JPS6021142Y2 - Tool holder mounting device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tool holder attachment device that allows a cutting tool such as a drill or a counterbore cutter to be attached to and detached from a spindle with a single touch.

A conventional tool holder attachment device is known in which the holder is coupled to the chuck body using steel balls and a collar.

In such a mounting device, the groove of the holder and the ball are in point contact, so the bonding force is weak, that is, the holding force in the rotational and axial directions is weak.Also, since the ball moves each time the holder is attached or removed, the contact area with the ball is weak. There are problems such as wear and tear.

In view of the above-mentioned inconveniences in holding the conventional tool holder on the drive shaft, etc., the inventors devised the present invention in order to solve this problem. A square thread groove is provided between the bases, and the angle of the thread groove with respect to the axial direction changes from small to large from the starting end to the terminal end, and the above thread groove and screw To provide a tool holder mounting device in which a matching pin is attached, and the tool holder is fitted and screwed into a mounting hole of a drive shaft to be connected with one touch while ensuring strong and reliable mounting and holding.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a longitudinal cross-sectional view of an embodiment in which a tool is attached to the support plate 1 of a multi-axis machining unit via a tool holder. A flange portion 2a provided at the front end portion is screwed to the peripheral portion of the mounting hole 1a of the support plate 1 via bolts 3.

A drive shaft 4 is fitted in the bearing sleeve 2 in the axial direction, and the shaft 4 is rotatably supported within the sleeve 2 by a bearing 5 or the like.

A tool holder 6 is fitted and screwed onto this shaft 4 and held therein.

The tool holder 6 is provided with a holding hole 6a that opens at the tip of the shaft.
The base of the tool 11 is fitted into this, and the setscrew 7 is screwed into the radial screw hole 6c provided perpendicularly to the large diameter flange 6b provided at the front of the holder 6, thereby fixing the base of the tool 11. An axial screw hole 6d is provided concentrically behind the holding hole 6a, and an adjustment screw 8 is screwed into the hole 6d to adjust the amount of axial protrusion of the tool 11.

A square screw groove 9 is carved on the rear circumference of the holder 6.

The thread groove 9 is formed by increasing the angle θ between the groove center line N1 of the thread groove starting end 9a and the perpendicular direction of the holder axis N, that is, by increasing the inclination angle, and by increasing the angle θ between the center line N2 of the terminal end 9b and the axis N. The angles θ□, θ2. It is formed continuously from the starting end to the ending end so that the angle becomes gradually smaller than θ3, that is, the inclination angle becomes gradually smaller.

On the other hand, on the inner wall of the mounting hole 4a opened at the tip of the drive shaft 4, a pair of pins 10° 10 facing each other are inserted at substantially the same position in the axial direction and parallel to the front direction (Fig. 3). Arrange.

Only the portion of this pin 10.10 which is interferingly engaged with the screw groove 9 of the holder 6 protrudes from the inner wall, and the other portion is buried in the vicinity of the mounting hole.

In addition, this pin 10.10 is arranged in accordance with the inclination angle of the approximately central portion in the axial direction of the square screw (see Fig. 3).
The outer diameter of the pin 10.10 is slightly larger than the groove width of the threaded groove 9 with some play.

This makes it possible to smoothly screw into other screw grooves with different angles of inclination.

In the above process, the small diameter main body 6C of the tool holder 6 holding the tool 11 is fitted into the mounting hole 4a of the drive shaft 4, and the starting end 9a of the threaded groove 9 engages with the pins 10, 10, and is inserted into the groove 9. invade.

This intrusion is easily performed because the angle θ1 of the full start end 9a is set to be large.

As the holder 6 rotates, the holder 6 screws into the mounting hole 4a, and the pins 10 and 10 are guided by the groove 9 and move toward the end so that the groove 9 has a smaller angle toward the end as described above. Axis line N
, and finally they are screwed together.

In this state, the rotational force is held by the tightening force of the thread groove,
Since the thread groove in the axial direction is as shown above, even if an axial thrust is applied between the pin and the thread groove, the component in the inclined direction that loosens the screw connection will not become large, and the axial direction will be held firmly and reliably. This also acts as a reaction force against the force in the rotational direction, and holds the rotational direction firmly and reliably.

As is clear from the above, according to the present invention, since the pins and thread grooves are connected by line contact, and the thread grooves are configured as described above, it is possible to obtain strong and reliable bonding force in both the rotational direction and the axial direction. Moreover, since the full start end is as shown above, it is easy to attach and detach with one touch.Furthermore, the structure is simple due to the formation of the thread groove and the arrangement of the pins, and it is also resistant to wear and lasts for a long time. It has many advantages such as being able to be expected to hold firmly and reliably.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a longitudinal cross-sectional view of the main parts of the machine tool including the mounting device, Fig. 2 is an enlarged side view of the tool holder, and Fig. 3 is a longitudinal cross-sectional end view of the tool holder. be. In the drawing, 4 is the drive shaft, 4a is the mounting hole, 9 is the square thread groove, 1
0 is a pin.

Claims (1)

[Scope of utility model registration request] A tool holder having a square thread groove formed around the base thereof such that the angle of the starting part of the thread groove with respect to a direction perpendicular to the axial direction is large and the angle gradually decreases from the starting part to the end part of the thread groove, and the tool holder The driving shaft is provided with a pin that is screwed into the square thread groove provided on the inner periphery of the axial mounting hole into which the base of the square screw is fitted in accordance with the inclination angle of the substantially central part in the axial direction of the square screw. Tool holder mounting device.