JP2016087729A - Reciprocating tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further reduce vibration of a reciprocation tool by regulating vibration and movement of a balance weight.SOLUTION: A jig saw comprising a blade 31 which is reciprocated and driven, comprises: a motor 10 as a driving source; a plunger 30 to which a blade 31 is attached, and which is reciprocated and driven by the motor 10; a balance weight 40 which is reciprocated and driven in a reverse phase with respect to the plunger 30 by the motor 10; and a first regulation mechanism 60 and a second regulation mechanism 70 for regulating vibration and movement of the balance weight 40 in a first direction where is almost vertical to a reciprocation movement direction of the balance weight 40.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reciprocating tool that performs operations such as cutting and cutting with a tip tool that is driven to reciprocate.

  A jigsaw is known as an example of a reciprocating tool. The jigsaw has a motor as a drive source housed in a housing, and a pinion is provided on the output shaft of the motor. The gear meshing with the pinion is provided with an eccentric pin for reciprocating the plunger and an eccentric cam for reciprocating the balance weight. The rotational movement of the motor is converted into the reciprocating movement of the plunger by the eccentric pin, and the blade as a tip tool mounted on the plunger is driven to reciprocate. At the same time, the rotational motion of the motor is converted into the reciprocating motion of the balance weight by the eccentric cam, and the balance weight is reciprocated in the opposite phase to the plunger and the blade (Patent Document 1).

JP 2000-225517 A

  In the jigsaw as described above, the vibration caused by the reciprocating motion of the plunger and the blade is canceled by the balance weight that reciprocates in the opposite phase to the plunger and the blade.

  However, in order to reciprocate the balance weight, it is necessary to provide a clearance around the balance weight. For this reason, the balance weight swings (flutters) within the clearance range when reciprocating. That is, the balance weight for reducing the vibration caused by the reciprocating motion of the plunger and the blade generates a new vibration.

  An object of the present invention is to further reduce the vibration of the reciprocating tool by restricting the swing movement of the balance weight.

  The reciprocating tool of the present invention includes a tip tool that is driven to reciprocate, a motor as a drive source, a plunger that is mounted with the tip tool and is driven to reciprocate by the motor, and a phase opposite to that of the plunger by the motor. A balance weight that is reciprocally driven; and a regulating mechanism that regulates swinging of the balance weight in a first direction substantially perpendicular to a reciprocating direction of the balance weight.

  In one aspect of the present invention, the reciprocating tool includes at least one of a first restricting mechanism located on the extension of the balance weight in the reciprocating direction and a second restricting mechanism located on the side of the balance weight. Have either one.

  In another aspect of the invention, the first restricting mechanism restricts the swing of the balance weight in the first direction at the top dead center, the bottom dead center, or both.

  In another aspect of the present invention, the first restriction mechanism includes a first elastic body and / or a second elastic body provided on a gear cover in which the balance weight is accommodated so as to be capable of reciprocating. The elastic body contacts the upper end surface of the balance weight swinging in the first direction at the top dead center, and the second elastic body is below the balance weight swinging in the first direction at the bottom dead center. Touch the end face.

  In another aspect of the invention, the gear cover is configured to be separable, and the first elastic body or the second elastic body or both are sandwiched by the gear cover.

  In another aspect of the present invention, the first regulating mechanism includes a first elastic body provided on an upper part of the balance weight, a second elastic body provided on a lower part of the balance weight, or both, When the balance weight swings in the first direction at the top dead center, the first elastic body contacts the inner surface of the gear cover in which the balance weight is accommodated, and the second elastic body moves at the bottom dead center at the bottom dead center. When the balance weight swings in the first direction, it comes into contact with the other inner surface of the gear cover.

  In another aspect of the present invention, the second restricting mechanism has a variable swing allowable amount with respect to the balance weight.

  In another aspect of the invention, the second restriction mechanism has a stopper member, and the stopper member can be switched between a first state and a second state, and the stopper member in the first state The interval with the balance weight is smaller than the interval in the second state.

  In another aspect of the present invention, a housing that houses the motor is provided, and the stopper member is rotatably provided on the housing, and is switched between the first state and the second state by a turning operation. .

