JP2009156221A - Engine starting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine starting device capable of obtaining more excellent startability in an engine to be started by injecting fuel into a cylinder. <P>SOLUTION: The engine starting device for starting engine 1 by cranking the engine 1 with a starter 6 and injecting fuel into a cylinder 1a of the engine. The device includes: engine temperature estimating means 3 and 71 for estimating the temperature inside of the cylinder 1a of the engine 1; a fuel injection stop time computing means 72 for computing the fuel injection stop time from a start of cranking to a start of fuel injection into the cylinder 1a based on the estimated temperature estimated by the engine temperature estimating means 3 and 71; and fuel injection devices 33, 34 and 73 for starting fuel injection into the cylinder 1a after the fuel injection stop time, which is computed by the fuel injection stop time computing means 72, passed after a start of cranking. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an engine starter that starts an engine by injecting fuel into the cylinder of the engine.

In general, the startability (ease of starting the engine) of the engine is lower during the cold start than during the warm start.
In particular, for example, a diesel engine or the like that spontaneously ignites fuel by injecting fuel into a place where the air in the combustion chamber of the engine (the space formed by the cylinder and piston) is compressed to a high temperature state. It is necessary to quickly raise the temperature in the combustion chamber to a temperature at which the fuel can be ignited.

For this reason, conventionally, various techniques for increasing the temperature in the combustion chamber of the engine and improving the startability of the engine have been proposed.
The simplest technique for improving engine startability is to install a heating device such as a glow plug in the intake passage or cylinder of the engine, and directly heat the intake passage and cylinder to improve engine startability. There is something to make.

Further, Patent Document 1 uses an EGR device that recirculates a part of the exhaust discharged from the cylinder of the engine to the intake passage side at the time of cold start, and is warmed by compression of the intake air by cranking the engine. A technique has been proposed in which exhaust gas discharged to the exhaust passage side is recirculated back to the intake passage side.
According to the technique of this patent document 1, since the air warmed by the compression of the combustion chamber is recirculated to the intake passage side again without using a glow plug or the like, the inflow of fresh air that becomes an obstructive factor for the cylinder temperature rise Therefore, the engine startability can be improved by efficiently raising the temperature in the combustion chamber by cranking the engine.
Japanese Patent Laid-Open No. 11-200955

By the way, in general, in order to improve the ignitability of fuel at the time of starting the engine, it is generally performed to inject more fuel into the combustion chamber than in normal operation to enrich the air-fuel ratio.
However, it has been found that even if fuel is injected while cranking, fuel combustion may not start easily, and the present inventors have found that this cause is from the start of engine cranking to the start of fuel combustion. It was determined that the fuel injected into the combustion chamber during this period (hereinafter referred to as the period before the first explosion) hinders the temperature rise in the combustion chamber of the engine and takes time to reach the combustible temperature.

That is, as shown in FIG. 5, the fuel is injected into the combustion chamber in the period ts before the first explosion from the start of cranking until the atmospheric temperature in the cylinder (combustion chamber) rises to the fuel ignition possible temperature T and the first explosion occurs. The vaporized fuel is promoted to be vaporized by the air compressed and heated in the cylinder.
However, when this fuel is vaporized, the heat of vaporization is deprived from the combustion chamber, which becomes an obstacle to the temperature rise in the cylinder in the period ts before the first explosion, and as a cause of a decrease in engine startability. It has become.

Furthermore, in the technique of Patent Document 1, unburned fuel recirculates through the EGR device together with the air warmed by the compression of the intake air in the period before the first explosion, and is again taken into the combustion chamber. Prior to the first explosion, the amount of fuel present in the combustion chamber will increase cumulatively.
Therefore, in the technique of Patent Document 1, there is a possibility that inconveniences such as a decrease in exhaust gas performance due to a sudden increase in engine speed when the engine is started or an increase in the amount of unburned HC in the exhaust gas may occur. is there.

  The present invention was devised in view of such problems, and provides an engine starter that can obtain higher startability in an engine that is started by injecting fuel into a cylinder. Objective.

