JPS63297743A - Engine stall preventing device for car engine - Google Patents

Abstract

PURPOSE:To certainly prevent the generation of engine stall by driving a starter by smoothly meshing the pinion of a starter with a ring gear on the engine side, when a revolution sensor detects the reduction of the engine revolution speed below a set level. CONSTITUTION:When a keyswitch 2 is turned to the (b) contact point side, a starter relay 3 is turned ON, and at the same time, a power transistor Tr13 is turned ON, and a magnetic switch 4 is operated. Then, a pinion 8 is moved rightward through a shift lever 5, and a ring gear 9 is meshed, and an engine is cranking-operated by the operation of a starter motor 6. Then, the engine revolution speed sharply lowers because of the external causes, and the output of a revolution sensor 11 becomes less than a standard value, pulse signals are applied onto the base of the Tr13, and an attracting coil 41 is supplied with the gradually increased electric power, and the pinion 8 is meshed smoothly with the ring gear 9, and the engine revolution speed is increased by the power of the starter motor 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stall prevention device for a vehicle engine.

[Conventional technology]

In the field of vehicle engines, there is a need to prevent engine rotation from dropping during operation to improve operational stability. Therefore, conventionally, the rotational state of the engine is monitored using a rotational speed detection sensor, and if the engine changes, the intake air amount of the engine air supply system is adjusted accordingly, and the intake air amount is adjusted accordingly. Means has been proposed for preventing a drop in the engine rotational speed by adjusting the generator torque (power generation amount) driven by the engine in cooperation with the amount adjustment.

In addition, as a conventional technique of this type of engine rotation speed adjusting means, there is one disclosed in, for example, Japanese Patent Laid-Open No. 103935/1983.

[Problem that the invention seeks to solve]

The conventional technology described above is effective as a means of stabilizing the engine rotation speed, but it only improves the engine speed by increasing the output of the engine itself or reducing the load, such as adjusting the intake air amount of one engine or adjusting the generator torque. In order to prevent the rotation from dropping, etc., if the rotation speed of the engine itself decreases due to external factors (for example, a temporary malfunction of the engine's fuel system 2 ignition system, etc.) and it becomes difficult to recover, However, it was not possible to avoid engine stall prevention, and there was a limit to countermeasures against engine stalling.

The present invention has been made in view of the above points, and its purpose is to provide a device that can effectively prevent engine stalling under any conditions without being restricted by the conditions that cause engine stalling. It's about doing.

[Means for solving problems]

The present invention focuses on the fact that in order to achieve the above object, it is sufficient to apply external torque to help increase the engine speed when the engine speed drops, and the engine stall prevention device is implemented as follows. Configure.

That is, the engine stall prevention device includes a magnetic shift starter, a rotation sensor that detects the rotational state of the engine, and voltage control means that controls the voltage applied to the coil for exciting the plunger suction coil of the magnetic switch of the starter. When the rotation sensor detects a decrease in engine rotation speed below a set level, the voltage control means applies a voltage that gradually increases to a plunger suction coil of the magnetic switch when the engine rotation speed decreases. Set to apply.

[Effect]

With the above configuration, when the engine speed drops below the set level during vehicle operation, the voltage control means gradually increases the voltage to the plunger suction coil of the magnetic switch in accordance with the detection signal of the rotation sensor. As the voltage is applied, the plunger of the magnetic switch is gradually attracted, slowing down the moving speed of the plunger and the starter's binion, reducing the impact force of the binion to the ring gear on the engine side, and smoothly meshing the starter to rotate the starter. let Therefore, the rotational force of the starter is applied when the engine speed drops, raising the engine speed to a predetermined range and effectively preventing engine stalling.

The voltage applied to the plunger suction coil of the magnetic switch is set to gradually increase when the engine speed decreases, but this can be done by changing it continuously or stepwise to gradually increase the voltage. .

〔Example〕

An embodiment of the present invention will be described based on FIGS. 1 to 3.

FIG. 1 is a circuit diagram of this embodiment. In the figure, 1 is an automobile battery and 2 is an engine key switch.

3 is a starter relay that is energized and controlled by operating the key switch 2, and 4 is a magnetic switch.

The magnetic switch 4 includes a single-turn attraction coil 41. The plunger 42 is attracted by energization (excitation) of the attraction coil 41. It consists of a movable contact 43 that moves toward the fixed contact 44 side by the force when the plunger 42 is attracted, and the plunger 4
When the attraction coil 41 is de-energized, each of the movable contact 2 and the movable contact 43 returns to its original state via a spring.

Reference numeral 5 designates a starter shift lever. One end of the shift lever 5 is connected to the plunger 42 side, and the other end is connected to a push sleeve 7 slidably attached to one end of a starter motor (armature) 6. 8 is a binion rotated by the starter motor 6, 9 is a ring gear on the engine side, 10
is the field coil of the starter motor.

11 is a rotation sensor that detects the rotational state of the engine; 12
1 is a control unit that generates a signal for controlling the voltage applied to the attraction coil 41 of the magnetic switch 4; 13 is a power transistor whose energization is controlled by the control unit 12; the transistor 13 is turned on in response to a signal from the control unit 12; .

