JPH01294947A - Starting control mechanism for rotary throttle valve type carburetor - Google Patents

Abstract

PURPOSE:To improve startability enabling a rich mixture to be formed in the time of starting with a throttle valve moved in the axial direction by turning a control lever reciprocating from its idle position to the reverse direction, in the case of the throttle valve being enabled to rotate further to move in the axial direction. CONSTITUTION:When an engine is started in cold time, an inner cable 5 is pressed back to the upper by a trigger lever not shown, and a control lever 28 is turned, till it is adapted to a mounting wall 26c, about a supporting shaft 27. Next the inner cable 5 is pulled to the bottom, and the control lever 28 is turned in the clockwise direction, here by adapting the control lever 28 in its side edge to an operating pin 32, a throttle lever 30 is turned to a required opening. While during this time, the control lever 28 hits an operating piece 41, passing through an idle position simultaneously tilting a cam 48 integrally with the operating piece 41. Thus lifting the throttle lever 30 and a needle valve 20, a nozzle hole 18 increases its opening area, forming a rich mixture.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a starting operation mechanism for an internal combustion engine carburetor installed in a portable working machine such as a chemical sprayer or a brush cutter, and more specifically, a starting operation mechanism for a rotary throttle valve type carburetor. It is related to.

[Prior Art] For example, in a rotary throttle valve type carburetor disclosed in Japanese Utility Model Publication No. 63-6438, the area of the intake passage is adjusted by rotating the throttle lever, and at the same time the area of the intake passage is adjusted by rotating the throttle lever.
The mechanism moves the needle valve in the axial direction in conjunction with the throttle valve.
The opening area of the fuel nozzle hole is adjusted, and the amount of fuel is adjusted in accordance with the amount of air sucked into the engine. In addition, since a rich air-fuel mixture is required to start the engine in cold weather, the throttle valve is moved in the axial direction via the cam mechanism by the starting lever, which operates independently of the throttle lever, to open the fuel nozzle hole. The opening area is increased.

However, with the starting operation mechanism of the rotary throttle valve type vaporizer mentioned above, it is necessary to operate both the starting lever and the throttle lever when starting between layers in cold weather, especially in backpack-type chemical sprayers. , starting the engine with the aircraft on its back is a nuisance.

It is also possible to start the aircraft by lowering it to the ground, but carrying the aircraft on your back after the engine has started will make the aircraft extremely unstable and there is a risk that the chemical may spray out unexpectedly.

Furthermore, when the carburetor is covered, installing a throttle lever and a rib bar will hinder compactness and cause movement to the engine.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the object of the present invention is to provide a low-crisp throttle valve type carburetor that allows cold starting of the engine by operating a single trigger lever even when the aircraft is on the back. The purpose of this invention is to provide a starting operation mechanism for the device.

Means for Solving Problem U] In order to achieve the above object, the present invention has a configuration in which the throttle valve moves in the axial direction at the same time as rotation to adjust the fuel, and the control lever is moved in the opposite direction from the idle position. By turning the throttle valve 11 times, the throttle valve is moved in the axial direction to obtain a rich air-fuel mixture at the time of starting.

[Function] When the operating lever 28 is rotated from the idle position in the opposite direction to the fully open direction, the operating lever 28 pushes down the operating piece 41 against the force of the spring and moves to the rear side of the operating piece 41. Therefore, when the operating lever 28 is returned to the idle position, the operating lever 28 hits the operating piece 41, the cam 48 is rotated together with the operating piece 41 around the support shaft 44, and the cam 48 pushes up the throttle lever 30. . The needle valve 20 is pushed up together with the throttle valve 21, and the fuel nozzle hole 1
8 opening area is increased. As a result, the amount of fuel at the time of cold starting can be increased by simply operating the control lever 28 remotely.

Embodiment 1 of the Invention As shown in FIG. 1, a cylindrical intake passage 1 is penetrated through a block-shaped main body 2, and this artificial end 1a is connected to an air cleaner through outlet ends 1bi, t [intake boat of the are connected to each. A cylindrical portion 24 whose upper end is open so as to cross the intake passage 1 is formed in the main body 2, and a cylindrical throttle valve 21 is rotatably supported inside the cylindrical portion 24. Throttle valve 2
The valve shaft 25 formed at the upper end of the main body 2 is connected to the cylindrical portion 24 of the main body 2.
is supported in the shaft hole 22 of the bearing member 3 which is opened. A cylindrical portion 17 provided at the lower end of the throttle hole 21 is fitted into a shaft portion 16 formed at the bottom 12 of the cylindrical portion 24 of the main body 2 .

A spring 9 interposed between the bearing member 3 and the throttle valve 21
The - end is locked to the throttle valve 21 and the other end is locked to the bearing member 3, respectively. The spring 9 rotationally biases the throttle valve 21 to the idle position, and the cam groove 34 on the lower surface of the throttle lever 30 connected to the upper end of the valve shaft 25 comes into contact with the ball 38 of the recess 36 protruding from the bearing member 3. Ru.