  In order to achieve the above-mentioned object, an engine starter according to the present invention (Claim 1) is an engine starter that cranks an engine by a starter and injects fuel into a cylinder of the engine. An engine temperature estimating means for estimating a temperature in the cylinder of the engine; and starting fuel injection into the cylinder from the start of cranking based on the estimated temperature by the engine temperature estimating means. Fuel injection stop time calculating means for calculating the fuel injection stop time of the fuel, and fuel injection into the cylinder is started after the fuel injection stop time calculated by the fuel injection stop time calculating means from the start of cranking And a fuel injection device.

Further, the engine temperature estimating means includes a cooling water temperature sensor for detecting a temperature of engine cooling water for cooling the engine, and the fuel injection stop time calculating means is based on the cooling water temperature detected by the cooling water temperature sensor. Preferably, the fuel injection stop time is calculated (claim 2).
Thereby, the temperature in the cylinder of the engine can be estimated based on the temperature of the cooling water of the engine, and the startability of the engine can be improved using a conventional mechanism.

Further, the engine temperature estimating means includes an exhaust temperature sensor for detecting the temperature of exhaust passing through the exhaust passage of the engine, and the fuel injection stop time calculating means is based on the exhaust temperature detected by the exhaust temperature sensor. Thus, it is preferable to calculate the fuel injection stop time.
By directly detecting the temperature of the exhaust gas passing through the exhaust passage, the temperature in the cylinder of the engine can be estimated more accurately, and the startability of the engine can be improved with high accuracy.

  The engine is provided in an intake passage, and an intake throttle valve that controls opening and closing of the intake passage; an exhaust throttle valve that is provided in an exhaust passage and controls opening and closing of the exhaust passage; the intake passage and the exhaust passage; And an EGR valve that opens and closes the EGR passage. During the fuel injection stop time, the intake throttle valve and the exhaust throttle valve are closed and the EGR passage is opened. It is preferable to control (claim 4).

  By exhausting the exhaust gas, which has been compressed in the cylinder and increased in temperature by cranking, back to the cylinder again and raising the temperature in the cylinder, temperature deficiency due to inflow of fresh air is reduced, and engine startability is further improved. The effect of improving can be acquired.

According to the engine starter of the present invention, the fuel injection into the cylinder is stopped for a predetermined time from the start of cranking according to the engine temperature, so that the inside of the cylinder due to the vaporization heat of the injected fuel at the initial start of cranking The temperature increase hindrance factor can be eliminated, the temperature increase in the cylinder is promoted, and the engine startability can be improved.
In addition, by stopping fuel injection into the cylinder, it is possible to suppress an increase in the amount of unburned HC generated at the start of the engine and improve the exhaust gas performance at the start of the engine, and to prevent the exhaust passage and the exhaust purification device from being contaminated. Can be prevented.

  Furthermore, it is possible to prevent the fuel injected before starting the engine from flowing down from the inside of the cylinder to a lubricating system such as an oil pan, so that the lubricating oil can be prevented from being diluted by the fuel, and fuel efficiency can be improved. There is also an advantage of being able to

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a system diagram of a principal part of a diesel engine for a vehicle, FIG. 2 is a flowchart showing an engine start control process, and FIG. 3 is a graph showing temporal changes in cylinder temperature, engine speed and fuel injection amount at the time of engine start. It is.

(Outline configuration)
The engine to which the engine starter according to the present embodiment is applied is a diesel engine for vehicles (hereinafter also simply referred to as an engine).
As shown in FIG. 1, the engine 1 includes a cylinder 1a, a crankshaft 1b, and a piston 1c. A combustion chamber 2 that is a space partitioned by the inner wall of the cylinder 1a and the top surface of the piston 1c is formed in the cylinder 1a. In addition, an engine control device (engine ECU) 7 constituted by a computer is equipped to control each part around the engine 1.

  The engine 1 is equipped with a lubrication system such as an oil pan (not shown) and is always lubricated with lubricating oil. Also, a starter motor (starter) 6 is connected to the crankshaft 1b so that power can be transmitted. When the starter switch signal is turned on by the ignition switch 5, the crankshaft 1b is rotated by driving the starter motor 6. The piston 1c is driven up and down while sliding in the cylinder 1a (hereinafter, this operation is simply referred to as cranking).

