JP2000254806A - Throw away type cutting tool's clamp structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact clamp structure that can attach and detach a cutting tip to/from a small-sized throw away cutting tool installed in an automatic lathe from a back face side. SOLUTION: In this clamp structure, a presser piece 8 is buried in the slide hole 5 provided from the front face 3 to the back face 4 of a cutting tool body 1. The cutting tool body 1 and the presser piece 8 are continuously connected to each other through a crosswise threaded clamp screw 12, and the presser piece 8 can slide along the slide hole 5. In this case, the clamp screw 12 is formed in such a way that the diameter of the section threadedly engaged with the presser piece 8 is made small and threaded at a large pitch, and the diameter of the section threadedly engaged with the cutting tip body 1 is made large and threaded at a small pitch. Following the operation of the clamp screw 12, the protrusion 9 of the presser piece 8 quickly fastens and loosens a cutting tip 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp structure of a throw-away type cutting tool, and more particularly to a clamp structure suitable for use in an automatic lathe.

[0002]

2. Description of the Related Art The most compact and simple clamping structure of a cutting edge tip in a small indexable cutting tool used by being mounted on an automatic lathe or the like is by screwing. However, as shown in FIG. 4, in many cases, the automatic lathe is mounted on the tool post in parallel at narrow intervals like teeth of a comb. In such a case, it is difficult for the screw clamp to replace the cutting tip with the cutting tool attached to the tool post, and there is also a problem that the removed screw is lost. Therefore, recently, there has been provided on the market a cutting tool that can be attached and detached from the back surface of the cutting tool by lever clamp or pin pull-in.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a small-sized cutting tool which can be operated from behind. The lever clamp structure reduces the clamping efficiency because the direction in which the cutting edge tip should be pressed and the direction in which the lever part is retracted do not match, or depending on the type of cutting tool, the outer dimensions become a special shape that deviates from international standards However, there is a problem that the return of the lever component when the clamp is loosened is slow and it is difficult to remove the cutting edge tip. The pink lamp structure has a problem that a pin must be pulled out like a screw. The present invention has been studied including the solution of such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a tip seat provided at one end of a bar-shaped cutting tool body. A cutting-away tip with a mounting hole drilled in the center is placed, and the cutting edge tip is pressed into contact with the tip seat by the projection of the holding piece inserted into this mounting hole and fixed there. In the clamp structure of the cutting tool,
The body of the holding piece is buried in the slide hole going from the front to the back of the bite body, the tool body is provided with a slide hole going from the front to the back, and the body of the holding piece is threaded in a right and left manner. The tightening screw is connected to the cutting tool body and slidably buried in the slide hole.The tightening screw is screwed to the holding piece with a small diameter screw and screwed to the cutting tool body. It is formed in a large-diameter screw, and it is characterized in that the tightening and loosening of the cutting blade tip can be loosened by turning the tightening screw from the back side of the cutting tool body. Further, the tightening screw is characterized in that a screw pitch of the screwing portion with the holding piece is formed larger than that of a screwing portion with the tool body.

In such a clamp structure, since the cutting edge tip can be set in the retraction direction corresponding to the direction in which the cutting edge tip is to be pressed against the wall surface of the tip seat, the loss of the clamping force is small, and various cutting shapes are available. Can be applied and has high applicability. Since the clamp structure is compact, the outer dimensions of the cutting tool can be configured without deviating from international standards.

The screwing portion of the tightening screw with the tool body has a large diameter, and a wrench hole for operation is provided on the end surface thereof. The screwing part with the holding piece has a small diameter to accommodate downsizing, and the large screw pitch on the large diameter side is small, so the holding piece slides greatly with a small turning operation of the tightening screw. As a result, a movement that reliably follows the loosening can be achieved.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, a tip seat 2 is attached to one end of a square shank tool body 1.
Are arranged. The lower part of the chip seat 2 has a sliding hole 5 in a direction from the front surface 3 to the back surface 4 of the cutting tool body 1.
Are drilled up to the middle part, and the fastening screw hole 6 penetrates continuously therethrough. The screw in the tightening screw hole 6 is cut to the left. On the other hand, a slide groove 7 is provided between the bottom surface of the chip seat 2 and the slide hole 5 in a direction coinciding with the axial direction of the slide hole 5.

FIG. 3 shows a holding piece 8 buried in a slide groove 7, and a projection 9 is provided on the outer peripheral surface of a cylindrical body. In addition, a fitting protrusion 10 is formed at the base end so as to fit with the slide groove 7. The inner peripheral surface of the cylindrical body is formed with a tightening screw hole 11 and is right-hand threaded. The size of each part is such that the diameter of the tightening screw hole 6 of the cutting tool body 1 is equal to or less than the diameter of the slide hole 7, and the diameter of the tightening screw hole 11 of the holding piece 8 is the It is formed smaller than the diameter. The screw pitch of the cutting tool body 1 is formed smaller than the screw pitch of the holding piece 8.

The tightening screw 12 is provided with the tightening screw holes 6, 11.
And a wrench hole 13 is provided on the large-diameter end face. This tightening screw 12
Are screwed together with both the cutting tool body 1 and the holding piece 8. Wrench hole 1 from back 4 side of tool body 1
If you insert a wrench into 3 and turn right, the holding piece 8
The sliding groove 7 and the fitting projection 10 slide in the direction of the back surface 4 while being fitted. On the tip seat 2, a cutting edge tip 15 having a mounting hole 14 in the form of a flat plate is placed at the center, and the cutting edge tip 15 is inserted into the mounting hole 14 so that the cutting edge tip 15 becomes a wall surface of the tip seat 2. And is pressed and fixed. At this time, the projection 9 may be formed by slightly bending in a direction to embrace the wall surface of the mounting hole 14. When the wrench is turned to the left, the protrusion 9 moves in a direction away from the wall surface of the tip seat 2, and the cutting blade tip 15 can be easily removed.

[0010]

According to the present invention, a clamp structure of a throw-away type cutting tool having a very simple structure and capable of attaching and detaching the cutting blade tip from the back side of the cutting tool is realized. The compact structure eliminates the need to specially define the outer dimensions of the cutting tool, making it convenient to use on automatic machines. It has a high applicability to the blade shape, in which a clamping configuration can be made to match the direction in which the cutting edge tip is to be clamped, and there is no loss of clamping force. Tightening and loosening work reliably and quickly by devising the screw pitch of the tightening screw.

[Brief description of the drawings]

FIG. 1 shows a tip portion of a cutting tool according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view of a holding piece used in FIG.

FIG. 4 is an explanatory diagram of a use state of a cutting tool in an automatic lathe.

[Explanation of symbols]

 Reference Signs List 5 Slide hole 6 Tightening screw hole 7 Slide groove 8 Holding piece 9 Projection 10 Fitting protrusion 11 Tightening screw hole 12 Tightening screw 15 Cutting edge tip

Claims (2)

[Claims] 1. A tip seat is disposed at one end of a bar-shaped cutting tool body, and a cutting edge tip having a flat plate shape and having a mounting hole formed at a center portion is mounted on the tip seat. In a clamp structure of a throw-away type bite configured to press and fix a cutting edge tip to a tip seat by a projection of a holding piece inserted into a hole, the bite body has a slide hole extending from a front surface to a rear surface. The main body of the holding piece is connected to the tool body by a fastening screw which is screwed in a right and left direction and is slidably embedded in the slide hole, and the fastening screw is screwed with the holding piece. The part to be screwed is formed into a small diameter screw, and the part to be screwed with the tool body is formed into a large diameter screw, so that the cutting tip can be loosened by turning the tightening screw from the back side of the tool body. The clamp structure of a throw-away type cutting tool, characterized in that 2. The throw-away type according to claim 1, wherein the screw pitch of the fastening screw with the holding piece is larger than that of the fastening screw with the cutting tool body. Tool clamp structure.