JP3877353B2 - 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 an object of the present invention is to achieve further operational stability and suction force enhancement for a pump device driven by an internal combustion engine that uses suction of the internal combustion engine in addition to pump suction.
[0011]
[Means for Solving the Problems]
About the 1st thru | or 3rd 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,
Communicating means for communicating intake air of the internal combustion engine with intake air of the pump;
Limiting means for limiting the communication state in the communication means;
Detecting means for detecting an operating state quantity of the internal combustion engine;
Control means for controlling a limit amount of the communication state by the restriction means according to a detection result of the detection means;
It is characterized by comprising.
[0013]
In such an internal combustion engine-driven pump device of the first solution, the communication means allows the intake air of the internal combustion engine to communicate with the intake air of the pump, so that the vacuum suction force is generated not only by the intake air of the pump but also by the internal combustion engine. It is also made by inhalation.
Thereby, the amount of intake air is increased and the vacuum suction force is enhanced.
[0014]
In addition, since the communication between the intake air of the internal combustion engine and the intake air of the pump is limited by the limiting means, it is possible to adjust the intake air amount of the internal combustion engine that is added to the intake air of the pump and is used to generate the vacuum suction force It becomes. Moreover, the operation state quantity of the internal combustion engine is detected by the detection means, and the limit amount of the communication state is controlled by the control means according to the detection result. As a result, the intake air amount of the internal combustion engine used for enhancing the vacuum suction force is adjusted according to the operating state of the internal combustion engine.
[0015]
Then, when it becomes an excessive burden on the internal combustion engine to use the intake air for increasing the vacuum suction force, the operating state of the internal combustion engine changes, and the intake air supply amount of the internal combustion engine to increase the vacuum suction force accordingly The limit is adjusted. Further, when the load on the internal combustion engine is reduced, the operating state of the internal combustion engine is improved, and the restriction on the intake air supply amount is relaxed accordingly.
As a result, the operating state of the internal combustion engine is stably maintained in a good state 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.
[0016]
Therefore, according to the present invention, when using suction of the internal combustion engine in addition to pump suction, further operational stability and suction power enhancement can be achieved.
[0017]
[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)
The detection means detects any one of intake pressure, rotational speed, and cooling water temperature as an operating state quantity of the internal combustion engine,
The control means performs control to increase the restriction amount of the restriction means when the detected intake pressure or rotation speed becomes a predetermined threshold value or less, or when the detected cooling water temperature becomes a predetermined threshold value or more.
It is characterized by this.
[0018]
In such an internal combustion engine-driven pump device of the second solution, when the intake pressure is too low and intake necessary for combustion in the internal combustion engine becomes difficult, or the burden on the internal combustion engine becomes heavy. This is detected when the rotational speed is too low or when the cooling water temperature is too high due to an overload of the internal combustion engine. And the restriction | limiting of a communication state is strengthened and the intake air supply amount of the internal combustion engine for vacuum suction power increase is reduced. As a result, the burden on the internal combustion engine is reduced and a stable operating state is maintained.
[0019]
Thus, by detecting a physical quantity having a value reflecting whether or not the load state of the internal combustion engine is appropriate as an operation state quantity of the internal combustion engine, intake of the internal combustion engine can be accurately controlled.
Therefore, according to the present invention, further operational stability and suction force enhancement can be reliably achieved.
[0020]
[Third Solution]
The internal combustion engine driven pump device of the third solution means (as described in claim 3 at the beginning of the application)
The detection means detects any one of an exhaust gas amount, a harmful substance content of the exhaust gas, and noise as an operation state amount of the internal combustion engine,
The control means performs control to increase the restriction amount of the restriction means when the detected exhaust gas amount, the harmful substance content of the exhaust gas, or the noise exceeds a predetermined threshold value.
It is characterized by this.
[0021]
In addition to reflecting whether the load state of the internal combustion engine is appropriate, these physical quantities also reflect the degree of inconvenience such as contamination given to the surrounding environment by using the device. Therefore, it is possible not only to accurately control the intake air of the internal combustion engine from the viewpoint of operation stability, but also to perform accurate control with few problems from the environmental viewpoint.
Therefore, according to the present invention, it is possible to achieve further operational stability and enhanced suction force while maintaining the surrounding environment.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment for implementing the internal combustion engine-driven pump device of the present invention achieved by the first to third solutions will be described.
[0023]
[First Embodiment]
The first embodiment of the present invention
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,
Communication means (provided between the intake line of the internal combustion engine and the intake line of the pump) for communicating the intake air of the internal combustion engine with the intake air of the pump;
Limiting means (such as a valve) for limiting the communication state in the communication means (provided by being inserted in the communication means);
Detecting means (such as a sensor) for detecting an operating state quantity of the internal combustion engine (directly or indirectly provided to the internal combustion engine);
Control means for controlling a restriction amount of the communication state by the restriction means (so that the operation of the internal combustion engine is stabilized) according to a detection result of the detection means;
It is provided with.
[0024]
[Second Embodiment]
The second embodiment of the present invention is the above-described internal-combustion-engine-driven pump device, wherein the limiting means is a proportional or open / close electromagnetic control valve.
