JP2518867Y2 - Control device for pump unit with engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a control device for a pump device with an engine such as a cleaning device, and more specifically, a control device for automatically controlling the engine according to the state of the pump. It is about.

[Conventional technology]

Cleaning equipment, etc. are equipped with a pump, an engine that drives this pump, and an unload valve that reduces the discharge pressure of the pump when the pump is unloaded.When the gun nozzle at the end of the hose is closed, the unload valve is installed. However, the cleaning liquid discharged from the pump is released, the discharge pressure of the pump is reduced, and the load on the engine is reduced.

In Japanese Patent Laid-Open No. 56-54980, a pump device with an engine including a pump and an engine for driving the pump is provided with a micro switch for detecting the discharge pressure of the pump on the discharge side of the pump, and after starting the operation of the pump. , If the pump does not suck the cleaning liquid and the pump is in the idle state, the engine is automatically stopped and the pump is idle.
Also, the seizure of the pump due to this is prevented.

In JP 58-59983 A and JP 58-59984 A, a pump with an engine is provided with a liquid flow detector on the suction side of the pump, which automatically stops the engine when cleaning liquid is no longer sucked into the pump. A controller for a device is disclosed.

Further, in Japanese Utility Model Laid-Open No. 58-63383, a temperature detector such as a thermostat is attached to the outer surface of the cylinder of the pump, and the idling operation of the pump is detected from the abnormally high temperature of the outer surface of the cylinder to stop the engine.

[Problems to be solved by the device]

In the control device for a pump device disclosed in Japanese Utility Model Laid-Open No. 58-63383, the idle operation of the pump is detected from an abnormal rise in the outer surface temperature of the cylinder. Therefore, the nozzle is closed for a long time, and the nozzle on the discharge side of the pump is closed. The cleaning liquid is returned to the tank via the unload valve, and the engine can be stopped due to the high temperature when the pump is running idle, but the cleaning liquid circulates between the tank and the pump for a long time, resulting in an abnormally high temperature. Has
It is not possible to accurately detect it and deal with the trouble related to the abnormally high temperature of the cleaning liquid.

It is an object of the invention of claim 1 to accurately deal with the situation where the liquid on the discharge side of the pump is returned to the tank via the unload valve, and the liquid circulates between the tank and the pump for a long time, resulting in an abnormally high temperature. It is to provide a control device for a pump device with an engine that can deal with

The purpose of the device of claims 2 and 3 is to provide an advantageous embodiment of the device of claim 1.

[Means for solving the problem]

The invention will be described with reference numerals corresponding to the drawings of the embodiments.

A pump device with an engine according to claim 1 is a pump (1) for sucking and discharging a liquid (30) from a tank (28).
4) and the engine (18) that drives this pump (14)
And an unload valve (34) for returning the liquid (30) on the discharge side of the pump (14) to the tank (28) when the pump (14) is unloaded. The control device for a pump device with an engine according to claim 1 detects the abnormal increase of the liquid temperature from the liquid temperature in the pump (14) when the engine (18) is detected.
It has engine stopping means (104, 118) for stopping the engine.

A control device for a pump device with an engine according to claim 2 is the control device for a pump device with an engine according to claim 1,
Furthermore, the thermistor (120) detects an abnormal rise in the liquid temperature in the pump (14).

A control device for a pump device with an engine according to claim 3 is the control device for a pump device with an engine according to claim 1 or 2, wherein the engine stopping means (104, 118) is an engine (1
8) A switch (104, 118) for disabling the ignition current is included.

[Action]

In the control device for the pump device with engine according to claim 1,
When the pump (14) is unloaded for a long time, the liquid (30) may repeatedly circulate between the pump (14) and the tank (28) and circulate, and the temperature may rise abnormally. The engine stopping means (104, 118) stops the engine (18) when the abnormal temperature is detected from the liquid temperature in the liquid (30).

