JPS6055705B2 - Variable bench lily type vaporizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel saving device for an internal combustion engine with a variable ventilator carburetor.

In a conventional carburetor, the cross-sectional shape of the ventilate remains constant regardless of the engine load, so the lower the load, the lower the velocity of the air flowing through the ventilate and across the tip of the main nozzle opening there. Therefore, there is a problem in that the fuel sucked out from the main nozzle is not sufficiently atomized during low load.

To address these issues, we vary the cross-sectional size of the ventilate throat depending on the load magnitude, providing a nearly constant ventilium throat air velocity over the entire load range and reducing fuel flow, especially at low loads. Variable ventilate type vaporizers designed to improve atomization are known. SU carburetor is known as a typical variable ventilator type carburetor, and this carburetor consists of a movable piston as a part of the throttle structure constituting the ventilator, and the piston is connected to atmospheric pressure and ventilator. The ventilator throat is positioned so that an approximately constant pressure (negative pressure) is always maintained at the ventilary throat by positioning the pressure differential between the pressure (negative pressure) at the throat and a spring device. It has a configuration that automatically changes the cross-sectional area of. An object of the present invention is to save fuel in an internal combustion engine equipped with a variable ventilee carburetor by reducing the fuel supply during deceleration of the variable ventilee carburetor.

According to the present invention, the purpose is to provide an air bleed passage that opens the main nozzle, an on-off valve that selectively communicates or shuts off the air bleed passage, and an on-off valve that opens and closes the air bleed passage by sensing that the engine is in a deceleration operating state. and an air bleed control device for opening a valve, and the air bleed to the main nozzle is achieved by a variable venture type vaporizer characterized in that the air bleed opens to the throat of the main nozzle.

By incorporating a device with the above configuration into a variable ventilee type carburetor, air bleed is performed to the slow jet and main nozzle during deceleration operation of the engine, so the amount of fuel sucked out from the main nozzle into the intake passage is substantially reduced. This makes it possible to achieve fuel savings during engine deceleration, and at the same time improve the deceleration performance of the bridge, that is, the engine braking characteristics in the case of automobiles. The air bleed control device that senses that the engine is in a decelerating state and opens the on-off valve includes a device that detects the engine speed and throttle valve position (idle position) to determine when the engine is decelerating, and an intake pipe. Various devices can be considered and adopted, such as a device that monitors negative pressure to determine when the engine is decelerating, but one of the simplest devices is one that monitors the intake pipe negative pressure downstream of the intake throttle valve. A device detects the negative pressure, determines that the engine is in deceleration operation when the negative pressure is greater than a predetermined value, and operates a negative pressure actuator such as a diaphragm device by the negative pressure to open the on-off valve. Suggested. That is, in a typical automobile internal combustion engine, the intake pipe negative pressure downstream of the intake throttle valve is -400? when the engine is in idling operation. Hg, and when the engine is in an acceleration or steady load operation state, the intake pipe negative pressure is, of course, a value smaller than this. On the other hand, when the engine is in deceleration mode, even though the intake throttle valve is throttled or fully closed, the piston is not connected to the rotating system of the engine or the inertial system of the vehicle body connected to it. Since the intake pipe is driven in reverse by the
! It becomes $LH compliance. Follow. Then, it senses that the intake pipe negative pressure has increased to a predetermined amount exceeding the amount at idling, and operates the on-off valve by a diaphragm device that is activated only by the increased negative pressure. By doing so, when the engine is in a deceleration operating state, the air bleed passages that open to the slow jet and the main nozzle can be communicated, and air can be bleed to the slow jet and the main nozzle. The accompanying figure is a somewhat exploded cross-sectional view showing one embodiment of a fuel saving device according to the present invention incorporated into an SU vaporizer.

