JP2016140934A - Power tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power tool capable of adjusting the performance of a vibration absorption mechanism interposed between a body and a handle.SOLUTION: A hammer drill 1 comprises: a body 2 having a brushless motor 20; a handle 3 connected to the body 2; and a vibration absorption mechanism 7 interposed between the body 2 and the handle 3 for absorbing the vibrations to be transmitted from the body 2 to the handle 3. The vibration absorption mechanism 7 has a first vibration transmission passage and a second vibration transmission passage, and changes into a first mode, in which the vibrations are transmitted through the first vibration transmission passage from the body 2 to the handle 3, and into a second mode, in which the vibrations are transmitted through the first vibration transmission passage and the second vibration transmission passage from the body 2 to the handle 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power tool including a power source such as an electric motor, an air motor, and an engine.

  Many power tools include a main body having a power source and a handle coupled to the main body. Generally, a user (operator) of a power tool performs work by holding the main body with one hand and holding the handle with the other hand.

  Here, among power tools, there is a power tool that generates a large vibration during its use. For example, a hammer drill that applies rotational force or striking force to a drill bit, drills an object (concrete wall, stone, etc.) with the drill bit or crushes the object generates large vibrations during use. It is an example of a power tool. Furthermore, when using a hammer drill, it is necessary to apply a force to the handle to press the tip of the drill bit against the object, and a large vibration is transmitted to the hand of the operator holding the handle.

  Therefore, a power tool is known in which a vibration absorbing mechanism is provided between the main body and the handle to reduce vibration transmitted from the main body to the handle (Patent Document 1).

JP-A-8-126975

  If a vibration absorbing mechanism is interposed between the main body and the handle, vibration transmitted from the main body to the handle is reduced. However, if the effect of the vibration absorption mechanism (vibration absorption performance) is too strong, the force applied by the operator to the handle becomes difficult to be transmitted to the main body, and the stability of the work is impaired.

  Further, among power tools, there is a power tool having a plurality of operation modes that can be switched according to work contents. In such a power tool, it is desirable to give priority to work stability over vibration absorption performance when a certain operation mode is selected, and when a different operation mode is selected, It is desirable to prioritize vibration absorption performance over stability.

  An object of the present invention is to provide a power tool capable of adjusting the performance of a vibration absorbing mechanism interposed between a main body and a handle.

  The power tool of the present invention includes a main body having a power source, a handle coupled to the main body, and a vibration that is interposed between the main body and the handle and absorbs vibration transmitted from the main body to the handle. A vibration absorption mechanism, and the vibration absorption performance can be adjusted by changing the form of the vibration absorption mechanism.

  In one aspect of the present invention, the vibration absorbing mechanism is disposed on two or more vibration transmission paths through which vibration is transmitted from the main body to the handle and on each of the vibration transmission paths, and absorbs vibration by elastic deformation. And having an elastic member. The vibration absorbing mechanism includes a first form in which vibration is transmitted from the main body to the handle via one or more vibration transmission paths, and the vibration transmission path having more vibration transmission paths than the first form. It is possible to switch to the second mode in which vibration is transmitted from the main body to the handle.

  In another aspect of the present invention, the vibration absorbing mechanism includes a first vibration transmission path and a second vibration transmission path. In the first aspect, the handle is moved from the main body via the first vibration transmission path. The vibration is transmitted to the handle through the first vibration transmission path and the second vibration transmission path in the second mode.

  In another aspect of the present invention, the number of the elastic members that absorb vibration in the first embodiment is different from the number of the elastic members that absorb vibration in the second embodiment.

  In another aspect of the present invention, at least two operation modes can be switched, and the form of the vibration absorbing mechanism is switched in conjunction with the switching of the operation modes.

  In another aspect of the present invention, the impact force is transmitted to the tip tool while the rotational force is not transmitted, and the second operation mode in which the torque is transmitted to the tip tool, When the first operation mode is selected, the form of the vibration absorbing mechanism is switched to the first form, and when the second operation mode is selected, the form of the vibration absorbing mechanism is switched to the second form. It is done.

