JPS6316838Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of application of the invention] The invention relates to an air-fuel ratio control device for an internal combustion engine.
More specifically, it includes at least one electromagnetic valve for fuel injection, detects the amount of air taken into the internal combustion engine with a heat-sensitive resistor, adjusts the injection amount of the electromagnetic valve according to the detection signal, and adjusts the amount of air to be injected into the internal combustion engine. Regarding an air-fuel ratio control device that controls a mixture ratio, in particular, a bypass flow path is provided that bypasses an inlet of a main air flow path to the narrowest part formed in the main air flow path, and This invention relates to a device in which the combined flow rate is indirectly determined from the flow rate ratio between the amount of air flowing through the main air flow path and the flow rate of bypass air flowing through the bypass air flow path by determining the amount of bypass air using a heat-sensitive resistor installed in the air flow path.

[Background of the idea]

In the conventional air-fuel ratio control device known from Japanese Utility Model Application Publication No. 52-38522, etc., the air flow rate value measured by the heat-sensitive resistor may differ from the actual value due to variations in the cross-sectional area ratio between the main air flow path and the bypass flow path. It may show quite different values for the air flow rate values.

In other words, in this type of device, a heat-sensitive resistance is provided in the middle of a bypass flow path that bypasses the main air flow path, and by determining the amount of bypass air using the heat-sensitive resistance, the amount of main air flowing through the main air flow path and the amount of bypass air are determined. The total flow rate is indirectly determined from the flow rate ratio of the amount of bypass air flowing through the flow path, and the fuel amount is determined from this result, so the flow rate ratio of the amount of air flowing through the main air flow path and the amount of air flowing through the bypass flow path must be accurately It must be determined.

However, in the manufacturing process, this flow rate ratio does not necessarily meet the design specifications, and as a result, there is a problem in that the total amount of air supplied to the internal combustion engine does not represent the true value.

[Purpose of invention]

An object of the present invention is to accurately determine the flow rate ratio of the amount of air flowing through the main air flow path and the bypass flow path.

[Summary of the idea]

The feature of the present invention is that an adjusting means is provided for externally adjusting the amount of bypass air flowing through the heat-sensitive resistor in the bypass flow path to adjust the flow rate ratio between the main air flow rate and the air flow rate flowing through the heat-sensitive resistor. Therefore, even if there is variation in the flow rate ratio between the main air flow path and the bypass flow path, the desired flow rate ratio can be obtained by adjusting the bypass air flow rate, making it possible to accurately detect the total air flow rate. This is the result.

[Example of idea]

An embodiment of the air-fuel ratio control device according to the present invention will be described below with reference to FIG. In the figure, reference numeral 1 denotes a slot chamber main body, and two throttle chambers 2 and 3 are formed inside the main body. 4
and 5 are throttle valves provided in each of the throttle chambers 2 and 3, 6 is a fuel injection solenoid valve mounted on the throttle chamber body 1, and 7 is mounted on the top surface of the throttle chamber body 1. A main air passage 8 is formed inside the housing and communicates with each of the throttle chambers 2 and 3, and a bench lily 9 is provided in the middle of the main air passage 8. 10
is a first bypass flow path that is bored in the side wall of the casing 7 and runs from the inlet of the main air flow path 8 to the bench lily 9; The confluence point with the flow path 8 is formed in a bell mouth shape, and an orifice 11 is provided near the confluence point with the main air flow path 8 on the downstream side. Further, the first bypass flow path 10 is provided with a heat-sensitive resistor 12 midway therein to detect the amount of intake air passing through the bypass flow path 10. The detection signal from the heat-sensitive resistor 12 is input to a solenoid valve control circuit 13, and the control circuit 13 controls the opening and closing of the solenoid valve 6 in accordance with the input signal. 14 is a heat-sensitive resistor 12 bored in the side wall of the casing 7 of the first bypass flow path 10.
This is a second bypass flow path that bypasses the upstream side and the downstream side, and the bypass flow path 14 is provided with an adjustment screw 15 in the middle thereof that can change the cross-sectional area of the flow path.
The adjustment screw 15 is screwed into the side wall of the casing 7, and has one end protruding outside the casing so that it can be adjusted from outside the casing 7. Reference numeral 16 denotes a third bypass flow path that is bored in the side wall of the throttle chamber main body 1 and bypasses the upstream side and the downstream side of the throttle valve 5 of the throttle chamber 3; Adjustment screw 1 that can change the cross-sectional area of the flow path
7 is provided. The adjustment screw 17 is screwed into the side wall of the throttle chamber main body 1, and has one end protruding outside the main body so that it can be adjusted from outside the main body 1.