The ignition switch 5 is configured such that, for example, when the driver inserts a key and rotates, the key switch signal is turned on to activate the electric system of the vehicle. Further, the starter switch signal of the engine 1 is turned on by further rotating the key.
Further, a cooling water temperature sensor 3 and a crank angle sensor (engine speed sensor) 4 are attached to the engine 1 as a sensor system.

The cooling water temperature sensor 3 detects the temperature of engine cooling water that cools the engine 1 by passing through the vicinity of the combustion chamber 2 of the engine 1 (hereinafter referred to as cooling water temperature Tw), and transmits the detected value to the engine ECU 7. It is like that.
On the other hand, the crank angle sensor 4 is configured to generate a signal for each predetermined crank angle, and transmits the crank angle signal to an engine ECU (control device) 7.

  In addition, an intake pipe (intake passage) 10 and an exhaust pipe (exhaust passage) 20 are connected to the engine 1, and an intake valve 31, an exhaust valve 32, and an injector 33 are provided on the cylinder 1 a. A fuel injection pump 34 is connected to the injector 33, and the operation of the injector 33 and the fuel injection pump 34 is controlled by an injector control unit 73 of the control device 7 as described later. Here, the injector 33, the fuel injection pump 34, and the injector control unit 73 function as a fuel injection device.

An intake duct 11 and an air filter 12 are connected upstream of the intake pipe 10. From the upstream, the compressor section 41 of the supercharger (turbocharger) 40, the intercooler 13, the intake throttle 14, and the exhaust are connected to the intake pipe 10. An inlet 51b of the reflux passage (EGR passage) 51 is sequentially provided.
From the upstream, the exhaust pipe 20 is equipped with a reflux port 51a of the exhaust gas recirculation passage 51, an exhaust turbine section 42 of the supercharger 40, an exhaust brake valve 21, and a catalytic converter 60 in that order.

  An exhaust gas recirculation device (EGR) 50 provided between the intake pipe 10 and the exhaust pipe 20 includes the exhaust gas recirculation path (EGR path) 51 that connects the intake pipe 10 and the exhaust pipe 20, and the exhaust gas recirculation apparatus (EGR path) 51. An EGR cooler 52 interposed in the middle of the recirculation passage 51 and an EGR valve 53 provided near the inlet 51b of the exhaust recirculation passage 51 to the intake pipe 10 and opening and closing the exhaust recirculation passage. .

The intake throttle (intake throttle valve) 14 is adjusted in opening degree by a drive motor 14a whose operation is controlled by a motor driver 14b, and has a function of opening and closing the ventilation area of the intake pipe 10. ing.
On the other hand, an exhaust brake valve (exhaust throttle valve) 21 is provided in the exhaust pipe 20, and is driven by an actuator (here, air pressure type) 21a. The actuator 21a is an air pressure source 21c comprising an air compressor and an air tank by a control valve 21b. It is configured to operate by supplying air pressure from and to open and close the ventilation area of the intake pipe 10.

Further, the exhaust turbine section 42 of the supercharger 40 is equipped with a wastegate valve 54 that avoids excessive supercharging. The supercharger 40 may be provided with a variable nozzle vane.
Therefore, during normal operation of the engine 1, air (intake air) introduced from the intake duct 11 is purified by the air cleaner 12 and taken into the intake pipe 10, and is pumped by the compressor unit 41 of the supercharger 40, thereby intercooler. 13 is appropriately cooled and supplied to the combustion chamber 2 from the opening of the intake throttle 14 through the opening of the intake valve 31. The fuel pressurized by the fuel injection pump is injected from the injector 33 into the compressed air in the combustion chamber 2 and ignited and combusted. The exhaust generated by the combustion drives the exhaust turbine section 42 of the supercharger 40 and is introduced into the catalytic converter 60 through the exhaust pipe 20.

