JP2008279565A - Impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact tool having high vibration damping effect. <P>SOLUTION: The impact tool 1 comprises a motor 21, a crank part to be rotated by the motor 21, a driving unit connected to the crank part and having a driving piece 53 reciprocating to the fore end direction and the rear end direction, and a dynamic damper mechanism located on the axis of the driving piece 53 having a weight 62 movable in the fore end direction and the rear end direction. The dynamic damper mechanism has a first spring 61A and a second spring 61B. The first spring 61A and the second spring 61B are arranged on the axis and on the driving piece side and the counter-driving piece side of the weight 62, respectively. The impact tool urges the weight 62. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a striking tool, and more particularly to a vibration control mechanism for a striking tool.

In the impact tool, for example, as shown in Patent Document 1, a configuration having a dynamic vibration absorber mechanism constituted by a weight and a spring arranged in the movement direction of the weight is known. In this striking tool, a vibration damping effect is obtained by moving the weight in a phase opposite to that of the striking element in the dynamic vibration absorber mechanism.
JP 52-109673 A

  However, the operation of the striker in the above-described dynamic vibration absorber mechanism is different from the striker in terms of speed and phase difference with respect to the piston when moving toward the tip tool side and returning from the tip tool side. There is a drawback that it is difficult to maintain the phase. Therefore, an object of this invention is to provide the impact tool with a high damping effect which eliminates the conventional fault.

  In order to solve the above-described problems, the present invention provides a motor, a crank portion that is rotationally driven by the motor, a striking portion that is connected to the crank portion and has a striking element that reciprocates in one direction and the other direction, Provided is a striking tool comprising a dynamic vibration absorber mechanism that has a weight that is located on an axis of the striking element and is movable in the one direction and the other direction.

  In the impact tool having the above-described configuration, the dynamic vibration absorber mechanism has an urging member, and the urging member is disposed on the shaft and on the striker side and the counter-brusher side of the weight so as to remove the weight. Preferably, it is energized.

  According to such a configuration, since the striker and the weight, which are the places where vibration is generated, are on the same axis, the vibration of the striker can be efficiently canceled by the weight. Further, by urging the weight with the urging member, the phase of vibration when an external force is applied to the weight can be delayed. Therefore, for example, the phase shift of the weight with respect to the striker driven by the piston can be reduced, and the vibration can be suitably reduced.

  The crank portion preferably has a cam portion that moves the weight in the other direction via the biasing member when the striker is moved in the one direction.

  According to such a configuration, the weight phase can be made substantially opposite to the striker phase.

  Further, it is preferable to further include a crankcase for holding the crank portion, the crank portion having a crankshaft, and the crankshaft being supported by the crankcase via a bearing.

  According to such a structure, a crank part can be unitized by a crankcase. Therefore, a striking tool can be manufactured by combining the unitized members, and workability at the time of manufacturing can be improved.

  Preferably, the motor has an output shaft, and the crank portion is disposed on the one direction side with the output shaft interposed therebetween, and the weight is disposed on the other direction side. According to such a configuration, the weight can be arranged in the surplus space, and the impact tool can be configured compactly. In addition, the striker, the weight, and the motor, which are heavy objects, can be arranged in a well-balanced manner, so that the center of gravity of the impact tool can be brought to the approximate center of the impactor, weight, and motor, improving the handling of the impact tool. Can be made.

  In order to solve the above problems, a motor, a crank portion having a crankshaft driven by the motor, a crankcase for housing the crank portion, and a dynamic vibration absorber provided in the crankcase for absorbing vibrations The dynamic vibration damping mechanism includes a weight and a biasing mechanism that biases the weight in a spring, and the biasing mechanism biases the weight in conjunction with the rotational movement of the crankshaft. Provide impact tools.

  According to the impact tool of the present invention, the vibration damping effect can be enhanced.

  Hereinafter, an impact tool according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. A hammer 1 as an impact tool shown in FIG. 1 mainly includes a handle portion 10, a motor case 20, a gear case 30, a crankcase 40, and a cylinder case 50. Hereinafter, the left side in FIG. 1 will be described as the front end side of the hammer 1, and the right side will be described as the rear end side of the hammer 1.

  A power cable 11 is attached to the handle portion 10 and a switch mechanism (not shown) is built therein. A trigger 12 that can be operated by a user is mechanically connected to the switch mechanism. The power cable 11 connects the switch mechanism to an external power source (not shown). The trigger 12 is switched between connection and disconnection of an electric motor 21 (described later) and an external power source by being operated.

  The motor case 20 is provided at the lower end on the front end side of the handle portion 10. An electric motor 21 is accommodated in the motor case 20. The electric motor 21 includes an output shaft 22 that outputs the rotational driving force. A pinion gear 23 is provided at the tip of the output shaft 22, and the pinion gear 23 passes through the gear case 30 and is positioned in the crankcase 40.

  The gear case 30 is disposed on the upper side of the motor case 20 and rotatably supports a lower end of a crankshaft 42 described later, and holds a bearing 31 that rotatably supports the output shaft 22.

  The crankcase 40 is disposed on the upper part of the gear case 30. A gear 41 that meshes with the pinion gear 23, a crankshaft 42 that rotates coaxially with the gear 41, and a bearing 45 that rotatably supports the crankshaft 42 in cooperation with the gear case 30 are disposed in the crankcase 40. . As shown in FIGS. 1 and 2, a cam portion 43 is provided on the upper end of the crankshaft 42. As shown in FIG. 2, a crank pin 44 is provided at a position opposite to the protruding portion in the diameter direction of the cam portion 43.

  In the crankcase 40, a weight case 60 is provided at a position on the rear end side of the crankshaft 42. In the weight case 60, a space 60a formed in a direction parallel to the axial direction of the striker 53 is formed in a portion substantially on the extension line of a shaft on which a later-described striker 53 reciprocates. The rear end of the space 60a The wall which comprises the crankcase 40 is located in the side opening part. Inside the space 60a, a first spring 61A, a weight 62, and a second spring 61B are arranged in this order from the tip side, and the weight 62 is urged by the first spring 61A and the second spring 61B. . The rear end portion of the second spring 61B is in contact with the crankcase 40. Therefore, in the direction connecting the front end side and the rear end side, the portion constituting the crank portion including the crankshaft 42 and the like is disposed on the front end side with the output shaft 22 interposed therebetween, and the weight 62 is on the rear end side with the output shaft 22 interposed therebetween. It becomes the composition arranged in. According to such a configuration, the weight 62 can be disposed in the surplus space, and the hammer 1 can be configured compactly.

  On the front side of the space 60 a in the weight case 60, a hole 63 a that communicates the space 60 a with the outside of the weight case 60 and extends substantially parallel to the axial direction of the striker 53 is formed. As shown in FIG. 2, a rod 63 </ b> A having a hemispherical tip is disposed in the perforation 63 a via a spring 64. The spring 64 biases the rod 63 </ b> A toward the distal end side, and the distal end of the rod 63 </ b> A is always in contact with the cam surface of the cam portion 43 by this biasing force. A flange 63B is provided at the rear end portion of the rod 63A, and the flange 63B is disposed on the distal end side of the first spring 61A and is in contact with the first spring 61A. Therefore, the first spring 61A is urged when the rod 63A moves to the rear end side, and the weight 62 moves rearward by this urging force. Since the weight 62 is connected to the rod 63A via the first spring 61A, the operation of the rod 63A and the operation of the weight 62 are not necessarily synchronized, and a phase shift occurs.

  A lid 46 is provided above the crankcase 40. When the hammer 1 is assembled, the weight case 60 is inserted and installed in the crankcase 40, and the cam portion 43 and the like are assembled, and then the lid 46 is attached, whereby the crankcase 40 and other components in the crankcase 40 are installed. Can be protected from the outside. Further, since the inside of the crankcase 40 can be accessed simply by removing the lid 46, when a failure occurs in the cam portion 43 or the like, the lid 46 can be opened for easy repair or the like.

  The cylinder case 50 is provided on the distal end side of the crankcase 40. The cylinder case 50 mainly includes a cylinder 51, a piston 52, a striker 53, and an intermediate element 54. The cylinder 51 is configured in a cylindrical shape, and is disposed in the cylinder case 50 so that the front and rear end direction is the axial direction. The piston 52 is slidably incorporated in the Linder 51 and is connected to the crankpin 44 by a connecting rod 52A. Therefore, the piston 52 reciprocates in the cylinder 51 in accordance with the rotation of the crankshaft 42. The striker 53 is slidably disposed on the tip end side of the piston 52 in the cylinder 51. An air chamber 51 a is formed between the striker 53 and the piston 52 in the cylinder 51. When the air chamber 51 a is compressed and expanded by the piston 52, the striker 53 can reciprocate in the cylinder 51. The intermediate element 54 is disposed at the tip end side position of the striker 53, and is configured to come into contact with the striker 53 when the striker 53 moves to the distal end side. Since the weight 62 is disposed substantially on the axis of the striker 53 that is a place where vibration is generated, the vibration of the hammer 1 caused by the striker 53 is efficiently canceled by the weight 62.

  In the hammer 1, a crank portion is configured as a unit from the crankcase 40, the crankshaft 42 provided in the crankcase 40, the cam portion 43, and the like, and a unit is formed from the weight case 60 and the weight 62, etc. provided in the weight case 60. A dynamic vibration absorber mechanism is configured, and a cylinder portion is configured as a unit from the cylinder case 50 and the striker 53 and the like. According to such a structure, a crank part can be unitized by a crankcase. Therefore, a striking tool can be manufactured by combining the unitized members, and workability at the time of manufacturing can be improved.

