JPH07299624A - Combination drill - Google Patents

Abstract

PURPOSE:To provide a drill by which cutting work productivity of a metallic product can be improved and a burr is not generated. CONSTITUTION:A hollow mill 2 to cut at least an outer peripheral surface of a metallic product 5 is fixed to the outer peripheral side of an inner mill 1 to cut at least an inner peripheral surface of the metallic product so as to be freely mountable and demountable, and a chip discharging window is arranged in a wide open shape in the hollow mill in response to a chip discharging groove of the inner mill.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combination drill, such as a lathe or a drilling machine, for drilling or turning a workpiece by relative rotation and advance / retreat of a blade and a workpiece.

[0002]

2. Description of the Related Art Metal products are usually manufactured by casting or the like into a rough shape and then cut into a required shape. However, when it is necessary to cut the inner peripheral surface and the outer peripheral surface, the conventional method is used. Is to cut the inner peripheral surface with a cutting tool or a drill for cutting the inner peripheral surface, and then cut the outer peripheral surface with a cutting tool for cutting the outer peripheral surface, or the outer peripheral surface first and then the inner peripheral surface. In any case, the cutting of the inner peripheral surface and the cutting of the outer peripheral surface are performed separately.

[0003]

However, in the case of the above-mentioned conventional method, it is inevitable to replace the cutting tool or the cutting tool for the inner peripheral surface with the cutting tool for the outer peripheral surface,
There is a problem that the net cutting time, that is, the productivity is low due to the time loss for the tool change. In addition, the end surface of the processed metal product can be cut simultaneously with the cutting of the inner peripheral surface with a general-purpose cutting tool, or by moving the cutting tool from the inner peripheral surface to the end surface, or similarly, it can be processed simultaneously with the cutting of the outer peripheral surface. It is cut with a forming tool or moved from the outer peripheral surface to the end surface for cutting. However, in the former case, since the inner peripheral surface and the end surface are cut at the same time, deformation of the product at the boundary portion between them, so-called burring does not occur, but the boundary portion between the outer peripheral surface and the end surface is not processed, so And a separate step of removing the burrs was required. Similarly, in the latter case, the boundary between the outer peripheral surface and the end surface is machined so that no burrs occur, but since the boundary between the inner peripheral surface and the end surface is not machined, burrs occur and this burr occurs. However, there is a problem that a separate step for removing is necessary. Therefore, the present invention can improve the productivity of cutting of metal products, and can also process the corners of the inner peripheral surface and the outer peripheral surface at the same time so that no burrs occur at the corners of the end. The purpose is to provide.

[0004]

According to the present invention, an inner mill for cutting at least the outer peripheral surface of a metal product is detachably fixed to the outer peripheral side of the inner mill for cutting at least the inner peripheral surface of the metal product. The above object is achieved by a combination drill characterized in that a window for discharging chips is provided in the hollow mill with a large opening corresponding to the groove for discharging chips. At that time, the end surface of the metal product can be cut by the inner mill or the hollow mill.

[0005]

With this combined drill, the inner and outer peripheral surfaces are cut at the same time, so that the productivity of the cutting process can be improved. The cutting tool for cutting the end surface can be attached either to the inner mill side or the hollow mill side, but in both cases the inner and outer peripheral surfaces and the end surface are cut at the same time, so there is a gap between the inner peripheral surface and the end surface. Moreover, no burrs are formed between the outer peripheral surface and the end surface, so that the step of removing burrs can be omitted.

