EP2512743B1 - Clamping device for rod-shaped profiled elements - Google Patents

Description

The invention relates to a tensioning device for rod-shaped profiles with a substantially circular cross-section according to the preamble of claim 1.

Clamping devices for pipes, as a special embodiment of a rod-shaped profile, are known in the art. In this case, the clamping devices on two spaced Zentrischspanner. The two centric clamps comprise the tube in a clamping position in the region of the tube ends. Pipe ends of the clamped in the clamping position tube can be supplied for further processing. For this purpose, the pipe ends are, for example, chamfered, deburred, brushed, etc. The problem with the known clamping devices is the insufficient position exactness of the clamped pipe. That is, due to multiple external circumstances such as temperature, material change, etc. deviates the desired central axis of the clamping device of the pipe center axis of the clamped pipe usually something. The deviations may be minimal, i. in the micrometer range. Due to ever stricter quality specifications of the processing industry to the manufacturer even such a small offset of the pipe center axis of the clamped pipe is no longer acceptable. Because the subsequent processing of the pipe ends, for example by the attachment of chamfers, which is also associated with a small but existing scattering, leads to an accumulated error, whereby the manufacturer runs the risk of no longer meeting the strict acceptance criteria.

From the DE 10 2006 035 131 B3 For example, a machine for introducing markings on the outer surface of a pipe is known. There, the relative position of the tube can be changed to a marking tool by means of one another movable support plates.

From the US 4,667,548 is a work edition for the processing of pipe end sections known. There, a pipe is clamped between pads. An adjustment of the pipe end is possible by means of a Schraubstabes, by the two halves of the work support are moved against each other, a targeted readjustment of the position of the pipe section in the cross-sectional plane perpendicular to the pipe axis is not possible.

In the DE 42 17 860 A1 a clamping device is provided by means of a pipe or milling machine at the end of a pipe is attachable. The clamping device does not allow the readjustment of the applied milling tool relative to the pipe section.

From the JP 631564 is a clamping device with two mutually movable clamping jaws, which are suitable for clamping long profiles.

From the US 6,065,744 is a holder for a component known with two juxtaposed pads between which forms a V-shaped support, which is the displacement of the pads horizontally and vertically changeable.

It is therefore an object of the invention to provide a clamping device for rod-shaped profiles available, which allows a more precise clamping of the rod-shaped profile.

The object is achieved by an aforementioned clamping device with the characterizing features of claim 1.

The invention makes use of the idea that to reduce when adjusting a rod-shaped profile in a clamping device over time adjusting or from the outset existing offset between the desired central axis and profile central axis by an adjusting device. Under rod-shaped profile are understood here, inter alia, tubes and solid profiles. The clamping device preferably has two Zentrischspanner. But it is also a training with an arbitrarily higher number of Zentrischspannern possible. The profiles are in a cross section transverse to its longitudinal direction substantially circular, preferably formed exactly circular. Conveniently, the profiles are substantially along their entire length, preferably exactly circular in cross-section. The cross section is conveniently arranged perpendicular to the longitudinal axis.

The profiles rest on supports of the centric clamps. The adjustment is done by changing the shape of the pads.

Each of the centric clamps preferably has exactly two centrically movable clamping jaws. Each of the Zentrischspanner can have three, four or even an arbitrarily higher number of clamping jaws.

The Zentrischspanner allows the exact approach to each other and each other driving away the jaws of opposing jaws in a traversing plane. Conveniently, each of the jaws on exactly one edition. Preferably, at least one of the pads is divided into two or a more arbitrary higher number of partial pads. The pads are preferably formed prismatic.

In a favorable embodiment of the invention, each of the clamping jaws in each case has a prismatically shaped support, wherein each of the prismatic supports has two straight bearing surfaces running in a longitudinal direction of the clamped tube, which are perpendicular to one another.

Conveniently, a deviation of the profile central axis of the clamped profile of the desired central axis in all directions of the process plane adjustable by the adjusting device. Thus, it is possible to correct the offset in any direction.

