Phase changing unit and valve timing changing device

Abstract

This phase changing unit changes the relative rotational phase of a first rotating body and a second rotating body, and comprises: a rotating member (80) to which an external drive shaft is connected,and to which a rotational driving force is applied; and a relative rotation mechanism (20, 40) that generates, by means of the rotation of the rotating member, a relative rotation between a first rotating body (CS) and a second rotating body (10). The rotating member (80) includes: a metal actuation part (84) that acts on the relative rotation mechanism; a resin connection part (82) to which thedrive shaft is connected; and a resin fragile part (82) that functions to cut the transmission of a rotational force between the drive shaft and the rotating member when an excessive load has occurred. Due to this configuration, the structure can be simplified, the number of parts can be reduced, the noise can be reduced, and the costs can be reduced, and damage to an electric motor, etc. can be prevented even when an excessive load has occurred.

Description

technical field [0001] The present invention relates to a phase change unit for changing the rotation phase of two rotating bodies, and in particular to a phase changing unit used when changing the opening and closing timing (valve timing) of an intake valve or an exhaust valve of an internal combustion engine. The phase changing unit and the valve timing changing device using it. Background technique [0002] A conventional valve timing changing device is known to include: a driving rotating body linked to the rotation of a crankshaft, a driven rotating body rotating integrally with a camshaft, a planetary carrier, planetary gears, an electric motor including a motor shaft, and A movable shaft joint mechanism or the like for connecting a motor shaft of an electric motor to a planetary carrier (for example, refer to Patent Document 1). [0003] Here, the movable shaft joint mechanism includes two joint members made of metal, and has a structure that transmits the rotational...

AI Technical Summary

Problems solved by technology

[0004] However, in the structure of the movable shaft joint mechanism and the planetary carrier, the structure is complicated, and machining such as providing a low-strength portion to the joint member is required, resulting in high cost.

[0005] In addition, since the motor shaft, the two joint members, and the planetary carrier are made of metal, the whole is a heavy object, so the moment of inertia is large, and the electric motor requires a large output torque.

[0006] Furthermore, when the torsion force fluctuates, there is a possibility that metal components may collide with each other to generate a crashing sound.

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