WO2007088821A1

WO2007088821A1 - Impact tool

Info

Publication number: WO2007088821A1
Application number: PCT/JP2007/051415
Authority: WO
Inventors: Masanori Furusawa
Original assignee: Makita Corporation
Priority date: 2006-01-31
Filing date: 2007-01-29
Publication date: 2007-08-09
Also published as: EP1980371B1; EP1980371A1; JP2007203388A; EP1980371A4

Abstract

An impact tool (101) comprises a motor (111), a first motion conversion mechanism (113) for converting the rotational output of the motor (111) into a linear motion, a first impact mechanism (117) driven by the first motion conversion mechanism (113) for performing linear motions, a second motion conversion mechanism (115) for converting the rotational output of the motor (111) into a linear motion, a second impact mechanism (119) driven by the second motion conversion mechanism (115) for performing linear motions, and a tip tool member (163) caused by the first and second impact mechanisms (117, 119) to perform alternate impact actions. With these alternate impacts by the first and second impact mechanisms (117, 119), the number of impacts of the tip tool member (163) per unit time is increased, and the first impact mechanism (117) and the second impact mechanism (119) alternately function as a counter weight.

Description

Specification

Impact tool

Technical field

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

Background 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. In this electric hammer, the rotation output of the motor is converted into a linear motion of the piston by the crank mechanism, and the striker linearly moves through the air panel that fluctuates due to the linear motion of the piston to strike the tool bit. give.

[0003] In the above impact tool, in order to increase the work efficiency, it is necessary to drive the tool bit at a high speed by increasing the number of rotations of the motor. However, the mechanical operation part used to drive the tool bit, such as a crank mechanism or a striking mechanism driven by a motor, has a limit in terms of followability with respect to the rotational speed of the motor, for example. However, there is still room for improvement in this regard.

Disclosure of the invention

Problems to be solved by the invention

The present invention has an object to provide a technique effective in improving the working efficiency of a striking tool in view of the power.

Means for solving the problem

[0005] In order to achieve the above-described object, the invention described in each claim is configured.

The impact tool according to the present invention includes a motor, a first motion conversion mechanism, a first impact mechanism, a second motion conversion mechanism, a second impact mechanism, and a tip tool member. The first motion 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 mechanism. Second The motion variation m «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 mechanism. The tip tool member is struck by the first and second striking mechanisms and moves linearly to perform a predetermined machining operation on the workpiece. The tip tool member is preferably struck alternately by each striking mechanism. As the “blow 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 straight striking motion in the long axis direction of the tip tool member is used. This applies to electric hammer drills that perform hammer drill work on workpieces by performing a long-axis striking motion and a rotational motion around the long-axis direction.

[0006] In addition, the "first motion conversion mechanism" and the "second motion conversion mechanism" in the present invention typically have 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, a mechanism that converts the rotational motion of the rotating body rotated by the motor into the swing motion of the swing member, and then converts the swing motion of the swing member into the linear motion of the piston, or It preferably includes a mechanism for converting to linear movement of the piston using a swash plate rotated by a motor. Further, the “first striking mechanism” and the “second striking mechanism” in the present invention typically include a striking element that performs a linear motion by a change in air pressure of an air chamber due to a linear linear motion of a piston, Furthermore, although it is set as the structure which has an intermediate | middle which transmits the linear motion of the said striker to a tip tool member, the structure which does not have an intermediate is included suitably.

In the present invention, “first and second motion conversion mechanisms” means 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 is included. An embodiment having a conversion mechanism and further a fourth motion conversion mechanism is suitably included. Similarly, “first and second striking mechanisms” means that there are at least two striking mechanisms. In addition to the first and second striking mechanisms, the third striking mechanism and further the fourth striking mechanism. An embodiment having a mechanism is suitably included. In addition, the “tip tool member” in the present invention suitably includes any of an aspect constituted by a single tool bit or an aspect constituted by a plurality of tool bits. In that case, a mode in which a single tool bit is struck by a plurality of striking mechanisms, and a plurality of tool bits have the same number of striking mechanisms as the plurality of tool bits. Any of a mode in which a plurality of tool bits are struck by a larger number of striking mechanisms than the plurality of tool bits, and a mode in which a plurality of tool bits are struck by a smaller number of striking mechanisms than the plurality of tool bits. Preferably included.

