JP2006255838A - Power tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power tool enabling a user to execute work with excellent workability while fittingly and easily gripping a casing to which a change lever is provided. <P>SOLUTION: The power tool 1 is composed so that an electric motor is housed in the casing 2 and the rotary change lever 26 for switching operations of transmitting power of the electric motor 2 to a tip tool is provided on a cover 4 (the casing 2). An exterior shape of the change lever 26 is formed into a protruded curve shape (a nearly hemispheric shape) so as to give continuity to the exterior shape of the change lever 26 and that of around the change lever 26 of the cover 4 as viewed in the axial direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric tool including a casing with a rotary change lever for switching an operation of transmitting power of an electric motor to a tip tool.

  Some electric tools such as hammer drills have a casing provided with a rotary change lever for switching the rotation speed and operation mode (for example, Patent Document 1). In such an electric power tool, as shown in FIG. 7, the change lever 126 includes a rectangular parallelepiped knob 126 b that protrudes below the cover 104 of the casing 102.

JP-A-10-291173

  By the way, in the change lever 126 shown in FIG. 7, considering the ease of turning, the height of the knob 126b needs to be at least about 5 mm. Therefore, when the operator grips the cover 104 and operates the knob 126b. Had a problem that it was difficult to operate.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric tool capable of easily gripping a casing provided with a change lever without discomfort and performing work with good workability. It is in.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided an electric tool including an electric motor incorporated in a casing and a rotary change lever for switching an operation of transmitting power of the electric motor to a tip tool. The outer shape of the change lever is a convex curved surface so that the outer shape of the change lever and the outer surface of the casing around the change lever are continuous when viewed in the axial direction.

  According to a second aspect of the present invention, in the first aspect of the present invention, the outer shape of the change lever is a substantially hemispherical shape.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the outer surface shape of the change lever and the outer surface shape around the change lever of the casing are continuous in a view perpendicular to the axis. A convex portion is provided on a part of the casing around the change lever.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the convex portion is covered with an elastic body.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the casing is constituted by a housing and a cover, and an elastic body is provided on an outer peripheral surface of the cover.

  The invention according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, a knob extending radially outward is provided on a part of the outer periphery of the change lever.

  The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein a plurality of slits are formed on the outer surface of the change lever.

  According to the first to third aspects of the invention, the outer shape of the change lever is, for example, a substantially hemispherical shape, and the shape and the outer surface shape around the change lever of the casing are made continuous. The provided casing can be easily gripped without a sense of incongruity and can be operated with good workability.

  According to the fourth aspect of the present invention, since the convex portion projecting from a part around the change lever of the casing is covered with the elastic body, the feel when the casing is gripped is good and the casing is easily gripped.

  According to the fifth aspect of the present invention, since the elastic body is provided on the outer peripheral surface of the cover constituting a part of the casing, the anti-slip effect of the hand and the anti-vibration effect when the work is performed while gripping the cover close to the tip tool. Is obtained.

  According to the sixth aspect of the present invention, the operator can easily turn the change lever by picking a knob extending radially outwardly protruding from a part of the outer periphery of the change lever. The operability is improved.

  According to the seventh aspect of the present invention, since the plurality of slits are formed on the outer surface of the change lever, the slit functions to prevent the hand from slipping, and the change lever can be rotated reliably and easily.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 is a side view of a hammer drill according to the present invention, FIG. 2 is a front view of the hammer drill, FIG. 3 is a bottom view of the change lever (a view in the direction of arrow A in FIG. 2), and FIG. FIG. 5 is a cutaway side view showing the internal structure of the hammer drill, and FIGS. 6A and 6B are bottom views of the front part of the hammer drill showing the switching position of the change lever in the hammer drill mode and the drill mode. FIG.

  The hammer drill 1 according to the present embodiment is configured by incorporating the electric motor 8 and the power transmission mechanism shown in FIG. 5 in the casing 2, but the casing 2 includes a handle portion 3a as shown in FIG. Similarly, a substantially cylindrical cover 4 made of resin is coupled to the front portion of the resin housing 3 with screws 5.

