WO2020175009A1

WO2020175009A1 - Work machine

Info

Publication number: WO2020175009A1
Application number: PCT/JP2020/003665
Authority: WO
Inventors: 茉奈美中澤; 村上　卓宏; 川又　隆
Original assignee: 工機ホールディングス株式会社
Priority date: 2019-02-28
Filing date: 2020-01-31
Publication date: 2020-09-03
Also published as: JP7218792B2; JPWO2020175009A1

Abstract

The present invention reduces occurrence of vibration in a direction different from the reciprocating direction due to contact between power transmission parts during power transmission of a work machine. The work machine has a rotating part (an eccentric shaft (36e), a ball bearing (45)) rotated by a spindle (36) connected to a motor, and a reciprocating motion converting part (swing arm (40)) that engages with the ball bearing (45) and converts the motion into reciprocating motion around an axis B1 with the rotation of the rotating part. The ball bearing (45) is configured to be movable relative to the swing arm (40) in the front-rear direction. A spring (46) is provided behind the ball bearing (45), and the ball bearing (45) is biased rearward in the axial direction by the spring (46).

Description

\¥0 2020/175009 1 卩 (: 17 2020 /003665 Clarification

Title of invention: Working machine

Technical field

The present invention relates to a working machine that works by operating a tip tool with power of an electric motor or the like.

Background technology

[0002] Conventionally, a working machine is known in which a tip tool is operated by the power of an electric motor as a drive source to perform a manual work, and the working machine is described in Patent Document 1. The working machine described in Patent Document 1 is a so-called multi-tool, in which an electric motor and a power conversion mechanism are housed inside the equipment body, and a battery pack is mounted outside the equipment body. To be done. The main body of the device has an output shaft at the front end of a cylindrical motor housing that faces the rotation axis of the motor in 90° direction. It is driven to swing. The output shaft is provided with a screw hole. By attaching a tip tool to the output shaft and inserting a bolt that penetrates the attachment hole of the tip tool into the screw hole and tightening it, the tip tool is fixed to the output shaft. There are various types of cutting tools for cutting, scraping, cutting, deep cutting, tile joint cutting, cutting, chamfering, polishing surface finishing, etc., and these can be selected and installed.

Prior art documents

Patent literature

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 2 0 1 6-8 7 7 25

Summary of the invention

Problems to be Solved by the Invention

[0004] In the conventional working machine, the tip tool reciprocates in the circumferential direction around the output shaft, and the reaction thereof causes vibration, and the vibration is also transmitted to the handle portion. Therefore, in the working machine described in Patent Document 1, a weight having a predetermined mass is first 〇 2020/175009 2 卩(：171? 2020/003665

By moving the end tool in a phase opposite to the swing, the reciprocating vibration generated on the output shaft is canceled. However, the use of weights has the drawback of significantly reducing vibration while increasing the weight of the work implement.

[0005] The present invention has been made in view of the above background, and an object thereof is to realize a working machine capable of effectively reducing vibration during operation. Another object of the present invention is to realize a working machine that suppresses the occurrence of vibration in a direction different from the reciprocating direction of the tip tool due to contact between the power transmission parts. Still another object of the present invention is to realize a working machine in which the vibration generated by the exciting force generated during power transmission in the reciprocating motion converting section is reduced.

Means for solving the problem

The typical features of the invention disclosed in this application will be described below. According to one feature of the present invention, a work having a power source such as a motor, a rotating portion that is eccentrically rotated by the power source, and a reciprocating motion converting portion that engages with the rotating portion and converts into a reciprocating motion. In the machine, the rotating part is configured to be movable relative to the reciprocating motion converting part in a direction intersecting with the reciprocating direction, and an urging member for providing an urging force in the relative moving direction of the rotating part is provided. In addition, the working machine has a rotating shaft that is rotated by a power source, and the rotating part is provided on the rotating shaft. This rotating part is movable in the axial direction of the rotating shaft.

According to another feature of the present invention, the biasing member is an elastic body that applies a biasing force in the direction of relative movement, and the elastic body is held by the rotating shaft. The rotating portion includes an annular member that is mounted on the eccentric shaft so as to be slidable in the axial direction, and the eccentric shaft is provided with a fixing member that fixes the biasing member to the eccentric shaft. The annular member may be a rotary bearing such as a ball bearing or a needle bearing, or may be a sliding bearing such as a cylindrical metal. Particularly in the case of metal, it is desirable to use a sintered material that can be impregnated with oil so that galling does not occur during sliding. The biasing member is a coil panel provided coaxially with the eccentric shaft, and is designed to apply a biasing force in the axial direction intersecting the reciprocating direction to the rotating portion. There are two coil panels on both sides in the axial direction for the ring member. 〇 2020/175009 3 卩(: 171-1?2020/003665

Alternatively, the first coil panel may urge the annular member toward one side in the axial direction, and the second coil spring may urge the annular member toward the other side in the axial direction.

[0008] According to still another feature of the present invention, a working machine has a housing for accommodating a power source, and a cylindrical gripping portion provided in the housing and provided with an operating portion for performing on/off operation of the power source. Then, the axial direction of the grip portion is configured to be substantially parallel to the moving direction of the annular member. In addition, the work machine has an output shaft having an axis in a direction intersecting with the rotation direction of the power source, and a cylindrical portion is formed in the reciprocating motion converting portion and is fixed to the output shaft. It has a II-shaped arm that extends in contact with the rotating part, and is configured so that the output shaft reciprocates by a predetermined angle in the circumferential direction by the reciprocating motion converting part. Here, at least a part of the biasing member is arranged so as to be located inside the L-shaped arm portion.

Effect of the invention

[0009] According to the present invention, it is possible to suppress reaction force transmission during reciprocating driving, and to significantly reduce vibration transmitted from the reciprocating motion converting unit to the rotating shaft side via the rotating unit. Moreover, since the annular member is urged by the urging means such as a spring, it is possible to maintain a good contact condition between the annular member and the reciprocating motion converting portion, and when the contact member collides with the reciprocating motion converting portion. The high-frequency load generated in the can be effectively damped. As a result, by providing urging members on both sides in the axial direction with respect to the annular member, the unnecessary load transmitted is attenuated or blocked in two directions, and the annular member such as ball bearings is blocked. It has become possible to greatly improve durability.

Brief description of the drawings

[0010] [Fig. 1] Fig. 1 is a vertical sectional view showing the overall structure of a working machine 1 according to an embodiment of the present invention.

FIG. 2 is a top view of the working machine 1 according to the embodiment of the present invention.

[Fig. 3] Fig. 3 is an enlarged vertical sectional view of a front portion of the working machine 1 of Fig. 1.

[Fig. 4] Fig. 4 is a view of the power transmission mechanism 35 of the working machine 1 of Fig. 1, (8) is a perspective view of the assembled state, and (M) is a perspective view of the unfolded state.

[Fig. 5] Fig. 5 is a view of the power transmission mechanism 35 of the work implement 1 of Fig. 1, (8) is a top view, \\0 2020/175009 4 卩 (: 17 2020 /003665

(Mami) is a side view (partially sectional view).

FIG. 6 is an enlarged vertical cross-sectional view of the front part of the working machine 1 according to the second embodiment of the present invention.

[Fig. 7] Fig. 7 is a view of the power transmission mechanism 75 of the working machine 18 of Fig. 6, where (8) is a top view and (M) is a side view (partially sectional view).

[Fig. 8] () is a partial vertical cross-sectional view of the front part of the conventional working machine 101, and (M) is a partial cross-sectional view (partial cross-sectional view).

[Fig. 9] Fig. 9 is a power transmission mechanism 1335 of the conventional working machine 101, where () is a top view and (M) is a side view.

FIG. 10 is a top view for explaining the load applied to the power transmission mechanism 1 3 5 of the conventional work machine 10 1.

MODE FOR CARRYING OUT THE INVENTION

Example 1

[001 1] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following figures, the same parts are designated by the same reference numerals, and repeated description will be omitted. In this specification, as an example of the working machine, a portable working machine in which the tip tool is oscillated by a few degrees in the circumferential direction along the drive shaft by an electric motor will be described. In this specification, the front-rear, left-right and up-down directions will be described as the directions shown in the drawings.

[0012] FIG. 1 is a vertical cross-sectional view of a working machine 1 according to an embodiment of the present invention. The working machine 1 has an apparatus body 10 accommodating the motor 15 and a battery pack 90 that supplies electric power to the motor 15. The battery pack 90 can be attached to and detached from the device body 10. The work machine 1 is a so-called cordless type in which a power cord for connecting to a commercial power outlet is not provided in the device body 10.

[0013] The housing of the device main body 10 has a cylindrical motor housing 2 whose longitudinal direction is the axis 81, and a cover 3 attached to one end of the motor housing 2 in the direction along the axis 81. .. The motor housing 2 and the cover 3 are separate units, and the cover 3 is fixed to the motor housing 2 with a fixing element such as a screw. The motor housing 2 has a cylindrical shape with the axis 81 as the longitudinal axis. 〇 2020/175009 5 卩 (：171? 2020 /003665

A battery pack mounting portion 6 for mounting the battery pack 90 is formed on the rear side of the casing 2 so as to extend in the radial direction of the axis 81.

The motor 15 as a power source is provided in the motor housing 2 near the center in the direction of the axis 81. The motor 15 is a brushless motor, in which a rotor 16 having a permanent magnet is fixed to a rotating shaft 18 and a stator 17 having a coil is arranged on the outer peripheral side of the rotor 16. The rear end of the rotary shaft 18 is axially supported by the motor housing 2 by the bearing 3 2. A spindle 3 6 is connected to the front end of the rotary shaft 18. The spindle 36 is a rotary shaft rotated by a motor 15 and is rotatably supported by a holder 29 by a large-diameter bearing 34.

[0015] Of the motor housing 2, the switch lever 2 6

A gripping part 5 is located between the vicinity 3 and the battery pack mounting part 6, and the worker performs the work while gripping the gripping part 5 with one hand. The switch lever 2 63 is slidable in the front-rear direction, and its operation is transmitted to the switch 25 by the sliding arm 26. The switch 25 is for turning on or off the rotation of the motor 15 and is provided in the motor housing 2.

[0016] From the vicinity of the center to the rear side of the motor housing 2, the motor 15 and the control circuit section 20 for controlling the rotation of the motor 15 are housed, and the speed adjusting dial 2 3 Is provided. The speed adjustment dial 23 is a mechanism for setting the target rotation speed of the motor 15 and is operated by the operator. The control circuit unit 20 has a microcomputer (not shown), a power supply circuit, a semiconductor switching element 22 and the like mounted on a circuit board 21. The semiconductor switching element 2 2 includes six M6 (field effect transistor) and M6 (insulated gate bipolar transistor), and forms an inverter circuit that supplies a drive current to the motor 15. The microcomputer (not shown) can use a commercially available one-chip microcomputer equipped with a calculation unit, a storage unit, an input port, an output port, etc., and the motor 15 Rotation control. 〇 2020/175009 6 卩(：171? 2020/003665

[0017] A rail portion (not visible in the figure) is formed in the battery pack mounting portion 6, and the battery pack 90 is mounted on the device body 10 by engaging with the rail groove portion of the battery pack 90. .. The mounting direction of the battery pack 90 intersects with the rotation axis 81 of the motor 15 and the mounting direction in this embodiment is from top to bottom. The battery pack 90 has a plurality of battery cells (not shown) housed in cases 9 1 and 9 2 made of synthetic resin. The battery cell is a secondary battery that can be repeatedly charged and discharged, and a known battery such as a lithium ion battery cell can be used. The upper case 91 is provided with a rail groove (not shown) for fitting with the rail portion on the battery pack mounting portion 6 side. When the battery pack 90 is attached to the battery pack mounting part 6, the main body side terminals 13 are fitted with the battery side terminals 94, so that the power of the battery pack 90 can not be supplied to the control circuit section 20. It will be possible. The main unit side terminal 13 is connected to the circuit board 21 by an electric cable 28 and a signal cable.

[0018] When removing the battery pack 90 from the battery pack mounting portion 6, the battery pack 90 is moved upward while pressing the latch buttons 93 provided on the left and right sides. On the front side of the battery pack mounting part 6,

An operation panel 24 having four lighting switches is provided.

[0019] On the front side of the rotary shaft 18 of the motor 15 are provided a spindle 36 that is a rotary shaft rotated by the motor 15 and a power transmission mechanism 35 that is driven by the rotational force of the spindle 36. .. The spindle 36 has a cooling fan 27 made of synthetic resin. The cooling fan 27 rotates in synchronization with the rotation of the motor 15 so that the intake port 9 ₃ of the motor housing 2 (see Fig. 2) After sucking the outside air from the air and cooling the heat generating parts such as the control circuit portion 20 and the motor 15, the air is exhausted to the outside from the exhaust port 9 13 formed near the outer periphery of the cooling fan 27.

The power transmission mechanism 35 is a cylindrical member that rotates eccentrically (the bearing 4 described in detail in FIGS. 3 and 4).

5) and a reciprocating motion conversion unit (swing arm 40) that converts eccentric rotation into motion in the reciprocating direction by contacting the cylindrical member. The power transmission mechanism 35 is arranged so that the output shaft 50 is centered on the axis 1 by the rotational force of the rotary shaft 18. 〇 2020/175009 7 卩(: 171-1?2020/003665

It is a mechanism that converts the force into a swinging motion in the circumferential direction within a range of a constant angle. The swing arm 40 is fixed to the output shaft 50 to which the accessory tool 80 is attached, and by swinging the swing arm 40, the output shaft 50 swings about the axial line 1. Become.

A cover 3 is attached to the opening on the front side of the motor housing 2. cover

A holder 29 made of synthetic resin is provided in the inside of 3, and supports a cylindrical output shaft 50 rotatably around an axial shaft 1. Further, a power transmission mechanism 35 is provided in the space inside the holder 29. The holder 29 fixes a bearing 34 for holding the spindle 36 through a cylindrical sleeve 33. The inside of the holder 29 and the periphery of the power transmission mechanism 35 are filled with a sufficient amount of grease to reduce the friction of the rotating portion and the sliding portion. The output shaft 50 extends in a direction orthogonal to the direction of the rotation axis of the spindle 36 (direction of the axis 81) and extends downward from the lower through hole 293 of the holder 29. A tip tool 80 is attached to the lower side of the output shaft 50 by a mounting bolt 58 that is a fixing member.

[0022] The motor housing 2 and the cover 3 are molded products of synthetic resin, and are formed so that they can be divided into left and right parts. On the left side of the motor housing 2 and cover 3, screw bosses 7 ₃ to 7 1< (7 3, 7 0, 7 are not visible in the figure) are formed, and on the right side there are screw bosses (in the figure, screw bosses). (Not visible) are formed correspondingly, and they are fixed with multiple screws (only screws 80 and 8 are shown in the figure). The front side surface of the cover 3 is provided with an illuminator 14 by !_0, which illuminates the vicinity of the work area by the tip tool 80.

[0023] Fig. 2 is a top view of the working machine 1 according to the embodiment of the present invention. The motor housing 2 has a cylindrical shape, and an area from the switch lever 2 63 to the speed adjusting dial 23 is a gripping portion 5 (see FIG. 1 for reference) for the operator to manually grip. An inlet 9 3 and an outlet 9 13 for cooling air are provided near the front end of the motor housing 2 and on both left and right sides of the cooling fan 27. On the front side of the motor housing 2, a cover 3 that houses the output shaft 50 (see Fig. 1) and the power transmission mechanism 35 (see Fig. 1) is connected. Tip tool 80 protrudes more forward than cover 3. 〇 2020/175009 8 (:171? 2020/003665), which is a blade that is substantially rectangular in a top view in the example of Fig. 2. A battery pack 90 is mounted on the rear side of the motor housing 2. Although the working machine 1 of the present embodiment uses the battery pack 90 as a power source, it is a cord-type work that is operated by a commercial AC power source by connecting a power cable (not shown) to the rear side of the motor housing 2. The present invention can be similarly applied to a machine.

[0024] Fig. 3 is an enlarged vertical sectional view of a portion in front of the motor 15 of the working machine 1 of Fig. 1. A fitting hole 36 is formed on one end side (rear end side) of the spindle 36, and the rotary shaft 18 of the motor 15 is press-fitted into the fitting hole 36. On the other end side (front end side) of the spindle 36, a bearing 45 mounted eccentrically with respect to the axis 1 is provided, and the rotational force of the spindle 36 is transmitted to the swing arm 40 via the bearing 45. To be done. The bearing 45 is a ball bearing and is called a bearing for convenience, but it does not support the spindle 36. The part of the spindle 36 that is provided with the bearing 45 is an eccentric shaft (small diameter part 360 described in detail in Fig. 4), and the rotation of the spindle 36 causes the bearing 45 to rotate. Revolve around. An eccentric cylindrical surface 37 coaxial with the eccentric shaft 3 is formed in the rear portion of the eccentric shaft 3, and a balance weight 39 is mounted on the eccentric cylindrical surface 37. The balance weight 39 is to balance the rotation by placing a weight for decentering the center of gravity position deviated from the rotation axis 1 in one direction by the eccentric shaft in the opposite direction. The swing arm 40 is fixed to the outer peripheral surface of the output shaft 50 and rotates together with the output shaft 50 around the axial line 1. The swing arm 40 has two arms 4 2 3 4 2 b (see Fig. 4 for reference numbers) that extend radially outward from the outer peripheral portion of the output shaft 50, and the outer ring of the bearing 4 5 is formed. Contact with.

[0025] about the output shaft 5 0 Jikusenmi 1, a rotary member which is held in the circumferential direction so as to be rotatable, the bearing 5 5 and the secondary ^_ dollar ball ^_ le formula (ball ^_ bearings) It is rotatably supported on the holder 2 9 by the bearing 5 6 of the formula (21 dollar bearing). The output shaft 5 0 includes a hollow cylindrical portion 5 1 having a large diameter portion 5 13 and a small diameter portion 5 1 and a support shaft 5 5 that closes the upper opening of the cylindrical portion 5 1 and is rotatably supported by a bearing 5 5. Comprised of seven. The large diameter part 5 1 3 and the small diameter part 5 1 of the cylindrical part 5 1 are connected to the output shaft line 1. 〇 2020/175009 9 卩(：171? 2020/003665

The inner space of the large-diameter portion 5 13 is larger than the inner space of the small-diameter portion 5 1 3 and is arranged side by side. The small-diameter portion 51 is projected below the through hole portion 29 3 of the holder 29 and is exposed to the outside of the cover 3. The support shaft 57 has a cylindrical shape with two different diameters. The small diameter part of the support shaft 57 is rotatably supported by the holder 29 via the bearing 55, and the large diameter part is formed on the outer peripheral side. The formed male screw portion is screwed with the female screw portion formed on the inner peripheral side of the large diameter portion 5 13. The support shaft 57 is arranged concentrically with the output shaft 50, and the output shaft 50 and the support shaft 57 rotate integrally. The output shaft 50 and the support shaft 57 are pivotally supported by the holder 29 so as not to move substantially in the direction along the output shaft line 1. A holder 2 9 is provided with a needle bearing 5 6 so as to come into contact with the outer periphery of the large diameter portion 5 13 of the cylindrical portion 5 1. The lower part of the holder 29 is sealed with a seal member 6 6 so that the grease filled in the holder 29 does not leak outside.

A first shaft 52 is provided in the support shaft 57. A part of the first shaft 52 is arranged inside the cylindrical portion 51. A female screw hole is formed in the lower shaft center of the first shaft 52, and a male screw portion at the upper end of the second shaft 53 is screwed into the female screw hole. The second shaft 53 is located inside the cylindrical part 51, and by forming a female screw part at the lower end, the mounting bolt 58 for fixing the accessory tool 80 is screwed. belongs to. An outward flange 5 23 is provided at a position of the first shaft 5 2 which is located in the large diameter portion 5 13 3. A step is formed between the cylindrical portion 5 1 and the small diameter portion 51, and a spring 5 4 is provided between the step and the first shaft 5 2. The spring 54 is a compression coil panel made of metal, and urges the first shaft 52 and the cylindrical portion 51 away from each other along the direction of the output axis 1. The first shaft 52 is pushed upward by the force of the spring 54, and the upper end portion penetrates the through hole in the center of the support shaft 57. The outer peripheral surface of the upper small diameter portion of the first shaft 52 is slidable in the axial direction with respect to the inner peripheral surface of the support shaft 57.

[0027] The second shaft 5 3 is arranged in the small diameter portion 5 1 of the cylindrical portion 5 1. The first shaft 5 2 and the second shaft 5 3 can move integrally in the direction along the output axis line 1. A tool supporting portion 59 is provided at the lower end of the small diameter portion 51. D 〇 2020/175009 10 boxes (：171? 2020 /003665

A shaft hole is provided in the center of the tool support 59, and the mounting bolt is inserted through the shaft hole.

5 8 are stolen. Mounting bolt 5 8 is a detachable second shaft 3, the upper part is hexagonal head 5 8 spoon and the shaft portion 5 8 ₃ male threaded portion is formed is made form. From both sides in the direction along the output shaft line 1, the mounting bolt 5 8 and the tool support 5 9 cooperate to fix the tip tool 8 0 by sandwiching it.

A clamp member 63 is provided on the small diameter portion 51 of the cylindrical portion 51. Two clamp members 6 3 are provided, and the clamp member 6 3 is movable in the radial direction of the axial shaft 1 along the radial through hole formed in the small diameter portion 51. The mounting bolt 5 8 can be removed from the second shaft 5 3 by switching between the unlocked state and the unlocked state. The guide member 62 is movable to a first rotational position in which the clamp member 63 is in a locked state and a second rotational position in which the clamp member 63 is unlocked. The guide cover 60 is a cylindrical cover provided outside the guide member 62.

[0029] Fig. 4 is a view of the power transmission mechanism 35 of the working machine 1 of the present embodiment, where () is a perspective view of the assembled state and (M) is a perspective view of the deployed state. .. The power transmission mechanism 35 is connected to the rotary shaft 18 of the motor 15 and includes a spindle 36 that rotates integrally with the rotary shaft 18, a swing arm 40, and a spindle 3 6 to a swing arm 4 5. It consists of ball bearing type bearings 45 that connect 0.

