JPH06323222A - Air amount controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To eliminate engine stalling due to the drop in the amount of auxiliary air directly before complete warming in an air amount controller for controlling the amount of auxiliary air to be supplied to an intake route through alternate route around a throttle valve according to the temperature of cooling water. CONSTITUTION:At the temperature of 70 deg.C of cooling water directly before complete warming, a rod 5 is pressed by the pin 4 of a thermostat 3 against a spring 8, and a valve 9 is brought into close contact with a sheet 6 and is thus closed. The air leaking from the gap between the outer periphery of the rod 5 and the inner circumference of the valve 9 flows in the groove 9b of the front end 9a of the valve 9. The air flows in an auxiliary air route 2 and the drop in the amount of auxiliary air is thus prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air quantity control device for an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine equipped with a fuel injection device, a throttle body is equipped with an air amount control device for correcting the amount of air supplied to the engine when operating at a low intake air amount with a small throttle valve opening.

This air amount control device responds to the temperature of the engine so as to increase the amount of supplied air at the time of cold start and decrease the amount of supplied air as the engine warms up (for example, actual opening 5).
9-142439).

This type of air amount control device is disclosed in
As shown in FIG. 1 of Japanese Patent No. 142439, air flowing through an intake passage through an air cleaner is sucked from an inlet provided on an intake cylinder side wall upstream of the throttle valve to bypass the throttle valve. Thus, an auxiliary air passage is formed on the downstream side wall of the throttle valve to let the air flow out to the outlet.

A valve is provided in the middle of the auxiliary air passage, which operates by a temperature-sensitive member that expands and contracts when the temperature of the internal combustion engine is warmed up. When the temperature is low, the opening area of the auxiliary air passage is increased to increase the internal combustion engine. The amount of air supplied to the internal combustion engine is increased, the opening area is reduced as the engine warms, and the amount of air supplied is reduced, and the amount of air from the low temperature of the internal combustion engine to the completion of warming up is controlled according to the temperature.

7 to 9 show the structure of a flow rate control unit of the prior art. Reference numeral 1 is an adapter as a case of a flow rate control unit, 2 is an auxiliary air passage, 2a is its inlet, and 2b is its outlet. Reference numeral 3 denotes a thermostat, the right portion 3a of which faces the internal combustion engine cooling water passage 13, and its pin 4 moves forward and backward in the drawing in response to the temperature of the cooling water. That is, when the temperature rises, the pin 4 moves leftward, and when the temperature falls, the pin 4 retracts rightward.

The state of FIG. 9 shows that the engine has been warmed up and the cooling water temperature is 80 ° C., and the pin 4 has advanced to the left end position. Reference numeral 5 denotes a rod slidably fitted in the cylinder 3b of the thermostat 3, which is moved left and right by the left end of the pin 4. 6 is a (valve) seat screwed to the adapter, 7 is a spring retainer that engages with the stepped portion of the rod 5, and 8 is a spring retainer 7 and seat 6
A compression spring 9 is provided between the spring 6 and the valve 6, and 9 is a valve that cooperates with the seat 6. The valve 9 is fitted to the rod 5 and is always leftward by the relief spring 10 provided between the spring retainer 7 and the valve. Being energized. Reference numeral 11 is a washer fitted to the left end portion of the rod 5, and 14 is an O-ring for preventing cooling water from leaking to the auxiliary air passage 2.

Relief spring 10 and washer 11
Has a relief mechanism 12 in which the rod 5 can move to the left and right independently of the valve 9 even after the engine is warmed up. This relief mechanism 12 has the pin 4 leftward as shown in FIG. 9 after the engine is warmed up. Protect the thermostat 3 from being damaged by allowing it to advance.

In this prior art, when the cooling water temperature is lower than 70 ° C., the pin 4 is retracted to the right as shown in FIG. 7, the washer 11 contacts the left end 9a of the valve 9, and the valve 9 is rotated by the spring 8. In order to move the valve 9 to the position shown in the figure by the force of, the valve 9 is separated from the seat 6 and the opening area between them is increased. Since this opening area increases as the temperature of the cooling water decreases, the amount of air supplied to the internal combustion engine is increased through the auxiliary air passage 2.

During the warm-up operation after starting the engine, the temperature of the cooling water gradually rises. When the pin 4 moves to the left and reaches 70 ° C, the valve 9 comes into contact with the seat 6 and the opening area becomes zero (Fig. 8). However, the outer diameter of the rod 5 and the valve 9 fitted thereto
A small amount of air leaks through the gap with the inner diameter of the engine and is supplied to the engine.

When the temperature of the cooling water further rises, the pin 4 moves to the left as shown in FIG. 9, compresses the relief spring 10 to press the valve 9 against the seat 6 more strongly, and the washer 11 causes the valve 9 to move. Moves to the left away from the lower end 9a of the. The state of FIG. 9 shows a state in which the cooling water temperature is 80 ° C.

