JP3889080B2 - Internal combustion engine driven pump device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pump device that drives a pump by an internal combustion engine, and more particularly, to a pump device that drives an internal combustion engine that supplements intake air from the pump with intake air from the internal combustion engine. Such a pump device is used as a generation source of vacuum suction force by suction. For example, it is used in a soil excavation apparatus that uses a vacuum suction force to dig up soil without damaging existing buried objects when digging up soil or the like when installing or repairing underground pipes.
[0002]
Or, if you want to remove the difference water in the pipe to remove the sediment and mud accumulated in the pipe due to the earthquake, etc., or if you want to suck the dust in the pipe as a cleaning prior to the sealing in the pipe, line it in the pipe When sucking resin, when collecting and cleaning silica sand after polishing of pipe fittings and valves by sandblasting, after shot blasting for pipe rust removal, pigs are sucked in the pipe to remove silica sand and rust. In this case, the vacuum suction force is exerted when the parachute and the sponge pig are further sucked in the tube to perform draining, foreign matter removal, or the like.
[0003]
Here, the field of soil excavation in which a pump device driven by an internal combustion engine is used will be described in detail.
In general, a crusher that forcibly hammers a hammer with compressed air or a power shovel that scoops up strongly with a large bucket is used to dig up or raise an asphalt pavement surface. However, these are powerful and have high work efficiency, but have the negative side of producing a large impact sound and noise. In addition, when a buried pipe or the like is already installed in the basement because it is too strong, there is also a problem that inadvertently touching this causes inconvenience such as destruction of the contacted part or extreme deformation. Therefore, a crusher that can be held by hand and a vacuum excavator are also used for excavating in the ground in time, even if it does not have that much excavation capacity, so that the buried pipes and the like are not broken. ing.
[0004]
As such a handy type crusher, one disclosed in Japanese Utility Model Laid-Open No. 59-160174 is known. This crusher is provided with a chisel blade at the tip of a cylindrical body extending downward from the handle portion, and is provided with a passage for sending compressed air supplied from the compressor to the tip of the chisel blade, and a part of the compressed air at the chisel blade portion. It is a thing of the structure which provided the injection port which injects. In addition to mechanical crushing with a flea blade, soil crushing is also performed by blowing or subdividing earth and sand with compressed air injected from the vicinity of the flea blade.
[0005]
Further, as such a vacuum excavator, for example, one disclosed in Japanese Patent Application Laid-Open No. 58-222228 is known. This vacuum excavator includes a suction port for earth and sand at the tip of a vacuum hose communicated with a suction blower. Then, when the worker brings the soil suction port of the hose close to the soil surface to be excavated, the soil is sucked up by the suction force from the blower. Thereby, it is possible to dig up the soil without damaging or destroying the buried object in the soil.
[0006]
These crushers and vacuum suction devices are often used simultaneously. First, when the soil is crushed by a crusher and put into a state suitable for suction, and then the soil is sucked and transferred by a vacuum excavator, the advantages of both can be utilized and work can be performed efficiently. Furthermore, there is a soil excavation device in which a crushing portion and a suction transfer portion are integrated as in the embodiment of Japanese Patent Application No. 3-123040, for example. In this method, both the supply of compressed air to the crushing part and the vacuum suction from the suction transfer part are performed by a pump device driven by an internal combustion engine to dig up the soil.
[0007]
[Prior art]
In such an internal-combustion-engine-driven pump device, the engine (internal-combustion engine) and the compressor (pump) are housed in the same casing, and the engine-driven compressor supplies compressed air and performs vacuum suction. Yes. At least a vacuum suction force (negative pressure suction force) is generated. That is, in order to function as a generation source of vacuum suction force, at least one compressor or blower is provided, and an engine, not a motor, is provided due to restrictions on received power, and the engine generates rotational force. The compressor is driven.
