JPS5834300Y2 - Diesel engine starting aid device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a diesel engine starting assist device that energizes the plug for a certain period of time even after the engine is started.

Conventionally, one way to reduce the noise level of a diesel engine is to lower the compression ratio during operation, but lowering the compression ratio causes white exhaust smoke to be generated after engine startup and during engine idling. accompanies.

Various methods have been proposed to extinguish this white exhaust smoke, but one of them is to use a glow plug, which is used to assist in starting a diesel engine, and keep it energized even after the engine has started. It is known that the generation of exhaust white smoke can be suppressed by keeping the air in the sub-combustion chamber of the engine above a certain temperature.

There is a device that energizes the glow plug even if it is turned off after the engine has started, which energizes the glow plug while the engine coolant temperature is below a predetermined temperature. In addition, when the engine coolant temperature is very low, the AC plug must be energized for a very long time.

The present invention has been developed in view of the above problems, and includes a start detection means that detects the start of a diesel engine and generates a start signal;
timer means for generating an intermittent signal for a certain period of time when a starting signal from the starting detection means is detected; and energizing means for energizing the glow plug used for preheating the diesel engine based on the energizing signal from the timer means. It is an object of the present invention to provide a diesel engine starting auxiliary device which is capable of energizing a glow plug even after starting the engine without requiring an extra sensor.

The present invention will be described below with reference to embodiments shown in the drawings.

The accompanying drawing is an electrical wiring diagram showing one embodiment 1+1 of the present invention.

1 is a battery, 2 is a switch that closes when the engine key is put into the operating device, 3 is a glow plug installed in each cylinder of the engine to preheat the engine, and 4 is a glow plug that is fixed to 3 when switch 2 is closed. The first timer circuit 5 is energized for a certain period of time, and when the engine rotates, the contact point becomes NO (H).
A voltage regulator as a start detection means that switches to the i) side, 6 a thermistor having a custom-made negative resistance value with respect to the engine cooling water temperature, and 7 a water temperature detection device that generates a low level voltage when the resistance value of thermistor 6 is high. A circuit 8 is a second timer circuit as timer means for generating a low level voltage for a certain period of time (approximately 2 minutes) from when the contact of the voltage regulator 5 is switched to the Hi side; Water temperature detection circuit 7 when on Hi side
This is an energizing circuit that energizes the glow plug 3 when a low level voltage is generated simultaneously from the second timer circuit 8 and the second timer circuit 8.

1. The first timer circuit 4 includes a capacitor 10 that starts charging when the switch 2 is closed, and a capacitor 10 that starts charging when the switch 2 is closed.
A comparator 11 that compares the charging voltage with a reference voltage, transistors 12 and 13 that turn on when the output of the comparator 11 is at a - level voltage and the contact of the voltage regulator 5 is on the ground side, and a glow when the transistor 13 is turned on. It is composed of a relay 14 that energizes the plug 3.

In addition, the water temperature detection circuit 1 compares the input voltage based on the resistance value of the thermistor 6 and the reference voltage based on the resistance value of the variable resistor 15, and generates a low level voltage when the input voltage is higher than the reference voltage. We are prepared.

Furthermore, the second timer circuit 8 includes transistors 17 and 1B that are turned on when the contact of the voltage regulator 5 is switched to the H1 side, a capacitor 19 that starts charging when the transistor 18 is turned on, and the transistor 19 and the transistor 18. The comparator 20 compares the input voltage at the connection point with a reference voltage and generates a low level voltage when the input voltage is higher than the reference voltage.

Furthermore, the energizing circuit 9 includes a transistor 21 which is turned off when a low level voltage is simultaneously generated from the water temperature detection circuit 7 and the second timer circuit 8 when the contact point of the voltage regulator 5 is on the Hi side; It is composed of a transistor 22 that is turned on when the transistor 22 is turned off, a relay 23 that energizes the glow plug 3 when the transistor 22 is turned on, and a current limiting resistor 24 that limits the current flowing to the glow plug 3.

Next, the operation will be explained with reference to the above configuration.