In the control device for the pump device with engine according to claim 2,
The thermistor (120) detects an abnormal rise in the liquid temperature in the pump (14), and the engine stop means (104, 118) controls the stop of the engine (18) based on the output of the thermistor (120).

In the control device for the pump device with engine according to claim 3,
The switch of the engine stopping means (104, 118) invalidates the ignition current of the engine (18). As a result, no voltage is applied to the ignition coil (88), no spark is generated in the spark plug (90), and the engine (18) is stopped.

〔Example〕

 Hereinafter, this invention will be described with reference to embodiments of the drawings.

FIG. 2 shows a cleaning device 10 as a pump device with an engine.
FIG. The frame 12 has a pump 14 and
An engine 18 having an output shaft connected to an input shaft of a pump 14 via a coupling 16 is mounted and fixed.
Both ends of the winding drum 20 are rotatably supported by the frame 12, a handle 22 is integrally coupled to the take-up drum 20, and the winding drum 20 is rotated by the handle 22. The hose 24 can be wound around the winding drum 20, and a gun nozzle 26 is attached to the tip thereof. The tank 28 stores the cleaning liquid 30 therein, and the suction hose 32 has its lower end put in the cleaning liquid 30 of the tank 28 and its upper end connected to the suction port of the pump 14. Unload valve 34
The inlet side is connected to the discharge port of the pump 14, the discharge side is connected to the discharge hose 36, and the return port is connected to the return hose 38. The other end of the discharge hose 36 is connected to the end of the hose 24, and the lower end of the return hose 38 reaches the tank 28.

When the gun nozzle 26 is in the open state, the liquid from the pump 14 can flow out to the discharge hose 36, and therefore flows out toward the discharge hose 36 and is ejected from the gun nozzle 26 via the hose 24.

When the gun nozzle 26 is in the closed state, it is difficult for the liquid from the pump 14 to flow toward the discharge hose 36, so a predetermined valve body in the unload valve 34 is pushed open to open the unload valve 34.
To the tank 28 through the return hose 38.

3 is a structural diagram of the tip portion of the pump 14, and FIG. 4 is a structural diagram showing the pressure switch of FIG. 3 in a state different from that of FIG. A discharge side manifold 40 is coupled to the tip side of the pump 14, and the discharge side manifold 40 is connected to each pump chamber 42 of the pump 14.
Connected to The discharge valve 44 is provided at the front end side of the pump chamber 42 at the boundary between the discharge side manifold 40 and the pump chamber 42 and has a check valve structure.
To prevent backflow of liquid from the pump chamber 42 into the pump chamber 42. The pressure switch 46 connects the housing 48 to the discharge side manifold 40, the pressure chamber 50 communicates one end side into the discharge side manifold 40, the discharge pressure of the pump 14 is supplied, and the other end side is partitioned by the diaphragm 52. ing. The mover 54 is a housing
It is slidably arranged in 48, and the protruding end is in contact with the central portion of diaphragm 52 on the side opposite to pressure chamber 50. Compression coil spring 56
Is contracted in the housing 48 and urges the mover 54 toward the diaphragm 52. The contacts 58a and 58b are located apart from each other and can contact the conductive mover 54. Lead wire 60
The a and 60b are connected to the contacts 58a and 58b at one end and extend to the outside of the housing 48 at the other end.

When the cleaning liquid 30 from the pump 14 is being supplied to the gun nozzle 26, the discharge pressure of the pump 14 is equal to or higher than a predetermined value, the diaphragm 52 is convexly curved toward the pressure chamber 50 side, and the mover 54 is a contact point. Apart from 58a and 58b, the pressure switch 46 is off (Fig. 3).

At the time of unloading, that is, when the cleaning liquid 30 from the pump 14 is returned to the tank 28, the discharge pressure of the pump 14 is less than a predetermined value, the diaphragm 52 is curved convexly toward the pressure chamber 50 side, and the mover 54 Contacts contacts 58a, 58b and pressure switch 46
Is on (Fig. 4).

