JP2007203388A - Impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique effective for improving work efficiency of an impact tool. <P>SOLUTION: This impact tool 101 has: a motor 111; a first motion conversion mechanism 113 for converting rotation output of the motor 111 into linear motion; a first impact mechanism 117 driven by the first motion conversion mechanism 113 to perform linear movement; a second motion conversion mechanism 115 for converting rotation output of the motor 111 into linear motion; a second impact mechanism 119 driven by the second motion conversion mechanism 115 to perform linear motion; and an end tool member 163 impactingly operated alternately by the first and second impact mechanisms 117, 119. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a striking tool that performs a predetermined machining operation by a striking operation of a tool bit in a major axis direction.

  2. Description of the Related Art An electric hammer as a striking tool that performs a predetermined machining operation by a striking operation of a tool bit driven by a motor in the long axis direction is widely known. Such an electric hammer is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-335046 (Patent Document 1). In the electric hammer described in the publication, the rotation output of the motor is converted into a linear motion of the piston by a crank mechanism, and the striker moves linearly via an air spring in the air chamber that fluctuates due to the linear motion of the piston. It is the structure which gives a blow.

In the impact tool configured as described above, it is necessary to increase the rotation speed of the motor and drive the tool bit at a high speed in order to increase the working efficiency. However, the tool bit such as a crank mechanism or an impact mechanism driven by the motor is required. For example, there is a limit in terms of followability with respect to the rotational speed of the motor. For this reason, it is not possible to cope with the increase in the motor rotation speed, and there is still room for improvement in this respect.
JP 2005-335046 A

  In view of this point, the present invention has an object to provide a technique that is effective in improving the working efficiency of the impact tool.

In order to achieve the above object, the invention described in each claim is configured.
A striking tool according to a first aspect of the present invention includes a motor, a first motion converting mechanism, a first striking mechanism, a second motion converting mechanism, a second striking mechanism, and a tip tool member. Have The first motion conversion mechanism is configured to convert the rotational output of the motor into linear motion, and the first striking mechanism is configured to perform linear motion by being driven by the first motion conversion mechanism. The second motion conversion mechanism is configured to convert the rotational output of the motor into linear motion, and the second striking mechanism is configured to perform linear motion by being driven by the second motion conversion mechanism. The tip tool member is alternately struck by the first and second striking mechanisms and linearly moves to perform a predetermined machining operation on the workpiece. As the “striking tool” in the present invention, typically, an electric hammer or a tip tool member that performs a hammering operation on a workpiece by performing only a striking motion in which the tip tool member is linear in the long axis direction is used. This corresponds to an electric hammer drill that performs a hammer drill operation on a workpiece by performing a striking operation in the long axis direction and a rotating operation around the long axis direction.

The “first motion conversion mechanism” and “second motion conversion mechanism” in the present invention typically correspond to a mechanism that converts the rotational output of the motor into a linear motion of the piston by the crank mechanism. Not limited to this, after the rotational motion of the rotating body rotated by the motor is converted into the swing motion of the swing member, the swing motion of the swing member is converted into the linear motion of the piston, or the motor is rotated by the motor. The mechanism etc. which convert into the linear motion of a piston using the swash plate by which it is used are included suitably. Here, “use” refers to a configuration in which a piston is engaged with a swash plate so as to be relatively movable in the circumferential direction of the swash plate. The “first striking mechanism” and the “second striking mechanism” in the present invention typically include a striking element that performs linear motion by fluctuations in air pressure of the air chamber due to linear linear motion of the piston, Although it is set as the structure which has an intermediate element which transmits the linear motion of the said striker to a front-end tool member, the structure which does not have an intermediate element is included suitably.
In the present invention, the “first and second motion conversion mechanisms” mean that there are at least two motion conversion mechanisms, and in addition to the first and second motion conversion mechanisms, a third motion conversion mechanism, Furthermore, the aspect which has a 4th motion conversion mechanism is included suitably. Similarly, “first and second striking mechanisms” means that there are at least two striking mechanisms, and in addition to the first and second striking mechanisms, a third striking mechanism, and further a fourth striking mechanism. The aspect which has this is included suitably. In addition, the “tip tool member” in the present invention suitably includes both an aspect constituted by a single tool bit and an aspect constituted by a plurality of tool bits. In that case, a mode in which a single tool bit is hit by a plurality of hitting mechanisms, a mode in which a plurality of tool bits are hit by the same number of hitting mechanisms as the plurality of tool bits, and a plurality of tool bits from the plurality of tool bits Both of the mode of hitting by a large number of hitting mechanisms and the mode of hitting a plurality of tool bits by a smaller number of hitting mechanisms than the plurality of tool bits are suitably included.