  According to the present invention, the swinging movement of the balance weight is restricted, and the vibration of the reciprocating tool is further reduced.

1 is an external perspective view of a jigsaw to which the present invention is applied. It is a partial expanded sectional view which shows the internal structure of the jigsaw shown by FIG. It is a disassembled perspective view which shows the structure of a gear cover. (A) is a rear view of the balance weight when the second restriction mechanism is in the first state, and (b) is a rear view of the balance weight when the second restriction mechanism is in the second state. is there. It is a perspective view which shows the attachment structure of an upper damper, a lower damper, and a balance weight. (A), (b) is explanatory drawing which shows operation | movement of a 2nd control mechanism. (A) is sectional drawing of a balance weight provided with the changed 1st control mechanism, (b) is a front view. (A), (b), (c) is a schematic diagram which shows the modified example from which the elastic body which comprises a 1st control mechanism differs.

  Hereinafter, an example of an embodiment of a reciprocating tool to which the present invention is applied will be described in detail. The reciprocating tool according to the present embodiment is a jigsaw that cuts wood and other objects with a tip tool that is driven to reciprocate.

  A jigsaw 1 shown in FIG. 1 has a housing 2 formed of a synthetic resin, and has a substantially D-shaped side shape as a whole. The housing 2 includes a handle portion 3, a motor housing portion 4, and a gear housing portion 5. The handle portion 3 straddles the rear end of the motor housing portion 4 and the upper end of the gear housing portion 5, and a trigger switch 6 that is operated by a user is provided on the lower surface of the handle portion 3. However, the distinction between the handle part 3, the motor housing part 4 and the gear housing part 5 is a distinction for convenience of explanation, and the actual handle part 3, the motor housing part 4 and the gear housing part 5 are integrated.

  As shown in FIG. 2, a motor 10 as a drive source is accommodated in the motor housing portion 4 (FIG. 1), and a metal (in this embodiment) is contained in the gear housing portion 5 (FIG. 1). A gear cover 7 formed of aluminum is accommodated. Further, the gear cover 7 contains a motion conversion mechanism 20, a plunger 30, a balance weight 40, and the like.

  The rotational driving force output from the motor 10 is converted into a reciprocating driving force by the motion conversion mechanism 20 and transmitted to the plunger 30 and the balance weight 40. The plunger 30 to which the reciprocating driving force is transmitted, the blade 31 attached to the plunger 30, and the balance weight 40 reciprocate in opposite phases. That is, the plunger 30 and the blade 31 are reciprocated by the motor 10 via the motion conversion mechanism 20. At the same time, the balance weight 40 is driven to reciprocate by the motor 10 via the motion conversion mechanism 20.

  In the following description, the first direction parallel to the output shaft 10a of the motor 10 is “front-rear direction”, the second direction parallel to the reciprocating direction of the plunger 30, the blade 31 and the balance weight 40 is “up-down direction”, The third direction orthogonal to both the direction and the second direction may be referred to as the “left-right direction” (see FIGS. 1 and 2).

  As shown in FIG. 3, the gear cover 7 is configured to be separable by a front cover 7 a and a rear cover 7 b facing each other and an intermediate cover 7 c sandwiched between the covers 7 a and 7 b. The front cover 7a and the rear cover 7b are abutted with each other with the intermediate cover 7c interposed therebetween, and a space in which the motion conversion mechanism 20, the plunger 30, the balance weight 40 and the like are accommodated is formed inside these (FIG. 2).

  As shown in FIG. 2, one end side of the output shaft 10a of the motor 10 passes through the rear cover 7b, and a pinion 10b is provided at the end (tip portion) of the output shaft 10a entering the inside of the gear cover 7. It has been. On the other hand, a spindle 21 parallel to the output shaft 10a is provided inside the gear cover 7, and a gear 22 that meshes with the pinion 10b is rotatably supported by the spindle 21.

  The balance weight 40 is disposed in front of the gear 22, and the plunger 30 is disposed in front of the balance weight 40. That is, the gear 22, the balance weight 40, and the plunger 30 are arranged in this order along the front-rear direction.

  As shown in FIGS. 4A and 4B, the balance weight 40 is formed with one guide groove 41a and two guide holes 41b and 41c. Each of the guide groove 41a and the guide holes 41b and 41c extends in the vertical direction. That is, the guide groove 41a is a vertical groove extending in the vertical direction, and its upper end is open. The guide holes 41b and 41c are elongated holes extending in the vertical direction, and their upper and lower ends are closed. The guide groove 41a is located at the center in the left-right direction of the balance weight 40, and the guide holes 41b and 41c are located on both the left and right sides of the guide groove 41a. In other words, the guide groove 41a is located at the apex of the isosceles triangle, and the two guide holes 41b and 41c are located at both ends of the base of the isosceles triangle, respectively.

  Further, a horizontally long engagement hole 42 is formed at the center of the balance weight 40. On the other hand, as shown in FIG. 2, an eccentric cam 23 is provided on the front surface of the gear 22, and the eccentric cam 23 is fitted in the engagement hole 42 (FIG. 4) of the balance weight 40. Further, as shown in FIG. 5, three guide pins 44a, 44b, 44c projecting toward the front cover 7a (FIG. 3) are formed on the inner surface of the rear cover 7b. As shown in FIG. 3, the guide pin 44a is inserted into the guide groove 41a of the balance weight 40, the guide pin 44b is inserted into the guide hole 41b of the balance weight 40, and the guide pin 44c is inserted into the guide hole 41c of the balance weight 40. Has been inserted. That is, the balance weight 40 is supported by the three guide pins 44a, 44b, and 44c protruding from the rear cover 7b so as to reciprocate up and down. In other words, the balance weight 40 is supported at three points inside the gear cover 7 so as to be movable up and down.

  Refer to FIG. 2 again. In addition to the eccentric cam 23, an eccentric pin 24 is provided on the front surface of the gear 22. On the other hand, a connector 32 having a U-shaped cross section in a side view is provided at the upper end of the plunger 30, and the tip of the eccentric pin 24 is inserted inside the connector 32. That is, the plunger 30 is hung on the eccentric pin 24 via the connector 32. Further, an engagement protrusion 33 extending forward is formed on the front surface of the connector 32, and this engagement protrusion 33 passes through a long hole formed in the holding plate 34 installed in front of the plunger 30. ing. A retaining portion 33a having a diameter larger than the width of the elongated hole is formed at the tip of the engaging projection 33 that penetrates the elongated hole and projects forward of the holding plate 34. On the other hand, the plunger 30 passes through a sliding support member 35 sandwiched between the front cover 7a and the intermediate cover 7c. The sliding support member 35 has a substantially cylindrical tube portion 35a through which the plunger 30 passes, and a substantially rectangular flange portion 35b formed around the tube portion 35a. An O-ring (not shown) is interposed between the outer peripheral surface of the plunger 30 and the inner peripheral surface of the cylindrical portion 35a. The sliding support member 35 is movable within a predetermined range in the front-rear direction between the front cover 7a and the intermediate cover 7c, but is held substantially immovable in the vertical direction. Further, a coil spring 36 is disposed between the sliding support member 35 and the front cover 7a, and the sliding support member 35 is always urged rearward by the coil spring 36. Thus, the plunger 30 is supported so as to be able to reciprocate in the vertical direction (can be raised and lowered) and reciprocally movable in the front-rear direction (can swing).

  An orbital mechanism 50 is provided behind (behind) the blade 31. The orbital mechanism 50 is attached to a push rod 51 that is pushed down by a protrusion provided on the back surface of the gear 22 at a predetermined period, a swing arm 52 that is rotatably provided at the lower end of the rear cover 7b, and a tip of the swing arm 52. And a roller 53. Since the sliding support member 35 is urged rearward by the coil spring 36, the plunger 30 supported by the sliding support member 35 and the blade 31 attached to the plunger 30 are also urged rearward. The blade 31 is pressed against the roller 53.