  In another aspect of the present invention, the amount of movement of the handle relative to the main body per predetermined load applied to the handle varies between the first form and the second form.

  ADVANTAGE OF THE INVENTION According to this invention, the power tool which can adjust the performance of the vibrational absorption mechanism interposed between a main body and a handle | steering-wheel is implement | achieved.

It is sectional drawing of a hammer drill. It is other sectional drawing of a hammer drill. It is a top view of the partial cross section of a hammer drill. It is a disassembled perspective view of a vibration absorption mechanism. It is a perspective view of the vibration absorption mechanism at the time of hammer mode selection. It is a top view of the vibration absorption mechanism at the time of hammer mode selection, (a) is a top view of an unloaded state, (b) is a top view of a loaded state. It is a perspective view of the vibration absorption mechanism at the time of hammer drill mode selection. It is a top view of the vibration absorption mechanism at the time of hammer drill mode selection, (a) is a top view in a no-load state, (b) is a top view in a loaded state.

  Hereinafter, an example of an embodiment of the power tool of the present invention will be described. The power tool according to the present embodiment is a hammer drill in which a drill bit that is one of tip tools can be attached and detached. Although the use of the hammer drill according to the present embodiment is not particularly limited, it is suitable for an operation of making a hole in an object such as a concrete wall or a stone or crushing the object. In addition, the hammer drill according to the present embodiment has a first operation mode in which the striking force is transmitted to the drill bit while the rotational force is not transmitted, and a second operation mode in which at least the rotational force is transmitted to the drill bit. . Further, in the second operation mode in the present embodiment, the striking force is transmitted to the drill bit in addition to the rotational force. Therefore, in the following description, the first operation mode is referred to as “hammer mode”, and the second operation mode is referred to as “hammer drill mode”.

  As shown in FIG. 1, the hammer drill 1 has a main body 2 and a handle 3 connected to the main body 2. The main body 2 includes a cylinder housing 4, an intermediate housing 5, and a motor housing 6, which are fixed and integrated with each other. The cylinder housing 4 has a cylindrical shape as a whole, and an intermediate housing 5 and a motor housing 6 are disposed between the longitudinal end of the cylinder housing 4 and the handle 3. In the following description, the longitudinal direction of the cylinder housing 4 is defined as the “front-rear direction”. Further, of the both sides in the longitudinal direction of the cylinder housing 4, the side on which the intermediate housing 5 and the motor housing 6 are disposed is defined as “rear”, and the opposite side is defined as “front”. That is, the intermediate housing 5 and the motor housing 6 are disposed between the rear end of the cylinder housing 4 and the handle 3.

  The intermediate housing 5 and the motor housing 6 overlap each other, one end of the handle 3 is connected to the motor housing 6, and the other end of the handle 3 is connected to the intermediate housing 5 via the vibration absorbing mechanism 7. In the following description, one end of the handle 3 connected to the motor housing 6 is defined as “lower end”, and the other end of the handle 3 connected to the intermediate housing 5 is defined as “upper end”. In other words, the extending direction of the handle 3 is defined as “vertical direction”. A direction orthogonal to both the front-rear direction and the up-down direction is defined as a “left-right direction”.

  A cylindrical cylinder 10 and a retainer sleeve 11 are accommodated in the cylinder housing 4. The cylinder 10 and the retainer sleeve 11 are concentric, and a part of the retainer sleeve 11 protrudes from the tip of the cylinder housing 4. The cylinder 10 and the retainer sleeve 11 are engaged so as not to rotate relative to each other. When a rotational force is transmitted to the cylinder 10, the cylinder 10 and the retainer sleeve 11 rotate integrally with the central axis as a rotation axis. A part of the drill bit (not shown) is inserted into the retainer sleeve 11. The drill bit inserted into the retainer sleeve 11 engages with the retainer sleeve 11 so as not to move in the rotational direction and to move within a predetermined range in the front-rear direction. Therefore, when the cylinder 10 and the retainer sleeve 11 rotate, the rotational force is transmitted to the drill bit, and the drill bit rotates. Further, when the striking force is transmitted to the drill bit, the drill bit reciprocates within a predetermined range in the front-rear direction. Details of the movement of the cylinder 10, the retainer sleeve 11, and the drill bit will be described later.