The throttle valve 21 is provided with a throttle hole 19 that can communicate with the intake passage 1, and a nozzle pipe 15 projects from the shaft portion 16 of the main body 2 into one throttle hole. For example, a diaphragm type fuel supply F (not shown) is fitted and supported at the lower end of the fuel passage 14.
It communicates with the mailing room at 11111. Nozzle pipe 1
Nozzle hole 1 opened on the downstream side I\ of the intake passage 1 provided in 5
8 has its opening area adjusted by a needle valve 20 that fits into the fuel passage 14 from above. The upper end of the needle valve 20 is connected to an adjustment bolt 23, and by screwing the adjustment bolts 1 to 23 into the hole 6 of the valve shaft 25 against the force of the spring 10, the needle valve 20 is fixed.
0 into the throttle hole 19 is adjusted.

The cam groove 34 of the throttle lever 30 has an arc shape centered on the valve shaft 25 (see FIG. 2), and the depth of the cam groove 34 is deepest at the idle position and gradually becomes shallower as it reaches the fully open position. Therefore, the throttle lever 30
When VJ is turned from the idle position to the fully open position, the opening degree of the throttle hole 19 with respect to the intake passage 1 gradually increases, and at the same time, the needle valve 20 is pushed up together with the throttle valve 21 against the force of the spring 9, and the nozzle hole The frontage area of fuel passage 18 increases, and the amount of fuel sucked from fuel passage 14 to throttle hole 19 increases. The structure of such a rotary throttle valve type carburetor is the same as that of a conventional one.

According to the present invention, a bracket 1-26 made of a metal plate or the like is superimposed on the bearing member 3, and is coupled to the main body 2 together with the bearing member 3 by a plurality of bolts 8 (see FIG. 2). A support shaft 27 parallel to the valve shaft 25 is fixed to the bracket 26, and a boss portion 2 formed at the base end of the operating lever 28 is attached to this support shaft 27.
8a is rotatably fitted and not detached from the support shaft 2.
A seat plate is coupled to the upper end portion of 7 with bolts 29 . The operating lever 28 extends so as to overlap above the throttle lever 30. The lower end small-diameter shaft portion of the swivel 31 is rotatably inserted into the shaft hole at the tip of the operating lever 28, and a retaining ring is locked to prevent it from coming off.

An inch cable 5 is inserted into the groove 31a at the upper end of the swivel 31.
The ends of the two are joined by known means (FIG. 2). An operating pin 32 made of a cylindrical steel plate is fitted and fixed into a shaft hole formed at the end of the throttle lever 3o.

A cam 48 is attached to a bracket 43 formed integrally with the bearing member 3.
is rotatably supported by a support shaft 44.

The cam 48 has a roughly elliptical cross section, and is normally connected to the spring 4.
5, the bearing member 3 is placed horizontally on the plate surface of the bearing member 3. At this time, the lower surface of the throttle lever 30 approaches the upper surface of the cam 48 due to the force of the spring 9 described above. In the groove of the column 49 integrally formed on the right end of the cam 48,
The actuating piece 41 is rotatably supported by a pin 42 within a predetermined enclosure.

The spring 45 is wound around the support shaft 44 at a notch 47 (FIG. 4) formed in the cam 48, and one end is locked to the bearing member 3, and the other end is locked to the back surface of the actuating piece 41. Therefore, the actuating piece 41 is biased by the spring 45 into an upright state and can come into contact with the side edge of the operating lever 28 .

As shown in FIG. 4, the cam 48 has an actuating piece 41 attached to the upper end of a column 49 formed at one end of the cam 48, which has an approximately elliptical cross section.
A split groove 4G supporting the IJ groove 46 is formed on both side walls of the IJ groove 46, and a bottle hole 42 into which the bottle 42 that crosses the cut groove 46 is fitted is formed.
a is provided. Furthermore, six-shaft holes 44a are provided on both side walls of the notch 47 that accommodates the spring 45 of the cam 48, into which the support shaft 44 that crosses the notch 47 is fitted.

As shown in FIG. 2, the operating pin 32 is brought into contact with the end side edge of the operating lever 28. As shown in FIG. The guide tube 7 (which connects one end of the three outer tubes) is screwed into a tapped hole in the wall 26b and fixed by a lock nut 11. The inch cable 5 connected to the operating lever 28 is passed through the outer tube 39 through the guide tube 7. The other end of the outer tube 39 is fixed to a handle portion or an operating section of the work machine, while the other end of the inner cable 5 is connected to a triangular lever that is pivotally supported on the operating section.

