JPH021464Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a warm-up device for a vehicle diesel engine.

Conventionally, in diesel engines, the amount of fuel injection is increased by throttling the exhaust throttle valve or intake throttle valve provided in the exhaust passage or intake passage.
Techniques for suppressing white smoke emissions and improving warm-up performance are well known (for example, Japanese Patent Laid-Open No. 51
-Refer to Publication No. 19096).

On the other hand, vehicle interior heating systems that heat the vehicle interior using the heat of the engine's cooling water are commonly used. However, the cooling water temperature is still lower than the temperature suitable for good heating, the heating performance of the vehicle interior heating system is low, and there is a problem that it takes a long time to obtain good heating. Regarding warm-up, it is necessary to automatically close the exhaust throttle valve or intake throttle valve when the temperature is below a certain temperature, regardless of the driver's intention due to emission performance and product characteristics such as white smoke emission.
On the other hand, from the standpoint of heating performance, it is not necessarily necessary to automatically operate the intake throttle valve or exhaust throttle valve.
Activation based on the driver's request is more advantageous in terms of fuel efficiency and drivability.

Therefore, the present invention automatically warms up the engine by closing the throttle valve when the engine is cold, suppressing the emission of white smoke, and also automatically closes the throttle valve when the driver operates the cabin heating system. This is intended to improve heating performance by continuing to promote warm-up and quickly raising the cooling water temperature to a temperature suitable for heating.

The present invention achieves the above object by providing a throttle valve in at least one of the intake passage and the exhaust passage of the engine, and closing the throttle valve to a predetermined opening when the engine is cold. In the device, a warm-up circuit that closes the throttle valve when the temperature is below a first set temperature based on the output of a first temperature detector that detects a warm-up state of the engine, and a vehicle interior heating system connected in parallel to the warm-up circuit. a heating circuit that closes the throttle valve using a switch that closes when activated or a manual switch, and the heating circuit closes the throttle valve when the temperature is higher than a second set temperature that is higher than the first set temperature. It is equipped with a second temperature sensor that releases the temperature.

Hereinafter, the specific configuration of the present invention will be explained with reference to the drawings. In the diesel engine 1 shown in FIG. 1, 2 is a cylinder block with a piston 3 inside, 4 is a cylinder head, 5 is an intake passage that supplies intake air to a combustion chamber 6, and 7 is a cylinder that discharges exhaust gas from the combustion chamber 6. Exhaust passage, 8 is an intake valve, 9 is an exhaust valve,
Reference numeral 10 indicates a fuel injection nozzle which is disposed in the cylinder head 4 and supplies fuel directly to the combustion chamber 6.

Further, reference numeral 11 indicates an intake throttle valve installed in the intake passage 5, and reference numeral 12 indicates an exhaust throttle valve installed in the exhaust passage 7. The intake throttle valve 11 is opened and closed by the first actuator 13, and the exhaust The throttle valve 12 is opened and closed by a second actuator 14. The first and second actuators 13 and 14 are constituted by pressure actuators using diaphragms that use negative pressure as an operating source.
The negative pressure chambers 13a and 14a of No. 4 are connected to a pressure source 16 (vacuum pump) via a pressure passage 15, and when negative pressure is introduced from the pressure source 16, the intake and exhaust throttle valves 1
1 and 12 are closed to a predetermined opening degree, and the negative pressure chambers 13a and 14a are closed.
It is operated to open by springs 13b and 14b which are compressed.

The pressure passage 15 is branched into first and second branch pressure passages 15b and 15c on the downstream side of the branch portion 15a, and connected to the first and second actuators 13 and 14, respectively. Branch part 15a
On the upstream side of the
A common on-off valve 17 (3-way solenoid valve) for simultaneously operating 3 and 14 is installed,
A switching valve 18 is provided in the second branch pressure passage 15c on the exhaust side.
(3-way solenoid valve) and a pressure control valve 19 is interposed on the upstream side of the switching valve 18,
A delay valve 20 is provided upstream of the pressure control valve 19.

The pressure control valve 19 has a leak valve 19c that opens and closes the atmospheric hole 19b by means of a diaphragm 19a that responds to exhaust pressure on the upstream side of the exhaust throttle valve 12. It is configured to adjust the negative pressure introduced. Furthermore, the delay valve 20 is configured to delay transmission of the pressure to the first actuator 13 on the upstream side, that is, on the intake side, when the pressure on the pressure control valve 19 side increases.

