| 摘要 |
PROBLEM TO BE SOLVED: To provide an electromagnetic valve of a hydraulic control device which can suppress the sedimentation of foreign matters by expanding a range of the selection of a frequency of reciprocation and a reciprocation width of a spool.SOLUTION: In a hydraulic control device, a CPU controls a waveform of a time change of an energization amount in a period in which a slide engagement state and a command value of supply pressure are constantly maintained so as to exert a first vibration waveform part in which a second waveform, which is formed by controlling an energization amount to an electromagnetic valve at a cycle of a second frequency which is higher than a first frequency, is superimposed on a first waveform, which vibrates at the first frequency. Then, a spool reciprocates at the first frequency and a first amplitude by the first vibration waveform part. By this constitution, a frequency of the reciprocation of the spool can be determined by the first waveform, and an energization amplitude to the electromagnetic valve, that is, a reciprocation width of the spool can be controlled. Therefore, a range of the selection of the frequency of reciprocation and the reciprocation width of the spool is expanded, and foreign matters can be eliminated while suppressing a variation of supply pressure.SELECTED DRAWING: Figure 5 |