In the catalytic converter 60, purification by combustion of CO and unburned fuel in the exhaust gas is performed, and particulate matter (fine emission, PM) in the exhaust gas is collected and purified in the catalytic converter 60. Exhaust gas is discharged outside the machine.
When the engine 1 is in operation, the opening degree of the EGR valve 53 is controlled according to the operating condition, and the exhaust gas is recirculated to the intake side through the EGR passage 51, thereby reducing the combustion temperature in the combustion chamber and suppressing the generation of NOx and the like. It has a function to do.

  Further, when the opening degree of the intake throttle 14 is appropriately controlled to adjust the intake air amount and the operation of the exhaust brake is commanded, the exhaust brake valve 21 is closed and the exhaust flow is restricted, and a braking force can be obtained. It is like that.

(Functional configuration of control system)
As shown in FIG. 1, the engine ECU 7 includes an engine temperature estimation unit (engine temperature estimation unit) 71, an injection stop time calculation unit (fuel injection stop time calculation unit) 72, an injector control unit 73, and a valve control unit as functional components. 74 is set.

  In the engine temperature estimation unit 71, the correspondence between the coolant temperature Tw obtained from the coolant temperature sensor 3 and the temperature of the combustion chamber 2 (inside the cylinder 1a) at that time is obtained from experimental values and stored in advance as map data. The atmospheric temperature of the combustion chamber 2 of the engine 1 is estimated based on the cooling water temperature Tw.

The injection stop time calculation unit 72 is the atmosphere of the combustion chamber 2 of the engine 1 estimated by the engine temperature estimation unit 71 when the key switch signal or the starter switch signal is turned on (here, the starter switch signal is turned on). Based on the temperature, the fuel injection stop time t _delay from the start of cranking by the starter motor 6 to the start of fuel injection by the injector 33 into the combustion chamber 2 is calculated. Here, the atmospheric temperature in the combustion chamber 2 of the engine 1 is estimated from the cooling water temperature Tw. However, since the cooling water temperature Tw and the atmospheric temperature in the combustion chamber 2 are substantially proportional, the injection stop time calculation is performed. The unit 72 may be configured to obtain a correspondence relationship between the coolant temperature Tw and the fuel injection stop time t _delay directly by an experiment or the like and calculate the fuel injection stop time t _delay based on this correspondence relationship. In this case, the injection stop time calculation unit 72 serves as both engine temperature estimation means and fuel injection stop time calculation means.

That is, the atmosphere temperature in the combustion chamber 2 of the engine 1 at the start of cranking, and the time (fuel injection stop time t _delay ) required from the start of cranking until the atmosphere temperature in the combustion chamber 2 reaches the fuel ignitable temperature T1. Is obtained in advance by experiments or the like and stored in the engine ECU 7 as map data. The injection stop time calculation unit 72 calculates the fuel injection stop time t _delay based on this map data.

The fuel injection stop time t _delay may be set simply by the time from the start of cranking, but the number of times that the crank angle suitable for fuel injection has been reached from the start of cranking or the time from the start of cranking You may set by the rotation amount of the crankshaft 1b.
The injector control unit 73 controls the fuel injection amount and the fuel injection timing so that desired fuel is injected from the injector 33 when the phase of the piston 1b reaches a suitable crank angle during engine operation.

When the engine is started, an elapsed time (cranking time t _m ) from the start of cranking is measured by a built-in timer, and from the injector 33 until the cranking time t _m reaches the fuel injection stop time t _delay. The fuel injection is prohibited.
When the starter signal is turned on, the valve control unit 74 determines that the engine start mode has started, sets the opening of the EGR valve 53 to a predetermined opening or more (opens the EGR valve), and sets the intake throttle 14 The exhaust brake valve 21 is closed (the intake throttle valve and the exhaust throttle valve are closed).

When the cranking time t _m reaches the fuel injection stop time t _delay , the EGR valve 53 is closed (the EGR valve is closed) and the intake throttle 14 and the exhaust brake valve 21 are opened (the intake throttle valve and The exhaust throttle valve is opened), and the engine start mode is released.

(Function and effect)
Since the engine starting device according to the first embodiment of the present invention is configured as described above, when the engine 1 is started, the starting control is performed according to the following procedure.

