JPS5852338Y2 - vaporizer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a carburetor equipped with an automatic throttle valve opening adjustment device that utilizes intake cylinder negative pressure based on engine temperature.

As shown in Figure 1, the currently used automatic throttle valve opening adjusting device that uses intake cylinder negative pressure based on engine temperature has an actuator 2, a vacuum transmitting pulp 3, and a bimetallic vacuum switching pulp 4. Consisting of

The actuator 2 is connected to the negative pressure chamber 2 by the diaphragm 21.
2 and an atmospheric chamber 23, and a spring 24 is provided in the atmospheric chamber 23 to press the diaphragm toward the negative pressure chamber.
A rod 25 is fixed to the other end of the diaphragm and is pivoted to one end of a lever that is interlocked with a valve shaft of a throttle valve, which will be described later.

The vacuum transmitting pulp 3 is connected to the negative pressure chamber 22 of the actuator 2 on one side and the bimetallic vacuum switching pulp 4 on the other side, and is divided into two chambers connected to each of them by a partition wall, The partition wall is provided with an orifice 31 and a check pulp 32.

The bimetal vacuum switching pulp 4 includes a bimetal 41 that opens and closes an atmospheric communication hole 42 of the pulp according to the engine temperature, and communicates with the downstream side of the throttle valve of the carburetor intake cylinder to be described later through a negative pressure path 43.

Bimetal 41 has a sufficient engine temperature for warm-up (approximately 50°
C) or below, the atmospheric communication hole 42 is closed and the negative pressure path 4 is closed.
The opening 44 of No. 3 is opened, and when the temperature exceeds the above temperature, the atmosphere communication hole 42 is opened and the negative pressure path opening 44 is closed.

The carburetor 1 has an automatic throttle valve opening adjustment device with a throttle valve 1.
2. Throttle valve operating lever 13 fixed to its rotating shaft 17;
It has a throttle valve adjustment lever 16 which is also fixed to the shaft.

Also, an interlocking lever 19 swings about the support shaft 18, engages the tip of the throttle valve adjustment lever 16 at one end, and is pivoted to the actuator's rond 25 at the other end.
There is.

The throttle valve operating lever 13 is opened and closed by operating rods 14, 14'.

A coil spring 15 elastically connects the two rods.

With this structure, when the engine is started at room temperature (not a cold state but not sufficiently warmed up), the suction pipe negative pressure acts on the negative pressure chamber 22 of the actuator 2, causing the diaphragm 21 to move slightly. be lifted up.

Therefore, adjustment iron 25, interlocking lever 19, adjustment lever 1
6, the throttle valve 12 is opened to an opening degree to prevent engine stalling against the coil spring 15.

Therefore, when the starting device is not operated, the problem of engine stalling due to excessively low idling rotation can be prevented (without supplying a rich mixture for starting), and CO and HC in the exhaust gas are reduced.

And if the engine is sufficiently warmed up, the bimetallic vacuum switching valve 4
Since the atmospheric communication hole 42 of the actuator 2 is opened and the negative pressure path opening 44 is closed, the negative pressure chamber 22 of the actuator 2 becomes atmospheric pressure, and normal operation is performed.

Further, when the throttle valve is suddenly returned during engine operation, the operating resistance of the diaphragm 21 of the actuator 2 causes a dash pot effect of the throttle valve.

The orifice 31 of the vacuum transvincing valve 3 regulates the flow of negative pressure or atmospheric air to the negative pressure chamber 22, and the check valve 32 controls the balance of the negative pressure chamber 22 when the engine repeats acceleration and deceleration. This will speed up the process.

However, when starting the engine when it is cold, the above-mentioned automatic opening phenomenon of the throttle valve dilutes the starting air-fuel mixture, which is a drawback that impairs the startability when the engine is cold.

Currently, in order to compensate for this drawback, efforts are being made to add a diluter to the starting device so that the diluter does not work when starting in cold weather.

