DE10318848B4 - Engine starting system - Google Patents

Abstract

Engine starting system, comprising: a first starter (4) which operates to start an engine (1); a second starter (5) which is used to start the engine (1) instead of the first starter (4) in the event that there is a given engine start malfunction resulting in a difficulty in starting the engine (1) by the first Starter (4) leads; and an engine start malfunction detector circuit (2) that determines that the engine start malfunction has occurred when an acceleration of the engine (1) measured when the engine (1) starts does not reach a given target engine acceleration , and wherein the engine start malfunction detector circuit (2) has a list listing different target engine acceleration values as a function of one or some of the sizes according to an outside air temperature, engine temperature, temperature of the first starter (4), a load due to accessories driven by the machine (1) and a status of a battery.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention generally relates to an engine start system equipped with two engine starters and an engine start system adapted to provide an output of an engine starter.

2. State of the art

In recent years, idling stop systems have come into use gradually, operating in such a manner that an engine of an automobile is automatically stopped when the vehicle stops at an intersection, thereby improving the fuel economy or the exhaust emission quality. For example, in the Japanese Patent First Publication JP 10-136508A . JP 2001-159 385 A and the JP 2001-165 019 A Idling stop systems proposed with two starters (eg, a gear starter and a belt starter) and operating in such a way to start a machine first using one of the starters and the machine using the other starter to restart after an idle stop.

Typical gear or gear starters used in engine starting systems are provided with a power transmission mechanism formed of a pinion gear and a ring gear meshing with the pinion gear, thereby producing undesirable mechanical noise.

Typical belt starters are subject to mechanical constraints relating to a pulley ratio with difficulty in increasing the pulley ratio. It is thus difficult to provide a large reduction gear ratio unlike the gear or gear starters.

Accordingly, it is advisable that the gear or transmission starter be first turned on by manual operation of an ignition switch for starting the engine, and then that the belt starter be used to restart the engine.

When the machine is activated by the starter, the starting response, i. H. a time interval between turning on the starter and starting the engine (i.e., completing combustion after cranking the engine) is an essential convenience feature for a vehicle driver. Specifically, it is desirable to start the engine quickly. The above publications teach the alternate use of the belt starter when a malfunction of the gear starter occurred when the engine was started, but they are silent about how to detect such a malfunction in connection with the starting response. Thus, it is difficult to start the engine quickly if any malfunctions have been detected, causing discomfort to the driver.

SUMMARY OF THE INVENTION

It is therefore a principal object of the invention to avoid the disadvantages inherent in the prior art.

Another object of the invention is to provide a machine start system which operates to start a machine quickly, even if any malfunctions are detected, without compromising operator comfort.

According to one aspect of the invention, an engine starting system is provided which can be used to start an internal combustion engine for automobiles.

The engine start system includes: (a) a first starter used to start a machine; (b) a second starter used to start the engine instead of the first starter in a case where an engine start malfunction is given, resulting in difficulty in starting or starting the engine by means of the first starter; and (c) an engine start malfunction detector circuit operating in such a manner as to detect a given engine start malfunction as a function of a preselected time factor.

Specifically, when the engine start malfunction is determined to have occurred based on the time factor, the second starter is set to start the engine instead of the first starter. The use of such a time factor results in early detection of engine start malfunction.

In the preferred mode of the invention, the engine start malfunction detector circuit determines that the engine start malfunction has occurred when acceleration of the engine start malfunction detection circuit has occurred Machine measured at the start of the engine does not reach a given target engine acceleration. Usually, the acceleration of the engine is subjected to a change due to the operations of the first starter, an engine power transmission mechanism, the engine, accessories, or the status of the battery carried in the vehicle. Thus, the determination of the engine start malfunction using the engine acceleration enables the detection of any errors of the above-explained elements.

The engine start malfunction detection circuit may include a map that includes different values of the target engine acceleration that may be used as a function of one or more of the outside air temperature, the engine temperature, the first starter temperature, the load of the accessory device driven by the machine and the status of the onboard battery.

The target engine acceleration may alternatively be determined based on an output characteristic of the first starter and the load characteristic at the start of the engine. Specifically, the engine start malfunction is determined depending on a change in the output characteristic of the first starter or the load characteristic at the start of the engine, resulting in increased accuracy of such determination. This also eliminates the need for a plan as described above.

The acceleration of the engine used in determining the engine start malfunction may be determined using the engine speed measured in a given period of time after the first starter has been actuated. In particular, the engine start malfunction is detected without monitoring the acceleration of the engine for a long period of time, which then results in a simplification of the detection.

When the engine start malfunction detection circuit has detected an engine start malfunction, the first starter is made out of order while the second starter is simultaneously set in standby. This saves energy of the battery, especially if a fault of an engine of the first starter results from an electrical leakage condition.

When the engine start malfunction detection circuit detects the engine start malfunction, the second starter can be set in standby after the first starter is set out of order. This is useful in ensuring a required engine starting torque in a case where the first starter is in maintenance but the target engine acceleration is not achieved due to an increased load of the accessory.

Alternatively, if the engine start malfunction detection circuit has detected the engine start malfunction, the first starter may be disabled after the second starter has been readied. This avoids jumping of a pinion gear during a high-speed operation of the engine in a case where the second starter is implemented as a gear or transmission starter and thus constructed so that the pinion gear is engaged with a ring gear connected to the engine is connected to start the machine.

Alternatively, if the engine start malfunction detection circuit has detected an engine start malfunction, the first starter may be disabled, and then, when a rotational speed of the engine decreases below a given value or to zero, the second starter may be readied. This assures engagement of the pinion gear with the ring gear and avoids breakage of or unwanted mechanical impact on the gears.

