JP2501134Y2 - Chuck - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a chuck for a cutting tool such as an end mill.

[Conventional technology]

As shown in FIGS. 4 and 5, the conventional supporting means for a chuck for a cutting tool has a plurality of screws which are screwed into the chuck 1 after inserting a straight shank 4 of a cutting tool 3 into a straight hole 2 of the chuck 1. The straight shank 4 is pressed into the straight hole 2 while the bolts 5 are screwed in respectively.

A flat surface portion 6 is provided on the outer peripheral surface of the straight shank 4 along the axial direction, and the tip of the bolt 5 is brought into contact with the flat surface portion 6.

[Problems to be Solved by the Invention] If the straight shank of the cutting tool does not have a flat surface portion, it cannot be supported by the chuck. Therefore, the shank must be cut to provide the flat surface portion.

 Therefore, there is a problem that it takes time.

Further, when the shank is inserted into the straight hole, the bolt and the flat surface portion are opposed to each other, which is troublesome.

Further, since the tip surfaces of a plurality of bolts arranged on the axis of the chuck are brought into contact with the flat surface portion and the shank is pressed against the straight hole, the pressing portion has a narrow contact surface X between the bolt and the flat surface portion of the shank, and a straight surface. It supports at two points, the contact point Y between the hole wall facing the bolt and the shank, and because the area supporting the shank is small, vibration is likely to occur during heavy cutting. There is a problem that it cannot be absorbed and a chattering phenomenon may occur, and seizure occurs between the substrate and the shank at the Y portion where the pressure is concentrated, so that the shank cannot be removed smoothly.

In addition, when the shank is pressed down with a bolt, the rotational force of the bolt is directly transmitted to the shank and tends to bend the shank, which is not preferable in terms of chucking deflection accuracy.

Therefore, an object of the present invention is to provide a chuck that can absorb vibration and perform heavy cutting, and that does not require a flat surface portion on the shank.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention is directed to a base body having a shank portion at its end, a straight hole provided inward from the center of the tip surface of the base body, and an axial direction of the base body in the hole wall of the straight hole. A groove provided along with, a pressing pad fitted into the groove by providing a concave arc surface closely contacting the straight shank of the cutting tool on the surface, and allowing the radial sliding of the pressing pad in the groove, A retaining means for preventing the pressing pad from falling out of the groove, and a plurality of bolts screwed into the base body so that the back end of the pressing pad contacts the back surface of the pressing pad. The bolt is formed to have a size that covers approximately one-third, and the bolts are arranged so as to come into contact with both circumferential ends of the back surface of the pressing pad on at least the same circumference.

[Action]

To support the cutting tool on the chuck, the straight shank of the cutting tool is inserted into the straight hole, and then the pressing pad is pressed against the outer periphery of the shank while screwing the respective bolts to support the shank of the cutting tool on the substrate.

In this case, the bolt presses both ends of the pressing pad to press the both ends to the straight shank of the cutting tool, and the crimp presses the straight shank to the surface of the straight hole. As a result, the straight shank is supported at at least three positions in the circumferential direction between the press pad and the straight hole, and is securely fixed.

When removing the cutting tool, loosen each bolt to release the pressing pad from the pressing pad, and pull out the shank of the cutting tool from the straight hole.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In the figure, 11 is a base having a shank portion 12 at its end, and a straight hole 13 is provided inward from the center of the front end surface of the base 11.

Further, the hole wall of the straight hole 13 has a predetermined width,
A groove 14 is provided along the axial direction of the base 11.

The above-mentioned groove 14 is formed in the base 11 as shown in FIGS.
The tip surface of the tool is opened and the cutting tool A (not shown)
The straight shank a inserted into the straight hole 13 has a length close to the substantially entire length.

Further, a pressing pad 16 having a concave arcuate surface 15 which is in close contact with the outer periphery of the shank a is fitted into the groove 14.

As shown in FIG. 2, the concave arcuate surface 15 of the presser pad 16 is approximately 3 times the peripheral surface of the straight shank a of the cutting tool.
It is formed in a size of about one-third.

The pressing pad 16 is allowed to slide in the radial direction, and is prevented from falling out of the groove 14 by the retaining means.

As shown in FIG. 1, the above-mentioned retaining means has a recessed hole 17 in the axial direction from the outer peripheral surface of the base body 11, and a through hole through which the central portion of the bottom surface of the recessed hole 17 communicates with the straight hole 13. 18 is provided, the bolt 19 dropped into the recessed hole 17 is passed through the through hole 18, and the tip of the bolt 19 is screwed into the pressing pad 16, and the bolt 19 is attached to the outside of the bolt 19 as shown in the drawing. When both ends of the fitted spring 20 are brought into contact with the head of the bolt 19 and the bottom of the recessed hole 17 and the pressing pad 16 is drawn toward the bottom of the groove 14, the shank a to be inserted and the pressing pad 16 are inserted. It is possible to eliminate the problem of difficult insertion due to collision with.

Further, a plurality of bolts 21 whose tips are in contact with the back surface of the pressing pad 16 are screwed into the base 11.

As shown in FIG. 1 and FIG. 2, two bolts 21 are arranged on the same circumference, and the two bolts 21 and 21 are arranged on both sides of the back surface of the pressing pad 16 in the circumferential direction. It comes in contact with the part.

Although four bolts 21 are arranged in the illustrated case, two or six bolts may be arranged.

In addition, as shown in the drawing, the width of the opening of the groove 14 is set to the straight hole 13
If it does not exceed half the circumference, the straight hole 13 will hold more than half the circumference of the shank a for stability.

In the figure, 22 is a screw hole into which the bolt 21 is screwed, and 23 is a concave arc surface.
15 is a mesh-shaped groove for slip prevention and oil draining.

The chuck according to the present invention is configured as described above, and after inserting the straight shank a of the cutting tool A into the straight hole 13, the bolts 21 are screwed in to press the pressing pad 16 onto the outer periphery of the shank a to form the base 11 Cutting tool A
Support the shank a.

When the bolt 21 is tightened in this manner, both ends of the pressing pad 16 are crimped to the straight shank a, and the straight shank a is crimped to the wall of the straight hole 13 and is supported at at least three positions in the circumferential direction.

When removing the cutting tool, each bolt 21 is loosened to release the pressing pad 16 from the shank a and then pulled out from the straight hole 13.

〔effect〕

According to the chuck according to the present invention described above, since the concave arcuate surface of the pressing pad is brought into close contact with the outer periphery of the shank to press the shank, it is not necessary to process the flat surface portion on the shank.

Further, since both ends of the pressing pad are crimped to the straight shank of the cutting tool by the bolts and the shank is held between at least two surface points of the pressing pad and the hole wall of the straight hole, at least the shank should be held. It can be supported at three places and the cutting tool can be stably and firmly held.

Therefore, vibration can be absorbed to avoid the chattering phenomenon, and heavy cutting can be performed.

Further, it is possible to prevent seizure such as a shank having a flat surface portion.

Further, since the rotational force of the bolt when tightening the shank is absorbed by the pressing pad that is elastically deformed by the bolt, the chucking deflection accuracy is improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a chuck according to the present invention, FIG. 2 is a front view of the same as above, FIG. 3 is a perspective view of a presser pad, FIG. 4 is a vertical sectional side view of a conventional product, and FIG. It is a front view. 11 …… Base, 12 …… Shank part, 13 …… Straight hole,
14 ... Groove, 15 ... Recessed arcuate surface, 16 ... Presser pad, 21 ...
…bolt.

Claims (1)

(57) [Scope of utility model registration request] 1. A base having a shank portion at its end, and a straight hole provided inward from the center of the tip surface of the base,
A groove provided along the axial direction of the base body on the hole wall of this straight hole, a press-fitting pad fitted on the groove by providing a concave arcuate surface close to the straight shank of the cutting tool on the surface, and a presser foot in the groove. The pad comprises a retaining means for allowing the pad to slide in the radial direction and preventing the pressing pad from falling out of the groove, and a plurality of bolts screwed into the base body so that the tip of the pressing pad contacts the back surface of the pressing pad. The pressing arcuate surface of the presser pad is formed to have a size that covers approximately one-third of the circumference of the straight shank, and the bolts are brought into contact with both ends of the back surface of the presser pad in the circumferential direction on at least the same circumference. Arranged in a chuck.