To provide a device for measuring Q characteristic of a fuel injection valve, capable of enhancing measuring efficiency of a Q characteristic, by automatically determining a breaking point of the Q characteristic.
This device for measuring Q characteristic of the fuel injection valve is provided for measuring the Q characteristic effected between current-carrying time to the fuel injection valve of an internal combustion engine and a fuel injection quantity Q injected from the fuel injection valve when carrying an electric current, and has an approximate straight line calculating means for calculating an approximate straight line corresponding to respective measuring points up to (i-1)th measuring point ai-1 from the largest measuring point a1 of from a plurality of measuring points composed of Q measured by changing and corresponding to the Q, and a breaking point determining means for determining the breaking point of the Q characteristic by using a distance between the approximate straight line calculated by the approximate straight line calculating means and a measuring point ai of short in the next place of the shortest measuring point ai-1 of out of the respective measuring points corresponding to the approximate straight line.
Toshiyuki Hatta
High Yoshitaka Hayashi