  A piston 12 and a striker 13 are accommodated in the cylinder 10 so as to be able to reciprocate. Further, an intermediate element 14 is accommodated so as to be able to reciprocate across the cylinder 10 and the retainer sleeve 11. The piston 12, the striker 13 and the intermediate element 14 are arranged in a line in this order from the rear side of the cylinder 10 toward the front side. Further, an air chamber 15 is provided in the cylinder 10 between the piston 12 and the striker 13.

  A motor 20 that is a power source is accommodated in the motor housing 6. The motor 20 is an inner rotor type brushless motor, and includes a cylindrical stator 21, a rotor 22 disposed inside the stator 21, and an output shaft 23 disposed inside the rotor 22. The output shaft 23 is fixed to the rotor 22 and extends vertically through the rotor 22. The central axis of the output shaft 23 and the central axes of the cylinder 10 and the retainer sleeve 11 are orthogonal to each other.

  The upper part of the output shaft 23 protruding from the rotor 22 penetrates the partition wall between the motor housing 6 and the intermediate housing 5 and enters the intermediate housing 5. A pinion gear 24 is provided at the upper end of the output shaft 23 protruding into the intermediate housing 5. In the intermediate housing 5, a first drive shaft 30 is rotatably disposed on one side of the output shaft 23, and a second drive shaft 40 is rotatably disposed on the other side of the output shaft 23. Yes. The output shaft 23, the first drive shaft 30, and the second drive shaft 40 are parallel to each other.

  A first gear 31 that meshes with the pinion gear 24 is provided at the lower portion of the first drive shaft 30, and an eccentric pin 32 is provided at the upper portion of the first drive shaft 30, and the eccentric pin 32 is connected via a connecting rod 33. Are connected to the piston 12.

  A second gear 41 that meshes with the pinion gear 24 is provided at the lower portion of the second drive shaft 40, and a bevel gear 42 is provided at the upper portion of the second drive shaft 40, and the bevel gear 42 is disposed around the cylinder 10. The ring gear 43 is engaged. The ring gear 43 is mounted on the outer peripheral surface of the cylinder 10 via a sliding bearing (metal), and freely rotates with respect to the cylinder 10.

  In addition to the ring gear 43, a sleeve 44 is provided on the outer peripheral surface of the cylinder 10. The sleeve 44 rotates integrally with the cylinder 10 and slides alone in the axial direction (front-rear direction) of the cylinder 10. The sleeve 44 is always urged rearward by a spring.

  As shown in FIG. 3, a mode switching dial 50 is provided on the upper surface of the intermediate housing 5, and the operation mode is switched by rotating the mode switching dial 50. Specifically, a hammer mode in which only the striking force is transmitted to the drill bit and a hammer drill mode in which the striking force and the rotational force are transmitted to the drill bit are switched by the rotation operation of the mode switching dial 50. More specifically, when the mode switching dial 50 is rotated in the first direction shown in FIG. 1, the sleeve 44 slides forward against the spring bias, and the ring gear 43 and the sleeve 44 are engaged. Is released. When the engagement between the ring gear 43 and the sleeve 44 is released in this way, the rotational force is not transmitted to the cylinder 10. On the other hand, when the mode switching dial 50 is rotated in the second direction shown in FIG. 2, the sleeve 44 slides rearward by the bias of the spring, and the ring gear 43 and the sleeve 44 are engaged. When the ring gear 43 and the sleeve 44 are engaged in this manner, the rotational force is transmitted to the cylinder 10.

  When the brushless motor 20 shown in FIGS. 1 and 2 operates, the rotation of the output shaft 23 is transmitted to the first drive shaft 30 via the pinion gear 24 and the first gear 31, and the first drive shaft 30 rotates. The rotation of the output shaft 23 is transmitted to the second drive shaft 40 via the pinion gear 24 and the second gear 41, and the second drive shaft 40 rotates.

