Work machine

Abstract

To contribute to miniaturization or improvement of durability.SOLUTION: In an eccentric portion 50 of a multi-tool 10, an outer peripheral surface of the eccentric portion 50 is constituted by a pair of extension outer peripheral surfaces 54D, front and rear, and a power transmission surface 54C. In a vertical cross-section of the eccentric portion 50, the extension outer peripheral surfaces 54D extend in frontward and rearward directions, and the power transmission surface 54C protrudes outward in a radial direction of the eccentric portion 50 from the extension outer peripheral surfaces 54D and is formed in an arc shape protruding outward in the radial direction of the eccentric portion 50. Accordingly, the power transmission from the eccentric portion 50 to a swing arm 60 can be smoothly performed by the arc-shaped power transmission surface 54C. Further, the outer peripheral surface of the eccentric portion 50 is constituted by the extension outer peripheral surface 54C in addition to the power transmission surface 54D; therefore, in a connecting piece 54, an extension portion 54B extends from a power transmission portion 54A to both sides in the frontward and rearward directions to reinforce the power transmission portion 54A. Accordingly, the durability of the eccentric portion 50 can be improved.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a working machine.

Background Art

[0002] In the working machine of Patent Document 1 below, an eccentric shaft eccentrically rotates about an axis extending in the front-rear direction. A bearing is assembled to the eccentric shaft, and an arm portion of a swing arm is adjacently disposed on the outer side in the left-right direction of the bearing. The swing arm is integrally rotatably connected to the output shaft. Thus, when the bearing eccentrically rotates together with the eccentric shaft, the swing arm swings around the axis of the output shaft, and a tip tool attached to the output shaft portion swings to perform cutting work or the like on a workpiece. Here, in the power transmission from the bearing to the swing arm, a relatively large load acts on the bearing.

[0003] Further, in the working machine described in Patent Document 2, a needle bearing is assembled to the eccentric shaft, and the outer peripheral surface of the outer ring of the needle bearing is formed in a spherical shape. And an engaging portion of the swing arm with the needle bearing is formed as a concave curved surface. Due to this spherical (curved surface) shape, it is possible to suitably cope with the operation of the swinging swing arm. Further, by using needles (needle rollers), it is possible to ensure durability against a radial load as compared with a spherical roller.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, if the outer peripheral surface of the eccentric part is spherical like the working machine of Patent Document 2 described above, there is a problem that the eccentric part becomes large. On the other hand, if the rolling members in the eccentric part are miniaturized, the durability of the eccentric part may decrease. Further, if the entire outer peripheral surface of the eccentric part is spherical, a thin-walled portion is generated at the end of the outer ring (the part outside the roller), and there is a risk of wear, breakage, etc. occurring from here.

[0006] In view of the above facts, an object of the present invention is to provide a working machine that can contribute to miniaturization or can contribute to improving durability.

Means for Solving the Problems

[0007] One or more embodiments of the present invention include a motor, an eccentric part that eccentrically rotates about a predetermined axis extending along a predetermined direction by driving the motor, and an output shaft that is driven by transmitting power from the eccentric part. The output shaft is configured to be capable of swinging about an intersection direction that intersects the predetermined direction. The eccentric part has an eccentric shaft extending in the predetermined direction and an intervening part held by the eccentric shaft. The intervening part has a power transmission part configured as a curved surface and having a power transmission surface for transmitting the power of the motor to the output shaft on the outer periphery, and an extending part connected to the power transmission part in the predetermined direction and extending in the predetermined direction. The intervening part receives the power of the motor from both the power transmission part and the extending part, and is configured to transmit power to the output shaft by the power transmission part.

[0008] One or more embodiments of the present invention are such that the intervening part is formed in a cylindrical shape having the predetermined direction as the axial direction, and a bearing part having a rolling member for supporting the intervening part is provided between the eccentric shaft and the intervening part. At least a part of the bearing part is located between the extending part and the eccentric part in a direction orthogonal to the predetermined direction.

[0009] In one or more embodiments of the present invention, a relay member is provided on the output shaft so as to be integrally rotatable. The relay member includes a main body portion fixed to the output shaft and an arm portion extending from the main body portion to the other side in the predetermined direction. The arm portion has a portion to which power is transmitted from the power transmission surface, and at least a part of the extending portion is provided on one side in the predetermined direction with respect to the portion to which power is transmitted. This is a working machine.

