JP2013078822A - Work tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology by which the flow-out of a lubricant to the outside of a housing space is suppressed.SOLUTION: A hammer drill includes a driving mechanism such as a motion conversion mechanism in which a lubricant to drive a hammer bit and the like is arranged, and a gear housing space 105a in which the driving mechanism is disposed. The driving mechanism includes a driving motor. The motor shaft 111 of the driving motor includes an inner communicating opening 191, an outer communicating opening 192 and an air passage 193 which connects the openings in the motor shaft 111. The air passage 193 communicates with the inside of the gear housing space 105a via the inner communicating opening 191 and also communicates with the outside of the gear housing space 105a via the outer communicating opening 192.

Description

  The present invention relates to a work tool in which a drive mechanism chamber is formed.

  Japanese Patent Application Laid-Open No. 2011-31363 discloses a filter chamber having a storage space of a drive mechanism in which a lubricant is enclosed, a path for adjusting the pressure of the storage space, and a predetermined volume in which a filter is disposed in the path. A work tool provided with is disclosed. As a result, the internal pressure of the containment space rises, and when the lubricant and the air are about to flow out through the path, the lubricant is captured by the filter and prevents the lubricant from flowing out. doing.

JP 2011-31363 A

  By the way, when the lubricant is captured by the filter, if the amount of the lubricant passing through the path is large, the lubricant cannot be captured by the filter and the lubricant may flow out of the filter. Then, an object of this invention is to provide the technique which can suppress efficiently that a lubricant flows out out of predetermined | prescribed accommodation space in view of the above.

  In order to solve the above problems, according to a preferred embodiment of the work tool according to the present invention, the work tool has a drive mechanism for driving the tip tool and a drive mechanism chamber in which the drive mechanism is arranged. Further, in the drive mechanism chamber, the drive mechanism is provided with a lubricant. This drive mechanism has a movable member provided with a movable drive shaft, and the movable member is formed with a first opening and a second opening, and a communication path for communicating the first opening and the second opening. . The communication path is formed at least partially inside the movable drive shaft, communicates with the inside of the drive mechanism chamber through the first opening, and communicates with the outside of the drive mechanism chamber through the second opening. It should be noted that at least a part of the drive mechanism may be disposed in the drive mechanism chamber.

  According to the present invention, since the communication path that connects the inside and the outside of the drive mechanism chamber is formed, it is possible to suppress an increase in the pressure in the drive mechanism chamber. Furthermore, since the communication path is formed in the movable member, the position of the first opening changes as the movable member moves. Therefore, when the first opening is formed in the non-moving member, that is, when the first opening is fixed and always opened at the same position, the lubricant is less likely to flow into the communication path from the first opening. Become. As a result, the lubricant can be prevented from flowing out of the drive mechanism chamber.

  According to the further form of the working tool which concerns on this invention, a movable member is a rotation member provided with the rotational drive shaft, At least one part of the communicating path is formed in the inside of the rotational drive shaft, It is characterized by the above-mentioned. And

  According to this embodiment, since the communication path is formed in the rotating member as the movable member, the position of the first opening changes with respect to the rotation axis of the rotating member as the rotating member rotates. . Therefore, compared with the case where the 1st opening is formed in the member which does not rotate, it becomes difficult for a lubricant to flow into the communicating path from the 1st opening.

  According to the further form of the working tool which concerns on this invention, the communicating path is extended in the rotation radial direction of the rotating member, and is connected to the 1st opening. It should be noted that the communication path “extends in the rotational radial direction” only needs to extend the communication path having a component in the rotational radial direction.

  According to this embodiment, even when the lubricant flows into the communication path from the first opening, the rotation member rotates because the communication path extends in the radial direction and is connected to the first opening. Due to the centrifugal force, the lubricant is discharged from the first opening toward the drive mechanism chamber. As a result, the lubricant can be prevented from flowing out of the drive mechanism chamber.

  According to the further form of the working tool which concerns on this invention, the communicating path is extended in the rotating shaft direction of the rotating member, and is connected to the 2nd opening. The communication path “extends in the direction of the rotation axis” only needs to extend the communication path having a component in the direction of the rotation axis.

  According to this embodiment, even when the lubricant flows into the communication path, the communication path extends in the direction of the rotation axis and is connected to the second opening, so that the centrifugal force when the rotation member rotates In some cases, the lubricant is less likely to flow out of the second opening. As a result, the lubricant can be prevented from flowing out of the drive mechanism chamber.

  According to the further form of the work tool which concerns on this invention, the communicating path is extended in parallel with the said rotating shaft including the rotating shaft of a rotational drive shaft, It is characterized by the above-mentioned.

  When the communication path extends in the direction of the rotation axis of the rotating member and is connected to the second opening, the communication path includes the rotation axis of the rotation drive shaft and extends parallel to the rotation axis and is connected to the second opening. This makes it more difficult for the lubricant to flow out of the second opening.

  According to the further form of the working tool which concerns on this invention, a drive mechanism has a motor, and a rotation member is an output shaft of a motor, It is characterized by the above-mentioned. The front end of the output shaft has an external communication chamber that is separated from the drive mechanism chamber and communicates with the outside of the drive mechanism chamber. The second opening is formed at the front end of the output shaft, and the second opening is external. More preferably, the communication chamber is disposed so as to open.

  According to this embodiment, the communication path can be formed in the output shaft of the motor as the rotating member, and there is no need to add a special member to the work tool in order to form the communication path.

  According to the further form of the working tool which concerns on this invention, a drive mechanism has a motor and the driven member rotationally driven by the said motor, and a rotating member is a driven member, It is characterized by the above-mentioned. The driven member is more preferably a crankshaft provided in a crank mechanism that converts the rotational output of the motor into linear motion.

  According to this form, a communicating path can be formed in the driven member driven by the motor as the rotating member. For example, it is not necessary to add a special member to the work tool in order to form a communication path on a crankshaft provided in a crank mechanism as a driven member.

  According to the further form of the working tool which concerns on this invention, the communicating path is comprised by the some internal space communicating, It is characterized by the above-mentioned.

  According to the present embodiment, since the communication path is configured by a plurality of internal spaces communicating with each other, even when the lubricant flows into the communication path, the lubricant is held in each internal space and the drive mechanism chamber. Can be prevented from flowing out to the outside.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which can suppress efficiently that a lubricant flows out out of predetermined | prescribed accommodation space can be provided.

It is a sectional side view which shows the whole structure of the hammer drill which concerns on embodiment of this invention. It is sectional drawing which expands and shows the structure of the drive mechanism of a hammer drill. It is sectional drawing which expands and shows a motor shaft periphery. It is a sectional side view which shows the whole structure of the hammer drill which concerns on the modification of this invention. It is sectional drawing equivalent to FIG. 2 of the hammer drill which concerns on the modification of this invention. It is sectional drawing which expands and shows the motion conversion mechanism periphery.

  An embodiment of the present invention will be described in detail with reference to FIGS. The present embodiment will be described using an electric hammer drill as an example of a rotary tool. As shown in FIG. 1 and FIG. 2, the hammer drill 100 according to the present embodiment is configured mainly by a main body 101 as a tool main body forming an outline of the hammer drill 100 when viewed generally. A hammer bit 119 is detachably attached to the distal end region (left side in FIG. 1) of the main body 101 via a cylindrical tool holder 159. The hammer bit 119 is mounted so as to be movable relative to the tool holder 159 in the axial direction and integrally rotate in the circumferential direction. A hand grip 107 gripped by the operator is connected to the opposite side of the tip region of the main body 101. The hammer bit 119 is an implementation configuration example corresponding to the “tip tool” in the present invention. For convenience of explanation, the hammer bit 119 side of the hammer drill 100 is referred to as the front, and the hand grip side is referred to as the rear.

  The main body 101 includes a motor housing 103 that houses the drive motor 110, and a gear housing 105 that houses the motion conversion mechanism 120, the striking element 140, and the power transmission mechanism 150. The drive motor 110 has a rotation axis (rotation axis of the motor shaft 111) in a vertical direction (vertical direction in FIG. 1) substantially orthogonal to the long axis direction of the main body 101 (long axis direction of the hammer bit 119). Has been placed. The torque of the drive motor 110 is appropriately converted into a linear motion by the motion conversion mechanism 120 and then transmitted to the striking element 140, and an impact force in the major axis direction of the hammer bit 119 is generated via the striking element 140. The drive motor 110 corresponds to the “movable member”, “rotating member”, and “motor” in the present invention, and the motor shaft 111 corresponds to the “movable drive shaft”, “rotary drive shaft”, “output shaft” in the present invention, It is the implementation structural example corresponding to.

  The torque of the drive motor 110 is transmitted to the hammer bit 119 through the tool holder 159 after the rotational speed is appropriately reduced by the power transmission mechanism 150, and the hammer bit 119 is rotated in the circumferential direction. The drive motor 110 is energized and driven by pulling a trigger 107 a disposed on the handgrip 107.

  The motion conversion mechanism 120 includes a first drive gear 121 formed on the motor shaft 111 of the drive motor 110 and a crank mechanism that is driven via a driven gear 123 that is engaged with and engaged with the first drive gear 121. . The crank mechanism includes a crankshaft 125 that rotates integrally with the driven gear 123, an eccentric shaft 127 provided at a position shifted from the axis of the crankshaft 125, a piston 131, a connecting rod 129 that connects the piston 131 and the eccentric shaft 127, and the like. Consists of. The crankshaft 125 is rotatably supported by the gear housing 105 via upper and lower bearings at both ends in the axial direction. The piston 131 is provided as a driver for driving the striking element, and can slide in the cylinder 141 in the same direction as the long axis direction of the hammer bit 119. The motor shaft 111 and the crankshaft 125 of the drive motor 110 are arranged in parallel and side by side. Further, the drive motor 110 and the cylinder 141 are arranged so that the long axes are orthogonal to each other. The cylinder 141 is fixedly supported by the gear housing 105.

  The striking element 140 is striker 143 as a striker slidably disposed in the cylinder 141 and slidably disposed in the tool holder 159, and transmits the kinetic energy of the striker 143 to the hammer bit 119. It is mainly composed of an impact bolt 145 as a meson. The cylinder 141 is arranged behind the tool holder 159 and has an air chamber 141 a partitioned by the piston 131 and the striker 143. The striker 143 is driven via a pressure fluctuation (air spring) of the air chamber 141 a accompanying the sliding motion of the piston 131, collides (hits) with the impact bolt 145, and strikes the hammer bit 119 via the impact bolt 145. Transmit power.

  The power transmission mechanism 150 includes a second drive gear 151, a first intermediate gear 161, a first intermediate shaft 163, an electromagnetic clutch 170, a second intermediate gear 165, a mechanical torque limiter 167, a second intermediate shaft 153, a small bevel gear 155, The large bevel gear 157 and the tool holder 159 are mainly configured to transmit the torque of the drive motor 110 to the hammer bit 119. The tool holder 159 is a substantially cylindrical tubular member, and is held by the gear housing 105 so as to be rotatable around the long axis of the hammer bit 119. The second drive gear 151 is fixed to the motor shaft 111 of the drive motor 110 and is driven to rotate. In torque transmission, the first intermediate shaft 163 and the second intermediate shaft 153 located on the downstream side of the motor shaft 111 are arranged in parallel and sideways with respect to the motor shaft 111. The first intermediate shaft 163 is rotatably supported by the gear housing 105 at its axial end via upper and lower bearings. The second intermediate shaft 153 is rotatably supported by the gear housing 105 at its axial end through upper and lower bearings. The first intermediate shaft 163 is provided as a shaft for mounting an electromagnetic clutch, and is disposed between the motor shaft 111 and the second intermediate shaft 153, and is always in meshing engagement with the second drive gear 151. 161 is driven to rotate through the electromagnetic clutch 170. The first intermediate gear 161 has a reduction ratio with respect to the second drive gear 151 so that the first intermediate gear 161 is decelerated with respect to the second drive gear 151.

  The electromagnetic clutch 170 transmits and interrupts torque between the drive motor 110 and the hammer bit 119, more specifically between the motor shaft 111 and the second intermediate shaft 153. During the hammer drilling operation, the hammer bit is used. When 119 is caught and locked by the workpiece, the reaction torque acting on the main body 101 side (torque acting in the direction opposite to the rotation direction of the hammer bit 119) increases abnormally and the main body 101 It is provided as means for preventing it from being swung. The electromagnetic clutch 170 is disposed above the first intermediate gear 161 in the major axis direction of the first intermediate shaft 163, and is disposed closer to the operation axis of the striker 143 than the first intermediate gear 161. .

  The electromagnetic clutch 170 is a friction type using friction, and has a disk-like driving side clutch member 171, a disk-like driven side clutch member 173, a clutch spring 175, an electromagnetic coil 177, and a built-in coil including the electromagnetic coil 177. The member 179 is mainly configured. The drive-side clutch member 171 and the driven-side clutch member 173 are disposed so as to be relatively movable in the major axis direction opposite to each other in the major axis direction of the first intermediate shaft 163. Then, when the electromagnetic coil 177 is energized, the driving side clutch member 171 and the driven side clutch member 173 are moved relative to each other in a direction approaching each other by electromagnetic force, and transmit torque by the frictional force of the contact surface. To do. When the energization of the electromagnetic coil 177 is interrupted, the urging force of the clutch spring 175 releases the contact between the drive side clutch member 171 and the driven side clutch member 173, thereby interrupting the transmission of torque.

  Torque output from the electromagnetic clutch 170 is configured to be transmitted to the second intermediate shaft 153 via the mechanical torque limiter 167. The mechanical torque limiter 167 is provided as a safety device against overload applied to the hammer bit 119. When an excessive torque exceeding a design value (hereinafter also referred to as a maximum transmission torque value) acts on the hammer bit 119, the hammer bit 119 is provided. Is cut off on the second intermediate shaft 153 coaxially.

  The mechanical torque limiter 167 includes a driving side member 168 having a third intermediate gear 168a meshingly engaged with the second intermediate gear 165, and a driven side member 169 that rotates integrally with the second intermediate shaft 153. If the torque value acting on the second intermediate shaft 153 (corresponding to the torque value acting on the hammer bit 119) is less than or equal to the maximum transmission torque value determined in advance by the urging force of the spring 167a, the driving side member 168 and the driven side member 169 transmits torque. On the other hand, when the torque value acting on the second intermediate shaft 153 exceeds the maximum transmission torque value, the torque transmission between the driving side member 168 and the driven side member 169 is cut off. The speed ratio of the third intermediate gear 168 a of the drive side member 168 is set so as to be decelerated with respect to the second intermediate gear 165.

  The torque transmitted to the second intermediate shaft 153 is coupled to the large bevel gear 157 engaged with and engaged with the small bevel gear 155 from the small bevel gear 155 formed integrally with the second intermediate shaft 153, and the large bevel gear 157. Further, it is configured to be transmitted to the hammer bit 119 via a tool holder 159 as a final output shaft.

  The movement converting mechanism 120, the striking element 140, the power transmission mechanism 150, and the tip portion of the motor shaft 111 of the drive motor 110 are accommodated in a gear accommodating space 105 a as an internal space surrounded by the gear housing 105. A lubricant that lubricates the motion conversion mechanism 120, the striking element 140, and the power transmission mechanism 150 is disposed in the gear housing space 105a. The gear housing space 105a corresponds to the “drive mechanism chamber” in the present invention, and the motion conversion mechanism 120, the striking element 140, the power transmission mechanism 150, and the drive motor 110 correspond to the “drive mechanism” in the present invention. It is an example.

  The electromagnetic clutch 179 transmits torque by the frictional force between the contact surfaces of the drive side clutch member 171 and the driven side clutch member 173. Therefore, when the lubricant adheres to the friction surface, the friction surface causes slipping, resulting in torque transmission capability. May be reduced. Therefore, a first oil seal 181 and a second oil seal 183 are arranged in order to prevent the lubricant from entering the clutch housing space 105a.

  The hammer drill 100 configured as described above is driven by energizing the drive motor 110 when the trigger 107a is operated. The torque of the drive motor 110 is transmitted to the motion conversion mechanism 120, and the piston 131 is linearly slid along the cylinder 141. Thereby, the striker 143 moves linearly in the cylinder 141 by the pressure change of the air in the air chamber 141a, that is, the action of the air spring. The striker 143 collides with the impact bolt 145 to transmit the kinetic energy to the hammer bit 119.

  On the other hand, the torque of the drive motor 110 is transmitted to the power transmission mechanism 150. Thereby, the tool holder 159 is rotationally driven, and the hammer bit 119 is rotated together with the tool holder 159. In this way, the hammer bit 119 performs the hammer operation in the axial direction and the drill operation in the circumferential direction, and performs the hammer drill operation on the workpiece.

  The hammer drill 100 according to the present embodiment is not limited to the working mode in the hammer drill mode in which the hammer bit 119 performs the hammer operation and the drill operation, and the drill mode in which the hammer bit 119 performs only the drill operation. It is possible to switch to a work mode or a work mode in a hammer mode in which the hammer bit 119 performs only a hammer operation. However, the description of the mode switching mechanism is omitted for convenience.

  As described above, when the hammer drill 100 is driven, the pressure in the gear housing space 105a rises due to heat generated by the driving mechanisms such as the motion conversion mechanism 120, the striking element 140, and the power transmission mechanism 150. Therefore, it is necessary to make the air in the gear housing space 105a communicate with the outside so that the pressure in the gear housing space 105a does not increase. On the other hand, since the lubricant for lubricating the drive mechanism is disposed in the gear housing space 105a, the lubricant can be obtained only by forming a through hole in the gear housing 105 constituting the gear housing space 105a. There is a possibility of leaking outside. Therefore, in the present embodiment, an air communication portion 190 that communicates the gear housing space 105a with the outside is formed at the tip portion of the motor shaft 111 of the drive motor 110 and disposed in the gear housing space 105a. Yes.

  The air communication unit 190 includes an internal communication opening 191, an external communication opening 192, and an air communication path 193. Specifically, as shown in FIG. 3, an internal communication opening 191 is formed in the side surface of the motor shaft 111, and an external communication opening 192 is formed in the axial end of the motor shaft 111. An air communication path 193 is formed.

  The air communication path 193 includes an axially extending portion 194 that extends in parallel with the rotational axis direction at the axial center portion of the motor shaft 111, and a side of a substantially central portion in the rotational axis direction of the axially extending portion 194. And a radially extending portion 195 extending in the rotational radial direction from the internal communication hole 191 toward the internal communication hole 191. That is, the air communication passage 193 is connected to the internal communication opening 191 through the radially extending portion 195 and is connected to the external communication opening 192 through the axial extending portion 194. Thereby, the internal communication opening 191 and the external communication opening 192 communicate with each other. The internal communication opening 191, the external communication opening 192, and the air communication passage 193 are implementation examples corresponding to the “first opening”, “second opening”, and “communication passage” in the present invention, respectively.

  A cylindrical outside air communication chamber 196 communicating with outside air is formed at the tip of the motor shaft 111 (upper side in FIG. 3). That is, the third oil seal 197 is disposed between the inner housing portion 106 and the motor shaft 111, and the outside air communication chamber 196 is formed by the wall of the inner housing portion 106 and the third oil seal 197. . The third oil seal 197 is formed in an annular shape combining a metal ring and a synthetic rubber. In the third oil seal 197, the metal ring is press-fitted and fixed to the inner peripheral portion of the inner housing portion 106, and the synthetic rubber on the inner peripheral portion side is held in close contact with the motor shaft 111 due to its elasticity. Yes. The outside air communication chamber 196 communicates with outside air through a through hole (not shown) formed in the gear housing 105. The front end portion of the motor shaft 111 is disposed in the outside air communication chamber 196, whereby the external communication opening 192 communicates with the outside air.

  According to the present embodiment described above, the air communication portion 190 is formed, so that the air in the gear housing space 105a can communicate with the outside air, and the motion conversion mechanism 120, the striking element 140, and the power transmission mechanism can be communicated. It is possible to suppress an increase in pressure in the gear housing space 105a due to heat generated by driving a driving mechanism such as 150.

  Further, according to the present embodiment, the air communication portion 190 is formed on the motor shaft 111 of the drive motor 110. When the air communication portion 190 is formed on the rotating member, the lubricant is less likely to flow into the air communication portion 190 than when the air communication portion 190 is formed on the non-rotating member. That is, since the position of the internal communication opening 191 changes with respect to the rotation shaft of the motor shaft 111 as the motor shaft 111 rotates, the lubricant is connected to the internal communication as compared with the case where the position of the internal communication opening 191 does not change. It is difficult to flow into the air communication path 193 from the opening 191. Therefore, the lubricant can be prevented from flowing into the air communication path 190 by the rotating motor shaft 111. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the present embodiment, the air communication passage 193 is connected to the internal communication opening 191 with the radially extending portion 195 extending in the rotational radial direction of the motor shaft 111. Therefore, even when the lubricant flows into the air communication passage 193 from the internal communication opening 191, the lubricant is returned from the internal communication opening 191 into the gear housing space 105 a by the centrifugal force due to the rotation of the motor shaft 111. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the present embodiment, the air communication passage 193 is connected to the external communication opening 192 at the axially extending portion 194 extending in the rotation axis direction of the motor shaft 111. Therefore, even when the lubricant flows into the air communication passage 193 from the internal communication opening 191, the centrifugal force due to the rotation of the motor shaft 111 causes the lubricant to move to the external communication opening 192 in the axially extending portion 194. The lubricant does not work in the direction, and the lubricant remains held in the axial extension 194. In particular, it is more effective when the axially extending portion 194 includes a rotation axis and extends parallel to the rotation axis. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the present embodiment, the radially extending portion 195 extends in the rotational radial direction from the side of the substantially central portion in the rotational axis direction of the axially extending portion 194 toward the internal communication hole 191. Is formed. Therefore, even when the lubricant flows into the axially extending portion 194, there is a space for holding the lubricant on the opposite side of the axially extending portion 194 from the external communication opening 192 in the rotational axis direction. Can be prevented from flowing out from the axially extending portion 194.

  Moreover, according to this embodiment, since the air communication part 190 is formed in the motor shaft 111 of the drive motor 110, an existing rotating member is used without newly adding a rotating member to the hammer drill 100. Thus, the air communication portion 190 can be formed.

  In the above-described embodiment, the air communication passage 193 is configured by the axially extending portion 194 and the radially extending portion 195, but is not limited thereto. For example, a capturing space for capturing the lubricating oil may be formed between the axially extending portion 194 and the radially extending portion 195. Alternatively, the inside of the axially extending portion 194 or the radially extending portion 195 may be partitioned into a plurality of spaces. Further, the axially extending portion 194 is not limited to the configuration including the rotating shaft, and may be formed at a position eccentric with respect to the rotating shaft, and is inclined with respect to the rotating shaft. Also good.

  Next, modifications of the air communication portion according to the embodiment of the present invention will be described with reference to FIGS. The configuration other than the air communication portion is the same as that of the above embodiment, and the same reference numerals are given and the description thereof is omitted. As shown in FIGS. 4 and 5, in the modification, the air communication portion 200 is formed around the crankshaft 125 of the motion conversion mechanism 120.

  The air communication unit 200 includes an internal communication opening 201, an external communication opening 202, and an air communication path 203. Specifically, as shown in FIG. 6, an internal communication opening 201 is formed on the side that intersects the rotation axis direction of the crankshaft 125, and an external communication opening 202 is formed at the lower end in the rotation axis direction of the crankshaft 125. Has been. Further, an air communication passage 203 is formed around and inside the crankshaft 125. The air communication path 203 includes a first room 204, a second room 205, a first communication path 206, a second communication path 207, and a third communication path 208. The crankshaft 125 and the driven gear 123 that rotate integrally with the air communication passage 203 correspond to the “movable member”, “rotating member”, and “driven member” in the present invention, and the crankshaft 125 in the present invention. This is an implementation configuration example corresponding to “movable drive shaft”, “rotary drive shaft”, and “crank shaft”.

  The air communication path 203 is formed around the crankshaft 125 in a first chamber 204 that surrounds the crankshaft 125 in an annular shape and is partially sealed by the driven gear 123 (downward in FIG. 6). A first communication path 206 extending in the rotational radial direction of the crankshaft 125 is formed in the outer peripheral portion of the first chamber 204, and the first chamber 204 is connected to the internal communication opening 201 through the first communication path 206. Connected to. A second chamber 205 is formed inside the crankshaft 125. The first chamber 204 and the second chamber 205 communicate with each other through a second communication passage 207 that extends in the rotational radial direction of the crankshaft 125. Furthermore, a central portion of the crankshaft 125 projects into the second chamber 205 and is formed in a sleeve shape. The second shaft 205 extends from the second chamber 205 to the central portion of the crankshaft 125 in parallel with the rotation axis direction. 3 communication passages 208 are formed, and the second chamber 205 is connected to the external communication opening 202 through the third communication passage 208.

  By forming the air communication path 203 in this way, the internal communication opening 201 and the external communication opening 202 are communicated with each other through the crankshaft 125. The internal communication opening 201, the external communication opening 202, and the air communication path 203 are implementation examples corresponding to the “first opening”, “second opening”, and “communication path” in the present invention, respectively. Further, the first room 204 and the second room 205 are an implementation configuration example corresponding to “a plurality of internal spaces” in the present invention.

  A cylindrical outside air communication chamber 209 is formed below the crankshaft 125, and the outside air communication chamber 209 communicates with outside air via the filter 210. That is, the fourth oil seal 211 is disposed between the gear housing 105 that holds the crankshaft 125 and the crankshaft 125, and the wall of the gear housing 105, the fourth oil seal 211, and the filter 210 communicate with the outside air. A chamber 209 is formed. The fourth oil seal 211 is formed in an annular shape combining a metal ring and a synthetic rubber. In the fourth oil seal 211, a metal ring is press-fitted and fixed to the inner peripheral portion of the gear housing 105, and the synthetic rubber on the inner peripheral portion side is held in close contact with the crankshaft 125 by its elasticity. . The external communication opening 202 opens toward the outside air communication chamber 209, and thereby the external communication opening 202 communicates with the outside air.

  According to the above modification, the air communication portion 200 is formed, whereby the air in the gear housing space 105a and the outside air can be communicated, and the motion conversion mechanism 120, the striking element 140, the power transmission mechanism 150, and the like It is possible to suppress an increase in the pressure in the gear housing space 105a due to the heat generated by the drive mechanism.

  Further, according to the modification, the air communication portion 200 is formed around the crankshaft 125, so that the internal communication opening 201 is rotated along with the rotation of the crankshaft 125 and the driven gear 123 as in the present embodiment. Since the position changes, the lubricant can be prevented from flowing into the air communication path 200. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the modification, the air communication passage 203 is connected to the internal communication opening 201 via the first communication passage 206 extending in the rotation radial direction of the crankshaft 125. Therefore, even when the lubricant flows into the air communication passage 203 from the internal communication opening 201, the lubricant is caused to enter the gear housing space 105a from the internal communication opening 201 by the centrifugal force due to the rotation of the crankshaft 125 and the driven gear 123. Returned. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the modification, the air communication passage 203 is connected to the external communication opening 202 in the third communication passage 208 extending in the direction of the rotation axis of the crankshaft 125. Therefore, even when the lubricant flows into the air communication passage 203 from the internal communication opening 201, the centrifugal force due to the rotation of the crankshaft 125 causes the lubricant to move to the external communication opening 202 in the third communication passage 208. The lubricant does not work in the direction, and the lubricant remains held in the air communication passage 203, that is, the first chamber 204 or the second chamber 205. In particular, it is more effective when the third communication path 208 includes a rotation axis and extends parallel to the rotation axis. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  Further, according to the modification, the third communication path 208 is formed so as to protrude into the second chamber 205. Therefore, even when the lubricant flows into the second chamber 205, there is a space for holding the lubricant in the second chamber 205, so that the lubricant can be prevented from flowing into the third communication path 208. As a result, the lubricant can be prevented from flowing out of the gear housing space 105a.

  In addition, according to the modification, the air communication path 203 is configured such that the first room 204 and the second room 205, which are a plurality of rooms, communicate with each other, so that the lubricant is supplied to the third communication path 208. It is difficult to reach up to. In addition, since the third communication path 208 is formed at the center of the crankshaft 125, the lubricant is further prevented from reaching the third communication path 208 by the centrifugal force of the rotating crankshaft 125. it can.

  Further, according to the modification, the air communication part 200 is formed around the crankshaft 125 and the driven gear 123, so that an existing rotating member can be used without newly adding a rotating member to the hammer drill 100. Utilizing this, the air communication part 200 can be formed.

  In the above modification, the air communication path 203 is configured by two rooms, but may be configured by connecting three or more rooms. The third communication path 208 is not limited to the configuration including the rotation shaft, and may be formed at a position eccentric with respect to the rotation shaft, or may be formed to be inclined with respect to the rotation shaft. Also good.

  In the above description, the internal communication openings 191 and 201 are formed to open in the circumferential direction of the motor shaft 111 and the crankshaft 125 as rotating members, but are not limited thereto. That is, the internal communication openings 191 and 201 may be formed eccentrically with respect to the rotation axis at the rotation axis direction end of the rotation member. Even if the internal communication openings 191 and 200 are formed in this way, the position of the internal communication openings 191 and 201 changes with the rotation of the rotating member, so that the lubricant passes from the internal communication openings 191 and 200 to the air communication path. It is difficult to flow into 193,203.

  In the above description, the motor shaft 111 of the drive motor 110, the crankshaft 125, and the driven gear 123 are set as the rotating members. However, other rotating members may be used. That is, an air communication portion may be provided around the rotating first intermediate shaft 163, the second intermediate shaft 153, and the tool holder 159, or another rotating member may be provided. In addition, as long as the position of the internal communication openings 191 and 201 is changed as the hammer drill 100 is driven, the air communication portions 190 and 200 are not limited to the rotating members. That is, the air communication paths 190 and 200 may be formed in movable members such as the connecting rod 129 and the piston 131 that operate in the major axis direction of the hammer bit 119. An outside air communication chamber is provided at a position where the outside air communication openings 192 and 202 are opened so that the air in the gear housing space 105a communicates with the outside through the air communication passages 193 and 203 formed inside the movable member. Alternatively, the outside air communication openings 192 and 202 may be directly opened to the outside air. In this case, the connecting rod 129, the piston 131, and the like are implementation examples corresponding to the “movable member” or “movable drive shaft” in the present invention.

  In the above description, an electric hammer drill has been described as an example of a work tool. However, if the work tool has a drive mechanism chamber, a work tool other than a hammer drill, for example, an electric disc grinder, a screw tightener, etc. The present invention can also be applied to.

100 Hammer Drill 101 Main Body 103 Motor Housing 105 Gear Housing 105a Gear Housing Space (Drive Mechanism Chamber)
107 hand grip 110 drive motor (movable member, rotating member, motor)
111 Motor shaft (movable drive shaft, rotary drive shaft, output shaft)
119 hammer bit 120 motion conversion mechanism 121 first drive gear 123 driven gear 125 crankshaft 127 eccentric shaft 129 connecting rod 131 piston 140 striking element 141 cylinder 141a air chamber 143 striker 145 impact bolt 150 power transmission mechanism 151 second drive gear 153 first 2 intermediate shaft 155 small bevel gear 157 large bevel gear 159 tool holder 161 first intermediate gear 163 first intermediate shaft 165 second intermediate gear 167 mechanical torque limiter 168 drive side member 168a third intermediate gear 169 driven side member 170 electromagnetic clutch 171 drive Side clutch member 173 Driven side clutch member 175 Clutch spring 177 Electromagnetic coil 179 Coil built-in member 181 First oil seal 183 Second oil seal 190 Air communication portion 191 Internal communication Mouth (first opening)
192 External communication opening (second opening)
193 Air communication passage (communication passage)
194 Axial extension portion 195 Radial extension portion 196 Outside air communication chamber 197 Third oil seal 200 Air communication portion 201 Internal communication opening (first opening)
202 External communication opening (second opening)
203 Air communication passage (communication passage)
204 1st room (internal space)
205 Second room (internal space)
206 First communication passage 207 Second communication passage 208 Outside air communication chamber 209 Filter 210 Fourth oil seal

Claims (10)

It is a work tool that drives a tip tool that is detachably attached,
A drive mechanism for driving the tip tool;
A drive mechanism chamber in which the drive mechanism is disposed;
In the drive mechanism chamber, the drive mechanism is provided with a lubricant,
The drive mechanism includes a movable member having a movable drive shaft, and the movable member is formed with a first opening and a second opening, and a communication path that communicates the first opening and the second opening. And
The communication path is formed at least partially inside the movable drive shaft, communicates with the interior of the drive mechanism chamber through the first opening, and communicates with the outside of the drive mechanism chamber through the second opening. A working tool characterized by The work tool according to claim 1,
The movable member is a rotary member having a rotary drive shaft,
The work tool characterized in that at least a part of the communication path is formed inside the rotary drive shaft. The work tool according to claim 2,
The work tool characterized in that the communication path extends in a rotational radial direction of the rotating member and is connected to the first opening. The work tool according to claim 2 or 3,
The work tool characterized in that the communication path extends in the rotation axis direction of the rotating member and is connected to the second opening. The work tool according to claim 4,
The communication path includes a rotation shaft of the rotation drive shaft, extends parallel to the rotation shaft, and is connected to the second opening. The work tool according to any one of claims 2 to 5,
The drive mechanism has a motor,
The rotary tool is an output shaft of the motor. The work tool according to claim 6,
The front end portion of the output shaft has an external communication chamber that is separated from the drive mechanism chamber and communicates with the outside of the drive mechanism chamber,
The work tool, wherein the second opening is formed at a distal end portion of the output shaft, and the second opening is disposed so as to open into the external communication chamber. The work tool according to any one of claims 2 to 5,
The drive mechanism includes a motor and a driven member that is rotationally driven by the motor,
The working tool, wherein the rotating member is the driven member. The work tool according to claim 8,
The work tool, wherein the driven member is a crankshaft provided in a crank mechanism that converts a rotational output of the motor into a linear motion. The work tool according to any one of claims 1 to 9,
The communication path is configured by a plurality of internal spaces communicating with each other.

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