摘要 |
<p>The present invention provides a center frame designed so that a center member, legs, and a lower plate can be formed by bending metal sheets, and to provide a manufacturing method for the center frame. A pair of front legs 13 and a pair of rear legs 14 are formed by bending metal sheets so as to have substantially reverse U-shaped cross-sections. The center member 10 is formed by bending a metal sheet so as to have a substantially square U-shaped cross-section. The front legs 13, the rear legs 14, the center member 10, a center front plate 22, and a center rear plate 23 are placed on and securely weld to the lower plate 18, which has an approximate X shape, in a plan view, and an isosceles trapezoidal shape in a lateral cross-section. This eliminates the need for expensive molds and makes it possible to easily manufacture the center frame from the center member, legs, and lower plate formed by bending metal sheets.</p> |