JP2002118959A - Start system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a start system of a vehicle, capable of flowing current- carrying request current needed for a start permit switch connected in series with a coil of a starter relay, preventing unnecessary ON of the starter relay by leak current from an electronic controller, and promptly detecting that a starter motor shifts from an active state to an inactive state by the electronic controller. SOLUTION: The switch 7, which turns on when a shift position of an AT is in 'N' or 'P', is disposed downstream the coil L of the starter relay 5, a signal wire 19 extending from the path between the coil L and the switch 7, which is defined as a signal input line S-NSW and a power line 11 connected to a battery 9 via a starter switch STASW which is defined as a signal input line S-STA are connected to an ECU 15 respectively. The ECU 15 decides that switch 7 is at on state, when the S-NSW is low, and the starter motor 3 is active, when the S-STA is high and the S-NSW is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting system for an automobile, and more particularly to a starting system in which a start permitting switch is arranged in series with a coil of a starter relay for operating a starter motor for starting an engine. Things.

[0002]

2. Description of the Related Art Conventionally, in an automobile equipped with an automatic transmission (AT: automatic transmission) (so-called AT car), even if a starter switch for operating a starter motor for starting an engine is turned on, the automatic transmission is turned on. Shift position is neutral position (N range)
And parking position (P range)
A start-up system that prevents the starter motor from operating is employed.

Here, such a conventional starting system for an AT car will be specifically described with reference to FIG. First,
As shown in FIG. 6A, the starting system of the AT vehicle includes a starter relay 5 that operates the starter motor 3 by short-circuiting the contact point J when the coil L is energized. A neutral start switch 7 that is turned on only when the switch is in one of the neutral position and the parking position is provided.

In the conventional starting system, the neutral start switch 7 and the starter relay 5 are used.
Is connected to a positive terminal of the battery 9 via a starter switch STASW (hereinafter, referred to as a power line).
A neutral start switch 7 is connected in series between a starter system power supply line 11 and a ground potential line (hereinafter referred to as a ground line) 13 connected to the negative terminal of the battery 9 so that the neutral start switch 7 is on the upstream side. It is connected.

In the conventional starting system, the starter system power supply line 11 is used as a signal input line S-NSW for monitoring the on / off state of the neutral start switch 7, and an electronic control unit for controlling the engine ( The signal line 1 is connected to an energizing path 17 between the coil L of the starter relay 5 and the neutral start switch 7.
The ECU 15 serves as a signal input line S-STA for monitoring the operation / non-operation of the starter motor 3.
It is connected to the.

Further, inside the ECU 15,
The signal input line S-NSW is connected to a voltage VIG corresponding to a high level via a pull-up resistor 21, and the signal input line S-STA is connected to a pull-down resistor 23.
Connected to the ground line. And E
In the CU 15, the voltage level of the signal input line S-NSW and the voltage level of the signal input line S-STA are
Each is converted into a binary signal from 0 V to about 5 V by an input circuit (not shown), and each of the binary signals is
15 (hereinafter referred to as a CPU).
25).

The voltage VIG is determined by an ignition switch I of an automobile (vehicle) equipped with the starting system.
A power supply line (hereinafter referred to as an ignition power supply line) 2 connected to the plus terminal of the battery 9 via the GSW
7 is the battery voltage (the voltage at the plus terminal of the battery 9) supplied to the ECU 15 via the. The voltage VIG is also a power source for operating the ECU 15.

In a general vehicle, a starter switch STASW is connected to an ignition key switch 29.
Among the plurality of contact terminals provided in the first embodiment, when the common contact terminal CM constantly connected to the plus terminal of the battery 9 and its ignition key switch 29 are operated to the engine start position (so-called START position) ( In other words, it is a switch portion including a contact terminal ST connected to the common contact terminal CM when the vehicle key inserted into the ignition key cylinder is being twisted to the engine start position). Similarly, the ignition switch IGSW is the common contact terminal C among the plurality of contact terminals provided on the ignition key switch 29.
M and when the ignition key switch 29 is operated to an ignition-on position (so-called IG / ON position) and an engine start position (in other words, the vehicle key inserted into the ignition key cylinder is moved to the ignition-on position and And a contact terminal IG that is connected to the common contact terminal CM when the engine is twisted to the engine start position).

On the other hand, the starter motor 3 has a clutch power supply terminal 3a connected to the plus terminal of the battery 9 via the contact J of the starter relay 5, and a motor power supply terminal always connected to the plus terminal of the battery 9. Terminal 3b;
A ground terminal 3c which is always connected to the ground line, and when a battery voltage is supplied to the clutch power supply terminal 3a via the contact J of the starter relay 5,
The electromagnetic clutch in the starter motor 3 operates to supply the battery voltage from the motor power supply terminal 3b to the internal motor winding, thereby rotating and cranking the engine.

