阅读说明：本技术 引擎的起动控制装置及起动控制方法 (Engine start control device and start control method ) 是由 幾竹弘志 于 2018-05-08 设计创作，主要内容包括：包括：判定部(110),其在引擎(10)的起动时,判定引擎(10)是否处于预定的低温起动状态；以及起动控制部(120),当由判定部(110)判定为处于低温起动状态时,在使引擎(10)的燃料喷射停止的状态下,从起动电动机(63)向曲轴(16)传递旋转力而使引擎(10)在预先设定的阈值时间期间进行启动,并且当从启动开始起经过了阈值时间时,使引擎(10)的燃料喷射开始。(The method comprises the following steps: a determination unit (110) that determines whether the engine (10) is in a predetermined low-temperature start state when the engine (10) is started; and a start control unit (120) that, when the determination unit (110) determines that the engine (10) is in the low-temperature start state, transmits a rotational force from the starter motor (63) to the crankshaft (16) in a state in which fuel injection of the engine (10) is stopped, starts the engine (10) for a preset threshold time period, and starts fuel injection of the engine (10) when the threshold time has elapsed since the start of the start.)

1. A start control device for an engine having a starter motor capable of transmitting a rotational force to a crankshaft, comprising:

a determination unit that determines whether or not the engine is in a predetermined low-temperature start state at the time of starting the engine, an

And a start control unit that, when it is determined by the determination unit that the engine is in the low-temperature start state, transmits a rotational force from the starter motor to the crankshaft to start the engine for a preset threshold time period in a state where fuel injection of the engine is stopped, and starts fuel injection of the engine when the threshold time period has elapsed from the start of the start.

2. The start control device of an engine according to claim 1,

the determination means determines that the engine is in the low-temperature start state when the cooling water temperature of the engine is equal to or lower than a predetermined low-temperature threshold at the time of starting the engine.

3. The start control device of an engine according to claim 1 or 2,

the threshold time is set to a relatively short time.

4. A method for controlling the starting of an engine having a starter motor capable of transmitting a rotational force to a crankshaft,

determining whether the engine is in a predetermined low-temperature starting state at the time of starting the engine,

in a case where it is determined that the engine is in the low-temperature start state, the engine is started by transmitting a rotational force from the starter motor to the crankshaft while stopping fuel injection of the engine for a predetermined threshold time,

it is determined whether the threshold time has elapsed from the start of the startup,

and starting fuel injection of the engine in response to determining that the threshold time has elapsed since the start.

Technical Field

The present disclosure relates to an engine start control device and a start control method.

Background

Generally, at the time of starting the engine, fuel injection is started from the injector at the same time as the starter is started. Therefore, for example, when the engine is started in a state where the viscosity of the lubricating oil is high, such as at the time of low-temperature start, the engine may be driven by a load due to combustion of the fuel before the lubricating oil is sufficiently supplied to each sliding element of the engine, and damage, seizure, or the like may be caused to each sliding element.

For example, patent document 1 discloses the following technique: when the engine is started, only the starter is started, and then when the lubricating oil pressure reaches a predetermined pressure, fuel injection is started by the injector, thereby preventing the sliding elements from being damaged.

Disclosure of Invention

Problems to be solved by the invention

In the technique described in patent document 1, the start of fuel injection is always stopped before the lubricating oil pressure reaches a predetermined pressure at the time of engine start, regardless of the level of the outside air temperature or the cooling water temperature. Therefore, particularly at the time of low-temperature start requiring a time for increasing the lubricating oil pressure, there is a problem that the start of the engine is greatly delayed against the intention of the driver, and the driver feels a sense of discomfort.

Further, when the engine stalls due to road conditions such as an expressway or a road junction, it is necessary to restart the engine early and to quickly start the vehicle. In such a situation, in the technique described in patent document 1, since the rise of the lubricating oil pressure is required for the start of the engine, for example, if it takes time for the rise of the lubricating oil pressure, the start delay of the engine is accompanied, and rapid start of the vehicle is hindered, which may give a large unpleasant feeling to the driver.

The disclosed technology aims to effectively prevent each sliding element from being damaged due to insufficient lubricating oil when an engine is started, and to reduce the uncomfortable feeling given to a driver.

