JP2017012009A - Reciprocating tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive cutter with high working efficiency which solves the above-mentioned drawbacks with a simple constitution, and improves the life span thereof.SOLUTION: The cutter is provided with a driving source, a housing which accommodates the driving source, a cam mechanism driven by the driving source, first and second blades reciprocated relative to each other by the cam mechanism, and an engagement surface shape for the cam, the blade or the cam and the blade in the engagement surface of the cam and blade such that component forces are applied in the diverging direction of the cam and the blade.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reciprocating tool including a working tool that is driven to reciprocate.

  Various reciprocating tools equipped with a reciprocating work tool are known. The work tool is engaged with a cam and a blade portion in which a plurality of cutting edges are formed along both edges in the width direction perpendicular to the longitudinal direction. The upper blade and the lower blade on which the cam engaging portion and the connecting portion for connecting them are formed are vertically stacked, and the rotation of the motor is converted into a reciprocating linear motion of the upper blade and the lower blade by the cam. An example is a hedge trimmer in which the lower blades are alternately reciprocated in opposite directions to perform a necessary trimming operation. As described in Patent Document 1, a general hedge trimmer includes a motor as a driving source, a power transmission mechanism unit that converts a rotational driving force output from the motor into a reciprocating driving force of an upper blade and a lower blade, A work tool (upper blade and lower blade) driven reciprocally by the reciprocating driving force output from the mechanism section is provided, and is used for pruning trees, shaping hedges, cutting grass and the like.

  Here, when trying to cut thick branches or hard branches with a hedge trimmer, or when something that cannot be cut such as an iron fence is bitten, the movement of the blade may stop and the motor may be locked . In the configuration of Patent Document 1, all surfaces where the upper cam ring and the upper blade are engaged are all flat surfaces, and the upper cam ring is thicker than the upper blade in the direction of the rotation axis so that the engagement is not released during normal operation. Therefore, depending on the trimming work, even if a sudden force is applied, such as when a hard tree or pebbles are bitten, the upper cam ring does not disengage from the upper blade, and the impact is directly applied to the gear tooth surface. In addition, the life of the gear may be reduced.

  In order to solve such a problem, a configuration is considered in which the speed change mechanism portion is constituted by a pulley and a V belt, and the speed change mechanism portion is slipped when an abnormally large transmission torque is applied.

JP-A-9-233946

  However, in the above-described conventional technology, since the pulley and the V belt are interposed between the drive shaft and the eccentric cam, there are problems that the parts of the transmission mechanism section increase, the configuration becomes complicated, and the main body becomes large. there were. An object of the present invention is to solve the above-described drawbacks with a simple configuration, to improve the life, and to provide an inexpensive and good working efficiency.

  In order to achieve the above object, in the present invention, a drive source, a housing that houses the drive source, a cam mechanism that is driven by the drive source, and a first and a first that are relatively reciprocated by the cam mechanism. 2 and a cam or blade or a cam-blade engagement surface shape for applying a component force in a direction in which the cam and the blade are separated from each other on the cam-blade engagement surface.

  According to the present invention, by providing a cam or a blade or a cam and blade engagement surface shape for exerting a component force in a direction in which the cam and the blade are separated from each other, the wire and the thick branch are bitten and the blade is rotated. When a strong force that restrains is applied, the sliding surface of the blade is disengaged from the sliding surface of the cam, so that the transmission of the force is released and the gear tooth surface can be prevented from being damaged.

