JPS6037301B2 - Auxiliary fuel supply control device for vehicle internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an auxiliary fuel supply device for an internal combustion engine for driving a vehicle.

Generally, in internal combustion engines for vehicles, during deceleration operation,
When the normal fuel supply is cut off, the fuel adhering to the carburetor and the inner wall of the intake passage of the intake pipe is sucked into the engine body as the deceleration time passes.

Therefore, even if normal fuel supply is restarted when the engine is shifted from deceleration to acceleration, at the beginning, some of the supplied fuel is absorbed while adhering to the inner wall of the intake passage. There is a condition where the amount of fuel necessary for engine operation is not supplied to the engine itself. That's why it's more traditional)
In order to solve this problem, it is known that a certain amount of auxiliary fuel is supplied to the intake passage during acceleration.
The amount of fuel that adheres to the inner wall of the intake passage differs depending on the length of the deceleration time. Therefore, if a fixed amount of fuel is supplied as described above, the intake air-fuel mixture will change depending on the length of the deceleration time when the operation shifts to acceleration. It tends to be too thick or too thin, making it impossible to always obtain smooth acceleration operation, and not always producing satisfactory results.

In view of the above, the present invention cuts off the supply of fuel from the normal fuel supply system to the carburetor during deceleration operation of the engine, and when transitioning from deceleration to acceleration operation, the carburetor is operated during deceleration operation. Operational precision enables the supply of auxiliary fuel that is adjusted to the appropriate amount depending on the time, allowing the engine to smoothly transition from deceleration to acceleration, improving driving performance and driving feeling. Another object of the present invention is to provide an auxiliary fuel supply control device for the internal combustion engine for a vehicle, which has a high acceleration fuel combustion efficiency, and has the following characteristics:
A fuel passage formed in the carburetor body and an auxiliary fuel supply passage extending between the float chamber; a negative pressure responsive type interposed in the middle of this auxiliary fuel supply passage for supplying fuel to the fuel passage; a fuel pump; a pump discharge pump connected to the fuel pump and configured to operate the fuel pump when the internal combustion engine shifts from deceleration operation to acceleration operation, and to variably control the discharge amount according to the deceleration operation time; a quantity control device; the auxiliary fuel supply passage is provided such that its fuel outlet faces an air bleed jet of an air bleed device attached to the fuel passage; and the pump discharge quantity control device is An air passage connected to the negative pressure working chamber of the fuel pump, an electromagnetic switching valve that selectively connects the air passage to a negative pressure source or the atmosphere, and an air passage between the electromagnetic switching valve and the negative pressure working chamber. A one-way throttle valve that restricts only the flow of air from the negative pressure working chamber to the electromagnetic sliding valve side, and a one-way throttle valve that distinguishes and senses the normal running state and deceleration driving state of the vehicle, Place the solenoid switching valve on the atmospheric transport side.
Further, during deceleration operation, a sensing device is provided to control switching of the electromagnetic switching valve to the negative pressure source transport side.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A low-velocity fuel passage 2 is formed in a pipe wall of a carburetor main body 1,
One end of the auxiliary fuel supply passage 4 faces the air bleed jet 32 of the air bleed device 2a attached to the fuel passage 2 with a gap therebetween and is closed, and one end of the entrance of the auxiliary fuel supply passage 4 is closed. A fixed orifice 5 is provided in the section.

The other end of the auxiliary fuel supply passage 4 is passed through the float chamber 3 of the carburetor. A negative pressure operated diaphragm fuel pump P is interposed in the middle of the auxiliary fuel supply passage 4. This diaphragm fuel pump P has a conventionally known structure, that is, the inside of the pump case is divided by a diaphragm 7 into a pump chamber 8 and a negative pressure working chamber 9, and the inside of the negative pressure working chamber 9 is divided into a pump chamber 8 and a negative pressure working chamber 9. A diaphragm spring 10 is housed therein, which urges the diaphragm 7 to move toward the pump chamber 8 . The pump chamber 8 has a suction port 11
and a discharge port 12 are opened, the suction port 11 is connected to the auxiliary fuel supply passage 4 on the side where the float chamber 3 is connected, that is, the upstream side, and the discharge port 12 is connected to the low-speed fuel in the auxiliary fuel supply passage 4. The passages 2 are connected to each other on the downstream side. Check valves 13 and 1 are provided on the upstream and downstream sides of the diaphragm fuel pump P in the auxiliary fuel supply passage 4, respectively.
4 is interposed, and when the pump P is in operation, the fuel in the float chamber 3 passes through the auxiliary fuel supply passage 4 to the carburetor main body 1.
The fuel is supplied to the low-speed system fuel passage 2. The fuel pump P
A pump discharge amount control device C for variably controlling the discharge amount of this pump P is connected to.