In the example shown in FIG. 6A, the opposite side of the contact J of the starter relay 5 from the starter motor 3 is always connected to the positive terminal of the battery 9 via the fuse 31. Furthermore, the ignition key switch 29
The above-mentioned common contact CM is always connected to the plus terminal of the battery 9 via the fuse 33.

In such a starting system, when the starter switch STASW is on and the neutral start switch 7 is on, a current flows from the battery 9 to the coil L of the starter relay 5 and the contact of the starter relay 5 J is short-circuited, and the short-circuit of the contact J activates the starter motor 3 to crank the engine. Therefore, only when the neutral start switch 7 is turned on (that is, when the shift position of the AT is either the neutral position or the parking position), the energization of the coil L of the starter relay 5 (in other words, The operation of the starter motor 3 and the start of the engine) are permitted.

Further, when an ignition switch IGSW is turned on, the voltage VI as a power source is supplied to the ECU 15.
When G is supplied, the ECU 15 starts operating. In the starting system shown in FIG.
Reference numeral 5 controls the engine while detecting whether or not the starter motor 3 is operating and whether or not the neutral start switch 7 is on in the procedure of FIG. 6B.

That is, first, the voltage level of the signal input line S-STA is set only when the current actually flows through the coil L of the starter relay 5 (that is, when the starter motor 3 is actually operating). , The battery voltage corresponding to the high level, otherwise, the pull-down resistor 23 operates to the ground potential corresponding to the low level.

Therefore, the ECU 15 is connected to the signal input line S
If the voltage level of the STA is high, it is determined that the starter motor 3 is operating, and the signal input line S-
If the voltage level of the STA is low, it is determined that the starter motor 3 is not operating. And ECU1
When it is determined that the starter motor 3 is operating, the control unit 5 performs a specific control at the time of starting the engine (so-called start-time control).

On the other hand, the voltage level of the signal input line S-NSW is such that the starter switch STASW is off and
When the neutral start switch 7 is on, the level becomes low through the coil L of the starter relay 5. If both the starter switch STASW and the neutral start switch 7 are off, the level becomes high due to the action of the pull-up resistor 21. . Further, when both the starter switch STASW and the neutral start switch 7 are on (that is, when the starter motor 3 is operating), not only the signal input line S-STA but also
The voltage level of the signal input line S-NSW also becomes the high level.

Therefore, the ECU 15 is connected to the signal input line S
The voltage level of -NSW is low level, or
When the voltage level of the signal input line S-STA is at the high level, it is determined that the neutral start switch 7 is on, and otherwise, it is determined that the neutral start switch 7 is off. And ECU
Reference numeral 15 corrects the fuel injection amount according to the on / off state of the neutral start switch 7 during normal operation of the engine. For example, when the neutral start switch 7 is off (that is, when the shift position of the AT is at a shift position where the vehicle can travel), the load from the AT is applied to the engine, so that the neutral start switch 7 is turned on. Correction processing such as increasing the fuel injection amount more than a certain case is performed.

The various processes for controlling the engine, including the process of determining whether the starter motor 3 is operating and whether the neutral start switch 7 is on, are actually performed by the CPU 25 of the ECU 15. Executed in

[0018]

However, the conventional starting system has the following problems. First, in general,
Since the starter relay 5 needs to be able to hold the on state (specifically, the short-circuit state of the contact J) even when the battery voltage is reduced, the starter relay 5 needs the minimum current to the coil L capable of holding the on state. A certain holding current is set to a small value, for example, 10 mA.

On the other hand, the required current for the neutral start switch 7 (that is, the required current for breaking the oxide film of the contact) is, for example, 20 mA, which is larger than the holding current for the starter relay 5. It has a large value. In the conventional starting system shown in FIG. 6, the neutral start switch 7 is arranged on the upstream side of the coil L of the starter relay 5, and when the starter switch STASW is off and the neutral start switch 7 is on, the ECU 15 Pull-up resistance 2
Since the current flows from 1 through the neutral start switch 7 to the coil L, the resistance value of the pull-up resistor 21 is higher than the holding current (10 mA) to the coil L of the starter relay 5 when the starter switch STASW is off. Must be set to a value at which no current flows through the neutral start switch 7 through the pull-up resistor 21.

That is, the resistance value of the pull-up resistor 21 is
In order to prevent the starter relay 5 from staying on, it must be set to a relatively large value,
The value of the neutral start switch 7 was inevitably unable to satisfy the specifications.

Further, in the starting system shown in FIG. 6, a terminal T of the ECU 15 to which the signal input line S-STA is connected is connected.
If the current leaks from s to the signal line 19 serving as the signal input line S-STA for some reason, at the worst, the starter relay 5 is turned on (that is, the contact J is short-circuited) and the starter motor 3 Will operate, causing large power consumption of the battery 9.

On the other hand, in order to solve the above two problems, the present inventor considered the configuration shown in FIG. That is, the starting system of FIG. 7 differs from the starting system of FIG. 6 in the following points in terms of hardware. First, the neutral start switch 7 is connected to the downstream side of the coil L of the starter relay 5.