[0010] In one or more embodiments of the present invention, the output shaft reciprocally rotates about its own axis by power being transmitted from the relay member. The arm portion has a relief portion, and the relief portion is disposed spaced apart radially outside the eccentric portion with respect to the extending portion. The portion to which power is transmitted protrudes radially inward of the eccentric portion with respect to the relief portion. This is a working machine.

[0011] In one or more embodiments of the present invention, the power transmission surface is a curved surface that is convex outward in the radial direction. In a longitudinal section including the axis of the eccentric shaft, a part of a virtual circle whose center point is located on the axis of the eccentric portion coincides with the power transmission surface, and at least a part of the extending portion is located outside the virtual circle. This is a working machine.

[0012] In one or more embodiments of the present invention, the power transmission surface is a curved surface that is concave inward in the radial direction. In a longitudinal section including the axis of the eccentric shaft, the extending portion is located closer to the eccentric shaft side than a virtual circle that partially coincides with the power transmission surface. This is a working machine.

[0013] In one or more embodiments of the present invention, a groove portion is formed on the outer peripheral surface of the eccentric portion along the circumferential direction of the eccentric portion, and a lubricant is held in the groove portion. This is a working machine.

[0014] In one or more embodiments of the present invention, the groove portion is disposed adjacent to the power transmission surface in the predetermined direction. This is a working machine.

[0015] One or more embodiments of the present invention are work machines in which the groove portion is provided in the power transmission portion.

[0016] One or more embodiments of the present invention are work machines in which a relay member is integrally rotatably connected to the output shaft, the relay member includes a main body portion fixed to the output shaft and an arm portion extending from the main body portion to the other side in the predetermined direction, the arm portion has a portion to be transmitted with power transmitted from the power transmission portion, and a part of the portion to be transmitted is located radially outside the eccentric portion with respect to the groove portion.

[0017] One or more embodiments of the present invention are work machines in which the bearing portion is a needle bearing and the rolling member is a needle-shaped roller.

Advantages of the Invention

[0018] According to one or more embodiments of the present invention, it is possible to contribute to miniaturization or to contribute to improvement of durability.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Best Mode for Carrying Out the Invention

[0020] Hereinafter, with reference to the drawings, the multi-tool 10 as a working machine according to this embodiment will be described. The arrows UP, FR, and RH appropriately shown in the drawings indicate the upper side, the front side, and the right side of the multi-tool 10, respectively. In the following description, when the up-down, front-back, and left-right directions are used for the description, unless otherwise specified, they indicate the up-down direction, the front-back direction, and the left-right direction of the multi-tool 10.

[0021] As shown in FIG. 1, the multi-tool 10 is a power tool that swings a tip tool T attached to the front end portion in the vertical direction as the axial direction to perform cutting or the like on a workpiece. The multi-tool 10 includes a housing 12, a motor 24, an output shaft 30, and a power transmission mechanism 40.

[0022] (Regarding the housing 12) The housing 12 constitutes the outer contour of the multi-tool 10. The housing 12 is formed as a hollow columnar shape extending in the front-rear direction as a whole. At the upper end of the middle part of the housing 12 in the front-rear direction, a trigger 14 is provided. The trigger 14 is slidably connected to the housing 12 in the front-rear direction and is exposed so as to be operable upward from the housing 12. Inside the housing 12, a trigger switch 16 is provided on the rear side of the trigger 14, and the trigger switch 16 is connected to the trigger 14 by a switch lever 18. The trigger switch 16 is electrically connected to a controller 20, and the controller 20 is housed in the rear end side portion of the housing 12. The trigger 14 is arranged in the off position shown in FIG. 1. When the trigger 14 is slid from the off position to the on position on the front side, the trigger switch 16 switches from off to on, and a motor 24 described later is driven by the controller 20. A battery 22 is mounted on the rear end portion of the housing 12 from above, and the battery 22 is located on the rear side of the housing 12. The battery 22 is electrically connected to the controller 20.

[0023] (Regarding the motor 24) The motor 24 is housed in a motor case 26 provided in the front part of the housing 12 and is held by the motor case 26. The motor 24 has a rotating shaft 24A, and the rotating shaft 24A is arranged with the front-rear direction as the axial direction. That is, the axis line AL1 of the rotating shaft 24A extends along the front-rear direction, and the axis line AL1 corresponds to the predetermined axis line of the present invention. The rear end portion of the rotating shaft 24A is rotatably supported by a motor bearing 28 held by the motor case 26.