  Here, as shown in FIGS. 1 and 2, screw seats 4 a are integrally formed at four locations of the upper, lower, left, and right corners of the cover 4, and the outer surface of the cover 4 is shown in FIGS. As shown in FIG. 4, a recessed groove-like extension 4b (only part of which is shown in FIGS. 1 and 4) extending forward from each screw seat 4a is formed. The extension 4b is a groove for allowing the screw 5 to pass through the screw seats 5a from the front when the cover 4 is screwed to the housing 3. By providing this, the screw 5 and the cover 4 The amount of outward protrusion of the screw seat 4a can be minimized as much as possible.

  By the way, since the hammer drill 1 performs a stable operation, as shown in FIG. 4, in the operation using this hammer drill, the operator holds the cover 4 closer to the tip tool 30 described later with one hand (left hand). And grip the handle portion 3a with the other hand (right hand). In this case, the outer periphery of the cover 4 and the handle portion 3a gripped by the operator is softer than the material of the cover 4 and the housing 3 (polycarbonate, nylon, aluminum, etc.) for the purpose of preventing hand slipping and vibration. In addition, elastic bodies 6 and 7 made of resin or rubber having a high frictional resistance are provided. The elastic bodies 6 and 7 are provided integrally with the cover 4 and the housing 3 by two-layer molding, or are formed separately from the cover 4 and the housing 3 and are attached to the outer peripheral surfaces of the cover 4 and the housing 3. The

  Thus, in the present embodiment, as shown in FIGS. 1, 2, and 4, the elastic body 6 provided on the outer peripheral surface of the cover 4 has a continuous shape, and the outer peripheral surface of the cover 6. As shown in FIGS. 1 and 4, a part of the cutout is cut into a V shape so as to avoid the extension 4 b formed on the outer peripheral surface of the cover 4. 6a is formed in a total of four places.

  A rotary change lever 26 for switching the operation mode is rotatably provided at the lower part of the cover 4. As shown in FIGS. 1 and 2, the change lever 26 has an outer peripheral surface formed in a substantially hemispherical shape. As shown in FIG. 2, the change lever 26 has an outer peripheral surface of the change lever 26 in front view (axial view). Continuity is given to the outer surface shape around the change lever 26 on the lower surface of the cover 4.

  Also, in the side view (viewed in the direction perpendicular to the axis), the outer peripheral surface of the change lever 26 and the outer surface shape of the lower surface of the cover 4 around the change lever 26 are made continuous. The convex part 4c is protrudingly provided integrally. Here, in the present embodiment, since the rotating shaft of the change lever 26 and the removal direction of the mold of the cover 4 are substantially orthogonal to each other, it is necessary to form the convex portion 4c with a plurality of ribs (not shown) in order to prevent undercut. However, the convex portion 4 c is covered with the elastic body 6.

  Further, as shown in FIG. 3, a knob 26a extending radially outward is projected from a part of the outer periphery of the change lever 26, and is opposite to the outer periphery of the change lever 26 (left side in FIG. 3). Is provided with a push button 26b. The push button 26b is used to release the rotation lock of the change lever 26 by pressing the push button 26b.

  Further, three slits 26c each inclined in a laterally oblique direction are formed on the left and right sides (upper and lower sides in FIG. 3) of the outer surface of the change lever 26, respectively.

  Next, the internal structure and operation of the hammer drill 1 will be described with reference to FIGS.

  An electric motor 8 as a drive source is built in the housing 3, and a power cable 9 for supplying power to the electric motor 8 extends from the lower end of the handle portion 3 a of the housing 3. In addition, a switch mechanism 10 is built in the handle portion 3a, and a trigger 11 that is operated by an operator is mechanically connected to the switch mechanism 10. The switch mechanism 10 is connected to an external power source (not shown) via the power cable 9, and when the trigger 11 is operated by an operator, the switch mechanism 10 and the external power source are connected and disconnected. Power supply to the electric motor 8 is turned on / off.

  On the other hand, an output shaft (motor shaft) 12 extends horizontally forward from the electric motor 8 built in the horizontal portion (motor housing portion) of the housing 3, and a pinion gear 13 is formed at the tip of the output shaft 12. ing.

  A metal support member 14 that partitions the cover 4 and the housing 3 is provided in the cover 4, and a deceleration chamber 15 is defined by the support member 14 and the cover 4. The cover 4 including the deceleration chamber 15 is filled with grease that is a lubricant for reducing friction of the sliding portion, and this grease is supplied to each sliding portion. In addition, as grease, what has a soap base and oil components, such as silicone oil, as a main component is used.

  Further, an intermediate shaft 16 parallel to the output shaft 12 of the electric motor 8 is provided in the cover 4, and the intermediate shaft 16 has both front and rear ends via bearings 17 and 18 and the cover 4 and a support member. 14 are rotatably supported. A first gear 19 is fixed to the rear end of the intermediate shaft 16, and the first gear 19 meshes with the pinion gear 13 provided on the output shaft 12 of the electric motor 8. Further, a motion conversion unit 20 for converting a rotational motion into a reciprocating motion is externally provided in front of the first gear 19 of the intermediate shaft 16, and is urged rearward by a spring 21 on the intermediate shaft 16. The clutch 22 is spline-fitted.

  Here, the motion converting portion 20 is provided with an arm portion 20a that reciprocates in the front-rear direction by the rotation of the intermediate shaft 16, and the arm portion 20a is slidably fitted in a cylinder 23 described later. The piston 24 is connected to the inserted piston 24 via a piston pin 25. Further, the clutch 22 is moved on the intermediate shaft 16 by the turning operation of the change lever 26 rotatably provided at the lower portion of the cover 4 and is engaged with and disengaged from the motion converting portion 20, thereby operating mode. Is switched between hammer drill mode and drill mode.

  By the way, the cylinder 23 is provided in parallel with the intermediate shaft 16 above the intermediate shaft 16 in the cover 4, and the cylinder 23 is rotatably supported by the support member 14. The second gear 27 fixed to the outer periphery of the portion meshes with the gear portion 28 formed at the front end portion of the intermediate shaft 16.

  A tool holding portion 29 is provided at the tip of the cylinder 23, and a tip tool 30 shown in FIG. 4 is detachably attached to the tool holding portion 29. The reason why the support member 14 is made of metal is that the support member 14 supports the pinion gear 13, the intermediate shaft 16 and the cylinder 23, and therefore requires higher mechanical strength than the cover 4 and the housing 3. is there.

  On the other hand, a striking member 31 is fitted in the piston 24 so as to be slidable in the front-rear direction, and an air chamber 32 is defined between the piston 24 in the cylinder 24 and the striking member 31. Further, an intermediate element 33 is slidably inserted in the front and rear direction of the impact element 31 in the cylinder 23, and the impact element 31 is located on the rear end side of the intermediate element 33. The tip tool 30 (see FIG. 4) is located on the front end side of 33.

  Next, the operation of the hammer drill 1 configured as described above will be described.

  As shown in FIG. 4, the hammer drill 1 is used for work with the operator holding the cover 4 and the handle 3 a of the housing 3. The operator operates the trigger 11 to activate the electric motor 8. When driven, the output shaft 12 of the electric motor 8 is rotationally driven, the rotation is decelerated through the pinion gear 13 and the first gear 19 and transmitted to the intermediate shaft 16, and the intermediate shaft 16 is rotationally driven at a predetermined speed. The Since the rotation of the intermediate shaft 16 is decelerated via the gear portion 28 and the second gear 27 and transmitted to the cylinder 23, the tool holding portion 29 provided in the cylinder 23 and the tip attached thereto The tool 30 is rotationally driven.

  Here, when the push button 26b of the change lever 26 is pushed to release the rotation lock and the change lever 26 is rotated from the neutral position in the direction of the arrow by an angle α as shown in FIG. The hammer drill mode is selected as In this hammer drill mode, the clutch 22 is urged rearward by the spring 21 and engages with the motion converter 20 as shown in FIG. Is converted into a reciprocating motion in the cylinder 23. When the piston 24 reciprocates in the front-rear direction in this manner, the air in the air chamber 32 in the cylinder 23 repeatedly compresses and expands, whereby a striking force is intermittently applied to the striking element 31, and therefore the intermediate element 33. The striking force is transmitted to the tip tool 30 via the. Accordingly, in the hammer drill mode, a rotational force and a striking force are simultaneously applied to the tip tool 30.

  On the other hand, the operation mode in which the push button 26b is pushed and the change lever 26 is rotated by an angle β in the direction of the arrow (opposite direction) from the neutral position as shown in FIG. 6B is switched to the drill mode. In this drill mode, the clutch 22 is moved forward on the intermediate shaft 16 against the urging force of the spring 21 by the change lever 26, and the engagement with the motion converting portion 20 is released. The rotation of 16 is not transmitted to the motion conversion unit 20, and the piston 24 remains stationary and does not reciprocate. Therefore, in this drill mode, since the rotation of the intermediate shaft 16 is transmitted to the cylinder 23 via the gear portion 28 and the second gear 27, only the rotational force is applied to the rotary tool 30 as described above.

  In the above, in the hammer drill 1 according to the present embodiment, the outer surface shape of the change lever 26 is substantially hemispherical, and the shape and the outer surface shape around the change lever 26 of the cover 4 are made continuous. The cover 4 provided with the change lever 26 can be easily gripped without a sense of incongruity and can be operated with good workability. In this case, the operator can easily turn the change lever 26 by picking a knob 26a extending outward in the radial direction protruding from a part of the outer periphery of the change lever 26. Operability is improved. Further, since the plurality of slits 26c are formed on the outer surface of the change lever 26, the slits 26c serve to prevent the hand from slipping, and the change lever 26 can be rotated reliably and easily.

  Further, in the hammer drill 1 according to this embodiment, the convex portion 4c protruding from the rear position of the change lever 26 on the bottom surface of the cover 4 is covered with the elastic body 6, so that an undercut at the time of mold forming is prevented. There is no sense of incongruity even when the convex portion 4c composed of a plurality of ribs touches the operator's hand, the feeling when the cover 4 is gripped is improved, and the anti-slip effect and vibration-proofing effect of the hand by the elastic body 6 Can also be obtained.

  The present invention can be applied to any power tool provided with a rotary change lever for switching an operation mode in addition to a hammer drill.

It is a side view of the hammer drill concerning the present invention. 1 is a front view of a hammer drill according to the present invention. It is a bottom view (figure of the arrow A direction of FIG. 2) of the change lever which concerns on this invention. It is a perspective view which shows the use condition of the hammer drill which concerns on this invention. It is a fracture | rupture side view which shows the internal structure of the hammer drill which concerns on this invention. (A), (b) is a bottom view of the front part of the hammer drill showing the change position of the change lever in the hammer drill mode and in the drill mode. It is a front view of the conventional hammer drill.

Explanation of symbols

1 Hammer drill (electric tool)
2 Casing 3 Housing 4 Cover 4c Protrusion 6, 7 Elastic body 8 Electric motor 26 Change lever 26a Knob 26b Push button 26c Slit 30 Tip tool

Claims (7)

In an electric tool that incorporates an electric motor in a casing and includes a rotary change lever for switching the operation of transmitting the power of the electric motor to a tip tool.
An electric power tool characterized in that the outer shape of the change lever is a convex curve so that the outer surface shape of the change lever and the outer surface shape around the change lever of the casing are continuous when viewed in the axial direction.   2. The electric tool according to claim 1, wherein an outer surface shape of the change lever is a substantially hemispherical shape.   A convex portion is provided on a part of the casing around the change lever so that the outer shape of the change lever and the outer shape of the casing around the change lever have continuity in a direction perpendicular to the axis. The power tool according to claim 1 or 2, characterized in that   The electric tool according to claim 3, wherein the convex portion is covered with an elastic body.   The electric tool according to any one of claims 1 to 4, wherein the casing includes a housing and a cover, and an elastic body is provided on an outer peripheral surface of the cover.   The power tool according to any one of claims 1 to 5, wherein a knob extending radially outward is provided on a part of the outer periphery of the change lever.   The power tool according to claim 1, wherein a plurality of slits are formed on an outer surface of the change lever.

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