JPS58167867A - Carburettor provided with deceleration fuel shut-off device - Google Patents

Abstract

PURPOSE:To improve the performance of acceleration upon reacceleration, by providing an electronic control device which opens a solenoid valve for closing a low speed fuel supply system upon deceleration, for carrying out reacceleration when the vehicle speed is lower than a predetermined speed. CONSTITUTION:A signal indicating an open degree of a throttle valve 2 and a signal indicating a vehicle speed are calculated in an electrinic control device 20 and actuate, when they reach predetermined values, a solenid valve 12 for shutting off low speed fuel. That is, a valve seat 13 is closed for shutting off the supply of low speed fuel when the rate of closing the throttle valve reaches a predetermined value. Then, a signal is issued to the solenoid valve 12 which is therefore closed, when the vehicle speed is gradually decreased to a value lower than a predetermined vehicle speed.

Description

DETAILED DESCRIPTION OF THE INVENTION This *#JA relates to an improvement in an automobile carburetor having a device for cutting off fuel supply during deceleration.

A connecting device is installed in the fuel passage of the low-speed fuel supply system of the carburetor,
Conventionally, this passage tm definitely improves the deceleration performance during deceleration.

FIG. 1 is a system M diagram of a conventional vaporization gain system with a direct speed fuel severance device. A throttle valve 2 is installed in the intake cylinder of the carburetor body 1,
The main nozzle 11 is installed in the small bench lily section provided upstream of the main nozzle 11.
is open. Main nozzle 11 is May/Jet 4
It communicates with the paper portion of the float 3i13 via the main air bleed 10, and forms a main fuel supply path together with the main air bleed 10. A slow fuel supply **1 branched from the main fuel supply path downstream of the main jet 4 as shown by a two-dot chain line is connected to a slow mixture passage 7 via a slow jet 5 . Note that the upper m of this slow mixture passage 7 forms a slow air bleed 6, and the lower part forms a slow boat 8. The idle port 9 is opened to the intake passage.

A connecting portion between the slow fuel passage downstream of the slow jet 5 and the slow mixture passage 7 is formed in the valve seat 13, and this valve ji1
A solenoid valve 12 having a movable valve facing 3 is installed. This solenoid valve 12 includes a deceleration fuel cutoff valve, a negative pressure switch 14. It is connected to a power source 16 via a neutral switch 5t. Note that the one-dot chain 11F-F indicates the position of the fuel oil level.

In the thus configured vaporizer with deceleration fuel cutoff device, when the deceleration operation state is entered, one wrinkle of the throttle valve 2 contracts and the amount of intake air decreases, so the negative pressure generated in the main nozzle 11 decreases and the main Fuel supply will be stopped.

However, since the lower RO negative pressure of the one-way throttle valve 2 increases, the amount of low-speed fuel sucked into the slow mixture passage 7 via the slow jet 5t increases, and the speed is not decelerated rapidly. This is prevented by the solenoid valve 12 for cutting off the deceleration fuel.When the negative pressure downstream of the throttle valve 2 is detected, the negative pressure switch 14 is connected, and when the neutral switch 15 detects the deceleration operation state, the movable valve is activated. Take out the center and close the valve jli13. Therefore, the fuel supply to the engine is stopped and the engine is rapidly decelerated.

However, the negative pressure switch 14. 2, 21 tral switch 1
No. 5 has a hysteresis phenomenon, so the valve closing operation is delayed and response is low, and during that time, excess fuel is supplied. In addition, the valve seat 13 that is shut off during deceleration
Since the upper flL1111 is almost at atmospheric pressure, the fuel oil level has dropped to F-F. For this reason, there is a delay in the supply of fuel in response to the generation of negative pressure during re-acceleration.

Figure 3 shows the vehicle speed and throttle valve when accelerating again after deceleration.
[This is m- shown.] When a car that has been driving steadily reduces the throttle p valve by 1 and changes from T2 to T1,
Although the vehicle speed was S2 speed, it started to decelerate slightly after the beginning of the decrease in the opening wrinkles, and gradually decelerated to 81.
The temperature decreases to point A. When the vehicle speed is then increased again along the curve ttFm, the vehicle speed once decreases from point A and then gradually increases along the curve Q. That is, the response upon re-acceleration is slow, and a time delay of tl occurs.

This has the disadvantage of reducing the arresting performance, consuming unnecessary fuel, and increasing the amount of carbon dioxide in the exhaust gas. This phenomenon occurs when the first solenoid valve 1
Even when low-speed fuel path blocking means other than 2 were used, the piggyback was not reformed.

An object of the present invention is to provide a carburetor with a deceleration fuel cutoff device that can improve acceleration performance when accelerating again from a deceleration state, and its characteristic is that the low speed of the low speed fuel supply system Fuel amount Ii2! means for opening and closing I, a throttle valve opening detecting means for detecting the opening of a throttle valve installed in the intake cylinder and outputting an electric signal, a vehicle speed detector, and inputting signals from these detecting means. An electronic control device is provided which calculates the speed and sends a signal t to the low-speed fuel passage opening/closing means. During deceleration, when the reduction speed expansion of the throttle valve M& exceeds the set value, the low-speed fuel passage is closed and the speed is lower than the set speed. The reason is that the low-speed fuel passage is configured to open when the vehicle speed decreases.