  Next, the operation of the jigsaw 1 shown in FIG. 1 will be described. When the user holding the handle 3 operates the trigger switch 6, electric power is supplied to the motor 10 shown in FIG. 2, and the output shaft 10a of the motor 10 rotates. That is, the rotational driving force is output from the motor 10. When the output shaft 10a rotates, the gear 22 meshed with the pinion 10b rotates around the spindle 21 as a rotation center. Then, the eccentric pin 24 rotates on the circumference of a circle having an eccentric distance with respect to the spindle 21 as a diameter. Since the eccentric pin 24 rotates while sliding on the inner surface of the connector 32, the rotational movement of the eccentric pin 24 is converted into the linear movement (reciprocating movement) of the connector 32, that is, the plunger 30. As a result, the blade 31 attached to the plunger 30 is driven to reciprocate, and an object (not shown) is cut. Further, the eccentric cam 23 fitted in the engagement hole 42 (FIG. 4) of the balance weight 40 rotates while sliding on the inner peripheral surface of the engagement hole 42, so that the balance weight 40 is moved to the plunger 30. In addition, the linear motion (reciprocating motion) is performed in the opposite phase to the blade 31. Such reciprocating motion of the balance weight 40 cancels vibrations caused by the reciprocating motion of the plunger 30 and the blade 31. Further, when the gear 22 rotates, the push rod 51 of the orbital mechanism 50 is pushed down and the rear end of the swing arm 52 is pushed. Then, the swing arm 52 rotates, the roller 53 approaches forward, and pushes out the blade 31 in the same direction against the bias of the coil spring 36. When the blade 31 is pushed out, the plunger 30 on which the blade 31 is mounted and the sliding support member 35 integral with the plunger 30 are also pushed out in the same direction. At this time, the coil spring 36 is compressed by the sliding support member 35 that moves forward. Thereafter, when the push rod 51 is released from being pushed down, the plunger 30 and the sliding support member 35 are returned to their original positions by the bias of the coil spring 36, and the blade 31 is also returned to its original position. Thus, the blade 31 swings back and forth by repeatedly pushing down and releasing the push rod 51. As a result, the blade 31 cuts an object not shown in a trajectory that draws an arc with respect to the object.

  Here, the balance weight 40 is supported at three points by three guide pins 44a, 44b and 44c shown in FIG. For this reason, when the balance weight 40 reciprocates (lifts) as described above, the balance weight 40 swings in the axial direction of the guide pins 44a, 44b, 44c. In other words, the balance weight 40 swings in the front-rear direction (first direction) substantially orthogonal to the reciprocating direction of the balance weight 40. In particular, the balance weight 40 swings greatly when its moving direction is reversed. That is, the balance weight 40 swings while moving up and down and at the top dead center and the bottom dead center, but swings particularly greatly at the top dead center and the bottom dead center.

  Therefore, in the present embodiment, the first restriction mechanism 60 is located on the extension of the balance weight 40 in the reciprocating direction and restricts the swinging of the balance weight 40 in the front-rear direction (first direction) at the top dead center and the bottom dead center. And a second regulating mechanism 70 that is located on the side of the balance weight 40 and regulates the swinging of the balance weight 40 in the front-rear direction (first direction).

  The first regulating mechanism 60 includes a first elastic body 61 and a second elastic body 62 shown in FIG. The first elastic body 61 is arranged on the upper part of the gear cover 7, and comes into contact with the balance weight 40 that has reached the top dead center to restrict the swing of the balance weight 40. The second elastic body 62 is disposed below the gear cover 7 and contacts the balance weight 40 that has reached the bottom dead center to restrict the swing of the balance weight 40. Thus, the first elastic body 61 and the second elastic body 62 are arranged on the extension line of the balance weight 40 in the reciprocating direction. More specifically, the first elastic body 61 is disposed above the balance weight 40 in the reciprocating direction, and the second elastic body 62 is disposed below the balance weight 40 in the reciprocating direction. Therefore, in the following description, the first elastic body 61 is referred to as “upper damper 61”, and the second elastic body 62 is referred to as “lower damper 62”. Note that the upper damper 61 and the lower damper 62 in the present embodiment are plate-shaped rubber.

  As shown in FIG. 2, the upper damper 61 is sandwiched between the ceiling of the front cover 7 a constituting the gear cover 7 and the ceiling of the rear cover 7 b constituting the gear cover 7. As shown in FIG. 5, the upper damper 61 includes a flat plate-like locking portion 61a and a contact portion 61b that are parallel to each other, and a prismatic connection portion 61c that connects the locking portion 61a and the contact portion 61b. Have. However, such distinction is merely a distinction for convenience of explanation, and the locking part 61a, the contact part 61b, and the connecting part 61c are integrally formed.