As shown in FIG. 2, first, in step S100, when the ignition switch 5 is operated by the driver or the like and the key switch is turned on, control power is supplied to the electric system of the vehicle, and the electric system is turned on. The
In step S110, it is determined whether the ignition switch 5 is operated and the starter switch is turned on, and the standby state is maintained until the starter switch is turned on (that is, a starter signal is input to the engine ECU 7). Become.

If it is determined in step S110 that the starter switch has been turned on, the process proceeds to step S120.
In step S120, the starter motor 6 is driven based on a control signal from the engine ECU 7, and cranking of the engine 1 is started.
In step S130, the atmospheric temperature of the combustion chamber 2 of the engine 1 is estimated based on the cooling water temperature Tw obtained from the cooling water temperature sensor 3 when the starter switch is determined to be on in S110.

In step S140, the injection stop period t _delay is calculated from the ambient temperature of the combustion chamber 2 of the engine 1 estimated based on the coolant temperature Tw.
On the other hand, in step S150, the engine start mode is set, the EGR valve is opened, and the intake throttle 14 and the exhaust brake valve are closed.
Further, in step S160, the timer value t of the timer function in the engine ECU7 starts counting, measuring cranking time t _m is started. Note that the processes in steps S120 to S160 described above are executed almost simultaneously.

Then, in step S170, whether or not cranking time t _m by the starter motor 6 has reached the injection stop period t _delay is determined.
If it is determined in step S170 that the cranking time t _m has reached the injection stop period t _delay (ie, t _m ≧ t _delay ), the process proceeds to step S180.
On the other hand, if it is determined in step S170 that the cranking time t _m has not reached the injection stop period t _delay (ie, t _m <t _delay ), the cranking time t _m reaches the injection stop period t _delay . Until then, cranking by the starter motor 6 is continued.

  In step S180, fuel is injected from the injector 33 into the combustion chamber 2 of the engine 1 for the first time, the EGR valve 53 is closed, and both the intake throttle 14 and the exhaust brake valve 21 are opened. In the engine start mode, the fuel injection amount is larger than the fuel injection amount during idle operation in order to improve ignitability. At this time, if there is no particular problem, the atmospheric temperature in the combustion chamber has reached the fuel ignitable temperature T1, and therefore in step S180, the first explosion of the fuel occurs and the engine speed is increased.

In step S185, it is determined based on the engine speed obtained from the crank angle sensor 4 whether or not the engine 1 has completely exploded.
If it is determined in step S185 that the engine 1 has not completely exploded, cranking is continued until it is determined that the engine 1 has completely exploded. If it is determined in step S185 that the engine 1 has completely exploded, the process proceeds to step S190.

In step S190, the engine start mode is canceled. That is, the fuel injection amount becomes the fuel injection amount during normal idle rotation from the fuel injection amount in the engine start mode, and the engine start control is terminated.
Thus, according to the engine starter of the first embodiment of the present invention, as shown in FIG. 3, the cylinder is cranked based on the coolant temperature Tw at the time when the starter switch signal is turned on. An injection stop period t _delay is calculated as a time until the atmospheric temperature in 1a (combustion chamber 2) rises to a temperature T1 at which fuel can be sufficiently ignited, and the injection stop period t _delay from the start of cranking to the cylinder 1a. By continuing the cranking without performing the fuel injection, the increase in the atmospheric temperature in the combustion chamber 2 is not hindered by the heat of vaporization of the fuel before the initial explosion of the fuel in the combustion chamber 2, The temperature rise in the cylinder is promptly promoted.

As a result, the time from the start of cranking to the first explosion (pre-first explosion period ts) can be shortened compared to that shown in FIG. 5, and the startability of the engine 1 can be improved.
In other words, since the fuel is not injected into the combustion chamber 2 until the atmospheric temperature of the combustion chamber 2 of the engine 1 reaches the fuel ignitable temperature T1, the fuel that has not ignited It is possible to prevent such an inconvenience that the oil flows through the inner wall of the cylinder 1a and then flows down to the crankshaft 1b and is diluted with the lubricating oil flowing in a lubricating system such as an oil pan (not shown).

