JPH0134721B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a device for releasably clamping a tool or workpiece having a central hole to a mandrel or the like in the radial and axial directions, comprising:
a clamping sleeve arranged between the mandrel or the like and the tool or workpiece, radially elastically deformable under an externally variable fluid pressure, and axially adjacent to the tool or workpiece; and a nut which can be screwed onto a mandrel or the like, and which presses a tool or workpiece against the collar or the like of the mandrel or the like.

In the clamping device known from DE 743 530, the tool or workpiece is fixed to a mandrel or the like by means of a clamping sleeve that is elastically deformable under variable fluid pressure. Ru. In this case, the clamping sleeve fills the annular space between the mandrel or the like and the tool or workpiece. With this known tightening device, tightening takes place only in the radial direction; axial tightening is not possible.

It is known, for example, for tools such as shaving cutters for precision machining of gear wheels to be mounted directly on the mandrel, but in this case the centering necessarily involves play. In this case, the tightening takes place in the axial direction via a mechanical or hydraulic nut towards the collar of the mandrel or another stationary stop (see German Utility Model No.
7616406 specification). The disadvantages of this solution include: This means that even though the tool, such as a shaving cutter, which is clamped to the mandrel, is made with great precision and has the smallest possible manufacturing tolerances, the tool, for example the mandrel,
The individual tolerances of the clamping sleeve and tool can add up to a concentricity error that is no longer acceptable.

The object of the invention is therefore to provide a method for centering and clamping very accurately operating tools or workpieces that must be processed very precisely on mandrels or the like as precisely and without play as possible. and to provide a tightening device in which radial and axial tightening can be carried out by only one element, in order to avoid inaccuracies caused by cooperating two elements. .

In order to solve this problem, in the configuration of the present invention,
The clamping sleeve is constructed integrally with the nut, forming a sleeve section and a nut section, and the axial contact surface of the nut section is elastically deformable in the axial direction under fluid pressure that can be varied from the outside. I made it so.

A clamping sleeve constructed in this way is screwed onto a mandrel or the like until the contact surface of the nut section contacts the tool or workpiece. In this case, the sleeve section is located in an annular space between the mandrel or the like and the tool or workpiece. By varying the pressure of the fluid, the tool or workpiece is then tightened radially and axially. For axial tightening,
A ring-shaped chamber for accommodating fluid is provided in the nut section and two ring-shaped chambers in the sleeve section for radial tightening.
Advantageous embodiments for this purpose are described in the claims 2 and 3. Instead of a ring-shaped chamber, a plurality of chambers may also be provided, each equally distributed in the circumferential direction. The patent claims 5 to 8 indicate various advantageous embodiments for this purpose. If each chamber can be loaded independently in all embodiments, the position of the tool or workpiece to be clamped can be varied precisely. It is sufficient in many applications that the ring-shaped chambers (claim 4) or the respective radially adjacent chambers (claims 9 and 10) are common. If the pressure is loaded, the manufacturing cost of the pressure regulating device can be reduced.

Next, embodiments of the present invention will be described with reference to the drawings.

A tool 30 or a workpiece, for example a shaving cutter, is fastened to the mandrel 10, which is partially shown in FIGS. 1 and 3, via a clamping sleeve 20. The clamping sleeve 20 has a nut section 21 threaded onto the thread 11 of the mandrel 10.
and a sleeve section 22 following this nut section 21.
It has Inner peripheral surface 23 of sleeve section 22
surrounds the cylindrical section 12 of the mandrel 10, and the outer circumferential surface 24 of the sleeve section 22 is surrounded by the bore wall 31 of the tool 30. One flat side 32 of the tool 30 is in contact with the collar 13 of the mandrel 10 through an interposed disc 55, and the other flat side 33 of the tool 30 is in contact with the collar 13 through an interposed disc 56. The contact surfaces 25 of the nut sections 21 are in contact.

The sleeve section 22 of the clamping sleeve 20 has a first closed ring-shaped chamber 41 and an likewise closed ring-shaped second chamber 41 surrounding this chamber 41.
A chamber 42 (see FIGS. 1 and 2) is provided. (In this case, the concept of "closed" is
This does not negate the presence of a conduit opening into the chamber, which means that the chambers 41, 42 are bounded on all sides by the clamping sleeve 20. ) The chamber 41 has a small radial distance 43 with respect to the inner circumferential surface 23 and the chamber 42 has a small radial distance 44 with respect to the outer circumferential surface 24. In order to give the sleeve section 22 the necessary inherent dimensional stability, the radial distance 45 between the first chamber 41 and the second chamber 42 is greater than the radial distances 43, 44.

The nut section 21 of the clamp sleeve 20 includes:
A closed ring-shaped third chamber 46 is provided, which has a small axial distance 47 relative to the contact surface 25.

Chambers 41, 42, 46 are filled with fluid.
Via the pressure regulating screw 60, the pressure in the chambers 41, 42, 46 can be varied. For this purpose, these chambers are connected via a conduit 64 to a pressure regulating screw 60 . At the connection to the thread section 61, the pressure regulating screw 60 has a cylindrical shaft 62 with a sealing ring 63. The clamping sleeve 20 is threaded onto the thread 11 until the contact surface 25 loosely contacts the flat side 33 and the flat side 32 loosely contacts the collar 13.
After being screwed in, the tool 30 is tightened by the pressure adjusting screw 60. The more the pressure adjustment screw 60 is screwed in, the more the clamp sleeve 2
Based on the elastic deformation of 0, the surfaces 23, 12; 24, 31; 32, 13; 33, 2 that are in contact with each other
5 are pressed tightly together. Conduit 6 is connected via conduit 71 to indicate the pressure occurring to the operator.
A pressure indicator 70 is provided which is connected to 4. In this pressure indicator 70, a sealed piston 73 slides against the force of a spring 72, and the piston 73 has a bar mark 75.
A pin 74 is fixed thereto and protrudes from the clamp sleeve 20. The pressure is indicated by the number or color of the bars of the bar mark 75.

In practice, it has been found that in many cases it is sufficient to provide one common pressure regulating screw 60 for all chambers 41, 42, 46. Frequently, however, at least for the axially tightening third chamber 46, and possibly for the three chambers 41, 42, 46, a respective pressure adjusting screw 60, 60' and a pressure indicator are provided. 70, 70' are advantageously provided (see FIG. 2). The embodiment shown in FIG. 2 is used in particular in tools with narrow radial contact surfaces and axially wide tools, such as hobs.

In order to eliminate possible concentricity errors of the tool to be tightened, it is usually desirable to be able to straighten the tool in the radial direction. There, the sleeve section 22 of the clamping sleeve 20 has first openings which are evenly distributed in the circumferential direction and are closed.
a second chamber 48 (see FIGS. 3 and 4) and a second chamber 49 which is also equally distributed in the circumferential direction; It extends to first chamber 4
8 is a slight radial distance 43 with respect to the inner peripheral surface 23
, and the second chamber 49 has a small radial distance 44 relative to the outer circumferential surface 24 . First chamber 48
The radial distance 45 between the first and second chambers 49 is
As in the embodiment, it is larger than the radial distances 43, 44. The nut section 21 of the clamping sleeve 20 is provided with a circumferentially evenly distributed and closed third chamber 50, which is located at a small axial distance from the contact surface 25. 47
and extends mainly in the radial and circumferential directions.

The chambers 48, 49, 50 are filled with fluid, and the pressure of this fluid is adjusted by the pressure adjusting screw 60 mentioned above.
can be changed via individual room 4
If a respective pressure adjusting screw 60, 60' is provided for 8, 49, 50, concentricity errors of the tool 30 can be compensated very precisely. The pressure in the first chamber 48 causes the clamping sleeve 20 to
is fixed to the mandrel 10, whereas the second chamber 4
The pressure at 9 is applied to the clamping sleeve 10 by the tool 3.
0, the pressure in the third chamber 50 causes an axial tightening. In the concentricity test, for example, the tool 30
If it is determined that the pressure has to be lifted relative to the mandrel 10 in the figure, the pressure in the chamber 48' and possibly also the pressure in the chamber 49' is increased, and at the same time the pressure in the chamber 48'', if any, is increased. Consequently, the pressure in chamber 49'' is also reduced somewhat.
In this case, if necessary, a third chamber 5 may be provided to enable movement of the tool 30 in the radial direction.
It is necessary to temporarily lower the pressure at 0.

In order to clearly match the chambers 48, 49, 50 which are loaded with high or low pressure to compensate for concentricity errors, the first chamber 48, the second chamber 49 and the third chamber 50 are The same number is provided. In this case, the first chamber 48 and the second chamber 49 are adjacent to each other in the radial direction, and the third chamber is adjacent to both chambers 48, 49.
49 in the axial direction.

In many cases, it is sufficient for each radially adjacent chamber 48, 49 to have a common pressure regulating screw 60 and likewise a common pressure indicator 70. In this case, instead of the axially acting chamber 50, a ring-shaped chamber 46 as described in connection with FIGS. 1 and 2 may be provided. The radially adjacent chambers 48, 49 may also be connected to each other via conduits 65, which are shown in broken lines in FIG. The pressure drop that occurs in chamber 48'' during the compensation of concentricity errors, as in the process described above, is compensated by a pressure increase in chamber 48'.

In Figures 1 to 4, the clamp sleeve 2
0 is shown as a uniform piece, there are many different possibilities for manufacturing the clamping sleeve. Clamping sleeves usually consist of a plurality of parts, each having a suitable chamber formed by cutting and/or turning, and welded together in a pressure-tight manner. In the embodiment shown in FIG.
The clamping sleeve consists of four parts 51 to 54, but other embodiments are of course possible.

The invention is not limited to the embodiments shown and described. For example, the pressure adjusting screws 60, 60'... and/or the pressure indicators 70, 70'... may be arranged in the axial direction instead of the radial direction, and the number of chambers is limited to four each. It's not a thing.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a first embodiment of the tightening device according to the present invention, FIG. 2 is a cross-sectional view taken along the line - in FIG. 1, and FIG. 3 is a second embodiment of the tightening device according to the present invention. A longitudinal sectional view showing an example, Fig. 4 is a - of Fig. 3.
FIG. 5 is a cross-sectional view along a line, and FIG. 10...Mandrel, 11...Thread, 12...Division, 13...Brim, 20...Clamp sleeve,
21...Nut section, 22...Sleeve section, 2
3... Inner circumferential surface, 24... Outer circumferential surface, 25... Contact surface, 30... Tool, 31... Hole wall, 32, 33...
...Plane side, 41, 42, 46, 48, 48', 4
8″, 49, 49′, 49″, 50...room, 43,
44, 45... Radial distance, 47... Axial distance, 51, 52, 53, 54... Portion, 55, 5
6... Disk, 60, 60', 60''... Pressure adjustment screw,
61...screw thread, 62...shaft, 63...packet, 64,65,71...conduit, 70,7
0', 70''...Pressure indicator, 72...Spring, 73
... Piston, 74 ... Pin, 75 ... Bar mark.

Claims (1)

[Claims] 1. A device for releasably tightening a tool or workpiece having a hole in the center to a mandrel or similar in the radial and axial directions, which can be changed from the outside. a clamping sleeve disposed between the mandrel or the like and the tool or workpiece, which is elastically deformable in the radial direction under a fluid pressure that can In the case of a type having a nut which can be screwed onto a similar material and which presses a tool or workpiece against the collar of a mandrel or similar material, or a similar material, the clamping sleeve is integrated with the nut. are configured to form a sleeve section 22 and a nut section 21, and the nut section 21
A tightening device characterized in that the axial contact surface 25 of the is elastically deformable in the axial direction under externally changeable fluid pressure. 2. Tightening device according to claim 1, in which the nut section 21 has a closed annular chamber 46 for accommodating fluid at a small axial distance 47 from the contact surface 25. 3. The sleeve section 22 has two ring-shaped chambers 41, 42 for accommodating fluid, the first chamber 41 of which is located at a small radial distance 43 from the inner circumferential surface 23, 2 chamber 42 is on the outer peripheral surface 2
4, the second chamber 42 surrounds the first chamber 41 and the radial distance between the first chamber 41 and the second chamber 42 45 is larger than the radial distance 43 of the first chamber 41 with respect to the inner circumferential surface 23 and the radial distance 44 of the second chamber 42 with respect to the outer circumferential surface 24. Tightening device. 4. The tightening device according to claim 2 or 3, wherein the chambers 41, 42, 46 are fluidly connected to each other. 5. The sleeve section 22 and/or the nut section 21 have a plurality of chambers for accommodating fluid, which are evenly distributed in the circumferential direction and can be loaded independently of each other. The tightening device according to item 1. 6 First chambers 4 evenly distributed in the circumferential direction
8 is arranged at a small radial distance 43 from the inner circumferential surface 23 of the sleeve section 22, and a second chamber 49 evenly distributed in the circumferential direction is arranged at a small radial distance 43 from the outer circumferential surface 24 of the sleeve section 22. 44, and the radial distance 45 between the first chamber 48 and the second chamber 49 is the same as the radial distance 43 of the first chamber 48 with respect to the inner circumferential surface 23 and with respect to the outer circumferential surface 24. Radial distance 44 of second chamber 49
A third chamber 50, which is larger than the contact surface 25 of the nut section 21 and evenly distributed in the circumferential direction,
6. The tightening device according to claim 5, wherein the tightening device is arranged at a small axial distance 47 from . 7 First chamber 48, second chamber 49, and third chamber 50
7. The tightening device according to claim 6, wherein the number of . 8 A first chamber 48 and a second chamber 49 are located one above the other in radial direction in the sleeve section 22, and a third chamber 50 is located above both chambers 48, 4.
8. The tightening device according to claim 7, wherein the tightening device is arranged in the nut section 21 radially and axially offset relative to the nut section 9. 9. A first chamber 48, a second chamber 49, and both chambers 48, which are located above and below each other when viewed in the radial direction, respectively.
9. A tightening device according to claim 8, wherein the third chamber 50, which is arranged offset with respect to 49, is fluidly connected to one another. 10. Tightening device according to claim 6 or 9, characterized in that instead of the third chamber 50, which is evenly distributed in the circumferential direction, a closed ring-shaped chamber 46 is provided.