JPH0314252Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw member for press-fitting a tapered member between a shell-type milling cutter having a tapered attachment hole in the center when attaching it to a milling arbor.

In general, shell-type milling cutters that are attached to a milling arbor have poor attachment to the milling arbor compared to those with an integrated blade and shank, and as a result, various cutting performances are inferior. However, when the size of the milling cutter is large, it is expensive to manufacture an integrated milling cutter, and when the blade part wears out, the shank part must be replaced, which is extremely uneconomical. A shell-type milling cutter is used in which only the parts can be replaced. The conventional method for attaching the replaceable shell-type milling cutter to the milling arbor is to screw a left-hand thread into the mounting shaft of the milling arbor and the mounting hole of the shell-type milling cutter, and then attach the two by screwing them together. However, neither of these methods is necessarily satisfactory compared to an integrated type, and from this point of view, the present inventor proposed "Patent Application No. 005771 of 1988". proposed an installation method for a shell-type milling cutter with performance similar to that of an integrated type.The installation method involves attaching a tapered cutter that is appropriately larger than the installation shaft to the installation shaft of a milling arbor whose tip is formed into a straight step. A mounting method in which a shell-type milling cutter drilled in the center of a mounting hole is loosely fitted, and a tapered member is press-fitted between the mounting shaft and the mounting hole using a screw member to fix the shell-type milling cutter to a milling arbor. Based on this, it is an object of the present invention to provide a screw member into which the tapered member can be reliably and easily press-fitted or pulled out.

Hereinafter, embodiments of the present invention will be described based on the drawings. A is a screw member, 1 is a cylindrical head, and 2 is a screw member.
is the threaded part. Further, a tapered groove 1a is formed on the side peripheral surface of the head 1, and a hexagonal hole 1b is formed on the end surface. The shape of the tapered groove 1a may be either one-sided or both-sided, but it is preferably tapered on both sides. Also, the taper degree is 20° ~
Although the angle is within the range of 45°, it is not limited thereto. Reference numeral 3 denotes a tapered member having a tapered outer surface and a straight inner surface, and a tapered protruding peripheral portion 3a that fits into the tapered groove 1a of the screw member A in the inner circumferential direction of the thick end. is forming. Reference numeral 4 designates a shell-type milling cutter having a tapered mounting hole 4a that expands downward in the center and a keyway 4b for preventing rotation at the upper end. Reference numeral 5 denotes a milling arbor having a mounting shaft 5a having a straight stepped portion at its tip and a locking key 5b protruding from the stepped portion, and a screw hole 5c is screwed into the mounting shaft 5a.

Next, how to use the present invention will be explained. First, the mounting hole 4a of the shell-type milling cutter 4 is loosely fitted into the mounting shaft 5a of the milling arbor 5, and the key groove 4b for preventing rotation of both is also fitted.
Next, the protruding peripheral portion 3a of the tapered member 3 divided into two pieces is fitted into the tapered groove 1a of the threaded member A of the present invention, and the tapered member 3 is engaged with the threaded member A in a ringed state. In this state, if the taper member 3 is inserted into the gap between the mounting shaft 5a and the mounting hole 4a and the screw member A is also screwed into the screw hole 5c of the mounting shaft 5a, insert a hexagon wrench into the hexagon hole 1b of the screw member A.
When the tapered member 3 engaged with the screw member A is strongly pushed and press-fitted by the screw member A, the shell-type milling cutter 4 is firmly attached to the milling arbor 5. Furthermore, when removing the shell-type milling cutter 4 from the milling arbor 5, by loosening the screw member A with a hexagonal wrench, the taper member 3, which was firmly press-fitted, can also be easily pulled out, making it extremely easy to remove. can. Also, when the taper member 3 is press-fitted or pulled out, a considerable force is applied to the head 1 of the screw member A and the protruding peripheral portion 3a of the taper member 3, making it easy to deform. However, the length of the head 1 of the screw member A is limited. In other words, it is better for the tapered member 3 to be in direct contact with the mounting shaft 5a of the milling arbor 5 in terms of mounting accuracy and strength, and for this reason, the head 1 of the screw member A cannot be made too long.
Therefore, when forming a straight groove in the short head 1, the protruding peripheral part 3a of the tapered member 3 is also formed straight, and if the groove is narrow, the head 1 is strong, but the protruding peripheral part of the tapered member 3 that engages with it is strong. 3a becomes weaker,
On the other hand, if it is widened, the protruding peripheral portion 3a of the tapered member 3 will be strong, but the head 1 of the screw member A will be weak and will not hold up. Therefore, in the present invention, this groove is called a tapered groove 1a.
By forming the head 1 of the screw member A, even if the length of the head 1 of the screw member A is reduced, the base portions of both the head 1 of the screw member A and the protruding peripheral portion 3a of the tapered member 3 are wider than the tips, resulting in structural problems. It can have satisfactory strength. In addition, when the taper member 3 is press-fitted, since the taper member 3 and the head 1 are tapered, they are in close contact with each other to prevent chatter during heavy cutting, and the reaction force from the taper member 3 that engages with the taper groove 1a As a result, a strong force is applied to the screw member A, which has the effect of preventing it from loosening.

As described above, the present invention allows the taper member 3 used when attaching the shell-type milling cutter 4 to the milling arbor 5 to be firmly and securely press-fitted, and enables the installation state to be almost the same as that of an integrated milling cutter. Moreover, it is extremely easy to remove and greatly improves the workability of milling work.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, a is a side view,
b is a front view, and FIG. 2 is a usage state diagram. A... Screw member, 1... Head, 1a... Tapered groove, 1b... Hexagonal hole, 4... Shell type milling cutter, 4a... Mounting hole, 5a... Mounting shaft, 5
...Flying Arbor.

Claims (1)

[Scope of utility model registration request] A bolt-shaped screw member A is used to press fit a taper member 3 used when attaching a shell-type milling cutter 4 having a tapered attachment hole 4a to an attachment shaft 5a of a milling arbor 5.
A screw member for attaching a shell-type milling cutter, characterized in that the head 1 of the head 1 has a tapered groove 1a formed on the side peripheral surface and a hexagonal hole 1b formed on the end surface.