JP2517631Y2 - Engine decompression device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decompression device used in an engine of the type started by a recoil starter.

[0002]

2. Description of the Related Art As is well known, the decompression device is a device for reducing the pressure in the cylinder at the time of starting the engine, facilitating the rotational operation of the recoil starter, and facilitating the starting of the engine.

An example of such a decompression device is disclosed in Japanese Utility Model Publication No. 57-47408. In this device, in a valve chamber formed in a pressure reducing passage that communicates the inside of the cylinder with the atmosphere side, a valve body that is pressed against a valve seat by the internal pressure of the cylinder and closes the pressure reducing passage is provided, and the valve body is The structure is such that the spring is urged in the opening direction, and the pressure reducing passage is opened and closed by the difference between the cylinder internal pressure and the spring urging force.

In addition, as described in Japanese Utility Model Laid-Open No. 60-122511, an electromagnetic on-off valve is provided in a pressure reducing passage that communicates the inside of the cylinder with the atmosphere side, and the current generated by the rotation of the magnet wheel is used. There is a decompression device with a structure that closes the electromagnetic on-off valve.

[0005]

Among the decompression devices described in the above publication, the former is delicate and difficult to adjust the spring force for urging the valve element in the opening direction. There are disadvantages such that the valve body is likely to be opened and closed due to the gap between the valve body and the valve seat, and the valve body is always in contact with the exhaust gas, so that the valve body is easily corroded.

In the latter, the decompression passage communicating with the atmosphere side is electrically opened / closed, so that a battery, a magnet wheel or the like is required, the apparatus becomes large in size and weight, and the electric system is complicated. There is.

Although there are some conventional engines that are started by a recoil starter and are not equipped with a decompression device, this engine requires a large traction force to rotate the recoil, and the starting operation of the engine is difficult. is there.

The present invention has been made in view of the above points, and provides a decompression device that reduces the internal pressure of the cylinder by mechanical operation when starting the engine and facilitates starting of the engine by the recoil starter. .

[0009]

In order to achieve the above object, the decompression device of the present invention comprises: a) winding of a rope
Lee biased by a spring-type return spring
In decompression device for use in scheme engine to be started with a recoil starter having a le, a vacuum passage for providing communication between b) in the cylinder and the atmosphere side is provided, c) the opening and closing valve to the vacuum through <br/> path It is installed so that it can be opened and closed, and d)
Attach a lever to the on-off valve, and
The on / off valve closes the stopper to fit the open position.
Set a predetermined interval so that the
F) so that it can rotate integrally with the reel.
Substantially ring-shaped friction is provided in the annular groove of the ring
Fits so that the spring slides when the specified friction force is exceeded.
G) the lever of the on-off valve and the friction
The one end of the spring is connected via a connecting member.

Further, as described in claim 2, A) rope
It is biased by the spring return spring in the winding direction of
In a decompression device used in a recoil starter-type engine equipped with a reel , a B) a decompression passage for communicating the inside of the cylinder with the atmosphere side is provided, and C)
An on-off valve is installed in the decompression passage so that it can be opened and closed, and the on-off valve is biased in the closing direction by a spring, and D) a lever is attached to the on-off valve, and E) this.
The on-off valve opens the stopper that engages with the lever
Predetermined to be positioned in position and closed position respectively
Provided at a distance, F) to form a bearing portion around the crank shaft, on said bearing portion rotatably mounted ring member, G) into the annular groove of the ring body, substantially ring-shaped pretend
So that it will slip when the friction spring exceeds a certain frictional force
Fitted to, H) wherein said lever of said opening and closing valve pretend
I) One end of a spring is connected via a connecting member, and I) A pulley or a flywheel fixed on the crankshaft is provided with a locking claw that can be radially expanded by centrifugal force and a spring in the opposite direction. It is also possible to attach the ratchet to which the locking claws are normally engaged in the ring body while being urged to attach the ratchet.

[0011]

According to the decompression device of the present invention having the above-mentioned structure, when the rope for rotating the reel of the recoil starter is pulled against the urging force of the spring return spring and the reel is rotated, the ring portion of the ring portion is rotated. A friction spring fitted in the annular groove creates friction between them.
It rotates with the reel depending on the purpose . Then, by rotating the friction spring, the connecting member and lever are
Via closing valve is moved a predetermined amount, the lever is on the other hand (open
Side) and the decompression passage is opened by engaging the stopper . By opening this decompression passage, the inside of the cylinder is a scavenging port,
The pressure is reduced by communicating with an exhaust passage or an intake passage (the depressurization passage is opened to the scavenging port in the embodiment described later). Therefore, the operating force required to rotate the reel thereafter is reduced. Also, during the pulling operation of the rope,
The reel still rotates after opening and closing the on-off valve, but the on- off valve
Movement of the lever is restricted by the engagement of the lever and the stopper.
Friction spring connected with a connecting member
Because the rotation of the
The slip slips in the annular groove and does not rotate any further .

When the rope of the recoil starter is released after the engine is started, the rope is taken up by the reel by the urging force of the spring return spring , and at the same time the friction spring rotates in the opposite direction and the on-off valve moves in the opposite direction. After moving a predetermined amount , the lever stops at the other (closed side)
The pressure reducing passage is closed by engaging the par . The reel will rotate even after the on-off valve is closed, but the friction spring
Rotation of the ring also is restricted similarly to the movement of the opening and closing valve
Therefore, if you move it to the position where the on / off valve is
The torsion spring slips in the annular groove and
Does not rotate .

According to the decompression device of the second aspect, the same operation as that of the decompression device (claim 1) is achieved.
The opening / closing valve is opened when the reel of the recoil starter is rotated, and the opening / closing valve is closed when the reel is rotated in the reverse direction after the engine is started. (A) When the reel of the recoil starter is rotated, the crankshaft At the same time, the pulley or flywheel rotates, and this rotation is transmitted to the ring body via the locking claw and the ratchet that engages with this, and the opening / closing valve is opened by the rotation of the friction spring. B) Engine startup After that, the pulley or the flywheel rotates at a considerable speed together with the crankshaft, and the locking pawls are radially expanded by the centrifugal force to be disengaged from the ratchet, so that the recoil starter may be operated during the operation of the engine. Friction spring (ring body) even when the reel is rotated
Does not rotate and the on-off valve does not open, which is different from the above decompression device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. As shown in FIG. 1, the engine 1 is a two-cycle engine, and a crankcase 3 is integrally formed below a cylinder 2. A crankshaft 4 is rotatably arranged in a crankcase 3 by a bearing 5, and a crankshaft 4 and a piston 6 in the cylinder 2 are arranged.
Are connected by a connecting rod 7. A flywheel 8 is attached to one end (the left end in the drawing) of the crankshaft 4, and a pulley 9 is attached to the other end (the right end in the drawing) so as to be integrally rotatable. A recoil starter 10 is integrally attached to one end of the crankcase 3. In the case 11 of the recoil starter 10, a bearing portion 12 is formed by protruding a part of the case 11 inward, and on the bearing portion 12,
A reel 13 is rotatably arranged. Further, a spiral spring return spring 14 is provided between the reel 13 and the case 11. The rope winding groove 15 of the reel 13 is wound with a rope 16 for pulling operation, one end of which is fastened to the reel 13, and the other end of the rope 16 is drawn out of the case 11.

As shown in FIG. 2, a pair of protrusions 17 are provided at the tip of the reel 13 so as to protrude in the radial direction. A base end of a claw 18 engageable with the protrusion 17 is rotatably attached to the pulley 9 and is biased radially inward by a spring 19. With this configuration, when the rope 16 is pulled and the reel 13 is rotated, the claw 18 of the reel 13 engages with the protrusion 17 at the tip of the pulley 9 and the rotational force is transmitted to the pulley 9, so that the crankshaft 4 rotates. However, the engine 1 is started. The configuration up to this point is
It is known.