The system further includes a current limiter operating in such a manner as to lower a starting current flowing through the first starter when it is in standby. If the target engine acceleration is not reached after the engine has been started by the first starter, the current limiter is disabled. Specifically, the use of the current limiter may cause the target machine acceleration not to be achieved. To avoid this problem, and when such an event occurs, the current limiter is disabled. If the current limiter is disabled, but the acceleration of the engine being measured at engine startup does not reach the given target engine acceleration, the second starter may be selected to start the engine instead of the first starter. Specifically, the fact that the target engine acceleration has not been achieved and that does not result from a decrease in the starting current but results from the current limiter, so that the second starter is quickly selected to start the engine may be critical ,

The system may further include a speed sensor configured to measure the speed of the accessories which simultaneously rotates with the speed of the machine at a speed higher than the speed of the machine. The engine start malfunction detection circuit determines the rotational speed of the accessory measured by the rotational speed sensor as acceleration of the engine as used in detecting the engine start malfunction. In a case where the rotational speed sensor has substantially the same resolution as that of typical crankshaft sensors, the possibility is provided to measure the rotational speed of the accessory exactly within a low rotational speed range (eg, 200 rpm or less), which can not be measured with the help of the crankshaft angle sensor. This creates the possibility that the engine start malfunction can be detected early.

When a period of time allowed by a driver from the release of the first starter to the start of the engine is defined as a startup response corresponding to an allowable time ta, a time period required between that in standby of the first one Starter and detecting the engine start malfunction is defined as a required acceleration determination time t, and a time required to start the engine after the second starter has been prepared is referred to as a second starting time tb, with the required Acceleration determination time t is set shorter than the allowable start response time ta minus the second start time tb. Specifically, when the engine is started by the first starter, it is possible to quickly detect the engine start malfunction, thereby ensuring a quick or short start response time, as in the interest of the vehicle driver when the first starter to the second starter is switched.

The system may further include an automatic engine stop and start device operating to stop the engine when a given stop condition is met after the engine is started and then restarting the engine when a given restart condition occurs is satisfied. In a case where after starting the engine by the second starter in response to a manual operation of an ignition key switch, which is performed by a driver, the engine is restarted by the first starter after it has been stopped by the automatic engine stop and start Starting device is stopped, a period of time that is consumed between the manual operation and the start of the engine by the second starter, as a second start time. This creates the possibility that an engine start malfunction is detected as a function of the aging of the vehicle, i. H. Depending on the current state of the machine or due to a change in the time required for the second starter to start the machine.

The automatic engine stop and start device may operate to learn a time interval between the release of a brake pedal of a vehicle by a vehicle driver and depression of an accelerator pedal to restart the engine with the aid of the first starter after an automatic stop of the machine has taken place, and then the allowable start response time ta is determined as a function of the learned time interval. In particular, the allowable start response time is determined in light of the characteristics of the individual vehicle drivers, achieving substantially the same acceleration of the vehicle as that in typical automatic transmission vehicles upon depression of the accelerator pedal.

According to another aspect not covered by the invention, there is provided an engine starting system comprising: (a) a starter equipped with a DC motor and operating in such a manner as to generate a torque for starting a machine; and (b) a A motor control circuit operating in such a manner as to control a field current flowing through a motor winding of the DC motor to switch an output characteristic of the DC motor between a high-speed mode and a high-torque mode. The motor control circuit operates the DC motor in a high-speed mode to start the engine. When acceleration of the engine at engine startup does not reach a given target engine acceleration, the engine control circuit switches the output characteristic of the DC engine from a high speed mode to a high torque mode to start the engine, which then results in a quick start of the engine.

In the preferred mode of operation according to the further aspect not covered by the invention, the DC motor of the starter is implemented by a shunt-wound motor with a shunt winding. The motor control circuit operates to control the field current flowing through the shunt winding to switch the output characteristic of the DC motor between a high-speed mode and the high-torque mode.

The DC motor of the starter may alternatively be implemented by a double-wound motor equipped with a shunt winding and a series winding. The motor control circuit operates to control the field current flowing through the shunt winding to switch the output characteristic of the DC motor between the high-speed mode and the high-torque mode.

The engine control circuit may determine the target engine acceleration by looking up a schedule in which different values of the target engine acceleration as a function of at least one of the outside air temperature, the temperature of the engine, the temperature of the DC motor, the load by an accessory device , which is driven by the machine, and the status of a battery carried in the vehicle are listed.

The target engine acceleration may alternatively be determined by the output characteristic of the DC motor and by a load characteristic at the start of the engine. Specifically, the engine start malfunction is determined depending on a change in the output characteristic of the starter or the load characteristic at the start of the engine, resulting in an increase in accuracy in such a determination. This also eliminates the need for a plan as described above.

When it is necessary to switch between the high-speed mode and the high-torque mode, the motor control circuit may continuously change the output characteristic of the DC motor. This results in a decrease in the mechanical shock or stress generated during the transition between the high speed mode and the high torque mode.

The system may further include a second starter operating in such a manner to start the engine. When the engine control circuit starts the engine via the starter in the high torque mode but the acceleration of the engine does not reach the target engine acceleration, the engine control circuit uses the second starter to start the engine instead of using the other starter.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be more fully understood from the following detailed description and the accompanying drawings of preferred embodiments of the invention, which, however, should not be interpreted as limiting the invention to specific embodiments, but for purposes of illustration and understanding only ,

In the drawings show:

1 a block diagram showing an engine starting system according to a first embodiment of the invention;

2 a flowchart of an engine start program, which by the system of 1 is performed;

3 . 4 . 5 and 6 Schedules illustrating starter and engine speed in different control modes;

7 a diagram showing a circuit construction of a belt starter according to the second embodiment of the invention;

8th FIG. 12 is a diagram illustrating a modified circuit structure of a belt starter according to the second embodiment of the present invention; FIG.