[0024] (Regarding the output shaft 30) The output shaft 30 is formed in a substantially stepped cylindrical shape with the vertical direction as the axial direction. Specifically, the diameter of the upper end portion of the output shaft 30 is set smaller than the diameter of other portions. The output shaft 30 is provided inside the front end portion of the housing 12, and the lower end portion of the output shaft 30 protrudes downward from the housing 12. The upper end portion of the output shaft 30 is rotatably supported by a bearing 32, and the lower end side portion of the output shaft 30 is swingably supported by a bearing 34. The bearings 32 and 34 are held by a head case 36 housed inside the housing 12.

[0025] A clamp mechanism 38 for attaching the tip tool T is provided on the output shaft 30. The clamp mechanism 38 includes a clamp shaft 38A, a clamp lever 38B, and a clamp portion 38C. The clamp shaft 38A is arranged inside the output shaft 30 with the vertical direction as the axial direction. The clamp shaft 38A is connected to the output shaft 30 so as to be relatively movable in the vertical direction and integrally rotatable. The clamp lever 38B extends in the front-rear direction, and the front end portion of the clamp lever 38B is rotatably connected to the housing 12 with the left-right direction as the axial direction above the clamp shaft 38A. The clamp portion 38C is provided at the lower end portion of the clamp shaft 38A. When the clamp lever 38B is rotated and the clamp shaft 38A is moved up and down by the clamp lever 38B, the clamp portion 38C is switched between a state of clamping the tip tool T and a state of releasing the clamp on the tip tool T. In a state where the tip tool T is clamped by the clamp portion 38C, the tip tool T protrudes forward from the lower end portion of the output shaft 30. The output shaft 30 is connected to a power transmission mechanism 40 described later, and the power transmission mechanism 40 causes the output shaft 30 to reciprocally rotate within a predetermined rotation angle about its own axis. Thereby, when the multi-tool 10 is in operation, the tip tool T swings in the left-right direction by the clamp shaft 38A, and cutting processing or the like is performed on the workpiece by the tip tool T.

[0026] (Regarding the power transmission mechanism 40) The power transmission mechanism 40 is housed within the housing 12 and is positioned between the motor 24 and the output shaft 30. The power transmission mechanism 40 includes a spindle 42, an eccentric portion 50, and a swing arm 60 as an intermediate member. The spindle 42 is arranged with the front-rear direction as the axial direction and is positioned coaxially with the rotation shaft 24A of the motor 24 on the front side of the rotation shaft 24A. And, the front end portion of the rotation shaft 24A is integrally and rotatably connected to the rear end portion of the spindle 42. The intermediate portion in the front-rear direction of the spindle 42 is rotatably supported by a bearing 44. The bearing 44 is held by a bearing holder 46 housed within the housing 12. As also shown in FIGS. 2 to 4, the front end portion of the spindle 42 is an eccentric shaft 48, and the eccentric shaft 48 is arranged at a position eccentric with respect to the axis AL1 (in FIGS. 1 and 2, the axis AL2 of the eccentric shaft 48 is shown at a position eccentric upward with respect to the axis AL1).

[0027] The eccentric portion 50 has the eccentric shaft 48 of the spindle 42 described above, a needle bearing 52 as a bearing portion, and a connecting piece 54 as an intervening portion. The needle bearing 52 is formed in a substantially cylindrical shape with the front-rear direction as the axial direction, and the eccentric shaft 48 is inserted into the needle bearing 52. The needle bearing 52 has a roller 52A as a rolling member, a retainer 52B that holds the roller 52A, and an outer ring 52C that is rotatably supported by the roller 52A.

[0028] The connecting piece 54 is formed in a substantially cylindrical shape with the front-rear direction as the axial direction. And the needle bearing 52 is fitted into the connecting piece 54, and the needle bearing 52 and the connecting piece 54 are unitized. More specifically, the outer ring 52C is press-fitted into the inner surface of the connecting piece 54, whereby the outer ring 52C and the connecting piece can rotate integrally around the eccentric shaft 48 via the roller 52A. The connecting piece 54 includes a power transmission portion 54A that constitutes the middle portion in the front-rear direction of the connecting piece 54, and an extending portion 54B that constitutes the end portion in the front-rear direction of the connecting piece 54. In the present embodiment, a pair of front and rear extending portions 54B are connected to the power transmission portion 54A and extend in the front-rear direction. The inner peripheral surfaces of the power transmission portion 54A and the extending portion 54B are flush, and the needle bearing 52 is held from the radially outer side by the power transmission portion 54A and the extending portion 54B. Specifically, the length of the needle-shaped roller 52A (rolling member) in the needle bearing 52 is set to be larger than the front-rear length of the power transmission portion 54A, and the power transmission portion 54A and the extending portion 54B are supported from the radially inner side by the roller 52A.

