JPH0886233A - Engine control device and pump device - Google Patents

Abstract

PURPOSE: To suppress a lowering of operation speed of a reciprocating pump in respect to variation of moisture and temperature in a cleaning machine which is so designed that the reciprocating pump is not operated with speed exceeding a preset value. CONSTITUTION: An engine output control device 30 controls a small-sized two-cycle engine 14 based on input from a moisture sensor 32 and a temperature sensor 34. An output of the small-sized two-cycle engine 14 is increased so as to cancel a decreasing rate of the operation speed of a reciprocating pump 12 cased by variation of moisture and temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control device installed in a washing machine or the like and a pump device including the same, and more particularly to a reduction in engine rotation speed and pump operating speed due to changes in humidity and temperature. The present invention relates to an engine control device and a pump device that can compensate for the above.

[0002]

2. Description of the Related Art A washing machine in which water is jetted from a nozzle by a high-pressure jet is equipped with a small two-cycle engine and a reciprocating pump, and the small two-cycle engine drives the reciprocating pump. The reciprocating pump of the washing machine has an operating speed of, for example, 4000 r.p.m., as compared with the reciprocating pump provided in other working machines such as a brush cutter. p. m. Is set low to prevent the pump discharge pressure from becoming excessive.

A conventional small two-cycle engine, which is mounted on a washing machine and drives a pump, does not perform operation control with respect to changes in humidity and temperature.

[0004]

In a small two-cycle engine equipped in a washing machine or the like and rotating at a relatively low speed, the output drops drastically with changes in humidity and temperature. In a conventional small two-cycle engine, engine output control is not performed against changes in humidity and temperature.Therefore, the engine discharge pressure should not exceed the set value even under conditions of humidity and temperature where the engine will reach maximum output. Since the characteristics are set, there is a problem that the pump discharge pressure is much lower than the set value when the humidity and the temperature are other than the humidity and the temperature when the maximum engine output is generated.

It is an object of the invention of claim 1 to provide an engine control device capable of preventing a decrease in engine speed due to changes in humidity and temperature. An object of the inventions of claims 2 and 3 is to provide an engine control device provided with means capable of appropriately controlling the engine output. Claim 4
An object of the invention is to provide a pump device capable of preventing a decrease in pump discharge pressure due to changes in humidity and temperature. It is an object of the invention of claim 5 to provide a pump device capable of preventing the engine speed from increasing and the operating speed of the pump from exceeding a set value during no-load operation of the pump.

[0006]

The present invention will be described using reference numerals in the drawings corresponding to the embodiments. The engine control device according to claim 1 has the following components (a) to (c). (A) Temperature sensor (34) that detects the temperature (b) Humidity sensor (32) that detects the humidity of the atmosphere (c) The engine output is adjusted so as to eliminate the decrease in the rotation speed due to changes in the temperature and humidity. Engine output control means to increase (30)

According to a second aspect of the engine control apparatus of the first aspect, the engine output control means (30) further includes means for adjusting the engine output by increasing or decreasing the engine throttle.

According to a third aspect of the present invention, there is provided the engine control device according to the first aspect, wherein the engine output control means (30) further controls a flow rate of exhaust gas at the outlet (80) of the muffler (66). Including (82).

A pump device according to a fourth aspect of the present invention includes the following (a) to (a).
It has the component (c). The engine control device according to claim 1, wherein (a) the engine (14), (b) the pump (12) driven by the engine (14), and (c) the output of the engine (14) is controlled.

A pump device according to a fifth aspect is the pump device according to the fourth aspect, further including the following component (d). (D) Ignition timing control means for controlling the ignition timing of the engine (14) so that the engine output decreases when the rotation speed of the engine (14) exceeds a set value

[0011]

In the engine control device according to the first aspect, when the temperature and humidity change and the engine output decreases, the engine speed also decreases. The temperature sensor (34) and the humidity sensor (32) detect the temperature and humidity, respectively, and the decrease in the engine output indicates the temperature sensor (34) and the humidity sensor (3).
It is calculated based on the detection value of 2), and the engine output control means (30) increases the engine output so as to eliminate this decrease. As a result, the engine rotation speed is maintained at the set value.

In the engine control device of the second aspect, the amount of the air-fuel mixture supplied to the engine (14) is increased or decreased by increasing or decreasing the engine throttle, and the engine output is increased or decreased.

In the engine control device according to claim 3, the valve (82)
When the opening degree of the outlet (80) of the muffler (66) increases, the exhaust resistance of the two-cycle engine (14) decreases and the engine output increases. Thus, the valve (82) increases or decreases the engine output in connection with increasing or decreasing the opening degree of the outlet (80) of the muffler (66).