[0008]
[Problems to be solved by the invention]
However, in such a conventional internal-combustion engine-driven pump device, a built-in engine or compressor is expensive as a large-sized and high-powered one, so that a large-sized one is adopted under certain cost constraints. Cannot be used, and it must be relatively small. For this reason, the vacuum suction force is limited. Alternatively, not only the vacuum suction force but also the supply amount of the pressure gas is limited. Due to this, it has been difficult to raise the efficiency of soil suction transfer work and pipe suction work to a certain level or more.
[0009]
In order to solve this problem, the same applicant has invented Japanese Patent Application No. 7-84210. This was devised and devised focusing on the fact that intake and exhaust of the engine are not effectively used. In short, the intake of the engine is used in addition to the intake of the compressor as a source of vacuum suction force. Thus, the vacuum suction force is increased. In addition, pressure adjusting means and the like are provided on the intake side to stabilize the operation of the engine and the like.
[0010]
The present invention is a further advancement of the invention, and it is possible to achieve stable operation of a pump device driven by an internal combustion engine that uses suction of the internal combustion engine in addition to pump suction for enhancing suction power with a simple mechanism. Is the purpose.
[0011]
[Means for Solving the Problems]
About the 1st thru | or 2nd solution means invented in order to solve such a subject, the structure and effect are demonstrated below.
[0012]
[First Solution]
The internal combustion engine-driven pump device of the first solving means (as described in claim 1 at the beginning of the application)
In an internal combustion engine-driven pump device comprising an internal combustion engine and a pump driven by the internal combustion engine, and generating a vacuum suction force by intake of the pump,
A communication mechanism for communicating the intake air of the internal combustion engine and the intake air of the pump; the communication mechanism introduces a check valve for preventing a flow from the internal combustion engine side to the pump side; A pressure control valve is provided to keep the intake pressure of the engine at or above the minimum intake pressure of the internal combustion engine.
[0013]
Here, the “minimum intake pressure of the internal combustion engine” refers to the minimum pressure required for the internal combustion engine to operate stably with respect to the intake pressure of the internal combustion engine. Determined according to.
[0014]
In such an internal combustion engine-driven pump device of the first solving means, since the intake air of the internal combustion engine is communicated with the intake air of the pump by the communication mechanism, not only the suction of the pump but also the internal combustion engine is generated. It is also made by inhalation.
Thereby, the amount of intake air is increased and the vacuum suction force is enhanced.
[0015]
In addition, such a communication mechanism can be configured by a pipe line to which general piping is connected, and the connection of the check valve and the pressure control valve to the pipe line can be screwed, fitted, welded, etc. General techniques are available. That is, this mechanism is easy and easy to manufacture.
[0016]
The intake pressure of the internal combustion engine is always kept at or above the minimum intake pressure by the pressure control valve provided in the communication mechanism. Moreover, it is kept by introducing outside air. Therefore, when the intake pressure of the internal combustion engine decreases and it is likely that an excessive load will be imposed on the internal combustion engine to supply the intake air to the vacuum suction force, the external air is replenished so that the intake air amount of the internal combustion engine does not become insufficient. The As a result, an excessive burden on the internal combustion engine can be avoided, so that the operation state of the internal combustion engine is stably maintained at a satisfactory level at all times. If the operating state of the internal combustion engine is stable, not only the function of itself but also the function of the pump driven by this function can be fully exhibited. Therefore, the maximum amount of intake air is supplied to generate the vacuum suction force within a range that does not cause an excessive burden on the internal combustion engine.
[0017]
If the intake pressure of the internal combustion engine rises above the intake pressure of the pump due to the introduction of outside air, etc., the check valve provided in the communication mechanism prevents the flow from the internal combustion engine side to the pump side. Therefore, even in this case, the suction of the pump is supplied to generate the vacuum suction force. As a result, a large amount of intake air at least greater than that of the conventional one is reliably supplied to the generation of the vacuum suction force.
[0018]
Therefore, according to the present invention, the operation stability of the pump device driven by the internal combustion engine that uses the suction of the internal combustion engine in addition to the pump suction for enhancing the suction force can be realized with a simple mechanism.
