Reciprocating tool

Patent metadata

Field	Value
Publication number	US-11701722-B2
Application number	US-201816618032-A
Country	US
Kind code	B2
Filing date	Apr 27, 2018
Priority date	May 31, 2017
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

Providing a reciprocating tool capable of reducing vibrations generated during operations and improving work performance and processing precision. A reciprocating tool includes a transmission gear part 61 and a counter weight part 62. The transmission gear part 61 includes a bevel gear 611 and a weight 611A. The bevel gear 611 is rotatable in a first direction about an axis B by receiving a drive force of a motor 3. The weight 62A is rotatable in a second direction opposite to the first direction about the axis B by receiving the drive force of the motor 3. A center of gravity 61G of the transmission gear part 61 and a center of gravity 62G of the counter weight part 62 are separated farthest from a blade mounting part 8 when the blade mounting part 8 is positioned in a rearward position. The center of gravity 61G of the transmission gear part 61 and the center of gravity 62G of the counter weight part 62 are closest to the blade mounting part 8 when the blade mounting part 8 is positioned in a forward position.

First claim

The invention claimed is:

1. A reciprocating tool comprising:
a housing;
a motor accommodated in the housing and including a rotating shaft;
an output part reciprocally and movably supported by the housing between a first position and a second position, the output part being configured to hold an end bit;
a first rotary body rotatable in a first direction about an axis extending in a predetermined direction intersecting a reciprocating direction of the output part by receiving a drive force of the motor; and
a second rotary body rotatable in a second direction about the axis by receiving the drive force of the motor, the second direction being opposite to the first direction, wherein:
the first rotary body comprises:
a first gear part rotatable about the axis by receiving the drive force of the motor;
a protruding part provided at an eccentric position with respect to the axis; and
a first weight part rotatable together with the first gear part,

the output part is provided with a guide to transmit the drive force in the reciprocating direction to the output part by receiving the rotation of the protruding part,
the second rotary body comprises:
a second gear part rotatable about the axis by receiving the drive force of the motor; and
a second weight part rotatable together with the second gear part,

a mass of the first rotary body includes a mass of the protruding part and a mass of the first weight part, and a mass of the second rotary body includes a mass of the second weight part, and
a product of a first distance and the mass of the first rotary body is equivalent to a product of a second distance and the mass of the second rotary body, the first distance being a radial distance of the first rotary body from the axis to a center of gravity of the first rotary body, and the second distance being a radial distance of the second rotary body from the axis to a center of gravity of the second rotary body,
wherein:
the first rotary body further comprises an orbital guide rotatable together with the first gear part about the axis;
the orbital guide has a circular shape whose center is coincident with the axis, the orbital guide has an outer edge portion, the outer edge portion having a vertical thickness that varies along a circumferential direction,
the housing is provided with a support part slidably supporting the output part,
the support part comprises:
a receiving part contactable with a part of an end portion of the outer edge portion in a thickness direction; and
a swinging shaft;

when the orbital guide is rotated, the support part is pivotally movable about the swinging shaft with respect to the housing with a change in a contact position in an axial direction between the end portion of the outer edge portion and the receiving portion, and
the mass of the first rotary body includes a mass of the orbital guide.

2. The reciprocating tool according to claim 1 , wherein:
the protruding part comprises:
a pin protruding from the first gear part toward the guide; and
a connecting part provided between the pin and the guide and rotatable about the pin, and

the mass of the first rotary body includes a mass of the pin and a mass of the connecting part.

3. The reciprocating tool according to claim 2 , wherein the guide is formed with a groove extending in a direction orthogonal to the reciprocating direction and an axial direction, the connecting part being movable in the groove.

4. The reciprocating tool according to claim 1 , wherein:
the outer edge portion has a vertical thickness that varies along a circumferential direction with a thickest part and a thinnest part,
when the output part is positioned at the first position or the second position, a line connecting the thickest part and the thinnest part extends in a direction different from the reciprocating direction as viewed in the axial direction, and
the orbital guide has a part partially thickened and positioned inside of the thinnest part in a radial direction of the orbital guide.

5. The reciprocating tool according to claim 1 , wherein the second distance is longer than the first distance.

6. The reciprocating tool according to claim 1 , wherein a center of gravity of the second weight part is separated farther from the axis than a center of gravity of the first weight part is from the axis.

7. The reciprocating tool according to claim 1 , wherein the first weight part and the first gear part are integral with each other.

8. The reciprocating tool according to claim 1 , wherein the second weight part and the second gear part are integral with each other.

9. The reciprocating tool according to claim 1 , wherein the second gear part has a strength lower than that of the first gear part.

10. The reciprocating tool according to claim 1 , wherein the second gear part has a diameter decreased in an axial direction with an increasing distance from the output part.

11. The reciprocating tool according to claim 1 , wherein:
a vibration in the reciprocating direction caused by the output part is counterbalanced by the first rotary body, and
a vibration in an intersecting direction caused by the first rotary body is counterbalanced by the second rotary body, the intersecting direction being a direction orthogonal to both the reciprocating direction and the predetermined direction.

12. A reciprocating tool comprising:
a housing;
a motor accommodated in the housing and including a rotating shaft;
an output part reciprocally and movably supported by the housing between a first position and a second position, the output part being configured to hold an end bit;
a first rotary body comprising a first gear part and a first weight part, the first gear part being rotatable in a first direction about an axis extending in a predetermined direction intersecting a reciprocating direction of the output part by receiving a drive force of the motor, the first weight part being provided at the first gear part so as to rotate together with the first gear part;
a motion converting part interposed between the first gear part and the output part in a transmission path of the drive force of the motor and converting the rotational motion of the first gear part to the reciprocating motion of the output part; and
a second rotary body comprising a second weight part rotatable in a second direction about the axis by receiving the drive force of the motor, the second direction being opposite to the first direction;
wherein a first radial distance between a center of gravity of the first weight part and the axis is shorter than a second radial distance between a center of gravity of the second weight part and the axis,
wherein:
the first rotary body further comprises an orbital guide rotatable together with the first gear part about the axis;
the orbital guide has a circular shape whose center is coincident with the axis, the orbital guide has an outer edge portion, the outer edge portion having a vertical thickness that varies along a circumferential direction,
the housing is provided with a support part slidably supporting the output part,
the support part comprises:
a receiving part contactable with a part of an end portion of the outer edge portion in a thickness direction; and
a swinging shaft;

when the orbital guide is rotated, the support part is pivotally movable about the swinging shaft with respect to the housing with a change in a contact position in an axial direction between the end portion of the outer edge portion and the receiving portion, and
a mass of the first rotary body includes a mass of the orbital guide.

13. A reciprocating tool comprising:

Assignees

• Koki Holdings Co Ltd

Inventors

• Monzen Tetsuya
• Nakano Ryosuke

Classifications

• B23D51/161 Primary

  with dynamic balancing · CPC title

• B23D51/16 Primary

  of drives or feed mechanisms for straight tools, e.g. saw blades, or bows · CPC title

• B23D51/10

  for hand-held or hand-operated devices · CPC title

• B25F5/006

  Vibration damping means · CPC title

• B27B3/26

  Mechanisms for producing the reciprocating movement of the saw frame; Arrangements for damping vibrations; Arrangements for counter-balancing · CPC title