JP2009220199A - Impact tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for adding a new function to a cover member provided to cover an internal mechanism accommodated in a tool body of an impact tool. <P>SOLUTION: The impact tool is provided with a tool bit 119, the tool body 103, and a motor 111 and a motor shaft 112 as a plurality of the internal mechanisms accommodated in the tool body 103. The motor shaft 112 is arranged in a crossing state so as to cross a long axis line of the tool bit. The impact tool is further provided with the cover member 191 mounted to the tool body 103 and covering an end part of the motor shaft 112 in one end part side in a long axis direction of the motor shaft 112, and the cover member 191 holds at least part of the internal mechanisms. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cover technology for an internal mechanism housed in a tool body in an impact tool such as a hammer or a hammer drill.

  The conventional electric hammer is provided with a motor that drives the hammer bit linearly in the long axis direction. In the case of a motor in which a brush holder that holds a carbon brush for supplying electric current is arranged on one end side in the rotation axis direction, a motor cover is detachably provided so as to correspond to replacement of a consumable carbon brush. A configuration in which one end in the axial direction of the motor is covered with a motor cover in the motor housing that houses the motor is described in, for example, 2007-44869.

However, the motor cover is provided to cover the motor, in particular, the brush holder and its peripheral region, and has only a function as a cover.
JP 2007-44869 A

  This invention is made | formed in view of this point, and it aims at providing the additional technique of a new function about the cover member provided in order to cover the internal mechanism accommodated in the tool main body in an impact tool.

  In order to achieve the above object, a preferred embodiment of the impact tool according to the present invention is a tool body in which an impact tool that drives a tool bit linearly in the long axis direction and thereby performs a predetermined hammer operation on the tool bit is provided. And a plurality of internal mechanisms housed in the tool body, a motor as the internal mechanism, and a motor shaft as the internal mechanism. The motor shaft is rotationally driven by energization driving of the motor. The motor shaft is arranged in a crossing manner so as to cross the tool bit long axis with respect to the tool bit long axis. The “predetermined hammering work” in the present invention is preferably not only a hammering work in which the tool bit performs only a linear hitting operation, but also a hammer drilling work in which a linear hitting operation and a circumferential rotation operation are performed. Includes.

  In a preferred embodiment of the impact tool according to the present invention, on one end side in the longitudinal direction of the motor shaft, the impact tool is further attached to the tool body, and further includes a cover member that covers the end portion of the motor shaft, It was set as the structure which hold | maintains at least one part of an internal mechanism. The “holding” in the present invention is preferably either an aspect in which an external force in the motor long axis direction is applied to and held in at least a part of the internal mechanism or an aspect in which an external force is applied in a direction crossing the motor long axis direction. Included. According to the present invention, since the cover member has a function of holding the internal mechanism in addition to the function of covering the internal mechanism, for example, the internal mechanism is held for the internal mechanism held by the cover member. This eliminates the need to set a separate mechanism.

  According to the further form of the impact tool which concerns on this invention, a motor is arrange | positioned between the rotor which rotates with a motor shaft, the bearing which supports the longitudinal direction one end part of a motor shaft, and a rotor, and the said rotation. It has a brush holder unit that holds a carbon brush for supplying current to the child. The internal mechanism as a holding object is a bearing housing portion that houses the bearing, and the cover member is configured to press and hold the bearing housing portion in the radial direction while pressing the bearing housing portion from one end side in the long axis direction of the motor shaft. Yes. The “bearing housing portion” in the present invention is typically provided integrally as a part of the motor housing on one end side in the motor axial direction of the motor housing housing the motor. For this reason, in the case of a configuration in which the brush holder unit is disposed between the rotor and the bearing, the brush holder unit is disposed in a connection region between the main body region that accommodates the rotor and the like and the bearing accommodating portion that accommodates the bearing in the housing. Will be. As a result, a reinforcing rib cannot be set between the connecting region, that is, the bearing housing portion located at the end in the motor axis direction and the main body region, and at least the brush holder portion holding the carbon brush is on the motor shaft side (commutator). There is a possibility that the strength is reduced due to the setting of an opening that allows entry into the center, and the core may run out when the motor is driven.

  However, according to the present invention, since the bearing housing portion is configured to be pressed in the radial direction while being pressed from the longitudinal direction one end side of the motor shaft by the cover member, the brush holder unit is disposed. It is possible to compensate for a decrease in strength of the connection region between the main body region and the bearing housing portion, thereby preventing runout during motor driving.

  According to the further form of the impact tool which concerns on this invention, the drive shaft as an internal mechanism rotated by the motor shaft, and the inside which drives the tool bit linearly by converting the rotation output of the drive shaft into linear motion The tool main body has a sealed housing space that houses the drive shaft and the drive mechanism. The internal mechanism as a holding target is an air vent mechanism that adjusts the pressure in the housing space by communicating the inside and the outside of the housing space, and the cover member includes one end of the motor shaft in the axial direction of the motor shaft. It was set as the structure pressed from the side and hold | maintained. The “air bleeding mechanism” in the present invention typically includes a cylindrical member that has an air passage that communicates the inside of the housing space with the outside, and that contains a filter for adsorbing lubricant in the air passage. For example, it is attached by fitting along the axial direction of the motor shaft with respect to the opening provided in the tool main body that houses the drive mechanism. Further, as the filter, felt, sponge, cloth, or the like can be suitably used, but not limited thereto, a filter capable of adsorbing and capturing a lubricant can be used as appropriate.

  According to the present invention, the air bleed mechanism is configured to be pressed and held from the one axial end side of the motor shaft by the cover member, thereby reliably preventing the air bleed mechanism from falling off due to the internal pressure of the housing space. Is possible.

  According to the further form of the impact tool which concerns on this invention, the drive shaft as an internal mechanism rotated by the motor shaft, and the inside which drives the tool bit linearly by converting the rotation output of the drive shaft into linear motion The tool main body further includes a sealed housing space for housing the drive shaft and the drive mechanism. The internal mechanism as the object to be held is an oil supply cap that closes an oil supply port that supplies lubricating oil into the accommodation space, and the cover member holds the oil supply cap by pressing it from one end side in the axial direction of the motor shaft. It was set as the structure to do. According to the present invention, as in the case of the air bleeding mechanism described above, it is possible to reliably prevent the oil filler cap from falling off due to the internal pressure of the housing space.

  According to the present invention, in the impact tool, a technique for adding a new function is provided for the cover member provided to cover the internal mechanism housed in the tool body.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. This embodiment will be described using an electric hammer as an example of an impact tool. FIG. 1 shows an overall configuration of the electric hammer 101, FIG. 2 shows an enlarged configuration of a main part of the electric hammer 101, and FIG. 3 shows a part of FIG. 2 further enlarged. FIG. 4 shows a part of FIG. 3 further enlarged. 5 shows a plan view in which the entire configuration of the electric hammer 101 is partially cut, and FIG. 6 shows the entire configuration of the drive motor 111 as a cross-sectional view taken along line AA in FIG.

  As shown in FIG. 1, an electric electric hammer 101 according to the present embodiment generally includes a main body 103 that forms an outline of the electric hammer 101, and a tip region in the major axis direction of the main body 103. A tool holder 137 connected to (left side in the figure), a hammer bit 119 detachably attached to the tool holder 137, and an operator connected to the other end part (right side in the figure) in the major axis direction of the main body 103 are gripped. The hand grip 109 is mainly used. The main body 103 corresponds to the “tool main body” in the present invention, and the hammer bit 119 corresponds to the “tool bit” in the present invention. The hammer bit 119 is capable of relative reciprocation in the major axis direction (major axis direction of the main body 103) with respect to the tool holder 137, and relative rotation in the circumferential direction is restricted. Held in a state. For convenience of explanation, the hammer bit 119 side is referred to as the front, and the hand grip 109 side is referred to as the rear.

  The main body 103 includes a motor housing 105 that houses the drive motor 111, a gear housing 107 that is joined to the motor housing 105 and houses the motion conversion mechanism 113 and the gear reduction mechanism 161, and a joint that is joined to the gear housing 107 and strikes. The barrel portion 108 that houses the element 115 is mainly configured. The gear housing 107 is disposed on the front side and the upper region of the motor housing 105. The barrel portion 108 is disposed at the front end portion of the gear housing 107 and extends forward on the long axis of the hammer bit 119. In addition, the hand grip 109 is formed in a U shape with an opening at the front, and is connected to the rear portion of the motor housing 105. In the upper region of the handgrip 109, a power switch 131 that energizes and drives the drive motor 111 and an operation member 133 that operates the power switch 131 between an on position and an off position are disposed. The operation member 133 is assembled so that the hand grip 109 is slidable in the horizontal direction (left-right direction) intersecting the long axis direction of the hammer bit, and is slid by the operator's fingers to move the power switch 131 to the on position. Then, the drive motor 111 is energized.

  The rotational output of the drive motor 111 is appropriately converted into a linear motion by the motion conversion mechanism 113 and then transmitted to the striking element 115, and the major axis direction of the hammer bit 119 (the left-right direction in FIG. 1) via the striking element 115. Generates an impact force on. The drive motor 111 is arranged in an intersecting manner so that the axis of the motor shaft 112 crosses the long axis of the hammer bit 119. A motion conversion mechanism 113 that converts the rotational output of the drive motor 111 into a linear motion and transmits it to the striking element 115 is accommodated in the upper region of the internal space of the gear housing 107.