  When the first drive shaft 30 rotates, the eccentric pin 32 provided at the upper end of the first drive shaft 30 rotates with the central axis of the first drive shaft 30 as the rotation axis. That is, the eccentric pin 32 turns around the central axis of the first drive shaft 30. As a result, the piston 12 connected to the eccentric pin 32 via the connecting rod 33 reciprocates in the cylinder 10. When the piston 12 moves away from the striker 13, that is, when the piston 12 moves backward, the pressure in the air chamber 15 decreases and the striker 13 moves backward. On the other hand, when the piston 12 moves in the direction approaching the striker 13, that is, when the piston 12 moves forward, the pressure in the air chamber 15 rises and the striker 13 moves forward. When the striker 13 moves forward, the intermediate piece 14 is hit by the striker 13, and a drill bit (not shown) is hit by the intermediate piece 14. In this way, the striking force is intermittently transmitted to the drill bit.

  When the second drive shaft 40 rotates, the bevel gear 42 provided at the upper end of the second drive shaft 40 rotates, and the ring gear 43 engaged with the bevel gear 42 rotates. At this time, if the hammer mode is selected by the rotation operation of the mode switching dial 50, that is, if the engagement between the ring gear 43 and the sleeve 44 is released, the rotation of the ring gear 43 is not transmitted to the cylinder 10, and the ring gear 43 idles on the cylinder 10. Therefore, the rotational force is not transmitted to the drill bit, but only the striking force is transmitted.

  On the other hand, when the hammer drill mode is selected by rotating the mode switching dial 50, that is, when the ring gear 43 and the sleeve 44 are engaged, the rotation of the ring gear 43 is transmitted to the cylinder 10 via the sleeve 44, The cylinder 10 and the retainer sleeve 11 rotate integrally. Therefore, the striking force is intermittently transmitted to the drill bit held by the retainer sleeve 11 and the rotational force is continuously transmitted.

  Next, the vibration absorbing mechanism 7 interposed between the main body 2 and the handle 3 will be described. As described above, the upper end of the handle 3 is connected to the intermediate housing 5, the lower end of the handle 3 is connected to the motor housing 6, and the vibration absorbing mechanism 7 is interposed between the upper end of the handle 3 and the intermediate housing 5. ing. In other words, the upper end of the handle 3 is connected to the intermediate housing 5 via the transatry unit.

  The structure of the vibration absorbing mechanism 7 is shown in FIG. The vibration absorbing mechanism 7 is directly or indirectly fixed to the handle side support member 60 fixed directly or indirectly to the handle 3 (FIGS. 1 and 2) and to the intermediate housing 5 (FIGS. 1 and 2). A first main body side support member 71, and a second main body side support member 72 and a slide member 73 mounted on the first main body side support member 71.

  As shown in FIGS. 5 and 7, the handle side support member 60 has a substantially U-shape as a whole, and a first main body side support member 71 and a second main body side support member are disposed inside the handle side support member 60. 72 and a slide member 73 are arranged. As shown in FIG. 4, a stage 74 is integrally formed with the first main body side support member 71, and a second main body side support member 72 and a slide member 73 are mounted on the stage 74.

  As shown in FIG. 4, a first inner surface 60a and a third inner surface 60c are formed on one of the opposed side walls of the handle side support member 60, and a second inner surface 60b and a fourth inner surface 60d are formed on the other of the opposed side walls. Is formed. The first inner surface 60a and the second inner surface 60b are opposed to each other to form a pair, and the third inner surface 60c and the fourth inner surface 60d are opposed to each other to form a pair. However, the first inner surface 60a and the second inner surface 60b are inclined in opposite directions, and the third inner surface 60c and the fourth inner surface 60d are inclined in opposite directions. In other words, the first inner surface 60a and the third inner surface 60c are inclined in the same direction, and the second inner surface 60b and the fourth inner surface 60d are inclined in the same direction.

  On the other hand, a first outer surface 71 a that faces the first inner surface 60 a of the handle side support member 60 is formed on one side wall of the first main body side support member 71, and the other side wall of the first main body side support member 71. Is formed with a second outer surface 71 b opposite to the second inner surface 60 b of the handle-side support member 60. As shown in FIGS. 5 and 7, the first outer surface 71a is parallel or substantially parallel to the first inner surface 60a, and the second outer surface 71b is parallel or substantially parallel to the second inner surface 60b. .

