Valve timing control device for internal combustion engine

A valve timing control device for an internal combustion engine, comprising:

• a drive rotary member rotated by a crankshaft of the engine;
• a driven rotary member to rotate a camshaft of the engine upon rotation of the drive rotary member;
• a rotational phase control mechanism having an intermediate rotary member rotated relative to the drive and driven rotary members to cause relative rotation between the drive and driven rotary members;
• and
• a braking mechanism having a hysteresis brake that generates a braking force to cause the intermediate rotary member to rotate relative to the drive and driven rotary members,
• the drive and driven rotary members and the intermediate rotary member being arranged concentrically to be rotatable about a given axis relative to one another, and
• the rotational phase control mechanism further comprising:
• a radial guide provided on either one of the drive and driven rotary members;
• a spiral guide provided on the intermediate rotary member;
• a movable part guided by the radial guide and the spiral guide in a radial direction with respect to the given axis upon rotation of the intermediate rotary member relative to the drive and driven rotary members, the movable part having a sliding element slidably engaged in the spiral guide;
• and
• a link that links the movable part to the other of the drive and driven rotary members to change a rotational phase between the drive and driven rotary members according to radial movement of the movable part, the link having a lever connected to the other of the drive and driven rotary members at a position away from the given axis.

A valve timing control device for an internal combustion engine, comprising:

• a drive rotary member rotated by a crankshaft of the engine;
• a driven rotary member to rotate a camshaft of the engine;
• an intermediate rotary member rotated relative to the drive and driven rotary members to cause relative rotation between the drive and driven rotary members;
• biasing means for biasing the intermediate rotary member in a given rotation direction;
• a hysteresis brake that selectively applies a braking force to the intermediate rotary member to force the intermediate rotary member in a direction opposite to the given rotation direction,
• the hysteresis brake including:
• a first member having a hysteresis portion with a magnetic hysteresis characteristic, the hysteresis portion being coupled to the intermediate rotary member;
• a second member having a magnetic portion to provide a magnetic-field across the hysteresis portion;
• and
• a magnetic-field control unit that controls the magnetic field,
• the first and second members being movable relative to each other so that the hysteresis portion shows the magnetic hysteresis characteristics relative to the magnetic field generated from the magnetic portion to impart the braking force to the intermediate rotary member.