[0019]
[Second Solution]
The internal combustion engine-driven pump device of the second solution means (as described in claim 2 at the beginning of the application) is the internal combustion engine-driven pump device of the first solution means,
The communication mechanism includes a first connection port to the intake pipe of the internal combustion engine and a second connection port to the intake pipe of the pump, and the check valve and the pressure control valve are integrally incorporated. It is characterized by being.
[0020]
In such an internal combustion engine driven pump device of the second solution, since the communication mechanism is assembled as an integrated body, the conventional internal combustion engine driven pump device commercially available as a general-purpose product is used. The invention can be manufactured immediately by simply remodeling the communication mechanism and connecting the first and second connection ports.
Thereby, the apparatus of the 1st solution means can be embodied easily and cheaply.
[0021]
Therefore, according to the present invention, the operation stability of the pump device driven by the internal combustion engine that uses the suction of the internal combustion engine in addition to the pump suction for enhancing the suction force can be easily realized by a simple mechanism.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
The first embodiment of the present invention is the above-described internal-combustion-engine-driven pump device, wherein the check valve has a plate-like valve body and a valve seat obliquely intersecting the flow. It is characterized by that.
[0023]
In this case, since the valve body is plate-like, the weight is light for the opening area, and the inertial resistance when opening, that is, communicating, is small. In addition, since the valve seat is oblique to the flow, the pressure receiving area of the valve body seated on the valve seat is larger than the flow path area, so that a large force acts when opening the valve body. Therefore, even a check valve that opens and closes using a flow in intake air, which tends to have a small fluid force in a negative pressure state, operates reliably and promptly.
Therefore, this communication mechanism can exhibit sufficient performance while having a simple structure.
[0024]
【Example】
A specific configuration of a soil excavator as an embodiment using a pump device driven by an internal combustion engine of the present invention will be described with reference to the drawings. FIG. 1 is a pneumatic circuit diagram and a block diagram of an electronic circuit, FIG. 2 is a detailed cross-sectional structure diagram of the communication mechanism, and FIG. 3 is a schematic external view of a part of the entire apparatus. is there.
[0025]
This soil excavation apparatus supplies the pressure gas to the soil crushing unit 10 through the flexible hose 43 accommodated in the soil crushing unit 10, the soil suction unit 20, and the housing 100, and at the same time the soil suction unit 20 through the conduit 53. And a pump device (100) driven by an internal combustion engine for supplying a vacuum suction force.
First, after explaining the soil crushing unit 10 and the soil suction unit 20, the pump device driven by the internal combustion engine will be described in detail.
[0026]
The soil crushing unit 10 is a part obtained by removing the compressed air supply unit from the soil crusher, and crushes the soil using the pressure gas introduced through the flexible hose 43 as a motor drive source and a fumarole source. . For this purpose, the unit 10 introduces a pressure gas into the inner cavity of the cylinder 12 connected to the cylinder 12 at an upper portion thereof, a handle 12 that is gripped by a hand, a cylinder 12 that extends downward therefrom, and the cylinder 12. An introduction pipe 13, an air motor 14 fixed to the tip of the cylinder 12, receiving pressure gas from the cylinder 12 and rotating the rotation shaft 15 using this as a drive source, and fixed to the rotation shaft 15 at the center position and rotated. It is composed of a rotating plate 16. Along with the rotation of the rotating plate 16, the crushing blade 17 provided on the lower surface of the rotating plate 16 circulates and penetrates from the drain port of the air motor 14 to the rotating shaft 15 and the rotating plate 16. Pressure gas is injected below the rotating plate 16 through the hole.
