JP2008020320A - Method and instrument for measuring hardness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently and accurately measure the hardness of the whole region of a foamed roller. <P>SOLUTION: With the foamed rubber roller 1 remaining close to the vicinity of a stress measuring terminal 2 by driving a motor 8, the gap quantity between the foamed rubber roller 1 and the stress measuring terminal 2 is measured by a shape measuring instrument 11. The push-in set quantity of the foamed rubber roller 1 is added to the measured gap quantity to calculate the push-in quantity from the position where the gap quantity is measured and the motor 8 is further driven to raise the foamed rubber roller 1. With the stress measuring terminal 2 pressed to the foamed rubber roller 1, the stress developed in a load cell 3 is read. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and apparatus for measuring hardness of a foam rubber roller or the like used in a copying machine, a printer, or the like.

  Currently, a vulcanized rubber physical test method (JIS K 6301) and a plastic durometer hardness test method (JIS K 7215) are applied to hardness tests on rubber and plastics. The test machine used for these test methods is the distance by which the pressing needle protruding from the center hole of the pressing surface by the spring pressure is pushed back by the elasticity of the measuring surface when the pressing surface is brought into contact with the measuring surface. The system uses a quantitative hardness.

  As a measurement method other than the JIS standard, as disclosed in Patent Document 1, the stress of the load cell when the pressure member surrounding the measurement terminal and the measurement terminal attached to the load cell are pressed against the surface of the object to be measured. A method of measuring is known.

Further, as disclosed in Patent Document 2, when the roller is rotated while the pressing piece (measurement terminal) is in contact with the roller, the pressing piece is moved along the roller surface to measure the repulsive force of the entire roller. At the same time, a method for correcting the deflection of the roller by measuring the roller shape is also known.
JP-A-6-313752 JP 2001-74573 A

  However, when the foam rubber roller and the measurement terminal are brought into contact with each other and rotated, or when the stress is measured by moving the measurement terminal along the roller surface to measure the stress, not only the hardness of the foam rubber roller is measured, but between the roller and the measurement terminal. Resistance will also be measured. Therefore, in this method, an error occurs in the hardness measurement value of the foam rubber roller.

  The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and an object thereof is to provide a hardness measuring method and apparatus capable of measuring the hardness of a foamed rubber roller quickly and with high accuracy. To do.

  In order to achieve the above object, the hardness measuring method of the present invention is a hardness measuring method using a stress measuring terminal for measuring stress by pressing against a measured object, and the stress measuring terminal and the measured object are separated from each other. A first step of measuring a gap amount between the stress measurement terminal and the object to be measured at the gap measurement position, and the stress measurement terminal is pushed into the surface of the object to be measured from the gap measurement position. A second step of measuring the stress measurement terminal in the second step, a value obtained by adding the gap amount measured in the first step to the indentation set amount of the stress measurement terminal. It is characterized by.

  Since the stress is measured by accurately controlling the pressing force of the stress measurement terminal against the object to be measured such as a foam rubber roller, high-precision measurement is possible without receiving external factors other than the surface hardness.

  The best mode for carrying out the present invention will be described with reference to the drawings.

  As shown in FIG. 1 and FIG. 2, the hardness of the foam rubber roller 1 is measured by detecting the stress by pressing the stress measurement terminal 2 against the surface of the foam rubber roller 1 as the object to be measured. The feeding means of this apparatus includes a conveying mechanism that feeds the stress measurement terminal 2 in accordance with the measurement point in the longitudinal direction of the foam rubber roller 1 and the foam rubber roller 1 in accordance with the circumferential measurement point of the foam rubber roller 1 And a rotating mechanism for rotating.

  A stress measurement terminal 2 for measuring hardness by a repulsive force when pressed against the foam rubber roller 1 is attached to a load cell 3, and the load cell 3 is connected to a conditioner 4.

  The transport mechanism that adjusts the position of the stress measurement terminal 2 in accordance with the measurement point of the foam rubber roller 1 in the longitudinal direction of the roller uses a combination of a motor 5 such as a stepping motor or a servo motor and an LM guide actuator 6. .

  The rotation mechanism that rotates the foam rubber roller 1 equally according to the measurement point in the circumferential direction of the foam rubber roller 1 has a motor 7 such as a stepping motor or a servo motor disposed on one side of the foam rubber roller 1.

  The moving means for pushing the stress measurement terminal 2 into the foamed rubber roller 1 uses a form in which the foamed rubber roller 1 is moved by combining a motor 8 such as a stepping motor or a servo motor and an LM guide actuator 9. It should be noted that one or more moving means for moving the foamed rubber roller 1 may be provided, but it is preferable to provide each at both ends supporting the foamed rubber roller 1.

  The hardness of the foam rubber roller 1 is measured by the following process. The motor 8 is driven until the foamed rubber roller 1 and the stress measurement terminal 2 come into contact with each other after the foamed rubber roller 1 is placed on the roller support 10 with the roller support 10 separated from the stress measurement terminal 2. To raise the foam rubber roller 1. The shape measuring instrument 11 which is a gap measuring means shown in FIG. 2 measures the amount of the gap between the stress measuring terminal 2 and the foamed rubber roller 1 brought close to the position just before contact (gap measurement position). A set value (indentation setting amount) of the indentation amount of the stress measurement terminal 2 when measuring the stress is added to the gap amount thus measured, and a new stress measurement terminal 2 from the gap measurement position is added. The motor 8 is further driven as the pressing amount, and the foamed rubber roller 1 is pressed against the stress measuring terminal 2. In this way, the value of the stress generated in the load cell 3 when the stress measuring terminal 2 is pressed against the foamed rubber roller 1 is read as the hardness of the foamed rubber roller 1.

  The hardness of the foam rubber roller was measured using the apparatus shown in FIGS. A conditioner with a sampling period of 2000 times / second is used for a device that uses a load cell with a rated capacity of 50 N and digitally displays the stress of the load cell 3. Servo motors were used for the motors used for conveying the stress measurement terminal, rotating the foam rubber roller, and moving the foam rubber roller. As a shape measuring instrument for measuring the amount of gap between the stress measuring terminal and the foaming roller, a dimension measuring instrument having a sampling period of 2400 times / second was used.

  An object to be measured which is measured by the hardness measuring apparatus under the above conditions is a foamed rubber roller having an outer diameter of 13 mm and a length of 260 mm.

  The hardness of the foam rubber roller is measured by the following procedure. A foam rubber roller is mounted on the roller support, and the roller supports on both sides are brought close to the position immediately before contacting the stress measurement terminal at a speed of 50 mm / s.

  Measure the amount of gap between the foam rubber roller approaching the stress measurement terminal and the stress measurement terminal with a shape measuring instrument, and add the gap amount to the indentation set amount of the stress measurement terminal. Is moved at a speed of 10 mm / s. In the state where the stress measurement terminal is pressed against the foam rubber roller in this way, the measurement value displayed on the conditioner according to the stress generated in the load cell is taken as the hardness of the foam rubber roller.

It is an elevation view showing a hardness measuring device according to an embodiment. It is a side view which shows the hardness measuring apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Foam rubber roller 2 Stress measuring terminal 3 Load cell 4 Conditioner 5, 7, 8 Motor 10 Roller support 11 Shape measuring instrument

Claims (3)

In the hardness measurement method using the stress measurement terminal for measuring the stress by pressing against the object to be measured,
A first step of measuring a gap amount between the stress measurement terminal and the object to be measured at a gap measurement position where the stress measurement terminal and the object to be measured are separated from each other;
A second step of measuring the stress by pressing the stress measurement terminal into the surface of the object to be measured from the gap measurement position;
A hardness measurement method characterized in that a value obtained by adding the gap amount measured in the first step to an indentation setting amount of the stress measurement terminal is used as an indentation amount of the stress measurement terminal in the second step.   The hardness measurement method according to claim 1, wherein the object to be measured is a foam rubber roller.   A stress measurement terminal for pressing the object to be measured to measure stress, a feed means for moving the stress measurement terminal in the feed direction in a state of being separated from the object to be measured, and the stress measurement terminal being measured A moving means for pushing into the surface of the object, and a gap measuring means for measuring a gap amount between the stress measuring terminal and the object to be measured, and the stress measurement is performed on the gap amount measured by the gap measuring means. A hardness measuring apparatus characterized in that a value obtained by adding a terminal indentation set amount is used as an indentation amount of the stress measurement terminal when the stress is measured.

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