In the present invention, as shown in FIG. 1, the decompression passage 21 extends through the cylinder (block) 2 from the upper end of the cylinder 2 (more precisely, the cylinder block) to the scavenging port section 20 therebelow. Has been drilled. A part of the decompression passage 21 is configured as a concave valve chamber 21a, and a disc-shaped opening / closing valve 22 as shown in FIG. 3 is rotatably loosely inserted in the valve chamber 21a and closed by a cover 23. . A communication hole 22a is opened in the opening / closing valve 22 as shown in FIG. 3, the decompression passage 21 is opened by the communication hole 22a at the opening position of the opening / closing valve 22, and conversely at the closing position.
Is closed by the open / close valve 22. The open / close valve 22 has
As shown in FIGS. 1 and 2, an L-shaped lever 24 is integrally rotatably screwed, and two stoppers 25 and 26 provided on the cover 23 prevent the opening / closing valve 22 from rotating.
The open / close valve 22 is configured to rotate only between an open position and a closed position.

On the other hand, a part of the reel 13 is integrally formed with a ring portion (also referred to as a reel portion) 30 having an annular groove 31 on the outer periphery as shown in FIG. To
The open, generally ring-shaped friction spring 32
It is fitted in the annular groove 31. One end of the friction spring 32 is formed on the hook 32a.
2a and the lever 24 form a link 3 as a connecting member.
Connected by 3. The link 33 extends outward from the opening 11a of the case 11.

The decompression device according to this embodiment is constructed as described above. The operation mode of the device is described in the section of the operation, so the description thereof is omitted.

Next, FIGS. 4 and 5 show a second embodiment of the present invention. The decompression device of this embodiment is different from the device of the above embodiment in the following points. That is, as shown in FIGS. 4 and 5, a return spring 41 for urging the opening / closing valve 22 in the closing direction is provided between the cover 13 and the lever 24. On the inner surface side of the pulley 9, a base end of a locking claw 42 having the same function as that of the claw 18 is rotatably mounted and urged radially inward by a spring 43. In addition, a part of it in the crankcase 3,
A cylindrical bearing portion 44 is formed on the pulley 9 side so as to extend around the crankshaft 4, and a ring body 45 corresponding to the ring portion 30 is rotatably disposed on the bearing portion 44. . As shown in FIG. 5, a ratchet 46 that engages with the locking claw 42 in the normal state (before starting the engine 1) is integrally formed on the surface of the ring body 45 facing the pulley 9. Then, the friction spring 32 is fitted in the annular groove 47 formed on the outer periphery of the ring body 45. A retaining clip ring 48 for the ring body 45 is attached to the tip of the bearing portion 44. Further, constituent members common to the above-mentioned embodiment are shown in FIGS.
The same reference numerals as in FIG. 3 are used in the drawing.

The operation mode of the decompression device according to the present embodiment is also described in the section of the operation, so that the description thereof will be omitted. However, in the decompression device according to the present embodiment, the rope of the recoil starter 10 is operated during the operation of the engine 1. There is an advantage that the opening / closing valve 22 is not opened even if 16 is pulled.

Next, FIG. 6 shows a third embodiment of the present invention.

The decompression device of this embodiment is substantially the same as the decompression device of the second embodiment, except that the mounting positions of the ring body 45 and the locking claw 42 that engages with the ratchet 46 thereof are different. are doing. That is, the ring body 45 is arranged on the bearing portion 44 provided by extending a part of the crankcase 3 toward the flywheel 8 side. Further, the locking claw 42 that engages with the ratchet 46 of the ring body 45 is arranged on the support portion 51 that projects inward from the flywheel 8. Furthermore, the position of the opening / closing valve 22 is also symmetrical in correspondence with the change in the position of the ring body 45. Other configurations and operations are exactly the same as those in the second embodiment, and therefore the same reference numerals as those used in FIGS. 4 and 5 are used in the drawings.
Description is omitted.

[0023]

[Effect of the Invention] As is clear from the above explanation,
The decompression device of this invention has the following effects. (1) Since the cylinder internal pressure is reduced almost at the same time as the operation of the recoil starter is started, the operation (rope pulling force) is lightened and the engine can be started easily.

(2) Since the constituent members of the decompression device do not exist in the exhaust gas flow path and there is almost no contact with the exhaust gas, malfunctions may occur due to blockage of carbon or oil in the exhaust gas, or carbon or oil Component parts will not be corroded by contact with the parts.

