JPS6161977A - Electrification control device of glow plug - Google Patents

Abstract

PURPOSE:To prevent wasteful power consumption, by providing a voltage applying circuit which applies voltage to a glow plug detector terminal while an electrification control timer setting an electrification time to a glow plug in accordance with its voltage operates. CONSTITUTION:If a key switch is turned on, a control device, charging a capacitor C1 for determining the time constant of a delay switching circuit 51 in an electrification control timer 5, compares charge voltage V1 of the capacitor C1 with the reference voltage V2 in a comparator Cp. The comparator Cp, generating an output of high level while the capacitor C1 is charged, in this way turns on a transistor Tr to urge a relay 1, starting a glow plug G to be electrified. And the output of an amplifier AMP is applied only for a timer operating time of the delay switching circuit 51 to a glow plug detector terminal A through a detector terminal voltage applying circuit 53. In this way, the control device operates so as to enable the capacitor C1 to be charged even when glow plug voltage is not input to the terminal A due to a trouble or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an energization control device for a glow plug used to assist in starting an engine.

[Prior Art] As shown in Fig. 4, a conventional glow plug energization control device includes a battery SAT as a power source, a glow plug G for rapid stomach warming installed in an auxiliary combustion chamber, a battery BAT, and a rapid stomach warming control device. A non-energized OF provided between the drying glow plug G and
F terminal, ON terminal for energizing glow plug G, S for energizing glow plug G and starter motor
A key switch S having a T terminal, a relay 1 for rapid gastric warming consisting of a normally open contact 1a and a coil 1b for supplying a large current to the glow plug G to quickly make the stomach dry a humidity maintenance energizing relay 2 consisting of a normally open contact 1a and a coil 2b for passing a limited current through a current limiting resistor 3 in order to maintain the temperature after the temperature has been lent to the temperature; 1 rice relay 2
The energization control device 4 includes an energization control timer 5 for controlling the energization of the relay 1 and an afterglow timer 6 for controlling the energization of the relay 2. The energization control timer 5 is provided to start operating when the key switch S is turned on to the ON terminal, and the voltage applied from the glow plug detection terminal that detects the voltage of the glow plug G is the timer operating time. The capacitor C1 for determination is charged, and during charging, the comparator Cp generates a high-level output, energizes the coil 1b of the relay 1, and supplies a large current to the glow plug G, and when the capacitor C1 is completely charged. Coil 1b of relay 1 with the output of comparator Cp at low level
was de-energized and the supply of large current to glow plug G was stopped. If the lead wire A1 connecting the glow plug G and the glow plug detection terminal A to detect the voltage of the glow plug G is not input due to a poor contact of the coupler or a disconnection of the wire harness, the capacitor C1 will not be charged. Conventionally, resistor Ra and lead wire Rb
is provided so that a voltage is constantly applied to the glow plug detection terminal A through the glow plug detection terminal A, and when the glow plug detection terminal A is open, a voltage is applied to the glow plug detection terminal via the resistor Ra, and the power is supplied to the capacitor C1. Charging is performed using voltage to prevent the glow plug G from blowing out.

[Problems to be Solved by the Invention] In the conventional technology shown above, when the key switch S is turned on to the ON terminal, the glow plug detection terminal Δ and the power supply are connected to the resistor Ra.
Since the resistor Ra is always energized through the resistor Ra, the resistor Ra always consumes power after the energization control timer 5 times up (when the relay 1 is not energized). Also, since the resistor Ra is always energized while the ON terminal is turned on, it is necessary to increase the power capacity so that the resistor Ra does not generate heat.
The shape was large.

An object of the present invention is to shorten the resistor Ra by providing a detection terminal voltage application circuit that applies voltage to the glow plug detection terminal only while the energization control timer is activated and the glow plug is energized. It can be time rated and can be made small. In addition, the power consumption in the resistor Ra is only when the energization control timer is moved;
An object of the present invention is to provide a glow plug energization control device that can solve problems such as heat generation.

[Means for Solving the Problems 1] In order to solve the above-mentioned problems, the glow plug energization control device of the present invention has a glow plug detection terminal that detects the voltage of the glow plug, and controls the glow plug according to the voltage. In a glow plug energization control device equipped with an energization control timer that sets the energization time to the plug, only while the energization control timer is activated and the glow plug is energized,
A detection terminal voltage application circuit for applying a voltage to the glow plug detection terminal is provided.

[Operation and Effects of the Invention] The glow plug energization control device of the present invention having the above configuration applies voltage to the glow plug detection terminal only while the energization control timer is activated and the glow plug is energized. By providing a detection terminal type pressure application circuit,
The power consumption applied to the glow plug detection terminal is only consumed when the energization control timer is activated, and the power consumption by the resistor provided in the detection terminal voltage application circuit applied to the glow plug detection terminal can be reduced. Further, the resistor provided in the detection terminal voltage application circuit can be made small in size because it can be rated for a short time by being energized only when the energization control timer is activated.

[Embodiment] Next, a glow plug energization control device of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is an electrical circuit diagram showing a first embodiment of the glow plug energization control device of the present invention.

BAT is N8! , G is a glow plug for rapid temperature rise installed in the auxiliary combustion chamber, S is inserted between battery BAT and glow plug G, and 0FF4itt.
A key switch that has an ON terminal for energizing the glow plug G and an ST terminal for energizing the glow plug and starter motor, -〇-1 supplies a large current for the purpose of rapidly raising the temperature of the glow plug G. 2 is a rapid armpit warming relay consisting of a normally open contact 1a and a coil 1b, and 2 is a current limiting resistor 3 for maintaining the temperature after the glow plug G has reached a predetermined temperature.
a normally open contact 2a for carrying a limited current through the
, a temperature maintenance energization relay consisting of a coil 2b, and 4 a energization control device for a glow plug G for controlling the relays 1 and 2.