  As shown in FIG. 4, the second main body side support member 72 is opposed to the third outer surface 72 c facing the third inner surface 60 c of the handle side support member 60 and the fourth inner surface 60 d of the handle side support member 60. A fourth outer surface 72d is formed. As shown in FIGS. 5 and 7, the third outer surface 72c is parallel or substantially parallel to the third inner surface 60c, and the fourth outer surface 72d is parallel or substantially parallel to the fourth inner surface 60d. .

  As shown in FIGS. 5 and 7, a plurality of elastic members are disposed between the handle side support member 60, the first main body side support member 71, and the second main body side support member 72. Specifically, the first elastic member 81 is disposed between the first inner surface 60a and the first outer surface 71a, the second elastic member 82 is disposed between the second inner surface 60b and the second outer surface 71b, A third elastic member 83 is disposed between the third inner surface 60c and the third outer surface 72c, and a fourth elastic member 84 is disposed between the fourth inner surface 60d and the fourth outer surface 72d. That is, each elastic member is sandwiched and supported by two opposing surfaces. Therefore, in the following description, the first inner surface 60a, the second inner surface 60b, the third inner surface 60c, the fourth inner surface 60d, the first outer surface 71a, the second outer surface 71b, the third outer surface 72c, and the fourth outer surface 72d are referred to as “support surfaces”. "May be collectively referred to.

  As shown in FIG. 4, each elastic member is a substantially cylindrical rubber, and has a thick central portion and thin end portions. That is, the elastic member has a large diameter portion and a small diameter portion connected to both ends of the large diameter portion, and a stepped surface exists between the large diameter portion and the small diameter portion.

  The first main body side support member 71 is formed with a holding groove 75 that holds the slide member 73 so as to be able to advance and retreat, and a part of the holding groove 75 in the longitudinal direction is widened outward. On the other hand, the slide member 73 has a substantially prismatic shape, and a pair of locking portions 76 projecting outward are formed at the approximate center in the longitudinal direction. As shown in FIGS. 5 and 7, the locking portion 76 has entered the inside of the widened portion 75 a of the holding groove 75, and a spring 77 (see FIG. 5) is provided between the end surface of the widened portion 75 a and the locking portion 76. 6, FIG. 8) is arranged. The slide member 73 is always urged by the spring 77 in a direction away from the second main body side support member 72. That is, the slide member 73 is always urged toward the front. As shown in FIG. 3, a mode switching dial 50 is disposed in front of the vibration absorbing mechanism 7. Further, as shown in FIG. 4, a protrusion 51 that bulges radially outward is formed on the outer peripheral surface of the mode switching dial 50.

  As shown in FIGS. 5 and 6A, when the mode switching dial 50 is rotated in the first direction, that is, when the hammer mode is selected, the protruding portion 51 moves forward. On the other hand, as shown in FIGS. 7 and 8A, when the mode switching dial 50 is rotated in the second direction, that is, when the hammer drill mode is selected, the protrusion 51 moves backward.

  As shown in FIG. 8A, the protruding portion 51 of the mode switching dial 50 that has moved rearward contacts the slide member 73 and retracts the slide member 73 against the bias of the spring 77. In other words, when the hammer drill mode is selected, the slide member 73 comes close to the second main body side support member 72 and contacts the front surface of the second main body side support member 72.

  When the handle 3 (FIG. 2) is pushed forward in the state shown in FIG. 8A, the handle-side support member 60 fixed to the handle 3 is also pushed forward. Then, as shown in FIG. 8B, the first elastic member 81 and the second elastic member 82 between the handle side support member 60 and the first main body side support member 71 are compressed and elastically deformed. Specifically, the first elastic member 81 is compressed between two support surfaces that face each other with the first elastic member 81 interposed therebetween, and press-contacts these support surfaces. The second elastic member 82 is compressed between two support surfaces facing each other with the second elastic member 82 interposed therebetween, and presses against these support surfaces. In other words, an initial load (preload) is applied to the first elastic member 81 and the second elastic member 82.

