JP2004106136A - Electric tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an art contributing to rationalization of a structure related to buffer in a mechanism transmitting an impact and to prevention of the intrusion of foreign matters from the outside, in an electric tool transmitting a kinetic energy of an impact element to the tool and performing the machining. <P>SOLUTION: This electric tool is provided with an impact element 133 linearly moving via a motor, an intermediate element 151 moving in the moving direction of the impact element 133 by the impact by the impact element 133, the tool 171 performing a prescribed machining by the impact by the intermediate element 151, and a holder 155 holding, at least, the intermediate element 151. This electric tool is also provided with a buffer member 181 absorbing the impact force of the intermediate element 151 moved by the impact by the impact element to the holder 155. The impact member 181 is also served as a sealing member 183 between the intermediate element 151 and the holder 155. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric tool such as an electric hammer that performs a machining operation by transmitting kinetic energy of a linearly moving impactor to a tool by impact.
[0002]
[Prior art]
As an example of this type of power tool, the configuration of an electric hammer is disclosed in JP-A-9-174317 (Patent Document 1). This electric hammer has an impactor, a meson and a tool housed coaxially and slidably in a cylindrical tool holder. The impactor linearly moves through a motor, and the meson moves linearly by the impact of the linearly moving impactor. Further, the tool is configured to perform a predetermined hammering operation by hitting the linearly moving meson. That is, the impactor and the meson have the meaning of a striking element for applying a striking force to the tool.
[0003]
By the way, in the above-mentioned conventional electric hammer, the relative positional relationship between the impactor and the meson with respect to the tool is not particularly controlled. Therefore, when the meson performs a linear motion by the impact of the impactor, the tool is closest to the meson. It is not always stationary where to be located between the set position and the most distant position. For this reason, there may be cases where the tool cannot sufficiently receive the impact of the meson. In this case, the kinetic energy of the meson transmitted from the impactor is transmitted as a striking force to the tool holder side when the meson abuts on the tool holder, and gives an impact to the power tool main body. Measures are required.
[0004]
Further, since the impact element is a member that linearly moves while sliding in the tool holder, a predetermined area is set so that dust and the like do not enter the area where the impact element is disposed from obstructing the sliding operation. Measures are needed. On the other hand, because various mechanical elements are densely arranged in a limited space inside the electric hammer, when taking the above-mentioned countermeasures and measures to prevent intrusion of dust etc., design for each countermeasure as much as possible It is desirable to streamline
[0005]
[Patent Document 1]
JP-A-9-174317
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a power tool for performing a machining operation by transmitting the kinetic energy of an impactor to a tool by striking, a mechanism for transmitting striking and a mechanism for preventing foreign matter from entering from outside. The purpose of the present invention is to provide a technology that contributes to streamlining the structure.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the invention described in each claim is configured. According to the first aspect of the present invention, an impactor that linearly moves via a motor, a meson that moves in the direction of movement of the impactor by the impact of the impactor, and a tool that performs a predetermined machining operation by the impact of the meson And an electric tool having a holder for holding at least the meson. Further, the present invention has a buffer member for buffering a striking force on the holder of the meson when the meson moves by striking with the impactor. This buffer member is configured to also serve as a seal member between the meson and the holder. Measures for damping the impact force of the meson on the holder and measures for preventing external dust etc. from entering the power tool from between the holder and the meson by the structure in which the shock absorbing member also functions as the seal member. Need not be performed individually, and the durability and space saving of the power tool can be rationally secured. In addition, the shock absorbing member may be configured in various ways with respect to the striking force of the meson, such as a manner of being arranged between the meson and the holder and damping, and a manner of being arranged between the parts while the holder is configured with a plurality of parts and damping. It shall be preferably included. Further, as the degree of buffering by the buffer member, any of a mode in which the impact force of the meson is completely absorbed and a mode in which the impact force is moderated can be suitably included.
[0008]
The “impacter” in the present invention is a member that linearly moves through a motor and transmits kinetic energy due to the linear movement to the meson by hitting, and is also called a striker. As a mode of linearly moving the impactor via a motor, a piston-like impactor is slidably disposed on one end side in the cylinder, and the other end side is connected to the motor side and reciprocates on the drive side. A mode in which a piston is arranged and a piston-like impactor is driven by the action of an air spring in a cylinder when the drive-side piston reciprocates via a motor, and a piston-like impactor is provided on one end side in the cylinder. It is slidably arranged, and the other end of the cylinder is connected to the motor side to reciprocate. When the cylinder is reciprocated by the motor, the piston-like impactor is driven by the action of the air spring in the cylinder. In this embodiment, a piston connected to the motor and reciprocating is arranged on one end side of the cylinder, and a cylinder accommodating the piston is arranged as an impactor. By the action of the air spring during the reciprocating piston by, such as mode of driving the cylindrical impactor, various forms can be adopted.
