JPH0454826B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for opening and closing a choke valve in a small general-purpose engine equipped with a governor.

(Prior Art) A conventional example will be explained with reference to FIGS. 4 and 5. In these figures, a governor arm 1 is connected at one end to a governor sleeve 2 and at the other end to a throttle valve 4 via a throttle valve link 3. An intermediate portion of a throttle lever 6 is connected to the middle of the governor arm 1 via a governor spring 5, and a choke valve 7 is connected to the tip of the throttle lever 6. Before starting the engine, the throttle lever 6 is set at the choke closed position P, as shown in FIG. In this state, the choke valve 7 is in the fully closed position C0, and the throttle valve link 3 is in the fully open position S1. When starting is completed, the throttle lever 6 is returned to the throttle fully closed position R via the throttle fully open position Q in FIG. 4 by manual operation. This throttle fully closed position R
In this case, the throttle valve 7 occupies the open position C1, and the throttle valve 4 occupies the fully closed position S0.

(Problem to be Solved by the Invention) However, according to the above conventional structure, the throttle lever 6 is moved to the fully closed throttle position R after the engine starts.
When the throttle lever 6 is returned to the maximum position, the throttle lever 6 passes through the throttle fully open position Q. When the throttle lever 6 moves to the fully open throttle position Q, the throttle valve 4 occupies the fully open position S1, and the throttle valve 7 moves to the open position C1.
(normal operating position), the engine instantly rises to maximum rotation speed. However, at that point, the engine has not yet been sufficiently warmed up, and there is a possibility that the oil film formation in each part of the engine may be insufficient.

Further, in the conventional structure, it is necessary to manually operate the throttle lever 6 to open the throttle valve 7 after starting the engine, which causes a problem that the starting operation is troublesome.

(Means for Solving the Problems) In order to solve the above problems, the present invention connects a throttle lever connected to a throttle valve to a throttle lever via a governor spring, and uses an auxiliary spring having characteristics different from those of the governor spring. is connected to the throttle valve, a governor arm is connected to the throttle valve, and the governor arm and the throttle valve are connected so that they can rotate freely relative to each other, and each of the above members is connected to the throttle valve when the governor arm opens the throttle valve before starting the engine. ,
The throttle lever closes the throttle valve, and in a no-load state after the engine has started, the governor arm moves to the position where the throttle valve closes, and the throttle lever moves in conjunction with the governor arm to the position where the throttle valve opens. , the governor arm is arranged so that it occupies the position where the throttle valve opens when the throttle lever is operated in the opening direction to enable load operation.

(Function) According to the above configuration, the governor arm occupies a position where the throttle valve is opened before engine startup due to the action of the governor, and moves in a direction to close the throttle valve immediately after engine startup. Also, during normal operation, the governor arm moves in response to forces from the accelerator lever and the governor, and assumes a fully open throttle position, for example, when operating under full load conditions.

The choke lever is interlocked with the governor arm and moves as follows under the influence of the position of the connecting portion, the governor spring, and the auxiliary spring. That is, before the engine is started, the check lever occupies a position where the check valve is closed, and immediately after the engine is started, it moves to a position where the check valve is opened, and thereafter, in normal operating conditions, it occupies a position where the check valve is opened.

(Embodiment) In FIG. 1, a governor arm 10 is connected at one end to a governor sleeve 11 and at the other end to a throttle valve 13 via a throttle valve link 12. A portion of the governor arm 10 near the governor sleeve 11 is rotatably supported by a stationary member (not shown) via a fulcrum 15. A connecting portion 16 is provided on the governor arm 10 between the throttle valve link 12 and the fulcrum 15.
An intermediate portion of the choke lever 17 is connected to the governor arm 10 via a connecting portion 16 so as to be relatively rotatable.

One end of the choke lever 17 is connected to a choke valve 20 via a link 18, and the other end is connected to a throttle lever 22 via a governor spring 21. Also, between the end on the governor spring 21 side and the connecting portion 16, the lever 1
7 and the engine body 23 (or other stationary parts)
A return spring 24 (auxiliary spring) is provided between them. The governor spring 21 and return spring 24 are, for example, tension coil springs that pull the chain lever 17 in opposite directions, and their spring constants, installation loads (tensile loads during assembly), etc. of each part are as follows. The position of the connecting portion 16 and the length of each lever portion are set so as to operate.

Figure 1 shows the state before starting the engine.
Each part is in the following state. The throttle lever 22 is in the throttle closed position. Governor arm 10 receives no force from governor sleeve 11. The throttle valve 13 is in the fully open position S1. The check lever 17 positions the check valve 20 at the fully closed position C0 via the link 18. Since the throttle valve 13 is thus fully open and the choke valve 20 is fully closed, the engine can be started using, for example, a recoil starter (not shown).

When the engine is started, the governor sleeve 11 moves as the engine speed increases, and the governor arm 10 rotates about the fulcrum 15 to the state shown in FIG. 2. In the no-load operating state immediately after starting as shown in FIG. 2, the governor arm 10 moves the throttle valve 13 to the vicinity of the fully closed position S0. In addition, as the governor arm 10 rotates, the connecting portion 16 moves, and the governor spring 2
1 exerts a larger moment on the spring lever 17 than the return spring 24, so the spring lever 17 rotates around the connecting part 16,
The check valve 20 is moved to the fully open position C1.

When the engine is started as described above, the throttle valve 20 moves in the opening direction in conjunction with the governor arm 10, and in parallel, the throttle valve 1 moves in the opening direction.
3 moves in the closing direction, so the check valve 2
The throttle valve 13 will never be fully opened in the state where 0 is open. Therefore, the engine speed does not rise to the maximum value in a no-load operating state immediately after starting, and the engine quickly enters a low-speed operating state.

Furthermore, as the governor arm 10 moves during startup, each part automatically transitions from the state shown in FIG. 1 to the state shown in FIG. do not have to.

In the subsequent normal operating state (load operating state), the throttle lever 22 is operated in the opening direction as shown in FIG. 3, so the throttle valve 20 continues to be held at the fully open position C1. Furthermore, when the engine speed decreases in response to changes in load, the governor arm 10 moves in a direction that increases the opening degree of the throttle valve 13 in conjunction with the governor sleeve 11. 21 and the return spring 24 (particularly the mounting load of the return spring 24) are set appropriately, so the CHI YOKE lever 17 can be moved to the CHI Yoke valve 20.
is held at the fully open position C1.

In this manner, under normal operating conditions, the throttle valve 20 remains open, and the throttle lever 22 of the throttle valve 13 is interlocked with the governor sleeve 11, so that a predetermined normal operating condition can be maintained. Note that FIG. 3 shows a full load state.

(Effects of the Invention) As explained above, according to the present invention, the throttle valve 13 does not pass through the fully open position S1 when each part transitions from the start start state to the start completion state, so the engine The rotational speed does not rise to the maximum value, and when the start is completed, the check valve 20 automatically returns to the fully open position C1.
The starting operation becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the state of the embodiment of the present invention before starting, FIG. 2 is a schematic diagram showing the state of the embodiment of FIG. 1 immediately after startup, and FIG. 3 is a full-load operation of the embodiment of FIG. 1. FIG. 4 is a schematic diagram showing the conventional example, and FIG. 5 is a schematic diagram showing the state of the conventional example shown in FIG. 4 before starting. 10...Governor arm, 13...Throttle valve, 16...Connection part, 17...Chickure lever, 20...Chickure valve, 21...Governor spring, 22...Throttle lever, 24...
Return spring (auxiliary spring).

Claims (1)

[Claims] 1 Connect the throttle lever connected to the throttle valve via a governor spring, connect an auxiliary spring with characteristics different from the governor spring to the throttle lever, connect the governor arm to the throttle valve, and connect the governor arm and throttle lever. are relatively rotatably connected by a connecting part, and each of the above members is connected before starting the engine.
The governor arm opens the throttle valve and the throttle lever closes the throttle valve. In a no-load state after engine startup, the governor arm moves to the position where the throttle valve closes, and the throttle lever moves to the position where the throttle valve opens. It is characterized by being interlocked with a governor arm, and arranged so that in a load operation state, the governor arm occupies a position where the throttle valve is opened by operating the throttle lever in the opening direction to enable load operation. Throttle interlocking type choke valve opening/closing device.