Optical sensor with collision protection for a measurement machine

Abstract

The invention relates to an optical sensor with collision protection for a measurement machine, in particular for a coordinate measurement machine. The optical sensor comprises a sensor-side coupling part for mechanically and optically connecting to the measurement machine, and a sensor element. According to the invention, the sensor comprises a sensor protective coupling as collision protection, said protective coupling comprising a coupling part on the measurement machine side and a coupling part on the sensor element side, wherein a fiber optic cable is routed between the coupling parts of the sensor protective coupling and wherein a fiber optic cable protection element surrounds the fiber optic cable, wherein the ends of the fiber optic cable protection element are fastened to the associated coupling part of the sensor protective coupling.

Description

[0001] The invention relates to an optical sensor with collision protection for a measurement machine, in particular for a coordinate measurement machine, which has a sensor-side coupling part for mechanical and optical connection to the measurement machine and has a sensor element. BACKGROUND [0002] It is known in the prior art for tactile, but not optical, sensors for coordinate measurement machines to be equipped with collision protection. By way of example, EP 0 426 492 A2 discloses a tactile sensor which is intended for continuous measurement of workpieces and has a sensor element which is held in an equilibrium position by restoring forces. The restoring forces are produced by springs. The sensor element is held, preferably magnetically, on a sensor holder via precision bearings, with the restoring forces acting on the sensor holder. [0003] In contrast to this tactile sensor, an optical sensor is moved past the surface of a workpiece to be measured, without touching it. There ...

AI Technical Summary

Benefits of technology

[0011] In order to overcome this problem, the collision protection according to the invention has been created, in which a sensor protection coupling is provided in the sensor itself, instead of a protection coupling provided at the junction point between the sensor and the sensor holder on the measurement machine. The sensor protection coupling allows the sensor element to be released from the coupling part on the measurement machine side in the event of a collision, before the sensor element is damaged.

[0028] A defined reference plane may be introduced within the optical sensor for interferometric measurement methods, preferably in the form of a reflection from one of the optics surfaces in order in this way to achieve a short distance between the reference plane and object plane, which then corresponds to the measured distance. This makes it possible to minimize environmental influences. One such measurement method is also known as Common Path Interferometry.

Problems solved by technology

Therefore, the optical sensor has virtually no protection in the event of a collision with the workpiece at the side or, at least, it is not possible to determine whether the sensor has collided with the workpiece.

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