JPH02185309A - Chamfering device for through hole - Google Patents

Abstract

PURPOSE:To chamfer a through hole in hard and soft metal completely from a front surface by providing a rhomboid bite to the axial slot at the tip of a cylindrical rotating shaft with its center fixed rotatably to the slot walls, to position the bite by a centrifugal force. CONSTITUTION:With the rhomboid short diagonal line of a bite 27 faced in the direction of the periphery of a through hole 18, a rotating shaft 21 is pushed into a workpiece 19 from the front surface of the workpiece 19 until the bite comes out of the back surface B. When the rotating shaft 21 is turned at high speed, the direction of the bite 27 is altered by a centrifugal force to face its lingitudinal line in the direction of the periphery of the through hole. When the rotating shaft 21 is pulled upward, a cutting edge 28 provided on the opposed sides of the bite 27 is contacted on the corner section of the through hole 18 to chamfer it. After completing chamfering, the rotating shaft 21 is stopped and moved downward, and the short diagonal line of the bite 27 is faced in the direction of the periphery of the through hole 18 and the rotating shaft is pulled upward. Thus the chamfering is completed.

Description

[Detailed Description of the Invention] [Industrial Application Field] By attaching a cutting tool to the tip of a cylindrical rotating shaft and rotating this rotating shaft, a through-hole can be cut for chamfering, deburring, etc. This invention relates to a chamfering device.

[Conventional technology]

When a through hole is processed by cutting, pressing, laser processing, etc., flashes are always generated on both sides of the through hole. Depending on the purpose of the product, this pad may be used as is without being removed, but in many cases, the pad is removed by chamfering or the like. When removing the burr by chamfering, it is common to chamfer both sides (front and back surfaces) of the workpiece.In this case, it is particularly convenient from the viewpoint of man-hours to process only from the side (front) direction. good. However, in this case, although the front side can be chamfered easily, it is not easy to chamfer the back side from one direction, and a special device is usually used.

FIG. 6 shows a conventional through-hole back chamfering device for chamfering the back side of a workpiece from one side.
The mark in the figure is a vertical cross-sectional view showing the state in which the back chamfering device is being set on the workpiece, and (b) is during chamfering. This back chamfering device is installed at the tip of the cylindrical rotating shaft 41. A cutting tool 42 is attached to the large hole 54 so as to be supported by a pivot pin 46, and the workpiece 49
The structure is such that the back side B can be chamfered by machining from the front side A.

During machining, one end of the rotating shaft 41 is fixed to a chuck or the like of a drilling machine (not shown), and the workpiece 4 is held in a state where rotation is stopped.
When the tip of the rotary shaft 41 is inserted into the through hole 48 which has been machined to a diameter of 9, the protruding portion 52 of the cutting tool 42 is inserted into the through hole 48 7i! ! Pushed by the wall 53, it begins to rotate around the pivot pin 46, changing the angle of inclination of the slope 50 in contact with the tip 51 of the plunger 47, pushing the plunger 47 upward and compressing the spring 44. The spring 44 is connected to the rotating shaft 41 by a female screw 45.
It is fixed in the hollow part of.

When the rotating shaft 41 is further pushed and the protruding part 52 of the cutting tool 42 penetrates the back surface B of the workpiece 49, the protruding part 52 of the cutting tool 42 is pushed out of the large hole 54 by the force of the spring 44, as shown in the sixth step). To remove the rotary shaft 4, turn it in the direction of the arrow shown
1 is rotated and pulled upward in the drawing, the cutting blade 46 of the cutting tool 42 performs chamfering. After chamfering is completed, the rotation of the rotary shaft 41 is stopped and the protrusion 52 of the cutting tool 42 is removed in the same way as when installing by stopping the rotation of the rotary shaft 41 and pulling the rotary shaft 41 upward.
is pushed by the peripheral wall 56 of the through hole 48 and compresses the spring 44,
Since the protrusion 52 is contained within the peripheral wall 53, this rotating shaft 41
Pull it upward to complete the chamfering work.

