of a second inner bonding part 95 for bonding to the inner surface of the vertical plate 43 of the frame inner member 26 a second partitioning part 96 continuing from the second inner bonding part 95 a collar nut 79 provided to the second partitioning part 96 a second top bonding piece 97 extending upward from the top end of the second partitioning part 96 and a second bottom bonding piece 98 extending downward from the bottom end of the second partitioning part 96 the second partitioning part 96 is formed into a substantial quadrangular shape which partitions the inside of the front side frame 17 lengthwise the collar nut 79 is a member for attaching a mount not shown the second top bonding piece 97 is held and joined between the frame outer member 27 and the flange 74 shown in fig9 the second bottom bonding piece 98 is held and joined between the frame outer member 27 and the flange 75 shown in fig1 as shown in fig1 and 20 the sub frame mount stiffener 63 is provided to the bottom of the rear frame part 41 of the front side frame 17 and is composed of a mount 59 and a reinforcing part 65 furthermore the sub frame mount stiffener 63 is positioned so as to overlap the adapter 22 the mount 59 is a portion for attaching the sub.