Furthermore, ideally, since fuel is not injected during the cranking period until the first explosion, there is an advantage that fuel efficiency can be improved accordingly.
Further, since the fuel injection into the combustion chamber 2 is stopped for the injection stop period t _delay when the engine 1 is started, an increase in the amount of unburned HC generated when the engine 1 is started is prevented, and the exhaust gas performance when the engine is started. Can be improved.

In addition, the cooling water temperature sensor 3 is conventionally provided in a vehicle engine, and the existing mechanism is calculated by calculating the injection stop period t _delay based on the temperature of the cooling water temperature Tw. This can improve the startability of the engine.
Further, when the engine start mode is set, the combustion chamber in the cylinder is compressed by cranking, the temperature rises, and the exhaust discharged to the exhaust pipe 20 is recirculated into the cylinder again through the EGR passage, so that The atmospheric temperature in the combustion chamber can be increased efficiently.

  Further, in the engine start mode, the amount of exhaust discharged to the outside of the vehicle is suppressed, and the amount of fresh air sucked from the intake duct 11 is suppressed, so that the intake and exhaust air is introduced into the combustion chamber 2 through the EGR passage 51. The exhausted air is circulated, so that the amount of inhibition of the temperature rise in the combustion chamber due to the inflow of fresh air or the like can be reduced, and the engine startability can be further improved.

In addition, since fuel is not injected during cranking during the injection stop period t _delay , excessive fuel exists in the combustion chamber 2 while circulating through the intake pipe 10, the combustion chamber 2, the exhaust pipe 20, and the EGR passage 51. Thus, inconveniences such as a sudden increase in engine speed after the first explosion can be reliably avoided.

[Second Embodiment]
Subsequently, a second embodiment of the present invention will be described. This embodiment is configured in the same manner as the above-described first embodiment except for a part of the configuration, and the description of the same components as those in the first embodiment will be omitted, and will be described using the same reference numerals.

As shown in FIG. 4, in this embodiment, an exhaust temperature sensor 81 that detects the temperature of exhaust gas (exhaust temperature Tex) passing through the exhaust pipe 20 from the exhaust valve 32 to the reflux port 51 a of the EGR passage 51 is provided. The point provided is different from the first embodiment.
And the engine temperature estimation part 71 of engine ECU7 is comprised so that the atmospheric temperature in the combustion chamber 2 of the engine 1 may be estimated based on the exhaust temperature Tex.

Since the engine starter according to the second embodiment of the present invention is configured as described above, the exhaust pipe 20 between the exhaust valve 32 and the reflux port 51a of the EGR passage 51 is exhausted from the combustion chamber 2. By directly detecting the exhaust gas temperature (exhaust temperature Tex) immediately after being performed, the atmospheric temperature of the combustion chamber 2 of the engine 1 can be estimated more accurately, and based on this, the injection stop period t _delay is calculated. Therefore, after the injection stop period t _{delay has} elapsed from the start of cranking, the atmospheric temperature in the combustion chamber 2 reaches the fuel ignition temperature T1 more reliably, and the engine startability can be improved more accurately.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, in each embodiment, when the engine start mode is determined, the intake throttle valve and the exhaust throttle valve are closed and the EGR valve is opened. However, these are controlled independently. May be.

For example, when the engine start mode is determined, the intake throttle valve and the exhaust throttle valve are only closed, and the EGR valve may not be controlled. On the contrary, when the engine start mode is determined, the intake throttle valve and the exhaust throttle valve may be set. The valve is not particularly controlled, and the EGR valve may be closed.
Moreover, in each embodiment, since the existing EGR passage is used, an EGR cooler is interposed in the EGR passage. However, for starting, the exhaust passage and the intake passage are communicated separately from the existing EGR passage. An EGR passage may be provided and the EGR cooler may be bypassed at the start.

Further, the correspondence between the cooling water temperature Tw or the exhaust gas temperature Tex and the combustion chamber temperature is obtained by experiment or the like and used as map data, but more simply, the cooling water temperature Tw or the exhaust gas temperature Tex has several levels. A fuel injection stop time may be calculated by providing a threshold and applying a fuel injection stop time according to the threshold.
Furthermore, in each embodiment, although the diesel engine for vehicles was demonstrated to the example, the engine applied is not restricted to this, Various application is possible.

For example, even in a gasoline engine that injects fuel into a cylinder of an engine, the startability of the engine can be improved by improving the atmospheric temperature of the combustion chamber at a low temperature.
The fuel can be applied to various fuels such as ethanol.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an essential part system diagram of a vehicular diesel engine for explaining an engine starter according to a first embodiment of the present invention; 1 is a flowchart for illustrating an engine start control process for explaining an engine start device according to a first embodiment of the present invention. It is a graph for demonstrating the starting apparatus of the engine concerning 1st Embodiment of this invention, Comprising: It is a graph which shows the time change of the temperature in a cylinder, an engine speed, and fuel injection amount at the time of engine starting. It is for demonstrating the starting apparatus of the engine concerning 2nd Embodiment of this invention, Comprising: It is a principal part system diagram of the diesel engine for vehicles. FIG. 5 is a graph for explaining the problem of the present invention and showing temporal changes in the cylinder temperature, the engine speed, and the fuel injection amount when the engine is started.

Explanation of symbols

1 Engine 1a Cylinder 1b Crankshaft 1c Piston 2 Combustion chamber 3 Cooling water temperature sensor 4 Crank angle sensor 5 Ignition switch 6 Starter motor (starter)
7 Engine ECU (control device)
10 Intake pipe (intake passage)
11 Intake Duct 12 Air Cleaner 13 Intercooler 14 Intake Throttle (Intake Throttle Valve)
14a Drive motor 14b Motor driver 20 Exhaust pipe (exhaust passage)
21 Exhaust brake valve (exhaust throttle valve)
21a Actuator 21b Control valve 21c Air pressure source 31 Intake valve 32 Exhaust valve 33 Injector (fuel injection device)
34 Fuel injection pump (fuel injection device)
40 Turbocharger (turbocharger)
41 Compressor unit 42 Exhaust turbine unit 50 Exhaust gas recirculation system (EGR)
51 Exhaust gas recirculation passage (EGR passage)
51a Return port 51b Inlet port 52 EGR cooler 53 EGR valve 54 Wastegate valve 60 Catalytic converter 71 Engine temperature estimation unit (engine temperature estimation means)
72 Injection stop time calculation unit (fuel injection stop time calculation means)
73 Injector control unit 74 Valve control unit 81 Exhaust temperature sensor

Claims (4)

An engine starter that cranks the engine with a starter and starts the engine by injecting fuel into a cylinder of the engine,
Engine temperature estimating means for estimating the temperature in the cylinder of the engine;
Fuel injection stop time calculating means for calculating a fuel injection stop time from the start of cranking to the start of fuel injection into the cylinder based on the estimated temperature by the engine temperature estimating means;
And a fuel injection device for starting fuel injection into the cylinder after the fuel injection stop time calculated by the fuel injection stop time calculating means from the start of cranking. Starter. The engine temperature estimating means includes
A cooling water temperature sensor for detecting a temperature of engine cooling water for cooling the engine;
2. The engine starter according to claim 1, wherein the temperature in the cylinder of the engine is estimated based on a coolant temperature detected by the coolant temperature sensor. The engine temperature estimating means includes
An exhaust temperature sensor for detecting the temperature of the exhaust gas passing through the exhaust passage of the engine;
2. The engine starting device according to claim 1, wherein the temperature in the cylinder of the engine is estimated based on an exhaust temperature detected by the exhaust temperature sensor. The engine is
An intake throttle valve which is provided in the intake passage and controls the opening and closing of the intake passage;
An exhaust throttle valve that is provided in the exhaust passage and controls the opening and closing of the exhaust passage;
An EGR valve provided in an EGR passage communicating the intake passage and the exhaust passage, and opening and closing the EGR passage;
2. The engine starter according to claim 1, wherein, during the fuel injection stop time, the intake throttle valve and the exhaust throttle valve are closed and the EGR passage is opened. 3.

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