(3) Since the opening / closing operation of the decompression opening / closing valve is performed mechanically by utilizing the frictional force between the friction spring and the outer periphery of the ring portion (reel portion) or ring body,
The structure is simple, the number of parts is not increased, and the conventional general engine (with recoil starter) is simply improved, so that the decompression device can be installed conveniently.

(4) Unlike the conventional decompression device (which utilizes the difference between the cylinder internal pressure and the spring force), no delicate adjustment is required, and the opening / closing valve is opened / closed in conjunction with the operation of the recoil starter. Therefore, a battery and other electric system parts such as the conventional decompression device (which is electrically operated) are not required, and the decompression device is hardly attached to increase the weight or increase the size. Opening and closing bar
The amount of movement required to open and close the valve is
Easy to determine just by adjusting the distance between the engaging stoppers
The opening / closing valve can be opened and closed with high accuracy .

(5) In addition to the effects (1) to (4) described above, the decompression device according to claim 2 has an effect that the open / close valve is not opened even if the recoil starter is operated during engine operation. There is.

[Brief description of drawings]

FIG. 1 is a sectional view showing an outline of an engine equipped with a decompression device according to a first embodiment of the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1 and shows a connection relationship between an on-off valve and a friction spring.

FIG. 3 is a view taken in the direction of arrow P in FIG.

FIG. 4 is a sectional view showing an outline of an engine including a decompression device according to a second embodiment of the present invention.

5 is a view taken along the line BB of FIG. 4, showing the connection relationship between the on-off valve and the friction spring.

FIG. 6 is a sectional view showing an outline of an engine including a decompression device according to a third embodiment of the present invention.

[Explanation of symbols]

 1 Engine 2 Cylinder 3 Crankcase 4 Crankshaft 8 Flywheel 9 Pulley 10 Recoil Starter 11 Recoil Starter Case 13 Reel 16 Pulling Rope 17 Protrusion 18 Reel 13 Claw 21 Pressure Reduction Path 22 Open / Close Valve 24 Lever 25, 26 Stopper 30 Ring part (reel part) 31, 47 Annular groove 32 Friction spring 33 Link (connecting member) 41 Return spring 42 Locking claw 43 Spring 44 Bearing part 45 Ring body 46 Ratchet

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-38162 (JP, A) SAIKAI Sho-59-174371 (JP, U)

Claims (2)

(57) [Scope of utility model registration request] 1. A spring-type return in the winding direction of the rope.
In a decompression device used in an engine of a system that is started by a recoil starter equipped with a reel that is biased by a spring, a decompression passage that connects the inside of the cylinder and the atmosphere side is provided.
An open / close valve is installed in the decompression passage so that it can be opened / closed, and a lever is attached to the open / close valve and
The on / off valve closes the stopper to fit the open position.
Set a predetermined interval so that the
Only provided, wherein this and integrally rotatably disposed ring part with respect to the reel
Place a ring-shaped friction spring in the annular groove of
When the frictional force exceeds a certain level, it is fitted so that it slides , and the lever of the on-off valve and the friction spring
An engine decompression device, characterized in that it is connected to one end of the engine via a connecting member. 2. A spring-type return in the winding direction of the rope.
In a decompression device used in an engine of a system that is started by a recoil starter equipped with a reel that is biased by a spring, a decompression passage that connects the inside of the cylinder and the atmosphere side is provided.
An on-off valve is installed in the decompression passage so that it can be opened and closed, and the on-off valve is biased in the closing direction by a spring, and a lever is attached to the on-off valve.
The on / off valve closes the stopper to fit the open position.
Set a predetermined interval so that the
Only provided, to form the bearing portion around the crankshaft rotatably mounted a ring member on said bearing portion, the annular of the ring body
Install a roughly ring-shaped friction spring in the groove.
When the frictional force is exceeded, it fits so as to slide, and the lever of the on-off valve and the friction spring are fitted.
One end of the ring is connected via a connecting member, and the locking claw can be radially expanded by centrifugal force on the pulley or flywheel fixed on the crankshaft and is biased by a spring in the opposite direction. The decompression device for an engine, wherein the ratchet is fixedly attached to the ring body while the ratchet is fixedly attached to the ring body.