The power transmission mechanism 35 is composed of an “eccentric rotating part” and an “reciprocating motion converting part” that rotate eccentrically. The eccentric rotating part is a rotating part that is eccentrically rotated by the rotation of the rotating shaft. In the present embodiment, the spindle 36 is provided with the eccentric shaft 360 that constitutes a part of the rotating portion. In other words, the spindle 3 6

Performs both functions of 60. The spindle 36 is manufactured by carving metal and has a large diameter for forming a fitting hole 36 for press-fitting the rotating shaft 18 of the motor 15 from the rear side close to the motor 15. A portion 3 63, a medium diameter portion 3 6 which is rotatably supported by a ball type bearing 4 5 on the outer peripheral side, and a small diameter portion 3 6 0 are formed. Here, the small diameter portion 360 is formed in a cylindrical shape, but the center of the small diameter portion 360 is 〇 2020/175009 1 1 卩(：171? 2020/003665

The shaft is formed so as to be eccentric with respect to the central axis (axis 1) of the large diameter portion 363 and the medium diameter portion 36. The rotating shaft 18 of the motor 15 is pressed into the fitting hole 36. The large diameter part 3 63 is formed with a through hole 3 6 9 that penetrates in the radial direction for air bleeding, and the rotary shaft 18 is press-fitted into the fitting hole 3 6 so that the rotary shaft 1 8 And spindle 36 are fixed so as not to rotate relative to each other.

[0031] The eccentric rotating portion is composed of a small diameter portion 360 that is an eccentric shaft, a bearing 45, and its accessories. Here, the bearing 45 forms an annular member that rotates together with the eccentric shaft (small diameter portion 360). The bearing 45 is a ball bearing, and the shape of the outer peripheral surface is formed to be slightly curved in a barrel shape. The bearing 45 is not press-fitted into the small-diameter portion 360, but is just inserted and slidable in the axial direction. A spring 4 6 is provided on the rear side of the bearing 4 5. The spring 46 is a compression coil panel, the rear end of which is in contact with the inner ring of the bearing 45, and the washer 47 is interposed at the front end of the spring. It is fixed so that it does not fall out. A circumferential groove 36 ㊀ that is continuous in the circumferential direction for mounting the O-ring 48 is formed near the end of the small diameter portion 360. Bearings 4 5 are. It has an inner ring and an outer ring, and has multiple rolling elements between them, but it does not rotate continuously in a large amount, but the outer ring slightly swings due to eccentric motion. As described above, since the center line of the eccentric shaft 360 is located eccentric from the axis 1, the rotation of the spindle 36 causes the bearing 45 to revolve around the axis 81.

Swing arm 40 that contacts the swamp will reciprocate. The rotating part may be composed of an eccentric shaft 360 (or an eccentric cam) and a bearing 45 as in this embodiment, or may be composed of an eccentric shaft 360 and an annular metal (not shown). Alternatively, it may be configured with eccentric shaft 360 and 2-dol bearing.

[0032] The swing arm 40 is fixed to the output shaft 50, and the swing motion of the swing arm 40 centering on the output shaft line 1 causes the swing motion in the circumferential direction around the output shaft line 1 of the output shaft 50. Converted to reciprocating motion. The swing arm 40 is formed by integrally forming a cylindrical portion 41 and arm portions 4 2 3 and 4 2 each having a V-shape when viewed in the axial direction. 〇 2020/175009 12 卩(：171? 2020/003665

, Can be made of metal. Arm part 4 2

A flat surface 4 3 3, 4 3 is formed in a portion of the 4 2 bearing that comes into contact with the bearing 4 5. The flat surfaces 4 3 3 and 4 3 have been subjected to heat treatment such as carburizing in order to prevent wear. When the power transmission mechanism 35 is assembled as described above, almost all of the urging member is located inside the II-shaped arms 4 2 3 and 4 2 when viewed in the axial direction, so it has been conventionally used. The space that was not there can be effectively utilized. Therefore, this embodiment can be realized with substantially the same size without increasing the size of the conventional power transmission mechanism.

Here, in order to understand the power transmission mechanism 35 of the present embodiment, the power transmission mechanism of the conventional example will be described.

1 3 5 will be described with reference to FIGS. 8 to 10. FIG. 8 (8) is a partial vertical cross-sectional view of the front part of the conventional working machine 101, and (M) is a partial horizontal cross-sectional view. What is different from the working machine 1 of the present embodiment is the shape of the spindle 1 3 6 and the holding structure of the bearing 4 5. Here, the spindle 1 3 6 is not provided with a biasing member (spring 4 6 in FIG. 4). Other configurations, particularly the shape of the holder 29, the output shaft 50, and the swing arm 40 are the same as in this embodiment, and the same parts are used.

[0034] Fig. 9 shows a power transmission mechanism 1335 of the conventional working machine 101, where (8) is a top view and (M) is a side view (partial cross-sectional view). As for the shape of the spindle 1336, the axial length of the eccentric shaft 1360 forming a part of the eccentric rotating portion is only shorter than that of the spindle 36 shown in FIG. And, the bearing 45 is not provided with a spring for urging in the axial direction. The swing arm 40 is the same part as in this embodiment. The spindle 1 3 6 is manufactured by carving metal, and has a large diameter for forming a fitting hole 1 3 6 for press-fitting the rotary shaft 18 of the motor 15 from the rear side close to the motor 15. Section 1 3 6 3 and the central diameter section 1 3 6 6 of the large diameter section 1 3 6 3 and the medium diameter section 1 3 6 which are supported by ball type bearings 4 5 on the outer peripheral side. Medium-diameter part with a small-diameter part 1 360 that is formed so as to be eccentric to the axis 1) 1 3 6 A dent continuous in the circumferential direction near the connection with the large-diameter part 1 3 6 3 The 3 6 d is formed to facilitate the cutting process. The small diameter part 1 3 6 0 has only the axial length necessary and sufficient to fix the bearing 4 5 and the circumferential groove 1 3 6 6 is formed near the end to mount the ring 4 8 To be done. bearing 〇 2020/175009 13 卩(：171? 2020/003665

The inner ring 453 of 4 5 is held by the step portion of the medium diameter portion 1336 and the small diameter portion 1360 and the ring 448 so as to be substantially immovable in the axial direction. Therefore, the bearings 45 are press-fitted or attached to the small-diameter portion 136 in a form close to press-fitting. Thus, the conventional power transmission mechanism 1 3 5 has a certain amount of gap 1 4 3 between the small diameter portion 1 3 6 0 and the cylindrical portion 4 1 of the swing arm 4 0. 4 3 is dead space.