  A tip tool 2 is provided at the tip of the cylinder case 50. The tip tool 2 is configured to be able to transmit an impact generated when the striker 53 collides with the intermediate piece 54.

  The operation of the hammer 1 having the above configuration will be described. When the user pulls the trigger 12 while holding the handle 10, electric power is supplied to the electric motor 21 to rotate the output shaft 22, and the crankshaft 42 and the cam portion 43 connected to the output shaft 22 rotate.

  The piston 52 connected to the crankpin 44 moves to the tip side according to the rotation of the cam portion 43 (FIG. 3), and compresses the air chamber 51a. The striking element 53 moves to the tip side by the compressed air chamber 51a and abuts against the intermediate element 54 to generate an impact on the intermediate element 54 and the tip tool 2. Therefore, compared with the timing when the crankpin 44 and the piston 52 move to the most distal side, the timing at which the striker 53 moves to the most distal side and contacts the intermediate element 54 is delayed.

  In the cam portion 43, as shown in FIG. 4, the protruding portion abuts on the rod 63A in a state where the crank pin 44 has moved further to the tip side. In this state, since the rod 63A moves backward, the first spring 61A biased by the flange 63B connected to the rod 63A moves to the rear end side. As the first spring 61A moves toward the rear end, the weight 62 biased by the first spring 61A also moves toward the rear end. Therefore, the timing at which the weight 62 moves toward the rear end side is delayed as compared with the timing at which the rod 63A moves to the most rear end side (the timing at which the crank pin 44 and the piston 52 move to the most front end side).

  The movement of the striker 53 toward the distal end side and the movement of the weight 62 toward the rear end side cause a phase shift as compared with the movement of the cam portion 62 toward the distal end side of the crank pin 44. The movement to the side and the movement to the rear end side of the weight 62 occur at substantially the same timing. At this time, the striker 53 moves to the front end side, and the weight 62 moves to the rear end side of the opposite phase. Therefore, the vibration generated by the striker 53 by the weight 62 is suppressed, and the vibration is transmitted to the user. Can be reduced.

Side surface sectional drawing of the impact tool which concerns on embodiment of this invention. The plane fragmentary sectional view of the hitting tool concerning an embodiment of the invention. Side surface sectional drawing (at the time of impact) of the impact tool which concerns on embodiment of this invention. The plane partial sectional view of the hitting tool concerning an embodiment of the invention (at the time of hitting).

Explanation of symbols

1 .... hammer 2 .... tip tool 10..handle part 11..power cable 12..trigger 20..motor case 21..electric motor 22..output shaft 23..pinion gear 30..gear case 31..bearing 40 ·· Crankcase 41 · · Gear 42 · · Crankshaft 43 · · Cam portion 44 · · Crank pin 45 · · Bearing 46 · · Lid 50 · · Cylinder case 51 · · Cylinder 51a · · Air chamber 52 · · Piston 52A ·· Connecting rod 53 · · Batter 54 · · Intermediate 60 · · Weight case 61A · · First spring 61B · · · Second spring 60a · · · Space 62 · · Weight 63A · · Rod 63B · · · Flange 63a · · · 64 .. Spring

Claims (6)

A motor,
A crank portion rotationally driven by the motor;
A striking part having a striking element connected to the crank part and reciprocating in one direction and the other direction;
A striking tool comprising: a dynamic vibration absorber mechanism having a weight which is located on an axis of the striking element and is movable in the one direction and the other direction.   The dynamic vibration absorber mechanism has a biasing member, and the biasing member is disposed on the striker side and the counter striker side of the weight to bias the weight. The impact tool according to claim 1, wherein   2. The crank portion according to claim 1, wherein the crank portion has a cam portion that moves the weight in the other direction via the biasing member when the striker is moved in the one direction. The impact tool according to any one of 2 above.   4. The crankcase according to claim 1, further comprising a crankcase for holding the crank portion, wherein the crank portion has a crankshaft and the crankshaft is supported by the crankcase via a bearing. The impact tool as described in any one.   2. The motor according to claim 1, wherein the motor has an output shaft, the crank portion is disposed on the one direction side with the output shaft interposed therebetween, and the weight is disposed on the other direction side. Item 5. The impact tool according to any one of Items4. A motor,
A crank portion having a crankshaft driven by the motor;
A crankcase for storing the crank part;
A dynamic vibration absorber mechanism that is provided in the crankcase and absorbs vibration, the dynamic vibration absorption mechanism having a weight and a biasing mechanism that biases the weight in a spring, and the biasing mechanism is the crankshaft A striking tool characterized in that the weight is biased in conjunction with the rotational motion of the.

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