JPH03279675A - Start circuit for engine - Google Patents

Abstract

PURPOSE:To prevent generation of chattering in a main relay by providing a diode to allow current from a starter terminal side to an ignition terminal side between the ignition terminal and the starter terminal. CONSTITUTION:When the key contact 20 of an ignition key 10 is contacted with an ignition terminal 26, a relay coil 32 is excited, electric power is supplied from a battery 4, and a control part 44 and the like are started to control an engine. Nextly, when the contact 20 is contacted with a starter terminal 28, a starter is actuated to start the engine. Because a diode 54 to allow current from the starter terminal 28 side to the relay coil 32 side as the ignition terminal 26 side is provided, electric power from the battery 4 can be continuously supplied to the control part 44 and the like. Hereby, the function of the control part 44 and the like is held, a fuel injection valve or the other parts can be appropriately actuated, and maloperation of the system can be prevented.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an engine starting circuit, and particularly to an engine starting circuit that can prevent chattering from occurring in a main relay and ensure proper functions of a control section, etc. Regarding.

[Conventional technology]

A vehicle engine is provided with a starting device that ignites the ignition or drives a starter to start the engine by turning an ignition key.

That is, as shown in FIG. 3, in the engine starting circuit 102, a first line 108 in which a battery 104 and a filter 106 are sequentially connected is connected to a second line 112 that connects to an ignition key 110 and a main relay 114. 3rd to do
The line 116 is connected. ignition key 110
A key contact 120 that rotates around a key contact shaft support 118 connected to a second line 112, a stop terminal (OFF) 122 provided for contact with this key contact 120,
It has an accessory electrical component terminal (ACC) 124, an ignition terminal (IG) 126, and a starter terminal (STA) 128. The accessory electrical component terminal 124 is connected to an accessory electrical component circuit (ACC circuit) (not shown) via a fourth wire 130. Further, the ignition terminal 126 is connected to the fifth
Relay coil 1 of main relay 114 by wire 132
It is connected to 34. Additionally, starter terminal 128 is connected by a sixth wire 136 to a scooter circuit (not shown) that drives a starter (not shown).

In the main relay 114, a first relay terminal 138 connected to the third wire 116, a second relay terminal 140 provided in parallel to this first relay terminal 138, and these first and second A relay contact 142 that connects and disconnects the relay terminals 138 and 140 is provided. A seventh line 146 that communicates with the control section 144 is connected to the second relay terminal 140 .

Further, an eighth wire 150 that communicates with a diode 148 in the control section 144 is connected to the relay coil 134 . This relay coil 134 can also be directly grounded, as shown by the broken line in FIG.

In the controlled mechanism 152, the control section 144 controls, for example, a fuel injection valve 154, an idle speed control section (ISO
control unit) 156, ignition signal control unit 158, etc. to control the operation thereof. These fuel injection valves 154, idle speed control section 156, and ignition signal control section 158 are in communication with a crank angle sensor 160 and in communication with the control section 144 to output signals. This crank angle sensor 160 outputs a signal to the control section 144.

Furthermore, analog and digital signals are input to the control section 144.

As a result, in FIG. 3, the ignition key 11
When the 0 key contact 120 is located at the ignition terminal 126, the relay coil 134 is energized, so that the relay contact 142 contacts the first and 21st J-ray terminals 138 and 140 and connects the third wire 116 and the seventh wire 146. Therefore, power is supplied to the control unit 144, each sensor, etc. The control unit 144 starts operating when power is supplied from the battery 104 and controls the engine. Additionally, each sensor outputs a signal.

Then, by bringing the key contact 120 of the ignition key 110 into contact with the stop terminal 122, the main relay 1
14 relay contacts 142 are connected to the 11th second relay terminal 138
．． 140, and the control unit 144 stops controlling the engine.

The configuration of the starting circuit shown in FIG. 3 is low cost and commonly used.

As such a starting circuit, for example,
It is disclosed in Japanese Patent No. 732. The system described in this publication protects the starter motor from erroneous operation of the starter switch by not starting the engine until the starter inch is returned to the off mode when restarting the engine.

[Problem that the invention seeks to solve]

However, in the conventional starting circuit shown in FIG. 3, when the key contact 120 of the ignition key 110 comes into contact with and separates from the starter terminal 128, a large fluctuation occurs in the current flowing to the relay coil 134. 13
4, the current stops flowing momentarily, the relay contact 142 fluctuates unnecessarily, and chattering occurs in the main relay 114. Specifically, the key contact 120 of the ignition key is required to be durable due to the large current of 0N10FF, and at the same time, is required to be low cost.