The side view of the reciprocating tool which concerns on embodiment of this invention. The drive part enlarged view of the reciprocating tool shown by FIG. FIG. 2 is an enlarged view of a drive unit in a state where transmission of force of the reciprocating tool shown in FIG. The drive part enlarged view of the reciprocating tool which concerns on another embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  The reciprocating tool of the present embodiment is a hedge trimmer also called a plant clipper, and incorporates a drive source 7 such as an engine or an electric motor in the housing 1. The housing 1 is provided with a main handle (rear handle) 1a and a sub handle (front handle) 1b. The main handle 1a is provided with a trigger switch 1c operated by a user. The scattering protection cover 1d is erected on the front end portion of the housing 1, and prevents the clipped object from scattering to the user side. A blade set is attached to the lower portion of the housing 1. The blade set is obtained by integrating the upper blade 2, the lower blade 3, the blade guide 4, the blade holder 5, and the cam mechanism 11. The blade set is fixed to the housing 1 by screws 13a and nuts 13b. The upper blade 2 as the first blade and the lower blade 3 as the second blade are mutually sandwiched between the blade guide 4 and the blade holder 5 by means of screws 15a and nuts 15b (FIG. 3). And is slidably supported.

  The base end portions of the upper blade 2 and the lower blade 3 engage with the cam mechanism 11. The cam mechanism 11 includes an upper cam plate portion (first cam plate portion) 11a, a lower cam plate portion (second cam plate portion) 11b, and a flange portion 11c. The upper cam plate portion (first cam plate portion) 11a and the lower cam plate portion (second cam plate portion) 11b are provided eccentrically in a direction away from each other about the central shaft member 12. The flange portion 11c is a disk-like portion having a larger diameter than the upper cam plate portion 11a and the lower cam plate portion 11b, which is located between the upper cam plate portion 11a and the lower cam plate portion 11b. A slope 11d whose diameter decreases toward the gear is provided on the outer peripheral surface of the upper cam plate portion 11a.

  A slope 11e whose diameter decreases toward the blade holder is provided on the outer peripheral surface of the lower cam plate portion 11b. A wave washer 14 is disposed on the gear 9. The wave washer 14 always urges the gear 9 in the direction of the cam 11, that is, when the gear 9 moves in a direction away from the cam 11, a reaction force in a direction approaching the cam 11 side is generated. It is configured. The wave washer 14 may be configured not to be compressed at normal time but to be compressed by moving the gear 9.

  A long hole 2a (FIG. 3) having a long diameter in the direction intersecting the longitudinal direction of the blade is formed as a cam engaging portion at the base end portion of the upper blade 2, and the inner peripheral portion of the long hole 2a is the outer periphery of the upper cam plate portion. Engages with slope 11d. Similarly, a long hole (not shown) as a cam engaging portion is formed in the base end portion of the lower blade 3, and the inner peripheral portion of the long hole is engaged with the inclined surface 11e on the outer periphery of the lower cam plate portion. The flange portion 11c has a larger diameter than the short diameter (inner diameter in the short direction) of the long hole 2a of the upper blade 2 and the long hole of the lower blade 3, and the cam mechanism 11 comes out of the upper blade 2 and the lower blade 3. To prevent. A pin (not shown) protrudes from the upper portion of the cam mechanism 11 and is inserted into a hole (not shown) provided in the gear 9 and engaged in the rotation direction to transmit the rotation of the gear 9 to the cam mechanism 11. ing.

  As shown in FIGS. 1 and 2, a pinion (gear) 8 is provided at the tip of the output shaft 7 a of the drive source 7. The pinion 8 meshes with the gear 9 and transmits the rotation of the drive source 7 to the gear 9 with a predetermined reduction ratio. The gear 9 is a helical gear, for example, and is supported in the gear storage space 1 k of the housing 1. Specifically, the gear 9 is rotatably supported by a central shaft member (gear shaft) 12 fixed to the housing 1. A cam 11 is fitted to the gear 9. The central shaft member 12 passes through a central hole 16 provided in the blade set and protrudes downward from the blade holder 5. The rotation of the drive source 7 is transmitted to the pinion 8 and the gear 9, and the cam mechanism 11 rotates together with the gear 9. The cam mechanism 11 is rotationally driven by the drive source 7 and converts the rotation of the drive source 7 into a reciprocating motion of the blade 2 and the lower blade 3.