  As shown in FIGS. 3 and 5, notches are formed in the ceilings of the front cover 7a and the rear cover 7b, and the connecting portion 61c of the upper damper 61 is fitted between the notches that are abutted with each other. ing. As a result, the locking portion 61a of the upper damper 61 is located outside the ceiling of the front cover 7a and the rear cover 7b, and the contact portion 61b of the upper damper 61 is located inside the ceiling of the front cover 7a and the rear cover 7b. . As shown in FIG. 2, the contact portion 61 b of the upper damper 61 faces the upper end surface 40 a of the balance weight 40 inside the gear cover 7.

  As shown in FIG. 2, the lower damper 62 is sandwiched between the bottom plate of the rear cover 7b and the intermediate cover 7c. As shown in FIG. 5, the lower damper 62 includes a flat plate-like locking portion 62a and a contact portion 62b that are parallel to each other, and a prismatic connection portion 62c that connects the locking portion 62a and the contact portion 62b. Have. However, such distinction is merely a distinction for convenience of description, and the locking part 62a, the contact part 62b, and the connecting part 62c are integrally formed.

  As shown in FIGS. 3 and 5, a notch is formed in the bottom plate of the rear cover 7 b, and a connecting portion 62 c of the lower damper 62 is fitted into this notch. As a result, the locking portion 62a of the lower damper 62 is located outside the bottom plate of the rear cover 7b, and the contact portion 62b of the lower damper 62 is located inside the bottom plate of the rear cover 7b. As shown in FIG. 2, the abutting portion 62 b of the lower damper 62 faces the lower end surface 40 b of the balance weight 40 inside the gear cover 7.

  When the balance weight 40 swings in the front-rear direction at the top dead center, at least one side of the upper end surface 40 a of the balance weight 40 comes close to the contact portion 61 b of the upper damper 61. When the swing amount of the balance weight 40 becomes equal to or greater than a predetermined value, at least one side of the upper end surface 40a of the balance weight 40 comes into contact with the contact portion 61b of the upper damper 61, and further swing is restricted. Depending on the swing amount of the balance weight 40 and the stroke amount of the reciprocating motion, the contact between the balance weight 40 and the upper damper 61 may be started immediately before the balance weight 40 reaches the top dead center. That is, the upper damper 61 may start swinging regulation on the balance weight 40 before the balance weight 40 reaches the top dead center.

  Further, when the balance weight 40 swings in the front-rear direction at the bottom dead center, at least one side of the lower end surface 40 b of the balance weight 40 comes close to the contact portion 62 b of the lower damper 62. When the swing amount of the balance weight 40 becomes a predetermined value or more, at least one side of the lower end surface 40b of the balance weight 40 comes into contact with the contact portion 62b of the lower damper 62, and further swing is restricted. Depending on the swing amount of the balance weight 40 and the stroke amount of the reciprocating motion, the contact between the balance weight 40 and the lower damper 62 may be started immediately before the balance weight 40 reaches the bottom dead center. That is, the lower damper 62 may start swinging regulation on the balance weight 40 before the balance weight 40 reaches the bottom dead center.

  In other words, the balance weight 40 does not contact the upper damper 61 or the lower damper 62 until the swing amount of the balance weight 40 at or near the top dead center, the bottom dead center, or the like reaches a predetermined value. That is, the first regulating mechanism 60 allows the balance weight 40 to swing less than a predetermined value, and this swing allowable amount is unchanged.

  In addition, at the top dead center and the bottom dead center where the movement direction of the balance weight 40 is reversed, vertical vibration is applied to the jigsaw 1 by the inertial force of the balance weight 40. However, in the present invention, when the upper damper 61 and the lower damper 62 restrict the swing of the balance weight 40 at the top dead center and the bottom dead center, the inertia force of the balance weight 40 is absorbed, and the jigsaw 1 Vibration in the direction is reduced.