Thereby, fine proportional control or on / off control such as PWM can be easily performed using a microcomputer or the like.
[0025]
[Third Embodiment]
The third embodiment of the present invention is the above-described internal-combustion-engine-driven pump device, wherein the communication means includes an intake line of the internal-combustion engine, an intake line of the pump, and a supply line of the vacuum suction force. It is provided between them.
As a result, the restriction of the intake air amount of the internal combustion engine that is used to enhance the vacuum suction force is reliably performed by the restriction means.
[0026]
[Fourth Embodiment]
The fourth embodiment of the present invention is the above-described internal-combustion-engine-driven pump device, characterized by comprising means for communicating the exhaust gas of the internal-combustion engine with the exhalation of the pump.
Thereby, in addition to the suction force enhancement, the supply amount of high-pressure air such as fumarole can be increased.
[0027]
[Fifth Embodiment]
The fifth embodiment of the present invention is the above-described internal-combustion-engine-driven pump device, wherein the internal combustion engine, the pump, the communication means, the limiting means, the detection means, and the control means are all the same housing. It is characterized by being housed inside.
In this way, in addition to the internal combustion engine and pump that are usually housed in the same housing, additional means for increasing the vacuum suction force are also housed in the same housing, ensuring ease of handling during transportation and operation. can do.
[0028]
【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, and FIG. 2 is a schematic external view with a partial cross section.
[0029]
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 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.
[0030]
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.
[0031]
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.
[0032]
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. The high-pressure side pipes 41, 42, and 43 connected to each other, and the negative pressure side as communication means connected to supply the suction of the engine 30 to the intake of the compressor 60 and supply the vacuum suction force to the soil suction unit 20. From the pressure gauges 101, 52, 53, the solenoid valve 106 as the limiting means inserted in the pipe 51, the pressure gauge 101 as the detection means attached to the pipe 51 etc. The microcomputer (MPU) 103 and the like as control means for controlling the opening and closing of the electromagnetic valve 106 and the like according to the pressure detection signal A and the like.
[0033]
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.
[0034]
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. 5-7 kgf / cm to fully extract the crushing capacity of the crushing unit 10 ² This is because when a pressure gas of about (about 0.5 to 0.7 MPa) is desired, these types of compressors have a discharge pressure that reaches or exceeds that pressure. 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.
[0035]
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 4 to 7 kgf / cm for a diesel engine, for example. ² (About 0.4 to 0.7 MPa).
[0036]
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 a pipe line 53 connected to the other end. The other end of the pipe 51 is extended and connected to the pipe 52. As a result, the intake air of the engine 30 is communicated with the intake air of the compressor 60. Furthermore, the other end of the pipe line 53 is connected to the vacuum suction force introduction port 25 c of the soil collection unit 25, and the vacuum suction force that these intake airs merge is introduced into the soil suction unit 20 through the vacuum duct 23. It is like that.
[0037]
An electromagnetic valve 106 that opens and closes in accordance with the control signal Y is inserted in an extended portion of the pipe 51, which is connected to the pipes 52 and 53. Thereby, the solenoid valve 106 is closed by the control signal Y, and the communication state with the pipe lines 52 and 53 in the pipe line 51 is limited. In addition, an electromagnetic valve 105 that opens and closes according to a control signal X is inserted in the pipe 51 in order to supply outside air to the intake side of the engine 30. Further, in order to prevent overload of the compressor 60, an electromagnetic valve 107 that opens and closes in accordance with the control signal Z is inserted also into the pipe line 52.
[0038]
A pressure gauge 101 is attached to the pipe 51 so as to output a pressure detection signal A for the intake pressure of the engine 30. Further, the engine 30 is provided with a tachometer (not shown) so as to output a rotational speed detection signal B for the rotational speed of the engine 30. Further, near the exhaust port of the muffler 32, NO which is one of the harmful substances contained in the exhaust gas. _X A sensor that reacts with gas is attached to output a nitrogen oxide detection signal C. Thereby, the operation state quantity of the engine 30 is detected. The cooler of the compressor 60 is also provided with a thermometer so that the cooling oil temperature detection signal D is also output.
[0039]
These detection signals are input to the MPU 103 via the input circuit 102. In this manner, signal lines and the like are connected in the housing 100. Further, the MPU 103 determines a control target of the electromagnetic valve 106 according to the detection results of the detection signals A, B, and C, and sends the control signal Y to the electromagnetic valve 106 via the output circuit 104. Programmed like that. At the same time, a control target for the electromagnetic valve 105 is set, and the control signal X is also sent to the electromagnetic valve 105 via the output circuit 104. Although these control procedures will be described later, this restricts the amount of restriction on the communication state of the intake air of the engine 30 and the compressor 60 by the electromagnetic valve 106. The control signal Z for the electromagnetic valve 107 is generated according to the detection signal D.
[0040]
The operation in use of the apparatus of this embodiment having such a configuration will be described.
[0041]
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.
[0042]
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. 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. When the engine 30 is started, the electromagnetic valve 105 is controlled to be opened and the electromagnetic valve 106 is controlled to be closed by the MPU 103 in order to reduce the engine load.
