JPS5960041A - Safety device for vehicle driven by diesel engine - Google Patents

Abstract

PURPOSE:To prevent uncontrollable operation of a diesel engine and to reduce vibration of the same, by connecting an accelerator switch, a brake switch and a thermo-switch to a control circuit for a throttle valve of the engine, and reducing the flow rate of intake air at the time of actuating the brake and idling operation when the engine temperature is not low. CONSTITUTION:A vacuum driving mechanism 9 for an intake throttle valve 101 is connected to a vacuum pump 7 via a vacuum switch valve 8. A parallel circuit of a thermo-switch 11 that is operated in response to the engine temperature and a brake switch 4 that is turned ON when the brake pedal is depressed is connected in series to a control circuit for the valve 8. Further, an accelerator switch 6 that is turned OFF when the accelerator pedal is depressed is also connected in series to the control circuit for the valve 8. When the engine temperature is low, the thermo-switch 11 is opened and the valve 8 is kept closed. However, when the brake pedal is depressed without depressing the accelerator pedal at the time of idling operation or actuating the brake after the engine is warmed up or when the switch 5 is turned ON by cancelling automatic engine operation, the valve 8 is opened and the throttle valve 101 is closed. By thus reducing the flow rate of intake air, it is enabled to prevent uncontrollable operation of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safety device for a diesel vehicle that throttles intake air during idling and braking of a diesel engine to prevent runaway of the engine.

Diesel engines have higher thermal efficiency and are more economical in fuel consumption than gasoline engines, so they have recently been increasingly used in passenger cars. However, there is a problem in that they generate more vibration and noise than gasoline engines. In particular, during idling, the torque fluctuations within one cycle, that is, the angular velocity fluctuations, are large, resulting in large vibrations.

The reason why the angular velocity fluctuations are large during idling in a diesel engine is because the compression pressure is extremely high.
As a countermeasure, either lowering the compression ratio or throttling the intake air 9 can be considered. However, the former method may cause deterioration in startability or increase harmful exhaust gas components such as hydrocarbons (HC). Therefore, focusing on the latter intake throttle, a system was first proposed in Utility Model Application No. 53-117459 that effectively reduces angular velocity fluctuations during idling of a diesel engine and the accompanying rolling vibrations. .

However, the intake throttle mechanism in the prior art simply uses a spring to constantly bias the intake valve in the direction of closing the intake pipe.
The intake valve is moved in the opening direction by the intake air flow, and is only used as a countermeasure during idling. By the way, when you take your foot off the accelerator pedal during braking, the amount of fuel supplied decreases, but since the car and engine are still rotating, the amount of air taken into the engine immediately decreases and disappears. To that end, we need to consider the following: 1. With the prior art developed in 1. The engine continued to rotate for a while, and there was no effective braking aid. In addition, when idling, the engine temperature does not necessarily rise, and if the intake air is throttled even when the temperature is low, the engine operation deteriorates and it takes a lot of time to drive. 3. The present invention attempts to solve these problems (1), and its purpose is to throttle the intake air during idling and braking to prevent the diesel engine from running out of control, reduce vibration and noise, and An object of the present invention is to provide a safety device for a diesel engine that allows an effective braking action to be performed by the engine, but prevents the intake throttle from acting when the engine is at a low temperature.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 d shows the configuration of the embodiment of the present invention. In the figure, 1-control is used to control the transmission based on signals such as the engine speed and throttle input, and 1-control automatically runs. Controls 1-7 and 2 for the intake throttle mechanism 10 of the embodiment of the present invention are turned off during normal driving and turned on when not in use.

10 is an intake throttle mechanism provided in the intake pipe of the engine, and includes an on-off valve 101 provided in the intake pipe, and a shaft of the on-off valve 101 protruding from the intake pipe. Arm 10. which rotates integrally with 10□, and arm 1
02 is the diaphragm 98 of the vacuum actuator 9
It consists of a rod 108 that connects with.

The vacuum actuator 9 is connected to the chamber 9 by means of a diaphragm 9°. (Bakim room) and 9. (Atmospheric chamber) It is divided into two parts: the atmospheric chamber 9 degrees communicates with the atmosphere, and the vacuum chamber 9 degrees communicates with the atmosphere. It is configured to communicate with the chastity pump 7 via the vacuum switch valve 8. Note that 9o is a spring that presses the diaphragm 98.

The vacuum switch valve 8 is provided between the vacuum actuator 9 and the vacuum pump 7, and when the key switch 3, the accelerator switch 6 is closed, and either the brake switch 4 or the relay switch 5 is closed, the vacuum pump 7 is closed.
and the vacuum actuator 9 are communicated with each other 7.
, the key switch 5, the accelerator switch 6, both the brake switch 4 and the relay switch 5 are open, and when all the switches are open, the vacuum pump 9 is configured to communicate with the atmosphere. ing. In addition, 81 represents the state of the flow rate [7, when the vacuum switch valve 8 communicates the vacuum pump 7 and the vacuum actuator 9, the flow rate is throttled, and when there is no communication L7, the flow rate is released to the atmosphere. It represents.

The accelerator switch 6 is turned on by depressing the accelerator pedal, and the brake switch 4 is turned on by depressing the brake. The relay switch 5 consists of a coil part and a switch, and is synchronized with the key switch on and off. A thermoswitch 11 is turned on when the temperature of the engine room reaches 50° C. or higher, and is provided in series with a relay switch 5, and a circuit of the thermoswitch 11 and relay switch 5 is arranged in parallel with the brake switch 4. Note that 2 is a running indicator lamp that lights up during normal running, and 104 is a screw that adjusts the flow rate of the bypass 104.

FIG. 2 shows Table 17 how the operation based on the configuration shown in FIG. 1 is performed by operating each operating member (switch) corresponding to the driving conditions.

When the engine is stopped, the on-off valve 10Fi of the intake throttle mechanism 1 is at the chain line position in the diagram, and the mechanism is fully open. When the key switch 5 is turned on and the engine is started, the switch is turned on, the relay switch 5 is also turned on, and the accelerator switch 6 is on unless the accelerator pedal is depressed, but the thermo switch 11 is activated when the temperature in the engine compartment is 50°C or higher. It will not turn on unless the temperature reaches 50°C, and it will not turn on until the temperature reaches 50°C or higher. Therefore, when restarting or idling, the intake throttle mechanism 10 may be open.
, may be closed.

When I start driving normally, I step on the accelerator pedal, so
The accelerator switch 6 is turned off, and the vacuum switch valve 8 cuts off the communication between the vacuum pump 7 and the vacuum actuator 9, and also communicates the vacuum chamber 91 with the atmosphere, so the diaphragm 9s is pushed by the spring 9° and the atmosphere chamber is closed. 9. Move to the side and open/close valve 10. Move from the solid line position to the chain line position in the figure (between the intake throttle valve mechanisms). Next, when the control device 1 is set to automatic driving and the foot is released from the accelerator pedal, the accelerator switch 3 is turned on, but the relay switch 5 is turned off, so the vacuum switch valve 8 is not activated, and the vehicle is normally driven. The state is the same as that of , and the intake throttle mechanism 10 is opened. When automatic driving is canceled, the relay switch 5 is turned on, so when you take your foot off the accelerator pedal to coast, the accelerator switch 6 is turned on and the vacuum switch valve 8 is activated, causing the vacuum pump 7 and the vacuum chamber 9.
The intake throttle mechanism 10 is closed.

When you take your foot off the accelerator pedal and step on the brake pedal in order to brake in an emergency, the accelerator switch 6 and brake switch 4 are turned on, which activates the 8 vacuum switch valves and activates the intake throttle '!' just like when coasting. N10 is closed.

FIG. 5 shows another embodiment, in which the relay switch and controller are omitted from the embodiment shown in FIG. 1. Therefore, although automatic driving is not possible, other driving can be performed without any problem, and it functions similarly as a safety device.

As described above in detail, the present invention communicates the vacuum chamber of the vacuum actuator that opens and closes the on-off valve provided in the intake pipe with the vacuum pump via the vacuum switch valve, and connects the vacuum switch valve and the power source. A parallel circuit of a thermo switch and a brake switch is connected in series with an accelerator switch and a key switch between them, and the intake air is throttled during idling and braking to prevent the diesel engine from running out of control and reduce vibration and noise. Although a braking action is performed, it is also possible to prevent the intake throttle from acting when the engine is at a low temperature. Furthermore, since the degree of cooling of the engine can be determined by the thermo switch when the engine is about to stop, it is also possible to know when to turn off the key switch when stopping the engine.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation status of each operation part according to the operating state of the engine and the driving state, and Fig. 3 is an explanatory diagram of the configuration of another embodiment. It is. 1... Controller, 3... Key switch, 4...
・Brake switch, 5... Relay, 6... Accelerator switch, 7... Vacuum pump, 8... Vacuum switch valve, 9... Vacuum actuator, 10...
Intake throttle mechanism, 11...Thermoswitch patent applicant Isuso Automobile Co., Ltd.

Claims (1)

[Claims] A vacuum chamber of a vacuum actuator that opens and closes an on-off valve provided in an intake pipe is communicated with a vacuum pump via a vacuum switch valve, and a parallel circuit of a thermoswitch and a brake switch is connected between the vacuum switch valve and a power source. A safety device for diesel vehicles characterized by an accelerator switch and a key switch connected in series.