butterfly valve 38 is connected to the operating shaft 61 via the first rod 61a to form the unloader 62, which has a characteristic that the response speed is faster than that of a diaphragm regulator described later. ing. That is, the bellows 59 is a substantially cylindrical rubber body that is attached to the casing 58 in a partially folded state to partition the inside of the casing 58 into the first and second chambers 59a and 59b. Therefore, when the piston 60 is moved until the total pressure of the first chamber 59a and the force of the spring 61b are balanced, the piston 60 is moved simply by moving the folding position, and the piston 60 is moved by the expansion of the belophram 59 itself. Not the one, the first room 59a
The amount of movement of the piston 60 can be increased by a slight increase in pressure, so that the operating shaft 61 repeats advancing and retreating in proportion to the increase in pressure, and the operating shaft 61 moves due to the lack of sliding resistance of the piston 60. Is smooth and has a fast response speed.

On the other hand, the diaphragm type regulator 55 has a third
As shown in the drawing, a first chamber 63 connecting the third air passage 56 and a second chamber 65 communicating with the first chamber 63 via a central passage 64 are formed in the central passage 64. A needle valve 66 for opening and closing the needle valve 66 is provided, and a first diaphragm 67 made of a flat rubber body is stretched at the opening of the first chamber 63 to fix the needle valve 66. Further, a second diaphragm formed of a flat rubber body also in the opening of the second chamber 65.
A lever 70 having a base end pivotally attached to the regulator case 69 is provided outside the diaphragm 68, and the central protruding portion 70a is brought into contact with the second diaphragm 68. A regulator operating pressure adjusting bolt 72 is connected to the needle valve 66 via a spring 71. 73 is a spring for returning the lever 70, and 74 is an exhaust port. Therefore, when the internal pressure of the receiver tank 40 rises, the first chamber 63 becomes high pressure, and the load pressing the first diaphragm 67 is the spring.
When the tension exceeds 71, the needle valve 66 opens, air flows from the first chamber 63 to the second chamber 65, the second diaphragm 68 extends, and the lever 70 is pushed by the second diaphragm 68.
Rotates. Thus, the diaphragm type regulator
In 55, the second diaphragm 68 itself, which is a flat rubber body, extends to rotate the lever 70, but the extension of the second diaphragm 68 cannot be increased in view of the strength of the diaphragm. Therefore, the expansion of the second diaphragm 68 is small with respect to a slight increase in pressure in the second chamber 65, and the response speed of the diaphragm regulator 55 is slower than that of the bellows regulator 52. A lever 76 of a governor 75 for controlling the rotation speed of the engine 54 is connected to a lever 70 of the diaphragm regulator 55 via a second rod 76a, and when the internal pressure of the receiver tank 40 rises and reaches a specified pressure, the lever is The rotation of the engine 54 is reduced by rotating the 76 in the L direction. Then, the air in the second chamber 65 is returned from the exhaust port 74 through the first return air passage 77 and the orifice 77a which is narrowed to the suction port 32a side.

This first return air passage 77 and the bellows type regulator
A second return air passage 78 is also provided between 52.

Furthermore, the engine is installed between the discharge chamber 33 and the receiver tank 40.
54 When the compressor 31 and the receiver tank 40 at the time of stoppage are provided with an equalizer pipe 79 for keeping the same pressure.

Next, the operation will be described with reference to FIGS. 4 (A) and 4 (B). Note that the following actions show the case where the viscosity of the engine oil is high and the sliding resistance of each part is large, especially when the engine is started at a low temperature in a cold region.

Since the internal pressure of the receiver tank 40 is zero in the stroke before starting, the bellows 59 of the bellows type regulator 52 is
Is pressed by the spring 61b to fully open the butterfly valve 38 via the operation shaft 61, and the needle valve 66 in the diaphragm regulator 55 also closes the central passage 64 by the tension of the spring 71, and the lever 70 also returns. It is pressed by the spring 73 and is positioned on the high speed side (direction H in FIG. 1).

First, in the starting stroke at low temperature, the opening / closing valve 53a of the second air passage 53 is opened to start the engine 54 in order to reduce the starting load of the compressor. When the compressor 31 that is directly connected to the engine 54 rotates, the air has its dust removed by the air cleaner, enters the suction chamber 32 through the suction port 32a, and the air compressed in the working chamber 37 passes through the discharge pipe 42 and is built into the receiver tank. It reaches the separator 41, and the separator 41 separates the compressed air from the lubricating oil.