  According to the present invention, the tip tool member is alternately arranged by the first motion conversion mechanism and the first striking mechanism driven by the motor, and the second motion conversion mechanism and the second striking mechanism driven by the motor. It is possible to perform a predetermined processing operation. For this reason, when the number of rotations of the motor is set to be the same as that of the conventional impact tool configured to drive the end tool member by a single motion conversion mechanism and impact mechanism, the number of impacts of the end tool member is twice or more. It is possible to hit with a, and work efficiency is improved. In other words, when the number of strikes of the tip tool member per unit time is set to the same level as before, the rotational speed of the motor, the motion conversion mechanism driven by the motor, and the drive speed of the striking mechanism are reduced. This makes it possible to reduce the wear of the sliding portion and improve the durability without reducing the working efficiency.

(Invention of Claim 2)
According to a second aspect of the present invention, in the striking tool according to the first aspect, the first tool bit struck by the first striking mechanism and the second striking mechanism are used as the tip tool member. And a second tool bit. In invention of Claim 2, compared with the conventional impact tool, when the number of rotations of the motor is set to be the same, the total of the first tool bit and the second tool bit for the work material Since the number of hitting operations is more than twice, work efficiency is improved. On the other hand, when the total number of hitting operations by the first tool bit and the second tool bit is set to the same level as the conventional one, the motor, the motion conversion mechanism and the hitting mechanism can be driven at low speed. Durability can be improved by reducing wear at the sliding portion without reducing efficiency. Further, according to the present invention, since the machining operation is performed using the first and second tool bits, a wide range can be machined simultaneously as compared with the case of one tool bit.

(Invention of Claim 3)
According to the invention described in claim 3, the first striking mechanism and the second striking mechanism in the striking tool according to claim 1 or 2 are configured to perform linear motion in a mutually opposing manner. . In the present invention, since the first striking mechanism and the second striking mechanism are linearly moved in opposition to each other, when one striking mechanism strikes the tip tool member, The other striking mechanism linearly moves in the opposite direction, so that it functions as a counterweight, which effectively reduces vibration in the longitudinal direction of the tip tool member that occurs during machining operations. Effective for vibration.

  According to the present invention, a technique effective in improving the working efficiency of the impact tool is provided.

(First embodiment of the present invention)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. This embodiment will be described using an electric hammer as an example of an impact tool. FIG. 1 is a side sectional view showing the overall configuration of the electric hammer according to the present embodiment. As shown in FIG. 1, the electric hammer 101 according to the present embodiment is generally viewed from the main body 103 that forms the outline of the electric hammer 101 and a hollow in the tip region (left side in the drawing) of the main body 103. A single hammer bit 163 that is detachably attached via a tool holder 161 and a hand grip 109 gripped by an operator connected to the opposite side of the hammer bit 163 of the main body 103. Yes. The hammer bit 163 corresponds to the “tip tool member” in the present invention. For convenience of explanation, the hammer bit 163 side is referred to as the front, and the hand grip 109 side is referred to as the rear.