  The second restriction mechanism 70 includes an abutting member 71 and a stopper member 72 shown in FIG. The abutting member 71 is a rib provided inside the gear cover 7 and is located on the side (back) of the balance weight 40. In other words, the abutting member 71 faces the balance weight 40 in the front-rear direction. On the other hand, the stopper member 72 is rotatably provided on the housing 2. The stopper member 72 is always provided at a position (height) interposed between the balance weight 40 and the abutting member 71 while the balance weight 40 is raised and lowered.

  As shown in FIG. 4, a pair of opposing support plates 73 and 74 are provided on the left and right sides of the balance weight 40, and the stopper member 72 is rotatably supported by the support plates 73 and 74. . The support plates 73 and 74 are supported by the gear cover 7, respectively. Specifically, the stopper member 72 has a rod shape, and at both ends thereof, there are formed insertion portions 75 having a circular cross section to be inserted into holes provided in the support plates 73 and 74. A contact portion 76 having a rectangular cross section is formed between 75 and 75.

  A positioning mechanism 77 that rotates together with the stopper member 72 is provided at one end side of the stopper member 72, and a knob 78 is formed at one end of the stopper member 72. The knob 78 is exposed to the outside of the housing 2 (FIG. 1), and the user can rotate the stopper member 72 by operating the knob 78 exposed to the outside.

  As shown in FIG. 2, when the balance weight 40 swings in the front-rear direction while moving up and down, the stopper member 72 approaches the balance weight 40. When the swinging amount of the balance weight 40 becomes a predetermined value or more, the balance weight 40 comes into contact with the stopper member 72 and slides with respect to the stopper member 72 while further swinging is restricted. At this time, the restricted swinging force is absorbed by the abutting member 71 through the stopper member 72. In other words, the stopper member 72 and the balance weight 40 do not come into contact until the swinging amount of the balance weight 40 that is being raised and lowered reaches a predetermined value. That is, the second restriction mechanism 70 allows the balance weight 40 to swing less than a predetermined value.

  As shown in FIGS. 6A and 6B, the cross-sectional shape of the contact portion 76 of the stopper member 72 is a substantially rectangular shape, more precisely, a substantially rectangular shape. Therefore, the contact portion 76 includes a first contact surface 76a parallel to the short side and a second contact surface 76b parallel to the long side. The stopper member 72 has a first state in which the first contact surface 76a faces the abutting member 71 (FIG. 6A) and a second abutting surface 76b. It is possible to switch to the opposing second state (FIG. 6B). As is clear from comparison between FIG. 6A and FIG. 6B, the distance between the stopper member 72 and the balance weight 40 in the front-rear direction, that is, the swing allowable amount, is the first state and the second state. And different. Specifically, the distance D2 (FIG. 6B) when the stopper member 72 is in the second state is larger than the distance D1 when the stopper member 72 is in the first state (FIG. 6A). In other words, the distance D1 (FIG. 6A) when the stopper member 72 is in the first state is smaller than the distance D2 when the stopper member 72 is in the second state (FIG. 6B). That is, the allowable swing amount when the stopper member 72 is in the second state is larger than the allowable swing amount when the stopper member 72 is in the first state, and the allowable swing amount when the stopper member 72 is in the first state is This is smaller than the allowable swing amount in the second state.

  As described above, the first restriction mechanism 60 and the second restriction mechanism 70 shown in FIG. 2 are common in that the swinging of the balance weight 40 in the front-rear direction (first direction) is restricted. However, the allowable swing amount of the first restricting mechanism 60 is unchanged, whereas the allowable swing amount of the second restricting mechanism 70 is variable.

  As shown in FIGS. 4A and 4B, the positioning mechanism 77 includes two recesses 80 provided in the support plate 74, a ball 82 biased toward the support plate 74 by a spring 81, Is provided. Although only one recess 80 is shown in the figure, in practice, two recesses are formed at positions different by 90 degrees. Further, the spring 81 and the ball 82 rotate together with the stopper member 72. When the stopper member 72 is rotated to the position where the ball 82 fitted in the recess not shown fits into the recess 80 shown in the drawing, the stopper member 72 is switched from the second state to the first state and held in the first state. Is done. On the other hand, when the stopper member 72 is rotated to the position where the ball 82 fitted in the illustrated recess 80 fits in the not illustrated recess, the stopper member 72 is switched from the first state to the second state, and the second state. Retained.