In the pump device according to the fourth aspect, when the temperature and humidity change and the engine output decreases, the engine output decreases.
The engine speed decreases and the discharge pressure of the pump (12) also decreases. The temperature sensor (34) and the humidity sensor (32) detect the temperature and humidity, respectively, and the decrease in the engine output is calculated based on the detected values of the temperature sensor (34) and the humidity sensor (32), and the engine output The control means (30) increases the engine output so as to eliminate this decrease. As a result, the engine rotation speed and the operating speed of the pump (12) are maintained at the set values, and the discharge pressure of the pump (12) is also maintained at the set value.

In the pump device according to the fifth aspect, when the pump (12) is unloaded, the engine speed increases even though the engine output is constant. The ignition timing control means,
The ignition timing of the engine (14) is controlled to reduce the engine output and reduce the engine speed to a set value, whereby the operating speed of the pump (12) is maintained below the set value.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of the washing machine 10. Reciprocating pump
12 is driven by a small two-cycle engine 14, sucks water 20 in a tank 18 through a suction pipe line 16, and discharges it.
Discharge to 22. The pressure regulating valve 24 is connected to the tank via the return line 26.
By controlling the flow rate of the water 20 in the discharge conduit 22 returning to 18, the hydraulic pressure in the discharge conduit 22 is maintained at a desired value. Nozzle 28
Is connected to the distal end side of the discharge pipe line 22, is grasped by an operator, is operated to open and close, and injects the water 20 pumped from the reciprocating pump 12 via the discharge pipe line 22 at high pressure. The small two-cycle engine 14 has a rotation speed lower than that of a small two-cycle engine mounted on another working machine such as a brush cutter, for example, 4000 r. p. m. Reciprocating pump set to 12
To operate at the set speed. The engine output control means 30 controls the small two-cycle engine 14 based on inputs from the humidity sensor 32, the temperature sensor 34, and the set pressure indicator 36.
Control the output of. The humidity sensor 32 and the temperature sensor 34 detect the humidity and the temperature of the atmosphere, respectively, and the set pressure indicator 36 allows the operator to manually set the set value of the discharge pressure of the reciprocating pump 12.

FIG. 2 is a block diagram showing a first example of the engine output control means 30. The throttle lever 38 is manually rocked by an operator for adjusting the engine throttle, and the position sensor 40 is composed of a potentiometer and detects the rocking position of the throttle lever 38. The engine output control means 30 includes a controller 44 and an actuator 46, and the controller 44 includes a humidity sensor 32 and an air temperature sensor.
Position sensor together with 34 and set pressure indicator 36
The control signal calculated based on the input from 40 is output to the actuator 46. The actuator 46 controls the opening of the throttle valve 48 that controls the flow cross-sectional area of the intake passage of the small two-cycle engine 14, that is, the engine throttle. As the opening degree of the throttle valve 48 increases, the amount of air-fuel mixture supplied to the cylinder 60 (FIG. 3) of the small two-cycle engine 14 increases and the engine output increases.

FIG. 3 is a configuration diagram of an engine which is an object of engine output control. In the engine body 56, the piston
58 slides in the cylinder 60 to increase or decrease the volume of the combustion chamber 62. The exhaust port 64 is formed in the cylinder 60 and is connected to the inlet 68 of the muffler 66 so that it opens into the combustion chamber 62 when the piston 58 is appropriately close to bottom dead center.

FIG. 4 is a block diagram showing a second example of the engine output control means 30. Muffler body 78 is engine body 56
In addition to the inlet 68 connected to the exhaust port 64 (FIG. 3), a tail pipe 80 as an outlet for exhausting exhaust gas is provided. The flow rate adjusting valve 82 is arranged on the tail pipe 80, and increases or decreases the flow cross-sectional area of the tail pipe 80 based on inputs from the humidity sensor 32, the temperature sensor 34, and the set pressure indicator 36. The larger the flow cross-sectional area of the tail pipe 80, the more the exhaust resistance of the small two-cycle engine 14 decreases and the engine output increases.

FIG. 5 is a graph showing the relationship between the air temperature and the discharge pressure of the reciprocating pump 12 using the humidity of the atmosphere as a parameter.
In this washing machine, the reciprocating pump 12 is set so that the discharge pressure does not exceed 70 kg / square cm. The operation of the washing machine 10 will be described with reference to FIG.

In the set pressure indicator 36, an operator preliminarily indicates a set value of the discharge pressure of the reciprocating pump 12, here 70 kg / square cm. As the humidity and the temperature rise, the output of the small two-cycle engine 14 decreases, the operating speed of the reciprocating pump 12 decreases, and the discharge pressure of the reciprocating pump 12 decreases. The engine output control means 30 detects the set value of the discharge pressure of the reciprocating pump 12, that is, the set pressure from the input from the set pressure indicator 36,
A set value of engine output corresponding to the set pressure is obtained.
Then, a decrease in the engine output with respect to the set value of the engine output is calculated from the inputs from the humidity sensor 32 and the temperature sensor 34, and the opening degree of the throttle valve 48 is increased to compensate for the decrease (the embodiment of FIG. 2). Alternatively, the distribution cross-sectional area of the tail pipe 80 is increased (the embodiment of FIG. 4). As a result, the rotation speed of the small two-cycle engine 14 and the operating speed of the reciprocating pump 12 are about 4000 r. p. m. Then, the discharge pressure of the reciprocating pump 12 returns to and is maintained at the set value indicated by the set pressure indicator 36. For example, temperature 30 ° C and humidity 4
When it is 0%, the reciprocating pump 12 uses the parameter 4 in FIG.
The operation will be changed from the 0% characteristic line to the dashed characteristic line.