  The main body 103 constituting the tool main body includes a motor housing 105 that houses a drive motor 111, first and second sets of crank mechanisms 113 and 115, and first and second sets of striking elements 117, And a gear housing 107 that accommodates 119. The rotational output of the drive motor 111 is appropriately converted into a linear motion by the first and second crank mechanisms 113 and 115 and then transmitted to the first and second striking elements 117 and 119, and the first and second An impact force in the major axis direction (left and right direction in FIG. 1) of the hammer bit 163 is generated via the striking elements 117 and 119. The drive motor 111 corresponds to the “motor” in the present invention. The first crank mechanism 113 corresponds to the “first motion conversion mechanism” in the present invention, and the second crank mechanism 115 corresponds to the “second motion conversion mechanism” in the present invention. The first striking element 117 corresponds to the “first striking mechanism” in the present invention, and the second striking element 119 corresponds to the “second striking mechanism” in the present invention. The drive motor 111 is energized and driven by a pulling operation of a trigger 109 a disposed on the hand grip 109.

  FIG. 2 is a cross-sectional view showing an enlarged main portion of the electric hammer 101, and FIG. 3 shows a cross-sectional structure based on the cross-sectional instruction line of FIG. As shown in FIG. 2, the first and second crank mechanisms 113 and 115 are arranged in parallel in the vertical direction in the gear housing 107. The first crank mechanism 113 includes a first crank plate 125 that is rotatable in a horizontal plane, a first eccentric shaft 127 that is shifted from the center of rotation to the first crank plate 125, and one end on the first eccentric shaft 127. Is connected to the other end of the first crank arm 129 so as to be relatively rotatable via a first connecting shaft 131, and a first piston 133 as a first driver is connected to the other end of the first crank arm 129. Consists of the subject. The first crank plate 125 is formed in a circular shape, and has a driven gear 125 a on the outer peripheral surface thereof. The driven gear 125 a is meshed and engaged with a drive gear 121 that is rotationally driven by the drive motor 111. The first piston 133 is slidably disposed in the first bore 151a of the cylinder 151, and moves linearly in the major axis direction (hammer bit major axis direction) of the cylinder 151 when the drive motor 111 is driven to energize. I do.

  The second crank mechanism 115 includes a second crank plate 137 that is rotatable in a horizontal plane, a second eccentric shaft 139 that is shifted from the center of rotation to the second crank plate 137, and one end on the second eccentric shaft 139. Is connected to the other end of the second crank arm 141 through a second connecting shaft 143 so as to be relatively rotatable. Consists of the subject. The second piston 145 is slidably disposed in the second bore 151b of the cylinder 151.

  The first crank plate 125 and the second crank plate 137 are set so that their rotational axes are the same axis. The shift amount of the first eccentric shaft 127 from the rotation center of the first crank plate 125 and the shift amount of the second eccentric shaft 139 from the rotation center of the second crank plate 137 are both set equal. The first eccentric shaft 127 and the second eccentric shaft 139 are connected by a connecting member 147 so as to have a phase difference of approximately 180 degrees in the rotation direction of the first crank plate 125. That is, the second crank mechanism 115 is driven from the first crank mechanism 113 driven by the drive motor 111 via the connecting member 147, and the second piston 145 is approximately 180 degrees at a crank angle with respect to the first piston 133. It is configured to perform an opposing linear motion with a delay of degree.

  The first and second striking elements 117 and 119 are arranged in parallel in the vertical direction. The first striking element 117 is slidably disposed in the first bore 151a of the cylinder 151 and linearly moves in the longitudinal direction of the cylinder 151. The first striker 153 as a first striking element, and a cylindrical tool holder In addition to being slidably disposed within 161, it is configured mainly with an impact bolt 157 as an intermediate that transmits the kinetic energy of the first striker 153 to the hammer bit 163. The first striker 153 is driven via a fluctuation of the air pressure of the first air chamber 151c of the cylinder 151 accompanying the sliding movement of the first piston 133, that is, an air spring, and collides with (impacts) the impact bolt 157. The striking force is transmitted to the hammer bit 163 held by the holder 161. That is, the first striking element 117 is driven by the first crank mechanism 113.

  The second striking element 119 includes a second striker 155 as a second striking element that is slidably disposed in the second bore 151b of the cylinder 151 and linearly moves in the long axis direction of the cylinder 151, and the impact bolt described above. 157. The second striker 155 is driven via the air spring of the second air chamber 151d of the cylinder 151 that accompanies the sliding movement of the second piston 145, and is held by the impact bolt 157 by colliding (striking) with the impact bolt 157. The striking force is transmitted to the hammer bit 163. That is, the second striking element 117 is driven by the second crank mechanism 115.

  The impact bolt 157 can receive the striking operation of the first striker 153 in the radially lower region of the rear end portion in the major axis direction, and can receive the striking operation of the second striker 155 in the radially upper region. A hit surface 157a having a large width is provided.

  The cylinder 151 includes a circular first bore 151a in which the first piston 133 and the first striker 153 are slidably arranged, and a circular second in which the second piston 145 and the second striker 155 are slidably arranged. And a bore 151b. The gear housing 107 is mounted in a state in which movement in the long axis direction and the circumferential direction is restricted. FIG. 3 shows a cross-sectional structure of the cylinder 151. The tool holder 161 is attached to the distal end portion of the gear housing 107 in a state where movement in the long axis direction and the circumferential direction is restricted. The hammer bit 163 is held by the tool holder 161 in a state where relative movement in the major axis direction is allowed.

  Next, the operation of the electric hammer 101 configured as described above will be described. When the drive motor 111 shown in FIG. 1 is energized and driven, the drive gear 121 rotates by the rotation output. Accordingly, the first crank plate 125 is rotated via the driven gear 123 that meshes with and engages with the drive gear 121. Then, the first eccentric shaft 127 arranged on the first crank plate 125 rotates, whereby the first crank arm 129 swings, and the first piston 133 attached to the tip of the first crank arm 129 moves. The cylinder 151 is slid linearly. When the first piston 133 slides from the non-compression side (the right side in FIGS. 1 and 2) to the hammer bit 163 side, the first air chamber 151c is caused to fluctuate in the air pressure in the first air chamber 151c. The striker 153 moves linearly in the cylinder 151. The first striker 153 collides with the impact bolt 157 to transmit the kinetic energy (striking force) to the hammer bit 163, whereby the hammer bit 163 slides in the tool holder 161 and the workpiece is processed. Carry out hammering work against

  On the other hand, on the second crank mechanism 115 side, the second eccentric shaft 139 is connected to the second crank plate 137 via the connecting member 147 in conjunction with the rotating operation of the first eccentric shaft 127 accompanying the rotation of the first crank plate 125. Operates around the center of rotation. As a result, the second crank arm 141 swings and the second piston 145 slides in the second bore 151b of the cylinder 151. In the present embodiment, the first eccentric shaft 127 and the second eccentric shaft 139 have a phase difference of approximately 180 degrees in terms of crank angle. Therefore, the second piston 145 is linearly slid within the second bore 151b of the cylinder 151 with a delay of about 180 degrees with respect to the first piston 133. When the second piston 145 slides from the non-compression side to the hammer bit 163 side, the second striker 155 moves linearly in the cylinder 151 by the action of the air spring of the second air chamber 151d, and the impact bolt 157 The kinetic energy (striking force) is transmitted to the hammer bit 163. As a result, the hammer bit 163 slides in the tool holder 161 to perform a hammering operation on the workpiece.

  As described above, according to the present embodiment, a single hammer bit 163 can be subjected to two hitting operations with one crank rotation. For this reason, the number of hits of the hammer bit 163 is doubled when the number of revolutions of the drive motor 111 is set to be the same as that of a conventional electric hammer that performs one hitting operation with one revolution of the crank. Will improve. In other words, when the number of hits of the hammer bit 163 per unit time is set to the same level as the conventional one, the rotational speed of the drive motor 111 and the first and second crank mechanisms 113 driven by the drive motor 111 are used. 115, and the driving speeds of the first and second striking elements 117 and 119 can be reduced, respectively, so that wear of sliding parts such as sliding members or O-rings can be reduced without lowering work efficiency. And durability can be improved.