  According to the present embodiment, the following effects can be achieved. Since the component force acts on the outer periphery of the cam in the direction in which the blade moves away from the cam toward the gear side (the direction in which the blade and the cam are separated), a strong force that engages the wire or a thick branch and restrains the blade works. For example, when the upper blade 2 is detached as shown in FIG. 3, the cam 11 is about to rotate while the blade is constrained, so that the cam 11 is pressed against the upper blade 2, that is, the inclined surface 11d is a long hole. The upper blade 2 is pushed up by the cam 11 by being pressed against 2a. In other words, the cam engaging surface of the upper blade 2 slides on the slope 11d, the upper blade 2 is pushed upward, and the upper blade 2 pushes the gear 9 while pushing and shrinking the wave washer 14, thereby A gap is generated between the gears 9, and the upper blade 2 enters between the cam 11 and the gear 9, and the transmission of force from the cam 11 to the blade is released. Further, when the lower blade 3 is detached, the slope 11e slides on the cam engaging surface of the lower blade 3, the lower blade 3 does not move up and down, and the gear 9 and the cam 11 are pushed up while the wave washer 14 is compressed. The cam 11 is brought into contact with the lower blade 3 and the gear 9 is positioned thereon, and the transmission of force from the cam 11 to the blade is released. By releasing the transmission of these forces, it is possible to prevent the gear tooth surface from being damaged.

  Furthermore, when the main body is driven in a state where the transmission of force is released, the engagement hole with the cam of the blade is a long hole. Then, power transmission is resumed.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the above-mentioned embodiment, A various change is possible within the range which does not deviate from the meaning.

  For example, in the above-described embodiment, the inclined surface 11d is formed on the outer periphery of the cam, and the upper hole 2 is configured upward by moving the elongated hole 2a along the inclined surface 11d of the cam. For example, as shown in FIG. Furthermore, the inner surface of the long hole of the upper blade 102 may be the inclined surface 102a, and the force that pushes the upper blade 102 by the cam 111 may be converted to the force that moves the upper blade 102 upward by the inclined surface 102a. At this time, the outer peripheral surface of the cam 111 is described as a flat surface 111d, but as shown in the embodiment in FIGS.

  Moreover, although the example of the hedge trimmer in which both the upper blade and the lower blade reciprocate has been described, the present invention can be similarly applied to a hedge trimmer in which only the upper blade moves while the lower blade is fixed. Further, as described above, the drive source is not limited to the electric motor, and an engine may be used.

1 Housing 1a Main handle (rear handle)
1b Sub handle (front handle)
1c Trigger switch 1d Splash protection cover 1e Gear storage space 2 Upper blade (first blade)
2a Long hole (cam engagement part)
3 Lower blade (second blade)
4 Blade guide 5 Blade holder 7 Drive source 7a Output shaft 8 Pinion (gear)
9 Gear 11 Cam mechanism 11a Upper cam plate (first cam plate)
11b Lower cam plate (second cam plate)
11c Flange portion 11d Upper cam engaging slope 11e Lower cam engaging slope 12 Center shaft member (gear shaft)
13a Screw 13b Nut 14 Wave washer 15a Screw 15b Nut 16 Center hole

Claims (4)

A driving source; a gear that is rotated by transmission of the rotational force of the driving source; a cam that is arranged adjacent to the gear and interlocked; and an upper blade and a lower blade that are superimposed and moved relative to each other. In the reciprocating tool for rotating the cam and reciprocating the upper blade engaged with the cam,
A reciprocating motion comprising the cam or / and the engagement surface shape of the upper blade for generating a component force from the cam toward the gear side in the engagement portion of the upper blade by the rotation of the cam tool. The gear is movable in a direction away from the cam;
The reciprocating tool according to claim 1, wherein the upper blade moves the gear in a direction away from the cam by rotation of the cam and enters between the cam and the gear.   The reciprocating tool according to claim 2, wherein the gear is configured to generate a reaction force in a direction approaching the cam side when moving in a direction away from the cam. The lower blade engages with the cam and reciprocates,
The cam or / and the engagement surface shape of the lower blade that causes the engaging portion of the lower blade to generate a component force from the cam toward the opposite side of the gear by the rotation of the cam. The reciprocating tool according to any one of claims 1 to 3.