JPS6036783Y2 - Automatic decompression of general-purpose engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic decompression for a general-purpose engine that is linked with a decompression coil starter.

Conventionally, decompression in general-purpose engines has been achieved by disposing a manual relief valve operated by a link mechanism in the decompression passage formed in the cylinder, opening the relief valve by hand when the engine is started, and then opening the relief valve by hand again after starting the engine. Many have a manual structure in which the relief valve is closed by operation.

Also, automatic decompression has been proposed, but both have complicated structures.

An example of this is the one described in Japanese Utility Model Application Publication No. 53-73325, in which a movable pulley is attached via a support shaft to an input-side moving member such as a swing arm or handle for applying human power to the coil starter. , the recoil starter's actuating traction cord is wound around the movable pulley in the middle and folded back toward the recoil starter side, and the tip end on the recoil starter side and the starting auxiliary device are configured so that the starting auxiliary device is activated when the recoil starter is activated. However, the number of parts is large and the structure is complicated.

The present invention has been developed in view of the above points, and includes a cylinder with a reduced pressure air passage leading to the atmosphere side, a valve provided in this reduced pressure air passage, and a direction in which the reduced pressure air passage is always closed to the valve. an elastic member that is biased by the recoil starter, and a pull member that moves forward in response to a stroke that opens the valve by pulling the knob of the recoil starter, and the pull member and the valve are connected by a connecting member. It has become.

This invention operates only when the engine starts (open circuit).
To provide an automatic decompression for a general-purpose engine, which has a simple structure and enables automatic decompression by linking a decompression that activates the engine with a recoil starter that operates only when starting the engine.

Next, an embodiment of the present invention will be described with reference to the drawings.

The decompression air passage 1 is formed from the combustion chamber 2 to the intake port 3, and is configured to release the internal pressure of the cylinder toward the intake port 3 when the engine is started.

The cylinder block 5 has a valve hole 6 which is bored from the outer periphery and is perpendicular to the decompression air passage 1 .

The valve 7 is inserted into the valve hole 6 from the outer circumferential direction of the cylinder block 5 and is arranged to open and close the reduced pressure air passage 1.

This valve 7 is wound with a coil spring 8 and is always biased in the direction of closing the reduced pressure air passage 1.

On the other hand, on the recoil starter 9 side, a knob receiver 11 that is pulled out by pulling the knob 10 is disposed between the knob 10 and the receiver part 13 on the recoil starter cover 12 side.

The knob receiver 11 has a sliding cylindrical body 14 which is inserted into a cylindrical body 15 formed in the receiving part 13 so that it can slide.

The sliding stroke h of this knob receiver 11 is the same as that of the sliding cylinder 14.
Stoppers 16 and 17 provided on the cylindrical body 15 of the receiving portion 13
The operating range of the valve 7 that opens and closes the depressurized air passage 1 is regulated by this.

Further, a drawstring 18 is inserted through the sliding cylinder 14 of the knob receiver 11, and a coil spring 19 is disposed between the knob receiver 11 and the receiver portion 13 of the cover 12.
1 is biased toward part 13 by the ash receiver.

Further, the biasing force of the coil spring 19 is set to be larger than that of the valve spring 8 and smaller than the biasing force of the recoil starter 9's drawstring rewinding spring.

The valve 7 and the extending portion 20 of the knob receiver 11 are connected to the connecting rod 2.
1, and the valve 7 of the reduced pressure air passage 1 and the recoil starter 9 side are configured to interlock with each other.

In the drawing, reference numeral 22 indicates a cap of the valve hole, 23 indicates a piston, 24 indicates a fin, and 25 indicates an exhaust port.

Next, the operation of the automatic decompression according to the present invention will be explained.

Before starting the engine, the drawstring 18 is pulled in the direction of arrow A by the rewinding device (not shown) of the recoil starter 9, and the tip 10a of the knob 10 is attached to the saucer 1 as shown in FIG.
1 is pressed against the coil spring 19.

