JPH0633841A - Internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an internal combustion engine capable of promoting vaporization of injected fuel in a cold state, reducing production cost, and improving fuel consumption. An injector 13 for injecting fuel toward an inner wall of an intake passage 7, and a bypass passage 1 for diverting engine cooling water from a radiator 15 when the engine is in a cold state
In the internal combustion engine 1 including the fuel injection position 8
A circulating water channel 9 is provided in the
The engine cooling water in 8 is circulated. When the engine 1 is in a cold state, the engine cooling water, which has been warmed to some extent by cooling the cylinder head 6 and the like, flows through the bypass passage 18 and the circulating water passage 9 to warm the fuel injection position 8. On the other hand, the engine cooling water having a high temperature flows into the radiator 15 to prevent the fuel injection position 8 from having a high temperature.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an internal combustion engine,
In particular, the present invention relates to an internal combustion engine that can warm engine intake air when the engine is cold.

[0002]

2. Description of the Related Art Conventionally, in an internal combustion engine of an automobile,
In some cases, a heater that uses electric resistance is provided in the intake passage, and fuel is injected toward the heater from an injector attached to the intake manifold. In this type of internal combustion engine, the injected fuel is heated to promote vaporization, HC (unburned hydrocarbons) in the exhaust gas is reduced, and the fuel consumption rate (fuel consumption) is improved.

[0003]

However, in the above-mentioned conventional internal combustion engine for automobiles, a dedicated heater is provided for heating the fuel. This heater itself,
An additional component such as a wire harness, a heater control device, etc. are newly required, which causes an increase in production cost. In addition, there is a problem that the electric power supplied to the heater is eventually generated by the engine, and the fuel efficiency cannot be improved as expected.

The present invention has been made to solve the above-mentioned problems, and it is possible to promote the vaporization of the injected fuel, and further, it is possible to reduce the production cost and improve the fuel consumption. The purpose is to provide.

[0005]

To achieve the above object, according to the present invention, a fuel injection device for injecting fuel toward an inner wall of an intake passage, and engine cooling water from a radiator when the engine is in a cold state. In an internal combustion engine having a bypass passage for bypassing, a circulating water passage is provided at a position where the fuel is injected, and the engine cooling water in the bypass passage is configured to flow through the circulating water passage.

[0006]

When the internal combustion engine is cold, the inside of the intake passage is cold. In this case, the engine cooling water bypasses the radiator, flows in the bypass passage, and then flows in the circulating water passage. Therefore, the engine cooling water, which has been warmed to some extent by cooling the cylinder head, warms the fuel injection position.

On the other hand, when the warm-up operation of the internal combustion engine ends, the temperature in the intake passage also rises. In this case, the engine cooling water is hot, but this engine cooling water is
It does not flow into the bypass passage but flows into the radiator, thus preventing the fuel injection position from becoming hot.

[0008]

An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows a schematic configuration of an internal combustion engine to which the present invention is applied. The internal combustion engine 1 is, for example, a multi-cylinder engine, and includes an engine body 3, a cooling device 4, a fuel injection device, and the like. In FIG. 1, only one cylinder is shown and the other cylinders are not shown.

In the cylinder head 6 of the engine body 3,
An intake passage (only one intake passage is shown) 7 is provided, and a predetermined portion of the inner wall of each intake passage 7 slightly bulges toward the inside of the intake passage 7 and is at a fuel injection position 8. A circulating water channel 9 is provided at the fuel injection position 8. The inflow port 9a and the outflow port 9b of the circulating water passage 9 are provided at predetermined positions of the cylinder head 6.

An intake manifold 11 is screwed and fixed to the cylinder head 6. An injector 13 of the fuel injection device is attached to the intake manifold 11. The injector 13 injects fuel toward the fuel injection position 8. The cooling device 4 is, for example,
It has an in-line type cooling water passage system, and is provided with a passage 16 that circulates the radiator 15 and a bypass passage 18 that bypasses the radiator 15. In other words, the engine cooling water discharged from the water pump 19 reaches the thermostat 21 after flowing through the water jacket (not shown) of the cylinder head 6 or the like, and when the thermostat 21 is opened, the radiator 15 is turned off. Pass by
Alternatively, when the thermostat 21 is closed, it flows through the bypass passage 18 and circulates to the water pump 19.