In the figure, 1 is an SU carburetor, and an intake passage 2 is formed inside thereof. A protrusion 4 that forms part of the throttle structure of the ventilate 3 is formed in the middle of the intake passage 2 . The hench turret 3 cooperates with the fixing protrusion 4.
The other protrusion forming the piston 5 is provided by the lower end 5a of the piston 5. The piston 5 is engaged in a cylinder 6 along which it can move up and down in the figure. A cylinder chamber 7 is formed in the interior of the cylinder 6 above the piston 5, and the cylinder chamber cooperates with the lower surface of the lower end 5a of the piston 5, that is, the fixed protrusion 4 to form the novelty 3. Pressure (negative pressure) at the throat of the ventilate is supplied through a boat 8 that opens in the wall. Another cylinder chamber 9 is formed within the cylinder 6 in a region below the piston 5. This cylinder chamber is boat 10
The cylinder chamber 9 is opened to the upstream portion of the ventilate 3 through the cylinder chamber 9, and thus the cylinder chamber 9 is substantially exposed to atmospheric pressure. 1
Reference numeral 1 denotes a compression coil spring, which exerts a downward spring force on the piston 5 in the figure.

This spring force balances the pressure difference in the cylinder chambers 7 and 9 and acts on the upper and lower surfaces of the piston 5, and positions the piston 5 so that the pressure at the throat of the ventilate 3 is always approximately constant. It has the effect of Incidentally, the piston 5 is further provided with an oil chamber 12,
A fixed piston 14 supported by a housing 13 constituting the cylinder 6 is loosely engaged in the oil chamber, and this structure provides a damping effect to the piston 5, causing the piston to be damped by the rapid opening and closing of the intake throttle valve. 5 is designed to prevent an impact movement from occurring. A main nozzle (or main jet) 15 is installed in the fixed throttle part 4.
is provided, which is adapted to supply fuel stored in a float chamber 17 via a fuel passage 16.

18 is a float.

The main nozzle or main jet 15 includes a piston 5.
A tapered jet needle 19 supported by a jet needle 19 is inserted, and the effective opening area of the main nozzle is changed in accordance with the vertical movement of the piston 5. A throttle valve 20 is provided downstream of the ventilator 3.

A slow port or slow jet 21 is opened downstream of the throttle valve 20, and the boat is supplied with fuel from the float chamber 17 via a slow system fuel passage 22. 23 is a screw for adjusting the slow port.

An air bleed passage 24 is open to the main nozzle 15 and the slow system fuel passage 22.

In this case, especially in the main nozzle 15, the air bleed passage 24 opens at the constricted part of the main nozzle, that is, the throat, so that air is sucked out from the main nozzle by the air bleed during deceleration. At the same time, it increases the effect of reducing the amount of fuel used, promotes fuel atomization, improves combustion of lean mixture during deceleration, eliminates uneven engine rotation due to uneven combustion, and improves afterburn of fuel. Alternatively, the discharge of unburned gas can be suppressed more effectively.
The air bleed passage 24 communicates with the atmosphere via an on-off valve 25. However, in some cases, the air bleed passage 24 may be connected to a discharge port of an air pump via an on-off valve 25, so that air at a certain positive pressure is supplied instead of air at atmospheric pressure. The on-off valve 25 has a valve seat 26 and a valve element 2.
7, with the valve element 27 being displaced upwardly in the figure and the valve seat 26
When the valve element 27 is in contact with the valve seat 26, the shut-off valve is closed, whereas when the valve element 27 is pulled downwardly away from the valve seat 26, the shut-off valve is opened.
Valve element 27 is adapted to be actuated by a diaphragm device 28. Diaphragm device 28 is connected to valve element 27
When a negative pressure of a predetermined level or higher is applied to a diaphragm chamber 30 formed below the diaphragm, the diaphragm resists the action of the compression coil spring 31 as shown in the figure. The valve element 27 is deflected downwardly, separating the valve element 27 from the valve seat 26, and opening the on-off valve 25. The diaphragm chamber 30 is a negative pressure transmission passage 32
A negative pressure taken out from a negative pressure take-out boat 33 opening into the intake passage 2 at a position downstream of the throttle valve 20 is applied to the throttle valve 20 . When the engine is in an idling operating state, an accelerating operating state, or a steady load operating state, the negative pressure acting on the negative pressure take-out boat 33 is equal to or smaller than the intake pipe negative pressure during idling (generally about -400TsnHg). In such a negative pressure state, the diaphragm 29 of the diaphragm device 28 is pushed upward in the figure by the action of the spring 31, the valve element 27 comes into contact with the valve seat 26, and the on-off valve 25 is in a closed state. Therefore, under such operating conditions, no air is supplied through the air bleed passage 24, and the main nozzle and slow port operate normally as before. When the engine is in deceleration mode,
Normally, the throttle valve 20 is in a fully closed state, but the engine speed is higher than when idling, and the piston is moved by the inertial energy of the engine's rotational system or the inertial system of the vehicle body connected to it. Since the throttle valve 20 is driven in the opposite direction, a negative pressure is generated in the intake pipe downstream of the throttle valve 20, which is substantially larger than the negative pressure during idling.

