JPH0338454Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a spring ratchet for an engine recoil starter in an engine chain saw or the like.

[Conventional technology]

A conventional spring ratchet for this type of engine is shown in FIG. That is, a shaft hole 1a is provided in the center of the disc body of the cooling fan, which has a plurality of fins 1b arranged on its peripheral surface so as to be able to blow air when rotating, and in the center thereof is provided a shaft hole 1a through which a rotating shaft of the engine (not shown) is inserted. At a symmetrical position around the circumference of the shaft hole 1a, a hook portion 2b that engages with the arc-shaped pole 6 of the recoil starter 5 as partially shown in FIG. 1
A spring latch 2 provided with an elongated support part 2a that is engaged with a part of the spring latch 2 is supported by a loose fit on a support shaft bolt 3 that is screwed in a symmetrical position on the circumferential part. The helical part of the intermediate belt is fitted around the support bolt 3, and the elongated part 9a at one end is locked to a part of the fin 1b described above, and the hook part 9b at the other end is attached to the spring latch 2. In the spring latch 2 for an engine recoil starter, which is assembled so that the recoil starter 5 can be elastically engaged with the pole 6 by the elastic force of the spring 9 partially engaged, the spring 9 The hook portion 9b is located at the axis A of the shaft hole 1a.
It was configured to be engaged with the hook portion 2b at a position away from the line of maximum action C of the centrifugal force, which is a straight line connecting the circumferential surface B of the support bolt 3, and in a direction in which it is separated by the centrifugal force.

[Problem that the invention attempts to solve]

Due to the above configuration, the spring ratchet 2 for the recoil starter in the conventional engine has the following problems.

(1) Since the hook portion 9b of the spring 9 is configured to be hooked to the hook portion 2b side of the spring latch 2, if the recoil starter 5 is assembled with the recoil starter 5 misaligned with the axis A, the recoil will be damaged. There were cases where the pawl 6 of the starter 5 came into contact with the hook portion 9b, and the hook portion 9b was removed from the hook portion 2b of the spring latch 2, or the hook portion 9b was assembled in a bent state.

(2) Also, by pulling the wire 8 with the knob 7 wound around the reel of the recoil starter 5 in the feeding direction, the engine can be started via the spring latch 2 that is elastically engaged with the pawl 6. When a rotation in the E direction is applied, the centrifugal force generated by the rotation acts in a radial direction from the axis A, which is the center of the rotation. In the spring ratchet 2, both the hook portion 2b and the support portion 2a are connected to the support shaft bolt 3.
Since it is located on the opposite side of the axis of the engine to the direction of rotation of the engine, it rotates in the direction D in the figure due to centrifugal force, resulting in the state shown by the chain line, and the hook portion 2b separates from the pole 6.

On the other hand, since the hook portion 9b of the spring 9 is engaged with the hook portion 2b in the direction of detachment due to centrifugal force, the hook portion 9b is engaged with the hook portion 9b due to the centrifugal force regardless of the detachment of the hook portion 2b from the pole 6. is hook part 2
A force to separate from b acts. As shown in Fig. 5, when the movement of the hook part 9b is shown in terms of the position of its equivalent mass M, it is initially at the engagement position a with the hook part 2b, but after detachment, it moves in the direction D due to centrifugal force. After passing through positions b, c, ... due to the moment, the position x on the straight line C connecting the axis A and the circumferential surface B of the support bolt 3
A force acts that leads to . When it crosses straight line C, the moment reverses, so it is pulled back to position x and stopped. That is, the hook portion 9b moves to position x and stops when the rotational speed increases and the moment in the D direction due to centrifugal force becomes larger than the spring moment.

Also, since the distance from the axis A increases in the order of positions a, b, c..., x, the centrifugal force is Fa, Fb, Fc...,
Since Fx increases in the order of Fx and reaches its maximum, the straight line C is the line of maximum action of the centrifugal force where the centrifugal force acting on the hook portion 9b becomes maximum. This phenomenon occurs more frequently as the rotation speed increases. As a result, in the conventional spring latch 2, the engine cannot be started due to detachment or bending of the hook part 9b, and when the spring 9 comes off from the spring latch 2, the spring 9 collides with various parts of the engine. The engine could be adversely affected by being stuck or caught in the engine.

[Means for solving problems]

This invention solves the above-mentioned problems of the prior art, and even when the spring latch is rotated for engine starting, the hook portion of the spring does not come off the latch and always maintains its original engagement state. An object of the present invention is to provide a spring ratchet for an engine recoil starter that can be firmly maintained and improve its functionality.