Next, to explain the configuration of this device C, the negative pressure working chamber 9 of the diaphragm fuel pump P is connected to a negative pressure source 16 such as an intake path of an internal combustion engine via an electromagnetic switching valve 15, or via a air cleaner 17. air passage 18 that selectively passes through to the atmosphere.
Further, a one-way throttle valve 19 is interposed in the middle of the air passage 18 to restrict only the flow of the atmosphere from the negative pressure working chamber 9 to the dew/water switching valve 15 side. The electromagnetic switching valve 15 includes a valve body 23 in a valve case 20 that switches between opening and closing a negative pressure passage 21 connected to the negative pressure source 16 and an atmospheric passage 22 connected to the atmosphere via an air cleaner 17. body 2
3 switches upward to pass the air passage 18 to the negative pressure source 16 as shown in the figure by demagnetizing the solenoid 24, and switches downward to pass the air passage 18 through the negative pressure source 16 when the solenoid 24 is energized. into the atmosphere. The solenoid 24 is sensed by the sensing device S and energized when the vehicle is running normally, and deenergized when the vehicle is decelerating. The one-way shark valve 19 has a check valve 27 in the valve box 26 that allows air to flow from the lightning switching valve 15 to the diaphragm fuel pump P.
and a fixed throttle 28 are arranged in parallel, and when the electromagnetic switching valve 15 is switched to the upper side, negative pressure from the negative pressure source 16 is passed through the fixed throttle 28 to the negative pressure working chamber 9 of the diaphragm fuel pump P. When the electromagnetic switching valve 15 is switched to the lower side, the negative pressure in the negative pressure working chamber 9 is released to the atmosphere through the check valve 27. In this embodiment, the fixed throttle 28 is set so that the time required for the diaphragm 7 to move to the maximum by introducing negative pressure into the negative pressure working chamber 9 is approximately one night. In the figure, 29 is an intake passage of the carburetor, 30 is a main venturi, 31 is a throttle valve, 33 and 34 are an idle boat and a bypass boat that allow the low-speed fuel passage 2 to pass through the intake passage 29 of the carburetor, and 35 is a bypass boat. idle boat 3
3 and the low speed fuel passage 2 on the upstream side of the bypass boat 34
A solenoid valve interposed in the low-speed fuel passage 2 senses the deceleration of the vehicle and closes the low-speed fuel passage 2. Next, to explain the operation of one embodiment of the present invention, when the vehicle is running normally, fuel from the normal main fuel supply system is supplied to the main venturi 3 of the carburetor.
The river is supplied.