When this negative pressure is transmitted to the diaphragm chamber 30 of the diaphragm device 28 via the negative pressure take-off boat 33, the diaphragm 29 is deflected downward in the figure against the action of the spring 31, and the valve element 27 is moved against the valve seat 26. The opening/closing valve 2 is pulled further apart.
5 is in the open state. When the on-off valve 25 is opened, air is sucked through the air bleed passage toward the main nozzle 15 and the slow port 21, and is mixed with the fuel sucked out through the main nozzle and slow port. Alternatively, the amount of fuel delivered through the slow port is substantially reduced. When the engine finishes decelerating and accelerates again or reaches a steady operating state at a certain low speed or an idling operating state, the negative pressure acting on the negative pressure take-out boat 33 becomes the idling negative pressure or a relatively small negative pressure lower than that. , so that the diaphragm 29 is again deflected upwardly in the figure by the action of the spring 31, and the valve element 27 is moved against the valve seat 26.
The on-off valve 25 is closed, and the air bleed passage 2 is closed.
4 is blocked. Thus, according to the present invention, air is mixed into the fuel sucked out by the main nozzle or the main nozzle and the slow port only when the engine is in a deceleration operating state, and the fuel is mixed in when the engine is in an operating state where the engine does not require fuel. Supply can be reduced or cut off to save fuel.

Although the present invention has been described in detail with respect to one embodiment above, those skilled in the art will recognize that the present invention is not limited to this embodiment and that various modifications can be made within the scope of the present invention. It would be obvious to

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawing is a partially exploded sectional view showing an embodiment of a fuel saving device for an internal combustion engine with a variable ventilary carburetor according to the invention.

1... SU carburetor, 2... Intake passage,
3...Bentiary, 4...Fixing protrusion, 5a...Lower end of Zestone, 6...
Cylinder, 7... Cylinder chamber, 8...
...Boat, 9...Cylinder chamber, 10...
... Boat, 11 ... Compression coil spring, 12
...Cylinder, 13...Cylinder housing, 14...Piston, 15...
...Main nozzle, 16...Passage, 17...
...Float chamber, 18...Float, 19.
... Jet needle, 20 ... Throttle valve, 21 ... Slow port, 22 ... Slow system fuel passage, 23 ... Adjustment screw, 24...
...Air bleed passage, 25...Opening/closing valve,
26... Valve seat, 27... Valve element, 28
...Diaphragm device, 29...Diaphragm, 30...Diaphragm chamber, 31...
. . . Compression coil spring, 32 . . . Negative pressure transmission passage, 33 . . . Intake pipe negative pressure take-out boat.

Claims (1)

[Claims] 1. An air bleed passage that opens to the main nozzle, an on-off valve that selectively communicates or shuts off the air bleed passage, and an air bleed control device that senses that the engine is in a deceleration operation state and opens the on-off valve. A variable ventilee type carburetor, characterized in that an air bleed that opens to the main nozzle opens to a throat of the main nozzle.