JPS60155049A - Reciprocation driving device - Google Patents

Abstract

PURPOSE:To achieve a reciprocation driving device which has a clutch function by providing an eccentric pin for converting reciprocation mounted on a rotary member, which is disengaged from a hole at the time of overload. CONSTITUTION:A reciprocation driving device 8 comprises a driving gear 11 engaged with a pinion 9 of an output shaft of a motor 7 through an intermediate gear 10, and eccentric pin 13 mounted in a hole 12 in such a manner as to freely project downward and retreat, and a driving bush 15. The motor 7 is rotated to rotate the driving gear 11, and the eccentric pin 13 is engaged with an elongated hole 14 to reciprocate a movable cutting edge 2. When overload is applied to the movable cutting edge 2, the eccentric pin 13 goes up a taper surface 14a of the elongated hole 14 against a clutch spring 18 and escapes from the elongated hole 14. Thus, rotation of the motor 7 is not transmitted to liberate overload.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a reciprocating drive device used in a mower or the like.

[Background technology]

Conventionally, a device shown in FIG. 5 has been used in a mowing machine as a mechanism for converting rotation of a motor into reciprocating motion of a movable blade. In the figure, 20 is a movable blade that reciprocates in the direction of arrow Q, and 21 is a drive plate.

An eccentric pin 24 that engages with the long hole 23 of the movable blade 20 is attached to the drive plate 21, and the eccentric pin 24 causes the movable blade 20 to reciprocate. The eccentric pin 24 is protrusively retractable and biased to protrude by a spring body 25 for convenient replacement of the movable blade 20 and the like.
It may be fixed to the drive plate 21. The drive plate 21 is the drive gear 2
A clutch spring 28 that engages with the clutch protrusion 27 of No. 6 is fixed with a screw 29, and its rotation is transmitted by the motor via a drive gear 26.

The clutch plate 28 is provided to release overload from the movable blade 20. However, the mechanism for converting the reciprocating motion and the clutch mechanism are provided separately, and there is a problem that the structure is complicated due to the large number of parts.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reciprocating drive device having a simple structure and having a clutch function for overload prevention.

[Disclosure of the invention]

In the reciprocating motion drive device of the present invention, the eccentric pin for converting reciprocating motion provided on the rotating member is configured to escape from the long hole of the reciprocating member when overloaded, and the eccentric pin and the long hole have a clutch function. It is something that can be done.

Embodiment An embodiment of the present invention is shown in FIGS. 1 to 4. In the figure, 1 is a main body case, in which a fixed blade 2 in the shape of a comb tooth is provided extending forward, and a movable blade 3 in the form of a comb tooth is provided on the upper surface of the fixed blade 2 so as to be able to reciprocate in the longitudinal direction. ing. It is a four-piece cover and is attached to the fixed blade 2 with attachment screws 4a.

5 is a switch, and 6 is a power cord. The main body case 1 houses a motor 7 and a reciprocating drive device 8 that transmits the rotation of the motor 7 to the movable blade 3.

The reciprocating drive device 8 has a pinion 9 on the output shaft of the motor 7.
A drive gear 11 meshes with the drive gear 11 via an intermediate gear 10, an eccentric pin 13 is attached to a hole 12 of the drive gear 11 so as to be able to protrude and retract downward, and a tip of the eccentric pin 13 provided on the movable blade 3 engages. The drive bushing 15 has an elongated hole 14.

The eccentric pin 13 has a retaining flange 13&, and is urged to protrude by a clutch spring 18 in the hole 12. Eccentric bottle 1
The tip of 3 is spherical. The clutch spring 18 is held down by a holding plate 17 fixed to the drive gear 11 with screws 16. The long hole 14 of the drive bush 15 extends in a direction perpendicular to the reciprocating direction of the movable blade 3, and the inner wall surface on the tip side of the movable blade 3 is a tapered surface 14&.

The rotation of the operation motor 7 causes the drive gear 11 to rotate, and the engagement between the eccentric pin 13 and the elongated hole 14 causes the movable blade 2 to reciprocate.

An overload is applied to the movable blade 2. When this occurs, the eccentric pin 13 rises up the tapered surface 14& of the elongated hole 14 against the clutch spring 18 and escapes from the elongated hole 14. Therefore, the rotation of the motor 7 is no longer transmitted, and overload can be relieved.

In this way, overload prevention is achieved, but since the clutch function is maintained by engaging and disengaging the eccentric pin 13 for conversion into reciprocating motion and the elongated hole 14, there is no need to use an independent clutch. Therefore, the number of parts is small and the structure is simple. Furthermore, by changing the slope of the tapered surface 141L along the longitudinal direction of the elongated hole 14, the clutch operating load during one reciprocating movement of the movable blade 3 can be changed.
Therefore, an appropriate latch operation load can be designed depending on the state of engagement between the fixed blade 2 and the movable blade 3. Furthermore, since the eccentric pin 13 is freely protrusive and retractable, the movable blade 3 can be easily replaced due to wear or damage. In addition, the life of the eccentric pin 13 and the drive bush 15 due to wear, and the movable blade 3
If the lifespan due to wear of the cutting edge (5) is kept at the same level, the eccentric pin 3 and the drive bushing 15, which serve as the clutch section, can be replaced at the same time as the blade is replaced.

〔Effect of the invention〕

The reciprocating drive device of the present invention has the advantage of having a small number of parts and a simple structure while having a function for preventing overload.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a mower to which an embodiment of the present invention is applied, FIG. 2 is a cutaway side view thereof, and FIGS. 3 and 4 are exploded perspective views and sectional views of the reciprocating device, respectively. FIG. 5 is an exploded perspective view of a conventional example. 1...Body case %2...Fixed blade, 3...Movable blade, 7...Motor, 11...Drive gear, 13...Eccentric bottle, 14...Elongated hole, 14a. ...Tapered surface, 15
...Driving bush. 18...Clutch spring (6)

Claims (3)

[Claims] (1) A reciprocating body provided to be able to freely reciprocate; a rotating member that is provided with its axis of rotation intersecting the reciprocating direction of the reciprocating body and rotationally driven by a motor; An eccentric bottle provided so as to be able to protrude and retract toward the moving body, a spring body that urges the eccentric bottle to protrude, and a spring body provided on the reciprocating body in a direction perpendicular to the reciprocating direction to hold the tip of the eccentric bottle. a reciprocating motion drive device, comprising: a groove portion that converts the rotation of the eccentric bin due to the rotation of the rotating member into a reciprocating motion of the reciprocating body, and allows the eccentric bin to escape in an overload state. (2) The reciprocating drive device according to claim (1), wherein the tip of the eccentric bottle is spherical. (3) The reciprocating motion drive device according to claim 1 or 2, wherein the inner wall surface on one side of the groove is tapered.