JP7580767B2 - Recoil Starter - Google Patents

Description

This invention relates to a recoil starter, and in particular to a recoil starter suitable for high-vibration machines.

Conventionally, recoil starters have been in practical use, in which a rope wound around a reel is pulled to rotate the reel, and the rotation of the reel is transmitted to a drive pulley or the like, which then rotates the engine crankshaft connected to the drive pulley, thereby starting the engine.

This type of recoil starter is equipped with a ratchet mechanism for transmitting the rotational force of the reel to the drive pulley when the rope is pulled and the reel rotates in the direction to start the engine. This type of ratchet mechanism is configured to be able to engage and disengage with the drive pulley on the engine side, and is configured to transmit the rotational force of the reel to the engine side when the rope is pulled, but not to transmit the rotational force of the engine to the reel side after the engine has started.

For example, the invention described in Patent Document 1 configures a ratchet mechanism using a ratchet member that pops out toward the outer periphery when rotation begins. This ratchet member is normally stored on the inner periphery side as it is biased by a spring, but when the reel starts to rotate it engages with a ratchet guide and pops out toward the outer periphery. By popping out in this way, the ratchet member engages with the drive pulley and the rotational force of the reel can be transmitted to the drive pulley.

The ratchet guide described above is provided with a certain amount of frictional resistance to push out the ratchet member. The magnitude of this frictional resistance is set to an extent that allows the ratchet member to be opened (to an extent that overcomes the spring force of the ratchet member's return spring). However, if this frictional resistance is set too high, there is a risk that operability will decrease. In other words, since the resistance when the ratchet guide rotates integrally with the reel after the ratchet member is opened becomes large, a problem may arise in that a large force is required to pull the rope. Therefore, the frictional resistance of the ratchet guide needs to be set within an appropriate range, taking into consideration the effect on the performance of guiding the ratchet member and on operability.

JP 2016-98677 A

However, when such a recoil starter is used in a machine that generates high vibrations (such as a rammer), there is a risk that the ratchet member will pop out unintentionally due to the vibrations. In other words, while the machine is operating (the engine is running), the ratchet member should be stored and biased by the spring, but if vibrations exceeding the spring force are applied, the ratchet member may pop out unintentionally. If the ratchet member pops out unintentionally in this way, it can cause parts to wear out, break, or fall off.

This type of popping out of the ratchet member can be prevented by increasing the spring force used to store the ratchet member. However, increasing the spring force can affect the torque relationship of the reel and ratchet guide, which can lead to new problems. For example, the frictional resistance of the ratchet guide may be insufficient against the spring force, making it impossible to pop out the ratchet member. Furthermore, if the frictional resistance of the ratchet guide is increased in an attempt to solve this problem, a larger force is required to pull the rope, which can lead to problems such as reduced operability.

The present invention aims to provide a recoil starter that can prevent the ratchet member from accidentally popping out without increasing the spring force required to store the ratchet member.

To solve the above problems, the present invention comprises a starter case, a reel rotatably attached to the starter case, a ratchet member swingably attached to the reel, and a magnet attached to the reel, the ratchet member swinging when the reel rotates and engaging with a member on the engine side, and the magnet attracts the ratchet member to suppress the swinging when the reel is not rotating.

The present invention is as described above, and is configured so that the magnet attracts the ratchet member and suppresses rocking when the reel is not rotating. With this configuration, the holding force of the ratchet member can be increased by the attraction force of the magnet, so that unintended jumping out of the ratchet member can be prevented without increasing the spring force for storing the ratchet member. Also, because only the holding force when the ratchet member is stored can be increased, there is almost no effect on the torque when the ratchet guide rotates integrally with the reel. In other words, there is almost no effect on the force when the operator pulls the rope, so unintended jumping out of the ratchet member can be prevented without reducing operability.

The ratchet member may be made of a metal that can be attracted to a magnet. In this way, the magnetic force of the magnet can be used without special processing of the ratchet member. Also, by making the ratchet member out of metal, the strength is improved, so a recoil starter that is resistant to vibration can be manufactured.

The ratchet member may also have a tip that is arranged parallel to the surface of the magnet, and the tip may be made of a ferromagnetic material. This configuration allows the magnetic force to be applied over a wide area of the tip, increasing the holding force of the ratchet member when it is stored.

Alternatively, a cylindrical portion protruding from the center of the reel may be formed, and a ratchet accommodating recess for accommodating the tip of the ratchet member may be formed on the circumferential surface of the cylindrical portion, while a magnet accommodating portion for accommodating a magnet may be formed inside the cylindrical portion adjacent to the ratchet accommodating recess. This configuration allows the recoil starter to be kept compact while still ensuring that a magnetic force is applied to the tip of the ratchet member.

FIG. FIG. 2 is a side cross-sectional view of the recoil starter. 4A is a side view of the ratchet member, and FIG. FIG. 2A is a front view and FIG. 2B is a side view of the magnet. FIG. 2 is a cross-sectional view of the reel taken along line AA. FIG. 4 is a front view of the recoil starter with the ratchet member open. 13 is a front view showing the relationship between the ratchet member and the reel in an open state. FIG.

The embodiment of the present invention will be described with reference to the drawings.

The recoil starter 10 is used to provide starting torque to the engine, and is attached to cover the side of the engine. As shown in Figures 1 and 2, the recoil starter 10 has a starter case 11 that houses the main components of the recoil starter 10. A reel spindle 11a is formed to protrude from the center of the inner surface of the starter case 11 so as to face the crankshaft of the engine. A reel 12 with a rope 20 wound around it is rotatably attached to the reel spindle 11a.

As shown in FIG. 2, the rope 20 is wound around a rope groove 14 formed on the outer circumference of the reel 12, one end of which is fixed to the reel 12, and the other end of which is pulled out from an opening formed in the starter case 11 to the outside of the starter case 11. When the pulled-out rope 20 is pulled, the reel 12 rotates around the reel spindle 11a as the rotation axis.

As shown in FIG. 2, a recoil spring 21 is disposed between the reel 12 and the reel spindle 11a to rewind the pulled-out rope 20 onto the reel 12. One end of the recoil spring 21 is fixed to the reel 12 and the other end is fixed to the reel spindle 11a. This recoil spring 21 stores rotational force when the rope 20 is pulled out and the reel 12 rotates, and when the rope 20 is released, the stored rotational force is used to rotate the reel 12 in the reverse direction. By rotating the reel 12 in the reverse direction in this way, the rope 20 that has been pulled out to the outside of the starter case 11 is rewound onto the reel 12.

As shown in FIG. 2, a cylindrical portion 13 that protrudes toward the engine is formed on the surface of the reel 12 opposite the starter case 11. Although not shown in the figure, a cylindrical drive pulley is disposed to cover this cylindrical portion 13. The drive pulley is attached to the crankshaft of the engine and is used to transmit the rotational force of the reel 12 to the engine. An engaged portion that can engage with a ratchet member 22, which will be described later, is formed on the inner peripheral wall of the drive pulley.

The cylindrical portion 13 of the reel 12 is formed with an axial hole 13e through which the reel spindle 11a passes, a ratchet mounting portion 13a for mounting the ratchet member 22, a ratchet accommodating recess 13b for accommodating the tip portion 22c of the ratchet member 22, and a magnet accommodating portion 13c for attaching the magnet 28.

The shaft hole 13e is formed through the center of the cylindrical portion 13. The reel spindle 11a passes through this shaft hole 13e, so that the reel 12 is rotatably attached to the starter case 11.

The ratchet attachment portion 13a is a circular hole parallel to the shaft hole 13e, and is formed at a position offset from the shaft hole 13e (a position eccentric from the center of the cylindrical portion 13). In this embodiment, the reel 12 is formed with two ratchet attachment portions 13a at equal intervals of 180 degrees in the circumferential direction. A ratchet member 22 is rotatably attached to each of the two ratchet attachment portions 13a.

The ratchet accommodating recess 13b is a recess formed by cutting out the circumferential surface of the cylindrical portion 13, as shown in FIG. 8. In a natural state in which the reel 12 is not rotating, as shown in FIG. 1, the tip 22c of the ratchet member 22 is accommodated in the ratchet accommodating recess 13b. In this state, the ratchet member 22 does not protrude from the cylindrical surface defined by the cylindrical portion 13.

The magnet storage section 13c is a recess for storing a rectangular magnet 28 as shown in FIG. 4. The magnet storage section 13c is formed with dimensions that allow it to hold the magnet 28 without rattling. As shown in FIG. 6, the magnet storage section 13c is also provided with a check claw 13d for preventing the magnet 28 from falling off. The check claw 13d allows the magnet 28 to be easily attached to the reel 12 simply by pushing the magnet 28 into the magnet storage section 13c, but is also formed so that the magnet 28 does not easily fall off the magnet storage section 13c.

The magnet 28 fixed to the magnet housing 13c is intended to attract the ratchet member 22 and suppress its oscillation when the reel 12 is not rotating. In other words, since the ratchet member 22 is made of metal as described below, the tip 22c of the ratchet member 22 is attracted by the magnet 28, so that the tip 22c of the ratchet member 22 does not open easily.