Furthermore, 21 is an intake throttle valve 11 for the intake passage 5.
22 is a bypass valve that opens and closes the bypass passage 21, and this bypass valve 22 is operated by a diaphragm 22a that responds to the pressure (negative pressure) downstream of the intake throttle valve 11. The combustion chamber 6 has a valve body 22b that adjusts the suction pressure into the combustion chamber 6 to be constant.

The pressure passage 15 branches on the upstream side of the on-off valve 17, and the other end is connected to the switching valve 18 for the second actuator 14, and is connected to the first idle actuator 24 via the second on-off valve 23. An auxiliary pressure passage 15d connected to the first idle actuator 24 is formed.
is linked to the increase lever 25a of the fuel injection pump 25 that feeds fuel to the fuel injection nozzle 10, and operates to increase the amount of fuel injected when negative pressure is introduced.

The switching valve 18 connects the second branch pressure passage 15c and the second actuator 14 when it is not in operation, and connects the auxiliary pressure passage 15d and the second actuator 1 when it is in operation.
4, and when the switching valve 18 is operated to close the exhaust throttle valve 12 to a predetermined opening, the exhaust brake is activated, and the exhaust resistance is increased to enhance the engine braking effect.

FIG. 2 shows a circuit for controlling the operation of the on-off valve 17, the switching valve 18, and the second on-off valve 23. water temperature switch),
They are connected via a second temperature detector 30 (water temperature switch), feed switch 31, and relay 32. A heating switch 33 is connected in parallel to the first temperature detector 29.

The first temperature detector 29 detects the warm-up state of the engine from the cooling water temperature, and closes when the temperature is below the first set temperature (approximately 50°C), and the second temperature detector 3
0 is opened when the cooling water temperature is higher than the second set temperature (approximately 80°C) which is higher than the first set temperature. Further, the acceleration switch 31 is configured to open when the accelerator is operated, and the relay 32 is configured to close when the accelerator switch 34 is closed due to no accelerator operation, that is, in a no-load condition. . Furthermore, the heating switch 33 is configured with a switch or a manual switch that closes in conjunction with the operation of a vehicle interior heating system (not shown) that heats the interior of the vehicle using the calorific value of cooling water. , which is closed when attempting to heat the interior of the vehicle.

Further, a second on-off valve 23 is connected between the acceleration switch 31 and the relay 32, and an indicator light 35 is connected in series with the heating switch 33.

On the other hand, a power source 26 is connected to the switching valve 18 via an exhaust brake switch 36, a neutral switch 37, a clutch switch 38, and a relay 39.

The exhaust brake switch 36 is a manual switch that is closed when it is necessary to operate the exhaust brake, the neutral switch 37 is opened when the transmission is in the neutral position, and the clutch switch 38 is closed when the clutch is engaged. The relay 39 is connected to the relay 3.
2, it is configured to close when the accelerator switch 34 is closed.

Further, an indicator light 40 is connected in series with the exhaust brake switch 36, and diodes 41, 42,
43 is interposed to prevent malfunction.

In the above configuration, a warm-up circuit A is formed in which the on-off valve 17 is opened by closing the first temperature detector 29 below the first set temperature, and the intake throttle valve 11 and the exhaust throttle valve 12 are closed. A heating switch 33 is connected in parallel with the machine circuit A up to the second set temperature.
When closed, a heating circuit B is formed which closes the on-off valve 17 and closes the intake throttle valve 11 and the exhaust throttle valve 12, and further includes an exhaust brake switch 36 in parallel with the warm-up circuit A and the heating circuit B. An exhaust brake circuit C is formed.

Next, the operation will be explained. First, when the engine is cold, that is, when the cooling water temperature is below the first set value,
When the vehicle is stopped to warm up, an activation signal is output to the on-off valve 17 by closing the first temperature sensor 29, second temperature sensor 30, acceleration switch 31, and relay 32, and this on-off valve Reference numeral 17 connects the pressure passage 15 to the pressure source 16 from an open state to the atmosphere, introduces negative pressure into the first and second actuators 13 and 14, and closes the intake and exhaust throttle valves 11 and 12. As a result, the engine load increases due to the increase in intake resistance and exhaust resistance, and accordingly, the fuel injection amount also increases, the amount of heat generated increases, and warm-up is promoted.