A signal line 19 having one end connected to an energizing path 17 between the coil L of the starter relay 5 and the neutral start switch 7 instead of the starter system power supply line 11 is connected to the on / off state of the neutral start switch 7. Signal input line S- for monitoring the OFF state
The NSW is connected to the ECU 15.

A signal line 37 having one end connected to an energizing path 35 between the contact J of the starter relay 5 and the clutch power supply terminal 3a of the starter motor 3 activates / deactivates the starter motor 3. It is connected to the ECU 15 as a signal input line S-STA for monitoring.

In the starting system shown in FIG.
If the voltage level of the signal input line S-NSW is low, the CU 15 sets the neutral start switch 7
Is turned on, and if the voltage level of the signal input line S-NSW is at a high level, it is determined that the neutral start switch 7 is turned off. When the voltage level of the signal input line S-STA is at a high level, the ECU 15 determines that the starter motor 3 is operating and determines the voltage of the signal input line S-STA, as in the starting system of FIG. If the level is low, it is determined that the starter motor 3 is not operating.

In the starting system shown in FIG. 7, since the neutral start switch 7 is disposed on the downstream side of the coil L of the starter relay 5, the pull-up resistor 21
Has no effect on the operation of the starter relay 5 and the resistance of the pull-up resistor 21 can be set to a value that allows the current required to flow through the neutral start switch 7. . Further, the starter relay 5 is not unnecessarily turned on by a leak current from the terminal of the ECU 15 to the external wiring.

However, in the starting system of FIG.
The ECU 15 monitors the voltage level of the clutch power supply terminal 3a of the starter motor 3 in order to detect the operation / non-operation of the starter motor 3; In some cases, it may not be possible to quickly detect that the starter motor 3 has changed from operating to non-operating (that is, the change from the start to the off of the starter relay 5), which may impair optimal control of the engine. . This is because the voltage level of the clutch power supply terminal 3a of the starter motor 3 may not immediately return from the high level to the low level even if the starter relay 5 is turned off.

In the above description, a starting system for an AT vehicle provided with a neutral start switch 7 as a start permission switch that is turned on only when a condition for permitting energization of the coil L of the starter relay 5 is satisfied has been described. However, each of the above-mentioned problems is caused by an automobile equipped with a manual transmission (MT: manual transmission) (so-called MT).
Car). That is, for the MT car, the neutral start switch 7 of the starting system shown in FIGS. 6 and 7 is replaced with a clutch switch that is turned on only when the clutch is depressed.
A starting system in which energization of the coil L of the starter relay 5 is permitted only when the clutch is depressed can be constructed.
The above-described problems occur.

Therefore, according to the present invention, it is possible to supply a required energizing current to a start permission switch connected in series to a coil of a starter relay, and to connect an engine control electronic control device to external wiring. Provided is a vehicle starting system that can prevent a starter relay from being unnecessarily turned on due to a leak current, and can quickly detect that the starter motor has been switched from operation to non-operation by the electronic control unit. It is intended to be.

[0030]

According to a first aspect of the present invention, there is provided a starting system for an automobile, which is provided with the above-mentioned object. A starter relay that activates a starter motor for starting an automobile engine by short-circuiting, and a start permission switch that is turned on only when a start permission condition for permitting energization of a coil of the starter relay is satisfied. And an electronic control unit that controls the engine while detecting whether the starter motor is operating and whether the start permission switch is on.

Also in the starting system according to the first aspect, a power supply line (hereinafter referred to as a starter system power supply line) connected to a positive terminal of a vehicle battery via a starter switch that is turned on when the starter motor is operated. ) And a ground potential line (hereinafter referred to as a ground line) connected to the negative terminal of the battery, the coil of the starter relay and the start permission switch are connected in series, so that the starter switch is turned on. And, when the start permission switch is turned on, a current flows from the battery to the coil of the starter relay, and the starter motor operates.In particular, the start permission switch is connected to the downstream side of the coil of the starter relay. ing.

Further, in the starting system according to the first aspect, a signal line having one end connected to an energizing path between the coil of the starter relay and the start permitting switch is connected to the electronic control unit as a first signal input line. Have been. Also,
A starter system power line to which the coil of the starter relay is connected, or a starter system power line of a system different from the starter system power line, and a starter system power line to which the coil is connected when the starter switch is off. The starter system power supply line to be disconnected is connected to the electronic control unit as a second signal input line.

As an ignition key switch for a vehicle, contact terminals CM, IG, ST shown in FIGS.
(See FIG. 3). In this case, a starter switch STASW in the dimension of the contact terminals CM and ST and an ignition switch IGSW in the dimension of the contact terminals CM and IG shown in FIGS. And two sets of the same type, and the same type of switch in each set is turned on /
It will be turned off. In a vehicle equipped with such an ignition key switch, a starter system power line may be provided for each starter switch STASW. In this case, the two starter system power lines are
When the starter switches are turned off, they are disconnected from each other. Therefore, in the case of an automobile having two starter system power lines, a starter relay coil is connected to one starter system power line and the other starter system power line is used as a second signal input line. The electronic control unit may be connected to the electronic control unit, or a starter system power supply line to which a starter relay coil is connected may be connected to the electronic control unit as a second signal input line. Also,
In the case of an automobile having only one starter system power line, the starter system power line (that is, the starter system power line to which the coil of the starter relay is connected) is connected to the electronic control unit as a second signal input line. Just do it.

In the starting system according to the first aspect of the present invention, since the starting permission switch is arranged downstream of the coil of the starter relay, the voltage level of the first signal input line is reduced when the starting permission switch is turned on. And a low level corresponding to the voltage level (ground potential) of the ground line. For this reason, the electronic control unit determines that the start permission switch is on when the voltage level of the first signal input line is the low level of the high level and the low level.

Here, in order to determine the voltage level of the first signal input line to a high level when the start permission switch is off, the first signal input line must be pulled inside the electronic control unit. The starting system may be connected (pulled up) to a voltage corresponding to a high level via an up resistor. According to the starting system of the first embodiment, the start permission switch is connected to the starter as in the case of the starting system shown in FIG. Even if the resistance value of the pull-up resistor (corresponding to the resistor 21 in FIG. 7) for pulling up the first signal input line to a high-level voltage is reduced, since it is arranged downstream of the coil of the relay, the starter Without affecting the operation of the relay, the resistance value of the pull-up resistor can be set to a value that allows the required current to flow through the start permission switch.

On the other hand, in the starting system according to the first aspect, the voltage level of the second signal input line becomes a high level corresponding to the battery voltage (voltage of the positive terminal of the battery) when the starter switch is turned on. Since the starter motor operates when both the starter switch and the start permission switch are turned on, the electronic control unit determines that the voltage level of the second signal input line is a high level between a high level and a low level. When the voltage level of the first signal input line is low, it is determined that the starter motor is operating. That is, the electronic control unit detects whether the starter motor is operating based on a combination of the voltage level of the first signal input line and the voltage level of the second signal input line.

Here, in particular, the starter system power supply line connected to the electronic control unit as the second signal input line is usually a line that is disconnected from the terminal of the starter motor when the starter switch is off. In addition, the electronic control unit can quickly detect that the starter motor has changed from operation to non-operation without being affected by the residual magnetic field on the starter motor side.

Further, in the starting system according to the first aspect, similarly to the starting system shown in FIG. 7, one end of the coil of the starter relay is connected to the ground line via the starting permission switch. Even if a current leaks from a terminal of the electronic control device to an external wiring (in particular, from a terminal to which the second signal input line is connected to the second signal input line), as long as the start permission switch is off, The starter relay does not needlessly turn on and the starter motor does not operate. Note that turning on the starter relay means that the contacts of the starter relay are short-circuited.

As described above, according to the starting system for an automobile according to the first aspect, it is possible to supply a required energization request current to the starting permission switch connected in series to the coil of the starter relay and to control the engine. Prevents the starter relay from being turned on unnecessarily due to leakage current from the electronic control device to the external wiring, and can quickly detect that the starter motor has changed from active to inactive. Become like

By the way, in order to determine each voltage level of the first signal input line and the second signal input line to one of a high level and a low level, each of the signal input lines is connected to an electronic control unit. Is pulled up or pulled down by a resistor inside.

Therefore, in the starting system according to the first aspect, when the starter system power supply line to which the coil of the starter relay is connected is connected to the electronic control unit as the second signal input line, What is necessary is just to comprise as follows. That is, inside the electronic control unit, the second signal input line is connected (pulled down) to the ground line via a pull-down resistor, and the first signal input line is set to a high level via a pull-up resistor. Connect (pull up) to the corresponding voltage. Further, in the energization path between the coil of the starter relay and the start permission switch, a portion from the coil of the starter relay to a connection point between the energization path and the first signal input line is connected to the starter relay coil. The diodes may be provided in series with the direction toward the connection point being the forward direction.

With this configuration, the voltage level of the first signal input line becomes high level by the pull-up resistor when the start permission switch is off, and becomes low level when the start permission switch is on. Further, the voltage level of the second signal input line becomes low level by the pull-down resistor when the starter switch is off, and becomes high level when the starter switch is on. Therefore, the electronic control unit can reliably detect whether the starter motor is operating and whether the start permission switch is on according to the above-described procedure.

When both the starter switch and the start permission switch are off, a pull-up resistor → first
The diode can prevent the reverse current from flowing through the signal input line → starter relay coil → second signal input line → pull-down resistor, and the unnecessary current consumption can be prevented. it can.