[0027]
The soil suction unit 20 is a unit obtained by removing a vacuum suction force generation / transmission unit from a soil vacuum excavator. The soil suction unit 20 introduces a vacuum suction force through a pipe 53 and sucks and transfers the soil with this force. . For this purpose, the unit 20 includes a suction pipe 22 having a soil suction port 21 at the lower end, and an internal sediment collection chamber 25a and further a filter chamber 25b at the upper end of the suction pipe 22 via the vacuum duct 23. It is comprised with the earth-collecting dust collection part 25 which connected. Then, when vacuum suction is performed via the vacuum suction force inlet 25c provided in the upper part of the filter chamber 25b, a high-speed air flow involving a part of the soil 70 is passed through the suction pipe 22 from the suction port 21. The air is further decelerated to the sediment collection chamber 25a through the cavity 23 and the vacuum duct 23, and fine dust is also removed in the filter chamber 25b to form a clean air flow. However, when the material is decelerated in the sediment collection chamber 25a, The soil that has been sucked and transferred is collected by leaving behind.
[0028]
The pump device (100) driven by the internal combustion engine adds the engine 30 as an internal combustion engine, the compressor 60 as a pump driven by the engine 30, and the exhaust gas of the engine 30 to the exhaust gas of the compressor 60 and supplies the exhaust gas to the soil crushing unit 10. High pressure side pipes 41, 42, 43 connected to each other, and negative pressure side pipes 51, 52, 53 for supplying vacuum suction force by the intake air of the compressor 60 and the intake air of the engine 30 to the soil suction unit 20, In order to increase the vacuum suction force by allowing the intake air of the engine 30 to communicate with the intake air of the compressor 60, the communication mechanism 110 is connected to the pipelines 51, 52, and 53.
[0029]
The engine 30 operates to generate a rotational force and to drive the compressor 60 by being rotationally driven by this rotational force. For this purpose, the output shaft is connected to the drive shaft of the compressor 60 via a coupling. Has been. The engine 30 is preferably a diesel engine that is relatively resistant to fluctuations in intake / exhaust pressure, and is accompanied by intake and exhaust for internal combustion during operation.
[0030]
The compressor 60 is preferably a reciprocating compressor, a screw compressor, or the like in order to generate a vacuum suction force by intake air and high pressure air by exhalation. In order to extract the crushing capacity of the crushing unit 10 sufficiently, a pressure gas of about 5 to 7 kgf / cm ² (about 0.5 to 0.7 MPa) is desired. This is because it reaches However, even if the discharge pressure is lower than that, it can be driven in accordance with it, so in short, any other type of compressor can be used as long as it can suck air, compress this suction air, and discharge this compressed air. Or any of a blower may be sufficient.
[0031]
The pipe lines 41, 42, and 43 are for supplying exhaust gas from the engine 30 in addition to compressed air from the compressor 60 to the soil crushing unit 10 as pressure gas. Therefore, these pipe lines are a pipe line 41 having one end connected to the tip of the muffler 32 in the engine 30, that is, an exhaust port, a pipe line 42 having one end connected to the discharge port of the compressor 60, and one end being a pipe line 42. And a flexible hose 43 connected to the other end. Then, the other end of the pipe 41 is extended and connected to the pipe 42, and the other end of the flexible hose 43 is connected to the introduction pipe 13 of the soil crushing unit 10. Exhaust gas is also supplied to the soil crushing unit 10. Note that a variable throttle valve is inserted in the atmosphere release portion of the pipe line 41, and the exhaust pressure of the engine 30 is reduced by bypassing the flow rate according to the throttle amount from the pipe line 41 to the atmosphere. It is adjustable so as not to have a significant effect on operation. This value is usually about 4 to 7 kgf / cm ² (about 0.4 to 0.7 MPa) in the case of a diesel engine, for example.
[0032]
The pipes 51, 52, and 53 are for circulating the intake air of the engine 30 in addition to the intake air of the compressor 60 from the soil suction unit 20 as a source of vacuum suction force. Therefore, these pipes are a pipe 51 having one end connected to the tip of the air cleaner 31 in the engine 30, that is, an air inlet, a pipe 52 having one end connected to the air inlet of the compressor 60, and one end collecting soil. It is comprised with the pipe line 53 connected to the vacuum suction inlet 25c of the dust part 25. FIG. The other ends of the pipes 51, 52, 53 are connected to each other via a communication mechanism 110 described below. As a result, the intake air of the engine 30 communicates with the intake air of the compressor 60, and the vacuum suction force obtained by combining these intake airs is introduced into the soil suction unit 20 through the soil collection part 25 and the vacuum duct 23. ing.