A ratchet member 22 as shown in FIG. 3 is attached to the reel 12 so as to be able to swing. This ratchet member 22 is configured to swing when the reel 12 rotates and engage with a drive pulley on the engine side. The ratchet member 22 in this embodiment is a bent metal linear member. The entire ratchet member 22 is made of a metal that can be attracted to the magnet 28, in other words, it is made of a ferromagnetic material including the tip portion 22c.

As shown in FIG. 3, the ratchet member 22 is formed in a generally U-shape and is composed of a pivot shaft 22a inserted into the ratchet attachment portion 13a, an arm portion 22b continuing at a generally right angle to the pivot shaft 22a, and a tip portion 22c continuing at a generally right angle from the arm portion 22b. The pivot shaft 22a and tip portion 22c are formed parallel to each other, but the tip portion 22c is formed slightly shorter than the pivot shaft 22a. The pivot shaft 22a is formed with a circular cross section and is rotatably inserted into the ratchet attachment portion 13a.

The ratchet member 22 can rotate within a predetermined range around the pivot shaft 22a. More specifically, it can rotate between the storage position shown in FIG. 1 and the engagement position shown in FIG. 7. A return spring 23 is attached to the arm 22b, which constantly biases the ratchet member 22 in the inward direction, so that the ratchet member 22 waits in the storage position when the reel 12 is not rotating.

When the ratchet member 22 is waiting in the storage position in this way, as shown in Figure 1, the tip 22c of the ratchet member 22 is stored in the ratchet storage recess 13b of the cylindrical portion 13 and does not protrude in the outer circumferential direction. In this state, the ratchet member 22 does not engage with the drive pulley, and torque is not transmitted to the engine side.

On the other hand, when the rope 20 is pulled and the reel 12 rotates, as shown in FIG. 7, the tip 22c of the ratchet member 22 swings outward and pops out of the ratchet accommodating recess 13b. When the tip 22c of the ratchet member 22 opens in this way, the ratchet member 22 engages with the inner circumferential surface of the drive pulley, enabling the torque of the reel 12 to be transmitted to the engine.

The opening movement of the ratchet member 22 is guided by a ratchet guide 24 attached to the reel spindle 11a. As shown in FIG. 2, the ratchet guide 24 is a disk-shaped member attached to the tip side of the reel spindle 11a by a set screw 25. The ratchet guide 24 is rotatably attached to the reel spindle 11a, but a predetermined frictional force (frictional force sufficient to overcome the biasing force of the return spring 23) is applied to prevent it from rotating easily. Specifically, a friction spring 26 and a washer 27 are disposed between the ratchet guide 24 and the reel spindle 11a. The friction spring 26 presses the ratchet guide 24 against the set screw 25, thereby generating a predetermined frictional force between the ratchet guide 24 and the set screw 25.

The ratchet guide 24 has an engagement portion 24a on the surface facing the ratchet member 22 that can engage with the ratchet member 22. When the ratchet member 22 rotates in conjunction with the rotation of the reel 12, the engagement portion 24a engages with the ratchet member 22 to rotate the ratchet member 22.

The magnet housing portion 13c is formed adjacent to the ratchet housing recess 13b inside the cylindrical portion 13. Therefore, when the tip portion 22c of the ratchet member 22 is housed in the ratchet housing recess 13b, the magnet 28 is set to be close to the tip portion 22c of the ratchet member 22 (at least, the distance from the magnet 28 to the tip portion 22c of the ratchet member 22 is shorter than the distance from the magnet 28 to the rotation shaft portion 22a of the ratchet member 22). This arrangement ensures that the magnet 28 acts on the tip portion 22c of the ratchet member 22, holding the ratchet member 22 from popping out.

Furthermore, the magnet 28 held in the magnet accommodating portion 13c is disposed parallel to the tip portion 22c of the ratchet member 22 housed in the ratchet accommodating recess 13b. This allows the entire surface of the magnet 28 to be close to the tip portion 22c of the ratchet member 22, allowing the magnetic force to act over a wide range of the tip portion 22c of the ratchet member 22. In other words, this structure allows for increased holding power when the ratchet member 22 is housed.
The recoil starter 10 operates as follows.

First, before the engine is started, as shown in FIG. 1, the ratchet member 22 is biased to the storage position by the action of the return spring 23. Also, the tip 22c of the ratchet member 22 is attracted to and held by the magnet 28. In this state, the ratchet member 22 is not engaged with the drive pulley.

When the rope 20 is pulled from this state and the reel 12 rotates, the ratchet member 22 attached to the reel 12 moves around the reel spindle 11a. At this time, the ratchet guide 24 is attached to the reel spindle 11a with a certain rotational resistance and does not rotate, and the ratchet member 22 comes into contact with the engagement portion 24a of the ratchet guide 24 and is pushed outward. This causes the ratchet member 22 to rotate, and as shown in Figures 7 and 8, the tip portion 22c of the ratchet member 22 protrudes from the cylindrical portion 13. By opening the ratchet member 22 in this way, the ratchet member 22 engages with the drive pulley, and the torque of the reel 12 can be transmitted to the drive pulley (the crankshaft of the engine).