[0006]

The present invention will be described with reference to the drawings. The drawing shows an embodiment of the present invention, and the combination drill of this embodiment is shown in FIG.
And as shown in FIG. 2, the inner mill 1 and the hollow mill 2
And a nut 3, and a female threaded short tube 5 for mounting a gas pipe
For manufacturing. First, as shown in FIGS. 3 and 4, the inner mill 1 has blades 1a and 1a at the tip end thereof for punching the inner peripheral surface of the female screw short pipe 5, and the end face of the female screw short pipe 5 is provided at the base of the blade 1a. There are cutting blades 1b and 1b.
Grooves 1c, 1c for discharging chips cut in the rotational direction of the blades 1a, 1a; 1b, 1b are provided. In addition, the blade portions 1a and 1b
A parallel portion 1d for attaching the hollow mill 2 is formed on the rear portion thereof, and a male screw 1e for attaching the nut 3 is further provided on the rear portion thereof, and a chuck (not shown) of the numerically controlled machine body is provided at the rearmost portion. ) Is secured to the shank 1f. On the other hand, as shown in FIGS. 5 and 6, the hollow mill 2 has blades 2a, 2a for cutting the outer peripheral surface of the female screw short tube 5 on the inner surface of the tip portion, and the groove 1 of the inner mill on the rear portion thereof.
A window 2b for discharging chips corresponding to c and 1c is provided.
The inner surface of the cylindrical portion at the rear of the window 2b is the parallel portion 1 of the inner mill.
Bolt holes 2c for fixing the hollow mill 2 to the inner mill 1 are provided in the cylindrical portion in a diametrical direction with an inner surface shape that fits in d.

This embodiment is constructed as described above,
First, the nut 3 is screwed into the inner mill 1, and then the hollow mill 2 is externally fitted to the inner mill 1 to determine the insertion depth in the axial direction. In this state, a bolt (not shown) is screwed into the bolt hole 2c of the hollow mill, and the tip of the bolt is pressed against the parallel portion 1d of the inner mill 1 to fix the inner mill 1 and the hollow mill 2. Then, the nut 3 is unscrewed and tightened to the hollow mill 2. That is, at the time of cutting, a force acts on the hollow mill 2 in the circumferential direction and in the direction of pressing the nut 3 (right direction in the drawing), but the former is received by the parallel portion 1d of the inner mill 1 and the latter is received by the nut 3. Accepted by. When the female screw short pipe 5 is cut by the combined drill thus assembled, the inner peripheral surface, the outer peripheral surface, and the end surface are all cut at the same time,
At the same time as the productivity is improved, burrs do not occur because processing is performed at the boundary between the inner peripheral surface and the end surface and the boundary between the outer peripheral surface and the end surface. In the present embodiment, the blades 1b, 1b for cutting the end face are provided on the inner mill 1 side, but they may be provided on the hollow mill 2 side. Also, groove 1 of inner mill
c and the window 2b of the hollow mill correspond to each other and the blades 1a, 1a; 1
b, 1b; Since it is a passage for discharging chips that is open to the rear side from between 2a and 2a, chips that cut the inner and outer peripheral surfaces are discharged through the groove 1c and the window 2b, and the chips are clogged. Absent.

[0008]

According to the present combination drill, since the inner and outer peripheral surfaces are cut at the same time, the productivity of cutting metal products is improved. Further, since the burr does not occur, the removing step can be omitted, and the productivity of the cutting process can be improved also from this aspect.

[Brief description of drawings]

FIG. 1 is a side view of an essential part of an embodiment of the present invention.

FIG. 2 is a schematic front view of the same.

FIG. 3 is a side view showing an inner mill.

FIG. 4 is a sectional view taken along line (A) AA, (B) taken along line BB, and (C) taken along line CC of FIG. 3;

FIG. 5 is a side view showing a hollow mill.

FIG. 6 is a sectional view taken along line AA in FIG. 5 and FIG.
B line cross section

[Explanation of symbols]

1 ... Inner mill 1a, 1b ... Blade 1
c ... Groove 1d ... Parallel part 1e ... Male thread 1
f ... Shank 2 ... Hollow mill 2a ... Blade 2
b ... window 2c ... bolt hole 3 ... nut 5
… Female screw short tube

Claims (1)

[Claims] 1. A hollow mill that cuts at least the outer peripheral surface of the metal product is detachably fixed to the outer peripheral side of an inner mill that cuts at least the inner peripheral surface of the metal product, and corresponds to a chip discharge groove of the inner mill. Then, the combination drill is characterized in that the hollow mill is provided with a large window for discharging chips.