FIG. 5 is a block diagram of the engine output reduction means. The carburetor 62 has a throttle valve 64, and the throttle lever 66 is adapted to rotate integrally with the throttle valve 64. The lever 68 is rotatably supported at one end, is fixed at the other end to the core wire portion of the throttle wire 70, and is rotated by the operation of the throttle wire 70. The compression coil spring 72 pulls the core of the throttle wire 70 toward the lever 68. The governor lever 74 is rotatably supported at one end, is connected to the lever 68 via the tension coil spring 76 at the middle part, and is connected to the throttle lever 66 at the other end via the link rod 78. The tension coil spring 80 pulls the other end of the governor lever 74 toward the carburetor 62. An operator operates a predetermined operation lever to move the throttle wire 70 to the opposite lever.
When pulled to the 68 side, the lever 68 and the governor lever 74 swing against the compression coil spring 72, and the opening degree of the throttle valve 64 increases. The solenoid 82 is connected to the upper end of the governor lever 74 via the link rod 84, and when the solenoid 82 is energized, the governor lever 74 is pulled toward the solenoid 82 to set the throttle valve 64 of the carburetor 62 to the idling opening degree.

FIG. 1 is a control circuit diagram of the engine 18. The flywheel magnet 86 generates an ignition primary current in synchronization with the rotation of the output shaft of the engine 18, and the ignition coil 88 generates an ignition primary current based on the ignition primary current from the flywheel magnet 86.
An ignition secondary current is supplied to 18 spark plugs 90.

When the main switch 92 is turned from off to on (the upper end is tilted from left to right in FIG. 1), the voltage of the DC power supply 94 is applied to each element of the control circuit. Timer
At 96, immediately after the main switch 92 is turned on,
Since the voltage on the NPN transistor 100 side of the capacitor 98 is low, both the NPN transistor 100 and the PNP transistor 102 are off, and the relay 104 is off. Therefore, the terminal 106 between the flywheel magnet 86 and the ignition coil 88 is not connected to the ground, and the engine 18 can be operated by the spark of the ignition plug 90.

The pair of electrode plates 108a and 108b as the liquid inhalation detector are
It is attached to the suction port of the pump 14 and turns on when the cleaning liquid 30 enters between them. The pump 14 is operated by turning on the main switch 92 and starting the engine 18 accordingly. When the cleaning liquid 30 is sucked into the suction port of the pump 14 by the operation of the pump 14, the electrode plates 108a and 108b are turned on. Becomes, P
The NP transistor 110 also turns on. Since the main switch 92 was turned on, the capacitor 98 NPN transistor 1
The voltage on the 00 side rises, but the electrode plates 108a, 108
When b is turned on, the relay 112 is turned on (the lower ends of the switch parts 112a, 112b, 112c are tilted to the left in FIG. 1) and is discharged through the switch part 112a of the relay 112. The voltage on the NPN transistor 100 side of 98 does not reach a predetermined value or more, therefore the NPN transistor 100, the PNP transistor 102 and the relay 104 are not turned on, and the spark discharge of the spark plug 90 is maintained.

On the other hand, even though the main switch 92 is turned on, if the cleaning liquid 30 is not sucked into the pump 14 after a certain period of time and the electrode plates 108a and 108b are kept off, the switch portion 112a of the relay 112 is operated. Since the capacitor 98 is not discharged, the voltage on the NPN transistor 100 side of the capacitor 98 reaches or exceeds a predetermined value after a certain period of time, and the relay 104 is turned on. As a result, since the terminal 106 is grounded, the spark discharge of the spark plug 90 is stopped and the engine 18 is stopped.

