Weight-reduced guide bar of solid material
A guide bar ( 1 ) for the saw chain ( 2 ) of a motor-driven chain saw includes a longitudinal bar base body ( 3 ) of solid material having a reversal section ( 5 ) and a mounting section ( 8 ). A weight recess ( 11 ) is formed in a flat side ( 13 ) of the bar base body ( 3 ). The weight recess ( 11 ) extends essentially along the bar base body ( 3 ) and is closed by a cover plate ( 12 ). A light-weight, torsion-resistant guide bar is produced in that a longitudinal rib ( 14, 15 ) supporting the cover plate ( 12 ) is arranged in the weight recess ( 11 ) and extends in the longitudinal direction ( 19 ) of the guide bar ( 1 ).
1 . A guide bar for a saw chain of a motor driven chain saw, the guide bar comprising:
an elongated bar base body of solid material having a first end and a second end;
a direction reversal section for said saw chain and said direction reversal section being arranged at said first end of said bar base body;
a mounting section for fixating said guide bar and said mounting section being arranged at said second end;
said bar base body defining an edge and having a flat side;
a guide groove formed in said edge of said bar base body and being configured to guide said saw chain;
a weight recess formed in said flat side of said bar base body and extending essentially along said bar base body between said mounting section and said reversal section;
a cover plate for closing said weight recess; and,
said weight recess having a longitudinal rib arranged therein for supporting said cover plate and said longitudinal rib extending in the longitudinal direction of said bar base body.
2 . The guide bar of claim 1 , wherein said flat side is a first flat side and said bar base body has a second flat side; and, said weight recess opens to only one of said first and second flat sides of said bar base body.
3 . The guide bar of claim 1 , wherein said longitudinal rib partitions said weight recess into component recesses.
4 . The guide bar of claim 3 , wherein said weight recess is one of a plurality of weight recesses lying one next to the other transversely to the longitudinal direction of said bar base body.
5 . The guide bar of claim 1 , wherein said weight recess extends essentially from said mounting section to said reversal section.
6 . The guide bar of claim 1 , further comprising a countersink having a distance to said flat side of said bar base body; and, said longitudinal rib extending to said countersink.
7 . The guide bar of claim 1 , wherein said cover plate has an outer side lying in a plane with said flat side of said bar base body.
8 . The guide bar of claim 1 , wherein said cover plate has an edge; said weight recess has a peripheral edge; and, said edge of said cover plate and said peripheral edge of said weight recess conjointly define a gap.
9 . The guide bar of claim 8 , wherein said cover plate is fixed on said bar base body with a welding seam.
10 . The guide bar of claim 1 , wherein said welding seam is a bifocal laser welding seam.
11 . The guide bar of claim 9 , wherein said welding seam bridges said gap.
12 . The guide bar of claim 9 , wherein said welding seam fills said gap.
13 . The guide bar of claim 1 , wherein said weight recess is ventilated.
14 . The guide bar of claim 8 , wherein said welding seam is an intermittent welding seam; and, said weight recess is ventilated through said intermittent welding seam.
15 . The guide bar of claim 1 , wherein the material of said cover plate has a degree of hardness of 20 to 58 HRC.
16 . The guide bar of claim 1 , wherein the material of said cover plate has a carbon content between 0.25% and 1%.
17 . The guide bar of claim 15 , wherein the material of said cover plate is a hardened and tempered steel.
18 . The guide bar of claim 16 , wherein the material of said cover plate has a carbon content at least as high as the carbon content of said bar base body.
19 . The guide bar of claim 15 , wherein said cover plate consists essentially of 50CrMo4.
20 . The guide bar of claim 1 , wherein said flat side is a first flat side and said bar base body has a second flat side defining an uninterrupted surface devoid of any recesses.