The present invention connects the negative pressure path 43 of the automatic throttle valve opening adjustment device to the disc type starter device without directly communicating it to the suction pipe,
The above drawbacks are corrected by communicating the starting air-fuel mixture supply path of the starter with the negative pressure path of the automatic throttle valve opening adjustment device through a disc groove of the starter.

Next, the present invention will be explained with reference to the drawings.

The second figure is a longitudinal cross-sectional view of the two devices, showing an embodiment of a carburetor combining the throttle valve actuator device and the disc-type starter device according to the present invention, and FIG. 3 is a plan view thereof.

Parts referred to in both figures are indicated by the same reference numerals as in Fig. 1, but the disc-type starter part 5 has a conventionally known structure, with a numeral 51 communicating with the air intake port of the intake cylinder 11. A starting air intake passage 52 is a starting fuel intake passage that leads to the air intake passage 51 and communicates with a carburetor fuel chamber (not shown).

53 is a starting mixture supply path, 55 is a starting disk, 56
is an opening/closing groove of the air-fuel mixture supply passage 53 provided in the disk,
57 (Fig. 3) is a lever for operating the disk 55;
When the lever is brought into contact with a bottle 58 installed in the carburetor main body 1, the air intake passage 51 and the mixture supply passage 53 are communicated with each other (as shown in the figure).

And 54 is a negative pressure path leading to the above-mentioned bimetal vacuum switching valve 4.

In the above configuration, if the operating lever 57 is rotated clockwise and brought into contact with the bottle 59 (installed in the carburetor main body) (as indicated by the dotted line 57' in FIG. 3), the groove 56 will open as shown in FIG. 56'
At this position, the air intake passage 51 and the mixture supply passage 53 are disconnected from each other, and the mixture supply passage 53 and the negative pressure passage 54 are communicated with each other.

If the operating lever 57 is placed in the intermediate position between the bins 58 and 59, the groove 56 of the disc 55 will be in the position 56', communicating with the atmospheric high metal vacuum switching valve.

With the above structure, when starting in cold weather, if the operation lever 57 of the starting disk 55 is brought into contact with the bottle 58 to start, a rich air-fuel mixture is supplied in the same way as a conventional starting device.

After the complete explosion, if the lever 57 is placed in the intermediate position, the bimetallic valve 41 of the bimetallic vacuum switching valve 4 closes the atmosphere communication hole 42 but opens the opening 44, so that the atmosphere is transferred to the actuator 2. It acts on the negative pressure chamber 22 and acts as a damp pump.

After the engine has warmed up sufficiently, put the lever 57 on the bottle 59.
7', the supply of starting air-fuel mixture is stopped and the bimetallic valve 41 closes the negative pressure path 54, so that the throttle valve position is normally at the idling position.

As described above, the device according to the present invention has a simple configuration that does not impair starting performance in cold conditions, and also functions as a damping pond. The device can also have the effect of completely preventing the supply of

[Brief explanation of the drawing]

FIG. 1 shows a general example of a carburetor with a throttle valve actuator device. FIG. 2 shows an embodiment of a carburetor in which a throttle valve actuator device and a disk-type starter device according to the present invention are combined, and the two device parts are cut away. FIG. 3 is a plan view of the carburetor shown in FIG. 2. 2...actuator, 3...vacuum transvining valve, 4...
Bimetal vacuum switching valve, 5.
...Disk type starting device, 53...Starting mixture supply path, 56...Disk groove.

Claims (1)

[Scope of utility model registration request] In a carburetor equipped with an automatic throttle valve opening adjustment device that uses intake cylinder negative pressure based on engine temperature, the vacuum transmitting pulp negative pressure path of the throttle valve opening automatic adjustment device is connected to a disc-type starter device. A carburetor, characterized in that the starting air-fuel mixture supply path of the starting device and the negative pressure path are communicated through a disc groove of the starting device.