  In the present embodiment, the first piston 133 and the second piston 145 are driven with a phase difference of approximately 180 degrees in crank angle. Thereby, the 1st striker 153 and the 2nd striker 155 carry out mutually opposing linear motion. For this reason, when one, for example, the first striker 153 linearly moves toward the hammer bit 163 (forward), the other, for example, the second striker 155 moves linearly toward the side away from the hammer bit 163 (rear). By so doing, it functions as a counterweight. As a result, the vibration in the long axis direction of the hammer bit that occurs during the machining operation is reasonably reduced, which is effective in reducing the vibration of the electric hammer 101.

(Second embodiment of the present invention)
Next, a second embodiment of the present invention will be described with reference to FIGS. The electric hammer 101 according to the second embodiment is a two-bit type using a first hammer bit 173 and a second hammer bit 175 as a tip tool member, and is the same as that described above except for the configuration related thereto. The configuration is the same as that of the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified. The first hammer bit 173 corresponds to the “first tool bit” in the present invention, and the second hammer bit 175 corresponds to the “second tool bit” in the present invention.

  FIG. 4 shows the overall configuration of the electric hammer 101, and FIG. 5 shows the configuration of the main part. 6 and 7 each show a cross-sectional structure based on the cross-section indicating line in FIG. As shown in FIGS. 4 and 5, the tool holder 171 of the second embodiment has two cylindrical holes for mounting the first hammer bit 173 and the second hammer bit 175, and the tip of the gear housing 107. It is mounted on the side (front end side) in a state where movement in the major axis direction and circumferential direction of the hammer bit is restricted. The first hammer bit 173 and the second hammer bit 175 are held by the tool holder 171 in a state where relative movement in the major axis direction is allowed.

  The first striking element 117 is slidably disposed in the tool holder 171 and the first striker 153 as a first striking element that linearly moves in the first bore 151a of the cylinder 151 in the longitudinal direction of the hammer bit. The first impact bolt 177 as a first meson that transmits the kinetic energy of one striker 153 to the first hammer bit 173 is mainly configured. The first striker 153 is driven via the air spring of the first air chamber 151c of the cylinder 151 accompanying the sliding movement of the first piston 133, and collides (hits) the first impact bolt 177, thereby the tool holder. The striking force is transmitted to the first hammer bit 173 held at 171. The first striking element 117 corresponds to the “first striking mechanism” in the present invention.

  The second striking element 119 is slidably disposed in the tool holder 171 and a second striker 155 as a second striking element that linearly moves in the second bore 151b of the cylinder 151 in the longitudinal direction of the hammer bit. The second striker 155 is mainly composed of a second impact bolt 179 as a second meson that transmits the kinetic energy of the two striker 155 to the second hammer bit 175. The second striker 155 is driven via the air spring of the second air chamber 151d of the cylinder 151 accompanying the sliding movement of the second piston 145, and collides (hits) the second impact bolt 179, thereby the tool holder. The striking force is transmitted to the second hammer bit 175 held at 171. The second striking element 119 corresponds to the “second striking mechanism” in the present invention.

  The first crank mechanism 113 that drives the first striking element 117 and the second crank mechanism 115 that drives the second striking element 119 are configured in the same manner as in the first embodiment described above. Therefore, when the drive motor 111 is energized, the first striking element 117 is driven by the first crank mechanism 113 and the second striking element 119 is driven by the second crank mechanism 115. For this reason, the first hammer bit 173 and the second hammer bit 175 perform one hitting operation for each rotation of the crank. That is, the total number of hitting operations by the first hammer bit 173 and the second hammer bit 175 is performed twice in one crank rotation, and the work efficiency can be improved as in the first embodiment. On the other hand, when the total number of striking motions of the first hammer bit 173 and the second hammer bit 175 is set to the same level as in the prior art, the rotational speed of the driving motor 111 and the first and second driving motors 111 are driven. As a result, the driving speed of the crank mechanisms 113 and 115 and the first and second striking elements 117 and 119 can be reduced. As a result, the wear of sliding parts such as sliding members or O-rings is reduced without reducing the working efficiency. Can be reduced and durability can be improved.