[0008] According to the present invention, the first motion conversion mechanism and the first striking mechanism driven by the motor, and the second motion mechanism and the second striking mechanism driven by the motor, The tip tool member can be hit to perform a predetermined processing operation. For this reason, the working efficiency is improved as compared with the conventional impact tool in which the tip tool member is driven by a single motion conversion mechanism and impact mechanism. 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 can be reduced. It is possible to reduce the wear of the sliding portion and improve the durability without reducing the working efficiency.

[0009] It is preferable that the first striking mechanism and the second striking mechanism in the striking tool are configured to perform a linear motion opposite to each other. As a result, when one striking mechanism strikes the tip tool member, the other striking mechanism moves linearly in opposition to the one striking mechanism, so that it functions as a counterweight. As a result, the vibration in the long axis direction of the tip tool member is reasonably reduced, which is effective for lowering the vibration of the impact tool in addition to improving work efficiency.

[0010] For example, the first striking mechanism has a cylindrical first striking element that linearly moves to drive the tip tool member, and the second striking mechanism linearly moves to drive the tip tool member. It is preferable to have a second striker that is cylindrical and has approximately the same mass as the first striker. In this case, it is preferable that the first striker and the second striker are configured to linearly move in opposition to each other. As a result, the tip tool member is alternately struck by the first and second strikers and linearly moves, thereby increasing the number of strikes of the tip tool per unit time and further increasing the number of strikes from the first and second strikers. The counterweight function between the two strikers can be further enhanced.

[0011] In the hitting tool, it is preferable that the first hitting mechanism and the second hitting mechanism are arranged in parallel in the vertical direction. This makes it possible to further improve the tool drive balance. The invention's effect

[0012] According to the present invention, a technique effective in improving the working efficiency of the impact tool has been provided.

BEST MODE FOR CARRYING OUT THE INVENTION

(First embodiment of the present invention)

Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3. 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 generally has a main body 103 that forms an outline of the electric hammer 101 and a tip region (left side in the drawing) of the main body 103. Mainly composed of a single hammer bit 163 detachably attached via a hollow 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. It is configured. 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.

[0014] The main body 103 constituting the tool main body includes a motor housing 105 containing a drive motor 111, first and second sets of crank mechanisms 113 and 115, and first and second sets of two. A gear housing 107 that houses the striking elements 117 and 119 is formed. The rotational output of the drive motor 111 is appropriately converted into linear motion by the first and second crank mechanisms 113, 115 and then transmitted to the first and second striking elements 117, 119, and the first and second An impact force in the major axis direction of the hammer bit 163 (left and right direction in FIG. 1) is generated via the second 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 variable shelf” in the present invention, and the second crank mechanism 115 corresponds to the “second motion variable structure” 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 109a disposed on the handgrip 109.

FIG. 2 is a sectional view showing an enlarged state of the main part of the electric hammer 101, and FIG. 3 shows a sectional structure based on the sectional instruction line of FIG. As shown in Figure 2, the first and second clan The gear mechanisms 113 and 115 are arranged in parallel in the gear housing 107 in the vertical direction. 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 of the first eccentric shaft 127. Is connected to the other end of the first crank arm 129 via a first connecting shaft 131 so as to be relatively rotatable. 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 engaged with 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 when the drive motor 111 is energized and driven, the long axis direction of the cylinder 151 (the non-mabit long axis direction) ) Perform a linear motion.

[0016] 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 arranged with a rotational center force shifted to the second crank plate 137, and a second eccentric shaft. A second crank arm 141, one end of which is connected to the shaft 139 in a loose fit, and a second driver as a second driver attached to the other end of the second crank arm 141 via a second connecting shaft 143 so as to be relatively rotatable. Mainly composed of 2 pistons 145. The second piston 145 is slidably disposed in the second bore 151b of the cylinder 151 !.

[0017] 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 rotational 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 substantially at a crank angle with respect to the first piston 133. It is configured to perform opposing linear motion with a delay of 180 degrees.

[0018] The first and second striking elements 117, 119 are arranged in parallel in the vertical direction. The first striking element 117 includes a first striker 153 as a first striking element slidably disposed in the first bore 151a of the cylinder 151 and moving linearly in the longitudinal direction of the cylinder 151, and a cylindrical tool. The holder 161 is slidably disposed, and 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 through the fluctuation of the air pressure in the first air chamber 151c of the cylinder 151 accompanying the sliding movement of the first piston 133, that is, through the air panel, and collides (hits) with the impact bolt 157. The striking force is transmitted to the non-mabit 163 held in the tool holder 161. That is, the first striking element 117 is driven by the first crank mechanism 113.

