JPH042730Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a tool holding arbor device used in a machine tool.

(Prior technology) The tool holding arbor, which is removably inserted and fixed into the mounting hole of the spindle of a machine tool, has centripetal properties that allow the center of rotation of the spindle and the center of rotation of the tool to match with high performance, and a High bonding rigidity is required to prevent chatter during cutting.

In conventional general-purpose milling machines, the tool holding arbor was firmly pulled with a tension screw, and the tapered surface of the arbor's shank and the tapered surface of the spindle mounting hole were tightly fixed, which improved centripetal performance. The bonding rigidity was also good.

However, in machining centers equipped with automatic tool changers, the tension of the tension screw is about 1/10 of that of conventional general-purpose milling machines, making it difficult to obtain sufficient centripetality and joint rigidity. Ta.

Therefore, an attempt was made to make the end face of the arbor's flange part closely contact the end face of the main shaft to increase the joint rigidity.
In taper fitting, it is extremely difficult to bring the end faces of the flange portion into close contact.

In other words, if you try to bring the flange end face and the spindle end face into close contact, the taper fit becomes loose and the centripetality deteriorates, and conversely, if the taper fit becomes tight, the adhesion between the flange end face and the spindle end face deteriorates. However, there was a problem that the joint rigidity deteriorated.

Therefore, a tapered sleeve is interposed between the shank part of the arbor and the mounting hole of the main shaft, and this tapered sleeve improves the centripetal property and also firmly connects the flange end face and the main shaft end face. has already been proposed. (For example, see Utility Model Publication No. 47-5197 and Utility Model Application Publication No. 60-143628).

(Problems to be Solved by the Invention) In the conventional tapered sleeve type, it was not possible to make the tapered sleeve long enough to cover the entire length of the shank portion or the entire length of the tapered hole of the main shaft.

In other words, in a tapered sleeve, either the inner or outer circumference is a tapered surface and the other is a straight surface, so if it is formed long enough to cover the entire length of the shank or the entire length of the main shaft taper hole, the center of the inner and outer circumferential surfaces will be It was difficult to ensure a high level of ejecting accuracy. Furthermore, when the length of the tapered sleeve is increased, the wall thickness at one end of the sleeve becomes thicker, making it difficult to expand or contract the diameter of the sleeve. Also, for example, if the inner surface of the sleeve is a straight surface,
When the length of the sleeve is increased, the diameter of the shank becomes smaller and the rigidity decreases.On the other hand, if the outer surface of the sleeve is a straight surface, the wall pressure of the main shaft mounting hole becomes thinner and the rigidity of the main shaft decreases. There was a problem. (For example, see Utility Model Application Publication No. 141034/1983).

Therefore, the conventional tapered sleeve type
In order to solve the above problems, we shortened the length of the sleeve, mainly improved the centripetal property at the joint between the shank part and the main shaft mounting hole, and improved the joint rigidity at the close contact between the flange end face and the main shaft end face. The company was trying to improve its performance.

Therefore, since the joint rigidity at the joint between the shank portion and the spindle mounting hole was not improved sufficiently, the overall joint rigidity was not sufficiently improved, and chatter and the like occurred.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a tool holding arbor device that can improve the joint rigidity at the joint between the attachment hole of the spindle and the shank portion.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes the following measures. That is, the features of the present invention include: a shank portion inserted into a tapered hole for attaching an arbor formed at the tip of the spindle of a machine tool; a flange portion having an end surface that comes into contact with the tip surface of the spindle; an arbor each equipped with a tool attachment part; a sleeve fitted onto the shank part of the arbor and tapered into the tapered hole; In the tool holding arbor device comprising an elastic member provided on the shank portion to bias the sleeve, the shank portion is formed in a tapered surface having approximately the same angle as the tapered hole, and A straight portion is formed at the large end and small end of the tapered surface, and the sleeve has a length that covers approximately the entire length of the shank portion, and the wall thickness thereof is approximately the same,
In addition, inner surfaces of both ends of the sleeve are formed into straight surfaces that fit onto the straight portion of the shank portion, and there is a gap between the inner circumferential surface of the intermediate sleeve sandwiched between the straight surfaces and the tapered surface of the shank portion. ,
This is at the point where a play gap is formed.

(Function) According to the present invention, the shank portion of the arbor fits into the tapered hole of the main shaft via the sleeve. The arbor is pulled into the back of the main shaft by the tensioning means. The sleeve is pushed into a tight tapered fit by the elastic means, and the arbor and the main shaft are aligned with high precision. Since the inner surface of the sleeve and the shank part of the arbor are fitted on straight surfaces, the arbor is pulled into the back of the main shaft by the tensioning means, and the end face of the flange part and the end face of the main shaft are firmly attached. .

At this time, the sleeve is long and covers the entire length of the shank part, and the outer surface of the sleeve tapers into the tapered hole of the main shaft, and also fits into the shank part at both ends, so the coupling rigidity is low. improves.

Since the inner and outer surfaces of the sleeve are tapered at approximately the same angle, the diameter of the shank portion does not become thinner, the wall pressure of the mounting hole of the main shaft does not become thinner, and a decrease in rigidity is prevented.

Since the shank portions are straight-fitted at both ends of the sleeve, processing is easier and the fitting accuracy can be improved compared to a case where the shank portions are fitted over the entire length of the sleeve.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In Fig. 1, 1 is the main axis, and this main axis 1 is
It is provided in machine tools, for example, automatic tool change machine tools such as machining centers.

The main shaft 1 is hollow, and a tapered hole 3 is formed in the axial direction from the distal end surface 2 of the main shaft 1 . 4 is
The arbor device 4 is a tool holding arbor device, and the arbor device 4 is removably attached to the taper hole 3 of the main shaft 1.

The arbor device 4 includes an arbor 5, a tapered sleeve 6, an elastic member 7, and a tension bolt 8.
and a seal ring 9.

The arbor 5 is a tapered hole 3 of the main shaft 1.
a shank portion 10 to be inserted into the main shaft 1; and a flange portion 12 having an end surface 11 that comes into contact with the tip surface 2 of the main shaft 1.
and a tool attachment part 13 to which a tool is attached.

The shank portion 10 is a tapered hole 3 of the main shaft 1.
The tapered surface 14 is formed at substantially the same taper angle as the taper angle. Straight portions 15,
16 are formed.

The tapered sleeve 6 is fitted onto the shank portion 10, and its entire length spans almost the entire length of the shank portion 10. The outer circumferential surface of the tapered sleeve 6 is formed into a tapered surface 17 that taper-fits tightly into the tapered hole 3 of the main shaft 1. Both ends of the inner peripheral surface of the tapered sleeve 6 are connected to the straight parts 15 and 16 of the shank part 10.
a straight portion 18 that is slidably fitted in the axial direction;
It is formed in 19. The inner circumferential surface of the tapered sleeve 6 sandwiched between the straight parts 18 and 19 is formed into a play surface 20 that does not come into contact with the tapered surface 14 of the shank part 10.

The tension bolt 8 is screwed onto the tip of the shank portion 10, and the flange portion 21 of the bolt 8 protrudes outward from the outer periphery of the small diameter straight portion 16 of the shank portion 10 to prevent the tapered sleeve 6 from coming off. is being carried out.

The elastic member 7 is composed of a disk spring, and is housed in a groove 22 formed in the end surface 11 of the flange portion 12 of the arbor 5, and presses the tapered sleeve 6 toward the tension bolt 8.

The seal ring 9 is housed in a ring groove 23 formed in the middle of the shank portion 10, and is in elastic contact with the play surface 20 on the inner surface of the tapered sleeve 6.

According to the embodiment of the present invention, the arbor device 4
is inserted into the tapered hole 3 of the main shaft 1, the tension bolt 8 is pulled by a tensioning means (not shown), and the arbor device 4 is pulled to the back side of the tapered hole 3.

At this time, the arbor 5 is connected to the tapered hole 3 of the main shaft 1.
When the tapered sleeve 6 is pulled to the back side of the tapered hole 3, the flange portion 12 of the arbor 5 presses the tapered sleeve 6 to the back side of the tapered hole 3 via the elastic member 7.

As a result, the tapered sleeve 6 moves to the back side along the inner surface of the taper hole 3 of the main shaft 1, and contracts radially inward, so that the shank portion 1 of the arbor 5
The straight parts 15 and 16 of 0 are tightened and fixed, and the arbor 5 is centered with respect to the main axis with high precision and fixed rigidly.

Moreover, the arbor 5 and tapered sleeve 6 are
Since the straight parts 15 and 16 of the shank part 10 and the straight parts 18 and 19 on the inner surface of the sleeve fit together, relative movement in the axial direction is facilitated.
The end face 11 of the flange portion 12 of the arbor 5 is firmly pressed against the tip end face 2 of the main shaft 1, increasing the joint rigidity.

What is shown in FIG. 2 is a second embodiment of the present invention, in which an elastic body 24 is interposed between the end surface 11 of the flange portion 12 and the distal end surface 2 of the main shaft 1. As shown in FIG.

In this embodiment, both the elastic body 24 and the elastic member 7 that presses the tapered sleeve 6 are formed of rubber rings.

Note that the present invention is not limited to the above embodiments.

(Effects of the invention) According to the invention, since the tapered sleeve is long and has a length that spans almost the entire length of the shank portion of the arbor, the joint rigidity can be improved.

In addition, since the inner and outer surfaces of the sleeve are tapered at almost the same angle, the diameter of the shank does not become thinner, the wall pressure of the main shaft mounting hole does not become thinner, and a decrease in rigidity is prevented. .

Since the shank portions are straight-fitted at both ends of the sleeve, machining is easier and the fitting precision can be improved compared to a case where the shank portions are fitted over the entire length of the sleeve.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of main parts showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Main shaft, 2... Tip surface, 3... Tapered hole, 4... Tool holding arbor device, 5... Arbor, 6... Taper sleeve, 7... Elastic member, 10... Shank portion, 11 ...End face, 12...
...Flange part, 13...Tool mounting part, 15, 1
6, 18, 19...straight part, 20...play surface.

Claims (1)

[Claims for Utility Model Registration] A shank portion 10 inserted into a tapered hole 3 for attaching an arbor formed at the tip of a main spindle 1 of a machine tool, a flange portion 12 having an end surface that comes into contact with the tip surface of the main spindle 1, an arbor 5 each provided with a tool attachment part 13 for attaching a tool; a sleeve 6 externally fitted onto the shank part 10 of the arbor 5 and tapered fitted into the tapered hole 3; and a sleeve 6 and the tapered hole. In the tool holding arbor device, the shank part 10 includes an elastic member 7 provided on the shank part 10 to urge the sleeve 6 in a direction to tighten the fitting with the sleeve 6. The sleeve 6 is formed in a tapered surface 14 having approximately the same angle as the tapered hole 3, and is formed in straight portions 15 and 16 at the large and small ends of the tapered surface 14.
has a length that covers approximately the entire length of the shank portion 10 and has approximately the same wall thickness, and the inner surfaces of both ends of the sleeve 6 are externally fitted into the straight portions 15 and 16 of the shank portion 10. A play gap is formed between the inner peripheral surface of the sleeve 6 at the intermediate portion sandwiched between the straight surfaces 18 and 19 at both ends and the tapered surface 14 of the shank portion 10. A tool holding arbor assembly characterized by: