JPS59201956A - Carburetor used for internal-combustion engine - Google Patents

Abstract

PURPOSE:To suppress a rapid increase of torque, by providing an accelerator pump, which delivers accelerating fuel into an intake passage, and a diaphragm device for driving said pump so as to generate its driving power by the intake negative pressure through a negative pressure delay device. CONSTITUTION:An accelerator pump 4, which delivers accelerating fuel into an intake passage 6 of a carburetor 5, is formed by a rod 7 and a piston 8, continuously urging the rod 7 and the piston 8 upward by a compression coil spring 11. A pressure chamber 10 communicated to a float chamber 13 is formed below the piston 8 and communicated to a nozzle 17 through a fuel delivery passage 15. The rod 7, whose upper end part is connected to one end of a lever 21 swivellably moved about a supporting point 23, is driven by actuating a diaphragm device 25 connected to the other end of the lever 21 through a rod 27. The diaphragm device 25, being connected to an intake manifold 28 through a negative pressure delay device 29, generates driving power when the intake negative pressure approaches the atmospheric pressure.

Description

[Detailed description of the invention] The present invention relates to improvements in carburetors for internal combustion engines.

In a vehicle equipped with an internal combustion engine with a carburetor, when the accelerator is suddenly operated to accelerate the vehicle, the vehicle may vibrate in the longitudinal direction. Such back-and-forth vibration of the vehicle is called a shakuri phenomenon, and this is caused by the following causes.

That is, as shown in FIG. 1, in the vaporizer,
The valve shaft 1 of the throttle 1 fuel valve (not shown) is connected to the acceleration pump 2 by a link 3, so a sudden accelerator operation causes the acceleration pump 2 to suddenly pump a large amount of fuel into the intake passage (not shown). Exhale. Therefore, the torque of the engine increases rapidly, causing torsional vibration in the power transmission shaft that transmits power from the engine to the wheels. If the frequency of this torsional vibration happens to almost match the torsional natural frequency of the power transmission shaft, it will resonate and become an extremely large torsional vibration, which will shake the wheels and cause this to occur. This is because it is transmitted throughout the vehicle.

At present, no effective technique has been proposed to prevent this hiccup phenomenon.

An object of the present invention is to prevent a large amount of fuel from being suddenly discharged from an accelerator pump in a carburetor for an internal combustion engine even if the accelerator is suddenly operated.
The purpose is to suppress the sudden increase in torque of the engine, thereby preventing the occurrence of a stalling phenomenon when the vehicle accelerates.

According to the present invention, this object includes an acceleration pump that discharges acceleration fuel into an intake passage, and a diaphragm device that drives the acceleration pump. It has a first diaphragm chamber and a second diaphragm chamber separated by -ζ, the first diaphragm chamber is always open to the atmosphere, and the second diaphragm chamber is inlet by a negative pressure pipe. The guide flam device drives the acceleration pump and discharges the acceleration fuel only when the pressure in the second diaphragm chamber approaches atmospheric pressure. A check valve and an orifice are interposed in parallel in the middle of the negative pressure pipe, and the check valve only allows air to flow from the second diaphragm chamber toward the intake manifold. This is achieved by a carburetor for an internal combustion engine, which is characterized by:

According to the carburetor for an internal combustion engine having such a configuration, even when accelerated operation is performed by sudden accelerator operation, the pressure in the second Daite Solum chamber immediately becomes the same as the pressure in the intake Mayubold due to the presence of the orifice. It does not reach near atmospheric pressure, but gradually approaches that pressure. Therefore, the accelerator pump is
Since a large amount of acceleration fuel is not suddenly discharged, the engine does not cause a sudden increase in l/lux.

Thus, according to the present invention, the occurrence of the phenomenon of wasted vehicle acceleration 11.1 is prevented.

In addition, in the present invention, since a check valve is provided, after the vehicle accelerates, the vehicle shifts to a steady running state and then suddenly accelerates again. It works the same way.

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows an inner furnace according to an embodiment of the present invention.
The front view of the engine carburetor, Figure 3, is the same as the one shown in Figure 2.
FIG. In No. 31 B, 4 is an acceleration pump that discharges acceleration fuel into the intake passage 6 of the carburetor 5;
The rod 7 includes a rod 7 and a piston 8 mounted at the tip of the rod 7 in several cases. The piston 8 is slidably inserted into a cylinder bore 9 provided in the carburetor 5, and a pressure chamber 10 whose upper limit is limited by the cylinder 8 is formed in the lower part of the piston 8. Ru. A compression coil spring 11 is disposed within the pressure chamber 10 and acts to lift the piston 8 and the Hino 1 nearer upward. 18, the compression:
This is a spring holding member for receiving the spring 11, and is attached to the tip of the opening or door. The pressure chamber 10 is connected to a float chamber 13 through a fuel supply passage 12, and a check valve 14 is provided at the inlet of the pressure chamber 10. The check valve 14 is made of a steel ball and only allows fuel to flow from the flow 1 chamber 13 toward the pressure chamber 10 . The pressure chamber 10 is also connected to the henchuri section 1 by a fuel discharge passage 15.
It is connected to the intake passage 6 directly above the fuel discharge passage 15, and a nozzle 17 is attached to the open end of the fuel discharge passage 15 that enters the intake passage 6. A check valve 19 is provided in the middle of the fuel discharge passage 15, and the check valve 19 is made of a steel ball. The check valve 19 only allows fuel to flow from the pressure chamber 10 toward the nozzle 17 . 20 is a weight for holding down the steel ball. The upper end of the rod 7 has a small (
4 parts 2I, and a gasket 1 is provided around the small diameter part 21 to prevent dust, etc. from entering the Norinda bore 9.
- Sheet 22 is attached. As shown in FIG. 2, it is rotatably attached to the right end of a lever 24 that rotates around the small diameter portions 21 and 23 as fulcrums.

Reference numeral 25 denotes a Gwit flam device for driving the acceleration pump 4, and the diaphragm device ? 27 is connected to a diaphragm (not shown), and the tip of the rod 27 is connected to the left side of the lever 24:
It is rotatably attached to i. Further, the tight flush device 25 is connected to an intake manifold 28 via a negative pressure pipe 26, and a negative pressure delay device 29 is interposed in the middle of the negative pressure pipe 26.

Nozao 30 is the main body of the engine. Diaphragm device 2
5 and the negative pressure delay device 29 will be explained in detail with reference to FIG. The diaphragm device 25 includes a diaphragm case 3
It has a first diaphragm chamber 34 and a second diaphragm chamber 35, each of which is partitioned by a diaphragm 33. The first diaphragm chamber 34 is always at human pressure through the popular open hole 36, and the second diaphragm chamber 35 contains:
A compression coil spring 37 is arranged to press the diaphragm 33. The rod 27 is connected to the diaphragm 33, and the tip of the rod 27 is rotatably connected to the left end of the lever 24, as described above. As described above, the second diaphragm chamber 35-1 is communicated with the intake eyebrow board 2) 3 through the negative pressure pipe 26. In the negative pressure delay device 21, a check df'38 and an orifice 39 are installed in parallel, and the check valve 3
8 allows only the flow of air from the second tire flam chamber 35 toward the intake manifold 28.

The operation and effects of the above embodiment will be explained. When the vehicle is in a steady running state, a strong negative pressure is generated within the intake manifold 28, and the second die and flam chamber 35 of the diaphragm device 25 also have the same strong negative pressure. There is.

Therefore, against the pressing force of the compression -1 spring 37, the deit flora J: (3 is being sucked, so the piston 8 of the acceleration pump 4 shown in FIG. 3 rises, and the pressure chamber 1
The volume of 0 is large.

When the vehicle accelerates due to sudden accelerator operation, the load inside the intake manifold 28 suddenly weakens.
The pressure becomes close to atmospheric pressure. However, due to the negative pressure delay device 29 in FIG. 4, the check valve 3B+1 is closed.
Therefore, air is allowed to flow into the second diaphragm chamber 35 of the dieth flushing device 25 through the orifice;
Pressure inside 4J, direct t) 6:z, intake-l nifold 28
The pressure inside is not close to the same, but gradually approaches the pressure (therefore, the compression: 2 lbs. 37 also gradually expands, so the acceleration pump 4 shown in the 3rd IQ) For example, a large amount of acceleration fuel is suddenly discharged into the intake passage 6, and the acceleration fuel is gradually discharged in accordance with the extension/retraction speed of the compression coil spring 37.

In this way, the 1-lux of the engine 30 does not increase rapidly, and therefore, according to this embodiment, the occurrence of the jerking phenomenon when the vehicle is accelerated is effectively prevented.

11: In order to allow the check valve 38υ provided in the negative pressure delay device 29 of this embodiment, 1, the flow of air +J from the second tire flamm chamber 35 of the diaphragm device 25 toward the intake eyebrow bold 28, After the vehicle accelerates, if the vehicle returns to a steady running state, the second die flam chamber (35
There is a strong negative pressure inside the intake manifold 28.

Therefore, even if the vehicle shifts to a steady running state after accelerating the vehicle and then suddenly accelerates again in the rear, the acceleration pump 4 operates in exactly the same manner as described above.

Furthermore, according to this embodiment, although the acceleration of the vehicle is somewhat slow, this does not pose any practical problem as long as the effective flow path area of the orifice 39 is selected to an appropriate value.

[Brief explanation of the drawing]

1 is a front view of a conventional carburetor for an internal combustion engine, FIG. 2 is a front view of a carburetor for an internal combustion engine according to Embodiment 6 of the present invention, and FIG. 3 is a front view of a carburetor for an internal combustion engine according to a sixth embodiment of the present invention. 4 is a longitudinal sectional view of the die, soson, and negative pressure delay device shown in FIG. 2. 6-----Intake passage 4---Acceleration pump 25--Diaphragm device 3m--Diaphragm case 33--Die-1 Nophram 34-11 First diaphragm chamber 35--Second Daito Solum chamber 36 --- Atmospheric opening hole 26 --- Negative pressure pipe 28 --- = Intake manifold 38 --- Gosho stop valve 39 --- Orifice

Claims (1)

[Claims] It has an acceleration pump that discharges acceleration fuel into an intake passage, and a diaphragm device that drives the acceleration pump. diaphragm chamber, the first diaphragm chamber is always open to the atmosphere, the second diaphragm chamber is communicated with the intake manifold through a negative pressure pipe, and the diaphragm device has a Only when the pressure in the room becomes close to atmospheric pressure, the acceleration pump is driven to discharge the acceleration fuel, and a check valve and an orifice are interposed in parallel in the middle of the negative pressure pipe. A carburetor for an internal combustion engine, wherein the check valve only allows air to flow from the second diaphragm chamber toward the intake manifold.