9 and 10 Timetables representing operations of the starters and the number of revolutions of a machine in the second embodiment;

11 FIG. 10 is a graph illustrating a variation in rotational speed of a machine in the engine starting control of the third embodiment of the invention; FIG.

12 an explanatory view showing how a required acceleration determination time is determined;

13 a block diagram showing an engine starting system according to a fourth, not falling under the invention embodiment;

14 a circuit diagram of the engine start system of the fourth embodiment;

15 a graph illustrating a relationship between the torque of a crankshaft of an engine and the rotational speed of the crankshaft in terms of the output characteristics of a starter;

16 a flowchart of an engine start program, which by the engine start system of 14 is performed;

17 a time chart illustrating an operation of a starter and the rotational speed of a machine in the fourth embodiment;

18 a block diagram illustrating an engine start system according to a fifth not falling under the invention embodiment;

19 a flowchart of an engine start program, which is executed by an engine start system according to a sixth, not falling under the invention embodiment; and

20 a flowchart of an engine start program, which is executed by a machine starting system according to a seventh, not falling under the invention embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, wherein like reference numerals designate like parts throughout the several views, and more particularly 1 an engine starting system according to the first embodiment of the invention shown, which with two starters 4 and 5 equipped with an engine ECU (electronic control unit) 2 operating in such a way to operate an internal combustion engine 1 to control, and with an idle-stop ECU 3 , which works in such a way to start and restart the machine 1 to control automatically.

The ignition 4 consists of a belt-driven type and is used when starting the machine 1 used in a usual condition. The ignition 5 is of a gear drive type and is used when starting the machine 1 used at low ambient temperatures or if any malfunctions (for example, a failure of the belt starter 4 , a malfunction of the machine 1 or a wear of the belt have occurred) have taken place. Each of the starters 4 and 5 may also operate as a generator motor, which then generates electricity and supplies electricity to an on-vehicle battery (not shown).

The belt starter 4 has a pulley 6 which is mounted on an output shaft thereof and which is provided with a crankshaft pulley 7 the machine 1 over a belt 8th is coupled and operates in such a way to output torque to the crankshaft pulley 7 to start the machine 1 transferred to.

additional equipment 9 such as an alternator, an air conditioning compressor and a water pump are around the machine 1 installed around and these are mechanically through the machine 1 over the belt 8th driven.

The gear-starter 5 includes a small gear (not shown) which meshes with a ring gear (not shown) attached to the machine 1 is installed and has a typical mechanical construction, which is well known as an engine starting device for automobiles. An explanation thereof in detail will therefore be omitted here.

The engine ECU 2 receives sensor outputs indicative of intake air amount, engine speed, and engine coolant temperature, etc., to determine the amount of fuel that must be injected to provide optimum air-fuel ratio, and also determines a suitable spark timing as a function of engine speed and the load for electronically controllable electronic fuel injectors 10 (Only one is shown for the sake of brevity).

The engine ECU 2 is also connected to sensors to indicate an operating condition or operating condition of the machine 1 and also acquires information (eg, vehicle speed, angular position of the engine) 1 , Accelerator pedal position, engine coolant temperature 1 , battery condition and ambient temperature) used to control the machine 1 required are.

The idling stop ECU 3 operates in such a manner as to perform idle-stop control, as will be described below, and if there is some difficulty in starting the engine 1 using the belt starter 4 occurs, this switches the belt starter 4 on the gear wheel starter 5 to the machine 1 to start.

The idle stop control is used to power the machine 1 stop automatically when the vehicle stops at an intersection and around the machine 1 to restart following, if given starting conditions are met. More specifically, when the engine stop conditions occur, the idle stop ECU indicates 3 Machine stop signals (ie, a fuel cut signal and an ignition cut signal) to the engine ECU 2 , When engine start conditions occur, the idle stop ECU indicates 3 Machine start signals to the engine ECU 2 off (a fuel injection and an ignition signal).

The starter control provided by the engine starting system of this embodiment for starting the engine 1 will be executed, now described below with reference to a control program which in 2 is illustrated.

After entering the program, the routine goes to the step 10 in which the engine ECU 2 determines whether a start signal has been issued and this has been detected or not. The start signal is supplied by an ON signal from an ignition key switch or in the form of a restart signal, which is output to the idling stop control means. If the answer is YES, meaning that the start signal has been issued, the routine proceeds to the step 20 in which the idle stop ECU 3 the belt starter 4 turns.

The routine then proceeds to the step 30 in which the acceleration of the machine 1 is determined. This determination can be achieved by differentiating an output of a speed sensor (not shown), which then indicates the acceleration of one of the devices such as the crankshaft, the drive shaft, a wheel, and a transmission.

The routine then proceeds to the step 40 in which, based on in the step 30 derived acceleration of the machine 1 It is determined whether or not an engine start malfunction has occurred, causing a problem in starting the engine 1 using the belt starter 4 leads,. In particular, it is determined whether an engine acceleration a 'at the start of the engine 1 , as in 3 is shown, has reached a target engine acceleration a or not. The engine acceleration a 'may be a function of the speed of the engine 1 which is continuously monitored after the belt starter 4 has been turned on or immediately after a preselected period of time after the belt starter 4 was turned on.

If at the step 40 the answer is YES, which means that an engine start malfunction has occurred, that is, that the engine acceleration a 'has not yet reached the target engine acceleration a, the routine proceeds to the step 50 in which the belt starter 4 on the gear wheel starter 5 is switched.