The feature of the spring ratchet in this invention is that a large number of fins are arranged on the peripheral surface so that air can be blown at symmetrical positions around the central axis hole of the disc body of the cooling fan, and the recoil starter is installed at the tip. A spring ratchet is provided with a hook part that engages with the pole, and a support part that engages with a part of the fin at the base end. The intermediate band is wound around the fin, and the elongated portion at one end is engaged with a portion of the fin, and the hook portion at the other end is engaged with the spring latch by the elastic force of the spring that is engaged with a portion of the spring ratchet. In a spring latch for an engine recoil starter that is assembled so as to be able to be elastically engaged with a pole, the hook portion of the spring is moved toward the outside of the support bolt in the direction of the maximum centrifugal force acting on the hook portion. The reason is that the spring ratchet is engaged with the supporting part of the spring ratchet.

[Effect]

When the recoil starter is rotated when the engine is started, and the engine is rotated in a specified direction through the spring ratchet that is elastically engaged with the pole of the recoil starter, this rotation causes The centrifugal force acting on the spring acts in radial directions starting from the axis, which is the center of rotation, and the hook portion of the spring is located in the direction of the maximum centrifugal force acting on the hook portion of the spring. Because it is engaged with the support part of the et,
In other words, since the hook part is engaged with the support part of the spring ratchet which is on the line of maximum action of the centrifugal force acting on this hook part when the spring ratchet rotates, even if a strong centrifugal force were to act on this hook part. However, since the hook portion is only displaced in the longitudinal direction of the support portion, it is possible to reliably prevent the hook portion from being disengaged from the original engagement position and to perform a stable engine starting operation at all times.

In addition, there is a spring hook on the outside of the support shaft 3, and even if you try to assemble the recoil starter 5 out of alignment with the axis A during the work of assembling the recoil starter 5, the pole 6 of the recoil starter 5 will not touch the hook 4.
There is no contact with b.

〔Example〕

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

First, to explain the engine chain saw incorporating the present invention, 10 is the engine, 11 is the saw chain, 12 is the front handle, 13 is the grip,
14 is a fuel tank.

Next, to explain the structure of a spring ratchet for an engine recoil starter, a circular plate of a cooling fan 1 is provided with a large number of arcuate fins 1b on its peripheral surface so as to be able to blow air when rotating in one direction. A shaft hole 1a through which a rotating shaft of an engine (not shown) is inserted is provided in the center of the body, and two support shaft bolts are screwed into and erected at symmetrical positions around the shaft hole 1a. 3, a spring latch 2 is loosely fitted in the intermediate zone so as to be rotatable.

The spring ratchet 2 is dogleg-shaped, and a pole 6 in the shape of an arc is provided at the tip of the recoil starter 5 in a central position inside the recoil starter 5 as partially shown in FIG. A hook part 2b that can be engaged is provided, and a support part 2a that can be engaged with a part of the fin 1b is provided at the base end. At the position where the spring latch 2 is rotated by centrifugal force and the support part 2a is locked to the fin 1b, the direction of the axis of the elongated part of the support part 2a is aligned with the axis A of the shaft hole 1a and the support bolt. The centrifugal force is made to almost coincide with the line of maximum action of centrifugal force C, which is a line connecting the circumferential surface of No. 3.

The spring 4 is constructed by winding a helical portion (not shown) of the intermediate band around the support bolt 3 and attaching the elongated portion 4 at one end thereof.
a is elastically locked to a part of the fin 1b described above, and the hook portion 4b at the other end is inserted into the elongated support portion 2a of the spring ratchet 2 from the width direction to be elastically engaged. are doing. Therefore, the ratchet 2 is assembled so that it can be elastically engaged with the pole 6 of the recoil starter 5 by being loosely fitted to the support bolt 3 and by the elastic force of the spring 4. .

The recoil starter 5 shown in FIG. 3 is entirely formed into a disk shape. Although not shown on the outside of this disc body, a flanged groove-shaped reel part is integrally formed, and a wire 8 of a predetermined length with a knob 7 attached to the tip is fed out from this reel part. and is fitted so that it can be rolled up. The recoil starter 5 has the above-mentioned letter-shaped pole 6 protruding from the inner central band thereof, which is disposed between the spring latches 2 and 2 and is engaged with the hook portion 2b on each side thereof. .