[0033]
The communication mechanism 110 includes a substantially H-shaped conduit portion having substantially the same diameter as the conduits 51 and 52, and a rotary plate valve 111 inserted and incorporated in a conduit 153 located at the center of the H-shaped conduit portion. , And a slip valve 112 incorporated at one end of the H-shaped pipe section. With respect to the H-shaped pipe section, a connection port 151 is formed at the opposite end of the slip valve 112 and is connected to the other end of the pipe 51. Further, a connection port 152 is formed at an end facing the connection port 151 with the pipe line 153 interposed therebetween, and is connected to the other end of the pipe line 52. The remaining end is connected to the other end of the conduit 53. As a result, the intake pipe 51 of the engine 30 communicates with the intake pipe 52 of the compressor 60 and the pipe 53 to the soil suction unit 20 via the pipe 153.
[0034]
The rotary plate valve 111 forms an inclined valve seat inside the pipe line 153, that is, a valve seat obliquely intersecting the air flow in the pipe line 153 is provided, and a packing part can be seated on the valve seat. The rotary plate 111a is formed as a plate-like valve body so that one side of the rotary plate 111a is screwed to the shaft 111b, and this is pivotally supported on the end of the valve seat in the conduit 153 so as to be bi-directionally rotatable. It is configured. Further, one end of a lever 111c outside the pipe 153 is attached to the shaft 111b, one end of a spring 111d is connected to the other end of the lever 111c, and the other end is engaged with any one of the H-shaped pipe sections, for example, the slip valve 112. Stopped. In this state, the lever 111c is always pulled by a relatively weak force of the spring 111d, and the shaft 111b is rotated so that the rotary plate 111a closes the conduit 153.
[0035]
Then, when the pressure in the pipe line 51 becomes lower than the pressure in the pipe line 52, a force that pushes and opens the rotary plate 111a is generated by the pressure difference, and when this overcomes the force of the spring 111d, the rotary plate 111a rotates. Since it is separated from the valve seat, air flows in the pipe line 153 from the air pipe line 52 side to the pipe line 51 side. On the other hand, when the pressure in the pipe line 51 becomes higher than the pressure in the pipe line 52, a force for pressing the rotary plate 111a against the valve seat is generated due to the pressure difference in the opposite direction, and this is added to the force of the spring 111d, Since the lumen of the pipe line 153 is closed, the air flowing from the pipe line 51 side to the pipe line 52 side is stopped here. As a result, the rotary plate valve 111 is integrally incorporated in the communication mechanism 110 and functions as a check valve that blocks air flow from the engine 30 side to the compressor 60 side.
[0036]
The slip valve 112 has an opening for introducing outside air formed at one end of a cylindrical main body, one end of a spring 112a is locked at one end thereof, and one end of a spool 112b is locked at the other end of the spring 112a. It is configured. The spool 112b is formed so as to be slidable in the main body, and moves to the pipe 51 side against the force of the spring 112a when the pressure on the pipe line 51 side becomes low. When one end of the spool 112b moves to the large-diameter portion of the cylindrical main body, that is, the open position 112c, a gap is formed between the open position 112c and the cylindrical main body, from one end of the cylindrical main body to the other end. Outside air is flowing.
[0037]
The other end of the cylindrical body of the slip valve 112 is threaded to form a threaded portion 112d. The slip valve 112 is screwed into the H-shaped pipe line portion by the threaded portion 112d and is integrally incorporated in the communication mechanism 110. Further, the spring force of the spring 112a is set so that one end of the spool 112b reaches the open position 112c when the pressure on the pipe 51 side approaches a value that significantly affects the operation of the engine 30. For example, when the engine 30 is a diesel engine, the pressure in the pipe line 51 that is the intake pressure is usually set to be about −200 to −500 mmHg (about −0.03 to −0.07 MPa). . As a result, the slip valve 112 functions as a pressure control valve that introduces outside air and keeps the intake pressure of the engine 30 at or above the minimum intake pressure of the engine 30.