• 1. Der Riemenanlasser 4 wird ausgeschaltet und zur gleichen Zeit wird der Zahnradanlasser 5 eingeschaltet (siehe 3).
• 2. Der Zahnradanlasser 5 wird eingeschaltet, bevor der Riemenanlasser 4 ausgeschaltet wird (siehe 4).
• 3. Der Zahnradanlasser 5 wird eine vorgewählte Zeitperiode eingeschaltet, nachdem der Riemenanlasser 4 ausgeschaltet wurde (siehe 5).
• 4. Der Zahnradanlasser 5 wird eingeschaltet, wenn die Maschinendrehzahl unter einem gegebenen Wert oder auf Null (0) abfällt, nachdem der Riemenanlasser 4 ausgeschaltet worden ist (siehe 6).

At the step 50 can the idle stop ECU 3 Determine times when the belt starter 4 should be turned off and when the geared starter 5 should be switched on and in four different modes, as they are given below.

• 1. The belt starter 4 is turned off and at the same time the gear start 5 switched on (see 3 ).
• 2. The cogwheel starter 5 is switched on before the belt starter 4 is switched off (see 4 ).
• 3. The cogwheel starter 5 is switched on a preselected period of time after the belt starter 4 was turned off (see 5 ).
• 4. The cogwheel starter 5 is turned on when the engine speed drops below a given value or to zero (0) after the belt starter 4 has been turned off (see 6 ).

As apparent from the above explanation, the engine starting system of this embodiment is designed so that the gear start 5 to start the machine 1 is used in a quick way if any error or failure when starting the machine 1 with the help of the belt starter 4 is observed. Specifically, the engine startup system operates to monitor the occurrence of engine startup malfunction as a function of a time factor (ie, based on engine acceleration a 'at engine startup) 1 ), thereby enabling early determination of the engine start malfunction. This represents a startup response of the machine 1 without compromise in connection with the comfort for the vehicle driver safe.

The four different modes of operation described above pertain to the times when the belt starter 4 should be turned off and when the geared starter 5 should be turned on, provide the following effects.

When the belt starter 4 has a malfunction (ie, if a fault of an engine of the starter 4 is present, which results from the occurrence of an electrical leakage current) can be carried out the first mode in which the belt starter 4 is turned off and the geared starter 5 is turned on at the same time, whereby energy of the battery is saved. If no errors in the operation of the belt starter 4 but an increasing burden on the accessories 9 causes the engine acceleration a does not reach the target engine acceleration a, the second mode, in which the gear start 5 is switched on before the belt starter 4 is switched off, ie at both the starter 4 as well as 5 be kept turned on for a predetermined period of time, whereby a required engine starting torque is ensured.

The third mode in which the gear start 5 is turned on and that according to a preselected time period after the belt starter 4 has been turned off, is effective in avoiding a jump of the small gear of the starter 5 during the rotation of the machine 1 (especially at high-speed rotation), thereby avoiding breakage of the gear and a larger physical impact on the starter 5 is kept minimal.

The fourth mode in which the gear start 5 is turned on when the engine speed falls below a given value or drops to zero (0) after the belt starter 4 has been turned off, is similar to the third mode for avoiding jumping of the starter's small gear 5 effective during the rotation of the machine 1 (especially a high-speed rotation).

The engine ECU 2 or the idle stop ECU 3 may include an engine acceleration schedule to determine the target engine acceleration a as a function of one or more of the parameters, such as the ambient temperature, the temperature of the engine 1 , the temperature of the belt starter 4 , the load through the accessories 9 and the status of the battery. The use of such a plan minimizes adverse effects of these parameters on the machine acceleration a 'when starting the machine 1 whereby the accuracy of the determination of the engine start malfunction is increased.

The target engine acceleration a may be a function of the output characteristics of the belt starter 4 and the load characteristics at the start of the machine 1 be determined, whereby the accuracy of the determination of the engine start malfunction is increased. The output characteristics of the belt starter 4 can be based on the temperature of the belt starter 4 and the status of the battery. The load characteristics at the start of the machine 1 can be based on the temperature of the machine 1 and the load and inertia load associated with the accessories 9 to be obtained.

The speed sensor used in determining the engine acceleration a 'may be implemented as a typical crank angle sensor or as a speed sensor designed to increase the speed of the belt starter 4 to measure or the speed of one of the accessories 9 (eg from an alternator or a water pump) that is mechanically connected to the machine 1 are connected and synchronous with the rotation of the machine 1 at a higher speed than the speed of the machine 1 be rotated through a pulley, which operates in such a way to increase the speed of the machine. Specifically, an output of the crank angle sensor or the speed sensor becomes the acceleration amount of the engine 1 used in starting them to determine the occurrence of the engine start malfunction. If the speed sensor has substantially the same rotation as that of the typical crank angle sensor, the possibility is created that the speed of the accessory device 9 can be measured accurately within a low speed range (eg, 200 rpm or less), which can not be measured by the crank angle sensor. This creates the possibility that an engine start malfunction can be detected early.

The 7 and 8th show circuit constructions of the belt starter 4 according to a second embodiment of the invention, each of which with a current limiter 11 equipped.

When the belt starter 4 the current limiter 11 This results in a reduction of the starting current caused by the belt starter 4 flows, so that from the engine of the belt starter 4 produced energy is lowered, which may lead to the target engine acceleration a not at the start of the machine 1 is reached. To avoid this problem, so if the machine acceleration a 'at the start of the machine 1 does not reach the target engine acceleration a, the engine starting system of this embodiment operates in such a way as to the current limiter 11 to turn off, thereby the starting current of the belt starter 4 to increase. However, if the target engine acceleration a is still not reached, the engine start system operates in such a manner that the belt starter 4 on the gear wheel starter 5 is switched.

The on-off control of the current limiter 11 is using relay switches 12 and 13 in the constructions of 7 and 8th each achieved.