When starting an engine (not shown) using the spring latch 2 configured as described above, the wire 8 with the knob 7 wound around the reel portion of the recoil starter 5 is pulled in the feeding direction, so that the pawl 6 has elasticity. By rotating the spring latch 2 that is engaged with the
0 rotates in the E direction. Further, the centrifugal force generated by the rotation acts in a radial direction from the axis A, which is the center of the rotation. When the number of rotations increases and the centrifugal force increases, the ratchet 2 rotates around the support bolt 3 in the D direction, reaching the state shown by the chain line, and the support part 2a presses the fin 1b in the E direction, and the hook part 2b leaves pole 6. Furthermore, in this state, the longitudinal axis of the support portion 2a substantially coincides with the maximum centrifugal force action line C.

Therefore, the longitudinal axis of the support portion 2a is the support portion 2a.
The position is located in the maximum direction of the centrifugal force acting on the hook portion 4b of the spring 4 engaged with the hook portion 4b. Since the centrifugal force acting on the hook portion 4b has almost no component in the width direction of the support portion 2a, the hook portion 4b is only slidably displaced in the longitudinal direction of the support portion 2a; It will never come off. Support part 2
The length of a in the longitudinal direction is set so that the hook portion 4b will not come off in the longitudinal direction even if the centrifugal force becomes strong.

The spring ratchet 2 can reliably prevent the hook portion 4b from disengaging from its original engagement position even in the face of a strong centrifugal force, so that the spring ratchet 2 always ensures stable engine starting by pulling the recoil starter 5. It is possible to perform guided rotation operations.

[Effect of idea]

This idea is based on a cooling fan in which a large number of fins are arranged on the peripheral surface so that air can be blown, and at symmetrical positions around the central axis hole of the disc body, a hook part is provided at the tip to engage with the pole of the recoil starter. A spring ratchet, which has a support part that locks on a part of the fin at the base end, is supported by loosely fitting it onto the spindle bolt, and by winding and fitting an intermediate band around the spindle bolt. The elongated part is engaged with a part of the fin, and the hook part at the other end can be elastically engaged with the pole by the elastic force of the spring engaged with a part of the spring latch. A spring latch for a recoil starter of an engine that is assembled into a spring latch is characterized in that the hook portion of the spring is engaged with a support portion of the spring latch located in the direction of maximum centrifugal force acting on the hook portion. It is something to do. Therefore, even if the spring latch is given rotation to start the engine by pulling the recoil starter, the hook part of the spring can bend and slide in the longitudinal direction of the support, so it will not come off the spring latch at all times. Since the original engagement state is maintained, the engagement function of this type of spring ratchet with the recoil starter can be greatly improved, which has great effects such as helping to improve the performance of the engine chain saw.

Furthermore, if the pole is so far off the axis that it comes into contact with the hook during assembly, the recoil starter cannot be assembled into the other party, which is effective in preventing problems.

[Brief explanation of the drawing]

Fig. 1 of the embodiment diagrams is a side view of an engine chainsaw to which the present invention has been applied, Fig. 2 is a front view showing a spring ratchet for a recoil starter equipped with a spring according to this invention in the main part, and Fig. 3 is a side view of an engine chain saw according to this invention. 4 is a rear view showing a part of a recoil starter that has a protruding pole that locks between the catch parts of a spring latch used in a conventional example; FIG. 4 shows a recoil starter that has a conventional spring in its main part FIG. 5 is an explanatory view showing the movement of the hook portion of the spring. DESCRIPTION OF SYMBOLS 1...Cooling fan, 1a...Shaft hole, 1b...Fin, 2...Spring ratchet, 2a...Support part, 2b...Hook part, 3...Spindle bolt, 4...
...Spring, 4a...Long part, 4b...Hook part, 5...Recoil starter, 6...Pole, 7
...Knob, 8...Wire, 9...Spring, 1
0...Engine, 11...Sochien, 12...
Front handle, 13... Grip, 14...
fuel tank.

Claims (1)

[Scope of utility model registration request] A large number of fins are arranged on the peripheral surface so that air can be blown.In the symmetrical position around the center axis hole of the disc body of the cooling fan, a hook part that engages with the pole of the recoil starter is provided at the tip, and a hook part that engages with the pole of the recoil starter is provided at the base end. The spring ratchet, which is provided with a support part that locks on a part of the fin or the boss, etc., is supported by loosely fitting it onto the spindle bolt, and by wrapping an intermediate band around the spindle bolt to extend the length of one end of the spring latch. The shank part is attached to a part of the fin, and the hook part at the other end is assembled so that it can be elastically fitted to the pole by the elastic force of a spring fitted to a part of the ratchet. A spring ratchet for a recoil starter for an engine, characterized in that the hook portion of the spring is engaged with a support portion of the ratchet located in the direction of maximum centrifugal force acting on the hook portion. Spring ratchet.