On the other hand, in the starting system according to claim 1,
When the starter relay power supply line to which the coil of the starter relay is connected is connected to the electronic control unit as the second signal input line, a configuration as described in claim 3 can be adopted. That is, inside the electronic control unit, the second signal input line is connected (pulled up) to a voltage corresponding to a high level via the pull-up resistor RU2, and the first signal input line is also connected to another pull-up. It may be connected (pulled up) to a voltage corresponding to a high level via the up resistor RU1.

With this configuration, the voltage level of the first signal input line is at a high level by the pull-up resistor RU1 when the start permission switch is off, and is low when the start permission switch is on. Also, the second
Set the resistance value of the pull-up resistor RU2 on the signal input line to a value much larger than the resistance value of the coil of the starter relay (for example, a value several tens to several hundred times), and the starter switch is turned off. If the voltage level of the second signal input line is set to a low level via the coil of the starter relay and the start permission switch when the start permission switch is turned on, the second signal input line Is low only when the starter switch is off and the start permitting switch is on, and goes high when the starter switch is on or the start permitting switch is off, so that the second signal input When the voltage level of the line is high and the voltage level of the first signal input line is low, the starter switch and the start permit switch It is on the both (i.e., the starter motor is operating) can be regarded as.

Thus, the electronic control unit can reliably detect whether or not the starter motor is operating and whether or not the start permission switch is on by the above-described procedure. Further, according to the configuration of the third aspect, even if the diode as in the second aspect is not provided, no reverse current flows from the pull-up resistor RU1 on the first signal input line to the coil of the starter relay. Therefore, the number of parts can be reduced.

On the other hand, in the starting system according to the first aspect, in order to eliminate the diode according to the second aspect,
It may be configured as described in claim 4. That is, first, a starter system power line different from the starter system power line to which the coil of the starter relay is connected is connected to the electronic control unit as a second signal input line. Then, the second signal input line is connected (pulled down) to a ground line via a pull-down resistor, and the first signal input line is connected to a voltage corresponding to a high level via a pull-up resistor ( Pull up).

With this configuration, the voltage level of the first signal input line is set to a high level by the pull-up resistor when the start permission switch is turned off, and the start permission switch is turned on. Becomes low level when is turned on. Further, the voltage level of the second signal input line becomes low level by the pull-down resistor when the starter switch is off, and becomes high level when the starter switch is on. Therefore, the electronic control unit can reliably detect whether the starter motor is operating and whether the start permission switch is on according to the above-described procedure.

In particular, in the starting system according to the fourth aspect, when the starter switch is off, the starter system power supply line connected to the coil of the starter relay and the starter system power supply line as the second signal input line. Is released, so that there is no reverse current path such as pull-up resistance → starter relay coil → pull-down resistance. Therefore, according to the configuration of the fourth aspect, similarly to the starting system of the third aspect, the diode of the second aspect can be omitted.

[0050]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a vehicle starting system according to an embodiment of the present invention; Note that each of the starting systems described below is for an AT vehicle, and similarly to the above-described starting systems in FIGS. 6 and 7, even if a starter switch for operating a starter motor for starting an engine is turned on. , The starter motor does not operate unless the shift position of the AT is one of the neutral position and the parking position. In the drawings used in the following description, components having the same functions as those of the starting system in FIGS. 6 and 7 are denoted by the same reference numerals as in FIGS.

FIG. 1 is an explanatory view for explaining a starting system according to the first embodiment. FIG. 1A shows the configuration of the starting system, and FIG. 1B shows the operation of the starting system. As shown in FIG. 1A, the starting system of the first embodiment has the following hardware (1-1) to (1) in terms of hardware as compared with the conventional starting system shown in FIG.
-4) is different.

(1-1): A neutral start switch 7 as a start permission switch is connected to the downstream side of the coil L of the starter relay 5. (1-2): The signal line 1 having one end connected to the current path 17 between the coil L of the starter relay 5 and the neutral start switch 7 instead of the starter system power supply line 11.
9 is connected to a signal input line S-NSW (first switch) for monitoring the on / off state of the neutral start switch 7.
(Corresponding to the signal input line of FIG. 2). The two points (1-2) and (1-1) are the same as those of the starting system of FIG. 7 described above.

(1-3): The starter system power supply line 11 to which the starter relay coil L is connected is connected to the ECU 15 as a signal input line S-STA. The signal input line S-STA corresponds to the second signal input line, and is a signal wiring for the ECU 15 to monitor the operation / non-operation of the starter motor 3 in a broad sense. In one embodiment, the signal input line S-STA is a starter switch ST in a narrow sense.
This is a signal line indicating the ON / OFF state of the ASW.

(1-4): coil L of starter relay 5
Energization path 1 between the neutral start switch 7 and
7, a diode 41 is connected in series from the coil L to a connection point between the current path 17 and the signal input line S-NSW (signal line 19) with the direction from the coil L to the connection point being a forward direction. Is provided. When both the starter switch STASW and the neutral start switch 7 are off, the diode 41 is connected to the pull-up resistor 21 → the signal input line S-NSW → the coil L of the starter relay 5 → the signal input line S-STA → the pull-down resistor. 23 is provided to prevent the backflow current from flowing through a path such as 23.

