| 摘要 |
Drain oil is discharged into an oil drain passage from an advance angle port and discharge port, or from a delay angle port and discharge port; the drain oil may be mixed with foreign matter. The flow of such foreign matter accompanying the drain oil, even if flowing toward an electromagnetic actuator, can be hindered from reaching a high magnetic flux density portion by each of a pipe, a hollow shaft, and a collar. The high magnetic flux density portion, which is easy to be affected by influence of the foreign matter, can be prevented from suffering from the arrival of the foreign matter; this prevents an occurrence of the slide abrasion and/or the slide defect of a plunger, improving the reliability of an oil control valve. |
| 主权项 |
1. An electromagnetic spool valve comprising:
an electromagnetic actuator which includes a plunger that is driven in an axial direction by magnetic force; and a spool valve combined with the electromagnetic actuator in the axial direction, the spool valve including a spool that is driven in the axial direction by the plunger, wherein: one axial side of the plunger faces a first space gap, and another axial side of the plunger faces a second space gap, the first and second space gaps each communicating with a drain space via an oil drain passage formed inside of the spool; the first space gap is a first magnetic flux density portion, which has a first magnetic flux higher than a second magnetic flux of the second space gap, the first magnetic flux density portion providing magnetic attraction power to the plunger; and a drain oil from the oil drain passage to the first magnetic flux density portion is hindered by (i) a pipe provided at an end of the spool, the pipe penetrating the end of the spool, the end being on a side of the pipe facing the electromagnetic actuator, (ii) a hollow shaft, which has a hollow interior and is sandwiched between the plunger and the spool, and (iii) a ring-shaped collar which increases the magnetic attraction power of the plunger. |
