JPS61218904A - Diameter measuring instrument - Google Patents

Abstract

PURPOSE:To measure the diameter with good accuracy and high efficiency by arranging plural photoelectric transducers at equal intervals along the peripheral direction in opposition to an object to be measured and comparing information detected by turning the transducer line and the object to be measured relatively with pattern information prior to this and calculating a deviated amount between both. CONSTITUTION:The photoelectric transducer line 11 is arranged along the peripheral direction which is the opposite position separated by an prescribed interval with reference to the outside peripheral face of the object 4 to be measured and the relative movement direction on a detecting head 9. A straight pipe type light source 12 or the like irradiating rays of light with reference to the outside peripheral face of the object 4 to be measured is provided. The photoelectric transducer line 11 is constituted with the photoelectric transducers 111-118 arranged at the equal intervals along the peripheral direction and an optical brightness pattern of the outside peripheral face of the object 4 to be measured is detected with the transducers 111-118 of the transducer line 11 and sent to a pattern processing part 21. Then, this information is amplified with an amplifier 22 and converted into a digital signal with an A/D converter 23 and stored in a detection pattern memory 26 and sent to an arithmetic circuit 27 every time a reading command 24 is given and compared with a reference pattern and the deviated amount is decided there.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a diameter measuring device, and is particularly applicable to measuring the diameter of a workpiece machined with a large vertical lathe or the like.

[Background technology and its problems] Conventionally, in order to measure the diameter, for example, the outer diameter, of a workpiece machined with a large vertical lathe, a dedicated large micrometer was used, or a position opposite to the outer diameter of the workpiece was measured. Measurements were taken by placing blocks between the blocks and connecting an inside micrometer between the blocks.

Measuring the former size using a micrometer has a problem in measurement accuracy because the micrometer itself is heavy and therefore difficult to operate. Furthermore, in the latter measurement using an inside micrometer, it is difficult to place the block accurately in contact with the workpiece, and it is also difficult to connect the inside micrometers accurately.

On the other hand, in addition to these methods, the table on which the workpiece is placed is rotated, a roller with a known diameter is pressed against the measurement surface of the workpiece, and the diameter of the workpiece is calculated from the number of rotations of the roller. There is a calculation method, but the rotation speed of the roller in contact with the workpiece has slippage, so the accuracy is reduced. Moreover, when the roller is pressed against the surface of the workpiece, a gloss may appear on that part of the workpiece, which may be objectionable.

Further, an inside micrometer is usually used to measure the inner diameter of the workpiece, but as the inner diameter of the workpiece becomes larger, the above-mentioned problems arise.

[Object of the Invention] The object of the present invention is to solve the above-mentioned conventional drawbacks, and is to provide a method for accurately and efficiently measuring the inner diameter or outer diameter of a relatively large-diameter object. The purpose of this invention is to provide a measuring device.

[Means and actions to solve the problem] Therefore,
In the present invention, a plurality of photoelectric conversion elements are arranged at equal intervals along the circumferential direction so as to face the inner peripheral surface or the outer peripheral surface of the object to be measured, and the photoelectric conversion element array and the object to be measured are rotated relative to each other.
In this state, the optical pattern information on the circumferential surface of the object detected by the photoelectric conversion element array is compared with the previously detected pattern information to determine the amount of deviation between the two, and this amount of deviation is determined by one relative rotation. The diameter of the object to be measured is determined by dividing the cumulative value by pi.

Specifically, it includes a light source for capturing the state of the inner or outer circumferential surface of the object to be measured as bright and dark optical information, and a device for measuring the inner or outer diameter of the object to be measured. A photoelectric conversion element array in which a plurality of photoelectric conversion elements are arranged at equal intervals along the circumferential direction facing the inner circumferential surface or the outer circumferential surface, and one of the photoelectric conversion element array and the object to be measured relative to the other. a rotational drive means for rotating while maintaining a predetermined interval; a one-rotation detector for detecting one rotation of a photoelectric conversion element array or an object to be measured by the rotational drive means; a first pattern storage section that stores pattern information on the peripheral surface of the object; and a first pattern storage section that stores pattern information detected by the photoelectric conversion element array before the pattern information of the first pattern storage section as a reference pattern. The deviation amount of the pattern information in the first pattern storage unit with respect to the reference pattern stored in the second pattern storage unit and the second pattern storage unit is determined, and according to the determination result, the obtained pattern information is determined. determining means for cumulatively storing the amount of deviation and updating the reference pattern in the second pattern storage section to the pattern information in the first pattern storage section; The present invention is characterized by comprising means for calculating the diameter of the object to be measured by dividing the cumulative value of the amount of deviation by pi.

[Embodiment 5] FIG. 1 shows an embodiment in which the diameter measuring device of the present invention is applied to a large-sized vertical lathe. In the same figure.

At the top of the bed l, there is a drive mechanism 2 as a one-rotation drive means.
A table 3 is provided which is rotated by. On the table 3, a workpiece 4 processed into a cylindrical shape as a workpiece to be measured is placed on the upper surface thereof, and a one-rotation detector 5 is disposed facing the table 3 on its outer peripheral surface. 1 revolution detector 5
is fixed to the bed 1 via a bracket (not shown) or the like.

It also includes a protrusion provided at one location on the outer peripheral surface of the table 3, a switch that is turned on when the mark 3A approaches, and the like.

Furthermore, columns 6 are erected on both sides of the bed 1, and a cross rail 7 is provided between the columns 6 on both sides so as to be movable up and down. A tool post 8 is attached to the cross rail 7 so as to be slidable in the left and right directions in the figure, and a detection head 9 is attached to the tip of a ram 8A of this tool post 8 so as to face the outer peripheral surface of the workpiece 4. There is. Here, on the outer peripheral surface of the workpiece 4.

In the direction of relative movement with the detection head 9, that is, in the circumferential direction, processing has been performed so that the brightness of the reflected light is not uniform for a certain light source (including natural light).For example, along the direction of relative movement, Marks such as irregular light and dark patterns are applied so that the brightness of the reflected light is not uniform.

On the other hand, as shown in FIG. 2, the detection head 9 has a photoelectric conversion element array 11 located at a position facing the outer peripheral surface of the workpiece 4 at a predetermined distance and in a relative movement direction, that is, in the circumferential direction. A straight tube type light source 12 and the like are arranged along the workpiece 4 and emit light onto the outer circumferential surface of the workpiece 4. The photoelectric conversion element row 11 is composed of eight photoelectric conversion elements 11+ to lla arranged at equal intervals along the circumferential direction. As a result, the optical brightness pattern on the outer peripheral surface of the workpiece 4 is detected by the eight photoelectric conversion elements 11 I''l lg of the photoelectric conversion element array 11, and then sent to the pattern processing section 21.

The pattern information sent to the pattern processing section 21 is amplified by an amplifier 22 and then converted into a digital signal by an A/D converter 3, as shown in FIG. The pattern information converted into a digital signal by the A/D converter 23 is stored in a detected pattern memory 26 as a first pattern storage section. The pattern information stored in the detection pattern memory 26 is read into the calculation circuit 27 every time the reading command 24 is given from the calculation circuit 2 as a determination means, and then stored in the reference pattern memory 28 as a second pattern storage section. The reference pattern in the reference pattern memory 28 is compared with the reference pattern that has been stored, and the amount of deviation from the reference pattern is determined.

According to the calculation results of the calculation circuit 27, the pattern information in the detection pattern memory 26 is sequentially updated. Also,
When a series of processes is performed, a read command 24 for the primary calculation is detected from the calculation circuit 27 to the detection pattern memory 26, and the pattern information in the detection pattern memory 26 is read into the calculation circuit 27.

Now, the pattern information stored in the detection pattern memory 26, that is, the vector of pattern information captured in the current sampling, is P (p+, p2...pa), and the reference pattern stored in the reference pattern memory 28 is , that is, the vector of the reference pattern updated up to the previous sampling is P'(p+' l P2'...p
6'), then in the arithmetic circuit 27, S0=Σ(pLpt')2 . . . (1
)LLIヱS,=Σ(pL PL-+')2 ・・・・・・・・・
・・(2) S−=Σ(PL−pt◆l′)2 ・・
......Calculate (3) and find the smallest value among S, , S, and S-.

Here, when ■S0 is the minimum value, it is determined that there is no deviation by one element, and when ■S and is the minimum value, it is determined that there is a deviation in the l element molecule direction, and ■S- is the minimum value. In this case, it is determined that there is a deviation in one direction by one element, and the reference pattern in the reference pattern memory 28 is updated and the count value in the displacement amount memory 29 is increased or decreased in accordance with the determination result.

That is.

In case (2), neither the reference pattern in the reference pattern memory 28 nor the count value in the displacement amount memory 29 are updated.

In case (2), the reference pattern in the reference pattern memory 28 is updated to the pattern information in the detection pattern memory 26, and the count value in the displacement amount memory 29 is increased by +1.

In case (2), the reference pattern in the reference pattern memory 28 is updated to the pattern information in the detection pattern memory 26, and the count value in the displacement newt 29 is counted down by one.

Therefore, when the workpiece 4 remains stationary, So becomes the minimum value, so the reference pattern in the reference pattern memory 28 and the count value in the displacement memory 29 are not updated.However, when the workpiece 4 is rotating Then, S or S- becomes the minimum value depending on the rotation direction, so the reference pattern in the reference pattern memory 28 is updated to the pattern information in the detection pattern memory 26, and the count value in the displacement amount memory 29 increases or decreases depending on the rotation direction. be done.

In this way, the workpiece 4 rotates.

In the displacement amount memory 29, the total moving distance of the outer circumferential surface of the workpiece 4 is stored.

The value stored in the displacement memory 29 is reset when a reset signal from the reset/hold circuit 30 is given, and is held when a hold signal is given, and is divided by pi in the diameter calculation 11131. After that, it is displayed on the 1 display section 32. The reset/hold circuit 30 outputs a reset signal when the one-rotation detector 5 turns on for the first time, and outputs a hold signal when it turns on for the second time. Therefore, when the table 3 is rotated by the drive mechanism 2 and the movement distance of the outer peripheral surface of the workpiece 4 is stored in the displacement amount memory 29, when the one-rotation detector 5 is turned on for the first time, the reset/hold circuit 30 The value of the displacement amount memory 29 is reset by a reset signal from the displacement amount memory 29.

Furthermore, as the table 3 rotates, the distance traveled by the outer circumferential surface of the workpiece 4 from the time of resetting is accumulated and stored in the displacement amount memory 29, eventually.

When the table 3 makes one rotation, the one-rotation detector 5 is turned on, so the value of the displacement amount memory 29 is held by a hold signal from the reset/hold circuit 30. Then, the hold value is determined by the diameter calculation unit 31 as pi
The result, that is, the outer diameter of the workpiece 4 is displayed on the display section 32.

Therefore, according to this embodiment, the optical pattern information on the outer peripheral surface of the workpiece 4 is converted into an electrical signal by the photoelectric conversion element array 11, and this converted pattern information 4 is updated and stored before the previous sampling. The amount of deviation of the detected pattern information with respect to the reference pattern is determined by comparing the detected pattern information with the reference pattern, and the amount of deviation is accumulated for one rotation of the workpiece 4.
This cumulative value is divided by pi to determine the outer diameter of the workpiece 4, so there is no need to use a large and heavy micrometer or inside micrometer, making operation extremely easy. Moreover, highly accurate measurements are possible.

In particular, since the optical pattern information on the outer peripheral surface of the workpiece 4 is detected, the brightness of the reflected light should not be uniform in the circumferential direction of the outer peripheral surface of the workpiece 4. For example, irregular marks or even scratches can be treated as long as the pattern is 1. In extreme cases, the pattern of machined surface roughness can be used as is without any treatment. is almost unnecessary.

Moreover, since it is a non-contact type with respect to the workpiece 4, it does not damage the measurement surface.

Compared to the conventional method of pressing rollers, there is no slippage, allowing for highly accurate measurements.

This method has the advantage of being able to measure with high precision even relatively soft materials of the workpiece.

In addition, in carrying out the process, a lens is provided between the outer peripheral surface of the workpiece 4 and the photoelectric conversion element 11 to form an image of the reflected light from the outer peripheral surface of the workpiece 4 onto the photoelectric conversion element array 11 at a predetermined magnification. For example, the distance L from the outer peripheral surface of the workpiece 4 to the lens is
A resolution that is twice the distance L from the I/lens to the photoelectric conversion element array 11 can be obtained. Furthermore, by preparing n photoelectric conversion element arrays 11 in advance and arranging them in parallel in the circumferential direction of the workpiece 4 by shifting 1/n of the element spacing, the resolution can be improved by n times. can.

Furthermore, regarding the reference pattern to be compared with the detected pattern information, not only one reference pattern updated and stored up to the previous sampling time, but also multiple reference patterns updated before that are stored. By comparing the pattern information detected for all of these, it is possible to analyze the pattern more accurately, and even when the amount of relative rotation is fast and more than one element is moved in one calculation. Measurable. Furthermore, in calculating the diameter, the workpiece 4 is not limited to one revolution, but is rotated multiple times, the amount of movement of the outer peripheral surface per one revolution is determined, and this is divided by the pi ratio π. By determining the diameter of the workpiece, more accurate measurements can be made.

Further, in the above embodiment, the workpiece 4 is rotated, but the same effect can be expected even if the photoelectric conversion element array 11 is rotated along the outer peripheral surface of the workpiece 4.

In addition, although the above embodiment describes the measurement of the outer diameter of the workpiece 4, if the photoelectric conversion element rows are arranged in parallel along the inner peripheral surface of the workpiece, the inner diameter of the workpiece can also be measured. can do. Furthermore, although an example has been described in which the diameter measuring device of the present invention is applied to a large vertical lathe, the diameter measuring device of the present invention is not limited to a large vertical lathe, and may be a dedicated measuring device.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a diameter measuring device that accurately and efficiently measures the diameters, such as the inner diameter and outer diameter, of a relatively large-diameter workpiece.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention; Fig. 1 shows the overall theory and layout, Fig. 2 shows the relationship between the workpiece and the detection head, and Fig. 3 shows the pattern processing section. It is a block diagram. 2... Drive mechanism as a rotational drive means, 4... Workpiece as a measured object, 5... 1 rotation detector, 11.
...Photoelectric conversion element array, 12...Light source, 13...Lens. lit~lla...Photoelectric conversion element, 26...Detection pattern memory as a first pattern storage section, 27...
- Arithmetic circuit as determination means, 28... Reference pattern memory as second pattern storage section, 29... Displacement amount memory, 31... Diameter computing section.

Claims (1)

[Claims] (1) A device for measuring the inner diameter or outer diameter of an object to be measured, which includes a light source for capturing the state of the inner or outer circumferential surface of the object as bright and dark optical information, and an inner circumference of the object to be measured. A photoelectric conversion element array in which a plurality of photoelectric conversion elements are arranged at equal intervals along the circumferential direction facing a surface or an outer circumferential surface, and either the photoelectric conversion element array or the object to be measured is placed at a predetermined distance with respect to the other. a rotational drive means for rotating while maintaining an interval; a one-rotation detector for detecting one rotation of a photoelectric conversion element array or a measured object by the rotational driving means; and a circumferential surface of the measured object detected by the photoelectric conversion element array. a first pattern storage section that stores pattern information of the first pattern storage section; and a second pattern that stores pattern information detected by the photoelectric conversion element array before the pattern information of the first pattern storage section as a reference pattern. determining the amount of deviation of the pattern information in the first pattern storage unit with respect to the reference pattern stored in the storage unit and the second pattern storage unit, and determining the calculated amount of deviation according to the determination result. determining means for cumulatively storing and updating the reference pattern in the second pattern storage section to the pattern information in the first pattern storage section; and the amount of deviation when one rotation is detected by the one rotation detector. A diameter measuring device comprising: means for determining the diameter of an object to be measured by dividing the cumulative value of by pi.