If in the construction of 7 the relay switch 12 is turned off, it is caused by the fact that the current limiter 11 which consists of a resistor is turned on. Alternatively, the relay switch 12 is turned on, this has the consequence that the current limiter 11 is turned off.

If in the construction of 8th the relay switch 13 is placed in a first position, as indicated by a solid line in the drawing, causes the current limiter 11 which consists of a winding parallel to the field winding 14 is switched so that the current limiter 11 is turned on. Alternatively, the relay switch 13 is placed in a second position, as indicated by a broken line, this causes the field winding 14 the current limiter 11 bypasses, so that the current limiter 11 is turned off.

When in operation the activity of the current limiter 11 to a decrease in the starting current of the starter 4 leads, so that the machine acceleration a 'when starting the machine 1 does not reach the target engine acceleration a, the engine start system operates in such a way that the current limiter 11 is turned off, as in 9 is shown to bring the engine acceleration a 'in accordance with the target engine acceleration a.

When the current limiter 11 is off, but the target engine acceleration a is still not reached, the engine start system operates in such a way that the transmission or Zahnradanlasser 5 as shown in 10 to start the machine 1 instead of the belt starter 4 is used.

The engine starting system of the third embodiment will be described below with reference to FIG 11 described.

11 shows a variation in the speed of the machine 11 , The engine starting system of this embodiment is configured to set a time interval between when the belt starter is turned on 4 and detecting an engine start malfunction, which will also be referred to as a required acceleration determination time t in the following.

The required acceleration determination time t is determined as a function of an allowable start response time ta and a second start time tb, as in FIG 12 is shown. The allowable start response time ta is a time typically a vehicle driver turns on the belt starter 4 until the machine starts 1 is allowed. The second start time tb is a time to start the machine 1 after switching on the gear starter 5 is required. The required acceleration determination time t is smaller than the allowable start response time ta minus the second start time tb (t <ta-tb).

In a case where some engine start malfunction occurs and the machine is required 1 using the geared starter 5 instead of the belt starter 4 To start, the engine start system of this embodiment operates in such a way that the machine 1 is started within the allowable start response time ta permitted by the vehicle driver. More specifically, if required, the machine 1 using the belt starter 4 To start, the engine start system sets the required acceleration determination time t in the manner explained above, resulting in a quick determination of the engine start malfunction. This ensures a fast engine starting response when the belt starter 4 on the gear wheel starter 5 is switched.

The engine start system may alternatively be configured to measure the time that elapses between the engagement of the geared starter 5 and the response to manual override of an ignition key switch is spent (eg, an ignition switch) and to start the engine 1 is required, in which case this measured time is used as the second start time tb and is also used in determining the required acceleration determination time t. Specifically, when the vehicle driver gets on the vehicle and the machine 1 starts, first becomes the gear wheel starter 5 preferably used, since the gear starter 5 has a higher reliability in torque transmission than the belt starter 4 , Thus, the time actually spent by the cogwheel 5 to start the machine 1 is required, from the manual operation of the ignition key switch, to be determined as the second start time tb, thus providing the opportunity to determine the required acceleration determining time t as a function of the aging of the vehicle, ie as a change in the state of the engine 1 or the machine start time.

The engine start system may also be designed to provide a time interval between the release of a brake pedal by the vehicle driver and depression of the accelerator pedal to restart the engine 1 over the belt starter 4 after an automatic stop of the machine 1 learns and the allowable start response time ta determined as a function of the learned time interval. Specifically, the allowable start response time ta is determined based on the characteristics of individual vehicle drivers, achieving substantially the same acceleration of the vehicle as that of typical automatic transmission vehicles after depressing the accelerator pedal. The engine start system of this embodiment may also be used in conjunction with automobiles designed to not stop the idling of the engine. The engine start system can be designed to be the geared starter 5 preferred over the belt starter 4 to use.

In addition, the engine start system can be used on automobiles that are designed for this purpose are designed to start the machine by a generator motor.

Furthermore, the engine starting system may be used on automobiles that have two belt starters 4 or two geared starters 5 to start the machine.

13 shows an engine start system according to a fourth. Not covered by the invention embodiment.

The engine start system includes a machine starter 15 , a machine ECU 2 which works in such a way to the operation of the machine 1 to control, and a start-up control ECU 16 , which works in such a way to the output characteristics of the starter 15 to control. The engine ECU 2 and the accessories 9 are identical to those in the first embodiment, and an explanation thereof in detail will therefore be omitted here.

The ignition 15 is implemented as a gear-type starter with a shunt-wound DC motor, which transmits an output torque of the shunt-wound motor to a ring gear via a pinion gear to the machine 1 boost.

The shunt-wound engine of the starter 15 contains an anchor 7 provided with an armature winding (not shown) and a shunt winding 19 equipped with a driver circuit 18 are connected. The shunt-wound motor gets power from the battery in the vehicle 23 via a starter relay 21 and a solenoid switch 22 supplied in response to turning on an ignition key switch 20 (ie a switching position ST).

The driver circuit 18 consists of four controlled elements 24 such as MOSFETs, which are connected in the form of a bridge and with an input terminal 18a at a positive connection of the battery carried in the vehicle 23 over the solenoid switch 22 is connected and at an input terminal 18b connected to ground or earth.

The start-up control ECU 16 works in such a way that a field current through the shunt winding 18 flows through the driver circuit 18 is controlled. Specifically, the startup control ECU controls 16 the amount of electricity passing through the shunt winding 19 flows as a function of a duty cycle of a signal which is applied to each of the controlled elements 24 the driver circuit 18 is created. This causes, as in 15 it is shown that the starter 15 rotating at a high speed, which increases as the field current decreases, and generates a high torque, which increases as the field current increases.

