JPS6240122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating tool mounting device, and particularly, but not exclusively, to a rotating tool mounting device of a type that is small and lightweight and suitable for machining operations.

A hand-held machining grinder, known as a pencil grinder, has a coaxially rotating shaft within a cylindrical housing and a drive for driving the shaft, the front end of the shaft having a rearwardly tapered taper. A type of collet is known in which a collet body having a hole is attached, the collet has a cylindrical hole for accommodating a shank portion of a rotating tool, and a taper portion corresponding to the taper hole of the collet body is screwed into engagement with the collet body. This is lightweight and compact and suitable for various machining operations, and it securely holds the rotating tool and fully guarantees coaxiality, but it is somewhat difficult to replace the rotating tool, and the collet is tightened at the front end of the device. There are some parts that may interfere with the work.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotary tool mounting device which eliminates the disadvantages of the prior art devices mentioned above, and according to the present invention includes a shaft rotatable coaxially within a cylindrical housing and a shaft at the front end of the shaft. A cap that is attached so as to be adjustable in direction and position and has a tapered inner surface adjacent to an opening at its front end, and a tapered portion that is inserted into the coaxial hole of the shaft from its front end and cooperates with the tapered surface of the cap. a collet provided at the front end; a pressing body slidably provided in the coaxial hole of the shaft and abutting the rear end of the collet; and a cam insertion hole provided transversely in the shaft and communicating with the coaxial hole; The cam is inserted into the cam insertion hole and has a cam portion, and by rotating the cam around its axis, the cam portion presses the collet forward via the pressing body, and the taper portion of the collet presses the collet forward through the pressing body. Provided is a rotating tool mounting device characterized in that the rotating tool is clamped by a collet that is pressed against a surface.

As the drive device for driving the shaft, a compressed air-operated air turbine or an electric motor is preferably provided coaxially within the housing.

A tightening tool insertion hole is provided at one end of the cam, and a tool insertion opening is provided in the housing that aligns with the tool insertion hole at a specific rotational position of the shaft. When the tightening tool is inserted into the tool insertion hole through the tool insertion opening, rotation of the shaft is inhibited, and the operation of attaching and detaching between the collet and the rotary tool can be performed quickly and reliably.

Reference will now be made to the accompanying drawings that illustrate embodiments of the invention.

FIG. 1 shows a grindstone 1 having a head 2 and a shank 3 as an example of a rotary tool. 2 and 3 are views showing the rotary tool mounting device according to the present invention divided into two in the length direction, and the elongated cylindrical housing consists of a front part 4, a middle part 5 and a rear part 6, which are They are coaxially connected to each other. At the rear end of the housing there is provided a joint 7 which is connected to a compressed air conduit (not shown), and in the central housing an air turbine (not shown) is provided for driving a shaft 8.

A shaft 10 driven by shaft 8 via coupling ring 9 rotates coaxially within front housing 4 . A male thread is provided at the front end of the shaft 10, and a cap 20 and a lock nut 21 are threadedly engaged. A tapered surface 22 that tapers forward is provided at the front end of the inner surface of the cap 20. A collet 24 having a tapered portion 23 tapered in correspondence with the tapered surface 22 engages with the cap 20 and is connected to the shaft 1.
It is inserted into the axial hole 11 of 0. Reference numeral 25 indicates a notch groove in the collet 24, but of course this may extend to the rear end of the collet 24, or a plurality of notch grooves may be provided. The shaft 10 has a lateral hole 1
4 is provided, and a small diameter hole 1 as an extension of the hole 11 is provided.
It communicates with 2 and 13. A cam 30 is disposed within the hole 14 . The cam 30 has a small diameter portion 3 at the center of its length.
1 has large diameter portions 32 and 33 on both sides thereof, and the large diameter portions 32 and 33 fit into the hole 14. Cam small diameter part 3
A stepped cylindrical pressing body 26 is disposed between the collet 1 and the rear end of the collet 24. Cam small diameter part 31
is under the force of a spring 28 via a support 27 which slides within the bore 13. A tightening tool insertion hole 34 is provided in at least one end surface of the cam 30, and the shaft 10
It aligns with at least one tool insertion hole 4A provided in the housing 4 at a specific rotational position. axis 10
In terms of balance, tool accommodation holes 34 are provided at both ends of the cam 30.
It is desirable to provide

Insert the rotary tool 1 into the collet 24 and turn the cam 30
When the collet 24 is rotated, the collet 24 moves to the left and the taper surface 22 of the cap 20 and the collet 24
The taper portion 23 of the collet comes into close contact with the collet, and the collet is tightened. The rotation of the cam 30 in the loosening direction is caused by rotational friction between the hole 14 and the large diameter portions 32 and 33 of the cam 30,
The force of the spring 28 prevents the tightening force from loosening. Since the tightening tool passes through the hole 4A of the housing 4 during this tightening, rotation of the shaft 10 is simultaneously prevented, allowing safe tightening work.

In the figure, 40 and 41 are ball bearings that support the shaft 10, 43 is a retaining ring, and 44 is a housing 4, 5.
45 is a joint that connects the shafts 8 and 10, and 42 and 46 are pins provided on the shafts 10 and 8, respectively, and drivingly connected to the joint 45.

As described above, in the present invention, attachment and detachment of the rotary tool 1 is extremely easy, quick, and reliable, and the tool can be made lightweight and compact, and machining efficiency is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an example of a machining tool (rotary tool). FIGS. 2 and 3 are longitudinal cross-sectional views showing an example of the rotary tool device according to the present invention, with a part omitted and divided into two parts in the length direction. FIG. 4 is a vertical cross-sectional view in the direction of the paper of FIG. 2 showing the main parts of the internal parts of the front housing. FIG. 5 is a perspective view of the cam. 1: Rotary tool, 4, 5, 6: Housing, 1
0: Axis, 20: Cap, 21: Lock nut,
23: Tapered surface, 24: Collet, 26: Pressing body, 30: Cam, 11, 12, 13, 14: Hole,
34, 4A: Tool insertion hole, 31: Cam portion.

Claims (1)

[Claims] 1. A shaft rotatable coaxially within a cylindrical housing, and an inner surface adjacent to an opening at the front end of the shaft, which is attached to the front end of the shaft so as to be adjustable in axial direction. a collet that is inserted into the coaxial hole of the shaft from its front end and has a tapered portion at its front end that cooperates with the tapered surface of the cap;
a pressing body slidably provided in the coaxial hole of the shaft and abutting the rear end of the collet; a cam insertion hole provided transversely in the shaft and communicating with the coaxial hole; and a cam inserted into the cam insertion hole. When the cam is rotated around its axis, the cam portion presses the collet forward via the pressing body, and the tapered portion of the collet is pressed against the tapered surface of the cap, causing the collet to A rotary tool mounting device characterized in that a rotary tool is tightened. 2. The rotary tool mounting device according to claim 1, wherein the shaft is rotated by a pneumatic or electric drive provided in the housing. 3. A tool insertion hole is provided at one end of the cam, and the housing is provided with a tool insertion opening that can be aligned with the tool insertion hole at a specific rotational position of the shaft to enable rotational operation of the cam. A rotary tool mounting device as claimed in claim 1. 4. The rotary tool according to claim 1, wherein the cap is threadedly engaged with the shaft, and a lock nut for fixing the threaded engagement position of the collar with respect to the shaft is also threadedly engaged with the shaft. Mounting device.