JPH08257820A - Pin milling cutter - Google Patents

Abstract

PURPOSE: To improve the durability of a key groove and the operability of key engagement in a pin milling cutter. CONSTITUTION: A key receiving part 6 is fixed, being tightened by a screw, to both wall part of a groove 13 widely arranged in the cutter main body 2 of a pin milling cutter 1 so as to be easily changed. The width of a key groove 5 is formed with the interval between the upper surfaces 11 of the receiving plates 7 of the opposing key receiving part 6. The key receiving part 6 is composed of an attaching plate protruding backward more than a part of the back surface of the receiving plate 7, in addition to the receiving plate 7 forming the wall surface of the key groove 5, and tightened by a screw so as to be fixed from the end surface side of the cutter main body 2 via an attaching hole. On the upper surface 11 of the receiving plate 7, a step surface 12 retreated by 0.01 to 0.05mm more than the upper surface 11 is provided in one end part of a side as a key inserting port.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a key groove portion of a pin milling cutter used for machining a crankshaft pin.

[0002]

2. Description of the Related Art Conventionally, the key groove of a pin milling cutter is generally formed directly on the cutter body.
In addition, in order to prevent the deformation of the keyway, a method of joining the high hardness materials by brazing or the like to form the keyway is also adopted.

[0003]

Since the accuracy of assembling the cutting edge of the pin milling cutter is usually based on the key grooves provided at equal positions in four places, the working accuracy is high.
Moreover, the clearance with the key is small and the fitting accuracy is high. However, since the pin milling cutter has a heavy weight and also has a high fitting accuracy as described above, it is difficult to perform the operation when attaching and detaching the pin milling cutter to the machine tool, and the workability is deteriorated. Also, if the key groove is worn or deformed due to attachment / detachment work or chatter vibration during cutting, etc., the accuracy of assembling the cutting edge will deteriorate, resulting in poor machining and shortened cutting edge life. May invite you.

The method of joining has problems such as a decrease in hardness due to heat during brazing and thermal deformation in brazing. The materials to be joined are also limited, and even if they can be joined successfully, there was a problem that they would fall off from the joint during use due to insufficient brazing strength.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a pin milling cutter rotationally driven by fitting with a key provided in a spindle of a machine tool at a key groove, The key receiving part is fixed by screwing on both walls of the groove that is widely arranged in the cutter body so that it can be replaced, and the width of the key groove depends on the distance between the upper surfaces of the receiving plates of the facing key receiving parts. To form.

The key receiving component is composed of a receiving plate forming the wall surface of the key groove and a mounting plate projecting rearward from a part of the back surface of the receiving plate, and is connected to one end of the groove provided in the cutter body. The cutout step portion and the mounting plate are brought into contact with each other, and the cutter body is screwed and fixed from the end face side through a mounting hole formed in the mounting plate. A stepped surface that is recessed from the top surface by 0.01 to 0.05 mm is provided at one end of the top surface of the receiving plate that forms the key groove, on the side where the key is inserted.

[0007]

In the present invention, since the key groove is composed of replaceable key receiving parts, not only hardened steel but also high speed steel, cemented carbide, ceramics, etc., which have high hardness and wear resistance
Various materials having excellent deformation resistance can be used.
In addition, even if the key receiving parts are worn or deformed, only the parts need be replaced, and it is not necessary to replace the entire cutter body unlike the conventional direct key groove type pin milling cutter, which is economical.

At one end of the receiving plate on the side where the key is to be inserted, a step which is slightly retracted is provided to promote the guiding of the key, and the small clearance between the key and the key groove ensures smooth fitting. It was done.

[0009]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an example in which an embodiment of the present invention is applied to an internal type pin milling cutter 1 and showing the whole. Since the cutter structure is not directly related to the present invention, only the outline thereof will be described.
The throw-away tip 3 arranged in combination along the inner peripheral portion of the hollow disk-shaped cutter body 2 so that the rotation locus of the cutting edges totally composes the pin portion shape of the crankshaft is provided with the screw 4
It is fastened and fixed to the cutter body 2. Further, on the outer circumference of the cutter main body 2, key grooves 5 which are fitted into a key of a machine tool and driven to rotate are equally arranged at four positions.

2 to 4 are partial views of the vicinity of the key groove 5, in which the key receiving component 6 is mounted. Details of the key receiving part 6 are shown in FIGS. The key receiving component 6 is basically formed by a receiving plate 7 and a mounting plate 9 which is orthogonal to the receiving plate 7 and protrudes rearward from a part of the rear surface 8. The mounting plate 9 has a mounting hole 10 penetrating therethrough. There is. On the other hand, at one end of the upper surface 11 of the receiving plate 7, the upper surface 11
A stepped surface 12 is provided that retreats slightly. The stepped surface 12 is provided on the side of the machine tool that serves as a key insertion opening, and facilitates the guiding and insertion of the key. In order to promote smooth induction and maintain the performance as a key,
The size of the step is preferably in the range of 0.01 to 0.05 mm.

As the material of the key receiving part 6, not only hardened steel but also various materials such as high speed steel, cemented carbide and ceramics having high hardness and excellent abrasion resistance and deformation resistance can be used.

The key receiving component 6 as described above is assembled as a set of two differently handed members so as to face the groove 13 of the cutter body 2. In this installation, the mounting plate 9 is brought into contact with the notch step portion 14 provided in series with one end of the groove 13, and the mounting plate 9 is inserted through the mounting hole 10.
It is performed by tightening screws from the end face side of the cutter body 2 with bolts 15. The width of the key groove 5 is adjusted by the width of the groove 13 or the thickness of the receiving plate 7 so that the gap between the upper surfaces 11 of the two facing receiving plates 7 becomes a predetermined width.

[0014]

With the above-mentioned structure, it is possible to arbitrarily select a material having excellent wear resistance and deformation resistance for the key groove portion. By improving the wear resistance and deformation resistance of the key groove, the initial assembling accuracy of the cutting edge can be maintained for a long time, so good machining accuracy and extension of tool life can be achieved. In addition, when the key receiving parts are worn or deformed, only the parts need be replaced, and it is not necessary to replace the entire cutter body as in the conventional direct key groove type pin milling cutter, which is economical.

Since the step of slightly retracting is provided at one end of the receiving plate on the side where the key is inserted, the key is easily guided, and even if the clearance between the key and the key groove is small, The mating will be performed smoothly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a pin milling cutter of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a front view of the vicinity of the key groove in FIG.

FIG. 4 is a plan view of FIG. 3;

5 is a front view of the key receiving component used in FIG. 1. FIG.

FIG. 6 is a plan view of FIG.

FIG. 7 is a side view of FIG.

[Explanation of symbols]

 1 Pin milling cutter 3 Throw-away tip 5 Key groove 6 Key receiving part 7 Receiving plate 9 Mounting plate 12 Step surface

Claims (3)

[Claims] 1. A key and a keyway 5 provided on a spindle of a machine tool.
In the pin milling cutter 1 that is driven to rotate by being fitted with, the key receiving component 6 can be screwed and fixed to both wall portions of the groove 13 that is widely arranged in the cutter body 2 for replacement. A pin milling cutter in which the key groove width is formed by the space between the upper surfaces 11 of the receiving plates 7 of the key receiving components 6 that are opposed to each other. 2. The key receiving component 6 is composed of a receiving plate 7 forming a wall surface of the key groove 5 and a mounting plate 9 projecting rearward from a part of a back surface 8 of the receiving plate 7, and is attached to the cutter body 2. The notch step portion 14 connected to one end of the provided groove 13 is brought into contact with the mounting plate 9, and from the end face side of the cutter body 2 via the mounting hole 10 formed in the mounting plate 9. The pin milling cutter according to claim 1, wherein the pin milling cutter is configured to be screwed and fixed. 3. An upper surface 11 of the receiving plate 7 forming the key groove 5.
At the one end on the side where the key is inserted,
Step surface 12 retracted from the upper surface 11 by 1 to 0.05 mm
The pin milling cutter according to claim 1 or 2, wherein the pin milling cutter is provided.