JPS6143955Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is an engine equipped with a fuel injection device, in which the flow rate of auxiliary air supplied to the engine is controlled during warm-up operation of the engine. This invention relates to an auxiliary air control device for a fuel injection device.

(Prior Art) Conventionally, in an engine fuel injection device, a bimetal is displaced by heat generated by an electric heater, and a passage area of a bypass air passage is controlled according to the displacement of the bimetal that is engaged with one end of the bimetal. An air valve device is provided which includes a valve body and a valve body (see, for example, Japanese Utility Model Application Publication No. 49-42307). This air valve device displaces a bimetal due to heating by the electric heater and an increase in engine wall temperature during engine warm-up, that is, when the engine temperature is below the engine warm-up temperature, and due to the displacement of the bimetal, the valve body While controlling the passage area of the bypass air passage so that it gradually decreases from its maximum area, auxiliary air is supplied to the engine to warm up the engine, and when the warm-up temperature of the engine is completed by reaching the above-mentioned warm-up temperature, the above-mentioned bimetal The operation is controlled so that the passage area of the bypass air passage becomes zero by the maximum displacement of , and the supply of auxiliary air to the engine is stopped.

(Problem to be solved by the invention) In controlling such an air valve device, when the engine temperature is below the engine warm-up temperature and relatively low, the passage area of the bypass passage is enlarged. Increasing the amount of auxiliary air supplied to the engine and the amount of fuel injection associated with it increases the engine speed to warm up the engine early. There is a demand for control to reduce the passage area of the bypass air passage to reduce the auxiliary air flow rate and fuel injection amount, and to lower the engine speed to achieve low fuel consumption and low noise.

However, in the conventional engine fuel injection system, if the control of the air valve device is set to meet the above requirements, when the engine is about to warm up, that is, when the engine temperature is below the warm-up temperature and near the warm-up temperature, Because the engine speed has fallen, the engine is likely to stop even when the engine load increases slightly, such as when operating from N range to D range in a vehicle equipped with a torque converter, and the engine is likely to stop when the engine is about to warm up. A problem arises in that load stability is impaired.

The present invention was developed in response to this problem, and when the engine temperature is below the engine warm-up temperature and within a specific temperature range around the warm-up temperature, the electric heater is stopped and the engine wall temperature is reduced. By displacing the bimetal only by the heating of It is maintained at a relatively high level, thereby satisfying the requirements for early warm-up, low fuel consumption, and low noise during engine warm-up operation, and improving engine load stability near the end of warm-up. The object of the present invention is to provide an auxiliary air control device for a fuel injection device of an engine.

(Means for solving the problem) In order to achieve this object, the solution means of the present invention includes a bimetal that is displaced by heat generated by an electric heater, and a bimetal that is engaged with one end of the bimetal and that responds to the displacement of the bimetal. auxiliary air is supplied through the bypass air passage when the temperature is below the warm-up temperature of the engine, and when it is above the warm-up temperature, In a fuel injection system for an engine in which auxiliary air is reduced to zero by the maximum displacement of a bimetal, a control circuit is provided that stops the operation of the electric heater when the engine temperature is below the warm-up temperature and within a specific temperature range around the warm-up temperature. This is a configuration in which it is provided.

(Function) With the above configuration, in the present invention, when the engine temperature is lower than the engine warm-up temperature and is low, the bimetal is hardly displaced by the operation of the electric heater of the air valve device. First, since the passage area of the bypass air passage is maintained large by the valve body, the flow rate of auxiliary air flowing through the bypass air passage is large, and the amount of fuel injection increases accordingly, causing the engine speed to rise and the engine speed to increase. Warming up is promoted.

As the engine continues to warm up, the bimetal is gradually displaced by heating by the electric heater and by heat conduction from the engine wall temperature, and the passage area of the bypass air passage is reduced by the valve body. The engine speed gradually decreases, but when the engine temperature is below the warm-up temperature and within a certain temperature range around the warm-up temperature, the control circuit stops operating the electric heater, and the bimetallic heater stops operating. is now heated only by heat transfer from the engine wall temperature, and as a result, the degree of displacement of the bimetal becomes gentler.
As a result, the amount of auxiliary air flowing through the bypass air passage is gradually reduced, thereby maintaining the engine speed at a slightly higher speed. Therefore, even if the engine load increases, such as when operating from the N range to the D range in a vehicle equipped with a torque converter, the engine will not stop.

Furthermore, when warm-up of the engine is promoted and the engine temperature rises above the specified temperature range, the electric heater is reactivated due to the deactivation of the control circuit, and the flow rate of auxiliary air flowing through the bypass air passage is reduced to the initial state. It decreases at the same rate of decrease, and when the engine temperature reaches the warm-up temperature, the passage area of the bypass air passage becomes zero, and the warm-up of the engine is completed.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

In FIG. 1, 1 is an engine, 2 is an intake passage of the engine 1, and an air flow meter 3 for detecting the flow rate of air flowing through the intake passage 2 is disposed on the upstream side of the intake passage 2. 3
A fuel injection nozzle 4 is arranged in series on the downstream side of the intake passage 2 via a control device (not shown), and the control device operates the engine according to the air flow rate signal from the air flow meter 3. By controlling the opening time of the fuel injection nozzle 4 using a pulse signal with a pulse width corresponding to the injection amount per rotation, an amount of fuel proportional to the air flow rate flowing through the intake passage 2 is delivered from the fuel injection nozzle 4. An electronically controlled fuel injection device is configured to inject the fuel.
Furthermore, 5 is the intake passage of the engine 1, and 6 is the engine 1.
A cooling water passage formed in the cylinder block 1a,
7 is a piston, 8 is an intake valve, and 9 is an exhaust valve.

Further, 10 is a bypass air passage that bypasses the intake passage 2, and the bypass air passage 1
An air valve device 11 is disposed at 0. As shown in detail in FIGS. 3 and 4, the air valve device 11 includes an electric heater 12 that is operated by electricity from a battery (not shown), and the electric heater 1.
2 and the wall temperature of the engine 1 is displaced by the heat transmitted through the intake pipe forming the intake passage 2;
3 and rotates around the support pin 14 in accordance with the displacement of the bimetal 13 to open the ventilation hole 1.
5a to reduce the passage area of the bypass air passage 10, and when the engine temperature is below the warm-up temperature of the engine 1 and low, the electric heater 12 may 13 does not displace much, the passage area of the bypass air passage 10 is maintained large by the valve body 15, the auxiliary air flow rate of the bypass air passage 10 is increased, and the amount of fuel injected from the fuel injection nozzle 4 is increased accordingly. While increasing the rotation speed of the engine 1, when the engine temperature rises below the warm-up temperature and near the warm-up temperature, the electric heater 1
The bimetal 13 is largely displaced by the sufficient heating by 2 and the rise in the wall temperature of the engine 1, and the passage area of the bypass air passage 10 is controlled to be small by the valve body 15 according to the amount of displacement. It is configured to reduce the auxiliary air flow rate and accordingly reduce the amount of fuel injected from the fuel injection nozzle 4, thereby lowering the rotational speed of the engine 1. Note that 16 is a spring that urges the valve body 15 of the air valve device 11 to rotate back.

Furthermore, 17 is a water temperature sensor that detects the temperature of the engine cooling water flowing through the cooling water passage 6, and a control circuit 18 is connected to the water temperature sensor 17. The control circuit 18 is connected to the water temperature sensor 17.
It is activated when the engine coolant temperature (engine temperature) is detected to be below the warm-up temperature of engine 1 and within a specific temperature range (for example, a range from 30 degrees Celsius to 50 degrees Celsius) near the warm-up temperature, This is to control the operation of the electric heater 12 of the air valve device 11 to be stopped. Specifically, the control circuit 18 controls, for example, when the engine temperature is 30°C or higher.
A switch that turns on and a switch that turns on at temperatures below 50°C are provided, and the relay is activated by the ON signal from both switches to turn on the electric heater 1 from the battery.
What is necessary is just to configure it so that the power supply to 2 is cut off.

Next, the operation of the above embodiment will be explained.
Immediately after starting the engine 1 to warm up the engine 1, when the engine temperature is below the warm-up temperature of the engine 1 and low, the bimetal 13 is hardly displaced by the operation of the electric heater 12 of the air valve device 11. Since the valve body 15 is held substantially open by the spring 16 and the passage area of the bypass air passage 10 is maintained large, the flow rate of air flowing through the bypass air passage 10 is large as shown by line A in FIG. Accordingly, the amount of fuel injected from the fuel injection nozzle A also increases, the engine speed increases, and warm-up of the engine 1 is promoted.