Further, the second striking element 119 is slidably disposed in the second bore 151b of the cylinder 151, and the second striker 155 as a second striker that linearly moves in the longitudinal direction of the cylinder 151; No. impact bolt 157. The second striker 155 is driven through the air panel of the second air chamber 151d of the cylinder 151 accompanying the sliding motion of the second piston 145, and collides with the impact bolt 157 to hit the impact bolt 157. The striking force is transmitted to the retained non-mabit 163. That is, the second striking element 117 is driven by the second crank mechanism 115.

[0020] The impact bolt 157 receives a striking motion of the first striker 153 in the radially lower region of the rear end portion in the long axis direction and receives a striking motion of the second striker 155 in the radially upper region. The impact surface 157a is as large as possible.

[0021] The cylinder 151 has a circular first bore 151a in which the first piston 133 and the first striker 153 are slidably arranged, and a circle in which the second piston 145 and the second striker 155 are slidably arranged. The second bore 151b is attached to the gear housing 107 in a state where movement in the long axis direction and the circumferential direction is restricted. FIG. 3 shows the 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, 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. This causes the first crank arm 129 to swing, and the first piston 133 attached to the tip of the first crank arm 129 is slid linearly within the cylinder 151. 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. Then, the first striker 153 collides with the impact bolt 157 to transmit the kinetic energy (striking force) to the hammer bit 163, which causes the hammer bit 163 to slide in the tool holder 161 and to be covered. Perform hammering work on the workpiece.

On the other hand, on the second crank mechanism 115 side, the second eccentric shaft 139 is connected to the second eccentric shaft 139 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. Crank plate 137 circulates 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 slid linearly within the second bore 151b of the cylinder 151 with a delay of about 180 degrees with respect to the first piston 133. Then, when the second piston 145 slides to the hammer bit 163 side also with the non-compression side force, the second striker 155 moves linearly in the cylinder 151 due to the action of the air panel of the second air chamber 151d, and the impact bolt 157 The kinetic energy (striking force) is transmitted to the hammer bit 1 63. As a result, the hammer bit 163 slides in the tool holder 161 to perform a hammering operation on the workpiece.

[0024] As described above, according to the present embodiment, a single hammer bit 163 can be struck twice by 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 equal to that of a conventional electric hammer that performs a single hitting operation with one crank rotation. Work efficiency is improved. In other words, when the number of hammer bits 163 hit 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 cranks driven by the drive motor 111 are changed. The driving speed of the mechanisms 113, 115 and the first and second striking elements 117, 119 can be reduced at low speeds, resulting in a sliding part without reducing work efficiency. Durability can be improved by reducing wear on sliding parts such as materials or O-rings.

In the present embodiment, the first piston 133 and the second piston 145 are configured to be driven with a phase difference of approximately 180 degrees in terms of crank angle. As a result, the first striker 153 and the second striker 155 perform linear movements that face each other. Therefore, when one, for example, the first strike force 153 linearly moves to the side hitting the hammer bit 163 (front), the other, for example, the second striker 155 goes straight to the side away from the hammer bit 163 (rear). In operation, it functions as a counterweight. As a result, the vibration in the long axis direction of the hammer bit that occurs during the carpentry work 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 the first hammer bit 173 and the second hammer bit 175 as the tip tool members, 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 attaching the first hammer bit 173 and the second hammer bit 175, and the tip of the gear housing 107. Mounted on the side (front end side) in a state where movement in the long 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.

[0028] The first striking element 117 is slidable 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. Arranged to transmit the kinetic energy of the first striker 153 to the first hammer bit 173. It is mainly composed of a first impact bolt 177 as a meson. The first striker 153 is driven through the air panel of the first air chamber 151c of the cylinder 151 as the first piston 133 slides, and collides (hits) with the first impact bolt 177. The striking force is transmitted to the first hammer bit 173 held by the tool holder 171. The first striking element 117 corresponds to the “first striking mechanism” in the present invention.

[0029] The second striking element 119 is slidable 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 impact bolt 179 as a second meson that is arranged and transmits the kinetic energy of the second striker 155 to the second hammer bit 175 is mainly configured. The second striker 155 is driven through the air panel of the second air chamber 151d of the cylinder 151 accompanying the sliding movement of the second piston 145 and collides (hits) with the second impact bolt 179. The striking force is transmitted to the second hammer bit 175 held by the tool holder 171. The second striking element 119 corresponds to the “second striking mechanism” in the present invention.

