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US-12623330-B2 - Working machine

US12623330B2US 12623330 B2US12623330 B2US 12623330B2US-12623330-B2

Abstract

Provided is a working machine in which a counterweight is appropriately supported, thereby avoiding deterioration of workability. The working machine includes: a motor; a plunger reciprocated in a front-back direction by a drive of the motor; a crankshaft rotated around an axis extending in an up-down direction by the drive of the motor; a counterweight driven in a front-back direction by rotation of the crankshaft so as to cancel out vibration due to the reciprocation of the plunger; a transmission mechanism (gear, crankshaft, and connector) converting a rotation driving force of the motor into a driving force for the plunger and counterweight and transmitting the driving force to the plunger and counterweight; and a gear case (transmission mechanism accommodation portion and lid portion) accommodating the transmission mechanism and elastically supporting the counterweight in the right-left direction.

Inventors

  • Keigo Iseda
  • Ken INUI
  • Shota Hirano

Assignees

  • KOKI HOLDINGS CO., LTD.

Dates

Publication Date
20260512
Application Date
20221202
Priority Date
20211203

Claims (20)

  1. 1 . A working machine comprising: a motor; a plunger that can attach a tool and reciprocates in a front-back direction by a drive of the motor; a rotating body that rotates around an axis extending in an up-down direction by the drive of the motor; an eccentric portion provided on the rotating body to be offset from the axis and configured to rotate around the axis; a counterweight that is connected to the eccentric portion and reciprocates in the front-back direction so as to counteract vibration due to the reciprocation of the plunger by transmitting a forward biasing force from a forward movement of the eccentric portion to the counterweight and by transmitting a rearward biasing force from a rearward movement of the eccentric portion to the counterweight; and an elastic body that is arranged on at least one side of the counterweight in a right-left direction and elastically supports the counterweight in the right-left direction.
  2. 2 . The working machine according to claim 1 , wherein the counterweight is elastically supported in the up-down direction.
  3. 3 . The working machine according to claim 1 , wherein the rotating body has an eccentric portion, the counterweight is provided with an elongated hole extending in the right-left direction, and power from the eccentric portion inserted through the elongated hole is transmitted to the counterweight.
  4. 4 . The working machine according to claim 1 , wherein the counterweight is elastically supported via a rolling element.
  5. 5 . The working machine according to claim 1 , wherein the elastic body is arranged on both left and right sides of the counterweight.
  6. 6 . The working machine according to claim 1 , wherein a gravity center is positioned on a side opposite the counterweight with respect to the plunger.
  7. 7 . The working machine according to claim 6 , wherein the plunger is supported by two rollers respectively positioned above and below so as to be movable in the front-back direction.
  8. 8 . The working machine according to claim 1 , further comprising a transmission mechanism case that accommodates the rotating body, wherein the transmission mechanism case accommodates the elastic body and a metal support member, the metal support member is supported on the transmission mechanism case via the elastic body, and the counterweight is supported by the metal support member that is elastically supported by the elastic body and is configured to reciprocate in the front-back direction relative to the metal support member.
  9. 9 . The working machine of claim 1 , wherein the plunger and the counterweight are reciprocated with a predetermined phase difference.
  10. 10 . The working machine of claim 1 , wherein the eccentric portion comprises: a first eccentric portion that drives the plunger; and a second eccentric portion that drives the counterweight, wherein each of the first eccentric portion and the second eccentric portion rotates around the axis.
  11. 11 . The working machine of claim 1 , wherein the counterweight has an elongated hole that extends in the right-left direction and passes through in the up-down direction, and the counterweight is driven by the eccentric portion transmitting a driving force to an inner surface of the elongated hole of the counterweight.
  12. 12 . The working machine of claim 11 , wherein the elastic body absorbs vibrations generated when the eccentric portion transmits the driving force to the elongated hole and the counterweight tilts around an up-down axis.
  13. 13 . A working machine comprising: a motor; a plunger that can attach a tool and reciprocates in a front-back direction by a drive of the motor; a counterweight that is driven so as to counteract vibration due to the reciprocation of the plunger by the drive of the motor; and a transmission mechanism that transmits a rotation driving force of the motor to the plunger and the counterweight; and a transmission mechanism case that accommodates the transmission mechanism, an elastic body, and a metal support member, wherein the metal support member is supported by the transmission mechanism case via the elastic body, wherein the elastic body and the metal support member are arranged on at least one side of the counterweight in a direction orthogonal to the front-back direction, and wherein the counterweight is supported by the metal support member that is elastically supported by the elastic body and is reciprocable relative to the metal support member in the front-back direction.
  14. 14 . The working machine according to claim 13 , wherein the counterweight is configured to reciprocate in the front-back direction by a rotating body that rotates around an axis extending in an up-down direction by the drive by the motor, and the counterweight is elastically supported in a right-left direction by the elastic body.
  15. 15 . The working machine according to claim 13 , wherein the elastic body includes any one of rubber, urethane, sponge, and spring.
  16. 16 . The working machine according to claim 13 , further comprising a transmission mechanism, wherein the transmission mechanism has a gear that is driven so as to rotate around an axis extending in an up-down direction by the drive of the motor, and a crankshaft that rotates together with the gear, one end of the crankshaft is eccentric from the axis and is coupled to the plunger, the direction orthogonal to the front-back direction is a right-left direction, the other end of the crankshaft is eccentric from the axis and is engaged with the counterweight, and the plunger and the counterweight are driven by movement of the crankshaft.