As the warm-up operation of the engine 1 continues, the bimetal 13 gradually displaces greatly due to heating by the electric heater 12 and heating due to heat conduction from the wall temperature of the engine 1, and the valve body 1
5, the passage area of the bypass air passage 10 gradually decreases due to the rotation of the valve body 15, and the engine speed decreases, but when the engine temperature is below the warm-up temperature and around the warm-up temperature, When the temperature reaches a specific temperature range (30°C to 50°C), the control circuit 18 is activated by the detection signal from the water temperature sensor 17, and the electric heater 12 stops operating, and the bimetal 13 is activated to reduce the temperature from the wall temperature of the engine 1. Only by heat transfer, that is, the wall temperature of the engine 1 is heated only by the heat transmitted through the intake pipe forming the intake passage 2, and accordingly, the degree of displacement of the bimetal 13 and the rotation of the valve body 15 are increased. As a result, the air flow rate flowing through the bypass air passage 10 is gradually reduced as shown by line B in Fig. 2 compared to the conventional flow rate shown by the broken line in Fig. 2, and the engine speed is also slightly higher. The rotational speed will be maintained.
Therefore, in a vehicle equipped with a torque converter, N
Even if the load on the engine 1 increases, such as when operating from the range to the D range, the engine 1 will not stop like in the past, and the engine 1 will continue to operate smoothly.
load stability can be improved.

Furthermore, when warm-up of the engine 1 is promoted and the engine temperature exceeds the specified temperature range (50° C. or higher), the electric heater 12 is reactivated due to the deactivation of the control circuit 18, and the air flowing through the bypass air passage 10 is activated. As shown by line c in Figure 2, the flow rate decreases at approximately the same rate as in the initial state, and when the engine temperature reaches the warm-up temperature (80°C) of the engine 1, the bypass air passage 10 Warming up of the engine 1 is completed when the area becomes zero.

(Effects of the invention) As described above, according to the invention, the bimetal is displaced by heat from an electric heater, and the passage area of the bypass air passage that is engaged with one end of the bimetal and is adjusted according to the displacement of the bimetal. It has an air valve device consisting of a valve body that controls the temperature of the engine, and when the temperature is below the warm-up temperature of the engine, auxiliary air is supplied through the bypass air passage, while when the temperature is above the warm-up temperature, the auxiliary air is supplied by the maximum displacement of the bimetal. In a fuel injection system for an engine that reduces the temperature to zero, when the engine temperature is below the warm-up temperature and within a specific temperature range around the warm-up temperature, the operation of the electric heater is stopped. Since the rotation speed can be corrected to a higher value,
In warm-up operation of the engine, it is possible to improve the load stability of the engine while ensuring early warm-up performance, low fuel consumption, and low noise.

[Brief explanation of drawings]

The drawings illustrate the embodiments of the present invention.
The figure is an overall schematic diagram, Figure 2 is a graph showing changes in the air flow rate flowing through the bypass air passage with respect to engine temperature, Figure 3 is a longitudinal sectional view of the air valve device, and Figure 4 is a sectional view taken along the - line in Figure 3. be. 1...Engine, 1a...Cylinder block,
2...Intake passage, 3...Air flow meter, 4...
...Fuel injection nozzle, 5...Exhaust passage, 6...Cooling water passage, 7...Piston, 8...Intake valve, 9...
Exhaust valve, 10... Bypass air passage, 11... Air valve device, 12... Electric heater, 13... Bimetal, 14... Support pin, 15... Valve body, 1
5a...Vent hole, 16...Spring, 17...
Water temperature sensor, 18...control circuit.

Claims (1)

[Scope of utility model registration request] The air valve device includes a bimetal that is displaced by heat generated by an electric heater, and a valve body that is engaged with one end of the bimetal and controls the passage area of a bypass air passage according to the displacement of the bimetal, and In an engine fuel injection system, auxiliary air is supplied through the bypass air passage when the engine temperature is below the warm-up temperature, while the auxiliary air is reduced to zero by the maximum displacement of the bimetal when the engine temperature is above the warm-up temperature. An auxiliary air control device for a fuel injection device for an engine, characterized in that a control circuit is provided for stopping the operation of the electric heater when the temperature is below the temperature and in a specific temperature range near the warm-up temperature.