Also in the starting system of the first embodiment, the coil L of the starter relay 5 and the neutral start switch 7 are connected in series between the starter system power supply line 11 and the ground line 13. ,
When the starter switch STASW is on and the neutral start switch 7 is on, current flows from the battery 9 to the coil L of the starter relay 5, and the starter motor 3 operates.

In this starting system, the voltage level of the signal input line S-NSW becomes high level (battery voltage) by the pull-up resistor when the neutral start switch 7 is off, and becomes low when the neutral start switch 7 is on. Level (ground potential)
Becomes Further, the voltage level of the signal input line S-STA becomes low level by the pull-down resistor 23 when the starter switch STASW is off, and becomes high level when the starter switch STASW is on. Naturally, such a change in the voltage level occurs when the ignition switch IGSW is turned on and the voltage VIG which is a battery voltage is supplied from the ignition power supply line 27 to the ECU 15 (that is, the ECU 15).
Is working).

Therefore, in the starting system according to the first embodiment, as shown in FIG. 1B, the ECU 15 (specifically, the CPU 25) operates when the voltage level of the signal input line S-NSW is low. It is determined that the neutral start switch 7 is on, and otherwise (when the voltage level of the signal input line S-NSW is high), it is determined that the neutral start switch 7 is off. The ECU 15 determines that the starter motor 3 is operating when the voltage level of the signal input line S-STA is at a high level and the voltage level of the signal input line S-NSW is at a low level. In other cases, it is determined that the starter motor 3 is not operating. That is, the voltage level of the signal input line S-STA is high and the signal input line S-N
If the SW voltage level is low, the starter switch STASW = ON and the neutral start switch 7 = ON. In this case, the starter relay 5 is turned on and the starter motor 3 operates.

According to the starting system of the first embodiment, since the neutral start switch 7 is disposed downstream of the coil L of the starter relay 5, the signal input line S-NSW is set to the high level voltage. Even if the resistance value of the pull-up resistor 21 that is pulled up to VIG is reduced, the operation of the starter relay 5 is not affected, and the resistance value of the pull-up resistor 21 is set to the necessary power supply for the neutral start switch 7. Current (eg, 20
mA) can be set to a value at which the current can flow.

Further, E is used as the signal input line S-STA.
The starter system power supply line 11 connected to the CU 15 is a line that is disconnected from the terminals 3a and 3b of the starter motor 3 when the starter switch STASW is turned off. Can be quickly detected without being affected by the residual magnetic field on the starter motor 3 side.
This is because the voltage level of the starter system power supply line 11 as the signal input line S-STA is the starter switch ST
This is because when the ASW switches from on to off, it immediately returns from high level to low level.

Further, in the starting system according to the first embodiment, since one end of the coil L of the starter relay 5 is connected to the ground line 13 via the neutral start switch 7, ECU1
5 to the external wiring (in particular, from the terminal Ts to which the signal input line is connected S-STA to the signal input line S
Even if a current leaks, the starter relay 5 is not unnecessarily turned on and the starter motor 3 does not operate as long as the neutral start switch 7 is off.

As described above, according to the starting system of the first embodiment, the required energization request current can be passed to the neutral start switch 7 connected in series with the coil L of the starter relay 5, and the engine can be driven. It is possible to prevent the starter relay 5 from being unnecessarily turned on due to a leak current from the control ECU 15 to the external wiring,
In addition, the ECU 15 can quickly detect that the starter motor 3 has been switched from operation to non-operation.

Next, FIG. 2 is an explanatory view for explaining a starting system according to a second embodiment. FIG. 2A shows the configuration of the starting system, and FIG. 2B shows the operation of the starting system. As shown in FIG. 2A, the starting system of the second embodiment differs from the starting system of FIG. 1 in the following points (2-1) and (2-2) in terms of hardware. ing.

(2-1): Inside the ECU 15,
The signal input line S-STA is connected (pulled up) to the voltage VIG via the pull-up resistor 24. The resistance value of the pull-up resistor 24 is such that when the starter switch STASW is off and the neutral start switch 7 is on, the voltage level of the signal input line S-STA is equal to the coil L of the starter relay 5 and the neutral start switch 7. Is set to a value sufficiently larger than the resistance value of the coil L of the starter relay 5 (for example, a value of about several tens to several hundreds of times) so as to be determined to a low level via.

(2-2): When the signal input line S-STA is changed to pull-up, the pull-up resistor 21
→ coil L of starter relay 5 → signal input line SS
Since the reverse current of the path such as TA does not occur, the diode 41 is omitted.

In the starting system according to the second embodiment, as shown in FIG. 2B, the voltage level of the signal input line S-NSW is set to the neutral level just like the first embodiment. It goes low only when the start switch 7 is on. Also, the signal input line S-ST
The voltage level of A goes low only when the starter switch STASW is off and the neutral start switch 7 is on, and goes high when the starter switch STASW is on or the neutral start switch is off. Therefore, the signal input line S
When the voltage level of -STA is at a high level and the voltage level of the signal input line S-NSW is at a low level, both the starter switch STASW and the neutral start switch 7 are turned on (that is, the starter motor 3 operates. Has been identified).