[0029] The outer peripheral surface of the power transmission portion 54A is a power transmission surface 54C. The power transmission surface 54C has a partially spherical (curved surface shape). That is, the power transmission portion 54A is the portion in the range where the power transmission surface 54C is formed in the front-rear direction, and the portion extending in the front-rear direction from there is the extending portion 54B. The power transmission surface 54C has a convex shape that bulges outward in the radial direction (up-down, left-right direction). The power transmission surface 54C protrudes radially outward from the outer peripheral surface of the extending portion 54B. The power transmission surface 54C is curved in an arc shape that protrudes radially outward of the connecting piece 54 in a longitudinal section including the axis AL2 of the eccentric portion 50 (eccentric shaft 48). Specifically, in the longitudinal section of the connecting piece 54, the power transmission surface 54C coincides with a part of a virtual circle CR whose center point is located on the axis AL2 of the eccentric portion 50 (see FIG. 2).

[0030] The outer peripheral surface of the extending portion 54B is an outer peripheral surface 54D of extension (an element grasped as an extending surface in a broad sense). The outer peripheral surface 54D of extension extends linearly in the front-rear direction in the longitudinal section of the connecting piece 54, and extends from the end of the power transmission surface 54C to both sides in the front-rear direction. That is, in the longitudinal section of the connecting piece 54, the outer peripheral surface 54D of extension is located outside the imaginary circle CR. The thickness dimension of the extending portion 54B (the dimension in the radial direction of the connecting piece 54) is set to the minimum dimension that can ensure the mechanical strength of the extending portion 54B during the operation of the multi-tool 10. Note that the outer peripheral surface 54D of the extending portion 54B only needs to have a structure that is not continuous (not connected with the same curvature) with the power transmission surface 54C.

[0031] On the outer peripheral portion of the connecting piece 54 (extending portion 54B), at the boundary between the power transmission surface 54C and the outer peripheral surface 54D of extension, a lubricant supply groove portion 54E as a groove portion is formed. That is, a pair of front-rear lubricant supply groove portions 54E are formed on the outer peripheral portion of the connecting piece 54. The lubricant supply groove portion 54E is open to the outside in the radial direction of the connecting piece 54, extends along the circumferential direction of the connecting piece 54, and is formed over the entire circumference of the connecting piece 54. A lubricant GR (see FIGS. 3 and 4), such as grease, is applied to the lubricant supply groove portion 54E, and the lubricant is held by the lubricant supply groove portion 54E.

[0032] The swing arm 60 includes a fixed cylinder portion 60A as a main body portion and a pair of left and right arm portions 60B. The fixed cylinder portion 60A is formed in a substantially cylindrical shape with the vertical direction as the axial direction. The upper end side portion of the output shaft 30 is fitted into the fixed cylinder portion 60A, and the fixed cylinder portion 60A (swing arm 60) is integrally rotatably connected to the output shaft 30.

[0033] The pair of arm portions 60B extend rearward from the outer peripheral portion of the fixed cylinder portion 60A, and the rear end portion (tip portion) of the arm portion 60B is located outside the left and right sides of the connecting piece 54. An arm connecting portion 60C is provided between the front portions of the pair of arm portions 60B. The arm connecting portion 60C extends rearward from the fixed cylinder portion 60A and connects the proximal end portions of the pair of arm portions 60B to each other. Further, the arm portion 60B and the arm connecting portion 60C are formed in a plate shape with the vertical direction as the thickness direction.