Therefore, since the key contact 120 of the ignition key 110 is a press-formed leaf spring, the current flowing to the relay coil 134 fluctuates, particularly at low temperatures, and chattering is likely to occur in the main relay 114.

Therefore, in the main relay 114, relay contact 1
42 is momentarily turned off, that is, separated from the first and second relay terminals 138 and 142, and power is no longer supplied to the control section 144 and each unit.

During this period, although it is not long before the control unit 144 is reset, the fuel injection valve 154 that is injecting fuel may come to a halt, current may no longer be supplied to a coil that is energized, or a valve that is energized may come to a halt. However, there is an inconvenience that the system may malfunction.

As shown in FIG. 4, chattering of the main relay 114 occurs when the ignition key 110 is turned from OFF to ON (indicated by position a) and then when the key contact 120 contacts the starter terminal 148 (at position b). ) or when the key contact 120 leaves the starter terminal 148 (shown in position C), there will be large fluctuations in the current to the relay coil 134, especially longer at lower temperatures; Starting performance deteriorates as the temperature increases to 30°C). As shown in FIG. 5, if the engine speed reaches a certain level, there may be some trouble, but if chattering occurs in the main relay 114 at time X in FIG. 5, when the engine speed is still low during startup, There was an inconvenience that the engine speed decreased momentarily (as shown by P in FIG. 5), making it impossible to start the engine.

[Purpose of the invention]

Therefore, the purpose of this invention is to eliminate the above-mentioned disadvantages (
By providing a diode between the ignition terminal and starter terminal that allows current to flow from the starter terminal side to the ignition terminal side, when the key contact of the ignition key connects and disconnects from the starter terminal, the current of the relay coil of the main relay increases. The object of the present invention is to realize an engine starting circuit that can avoid such fluctuations, prevent chattering from occurring in the main relay, and properly ensure the functions of a control section and the like.

[Means for solving problems]

To achieve this object, the present invention provides an ignition key having a key contact, an ignition terminal and a starter terminal arranged so that the key contact contacts, a relay coil communicating with the ignition terminal, and a starter terminal. In an engine starting circuit including a main relay having a relay contact that operates so as not to supply power to a control section of the engine when excited, a main relay is provided between the ignition terminal and the starter terminal from the starter terminal side to the ignition terminal. It is characterized by the provision of a diode that allows current to flow to the side.

[Effect]

According to the configuration of the present invention, when the key contact of the ignition key contacts or separates from the starter contact, current flows from the starter terminal side to the ignition terminal side via the diode, so that current always flows to the relay coil of the main relay. As a result, the relay contacts do not fluctuate unnecessarily, and the functions of the control unit and each sensor are ensured properly.
Particularly when starting the engine at low temperatures, deterioration in startability can be prevented.

〔Example〕

Embodiments of the present invention will be described in detail and specifically below based on the drawings.

Figure 1.2 shows an embodiment of the invention. In the figure, 2 is an engine starting circuit, and 4 is a battery. This battery 4 is connected to the first line 6. A filter 8 is provided in the middle of this first line 6 .

A second line 12 that connects to the ignition key 10 and a third line 16 that connects to the main relay 14 are connected to the first line 6 .

The ignition key 10 includes a key contact 20 that is pivotally supported by a key contact shaft support 18 to which a second wire 12 is connected, and a stop terminal (OFF>
22, accessory electrical component terminal (ACC) 24, ignition terminal (IG) 26, and starter terminal (STA) 28
It has

The accessory electrical equipment terminal 24 is connected to the accessory electrical equipment circuit (ACC
A third line 30 is connected to the circuit.

A fourth wire 34 that communicates with the relay coil 32 of the main relay 14 is connected to the ignition terminal 26 .

A fifth line 36 is connected to the starter terminal 28, which communicates with a starter circuit having a starter and the like.

On the other hand, the third wire 16 is connected to a first relay terminal 40 to which the relay contact 38 of the main relay 14 connects and disconnects.

In this main relay 14, a second relay terminal 42 is parallel to the first relay terminal 38 and the relay contact 38 connects and disconnects.
is provided.

A sixth line 46 that communicates with the control section 44 is connected to the second relay terminal 42 .

Furthermore, the relay coil 32 of the main relay 14 includes:
A seventh line 50 is connected to the control unit internal diode 48 in the control unit 44 .

The relay coil 32 can also be directly grounded, as shown by the broken line in FIG.

The control section 44 receives signals from each sensor as in the conventional one shown in FIG. 3, controls the operation of each drive mechanism, and drives the engine appropriately.