[0035] Fig. 10 is a top view for explaining a load applied to the power transmission mechanism 1 3 5 of the conventional working machine 1 0 1. In Fig. 10 (eight), the rotating spindle 1 3 6 reciprocates the bearing 45 in the left-right direction when viewed from the top, moving slightly to the right from the left end position, and the right side of the bearing 45 is a flat surface 43. It shows the state at the moment when you start pressing the swamp. That is, Fig. 10 (eight) shows the moment when the bearing 4 5 that has moved to the right begins to press the flat surface 43 that has been moving to the left (clockwise in the figure). Since the outer peripheral shape of the bearing 45 is curved in a sectional view as can be seen from the figure, the contact position between the bearing 45 and the flat surface 433 changes depending on the swing position of the swing arm 40. In the case of Fig. 10 (eight), the bearing 45 and the flat surface 43 contact with each other slightly behind the center position of the bearing 45. As a result, the normal direction of the outer circumference of the bearing 45 that contacts the flat surface 4 3 crosses the reciprocating direction of the swing arm 40 (left-right direction). The pressing force (load) on 4 3 10 is in two directions, and the reaction force received by bearings 45 is in one direction. Load 2 is a large load during one rotation of bearing 4 5 because it is a load when the movement direction of the parts is reversed so that the member moving to the left moves to the right. .. The component force of 2 is the radial component force in the direction orthogonal to the axis 8 1 as shown in the figure.

And the thrust component force 32 in the direction parallel to the axis 8 1. (The tilt angle of 1 is shown larger in the figure for easier understanding). The load of 1 which is the reaction force of 2 is also large, and the component of 1 is the radial component 81 in the direction directly intersecting with the axis 81 and the thrust component 3 in the direction parallel to the axis 8 as shown in the figure. 1

[0036] In Fig. 10 (Mimi), the bearing 45 moves slightly to the left from the right end position, and the bearing 4 〇 2020/175009 14 卩(：171? 2020/003665

The left part of 5 represents the state at the moment when the flat surface 4 3 3 is pressed. In other words, Fig. 10 (M) is the moment when the bearing 4 5 that moved to the left started pressing the flat surface 4 3 3 that was moving to the right (counterclockwise in the figure). Represents. The load applied to the bearing 45 at that time is 1 as in Fig. 10 (eight), and the component force is component force 81 and component force 31. Here, as can be seen by comparing (8) and (M), the component forces 1 and 2 in the radial direction change depending on the swinging direction of the swing arm 40, but the component forces 3 1 and 3 2 There is no change in direction. Therefore, the component force 31 is intermittently applied to the bearing 45 on the right side and the left side of the axis 01, and a force that moves the bearing 45 forward is intermittently applied. The component force 31 is a reaction force of the component force 32 that does not function as a force for operating the accessory tool 80, and is transmitted to the bearing 45 as an extra load, so it needs to be reduced. Against such a phenomenon, in order to absorb the component force 31 of the load received by the bearing 45, the bearing 45 can be moved in the direction of 3 1 (sliding), and the elastic member is used. The present invention is elastically held.

Next, the power transmission mechanism 35 of this embodiment will be described with reference to FIG. FIG. 5 () is a top view of the dynamic force transmission mechanism 35, and (M) is a side view thereof. Spindle 36 has a large diameter

A medium diameter part 36 and a small diameter part (eccentric shaft) 360 are formed. Here, the shapes of the large-diameter portion 363 and the medium-diameter portion 36 are exactly the same as those of the conventional spindle 1336 shown in FIG. On the other hand, the small-diameter portion 360 has the same diameter, but is extended to the front side in the axis 1 direction with respect to the conventional small-diameter portion 1360 (see Fig. 9). Then, a compression coil type spring 46 was arranged in the extended portion. The spring 4 6 is arranged coaxially with the small diameter portion 1 3 6 0, the rear side abuts on the annular side wall on the front side of the inner ring 4 5 3 of the bearing 4 5, and the front side is a metal washer 4 7 Abut. In front of the washer 4 7, a ring 4 8 is mounted in the circumferential groove 36 ㊀ to prevent the washer 4 7 from moving forward in the axial direction. The bearing 45 is a well-known ball bearing in which a plurality of steel balls 45 are arranged between the inner ring 453 and the outer ring 450, and the entire bearing 45 is the arrow 3 shown in Fig. 3. It can move in the axial direction like 1. As described above, conventional spin 〇 2020/175009 15 卩(：171? 2020/003665

The bearing 4 5 can be moved in the direction of the axis 8 1 (direction of the arrow 3 1) simply by extending the small diameter portion 1 3 6 0 of the handle 1 3 6 and adding the spring 4 6 and the washer 4 7. I was able to configure. The outer diameter of the small diameter part 360 is slightly smaller than that of the conventional spindle 1 3 6 and the bearing 4 5 is a loose fit from the conventional press fit. To change it. By holding the bearings 45 movably in the axial direction in this way, the periodic reaction force in the direction parallel to the axis 8 1 generated when the swing arm 40 swings in the circumferential direction around the axis No. 1 is generated. Since the change can be effectively absorbed by the spring 46, the locally applied force of the bearing 45 can be reduced. Further, since the reaction force received by the bearing 45 is reduced, the vibration transmitted to the motor 15 and the motor housing 2 side via the spindle 36, which is the rotating shaft, can be reduced.