  Further, since the forward movement of the second main body side support member 72 is restricted by the slide member 73, the third elastic member 83 and the second elastic member 83 between the handle side support member 60 and the second main body side support member 72 are provided. The fourth elastic member 84 is also compressed and elastically deformed. Specifically, the third elastic member 83 is compressed between two support surfaces that face each other with the third elastic member 83 interposed therebetween, and press-contacts the support surfaces. Further, the fourth elastic member is compressed between two support surfaces opposed to each other with the fourth elastic member 84 interposed therebetween, and is pressed against these support surfaces. In other words, an initial load (preload) is applied to the third elastic member 83 and the fourth elastic member 84.

  When vibration occurs on the main body side in the state shown in FIG. 8B, the vibration is transmitted to the handle side support member 60 via the first main body side support member 71, the first elastic member 81, and the second elastic member 82. Communicated. At the same time, the vibration is transmitted to the handle side support member 60 via the slide member 73, the second main body side support member 72, the third elastic member 83, and the fourth elastic member 84. That is, the vibration generated on the main body side is the first vibration transmission path including the first elastic member 81 and the second elastic member 82 and the second vibration transmission path including the third elastic member 83 and the fourth elastic member 84. It is transmitted to the handle side by two vibration transmission paths. At this time, the 1st elastic member 81 and the 2nd elastic member 82 which are arrange | positioned on the 1st vibration transmission path receive rolling compression between the opposing support surfaces, and exhibit a nonlinear spring characteristic. As a result, the vibration transmitted from the main body side to the handle side via the first vibration transmission path is absorbed. Similarly, the 3rd elastic member 83 and the 4th elastic member 84 which are arrange | positioned on a 2nd vibration transmission path receive rolling compression between the opposing support surfaces, and exhibit a nonlinear spring characteristic. As a result, the vibration transmitted from the main body side to the handle side via the second vibration transmission path is absorbed.

  On the other hand, as shown in FIG. 6A, when the protrusion 51 of the mode switching dial 50 moves forward, the push on the slide member 73 is released. Then, the slide member 73 moves forward by the bias of the spring 77 and moves away from the second main body side support member 72. When the handle 3 (FIG. 1) is pushed forward in the state shown in FIG. 6A, the handle-side support member 60 fixed to the handle 3 is also pushed forward. Then, as shown in FIG. 6B, the first elastic member 81 and the second elastic member 82 between the handle side support member 60 and the first main body side support member 71 are compressed in the same manner as described above. Elastically deforms. That is, an initial load (preload) is applied to the first elastic member 81 and the second elastic member 82. On the other hand, in the state shown in FIG. 6A, the slide member 73 is not in contact with the second main body side support member 72, and the forward movement of the second main body side support member 72 is not restricted. Therefore, the third elastic member 83 and the fourth elastic member 84 between the handle side support member 60 and the second main body side support member 72 are not compressed and elastically deformed. That is, no initial load (preload) is applied to the third elastic member 83 and the fourth elastic member 84. Therefore, when vibration occurs on the main body side in the state shown in FIG. 6B, the vibration is transmitted to the handle side only through the first vibration transmission path.

  As described above, the hammer drill 1 according to the present embodiment has at least two operation modes (hammer mode and hammer drill mode), and these operation modes can be switched. The vibration absorbing mechanism 7 has two or more vibration transmission paths (a first vibration transmission path and a second vibration transmission path). The vibration absorbing mechanism 7 includes a first mode in which vibration is transmitted from the main body 2 to the handle 3 via the first vibration transmission path, and a first vibration transmission path and a second vibration transmission path from the main body 2 to the handle 3. And a second mode in which vibration is transmitted through the second mode. In other words, the vibration absorbing mechanism 7 includes a first form in which vibration is transmitted from the main body 2 to the handle 3 via one or more vibration transmission paths (in this embodiment, one vibration transmission path), It changes to the 2nd form in which a vibration is transmitted from the main body 2 to the handle | steering-wheel 3 via more vibration transmission paths (this embodiment two vibration transmission paths) than one form. Then, in conjunction with the switching of the operation mode, the form of the vibration absorbing mechanism 7 is automatically switched to the first form or the second form. Specifically, when the hammer mode is selected, the mode is switched to the first mode, and when the hammer drill mode is selected, the mode is switched to the second mode.

  Further, two elastic members are arranged on each vibration transmission path. Therefore, in the first mode (when the hammer mode is selected), the vibration is absorbed by the two elastic members, and in the second mode (when the hammer drill mode is selected), the vibration is absorbed by the four elastic members. . That is, the number of elastic members contributing to vibration absorption in the first form is different from the number of elastic members contributing to vibration absorption in the second form. In addition, although four elastic members are interposed between the main body 2 and the handle 3, in the first mode (when the hammer mode is selected), two of the four elastic members (the first elastic member) An initial load is applied to the elastic member 81 and the second elastic member 82). On the other hand, in the second configuration (when the hammer drill mode is selected), the initial load is applied to all four elastic members (the first elastic member 81, the second elastic member 82, the third elastic member 83, and the fourth elastic member 84). Is granted.

  As described above, the first form has a smaller number of elastic members to which an initial load is interposed between the main body 2 and the handle 3 than the second form. Therefore, the first form has higher vibration absorption performance than the second form, but the handle 3 is easy to move relative to the main body 2. On the other hand, the second form has lower vibration absorption performance than the first form, but the handle 3 is difficult to move relative to the main body 2. That is, the vibration absorbing performance of the vibration absorbing mechanism 7 can be changed (adjustable) by changing the form of the vibration absorbing mechanism 7 to the first form or the second form. Further, in the first form, the handle 3 is fixed relatively loosely with respect to the main body 2, and in the second form, the handle 3 is fixed relatively firmly with respect to the main body 2. In other words, when a predetermined load in the front-rear direction is applied to the handle 3, the movement amount of the handle 3 relative to the main body 2 is relatively large in the first form, and the movement amount of the handle 3 relative to the main body 2 is large in the second form. Relatively few. That is, the spring constant of the vibration absorbing mechanism 7 in the second form is larger than the spring constant of the vibration absorbing mechanism 7 in the first form. Furthermore, in the first embodiment, only the two elastic members (the first elastic member 81 and the second elastic member 82) arranged in front of the vibration absorbing mechanism 7 absorb the load in the left-right direction applied to the handle 3. Act on. On the other hand, in the second embodiment, the four elastic members (first elastic member 81 to fourth elastic member 84) arranged before and after the vibration absorbing mechanism 7 act so as to absorb the lateral load applied to the handle 3. To do. In other words, the upper end of the handle 3 is supported only in front of the vibration absorbing mechanism 7 in the first form, and is supported before and after the vibration absorbing mechanism 7 in the second form. That is, in the second configuration, the support points of the handle 3 in the front-rear direction are increased compared to the first configuration, and thus the support force in the left-right direction of the handle 3 is enhanced. That is, even when a predetermined load in the left-right direction is applied to the handle 3, in the first form, the amount of movement of the handle 3 relative to the main body 2 is relatively large, and in the second form, the amount of movement of the handle 3 relative to the main body 2 is small. Relatively few. Therefore, in the second embodiment, the force applied to the handle 3 by the operator is more reliably transmitted to the main body 2 and the stability of the work is increased. On the other hand, in the first form, vibration is less likely to be transmitted to the operator. Therefore, when performing work in which work stability has priority over vibration absorption performance, the vibration absorbing mechanism 7 is switched to the second form, and in performing work in which vibration absorption performance has priority over work stability. Preferably, the vibration absorbing mechanism 7 is switched to the first form.

  Therefore, in this embodiment, when the operator operates the mode switching dial 50 to select a hammer drill mode suitable for drilling work or the like, the vibration absorbing mechanism 7 is in the second form in conjunction with the operation of the mode switching dial 50. Similarly, when a hammer mode suitable for crushing work or the like is selected, the vibration absorbing mechanism 7 is switched to the first mode in conjunction with the operation of the mode switching dial 50. That is, since the second form is selected in the hammer drill mode that requires accuracy, the stability of the work is high, and the first form is selected in the hammer mode that requires vibration absorption performance rather than the accuracy. Vibrations are less likely to be transmitted to the operator, and comfortable work can be realized.