[Problem to be solved by the invention]

By using the above-mentioned device for chamfering the back side of a through hole, it is possible to chamfer the back side from one direction, but this is only possible when the workpiece is a relatively soft metal such as a light alloy. In the case of hard metals such as steel, especially stainless steel, there is a problem that the cutting resistance (cutting resistance) causes the cutting edge to escape and machining cannot be performed properly.Also, in order to prevent this cutting edge from escaping, increasing the spring force When passing through the through hole, the resistance increases and there is a risk of damaging the inner wall of the through hole, so the spring force must be set to an appropriate strength taking these things into account.

[Means to solve the problem]

The present invention provides an axial cut groove at the tip of a cylindrical rotating shaft, inserts a diamond-shaped cutting tool into this groove, and rotatably attaches the center part to the groove wall. The cutting tool is positioned using the centrifugal force generated by the rotation of the rotating shaft.

[Effect]

Since the chamfering device of the present invention is configured as described above, when chamfering the back side of a workpiece, the device can be attached to and removed from the workpiece by pointing the short diagonal of the diamond shape in the circumferential direction of the through hole. The cutting tool is made to pass through the through hole, and during cutting, by rotating the rotating shaft, a centrifugal force is applied to the rhombic cutting tool, and the cutting tool is made to pass through the rotating shaft with the long diagonal of the rhombus facing the circumferential direction of the through hole. Therefore, according to the present invention, the two sides of the diamond-shaped cutting tool are evenly abutted against the wall of the through-hole, centering on the center part, thereby causing relief in the cutting tool. In addition, it is possible to process hard metals without causing damage to the walls of the through holes in the workpiece.

〔Example〕

The present invention will be explained in detail below based on embodiments shown in the drawings.

FIG. 1 is a perspective view of a through-hole back chamfering device showing an embodiment of the present invention, in which 21 is a cylindrical rotating shaft, 22 is a cut groove provided at the tip of this rotating shaft 21, and 23 is a pin hole provided in one side wall 24 of the cut groove 22,
Although not shown, the opposing side wall 25 is provided with a screw hole into which the threaded portion 26' of the shaft pin 26 passing through the pin hole 26 is screwed. Reference numeral 27 is a cutting tool having a substantially diamond-shaped outer shape, and cutting blades 28 are provided on opposite sides of the cutting tool 27, and a pin hole 29 through which the aforementioned shaft pin 26 passes is provided in the center thereof.

Therefore, the cutting tool 27 is inserted into the cut groove 22 of the rotating shaft 21, and the shaft pin 26 is inserted into the pin hole 29 of the side wall 24.
3 and insert the threaded portion 26' of the shaft pin 26 into the side wall 2.
5 is screwed into the screw hole 5 and rotatably supported on the rotating shaft 21, thereby forming a through-hole chamfering device.

FIG. 2 is an explanatory diagram of the operation of the through-hole chamfering device 20 according to the present invention constructed as described above, and (6) shows how the chamfering device 20 according to the present invention is applied to the through-hole 18 provided in the workpiece 19. In the middle of insertion, (Isao shows a longitudinal cross-sectional view during chamfering.)

In the chamfering operation, first, the rotating shaft 21 is pushed into the cutting tool 27 until the short diagonal of the rhombus protrudes from the direction B in the circumferential direction of the through hole 18.

In this state, when the rotating shaft 21 is rotated at high speed in the direction of the arrow as shown in FIG. 2(0), the direction of the diamond-shaped cutting tool 27 changes due to centrifugal force, so that the long diagonal line thereof faces in the circumferential direction. Therefore, the rotating shaft 2119 continues to rotate, and the corner of the through hole 18 of the rotating shaft 2119 is chamfered.

