JP5994346B2 - Bit attachment / detachment mechanism such as concrete drill and drill tool - Google Patents

Description

  In the present invention, a bit having a drilled blade formed at the tip is attached to a chuck portion of a concrete drill driven by power such as electric power or compressed air, and a hole is drilled in a concrete wall or stone by rotating the attached bit. More particularly, the present invention relates to a core bit attaching / detaching mechanism such as a concrete drill for attaching and detaching a bit to and from a chuck portion and a drill tool.

  When performing piping work for gas, water, or air conditioning on the walls, floors, or foundations of buildings constructed with concrete, these concrete drills are used using a power drill such as electric power or compressed air. Drilling work is performed on walls and the like. Specifically, the bit attached to the chuck portion formed at the tip of the concrete drill is rotated from the concrete drill side and, if necessary, vibration is applied, and the concrete wall is formed by a cylindrical drilling blade formed at the tip of the bit. A hole with a predetermined diameter is drilled. A variety of bits are available depending on the diameter and depth of the hole to be drilled, and the bit is exchanged according to the hole diameter and wall thickness to be drilled. A detaching operation is performed. Also, in the case of a core bit that drills a deep hole, the concrete core may get stuck in the opening in the center of the core bit. To remove this, it is necessary to remove the core bit from the concrete drill. Is done frequently.

  In the conventional structure for mounting a bit to a concrete drill, the bit is inserted into the chuck, twisted to a predetermined position, and the mounting of the bit is completed by operating a detachable lever or the like in this state. At this time, the bit and the chuck were engaged to position in the rotational direction. However, since there is no rotation restriction in the reverse direction, the angular position between the bit and the chuck changes before the detachable lever or the like is operated. There was a case that a bit was not installed correctly.

  In order to avoid such a problem, for example, Patent Document 1 discloses a bit attaching / detaching mechanism such as a concrete drill having a mechanism for temporarily fixing a bit.

Japanese Patent No. 4433721

  However, in the bit attaching / detaching mechanism such as the concrete drill described in Patent Document 1 described above, since the mechanism for temporarily fixing the bit is formed on the outer peripheral side surface of the bit base, the outer diameter of the chuck becomes large, There was a problem that led to an increase in size.

  Therefore, an object of the present invention is to provide a bit attachment / detachment mechanism such as a concrete drill that can prevent a defective mounting of a bit by temporarily fixing the mounting of the bit without increasing the size of the chuck.

  The present invention has been made to solve the above-described problems, and is characterized by the following.

(Claim 1)
The invention described in claim 1 is characterized by the following points.

That is, a bit attaching / detaching mechanism such as a concrete drill according to claim 1 includes a bit having a mounting portion formed on a rear end side thereof, and a chuck portion to which the bit mounting portion can be attached / detached. A chuck body that engages with the mounting portion to transmit torque to the bit, a chuck cover having an engagement protrusion on an inner periphery thereof, and is slidably disposed with respect to the chuck cover. And a locking member biased in the direction of discharging the bit, and the bit is formed when an engaged portion is formed on the outer peripheral surface of the mounting portion and a predetermined locking operation is performed. The engaged portion is fixed to the chuck portion by being engaged and attracted to the engaging protrusion, and the end surface of the locking member and the end surface of the bit mounting portion are engaged with each other. Positioning mechanism Is, the positioning mechanism the rotational direction of the positioning between the bit and the chuck portion before performing the predetermined lock operation by the engagement with each other is performed, the positioning mechanism, and the bit and the chuck portion It is characterized by comprising a ratchet mechanism that is disengaged when it is relatively rotated in a predetermined direction .

(Claim 2)
The invention according to claim 2, characterized by the following points.

In other words, a bit having a mounting portion formed on the rear end side and a chuck portion to which the bit mounting portion can be attached and detached are provided, and the chuck portion engages with the mounting portion and transmits torque to the bit. A chuck body having an engagement protrusion on the inner periphery, and a locking member that is slidably arranged with respect to the chuck cover and biased in the direction of discharging the bit. The engaging portion is formed on the outer peripheral surface of the mounting portion, and the engaged portion engages with the engaging protrusion when a predetermined locking operation is performed. It is fixed to the chuck portion by being attracted, and a positioning mechanism that engages with each other is provided on the end surface of the locking member and the end surface of the mounting portion of the bit. By doing the predetermined Prior to performing a locking operation, the bit and the chuck portion are positioned in the rotational direction, and provided with a guide portion that guides the sliding of the locking member, and when the bit is mounted, A gap is formed between the member and the guide portion, and the gap member is formed so that the locking member does not transmit torque to the bit .

(Claim 3)
The invention according to claim 3, characterized by the following points.

In other words, a bit having a mounting portion formed on the rear end side and a chuck portion to which the bit mounting portion can be attached and detached are provided, and the chuck portion engages with the mounting portion and transmits torque to the bit. A chuck body having an engagement protrusion on the inner periphery, and a locking member that is slidably arranged with respect to the chuck cover and biased in the direction of discharging the bit. The engaging portion is formed on the outer peripheral surface of the mounting portion, and the engaged portion engages with the engaging protrusion when a predetermined locking operation is performed. It is fixed to the chuck portion by being attracted, and a positioning mechanism that engages with each other is provided on the end surface of the locking member and the end surface of the mounting portion of the bit. By doing the predetermined Positioning in the rotational direction between the bit and the chuck portion is performed before performing a locking operation, and the positioning mechanism is disengaged when the bit and the chuck portion are relatively rotated in a predetermined direction. A ratchet mechanism that includes a guide portion that guides the sliding of the locking member, and is formed so that a gap is formed between the locking member and the guide portion when the bit is mounted. The locking member is formed so as not to transmit torque to the bit when the gap is generated .

(Claim 4)
The invention according to claim 4 is characterized by the following points in addition to the features of the invention according to any one of claims 1 to 3.

That is, when the positioning mechanism relatively rotates the bit and the chuck portion in the predetermined direction, the positioning mechanism is disengaged and the engagement portion and the engagement protrusion are engaged. The bit is pushed out in the discharge direction by the locking member .

(Claim 5)
A drill tool according to a fifth aspect includes the bit attaching / detaching mechanism according to any one of the first to fourth aspects.

The inventions described in claims 1 to 3 are as described above, and a positioning mechanism that engages with each other is provided on the end surface of the locking member and the end surface of the mounting portion of the bit, and the positioning mechanisms engage with each other. Since the positioning of the bit and the chuck portion in the rotational direction is performed, the angle of the bit can be reliably held until the fixing operation by the operation of the detachable lever or the like is completed.

  In addition, since the positioning mechanism is provided on the end surface of the locking member and the end surface of the bit mounting portion, there is no need to enlarge the chuck portion in the radial direction, and the positioning mechanism is increased in size. There is no problem. Therefore, it is possible to prevent the bit from being mounted poorly without increasing the size of the chuck.

Further, the invention described in claims 1 and 3 is as described above, and the positioning mechanism is a ratchet mechanism that is disengaged when the bit and the chuck portion are relatively rotated in a predetermined direction. Since it is comprised, when rotating to a predetermined direction, engagement of a positioning mechanism can be cancelled | released easily and removal of a bit can be made easy.

  Further, when engaging the positioning mechanism, the positioning mechanism can be reliably engaged by rotating in the direction opposite to the predetermined direction.

The invention according to claim 4 is as described above, and when the positioning mechanism relatively rotates the bit and the chuck portion in the predetermined direction, the engagement of the positioning mechanism is released, The engagement between the engaged portion and the engagement protrusion is also released, and the bit is pushed out in the discharging direction by the locking member, so that the positioning mechanism can be easily engaged when rotated in a predetermined direction. Not only can it be released, but the bit is pushed out in the ejection direction, so that the bit can be easily removed.

The invention according to claim 2 and 3 is as described above, and includes a guide portion that guides sliding of the locking member, and the locking member and the guide portion when the bit is mounted. Since the gap is formed so that the locking member does not transmit torque to the bit, the guide portion is locked before the bit is mounted. It is necessary to increase the strength of the locking member because the locking member does not transmit torque to the bit after the bit is mounted (the locking member does not participate in torque transmission). Therefore, an increase in product size and an increase in manufacturing cost can be avoided.

  The invention according to claim 5 is as described above, and the drill tool has the same effect as the bit attaching / detaching mechanism according to any one of claims 1 to 4.

It is a side view of a concrete drill. It is a side view of the concrete drill which removed the core bit. It is a disassembled perspective view of a core bit and a chuck | zipper part. It is (a) perspective view, (b) side view, and (c) rear view of the core bit mounting portion. It is (a) perspective view, (b) front view, and (c) side view of the chuck body. It is the (a) perspective view, (b) front view, and (c) sectional view of a chuck cover. It is (a) perspective view, (b) front view, and (c) side view of a locking member. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing a state before releasing operation of a detachable lever. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing a state after releasing operation of a detachable lever. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing the state where the end face of a core bit contacted a locking member. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing the state where core bit was inserted to the back of a chuck part. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing a state where a core bit was rotated and a ratchet mechanism was engaged. It is a figure explaining a mode that a core bit is attached to a chuck part, and is a figure showing a state where attachment to a chuck part of a core bit was completed by locking operation of a detachable lever. It is a figure explaining the relationship between a chuck | zipper main body and a locking member, Comprising: It is a figure which shows the state before mounting | wearing of a core bit. It is a figure explaining the relationship between a chuck | zipper main body and a locking member, Comprising: It is a figure which shows the state after mounting | wearing with a core bit.

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

  As shown in FIGS. 1 and 2, the concrete drill 10 according to the present embodiment is formed at a rear end by attaching a core bit 30 as a bit to a chuck portion 20 formed at an end facing forward. The grip 12 is formed so as to perform a drilling operation. Then, by operating the trigger 13 formed in the vicinity of the grip 12, the motor accommodated in the main body of the concrete drill 10 is rotated to rotate the chuck portion 20, and the chuck portion 20 is mounted. The core bit 30 is rotated so as to be perforated into concrete or the like by a perforating blade 31 formed at the tip of the core bit 30.

  As shown in FIG. 3, the core bit 30 is formed by forming a drilling blade 31 at the tip edge of a hollow cylindrical drill portion 39. The drill portion 39 is formed in a dimensional shape having different outer diameters and lengths corresponding to the diameter of the hole to be drilled and the depth of the hole.

  A mounting portion 32 for mounting the core bit 30 to the chuck portion 20 of the concrete drill 10 is formed on the rear end side of the drill portion 39. By inserting the mounting portion 32 into a recess formed in the chuck portion 20 of the concrete drill 10, the rotation axis of the concrete drill 10 and the central axis of the core bit 30 are guided.

  As shown in FIG. 4, the mounting portion 32 is a hollow cylindrical member and includes an annular flange portion 37 protruding in the outer peripheral direction. On the rear end surface of the annular flange 37, three rotational locking portions 36 are recessed at equal intervals in the circumferential direction. As a result, when the chuck part 20 is abutted against the annular flange 37 and fixed, the rotation transmission part 22 of the chuck part 20 engages with the rotation locking part 36, and torque is applied from the chuck part 20 to the mounting part 32. It is to be transmitted.

  Further, the insertion portion 38 provided on the rear end side of the annular flange portion 37 is formed to have a smaller diameter than the annular flange portion 37 and can be accommodated in a recess formed in the chuck portion 20 of the concrete drill 10. It has become. In the vicinity of the distal end of the insertion portion 38, a flange portion 33 as an engaged portion for fixing to the chuck portion 20 is formed to protrude on the outer peripheral surface. Further, by providing the flange portion 33, an engagement groove 34 is formed on the distal end side of the flange portion 33. The flange portion 33 is not provided on the entire outer periphery of the mounting portion 32, but is notched by providing three notch portions 33a at equal intervals in the circumferential direction. By providing the notch 33 a, an engagement protrusion 25 described later can enter the engagement groove 34 while avoiding interference with the flange 33.

  Further, three ratchet grooves 35 are recessed in the end surface outer peripheral portion 32b of the end portion 32a of the mounting portion 32 at equal intervals in the circumferential direction. The ratchet groove 35 constitutes a ratchet mechanism (positioning mechanism) for positioning the core bit 30 and the chuck portion 20 in the rotational direction together with the ratchet pawl 28 described later.

  On the other hand, as shown in FIG. 3, the chuck portion 20 to which the mounting portion 32 can be attached and detached is engaged with the mounting portion 32 of the core bit 30 to transmit torque to the core bit 30, and the core bit 30. A locking member 26 used for positioning in the rotation direction with the chuck portion 20, a chuck cover 24 that houses the chuck body 21 and the locking member 26 described above, the locking member 26, and the chuck By urging the cover 24 in a direction away from each other, the pressing spring 40 that urges the locking member 26 in the distal direction, and the chuck cover 24 and the chuck body 21 are urged in directions away from each other. Thus, the disc cover 41 is configured to bias the chuck cover 24 toward the rear end.

  The chuck body 21 is a member that is connected to a rotation mechanism formed in the concrete drill 10 and transmits torque to the core bit 30 side, and includes a cylindrical portion 21a on the tip side as shown in FIG. . Three guide slits 23 are formed through the outer periphery of the cylindrical portion 21a at equal intervals in the circumferential direction. The guide slit 23 serves as a guide portion that guides sliding of a locking member 26 described later. Moreover, the three rotation transmission parts 22 are protrudingly provided by the opening edge of the cylindrical part 21a at equal intervals in the circumferential direction. The rotation transmitting portion 22 is adapted to be fitted into the rotation locking portion 36 of the mounting portion 32 described above when the core bit 30 is mounted, thereby transmitting the rotation on the concrete drill 10 side to the core bit 30 side. It is formed as follows.

  The chuck cover 24 is a cylindrical member as shown in FIG. 6, and three engagement projections 25 project from the inner periphery of the chuck cover 24 at equal intervals in the circumferential direction. When the core bit 30 is mounted, the engagement protrusion 25 enters the engagement groove 34 of the mounting portion 32 and engages with the flange portion 33 to attract and hold the core bit 30 toward the concrete drill 10. Is.

  Specifically, the chuck body 21 and the chuck cover 24 are urged in opposite directions by the disc spring 41, the chuck body 21 is urged in the front end direction, and the chuck cover 24 is moved in the rear end direction. It is energized. Then, the edge of the chuck body 21 biased in the distal direction supports the rear end side of the flange portion 33 of the mounting portion 32 in the distal direction, and the engagement of the chuck cover 24 biased in the rear end direction. Since the protrusion 25 supports the front end side of the flange portion 33 of the mounting portion 32 in the rear end direction, the flange portion 33 can be sandwiched between the chuck cover 24 and the chuck body 21 and firmly fixed. .

  When the fixing of the mounting portion 32 by the chuck cover 24 and the chuck body 21 is released, the lock is released by raising the detachable lever 11 provided at the upper end of the concrete drill 10. When the detachable lever 11 is raised, the chuck cover 24 is forcibly shifted toward the distal end, and the urging force of the disc spring 41 is invalidated.

  Conversely, when the core bit 30 is pushed into the chuck portion 20 and temporarily fixed, the attachment portion 32 can be locked by tilting the detachable lever 11. When the detachable lever 11 is tilted, the urging force of the disc spring 41 becomes effective, so that the chuck cover 24 is shifted toward the rear end by the urging force of the disc spring 41, and the engagement protrusion 25 of the chuck cover 24 is attached to the mounting portion 32. Can be attracted toward the rear end to completely fix the mounting portion 32.

  The locking member 26 is a member that is slidably disposed behind the engagement protrusion 25, and is urged by the pressing spring 40 in the direction of pushing out the core bit 30.

  As shown in FIG. 7, three protrusions 27 project from the front end side of the locking member 26 at equal intervals in the circumferential direction. The protrusion 27 is a narrow portion 27b whose tip side is narrower than the base portion 27a. A ratchet claw 28 whose teeth are inclined in a predetermined direction is provided at the tip of the protrusion 27. The ratchet pawl 28 is adapted to fit into the ratchet groove 35 of the mounting portion 32.

  Next, how the core bit 30 is attached to the chuck portion 20 will be described with reference to FIGS.

  FIG. 8 is a view showing a state before the detachable lever 11 is released. In this state, the chuck cover 24 is biased toward the rear end by the biasing force of the disc spring 41. In other words, the chuck body 21 is biased toward the front end. In this state, even if the mounting portion 32 of the core bit 30 is pushed into the chuck portion 20, the rotation transmitting portion 22 on the front end side of the chuck body 21 and the flange rear end surface 37 a of the mounting portion come into contact with each other, Since the joint protrusion 25 cannot enter the engaging groove 34 of the mounting portion 32, the core bit 30 cannot be mounted on the chuck portion 20.

  FIG. 9 is a view showing a state after the release lever 11 is raised and released. In this state, the chuck cover 24 is displaced in the front end direction, in other words, the chuck body 21 is displaced in the rear end direction. For this reason, when the mounting portion 32 of the core bit 30 is pushed into the chuck portion 20, only a biasing force of the pressing spring 40 is applied compared to the biasing force of the disc spring 41, so the core bit 30 is applied to the chuck portion 20. The operation to push in can be performed. When inserting the mounting part 32 of the core bit 30 into the chuck part 20, the flange part 33 is inserted by aligning the positions of the notch part 33 a of the flange part 33 and the engagement protrusion 25 of the chuck cover 24. The mounting portion 32 can be inserted without interfering with the engaging protrusion 25.

  FIG. 10 is a diagram illustrating a state in which the end surface 32 a of the core bit 30 is in contact with the locking member 26 as a result of inserting the mounting portion 32 of the core bit 30 into the chuck portion 20. In this state, the end surface 32 a of the core bit 30 is in contact with the protrusion 27 of the locking member 26 biased by the pressing spring 40.

  FIG. 11 is a diagram showing a state in which the core bit 30 is inserted from the state shown in FIG. That is, it is a view in which the locking member 26 is pushed against the urging force of the pressing spring 40. The mounting portion 32 can be inserted until the engagement protrusion 25 of the chuck cover 24 abuts on the front end surface of the engagement groove 34. When the insertion portion 32 is inserted all the way into the mounting portion 32 as shown in FIG. The engagement protrusion 25 of the chuck cover 24 is formed so as to enter the engagement groove 34 of the mounting portion 32.

  FIG. 12 is a view showing a state in which the core bit 30 is rotated from the state shown in FIG. 11 and the ratchet mechanism is engaged. At this time, as described above, since the engagement protrusion 25 of the chuck cover 24 is in the engagement groove 34 of the mounting portion 32, the core bit 30 can be rotated and the engagement protrusion 25 is engaged. The groove 34 is engaged, and the core bit 30 is positioned in the forward / backward direction.

  Then, by rotating the core bit 30, when the ratchet pawl 28 of the locking member 26 constituting the ratchet mechanism is engaged with the ratchet groove 35 of the mounting portion 32, the core bit 30 is not further rotated. In the present embodiment, the ratchet mechanism is engaged when the core bit 30 is rotated in the direction indicated by the arrow in FIG. 12A, and the ratchet is rotated by rotating the core bit 30 in the opposite direction. The mechanism can be released. As described above, the engagement of the ratchet mechanism allows positioning of the core bit 30 and the chuck portion 20 in the rotational direction.

  FIG. 13 is a diagram showing a state where the mounting of the core bit 30 to the chuck portion 20 is completed. That is, the chuck cover 24 is urged toward the rear end by the urging force of the disc spring 41 by tilting the detachable lever 11 from the temporarily fixed state shown in FIG. Thereby, the engagement protrusion 25 of the chuck cover 24 pulls the flange portion 33 of the mounting portion 32, and the core bit 30 is securely fixed to the chuck portion 20.

  When the core bit 30 is fixed to the chuck portion 20 in this way, as shown in FIG. 15A, the rotation transmitting portion 22 of the chuck body 21 is engaged with the rotation locking portion 36 of the mounting portion 32, and a concrete drill is formed. The rotational force on the 10 side is transmitted to the core bit 30 side.

  In the present embodiment, when the rotational force on the concrete drill 10 side is transmitted to the core bit 30 side in this way, the locking member 26 is not related to the transmission of the rotational force.

  That is, as shown in FIG. 14, the locking member 26 is biased in the distal direction before the core bit 30 is mounted, and the protrusion 27 of the locking member 26 extends along the inside of the guide slit 23 of the chuck body 21. Is arranged. At this time, since the base portion 27a of the protrusion 27 is disposed inside the guide slit 23, there is almost no gap between the guide slit 23 and the protrusion 27, and the locking member 26 is the chuck body 21. The guide slit 23 (guide portion) and the base portion 27a of the locking member 26 are slidably guided.

  On the other hand, after the core bit 30 is mounted, the locking member 26 is pushed toward the rear end as shown in FIG. At this time, the base portion 27 a of the protrusion 27 protrudes outside the guide slit 23, and only the narrow portion 27 b of the protrusion 27 is disposed inside the guide slit 23, and therefore, between the guide slit 23 and the protrusion 27. A large gap is formed. Since this gap is sufficiently larger than the play between the rotation transmitting portion 22 and the rotation locking portion 36, the chuck body 21 does not transmit the rotational force to the locking member 26, and as a result The locking member 26 is formed so as not to transmit torque to the core bit 30.

  Although not particularly illustrated, when removing the core bit 30 from the chuck portion 20, after the release lever 11 is raised and released, the core bit 30 is removed (reverse to the direction indicated by the arrow in FIG. 12A). Direction). Thereby, the engagement of the ratchet mechanism is released, and the engagement between the flange portion 33 and the engagement protrusion 25 is also released. At this time, since the locking member 26 is biased by the pressing spring 40, the core bit 30 is pushed out in the discharge direction by the locking member 26.

  As described above, according to the present embodiment, the positioning mechanism (the ratchet pawl 28 and the ratchet groove 35) that engage with each other is provided on the end surface of the locking member 26 and the outer peripheral portion 32b of the mounting portion 32 of the core bit 30. Since the positioning mechanism is engaged with each other to position the core bit 30 and the chuck portion 20 in the rotational direction, the angle of the core bit 30 is surely maintained until the chucking operation is completed by operating the detachable lever 11. Can be held.

  Further, since the positioning mechanism is provided on the end surface of the locking member 26 and the end surface outer peripheral portion 32b of the mounting portion 32 of the core bit 30, it is not necessary to enlarge the chuck portion 20 in the radial direction. There is no problem of enlargement. Therefore, it is possible to prevent the bit from being mounted poorly without increasing the size of the chuck.

  The positioning mechanism is composed of a ratchet mechanism that is disengaged when the core bit 30 and the chuck portion 20 are relatively rotated in a predetermined direction. Thus, the positioning mechanism can be easily disengaged, and the core bit 30 can be easily removed.

  Further, when engaging the positioning mechanism, the positioning mechanism can be reliably engaged by rotating in the direction opposite to the predetermined direction.

  Further, when the core bit 30 and the chuck portion 20 are relatively rotated in a predetermined direction to a predetermined position from a state where the positioning mechanisms are engaged with each other, the engagement of the positioning mechanism is released and the flange portion 33 is also engaged. Since the engagement between the (engaged portion) and the engagement protrusion 25 is also released, and the core bit 30 is pushed out in the discharge direction by the locking member 26, the positioning mechanism can be easily operated when rotated in a predetermined direction. Not only can the engagement be released, but the core bit 30 is pushed out in the discharging direction, so that the removal of the core bit 30 can be facilitated.

  In addition, a guide slit 23 (guide portion) that guides the sliding of the locking member 26 is provided, and a gap is generated between the locking member 26 and the guide slit 23 when the core bit 30 is mounted. By forming this gap, the locking member 26 is formed so as not to transmit torque to the core bit 30, so that the guide slit 23 slides on the locking member 26 before the core bit 30 is mounted. In addition to guiding the movement, the locking member 26 does not transmit torque to the core bit 30 after the core bit 30 is mounted (the locking member 26 is not involved in torque transmission). There is no need to increase the size, and an increase in product size and an increase in manufacturing cost can be avoided.

  In the present embodiment, the hollow core bit 30 has been described as an example. However, the present invention is not limited to this, and a solid bit may be used.

  Moreover, although the concrete drill 10 was demonstrated to the example in this embodiment, you may apply not only to this but a hammer drill, a peeling machine, etc.

DESCRIPTION OF SYMBOLS 10 Concrete drill 11 Removable lever 12 Grip 13 Trigger 20 Chuck part 21 Chuck body 21a Cylindrical part 22 Rotation transmission part 23 Guide slit (guide part)
24 chuck cover 25 engaging protrusion 26 locking member 27 protrusion 27a base 27b narrow part 28 ratchet claw 30 core bit 31 drilling blade 32 mounting part 32a end face 32b end face outer peripheral part 33 flange part (engaged part)
33a Notch 34 Engagement groove 35 Ratchet groove 36 Rotation locking part 37 Annular collar part 37a Butt part rear end face 38 Insertion part 39 Drill part 40 Pressing spring 41 Disc spring

Claims (5)

A bit having a mounting portion formed on the rear end side;
A chuck part to which the mounting part of the bit can be attached and detached;
With
The chuck portion is disposed so as to be slidable with respect to the chuck cover, a chuck body that engages with the mounting portion and transmits torque to the bit, a chuck cover having an engagement protrusion on an inner periphery thereof, and And a locking member biased in the direction of discharging the bit,
The bit has an engaged portion formed on the outer peripheral surface of the mounting portion, and when the predetermined locking operation is performed, the engaged portion engages with the engaging protrusion and is pulled. It is fixed to the chuck part,
A positioning mechanism that engages with each other is provided on an end surface of the locking member and an end surface of the mounting portion of the bit, and the positioning mechanism engages with each other before performing the predetermined locking operation. Positioning in the rotation direction with the chuck is performed ,
A bit attachment / detachment mechanism such as a concrete drill, wherein the positioning mechanism includes a ratchet mechanism that is disengaged when the bit and the chuck portion are relatively rotated in a predetermined direction . A bit having a mounting portion formed on the rear end side;
A chuck part to which the mounting part of the bit can be attached and detached;
With
The chuck portion is disposed so as to be slidable with respect to the chuck cover, a chuck body that engages with the mounting portion and transmits torque to the bit, a chuck cover having an engagement protrusion on an inner periphery thereof, and And a locking member biased in the direction of discharging the bit,
The bit has an engaged portion formed on the outer peripheral surface of the mounting portion, and when the predetermined locking operation is performed, the engaged portion engages with the engaging protrusion and is pulled. It is fixed to the chuck part,
A positioning mechanism that engages with each other is provided on an end surface of the locking member and an end surface of the mounting portion of the bit, and the positioning mechanism engages with each other before performing the predetermined locking operation. Positioning in the rotation direction with the chuck is performed ,
A guide portion for guiding sliding of the locking member is provided, and a gap is formed between the locking member and the guide portion when the bit is mounted. A bit attaching / detaching mechanism such as a concrete drill , wherein the locking member is formed so as not to transmit torque to the bit. A bit having a mounting portion formed on the rear end side;
A chuck part to which the mounting part of the bit can be attached and detached;
With
The chuck portion is disposed so as to be slidable with respect to the chuck cover, a chuck body that engages with the mounting portion and transmits torque to the bit, a chuck cover having an engagement protrusion on an inner periphery thereof, and And a locking member biased in the direction of discharging the bit,
The bit has an engaged portion formed on the outer peripheral surface of the mounting portion, and when the predetermined locking operation is performed, the engaged portion engages with the engaging protrusion and is pulled. It is fixed to the chuck part,
A positioning mechanism that engages with each other is provided on an end surface of the locking member and an end surface of the mounting portion of the bit, and the positioning mechanism engages with each other before performing the predetermined locking operation. Positioning in the rotation direction with the chuck is performed ,
The positioning mechanism includes a ratchet mechanism that is disengaged when the bit and the chuck portion are relatively rotated in a predetermined direction.
A guide portion for guiding sliding of the locking member is provided, and a gap is formed between the locking member and the guide portion when the bit is mounted. A bit attaching / detaching mechanism such as a concrete drill , wherein the locking member is formed so as not to transmit torque to the bit. When the positioning mechanism relatively rotates the bit and the chuck portion in the predetermined direction, the positioning mechanism is disengaged and the engaged portion and the engaging protrusion are also engaged. The bit attachment / detachment mechanism such as a concrete drill according to any one of claims 1 to 3 , wherein the bit is released and the bit is pushed out in the discharge direction by the locking member.   A drill tool comprising the bit attaching / detaching mechanism according to claim 1.

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