On the other hand, the valve 7 closes the reduced pressure air passage 1 by means of a coil spring 8.

In this case, the engaging portion 21a of the connecting rod 21 and the extending portion 20 of the knob receiver 11 are not engaged with each other.

When starting the engine from the above state, when the knob 10 of the recoil starter 9 is pulled, the knob receiver 11 is pulled out together with the drawstring 18 by the repulsive force of the coil spring 19, and the extension portion 20 of the knob receiver 11 and the connecting rod 21 are engaged. The portion 21a comes into contact and pulls the valve 7 through the connecting rod 21 to open the reduced pressure ventilation path 1.

By opening this reduced pressure air passage 1, the cylinder internal pressure passes through the reduced pressure air passage 1 to the intake port 3 side, and the starting torque of the recoil starter 9, in other words, the force that pulls the drawstring 18 is reduced.

The stroke range of the knob receiver 11 is determined by a stopper 16,
17 restricts the operating range of the valve 7, while the drawstring 18 is pulled out as it is to operate the recoil starter 9.

When the engine is started by the operation of the recoil starter 9 and the drawstring 18 is wound back, the knob receiver 11 is pressed by the tip lea of the knob 10, and the extending portion 20 of the knob receiver 11 and the engaging portion 21a of the connecting rod 21 are pressed. is disengaged, the valve 7 returns to its original position by the biasing force of the coil spring 8, and the valve 7 closes the reduced pressure air passage 1.

The knob receiver 11 has a conical shape so that the end of the knob 10 can be accommodated, so when the knob 10 is released, the spring force of the recoil starter 9 resists the spring 19.
The sliding cylinder 14 enters the cylinder 15 and can be maintained in a stable state at all times.

In the present invention, the opening in the cylinder of the reduced pressure air passage 1 is not limited to the combustion chamber 2, but may be the inner circumferential surface of the cylinder block 5.

Moreover, the material and shape of the connecting member 21 are not limited in any way.

As mentioned above, the present invention is made by linking a decompression that operates (closes the circuit) only when the engine starts and a recoil starter that similarly operates when the engine starts. The device can be operated only by the operation of the device, has a simple structure, and is easy to operate.

[Brief explanation of the drawing]

The figures are explanatory sectional views showing one embodiment of the present invention, of which Fig. 1 is a sectional view showing a state in which the starter knob is not pulled and the valve closes the depressurized air passage, and Fig. 2 is a sectional view showing a state in which the starter knob is not pulled. FIG. 3 is a cross-sectional view showing a state in which the valve is opened to open the depressurized air passage. In the figure, 1 is a decompression air passage, 2 is a combustion chamber, 3 is an intake port, 4 is a cylinder head, 5 is a sill block, 7 is a valve, 8 is an elastic member, 9 is a recoil starter, 10 is a knob, and 11 is a puller. The member (knob receiver) 21 indicates a connecting member.

Claims (1)

[Scope of utility model registration request] In a general-purpose engine equipped with a recoil starter, a cylinder is provided with a reduced pressure air passage leading to the atmosphere, and a valve that is slidable to open and close the reduced pressure air passage is disposed in the cylinder. While an elastic member is provided that always biases the recoil starter in the direction of closing, a knob receiver having a sliding cylinder that is slidably inserted into the recoil starter is provided at the drawstring pull-out portion of the recoil starter. A drawstring of the recoil starter is inserted into the cylindrical body, and the receiver of the knob fixed to the end of the drawstring is brought into contact with the knob receiver, and a knob receiver is provided between the knob receiver and the coil starter side. An elastic body is provided that biases the warped coil in a direction to push it out toward the starter side, has a greater bias force than the valve elastic body, and has a lower bias force than the recoil starter pull string rewind spring, and connects the knob receiver and the valve. A general-purpose device characterized in that the valve is connected so that it opens when the knob receiver is pushed out toward the warped coil starter side, and a stopper is provided in the opening/closing sliding range of the valve to restrict the amount of push-out by the elastic member of the knob receiver. Automatic engine decompression.