JPS5821631Y2 - Collection check - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a collet chuck, and particularly to a collet chuck that has a function of ensuring the gripping ability of the chuck against strong cutting forces.

In recent years, as the performance of machine tools has improved, there has been a demand for cutting tool holders with greater gripping force in order to perform powerful cutting.

A collet chuck is a device that draws the taper part of the collet into the taper hole of the chuck body and creates a gripping force by contraction of the collet.
Since the retracting force is limited to a certain extent and is regulated by the collet used, there is a limit to the inherent gripping force of the chuck.

Therefore, if a strong cutting force exceeds the original gripping force of the collet chuck during cutting, the cutting tool will slip or slip out.

This problem often occurs because the higher the performance of a machine tool, the more powerful cutting is required.

Therefore, this invention aims to solve the problem by not only grasping the tool shank using the collet but also having a fastening function for fastening the tool shank to the chuck body.

That is, this fastening function holds the tool shank against the cutting force that exceeds the collet's original gripping force, thereby ensuring the gripping ability of the chuck.

Furthermore, this fastening function utilizes the torque acting on the tool shank during cutting to increase the fastening force, and as the cutting force increases, the fastening force is increased by the correspondingly increased torque.

Therefore, the main purpose of this invention is to provide a collet chuck that not only grips the tool shank with the collet but also has the function of fastening the tool shank to the chuck body.

Another object of this invention is to provide a collet chuck according to the above object, which has a function of increasing the fastening force as the cutting force increases during cutting.

Still another object of this invention is to provide a collet chuck in which the collet is guided to a predetermined position with respect to the chuck body when the collet is fitted into the tapered hole of the chuck body.

Still another object of the present invention is to provide a collet chuck according to the above object, in which a front ring for activating the collet is guided so as to be able to translate in the axial direction without rotation.

Hereinafter, preferred embodiments of this invention will be described based on the drawings.

As shown in Fig. 1, the chuck body 1 of the collet chuck has a handle 2 having a taper and retracting bolt hole to match the main shaft hole of a machine tool, a taper hole 4 into which a taper collet 3 is inserted, and a taper hole 4 into which a taper collet 3 is inserted. It has a wall 5 surrounding the hole 4.

The collet 3 has a cavity 8 for receiving a straight shank 7 of a cutting tool 6.

At the end of the straight shank 7, as shown in Figs. 1.2.3i and 7, a flat surface 9 is cut into a button.
This flat surface 9 is formed along the dividing line of the outer circumferential circle of the shank.

In FIG. 2, the wall 5 of the chuck body 1 has an angle α with respect to the flat surface 9 of the straight shank 7 inserted into the tapered hole 4 of the chuck body through the collet 3, and is oriented generally in the tangential direction of the shank. A tangential hole 10 is bored along the elongated axis A.

The angle of inclination α of the tangential hole is about 10 to 20 degrees.

The tangential hole 10 is a stepped cylindrical hole passing through the wall 5 along the axis A, and has an insertion opening 1 opened on the outer surface 11 of the wall.
2, and a screw head receiving hole 15 having an insertion port 14 opened on the outer surface 11, and a reduced diameter portion 16 between these passages 13 and the hole 15 to form a stepped portion 1.
7 is formed.

The contact passage 13 of the tangential hole 10 intersects the tapered hole 4 and forms an elliptical opening 18 (FIG. 11) on the inner surface of the wall 5 along its curved surface.

This opening 18 is located on the flat surface 9 of the straight shank.
As will be described later, the slope of the tightening bolt is wide enough to protrude from this side toward the collet cavity 8 side.

As shown in FIG. 2, a tightening collar 20 is attached to the clamping passage 13 of the tangential hole 10 so as to be movable along the axis A.

The tightening lever 20 is a cylinder that fits loosely into the cylindrical hole of the tightener passage 13, and has a slope 21 on one side as shown in FIG. 12, and the slope 21 has a slope as shown in FIG. The angle of inclination α of the tangential hole 10 is made to match.

During installation, the tightening collar 20 can be inserted into the collar passageway 13 through the insertion opening 12 of the tangential hole.

In FIG. 2, a tightening screw 30 is screwed into the tightening screw 20, and the rotation of the tightening screw 30 causes the tightening screw 20 to
begins to move along the tangential hole 20.

The tightening screw 30 is a flat head bolt with a hexagonal socket, and includes a head 31 that is loosely fitted into the screw head receiving hole 15 of the tangential hole, and a shaft support 32 that is supported by the reduced diameter portion 16 of the tangential hole. It has a threaded portion 33 that is screwed into and passes through the axial through screw hole 22 provided in the tightening bolt 20.

During installation, the tightening screw 30 can be inserted through the insertion opening 14 of the tangential hole.

The head 31 of the tightening screw is rotatably seated on the stepped portion 17 within the receiving hole 15, and a stop ring 34 is loosely fitted into a groove formed in the screw head receiving hole 15 of the tangential hole. 34, the tightening lever 20 is the third one as will be described later.
When moving to the position shown in the figure, the tightening screw 3 comes into contact with the head 31.
0 is prevented from flying away from the stepped portion 17.

As shown in the second and third buttons and in FIG. set screw 25
The tip of the rod is loosely fitted into the groove 23, and thereby the tightening screw 30
The slope 21 is prevented from rotating due to the rotation of the tightening bolt 20.
is translated in such a way that it is always kept in a constant direction with respect to the flat surface 9.

The tip of the set screw 25 in the housing contacts the end wall of the groove 23 to limit the amount of movement of the tightening screw.

In FIG. 2, the tightening bolt 20 is in a fastening position with its slope 21 protruding from the opening 18 toward the collet cavity 8 to fasten the straight shank to the holder as described later.

When the tightening screw 30 is turned in one direction with a suitable screwdriver, the tightening screw 20 moves from the position shown in FIG. 2 to the position shown in FIG. The shank is moved from the fastening of the holder to the release position where it is released.

When the tightening screw 30 is rotated in the other direction, the tightening screw 20
moves from the position shown in FIG. 3 to the position shown in FIG.

In this way, the clamping screw 30 moves the clamping pin 20 forward toward or backward from the flat surface 9 along the tangential hole 10.

FIGS. 13 and 14 show a modification example for moving the tightening bolt 20 forward or backward more quickly to shorten the time required for fastening or releasing, and in which the tangential hole 40, the fastening screw 50, and the connection relationship between the two are The structure is the same as the second button and the structure shown in FIG. 3 except for the difference.

13 and 14, the tangential hole 40 is a cylindrical hole passing through the wall 5 along the axis A, while the outer surface 1 of the wall
a cock passage 13 having an insertion port 12 opened at one end, and a threaded hole 41 having an insertion port 14 opened at the outer surface 11 on the other hand;
It has

The tightening screw 50 has a threaded head 51 screwed into the screw hole 41 of the tangential hole 40 and a through screw hole 22 of the tightening bolt 20.
The tightening screw 50 has a threaded portion 52 that is screwed into the flat surface 9 and passes through it, and the tightening screw 50 advances or retreats along the axis A by its rotation, and moves the tightening screw 20 forward or backward with respect to the flat surface 9. This reduces the time required for fastening or releasing.

As shown in FIGS. 7 to 10, the collet 3 has a notch 60 according to the prior art, and a channel-shaped collet notch 61 with an open end face is provided in the wall of the collet 3 at the end on the diameter-reducing side. A guide groove 62 is formed from the bottom of the notch 61 of the collet to the large diameter portion.

When the straight shank 7 is inserted into the collet 3, the collet notch 61 is generally aligned with the flat surface 9, as shown in FIG.

1 and 7, the wall 5 of the chuck body includes portions protruding from the inner and outer wall surfaces, an inner portion 71 and an outer portion 72.
A guide pin 70 having a diameter is attached.

The inner part 71 of the guide pin 70 is the guide groove 6 of the collet.
2, so that when the collet 3 is inserted into the chuck body, its notch 61 is aligned with the opening 18 on the inner surface of the wall 5, as shown in FIG.

After inserting the tool shank 7 into the collet cavity 8 while aligning the flat surface 9 with a matching mark 80 (FIG. 2) provided on the outer surface 11 of the chuck body wall, the tool shank 7 is inserted into the collet cavity 8, and then the tightening screw 30 is inserted. If the tightening tip 20 is rotated and moved forward, the flat surface 9 and the slope 21 will naturally align accordingly.

In FIG. 1, a front ring 90 is supported on the wall 50 of the chuck body so as to be movable in the axial direction.

When the front ring 90 moves upward, collet 3
According to the prior art, the collet 3 is engaged with the collet 3 at its end so as to be pushed into the tapered hole 4 and to retract the collet 3 from the tapered hole 4 when moving downward.

The front ring 90 has a vertical groove 91 on its inner surface, and the outer part 72 of the guide pin 70 is loosely fitted into this vertical groove 91.
Thereby, when the front ring 90 moves in the axial direction, it is guided to perform a single translational movement without rotating.

A thread is formed on the outer periphery of the front ring 90, and a tightening ring 100 is screwed onto the thread as shown in FIG.

The tightening ring 100 is a screwed Freon) IJ ring 90
After fitting it into the outer surface of the wall of the chuck body with the stopper 82
It is supported on the circumferential surface of the chuck body via a steel ball 81 inserted into a groove 83 from the location shown in FIG. 5, and can freely rotate.

Therefore, as the tightening ring 100 rotates, the front ring 90 translates up and down in the axial direction.

The function of the collet chuck of this invention is as follows.

Place the straight shank 7 of the cutting tool on its flat surface 9.
After inserting the collet into the collet cavity 8 to the position shown in FIG. 3 while aligning it with the alignment mark 80, insert the tightening ring 10 shown in FIG.
0 in one direction, the front ring 90 moves upward in the axial direction, which causes the collet 3 to align with the tape hole 4.
The shank is pushed inwards and performs a normal shank grasping motion.

Next, insert the screwdriver into the head 3 through the insertion port 14 shown in FIG.
When the tightening screw 30 is engaged with the hexagonal hole 1 and rotated in one direction, the tightening tip 20 advances toward the flat surface 9.

As the tightening screw rotates, the tightening tip 20 is pushed along the tangential hole, and its slope 21 passes through the collet notch 61 from the tangential direction of the shank at the opening 18 to the flat surface 9. The direction begins to protrude and moves parallel to the flat surface 9, and finally, as shown in FIG. 2, the slope 21 of the tightening bolt comes into close contact with the flat surface 9 of the shank in a wedge-like manner.

By further rotating the tightening screw, a thrust force P is applied to the tightening screw 20 in the direction of the axis A.

Therefore, frictional force due to the wedge effect of the slope 21 is generated between the outer peripheral surface of the tool shank, the inner and outer surfaces of the wall of the collet 3, and the inner surface of the wall 5 of the chuck body. Furthermore, it is fastened to the chuck body 1 by a tightening bolt.

When torque based on cutting force is applied to the shank 7 in the direction of the arrow in Fig. 2 during cutting, the taper hole 4 of the chuck body
A force F is generated in the tangential direction, and this force F, together with the thrust force P, acts to further bite the slope 21 of the tightening bolt into the shank flat surface 9, thereby increasing the wedge effect and increasing the frictional force. .

Accordingly, the fastening force for holding the tool shank against the cutting force increases.

Since the force F is generated by the torque based on the cutting force, the more the cutting force increases, the more the force F increases, and the frictional force due to the wedge effect increases accordingly, increasing the fastening force.

In this way, the gripping ability of the chuck can be guaranteed against strong cutting forces during cutting.

After the cutting process is completed, the force F acting on the tightening bolt 20 disappears, so that the tightening screw 30 can be easily rotated.

When the tightening screw 30 is rotated in the other direction, the tightening screw 30 moves in translation from the tightening position shown in FIG. This is the release position shown in Fig. 3, where .

Then, by rotating the clamping ring 100 in the other direction and moving the front ring 90 downward, the tool shank 7 can be removed from the collet cavity.

The collet chuck of this invention has a movable inclined wedge-shaped fastening surface arranged along a tangential hole that forms an angle with the flat surface of a straight shank and extends in the tangential direction of the shank. Since the torque based on the cutting force is applied to the wedge and the torque is used for the thrust of the wedge, the more the cutting force increases during cutting, the more the torque increases, causing the wedge-shaped fastening surface to bite into the flat surface and reduce friction. This increases the force, thereby ensuring the chuck's gripping ability against cutting forces that exceed the chuck's original gripping force.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view of the collet chuck of this invention, Figure 2
The figure is a cross-sectional view taken along the mountain-■ line in Figure 1, Figure 3 is a diagram similar to Figure 2 showing the state in which the fastening is released, and Figure 4 is the mV-mV line in Figure 2. Sectional view taken along the fifth
The figure is a sectional view taken along the line ■-■ in Fig. 1, Fig. 6 is a sectional view taken along the line Vl-Vl in Fig. 1, and Fig. 7 is a sectional view taken along the line Vl-Vl in Fig. 1.
The figure is a partial vertical sectional view showing the combination of the collet and tool shank attached to the chuck body, Figure 8 is an end view of the collet shown in Figure 7, seen from the tapered diameter side, and Figure 9 is a side view of the collet. Figure 10 is an end view of the collet seen from the taper large diameter side, Figure 11 is a partial elevational view taken along line XI-XI in Figure 1, Figure 12 is a perspective view of the tightening bolt, FIG. 13 is a sectional view similar to FIG. 2 showing a modification of the tangential hole and the tightening screw, and FIG. 14 is a sectional view similar to FIG. 3 showing a modification of the tangential hole and the tightening screw. 1...Chuck body, 3...Collet, 4...Tapered hole, 5...Wall, 6...
... Cutting tool, 7 ... Straight shank, 8 ... Thread cavity, 9 ... Flat surface, 10 ... Tangential hole, 13 ... ...Kotta passage, 15...Screw head receiving hole, 16...
・Reduced diameter part, 18... Opening part, 20...
Tightening screw, 21... Slope, 22...
Through screw hole, 23... Groove, 25...
Set screw, 30...Tightening screw, 31...
Head, 32... Pivotal support, 33... Threaded portion, 40... Tangential hole, 41... Threaded hole,
50...Tightening screw, 51...Threaded head, 52...Threaded portion, 61...Collet notch, 62...・Guide groove, 70...
...Guide pin, 90...Front ring,
100...Tightening ring.

Claims (4)

[Scope of utility model registration request] (1) A collet having a cavity and a slit for receiving the shank of a cutting tool or tool adapter, and a chuck body having a hole into which the collet is inserted and a wall surrounding the hole, the collet being pushed into the hole. A collet chuck for grasping the shank by advancing the collet chuck, the collet chuck having a flat surface formed on the shank along a secant line of an outer circumferential circle thereof, and a wall of the collet provided so as to obtain a roughly aligned tassel on the flat surface. a collet notch and a tangential hole extending generally tangentially to the shank at an angle to the flat surface of the shank received through the collet in the hole of the chuck body; a tangential hole protruding from the wall to form an opening that can be generally aligned with the flat surface along the tangential hole on the inner surface of the wall of the main body; and a tangential hole mounted so as to be movable along the tangential hole. a tightening piece having an inclined surface that passes through the collet cutout from the tangential direction to the flat surface of the shank at the opening and contacts the flat surface of the shank at the opening; It is equipped with a tightening screw screwed into the tightening bolt so as to move forward or backward from the flat surface, and in addition to gripping the shank by the collet, the tightening bolt further tightens the shank to the chuck body. collet chuck. (2) The collet notch is provided at the end of the collet on the diameter reduction side with an open end face, and the flat face is carved at the end of the shank in accordance with this. The collet chuck described in item (1). (3) The tightening knob has a slope on one side thereof with a slope approximately equal to the angle of the tangential hole, and the slope is configured to move in translation along the tangential hole and contact the flat surface in a wedge-like manner. A collet chuck according to claim (1) of claim 1, which has been registered as a utility model. (4) The tightening screw is screwed into a through screw provided in the axial direction of the tightening knob, and its rotation moves the tightening knob forward or backward with respect to the flat surface along the tangential hole. A collet chuck according to claim (3) of the utility model registration.