To fasten a core to a spring retainer reliably with sufficient joining strength.
In a device for measuring displacements of an engine valve, displacements of an engine valve 2 are measured by a differential transmformer- type displacement sensor 12. The displacement sensor 12 is formed of a bobbin 14 and a tubular core 15. The bobbin 14 is fastened to a cylinder head 3 concentrically with the engine valve 2, and a sensor coil 13 formed of a primary coil and secondary coil is wound on the peripheral surface of the bobbin 14. The tubular core 15 is movable inside the bobbin 14, and the upper end part of the core 15 is mounted on a spring retainer 6. In this case, an outward directed flange part 15a is provided at the upper end part of the core 15, and the flange part 15a and the inner surface of the upper part of the core 15 are adhered to the lower surface of the spring retainer 6 inner than the part for receiving and stopping a valve spring 8 and the peripheral surface of the tubular part of the spring retainer 6 connected to the lower surface by an adhesive 21, respectively.
ADEGAWA MAKOTO
KOBAYASHI HARUKI