16 Fig. 10 is a flowchart of a program or a sequence of logical steps executed by the engine starting system of the fourth embodiment.

After entering the program, the routine proceeds to the step 100 in which a machine start command signal is provided or not. This provision is made in the engine ECU 2 by monitoring a turn-on signal issued by the key switch 20 is output, which is operated by a vehicle driver by hand.

If the answer is received YES, which means that the machine 1 had to be restarted, the routine goes to the step 120 in which it is determined whether or not the engine temperature Tw (eg, the temperature of engine coolant) is within a given range (x <Tw <y). If the answer is YES, the routine goes to the step 130 , The determination at the step 120 may alternatively be performed using the ambient temperature (ie, the outside air temperature) or based on the temperature of the starter 15 (ie the DC motor). It should be noted that the lower and upper limits x and y of the temperature range can be set, for example, to -10 ° C and + 100 ° C, respectively. These values depend on the type of machine 1 from. When the engine temperature Tw falls outside the range of -10 ° C to + 100 ° C, the starting torque is greatly increased.

At the step 130 controls the start control ECU 16 as described above, the starter 15 to start at a high speed when starting the machine 1 to turn. Specifically, the starting control ECU reduces 16 the field current or brings this to zero, passing through the shunt winding 19 of the starter 15 via the driver circuit 18 flows.

The routine then proceeds to the step 140 in which the acceleration of the machine 1 is determined. This determination can be accomplished by differentiating an output of a speed sensor (not shown), which then indicates the speed of one of the variables such as crankshaft, drive shaft, a wheel, and a transmission.

The routine then proceeds to the step 150 in which it is determined whether or not an engine start malfunction has occurred based on the Acceleration of the machine 1 as she did at the step 130 was derived. More specifically, it is determined whether the engine acceleration a 'at the start of the engine 1 like this in 17 (b) is shown, the target machine acceleration a has reached or not. If the answer is NO, meaning that no malfunction has occurred, the routine is ended.

Alternatively, if the answer is YES, the routine proceeds to the step 160 , The machine acceleration a 'may be a function of the speed of the machine 1 which is continuously monitored after the starter 15 has been turned on, or is currently being monitored for a preselected period of time after the starter 15 has been turned on.

At the step 160 controls the start control ECU 16 as described above, the starter 15 to, as in 17 (a) shown is a higher torque to start the machine 1 to create. Specifically, the startup control ECU increases 16 the field current passing through the shunt winding 19 of the starter 15 via the driver circuit 18 flows. To avoid a physical shock resulting from a sudden change in the output characteristics of the starter 15 results, the start control ECU 16 increase the duty cycle of the signal applied to each of the controlled elements 24 the driver circuit 18 is applied, and in a gradual form, thereby the output characteristics of the starter 15 continuously change from the high-speed mode to the high-torque mode.

As apparent from the above explanation, the engine starting system of the present embodiment operates in such a manner as to produce a high-speed mode in which the starter 15 rotating at high speed to the machine 1 to start at a high speed when the temperature of the machine 1 within or within the given range, thereby reducing exhaust emissions from the engine 1 is reduced.

When the temperature of the machine 1 Outside the given range, this leads to an increase in torque, which is used to start the machine 1 is required. This is the case because then when the machine 1 is cold, the viscosity of the engine oil increases, resulting in an increase in the engine starting torque, but then when the engine 1 is warm, a certain extent of airtightness of the cylinder of the machine 1 is increased, resulting in an increase in the engine starting torque. Therefore, the engine start system switches the output characteristic or output characteristic of the starter 15 from the high speed mode to the high torque mode to the engine 1 to start quickly when the temperature of the machine 1 outside the given range.

When the temperature of the machine 1 is actually outside the given range, but at the step 120 an erroneous determination is made that this temperature is within the given range in the event of failure of the engine temperature sensor, for example, this may lead to difficulty in starting the engine 1 because the engine starting torque is increased due to the cause described above. To avoid this problem, when the engine acceleration a 'does not reach the target engine acceleration a in a case where the output characteristic of the starter 15 to the high-speed mode to start the machine 1 The engine starting system may make the conclusion that it is difficult to machine 1 to start and then can the starting property of the starter 15 Change to the high torque mode to start the machine quickly 1 to reach.

18 shows an engine starting system according to a fifth non-inventive embodiment, which differs from the fourth embodiment in the construction of the direct current motor of the starter 15 different.

The DC motor is implemented by a double-wound motor, which consists of a series winding 25 which is in series with an anchor 17 is switched, and from a shunt winding 19 that exists with a driver circuit 18 connected is.

The start-up control ECU 16 works in such a way to control the size and direction of the current passing through the shunt winding 19 flows as a function of a duty cycle of a signal which is applied to each of the controlled elements 24 the driver circuit 18 is created. The other arrangements and operation are the same as those in the fourth embodiment, and a detailed explanation thereof will be omitted here.

An engine starting system according to the sixth embodiment will now be described below which is adapted to the engine 1 to restart after an automatic idle stop of the machine 1 has occurred when the vehicle stops at an intersection, for example.

The engine starting system of this embodiment is a modification of the fourth or fourth embodiment the fifth embodiment in which the idle-stop ECU, which operates in such a way to the machine 1 to stop and restart automatically instead of the ECU 16 is used. The other arrangements are identical with those of the fourth or fifth embodiment, and a detailed explanation thereof will be omitted here.

19 FIG. 10 is a flowchart of a program executed by the engine starting system of the sixth embodiment. FIG.

After entering the program, the routine goes to the step 210 in which it is determined whether or not a start request signal has been generated. The start request signal is generated either when the key switch 20 , as in 14 shown is turned on to the machine 1 to start first, or if necessary, the machine 1 start again after the machine 1 has been stopped under the automatic idle stop control.