[0034] A transmitted portion 60D is provided at the rear end portion of the arm portion 60B. The transmitted portion 60D protrudes inward in the left and right direction (toward the connecting piece 54 side) from the arm portion 60B and is adjacently disposed outside the left and right sides (radially outside the connecting piece 54) of the power transmission portion 54A of the connecting piece 54. The surface (transmitted surface) of the transmitted portion 60D adjacent to the power transmission portion 54A is formed in a substantially arc shape that opens inward in the left and right direction in a plan view seen from above, corresponding to the power transmission surface 54C, and substantially coincides with a part of the imaginary circle CR. That is, the surface (transmitted surface) of the transmitted portion 60D that is transmitted power from the power transmission portion 54A is a concave curved surface that is concave outward in the radial direction. Thereby, when the eccentric portion 50 eccentrically rotates about the axis AL1 due to the rotation of the spindle 42, the swing arm 60 swings left and right (clockwise and counterclockwise) about the axis AL2 of the output shaft 30, and the output shaft 30 reciprocally rotates within a predetermined rotation angle. At this time, the transmitted portion 60D slides on the power transmission surface 54C.

[0035] Both front and rear ends of the transmission part 60D in the arm part 60B protrude outward in the front-rear direction with respect to the power transmission part 54A of the connecting piece 54, and are located outside the lubricant supply groove part 54E in the left-right direction. And at the position where the swing arm 60 swings the most, the front end or the rear end of the transmission part 60D of the arm part 60B is set to enter the lubricant supply groove part 54E (see FIG. 4). Thereby, the lubricant GR in the lubricant supply groove part 54E is configured to be supplied between the transmission part 60D and the power transmission part 54A. In FIG. 4, the state where the swing arm 60 swings most to the left side is illustrated. The front end of the transmission part 60D on the right side enters the lubricant supply groove part 54E, and the rear end of the transmission part 60D on the left side enters the lubricant supply groove part 54E.

[0036] The front side portion with respect to the transmission part 60D in the arm part 60B is a relief part 60E, and the transmission part 60D protrudes inward in the left-right direction from the relief part 60E. In other words, the relief part 60E is arranged at a position that is stepped down outward in the left-right direction with respect to the transmission part 60D. The relief part 60E is arranged to be spaced apart outward in the left-right direction with respect to the front side extended outer peripheral surface 54D of the connecting piece 54. And at the most swinging position of the swing arm 60, the separation distance between the relief part 60E and the extended outer peripheral surface 54D is set so that the relief part 60E does not interfere with the extended outer peripheral surface 54D.

[0037] (Function and Effect) Next, the operation and effect of the present embodiment will be described.

[0038] In the multi-tool 10 configured as described above, when the trigger switch 16 is turned on by sliding the trigger 14, the motor 24 is driven by the controller 20. When the motor 24 is driven, the spindle 42 rotates together with the rotation axis 24A of the motor 24, and the eccentric portion 50 rotates eccentrically about the axis AL1. As a result, the swing arm 60 swings left and right around the axis AL2 of the output shaft 30, the output shaft 30 reciprocally rotates about its own axis, and the tip tool T swings left and right around the axis AL2 of the output shaft 30. Therefore, the workpiece can be cut or otherwise processed by the tip tool T.

[0039] Here, in the eccentric portion 50, the outer peripheral surface of the eccentric portion 50 is constituted by a pair of front and rear extending outer peripheral surfaces 54D and a power transmission surface 54C. In the longitudinal section of the eccentric portion 50, the extending outer peripheral surface 54D extends in the front and rear directions, and the power transmission surface 54C protrudes radially outward of the eccentric portion 50 more than the extending outer peripheral surface 54D and is formed in an arc shape convex radially outward of the eccentric portion 50. Thereby, the power transmission from the eccentric portion 50 to the swing arm 60 can be smoothly performed by the arc-shaped power transmission surface 54C. Further, since the outer peripheral surface of the eccentric portion 50 is also constituted by the extending outer peripheral surface 54D in addition to the power transmission surface 54C, the axial length of the connecting piece 54 can also be ensured. That is, in the connecting piece 54 of the eccentric portion 50, the extending portion 54B extends from both sides in the front and rear directions of the power transmission portion 54A and acts to reinforce the power transmission portion 54A. As described above, it is possible to contribute to improving the durability of the eccentric portion 50. Further, regarding the outer peripheral surface of the connecting piece 54, since the central portion is spherical (curved surface) and the end portions in the front and rear directions are linear, it is possible to suppress the generation of a thin-walled portion (particularly a thin-walled portion in the radial direction) at the end portion of the connecting piece 54, and the durability of the connecting piece 54 can be improved.