Controlled off. 14 is a flywheel diode.

Next, the operation of this embodiment will be explained.

During normal engine starting, when the key switch 2 is turned on, the switch 2 moves to the b contact, the starter relay 3 is turned on, a starter operation command is given to the control unit 12 via the wiring 16, and the control unit 12 is connected to the power transistor Turn on 13. Then, by energizing the starter relay 3 and the power transistor 13, an excitation current flows through the attraction coil 41 of the magnetic switch 4 via the wiring 18, and the plunger 42 is electromagnetically attracted.

This movement of the plunger 42 causes the shift lever 5 to
The pinion 8 moves in the direction of the arrow through the ring gear 9.
At the same time, the movable contact 43 connects to the fixed contact 44, and current flows from the battery 1 to the field coil 10 and the armature 41.

The armature 41 and pinion 8 rotate and the engine starts. After starting the engine, the key switch 2 returns to the contact a side, the starter relay 3 is turned off, and the suction coil 41 is demagnetized (
OFF), the shift lever 5 and movable contact 43 also return to the OFF state, and the pinion 8 separates from the ring gear 8 and stops rotating.

Next, FIG. 2 shows the operation of the starter when the engine speed suddenly decreases due to external factors or the like.

This will be explained with reference to FIG. FIG. 2 shows an example of the engine rotation state when the vehicle is running, and FIG. 3 shows the voltage applied to the attraction coil 41 of the magnetic switch 4 when the engine speed decreases when the vehicle is running.

During driving, the engine speed drops and the output level of the rotation sensor 11 reaches the 21st level! ! As shown in the T region of iI, when the rotation speed becomes less than the reference value (in this example, the reference value is set to the idle rotation speed), the control unit 12 controls the power transistor 1.
A pulsed signal, which is the basis of the waveform shown in FIG. 3, is applied to the base of FIG. This pulse signal is emitted multiple times per hour,
The pulse width is also set to be short at first and to become longer as time passes. When this base signal is applied to the power transistor 13, since the key switch 2 is in the a contact, the current of the battery 1 is applied to the wiring 15.
Control unit 12. The current flows to the attraction coil 41 via the wiring 17. At this time, the average voltage of the pulsed applied voltage (shown in FIG. 3) applied to the attraction coil 41 gradually increases over an hour.

Therefore, the plunger 42 is gradually attracted, and the pinion 8
The pinion 8 gradually meshes with the ring gear 9 via the shift lever 5, and as a result, the pinion 8 meshes smoothly with the ring gear 9 without impacting, and at the same time, the armature 6 and pinion 8 rotate, increasing the rotation of the engine. do.

When such an increase in engine speed reaches the idle speed, the output level of the rotation sensor 11 reaches the reference value, the base signal applied from the control unit 12 to the power transistor 13 is turned off, and as a result, the pinion 8 also separates from the ring gear 8 with the return operation of the plunger 42,
When the armature 6 stops rotating, it stops and returns to the normal state. Thereafter, even if the engine rotation level drops again, similar control is repeated to prevent engine stalling.

According to this embodiment, even in situations where the engine speed suddenly drops due to external factors and it is difficult for the engine itself to recover the speed by itself, the power of the starter motor can be applied to the engine to increase the engine speed. It becomes possible to raise the amount to a predetermined range. Therefore, in any driving condition of the vehicle.

Engine stall can be effectively prevented. Furthermore, even if the starter is used as a means to prevent engine stalling, by gradually increasing the voltage applied to the magnetic switch 4, the impact of the meshing between the pinion 8 and the ring gear 9 can be alleviated. It is possible to prevent problems from occurring.

〔Effect of the invention〕

As described above, according to the present invention, supplementary rotational force can be applied to the engine from the outside when the engine speed temporarily decreases, so that engine stalling can be effectively prevented in any operating state of the vehicle.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram showing one embodiment of the present invention;
The figure is a characteristic diagram showing an example of the engine speed when the vehicle is running, and FIG. 3 is a waveform diagram showing the voltage applied to the magnetic switch coil of the starter when the engine speed decreases. 1... Battery, 2... Key switch, 4... Magnetic switch, 5, 6.42... Starter mechanism (shift lever, starter motor, plunger), 8...
...Pinion 49...Ring gear, 11...Rotation sensor. 12.13... Voltage control means (control unit, power transistor).

Claims (1)

[Claims] 1. A magnetic shift starter that excites the plunger attraction coil of the magnetic switch to operate the starter mechanism, a rotation sensor that detects the rotational state of the engine, and a voltage applied to the coil that excites the plunger attraction coil. further comprising voltage control means for controlling the plunger suction coil, when the rotation sensor detects a decrease in engine rotation speed below a set level, the voltage control means gradually increases the voltage applied to the plunger suction coil when the engine rotation speed decreases. An engine stall prevention device for a vehicle engine, characterized in that the device is configured to apply a voltage of: