Rock breaking device

The invention relates to a rock breaking device (8) and a method of monitoring a condition of a tool (9) of a rock breaking device (8). The rock breaking device comprises a frame (8'), a tool (9), a device (5) for generating stress waves in the tool (9), measuring means (15) for measuring the stress wave propagating in the tool and at least one computing unit (16) for monitoring a condition of thetool on the basis of the measured stress wave. The at least one computing unit (16) is configured to determine a condition of the tool on the basis of a time of propagation of at least one reflectedstress wave component (RC1, RC2, RC3, RC4) of the stress wave and at least one additional property of the same reflected stress wave component. 本发明涉及一种岩石破碎装置(8)，并且涉及监测岩石破碎装置(8)的工具(9)的状态的方法。该岩石破碎装置包括：框架(8')；工具(9)；用于在所述工具(9)中产生应力波的装置(5)；测量装置(15)，其用于测量在所述工具中传播的所述应力波；以及至少一个计算单元(16)，其用于基于所测得的应力波来监测所述工具的状态。所述至少一个计算单元(16)被配置用以基于至少一个反射的应力波分量(RC1、RC2、RC3、RC4)的传播时间以及相同的所述反射的应力波分量的至少一个附加特性来确定所述工具的状态。