[0040] From another perspective, in the eccentric portion 50 (connecting piece 54), a power transmission surface 54C, which is a part of the outer peripheral surface, protrudes radially outward from the extended outer peripheral surface 54D. As a result, for example, when forming the entire outer peripheral surface of the connecting piece 54 in a spherical shape so as to pass through the front end of the front extended outer peripheral surface 54D and the rear end of the rear extended outer peripheral surface 54D (refer to the connecting piece 54 shown by the two-dot chain line in FIG. 3), the outer diameter dimension of the eccentric portion 50 can be made smaller compared to the case where the entire outer peripheral surface of the connecting piece 54 is formed in a spherical shape. Therefore, it can contribute to the miniaturization of the eccentric portion 50.

[0041] Further, in the eccentric portion 50, the connecting piece 54 forms the radially outer portion of the eccentric portion 50, and the needle bearing 52 is disposed radially inside the connecting piece 54. The connecting piece 54 includes a power transmission portion 54A having a power transmission surface 54C and an extending portion 54B having an extending outer peripheral surface 54D, and the power transmission portion 54A and the extending portion 54B are supported by the rollers 52A (needles) of the needle bearing 52. That is, in addition to the conventional curved power transmission surface 54C, by providing the extending portion 54B extending in the front-rear direction, the front-rear dimension of the connecting piece 54 can be increased, and the contact area with the bearing portion provided inside can be increased in the front-rear direction. Thereby, the connecting piece 54 can be supported over substantially the entire axial direction by the bearing portion (needle bearing 52) whose length in the front-rear direction is longer than the power transmission surface 54C. As a result, the length of the rollers 52A in the front-rear direction can also be made larger than the power transmission surface 54C. Therefore, when the rotational force of the spindle 42 is transmitted to the swing arm 60 by the eccentric portion 50, the load generated on the bearing portion (rollers 52A) can be dispersed in the axial direction. Thus, it can further contribute to improving the durability of the eccentric portion 50. In this embodiment, in order to disperse the load in the axial direction, the length of a single bearing member (needle bearing) in the front-rear direction is increased. However, a plurality of bearing members may be arranged side by side in the front-rear direction, or other members (for example, ball bearings) may be used as the bearing members. Specifically, two or more ball bearings, or a multi-row type ball bearing in which a plurality of balls are interposed between the inner ring and the outer ring, may be press-fitted inside the connecting piece 54 and configured to be supported by the extending portion 54B so as to disperse the load over a wide range.

[0042] Also, as described above, since the connecting piece 54 is configured to include a power transmission portion 54A having a power transmission surface 54C and an extending portion 54B having an extended outer peripheral surface 54D, by setting the thickness of the extending portion 54B to the minimum dimension that can ensure the strength of the connecting piece 54, the inner diameter of the connecting piece 54 can be increased. As a result, a large-diameter needle bearing 52 can be employed. Consequently, it can further contribute to improving the durability of the eccentric portion 50.

[0043] Further, the swing arm 60 is configured to include a fixed cylinder portion 60A fixed to the output shaft 30 and a pair of left and right arm portions 60B extending rearward from the fixed cylinder portion 60A. A portion to be transmitted 60D to which power is transmitted from the power transmission surface 54C of the connecting piece 54 is provided at the rear end portion of the arm portion 60B. And the front extending portion 54B of the connecting piece 54 extends forward from the power transmission portion 54A and is located in front of the portion to be transmitted 60D. That is, by utilizing the space between the portion to be transmitted 60D and the fixed cylinder portion 60A, the front extending portion 54B can be provided on the connecting piece 54.

[0044] Further, the swing arm 60 has a relief portion 60E. The relief portion 60E is disposed at a distance outward in the left and right direction (radially outward of the eccentric portion 50) from the extended outer peripheral surface 54D of the connecting piece 54, and the portion to be transmitted 60D protrudes inward in the left and right direction (radially inward of the eccentric portion 50) with respect to the relief portion 60E. Thereby, when the swing arm 60 swings around the axis of the output shaft 30, the interference between the swing arm 60 and the connecting piece 54 can be suppressed by the relief portion 60E.

[0045] Also, in the longitudinal section of the connecting piece 54, a part of a virtual circle CR whose center point is located on the axis of the eccentric shaft 48, the power transmission surface 54C coincides therewith, and the extended outer peripheral surface 54D is located outside the virtual circle CR. Thereby, the axial length of the connecting piece 54 can be ensured, and the needle bearing 52 can be held well by the connecting piece 54.

[0046] Further, on the outer peripheral portion of the connecting piece 54, a pair of front and rear lubricant supply groove portions 54E are formed, and the lubricant GR is applied to and held in the lubricant supply groove portions 54E. Further, both front and rear ends of the power transmission portion 60D of the arm portion 60B protrude outward in the front-rear direction with respect to the power transmission portion 54A of the connecting piece 54 and are located outside the lubricant supply groove portions 54E in the left-right direction. And at the maximum swing position of the swing arm 60, the front end portion or the rear end portion of the power transmission portion 60D of the arm portion 60B enters into the lubricant supply groove portion 54E. Thereby, the lubricant GR in the lubricant supply groove portion 54E is supplied between the power transmission portion 60D and the power transmission portion 54A. Therefore, the durability of the connecting piece 54 and the swing arm 60 can be effectively improved.

[0047] In addition, in the present embodiment, the connecting piece 54 is configured as an indivisible single member, but the connecting piece 54 may be configured by two members. For example, as shown in FIG. 5, the connecting piece 54 may be configured by a cylindrical piece body 55 having the front-rear direction as the axial direction and a ring-shaped ring member 56, and the ring member 56 is fitted into the piece body 55 to integrate the piece body 55 and the ring member 56 to form the connecting piece 54. And the outer peripheral surface of the ring member 56 is configured as the power transmission surface 54C, and the outer peripheral surface of the piece body 55 is configured as the extended outer peripheral surface 54D.

[0048] In addition, in the present embodiment, the power transmission surface 54C is configured as a convex curved surface, and the power transmission surface of the power transmission portion 60D is configured as a concave curved surface. However, this concave-convex relationship may be reversed. FIG. 6 shows a cross-sectional view from above of a modified example in which the concave-convex relationship is reversed. In the configuration shown in FIG. 6, a concave curved surface power transmission surface 154C is formed on the connecting piece 54, and a convex curved surface power transmission surface is formed on the power transmission portion 160D of the swing arm 60. An imaginary circle that is a circle centered on a direction orthogonal to the front-rear direction in cross-sectional view and a part of the arc of which coincides with the curved surface of the power transmission surface 154C is shown by a two-dot chain line in FIG. 6. When the power transmission surface of the connecting piece 54 is configured as a concave curved surface as a whole, there is a risk that the front and rear ends of the connecting piece 54 will become larger as in the imaginary circle in FIG. 6. However, in this modified example, since the extending portion 54B is located entirely inside the imaginary circle, the enlargement can be suppressed. Even in such a modified example, the above-described effects can be obtained.

[0049] In addition, in the present embodiment, the eccentric portion 50 is applied to the multi-tool 10 as a working machine, but the eccentric portion 50 may be applied to other working machines. For example, as shown in FIG. 7, the eccentric portion 50 may be applied to a jigsaw 100 as a working machine.

[0050] Hereinafter, the jigsaw 100 will be described with reference to FIG. 7. In the jigsaw 100, a pinion gear 104 is provided at the tip of the rotating shaft 102 of the motor, and the pinion gear 104 is meshed with a gear 106. The gear 106 is configured to be rotatable with the front-rear direction as the axial direction. A rotating body 108 is integrally rotatably attached to the gear 106. An eccentric shaft 48 is provided on the rotating body 108, and the eccentric shaft 48 is disposed at a position eccentric from the axis AL3 (predetermined axis) of the gear 106. Then, the connecting piece 54 of the eccentric portion 50 is externally inserted into the eccentric shaft 48, and the eccentric portion 50 is provided on the rotating body 108.

[0051] A connector member 110 is connected to the connecting piece 54. Specifically, the connector member 110 has a pair of upper and lower arm portions 110A, and the arm portions 110A are adjacently arranged on both the upper and lower sides of the power transmission surface 54C of the connecting piece 54 in the vertical direction. The connector member 110 is connected by a guide member 112 so as to be movable in the vertical direction and is configured to be swingable about the axis of the overhead shaft AX extending in the left and right directions. A plunger 114 is connected to the connector member 110, and the plunger 114 extends downward from the connector member 110. Further, a saw blade 116 is attached to the plunger 114, and the saw blade 116 extends downward from the plunger 114.

