Patent ID: 7354066

Claim:
A counterweight device for a construction machine, utilized to mount a counterweight at a body frame of the construction machine, comprising: two pairs of support plates, with one pair of support plates disposed at a right region of the counterweight and another pair of support plates disposed at a left region of the counterweight; two brackets provided on the body frame, each of which is insertable between the two pairs of support plates; a first engaging groove formed at an upper end of each of the two pairs of supports plates; a second engaging groove formed at a lower end of each of the two brackets; a first engaging pin projecting from a lower part of each of the two pairs of support plates, that engages at the second engaging groove when mounting the counterweight; a second engaging pin projecting from an upper part of each of the two brackets, that engages at the first engaging groove when mounting the counterweight; a pinhole formed between the first engaging groove and the first engaging pin of each of the two pairs of support plates; a pinhole formed between the second engaging groove and the second engaging pin of each of the two brackets; two hydraulic cylinders provided on the counterweight so as to raise/lower the counterweight relative to the body frame; a rod pin provided at an upper end of the piston rod of each of the two hydraulic cylinders; two pairs of cylinder brackets provided on the body frame, that extend rearward with respect to the body frame, and a notch formed at an upper end of each of the two pairs of cylinder brackets at a position further rearward relative to a rear end of the body frame, that engages with the rod pin.