Then, when the internal pressure of the receiver tank 40 gradually rises,
The pressure is introduced into the first chamber 59a of the bellows type regulator 52 through the second air passage 53, and the piston 60 causes the spring 6 to move.
It overcomes the tension of 1b and pushes and moves to the right in FIG. 2 to rotate the butterfly valve 38 connected through the operation shaft 61 to rotate the suction port.
32a is gradually closed. And the low pressure (about 5 kg) before the receiver tank pressure reaches the specified pressure of 7 kgf / cm ^2.
The valve closing is completed at f / cm ² ). As described above, at low temperature starting, the viscosity of the engine oil is high, the sliding resistance of each part is large, and the starting torque of the engine is small. Therefore, the butterfly valve 38 is closed when the internal pressure of the receiver tank is approximately 5 kgf / cm ^2. Drive torque is reduced.

On the other hand, at this time, the internal pressure of the second air passage 53 is the second return air passage 78,
Diaphragm type regulator 55 via the first return air passage 77
The lever 76 of the governor 75 of the engine 54 is moved to the low speed side (direction L in FIG. 1) by the diaphragm type regulator 55. Here, the bellows type regulator 52 has a faster response speed than the diaphragm type regulator 55, and operates as indicated by A in FIG. 4 (B).
For this reason, the butterfly valve 38 is closed immediately after starting, so that the internal pressure of the receiver tank 40 can be lowered, and the driving torque applied to the engine 54 at the time of starting the engine 54 is small. Further, since the diaphragm regulator 55 operates as shown by B in FIG. 4 (B), the lever 76 of the governor 75 is
Before the low speed side L, the butterfly valve 38 closes, thereby stopping the intake of the compressor 31, and the driving torque applied to the engine 54 at the low speed rotation of the engine 54 can be reduced, so that the engine 54 does not stall. Will start. Then, the rotation is continued as it is, and the warm-up operation is performed for a while.
After warm-up operation, close the manual on-off valve 53a to close the second air passage 5
Since the flow of air from 3 to the bellofram type regulator 52 is stopped, the compressed air in the first chamber 59a escapes to the suction port 32a by a small amount through the orifice 77a which is a throttle, so that the operation shaft 61
Is pushed back by the tension of the spring 61b, which causes the butterfly valve 38 to open again and start sucking air to raise the internal pressure of the receiver tank 40 to the specified pressure, and the diaphragm regulator 55 operates to move the lever of the governor 75.
76 moves to the high speed side H and shifts to full load operation. Next, in the transition process from full load operation to no load operation, when the internal pressure of the receiver tank 40 reaches the specified pressure (7 kgf / cm ² ), and exceeds the specified pressure, the compressed air from the third air passage 56 is compressed. The needle valve 66 is opened by pressing the first diaphragm 67 facing the first chamber 63 of the mold regulator 55.
As a result, the compressed air flows into the second chamber 65 and the diaphragm
68 is pressed to rotate the lever 70 in the right direction in the figure, whereby the governor lever 76 moves in the low speed side L direction.

At the same time, the compressed air again flows into the first chamber 59a of the bellows type regulator 52 connected to the first return air passage 77 and the second return air passage 78 through the exhaust port 74, and presses the piston 60. Therefore, the operation shaft 61 moves in the closing direction of the butterfly valve 38.

At this time, the bellows type regulator 52 operates as indicated by A in FIG. 4 (B), the piston 60 moves substantially in proportion to the increase in the internal pressure of the first chamber 59a, and the butterfly valve 38 closes. The diaphragm regulator 55 is shown in Fig. 4 (B).
The valve 70 of the diaphragm type regulator closes the intake port 32a before the governor lever 76 of the engine reaches the low speed position L.

Therefore, in this case as well, the butterfly valve 38 closes and the intake air of the compressor 31 is stopped, and then the engine 54 shifts to the low speed side, so that the drive torque applied to the engine 54 can be reduced in the low speed rotation of the engine 54, and there is a fear of engine stall. There is no.

Then, in the transition process from the no-load operation to the full-load operation, when the pressure in the receiver tank 40 drops below the specified pressure due to consumption of compressed air on the use side, the needle valve 66 of the diaphragm regulator 55 closes, and the lever
Since 70 also returns to the original position, the engine 54 rises to the rated speed and the first chamber of the bellofram type regulator 52
The pressure in 59a also gradually drops due to the outflow from the orifice 77a, and the butterfly valve 38 is rotated to open the air suction port 32a and start sucking air.