  In the second form of the vibration absorbing mechanism 7, if the slide member 73 shown in FIGS. 8A and 8B enters the inside of the second main body side support member 72, the handle 3 with respect to the main body 2 is moved. The amount of movement (blur amount) in the left-right direction can be further reduced. Specifically, if the end of the slide member 73 is inserted into a groove or a hole formed in the second main body side support member 72, the amount of movement (blur amount) of the handle 3 relative to the main body 2 in the left-right direction. ) Can be further reduced.

  Although the configuration of the vibration absorbing mechanism 7 is automatically switched to the first mode or the second mode in conjunction with the switching of the operation mode, the mode of the vibration absorbing mechanism 7 can be switched regardless of the operation mode. It is good also as a structure.

  The shapes and spring constants of the elastic members arranged on each vibration transmission path may be the same or different from each other. The number of elastic members arranged on each vibration transmission path may be the same or different.

  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, the present invention can also be applied to a power tool in which the rotational motion of a motor is converted into a reciprocating motion of a piston by a reciprocating type conversion mechanism. Further, the first operation mode in the present invention includes an operation mode in which only the striking force is transmitted to the tip tool, and the second operation motor includes an operation mode in which only the rotational force is transmitted to the tip tool. .

DESCRIPTION OF SYMBOLS 1 Hammer drill 2 Main body 3 Handle 4 Cylinder housing 5 Intermediate housing 6 Motor housing 7 Vibration absorption mechanism 10 Cylinder 20 Motor (brushless motor)
23 output shaft 24 pinion gear 30 first drive shaft 40 second drive shaft 50 mode switching dial 51 protrusion 60 handle side support member 60a first inner surface 60b second inner surface 60c third inner surface 60d fourth inner surface 71 first main body side support member 71a First outer surface 71b Second outer surface 72 Second body side support member 72c Third outer surface 72d Fourth outer surface 73 Slide member 74 Stage 75 Holding groove 75a Widened portion 76 Locking portion 77 Spring 81 First elastic member 82 Second elastic member 83 3rd elastic member 84 4th elastic member

Claims (7)

A body with a power source;
A handle coupled to the body;
A vibration absorbing mechanism that is interposed between the main body and the handle and absorbs vibration transmitted from the main body to the handle;
The vibration absorbing performance can be adjusted by changing the form of the vibration absorbing mechanism.
Power tool. The vibration absorbing mechanism includes two or more vibration transmission paths through which vibration is transmitted from the main body to the handle;
An elastic member that is disposed on each of the vibration transmission paths and absorbs vibration by elastic deformation;
Vibration is transmitted from the main body to the handle via one or more vibration transmission paths, and vibration from the main body to the handle is transmitted through more vibration transmission paths than the first form. Switchable to the second form to be transmitted,
The power tool according to claim 1. The vibration absorbing mechanism has a first vibration transmission path and a second vibration transmission path,
In the first form, vibration is transmitted from the main body to the handle via the first vibration transmission path,
In the second mode, vibration is transmitted from the main body to the handle via the first vibration transmission path and the second vibration transmission path.
The power tool according to claim 2. The number of the elastic members that absorb vibration in the first form is different from the number of the elastic members that absorb vibration in the second form.
The power tool according to claim 2 or 3. At least two modes of operation can be switched,
The form of the vibration absorbing mechanism is switched in conjunction with the switching of the operation mode.
The power tool according to any one of claims 2 to 4. A first operation mode in which the impact force is transmitted to the tip tool while no rotational force is transmitted; and a second operation mode in which the rotational force is transmitted to the tip tool;
When the first operation mode is selected, the form of the vibration absorbing mechanism is switched to the first form,
When the second operation mode is selected, the form of the vibration absorbing mechanism is switched to the second form.
The power tool according to claim 5. The power tool according to claim 2, wherein an amount of movement of the handle relative to the main body per predetermined load applied to the handle varies between the first form and the second form.

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