| 摘要 |
PROBLEM TO BE SOLVED: To enhance strength against an external shock, a load, etc., while suppressing an increase in weight of a support arm, and to join a cylinder fitting beam to each support arm with high strength.SOLUTION: Left and right support arms 12, 17 comprise vertical plates 13, 18 made of thick solid plate materials extending in front-rear directions and channel-shaped reinforcing plates 14, 19 made of thin plate materials thinner than the vertical plates 13, 18, extending along external surfaces 13B, 18B of the vertical plates 13, 18, and made open on sides of end faces 14D, 19D facing the vertical plates 13, 18. Then a hollow structure is formed of the vertical plates 13, 18 and reinforcing plates 14, 19 by welding sides of the end faces 14D, 19D of the reinforcing plates 14, 19 to the external surfaces 13B, 18B of the vertical plates 13, 18. Consequently, the respective support arms 12, 17 can be increased in strength against an external shock, a load in a vending direction, etc., while suppressed from increasing in weight. |