At this time, if the exhaust pressure upstream of the exhaust throttle valve 12 fluctuates due to fluctuations in the engine speed, etc., the pressure control valve 19, which operates according to this pressure, introduces atmospheric air into the second branch pressure passage 15c, causing a negative The pressure is adjusted and the opening degree of the exhaust throttle valve 12 is changed to keep the exhaust pressure constant. Further, in the above state, the second branch pressure passage 1 is controlled by the pressure control valve 19.
5c, the transmission of this pressure increase is delayed by the delay valve 20, so that fluctuations in the negative pressure to the first actuator 13 are small, and as a result, the opening degree of the intake throttle valve 11 is reduced. increases without making the engine unstable.
The suction pressure is regulated by a bypass valve 22.
Thereby, predetermined opening/closing operations can be performed with a simple structure without disposing the opening/closing valve 17 for each of the first and second actuators 13, 14.

At the time of promoting warm-up, the second on-off valve 23
An activation signal is also output to the first idle actuator 24, and the fuel injection amount is increased more actively.

When the cooling water temperature rises above the first set temperature (approximately 50°C), the warm-up promotion operation is stopped by opening the first temperature detector 29, but heating is resumed by using the vehicle interior heating system or by manual operation. When the switch 33 is closed, the warm-up promotion operation continues even if the first temperature detector 29 is opened, and when the cooling water temperature reaches the second set temperature (approximately 80°C) or higher, the second temperature
The on-off valve 17 and the second on-off valve 23 operate until the temperature detector 30 opens, and the intake throttle valve 11 and the exhaust throttle valve 12 close. This results in
The cooling water temperature quickly rises to a temperature suitable for heating the vehicle interior, and good heating performance is obtained.

Note that when a brake operation is performed while the vehicle is running, the transmission is in a position other than neutral and the clutch is connected, so that the neutral switch 37 and the clutch switch 38 close together with the exhaust brake switch 36. and the accelerator switch 3 when decelerating.
4 closes the relay 39, an actuation signal is output to the switching valve 18, and this switching valve 18
from the second branch pressure passage 15c side to the auxiliary pressure passage 1
5d, negative pressure is introduced into the second actuator 14, and the exhaust throttle valve 12 is closed. This increases the engine braking effect due to the increased exhaust resistance, thereby doubling the braking force.

In the above embodiment, the throttle valves 11 and 12 are provided in the intake passage 5 and the exhaust passage 7, respectively, but the throttle valves 11 and 12 may be provided in either one.

As explained above, according to the present invention, a warm-up circuit is provided that automatically closes the throttle valve provided in at least one of the intake passage and the exhaust passage when the engine is in a cold state. By installing a heating circuit that closes the above-mentioned throttle valve in parallel with the operator's operation, such as a switch or manual switch linked to the heating device, warm-up performance is improved and white smoke countermeasures are reliably achieved.
When the vehicle interior heating device is operated, warm-up promotion is continued, and the coolant temperature is quickly raised to a temperature suitable for heating, which has the advantage that good heating performance can be obtained.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, with FIG. 1 being a schematic configuration diagram of a diesel engine, and FIG. 2 being an electric circuit diagram showing a control system. 1... Diesel engine, 5... Intake passage,
7... Exhaust passage, 11... Intake throttle valve, 12... Exhaust throttle valve, 13, 14... Actuator, 15...
...Pressure passage, 17...Opening/closing valve, 18...Switching valve,
29...First temperature detector, 30...Second temperature detector, 33...Heating switch, A...Warming circuit, B
...Heating circuit.

Claims (1)

[Scope of utility model registration request] In a warm-up device for a diesel engine for a vehicle, the warm-up state of the engine is detected in a warm-up device for a diesel engine for a vehicle, which includes a throttle valve in at least one of an intake passage and an exhaust passage of the engine, and the throttle valve is closed to a predetermined opening when the engine is cold. A warm-up circuit that closes the throttle valve when the temperature is lower than the first set temperature according to the output of the first temperature detector, and a warm-up circuit that closes the throttle valve when the temperature is below the first set temperature, and a switch or a manual switch that closes the throttle valve when the vehicle interior heating system is activated are connected to the warm-up circuit. a heating circuit that closes the throttle valve, and the heating circuit includes a second temperature detector that releases the closing operation of the throttle valve when the temperature is higher than a second set temperature that is higher than the first set temperature. A warm-up device for a vehicle diesel engine, characterized by: