JPH0737770Y2 - Jig for drilling - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to a drilling jig used for drilling a brittle material such as ceramics. The present invention relates to a jig for drilling, which prevents chipping or cracking.

(Prior Art) There are various types of drilling, and among them, there is a method of drilling using a core drill.

A conventional drilling process using a core drill will be described with reference to FIG.

The core drill 21 is formed to be hollow. A metal or wooden caul plate 23 is laid under the work piece 22. The core drill 21 is rotated and pushed down to form a through hole 24 in the workpiece 22.

However, since the core drill 21 is formed by excavating an annular groove to form the through hole 24, the inner portion 22a of the core drill is generated when the through hole 24 is formed. As the core drill 21 rotates, the core drill inner portion 22a rotates together. As a result, if it is a brittle material such as ceramics, there is a possibility that chips or cracks may occur around the through hole 24.

Therefore, Japanese Utility Model Laid-Open No. 1-3922 discloses a device for preventing rotation of the core drill inner portion 22a as shown in FIG. That is, this device includes a cylindrical core drill 21, a drill holder 25 that holds the core drill 21 and transmits a rotational force, and a bearing 26 in the drill holder 25.
Via a fixed shaft 27, a guide portion 28 slidably provided in the hollow portion of the fixed shaft 27 in the vertical direction, a rod 29 fixed to the tip of the guide portion 28, A cap 31 fixed to the fixed shaft 27 and having a hole 30 for projecting the rod 29 at the tip end surface, and a disc-shaped member screwed and fixed to the male screw portion 29a formed at the tip end of the rod 29. The pressing plate 32 includes a pressing plate 32 and a biasing spring 33 that is provided between the pressing plate 32 and the cap 31 to bias the pressing plate 32 downward.

Here, the pushing plate 32 is made of a metal plate.

(Problems to be solved by the invention) However, according to the device shown in FIG.
Since it is a metal plate, the friction coefficient is small, slippage between the pressing plate 32 and the core drill inner portion 22a is likely to occur, and the result is that the core drill inner portion 22a is allowed to rotate.
In particular, immediately before the through hole 24 was formed, the core drill inner portion 22a was easily rotated together with the core drill 21 due to the rotation of the core drill 21.

In addition, the drilling device shown in FIG.
Is a fixed shaft type in which the drill holder 21 rotates around the outer periphery of the. In this fixed shaft type, since the pressing plate 32 may be provided in the fixed shaft 27, the structure may be simple. However, as a drilling device, there is also a chuck type device in which the upper end of the drill holder 25 is attached to and detached from the rotary chuck. In this chuck type, since there is no fixed shaft, a working plate must be provided in the rotating drill holder 25. 6th of fixed axis type to this chuck type
The structure of the figure cannot be applied as it is. For example,
When the rotation of the drill holder is transmitted to the pressing plate via the biasing spring, the pressing plate rotates and it becomes impossible to press the inside part of the core drill of the workpiece.

The object of the present invention is to provide a chuck-type drilling device in which the upper end of the drill holder is attached to and detached from the rotary chuck, and a jig for drilling that reliably prevents the inner part of the core drill from rotating together with the rotation of the core drill. To provide.

(Means for Solving the Problems) In order to achieve the above object, the jig for drilling of the present invention is a core drill having through holes formed in the length direction, and a drill for holding a core drill and transmitting a rotational force. A holder, a pressing member having a rod part that is vertically movable in a through hole of a core drill, and a pressing part made of hard rubber provided at a tip of the rod part, a rod part of the pressing member, and an inner wall side circumference of the drill holder. The outer ring is provided so as to be vertically slidable on the inner wall side peripheral surface of the drill holder.
A movable bearing in which the inner ring is integrally movable with the rod portion in the vertical direction, a spring tray mounted on the upper end of the outer ring of the movable bearing, and provided between the spring tray and the upper surface of the inner wall of the drill holder. And a biasing spring provided inside the drill holder so as to bias the pressing body toward the workpiece.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 and FIG. 2 show an embodiment of a drilling jig of the present invention. This drilling jig includes a core drill 1 having a through hole 2 formed in the length direction, and a drill holder 3 for holding the core drill 1 and transmitting a rotational force.
And a pressing body 6 made of hard rubber provided in a through hole 2 of the core drill 1 so as to be movable up and down, and the pressing body 6 being a workpiece 11
An urging spring 9 provided inside the drill holder 3 so as to urge it to the side.

Here, the drill holder 3 is configured such that the upper mounting portion 3a is mounted on a chuck (not shown) of a drilling machine.

Further, the core drill 1 has a blade of diamond or the like. The core drill 1 is detachably attached to the lower portion of the drill holder 3. That is, as shown in FIG. 3, the plurality of fitting protrusions 4 radially formed on the upper end of the core drill 1 are fitted into the fitting grooves 5 formed on the lower end of the drill holder 3 so that they can be attached and detached. Has become.

The pressing body 6 is for pressing the workpiece 11 from above and fixing it. The pressing body 6 includes a rod portion 6a and a pressing portion 6b made of hard rubber provided at the lower end of the rod portion 6a.
It consists of and.

The reason why the hard rubber is used as the material of the pressing portion 6b is that the friction coefficient is larger than that of a metal plate, and the pressing portion 6b and the workpiece 11 are
This is because slippage does not easily occur between the inner part 11a of the core drill and the inner part 11a. As a result, even if the core drill inner portion 11a of the workpiece 11 tries to rotate with a strong force immediately before forming the through hole,
Rotation of the core drill inner portion 11a of the workpiece 11 can be reliably prevented. Further, if the pressing portion 6b is made of soft rubber, a shearing force is applied to the soft rubber by the core drill inner portion 11a of the workpiece 11 to which a strong rotational force is applied, and the soft rubber is deformed in the same direction as the rotational force, resulting in a workpiece. The core drill inner part 11a of 11 is allowed to rotate to some extent. On the other hand, when the pressing portion 6b is made of hard rubber as in the present invention, it is less likely to be deformed than the soft rubber, and therefore the rotation of the core drill inner portion 11a of the workpiece 11 is surely prevented even immediately before forming the through hole. it can.

In addition, a movable bearing 7 is provided at an intermediate portion of the rod portion 6a. The movable bearing 7 is provided so as to be interposed between the rod portion 6a of the pressing body 6 and the inner wall side peripheral surface of the drill holder 3. The movable bearing 7 is provided with an outer ring slidable in the vertical direction on the inner wall side peripheral surface of the drill holder 3, and the inner ring is placed on a receiving portion 6c integrally provided with the rod portion 6a. A spring tray 8 is placed on the outer ring. A biasing spring 9 is arranged between the upper surface of the spring tray 8 and the upper surface of the inner wall of the drill holder 3. Therefore, the downward urging force of the urging spring 9 is transmitted in the order of the spring tray 8 → the outer ring of the movable bearing 7 → the receiving portion 6c → the rod 6a → the pressing portion 6b. On the other hand, the rotation of the drill holder 3 is caused by the urging spring 9,
It is transmitted to the spring receiving tray 8 and the outer ring of the movable bearing 7. However, since the spring receiving tray 8 contacts only the outer ring of the movable bearing 7, it is not transmitted to the inner ring of the movable bearing 7. Since the outer ring of the movable bearing 7 does not rotate, the rod portion 6a and the pressing portion 6b do not rotate.
In short, the mechanism consisting of the spring tray 8 and the movable bearing 7
Although the urging spring 9 urges the pressing portion 6b downward, the pressing body 6b
Is configured not to rotate.

Further, the fixed bearing 10 is fixed to the inner wall of the drill holder 3 apart from below the receiving portion 6c to support the rod portion 6a.
With the movable bearing 7 and the fixed bearing 10, the drill holder 3
Is supported so that the rotation thereof is not transmitted to the rod portion 6a.

As shown in FIG. 4, if a backing plate 12 made of a material having a high friction coefficient such as a rubber plate is laid under the workpiece 11 as shown in FIG. The fixing effect of the object 11 is enhanced.

The jig for drilling thus configured carries out drilling as described below.

A backing plate 12 made of a rubber plate or the like is laid on a processing table 13 of a drilling machine (not shown), and a fragile work piece 11 such as ceramics is placed on the backing plate 12.

Then, the drill holder 3 to which the core drill 1 is attached is mounted on the chuck part (not shown) of the drilling machine to
The workpiece 11 is perforated by lowering it while rotating.

At this time, as shown in FIG. 4, the pressing body 6 is urged by the urging spring 9 so that the inner portion of the core drill of the workpiece 11 is pressed.
11a is pressed and fixed. A patch plate 12 made of a rubber plate or the like laid below the workpiece 11 enhances the fixing effect.
Then, as the drilling by the core drill 1 progresses, the pressing body 6 resists the urging force of the urging spring 9 and continues to press while moving upward in the core drill 1. Since the core drill inner portion 11a of the workpiece 11 is prevented from rotating, the core drill inner portion 11a is not rotated together with the core drill 1 even immediately before the through hole penetrates the workpiece 11. .
Therefore, it is possible to prevent the workpiece 11 from chipping or cracking.

Since the workpiece 11 is pressed by the pressing portion 6b made of hard rubber, the pressing body 6b and the core drill inner portion 11a of the workpiece 11 are pressed.
Slip does not easily occur between and, and it is difficult to deform even if a rotational force is applied. Therefore, even immediately before forming the through hole, rotation of the core drill inner portion 11a of the workpiece 11 is reliably prevented.

(Effects of the Invention) In the above-described jig for drilling processing of the present invention, the pressing portion of the pressing body that presses the inner portion of the core drill of the workpiece is made of hard rubber, and has a large friction coefficient compared with a metal plate, Since slippage does not easily occur between the pressing body and the inner part of the core drill of the workpiece, even if the inner part of the core drill of the workpiece tries to rotate with a strong force immediately before forming the through hole, the inner part of the core drill of the workpiece will rotate. Can be reliably prevented. Also, if the pressing part is made of soft rubber, shearing force will be applied to the soft rubber by the inner part of the core drill of the workpiece to which a strong rotational force is applied, and it will be deformed in the same direction as the rotational force, and the inner part of the core drill of the workpiece Although a certain amount of rotation is allowed, in the present invention, the pressing part is made of hard rubber and is less likely to be deformed than soft rubber, so rotation of the inner part of the core drill of the work piece is ensured even before the through hole is formed. Can be prevented. Therefore, there is a particular effect that high-precision drilling without chipping or cracking is achieved.

Further, a movable bearing is provided between the rod portion of the pressing body and the inner wall side peripheral surface of the drill holder, and the outer ring of the movable bearing is provided slidably in the vertical direction on the inner wall side peripheral surface of the drill holder, while the inner ring is provided. Is provided so as to be vertically movable integrally with the rod portion, the spring tray is placed on the upper end of only the outer ring of the movable bearing, and the biasing spring is provided on the spring tray. The pressing body can be biased downward by the biasing spring without being rotated.
Therefore, it can be suitable as a workpiece pressing device for a chuck type drilling device in which the upper end of the drill holder is attached to and detached from the rotary chuck.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an embodiment of a jig for drilling of the present invention. FIG. 2 is a perspective view of the drilling jig shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA of FIG. FIG. 4 is a vertical cross-sectional view showing a usage state of the jig for drilling of FIG. FIG. 5 is a vertical sectional view of a conventional technique. FIG. 6 is a vertical cross-sectional view of another prior art. 1: Core drill, 2: Through hole, 3: Drill holder, 6: Pressing body,
6a: rod part, 6b: pressing part, 6c: receiving part, 7: movable bearing, 8:
Spring tray, 9: bias spring, 10: fixed bearing, 11: workpiece, 1
2: Patch plate.

Claims (1)

[Scope of utility model registration request] 1. A core drill having a through hole formed in a longitudinal direction thereof, a drill holder for holding the core drill and transmitting a rotational force, a rod portion provided in the through hole of the core drill so as to be vertically movable, and A pressing body having a pressing portion made of hard rubber provided at the tip of the rod part, and an outer ring provided between the rod part of the pressing body and the inner peripheral surface of the drill holder, and the outer ring of the drill holder. A movable bearing, which is provided so as to be slidable in the vertical direction on the inner wall side peripheral surface, and in which the inner ring is vertically movable integrally with the rod part, and a spring tray mounted on the upper end of the outer ring of the movable bearing. An urging spring that is provided between the spring tray and the upper surface of the inner wall of the drill holder and that is provided inside the drill holder so as to urge the pressing body toward the pressed object. A jig for drilling.