[0038] The swing arm 40 is a cylindrical portion 41 fixed to the cylindrical portion 51 of the output shaft 50, and an arm portion 423, 4 which is an II-shaped arm portion for contacting the bearing 45. Configured with 2. The amount of movement of the swing arm 40 reciprocating in the circumferential direction is about ±5 degrees in terms of the rotation angle from the reference position with the axial line 1 as the center point. However, the swing angle may be set in the range of several degrees to several tens of degrees. Cylindrical part 4 1

The container 42 is a metal integrated product, and the inner peripheral surface 4 4 of the cylindrical portion 4 1 contacts the outer peripheral surface of the cylindrical portion 5 1 of the output shaft 50. The arm portions 4 2 ₃ , 4 2 of the swing arm 40 are arranged at an interval equal to the outer diameter of the outer ring of the bearing 4 5, and a flat flat surface 4 3 3, 4 3 is provided at the portion contacting the bearing 4 5. A pit is formed. Flat surface 4

The surfaces of 3 3 and 4 3 1 0 should be anodized to give a high hardness surface that does not easily wear, and to give surface characteristics such as slipperiness. bearing

The outer ring 450 of 45 is curved in an arc shape in a cross section including the axis <31, and the contact area with the flat surfaces 43 3, 43 is reduced to reduce the resistance. In this way, the outer ring 405 of the bearing 45 is held by being sandwiched between the pair of arm portions 423 and 4213.

With this configuration, in the present embodiment, the eccentric rotating cylindrical member (bearing 45) is connected to the reciprocating motion converting section (swing arm 40) which is in contact with the axis line 8 1. 〇 2020/175009 16 卩(：171? 2020/003665

Since it is configured to be relatively movable in the direction, it is possible to suppress the reaction force transmission when the swing arm 40 is reciprocatingly driven, and it is possible to significantly reduce the vibration transmitted from the reciprocating motion converting unit to the rotating shaft side through the rotating unit. Particularly, in the present embodiment, it is possible to suppress the occurrence of vibration in a direction different from the reciprocating direction of the tip tool. The annular member (bearing 45) is urged toward the motor 15 by an axial urging means such as a spring 46, and the annular member (bearing 45) and reciprocating motion converting section (swing arm 40). Since the contact condition of is maintained well, the axial load generated when the contact member collides with the reciprocating motion converting portion can be effectively damped. Therefore, it is possible to effectively suppress the transmission of the axial vibration to the worker.

Example 2

[0040] Fig. 6 is an enlarged vertical cross-sectional view of the front portion of the working machine 1 according to the second embodiment of the present invention. In the second embodiment, the shape of the spindle 76 is changed so that the small diameter portion 760 of the spindle 7 6 serving as an eccentric shaft is further lengthened in the axial direction, and the spring is applied from both sides in the axial direction. The bearing 4 5 is configured to be held by 4 6 and 8 6. Therefore, the length of the cover 73 in the direction of the axis 81 is slightly longer than that of the cover 3 of the first embodiment, and the space for accommodating the power transmission mechanism 75 is widened. The swing arm 40 is the same part as the first embodiment, and the structure around the output shaft 50 is also the same.

[0041] Fig. 7 is a diagram of the power transmission mechanism 75 of the second embodiment, (8) is a top view,

B) is a side view (partially sectional view). The bearing 45 mounted on the eccentric shaft (thin diameter part 760) has the same ball bearing as that of the first embodiment, but it is also possible to use a needle bearing or a cylindrical metal. .. Also, without providing an eccentric shaft (thin diameter part 760), an annular member is attached directly to the middle diameter part 7 6 so that the center position is displaced from the axis 81, and the cam-shaped rotating part has an axis part. It may be configured to rotate about 1. One end of the spring 4 6 (rear) abuts the front side of the inner ring 4 5 ₃ of the bearing 4 5, the other end (front end) of you abuts the washer 4 7. The washer 4 7 is held on the spindle 7 6 by a ring 4 8 fitted in the circumferential groove 7 6 6. The spring 8 6 located behind the bearing 4 5 〇 2020/175009 17 卩(：171? 2020/003665

By using the same coil panel as the spring 46, the biasing force is made the same. The rear end of the spring 8 6 abuts on the rear side surface of the inner ring 4 53 of the bearing 45, and the other end (front end) is a step between the small diameter portion 7 60 and the middle diameter portion 7 6 via the washer 87 Abut the part. The outer surface 4 5 of the outer ring 4 50 of the bearing 4 5 is the flat surface 4 3 3 of the arm part 4 2 3, 4 2 of the swing arm 40 formed in the II shape.

4 3 Abut on the swamp. The spindle 76 is axially longer than the spindle 36 of the first embodiment shown in FIG. 5 by an area for accommodating the spring 86.

[0042] According to the second embodiment, the bearing 4 5 can move not only to the front side in the axial direction but also to the rear side through elastic force according to the load received from the swing arm 40. Both front and rear loads can be suitably damped. Further, the followability of the bearing 45 is further improved, and the contact condition between the bearing 45 and the flat surfaces 4 3 3 and 4 3 is greatly improved, so that the occurrence of vibration can be greatly suppressed. Therefore, according to the second embodiment, the vibration of the grip portion 5 (see FIG. 1) can be suppressed.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-mentioned embodiment, the bearing 45 is used and the rotating part is formed by the combination of the ball bearing and the spring, but the spring that is the biasing member is a spring made of rubber or another elastic body such as a ring. It may be configured to replace with. Further, in the above-described embodiment, the annular member (bearing 45), which is a part of the rotating portion, is slidably attached to the spindle 76, so that the annular member reciprocates (swing arm 40). ), but the entire spindle 7 6 fixed so that the annular member cannot move in the axial direction can move relative to the reciprocating motion converting section (swing arm 40). In other words, the assembly of the spindle 76 and the annular member can be moved in the axial direction so that the annular member can move relative to the reciprocating motion converting portion.