[0038]
The operation in use of the apparatus of this embodiment having such a configuration will be described.
[0039]
When the asphalt or the like above the soil 70 is discharged by a power shovel or the like and the soil 70 covering and burying the buried pipe 80 is exposed, this is the turn of the soil excavator. Then, after retracting the power shovel or the like, the soil excavator is carried to the excavation site by a truck or the like (not shown), and the pump device (100) driven by the internal combustion engine is installed near the excavation hole.
[0040]
Next, in order to perform soil excavation work, that is, to perform soil crushing and soil suction in parallel, one worker holds the handle portion 11 of the soil crushing unit 10 and puts the crushing blade 17 into the soil 70. The other worker holds the suction pipe 22 of the soil suction unit 20 and points the soil suction port 21 toward the soil 70. At this time, the communication mechanism 110 is in an initial state, and both the rotary plate valve 111 and the slide valve 112 are closed.
[0041]
When the engine 30 is started to operate the compressor 60, compressed air is discharged from the compressor 60 and exhaust gas is discharged from the engine 30. Then, the crushing blade 17 of the soil crushing unit 10 performs a revolving motion using these compressed air and exhaust as a driving source, and also blows toward the soil below the crushing blade 17 using these compressed air and exhaust as a fume source. Is done. Therefore, when one worker manipulates the handle portion 11 to bring the crushing blade 17 into contact with the soil 70, the clot at that portion is rapidly dried by the injection of gas containing high-temperature exhaust gas and at the same time the crushing blade. 17 is mechanically crushed, or mechanically crushed by the crushing blade 17, and at the same time, finely divided and blown off by injection such as exhaust, so that the soil is efficiently crushed. As described above, not only the compressed air from the compressor 60 but also the exhaust of the engine 30 is used as the drive source and the fumarole source. Therefore, the flow rate of the pressure gas is increased compared to the conventional case, and the soil crushing work efficiency is improved. .
[0042]
Further, during the operation of the engine 30 or the like, air is sucked by the compressor 60 and also by the engine 30. Then, a part of the air sucked through the pipe line 53 is sucked into the compressor 60 through the pipe line 52, and at the same time, the rest pushes and opens the rotary plate valve 111. It is sucked into the engine 30 through 51. Then, vacuum suction force is introduced into the soil suction unit 20 using these intake air as a source, and outside air suction is performed from the soil suction port portion 21. Therefore, when the other worker manipulates the suction pipe 22 of the soil suction unit 20 to bring the soil suction port 21 close to the soil crushed by the soil crushing unit 10, the soil is sucked and transferred by the soil suction unit 20. Then, it is collected one after another in the earth and sand collection chamber 25a. Thus, since not only the intake air of the compressor 60 but also the intake air of the engine 30 is used as a source of the vacuum suction force, the vacuum suction force is increased as compared with the conventional case, and the work efficiency of the soil suction transfer is improved.
[0043]
If the soil suction unit 20 is clogged during this operation and the pressure in the pipelines 51, 52, 53 falls below the set value of the slip valve 112 or attempts to drop, the output of the engine 30 decreases. Before that, the slip valve 112 opens. If it does so, sufficient external air will be replenished by the side of the pipe line 51, and the pressure in the pipe line 51 will be returned more than a setting value. At this time, if the pressure in the pipe line 52 remains low and the pressure in the pipe line 51 becomes relatively high, the rotary plate valve 111 is closed, so that the communication state between the pipe line 51 and the pipe line 52 is interrupted. The pressure in the pipe line 52 is controlled independently of the pressure in the pipe line 51.