[0030] 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 each time the crank rotates. 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 rotation of the crank, and 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. The driving speed of the crank mechanisms 11 3, 115 and the first and second striking elements 117, 119 can be reduced, so that the sliding parts such as sliding members or O-rings can be moved without reducing the working efficiency. Wear can be reduced and durability can be improved.

[0031] 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. Yes. 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, and this is effective in reducing the vibration of the electric hammer 101. Further, in this embodiment, the construction work is performed using the first and second two hammer bits 173 and 175, so that a wide range is simultaneously checked as compared with the case of one. be able to.

In the embodiment described above, 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 drive motor 111 After the rotating motion of the rotating body rotated by is converted into the swinging motion of the swinging member, the swinging motion of this swinging member is converted to the linear motion of the pistons 133, 145 or rotated by the drive motor 111. A mechanism that converts the pistons 133 and 145 into linear motion using a swash plate may be used. 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.

In addition, the present embodiment is not limited to the force described with the electric hammer 101 as an example of a striking tool, and the umbilits 163, 173, and 175 are not limited to the striking motion in the long axis direction. It can be applied to a hammer drill that performs rotational movement.

Brief Description of Drawings

FIG. 1 is a side sectional view showing an overall configuration of an electric hammer according to a first embodiment of the present invention.

FIG. 2 is a side sectional view showing a main part of the electric hammer.

FIG. 3 is a longitudinal sectional view based on the line AA in FIG.

FIG. 4 is a side sectional view showing an overall configuration of an electric hammer according to a second embodiment of the present invention.

FIG. 5 is a side sectional view showing a main part of the electric hammer.

6 is a cross-sectional view based on the line BB in FIG.

FIG. 7 is a cross-sectional view based on the line CC in FIG.

Explanation of symbols

[0034] 101 Electric hammer (blow tool) 105 Motor housing

107 Gearno

109 Hand grip

109ε 1 trigger

111 Drive motor

113 1st crank mechanism

115 2nd crank mechanism

117 First Strike Element

119 Second strike element

121 Drive gear

125 1st crank plate

125a. Driven gear

127 First eccentric shaft

129 1st crank arm

131 1st connecting shaft

133 1st piston

137 2nd crank plate

139 Second eccentric shaft

141 2nd crank arm

143 Second connecting shaft

145 2nd piston

147 Connecting member

151 cylinders

151a 1st bore

151b 2nd bore

151c 1st air chamber

151d 2nd 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 2nd impact bolt

Claims

The scope of the claims

[1] 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 a linear motion by being driven by the first motion mechanism;

A second motion converting mechanism that converts the rotational output of the motor into a linear motion; a second striking mechanism that performs a linear motion by being driven by the second motion mechanism;

A striking tool comprising a tip tool member that is struck by the first and second striking mechanisms and linearly moves to perform a predetermined processing operation on a workpiece.

[2] The impact tool according to claim 1,

The first striking mechanism has a first striking element that moves linearly to drive the tip tool member;

The second striking mechanism has a second striking element that linearly moves to drive the tip tool member and has substantially the same mass as the first striking element,

The first striker and the second striker are configured to linearly move in opposition to each other, and the tip tool member is configured by a single tool bit that performs a predetermined machining operation on the workpiece. In addition, the first striker and the second striker are alternately struck and operated in a straight line, thereby increasing the number of strikes of the tip tool per unit time, and further, the first striker and the A striking tool characterized in that the second striking element is configured so as to function as a counterweight.

[3] The impact tool according to claim 2,

The striking tool characterized in that the first striking element and the second striking element are both formed in a cylindrical shape and have substantially the same diameter.

[4] A striking tool according to claim 1,

A striking tool comprising, as the tip tool member, a first tool bit striking by the first striking mechanism and a second tool bit striking by the second striking mechanism.

[5] The impact tool according to claim 4,

The striking tool, wherein the first striking mechanism and the second striking mechanism are configured to perform linear motions in opposition to each other.

[6] The striking tool according to any one of claims 1 to 5, wherein the first striking mechanism and the second striking mechanism are arranged in parallel vertically. Blow tool to perform.

V, a striking tool characterized by that.