  Further, the first piston 133 of the first crank mechanism 113 and the second piston 145 of the second crank mechanism 115 are configured to linearly move in the cylinder 151 with a phase difference of 180 degrees in terms of crank angle. For this reason, as in the first embodiment, the vibration in the long axis direction of the hammer bit that occurs during the machining operation can be rationally reduced, which is effective in reducing the vibration of the electric hammer 101. In the present embodiment, since the processing operation is performed using the first and second hammer bits 173 and 175, a wide range can be processed simultaneously as compared with the case of one.

In the above-described embodiment, the crank mechanisms 113 and 115 are employed as means for converting the rotational output of the drive motor 111 into the linear motion of the pistons 133 and 145. However, the present invention is not limited to this, and for example, the crank motor 113 is rotated by the drive motor 111. A mechanism for converting the swinging motion of the swinging member into the swinging motion of the swinging member after converting the rotating motion of the rotating body into the swinging motion of the swinging member, or a swash plate rotated by the drive motor 111 You may employ | adopt the mechanism etc. which convert into the linear motion of piston 133,145 using. In the above-described embodiment, the case where the two crank mechanisms 113 and 115 and the two striking elements 117 and 119 are provided has been described. However, these may be further added.
Moreover, although this Embodiment demonstrated the electric hammer 101 as an example of an impact tool, it is not restricted to this, The hammer bits 163, 173, and 175 are the circumference | surroundings of a major axis direction in addition to a major axis direction hit | damage operation | movement. You may apply to the hammer drill which performs rotation operation.

In view of the gist of the present invention, the following modes can be configured.
(Aspect 1)
“A striking tool according to claim 1,
The tip tool member is constituted by a single tool bit that is struck alternately by the first and second striking mechanisms and linearly moves to perform a predetermined machining operation on a workpiece. Blow tool to do. "

It is a sectional side view showing the whole electric hammer composition concerning a 1st embodiment of the present invention. It is a sectional side view which shows the principal part of an electric hammer. It is a longitudinal cross-sectional view based on the AA line in FIG. It is a sectional side view which shows the whole structure of the electric hammer which concerns on the 2nd Embodiment of this invention. It is a sectional side view which shows the principal part of an electric hammer. It is sectional drawing based on the BB line in FIG. It is sectional drawing based on the CC line in FIG.

Explanation of symbols

101 Electric hammer (blow tool)
103 Body 105 Motor housing 107 Gear housing 109 Hand grip 109a Trigger 111 Drive motor 113 First crank mechanism (first motion conversion mechanism)
115 Second crank mechanism (second motion conversion mechanism)
117 First striking element (first striking mechanism)
119 Second striking element (second striking mechanism)
121 driving gear 125 first crank plate 125a driven gear 127 first eccentric shaft 129 first crank arm 131 first connecting shaft 133 first piston 137 second crank plate 139 second eccentric shaft 141 second crank arm 143 second connecting shaft 145 Second piston 147 Connecting member 151 Cylinder 151a First bore 151b Second bore 151c First air chamber 151d Second air chamber 153 First striker 155 Second striker 157 Impact bolt 157a Impact surface 161 Tool holder 163 Hammer bit (tip) Tool member, tool bit)
171 Tool holder 173 First hammer bit (tip tool member, first tool bit)
175 Second hammer bit (tip tool member, second tool bit)
177 First impact bolt 179 Second impact bolt

Claims (3)

A motor,
A first motion conversion mechanism that converts the rotational output of the motor into a linear motion;
A first striking mechanism that performs linear motion by being driven by the first motion conversion mechanism;
A second motion conversion mechanism for converting the rotational output of the motor into a linear motion;
A second striking mechanism that performs linear motion by being driven by the second motion conversion mechanism;
A striking tool comprising: a tip tool member that is struck alternately by the first and second striking mechanisms and linearly moves to perform a predetermined processing operation on a workpiece. The impact tool according to claim 1,
A striking tool comprising a first tool bit struck by the first striking mechanism and a second tool bit struck by the second striking mechanism as the tip tool member. The impact tool according to claim 1 or 2,
The striking tool, wherein the first striking mechanism and the second striking mechanism are configured to perform linear motions in a mutually opposing manner.

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