Clamping and holding apparatus
The invention relates to a tensioning and holding apparatus ( 6 ) having at least one tensioning means ( 12 a, 12 b, 13 a, 13 b ) for a cubic or cuboidal object ( 1 ) of variable geometry and/or dimensions that can be fixed by pretensioning, wherein the object has a respective end plate ( 4, 5 ) at two opposite ends. According to the object of the invention, this tensioning and holding apparatus should be able to be mounted particularly easily and be produced cost-effectively. To that end, it is provided that, at least at one of the end plates, two laterally opposite attachments ( 7, 8; 14, 15 ) that extend perpendicularly to the stacking and pretensioning direction ( 3 ) and parallel to one another and are intended to receive a respective associated holding rod ( 19, 20; 21, 22 ) are arranged or formed, that the attachments laterally protrude from the respective end plate, that the attachments, in their longitudinal direction, have cutouts ( 10 a, 10 b, 11 a, 11 b; 17 a, 17 b; 18 a, 18 b ) for guiding one or more tensioning means ( 12 a, 12 b; 13 a, 13 b ) that wrap around the holding rods and are in the form of endless elastic bands, that the holding rods are in force-fitting engagement with the respective attachments ( 7, 8; 14, 15 ) in the pretensioned state of the object ( 1 ), and that the end plates ( 4, 5 ) are braced against one another by means of the at least one tensioning means ( 12 a, 12 b; 13 a, 13 b ).
1 . A tensioning and holding apparatus for a fuel cell stack, the apparatus comprising:
a tensioning belt having a fixed pretensioning;
first and second end plates;
an endplate of the first and second end plates comprises attachments that extend perpendicular to a pretensioning direction and parallel to one another;
the attachments configured to receive respective associated holding rods;
the attachments laterally protrude from the end plate;
the attachments have cutouts in their longitudinal direction for guiding the tensioning belt to wrap around the holding rods;
the holding rods are in force-fitting engagement with the attachments in a pretensioned state;
the first and second end plates are braced against one another by the tensioning belt.
2 . The apparatus of claim 1 , the tensioning belt wraps around the first end plate.
3 . The apparatus of claim 1 , the end plate has a surface region having a guiding aid.
4 . The apparatus of claim 3 , the guiding aid comprising a guide rail.
5 . The apparatus of claim 3 , the guiding aid comprising a curved surface rounded in an edge region of the end plate.
6 . The apparatus of claim 1 , the tensioning belt is an endless belt.
7 . The apparatus of claim 1 , a holding rod of the holding rods is in the form of a shaft with an eccentric cross section, the holding rod is configured to be rotated about its longitudinal axis and fixed in a rotated position to increase or reduce a tensile force on the fuel stack.
8 . The apparatus of claim 7 , further comprising a spacer for retensioning the fuel stack, the spacer inserted between a depression or channel of the attachments and the holding rod.
9 . A method of mounting a tensioning belt and holding apparatus on a fuel cell stack, the method comprising:
placing a tensioning belt resting on a first upper holding rod onto a channel-like mounting tool;
placing the tensioning belt on a second upper holding rod onto a second channel-like mounting tool;
inserting the first and second upper holding rods into a first attachment and a second attachment;
applying force to an end plate to pretension a fuel cell stack;
inserting the channel-like mounting tool carrying the tensioning belt at a second end plate into a third attachment;
inserting the second channel-like mounting tool carrying the tensioning belt into a fourth attachment at the second end plate;
introducing a first lower holding rod into the first mounting tool and a second lower holding rod into the second mounting tool;
removing the first and second mounting tools; and
relieving the force on the end plate.