JPH0417290Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention is a cutting tool that removes cutting chips that tend to get clogged in the annular tool when drilling a hole in a workpiece with an annular tool attached to a drilling machine. Relating to an exclusion device.

"Prior Art" In a conventional drilling machine, when a large diameter hole 2 can be drilled in a workpiece 1 while lowering the annular cutter 5 as shown in FIG. As a result of obliquely entering the circular cutting piece 3 from the workpiece into the downward facing cavity 6 provided therein, it was easily clogged. Therefore, if the cutting piece 3 actually becomes stuck in the empty chamber 6, the drilling operation cannot be continued unless the drilling operation is interrupted and the cutting piece 3 is taken out. .

``Problem to be solved'' This invention was developed in consideration of the fact that in conventional drilling machines, cutting pieces easily entered the annular cutter obliquely and became clogged.
By guiding the cutting pieces with a holding cylinder with a flat bottom end so that the cutting pieces do not incline, the cutting pieces are prevented from getting stuck inside the annular cutter, and even if they become clogged, the holding cylinder can be lowered to forcefully remove the cutting pieces. The aim is to eliminate clogging of cutting chips by removing them.

"Means for solving the problem" This invention fixes the shank part of an annular cutter to a hollow shaft that is rotated by a motor and is movable up and down inside an outer cylinder, and penetrates through the axial center of the shank part. In a drilling machine in which a pilot pin is inserted into a hole provided in the shank portion, the pilot pin is inserted into the through hole provided in the shank portion, and a first compression spring is interposed in the lower part of a holding cylinder that is vertically movable. Both ends of a latching pin, which is provided so as to be freely protrusive and retractable with respect to the flat lower end surface of the holding cylinder and penetrated through a long hole provided in the axial direction of the hollow shaft, are pivotally attached to the outer cylinder, Inside, a second compression spring is provided which is stronger than the first compression spring, and a second compression spring is used to bias the pusher that pushes the holding cylinder up to the same level as the lower end surface of the annular cutter downward. A means for solving the problem is provided by having a configuration in which the locking pin and the presser are engaged with each other through the locking pin and the pressing element.

``Operation'' When drilling is completed, the circular cutting piece that separates from the workpiece and enters the annular cutter is guided by the lower end surface of the holding cylinder that supports the pilot pin in the vertical direction, and is pushed down into the annular cutter. Excluded from the knife. In addition, if cuttings remain in the holding cylinder, when the hollow shaft is pulled up, the presser engages with the latch pin via the second compression spring, stopping the holding cylinder from rising. The cutting pieces remaining inside the annular cutter are forcibly removed.

"Example" Embodiments of the present invention will be described based on the drawings.

In FIG. 1, a hollow chamber 11 whose lower end is open is provided inside an annular cutter 10 fixed to the lower part of a hollow shaft 8 which rotates by a drive shaft (not shown). Cutting teeth 9 are regularly arranged and formed on the lower end surface of the .

A through hole 13 is formed in the shank portion 12 of the annular cutter 10, through which a holding cylinder 15 (described later) is inserted so as to be vertically movable on its axis. Inside this through hole 13, there is a cavity 11 that opens downward.
A holding cylinder 15 is inserted through the axial center of the holding cylinder 15 so as to be vertically movable.

The lower end surface of the holding cylinder 15 is formed into a flat surface, and a small diameter pilot pin 19 is mounted in a small hole 18 provided in the axial direction so as to be movable up and down.
A collar piece 16 having a diameter larger than that of the holding cylinder 15 is screwed onto the upper end of the holding cylinder 15 . A pointed end 20 for centering is formed at the lower end of the pilot pin 19, and a flange section at the upper end of the pilot pin that also serves as a stopper to prevent the pilot pin from escaping downward from the through hole. 21 are provided.

A cavity is formed in the upper interior of the holding cylinder 15 in communication with the small hole 18, and the lower end of the first compression spring 22 inserted into this cavity is inserted into the pilot pin 1.
It is brought into contact with the upper surface of the collar piece 21 of No. 9. The upper end of the first compression spring 22 is fixed to the upper part of the holding cylinder 15 and brought into contact with the collar piece 16, and the upper end of the first compression spring 22 is attached to the pilot pin 1.
9 is always biased downward. A presser 23 fixed to the upper part of the holding cylinder 15 with the pilot pin 19 attached to the lower part is in contact with the upper surface of the collar piece 16, and is housed in a cavity a provided in the hollow shaft 8 so as to be vertically movable. has been done.

Reference numeral 25 denotes an outer cylinder attached to the outer periphery of the hollow shaft 8, and is rotatably supported by a support portion 4a provided on the lower front surface of the drilling machine 4. A locking pin 2 is fixed to the outer cylinder 25 by passing through it in a direction perpendicular to the axial direction of the outer cylinder 25.
6 is inserted into a long hole 8b provided in the axial direction of the hollow shaft 8, and the hollow shaft 8 and the outer cylinder 25 are coupled so as to rotate together.
The hollow shaft 8 can move up and down within a range until the locking pins 26 are hooked to both ends of the elongated holes 8b of the hollow shaft 8 through which they are inserted.

