JP2011002440A - Device for bringing measurement probe closer to object to be measured - Google Patents

Abstract

PROBLEM TO BE SOLVED: To bring a measurement probe closer to an undulating object to be measured speedily, and to minimize a physical influence to the object to be measured.SOLUTION: The device for bringing a measurement probe closer to an object to be measured includes: a probe cap that covers the tip of the measurement probe and can slide at the tip of the measurement probe; a probe cap support section that prevents the probe cap from falling off the measurement probe and performs support so that a fixed interval is maintained between the tip surface of the measurement probe and the inside of the probe cap until abutting on the object to be measured; a contact detection section for detecting contact with the object to be measured by float of the probe cap from the probe cap support section; and a function for stopping while allowing distance set between the tip surface of the measurement probe and the inside of the probe cap to remain after detecting the contact.

Description

  The present invention relates to a device for measuring a magnetic field and / or an electric field in the vicinity of a undulating surface of an object to be measured and bringing a measurement probe close to the object to be measured.

  Conventional measuring instruments that measure near magnetic field and / or near electric field detect the contact between the measuring probe and its fixing mechanism when the measuring probe is lowered, and then move down. The operation was stopped and then raised to make a gap necessary for measurement.

  In Patent Document 1, the probe tip surface cannot be protected when the contact detection portion is ring-shaped and the surface protrusion of the object to be measured is smaller than the probe tip diameter. In addition, it does not have a function of stopping the contact with the gap between the tip of the measurement probe and the object to be measured after contact detection.

  JP 2001-147115 A

  Since the weight and inertial force of the measurement probe and its fixing mechanism are applied to the object to be measured at the time of contact, it is necessary to lower the measurement probe at a low speed. In addition, after the descent operation stopped, an ascending operation was also required to make a gap necessary for measurement. These cause an increase in measurement time. In particular, in the case of a measuring machine that scans and measures the surface of an object to be measured, the length of the measurement time has become a serious problem. In addition, there is a problem that the measurement object may be deformed by the weight of the measurement probe and its fixing mechanism.

  The present invention relates to a probe cap that covers the tip of the measurement probe and is slidable at the tip of the measurement probe, and prevents the probe cap from falling off the measurement probe and until the probe touches the object to be measured. A probe cap support part that supports the inside of the cap so as to maintain a certain gap, a contact detection part that detects contact with the object to be measured when the probe cap is lifted from the probe cap support part, and a tip of the measurement probe after contact detection The above-described problem is solved by providing a function of stopping the distance set between the surface and the probe cap.

Reduction of measurement time and physical burden on the object to be measured.

  This is a state before the measurement probe is brought close to the object to be measured.   This is a state immediately after the measurement probe contacts the object to be measured.   This is a state where the measurement probe is stopped with a clearance set between the probe tip surface and the probe cap.

  The tip of the measurement probe 1 is covered with a probe cap 2. The probe cap 2 slides down from the measurement probe 1 due to its own weight, and the step on the top of the probe cap 2 stops on the probe cap support 3. Until the probe cap 2 comes into contact with the object to be measured 5, there is a steady gap D1 between the distal end surface of the measurement probe 1 and the inside of the probe cap 2.

  The contact detection unit 4 uses a transmissive photoelectric switch to detect the floating of the probe cap 3 by light shielding or incident light. This method provides a good balance between performance and cost, but other non-contact switches, contact switches, and displacement sensors can be substituted.

  The measurement probe vertical axis 6 is instructed to start descending. At this time, the stop target position of the vertical axis 6 of the measurement probe is set to a position where the measurement probe 1 and the object to be measured 5 reliably interfere with each other.

  When the tip of the probe cap 2 comes into contact with the object to be measured 5 while the measurement probe vertical axis 6 is descending, the step on the top of the probe cap 2 is lifted from the probe cap support 3. The contact detection unit 5 detects this lifting, and acquires the current position of the vertical axis 6 of the measurement probe at that moment.

  Thereafter, the measurement probe vertical axis 6 is instructed to change the stop target position. Even when a commercially available transmissive photoelectric switch is used, the contact detection delay time is around 30 microseconds, and the gap D2 between the tip surface of the measurement probe 1 and the inside of the probe cap 2 at the time of contact detection is considered to be substantially equal to the steady gap D1. Good. That is, the new stop target position of the measurement probe vertical axis 6 can be calculated from “the position of the measurement probe vertical axis 6 at the time of contact detection + the steady gap D1−the gap D3 necessary for measurement”. By changing the stop target position, the vertical axis 6 of the measurement probe stops with a gap D3 remaining between the tip surface of the measurement probe 1 and the probe cap 2.

  Since only the probe cap 2 which is a small and lightweight part contacts the object to be measured 5 during these series of operations, even if the measurement probe vertical axis 6 is lowered at high speed, the physical influence on the object to be measured 5 is slight. It is. In addition, since a gap necessary for measurement can be ensured by only one movement operation, the measurement time can be greatly shortened.

DESCRIPTION OF SYMBOLS 1 Measurement probe 2 Probe cap 3 Probe cap support part 4 Contact detection part 5 Measured object 6 Measurement probe vertical axis 7 Measurement probe fixing part

Claims (1)

  Measurement probe vertical axis, probe cap that covers the tip of the measurement probe and is slidable at the tip of the measurement probe, and prevents the probe cap from falling off the measurement probe and until the probe touches the object to be measured A probe cap support part that supports the probe cap so as to maintain a constant gap, a contact detection part that detects contact with the object to be measured when the probe cap is lifted from the probe cap support part, and a measurement after contact detection An apparatus for approaching a measurement probe to an object to be measured, which has a function of stopping the probe vertical axis while leaving a set distance between the probe probe end surface and the probe cap.

Images