[0009]
In order to convert the rotation output of the motor into the reciprocating motion of the driving member, various mechanisms such as a motion conversion mechanism using a crankshaft and a motion conversion mechanism using a swash plate can be adopted.
[0010]
The “meson” in the present invention is a member for transmitting the kinetic energy of the impactor to the tool by hitting the tool, and is also referred to as an impact bolt. In addition, the “predetermined machining operation by hitting” typically corresponds to a hammer operation on a workpiece. Note that, in the present invention, it does not prevent the electric tool from also performing a processing operation other than the impact, for example, a processing operation using a drill. For example, a configuration of a hammer drill or the like using both a hammer that performs a machining operation by reciprocating a tool and a drill that performs a machining operation by rotating a tool is possible. Further, the “holder” in the present invention is sufficient if it is a member that holds at least the meson, and may be configured separately from the tool holder that holds the tool, or may be configured as a tool holder that holds both the tool and the meson May be. Further, the holder may be configured to hold the meson as a whole, or may be configured to hold a part of the meson, and the holder may be configured by one part or by combining a plurality of parts. Can also be suitably adopted. When a holder is configured by combining a plurality of parts, the cushioning member may be disposed on any of the parts, or may be disposed between the parts.
[0011]
(Invention of claim 2)
According to the second aspect of the present invention, the cushioning member of the electric power tool according to the first aspect is disposed so as to orbit the outer peripheral surface of the rod-shaped meson while slidingly contacting the outer peripheral surface. It is defined by the elastic material. As the elastic material, for example, a rubber ring obtained by molding a rubber material into a ring shape corresponds to this. According to the present invention, when the meson moves in the long axis direction of the meson, the elastic material buffers the impact force of the meson input through the large diameter portion of the meson by deforming in the long axis direction of the meson. . The elastic material is slidably contacted with the outer peripheral surface of the meson so as to ensure the sealing property between the meson and the holder, and the elastic material is deformed in the long axis direction of the meson, so that the elastic material is deformed through the large diameter portion of the meson. The input meson impact force is buffered. Note that the “large diameter portion” of the meson refers to a portion formed to be relatively larger in the radial direction than the others at the outer peripheral portion of the meson, such as a flange portion formed at the outer peripheral portion of the meson. I do.
[0012]
(Invention of claim 3)
According to the third aspect of the present invention, in the power tool according to the second aspect, the elastic member constituting the buffer member is configured such that the amount of deformation of the elastic member in the longitudinal direction of the meson is limited. You. Although the amount of deformation of the elastic member is limited, a certain limit is imposed on the buffering capacity of the elastic member. However, the elastic member buffers the impact force of the meson because the elastic member also serves as a seal member. By restricting the amount of deformation at that time, it is possible to delay the deterioration of the cushioning member and effectively balance the securing of the cushioning capacity and the securing of the sealing ability over time. In order to regulate the amount of deformation of the cushioning member, for example, when the elastic material is deformed by the impact force of the meson, the deformation of the elastic material by a predetermined amount or more is restricted by restricting the movement of the meson by a predetermined amount with a stopper. A configuration such as restriction can be suitably adopted.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment of the present invention, description will be made using an electric hammer 101 as shown in FIG. The electric hammer 101 is configured as a type having both functions of a hammer and a drill so as to be switchable. As shown in FIG. 1, the electric hammer 101 according to the present embodiment generally includes various members and mechanisms arranged in a housing 103 including a motor housing 103a, a hand grip 103b, and a gear housing 103c. . Specifically, a motor 111 is provided in the motor housing 103a, a trigger switch 113 is provided in the hand grip 103b, and a motion conversion mechanism 120, an air cylinder mechanism 130, a striking force transmission mechanism 150, and a buffer seal mechanism are provided in the gear housing 103c. 180 are provided. Further, a tip tool mechanism 170 is detachably connected to a tip side (left side in the figure) of the gear housing 103c.
[0014]
The motor 111 is energized and driven by the operator turning on the trigger switch 113, and a rotational driving force is output to the motor output shaft 111a. On the other hand, the motion conversion mechanism 120 is connected to the gear 121 meshing with the motor output shaft 111a, the gear shaft 123 connected to the gear 121, the boss 125 fitted on the gear shaft 123, and the boss 125 via the steel ball 127. The engaged arm 129 is mainly configured.
[0015]
The air cylinder mechanism 130 includes a cylinder 131 in which the arm 120 constituting the motion conversion mechanism 120 is loosely fitted on one end side, a striker 133 reciprocally housed in a bore in the cylinder 131, and the cylinder 131 and the striker 133. The air chamber 135 is formed in the bore by the air chamber 135. Further, as can be understood from FIG. 2 showing the configuration of the main part of the electric hammer 101 in detail, a seal member 134 is arranged on the outer peripheral part of the striker 133 so as to go around the outer peripheral surface of the striker 133. A seal is provided between the bore inner wall and the striker 133, thereby shutting off the air chamber 135 from the outside. The striker 133 is an element corresponding to the “impacter” in the present invention.
[0016]
As shown in FIGS. 1 and 2, the impact transmitting mechanism 150 mainly includes an impact bolt 151 that receives a strike of the striker 133 that linearly moves at a high speed via the air cylinder mechanism 130 and linearly moves by receiving the impact. You. The impact bolt 151 is an element corresponding to the “meson” in the present invention. The impact bolt 151 is configured as a rod-shaped member having a long axis in the direction of its linear movement (left-right direction in the drawing), and is accommodated in the sleeve 153 and the tool holder guide 155 so as to be able to slide back and forth. The tool holder guide 155 is a member for accommodating the impact bolt 151 slidably and fastening the tip tool mechanism 170 to the electric hammer 101 side by engaging a tool holder 175 described later. Further, the impact bolt 151 has a flange portion 152 on the outer peripheral portion on the rear side of the center region. Note that the flange portion 152 is an element corresponding to the “large-diameter portion” in the present invention.
[0017]
Similarly to the tool holder guide 155, the sleeve 153 is a member that slidably accommodates the impact bolt 151. A shoulder 153a is formed on the inner periphery of the sleeve 153, and the impact bolt 152 faces the tip tool mechanism 170 (electric hammer). When moving in the direction of the front end (101), the flange 152 of the impact bolt 151 can contact the shoulder 153a. When the flange 152 abuts on the shoulder 153a, the impact force in the long axis direction (left direction in the drawing) of the impact bolt 151 is transmitted to the sleeve 153. The sleeve 153 and the tool holder guide 155 are elements corresponding to the “holder” in the present invention, respectively.
[0018]
The buffer seal mechanism 180 is mainly configured by a rubber ring 181. The rubber ring 181 is an element corresponding to the “buffer member” in the present invention, and is disposed between the sleeve 153 and the tool holder guide 155 so as to slide around the outer peripheral surface of the impact bolt 151 while slidingly contacting the outer peripheral surface. As an annular ring member made of rubber. The rubber ring 181 has a small-diameter portion 185 formed in a central region thereof, and a pair of seal portions 183 slidably contacting the outer peripheral surface of the impact bolt 151 at both ends. When the impact force of the impact bolt 151 is transmitted to the sleeve 153 by the flange 152 of the impact bolt 151 abutting on the shoulder 153a of the sleeve 153, the rubber ring 181 separates the sleeve 153 from the tool holder guide 155. The impact force of the impact bolt 151 is buffered (relaxed) while being compressed and deformed in the long axis direction (left-right direction in the drawing) of the impact bolt 151. The rubber ring 181 can be smoothly deformed by the small-diameter portion 185 of the rubber ring 181 that is set to have a small rigidity against deformation. In addition, since the seal portion 183 is slidably contacted with the outer peripheral portion of the impact bolt 151, external dust and the like are prevented from entering the striking force transmission mechanism 150 and the air cylinder mechanism 130 from the clearance 187.
[0019]
The rubber ring 181 is disposed so as to protrude from the inner end 155 a of the tool holder guide 155 on the sleeve 153 side by a distance D toward the sleeve 153 in the long axis direction (left-right direction in the drawing) of the impact bolt 151. You. As a result, when the sleeve 153 receives the impact of the impact bolt 151 and moves leftward in the drawing, the tip of the sleeve 153 contacts the inner end 155a of the tool holder guide 155, thereby compressing the rubber ring 181. The amount of deformation is regulated. In other words, the rubber ring 181 is allowed to deform by the distance D.