[0043]
When the start is completed, the electromagnetic valve 105 is controlled to be closed by the MPU 103 and the electromagnetic valve 106 is controlled to be opened. 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. .
[0044]
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, vacuum suction force is introduced into the soil suction unit 20 using these intake air as a source, and outside air is sucked 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.
[0045]
If the soil suction unit 20 is clogged during this operation and the pressure in the pipelines 51, 52, 53 falls below a predetermined threshold value, the output of the engine 30 will decrease. Is detected by the MPU 103 to which the pressure detection signal A is input. Then, the MPU 103 controls the electromagnetic valve 106 to the closed state and the electromagnetic valve 105 to the open state. Then, since sufficient outside air is replenished to the intake side of the engine 30, the rotational force of the engine 30 is recovered and the pressure in the pipe line 51 is returned. Then, the MPU 103 controls the original state, that is, the electromagnetic valve 105 is closed and the electromagnetic valve 106 is opened.
[0046]
When such on / off control is repeated according to the value of the pressure detection signal A, the intake pressure of the engine 30 has a significant effect on the operation of the engine 30 even when the intake pressure of the compressor 60 is extremely reduced. It is controlled to a value that does not affect. For example, in the case of a diesel engine, it is normally controlled to about −200 to −500 mmHg (about −0.03 to −0.07 MPa).
Thus, the intake pressure of the engine 30 is maintained in an appropriate state in accordance with the pressure detection signal A, so that stable operation of the engine 30 is ensured.
[0047]
Even when the rotational state of the engine 30 is abnormally reduced, this is detected by the rotational speed detection signal B, and the MPU 103 performs similar control on the electromagnetic valve 106 and the like. The same control is performed according to the nitrogen oxide detection signal C when the engine 30 is in an abnormal combustion state due to insufficient oxygen. Thus, the intake pressure of the engine 30 is maintained in an appropriate state in accordance with not only the pressure detection signal A but also the rotation speed detection signal B and the nitrogen oxide detection signal C. The exhaust gas is also kept clean. When the MPU 103 detects that the compressor 60 cannot be completely cooled due to an overload or the like based on the cooling oil temperature detection signal D, the solenoid valve 107 is controlled to be closed to For example, the intake air is not used for soil suction. Thus, a sufficient vacuum suction force is always supplied to the soil suction unit 20.
[0048]
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.
[0049]
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.
[0050]
【The invention's effect】
As is apparent from the above description, in the internal combustion engine-driven pump device of the first solving means of the present invention, the intake amount of the internal combustion engine that is used to increase the vacuum suction force is changed to the operating state of the internal combustion engine. By adjusting accordingly, there is an advantageous effect that further operational stability and suction force enhancement can be achieved.
[0051]
In the internal combustion engine-driven pump device according to the second solving means of the present invention, the intake of the internal combustion engine is controlled by detecting a physical quantity having a value reflecting whether or not the load state of the internal combustion engine is appropriate. By doing so, there is an advantageous effect that it is possible to reliably achieve further operational stability and suction force enhancement.
[0052]
Furthermore, in the internal combustion engine-driven pump device of the third solving means of the present invention, by detecting a physical quantity that reflects problems such as contamination of the surrounding environment and controlling the intake air of the internal combustion engine, There is an advantageous effect that further operational stability and suction force enhancement can be achieved while maintaining the surrounding environment.
[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 schematic diagram thereof.
[Explanation of symbols]
10 Soil crushing unit
20 Soil suction unit
30 engine (motor; internal combustion engine)
31 Air cleaner (intake port)
32 Muffler (exhaust port)
41 High-pressure side pipeline
42 High-pressure line
43 Flexible hose conduit
51 Pipeline on the negative pressure side
52 Pipeline on the negative pressure side (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 box
101 Pressure gauge
102 Input circuit
103 MPU (microprocessor; control means)
104 Output circuit
105 Solenoid valve
106 Solenoid valve (limitation means)
107 Solenoid valve

Claims (3)

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, and communication means for communicating the intake air of the internal combustion engine with the intake air of the pump Limiting means for limiting the communication state in the communication means, detection means for detecting the operation state quantity of the internal combustion engine, and controlling the restriction amount of the communication state by the restriction means according to the detection result of the detection means And an internal combustion engine driven pump device. The detecting means detects any one of an intake pressure, a rotational speed, and a cooling water temperature as an operating state quantity of the internal combustion engine, and the control means has a predetermined intake pressure or rotational speed as a predetermined value. 2. The internal combustion engine-driven pump device according to claim 1, wherein when the detected coolant temperature becomes equal to or lower than a predetermined threshold value or when the detected coolant temperature becomes equal to or higher than a predetermined threshold value, control for increasing the limit amount of the limiting means is performed. The detecting means detects any one of an exhaust gas amount, an exhaust gas harmful substance content, and noise as an operating state quantity of the internal combustion engine, and the control means detects the detected exhaust gas amount. 2. The pump device for driving an internal combustion engine according to claim 1, wherein when the content of harmful substances in exhaust gas or noise exceeds a predetermined threshold value, control is performed to increase the restriction amount of the restriction means.

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