JPH05179915A - Lubrication controller in two-cycle engine - Google Patents

Abstract

PURPOSE:To enable an engine to be surely lubricated even in the case where trouble has occurred in a microcomputer control part. CONSTITUTION:A solenoid three-way valve 3 is installed at the discharge side of an oil pump. A supply passage A to an engine and a reflux passage B returning to an oil tank 4 via this solenoid three-way valve 3 are formed there. This 2-cycle engine lubrication controller constitutes this solenoid three-way valve 3 so as to make an oil passage come to be normally opened at the side of the engine supply passage A, while it controls an amount of excessive oil to be put back to the oil tank 4 according to engine load. In this constitution via a microcomputer control part 6 in time of being energized. In this constitution, plural pieces of output ports (1), (2) are installed in this microcomputer control part 6. In addition, a drive circuit 7 of the solenoid three-way valve 3 consisting of a logical circuit using these output ports as input terminals is connected to these output ports (1) and (2), and the logical circuit is constituted to output a driving signal only at a time when each output of these output ports (1), (2) is a specific pattern.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication control device for a two-cycle engine.

[0002]

2. Description of the Related Art As a lubrication system for a two-cycle engine,
There is a system in which oil is separated and supplied separately from fuel. Japanese Patent Laid-Open No. 2-191807 discloses a separate oil supply system in which a solenoid-controlled three-way valve controlled by a microcomputer is connected to the discharge side of an oil pump so that the oil is returned to an oil tank together with a supply path to the engine side. Forming a path,
It is disclosed that an optimum engine lubrication is performed by returning excess oil to an oil tank according to the engine load. Further, the electromagnetic three-way valve is configured so as to be normally opened on the engine supply path side when the power is not supplied, so that the engine can be surely lubricated even if a failure occurs in the electric system.

However, in such a lubrication control device, if the microcomputer control unit for driving the electromagnetic three-way valve operates abnormally due to a failure, it is not always possible to supply oil to the engine, and the above-mentioned excellent control is provided. There was a problem that the benefits could not be utilized.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a lubrication control device for a two-cycle engine, which can surely lubricate an engine even when an abnormality occurs in the microcomputer controller as described above. Especially.

[0005]

According to the present invention for achieving the above object, an electromagnetic three-way valve is provided on the discharge side of an oil pump, and a supply path to an engine and a return path returning to an oil tank are provided through the electromagnetic three-way valve. The electromagnetic three-way valve is formed so that the oil passage is normally opened to the engine supply passage side when the solenoid is not energized, and when energized, excess oil is returned to the oil tank via the microcomputer control unit according to the engine load. In a lubrication control device for a two-cycle engine that is controlled as described above, the microcomputer control unit is provided with a plurality of output ports, and the plurality of output ports are connected to the drive circuit of the electromagnetic three-way valve including a logic circuit using these as input terminals. However, the logic circuit is configured to output a drive signal only when the outputs of the plurality of output ports have a specific pattern.

As a mode in which the microcomputer control section becomes abnormal, (a) when it cannot operate at all in the clock stopped state,
It is possible that (b) the program is out of control, or (c) there is a partial hardware failure. In the case of (b) of these abnormalities, it can be prevented by a watchdog circuit normally used. In the case of (a), since the microcomputer control unit is in the reset state, the drive circuit does not output, and in the case of (c),
Since the specific pattern is not output to the output port, the drive circuit does not output.

That is, according to the lubrication control apparatus of the present invention, when an abnormality occurs in the microcomputer control unit, the outputs of the plurality of output ports have a pattern other than a specific pattern, and therefore the drive signal is not output from the drive circuit. , The electromagnetic three-way valve is normally open on the engine supply path side. Therefore, the oil discharged from the oil pump is continuously supplied to the engine side, and the engine is lubricated.

[0008]

1 is a system diagram showing a lubrication control device for a two-cycle engine according to an embodiment of the present invention. In the figure, 1 is a two-cycle engine, and 2 is a plunger type oil pump. The oil pump 2 is driven by the power of the crankshaft of the engine 1, and the throttle opening V
The stroke amount is controlled to change the discharge amount. An electromagnetic three-way valve 3 is connected to the discharge side of the oil pump 2, and a supply path A to the engine 1 side and a return path B to the oil tank 4 are connected via the electromagnetic three-way valve 3.
Are formed.