After chamfering is completed, the rotation of the rotating shaft 21 is stopped, and the rotating shaft 21 is moved downward in the drawing (towards the back surface B), and the cutting tool 2 is moved.
The chamfering process is completed by pulling out the short diagonal length of 7 in the local direction of the through hole 18 upward in the drawing.

FIG. 6 is a perspective view showing another embodiment according to the present invention. In this embodiment, one side wall of a notch 632 provided at the tip of the rotating shaft 61 is a separable wall piece 64, and the cutting tool 3
The case where the shaft pin 66 is fixed to the shaft pin 7 is shown.

Therefore, in this embodiment, both walls 34 .
35 is provided with a pin hole 33.65', and a fixing member 38.3 is attached to the wall piece 64 to the rotating shaft 61 so that the shaft pin 36 of the cutting tool 67 can be inserted into the pin hole 33.33'.
It is concluded by 8'.

Regarding the device for chamfering the back surface of a through hole according to this embodiment,
Chamfering can be performed by the same operation as in the embodiment shown in FIG.

In addition, if the angle of the chamfer is specified, for example, the fourth
As shown in the figure, if the angle α is required to be close to 90° or larger than 90°, the requirement can be met by cutting off the corners c and c' of the long diagonal of the cutting tool.

Further, in the case where the cutting tool 27 is configured to rotate 660 times within the cut groove 22 as in the above-mentioned embodiment, the cutting tool 27 that has passed through the through hole 18 is inserted by centrifugal force due to rotation of the rotating shaft. In some cases, the time position may not be changed. That is, there is always one position where the cutting tool 27 maintains an equilibrium state.

It is extremely rare for the cutting tool 27 to be located in such an equilibrium position, but in order to eliminate this, for example, as shown in Figure 5 (a) or (2)), a A stop 50 or 50' may be provided at the center of the notch 1II22 to forcibly restrict the stopping position of the cutting tool 27 from the equilibrium position.

FIG. 5(a) shows a case in which a stopper 50 or 50' is provided on the upper part of the cutting tool 27, and ((b) on the lower part, respectively).

Figure 5 e ~ is the pad 50 or 50' shown in (6) or extension)
Instead of a bottle, the bottom surface 51 of the cut groove 22 is used, and the cut m22 is formed shallowly, and this bottom surface 5
1, separate the tip of the cutting tool 27 from the center of the rotating shaft 21.
, so that it is supported in the same position.

In the illustrated embodiment, the bottom surface 51 has an appropriate inclination angle β so as not to damage the cutting blade 28 of the cutting tool 27.
It doesn't matter if it's horizontal.

〔effect〕

According to the present invention, when chamfering both the front and back sides of a through hole, it is possible to chamfer both sides by machining only from one direction (the front surface), while maintaining the processing advantage that it is possible to chamfer from hard metal to soft metal. This has the practical effect that chamfer cutting of through holes can be reliably performed on wide workpieces, including metals, without any problems.

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) A cylindrical rotating shaft, a notched groove provided in the axial direction at one end of the rotating shaft, and a shaft inserted into the notched groove and rotatably centered around the notched groove on both walls of the notched groove. 1. A device for chamfering a through-hole, characterized in that the diamond-shaped cutting tool comprises a diamond-shaped cutting tool, and a portion of both ends of the diamond-shaped cutting tool on a long diagonal line protrude from both ends of the cut groove. (2) A cylindrical rotating shaft, a notch groove provided in the axial direction at one end of the rotating shaft, and the notch groove is inserted into the notch groove and is rotatably attached to both walls of the notch groove with the center part as the axis. It consists of a shaft-mounted diamond-shaped cutting tool, and the diamond-shaped cutting tool is arranged such that a part of both ends on its long diagonal line protrudes from both ends of the cut groove, and the position of the diamond-shaped cutting tool when inserted into the through hole is not the equilibrium position. A device for chamfering a through-hole, characterized in that a pad is provided to prevent chamfering.