As shown in FIG. 3, the brackets 1 to 26 include a hole 8a through which the bolt 8 is inserted, a shaft hole 27a into which the support @27 is fitted, and a pillar 36.
Mounting walls 26a, 26b, 26c are provided with holes 36a for passing through, and the edges are vertically bent.
is formed. Throttle adjustment bolt 4 on mounting wall 26a
are screwed together, and the end of the throttle lever 30 is brought into contact with this end 4a by the force of the spring 9 described above. At this time, the throttle lever 30 is in the state shown in FIG. 2, and the operating lever 28 is also returned to the state shown in the drawing by the actuating pin 32, but the operating lever 28 is moved by remote control of the inner cable 5! It can be rotated to a position where it hits the mounting wall 26c indicated by the Jt4 line.

Next, the operation of the starting operation mechanism of the rotary throttle valve type carburetor according to the present invention will be explained. In the idle position of the throttle valve 21 shown in FIG.
0 is urged to rotate counterclockwise by the force of a spring 9 shown in FIG. At the same time, the operating pin 32 is brought into contact with the side edge of the operating lever 28.

At this time, as shown in FIG. 5, the actuating piece 41 hits the stop wall 46a of the split groove 46 by the force of the spring 45, and is brought into an upright state.

When the engine is cold started, when the inner cable 5 is pushed back upward in FIG. 2 using a trigger lever (not shown), only the operating lever 28 rotates counterclockwise about the support shaft 27 and hits the mounting g26c. . During this time, as shown in FIG. 6, the operating lever 28 pushes the operating piece 41 backward against the force of the spring 45 to reach the position shown by the chain line. When the operating lever 28 passes the actuating piece 41, the actuating piece 41 returns to the upright state as shown by the chain line.

Next, when the bird pulls the inner cable 5 downward with the lever in FIG. The lever 30 is rotated to a required position, and the throttle valve 21 is opened to a required degree. During this time, the operating lever 28 hits the operating piece 41 in the upright state as shown by the line wA in FIG. 6, passes through the idle position, and at the same time, as shown in FIG. is tilted about the support shaft 44.

In FIG. 2, the throttle lever 3o is controlled by the cam 48.
is roughly pushed up beyond the contact position between the cam groove 34 and the ball 38, and the needle valve 20 is also pushed up together. As a result, the opening area of the nozzle hole 18 is increased compared to the normal state with respect to the opening degree of the throttle valve 21, and the rich air-fuel mixture necessary for starting the engine is supplied to the engine, thereby preventing cold starting of the engine. easily reached.

After starting the engine, pull the inner cable 5 further using the trigger lever and move the operating lever 28 to the support shaft 27 in FIG.
When rotated clockwise around , the operating lever 28 pushes down the operating piece 41 and the cam 48 and passes, as shown by the chain line in FIG.
is returned to the position shown in FIG.

[Effects of the Invention] As described above, the present invention adjusts the fuel by moving the throttle valve in the axial direction at the same time as it rotates, and by reciprocating the control lever in the opposite direction from the idle position, the throttle valve axially to obtain a rich air-fuel mixture at startup, even when you cannot see the aircraft directly, such as when you are working on a backpack, you can easily control cold and cold conditions by simply pushing and pulling a single trigger lever. A rich mixture can be obtained by increasing the amount of fuel at the time of starting, the cold-g starting operation is extremely simple, and warming up after starting is also easy.

If an increase in fuel is not required at the time of starting, the lever can be operated from the normal idle position to the fully open direction, thereby avoiding erroneous operation.

Since engine acceleration and starting operations are achieved with a single cable and operating lever, the carburetor configuration is compact and the cable hooks and turns are simple.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a rotary throttle valve type carburetor equipped with a starting operation mechanism according to the present invention, FIG. 2 is a plan view thereof,
Figure 3 is a plan view of the bracket, Figure 4 is a perspective view of the cam,
5 to 7 are side views illustrating the operation of the starting operation mechanism. 2: Main body 5: Inner cable 21: Throttle valve
25; Valve stem 28: Operating lever 30: Throttle lever 32: Operating bin 41: Operating piece 48: Cam

Claims (2)

[Claims] (1) In devices where the throttle valve moves axially at the same time as it rotates to adjust the fuel, the throttle valve is moved axially by reciprocating rotation of the operating lever in the opposite direction from the idle position, resulting in a rich fuel flow during startup. A starting operation mechanism for a rotary throttle valve type carburetor, which is characterized by obtaining an air-fuel mixture. (2) An elliptical cam that comes into contact with the lower surface of the throttle lever connected to the valve shaft is rotatably supported by the main body, and an operating lever that is disposed above the throttle lever and pushes the throttle lever in the fully open direction. The actuating piece, which is tilted against the spring by rotating from the idle position in the opposite direction to the fully open direction, is supported by the cam, and is activated by rotating the operating lever from the retracted position than the idle position to the idle position. A starting operation mechanism for a rotary throttle valve type carburetor, characterized in that the blade and the cam are rotated together, the throttle lever and needle valve are moved in the axial direction, and the fuel nozzle hole is enlarged.