JPS6121556Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a starting assist device for a diesel engine with an exhaust turbo.

In conventional diesel engines, an exhaust turbo (supercharger) was sometimes installed to improve the output, but in this case, a means of lowering the compression ratio in the cylinder was used to prevent the cylinder pressure from rising excessively. It was common practice.

Therefore, such a diesel engine with an exhaust turbo has the drawback that the compression temperature in the cylinder does not rise during cold starting, and the engine startability is extremely poor.

The present invention was devised in order to eliminate the above-mentioned drawbacks, and provides an ideal starting assist device that can quickly promote warm-up during a cold start in conjunction with the starting operation.

Hereinafter, one embodiment will be described with reference to the drawings. 1
is a V-type diesel engine, and has a left bank 2 and a right bank 3 including a plurality of cylinders, and each bank is provided with intake passages 4, 5 and exhaust passages 6, 7, respectively.

8 is an exhaust turbo disposed in the middle of the collective exhaust passage 9, and 8a is a compressor portion thereof, the lower portion of which is connected to the intake passages 4 and 5 via an intercooler 10, respectively.

Note that 11 is an air filter.

Further, a normally open exhaust throttle valve 12 that throttles the exhaust gas only when activated is arranged at the rear of the exhaust turbo 8 and is operated by an actuator 13.

Next, among the intake passages, the intake passages to some cylinders, for example, the intake passage 4 on the left bank 2 side and the intercooler 10.
A normally open intake throttle valve 14 that throttles the intake air only when activated is disposed between the intake throttle valve 14 and the intake throttle valve 14, which is operated by an actuator 15.

On the other hand, 16 is a circuit for operating the actuators 13 and 15, including a starting contact ST of a key switch 18 connected to a power supply 17 at a base end 18a, a normally open neutral detection switch 19 that closes only when the transmission is in a neutral state, and a normally open neutral detection switch 19 that is closed only when the transmission is in a neutral state. A normally closed type rotation speed detection switch 20 that closes when the engine temperature is below the set value, a normally closed temperature detection switch 21 that closes when the engine temperature is below the set value, and a normally closed temperature detection switch 21 that closes when the engine temperature is below the set value. The connection is made via a normally closed oil pressure detection switch 22.

Note that 23 is a starter relay connected to the starting contact ST, and 24 is a starter that is activated when the excitation is activated.

In the embodiment of the present invention configured as described above,
When the key switch 18 is connected to the starting contact ST during a cold start, each switch 1 in the operating circuit 16
Since actuators 9, 20, and 21 are in the closed state, the actuators 13 and 15 are energized, and their operation closes the exhaust throttle valve 12 and the intake throttle valve 14.

Therefore, the exhaust gas is throttled and a portion of the intake air, i.e.
Since the intake air in the intake passage 4 on the left bank 2 side is throttled, the temperature within each cylinder quickly reaches its upper limit, facilitating combustion within the cylinders.

At the same time as these operations, the starter relay 23 is energized, and the starter 24 is started.

Also, depending on whether the engine 1 starts up and the engine speed reaches a set value, e.g., 500 to 700 rpm, or whether the oil pressure reaches a set value, e.g., 1 to 3 Kg/cm ² , the rotation speed detection switch 20 or oil pressure detection is activated. When the power supply is cut off by opening the switch 21, the actuators 13 and 15 return to their inoperative state, so that the exhaust throttle valve 12 and the intake throttle valve 14 are immediately fully opened.

Therefore, there is no possibility that the arrangement of the throttle valves 12 and 14 will interfere with the starting operation of the engine.

Note that if the transmission is not in the neutral state, the neutral detection switch 19 will open, and if the engine temperature exceeds the set value, the temperature detection switch 20 will open, so in this case, connect the key switch 18 to the start contact ST. It goes without saying that the circuit 16 is not energized even if the voltage is changed.

As described above, the present invention has the effect of providing an ideal starting aid device that can quickly promote warm-up during a cold start in conjunction with the starting operation in a diesel engine equipped with an exhaust turbo to improve output. There is.

[Brief explanation of the drawing]

The figure is a schematic system diagram showing an embodiment of the present invention. 1... Engine, 2... Left bank, 3... Right bank, 4, 5... Intake path, 6, 7... Exhaust path, 8...
...Exhaust turbo, 12...Exhaust throttle valve, 14...Intake throttle valve, 13, 15...Actuator, 16
...Operating circuit, 18...Key switch, 19...
...Neutral detection switch, 20...Rotation speed detection switch, 21...Temperature detection switch, 22...
...Oil pressure detection switch, 23...Starter relay,
24...Starter.

Claims (1)

[Scope of utility model registration request] In a diesel engine with an exhaust turbo, an intake throttle valve that restricts the intake air only when activated is installed in the middle of the intake path to some cylinders, and the exhaust gas is restricted only when activated in the exhaust path behind the location of the exhaust turbo. An exhaust throttle valve is provided, and each actuator that operates each of the above valves has at least a starting contact of a key switch, a neutral detection switch that closes only when the transmission is in a neutral state, and a rotation speed detection switch that closes when the engine speed is below a set value. A starting assist device for a diesel engine with an exhaust turbo, characterized in that the device is connected via a temperature detection switch that closes when the engine temperature is below a set value, and an oil pressure detection switch that closes when the oil pressure is below the set value.