[0052] When the rotary shaft 102 rotates, the eccentric portion 50 eccentrically rotates about the axis AL3, and the plunger 114 (saw blade 116) connected to the connector member 110 reciprocates in the vertical direction. Further, when the plunger 114 (saw blade 116) reciprocates up and down, the plunger 114 (saw blade 116) swings about the axis of the overhead shaft AX by the biasing member 118 and the orbit adjusting mechanism 120. That is, the arm portion 110A slides on the power transmission surface 54C of the connecting piece 54. As described above, by applying the eccentric portion 50 to the jigsaw 100, it is possible to contribute to improving the durability of the jigsaw 100. Thus, in the power transmission mechanism, the present invention is applicable to a working machine having a curved surface engaging portion corresponding to the swinging output shaft.

Explanation of Signs

[0053] 10 Multi-tool (working machine) 24 Motor 30 Output shaft 50 Eccentric portion 52A Roller (rolling member) 54 Connecting piece (intervening portion) 54A Power transmission portion 54B Extending portion 54C Power transmission surface 54D Outer peripheral surface of the extension 54E Lubricant supply groove portion (groove portion) 60 Swing arm (relay member) 60A Fixed cylinder part (main body part) 60B Arm part 60D Part to be transmitted 60E Relief part 100 Jigsaw (working machine) AL1 Axis (predetermined axis) AL3 Axis (predetermined axis) CR Virtual circle GR Lubricant

Claims

1. A motor, an eccentric portion that eccentrically rotates about a predetermined axis extending along a predetermined direction by driving of the motor, an output shaft that is driven by transmission of power from the eccentric portion, and comprising, the output shaft is configured to be capable of a swinging motion about an intersection direction intersecting the predetermined direction, the eccentric portion includes, an eccentric shaft extending in the predetermined direction, an intervening portion held by the eccentric shaft, and having, the intervening portion includes a power transmission portion having a power transmission surface configured as a curved surface and having the power transmission surface on the outer periphery for transmitting the power of the motor to the output shaft, and an extending portion connected to the power transmission portion in the predetermined direction and extending in the predetermined direction, the intervening portion receives the power of the motor from both the power transmission portion and the extending portion, and is configured to transmit the power to the output shaft by the power transmission portion. A working machine.

2. the intervening portion is formed in a cylindrical shape having the predetermined direction as an axial direction, a bearing portion having a rolling member for supporting the intervening portion is provided between the eccentric shaft and the intervening portion, the working machine according to claim 1, wherein at least a part of the bearing portion is located between the extending portion and the eccentric portion in a direction orthogonal to the predetermined direction.

3. a relay member is integrally rotatably provided on the output shaft, the relay member includes a main body portion fixed to the output shaft and an arm portion extending from the main body portion to the other side in the predetermined direction, the arm portion has a portion to be transmitted with power transmitted from the power transmission surface, the working machine according to claim 2, wherein at least a part of the extending portion is provided on one side in the predetermined direction with respect to the portion to be transmitted.

4. the output shaft reciprocally rotates about its own axis by transmission of power from the relay member, the arm portion has a relief portion, the relief portion is disposed spaced apart radially outside the eccentric portion with respect to the extending portion, and the portion to be transmitted projects radially inward of the eccentric portion with respect to the relief portion. The working machine according to claim 3.

5. the power transmission surface is a curved surface that is convex outward in the radial direction, in a longitudinal section including the axis of the eccentric shaft, a part of a virtual circle whose center point is located on the axis of the eccentric portion coincides with the power transmission surface, and at least a part of the extending portion is located outside the virtual circle. The working machine according to claim 1.

6. the power transmission surface is a curved surface that is concave inward in the radial direction, The working machine according to claim 1, wherein in a longitudinal section including the axis of the eccentric shaft, the extending portion is located closer to the eccentric shaft side than the imaginary circle partially coinciding with the power transmission surface.

7. The working machine according to claim 1, wherein a groove portion is formed along the circumferential direction of the eccentric portion on the outer peripheral surface of the eccentric portion, and a lubricant is held in the groove portion.

8. The working machine according to claim 7, wherein the groove portion is arranged adjacent to the power transmission surface in the predetermined direction.

9. The working machine according to claim 8, wherein the groove portion is provided in the power transmission portion.

10. A relay member is integrally rotatably connected to the output shaft. The relay member includes a main body portion fixed to the output shaft and an arm portion extending from the main body portion to the other side in the predetermined direction. The working machine according to claim 8, wherein the arm portion has a portion to be transmitted with power transmitted from the power transmission portion, and a part of the portion to be transmitted is located radially outside the eccentric portion with respect to the groove portion.

11. The working machine according to claim 2, wherein the bearing portion is a needle bearing and the rolling member is a needle-shaped roller.

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