[0044]
Therefore, even when the intake pressure of the compressor 60, that is, the pressure in the pipe line 52 is extremely reduced, the pressure in the pipe line 51 is controlled to a value that does not have a significant influence on the operation of the engine 30. Since the intake pressure of the engine 30 is maintained in an appropriate state, the rotational force of the engine 30 is not reduced, and stable operation of the engine 30 is ensured. When the intake pressure of the compressor 60 returns to the intake pressure of the engine 30, the slip valve 112 is closed and the rotary plate valve 111 is opened, and the above is repeated.
Thus, a sufficient vacuum suction force is always supplied to the soil suction unit 20.
[0045]
Therefore, if the soil crushing unit 10 and the soil suction unit 20 are moved appropriately and the soil 70 appearing from the bottom after crushing and suction is further excavated, the presence of the buried pipe 80 can be confirmed eventually. Further, it is only necessary to dig around the buried pipe 80. As a result, the buried pipe 80 can be exposed without damaging it, and the role of the soil excavator is completed.
[0046]
Finally, after the engine 30 is stopped, the engine 30, the units 20, 30 and the like are placed on a truck and removed from the excavation site. This completes the work by the soil excavator using the pump device driven by the internal combustion engine.
[0047]
【The invention's effect】
As is apparent from the above description, the internal combustion engine-driven pump device of the first solving means of the present invention is provided with a communication mechanism that is easy to manufacture and the intake pressure of the internal combustion engine is always higher than the minimum intake pressure. In addition, the pump intake is always supplied to generate the vacuum suction force, so that the operation stability of the pump device driven by the internal combustion engine that uses the suction of the internal combustion engine in addition to the pump suction for the enhancement of the suction force There is an advantageous effect that can be realized by a simple mechanism.
[0048]
In the internal combustion engine-driven pump device according to the second solving means of the present invention, the communication mechanism is integrated so that it can be easily incorporated into a general-purpose product. There is an advantageous effect that the operation stability of the pump device driven by the internal combustion engine that uses the suction of the internal combustion engine in addition to the suction can be easily realized by a simple mechanism.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a soil excavation device using the pump device for driving an internal combustion engine according to an embodiment of the present invention.
FIG. 2 is a sectional view of the communication mechanism.
FIG. 3 is a schematic diagram of a soil excavator.
[Explanation of symbols]
10 Soil crushing unit 20 Soil suction unit 30 Engine (prime motor; internal combustion engine)
31 Air cleaner (intake port)
32 Muffler (exhaust port)
41 High-pressure side pipeline 42 High-pressure side pipeline 43 Flexible hose pipeline 51 Negative-pressure side pipeline 52 Negative-pressure side pipeline (communication means)
53 Pipeline on the negative pressure side (vacuum suction power supply unit)
60 Compressor (compression blower; pump)
70 soil 80 buried pipe 100 housing 110 communication mechanism 111 rotary plate valve (rotary valve / plate valve; check valve)
111a Rotary plate 111b Shaft 111c Lever 111d Spring 112 Slip valve (Slide valve; Spool valve; Pressure control valve)
112a Spring 112b Spool 112c Open position 112d Screw part 151 Connection port 152 Connection port 153 Pipe line

Claims (2)

An internal combustion engine-driven pump device comprising an internal combustion engine and a pump driven by the internal combustion engine and generating a vacuum suction force by the intake air of the pump, the communication for communicating the intake air of the internal combustion engine and the intake air of the pump The communication mechanism includes a check valve that blocks the flow from the internal combustion engine side to the pump side, and introduces external air to keep the intake pressure of the internal combustion engine at or above the minimum intake pressure of the internal combustion engine. A pump device for driving an internal combustion engine, characterized in that a pressure control valve is provided. The communication mechanism includes a first connection port to the intake pipe of the internal combustion engine and a second connection port to the intake pipe of the pump, and the check valve and the pressure control valve are integrally incorporated. The pump device for driving an internal combustion engine according to claim 1, wherein

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