Means for solving the problems

The disclosed device is a start control device for an engine having a starter motor capable of transmitting a rotational force to a crankshaft, the device being characterized by comprising: a determination unit that determines whether or not the engine is in a predetermined low-temperature start state when the engine is started; and a start control unit that, when it is determined by the determination unit that the engine is in the low-temperature start state, transmits a rotational force from the starter motor to the crankshaft in a state in which fuel injection of the engine is stopped to start the engine for a preset threshold time period, and starts fuel injection of the engine when the threshold time period has elapsed from the start of the start.

Preferably, the determination means determines that the engine is in the low-temperature start state when the cooling water temperature of the engine at the time of starting the engine is equal to or lower than a predetermined low-temperature threshold value.

In addition, it is preferable that the threshold time is set to a relatively short time.

The method of the present disclosure is a method of controlling starting of an engine having a starter motor capable of transmitting a rotational force to a crankshaft, wherein, at the time of starting the engine, it is determined whether or not the engine is in a predetermined low-temperature starting state, and, in accordance with a determination that the engine is in the low-temperature starting state, in a state where fuel injection of the engine is stopped during a preset threshold time, the engine is started by transmitting the rotational force from the starter motor to the crankshaft, it is determined whether or not the threshold time has elapsed since the start of the starting, and fuel injection of the engine is started in accordance with a determination that the threshold time has elapsed since the start of the starting.

Effects of the invention

According to the technique of the present disclosure, it is possible to effectively prevent each sliding element from being damaged due to insufficient lubrication oil at the time of engine start, and to reduce the sense of discomfort given to the driver.

Drawings

Fig. 1 is a schematic overall configuration diagram of an engine according to an embodiment of the present disclosure.

Fig. 2 is a flowchart illustrating an engine start control process according to an embodiment of the present disclosure.

Detailed Description

Hereinafter, a start control device and a start control method according to an embodiment of the present disclosure will be described with reference to the drawings. The same reference numerals are given to the same parts, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

Fig. 1 is a schematic overall configuration diagram of a diesel engine (hereinafter, simply referred to as an engine) 10 on which a start control device according to the present embodiment is mounted. The engine 10 includes an engine main body portion 11, a fuel injection device 20, a lubricating oil supply device 30, a starter unit 60, and an Electronic Control Unit (ECU) 100. In the figure, reference numeral 70 denotes a water temperature sensor for acquiring an engine cooling water temperature, reference numeral 71 denotes an outside air temperature sensor for acquiring an outside air temperature, reference numeral 72 denotes an oil temperature sensor for acquiring a lubricating oil temperature, and reference numeral 80 denotes an ignition switch.

The engine body portion 11 includes: a cylinder body 12; an oil pan 13 provided at a lower portion of the crankcase of the cylinder block 12; and a cylinder head 14. A cylinder bore 15 is provided in the cylinder block 12. A piston P is reciprocatingly accommodated in the cylinder bore 15. The piston P is connected to a crankshaft 17 via a connecting rod 16. That is, when the piston P reciprocates in the cylinder bore 15, the reciprocating motion is converted into a rotational motion by the connecting rod 16, rotating the crankshaft 17. Further, reference numeral 18 denotes a flywheel fixed to an output end of the crankshaft 17.

The fuel injection device 20 includes a fuel tank 21, a fuel intake pipe 22, a fuel filter 23, a supply pump 24A, a high-pressure pump 24B, a fuel supply pipe 25, a common rail 26, a plurality of injectors 27 for injecting fuel into the respective cylinders, a pressure control valve 28, and a return pipe 29.

The fuel tank 21 accumulates fuel (e.g., diesel). The fuel intake pipe 22 has one end immersed in the fuel tank 21 and the other end connected to an intake port of the supply pump 24A. The fuel filter 23 is inserted into the fuel intake pipe 22, and removes foreign matter from the fuel pumped up by the feed pump 24A.

The feed pump 24A and the high-pressure pump 24B are driven by power transmitted from the crankshaft 17 of the engine 10. The supply pump 24A supplies the fuel drawn up from the fuel tank 21 through the fuel intake pipe 22 to the high-pressure pump 24B. The high-pressure pump 24B includes a plunger that is driven to reciprocate by rotation of a shaft, both not shown, and pressurizes and discharges fuel by reciprocating movement of the plunger. The high-pressure fuel pressurized by the high-pressure pump 24B is supplied to the common rail 26 via a fuel supply pipe 25.

The common rail 26 accumulates pressure of the high-pressure fuel supplied from the high-pressure pump 24B and distributes the accumulated pressure to the injectors 27. The fuel injection of each injector 27 is controlled in accordance with a command from the ECU 100. The common rail 26 is provided with a pressure control valve 28, and when the pressure in the common rail 26 reaches a predetermined value, the high-pressure fuel is returned to the fuel tank 21 via a return pipe 29.

