JP2009090434A - Motor-driven drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for improving the workability of a bit exchange work in a motor-driven drill of the type of performing rotation around the axial line where a bit intersects the rotation axial line of a motor. <P>SOLUTION: The motor-driven drill has a tool body 103 and the motor 111 stored in the tool body 103 and makes a workpiece undergo a prescribed working operation by the bit rotating around the axis in the direction intersecting the rotation axial line of the motor 111. A tool shaft 131 which is rotatably driven by the motor 111 and can mount the bit, and rotation regulation parts 141, 151 are provided which are set in the tool body 103 and can prevent the rotation of the tool shaft 131 when exchanging the bit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric drill of a type in which a bit performs a rotational movement about an axis intersecting with a rotation axis of a motor.

  The electric drill has a configuration in which a drill chuck is provided on a tool shaft that is rotationally driven by a motor via a transmission device (deceleration mechanism), and the drill is detachably attached to the drill chuck. The bit replacement work is performed with one hand held so that the tool shaft side of the drill chuck does not rotate, but among the electric drills, the electric drill of the type in which the rotation axis of the bit intersects the rotation axis of the motor (this In the case of a type of electric drill, which is generally called an angle drill), a drill chuck is disposed in a direction substantially perpendicular to the major axis direction at the distal end region in the major axis direction of the tool body. The tip will interfere with the bit replacement work. For this reason, the electric drill is preferably provided with a shaft lock for locking the tool shaft so as not to rotate during bit replacement. An electric drill provided with a shaft lock is disclosed in, for example, Japanese Utility Model Publication No. 51-127181 (Patent Document 1).

The shaft lock described in the above publication is applied to an electric drill in which a bit rotates about an axis parallel to the rotation axis of the motor. A pin hole is provided in the tool shaft, and a lock pin is provided in the pin hole. Is inserted to lock the tool shaft. However, in the case of the shaft lock method using the insertion / removal type lock pin described in the publication, there is still room for improvement in that the management of the lock pin is troublesome.
Japanese Utility Model Publication No. 51-127181

  An object of the present invention is to provide a technique that contributes to improvement in workability of bit replacement work in an electric drill of a type in which a bit rotates about an axis intersecting with a rotation axis of a motor.

  In order to achieve the above object, a preferred embodiment of an electric drill according to the present invention has a tool body and a motor accommodated in the tool body, and a bit that rotates around an axis in a direction intersecting the rotation axis of the motor. In a power drill that performs a predetermined machining operation on a workpiece by the above, a tool shaft that is rotationally driven by a motor and that can be fitted with a bit, and a rotation restricting portion that can prevent the rotation of the tool shaft when the bit is replaced, It is characterized by having. The “rotation restricting portion” in the present invention allows the rotation of the tool shaft when a rotational force is input from the motor side, and rotates the tool shaft when the rotational force is input from the tool shaft side. Either an auto-lock type configured to prevent movement or a manual operation type configured to prevent rotational movement of the tool shaft by an operator's finger pressing operation or pulling operation may be preferably used. it can.

  According to the present invention, when the bit is replaced, the rotation restricting portion that prevents the rotation of the tool shaft is provided, so that the bit can be changed while the rotation of the tool shaft is blocked, that is, the drill chuck is loosened or tightened. Work can be performed and workability is improved. In particular, when the bit is arranged in a direction substantially perpendicular to the long axis direction in the long axis direction tip region of the tool body, that is, an angle drill, the long axis direction tip region is used for bit replacement work. The problem of getting in the way will be solved, which is effective in improving workability.

According to the further form of the electric drill according to the present invention, the rotation restricting portion reduces the transmission of the motor vibration in the power transmission path for transmitting the rotational force of the motor to the tool shaft, and the tool shaft side by the operator when replacing the bit. Are arranged in an optimization region that realizes both of the reduction in rotational force input from.
According to the present invention, since the rotation restricting portion is disposed in the region that realizes the reduction of the transmission of the motor vibration, the adverse effect due to the motor vibration can be reduced. On the other hand, when the rotation restricting portion is arranged in a region that realizes a reduction in the rotational force input from the tool shaft side by the operator when replacing the bit, the force acting on the rotation restricting portion is reduced, and the rotation restricting portion Durability can be improved.
And this invention is rationally implement | achieved by applying to the electric drill provided with the deceleration mechanism which decelerates the rotational speed of a motor and transmits to a tool shaft, for example. In this case, the “region for realizing reduction in transmission of motor vibration” in the present invention corresponds to the downstream region of the first reduction unit that reduces the rotational speed of the motor in the reduction mechanism. Further, the “region for realizing a reduction in the rotational force input from the tool shaft side by the operator at the time of bit replacement” is an upstream region of the second reduction unit that further reduces the rotational speed reduced by the first reduction unit. This is the case.

  Therefore, according to the further form of the electric drill which concerns on this invention, it further has a reduction mechanism which decelerates the rotational speed of a motor, and a rotation control part is the 1st reduction part which decelerates the rotational speed of the motor in a reduction mechanism. And a second reduction part that further reduces the rotational speed reduced by the first reduction part. By adopting such a configuration, the rotation restricting portion is rationalized in an optimization area that realizes both reduction of motor vibration transmission and reduction of rotational force input by the operator from the tool shaft side when replacing the bit. It is possible to arrange them.

According to the further form of the electric drill which concerns on this invention, it further has a deceleration mechanism which decelerates the rotational speed of a motor. The rotation restricting unit allows the rotation of the reduction mechanism by the motor when the rotation is input from the motor side, and prevents the rotation of the reduction mechanism when the rotation is input from the tool shaft. It is configured as follows.
The rotation restricting portion of the present invention has a configuration in which the tool shaft is not rotated in response to a rotational force input from the tool shaft side, that is, a configuration in which the tool shaft is automatically locked. In some cases, the bit changing operation can be easily performed without performing a special operation for locking the rotational movement of the tool shaft.

According to the further form of the electric drill which concerns on this invention, it has a reduction mechanism which decelerates the rotational speed of a motor, and a tool main body which accommodates a motor and a reduction mechanism. Then, the rotation restricting portion is moved between a rotation restricting position where the rotation operation of the reduction mechanism is blocked and a rotation permission position where the blocking of the rotation operation of the reduction mechanism is released by an operator's operation from outside the tool body. It is set as the structure which has a rotation control member.
According to the present invention, at the time of exchanging the bit, the operator can perform the bit exchanging operation in a state where the rotation restricting member is moved to the rotation restricting position to prevent the speed reduction mechanism from rotating. In addition, as a form of "movement of a rotation control member" in this invention, both the aspect moved in the direction which cross | intersects with respect to the outer surface of a tool main body, or the aspect slid along the outer surface of a tool main body are included suitably. .

  According to the present invention, in the electric drill of the type in which the bit rotates about the axis intersecting with the rotation axis of the motor, a technique that contributes to improvement in workability of the bit replacement work is provided.

(First embodiment of the present invention)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. This embodiment will be described using a rechargeable electric drill as an example of an electric drill. FIG. 1 is a side view showing the overall configuration of the electric drill according to the present embodiment, FIG. 2 is a cross-sectional view showing the main part of the electric drill, and FIG. 3 is a cross-sectional view based on the line AA in FIG.

As shown in FIG. 1, the electric drill 101 is generally disposed in a main body portion 103 that forms an outline of the electric drill 101 and a long-axis direction tip region (right side in FIG. 1) of the main body portion 103. The drill bit 133 (not shown for the sake of convenience) is mainly composed of a drill chuck 133 that detachably holds the drill bit. The main body 103 corresponds to the “tool main body” in the present invention, and the drill bit corresponds to the “bit” in the present invention. The drill chuck 133 as a bit holder is disposed so as to face one surface in the distal end region of the main body 103 and rotates around an axis in a direction intersecting the major axis direction of the main body 103.
In addition, a battery case 109 in which a battery serving as a power source for the drive motor 111 is accommodated is attached to the end of the main body 103 opposite to the drill chuck 133. The drive motor 111 corresponds to the “motor” in the present invention. For convenience of explanation, the drill chuck 133 side is referred to as the front side and the battery case 109 side is referred to as the rear side with respect to the major axis direction of the main body 103. The drill chuck 133 side is referred to as the lower side (lower surface side) with respect to the direction intersecting the major axis direction of the main body 103.

  The main body 103 is mainly composed of a motor housing 105 that accommodates the drive motor 111 and a gear housing 107 that accommodates the gear reduction mechanism 121, such that the motor housing 105 is the rear side and the gear housing 107 is the front side. Are connected to each other in a fixed manner. The motor housing 105 is formed in a substantially cylindrical shape, occupies most of the area of the main body 103, and a rear outer surface area close to the battery case 109 serves as a grip part 103 </ b> A for an operator to hold by hand. A trigger switch 108 that is set and is pulled by a finger to energize and drive the drive motor 111 is installed on the lower surface side of the grip portion 103A.

  As shown in FIG. 2, the drive motor 111 is housed in the motor housing 105 so that the rotation axis thereof is in the long axis direction of the main body 103, and between the rotor 113 and the commutator 115 in the drive motor 111. Is provided with a cooling fan 117. In the configuration of the drive motor 111, an empty space may exist between the rotor 113 and the commutator 115. In the present embodiment, a cooling fan 117 is arranged between the rotor 113 and the commutator 115 using this empty space. As a result, the drive motor 111 can be made compact in the long axis direction.

The drive motor 111 is arranged in a direction in which the commutator 115 is in front of the rotor 113, that is, in a direction in which the cooling fan 117 is in front of the rotor 113. The motor housing 105 is formed with a plurality of ventilation openings 105 a in a region corresponding to the outer periphery of the cooling fan 117. The ventilation opening 105a is set in front of the grip portion 103A in the motor housing 105, that is, in front of the trigger switch 108, and is configured such that air inside the motor housing 105 is discharged from the ventilation opening 105a to the outside by the cooling fan 117. Is done.
In the present embodiment, the cooling fan 117 is arranged in front of the rotor 113, so that the ventilation opening 105a for air discharged from the inside to the outside of the motor housing 105 is set in front of the grip portion 103A. can do.

  As shown in FIG. 2, the gear reduction mechanism 121 is provided as a transmission device that transmits the rotational force of the drive motor 111 to the spindle 131, and includes a plurality of gears that are engaged with each other. The gear reduction mechanism 121 corresponds to the “deceleration mechanism” in the present invention. The gear reduction mechanism 121 has a first stage reduction part 121A that reduces the rotational speed of the motor, and a second stage reduction part 121B that further reduces the speed reduced by the first stage reduction part 121A. The first stage reduction unit 121A corresponds to the “first reduction part” in the present invention, and the second stage reduction unit 121B corresponds to the “second reduction part” in the invention.

  The first stage speed reduction unit 121A includes a drive gear 123 that rotates integrally with the rotation shaft 111a of the drive motor 111, and a driven gear 125 that has a larger diameter than the drive gear 123 that meshes and engages with the drive gear 123. The rotation speed of the motor 111 is reduced at a predetermined reduction ratio. The rotational force (torque) of the driven gear 125 in the first stage reduction unit 121A is transmitted to the intermediate shaft 128 via a shaft lock mechanism 141 described later. The second reduction gear 121B includes a small bevel gear 127 that rotates together with the intermediate shaft 128 and a large bevel gear 129 that has a larger diameter than the small bevel gear 127 that meshes with and engages with the small bevel gear 127. Is rotated at a predetermined reduction ratio. The intermediate shaft 128 is rotatably supported at each end in the axial direction by a bearing 128a.

  The large bevel gear 129 in the second stage reduction unit 121B is attached to a spindle 131 supported by a bearing 131a so as to be rotatable around an axis intersecting the rotation axis of the drive motor 111 so as not to be relatively rotatable. That is, the spindle 131 is a rotating member that is rotationally driven at a speed reduced by the second stage reduction unit 121B, and constitutes an output shaft of the gear reduction mechanism 121. The spindle 131 corresponds to the “tool shaft” in the present invention. The spindle 131 is extended downward from the lower surface of the gear housing 107, and a drill chuck 133 for detachably holding the drill bit is attached to the extended end portion.

  Next, the automatic shaft lock mechanism 141 will be described with reference to FIGS. The shaft lock mechanism 141 according to the present embodiment is disposed between the first stage reduction unit 121A and the second stage reduction unit 121B in the gear reduction mechanism 121, specifically, between the intermediate shaft 128 and the driven gear 125. Has been. The shaft lock mechanism 141 corresponds to the “rotation restricting portion” in the present invention.

  Details of the shaft lock mechanism 141 are shown in FIG. The shaft lock mechanism 141 includes a lock cam 143 as a driven-side rotating member attached to the intermediate shaft 128, and a plurality (four in this embodiment) of power transmission pawls that transmit the rotational force of the driven gear 125 to the lock cam 143. 145, a lock ring 147 fixed to the gear housing 107, and a plurality (two in this embodiment) of lock pins 149 as lock members that prevent or allow the lock cam 143 to rotate. Yes. The lock cam 143 is fitted to the intermediate shaft 128 so as not to be relatively movable in the circumferential direction of the intermediate shaft 128 and to be relatively movable in the long axis direction, and is engaged with the power transmission claw portion 145 from the circumferential direction ( A plurality of power receiving portions 143a (two in this embodiment arranged at an interval of 180 degrees) that receive power by abutting are provided. The plurality of power transmission claws 145 are integrally provided in the circumferential direction of the driven gear 125 at equal intervals (90-degree intervals in the present embodiment). The lock ring 147 is fixed to the annular inner wall surface of the gear housing 107. The plurality of lock pins 149 are respectively disposed between the flat cam surface 143 b formed on the outer periphery of the lock cam 143 with a phase of 180 degrees and the inner surface of the lock ring 147.

  The shaft lock mechanism 141 includes two power transmission claws 145 having a phase relationship of 180 degrees when the rotational force is input from the drive motor 111 side, that is, the driven gear 125 side. When the lock pin 149 engages with the other two power transmission pawls 145 to rotate with the cam surface 143b, the lock cam 143 is allowed to rotate. When the rotational force is input from the spindle 131 side, that is, the intermediate shaft 128 side, the lock pin 149 is pushed against the cam surface 143b of the lock cam 143. By engaging between the cam surface 143b and the inner surface of the lock ring 147, the rotation operation of the lock cam 143 is prevented (prohibited). ) It is configured to.

  The electric drill 101 according to the present embodiment is configured as described above. Next, the operation will be described. When the operator grips the grip portion 103A and pulls the trigger switch 108 to drive the drive motor 111 in order to perform a machining operation (drilling operation) with the electric drill 101, the rotational force of the drive motor 111 reduces the gear speed. Input to the mechanism 121. In the gear reduction mechanism 121, after the rotational speed of the drive motor 111 is reduced by the first stage reduction part 121A, it is further reduced by the second stage reduction part 121B. As a result, the spindle 131 is rotationally driven at a reduced speed, and the machining operation by the drill bit held by the drill chuck 133 is performed.

  When a rotational force is input from the drive motor 111 side, the shaft lock mechanism 141 acts so as to allow the gear reduction mechanism 121 to rotate. In other words, the rotational force is transmitted from the two power transmission claws 145 out of the four provided on the driven gear 125 to the power receiving portion 143a of the lock cam 143, while being locked by the other two power transmission claws 145. The pin 149a is held in a state where it is not caught between the cam surface 143b of the lock cam 143 and the lock ring 147. As a result, the rotation of the lock cam 143 is allowed, and the rotational force of the driven gear 125 is transmitted to the intermediate shaft 128 via the lock cam 143.

  Next, the drill bit replacement operation will be described. When the drill bit is removed from the drill chuck 133, the movable sleeve 133a (shown on the lower side in FIG. 1) of the drill chuck 133 is gripped and turned in the direction of releasing (relaxing) the drill bit. At this time, the rotational force applied to the movable sleeve 133a is input from the spindle 131 to the intermediate shaft 128 via the large bevel gear 129 and the small bevel gear 127 of the second stage reduction unit 121B. At this time, the shaft lock mechanism 141 is It acts to prevent the spindle 131 from rotating. That is, when the lock cam 143 is slightly rotated clockwise, for example, in FIG. 3 together with the intermediate shaft 128, the lock pin 149 is pushed outward in the rotational direction by the cam surface 143b of the lock cam 143. The lock pin 149 pushed by the cam surface 143b is engaged between the cam surface 143b and the inner surface of the lock ring 147, thereby preventing the lock cam 143 from rotating. Thus, the rotation of the spindle 131 is prevented. Such rotation prevention of the spindle 131 by the shaft lock mechanism 141 is similarly performed when the movable sleeve 133a of the drill chuck 133 is rotated in the direction of gripping (tightening) the drill bit.

  As described above, according to the present embodiment, the shaft lock mechanism 141 is provided in the electric drill 101, so that when the drill bit is replaced, the drill chuck 133 is loosened while the rotation operation of the spindle 131 is prevented. Alternatively, tightening work can be performed, and workability is improved. In particular, in an angle drill having a configuration in which the drill chuck 133 is disposed in the gear housing 107, which is the distal end region of the main body portion 103, in a direction substantially perpendicular to the long axis direction, the gear housing 107 interferes with the bit replacement operation. This is effective in improving workability.

  Further, since the shaft lock mechanism 141 according to the present embodiment is an auto-lock type in which the rotation of the spindle 131 is automatically blocked when a rotational force is input from the spindle 131 side, At the time of replacement, the bit replacement work can be performed without performing a special operation for preventing the rotation operation of the spindle 131, and the workability can be further improved.

Further, in the present embodiment, the shaft lock mechanism 141 is installed between the downstream side of the first stage reduction part 121A and the upstream side of the second stage reduction part 121B in the gear reduction mechanism 121. The downstream side of the first stage reduction unit 121A is an area where the rotational speed of the drive motor 111 is reduced to reduce the transmission of motor vibration, and the shaft lock mechanism 141 is rotationally driven at a reduced speed. Therefore, the vibration generated with the rotation operation of the shaft lock mechanism 141 is also small.
On the other hand, when the shaft lock mechanism 141 is installed, for example, on the downstream side of the gear reduction mechanism 121, the rotational force input from the spindle 131 side causes the lock cam 143, the lock ring 167, and the lock pin 169 of the shaft lock mechanism 141. It acts directly on etc. However, according to the present embodiment, the force applied to the lock cam 143, the lock ring 167, the lock pin 169, and the like can be reduced by installing the shaft lock mechanism 141 on the upstream side of the second-stage reduction unit 121B. Thus, the durability of the shaft lock mechanism 141 can be enhanced.
That is, according to the present embodiment, the shaft lock mechanism 141 is in an optimization region in which the reduction of the rotational force input from the spindle 131 side by the operator at the time of bit replacement is realized while reducing the transmission of motor vibration. The electric drill 101 having the arranged configuration can be provided.

(Second embodiment of the present invention)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a side view showing a tip side (front side) region of the electric drill 101, and FIG. 5 is a sectional view of the same part. 6 and 7 are sectional views mainly showing a shaft locking mechanism. In the electric drill 101 according to the present embodiment, the shaft lock mechanism 151 that regulates the rotation of the spindle 131 is a manual type that is operated by an operator's operation. It is configured in the same way as the form. Therefore, constituent members other than the shaft lock mechanism 151 are denoted by the same reference numerals as those in the first embodiment, and the description thereof is omitted or simplified. The shaft lock mechanism 151 corresponds to the “rotation restricting portion” in the present invention.

  As shown in FIGS. 6 and 7, the shaft lock mechanism 151 according to the present embodiment includes a long rotation lock pin 153 as a rod-like member that is attached to the gear housing 107 so as to be operable from the outside, and a gear. The speed reduction mechanism 121 mainly includes a rotation lock ring 155 that is press-fitted and fixed to the outside of the intermediate shaft 128. The rotation lock pin 153 corresponds to a “rotation restricting member” in the present invention. The rotation lock pin 153 is attached to the side surface of the gear housing 107 in a penetrating manner in a direction orthogonal to the major axis direction of the main body 103. That is, it is inserted into a pin hole 107a penetrating inside and outside formed in the side surface portion of the gear housing 107, and a knob 154 is provided at the outer end portion. Then, by pushing the rotation lock pin 153 toward the inside of the gear housing 107, the tip 153 a of the rotation lock pin 153 is inserted into and engaged with a lock hole 155 a provided in the rotation lock ring 155, thereby rotating the intermediate shaft 128. Is configured to be prevented. The insertion engagement position of the rotation lock pin 153 with respect to the lock hole 155a (the position indicated by the two-dot chain line in FIGS. 6 and 7) corresponds to the “rotation restriction position” in the present invention.

  The shaft lock mechanism 151 has a coil spring 157 as a biasing member that applies a biasing force to the rotation lock pin 153 in a direction in which the tip 153a of the rotation lock pin 153 comes out of the lock hole 155a of the rotation lock ring 155. The coil spring 157 is interposed in a state where an initial load is applied between a spring receiving washer 159 that is loosely fitted to the rotation lock pin 153 and a knob 154 of the rotation lock pin 153. As a result, the rotation lock pin 153 is normally held at a position where the tip 153a comes out of the lock hole 155a, that is, a position where the engagement is released. The disengagement position of the rotation lock pin 153 with respect to the lock hole 155a (the position indicated by the solid line in FIGS. 6 and 7) corresponds to the “rotation allowable position” in the present invention.

  The disengagement position of the rotation lock pin 153 is defined (held) by the circlip 158 attached to the rotation lock pin 153 coming into contact with the inner wall surface of the gear housing 107 (see FIG. 6). When the rotation lock pin 153 is placed at the disengagement position, the axial end surface of the knob 154 of the rotation lock pin 153 is substantially flush with the side surface of the gear housing 107 as shown in FIG. Is set. The biasing force of the coil spring 157 is configured to act so as to compress the O-ring 156 via the washer 159. The O-ring 156 is provided to suppress leakage of the lubricating oil (grease) in the gear housing 107 from the pin hole 107a through which the rotation lock pin 153 passes, and is compressed by the urging force due to the initial load of the coil spring 157 acting at all times. As a result, sealing performance is ensured.

  According to the present embodiment, when a rotational force is input from the drill chuck 133 side while the knob 154 of the rotation lock pin 153 is pressed toward the inside of the gear housing 107 during the drill replacement operation, the spindle 131 The intermediate shaft 128 is rotated via the large bevel gear 129 and the small bevel gear 127. When the tip 153a of the rotation lock pin 153 coincides with the lock hole 155a of the rotation lock ring 155, the tip 153a is inserted and engaged with the lock hole 155a. As a result, the rotation operation of the intermediate shaft 128, that is, the rotation operation of the spindle 131 is prevented, so that the drill bit can be replaced in this state.

  Further, the rotation lock pin 153 is configured to prevent the rotation operation of the intermediate shaft 128 in the gear reduction mechanism 121, that is, the configuration provided between the first stage reduction part 121A and the second stage reduction part 121B in the gear reduction mechanism 121. Similar to the first embodiment described above, the influence of the motor vibration can be reduced, and the radial force acting on the rotation lock pin 169 from the intermediate shaft 128 can be reduced, thereby the shaft lock mechanism 151. Can increase the durability.

  Further, the shaft lock mechanism 151 according to the present embodiment has fewer parts than the first embodiment described above, is simple in structure, and is effective in achieving weight reduction. Further, by providing the rotation lock ring 155 on the intermediate shaft 128, the shaft lock mechanism 151 can be constructed while maintaining the strength of the intermediate shaft 128. However, if the strength of the intermediate shaft 128 is ensured, the lock hole 155a may be set in the intermediate shaft 128 and the rotation lock ring 155 may be omitted.

It is a side view showing the whole electric drill composition concerning a 1st embodiment of the present invention. It is sectional drawing which shows the principal part of an electric drill. It is the sectional view on the AA line of FIG. It is a side view which shows the front-end | tip area | region of the electric drill which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the front-end | tip area | region of an electric drill. FIG. 6 is a sectional view taken along line B-B in FIG. 5. It is CC sectional view taken on the line of FIG.

Explanation of symbols

101 Electric drill 103 Body (tool body)
103A Grip part 105 Motor housing 105a Ventilation opening 107 Gear housing 107a Pin hole 108 Trigger switch 109 Battery case 111 Drive motor (motor)
111a Rotating shaft 113 Rotor 115 Commutator 117 Cooling fan 121 Gear speed reduction mechanism (speed reduction mechanism)
121A First stage reduction part (first reduction part)
121B Second stage reduction part (second reduction part)
123 Drive gear 125 Driven gear 127 Small bevel gear 128 Intermediate shaft 128a Bearing 129 Large bevel gear 131 Spindle 131a Bearing 133 Drill chuck 133a Movable sleeve 141 Shaft lock mechanism (rotation restricting portion)
143 Lock cam 143a Power receiving portion 143b Cam surface 145 Power transmission claw portion 147 Lock ring 149 Lock pin 151 Shaft lock mechanism (rotation restricting portion)
153 Rotation lock pin (rotation restricting member)
153a Tip 154 Knob 155 Rotation lock ring 155a Lock hole 156 O-ring 157 Coil spring 158 Circlip 159 Washer

Claims (5)

An electric drill having a tool main body and a motor housed in the tool main body, and performing a predetermined processing operation on a workpiece by a bit that rotates around an axis in a direction intersecting the rotation axis of the motor,
A tool shaft that is rotationally driven by the motor and on which the bit can be mounted;
An electric drill comprising: a rotation restricting portion provided in the tool body and capable of preventing rotation of the tool shaft when the bit is replaced. The electric drill according to claim 1,
The rotation restricting unit reduces transmission of the motor vibration in a power transmission path for transmitting the rotational force of the motor to the tool shaft, and decreases the rotational force input from the tool shaft side by an operator when replacing the bit. An electric drill characterized by being arranged in an optimization region that realizes both. The electric drill according to claim 2,
A further reduction mechanism for reducing the rotational speed of the motor;
The rotation restricting portion is disposed between a first reduction portion that reduces the rotation speed of the motor in the reduction mechanism and a second reduction portion that further reduces the rotation speed reduced by the first reduction portion. An electric drill characterized by The electric drill according to any one of claims 1 to 3,
A further reduction mechanism for reducing the rotational speed of the motor;
When the rotational force is input from the motor side, the rotation restricting portion allows the motor to rotate the reduction mechanism, and when the rotational force is input from the tool shaft side, the rotation mechanism rotates. An electric drill characterized by being configured to prevent The electric drill according to any one of claims 1 to 3,
A speed reduction mechanism for reducing the rotational speed of the motor;
A tool main body that houses the motor and the speed reduction mechanism,
The rotation restricting portion is between a rotation restricting position where the rotation operation of the speed reduction mechanism is blocked by an operator's operation from the outside of the tool body and a rotation permission position where the block of the rotation operation of the speed reduction mechanism is released. An electric drill having a rotation restricting member to be moved.

Images