  17. 17 . The working machine according to claim 16 , further comprising a transmission mechanism case, wherein the counterweight has a plurality of groove portions, a rolling element is arranged inside the groove portions, the transmission mechanism case has a flexible plate-shaped lid portion, and the lid portion abuts against the rolling element.
  18. 18 . The working machine of claim 13 , wherein the elastic body is rubber having a thickness in a right-left direction, and the metal support member is arranged so as not to shift relative to the elastic body in the front-back direction.
  19. 19 . A working machine comprising: a motor; a plunger that can attach a tool and reciprocates in a first direction by the motor; a rotating body that rotates around an axis extending in a second direction orthogonal to the first direction by a drive of the motor; an eccentric portion provided on the rotating body and configured to rotate around the axis; a counterweight that is connected to the eccentric portion and reciprocates in the first direction so as to counteract vibration due to the reciprocation of the plunger by transmitting a forward biasing force from a forward movement of the eccentric portion to the counterweight and by transmitting a rearward biasing force from a rearward movement of the eccentric portion to the counterweight; and an elastic body arranged on at least one side of the counterweight in a third direction that is orthogonal to both the first direction and the second direction and elastically supports the counterweight in the third direction.
  20. 20 . The working machine of claim 1 , wherein the counterweight is rotatable about the up-down direction, and the elastic body is compressed by rotation of the counterweight about up-down direction.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is the U.S. National Phase under 35 U.S.C. § 371 of International Application No. PCT/JP2022/044625, filed on Dec. 2, 2022, which claims the benefit of Japanese Application Nos. 2021-197267, filed on Dec. 3, 2021, 2022-115659, filed on Jul. 20, 2022, and 2022-121261, filed on Jul. 29, 2022, and the entire contents of each are hereby incorporated by reference. TECHNICAL FIELD The present invention relates to a working machine. BACKGROUND ART Patent Document 1 discloses a saber saw (reciprocating saw) as a working machine. In this working machine, a motor drives a plunger to reciprocate in a front-back direction, and a blade provided at a tip of the plunger reciprocates to cut an object. RELATED ART DOCUMENTS Patent Documents Patent Document 1: International Publication No. WO2017/104380 SUMMARY OF THE INVENTION Problems to be Solved by the Invention In a working machine disclosed in Patent Document 1, a counterweight is operated to reduce vibration in a front-back direction, but an operation of the counterweight generates other vibrations and noise, which may hinder workability. In view of the above problems, an object of the present invention is to provide a working machine in which workability is not impaired by appropriately supporting the counterweight. Means for Solving the Problems A working machine of one embodiment includes: a motor; a plunger that reciprocates in a front-back direction by a drive of the motor; a rotating body that rotates around a shaft extending in an up-down direction by the drive of the motor; a counterweight that reciprocates in the front-back direction so as to cancel out vibration due to the reciprocation of the plunger by the rotation of the rotating body; a transmission mechanism that transmits a rotation driving force of the motor to the plunger and the counterweight; and an elastic transmission machine that elastically supports the counterweight in a right-left direction. Effects of the Invention In the working machine according to one embodiment, the vibration due to the operation of the counterweight is suppressed by the elastic body, so that workability is not impaired. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a left-side view of a working machine according to one embodiment; FIG. 2 is a partial cross-section left-side view of the working machine; FIG. 3 is an exploded perspective view of a transmission mechanism; FIG. 4 is a top view showing an inclination of a right-left direction of the counterweight; and FIG. 5 is a cross-sectional left-side view showing an inclination of the counterweight in a front-back direction. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Hereinafter, a working machine according to one embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a front-back direction and an up-down direction are directions indicated in the figures. Further, a direction orthogonal to the front-back direction and the up-down direction (that is, a direction perpendicular to a plane of paper) is referred to as a right-left direction. The front-back direction is one example of a first direction. The up-down direction and the right-left direction are one example of a second direction. The second direction is a direction orthogonal to the first direction. In the working machine 10, as shown FIG. 2, a plunger 30 reciprocates in the front-back direction by driving a motor 20. The working machine 10 according to the present embodiment is a saber saw (reciprocating saw), a blade 32 is attached on a front side of the plunger 30, and the blade 32 reciprocates in the front-back direction to cut an object. First, with reference to FIGS. 1 and 3, an outline of the working machine 10 will be described. As shown in FIG. 1, the working machine 10 includes a housing 11 configured by metal and a synthetic resin. The housing 11 can be divided into two in the right-left direction. The housing 11 is provided with a plunger accommodation portion 12, a motor accommodation portion 13, a handle 14, a trigger 15, an attachment portion 16, a base 19, and the like. The plunger accommodation portion 12 is formed into a cylinder shape extending in the front-back direction. The motor accommodation portion 13 is formed into a cylinder shape extending downwardly from a lower portion of the plunger accommodation portion 12. The handle 14 is formed into a shape extending downwardly from a back portion the plunger accommodation portion 12. The handle 14 is provided with the trigger 15. By an operator, the handle is grasped, and the trigger is operated. The attachment portion 16 is provided below the motor accommodation portion 13 and the handle 14. A battery pack 17 is attached to the attachment portion 16. The battery pack 17 supplies power to the motor 20. A controller 18 is provided inside the motor accommodation portion 13 (see FIG. 2). When the operator operates the trigger 15, a trigger swi