At this time, the operation characteristics of the regulators 52 and 55 are opposite to the operation described above, and the return B of the diaphragm type regulator 55 is slightly smaller than the return A of the bellows type regulator as shown in A to B of FIG. 4 (B). It is done quickly. That is, when returning from the no-load operation state to the full-load operation state,
After the engine speed has risen, the butterfly valve 38 will start opening, and will perform the air intake / compression operation.
The ratio of the load on the engine is appropriately balanced, and in this case as well, there is no fear of engine stall.

Then, after that, the above-described operation is repeated according to the increase or decrease of the consumed air amount.

As described above, the butterfly valve 38 is controlled by the fast-responsive bellows type regulator 52, while the governor 75 of the engine 54 is independently controlled by the diaphragm type regulator 55 having a slower response speed than the bellows type regulator 52. By doing so, it is possible to greatly improve the startability of the compressor 31 at low temperatures, and to change from full load operation to no load operation or from no load operation to full load operation in response to the increase or decrease in the amount of air consumption. When making a transition, the repeated operation can be smoothly performed without causing an engine stall.

In order to reduce the drive torque applied to the engine 54 when the engine oil viscosity is high and the sliding resistance of each part is large, especially when starting at low temperatures such as in cold regions, the opening / closing valve 53a is opened to start the operation. After the warm-up operation, close the on-off valve 53a,
The case of shifting from full-load operation to no-load operation or from no-load operation to full-load operation has been described. However, the opening / closing valve 53a may be started with the valve closed, except at the low temperature start.

In this case, since the opening / closing valve 53a is closed, when the internal pressure of the lever tank 40 rises and exceeds the specified pressure (7 kgf / cm ² ), the compressed air from the third air passage 56 is transferred to the first chamber of the diaphragm regulator 55. The diaphragm 67 facing 63 is pressed to open the needle valve 66, and thereafter, the same operation as in the transition process from full load operation to no load operation is performed to complete the start. Therefore, in this case as well, before the rotational speed of the engine 54 shifts to a low speed, the butterfly valve 38 closes to stop the intake of the compressor 31 and the engine 54 rotates at a low speed.
Since the drive torque applied to the engine 54 can be reduced, the engine 54 can be started without stall.

In order to further improve the operating characteristics of the regulators 52, 55, the spring 61b of the bellows type regulator 52 and the spring 7b of the diaphragm type regulator 52 are used.
It goes without saying that it is possible by appropriately changing or combining the spring constant of 3.

Further, in addition to the present invention, as shown in JP-A-57-195822, a lever 70 of a diaphragm type regulator is used.
An air cylinder (not shown) is provided on a second rod 76a that connects the engine governor 76 with the engine governor 76. When the engine 54 is started, the governor lever 76 is positioned at the speed increasing position, and after a certain time, the second rod It is even more effective to configure the 76a so that it can be restored to its original length.

[Advantages of the Invention] The invention is a bellows type that operates in response to the internal pressure of the receiver tank 40 by providing a receiver tank 40 that communicates with the discharge port 33a of the engine 54 drive type compressor 31 and stores compressed air. A regulator 52 is provided, and a butterfly valve 38 that controls the intake air amount in conjunction with the operation of the belofram type regulator 52 is provided at the intake port 32a of the compressor 31 and operates according to the internal pressure of the receiver-tank 40. A diaphragm regulator 55 having a response speed slower than that of the bellows type regulator 52 is provided, and is configured so as to increase or decrease the rotation speed of the engine 54 in conjunction with the diaphragm type regulator 55. The internal pressure of the receiver tank 40 is introduced into the first chamber 59a provided in one of the bellows 59 via the air passage 53 provided with the valve 53a. On the other hand, the bellows 59 is provided with a spring 61b for holding the piston 60 by the bellows 59 and pressing the piston 60, and the piston 60 has an operating shaft 61 for operating the butterfly valve 38. The diaphragm type regulator 55 is connected to a first chamber 63 for introducing the internal pressure of the receiver-tank 40, and the first chamber 63 has a second chamber 65.
Are provided in communication with each other through a passage 64, a first diaphragm 67 is provided in the first chamber 63 so as to face the passage 64, and a needle valve 66 for opening and closing the passage 64 is provided in the first diaphragm 67. Is integrally provided, and the engine 54 is provided on the other side of the second diaphragm 68 provided in the second chamber 65.
A rotation speed control lever 70 abuts and is rotatably provided, and the control lever 70 is pressed by a spring 73, and the first chamber 59a side of the bellows type regulator 52 and the compressor 31. Inlet 32a of return air passage 78
The return air passage 78 is provided with a throttle 77a in the middle of the return air passage 78, and the return air passage 77 having one end connected to the second chamber 65 of the diaphragm regulator 55 is connected to the first return air passage 78. It is connected between the side of the first chamber 59a and the throttle 77a to control the opening and closing of the butterfly valve 38 and the engine.
By independently controlling the increase / decrease control of the rotational speed of 54, it is possible to improve the engine starting characteristics, especially the engine startability at low temperatures, and from the no-load state to the load state during continuous operation. Transition and the reverse operation, etc.
It is possible to smoothly perform the repeated operation corresponding to the increase / decrease in the amount of consumed air without causing engine stalling.

