JPH07100705A - Attachment for straight drill - Google Patents

Abstract

PURPOSE:To enhance attaching/detaching operation performance or a drill by providing a drill shank part, in which a straight drill equipped with a projected part is installed, with a attaching/detaching mechanism containing both a key-like guide groove, which guides the projected part toward the circumferential direction in order to prevent a slip or a fall, and a steel ball, which is energized toward the radial direction. CONSTITUTION:In an attachment for a straight drill, a shank part 1 and a main body 2, in which a shank part 11 for the straight drill is installed, are formed into an integrated body, while a recessed hole 3, whose section is circular, is formed at the center part of the main body 2. A key-like groove 4, which guides a projected part 12, which is integrally formed in the shank part 11 for the straight drill, toward both radial and circumferential directions, is formed in the inner wall of this circular recessed hole 3, while a through-hole 5, which is made in the radial direction and communicated to the recessed hole 3, is formed in the outer peripheral part of the main body 2. A steel ball 6, a part of which is projected into the recessed hole 3, is accommodated in the through-hole 5, and the steel ball 6 is energized toward the inside in the radial direction by a spring 7 attached to the outer peripoheral part of the attachment main body 2, thereby locking the projected part 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an attachment which is attached to a three-jaw chuck of an electric drill, an SDS hammer drill or the like, to which a vibration and rotation straight drill is attached.

[0002]

2. Description of the Related Art In a drill used by attaching to a three-jaw chuck type electric drill, an SDS hammer drill or the like, a shank portion of a straight drill having a desired diameter is directly clamped and fixed to a chuck or the like of the electric drill. . Since the chuck part of the straight drill is usually formed to have a diameter approximately the same as the drill diameter, the shank part with a small drill diameter has a thin shank part, and the fixing force when attached to the chuck etc. is extremely high. It becomes small, and it becomes easy to idle during the drilling operation. Therefore, although a means for preventing the idling by forming a plurality of flat surfaces on the shank portion is adopted, high precision is required for the flat surface forming processing, and further, a satisfactory result cannot be obtained in practical use. Further, since such a thin straight drill is a consumable item which is easily broken, it is difficult to practically adopt flat machining which increases the unit price of the drill. From such an actual situation, various proposals have been made according to the material and shape of the material to be perforated.

As a typical example thereof, in the case of a straight drill having a drilling diameter of about 6 mm or less, a shank portion having a thickness suitable for preventing idling regardless of the diameter of the drill, for example, a thickness of about 10 mm. The drill is manufactured and put into practical use. The thickened shank for fastening does not run idle during drilling, but the unit price is significantly higher than that of an inexpensive thin diameter straight drill as a consumable item, and the shank is thickened. However, since the strength of the drilled portion is substantially the same as that of a straight drill having the same thickness, such a drill is industrially disadvantageous in view of economical efficiency and careful handling operability. .

[0004]

In view of the above situation, the inventors of the present invention have conducted trials and researches focusing on improving the practicality of a small diameter drill having a small mechanical strength. As a method of solving the above problem, it has been found that an attachment for mounting the structure using a structure of a straight drill having a specific idling prevention function is practically extremely desirable. That is, an object of the present invention is to provide an industrially advantageous drilling technique using a straight drill having a relatively small mechanical strength. Another technical problem is to provide an industrially advantageous technique in which a thin and inexpensive straight drill which must be often replaced can be easily attached and detached with good operability and which does not idle.

[0005]

Means for Solving the Problems As a means for solving the above-mentioned problems, the present inventors have focused on the structure of a straight drill having a slip prevention function in which a protrusion is formed on a shank part, As a result of repeated trial production research on a method that can advantageously use a thin drill with weak strength, as a result, it is possible to easily attach / detach using the above-mentioned idling prevention projection, and to prevent continuous idling during boring In the present invention, the inventors found that an attachment having a configuration in which the drill does not fall out when it is pulled out is extremely useful, and has arrived at the present invention.

That is, the present invention proposes an attachment for a straight drill, which has the requirements described in the claims. Such an attachment of the present invention is a member related to a special shape of a straight drill, in which a protrusion for preventing idling of the drill is integrally formed on the drill shank, and the protrusion is utilized. Technical features in the structure of a click-drill attachment / detachment mechanism and a attachment for a straight drill that guides the protrusion in the direction of the right angle (circumferential direction) and has a key-shaped guide groove that contributes to preventing slipping and falling Further, the attaching / detaching mechanism is technically characterized in that the attaching / detaching mechanism is configured by a combination of a rigid ball, a through hole formed in the attachment body that houses the rigid ball, and a spring that biases the rigid ball in the inner axial direction.

The attachment for a straight drill according to the present invention has a shank portion having a proper thickness and a thin strainer which can be attached to an electric drill for drilling, an SDS hammer drill or the like.
The body of the attachment is integrally formed with the corresponding recessed hole to which the shank portion of the todrill is attached, and the shank portion of the straight drill having a protrusion for preventing idling is received and fixed to the axial position of the body. A concave hole having a circular cross section is formed, and a groove for guiding the protrusion of the shank portion in the axial direction is further formed on the inner wall of the concave hole, and engagement and idle rotation for continuously guiding the protrusion in the direction perpendicular to the groove. A key-shaped guide groove for prevention is formed. Further, on the outer peripheral portion of the attachment, a concave hole for accommodating a hard sphere and a hole penetrating the outside are formed at appropriate places of a groove for guiding the protrusion of the shank portion.

A hard sphere is inserted into this through hole, and the hard sphere cannot pass through the recess formed in the axial position, but a part of the hard sphere can project into the recess. The straight ball shank having an opening inside the concave hole is always biased toward the concave hole side by a spring arranged so as to surround the outer peripheral surface of the attachment body, and the straight drill shank is partially extended by the elastic ball. The passage of the projection of the section is restricted. Normally, a steel spring urges the rigid sphere, but when the protrusion of the shank passes through the inside, it receives the rigid sphere that is pushed outward, and the protrusion is fitted in a click-stop shape, and when the drill is pulled out, It is easily extracted by the opposite phenomenon. The protrusion is rotated along a key-shaped guide groove that is formed in the circumferential direction opposite to the direction of drilling rotation, and the drill is held in an attachment state on the attachment, and this guide groove prevents slipping and slipping. To be

The steel spring, which is attached so as to pass through the outer peripheral portion of the attachment body inward and acts as described above, is always elastically inwardly with a proper pressing force to the hard sphere accommodated in the through hole. However, for example, a spiral ring that has been substantially contracted into substantial contact with each other may be pushed outwards slightly when pushed outward by a rigid sphere and axially pulled apart so that the rigid sphere is slightly outward. It acts to move to. Due to such interaction between the hard sphere and the spring, the protrusion of the shank portion is inserted in a click stop shape and then withdrawn.

The attachment of the present invention is a member attached to an electric drill or the like for drilling, and the shank portion is formed to have a suitable thickness that does not idle, for example, a diameter of about 10 mm. The straight drill attached to this is practically, for example, 3.2mm, 3.4mm, 3.5mm,
3.8mm, 4.0mm, 4.5mm, 4.8mm, 5.0mm, 5.5mm, 6.
Although it is a drill with a relatively small drilling diameter such as 0 mm and 6.4 mm, it is not a good idea to prepare an attachment for a concave hole corresponding to the thickness of the shank portion of each of those drills. The shank portion of the drilling diameter may be formed to have a common thickness to make a recessed hole attachment to which they can be applied.
It is possible to unify the shank portion with a diameter of about 5 mm and prepare an attachment having a corresponding axial recessed hole. The attachment technique of the present invention can be conveniently applied to a drill having a slightly larger drilling diameter.

The attachment of the present invention is provided with a shank portion to be attached to an electric drill or the like, an axial recessed hole for receiving the shank portion of a straight drill, a dropout, a key-like guide groove for preventing idling, and a through hole for storing a hard ball. A metal member integrally formed with the attached attachment body,
The tip portion of the main body is formed to have a thick build-up outer diameter so that the tip of the spring inserted from the shank portion side abuts, and the rear end portion of the body has a pulling fixing member, For example, a thick spring fixing annular member is locked and fixed by an elastic O-ring or the like. The O-ring can be easily implemented by fitting it in an annular groove formed to receive it. By fixing the spring, the hard sphere housed in the through hole is always urged inward.

[0012]

The attachment of the present invention having such a structure is a member that is extremely effective especially for drilling using a narrow-diameter straight drill, and the mounting and removing of the straight drill are simple and short by hand. It can be carried out on time, and when the inserted protrusion of the shank is rotated along the circumferential key-shaped guide groove to operate, the smoothness is exactly the same as when the straight drill is directly attached to the electric drill. A continuous drilling operation is guaranteed.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The todrill attachment will be described in more detail. Figure 1
Is a front view of an example of the attachment of the present invention,
For ease of understanding, the front side of the spring is not shown and the straight drill is shown separately. FIG. 2 is a sectional view including the axis of the attachment body and the center of the hard sphere.

The shank portion 1 of the attachment for a straight drill attached to an electric drill or the like and the main body 2 to which the shank portion 11 of a straight drill are attached are integrally formed, and the main body 2 has a center of its tip. Shank part of straight drill that opens to the part 11 Circular concave hole for receiving 3
Is formed at the axial position of the main body. Further, a groove 4 is formed on the inner wall of the circular recessed hole for axially guiding a projection 12 for preventing the straightening of a straight drill formed on the shank portion of the straight drill, and at the same time, the groove 4 of the main body is formed. On the outer periphery,
A through hole 5 communicating with the axial recessed hole 3 is formed, and a rigid ball 6 which cannot pass through the inner recessed hole 3 but partially protrudes is housed in the through hole, and the rigid ball is an outer peripheral portion of the attachment body 2. Is urged toward the concave hole side by a spring 7 attached to.

Further, on the inner surface of the circular recessed hole 3, a key-like guide groove (not shown in the drawing) is formed in a direction perpendicular to the groove 4, that is, in the circumferential direction, and passes through the groove 4. The slip-preventing protrusion 12 thus inserted is guided by the key-like guide groove to rotate the straight drill, and is engaged and fixed to the attachment of the shank portion. The key-shaped guide groove is formed in the direction opposite to the rotation direction of the straight drill in a state where the inner wall of the circular recessed hole 3 is engraved, but it is stably attached to the attachment of the straight drill and idle. It is important to obtain prevention, and the rotation angle of the guide groove is practically in the range of 30 to 90 °, for example. In the assembly of such an attachment, the spring 7 is inserted so as to cover the outer peripheral surface of the main body 2 of the attachment, and is pressed against the built-up tip portion 8 of the main body, and the rear end side thereof is fixed by the annular member 9 for spring fixing to the spring of the spring. After being sufficiently compressed against the force, the locking O-ring 10 is fitted into its fitting groove and the spring is stably fixed in a slightly loosened state.

A part of the hard sphere 6 pushed inward by the bias of the spring projects into the concave hole 3 and the guide groove 4 is narrowed by the projection, so that the straight drill shank portion 11 is projected. Part 12 is restrained. The protrusion is fitted in a click-stop shape by the pulling force of the hand against the urging force of the spring 7, and is removed by the pulling force of the hand which is within the elasticity of the spring. The straight drill inserted against the bias of the hard sphere is rotated further to the right to complete the operation. This attachment is attached to an electric drill or the like for efficient continuous drilling.

[0017]

The attachment for a straight drill according to the present invention has the advantage of being attached to a usual electric drill or the like.
It is extremely easy to install and remove, so it is easy to handle, and there is no risk that the drill will easily come off from the electric drill etc. in the drilling work of an inexpensive straight drill, and the continuous drilling work is exactly the same as when the attachment is not used. You can Therefore, it is extremely advantageous in terms of operability and economy for the user, and its industrial utility value is extremely high.

[Brief description of drawings]

FIG. 1 is a front view of an example of an attachment of the present invention.

FIG. 2 is a sectional view including an axis of the attachment.

[Explanation of symbols]

 1 ... Attachment shank part 2 ... Attachment body 3 ... Axial recessed hole 4 ... Projection guide groove 5 ... Through hole 6 ... Hard sphere 7 ... Spring 8 ....・ Pulse-like tip of the main body 9 ・ ・ ・ Spring fixing annular member 10 ・ ・ ・ O-ring 11 ・ ・ ・ Strate drill shank 11 12 ・ ・ ・ Protrusion

Claims (2)

[Claims] 1. An attachment in which a shank portion attached to an electric drill or the like and a main body to which the shank portion of a straight drill is attached are integrally formed, and the main body is provided with a storage opening at the center of its tip. -A circular recessed hole for receiving the shank portion of the todrill is formed at the axial position, and a projection for preventing the idle operation of the straight drill is further formed on the inner wall of the recessed hole as an integral part of the shank portion of the straight drill. And a key-shaped guide groove for guiding the protrusion in the circumferential direction to prevent slipping and slipping, and the outer peripheral portion of the main body is provided with the above-mentioned shaft. A hard sphere is stored in an appropriate location of the guiding groove in the direction, but a through hole is formed to prevent the stored hard sphere from passing through the inner concave hole, and the hard sphere is attached to the outer peripheral portion of the attachment body. More said circular concave hole is urged side, stress a portion of the rigid sphere is made is configured to project partially into the concave hole - Todoriru attachment. 2. The strain according to claim 1, wherein the spring is attached to the outer peripheral surface of the main body of the attachment for a straight drill by a build-up tip end portion and a spring compression fixing member applied to the rear end side. -Todrill attachment.