JPH08267331A - Tool fastening mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a tool fastening mechanism that prevents accidental fastening. [Structure] A key engaging portion consisting of a key and a key groove provided at the end of the taper fitting portion is provided at two positions facing each other at a position where the phase is changed by approximately 180 °. The key engaging portions are formed so that the height of each key and the depth of the key groove are the same, and the combination width of the key and the key groove of the two key engaging portions is set to be the same. The tool fastening mechanism is formed so as to be different from each other, and the cutting edge of the cutting tool is always positioned and engaged at a fixed position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool fastening mechanism for connecting a cutting tool and a tool fastening mechanism for fastening and holding the cutting tool by taper fitting and positioning and fastening by key engagement. is there.

[0002]

2. Description of the Related Art In the case of a tool fastening mechanism in which a cutting tool is connected and fastened by taper fitting, generally the phase of the cutting edge is always kept at a fixed position when the cutting tool is fastened and fastened. Therefore, two key engaging portions are provided at the end of the taper fitting portion at a position where the phase is changed by 180 °, and both the key width and the key groove width are the same. The key engaging part is formed to have different lengths and key groove depths in the axial direction when the tape is fitted to the cutting tool. A tool fastening mechanism formed so that the cutting edge is always positioned at the same position is usually used.

[0003]

By the way, in the case of the fitting portion of the tool fastening mechanism of this type, the outer diameter and the key length of the reference position of the taper surface, the key groove depth, and the like are determined. Even if the dimension error is amplified and the phases on the opposite side are mistakenly inserted, it may be inserted deeply, and the operator will judge as if they were correctly fastened and cut without noticing that it is an incorrect insertion. When cutting, the machining dimension error caused by the phase shift of the cutting edge, the reduction of the transmission torque, the chatter vibration due to the loss of dynamic balance, etc., the cutting edge is damaged, and the product is damaged. It has the drawback of causing serious problems.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tool fastening mechanism provided with a key engaging portion that does not erroneously insert when fastening a tool.

[0005]

In the tool fastening mechanism of the present invention, the taper portion provided at the rear end of the cutting tool is fitted into the taper hole of the tool fastening mechanism and provided at the end portion thereof. In a tool fastening mechanism formed to position and fasten a cutting edge by a key engaging portion, a key engaging is formed by a key and a key groove provided at an end of a taper fitting portion. Parts are provided at two positions facing each other with a phase shift of approximately 180 °, and the key height and the key groove depth of the key engaging parts provided at the two positions are formed to have the same size. The respective keys of the key engaging portions provided at the two locations
The tool fastening mechanism is characterized in that the width and the key groove depth are formed to have different dimensions, and the cutting edge is always mounted and engaged at a fixed position.

[0006]

According to the tool fastening mechanism of the present invention, the height of the key and the key at the two key engaging portions formed by the key and the key groove provided at the end of the taper fitting portion. -Give the same groove depth and 2
The key widths and key groove widths of the key engagement parts at different locations are formed to have different dimensions, and it is configured so that it can be immediately discerned that fastening cannot be done if it is inserted incorrectly, so the correct fastening position is prompt. It has the advantage that it can be attached to.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in more detail below with reference to the drawings. A cutting tool (not shown) on the head
Forming a cutting tool body 1 having a taper portion 3a at its rear part, and the taper portion 3 having the cutting tool body 1
a is fitted into the taper hole 3b provided in the tool fastening mechanism 2 and fastened. At the end of the taper fitting portion consisting of the taper portion 3a and the taper hole 3b, there is provided a key engaging portion 6 consisting of a key 4 and a key groove 5 having a phase of about 180 °. Two cutting positions are provided facing each other so that the cutting edge position of the cutting tool is always set at a fixed position. That is, in the two key engaging portions 6, the height Hb of each key-4 and the depth Ha of the key groove 5 are formed to have the same dimension, and the width of the two key-4 is the same. One has a wide key width 4a, and the other key width is a width 4b narrower than 4a. The key groove 5 has a wide groove width 5a and a narrow groove width 5b in conformity with the width of the key 4 similarly to the key.

FIG. 5 shows the taper portion 3a of the cutting tool body 1.
This shows the case where the key groove 5 and the key 4 provided in the taper hole 3b of the tool fastening mechanism 2 are engaged with each other in the opposite state. In this case, the key -4 and the key groove 5 are inserted in the opposite state, the key groove 5b having a narrow width is inserted.
The leading end surface 7 of the above has run over the upper surface 8 of the wide key 4a, and the taper portion 3a cannot enter any more, and therefore the fastening cannot be performed.
When the key groove 5b of the taper portion 3a is rotated 180 ° from this state to align with the position of the key-4b, the taper portion 3a
The key 4b is in a correct state where it can enter, and the key engagement can be performed only for the first time, so that both the taper portion 3a and the taper hole 3b are closely fitted and fastened.

In this embodiment, the key engagement is carried out by providing a key groove 5 in the taper portion 3a of the cutting tool body and a key-4 in the taper hole 3b of the tool fastening mechanism. Although key engagement is performed, the engagement relationship is reversed, and a key is provided in the taper portion 3a, and a key groove 5 is provided in the taper hole 3b so as to be fastened. Good.

[0010]

As described above, the tool fastening mechanism of the present invention has two key engaging portions formed by a key and a key groove provided at the end of the taper fitting portion. Since the key height and the key groove depth are formed to have the same size, and the key width and the key groove width provided at two places are formed to have different sizes, the keys are engaged with each other. When it is inserted by mistake, it is immediately determined that the fastening cannot be done, and it is possible to quickly fit and fasten it in the correct fastening position, and the taper portion and the key.
Since the engaging portions are closely fitted, there is an advantage that the dynamic balance is not lost and the transmission torque is large.

[Brief description of drawings]

FIG. 1 is a side view of a rear portion of a tool body according to the present invention.

FIG. 2 is a view as viewed in the direction of arrows AA in FIG. 1;

FIG. 3 is a side sectional view of the tool fastening mechanism of the present invention.

FIG. 4 is a view taken along the line BB of FIG.

FIG. 5 is a side sectional view showing a state where the taper portion of the tool body is inserted into the taper hole of the tool fastening mechanism.

[Explanation of symbols]

 1 cutting tool body 2 tool fastening mechanism 3a taper part of tool body 3b taper hole of tool fastening mechanism 4 key 4a wide key 4b narrow width key 5 key groove 5a wide key groove 5b Key groove with narrow width 6 Engagement part consisting of key and key groove 7 Tip surface of key groove 5 of cutting tool body 8 Upper surface of key provided in tool fastening mechanism Ha Key groove depth Hb Key height

Claims (1)

[Claims] 1. A key provided at the end of a taper portion of a cutting tool fitted into a taper hole of a tool fastening mechanism.
In a tool fastening mechanism formed so that the position of the cutting edge is positioned and fastened by the engaging portion, a key engaging portion including a key and a key groove provided at the end of the taper fitting portion is provided. Almost 180
° Two positions are provided facing each other with different phases. The two key engaging portions have the same key height and key groove depth. Key and key of the key engagement part
A tool fastening mechanism, characterized in that the width of combination of grooves is formed differently so that the cutting edge of the cutting tool is always positioned and engaged at a fixed position.