In this case, the solenoid 24 of the drain valve 15 is energized, the negative pressure working chamber 9 of the diaphragm fuel pump P is vented to the atmosphere, and the fuel pump is stopped. When the vehicle shifts from normal driving to deceleration driving (for example, internal combustion engine rotation is 3000 RPM or more, intake pipe negative pressure is 570 skin Hg or more), the sensing device S senses this state and the solenoid 24 is demagnetized.
Negative pressure from a negative pressure source 16 such as boost member pressure in the engine intake passage is introduced into the negative pressure working chamber 9 of the diaphragm fuel pump P through the electromagnetic gate valve 15 and the fixed throttle 28 of the one-way throttle valve 19. , the diaphragm 7 is moved upward to store the fuel in the float chamber 3 in the pump chamber 8 . In this case, by appropriately selecting the fixed throttle 28, the diaphragm 7 of the fuel pump P will move to the maximum if the deceleration state continues for more than one interval. Next, when there is a sudden transition from deceleration to acceleration, the solenoid 24 is energized and the electromagnetic switching valve 1 is activated.
5 communicates the air passage 28 with the atmosphere, so the fuel pump P
The negative pressure working chamber 9 is rapidly opened to the atmosphere via the check valve 27 of the one-way throttle valve 19. Therefore, the diaphragm 7 is moved downward by the diaphragm spring 10 to perform pump operation, and the fuel stored in the pump chamber 8 is discharged from the fixed orifice 5 of the fuel supply passage 4 to the intake passage 29 of the carburetor.
The setting of the auxiliary fuel supply time using the fixed throttle 28 is as follows:
Of course, it can be changed as appropriate depending on the unique characteristics of the engine. As described above, according to the present invention, the auxiliary fuel supply passage 4 is disposed between the fuel passage 2 formed in the carburetor body 1 and the float chamber 3; , a negative pressure responsive fuel pump P for supplying fuel to the fuel passage 2; connected to the fuel pump P, and operating the fuel pump P when the internal combustion engine shifts from deceleration operation to acceleration operation; a pump discharge amount control device C capable of variably controlling the discharge amount according to the deceleration operation time; and the pump discharge amount control device C is connected to the negative pressure working chamber 9 of the fuel pump P. air passage 1
8, an electromagnetic switching valve 15 that selectively communicates the air passage 18 with the negative pressure source 16 or the atmosphere, and the electromagnetic switching valve 1.
A one-way shark valve 19 is installed in the air passage 18 between the negative pressure working chamber 9 and the negative pressure working chamber 9, and restricts only the flow of air from the negative pressure working chamber 9 to the dew/water switching valve 15 side. The running state and the deceleration driving state are discriminated and sensed, and during normal driving, the electromagnetic switching valve 15 is switched to the atmospheric transport side, and during decelerating driving, the electromagnetic switching valve 15 is switched to the negative pressure source 16 side. Since it is equipped with a sensing device S, when the vehicle enters a deceleration driving state from a normal driving state, the electromagnetic switching valve 15 responds precisely to this.
is immediately switched to the negative pressure source 16 side, and the negative pressure can be gradually stored in the negative pressure working chamber 9 through the one-way throttle valve 19, and the stored amount is controlled by the throttling action of the one-way throttle valve 19. Since the amount of auxiliary fuel is adjusted according to the deceleration operation time based on the deceleration operation time, as a result, the fuel pump P can accurately pressure-feed the auxiliary fuel adjusted to the appropriate amount according to the deceleration operation time to the fuel passage 2 of the carburetor. Therefore, the transition from deceleration to acceleration of the vehicle is performed extremely smoothly, and driving performance and driving feeling can be improved.

Further, the auxiliary fuel supply passage 4 is provided so that its fuel outlet faces the air bleed jet 32 of the air bleed device 2a attached to the fuel passage 2, so that the fuel is pumped from the fuel pump P to the auxiliary fuel supply passage 4. Compared to the case where the auxiliary fuel is injected directly into the venturi part of the carburetor, the atomization or atomization of the fuel is further promoted, and the combustion of the air-fuel mixture within the engine during acceleration is extremely smooth. be exposed.

[Brief explanation of the drawing]

The drawing is a schematic diagram of the device of the invention. C... Pump discharge amount control device, P... Diaphragm fuel pump as a fuel pump, 1... Carburizer main body, 2.
...Fuel passage, 3...Float chamber, 4...Auxiliary fuel supply passage, 2a...Air bleed device, 9...Negative pressure operating chamber, 15...Solenoid switching valve, 16...Negative pressure Source, 18.
... Air passage, 19... One-way throttle valve, 32... Bleed jet, S... Sensing device.

Claims (1)

[Claims] 1 A fuel passage 2 formed in the carburetor body 1 and an auxiliary fuel supply passage 4 communicating between the float chamber 3 thereof; Interposed in the middle of this auxiliary fuel supply passage 4 to supply fuel to the fuel passage 2. Negative pressure response type fuel pump P for supply = When the internal combustion engine is connected to the fuel pump P and shifts from deceleration operation to acceleration operation, the fuel pump P is operated and its discharge amount is determined according to the deceleration operation time. a pump discharge amount control device C capable of variably controlling the pump discharge rate; The pump discharge amount control device C selectively communicates an air passage 18 connected to the negative pressure working chamber 9 of the fuel pump P with the negative pressure source 16 or the atmosphere. An electromagnetic switching valve 15 and a one-way air passage 18 interposed between the electromagnetic switching valve 15 and the negative pressure working chamber 9 to restrict only the flow of air from the negative pressure working chamber 9 to the electromagnetic switching valve 15 side. The throttle valve 19 distinguishes and senses the normal running state and deceleration driving state of the vehicle, and during normal driving, the electromagnetic switching valve 15 is set to the atmosphere communication side, and during decelerating driving, the electromagnetic switching valve 15 is set to the negative pressure source 16. An auxiliary fuel supply control device for a vehicle internal combustion engine, comprising a sensing device S for switching control to a communication side.