FIG. 6 is a graph showing the relationship between the engine speed of the small two-cycle engine 14 and the advance amount of the ignition timing. The ignition device of the small two-cycle engine 14 includes a circuit for generating a secondary voltage with the advance amount of the A characteristic and the B characteristic of FIG. 6, and as shown by the thick line portion, the A characteristic is related to the engine speed. And B characteristics are switched. That is, as when starting, 1000 r. p. m. At the engine rotation speed of, the B characteristic is used to secure the advance amount range of 20 to 23 ° to achieve a smooth start. Further, the engine rotation speed is 1000 to 4000 r.p.m. p. m. In the range of, the A characteristic is used to maintain the advance amount of approximately 25 °, which changes little with respect to the change of the engine rotation speed. When the small two-cycle engine 14 is in a no-load operation state, the engine rotation speed is 4000 rpm. p. m. However, at this time, the characteristic is switched to the B characteristic again, and as a result, the engine output is reduced and the engine rotation speed is 4000 rpm. p. m. Returning to the following, the reciprocating pump 12 is also 4000 r.p.m. p. m. The following operating speed is maintained.

In the illustrated embodiment, the reciprocating pump 12 and the small two-cycle engine 14 are described, but the present invention can be applied to pumps other than the reciprocating pump and other engines such as a four-cycle engine. In the illustrated embodiment, the washing machine 10 is described, but the present invention is also applicable to working machines other than the washing machine 10, such as a power sprayer for spraying a chemical solution on a field.

[0024]

According to the first aspect of the present invention, the decrease in the engine output due to the change in temperature and humidity is compensated, so that the engine speed can be maintained at the set value with respect to the change in temperature and humidity.

According to the second and third aspects of the present invention, the flow rate of the exhaust gas discharged from the engine throttle, the portion of the cylinder on the head side of the exhaust port of the cylinder of the two-cycle engine is adjusted, and the flow rate of the exhaust gas at the outlet of the muffler. The engine output can be controlled appropriately by adjusting the.

According to the fourth aspect of the invention, the decrease in engine output due to changes in temperature and humidity is compensated, and as a result,
The pump discharge pressure can be maintained at an appropriate value by maintaining the set value of the operating speed of the pump with respect to changes in temperature and humidity.

According to the fifth aspect of the present invention, by controlling the ignition timing of the engine, it is possible to prevent the pump from operating beyond the set value during no-load operation of the pump.

[Brief description of drawings]

FIG. 1 is a block diagram of a washing machine.

FIG. 2 is a block diagram showing a first example of engine output control means.

FIG. 3 is a configuration diagram of an engine which is a target of engine output control.

FIG. 4 is a configuration diagram showing a second example of the engine output control means.

FIG. 5 is a graph showing the relationship between the air temperature and the discharge pressure of the reciprocating pump using the humidity of the atmosphere as a parameter.

FIG. 6 is a graph showing a relationship between an engine rotation speed of a small two-cycle engine and an advance amount of ignition timing.

[Explanation of symbols]

12 Reciprocating pump (pump) 14 Small two-cycle engine (engine, two-cycle engine) 30 Engine output control means 32 Humidity sensor 34 Air temperature sensor 60 Cylinder 64 Exhaust port 66 Muffler 80 Tail pipe (outlet) 82 Flow control valve (valve)

Claims (5)

[Claims] 1. An air temperature sensor (34) for detecting an air temperature,
(B) a humidity sensor (32) for detecting the humidity of the atmosphere, and (c) engine output control means (30) for increasing the engine output so as to eliminate a decrease in the rotation speed due to changes in temperature and humidity. An engine control device comprising: 2. The engine control device according to claim 1, wherein the engine output control means (30) includes means for adjusting the engine output by increasing or decreasing an engine throttle. 3. The engine output control means (30) is a valve for controlling a flow rate of exhaust gas at an outlet (80) of a muffler (66).
The engine control device according to claim 1, further comprising (82). 4. The engine according to claim 1, wherein (a) the engine (14), (b) the pump (12) driven by the engine (14), and (c) the output of the engine (14) is controlled. A pump device comprising the engine control device according to any one of the claims. 5. (d) Ignition timing control means for controlling the ignition timing of the engine (14) so that the engine output decreases when the rotation speed of the engine (14) exceeds a set value. The pump device according to claim 4, wherein the pump device is a pump device.