JPH048266Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an explosion-proof mechanism for a pneumatic speed governor that controls the speed of a spark-ignition engine.

[Conventional technology]

As a conventional pneumatic speed governor for a spark ignition engine, for example, as shown in FIGS. Intake pipe 5 that guides airflow
A governor assembly 7 which is attached between the governor body 6 and has a governor shaft 7-1 that directly adjusts the amount of air, and an auxiliary governor connected to the governor shaft 7-1. A stabilizer piston assembly 8 having a control function and equipped with a stabilizer piston cylinder part 8-1, ball bearings 9 and 10 that support the governor shaft 7-1 at two points, bearing holders 11 and 12 for these, and adjustment The cam assembly 14 is fixed to the speed valve shaft 7-1 and housed in the cam chamber 13, and the cam assembly 14 is tensioned via a cam band 15 and a spring 16 whose one end is fastened to the cam assembly 14. Adjustable handle assembly 17 that can be set,
Dustproof cover 18 that protects the adjuster handle assembly 17, lid 19 of the cam chamber 13, packing 20, stabilizer piston cylinder part 8-1
and the clean side 3 of the air cleaner 2, and automatically adjusts the amount of air-fuel mixture flowing from the carburetor 4 through the mixing air passage 22 according to the operating condition of the engine. The structure is such that

In the figure, 23 indicates a bench lily portion, and 24 indicates a throttle valve.

[Problem that the invention attempts to solve]

However, in such a conventional pneumatic governor, it is impossible to avoid gaps between the governor shaft 7-1 and the bearing retainer 11 and between the ball of the ball bearing 9 and the cage or race. The gap allows the cam chamber 13 to connect to the air-fuel mixture passage 2.
It will communicate with 2. Therefore, cam chamber 1
3 performs a breathing operation in response to negative pressure fluctuations in the mixture passage 22, and as a result, mixture particles passing through the mixture passage 22 also flow into the cam chamber 13 through the gap. Once the gasoline particles have flowed into the cam chamber 13, they accumulate in the lower part of the cam chamber as a liquid. For example, if the engine experiences a backfire phenomenon, the gasoline vapor in the cam chamber 13 will ignite, and the pressure in the cam chamber 13 will decrease. There was a problem in that the dust-proof cover 18 could come off or be damaged due to the abnormal increase in dust, and the adjustment function of the adjuster handle assembly 17 would be hindered.

In order to solve these problems, the present invention attempts to prevent the air-fuel mixture from flowing into the cam chamber 13 by creating a structure in which the air in the cam chamber 13 always flows into the mixture passage 22 during engine operation. It is something.

[Means for solving problems]

The present invention solves the above-mentioned problems, and is attached between the carburetor of a spark-ignition internal combustion engine, which has an air cleaner located upstream, and the intake pipe that leads the air mixture to the engine. A pneumatic speed governor having a speed governor that can automatically adjust the air mixture flow passage to a predetermined air mixture amount, the air flow governor having electrical conduction through a gap between the air mixture flow passage and the shaft portion of the speed governor valve. A stabilizer piston assembly is provided which is connected to the clean side of the air cleaner through a conduit, and further includes means for communicating the cam chamber with the clean side of the air cleaner.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, a pneumatic speed governor 1,
Air cleaner 2, clean side 3, carburetor 4,
Intake pipe 5, governor body 6, governor valve assembly 7, governor shaft 7-1, stabilizer piston assembly 8, stabilizer piston cylinder part 8-1, ball bearings 9, 10, bearing retainers 11, 12, The cam chamber 13, the cam assembly 14, the cam band 15, the spring 16, the adjuster handle assembly 17, the dust cover 18, the lid 19, the packing 20, the conduction pipe 21, the air-fuel mixture passage 22, and their relative positions are the same as those in the seventh
There is no difference from the conventional example explained in FIG. 8 and FIG. However, in the present invention, the vent hole 23 is passed through the partition wall that partitions the stabilizer piston cylinder portion 8-1 and the cam chamber 13, and the cam chamber 13
is communicated with the clean side 3 of the air cleaner 2 via the vent 23, the stabilizer piston cylinder portion 8-1, and the conduction pipe 21.

Therefore, when the engine enters the operating state, air always flows from the cam chamber 13 to the mixture passage 22 between the mixture passage 22 and the cam chamber 13, which are normally in a negative pressure state. That is, the air-fuel mixture is continuously passed through the clean side 3 of the air cleaner 2, the conduit pipe 21, the stabilizer piston cylinder section 8-1, the vent 23, the cam chamber 13, the bearing presser 11, and the gap near the governor shaft 7-1. Since air flows through the passage, the inflow and outflow of air-fuel mixture due to the breathing action of the intake pulsation of the cam chamber 13, which conventionally occurs, can be completely eliminated.

Further, during engine operation, a considerable amount of negative pressure may be generated in the cam chamber 13, and in order to reliably prevent this and bring the inside of the cam chamber 13 as close to atmospheric pressure as possible, the examples shown in FIGS. It is best to increase the cross-sectional area of the communication path that connects to the clean side 3 of the air cleaner 2, such as the conduction pipe 21 and the vent 23, as shown in the figure.This will cause the internal pressure of the cam chamber 13 to approach atmospheric pressure, so that external dust will not be absorbed by the cam. Since the dust is not sucked into the chamber 13, the dust cover 18 can be made unnecessary.

Further, the examples shown in FIGS. 5 and 6 show other embodiments, in which the cam chamber 13 is connected directly to the clean side 3 of the air cleaner 2.
There is no difference from the conventional example except that a communication pipe 24 is provided between the clean side 3 of the air cleaner 2 and the communication pipe 24,
A series of flow paths consisting of the cam chamber 13 and the mixture air passage 22 is formed, and during engine operation, the air in the cam chamber 13 can form a unidirectional flow to the mixture air passage 22 due to normal intake negative pressure. It's summery. In this case as well, by increasing the cross-sectional area of the communication path between the cam chamber 13 and the clean side 3 of the air cleaner 2, the internal pressure of the cam chamber 13 can be brought close to atmospheric pressure, and the dust cover 18 can be made unnecessary.

[Effect of idea]

As described above, the present invention connects one end of the cam chamber to the atmosphere on the clean side of the air cleaner, and during engine operation, the air in the cam chamber constantly flows into the mixture passage through the gap due to the negative pressure in the mixture passage. Because of this structure, the conventional air-fuel mixture movement in and out of the cam chamber due to the breathing action of the intake pulsation is eliminated, preventing air-fuel mixture from entering the cam chamber and eliminating air-fuel mixture particles or liquid accumulation inside the cam chamber. Because you can
Even if an engine backfire phenomenon occurs, ignition and combustion in the cam chamber can be avoided, preventing the dust cover from falling off or being damaged due to abnormal pressure in the cam chamber, and preventing the adjustment function of the adjuster handle assembly from being inhibited. By enlarging the cross-sectional area of the communication path that connects the cam chamber and air cleaner, the cam chamber does not reach negative pressure even when the engine is running, making it possible to eliminate the need for a dust cover. This has the following effects.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing one embodiment of the present invention, FIG. 2 is a cross-sectional plan view of a portion thereof, and FIG. 3 is a partially cutaway front view showing another embodiment of the present invention. Fig. 4 is a cross-sectional plan view of a part of the same, Fig. 5 is a partially cut-away front view showing still another embodiment of the present invention, Fig. 6 is a cross-sectional plan view of a part thereof, and Fig. 7 is a conventional example. The partially cutaway front view shown in FIG. 8 is a cross-sectional plan view of that part. 1...Pneumatic speed governor, 2...Air cleaner, 3
...Clean side, 4...Carburizer, 5...Intake pipe, 6...Governor body, 7...Governing valve assembly, 7-1...Governing valve shaft, 8...Stabilizer piston assembly , 8-1... Stabilizer piston cylinder part, 9, 10... Ball bearing, 11, 12... Bearing holder, 13
...Cam chamber, 14...Cam assembly, 15...
...Cam band, 16 ... Spring, 17 ... Adjustment handle assembly, 18 ... Dust cover, 19 ... Lid, 20 ... Packing, 21 ...
... Conduction pipe, 22 ... Mixture passage, 23 ... Bench lily section, 24 ... Throttle valve, 25 ... Vent port, 26
...Communication pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A carburetor of a spark-ignition internal combustion engine that is attached between a carburetor that has an air cleaner located upstream and an intake pipe that leads a mixture flow to the engine, and that is installed between the carburetor and the intake pipe that leads the air mixture to the engine, and that generates a predetermined air-fuel mixture according to the operating state of the engine. a pneumatic speed governor having a speed governor that can automatically adjust the passage of the mixture flow according to the amount of air flow, the cam chamber being electrically connected through a gap between the passage of the mixture flow and a shaft portion of the speed governor valve; and a stabilizer piston assembly connected to the clean side of the air cleaner through a conduit, and further comprising means for communicating the cam chamber with the clean side of the air cleaner. 2. A utility model registration claim wherein the cam chamber is communicated with a cylinder portion of the stabilizer piston assembly connected to the conduit pipe through a vent, as means for communicating the cam chamber with the clean side of the air cleaner. Explosion-proof pneumatic governor as described in Scope 1. 3. The explosion-proof type according to claim 1, wherein the means for communicating the cam chamber with the clean side of the air cleaner is that the cam chamber and the clean side of the air cleaner are directly communicated through a communication pipe. Pneumatic governor.