FIG. 10 shows the result of measuring the relationship between the cooling water temperature and the amount of auxiliary air after the engine was started, while keeping the intake pipe negative pressure at a constant cage pressure. Although the amount of air flowing through the auxiliary air passage 2 gradually decreases as shown in FIG. 10 in the cooling water temperature range of 40 ° C. to 70 ° C. as described above, the state of FIG. Then, it becomes the minimum value, and in the state of FIG. The air amount indicated by the symbol B is in the idle adjustment state.

As described above, the amount of air in the state of FIG. 9 shown by reference numeral B is larger than that of FIG. 8 shown by reference numeral B. That is, the left end of the valve 9 is on the right side of the washer 11 in the state of FIG. This is because the left end of the valve 9 is separated from the washer 11 in the state of FIG. 9 to increase the gap between the two.

[0014]

In the prior art shown in FIGS. 7 to 9, in the state of the cooling water temperature of about 70.degree. C. shown in FIG. There was a problem that the engine stall resulting from this occurred just before the completely warmed up state.

Therefore, an object of the present invention is to provide an air quantity control device for an internal combustion engine, which can solve such problems.

[0016]

In order to achieve the above object, an air quantity control device for an internal combustion engine according to the present invention detects a warm-up state of the engine by a cooling water temperature and moves a pin (4) forward and backward. (3) between the rod (5) that is pushed forward and backward by the pin (4) and the seat (6) that slidably fits the rod (5) and moves forward and backward according to the forward and backward movement of the rod (5). And a valve (9) for controlling the opening area of the valve, and the rod (5) is provided with a relief mechanism (12) that can move independently of the valve (9) after the engine is warmed up. Slit (9) at the tip of 9)
b) is provided so that the air leaking from the gap between the valve (9) and the rod (5) flows.

[0017]

Function Even when the valve (9) is closed, the air leaking from the gap between the valve and the rod still has the slit (9) of the valve (9).
Flows easily through b). Therefore, the amount of air does not become too small when the cooling water temperature is about 70 ° C.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiments of FIGS. 1 to 3, the components having the same numbers as those of FIGS. 7 to 9 of the prior art are the parts having the same functions, and therefore the description thereof will be omitted.

The inlet 2a is used to communicate upstream of the throttle valve in the intake passage of an internal combustion engine (not shown), and the outlet 2b is used to communicate downstream of the throttle valve. A slit 9b extending in the diametrical direction is formed on the tip 9a surface (the left end surface in the drawing that contacts the washer 11) of the valve 9, as shown in an enlarged view in FIGS.
Is provided. Therefore, the cooling water temperature shown in FIG.
In this state, air leaking from the gap between the outer diameter of the rod 5 and the inner diameter of the valve 9 always flows into the auxiliary air passage 2 through the slit 9b with the tip 9a of the valve 9 in contact with one surface of the washer 11. .

FIG. 3 is a view corresponding to FIG. 9 of the prior art when the cooling water temperature is 80 ° C. and the valve 9 is pressed against the seat 6, and the washer 11 is separated from the left end 9a of the valve 9. ing.

Therefore, as shown in FIG. 6, when the cooling water temperature is about 70 ° C. or higher, the air amount is maintained at the same constant value as in the idle adjustment state. The measurement conditions (intake pipe negative pressure) in FIG. 6 are the same as those in FIG.

[0022]

Since the air amount control device of the present invention is constructed as described above, there is no drop in the air amount when the valve (9) and the seat (6) are in close contact with each other, and no engine stall occurs. There is.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of the present invention.

FIG. 2 is a diagram showing a different aspect of FIG.

FIG. 3 is a diagram showing still another aspect of FIG.

FIG. 4 is an enlarged plan view showing an example of a valve used in the present invention.

5 is a left side view of FIG.

FIG. 6 is a cooling water temperature vs. air flow rate diagram.

FIG. 7 is a vertical sectional view of a conventional technique.

FIG. 8 is a diagram showing another mode of FIG. 7;

9 is a diagram showing a further different aspect of FIG. 7. FIG.

FIG. 10 is a cooling water temperature vs. air flow rate diagram.

[Explanation of symbols]

3 ... Thermostat, 4 ... Pin, 5 ... Rod, 6 ... Seat 9 ... Valve, 9b ... Slit.

Claims (1)

[Claims] 1. A temperature-sensing member that senses a warm-up state of an engine based on a temperature of cooling water to move a pin forward and backward, a rod that is pushed and pushed by the pin, and a rod that is slidably fitted to the rod and that moves the rod forward and backward. A valve that controls the opening area between the seat and the seat, and a rod provided with a relief mechanism that allows the rod to move independently of the valve after the engine is warmed up. An air amount control device for an internal combustion engine configured to flow air leaking from a gap between a valve and a rod.