Reference numeral 28 denotes a second compression spring interposed between the locking pin 26 and the pusher 23, which is set to have a stronger elastic force than the first compression spring. This compression spring 28
Due to the action of the holding cylinder 15 through the presser 23
is biased downward. Therefore, the holding cylinder 15
At the maximum, it is possible to descend to the same level as the lower end surface of the annular cutter 10, that is, the cutting tooth surface.

Next, the operation of this embodiment will be explained.

As shown in FIG. 2, first, centering is performed by lowering the hollow shaft 8 and aligning the pointed end 20 of the pilot pin 19 with a punch mark (not shown) marked on the upper surface of the workpiece 1. conduct. The pilot pin 19 is vertically movably supported in the through hole 13 of the holding cylinder 15 provided at the axial center of the annular cutter 10 so as to be vertically movable.
Since the pilot pin itself can be made small in diameter, the punch mark can be easily seen and centering work can be performed easily.

Subsequently, when the rotating hollow shaft 8 is lowered, the pilot pin 19, whose lower end is in contact with the workpiece 1, resists the elastic force of the first compression spring 22 by the workpiece. and rise. At this time,
The annular cutter 10 and the holding cylinder 15 are as shown in FIG.
Both abut against the upper surface of the workpiece 1, the annular cutter forms an annular hole 2 with cutting teeth 9, and the cutting piece 3 is separated (FIG. 4).

Even if a reaction force against the elastic force of the second compression spring 28 acts on the circular cutting piece 3 separated from the workpiece 1 when drilling is completed, the cutting piece 3 will not hold the holding cylinder 15. Since a downward force is applied by the flat lower end surface of the cutter 3, the cutting piece 3 is immediately expelled from the annular cutter 10 without penetrating deeply into the cavity 11 of the annular cutter 10.

In addition, FIG. 5 shows an example in which the length of the holding cylinder 15a in the axial direction is slightly shortened, and in this embodiment, the annular cutter 1
0 begins to drill the hole 2 in the workpiece 1, the lower end surface of the holding cylinder 15a does not come into contact with the workpiece 1.

In the unlikely event that the cut piece 3 remains in the cavity 11 of the annular cutter 10, if the hollow shaft 8 is raised, the presser 23 provided inside the hollow shaft 8 will move through the collar piece 16 to the holding cylinder. 15, the lifting of the holding cylinder 15 is stopped, and by subsequently raising the hollow shaft, the cut piece 3 is forcibly removed by the lower end surface of the holding cylinder.

"Effect of ideas" The present invention has the following effects.

During drilling, the downward force of the holding cylinder is constantly acting on the top surface of the workpiece through the elastic force of the second compression spring, so that after the drilling is completed, the cutting pieces penetrate deep into the annular cutter. Therefore, the cutting pieces are automatically removed, and the trouble of taking out the cutting pieces can be saved.

The pilot pin is protected by being immersed in the holding cylinder immediately after the start of the drilling operation, so the load applied to the pilot pin during the drilling operation is dispersed by the flat lower end surface of the holding cylinder, and the pilot pin is protected in a short period of time. The tip will not wear out or break.

Since the lower end surface of the holding cylinder into which the pilot pin is recessed is a flat surface, the cutting piece separated by the drilling operation comes into contact with the lower end surface without being tilted, and the cutting piece is fitted diagonally into the cavity of the annular cutter. Since it does not get stuck, it is easy to eliminate it.

Since the pilot pin is protected by a holding cylinder, it does not require strength, and therefore can be made small in diameter, making centering work easier.

[Brief explanation of the drawing]

Figures 1 to 5 show one embodiment of the present invention, in which Figure 1 is a longitudinal cross-sectional side view of the main parts of the drilling machine showing the state during drilling, and Figure 2 is a vertical side view of the main parts of the drilling machine showing the state during drilling, and Figure 2 shows the pilot pin being inserted into the workpiece. A cross-sectional view of the main part showing the state aligned with the punch mark marked on the top surface, Fig. 3 is a cross-sectional view of the main part showing the state immediately before drilling with the annular knife, and Fig. 4 shows the state after drilling is completed. FIG. 5 is a cross-sectional view of the main part when the holding cylinder is slightly shortened and installed, and FIG. 6 is a cross-sectional view of the main part showing the state of drilling with a conventional drilling machine. 4...Drilling machine, 8...Hollow shaft, 10...
Annular knife, 11...vacant chamber, 12...shank part,
13... Through hole, 15... Holding cylinder, 19... Pilot pin, 22... First compression spring, 23...
Presser, 25...Outer tube, 26...Latching pin, 28
...Second compression spring.

Claims (1)

[Scope of utility model registration request] In a drilling machine in which a shank part of an annular cutter is fixed to a hollow shaft that is rotated by a motor and is movable up and down inside an outer cylinder, and a pilot pin is inserted into a hole penetrated through the axial center of the shank part. , a first compression spring is interposed at the lower part of a holding cylinder which is vertically movably mounted in the through hole provided in the shank part, so that the pilot pin can freely protrude and retract from the flat lower end surface of the holding cylinder. , and both ends of a locking pin that passes through a long hole provided in the axial direction of the hollow shaft are pivotally attached to the outer cylinder, and the inside of the hollow shaft has at most a lower end surface of the annular cutter. A second compression spring forces a presser that pushes down the holding cylinder to the same level as the first compression spring, and engages the locking pin and the presser through a second compression spring that is stronger than the first compression spring. Cutting piece removal device for drilling machines.