  As described above, the jigsaw 1 according to the present embodiment includes the first regulating mechanism 60 that regulates the swinging of the balance weight 40 in the front-rear direction at the top dead center and the bottom dead center, and the lateral side of the balance weight 40. And a second restricting mechanism 70 that is located and always restricts swinging of the balance weight 40 in the front-rear direction. Therefore, the swinging of the balance weight 40 in the front-rear direction during the reciprocating operation is always restricted by the second restriction mechanism 70, and the vibration of the jigsaw 1 is reduced. Further, at the top dead center and the bottom dead center, in addition to the restriction by the second restriction mechanism 70, the swinging of the balance weight 40 in the front-rear direction is further restricted by the first restriction mechanism 60, and the jigsaw 1 vibrates. It is reduced more. Further, the allowable swinging amount of the second regulating mechanism 70 with respect to the balance weight 40 is variable. That is, when the second restricting mechanism 70 is switched to the second state in which the swing allowance is relatively large, the swing amount of the balance weight 40 in the front-rear direction is increased. In other words, the swinging amount of the balance weight 40 in the front-rear direction can be adjusted by the second restriction mechanism 70. Here, when the balance weight 40 swings in the front-rear direction, the entire jigsaw including the blade 31 shown in FIG. 2 swings in the same direction. Then, at the time of cutting work, the blade 31 operates on a trajectory that draws an arc with respect to an object (not shown), and the same effect as the orbital mechanism 50 is obtained by such swinging. Specifically, when the second regulating mechanism 70 is switched to the second state and the orbital mechanism 50 is operated, the blade 31 is swung along with the swing of the balance weight 40, and the blade 31 is moved by the orbital mechanism 50. The cutting speed is improved by a synergistic effect with the swing. Further, when the second restriction mechanism 70 is switched to the second state, the cutting speed is improved to be equal to or higher than that when the orbital mechanism 50 is operated even if the orbital mechanism 50 is not operated. That is, it is possible to arbitrarily select a use mode in which vibration reduction is prioritized over the cutting speed and a use mode in which cutting speed is prioritized over vibration reduction.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the first elastic body and the second elastic body constituting the first restricting mechanism 60 are provided in the gear cover 7. However, the first elastic body and the second elastic body can be provided on the balance weight 40. For example, as shown in FIGS. 7A and 7B, an upper damper 61 as a first elastic body is provided above the balance weight 40, and a lower damper 62 as a second elastic body is provided below the balance weight 40. Can also be provided. The balance weight 40 shown in FIGS. 7A and 7B includes a front weight 43 and a rear weight 44 that face each other. The main surfaces of the front weight 43 and the rear weight 44 face each other and are fixed to each other by a screw 45. The upper damper 61 and the lower damper 62 are sandwiched between the front weight 43 and the rear weight 44. A part of the upper damper 61 protrudes from the upper end surface 40a of the balance weight 40, and a part of the lower damper 62 is balanced. It protrudes from the lower end surface 40 b of the weight 40. In this embodiment, when the balance weight 40 swings in the front-rear direction at the top dead center, a part of the upper damper 61 protruding from the upper end surface 40a of the balance weight 40 comes into contact with the inner surface (inside the ceiling) of the gear cover 7. Further swinging is restricted. Further, when the balance weight 40 swings in the front-rear direction at the bottom dead center, a part of the lower damper 62 protruding from the lower end surface 40b of the balance weight 40 comes into contact with the inner surface (inside the bottom plate) of the gear cover 7 and beyond. Is controlled. At this time, as described above, the upper damper 61 and the lower damper 62 may exert the regulating force from the time when the balance weight 40 reaches the top dead center and the time before the bottom weight reaches the bottom dead center.

  The upper damper 61 and the lower damper 62 included in the jigsaw 1 according to the above embodiment are in contact with the balance weight 40 only when the balance weight 40 swings at the top dead center and the bottom dead center. However, the upper damper 61 and the lower damper 62 may be brought into contact with the balance weight 40 regardless of whether the balance weight 40 swings at the top dead center and the bottom dead center. That is, the upper damper 61 and the lower damper 62 may be brought into contact with the balance weight 40 each time. In this case, vibration accompanying reversal of the movement direction of the balance weight 40 at the top dead center and the bottom dead center is suppressed.