In a particularly simple way, the support can be changed in shape in an embodiment in which each of the clamping jaws has at least three gaps. The gaps of a clamping jaw preferably extend in the longitudinal direction in each case over the entire length of the clamping jaw and thus each form a deformable tongue between them. The deformable tongue is conveniently formed in the clamping jaw so that it forms a partial support on the opposite clamping jaw facing outer wall.

By deformation of the tongue associated with the tongue part support is changed in position relative to the clamping jaw and formed of at least two partitions support the jaw receives a slightly different overall shape. A resting in the clamping position on the supports profile also changes its relative position to the jaw a piece. This change is used to reduce the offset.

Conveniently, each of the jaws on exactly three, an upper, a lower and a middle gap, which form between them exactly two juxtaposed deformable tongues, which are separated by the middle gap. At each of the tongues while a partial edition of the requirements of a jaw is provided. Each of the clamping jaws may be formed in one piece, in particular the tongues and the associated clamping jaw frame may be in one piece. The clamping jaw can be manufactured with high precision in the EDM process

Due to the deformation of the preferably two tongues of a clamping jaw, the shape of the preferably prismatic support is slightly changed. Conveniently, the changes are made such that the opposing and cooperating jaws of a Zentrischspanners be changed such that the desired central axis and the profile central axis coincide after adjustment.

According to the invention, the adjusting device comprises at least one adjustable width adjustable spacer member. The spacer member may be inserted in an associated gap and abut or penetrate the gap walls. By changing the width of the spacer in the gap, the gap width is variable. The gap width can also be adjusted by the width of the spacer component, that is, the gap width is maintained in the width set by the spacer component for the at least next processing step. You can then make new settings below.

Preferably, each of the jaws on exactly three column and spacer components are embedded in the next but one column. However, embodiments are also disclosed which have clamping jaws of any number of columns, in particular four or more columns. Spacer members are preferably recessed in each of the slots or in only selected slots.

After the profile is clamped in the clamping device, a profile machining of the clamped profile is preferably carried out. This profile ends, such as pipe ends can be provided with a chamfer. If the pipe central axis does not coincide with the desired central axis of the clamping device, the subsequent profile end machining leads to an eccentricity, which can be measured by a separate measuring device. The size and location of the measured eccentricity is used to make a corresponding readjustment by means of the adjusting device. Conveniently, a correlation table is created in advance, which makes it possible, depending on the measured eccentricity to immediately determine an adjustment of the adjustment, which leads to an at least significant reduction in the offset of the two central axes.

In a preferred embodiment of the invention, the spacer elements of the adjusting device have conical screws with a small cone angle of less than 1 degree, which are embedded in a thread inserted into an associated gap and increase or enlarge the gap width by turning in and out of the thread . reduce. Also, cone angles of less than 0.5 degrees, 0.2 degrees, or even less are conceivable.

In other embodiments of the adjusting device, the spacer components are designed as piezo elements or other, preferably wedge-shaped components. Mixed forms of the spacer components are also possible or the use of different spacer components in the same clamping device.

The tensioning device according to the invention may be a component of a profile cutting machine. It is preferably provided in the processing gear for a sawing tool. From the sawing tool, the cut-to-length profile can be inserted there by means of a gripping arm in the release position of the clamping device and then clamped there. In the clamping position, the high-precision post-processing is carried out as described above. The clamping device is then transferred back to the release position and removed the processed profile by means of a preferably other gripping arm.

Fig. 1

eine perspektivische Ansicht einer erfindungsgemäßen Spannvorrichtung in Nullstellung,

Fig. 2

eine Vorderansicht in Fig. 1,

Fig. 3

eine perspektivische Ansicht der Spannvorrichtung in Fig. 1 mit herausgedrehten oberen Kegelschrauben und hineingedrehten unteren Kegelschrauben,

Fig. 4

eine Vorderansicht in Fig. 3,

Fig. 5

eine Spannvorrichtung in Fig. 1 mit herausgedrehten rechten Kegelschrauben und hineingedrehten linken Kegelschrauben,

Fig. 6

eine Vorderansicht in Fig. 5,

Fig. 7

eine Spannvorrichtung in Fig. 1 mit herausgedrehten unteren Kegelschrauben und hineingedrehten oberen Kegelschrauben,

Fig. 8

eine Vorderansicht in Fig. 7,

Fig. 9

eine Spannvorrichtung in Fig. 1 mit herausgedrehter oberer rechter Kegelschraube und hineingedrehter unterer linker Kegelschraube,

Fig. 10

eine Vorderansicht in Fig. 9.

The invention will be described with reference to an embodiment in ten figures. Showing:

Fig. 1

a perspective view of a tensioning device according to the invention in zero position,

Fig. 2

a front view in Fig. 1 .

Fig. 3

a perspective view of the clamping device in Fig. 1 with unscrewed upper conical screws and lower conical screws screwed in,

Fig. 4

a front view in Fig. 3 .

Fig. 5

a tensioning device in Fig. 1 with unscrewed right-hand conical screws and left-hand tapered screws screwed in,

Fig. 6

a front view in Fig. 5 .

Fig. 7

a tensioning device in Fig. 1 with unscrewed lower conical screws and turned in upper conical screws,

Fig. 8

a front view in Fig. 7 .

Fig. 9

a tensioning device in Fig. 1 with upper right cone screw twisted out and lower left cone screw screwed in,

Fig. 10

a front view in Fig. 9 ,

The illustrations are not to scale, and the deformations are greatly exaggerated. Like reference numerals designate like components throughout the several figures.

Fig. 1 shows a clamping device according to the invention with a front 1 and a rear 2 in a longitudinal direction L spaced from each other Zentrischspanner between which a pipe 3 is clamped. The terms 'front', 'rear', 'top', 'bottom', 'left' and 'right' refer to the positions of the respective components relative to the tensioning device as shown in the figures. However, all other layers of the tensioning device are also disclosed. Each of the two centric clamps 1, 2 has two clamping jaws 6, 7 which can be moved centrally relative to each other. The plane traversed by the two clamping jaws 6, 7 of the respective centric clamp 1, 2 forms a traversing plane. The two Zentrischspanner 1, 2 are each mounted on a (not shown) traversing device, which is preferably operated by compressed air as a control medium. Each front jaw 6, 7 has a prismatic support. The front 1 and the rear Zentrischspanner 2 are identical.

This in Fig. 1 shown tube 3 has a tube center axis R, and the two Zentrischspanner 1, 2 have a desired central axis S, which extends centrally through the two Zentrischspanner 1, 2. The tube 3 is clamped in the two Zentrischspannern 1, 2. The clamping device is therefore in a clamping position.

Pipe ends of the clamped in the two centric clamps 1, 2 pipe 3 are in the clamping position a piece over the jaws 6, 7, 11, 12 of the centric clamp 1, 2 also off. The free pipe ends can in the clamping position thus processing in Be subjected to brushing, deburring and / or chamfering by means of a (not shown) tool head. The tool head is guided for machining from the outside to the free end of the tube, placed in a machining position, and it performs during machining a rotational movement about the set center axis S from.

Fig. 2 shows in a plan view, the tube 3 in the clamping position. The in Fig. 2 shown front Zentrischspanner 1 includes the left and right front jaw 6, 7, which cooperate for clamping the tube 3. The clamping jaws 6, 7 are centrically movable toward one another in order to clamp the tube 3 in the clamping position, in order then to be subjected to machining and to be moved centrally away from one another in order to release the tube 3 in a release position, which is then moved by means of a (not shown) Gripper arm can be removed from the clamping device.

The pipe center axis R and the set center axis S of the tensioning device fall in Fig. 1 and Fig. 2 together. At the desired central axis S, the subsequent processing of the pipe ends is aligned by means of the tool head. An offset between the pipe center axis R and the set center axis S thus leads to an eccentricity in the machining of the pipe end. In Fig. 2 If the zero position is shown, there is no offset.

Due to various influences such as temperature fluctuations, material changes over time and many other factors, the clamping device does not always clamp the ideal circular tube 3 in the zero position without offset, according to Fig. 2 , one. It can lead to an offset between pipe center axis R and Sollmittelachse S. The offset results from an eccentricity of the processing, ie, for example, from circumferentially different Anfastiefen the pipe end in the subsequent processing step.

Both centric clamps 1, 2 have exactly two clamping jaws 6, 7, 11, 12. The clamping jaws 6, 7, 11, 12 are in the respective Zentrischspanner 1, 2 associated traversing plane movable. The traverse plane is arranged perpendicular to the set center axis S. The two paths of the Zentrischspanner 1, 2 are parallel to each other.

The two clamping jaws 6, 7, 11, 12 of each Zentrischspanners 1, 2 each have three mutually parallel column 13a, 13b, 13c, 14a, 14b, 14c. The two upper columns 13c, 14c and the two lower columns 13a, 14a are each the same length and slightly longer than the two middle column 13b, 14b in Fig. 2 educated. The three gaps 13a, 13b, 13c, 14a, 14b, 14c of each clamping jaw 6, 7 extend from the wall of the clamping jaw 6, 7 facing the respective clamping jaw 6, 7 in the traverse plane straight into the respective clamping jaw 6, 7 , 11, 12 into it. The opposite column 13a, 13b, 13c, 14a, 14b, 14c of the two opposing jaws 6, 7 are in the same vertical height and in a straight line Extension arranged to each other. The three gaps 13a, 13b, 13c, 14a, 14b, 14c of a clamping jaw 6, 7 each form two deformable tongues 16a, 16b, 17a, 17b.

Each of the clamping jaws 6, 7 has two prismatic support parts 8a, 8b, 9a, 9b. A prismatic support is characterized by the fact that it has two straight bearing surfaces arranged at right angles to one another, which are curved into one another. Two opposing and cooperating prismatic supports make it possible to hold tubes 3 of different diameters firmly clamped in the clamping position, wherein the tube 3 rests in each Zentrischspanner 1, 2 along four support lines on the two prismatic support. Each of the prismatic supports forms two support lines. According to the invention, each of the prismatic supports is separated by a middle gap 13b, 14b into respectively an upper and a lower support part 8a, 8b, 9a, 9b. The left upper support part 8b is disposed on the left upper tongue 16b, and the left lower support part 8a is disposed on the left lower tongue 16a. Due to the mobility of the tongues 16a, 16b and the associated mutual displaceability of the partial supports 8a, 8b, 9a, 9b against each other, the two prismatic supports can be somewhat deformed in each case, whereby the position of the clamped tube 3 can be changed in the clamping position allows a z. B. due to the above-mentioned influences adjusting the pipe center axis R of the target center axis S. A resulting offset of the axes can thus be reduced and corrected. Accordingly, support parts are provided on the other tongues.

The adjusting device has in this embodiment four conical screws 19a, 19b, 21a, 21b per Zentrischspanner 1, 2. The conical bolts 19a, 19b, 21a, 21b are screwed into a respective threaded hole extending in the longitudinal direction L in the associated gap 13a, 13c, 14a, 14c on the end of the upper and lower gap 13a, 13c, 14a, 14c facing the pipe 3. In the in Fig. 1 shown zero position, the gap widths of the upper 13c, 14c and lower column 13a, 14a all the same. By screwing the cone screw 19a, 19b, 21a, 21b, the respective gap width can be increased by unscrewing the respective cone screw 19a, 19b, 21a, 21b, the associated gap width can be reduced. The four tongues 16a, 16b, 17a, 17b are each formed so as to have a bias against an adjacent upper and lower jaw frames 22a, 22b, 23a, 23b. The upper and lower clamping jaw frames 22a, 22b, 23a, 23b are significantly more difficult to deform than the four tongues 16a, 16b, 17a, 17b because the upper and lower clamping jaw frames 22a, 22b, 23a, 23b are significantly thickened in a region facing away from the tube 3 is and is also higher in the vertical direction than the four tongues 16a, 16b, 17a, 17b. The four tongues 16a, 16b, 17a, 17b of a centric clamp 1 all have an equal length in the longitudinal direction L, height in the vertical direction H and depth in the direction of travel V.

Fig. 3 shows the clamping device in Fig. 1 in a readjusted position. In this case, the upper left taper bolt 19b and the upper right taper bolt 21b are unscrewed so that the upper left tongue 16b and the upper right tongue 17b of the front Zentrischspanners 1 are deformed by their bias upwards, while the two lower taper bolts 19a, 21a of the left and right clamping jaw 6, 7 of the front Zentrischspanners 1 are screwed and its associated two lower tongues 16a, 17a thus deform upwards. As a result, the two left support parts 8a, 8b and right prismatic support parts 9a, 9b are displaced such that the clamped tube 3 shifts upward in the tensioned position.

Fig. 4 shows the displacement of the pipe center axis R relative to the set center axis S by an offset vertically upward.

Fig. 5 shows a perspective view of the Zentrischspanners 1 in Fig. 1 with right upper cone screw 21b and right lower cone screw 21a twisted out and left upper cone screw 19b and left lower cone screw 19a screwed in, respectively.

Fig. 6 shows the deformation of the four tongues 16a, 16b, 17a, 17b in a corresponding manner. By biasing and unscrewing the right upper screw 21b, the right upper tongue 17b is deformed upward. Accordingly, the right lower tongue 17a is deformed by unscrewing the right lower cone screw 21a down and thus the right prismatic edition slightly widened and the clamped tube 3 is a piece far offset to the right. The right upper 14c and the right lower gap 14a narrow and the right middle gap 14b widens.

In the same adjustment in Fig. 6 the left upper cone screw 19b and the lower left cone screw 19a are screwed in so that the two left tongues 16a, 16b are centered on each other, the left middle gap 13b narrows, the upper left and left lower gaps 13c, 13a widen, and the left prismatic overlay is also somewhat narrowed.

In principle, the adjusting device with its four conical screws 19a, 19b, 21a, 21b should be adjusted in such a way that an adjustment does not take place exclusively via a screwing or screwing in, but at the same time via an associated screwing in and out of corresponding conical screws. Fig. 6 shows in the position an offset of the pipe center axis R to the set center axis S to the right.

Fig. 7 shows the tensioner with turned left taper bolts 19a, 19b and screwed right taper bolts 21a, 21b, so that as in Fig. 8 4, the left upper 13c and lower gaps 13a are narrowed, and the upper left tongue 16b is deformed upward and the lower left tongue 16a is deformed downward. The left support parts 8a, 8b will be spaced further apart. On the right clamping jaw 7, the conical screws 21a, 21b are both unscrewed, and the two tongues 17a, 17b deform towards each other. The tube 3 goes crazy to the left.

FIGS. 9 and 10 show the tensioner with diagonally actuated tapered screws 19a, 21b, the right upper tapered screw 21b is turned off while the left lower tapered screw 19a is screwed. Thereby, the left lower tongue 16a is deformed upward, while the right upper tongue 17b also deforms upward. Due to the change in the two prismatic supports, the clamped tube moves a little way to the top right in the clamping position.

The in the FIGS. 3 to 10 shown settings of the adjustment illustrate the offset from the zero position in accordance Fig. 1 , In the real application of the adjusting device, the adjustment is carried out in the reverse manner, in accordance with the position Fig. 1 in which no adjustment is made, a trial processing of the tube ends is made, and then both ends of the tube 3 are measured with high accuracy. An eccentricity measured in this case is taken as the basis for the readjustment, so that the offset between the pipe center axis R and the setpoint axis S is reduced in accordance with the settings of the conical bolts 19a, 19b, 21a, 21b and, if possible, reversed. For this purpose, a correlation table is created in advance, which allows using the measured eccentricity of the processing of an end of a tube rotation depths of the individual cone screws 19a, 19b, 21 a, 21 b indicate in order to eliminate the eccentricity as completely as possible.

LIST OF REFERENCE NUMBERS

1

Centric clamping

2

Centric clamping

3

pipe

6

jaw

7

jaw

8a

Prismatic support parts

8b

Prismatic support parts

9a

Prismatic support parts

9b

Prismatic support parts

11

jaw

12

jaw

13a

column

13b

column

13c

column

14a

column

14b

column

14c

column

16a

tongue

16b

tongue

17a

tongue

17b

tongue

19a

cone screw

19b

cone screw

21a

cone screw

21b

cone screw

22a

Jaw frame

22b

Jaw frame

23a

Jaw frame

23b

Jaw frame

H

Height in vertical direction

L

longitudinal direction

R

Tube central axis

S

Target central axis

V

traversing

Claims (6)

1. A clamping device for rod-shaped profiled elements (3) having a substantially circular cross section
   and having a central axis (R) which runs along a longitudinal direction (L) of the rod-shaped profiled element (3), and having at least two centering clamps (1, 2) distanced from each other along a theoretical central axis (S),
   and having at least two opposing clamping cheeks (6, 7, 11, 12) that are centrally movable between a clamping position and a release position in a moving plane arranged transversely to the theoretical central axis (S), which cheeks each have a support and jointly surround the rod-shaped profiled element (3) in the clamped position and align the central axis (R) of the profiled element along the theoretical central axis (S), characterized in that a shape of the supports can be changed by an adjustable adjusting device which reduces an offset of the theoretical central axis (S) from the central axis (R) of the profiled element in the clamped position and the adjusting device comprises at least one spacer structural component that can be adjustably changed in width and that is insertable in an associated slot (13a, 13b, 13c, 14a, 14b, 14c) so as to rest on slot walls and in that
   each of the clamping cheeks (6, 7, 11, 12) has at least three adjacently arranged slots (13a, 13b, 13c, 14a, 14b, 14c) and the slots (13a, 13b, 13c, 14a, 14b, 14c) extend in a longitudinal direction (L) of the clamped-in, rod-shaped profiled element (3) over the entire length of the clamping cheek (6, 7, 11, 12) and form at least one deformable tongue (16a, 16b, 17a, 17b) between themselves on which tongue a partial support (8a, 8b, 9a, 9b) is formed.
2. The clamping device according to Claim 1,
   characterized in that an offset of the central axis (R) of the clamped-in profiled element (3) is adjustable in all directions in the moving plane by means of the adjusting device.
3. The clamping device according to Claim 1,
   characterized in that each of the clamping cheeks (6, 7, 11, 12) has three slots (13a, 13b, 13c, 14a, 14b, 14c) and at least two adjacently arranged tongues (16a, 16b, 17a, 17b) that are separated from each other by a slot (13a, 13b, 13c, 14a, 14b, 14c) and have a partial support (8a, 8b, 9a, 9b).
4. The clamping device according to Claim 1, 2 or 3,
   characterized in that the tongues (16a, 16b, 17a, 17b) of a centering clamp (1, 2) are adjustable by the adjusting device in a manner coordinated with each other.
5. The clamping device according to Claim 1,
   characterized in that each of the clamping cheeks (6, 7, 11, 12) has at least three slots (13a, 13b, 13c, 14a, 14b, 14c) and in that spacer structural components are let into a second following slot (13a, 13b, 13c, 14a, 14b, 14c).
6. The clamping device according to one of the aforementioned claims,
   characterized in that at least one of the supports is constructed as a prismatic support.

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