[Brief description of drawings]

Fig. 1 is a system diagram, Fig. 2 is a sectional view of a bellows type regulator, Fig. 3 is a sectional view of a diaphragm type regulator, Fig. 4 (A) is a graph showing a stroke, and Fig. 4 (B) is a regulator. A characteristic graph, FIG. 5 is a conventional system diagram, and FIG. 6 is another conventional system diagram. 31 ... Compressor 32a ... Suction port 33a ... Discharge port 38 ... Butterfly valve 40 ... Receiver tank 49 ... Auto relief valve 52 ... Bellofrum type regulator 53 ... Air passage 53a ... Manually operated valve 54 ... Engine 55 ... Diaphragm type regulator 59 ... Bellofram 59a ... First chamber 60 ... Piston 61b ... Spring 61 ... Operation shaft 62 ... Unloader 63 ... First chamber 64 ... Passage 65 ... Second chamber 66 ... Needle valve 67 ... First diaphragm 68 ... Second diaphragm 70 ... For control Lever 73 ... Spring 73 77a ... Orifice (throttle) 77 ... Return air passage 78 ... Return air passage

Claims (1)

[Scope of utility model registration request] 1. A receiver tank 40 for communicating compressed air with a discharge port 33a of an engine 54 drive type compressor 31 and a bellows type regulator 52 which operates according to the internal pressure of the receiver tank 40 are provided. A butterfly valve 38 that controls the amount of intake air in conjunction with the operation of the bellofram type regulator 52 is provided at the suction port 32a of the compressor 31, and operates according to the internal pressure of the receiver tank 40. A diaphragm type regulator 55 having a slow response speed is provided, and is configured so as to increase or decrease the rotation speed of the engine 54 in conjunction with the diaphragm type regulator 55. The bellows type regulator 52 is an air passage provided with a manually operated valve 53a. The internal pressure of the receiver tank 40 is introduced into the first chamber 59a provided on one side of the bellows 59 via 53, On the other side of the ram 59, a piston 60 is provided which is held by the bellows ram 59 and which presses the piston 60, and the operation shaft 61 for operating the butterfly valve 38 is connected to the piston 60. The diaphragm regulator 55 is provided with a first chamber 63 for introducing the internal pressure of the receiver tank 40, and a second chamber 65 is provided in the first chamber 63 in a communicating state via a passage 64, A first diaphragm 67 is provided in the first chamber 63 so as to face the passage 64, and a needle valve 66 for opening and closing the passage 64 is integrally provided in the first diaphragm 67, and the second chamber 65 is provided in the second chamber 65. The control lever 70 for controlling the rotation speed of the engine 54 abuts on the other side of the second diaphragm 68 provided, and the control lever 70 is rotatably provided.
Is configured to be pressed by a spring 73, and the first chamber 59a side of the bellows type regulator 52 and the suction port 32a of the compressor 31 are connected via a return air passage 78, and the return air passage 78 A diaphragm 77a is provided on the second side of the diaphragm type regulator 55.
The return air passage 77 having one end connected to the chamber 65 is replaced with the return air passage 78.
The compressor is characterized in that the compressor is connected between the first chamber 59a side and the throttle 77a, and controls the opening / closing control of the butterfly valve 38 and the increase / decrease control of the rotation speed of the engine 54 independently of each other. Capacity control device.