The lubricant oil supply device 30 supplies the lubricant oil accumulated in the oil pan 13 to each sliding element of the engine 10, and includes an oil strainer 31, an oil pump 32, a relief valve 33, an oil filter 34, and an oil passage 40.

The oil strainer 31 is a filter for removing foreign matters contained in the lubricating oil, and is immersed in the lubricating oil in the oil pan 13. The oil strainer 31 is connected to a suction port of the oil pump 32 via a lubricating oil suction pipe 35.

The oil pump 32 pumps the lubricating oil and is driven by the power transmitted from the crankshaft 17 of the engine 10. A discharge port of the oil pump 32 is connected to a 1 st lubricating oil supply pipe 36.

The relief valve 33 is inserted into a relief pipe 33A, and the relief pipe 33A connects the 1 st lube oil supply pipe 36 and the lube oil suction pipe 35 to bypass the oil pump 32. The relief valve 33 is opened to return the lubricating oil so that the oil pressure in the oil passage 40 does not excessively increase when the engine 10 rotates at a medium-high speed with an increased pressurized delivery amount of the oil pump 32.

The oil strainer 34 removes foreign matter contained in the lubricating oil pressure-fed from the oil pump 32, and a downstream end of the 1 st lubricating oil supply pipe 36 is connected to an inlet port thereof. Further, a 2 nd lube oil supply pipe 37 is connected to an outlet port of the oil strainer 34.

An oil passage 40 is connected to a downstream end of the 2 nd lube oil supply pipe 37. The lubricating oil introduced into the oil passage 40 is supplied to sliding elements, such as a valve train and an oil jet, a journal portion of the crankshaft 17, and a rotating shaft of the turbocharger 50, which are not shown, and after lubricating the sliding elements, the lubricating oil is returned to the oil pan 13.

The starter unit 60 includes: a ring gear 61 provided to the flywheel 18; a pinion gear 62 capable of meshing with the ring gear 61; and a starter motor 63 that is driven by electric power supplied from an in-vehicle battery 69 to rotate the pinion gear 62.

An output shaft of the starter motor 63 is connected to an input shaft of the pinion gear 62 via a one-way clutch 65. The one-way clutch 65 allows only power transmission from the starter motor 63 side to the pinion gear 62 side. The pinion gear 62 is movable in the axial direction by the solenoid valve 64, and is selectively movable to an engagement position where it engages with the ring gear 61 and a non-engagement position where it does not engage with the ring gear 61.

The operations of the starter motor 63 and the solenoid valve 64 are controlled in accordance with a command from the ECU 100. Specifically, when the ignition switch 80 is operated from off to on by the driver, the solenoid valve 64 is operated in accordance with a start command input from the ECU100, and the pinion gear 62 is moved to an engagement position where it engages with the ring gear 61. Further, electric power is supplied from the vehicle-mounted battery 69 to the starter motor 63, and the driving force of the starter motor 63 is transmitted from the ring gear 62 to the flywheel 18 to rotate the crankshaft 17, thereby starting the engine 10.

The ECU100 performs various controls of the engine 10 and the like, including a known CPU, ROM, RAM, input ports, output ports, and the like. The ECU100 includes, as a part of its functional elements, a low-temperature start determination unit 110 (an example of a determination means) and an engine start control unit 120 (an example of a start control means). These functional elements は and these functional elements are described as elements included in the ECU100 as integrated hardware, but any part of these elements may be provided as separate hardware.

The low-temperature start determination unit 110 determines whether or not the engine 10 is in a predetermined low-temperature start state at the time of starting the engine 10 from off to on when the ignition switch 80 is operated by the driver. In the present embodiment, whether or not the low-temperature startup state is present is determined based on the sensor value of the water temperature sensor 70. Specifically, the low-temperature start determination unit 110 determines that the engine 10 is in the low-temperature start state when the cooling water temperature input from the water temperature sensor 70 is equal to or lower than a predetermined low-temperature threshold (for example, about-25 ℃) indicating that the viscosity of the lubricating oil is high. The determination as to whether or not the cold start state is present may be made based on the outside air temperature obtained by the outside air temperature sensor 71, the lubricant oil temperature obtained by the oil temperature sensor 72, or the like.