  Either the upper damper 61 or the lower damper 62 included in the jigsaw 1 according to the above embodiment may be omitted, and the swing of the balance weight 40 may be restricted only at either the top dead center or the bottom dead center.

  The jigsaw 1 according to the above embodiment is provided with both the first restriction mechanism 60 and the second restriction mechanism 70. However, only one of the first restriction mechanism 60 and the second restriction mechanism 70 can be provided. Further, the orbital mechanism 50 can be omitted, and even if the orbital mechanism 50 is omitted, the second restriction mechanism 70 can obtain substantially the same effect as the orbital mechanism 50.

  The shape, structure, material and the like of the first elastic body and the second elastic body can be arbitrarily changed. For example, in order to avoid a decrease in cutting speed in the above embodiment, it is preferable to lower the spring constants of the upper damper 61 and the lower damper 62. For example, the abutting portions 61b and 62b of the upper damper 61 and the lower damper 62 can be made into a hollow structure as shown in FIG. Further, unevenness as shown in FIGS. 8B and 8C can be formed on the surfaces of the contact portions 61b and 62b of the upper damper 61 and the lower damper 62 to reduce the contact resistance.

  The present invention can also be applied to reciprocating tools other than jigsaws, such as saver saws and hedge trimmers.

DESCRIPTION OF SYMBOLS 1 Jigsaw 2 Housing 3 Handle 4 Motor housing 5 Gear housing 6 Trigger switch 7 Gear cover 7a Front cover 7b Rear cover 7c Intermediate cover 10 Motor 10a Output shaft 30 Plunger 31 Blade 35 Sliding support member 40 Balance weight 40a Upper end surface 40b Lower end surface 41a Guide Groove 41b, 41c Guide hole 44a, 44b, 44c Guide pin 50 Orbital mechanism 60 First restriction mechanism 61 First elastic body (upper damper)
62 Second elastic body (lower damper)
70 Second restriction mechanism 71 Abutting member 72 Stopper member

Claims (9)

A reciprocating tool comprising a tip tool that is driven to reciprocate,
A motor as a drive source;
A plunger to which the tip tool is mounted and driven to reciprocate by the motor;
A balance weight driven by the motor to reciprocate in the opposite phase to the plunger;
A regulation mechanism that regulates swinging of the balance weight in a first direction substantially perpendicular to the reciprocating direction of the balance weight.
Reciprocating tool. Having at least one of a first restricting mechanism located on an extension of the balance weight in the reciprocating direction and a second restricting mechanism located on the side of the balance weight;
The reciprocating tool according to claim 1. The first regulating mechanism regulates swinging of the balance weight in the first direction at top dead center or bottom dead center or both;
The reciprocating tool according to claim 2. The first restricting mechanism includes a first elastic body or a second elastic body or both provided in a gear cover in which the balance weight is accommodated so as to be capable of reciprocating.
The first elastic body is in contact with an upper end surface of the balance weight swinging in the first direction at a top dead center;
The second elastic body contacts a lower end surface of the balance weight swinging in the first direction at a bottom dead center;
The reciprocating tool according to claim 3.   The reciprocating tool according to claim 4, wherein the gear cover is configured to be separable, and the first elastic body and / or the second elastic body are sandwiched between the gear covers. The first regulating mechanism includes a first elastic body provided on an upper portion of the balance weight or a second elastic body provided on a lower portion of the balance weight, or both.
When the balance weight swings in the first direction at the top dead center, the first elastic body contacts an inner surface of a gear cover in which the balance weight is accommodated,
The second elastic body contacts the other inner surface of the gear cover when the balance weight swings in the first direction at the bottom dead center.
The reciprocating tool according to claim 3. The second restricting mechanism has a variable swing allowable amount with respect to the balance weight.
The reciprocating tool according to claim 2. The second regulating mechanism has a stopper member,
The stopper member can be switched between a first state and a second state,
An interval between the stopper member and the balance weight in the first state is smaller than the interval in the second state;
The reciprocating tool according to claim 7. A housing for housing the motor;
The stopper member is rotatably provided in the housing and is switched between the first state and the second state by a turning operation.
The reciprocating tool according to claim 8.

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