JPS641241B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cutting tool in which a head provided with a cutting edge is detachably attached to a holder.

[Conventional technology and issues to be solved]

Conventional cutting tools had a head with a cutting edge formed integrally with a holder, so the entire tool had to be replaced each time the type of cutting process changed. It takes time, requires a large space to store tools, and is heavy, which poses a problem in terms of safety during replacement work.

SUMMARY OF THE INVENTION Accordingly, a primary object of the present invention is to provide a cutting tool which solves the above-mentioned problems by forming a head and a holder separately and attaching the head to the holder in a detachable manner. A second object of the present invention is to provide a cutting tool that allows the head to be attached and detached easily and accurately.

[Means to solve the problem]

In order to solve the above problems, this invention
A cutting tool in which a head with a cutting edge is formed separately from a holder, and a shaft protruding from the head is inserted into a fitting hole provided in the holder to fix the head and holder together, Concave portions and convex portions having a constant width in the circumferential direction are alternately formed on the outer periphery of the shaft portion, and also on the inner circumference of the fitting hole, corresponding to the concave portions and convex portions and having the same width as these. A concave portion and a convex portion are provided, and the width of the convex portion of the shaft portion is narrower than the width of the concave portion of the fitting hole, and the two convex portions are formed to have a protrusion amount that allows them to come into close contact with each other. A notch having a bottom parallel to the plane including the axis and the diameter is provided, and the shaft is inserted into the fitting hole and the shaft and holder are relatively rotated by a certain angle θ. A clamp member that engages with is provided on the holder, a flat surface is formed continuously at one end in the circumferential direction of the shaft portion of the notch, and the angle formed between the flat surface and the bottom surface of the notch is equal to the constant angle θ. The configuration is set as follows.

[Effect]

After inserting the head by aligning the protrusion on the outer periphery of the head shaft with the recess on the inner circumference of the holder fitting hole, the head is relatively rotated by a certain angle θ to position the former protrusion in close contact with the latter protrusion. Thereafter, the clamp member is tightened and its tip is pressed against the notch, and the head is pulled in and clamped.

When replacing the head, after loosening the clamp member, rotate the head relatively by a certain angle θ, so that the convex part faces the concave part of the holder, and the tip of the clamp member is positioned on the flat surface of the shaft part. Remove the head in this condition.

〔Example〕

The present invention will be described below based on embodiments shown in the accompanying drawings.

The embodiment shown in the drawings is an example in which the present invention is applied to a boring tool, in which a head 1 and a holder 2 are formed separately as shown in FIG.
can be detachably attached to the holder 2. The head 1 is equipped with a cutting blade 3 at its tip, and has a large-diameter shaft portion 4 and a small-diameter shaft portion 5 protruding from its rear end surface in two stages. In addition, a large-diameter fitting hole 6 and a small-diameter fitting hole 7 are provided on the tip surface of the holder 2.
are formed in two stages, and the above-mentioned shaft parts 4 and 5 are inserted into these fitting holes 6 and 7.

As shown in FIGS. 2 and 4, the large-diameter shaft portion 4 of the head 1 has convex portions 8, 8 formed at axially symmetrical positions on its outer peripheral surface over an angular range slightly smaller than 90 degrees. Recesses 9, 9 are formed between each convex portion 8, 8 over an angular range slightly larger than 90 degrees. That is, a pair of convex portions 8 and a concave portion 9 having a constant width are formed on the outer periphery of the shaft portion 4 at opposing positions of 180°, and the width of the convex portion 8 is formed to be narrower than the width of the concave portion 9.

Also, in the large-diameter fitting hole 6 of the holder 2, as shown in FIG. 3 and FIG.
1 are formed in pairs at opposite positions of 180 degrees, with a convex portion 8 of the head 1 and a convex portion 10 of the holder 2.
are formed so that they closely fit and match each other. From the state where the protrusion 8 and the protrusion 10 match, the holder 2
However, when the head 1 is rotated approximately 90 degrees, the protrusions 8, 8 of the head 1 are narrower than the recesses 11, 11 of the holder 2, so the protrusions 8, 8 overlap the recesses 11, as shown in FIG. , 11.

A notch 12 is provided in the small diameter shaft portion 5 of the head 1 . The rear wall surface 13 of the wall surfaces in the axial direction of the small diameter shaft portion 5 forming the notch portion 12 is
As shown in Figure 1, it is tilted backwards. The bottom surface of the notch 12 has a surface parallel to a plane P including the axis and diameter of the small diameter shaft section 5, as shown in FIG.

An inclined through-screw hole 14 is provided at a position facing the notch 12 of the small diameter shaft portion 5 with the convex portion 8 and the convex portion 10 aligned, and the tip of the fixing screw 15 screwed into the screw hole 14 is inserted as described above. It is made to face the inclined wall surface 13 of. By screwing the fixing screw 15 deeply, the head 1 can be pulled toward the holder 2, so that the rear end surface of the head 1 and the front end surface of the holder 2 come into close contact, and the head 1 is clamped to the holder 2.

A flat surface 16 is formed on the side surface of the small diameter shaft portion 5 by partially cutting a portion of the shaft peripheral surface. This flat surface 16 is at a constant angle θ with the bottom surface of the notch 12.
(90° in the illustrated case), and one circumferential end of the small diameter shaft portion 5 of the notch 12 is continuous with the flat surface 16 via an arcuate surface 12' having a required curvature. Therefore, when the fixing screw 15 is slightly loosened and the head 1 is rotated approximately 90 degrees relative to the holder 2 in the direction of the arrow in FIG. reach. At the same time, the protrusions 8, 8 of the head 1 are loosely fitted into the recesses 11, 11 of the holder 2, as shown in FIG. 5, so that the head 1 can be easily removed. In addition,
When installing head 1, this procedure can be reversed.

Further, as shown in FIG. 2, the rear end surface of the head 1 is formed with a circular arc groove 17 extending over an angle range of approximately 90 degrees, and the distal end surface of the holder 2 is provided with a third groove.
As shown in the figure, the pin 1 that fits into the groove 17 described above
8 is provided protrudingly, and is fixed with a machine screw 19. By fitting the groove 17 and the pin 18, it is possible to position the head 1, and when the head 1 is fixed to the holder 2, the pin 18 is inserted into one end of the arcuate groove 17 as shown by the chain line in FIG. Head 1 when subjected to cutting force by engaging
We are trying to stop this from happening again.

In addition, in the above embodiment, the fixing screw 15
is inserted obliquely so that its distal end surface engages with the inclined wall surface 13 of the notch 12.As shown in FIG. However, this screw 15 may be screwed in in a direction perpendicular to the axis so as to engage with the inclined surface 13 of the notch 12. Also, the above fixing screw 1
5, an eccentric cylindrical cam 21 is incorporated as shown in FIG.
The head 1 may be retracted by engaging the head 1 and rotating the cam 21 from the outside. In short, by fixing one end of the clamp member such as the screw 15 and cam 21 to the holder 2 and engaging the other end with the notch 12 of the head 1, it is possible to prevent the head 1 from coming out and to draw it in. It is sufficient if the head 1 can be fixed to the holder 2 by the above-mentioned method.

〔Effect of the invention〕

As described above, in this invention, the head and holder are formed separately, and the head is detachably attached to the holder. Therefore, when changing the cutting mode, only the head needs to be replaced. In addition to being able to be replaced quickly, it is only necessary to store the required types of heads, which are significantly smaller than the entire tool, so the storage space is small and work safety is improved. In addition, at the fitting portion of the head and holder, due to the corresponding structure of the concave and convex portions formed on the mating surfaces of both, wobbling can be prevented by the convex portions coming into close contact with each other, and the head can be rotated by the required angle. Since the concave portion and the convex portion fit loosely, it can be easily inserted and removed.

In addition, by connecting the notch on the small diameter shaft of the head to the flat surface on the side of the shaft, it is possible to disengage the clamp member such as a screw by slightly retracting it, allowing quick replacement. can do.

[Brief explanation of drawings]

Fig. 1 is a vertical front view, Fig. 2 is a right side view of the head, Fig. 3 is a longitudinal left side view of the holder, Fig. 4 is a sectional view taken along the - line in Fig. 1, and Fig. 5 is a loosely fitted state. FIG. 6 is a left side view, and FIGS. 7 and 8 are partially omitted longitudinal sectional front views of other embodiments. 1... Head, 2... Holder, 3... Cutting blade,
4... Large diameter shaft part, 5... Small diameter shaft part, 6... Large diameter fitting hole, 7... Small diameter fitting hole, 8, 10... Convex part,
9, 11... recess, 12... notch, 13... inclined wall surface, 14... screw hole, 15... screw, 16...
...Flat surface, 21... Eccentric cylindrical cam.

Claims (1)

[Scope of Claims] 1. A head equipped with a cutting edge is formed separately from a holder, and a shaft portion protruding from the head is inserted into a fitting hole provided in the holder to fix the head and holder together. In such a cutting tool, recesses and protrusions having a constant width in the circumferential direction are alternately formed on the outer periphery of the shaft, and the inner periphery of the fitting hole also corresponds to the recesses and protrusions, respectively. In addition, a concave portion and a convex portion having the same width as these are provided, and the width of the convex portion of the shaft portion is narrower than the width of the concave portion of the fitting hole, and the protrusion amount of both convex portions is such that they can come into close contact with each other. A notch portion having a bottom surface parallel to a plane including the shaft center and the diameter is provided in the shaft portion, the shaft portion is inserted into the fitting hole, and the shaft portion and the holder are relatively rotated by a certain angle θ. The holder is provided with a clamp member that engages with the notch in the above-mentioned state, and a flat surface is formed continuously at one end of the notch in the circumferential direction of the shaft, and the angle between the flat surface and the bottom surface of the notch is set as described above. A cutting tool characterized in that the cutting tool is set to be equal to a constant angle θ. 2. The cutting tool according to claim 1, wherein the clamp member is formed by a screw screwed into the holder, and the tip of the screw is engaged with the inclined wall surface of the notch. 3. The clamping member is formed by an eccentric cylindrical cam built into a holder, and the cam is engaged with a curved wall surface of the notch in the axial direction of the shaft. The cutting tool according to item 1.