[0020]
The tip tool mechanism 170 includes a tool holder 175 fixed to the tool holder guide 155, a tool bit 171 slidably held by the tool holder 175 to perform a hammer operation on the workpiece, and a tool holder 175. A tool bit fastening portion 173 for detachably holding the bit 171 is mainly configured. The tool bit 171 is an element corresponding to a “tool” in the present invention.
[0021]
The operation and usage of the electric hammer 101 configured as described above will be described below. When the operator turns on the trigger switch 113, the motor 111 is energized and driven. When the motor 111 is driven, the rotational driving force of the motor 111 is transmitted to the gear shaft 123 through the motor output shaft 111a and the gear 121, and the gear shaft 123 is driven to rotate. By selecting the gear ratio of the gear 121 with respect to the motor output shaft 111a, the gear ratio from the motor 111 to the gear shaft 123 is appropriately set. The rotation of the gear shaft 123 causes the boss 125 fitted on the gear shaft 123 to rotate. When the boss 125 rotates, the arm 129 swings in the left-right direction in FIG. 1 by the action of the slope of the boss 125 facing the steel ball 127, and is thereby loosely connected to the upper end side of the arm 129 in the figure. The cylinder 131 performs a reciprocating linear motion in the left-right direction in the figure. With the reciprocating linear motion of the cylinder 131, the air chamber 135 between the cylinder 131 and the piston-shaped striker 133 repeats the compression / expansion action as appropriate, whereby the striker 133 can move linearly in the horizontal direction in the figure.
[0022]
For example, when the cylinder 131 linearly moves in the direction of the tip of the electric hammer 101 (leftward in the figure), the air chamber 135 is compressed. Accordingly, the striker 133 linearly moves toward the impact bolt 151 at a speed higher than the moving speed of the cylinder 131 by the action of a so-called air spring. When the striker 133 collides with the impact bolt 151, the kinetic energy of the striker 133 is transmitted to the impact bolt 151, and the impact bolt 151 linearly moves at high speed toward the tool bit 171. When the impact bolt 151 collides with the tool bit 171, the kinetic energy of the impact bolt 151 is transmitted to the tool bit 171, and the tool bit 171 linearly moves forward at a high speed. The work will be performed.
[0023]
The driving of the striker 133 is not shown in detail, but includes various positions such as the position and diameter of an intake hole formed in the cylinder 131, the weight of the striker 133, the swing distance of the arm 129, the bore diameter of the cylinder 131, and the like. The parameters can be set as appropriate by integrating them.
[0024]
In the electric hammer 101 according to the present embodiment, the relative positional relationship of the tool bit 171 with respect to the striker 133 and the impact bolt 151 is not automatically controlled, and the striker 133 and the impact bolt 151 move the tool bit at an optimal timing. 171 may not be driven. For example, in the state shown in FIG. 2, the tool bit 171 is located on the back side (the right side in the figure) of the electric hammer 101, so that the flange 152 of the impact bolt 151 is sufficiently separated from the shoulder 153 a of the sleeve 153. Since the impact bolt 151 comes into contact with the tool bit 171, the kinetic energy of the striker 133 is efficiently transmitted to the tool bit 171 via the impact bolt 151. However, when the tool bit 171 is located on the tip side (left side in the figure) with respect to the state shown in FIG. 2, the impact bolt 151 linearly moved by the strike of the striker 133 contacts the tool bit 171 before the flange portion. There is a possibility that the abutment 152 abuts the shoulder 153a of the sleeve 153.
[0025]
Further, for example, the electric hammer 101 may be driven in a no-load state in which the tool bit 171 does not contact the workpiece. In this case, the tool bit 171 does not come into contact with the workpiece, so that the movement in the long axis direction is not restricted at all. (Left side), the flange 152 of the impact bolt 151 collides with the shoulder 153a of the sleeve 153, and the impact bolt 151 hits the sleeve 153.
[0026]
When the impact bolt 151 hits the sleeve 153 via the flange 152 in this manner, the sleeve 153 attempts to move toward the tool holder guide 155 in the long axis direction (left direction in the drawing) of the impact bolt 151. . At this time, the rubber ring 181 constituting the cushioning seal mechanism 180 is compressed and deformed in the major axis direction of the impact bolt 151 between the sleeve 153 and the tool holder guide 155, so that the impact bolt 151 hits the sleeve 153. Buffer power. The rubber ring 181 can be smoothly deformed via the small-diameter portion 185 of the rubber ring 181 whose rigidity against deformation is reduced, and a deformation time delay during buffering is avoided as much as possible. Thus, when the impact force of the impact bolt 151 is transmitted to the sleeve 153, the rubber ring 181 is deformed, so that the impact force can be effectively buffered.
[0027]
Further, the rubber ring 181 has a pair of seal portions 183 arranged so as to slide around the outer peripheral surface of the impact bolt 151 with the small-diameter portion 185 interposed therebetween, so that dust and the like outside the electric hammer 101 are removed. Through the clearances 187 between the tool holder 175 and the tool bit 171 and between the tool holder guide 155 and the impact bolt 151, the impact force transmission mechanism 150 and the air cylinder mechanism 130 are prevented from entering.
[0028]
As described above, the rubber ring 181 at the time of buffering can be deformed by the amount of projection D from the inner end 155a of the tool holder guide 155 on the sleeve 153 side to the sleeve 153, and the impact force of the impact bolt 151 Although the cushioning performance of the rubber ring 181 slightly decreases, it is possible to suppress the deterioration due to the deformation of the rubber ring 181 correspondingly. That is, when the rubber ring 181 repeatedly undergoes large deformation in the axial direction when buffering the impact force transmitted from the impact bolt 151 to the sleeve 153, the rubber ring 181 can exhibit the maximum buffering capacity, May deteriorate over time, leading to a decrease in sealing ability. Furthermore, if the amount of deformation of the rubber ring 181 in the axial direction during buffering of the impact force is large, the distance that the seal portion 183 (especially the seal portion 183 on the side close to the sleeve 153) slides along the outer peripheral surface of the impact bolt 151 is increased. As the seal portion 183 is strongly pressed against the sliding surface with the deformation, the degree of wear on the sliding surface of the seal portion 183 increases, and the sealing ability of the seal portion 183 is reduced with time. May decrease. For this reason, in the present embodiment, the amount of deformation of the rubber ring 181 is limited to the distance D, thereby limiting the amount of deformation or sliding distance of the seal portion 183 in the axial direction. Deterioration due to deformation or wear is suppressed as much as possible, thereby effectively balancing the buffer capacity and the sealing capacity of the buffer seal mechanism 180.
[0029]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, in the power tool which transmits the kinetic energy of an impactor to a tool by impact and performs a machining operation, it contributes to rationalizing the structure regarding the buffer which transmits an impact, and the prevention of invasion of foreign matter from the outside. Technology will be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional plan view showing the entire configuration of an electric hammer according to the present embodiment.
FIG. 2 is a partial sectional view showing a configuration of a main part of the electric hammer according to the embodiment.
[Explanation of symbols]
101 Electric hammer 103 Housing 111 Motor 113 Trigger switch 120 Motion conversion mechanism 121 Gear 123 Gear shaft 125 Boss 127 Steel ball 129 Arm 130 Air cylinder mechanism 131 Cylinder 133 Striker (impacter)
134 Seal member 135 Air chamber 150 Impact force transmission mechanism 151 Impact bolt (meson)
152 Flange 153 Sleeve (holder)
155 Tool holder guide (holder)
157 Stopper 170 Tip tool mechanism 171 Tool bit (tool)
173 Tool bit fastening part 175 Tool holder 180 Buffer seal mechanism 181 Rubber ring (buffer member)
183 Seal part 185 Small diameter part 187 Clearance

Claims (3)

An impactor that moves linearly via a motor, a meson that moves in the direction of movement of the impactor by hitting with the impactor, a tool that performs a predetermined machining operation by hitting with the meson, and a holder that holds at least the meson A power tool having
A buffer member is provided for buffering the impact force of the meson moving by the impactor on the holder, and the buffer member also serves as a seal member between the meson and the holder. Power tool. The power tool according to claim 1,
The shock-absorbing member is defined by an elastic material disposed so as to orbit around the outer peripheral surface while being in sliding contact with the outer peripheral surface of the intermediate element formed in a rod shape,
When the meson moves in the major axis direction of the meson, the elastic material absorbs the impact force of the meson input through the large diameter portion of the meson by deforming the meson in the major axis direction of the meson. A power tool characterized in that: The power tool according to claim 2,
A power tool, wherein an amount of deformation of the elastic material in a longitudinal direction of the meson is limited.

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