Further, a fourth wire 34 connected to the ignition terminal 26
and the fifth line 36 connected to the starter terminal 28 are connected by an eighth line 52. In the middle of this eighth wire 52, there is a diode 54 that allows current to flow from the starter terminal 28 side to the ignition terminal side, that is, the relay coil 32 side.
is provided.

As a result, an OR circuit is formed by the fourth M34, the fifth line 36, the eighth line 52, and the diode 54.

Next, the operation of this embodiment will be explained.

Terminal 22 for stopping the key contact 20 of the ignition key 10
The engine stops and the circuit for the attached electrical equipment is turned off.

Then, when the key contact 20 of the ignition key 10 is brought into contact with the accessory electrical component terminal 24, the current from the battery 4 is supplied to the accessory electrical component circuit, the accessory electrical component circuit is turned on, and the Class I electrical component is turned on. Turns on.

When the key contact 20 of the ignition key 10 is brought into contact with the ignition terminal 26, power from the battery 4 is supplied to the relay coil 32 of the main relay 14, and this relay coil 32 is excited.

By energizing the relay coil 32, the relay contact 38
are in contact with the first and second relay terminals 40 and 42, and thereby the power from the battery 4 is connected to the first wire 6, the third wire 16, and the sixth wire.
The signal is supplied to the control unit 44 and the like through the line 46, and the control unit 44 and the like start operating, that is, start controlling the engine.

Next, when the key contact 20 of the ignition key 10 is brought into contact with the starter terminal 28, power from the battery 4 is supplied to the starter circuit, and the starter is activated to start the engine.

By the way, in this embodiment, the ignition terminal 2
A fourth wire 34 connected to the starter terminal 28 and a fifth wire 36 connected to the starter terminal 28 are connected by an eighth wire 52, and a relay on the starter terminal 28 side and the ignition terminal 26 side is connected in the middle of the eighth wire 52. Since the diode 54 that allows current to flow is provided on the coil 32 side, an OR circuit is formed between the fourth wire 34 on the ignition terminal 26 side and the fifth wire 36 on the starter terminal 28 side. As a result, as shown in FIG. 2, the ignition key 10 is turned from OFF to ON (that is, the key contact 20 is in contact with the ignition terminal 26 as shown in position A in FIG. 2), and then the key of the ignition key 10 is turned on. When the contact 20 is brought into contact with the starter terminal 28 (as shown in position B in FIG. 2) or when the key contact 20 is separated from the starter terminal 28 (as shown in position C in FIG. 2), the fifth wire 36 Since the current flows from the side to the fourth wire 34 side, the relay coil 32 of the main relay 14
is always energized, so relay contact 38
The battery 4 does not leave the first and second relay terminals 40 and 42 unnecessarily, and power from the battery 4 can be continuously supplied to the control section 44, etc., thereby ensuring the functions of the control section 44, etc. , fuel injection valves and other parts can be operated properly, and system malfunctions can be prevented.

In this embodiment, the diode 54 is provided between the fifth line 36 and the fourth line 34, but the diode 54 can also be incorporated into the ignition key 10.

〔Effect of the invention〕

As is clear from the above detailed description, according to the present invention,
By providing a diode between the ignition terminal and the starter terminal that allows current to flow from the starter terminal side to the ignition terminal side, current always flows to the ignition terminal side when the key contact contacts or separates from the starter terminal, and the ignition terminal This prevents the current from fluctuating and supplies current to the relay coil of the main relay without interruption, preventing chattering from occurring in the main relay.
Malfunctions of the system can be prevented by properly ensuring the functions of the control unit and the like.

[Brief explanation of the drawing]

1.2 shows an embodiment of the present invention, FIG. 1 is a configuration diagram of an engine starting circuit, and FIG. 2 is a time chart showing the state of power supply at the time of starting. Figures 3 to 5 show conventional engine starting circuits, Figure 3 is a configuration diagram of the starting circuit, Figure 4 is a time chart showing the power supply status during startup, and Figure 5 is the key contact of the ignition key. FIG. 3 is a diagram showing the relationship between the position of the engine and the engine speed. In the figure, 2 is a starting circuit, 4 is a battery, 10 is an ignition key, 14 is a main relay, 20 is a key contact,
26 is an ignition terminal, 28 is a starter terminal, 38 is a relay contact, 44 is an input terminal, and 54 is a diode.

Claims (1)

[Claims] 1. An ignition key having a key contact, an ignition terminal and a starter terminal arranged so that the key contact contacts, a relay coil connected to the ignition terminal, and an engine control unit when the relay coil is energized. In the engine starting circuit provided with a main relay having a relay contact that operates to supply power to the engine, a diode is provided between the ignition terminal and the starter terminal to allow current to flow from the starter terminal side to the ignition terminal side. An engine starting circuit characterized by being provided.