This electromagnetic three-way valve 3 is in a normally open state on the side of the engine supply path A when the drive signal is not output from the control unit 5 when there is no energization, and has a valve structure for supplying oil only to the engine 1. ing. Also, the electromagnetic three-way valve 3
When energized, the control unit 5 is driven according to the engine load to return the excess amount of oil discharged from the oil pump 2 to the oil tank 4. The control unit 5 determines the diversion ratio to the recirculation path B side by the duty ratio determined from the throttle opening V and the engine speed N, and is the minimum oil amount that does not generate white smoke in the exhaust gas for the engine 1. To supply.

As shown in FIG. 2, the control unit 5 is provided with a power supply circuit 9 via a main switch 8 and
It has a microcomputer control unit 6. The microcomputer controller 6 inputs the throttle opening V and the engine speed N, and is provided with two output ports on the output side. A drive circuit 7 including a logic circuit having these as input terminals is connected to the two output ports, and the electromagnetic three-way valve 3 is driven by a drive signal output from the drive circuit 7. The drive circuit 7 operates the electromagnetic three-way valve 3 only when the output port of the microcomputer control unit 6 has a specific pattern, that is, when the output port is in the H (Hi) state and the output port is in the L (Low) state. It is composed of a logic circuit that outputs a driving signal.

For example, when the microcomputer control unit 6 remains in the reset state due to a failure of the oscillation circuit or the like in the microcomputer control unit 6, the output terminal of the microcomputer control unit 6 has a pull-up resistor (not shown). ) Output port,
To H state together. Since it is not the above-mentioned specific pattern, the output of the drive circuit 7 (logic circuit) becomes L, and the drive signal is not output. Further, even when each of the output ports does not operate as in the case where the microcomputer controller 6 is in the reset state, the drive signal is not output.

When the drive signal is not output from the drive circuit 7 in this manner, the electromagnetic three-way valve 3 is not driven, so that the engine supply path A is normally opened and oil is continuously supplied to the engine 1. Therefore, even if an abnormality occurs in the microcomputer control unit, reliable engine lubrication becomes possible. FIG. 3 shows an actual application example of the above-described lubrication control device, in which one port of an open drain terminal (not shown) with a pull-up resistor of the microcomputer control unit 6 is connected to the base of the transistor 10 and the other port is connected. The configuration is such that the port is connected to the collector and this is connected to the FET (field effect transistor) 11. Also,
FIG. 4 is configured together with a microcomputer control unit for the ignition circuit. Since the input signals (throttle opening V and engine speed N) are made common, the control system can be simplified by combining them as in this example.

[0013]

As described above, according to the present invention, the electromagnetic three-way valve is provided on the discharge side of the oil pump, the supply path to the engine and the return path to the oil tank are formed through the electromagnetic three-way valve, and the electromagnetic The three-way valve is configured such that the oil passage is normally open to the engine supply passage side when the power is not supplied, and when the power is supplied, the microcomputer controller controls the excess oil to be returned to the oil tank according to the engine load. In a lubrication control device for a cycle engine, the microcomputer control unit is provided with a plurality of output ports, and the drive circuit of the electromagnetic three-way valve, which is composed of a logic circuit using these as input terminals, is connected to the logic circuit. Since the drive signal is output only when the output of the plurality of output ports has a specific pattern, the above-mentioned drive is activated when an abnormality occurs in the microcomputer control unit. Three-way solenoid valve driving signal of the circuit is not output is no longer driven. Therefore, oil is continuously supplied only to the engine, which enables reliable engine lubrication.

[Brief description of drawings]

FIG. 1 is a system diagram showing a lubrication control device for a two-cycle engine according to an embodiment of the present invention.

FIG. 2 is a system diagram showing a control unit portion of the lubrication control apparatus.

FIG. 3 is a system diagram showing a specific example of a control unit of the present invention.

FIG. 4 is a system diagram showing another specific example of the control unit of the present invention.

[Explanation of symbols]

1 2 cycle engine 2 oil pump 3 electromagnetic three-way valve 4 oil tank 5 control unit 6 microcomputer control unit 7 drive circuit (logic circuit)

Claims (1)

[Claims] 1. An electromagnetic three-way valve is provided on the discharge side of an oil pump, a supply path to an engine and a return path returning to an oil tank are formed through the electromagnetic three-way valve, and the oil path is provided when the electromagnetic three-way valve is not energized. In the lubrication control device for a two-cycle engine, which is configured to be normally opened to the engine supply path side and which controls to return excess oil to the oil tank according to the engine load via a microcomputer control unit when energized, The microcomputer control unit is provided with a plurality of output ports, the drive circuit of the electromagnetic three-way valve including a logic circuit having these as input terminals is connected to the plurality of output ports, and the logic circuit outputs the plurality of output ports. Is a lubrication control device for a two-cycle engine configured to output a drive signal only when a particular pattern is output.