If the answer is YES, the routine goes to the step 220 in which it is determined whether or not the start request signal indicates a start request for economical driving (ie, a restart request under the automatic idle stop control). If the answer is YES, meaning that a request for an economical driving has been made, the routine proceeds to the step 230 , Alternatively, if the answer NO is obtained, which means that the start request has not been made in response to turning on the key switch 20 , the routine proceeds to the step 260 ,

At the step 230 becomes the starter 15 in the high-speed mode for starting the engine 1 actuated. The routine then proceeds to the step 240 in which the acceleration of the machine 1 is determined in the same way as described above. The routine then proceeds to the step 250 in which it is determined whether or not an engine start malfunction has occurred based on the acceleration of the engine 1 like this at the step 240 was derived in the same way as described above.

If a NO answer is obtained, meaning that no malfunction has occurred, the routine is ended. Alternatively, if the answer is YES, the routine proceeds to the step 260 in which the output characteristic of the starter 15 to the high torque mode for starting the engine 1 is switched. To avoid a physical shock due to a sudden change in the output characteristics of the starter 15 results, the idle stop control ECU 16 increase the duty cycle of the signal applied to each of the controlled elements 24 the driver circuit 18 is applied in a gradual manner to the output characteristics of the starter 15 continuously changing from the high-speed mode to the high-torque mode.

Specifically, if necessary, the machine 1 to start again, and indeed in the start mode according to an economical driving style, the machine became 1 already warmed up, which means that the engine starting torque is lower. The ECU 16 thus switches the output characteristic or output characteristic of the starter 15 to the high-speed mode, which then leads to a quick start of the machine and without compromise in terms of comfort for the vehicle driver.

If necessary, the machine 1 in response to turning on the key switch 20 to start, is the machine 1 still cold, which means that the engine starting torque is higher. The ECU 16 thus actuates the starter 15 in the high torque mode, around the engine 1 to start, thereby ensuring a stability of the starting process of the machine 1 is ensured.

If the ECU 16 the output characteristics of the starter 15 has switched to the high-speed mode in the starting mode according to an economical driving manner, but the engine acceleration a 'has not yet reached the target engine acceleration a, pulls the ECU 16 the conclusion that it is difficult, the machine 1 normal start and then switches the output characteristics of the starter 15 from the high speed mode to the high torque mode. This then allows a quick start of the machine 1 ,

An engine starting system according to a seventh embodiment not falling under the invention will now be described below, which is a modified embodiment of the fourth and fifth embodiments, and with a second starter (not shown) in addition to the starter 15 equipped.

20 FIG. 10 is a flowchart of a program executed by the engine starting system of the seventh embodiment. FIG.

The steps 310 to 360 are identical to the steps 210 to 260 in the sixth embodiment, as in 19 is illustrated, and a detailed explanation thereof is therefore omitted here.

After the step 360 The routine goes to the step 370 in which the acceleration of the machine 1 is determined again. The routine then proceeds to the step 380 in which it is determined whether or not an engine start malfunction has occurred based on the acceleration of the engine 1 as she did at the step 370 was derived. If a NO answer is obtained, meaning that no malfunction has occurred, the routine is ended. Alternatively, if the answer is YES, the routine proceeds to the step 390 in which the ECU 16 the starter 15 puts out of readiness and puts the second starter in readiness to the machine 1 to start.

More specifically, if it is difficult the machine over the starter 15 In the starting mode according to an economical driving style, the engine starting system operates in such a manner that a change from the starter 15 on the second starter to start the machine 1 is made. When the starter 15 to start the machine 1 is used, the system monitors the acceleration of the machine 1 to determine if it is possible the machine 1 to start normally or not, thereby enabling early detection of engine start malfunction. This creates the possibility that the machine 1 is started quickly by the second starter in a case where there is an engine start malfunction, thereby ensuring a quick engine starting response without compromising the comfort of the vehicle driver.

The engine ECU 2 and the startup control ECU 16 (Also functioning as idle-stop ECU) in each of the fourth to sixth embodiments may include an engine acceleration schedule listing different values of the target engine acceleration a determined as a function of one or a combination of some parameters such as For example, the outside air temperature, the temperature of the engine, the temperature of the starter 16 , the load through the accessory device 9 and the status of the battery (ie, available energy). The use of such a plan minimizes adverse effects of the above parameters on the machine acceleration a when starting the machine 1 whereby the accuracy of the determination of the engine start malfunction is increased.

The target engine acceleration a may be a function of the output characteristics of the starter 15 and the load characteristics at the start of the machine 1 be determined, whereby the accuracy of the determination of the engine start malfunction is increased. The output characteristics of the starter 15 can be based on the temperature of the starter 15 and the status of the battery. The load characteristics at the start of the machine 1 can be based on the temperature of the machine 1 and the load and the inertia load of the accessories 9 to be obtained.

The speed sensor used in determining the engine acceleration a 'may be implemented by a typical crank angle sensor or a sensor designed to increase the speed of the starter 15 to measure, or may by one of the ancillary equipment 9 be implemented (for example, an alternator or a water pump), which mechanically to the machine 1 is connected and synchronous with the rotation of the machine 1 rotating at a higher speed than the speed of the machine 1 , If the sensor has substantially the same resolution as that of a typical crank angle sensor, this allows the speed of the accessory 9 can be accurately measured within a low speed range (eg, 200 rpm or less) that can not be measured by the crank angle sensor. This creates the possibility that an engine start malfunction can be detected early.

Although the present invention has been disclosed in connection with preferred embodiments in order to facilitate a better understanding thereof, it should be understood that the invention can be embodied in various ways without departing from the principle of the invention. The invention is therefore to be understood to include all possible embodiments and modifications in addition to the illustrated embodiments, which may be practiced without departing from the principle of the invention as set forth in the appended claims.

Claims (13)

Machine start system, comprising: a first starter ( 4 ), which is used to start a machine ( 1 ) is working; a second starter ( 5 ), which is used to start the machine ( 1 ) instead of the first starter ( 4 ) is used for a case that there is a given engine start malfunction resulting in a difficulty in starting the engine ( 1 ) by the first starter ( 4 ) leads; and a detector circuit ( 2 ) for an engine start malfunction that determines that the engine start malfunction has occurred when acceleration of the engine ( 1 ) when starting the machine ( 1 ) is not reached a given target machine acceleration, and wherein the detector circuit ( 2 ) for the engine start malfunction has a list in which different values of the target engine Engine speed listed as a function of one of the sizes or some of the quantities according to an outside air temperature, temperature of the engine, temperature of the first starter ( 4 ), a load due to accessories, which by the machine ( 1 ) and a status of a battery is determined. Machine start system, comprising: a first starter ( 4 ), which is used to start a machine ( 1 ) is working; a second starter ( 5 ), which is used to start the machine ( 1 ) instead of the first starter ( 4 ) is used for a case that there is a given engine start malfunction resulting in a difficulty in starting the engine ( 1 ) by the first starter ( 4 ) leads; and a detector circuit ( 2 ) for an engine start malfunction that determines that the engine start malfunction has occurred when acceleration of the engine ( 1 ) when starting the machine ( 1 is not reached a given target engine acceleration, and wherein the target engine acceleration based on an output characteristic of the first starter ( 4 ) and on a load characteristic at the start of the machine ( 1 ) is determinable. A machine starting system according to claim 1 or 2, wherein the acceleration of the machine ( 1 ) used in determining the engine start malfunction using a rotational speed of the engine ( 1 ) is measured, measured a given period of time after the actuation of the first starter ( 4 ). An engine start system according to any one of claims 1 to 3, wherein when the detector circuit ( 2 ) has detected a machine start malfunction for the engine start malfunction, the first starter ( 4 ), but the second starter ( 5 ) is prepared. An engine start system according to any one of claims 1 to 3, wherein when the detector circuit ( 2 ) has detected the engine start malfunction for the engine start malfunction, the second starter ( 5 ) is set in readiness after the first starter ( 4 ) has been set out of readiness. An engine start system according to any one of claims 1 to 3, wherein when the detector circuit ( 2 ) has detected a machine start malfunction for the engine start malfunction, the first starter ( 4 ) is put out of readiness after the second starter ( 5 ) is prepared. An engine start system according to claim 6, wherein when the detector circuit ( 2 ) the machine start malfunction has detected a machine start malfunction, the first starter ( 4 out of readiness, whereupon when a speed of the machine ( 1 ) falls below a given value or drops to zero, the second starter ( 5 ) is prepared. An engine start system according to any one of claims 1 to 7, further comprising a current limiter ( 11 ) operating in such a way as to reduce a starting current generated by the first starter ( 4 ) when it is in standby, and in which, when the target engine acceleration is not reached, after the engine ( 1 ) by the first starter ( 4 ), the current limiter ( 11 ) is set out of readiness. An engine start system according to claim 8, wherein when the current limiter ( 11 ), but the acceleration of the machine ( 1 ) when starting the machine ( 1 ), does not reach the given target engine acceleration, the second starter ( 5 ) instead of the first starter ( 4 ) to start the machine ( 1 ) is selected. An engine start system according to any one of claims 1 to 8, further comprising a speed sensor configured to adjust a speed of an accessory ( 9 ), which coincide with the speed of the machine ( 1 ) rotates at a speed higher than the speed of the machine ( 1 ), wherein the detector circuit ( 2 ) for the engine start malfunction the speed of the accessory device ( 9 ), measured by the speed sensor, to determine the acceleration of the machine ( 1 ) for use in detecting the engine start malfunction. An engine start system according to any one of claims 1 to 10, wherein, when a time period permitted by a driver, from the time the first starter is in standby mode ( 4 ) until the date on which the machine ( 1 ) is defined as an allowable start response time ta, a time that is intermediate between that in standby of the first starter ( 4 ) and detecting the engine start malfunction is defined as a required acceleration determination time t and a time necessary for starting the engine ( 1 ) is required after the second starter ( 5 ) is set to stand-by as defined as a second start time tb, the required acceleration determination time t being set shorter than the allowable start response time ta minus the second start time tb. An engine start system according to claim 11, further comprising an automatic engine stop and start device (10). 3 ), which works in such a way that she the machine ( 1 ) stops when a given stop condition is met after starting the engine ( 1 ), and which the machine ( 1 ) starts again when a given restart condition is satisfied, and in a case where after starting the engine (FIG. 1 ) by the second starter ( 5 ) in response to a manual operation of a key switch ( 20 ), which is done by a driver, the machine ( 1 ) by the first starter ( 4 ) is started again after being triggered by the automatic machine stop and start device ( 3 ), wherein a time period between the manual operation and the start of the machine ( 1 ) by the second starter ( 5 ) is consumed or needed is used as the second start time tb. An engine start system according to claim 11, further comprising an automatic engine stop and start device (10). 3 ), which works in such a way to the machine ( 1 ) when a given stop condition is met after the machine ( 1 ) and which the machine ( 1 ) starts again when a given restart condition is met with the automatic engine stop and start device ( 3 ) operates in such a way to a time interval between the release of a brake pedal of a vehicle by the vehicle driver and the depression of an accelerator pedal to restart the machine ( 1 ) by the first starter ( 4 ), after an automatic stop of the machine ( 1 ) and determining the allowable start response time ta as a function of the learned time interval.

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