When the ignition switch 80 is turned on by the driver, if the low-temperature start determination unit 110 determines that the engine 10 is not in the low-temperature start state, the engine start control unit 120 outputs a start instruction to the starter unit 60 and outputs an instruction signal to start fuel injection to the injector 27.

On the other hand, when the ignition switch 80 is turned on by the driver, and the low-temperature start determination unit 110 determines that the engine 10 is in the low-temperature start state, the engine start control unit 120 outputs a start command to the starter unit 60 in a state where fuel injection from the injector 27 is stopped, starts the engine 10 for a predetermined threshold time (for example, about 2 seconds), and outputs an instruction signal to start fuel injection to the injector 27 after the threshold time has elapsed from the start of the start.

In this way, at the time of low-temperature start where the viscosity of the lubricating oil is high, by stopping the fuel injection and starting only until the threshold time elapses, the lubricating oil is reliably supplied to each sliding element of the engine 10 such as the bearing of the turbocharger 50 before the rotation of the turbocharger 50 is increased by the load drive accompanying the combustion of the engine 10. This can effectively prevent the bearing of the turbocharger 50 from being damaged or burned due to insufficient lubricating oil. Further, by setting the threshold time for stopping the fuel injection to a relatively short time (about 2 seconds), it is possible to prevent a significant delay in starting the engine 10 and effectively reduce the driver's sense of discomfort.

Next, the start control process of the engine 10 according to the present embodiment will be described based on the flowchart of fig. 2.

In step S100, it is determined whether or not the ignition switch 80 is turned on by the driver. In the case where the ignition switch 80 is turned on (affirmative), the present control proceeds to step S110.

In step S110, it is determined whether the engine 10 is in the low-temperature start state based on the sensor value of the water temperature sensor 70. Specifically, if the cold start state is established (affirmative) in which the cooling water temperature is equal to or lower than a predetermined cold threshold (e.g., about-25 degrees), the present control proceeds to step S120. On the other hand, if the engine is not in the low-temperature start state (no), the control proceeds to step S200, where fuel injection is started simultaneously with the start, and normal start control is performed to stop the start in step S210.

In step S120, the starter motor 63 and the electromagnetic valve 64 of the starter unit 60 are operated in a state where the fuel injection from the injector 27 is stopped, and the start of the engine 10 is started.

In step S130, it is determined whether or not the elapsed time from the start-up has reached a predetermined threshold time (for example, about 2 seconds). If yes, the control proceeds to step S140 to start fuel injection from the injector 27, and in step S150, the operation of the starter unit 60 is stopped and the process returns.

As described above in detail, according to the present embodiment, at the time of low-temperature start where the viscosity of the lubricating oil is high, by stopping the fuel injection and starting only until the threshold time elapses, the lubricating oil is reliably supplied to each sliding element of the engine 10 such as the bearing of the turbocharger 50 before the rotation of the turbocharger 50 is increased by the load drive of the engine 10. This can effectively prevent the bearings of the turbocharger 50 from being damaged or burned due to insufficient lubricating oil at the time of low-temperature start. Further, by setting the threshold time for stopping the fuel injection to a relatively short time, the uncomfortable feeling given to the driver by the large delay in starting the engine 10 can be effectively reduced.

The present invention is not limited to the above-described embodiments, and can be implemented by being appropriately modified within a range not departing from the gist of the present invention.

For example, the start control is applied to the start when the ignition switch 80 is turned on by the driver, but the start control may be applied to the restart when the idling stop is released (for example, the accelerator operation is performed) when the engine 10 has the idling stop function.

The engine 10 is not limited to a diesel engine, and can be widely applied to other engines such as a gasoline engine.

The present application is based on the japanese patent application published on the 08 th.2017/05 th (japanese application 2017-092215), the contents of which are hereby incorporated by reference.

Industrial applicability

The present disclosure has an effect of effectively preventing each sliding element from being damaged due to insufficient lubricating oil at the time of engine start and reducing a sense of discomfort given to a driver, and is useful in a vehicle that can achieve a long life of an engine and can help to obtain a smooth engine starting feeling.

Description of the reference numerals

10 Engine

11 Engine body part

17 crankshaft

18 flywheel

20 fuel injection device

27 ejector

30 lubricating oil supply device

32 oil pump

50 turbo charger

60 Starter Unit

61 toothed ring

62 pinion

63 starting motor

70 water temperature sensor

80 ignition switch

100 ECU

110 low-temperature start judging part

120 engine start control unit