When the engine key switch is turned on and the switch 2 is closed, the first timer circuit 4 is activated and the glow plug 3 is energized during the charging time of the capacitor 10.

Thereafter, when the preheating of the glow plug 3 is completed and the engine key switch is turned on to the starter device and the starter is turned to start the engine, the contact point of the voltage regulator 5 is switched to the Hi side.

Due to this switching to the Hi side, the transistors 1γ and 18 of the second timer circuit 8 start operating, and the capacitor 19 starts charging, so that the comparator 20 generates a low level voltage.

Furthermore, in the water temperature detection circuit 7, a comparator 16 compares an input voltage based on the resistance value of the thermistor 6 when the engine cooling water temperature is low with a reference voltage based on the variable resistor 15, and generates a low level voltage. Φ.

Then, due to the low-level voltage from the water temperature detection circuit 7 and the second timer circuit 8, the transistor 21 is turned off and the transistor 22 is turned on in the energizing circuit 9, and the relay 23 is operated to activate the glow plug 3. to current limiting resistor 24
Electricity is supplied through the .

After that, the temperature of the engine coolant increases, and the input voltage based on the resistance value of the water temperature detection circuit 71/l- and the servo star 6 becomes lower than the reference voltage, resulting in a higher level voltage than the converter 1'6. occurs or the second timer circuit 8
Then, the input voltage based on the charging voltage of the capacitor 19 becomes lower than the reference voltage, and a voltage at a noise level is generated from the comparator 20, and a high level voltage is applied to the energizing circuit 9 by one of the circuits. When this occurs, the transistor 21 is turned on and the transistor 22 is turned off, so that the relay 23 stops operating and the supply of electricity to the glow plug 3 is stopped.

In this embodiment, the energization circuit 9 stops energizing the glow plug 3 based on the OR logic between the voltage at . . . level from the water temperature detection circuit 7 and the voltage at . . Therefore, when the engine coolant temperature is very low, the output of the second timer circuit determines the time to energize the glow plug 3 to prevent batch no rise.
If the engine cooling water temperature is relatively high, the water temperature detection circuit 7
The power supply time to the glow plug 3 is determined based on the output of the glow plug 3, thereby preventing unnecessary loss of battery power.

Although the voltage regulator 5 is shown as the start detecting means in the above embodiment, an engine rotation detector that detects when the engine speed exceeds a predetermined speed may be used as a means for detecting the start of the engine.

Furthermore, a current limiting resistor 24 is provided to control the current flowing to the glow plug 3 after the engine is started, since no current is required during preheating before starting the engine. The current may be intermittent.

As described above, the present invention includes a start detection means that detects the start of a diesel engine and generates a start signal, and a timer means that generates an intermittent signal for a fixed period of time when the start signal from the start detection means is detected. The engine is started in response to temperature detection means, upper Na movement detection means, timer means, and temperature detection means for detecting the temperature of the engine and generating an electric signal indicating a magnitude relative to the engine temperature. and energizing means for energizing the gummy plug used for preheating the engine either after the predetermined time has passed or when the engine temperature has reached a reference temperature. After the engine has actually started, energize the glow plug after starting.
This can be done for as long as needed, and unnecessary battery power loss can be avoided.

[Brief explanation of the drawing]

The accompanying drawing is an electrical wiring diagram showing an embodiment of the present invention. 3... Claw lug, 5... Voltage regulator as start detection means, 8... Second timer circuit as timer means, 9... Energization circuit as energization means.

Claims (1)

[Claims for Utility Model Registration] Start detecting means for detecting the start of a diesel engine and generating a start signal; generating a first electrical signal representing a certain period of time in response to the start signal from the start detecting means; timer means; temperature detection means for detecting the temperature of the engine and generating a second electrical signal indicating the magnitude of the engine temperature with respect to the reference temperature; in response to the death and the second electrical signal;
When the engine is started and running, energizing means energizes the glow plug used for preheating the engine either when the predetermined time period passes or when the engine temperature reaches a reference temperature. A diesel engine starting assist device comprising: