JPH06101606A - Method for starting engine - Google Patents

Abstract

PURPOSE:To reduce a load at the time of starting an engine, so as to reduce the side and weight of a starter to secure an oil pressure source of a hydraulic actuator, by driving an oil pump before starting the engine, and lubricating respective parts of the engine by means of discharged oil. CONSTITUTION:In the case when a key switch 1 is set ON at the time of starting an engine 5, at first, an electrically driven oil pump 12 is driven by a controller 2, and then oil inside an oil tank 4 is supplied to lubricated part of the engine 5. Next, a starter 7 is driven by the controller 2, and a pinion gear 14 is meshed with the ring gear 8 of the engine 5 and then the engine 5 is started. The electrically driven oil pump 12 and the starter 7 are respectively stopped by the controller 2. A changeover valve 9 is operated by the controller 2 after starting the engine 5, and flow of the oil is changed over from the lubricated part of the engine 5 to a hydraulic actuator, and is utilized as this oil pressure source. Consequently, rate of load for cranking at the time of starting the engine is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for starting an engine.

[0002]

2. Description of the Related Art Conventionally, an engine starting mechanism uses electric energy of a battery to drive a starter motor,
The obtained torque is transmitted to the engine for cranking.

[0003]

When a long time elapses after the engine is stopped, the oil on the lubrication surface of each part of the engine runs out, and the lubrication surface may be in a metal contact state.

In the above-mentioned prior art, the engine is driven regardless of whether the lubrication condition of each part of the engine is good or not. Therefore, for example, even if the main journal of the engine is in metal contact due to poor lubrication, cranking can be achieved. Had to generate that torque with the starter.
Figure 5 shows the calculated load torque (on the crankshaft) when the engine main journal is cranked under fluid lubrication, and Figure 6 shows the load torque (on the crankshaft) when the main journal is driven by metal contact. ) Shows the calculated value.
The condition is 100 mS when time is 0 when not rotating.
The angular acceleration motion is performed at an angular acceleration of 40π (rad / S2) up to and the uniform angular speed motion is performed at an angular velocity of 4π (rad / S) after 100 mS. The friction coefficient under metal contact was 0.3. Also, since it is during cranking, the pressure fluctuation of the main journal due to the combustion of the engine was not considered, and only the pressure due to the compression of gas was considered. At the time of fluid lubrication, due to the pressure fluctuation to the main journal due to the compression of gas,
Assuming that the fluid lubrication state is maintained, the load torque of the main journal during cranking is about 0.3 (N).
However, in the metal contact state, it is directly affected by the pressure fluctuation due to gas compression, and the maximum load is about 30 (N). That is, the load torque of the main journal under fluid lubrication and under metal contact is nearly 100 times. Also, this is a calculation for one main journal of the engine,
In the case of a multi-cylinder engine, the number of times becomes several times, and the starter for starting the engine becomes heavy and heavy, which puts pressure on the engine space and causes deterioration of fuel consumption.

[0005]

In order to solve the above-mentioned problems, the present invention uses the following means. That is, in the first embodiment, the oil pump is driven before the engine is started, and the discharged oil is used to lubricate each part of the engine, and then the starting mechanism for starting the engine is provided, and the metal contact state of the main journal or the like is provided. To reduce fluid lubrication.

In the second embodiment, of the engine starting mechanism shown in the first embodiment, the oil pump is built in the starter, the built-in oil pump is driven before cranking the engine, and the discharged oil causes various parts of the engine to run. After lubrication, crank the engine.

In the third embodiment, the engine starting mechanism shown in the first and second embodiments is provided with a lubrication state detecting mechanism for detecting the lubrication state of the engine, and whether lubrication before starting is determined depending on the quality of the engine lubrication state. The function to do is provided.

[0008]

According to the present invention, the lubrication state of each lubrication surface is changed from the metal contact state to the fluid lubrication state before the engine is started, so that the load ratio with respect to cranking at the time of engine start is reduced. Therefore, it is possible to reduce the weight and size of the cranking starter. Further, the lubrication state detection mechanism does not perform the above-described lubrication each time the engine is started, but performs lubrication only when the lubrication state is poor, thereby preventing a long start-up time each time. .

[0009]

1 is a system diagram of an engine starting mechanism according to a first embodiment of the present invention.

This embodiment comprises a key switch 1, a controller 2, an electric oil pump 3, a starter 7 and an engine 5.

The operation is performed in the following procedure. First, the driver tries to start the engine 5 by pressing the key switch 1
Turn on. The signal from the key switch 1 is input to the controller 2, and the controller first sends a signal for driving the electric oil pump 3 to the electric oil pump 3. When the electric oil pump 3 is driven, the oil in the oil tank 4 requires lubrication of the engine 5 (in the present embodiment, only the main journals 6a to 6e are included, but other cylinders, valve devices, etc. are also included). Is supplied to lubricate.
(Hereinafter, referred to as an oil supply mode.) After the oil is supplied to the lubrication surface, the controller 2 sends a signal to the starter 7 to start the starter 7. The starter 7 engages the internal pinion gear 14 with the ring gear 8 carved in the flywheel of the engine 5 to start the engine. (Hereinafter, referred to as cranking mode.) After starting the engine 5, the controller 2 sends a signal to stop the electric oil pump 3 and the starter 7, and the electric oil pump 3 and the starter 7 are stopped. Even after the engine 5 is started, the switching valve 9 is operated by the signal from the controller 2 to switch the oil flow from the lubrication section of the engine 5 to the hydraulic actuator mounted on the vehicle. It can be used as a hydraulic power source for hydraulic actuators.

By performing the above operation, the engine starting mechanism of this embodiment can reduce the load torque at the time of starting the engine, improve the starting performance, and reduce the weight of the starter 7. Further, even after the engine 5 is started, it can be utilized as a hydraulic pressure source of a hydraulic actuator mounted on the vehicle.

FIG. 2 is a system diagram of an engine starting mechanism according to a second embodiment of the present invention. This embodiment has the same effect as the above-described first embodiment, but the number of parts is reduced by integrating the electric oil pump 3 and the starter 7 in the first embodiment. The starter 10 with an oil pump used in this embodiment has two modes according to a signal from the controller 2. In the first mode, the built-in pinion gear 14 does not mesh with the ring gear 8 of the engine 5 to drive the built-in motor 11, and the built-in oil pump 12 supplies oil (the oil described in the first embodiment). Supply mode). The second mode is a mode in which the built-in pinion gear 14 meshes with the ring gear 8 of the engine 5 to drive the motor 11 to drive the engine 5 (cranking mode described in the first embodiment).

The operation is performed in the following procedure. First, the driver tries to start the engine 5 by pressing the key switch 1
Turn on. A signal from the key switch 1 is input to the controller 2, which first sets the starter 10 with a hydraulic pump in the oil supply mode. At this time, since the pinion gear 14 of the starter 10 with a hydraulic pump does not mesh with the ring gear 8 of the engine 5, the engine 5 is not started. Starter 1 with hydraulic pump
When the motor 11 of 0 drives the built-in oil pump 12, the oil in the oil tank 4 needs to lubricate the engine 5 (in this embodiment, the main journal 6a).
6e only, but also includes other cylinders, valve devices and the like. ) Is supplied to lubricate. After the oil is supplied to the lubrication surface, the controller 2 puts the starter 10 with an oil pump into the cranking mode, meshes the pinion gear 14 in the starter 10 with an oil pump with the ring gear 8 of the engine 5, and starts the engine 5. After starting the engine 5, the controller 2 sends a signal to stop the starter 10 with an oil pump, the starter 10 with an oil pump stops, and the engine start is completed. Further, even after the engine 5 is started, the switching valve 9 and the starter 10 with an oil pump are put into the oil supply mode by the signal of the controller 2 to send the oil to the hydraulic actuator mounted on the vehicle. Can be used as a hydraulic power source.

FIG. 3 is a system diagram of an engine starting mechanism according to the third embodiment of the present invention. Although the configuration is the same as that of the second embodiment, it is an engine starting mechanism in which the control flow of the controller 2 shown in FIG. 2 is changed. The controller 2 determines the necessity of the oil supply mode based on the lubrication state detected by the lubrication state detection mechanism 13. Of course, this embodiment can be applied to the first embodiment. By making such a determination, it is possible to reduce the time required for starting the engine, and the driver can start the engine comfortably.

FIG. 4 is a control flowchart of the controller 2 in the engine starting mechanism according to the third embodiment of the present invention. In the present embodiment, the lubrication state detection mechanism 13 detects the lubrication state of each part of the engine 5 by detecting the time from when the engine was last stopped to when the key switch 1 is turned on this time. is there. In other words, the necessity of the oil supply mode is determined by the time from the last engine stop to this restart, and if the time is short, the oil supply mode is omitted and the cranking mode is entered. . After the engine 5 starts, it operates as follows. When the key switch 1 is turned off, the rotation of the motor 11 of the starter 10 is stopped, and the pinion gear 14 is separated from the ring gear 8 of the engine. After that, if the hydraulic actuator specification signal is input,
The switching valve 9 is switched to the hydraulic actuator side, and oil is sent to the hydraulic actuator. When the hydraulic actuator use signal is turned off, the rotation of the motor 11 of the starter 10 is stopped and the switching valve 9 is switched to the engine side. When the hydraulic actuator signal is not input and the engine is turned off, the stop time is recorded and the operation is finished. By performing this kind of operation, the oil supply mode is omitted to stop the engine for a short time, the engine is started in a short time, and lubrication is performed before starting only when there is poor lubrication when left for a long time. , It always prevents the engine from starting slowly.

[0017]

According to the present invention, the load when starting the engine can be reduced, and the starter, which is a starter, can be made smaller and lighter. Further, wear due to metal contact can be prevented. It can also be used as a hydraulic power source for hydraulic actuators after the engine is started.

[Brief description of drawings]

FIG. 1 is a system diagram of an engine starting mechanism according to a first embodiment of the present invention.

FIG. 2 is a system diagram of an engine starting mechanism according to a second embodiment of the present invention.

FIG. 3 is a system diagram of an engine starting mechanism according to a third embodiment of the present invention.

FIG. 4 is a control flowchart of an engine starting mechanism according to a third embodiment of the present invention.

FIG. 5 is a load torque characteristic diagram under fluid lubrication at the time of starting in the main journal of the engine.

FIG. 6 is a load torque characteristic diagram under metal contact at the time of starting in the main journal of the engine.

[Explanation of Codes] 1 ... Key switch, 2 ... Controller, 5 ... Engine,
6a to 6e ... Main journal, 9 ... Switching valve, 10
… Starter with hydraulic pump.

Claims (1)

[Claims] 1. A method for starting an engine, comprising: driving an oil pump before starting the engine, lubricating the various parts of the engine with the discharged oil, and then starting the engine.