Therefore, also in the second embodiment, the EC
U15 determines that the neutral start switch 7 is turned on when the voltage level of the signal input line S-NSW is low, just as in the case of the first embodiment. 7 is determined to be off. Further, when the voltage level of the signal input line S-STA is at a high level and the voltage level of the signal input line S-NSW is at a low level, it is determined that the starter motor 3 is operating. , It is determined that the starter motor 3 is not operating.

According to the starting system of the second embodiment, in addition to the same effects as those of the starting system of the above-described first embodiment, the diode 41 can be further eliminated, thereby reducing the number of parts. Cost reduction and simplification of wiring in the vehicle can be achieved.

Next, FIG. 3 is a configuration diagram showing the configuration of the starting system according to the third embodiment. As shown in FIG.
The starting system of the embodiment differs from the starting system of FIG. 1 in the following points (3-1) and (3-2) in terms of hardware.

(3-1): First, in this starting system, the ignition key switch 29 has two sets of the aforementioned contact terminals CM, IG and ST. Therefore, as described above, the starter switch STASW in the dimension of the contact terminals CM and ST and the ignition switch IGSW in the dimension of the contact terminals CM and IG are provided in two sets each, and the same type in each set is provided. The switches are turned on / off in conjunction with each other. In this starting system, each starter switch STASW (specifically, the contact terminal S
Starter system power lines 11 and 12 are provided for each (T), and the coil L of the starter relay 5 is connected to the starter system power line 11 connected to one contact terminal ST. Further, another starter system power supply line 12 connected to the other contact terminal ST is connected to the ECU 15 as a signal input line S-STA.
5 is pulled down by a pull-down resistor 23. In this example, the ignition power supply line 27 to the ECU 15 is connected to the same set of contact terminals IG as the contact terminals ST to which the starter power supply line 11 is connected.

(3-2): The two starter system power supply lines 11 and 12 are connected to each other when the starter switch STASW is off (ie, when the ignition key switch 29 is not operated to the engine start position). Is disconnected, a reverse current path such as the pull-up resistor 21 → the coil L of the starter relay 5 → the pull-down resistor 23 does not occur. Therefore, the diode 41 is omitted.

In the starting system according to the third embodiment, the voltage levels of the signal input line S-NSW and the signal input line S-STA change in exactly the same manner as in the starting system of the first embodiment. Therefore, also in the third embodiment, the ECU 15 turns on the neutral start switch 7 when the voltage level of the signal input line S-NSW is at the low level, just like the case of the first embodiment. Otherwise, it is determined that the neutral start switch 7 is off.
Further, when the voltage level of the signal input line S-STA is at a high level and the voltage level of the signal input line S-NSW is at a low level, it is determined that the starter motor 3 is operating. Has a starter motor 3
Is determined not to be operating.

According to the starting system of the third embodiment, in addition to the same effects as those of the starting system of the first embodiment, the diode 41 can be further eliminated, and the number of parts can be reduced. Cost reduction and
Simplification of wiring in the vehicle can be achieved.

FIG. 4 is a configuration diagram showing a configuration of a starting system according to a fourth embodiment. As shown in FIG.
In the starting system according to the embodiment, as compared with the starting system according to the third embodiment shown in FIG. 3, the opposite side of the contact J of the starter relay 5 from the starter motor 3 side is always connected to the plus terminal of the battery 9. Instead, the starter system power supply line 1 connected to the coil L of the starter relay 5
1 connected. In other words, in this starting system,
The battery voltage is supplied to the clutch power supply terminal 3a of the starter motor 3 via the starter switch STASW and the contact J of the starter relay 5, and the other points are the same as those of the third embodiment. Same as starting system.

The same effects as those of the starting systems according to the second and third embodiments can be obtained by the starting system according to the fourth embodiment. Next, FIG.
FIG. 1 is a configuration diagram illustrating a configuration of a starting system according to an embodiment. As shown in FIG. 5, the starting system of the fifth embodiment is different from the starting system of the first embodiment shown in FIG. 1 in that the contact J of the starter relay 5 and the clutch power supply terminal 3a of the starter motor 3 are provided. A switch 43 that is turned on / off in conjunction with the neutral start switch 7 is provided in the energization path 35 between them.

According to the starting system of the fifth embodiment, even if the starter relay 5 is unnecessarily turned on for some reason, as long as the neutral start switch 7 is off, , Starter motor 3
Can be prevented from operating, and unnecessary power consumption of the battery 9 can be more reliably prevented.