The energization control device 4 includes an energization control timer 5 that turns on the relay 1'' for a set time after the key switch S is turned on to the ON terminal, and a energization control timer 5 that turns on the relay 2 under predetermined conditions even after the engine is started to reduce smoke exhaust. , aimed at rotational stability,
It consists of an afterglow timer 6 that performs so-called afterglow, and the energization control timer 5 is connected to the glow plug G.
capacitor C1 for determining the time constant;
Comparator Cp1 resistor R that inputs charging voltage of 1
1 to R10, diodes D1 to D4, and Zener diodes 71 to Z3, and generates a high-level output for a certain period of time while the capacitor C1 is being charged after the key switch S is turned on to the ON terminal; Amplifier AMP1
, resistor R11, transistor Tr1 diode D5
, D6, a relay RL consisting of a coil Co1 and a normally open contact J1, which are turned on and off by the operation of a transistor Tr.Relay 1 is activated only when receiving a high level output from the timer circuit 51.
A relay energizing circuit 52 that energizes, and the relay energizing circuit 5
The afterglow timer 6 includes a detection terminal voltage application circuit 53 that connects the output position of the amplifier AMPI No. 2 and the glow plug detection terminal A via a resistor Ra and a diode [)a. A charging detection terminal 61 of a regulator that produces a low level output and a high level output during charging, for example, a water temperature sensor switch 62 that is turned off when the engine coolant temperature is below a predetermined temperature, and a water temperature sensor switch 62 that is turned off when the vehicle is stopped. A logic circuit 64 that receives the vehicle speed sensor switch 63 as an input and operates the relay 2 when, for example, the coolant temperature is below a predetermined temperature, the vehicle speed is below a predetermined vehicle speed, and the voltage applied to the glow plug G is below a predetermined value. It consists of an amplifier AMP2 that amplifies the output of the circuit 64 and operates the relay 2.

The above operation will be explained.

When the key switch S is connected from the OFF terminal to the ON terminal, the time limit circuit 51 of the energization control timer 5 has the capacitor C1 for determining the time constant discharged, and the charging voltage 1 of the capacitor C1 and the resistors R7 and R8 The comparator Cp compares the determined reference voltage 2 and produces a high level output while the capacitor C1 is being charged. As a result, the output of the comparator Cp applies a voltage to the base of the transistor Tr of the relay energizing circuit 52 through the amplifier AMP1, thereby energizing the collector and emitter of the transistor ■r, and energizing the coil CO1 to close the normally open contact J1. The second relay 1 is turned on to raise the temperature of the glow plug G to a predetermined temperature range necessary for smooth engine starting, thereby facilitating engine starting.

The afterglow timer 6 uses the relay 2 to stabilize combustion immediately after the engine starts, and turns the relay 2 on via the current limiting resistor 3 for the purpose of stabilizing rotation, reducing smoke emissions, etc.
Turn it to N and energize the glow plug.

Here, if the glow plug voltage is not input to the glow plug detection terminal due to poor contact of the coupler of the lead wire A1 applied to the glow plug detection terminal or disconnection of the wire harness, the time limit circuit 51 of the energization control timer 5 Since the output of the amplifier AMP1, which is output only during the timer operation time, is applied to the glow plug detection terminal A by the detection terminal voltage application circuit 53, this charge causes the capacitor C1 to
After charging of the capacitor C1 is completed, the output of the amplifier AMPI via the comparator Cp is set to a low level, so that it is not output to the glow plug detection terminal A.

FIG. 2 shows an electric circuit diagram of a second embodiment of the glow plug energization control device of the present invention.

The detection terminal voltage application circuit 53 of this embodiment is composed of a resistor Ra and a diode Da as in the above embodiment, and has a normally open contact J1 of the relay RL of the relay energizing circuit 52.
11 and the glow plug detection terminal A, the normally open contact J1 of the normally open relay RL closes, and the relay 1
A voltage is applied to the glow plug detection terminal A via a detection terminal voltage application circuit 53 only when the coil 1b is energized.

FIG. 3 shows an electrical circuit diagram of a third embodiment of the invention.

The detection terminal voltage application circuit 53 of this embodiment consists of an inverter Ia, which is an inversion circuit, and a resistor Ra, and includes a transistor T.
r and the coil CO1 are connected to the glow plug detection terminal A, and while the capacitor C1 is being charged, the output of MPl to the comparator Cp and the amplifier is connected to the transistor Tr.
The voltage is applied to the base of the transistor Tr, and the voltage is applied to the glow plug detection terminal A via the detection terminal voltage application circuit 53 only when the collector and emitter of the transistor Tr are connected.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a first embodiment of the glow plug energization control device of the present invention, FIG. 2 is a circuit diagram showing a second embodiment of the glow plug energization control device of the present invention, and FIG. FIG. 4 is a circuit diagram showing a third embodiment of the glow plug energization control device of the present invention, and FIG. 4 is a circuit diagram showing a conventional glow plug energization control device.

Claims (1)

[Claims] 1) In a glow plug energization control device having a glow plug detection terminal that detects the voltage of the glow plug, and comprising an energization control timer that sets the energization time to the glow plug according to the voltage, the energization control timer 1. A glow plug energization control device comprising a detection terminal voltage application circuit that applies a voltage to the glow plug detection terminal only while the glow plug is activated and the glow plug is energized.