Next, the operation of the air-fuel ratio control device of this embodiment will be explained. Most of the air that has been purified after passing through the air cleaner passes through the main air flow path 8 and then through the throttle valve 4.
A throttle chamber 2 or a throttle valve 5 having
It is supplied to the engine through a throttle chamber 3 having a diameter. Further, some of the air flows through the first bypass flow path 10 and the second bypass flow path 14 and joins in front of the orifice 11 provided in the first bypass flow path 110, and then passes through the orifice 11 and flows into the main air flow. It merges with the air from Route 8. The amount of air flowing through the first bypass flow path 10 is detected by a heat-sensitive resistor 12, and the detection signal is inputted to a control circuit 13, and the fuel injection solenoid valve 6 is operated according to an output signal from the control circuit 13. Inject fuel. In this process, if the measured air flow rate value deviates from the actual air flow rate value due to variations in cross-sectional area between the main air flow path 8 and the first bypass flow path 8,
Adjusting the adjustment screw 15 to change the cross-sectional area of the second bypass flow path 14 and change the ratio between the amount of air passing through the second bypass flow path 14 and the amount of air in the first bypass flow path 10. Accordingly, the mixture ratio of air and fuel can be appropriately corrected. Further, due to the presence of the orifice 11 in the first bypass passage 10, variations in the ratio of the amount of air flowing through the bench lily 9 and the amount of bypass air are minimized. On the other hand, by adjusting the adjustment screw 17 to change the flow passage cross-sectional area of the third bypass flow passage 16 that bypasses the upstream and downstream sides of the throttle valve, the rotation speed of the engine can be adjusted. For example, it is possible to appropriately force the rotation speed during idling operation.

Figure 2 shows another embodiment of the present invention.
The first bypass passage 10 is provided with an adjusting screw 18 for changing the cross-sectional area of the passage.

According to this, the ratio between the main air flow rate and the bypass air flow rate can be appropriately corrected.

Further, by providing an adjusting screw 19 in the second bypass passage and changing the cross-sectional area of each bypass passage, the ratio between the main air flow rate and the bypass air flow rate can be changed more precisely. Therefore, the mixture ratio of air and fuel can be corrected more appropriately.

[Effect of idea]

As described above, according to the air-fuel ratio control device of the present invention, even if there are variations in the cross-sectional area ratio between the air flow path and the bypass flow path, accurate control can be achieved by adjusting the amount of air passing through the heat-sensitive resistance of the bypass flow path. The flow rate ratio can be obtained, and the true total air amount can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the air-fuel ratio control device of the present invention, and FIG. 2 is a cross-sectional view showing another embodiment of the present invention. 1... Throttle chamber body, 2, 3... Throttle chamber, 4, 5... Throttle valve, 6... Solenoid valve for fuel injection, 8... Main air flow path, 9... Bench lily, 10 ...First bypass channel, 11... Orifice, 12... Heat sensitive resistor, 14... Second bypass channel, 15, 17, 18, 19... Adjustment screw, 16... Third bypass flow rate.

Claims (1)

[Claims for Utility Model Registration] 1. At least one solenoid valve for fuel injection,
Detects the amount of air intake into the internal combustion engine using a heat-sensitive resistor,
The air-fuel ratio control device controls the mixture ratio of air and fuel by adjusting the injection amount of the solenoid valve based on the detection signal, By providing a bypass flow path that bypasses the narrow part, arranging the heat-sensitive resistor in the middle of this bypass flow path, and determining the bypass air flow rate using this heat-sensitive resistor, the main air flow rate flowing through the main air flow path can be determined. In the device that indirectly determines the total flow rate from the flow rate ratio with the bypass air flow rate flowing through the bypass air flow path, the air flow rate flowing through the heat-sensitive resistor of the bypass flow path is adjusted from the outside to be equal to the main air flow rate. An air-fuel ratio control device comprising an adjusting means for adjusting a flow rate ratio with respect to the flow rate of air flowing through the heat-sensitive resistor. 2 Utility Model Registration Scope of Claim 1, characterized in that the adjusting means is an adjusting screw provided in a second bypass flow path that bypasses the heat-sensitive resistance upstream side and the downstream side of the bypass flow path. air-fuel ratio control device. 3. Utility Model Registration The air-fuel ratio control device according to claim 1, wherein the bypass flow path includes an orifice near a confluence point with the main air flow path on the outlet side thereof. 4 Utility Model Registration The air-fuel ratio control device according to claim 1, wherein the bypass flow path has a confluence point with the main air flow path on the inlet side formed in a bell mouth shape. 5 Utility Model Registration The air-fuel ratio control device according to claim 1, wherein the adjusting means is an adjusting screw provided in the bypass passage. 6 Utility model registration Claim 5, wherein a second bypass flow path is provided that communicates between the heat-sensitive resistor upstream and the heat-sensitive resistor downstream provided in the bypass passage and the adjustment screw, and the second bypass flow An air-fuel ratio control device characterized in that a second adjustment screw is provided in the middle of the path.