When the relay 112 is turned on, the relays 114 and 116 are energized and are in the on state (for the relay 114, the switch units 114a and
The lower end of 4b is inclined to the left). Relay 114
Once turned on, electricity is supplied through the switch portion 114b, so that it is maintained on despite the subsequent turning off of the electrode plates 108a and 108b. Therefore, after the engine 18 is started, the pump 14 may be insufficient due to lack of the cleaning liquid 30 in the tank 28.
When the cleaning liquid 30 is no longer sucked into the electrode plate 108a, 1
08b turns off, which results in relay 118
The switch section 114a of the relay 112 and the switch section 112c of the relay 112 are energized to be turned on, the terminal 106 is connected to the ground, and the engine 18 is stopped.

During normal operation of the engine 18, that is, when the relay 112 is on and the gun nozzle 26 is open, the pressure switch 46 is off and the solenoid 82 is on as described with reference to FIGS. 3 and 4. Off. Therefore, the vaporizer
The opening of the throttle valve 64 of 62 corresponds to the operation amount of the throttle wire 70.

During normal operation of the engine 18, that is, when the relay 112 is on and the gun nozzle 26 is closed, the pressure switch 46 is on and the solenoid 82 is on as described with reference to FIGS. 3 and 4. Becomes Therefore, the vaporizer
The throttle valve 64 of 62 becomes the idling opening degree, and the output of the engine 18 decreases.

The thermistor 120 is attached to the pump 14 at a position where the temperature of the cleaning liquid 30 can be detected, and the resistance increases as the temperature of the cleaning liquid 30 rises. Cleaning solution in pump 14 30
However, when the temperature is normal, that is, below a predetermined value, the output of the operational amplifier 122 is at a low level, and the PNP transistor 124 is off. Therefore, the relay 118
Is off and the engine 18 continues to operate. When the temperature of the cleaning liquid 30 in the pump 14 rises due to a long unload period, the output of the operational amplifier 122 becomes high level, and the PNP transistor 124 is turned on. Therefore, the relay 118 is turned on and the engine 18 is stopped.

[Effect of device]

According to the first aspect of the invention, the abnormal temperature rise is detected from the liquid temperature inside the pump, and the engine is stopped when the abnormal temperature rise is detected. Therefore, the liquid on the discharge side of the pump passes through the unload valve to the tank. The liquid is circulated through the pump and the tank for a long time, and it is possible to appropriately deal with the case where the temperature becomes abnormally high.

[Brief description of drawings]

The drawings relate to an embodiment of the present invention, FIG. 1 is a control circuit diagram of an engine, FIG. 2 is an overall schematic view of a washing device as a pump device with an engine, FIG. 3 is a structural diagram of a tip portion of the pump, FIG. FIG. 4 is a structural view showing the pressure switch of FIG. 3 in a state different from that of FIG. 3, and FIG. 5 is a configuration diagram of engine output lowering means. 14 …… Pump, 18 …… Engine, 28 …… Tank, 30 ……
Cleaning liquid (liquid), 34 ... Unload valve, 66 ... Throttle lever (engine output reducing means), 104, 118 ... Relay (engine stopping means), 120 ... Thermistor (temperature detector).

Claims (3)

(57) [Scope of utility model registration request] A pump (14) for sucking and discharging a liquid (30) from a tank (28), an engine (18) for driving the pump (14), and the pump when the pump (14) is unloaded. In an engine-equipped pump device including an unload valve (34) for returning the liquid (30) on the discharge side of (14) to the tank (28), an abnormal increase in the liquid temperature from the liquid temperature in the pump (14) A control device for a pump device with an engine, comprising engine stop means (104, 118) for stopping the engine (18) when the engine is detected. 2. The control device for a pump device with an engine according to claim 1, wherein the thermistor (120) detects an abnormal rise in the temperature of the liquid in the pump (14). 3. A switch (10) for disabling the ignition current of the engine (18) by the engine stopping means (104, 118).
4, 118) is included, The control device of the pump apparatus with an engine of Claim 1 or 2 characterized by the above-mentioned.