FIG. 2 shows a system of a carburetor with a deceleration fuel cutoff device according to an embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In this case, a lever 16 is formed on the rotating shaft of the throttle valve 2, and a sliding rod 17 is always in contact with this lever 16.
A TiF18 is installed to detect the throttle valve once. In addition, a signal proportional to the resistance value of the sliding resistor of this throttle valve 8f detector 18, that is, a signal indicating the opening degree of the throttle valve 9, and a vehicle speed detection 6
19 and the other signals are input to the electronic control device 20.

In this way, the signal indicating once of the throttle valve 2 and the vehicle speed detection signal are calculated by the electronic control *f2G, and when a predetermined set value is reached, the electromagnetic valve 121 for deceleration fuel cutoff is operated. That is, when the valve closing speed 1ΔT/Δt of the throttle valve 2 falls below a predetermined value, the valve seat 13 is closed to cut off the supply of low-speed fuel.

Next, when the vehicle speed gradually decreases to below the set vehicle speed 83, a signal is output to the solenoid valve 12 to open the valve. If this is done, the fuel passage directly above the slow jet 5 will have a negative pressure, so the oil pressure will rise more than FF. When -II of the throttle valve 2 is then increased to increase the speed, the fuel immediately passes through the valve seat 13, and accelerating fuel can be quickly supplied. This accelerating fuel is supplied downstream of the throttle valve 2 from the idle boat 9 through the low-speed fuel system, so that the vehicle speed also increases rapidly.

The 4it line R that rises diagonally from point A of #I3- is the 2nd-
The device Q indicates an increase in vehicle speed during re-acceleration, and has the effect of quickly replenishing acceleration fuel during re-acceleration. That is, in this case, the stall state after passing the A point is not observed, and the speed is increased efficiently.

In the case of the Honto example, the deceleration state me is detected using the value ΔT/Δ1 shown in FIG. 3, and when j'l'/Δt≧setting value, it is determined that the deceleration is occurring. Further, this signal is held in the electronic control AI device 20 until the next signal from the vehicle speed detector 19 outputs the deceleration state I110 signal, and the solenoid valve 12 is operated to close. On the other hand, if the single speed S3 point is set in advance to indicate the completion of deceleration, when the single speed drops below 83, a signal is outputted to the solenoid valve 12 to open the valve seat 13 again. Therefore, after that t.

At the time of acceleration operation after a certain period of time, acceleration fuel 1* can be supplied immediately.

It should be noted that poor acceleration during re-acceleration of a yakurenki generally occurs when re-accelerating from an extremely low speed state. The setting of the vehicle speed S3 at the end of the upper speed range varies depending on the type of vehicle, but can be determined based on the balance between re-acceleration performance and fuel efficiency. That is,
It is sufficient to set the minimum vehicle speed 53t that is suitable for the vehicle.The fourth line is the line showing the characteristics of the throttle valve opening detector shown in Figure 2. Throttle 9 valve 2 is idle open ft1II
The output of the throttle 9 valve opening crease detection IfF 18 is increased in proportion to the amount of sliding rod displacement of the sliding resistance. In this way, # can be electrically detected with sufficient accuracy even if the rate of change ΔT/Δt of the opening degree of the nine consecutive throttle valves 2 is large.

Originally, the conventional carburetor with a standard speed fuel cutoff device was equipped with a throttle valve detection device and a vehicle speed detector, and when decelerating, it operated a solenoid valve that closed the low speed fuel supply system to close the low speed fuel supply system. When the speed drops below a predetermined speed, the electronic control 41 device opens the valve and accelerates the speed again, thereby greatly improving the acceleration performance when reaccelerating. 512! fruit is obtained.

As described in the above embodiment, the low-speed fuel flow # timing during deceleration is determined by selecting the reduction speed t of the strangling opening, so this can be set arbitrarily. Depending on the characteristics of the carburetor and the characteristics of the car in which it is installed, it can be added to the optimal location.

The carburetor with the deceleration fuel cutoff device of the present invention can quickly replenish acceleration fuel without delaying the increase in throttle valve opening when reaccelerating from a decelerated state, improving drivability and fuel economy. It has the effect of improving.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a conventional carburetor with a deceleration fuel 31IFr device, turtle 2- is a system diagram of a carburetor with a deceleration fuel cutoff device which is an embodiment of the present invention, and Fig. 3 is a system diagram of a carburetor with a deceleration fuel cutoff device, which is an embodiment of the present invention.・A graph of the elapsed sound level between the vehicle speed and the throttle valve opening, Figure 4 is the 2nd
FIG. 2 is a diagram showing the characteristics of the nine throttle opening degree detector shown in the figure.

Claims (1)

[Claims] 1. In a carburetor having a main fuel supply system and a low-speed fuel supply system and supplying an electronically controlled air-fuel mixture, means for closing the sluggish fuel passage of the low-speed fuel supply system; Throttle valve opening detection means that detects the opening f of the throttle valve installed in the cylinder and outputs an electric signal, vehicle speed detection (to), and signals from these detection means are calculated by all human resources to detect the low speed. It is integrated with an electronic control device that outputs a signal at the middle stage of opening and closing the fuel passage, and during deceleration, when the rate of decrease in the opening of the throttle valve reaches a set value or more, the low-speed fuel passage is closed.
The deceleration fuel release i1T iron-mounted carburetor is configured to open the sluggish fuel passage when the vehicle speed decreases.