The ratchet member 22, which has been opened to the position shown in Figures 7 and 8, is locked in the fully open state and cannot be opened any further. Therefore, when the reel 12 rotates further, the ratchet guide 24 engaged with the ratchet member 22 rotates together with the reel 12 in the engine starting direction against the rotational resistance of the friction spring 26. This rotation continues until the operator stops pulling the rope 20, and the rotational force is transmitted to the drive pulley.

When the operator then releases the rope 20, the torque stored in the recoil spring 21 rotates the reel 12 in the opposite direction, rewinding the rope 20 onto the reel 12. At this time, the ratchet guide 24 returns to the stowed position by the action of the return spring 23. The ratchet guide 24 that has returned to the stowed position is attracted to and held by the magnet 28. Therefore, after the engine starts (while the machine is operating), the ratchet guide 24 is held in the stowed position by the action of the return spring 23 and the magnet 28.

As described above, according to this embodiment, the magnet 28 is configured to attract the ratchet member 22 and suppress oscillation when the reel 12 is not rotating. With this configuration, the holding force of the ratchet member 22 can be increased by the attraction force of the magnet 28, so that unintentional jumping out of the ratchet member 22 can be prevented without increasing the spring force of the return spring 23. For example, even if the recoil starter 10 is incorporated into a high-vibration machine such as a rammer, the ratchet member 22 can be prevented from jumping out while the machine is in use, and problems such as wear, damage, and falling off of parts can be avoided.

In addition, because it is possible to increase only the holding force when the ratchet member 22 is stored, there is almost no effect on the torque during rotation of the reel 12. In other words, it is possible to prevent the ratchet member 22 from popping out while the machine is in operation (after the engine is running) without having much effect on the pulling action of the rope 20.

The ratchet member 22 is made of a metal that can be attracted to the magnet 28. Therefore, the magnetic force of the magnet 28 can be applied to the ratchet member 22 without special processing of the ratchet member 22. Furthermore, by making the ratchet member 22 out of a metal, the strength is improved, so a recoil starter 10 that is resistant to vibration can be manufactured.

The ratchet member 22 also has a tip 22c that is arranged parallel to the surface of the magnet 28, and the tip 22c is made of a ferromagnetic material. This allows the magnetic force to act over a wide area of the tip 22c, increasing the holding force of the ratchet member 22 when it is stored.

In addition, a cylindrical portion 13 is formed in the center of the reel 12, and a ratchet accommodating recess 13b that accommodates the tip end 22c of the ratchet member 22 is formed on the circumferential surface of the cylindrical portion 13. A magnet accommodating portion 13c that accommodates the magnet 28 is formed adjacent to the ratchet accommodating recess 13b inside the cylindrical portion 13. This allows the magnetic force to be reliably applied to the tip end 22c of the ratchet member 22 while keeping the recoil starter 10 compact.

REFERENCE SIGNS LIST 10 recoil starter 11 starter case 11a reel support shaft 12 reel 13 cylindrical portion 13a ratchet attachment portion 13b ratchet accommodating recess 13c magnet accommodating portion 13d non-return pawl 13e shaft hole 14 rope groove 20 rope 21 recoil spring 22 ratchet member 22a rotating shaft portion 22b arm portion 22c tip portion 23 return spring 24 ratchet guide 24a engagement portion 25 set screw 26 friction spring 27 washer 28 magnet

Claims (4)

A starter case,
A reel rotatably attached to the starter case;
a ratchet member pivotably attached to the reel;
a magnet attached to the reel;
Equipped with
The ratchet member is configured to swing and engage with a member on an engine side when the reel rotates,
The magnet is configured to attract the ratchet member and suppress swinging when the reel is not rotating.
Recoil starter. The ratchet member is made of a metal that can be attracted to the magnet.
2. The recoil starter according to claim 1. the ratchet member has a tip disposed parallel to a surface of the magnet;
The tip portion is formed of a ferromagnetic material.
3. A recoil starter according to claim 2. A cylindrical portion is formed at the center of the reel, the cylindrical portion protruding in a cylindrical shape,
a ratchet accommodating recess for accommodating a tip end of the ratchet member is formed on a circumferential surface of the cylindrical portion, and a magnet accommodating portion for accommodating the magnet is formed adjacent to the ratchet accommodating recess inside the cylindrical portion;
The recoil starter according to any one of claims 1 to 3.

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