  FIG. 2 shows the motion conversion mechanism 113, the gear reduction mechanism 161, and the striking element 115 in detail. The motion conversion mechanism 113 converts the rotational motion of the drive motor 111 into a linear motion and transmits it to the striking element 115. The crankshaft 121 that is rotationally driven by the drive motor 111 and the crank plate that rotates together with the crankshaft 121. 124, an eccentric pin 122 provided at a position shifted from the rotation center of the crank plate 124, a crank arm 123 connected through the eccentric pin 122, a piston 125 linearly reciprocated by the crank arm 123, and the like. Consists of a crank mechanism. The piston 125 as a driving element drives the striking element 115 and can slide in the cylinder 141 in the same direction as the long axis direction of the hammer bit 119.

  The crank mechanism is disposed in front of the drive motor 111 and is driven by the drive motor 111 at a reduced speed via the gear reduction mechanism 161. The gear reduction mechanism 161 includes a small gear 112a formed on the motor shaft 112, a first intermediate gear 163A meshingly engaged with the small gear 112a, a second intermediate gear 163B rotating integrally with the first intermediate gear 163A, and a second gear. An intermediate shaft 165 that rotatably supports the intermediate gear 163B and a driven gear 167 that meshes and engages with the second intermediate gear 163B are mainly configured. The driven gear 167 is fixed to the crankshaft 121 so as to rotate integrally. The crankshaft 121 is arranged in an intersecting manner so that its axis crosses the long axis of the hammer bit, and is arranged in parallel with the intermediate shaft 165 with respect to the motor shaft 112. The crank mechanism is housed in a crank chamber 116 that is a sealed internal space in the gear housing 107, and the gear reduction mechanism 161 is placed in a gear chamber 117 that is a sealed internal space above the crank chamber 116 in the gear housing 107. Be contained. The crank chamber 116 and the gear chamber 117 correspond to the “accommodating space” in the present invention.

  The striking element 115 is slidably disposed on the striker 143 slidably disposed on the bore inner wall of the cylinder 141 and the tool holder 137, and transmits the kinetic energy of the striker 143 to the hammer bit 119. And an impact bolt 145 as an intermediate element. An air chamber 141 a is formed in the cylinder 141 between the piston 125 and the striker 143. The striker 143 is driven via an air spring in the air chamber 141a of the cylinder 141 accompanying the sliding movement of the piston 125, and collides (hits) an impact bolt 145 as an intermediate element slidably disposed on the tool holder 137. The striking force is transmitted to the hammer bit 119 via the impact bolt 145. The gear reduction mechanism 161, the crank mechanism, and the striking element 115 constitute the “drive mechanism” in the present invention. Further, the crankshaft 121 in the crank mechanism corresponds to the “drive shaft” in the present invention.

  During processing of the electric hammer 101 (when the hammer bit 119 is driven), shock and periodic vibration in the long axis direction of the hammer bit occurs in the main body 103. It should be noted that the main vibration as a vibration suppression target generated in the main body 103 is the compression reaction force when the piston 125 and the striker 143 compress the air in the air chamber 141 a, and the striker 143 causes the hammer bit 119 to pass through the impact bolt 145. This is a striking reaction force generated slightly after the compression reaction force when striking.

  As shown in FIG. 2, the electric hammer 101 includes a dynamic vibration absorber 151 as a vibration suppression mechanism that suppresses the vibration generated in the main body 103 and an excitation that forcibly (positively) drives the dynamic vibration absorber 151. A mechanism 171 is provided.

  The dynamic vibration absorber 151 is assembled to the cylinder 141 and accommodated by the barrel portion 108. The dynamic vibration absorber 151 is mainly composed of an annular damping weight 153 and front and rear coil springs 155 and 157 disposed on the front side and the rear side of the weight 153 in the hammer bit major axis direction, respectively.

  The weight 153 is disposed outside the cylinder 141. The front coil spring 155 is interposed between the front end surface of the weight 153 and the front spring receiving sleeve 158 slidably fitted to the outer periphery of the front end of the cylinder 141 in the hammer bit major axis direction. The rear coil spring 157 is interposed between the rear end surface of the rear spring receiving sleeve 159 and the weight 153 which are fitted to the outer periphery of the rear end of the cylinder 141 so as to be slidable in the longitudinal direction of the hammer bit. The front and rear coil springs 155 and 157 act on the weight 153 so as to oppose the urging force in the hammer bit major axis direction. In other words, the weight 153 is movable in the hammer bit axis direction in a state where the urging forces of the front and rear coil springs 155 and 157 act in an opposing manner.

  The dynamic vibration absorber 151 mounted on the main body portion 103 has a weight 153 that is a vibration damping element in the dynamic vibration absorber 151 and front and rear coil springs with respect to the main body portion 103 that is the object of vibration suppression when the electric hammer 101 is processed. 155 and 157 cooperate to perform passive vibration suppression. As a result, the vibration generated in the main body 103 of the electric hammer 101 is suppressed.

  Next, the vibration mechanism 171 that actively drives the dynamic vibration absorber 151 will be described. As shown in FIG. 2, the vibration excitation mechanism 171 is disposed directly below the crankshaft 121 and behind the dynamic vibration absorber 151. The vibration mechanism 171 is shown in detail in FIGS. 3 and 4, particularly FIG. 4. The vibration exciting mechanism 171 drives the dynamic vibration absorber 151 by linearly operating in the longitudinal direction of the hammer bit based on the cam shaft 172, the circular eccentric cam 173 that rotates together with the cam shaft 172, and the rotational motion of the eccentric cam 173. The power transmission pin 174, the bearings 175 and 176 that rotatably support the cam shaft 172, and the bearing housing 177 that accommodates the bearings 175 and 176 are mainly configured.

The cam shaft 172 of the vibration mechanism 171 has a small-diameter portion 172a at the lower portion with the eccentric cam 173 interposed therebetween, a large-diameter portion 172b at the upper portion, and a crank plate 172c above the large-diameter portion 172b. The cam shaft 172 has a small-diameter portion 172a and a large-diameter portion 172b rotatably supported by bearing housing portions 177a and 177b via bearings 175 and 176, respectively. As a result, the cam shaft 172 is integrated with the bearing housing 177 via the bearings 175 and 176. A needle bearing 178 is attached to the outer side of the eccentric cam 173, thereby preventing wear due to sliding with the power transmission pin 174. The bearing housing 177 is inserted from below into a circular opening 107c for mounting formed on the lower surface side of the gear housing 107, that is, the side facing the crank mechanism, and is disposed in the crank chamber 116 of the gear housing 107. At the same time, it is fixed to the gear housing 107 by a screw 189.
The crank plate 172c of the cam shaft 172 is formed with an engaging portion 172d made of a U-shaped recess (may be a groove or a long hole) at a position shifted from the center. When the bearing housing 177 is assembled to the gear housing 107, the engaging portion 172d engages with a small-diameter protruding end portion 122a provided at the lower end of the eccentric pin 122 in the crank mechanism described above. As a result, the cam shaft 172 can rotate together with the crank shaft 121.

The power transmission pin 174 is constituted by two front and rear pins 174a and 174b arranged in series in the longitudinal direction of the hammer bit, and of the two pins 174a and 174b, an eccentric cam 173 (substantially a needle) One (rear) pin 174 a that abuts the outer ring of the bearing 178 (hereinafter the same) is attached to the bearing housing 177, and the other (front) pin 174 b is attached to the cylindrical portion 107 a of the gear housing 107. One pin 174a, that is, the pin 174a closer to the eccentric cam 173, as shown in FIGS. 2 and 3, intersects with the axis of the cam shaft 172 provided in the bearing housing 177 (hammer bit major axis direction). The pin guide hole 177c is slidably inserted, and the rear end surface as an end portion in the insertion direction is brought into contact with the eccentric cam 173.
One pin 174a has at least an eccentric cam so that the rear end surface of the pin 174a does not deviate from a straight line in the longitudinal direction of the hammer bit passing through the center of the eccentric cam 173 when the eccentric cam 173 is rotated. It is set to a thickness having a diameter that is at least twice the eccentric amount of 173 (the distance between the center and the center of rotation with respect to the eccentric cam 173).

The other pin 174 b, that is, the pin 174 b far from the eccentric cam 173 is attached in a penetrating state by being inserted from the front into a pin guide hole 107 b in the longitudinal direction of the hammer bit formed in the cylindrical portion 107 a of the gear housing 107. It is done. The front end surface in the major axis direction of the other pin 174b is in contact with the rear end surface of the rear spring receiving sleeve 159 of the dynamic vibration absorber 151 (see FIG. 2), and the rear end surface in the major axis direction is in contact with the front end surface of the one pin 174a. Abutted. Further, the other pin 174b is set as thin as possible within a range in which the strength is ensured. That is, the diameter is smaller than that of the one pin 174a, thereby enabling the cylindrical portion 107a to which the barrel portion 108 is attached to be reduced in diameter, and the barrel portion 108 can be reduced in diameter.
If the power transmission pin 174 is composed of one piece, the thickness of one pin 174a is required as a whole, and as a result, the diameter of the cylindrical portion 107a increases, and the barrel portion 108 also increases in diameter accordingly. It will be. However, according to the present embodiment, by configuring the power transmission pin 174 with the two pins 174a and 174b, the diameter of the barrel portion 108 can be reduced while maintaining the operation stability of the power transmission pin 174. The

  The lower portion of the bearing housing portion 177b of the bearing housing 177 has an opening 177d, and an air vent mechanism 181 for adjusting the pressure in the crank chamber 116 is assembled to the opening 177d from below. The air vent mechanism 181 is mainly configured by a filter case 184 having an air passage 182 communicating between the inside and the outside of the crank chamber 116. The filter case 184 has a filter housing chamber, and a filter 183 that adsorbs the lubricating oil that prevents the lubricating oil in the crank chamber 116 from leaking to the outside through the air passage 182 is housed in the filter housing chamber. Yes. The filter case 184 is detachably attached to the opening 177d of the lower bearing housing portion 177b by fitting from below, and is held in the fitting position by friction of the sealing O-ring 185 interposed between the fitting surfaces. . In the present embodiment, a filter case 184 for air bleeding is attached immediately below the cam shaft 172, and at least the inner opening of the air passage 182 is formed on the axis of the cam shaft 172. For this reason, it is difficult for the lubricating oil in the crank chamber 116 to enter the air passage 182 due to the centrifugal force generated by the rotation of the cam shaft 172, and leakage of the lubricating oil can be reduced.

  Further, the bearing housing 177 is formed with an oil supply port 186 for supplying lubricating oil (grease) to the crank chamber 116. A fuel filler cap 187 that closes the fuel filler 186 is removably attached to the fuel filler 186 by fitting from below. The oil filler cap 187 is held at the insertion position by the friction of the sealing O-ring 188 interposed between the fitting surfaces.

  In the electric hammer 101 configured as described above, when the crank mechanism is driven by energization driving of the drive motor 111, the cam shaft 172 of the vibration exciting mechanism 171 is rotationally driven together with the crank shaft 121 of the crank mechanism. The rotation operation of the cam shaft 172 is converted into a linear operation via the eccentric cam 173 and the power transmission pin 174 and input to the dynamic vibration absorber 151. That is, the weight 153 is forcibly driven in the long axis direction of the hammer bit via the rear spring receiving sleeve 159 and the rear coil spring, thereby causing the dynamic vibration absorber 151 to perform a vibration damping action. That is, the dynamic vibration absorber 151 acts as an active vibration damping mechanism by forced vibration that forcibly drives the weight 153 in addition to the above-described passive vibration damping action, and is generated in the main body 103 during the hammering operation. Vibration is suppressed more effectively.

  FIG. 6 shows details of the drive motor 111. As shown in the figure, the drive motor 111 is fixed to a motor shaft 112, a centrifugal cooling fan 132 that rotates integrally on the upper end side of the motor shaft 112, an armature 134 that rotates integrally with the motor shaft 112, and the motor housing 105. Stator 135, commutator 136 provided on the lower end side of motor shaft 112 (opposite side of cooling fan 132), and a plurality of (two) carbon brushes that slidably contact the outer peripheral surface of commutator 136 and supply current ( The brush holder unit 138 is housed in the main body, and is not shown for convenience. Each end of the motor shaft 112 in the major axis direction is rotatably supported by the motor housing 105 via upper and lower bearings 139a and 139b. The motor shaft 112, the armature 134, and the commutator 136 constitute a rotor.

  As shown in FIG. 3, the brush holder unit 138 includes a holder base 138 a made of a substantially cylindrical body, a brush holder portion 138 b that holds at least a carbon brush, and a male terminal of a controller 140 for controlling the drive motor 111. 140a is an assembly in which a plurality of parts such as a female terminal 138c connected to the rotor and a terminal (not shown for convenience) are connected in advance, and corresponds to the outer peripheral region of the commutator 136. It is disposed outside the motor housing 105. That is, the brush holder unit 138 includes a connecting region 105b between the large-diameter main body region portion 105c that houses the armature 134 and the stator 135 and the lower bearing housing portion 105a that houses the lower bearing 139b in the motor housing 105. It is arranged outside. The brush holder unit 138 is assembled by fitting the holder base 138 from below the motor housing 105 to the outside of the connection area 105b and fixing the holder base 138 to the connection area 105b with screws (not shown for convenience). The connecting region 105b has a predetermined length upward from the lower end so as to avoid interference with the brush holder portion 138b that passes through the connecting region 105b in the radial direction and is opposed to the outer peripheral surface of the commutator 134. A notch 105d that extends is formed.

  A wave washer 126 that acts on the bearing 139b in the major axis direction is interposed between the bearing housing portion 105a and the rear end surface of the bearing 139b in the major axis direction. When the wave washer 126 is simply fitted into the bearing housing space of the bearing housing portion 105a, for example, when the drive motor 111 is assembled to the motor housing 105, the motor housing 105 faces upward (the bearing housing portion 105a is on the upper side). If it does, it will drop | omit from the said bearing accommodating part 105a, and it is inconvenient on handling.

  In view of this, in this embodiment, a washer holding ring 127 is provided as a member for holding the wave washer 126 so as not to drop out of the bearing housing space. The washer retaining ring 127 is formed of a cylindrical member having a flange 127a at the upper end and a locking claw 127b at the lower end, and the locking claw 127b is locked to an opening edge formed on the bottom surface of the bearing housing portion 105a. By doing so, it is attached to the bearing housing portion 105a in a state in which relative movement in the major axis direction is allowed. The relative movement amount is set to be at least larger than the elastic deformation amount of the wave washer 126. The washer holding ring 127 holds the wave washer 126 between the upper end flange 127a and the bottom surface of the bearing housing portion 105a. Thus, the wave washer 126 is held in the bearing housing portion 105a and is prevented from falling off. For this reason, the assemblability when the drive motor 111 is assembled to the motor housing 105 is improved.

  The gear housing 107 is formed with a substantially circular motor arrangement space having a lower opening at the rear of the crank chamber 116. As shown in FIG. 2, the motor housing 105 assembled with the drive motor 111 is inserted into the motor arrangement space from below with the cooling fan 132 on the upper side, and is attached to the gear housing 107 by screws (not shown for convenience). Be joined. Thus, below the gear housing 107, a bearing housing portion 105 a that houses the bearing 139 b below the drive motor 111, the brush holder unit 138, the vibration exciting mechanism portion 171, the air vent mechanism portion 181, the filler cap 187, etc. Is placed in an exposed state. Therefore, a cover member 191 is disposed on the lower surface side of the gear housing 107 so as to cover the entire lower surface of the gear housing 107 including the exposed member.

  The cover member 191 is formed in a substantially rectangular dish shape, and is removably secured to the gear housing 107 by a plurality of screws (not shown) for convenience. As shown in FIG. It is set as the structure which presses and hold | maintains the accommodating part 105a, the filter case 184 of the air bleeding mechanism part 181 and the oil filler cap 187 from below. For this purpose, a first holding portion 192 that holds the bearing housing portion 105a, a second holding portion 193 that holds the filter case 184, and a third holding portion 194 that holds the filler cap 187 are provided inside the cover member 191. Is formed.

  As shown in FIG. 6, the first holding portion 192 is formed by an annular recess 192a, and an outer edge of the recess 192a is elastically formed on the lower edge of the bearing housing portion 105a via an O-ring 195. By engaging in a shape, the bearing housing portion 105a is pressed and held from the outer diameter side to the inner diameter side while pressing in the long axis direction from below. That is, the concave portion 192a and the bearing housing portion 105a are engaged with each other via an inclined surface or a curved surface, so that a pressing force of an axial component and a radial component acts on the bearing housing portion 105a.

  As shown in FIG. 4, the second holding portion 193 is configured by a generally cup-shaped cylindrical body 193 a that integrally protrudes upward from the bottom surface (inner surface) of the cover member 191 and has an upper opening. The filter case 184 is fitted so as to be covered from below, and the lower end surface in the axial direction of the filter case 184 is viewed from below by the step end surface 193b located above the bottom surface formed along the peripheral wall surface of the cylindrical body 193a. It is set as the structure pressed and hold | maintained to a major axis direction. In addition, a cross-shaped stopper 193c that contacts the lower surface of the filter 183 is provided on the bottom surface of the cylindrical body 193a, thereby forming a space as a predetermined oil reservoir between the lower surface of the filter 183 and the bottom surface of the cylindrical body 193a. Has been. For this reason, even if it is a case where lubricating oil passes the filter 183, this can be made to stay in an oil sump and the leakage to the exterior can be prevented.

  As shown in FIG. 4, the third holding portion 194 is configured by a protrusion 194 a that integrally protrudes upward on the bottom surface of the cover member 191, and the protrusion 194 a extends from the lower center of the lower end surface of the filler cap 187 from below. It is set as the structure pressed and hold | maintained to a major axis direction.

  In the present embodiment configured as described above, the cover member 191 has not only a function of covering various internal mechanisms housed in the gear housing 107, but also a plurality of structural members constituting the internal mechanism, that is, bearing housing. The portion 105a, the air vent mechanism portion 181 and the filler cap 187 are configured to have a function of holding. As described above, when the drive motor 111 includes the brush holder unit 138, the connecting region 105b between the main body region 105c of the motor housing 105 and the bearing housing portion 105a has an outer diameter because the brush holder unit 138 is disposed. However, the strength of the brush holder portion 138b is decreased, and the notch 105d for making the brush holder portion 138b face the commutator 136 is formed.

  However, according to the present embodiment, since the bearing housing portion 105a is pressed and held in the major axis direction and the radial direction by the cover member 191, it becomes possible to compensate for the insufficient strength of the connection region 105b. Thereby, the runout of the motor shaft 112 can be prevented. Further, since the bearing housing portion 105a is elastically held via the O-ring 195, an abnormal noise generated by the cover member 191 and the bearing housing portion 105a coming into contact with each other due to the dustproof effect and vibration on the bearing 139b ( The effect of preventing the chatter noise is produced. In the present embodiment, the bearing housing portion 105a is pressed and held from the outer diameter side, but may be changed to be pressed and held from the inner diameter side.

  Further, since the air vent mechanism 171 and the filler cap 187 are pressed and held by the cover member 191, measures for preventing the air vent mechanism 171 and the filler cap 187 from falling off due to vibration or the like are separately taken. There is no need. Also, for example, when the carbon brush is replaced, if the cover member 191 is removed from the gear housing 107, the replacement of the air bleed filter 173 and the replenishment of lubricating oil can be performed simultaneously with the brush replacement. High nature.

  Further, as shown in FIGS. 2 and 6, the cover member 191 is formed with a suction port 196 for taking in outside air for cooling the drive motor 111 in a peripheral region of the first holding portion 192 that holds the bearing housing chamber 105 a. Yes. During energization driving of the drive motor 111, the outside air sucked into the motor housing 105 from the suction port 196 by the rotation of the cooling fan 132 is between the armature 134 and the stator 135, and between the stator 135 and the inner wall surface of the housing. The drive motor 111 is cooled by passing through. In the present embodiment, the cooling flow path is set so that the air after cooling the motor is further used for cooling the gear reduction mechanism 161, the crank mechanism, the striking element 115, and the like. 1 and 5, the flow of cooling air is indicated by arrows.

  That is, in the electric hammer 101, air after motor cooling flows from the upper opening of the motor housing 105 into the space 106 a between the gear housing 107 and the main body cover 106 that covers the outside of the gear housing 107 by the cooling fan 132. After that, it flows forward through the space 106b between the barrel portion 108 and the main body cover 106 that covers the outside of the barrel portion 108, and then the discharge port 106c (FIG. 1) formed on the left and right side surfaces of the main body cover 106. And the air flow path is set so as to be discharged to the outside of the tool via a broken line in FIG. Thus, the air flowing through the flow path cools the gear reduction mechanism 161 in the gear chamber 117 of the gear housing 107, the crank mechanism in the crank chamber 116, the cylinder 141 in the barrel portion 108, the striking element 115, and the like. Thereby, the whole heat-emitting part in the electric hammer 101 can be cooled reasonably.

  In the present embodiment, the electric hammer has been described as an example of the impact tool. However, the hammer bit 119 may be applied to a hammer drill that performs an impact operation and a rotation operation.

In view of the gist of the present invention, the following aspects can be configured.
(Aspect 1)
“A striking tool according to claim 2,
The bearing housing portion includes a wave washer interposed between the bearing and a washer holding member that holds the wave washer, and the washer holding member allows the elastic deformation of the wave washer. A striking tool characterized by being attached to the bearing housing portion so as to be relatively movable. "
According to the invention described in aspect 1, it is possible to prevent the wave washer from falling off from the bearing housing portion, thereby improving the assembling property when the motor is assembled to the tool body.

(Aspect 2)
“A striking tool according to claim 2,
The impact tool according to claim 1, wherein the cover member has a recess that can be engaged with an end portion of the bearing housing portion, and an O-ring is interposed between the recess and the bearing housing portion. "
According to the second aspect of the invention, it is possible to obtain a dustproof effect on the bearing housing portion by the O-ring, an effect of preventing abnormal noise caused by friction between the cover member and the bearing housing portion, and the like.

(Aspect 3)
The impact tool according to claim 2,
The cover member is provided with a suction port for taking in outside air to cool the motor in a peripheral region of the bearing housing portion, and a main body that covers the tool main body and has an air discharge port outside the tool main body. A cover is provided, and the air after cooling the motor flows into the space between the tool body and the body cover and is discharged from the discharge port to the outside, thereby being accommodated in the tool body. A striking tool characterized in that the drive mechanism is cooled. "
According to the invention described in the third aspect, the driving mechanism of the impact tool can be cooled using the air for cooling the motor, which is rational.

It is sectional drawing which shows the whole structure of the electric hammer which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the principal part of an electric hammer. FIG. 3 is a partially enlarged view of FIG. 2. FIG. 4 is a partially enlarged view of FIG. 3. It is a partially cutaway top view which shows the whole structure of an electric hammer. It is the sectional view on the AA line of FIG.

Explanation of symbols

101 Electric hammer (blow tool)
103 Main body (tool body)
105 Motor housing 105a Bearing housing portion 105b Connection region portion 105c Main body region portion 105d Notch 106 Main body cover 106a Space 106b Space 106c Release port 107 Gear housing 107a Cylindrical portion 107b Pin guide hole 107c Opening portion 108 Barrel portion 109 Hand grip 111 Drive motor (motor)
112 Motor shaft 112a Small gear 113 Motion conversion mechanism (drive mechanism)
115 Stroke element (drive mechanism)
116 Crank chamber 117 Gear chamber 119 Hammer bit (tool bit)
121 Crankshaft (drive shaft)
122 Eccentric pin 122a Protruding end 123 Crank arm 124 Crank plate 125 Piston 126 Wave washer 127 Washer holding ring 127a Hook 127b Locking claw 131 Power switch 132 Cooling fan 133 Operation member 134 Armature 135 Stator 136 Commutator 137 Tool holder 138 Brush holder unit 138a Holder base 138b Brush holder 138c Female terminal 139a Upper bearing 139b Lower bearing 140 Controller 140a Male terminal 141 Cylinder 141a Air chamber 143 Strike 145 Impact bolt 151 Dynamic vibration absorber 153 Weight 155 Coil spring 157 Rear coil spring 158 Front spring receiving sleeve 159 Rear spring receiving sleeve 161 Gear reduction mechanism (drive mechanism)
163 Intermediate gear 165 Intermediate shaft 167 Driven gear 171 Excitation mechanism 172 Cam shaft 172a Small diameter portion 172b Large diameter portion 172c Crank plate 172d Engagement portion 173 Eccentric cam 174 Power transmission pin 174a One (rear) pin 174b The other (front) Pins 175, 176 Bearing 177 Bearing housing portion 177b Upper bearing housing portion 177b Lower bearing housing portion 177c Pin guide hole 177d Opening 181 Air venting mechanism 182 Air passage 183 Filter 184 Filter case 185 O-ring 186 Filling port 187 Filling port cap 188 O-ring 189 Screw 191 Cover member 192 First holding portion 192a Recessed portion 193 Second holding portion 193a Tubular body 193b Stepped end surface 193c Stopper 194 Third holding portion 194a Projection 195 O-ring 196 Suction port

Claims (4)

A striking tool that drives a tool bit linearly in the long axis direction, thereby causing the tool bit to perform a predetermined hammering operation,
A tool body;
A plurality of internal mechanisms housed in the tool body;
A motor as the internal mechanism;
A motor shaft as the internal mechanism that is rotationally driven by energization drive of the motor,
The motor shaft is arranged in an intersecting manner so as to cross the tool bit long axis with respect to the tool bit long axis,
On the one end side in the long axis direction of the motor shaft, the cover is attached to the tool body and covers the end of the motor shaft,
The hitting tool, wherein the cover member holds at least a part of the internal mechanism. The impact tool according to claim 1,
The motor includes a rotor that rotates together with the motor shaft, a bearing that supports one end of the motor shaft in the long axis direction, and a carbon brush that is disposed between the rotor and the bearing and that supplies current to the rotor. Has a brush holder unit to hold,
The internal mechanism as the holding object is a bearing housing portion that houses the bearing, and the cover member presses the bearing housing portion in the radial direction while pressing the bearing housing portion from one end side in the long axis direction of the motor shaft. A striking tool characterized in that it is configured to be held. The impact tool according to claim 1 or 2,
A drive shaft as the internal mechanism that is rotationally driven by the motor shaft;
A drive mechanism as the internal mechanism that converts the rotational output of the drive shaft into a linear motion to drive the tool bit in a straight line;
The tool body has a sealed housing space for housing the drive shaft and the drive mechanism,
The internal mechanism as the object to be held is an air vent mechanism that communicates the inside and outside of the housing space to adjust the pressure of the housing space, and the cover member is configured to connect the air vent mechanism to the motor shaft. A striking tool characterized by being configured to be pressed and held from one axial end side. The impact tool according to any one of claims 1 to 3,
A drive shaft as the internal mechanism that is rotationally driven by the motor shaft;
A drive mechanism as the internal mechanism that converts the rotational output of the drive shaft into a linear motion to drive the tool bit in a straight line;
The tool body has a sealed housing space for housing the drive shaft and the drive mechanism,
The internal mechanism as the object to be held is an oil supply cap that closes an oil supply port that supplies lubricating oil into the housing space, and the cover member is configured such that the oil supply cap is connected to the motor shaft from one axial end side. A striking tool characterized by being configured to be pressed and held.

Images