ROUNDNESS MEASURING APPARATUS

• US 20100293800A1
• Filed: 05/21/2010
• Published: 11/25/2010
• Est. Priority Date: 05/22/2009
• Status: Active Grant

• Current Assignee: Mitutoyo Corporation
• Original Assignee: Mitutoyo Corporation
• Inventors: Shindo, Hideki, Nakayama, Tatsuki
• Granted Patent: US 8,336,223 B2
• Time in Patent Office: Days
• US Class Current: 33/558
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• CPC Class Codes: G01B 5/201 for measuring roundness

Abstract

A roundness measuring apparatus includes a stylus stocker and a controller. The stylus stocker stores plural types of styli prepared corresponding to shapes of measurement sites of a measurement target object. The stylus stocker can store styli in such a manner that each stylus can be held thereon and taken out thereof. The stylus stocker is provided outside a measurement region, which is determined on the basis of the operation range of a turntable and a detector driving mechanism. The detector driving mechanism can move the detector to the outside of the measurement region. When a measurement command is given, the controller carries out roundness measurement of the object while controlling the turntable and the detector driving mechanism. When a stylus replacement command is given, the controller carries out stylus replacement operation between a detector main unit and the stylus stocker while controlling the detector driving mechanism.

Claims

1. A roundness measuring apparatus comprising:

a base;

a turntable that can rotate around a vertical axis, a measurement target object being placed on an upper surface of the turntable;

a detector that includes a stylus and a detector main unit, the stylus being brought into contact with the measurement target object, the stylus being detachably attached to the detector main unit, the detector main unit detecting displacement of the stylus and outputting the detected stylus displacement in the form of an electric signal;

a detector driving mechanism that drives the detector so as to move the detector in a direction of the vertical axis and in a direction orthogonal to the vertical axis toward and away from the turntable;

a stylus stocker that stores plural types of styli, which are prepared corresponding to shapes of measurement sites of the measurement target object, the stylus stocker being able to store the styli such that each stylus can be held on the stylus stocker and taken out of the stylus stocker; and

a control unit,

wherein the stylus stocker is provided outside a measurement region, which is determined based upon an operation range of the turntable and the detector driving mechanism,

the detector driving mechanism is configured to move the detector to the outside of the measurement region,

when a measurement command is given, the control unit carries out a measurement of roundness of the measurement target object while controlling operation of the turntable and the detector driving mechanism, and

when a stylus replacement command is given, the control unit carries out a stylus replacement operation between the detector main unit and the stylus stocker while controlling operation of the detector driving mechanism.

2. The roundness measuring apparatus according to claim 1, wherein the detector driving mechanism includes a column that is provided on the base, an elevation driving mechanism that drives an elevation slider so as to move the elevation slider upward and downward along the column, a first slide driving mechanism that drives a sliding arm so as to move the sliding arm in the direction orthogonal to the vertical axis toward and away from the turntable with respect to the elevation slider, a second slide driving mechanism that is provided at the tip of the sliding arm and causes the detector to slide in a direction orthogonal to a sliding axis of the sliding arm, and a swiveling drive mechanism that causes the second slide driving mechanism to move in a swiveling direction with the sliding axis of the sliding arm being the center of the swiveling movement of the second slide driving mechanism;

and the detector can be moved to the outside of the measurement region through the operation of the second slide driving mechanism and the swiveling drive mechanism.

3. The roundness measuring apparatus according to claim 2, wherein the stylus stocker is provided at a position between the turntable and the column near, or relatively close to, the back of the base behind the sliding axis of the sliding arm.

4. The roundness measuring apparatus according to claim 1, wherein the swiveling drive mechanism can change a position of the detector within an angular range from negative ninety degrees to positive ninety degrees;

and, in said angular range, an erect position of the detector at which the stylus is oriented in an upright direction is taken as zero degree.

5. The roundness measuring apparatus according to claim 2, wherein the swiveling drive mechanism can change a position of the detector within an angular range from negative ninety degrees to positive ninety degrees;

and, in said angular range, an erect position of the detector at which the stylus is oriented in an upright direction is taken as zero degree.

6. The roundness measuring apparatus according to claim 3, wherein the swiveling drive mechanism can change a position of the detector within an angular range from negative ninety degrees to positive ninety degrees;

and, in said angular range, an erect position of the detector at which the stylus is oriented in an upright direction is taken as zero degree.