Explanation of symbols

[0044] 1 working machine, 18 working machines, 2 motor housings, 3 covers, 5 grips 〇 2020/175009 18 units (: 171? 2020/003665 parts, 6 battery pack mounting part, 7 ₃ ~ 7 1< screw boss, 8 〇, 8 ~ screw, 9 8 intake port, 9 13 exhaust port, 1 〇 Device , 1 3 Main unit side terminal, 1 4 Lighting device, 1 5 motor, 1 6 ports, 1 7 stator, 1 8 rotating shaft, 2 0 control circuit section, 2 1 circuit board, 2 2 semiconductor switching element, 2 3 Speed adjustment dial, 2 4 Operation panel, 2 5 switch, 2 6 3 switch lever, 2 6 !○ slide arm, 2 7 cooling fan, 2 8 electric cable, 2 9 holder, 2 9 8 through hole, 3 1 axis direction, 3 2 bearing, 3 3 sleeve, 3 4 bearing, 3 5 power transmission mechanism, 3 6 spindle, 3 6 3 large diameter part, 3 6 6 medium diameter part, 3 0 6 small diameter part (eccentric shaft) ), 3 6 fitting hole, 3 6 circumferential groove, 3 6 indentations NOTE 3 6 ₉ - (radially) through hole 3 7 eccentric cylindrical surface 3 9 balance-wait, 4 0 swingarm 4 1 cylinder Section, 4 2 ○, 4 2 13 Arm section, 4 3 4 3 3 Flat surface, 4 4 Inner peripheral surface, 4 5 bearing, 4 5 3 Inner ring, 4 5 concealed steel ball, 4 5 ○ Outer ring, 4 5 ¢1 Outer peripheral surface, 4 6 spring (first coil panel), 4 7 washer, 4 8 0 ring, 5 0 output shaft, 5 1 (output shaft) cylindrical part, 5 1 3 large diameter part, 5 1 cup Small diameter part, 5 2 1st shaft, 5 2 3 outward flange, 5 3 2nd shaft, 5 4 spring, 5 5 bearing (ball bearing), 5 6 bearing (needle bearing), 5 7 support shaft, 5 8 Mounting bolt, 5 8 3 Shaft part,

5 8 Head, 5 9 Tool support, 60 Guide cover, 6 2 Guide member, 6 3 Clamp member, 6 6 Seal member, 7 3 Cover, 7 5 Power transmission mechanism, 7 6 Spindle, 7 6 3 Large diameter part, 7 6 sq. medium diameter part, 7 6 0 small diameter part (eccentric shaft), 7 6 fitting hole, 7 6 6 circumferential groove, 7 6 recess, 7 6 ₉ (radial direction) through hole, 7 7 Eccentric cylindrical surface, 7 9 holder, 80 tip tool,

8 6 spring (second coil panel), 8 7 washer, 90 battery pack, 9 1 upper case, 9 2 lower case, 9 3 latch button, 9 4 battery side terminal, 1 0 1 working machine, 1 3 5 Power transmission mechanism, 1 3 6 spindle, 1 3

6 3 Large diameter part, 1 3 6 匕 Medium diameter part, 1 3 6 ○ Thin diameter part (eccentric shaft), 1 3 6 Fitting hole, 1 3 6 6 Circumferential groove, 1 3 6 Dimple, 1 3 6 9 ··· (radial direction) \\0 2020/175009 19 hole (: 17 2020 /003665 through hole, 1 3 7 eccentric cylindrical surface, 1 4 3 gap, 1 (rotation) axis, 虳 1 (output) axis, 〇 1 (eccentricity) axis

Claims

\¥0 2020/175009 20 units (: 17 2020 /003665 Claims

[Claim 1] A power source, a rotating unit that is eccentrically rotated by the power source, and a reciprocating motion converting unit that engages with the rotating unit and converts the motion into a reciprocating direction. Is relatively movable with respect to the reciprocating motion converting portion in a direction intersecting the reciprocating direction,

A working machine comprising an urging member for applying an urging force in a direction of relative movement of the rotating portion.

2. The work machine according to claim 1, further comprising a rotating shaft that is rotated by the power source, and the rotating portion is provided on the rotating shaft.

3. The work machine according to claim 2, wherein the rotating portion is movable in the axial direction of the rotating shaft.

4. The work machine according to claim 3, wherein the biasing member is an elastic body that applies a biasing force in the relative movement direction, and the elastic body is held by the rotation shaft.

[Claim 5] An eccentric shaft is formed on the rotating shaft,

The rotating portion includes an annular member slidably attached to the eccentric shaft in the axial direction,

5. The work machine according to claim 3, wherein the eccentric shaft is provided with a fixing member that fixes the urging member to the eccentric shaft.

6. The urging member is a coil panel provided coaxially with the eccentric shaft, and applies an urging force in an axial direction intersecting the reciprocating direction to the rotating portion. Working machine.

[Claim 7] The coil panel is provided in two on both sides in the axial direction with respect to the annular member, and the first coil spring urges the annular member toward one side in the axial direction. 7. The working machine according to claim 6, wherein the coil panel of FIG. 6 urges the annular member toward the other side in the axial direction.

[Claim 8] A housing for accommodating the power source, and a cylindrical grip portion provided in the housing, in which an operating portion for turning the power source on and off is arranged. 〇 2020/175009 21 卩(：171? 2020/003665

The working machine according to any one of claims 5 to 7, wherein an axial direction of the grip portion is substantially parallel to a moving direction of the annular member.

[Claim 9] The work machine has an output shaft having an axis in a direction intersecting with a rotation direction of the power source,

A cylindrical part is formed in the reciprocating motion converting part and is fixed to the output shaft, and has a II-shaped arm part that extends in the radial direction from the cylindrical part and comes into contact with the rotating part.

9. The working machine according to claim 8, wherein the reciprocating motion converting unit reciprocates the output shaft in a circumferential direction by a predetermined angle.

10. The work machine according to claim 9, wherein at least a part of the urging member is arranged so as to be located inside the arm portion having a L-shape.