JPH0550305A - Cutting tool - Google Patents

Abstract

PURPOSE:To make manufacture easy and also alignment of a shank and a head certain in a tool having such construction wherein a head made of steel and the like is provided on the top end of the shank made of cemented carbide and the like. CONSTITUTION:This is a cutting tool wherein a projecting part 21 is provided in either one of a shank 1 and a head 2 and a recessed part 20 in the other one and, at the same time, a screw member 22 is housed in the recessed part 20, and the projecting part 21 is screwed into this screw member 22, and, at the same time, the screw member 22 is made movable within a specified range in axial and circumferential directions with respect to the member on one side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting tool, and more particularly to a tool for connecting a head and a shank with a screw.

[0002]

2. Description of the Related Art FIGS. 5 to 7 show a conventional example of a cutting tool. This cutting tool comprises a shank 1 attached to a chuck of a machine tool and a head 2 fixed to the tip of the shank 1, and a throwaway tip 3 is fixed to the tip of the head 2 by a screw 4. Has been done. The shank 1 is made of a high-hardness cemented carbide to prevent bending and chattering.
The head 2 is made of a material such as steel in consideration of workability. The shank 1 and the head 2 are joined to each other via a brazing part 5.

[0003]

Since the shank 1 and the head 2 are brazed to the tool of the above-mentioned conventional example, a new head can be used, for example, when the application is changed or the head portion is damaged. Even if an attempt is made to replace it, there is a problem that the replacement is not easy.

Therefore, it is conceivable to make the shank 1 and the head 2 detachable, but there has been no means for accurately positioning the head 2 with respect to the shank 1 and for detachably coupling them.

Therefore, it is conceivable to adopt a structure in which the shank and the head are connected by a screw, but in this case, when the shank is made of cemented carbide, the screwing is not easy and the workability is taken into consideration. If the threaded portion is formed as a separate member, a new step of brazing the threaded component to the shank is required.

The present invention has been made in view of the above circumstances, and an object of the present invention is to obtain a cutting tool in which the head can be replaced and the positioning of the head and the shank is good.

[0007]

In order to achieve such an object, the invention according to claim 1 of the present application is a cutting tool comprising a head to which a cutting tool is attached and a shank supported by a machine tool. A convex portion is formed on one of the head and the shank, and a concave portion into which the convex portion is inserted is formed on the other member, and a screw is formed on the convex portion and the concave portion is formed. Includes a screw member into which the screw of the convex portion is screwed, with a radial interval between the screw member and the inner circumference of the concave portion, and the screw member does not move in the axial direction and the circumferential direction in the concave portion. The structure is restricted within a predetermined range.

[0008]

With the above structure, the one member can be detachably coupled by screwing the one member into the other member, and the screw member can move with respect to the other member. The members are positioned with respect to each other depending on the contact state between one member and the other member, without depending on the positional accuracy between the member and the screw.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the figure, the same parts as those of the conventional example are designated by the same reference numerals to simplify the description.

1 to 4 show a first embodiment of the present invention.

A recess 20 is provided at the tip of the shank 1, and a projection 21 is provided at the base of the head 2. The recess 20 is formed with the same axis as the shank 1, and a screw member 22 having a diameter smaller than the inner diameter of the recess 20 by Δr1 is inserted therein. A female screw 23 is formed on the screw member 22 along its radial direction, and a shank 1 has a shank 1 having a hole 24 having an inner diameter slightly larger than the root diameter of the female screw 23. 1 is formed in the radial direction. Then, the screw member 22 is inserted into the recess 20 to align the female screw 23 with the hole 24 in the circumferential direction, and the bolt 25 having a gap Δr2 is passed through the hole 24 and screwed into the female screw 23. As a result, the screw member 2
2 is supported in the concave portion 20, and the movement of the screw member 22 (movement in the axial direction of the shank 1, circumferential direction, and movement in the direction inclined with respect to the axial line of the shank 1) is caused by the bolt 25 and the hole. The size of the gap between the recess 24 and the recess 20
It is designed to be limited within a range determined by the size of the gap between the screw member 22 and the screw member 22. A flat surface 26 perpendicular to the axis of the shank 1 is formed at the tip of the shank 1.

On the other hand, a male screw 27 is formed on the outer periphery of the convex portion 21 provided integrally with the end portion of the head 2, and the male screw 27 is formed in the axial direction of the screw member 22 so that it is screwed. It is adapted to be screwed with 28. Further, at the base end portion of the convex portion 21, a flat surface 29 perpendicular to the flat surface including the tip 3 of the head 2 (or the surface of the receiving seat thereof) is formed.

A part of the side surface of the head 2 is chamfered to form a flat portion 30. By using this flat portion 30, the head 2 can be rotated using a tool. It has become.

The shank 1 is preferably made of a hard material such as a cemented carbide for the purpose of reducing flexure and chatter, but for other parts, a material such as tool steel is mainly considered in consideration of workability. Is preferred.

The work of attaching the head 2 to the shank 1 configured as described above is performed as follows.

First, the screw member 2 is inserted into the recess 20 of the shank 1.
2 is inserted, the female screw 23 is aligned with the hole 24, and further, the bolts 25 are screwed into the respective mesets 23 through the holes 24. In the embodiment, the two bolts 2
By inserting 5 up to the position where their tips contact each other, loosening is prevented.

Next, as shown by the arrow in FIG.
Is brought into contact with the tip of the shank 1 and a tool or the like is engaged with the flat portion 3 on the outer periphery of the head 2 to rotate the male screw 27.
It is screwed into the female screw 28. Here, the screw member 2
2, the rotation and the movement in the axial direction are regulated within a predetermined range, so that by rotating the head 2,
The head 2 is inserted into the shank 1 and goes. Further, the screw member 22 and the recess 20 have a radial clearance Δr.
1, the axis C ′ of the screw member 22 can be inclined at an angle θ with respect to the axis C of the shank 1 as shown in FIG.

That is, if the screw member 22 can move with respect to the concave portion 20, even if the axis line of the external thread 27 of the convex portion 21 has an error with respect to the head 2 (the surface of the chip 3), the shank. The relative positional relationship between 1 and the head 2 is
By inserting the convex portion 21 into the concave portion 20, the position in the radial direction is defined, and the contact with the flat surfaces 26 and 29 defines the position in the axial direction. Therefore, the flat surface 26 is formed exactly perpendicular to the axis of the shank 1, and the flat surface 28 is formed at the tip 3 of the tip of the head 2.
If the head 2 is formed perpendicularly to the (reception seat in the case of density reduction), the head 2 can be accurately positioned with respect to the shank 1, and is suitable for machining when the screw 27 is to be formed on the head 2. No exceptionally high precision is required.

In the case of the embodiment, the shank made of a difficult-to-machine material such as cemented carbide only needs to be machined on the outer shape and formed with the recesses 20 and the holes 24. It is possible to obtain a predetermined shape at the time of powder molding or by slight grinding processing without requiring special processing such as.

The present invention can of course be modified and implemented as follows.

A. The specific shape of the head or the throw-away tip attached to the head is not limited to the above-mentioned embodiment, and the structure of the present application is easy except for a turning tool such as an end mill where the phase between the head and the shank is a problem. Can be applied to.

B. The structure for fixing the screw member to the shank is not limited to the one using the screw as in the above embodiment, and for example, a pin is inserted in place of the screw in the screw member, and the pin of the screw member is inserted between the pin and the hole of the shank. A structure that restricts movement may be used.

C. In the above-described embodiment, the shank side is provided with the concave portion to accommodate the screw member, but conversely, the screw member is accommodated in the concave portion provided on the head side and the shank is inserted into the female screw of the screw member. You may make it screw the male screw of the tip.

[0024]

As is apparent from the above description, the present invention is
Since the screws provided on one of the shank and the head are screwed into the screws movably supported on the other to connect the two, the members can be connected to each other regardless of the accuracy of the screws with respect to the members. Both of them can be positioned depending on the accuracy of the contact surface. Therefore, there is an effect that the head can be easily replaced by using the common shank in accordance with the damage of the head or the change of the application.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of an embodiment of the present invention.

2 is a left side view of the tool of FIG. 1. FIG.

FIG. 3 is a front view of the tool of FIG. 1 with the head and shank disassembled. ..

4 is an enlarged vertical cross-sectional view of a connecting portion between a shank and a head of the tool shown in FIG.

FIG. 5 is a partial vertical cross-sectional view of a conventional example of a cutting tool.

6 is a left side view of the tool of FIG.

FIG. 7 is a plan view of the tool of FIG.

[Explanation of symbols]

 1 ... Shank 2 ... Head 3 ... Throwaway tip 20 ... Recessed portion 21 ... Convex portion 22 ... Screw member 23 ... Female screw 24 ... Hole 25 ... Bolt 26 ... Plane 27 ... Male thread 28 ... Female thread 29 ... Plane

Claims (1)

[Claims] 1. A cutting tool comprising a head to which a blade is attached and a shank supported by a machine tool, wherein one of the head and the shank has a convex portion and the other member has a convex portion. A concave portion into which the convex portion is inserted is formed, a screw is formed in the convex portion, and a screw member into which the screw of the convex portion is screwed is formed between the concave portion and the inner circumference of the concave portion. A cutting tool which is housed at intervals in a radial direction, and the movement of the screw member in the axial direction and the circumferential direction in the recess is restricted within a predetermined range.