The switch 43 may be provided upstream of the contact point J of the starter relay 5. That is, the switch 43 may be provided in the current path from the plus terminal of the battery 9 to the clutch power supply terminal 3a of the starter motor 3. Although not shown, the provision of such a switch 43 is not limited to the starting system according to the first embodiment, and the above-described second to fourth switches may be used.
The same applies to each starting system of the embodiment.

On the other hand, in each of the starting systems according to the first to fourth embodiments, if a current larger than a current flowing from the ground terminal 3c of the starter motor 3 to the ground line can be supplied to the neutral start switch 7. Even if the ground terminal 3c of the starter motor 3 is connected to the ground line 13 via the neutral start switch 7, the same effect as in the fifth embodiment can be obtained.

Although the embodiment of the present invention has been described above, it goes without saying that the present invention can take various forms. For example, the starting system according to each of the above-described embodiments includes A
The present invention relates to an MT vehicle provided with a clutch switch that is turned on only when the clutch is depressed, as a start permission switch provided in series with the coil L of the starter relay 5. Can be similarly applied.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a starting system according to a first embodiment.

FIG. 2 is an explanatory diagram illustrating a starting system according to a second embodiment.

FIG. 3 is a configuration diagram illustrating a configuration of a starting system according to a third embodiment.

FIG. 4 is a configuration diagram illustrating a configuration of a starting system according to a fourth embodiment.

FIG. 5 is a configuration diagram illustrating a configuration of a starting system according to a fifth embodiment.

FIG. 6 is an explanatory diagram illustrating a conventional starting system for an automobile.

FIG. 7 is an explanatory diagram illustrating a configuration example of a starting system before reaching the present invention.

[Explanation of symbols]

3: Starter motor 5: Starter relay L: Coil J: Contact 7: Neutral start switch 9: Battery 11, 12: Starter system power line 13: Ground line 15: ECU (electronic control unit) 17: Power supply path
19 ... Signal lines 21, 24 ... Pull-up resistor 23 ... Pull-down resistor 25 ... CPU 27 ... Ignition power supply line 29 ... Ignition key switch STASW ... Starter switch IGSW ... Ignition switch 41 ... Diode 43 ... Switch S-NSW ...
First signal input line S-STA... Second signal input line

Continuation of the front page (72) Inventor Hiroyuki Kawabata 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 5G065 EA02 GA09 KA01 LA01 NA10

Claims (4)

[Claims] 1. A starter relay for operating a starter motor for starting an engine of an automobile by short-circuiting a contact with energization of a coil, and a start permission condition for permitting energization of the coil of the starter relay. A start permitting switch that is turned on only when is established, an electronic control unit that controls the engine while detecting whether the starter motor is operating and whether the start permitting switch is turned on. A power line (hereinafter referred to as a starter system power line) connected to a positive terminal of the battery of the vehicle via a starter switch that is turned on when the starter motor is operated, and a negative terminal of the battery Line of the ground potential connected to (hereinafter referred to as ground line)
A starter relay coil and the start permission switch are connected in series between the starter relay and the start permission switch, wherein the start permission switch is connected to a downstream side of the coil; A signal line having one end connected to an energization path between the start control switch and the start permission switch is connected to the electronic control unit as a first signal input line, and a starter system power supply line to which the coil is connected; Alternatively, a starter system power supply line that is different from the starter system power supply line to which the coil is connected, and is not connected to the starter system power supply line to which the coil is connected when the starter switch is off. A line connected to the electronic control unit as a second signal input line, wherein the electronic control unit is connected to the first signal input line. When the in voltage level is the low level of the high level and the low level, it is determined that the start permission switch is on, and the voltage level of the second signal input line is the high level and the low level. Of the high level, and
A starter motor configured to determine that the starter motor is operating when the voltage level of the first signal input line is low. 2. The starting system for an automobile according to claim 1, wherein the second signal input line is a starter system power supply line to which the coil is connected, and the second signal input line is Inside the electronic control unit, it is connected to a ground line via a pull-down resistor, and the first signal input line is connected to a voltage corresponding to a high level via a pull-up resistor inside the electronic control unit. In the energization path between the coil and the start permission switch, a portion from the coil to a connection point between the energization path and the first signal input line includes the connection from the coil. A starting system for an automobile, wherein a diode is provided in series with a direction toward a point being forward. 3. The starting system for a vehicle according to claim 1, wherein the second signal input line is a starter system power supply line to which the coil is connected, and the second signal input line is The first signal input line is connected to a voltage corresponding to a high level via a pull-up resistor inside the electronic control device. The first signal input line is different from the pull-up resistor inside the electronic control device. A start-up system for a vehicle, wherein the start-up system is connected to a voltage corresponding to a high level via a pull-up resistor. 4. The starting system for an automobile according to claim 1, wherein the second signal input line is the starter system power line that is different from the starter system power line to which the coil is connected, and The second signal input line is connected to a ground line via a pull-down resistor inside the electronic control device, and the first signal input line is connected to a pull-up resistor inside the electronic control device. Connected to a voltage corresponding to a high level via the start-up system.