The thermostat 21 starts to open when the temperature of the engine cooling water rises and reaches 82 degrees, for example. Therefore, when the temperature of the engine cooling water is relatively high, most of this cooling water passes through the radiator 15. On the other hand, when the temperature of the engine cooling water is relatively low, this cooling water flows into the bypass passage 18. The bypass passage 18 is composed of first and second passages 23 and 24. The first passage 23 includes the thermostat 21 and the circulating water passage 9.
Is connected to the inflow port 9a. The second passage 24 connects the outflow port 9b of the circulating water passage 9 and the water pump 19. Therefore, the engine cooling water that bypasses the radiator 15 flows into the circulating water passage 9 from the first passage 23, flows through the circulating water passage 9 and flows into the second passage 24.

Next, the operation of warming the fuel injection position 8 will be described. When the engine 1 is cold, the inside of the intake passage 7 and the fuel injection position 8 are cold. On the other hand, the engine cooling water for cooling the cylinder head 6 and the like flows into the bypass passage 18 and circulates in the cooling water passage system while bypassing the radiator 15 because the thermostat 21 is closed. Therefore, the engine cooling water is gradually warmed while cooling the cylinder head 6, and becomes higher in temperature than the fuel injection position 8. The cooling water warms the fuel injection position 8 while flowing in the circulating water passage 9.

The fuel injected from the injector 13 hits the warmed fuel injection position 8 and scatters, becomes a mixture with the intake air in the intake manifold 11, and is sucked into the combustion chamber 26. On the other hand, when the warm-up operation of the internal combustion engine 1 ends, the temperatures in the intake passage 7 and the fuel injection position 8 have reached a temperature sufficient for fuel vaporization. In this case, the engine cooling water also becomes high in temperature, and therefore the thermostat 21 opens and most of the high temperature engine cooling water flows into the radiator 15. This allows
A large amount of high-temperature cooling water is prevented from flowing into the circulating water passage 9 and the fuel injection position 8 is prevented from reaching a high temperature.

In this embodiment, the case where the invention is applied to the internal combustion engine 1 having the in-line type cooling water passage system has been described. However, the present invention is not limited to this, and it is applicable to the internal combustion engine having the bottom bypass type cooling water passage system. Of course, it may be applied.

[0015]

As described above, according to the present invention,
Since the internal combustion engine is configured so that the circulating water channel is provided at the position where the fuel is injected and the engine cooling water in the bypass channel is circulated in this circulating water channel, the cooling water channel system is used to promote the vaporization of the injected fuel. Can be planned. Therefore, the production cost can be reduced, and the load on the engine can be reduced to improve the fuel consumption. Further, since the engine cooling water in the bypass passage is used, it prevents the engine cooling water that has reached a high temperature from flowing into the circulation water passage, prevents the heat damage of the fuel injection device, and causes the intake air temperature to rise. There is an excellent effect that it is possible to prevent a decrease in engine output.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an internal combustion engine to which the present invention is applied.

[Explanation of symbols]

 1 Internal Combustion Engine 6 Cylinder Head 7 Intake Passage 8 Fuel Injection Position 9 Circulating Water Passage 11 Intake Manifold 13 Injector 15 Radiator 18 Bypass Passage 21 Thermostat

Claims (1)

[Claims] 1. An internal combustion engine including a fuel injection device for injecting fuel toward an inner wall of an intake passage, and a bypass passage for diverting engine cooling water from a radiator when the engine is in a cold state. An internal combustion engine, characterized in that a circulating water passage is provided at a certain position, and the engine cooling water in the bypass passage is circulated through the circulating water passage.