JPH08304046A - Bending measuring instrument - Google Patents

Abstract

PURPOSE: To simultaneously measure the bending in two directions where rod- shaped materials to be inspected cross at right angles. CONSTITUTION: A light emission part 31 and a light reception part 32 are arranged while holding a material W to be measured, laser beams are applied in parallel between them, the outer diameter in x-axis direction of the material W to be measured and a center point are obtained from the number of laser beams which are screened by the material W to be measured, and at the same time, the amount of displacement with the lower surface of the material W to be measured is obtained by a laser dilatometer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending measuring device for measuring the straightness, that is, the bending of a rod-shaped material to be measured such as a metal rod having a square or round cross section.

[0002]

2. Description of the Related Art Conventionally, the bending of a metal rod or the like is measured by applying a scale whose one surface is straightened to the metal rod to be measured, thereby forming a gap between the scale and the metal rod. Whether or not the metal rod is bent, and the degree of the gap are visually observed to detect whether or not the metal rod is bent, and to recognize the approximate direction and degree of the bending. However, although such a visual inspection can detect the presence or absence of a bend, there is a problem in that the direction and degree of the bend cannot be accurately evaluated.

As a countermeasure against this, an apparatus for automatically measuring the bending of a metal rod or the like has been proposed in recent years. FIG. 7 is an explanatory view of the principle of a conventional automatic bending measuring device, FIG. 8 (a) is a schematic plan view of the same, and FIG. 8 (b) is a partially enlarged plan view of slits and scales, in which 51 is a surface plate. , 52 is a straight tube fluorescent lamp, 53 is 2
1 shows a three-dimensional image sensor. The platen 51 is shown in FIG.
As shown in (a), a large number of short slits 51 are formed at substantially regular intervals.
a are formed in parallel with each other, and a scale 51b is formed on the surface of the surface plate 52 along one slit 51a from one end to the other end. As shown in FIG. 7, each slit 51a extends from the front side to the back side of the surface plate 51.

As shown in FIG. 8 (b), the scale 51b is graduated in the longitudinal direction of the slit 51a from a reference line Q which is defined along one end of each slit 51a in a direction orthogonal to the longitudinal direction of the slit 51b. There is. The straight tube fluorescent lamp 52 is installed on the back side of the surface plate 51 in parallel for each slit 51a so as to face the slit 51a over the entire length of each slit 51a. W is a rod-shaped material to be measured, such as a metal rod, and is set on the flat surface of the surface plate 51 in such a manner that it crosses the row of the slits 51b over substantially the entire length thereof.

The two-dimensional image sensor 53 is composed of a CCD or the like, and is mounted on the moving table 54. As shown in FIG. 8A, the movable table 54 is mounted on a linear guide 51c installed on the surface of the surface plate 51 along one side edge in the longitudinal direction thereof in parallel with the reference line Q, and 2
The three-dimensional image sensor 53 is supported so as to face directly above the slit 51b. When the moving table 54 is moved along the linear guide 51c by the driving of the motor M mounted on the moving table 54, the two-dimensional image sensor 53 is accordingly moved.
However, it can move right above the slit 51a from one end to the other end of the row.

Reference numeral 55 denotes an arithmetic and control unit, which performs lighting and extinguishing of each of the straight tube fluorescent lamps 52, forward and reverse driving of the motor M attached to the movable table 54, and stop control, and from the two-dimensional image sensor 53. The image signal of the keyboard 5
The measurement result is displayed on the CRT 56 and output to the printer 57 by the operation of 5a.

In such a conventional automatic bending measuring apparatus, the rod-shaped material to be measured W is placed on the surface of the surface plate 51 in a direction traversing the slit 51a as described above, and the straight tube fluorescent lamp 5 is used.
2 is turned on, and in this state, the moving table 54 is moved from one end of the row of the slits 51a toward the other end, and the rod-shaped measured material W and each slit 51 are measured by the two-dimensional image sensor 53.
An image of the scale 51b engraved along a is taken. The image signal obtained by the two-dimensional image sensor 53 is fetched and stored in the arithmetic control unit 55.

The arithmetic control unit 55 reads the stored image signal
Take out and measure each slit 51a as shown in FIG. 8 (b).
Of the measured material W, which is not covered by the fixed material W
Scales (m in contact with both sides)_j, N_j)… (M
_{j + q}, N_{j + q}) Is extracted, and each of the rod-shaped measured materials W is extracted from this.
Thickness of each slit 51a (n_j-M_j)… (N_{j + q}-M
_{j + q}) Is calculated and the position of the center point O of the measured material W is calculated.
(N_j-M_j) ・ 1/2 ... (n_{j + q}-M_{j + q}) ・ 1/2
(Distance L from the reference line Q_j... L_{j + q}).

Each of a predetermined number (three to several) that are continuously positioned
Center point O for each slit 51a_j… O _{j + q}The position of
And the center points obtained by the slits 51a at both ends
O_j, O _{j + q}Find the straight line connecting the
, The largest deviation from the straight line
Identifies the threshold center point and obtains the amount of deviation (called small bend)
Meru.

After that, the center point O at the next slit 51a
Each time is calculated and stored in the storage unit, the above-described calculation is repeated for the center point including this center point and a center point which is a predetermined number opposite to the center point, and the small bending amount is obtained. Then, the position of the center point O in the last slit 51a which the rod-shaped object to be measured crosses is calculated, and when it is stored in the storage unit, a straight line formula connecting the center points obtained in the first and last slits 51a is calculated, and The center point located with the largest deviation from the straight line corresponding to the straight line type is specified, and the deviation amount of this center point (this is called a large bend) is obtained. The obtained small bend and large bend are output from the arithmetic control unit 55 to the CRT 56 and displayed on the CRT 56, and also output to the printer 57 and printed out.

[0011]

By the way, in the conventional apparatus as described above, the rod-shaped material W to be measured is required for one measurement operation.
The bending is measured only in the plane in which the two-dimensional image sensor 53 in FIG. 2 faces each other, and when measuring the bending in different directions, the orientation of the rod-shaped material to be measured W must be changed. A holding means for holding the posture of the measured material W at a position rotated by a predetermined angle is required.

Further, even if the slit 51a is narrowed, there is a limit to it, and therefore the bending measurement data becomes discrete corresponding to the interval between the adjacent slits 51a, and the measurement interval is rough and the reliability is low. Further, the linear guide 51c is measured on the assumption that it is straight, but in reality, errors such as manufacturing, assembly, and installation errors cannot be avoided, but these errors cannot be corrected. There was a problem.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to make it possible to accurately measure the bending of a rod-shaped material to be measured in two directions simultaneously in one measurement operation. A second object is to enable the correction of an error due to the bending of the traveling path of the movable table and to significantly improve the measurement accuracy.

[0014]

A bend measuring apparatus according to a first aspect of the present invention measures a bend of a rod-shaped material to be measured by measuring a distance between the rod-shaped material to be measured arranged along a reference line and the reference line. In the device, the first and second rangefinders facing the two buses in the circumferential direction of the rod-shaped material to be measured and the first and second rangefinders are attached, and the parallel to the reference line. It is characterized by comprising a moving table for moving to.

A bending measuring apparatus according to a second aspect of the present invention is an apparatus for measuring the bending of a rod-shaped measured material by measuring the distance between the bar-shaped measured material arranged along a reference line and the reference line. First and second rangefinders facing the two buses of the material to be measured, which are different in the circumferential direction, and the first and second distance meters, respectively, which form the reference line.
A second reference scale, the first and second rangefinders, and the first and second
The 3rd and 4th rangefinders which measure the distance to the 2nd scale, and the 1st-4th rangefinders are attached, and it moves in parallel with the 1st and 2nd scales. And a movable table.

[0016]

In the first aspect of the invention, the bending of the rod-shaped material to be measured W in two directions is performed by the first distance meter and the second distance meter that face the two buses in the circumferential direction of the rod-shaped material to be measured. Can be measured simultaneously by one measurement operation.

In the second aspect of the invention, the first to fourth rangefinders are mounted by measuring the distance from the first and second reference scales, which are the reference lines, by the third and fourth rangefinders. It is also possible to correct the bending of the traveling path of the movable table, other installation errors, assembly errors, and the bending of the reference scale itself.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. FIG. 1 is a perspective view of a bending measuring apparatus according to the present invention. In the figure, 1 is a base, 2 is a bending measurement head,
S ₁ and S ₂ are standard scales, and W is a bar-shaped material to be measured.
Although not shown in the drawing, a control unit that controls the whole and performs arithmetic control is provided.

The bending measuring head unit 2 is perpendicular to the movable table 21.
The rod-shaped material W to be measured is placed on one side of the front surface of the vertically mounted mounting board 22.
Laser distance measurement, the first rangefinder to detect x-axis bending
A scale 23 and a standard scale S on the back side of the mounting board 22.₁of
Standard scale S facing the reference plane ₁Measure the distance from the reference plane
A laser displacement meter 24, which is a third rangefinder, is installed.
Opposite the other side of the front surface of the mounting board 22 and facing the rod-shaped measured material W
A laser displacement meter 25, which is a second distance meter, is attached to the mounting board 22.
Standard scale S at the bottom of₂A fourth rangefinder facing the reference plane
The laser displacement gauges 26 are installed respectively. Note that
Here, the x-axis direction is the short side direction of the base 1 having a rectangular parallelepiped shape,
The y-axis direction is the direction vertical to the surface of the base 1.

The movable table 21 is mounted on linear guides 28, 28 provided on the surface of an installation table 27 which is longitudinally installed at a position near one side edge of the surface of the base 1. Further, the moving table 21 is provided with a ball nut (not shown), which has the ball screw 2 provided between the linear guides 28, 28.
9 is screwed together. The ball screw 29 is axially supported between the linear guides 28, 28 by supporting brackets 29a, 29a provided at both ends of the installation base 27, and the ball screw 29 is normally or reversely rotated by a servo motor M provided at one end thereof. By rotating, the bending measurement head portion 2 is moved in the longitudinal direction of the base 1, and the line including the two points in the circumferential direction of the rod-shaped material to be measured W is measured by the laser dimension measuring device 23 and the laser displacement meter 25. (Hereinafter, this is called the bus bar.)

FIG. 2 is a diagram for explaining the principle of the laser dimension measuring device 23. The laser dimension measuring device 23 is composed of a light emitting portion 31 and a light receiving portion 32 for the laser beam, and the light emitting portion 31 is located above the rod-shaped material to be measured W. Further, the light receiving section 32 is located below, and the rod-shaped measured material W is installed so as to face the arrangement area between the upper and lower sides. The light emitting unit 31 is configured by combining an oscillator 31a that oscillates a laser beam in a pulse shape, a polygon mirror 31b, a total reflection mirror 31c, and a lens 31d, and a polygon mirror 31b that rotates a pulsed laser beam emitted from the oscillator 31a The reflection mirror 31c and the lens 31d are arranged to project downwardly and in parallel on the same vertical plane that traverses the rod-shaped material to be measured W.

On the other hand, the light receiving section 32 is provided with a lens 32a and a photoelectric converter 32b on which the light condensed by the lens 32a is incident, and the light reaching the lens 32a is photoelectrically converted without being blocked by the rod-shaped material W to be measured. It is incident on one point on the converter 32b and detected. The photoelectric converter 32b gives a detection signal for each pulsed laser beam to the control unit (not shown) when the pulsed laser beam is received and when it is not received.

Since the number of laser beams incident on one surface of the polygon mirror 31b is determined by the number of times the laser beam is emitted and the number of rotations of the polygon mirror 31b, the number of laser beams per scan is known, and the number of laser beams is one. Since the dimension Δd therebetween is also known, the control unit converts the outer diameter of the rod-shaped measured material W from the number of detection signals and the measurement conditions.

The laser displacement meters 24, 25 and 26 are structurally the same, and the laser displacement meter 24 is as shown in FIG. FIG. 3 is a diagram for explaining the principle of the laser displacement meter 24. The laser beam emitted from the laser oscillator 33a is projected through the lens 33b onto the reference surface of the first reference scale S ₁ and the reflected beam from this is received by one-dimensional analog reception. The device (PSD) 33c receives light. If there is a bend in the reference surface of the first reference scale S ₁ , and as a result, the reference surface is displaced from the straight surface f _{0 such} that the reference surfaces are displaced as f ₁ and f ₂ , Correspondingly, on the one-dimensional analog photodetector 33c, the light g ₀ ,
As a result of being projected at the displaced positions like g ₁ and g ₂ , V ₀ , V ₁ and V ₂ are respectively emitted from the one-dimensional analog photodetector 33c.
The voltage signal corresponding to the position of is output to the control unit.

The control section calculates the amount of displacement of the reference plane from this voltage signal. The light receiver is not limited to a one-dimensional analog light receiver, and a one-dimensional digital light receiver (linear diode array) may be used. Further, although the above description has described the case where the reference surface of the reference scale S ₁ has a bend, the present invention is not limited to this, and similar results can be obtained when the linear guides 8, 8 are bent, for example.

As shown in FIG. 1, the laser displacement gauges 25 and 26 are provided with fine scale adjusters 34 and 35 for adjusting the dimensions between the standard scale S ₂ which is the displacement detection object and the rod-shaped material to be measured W, respectively. It is mounted on the mounting board 22. This fine movement adjuster 3
Reference numerals 4 and 35 have the same structure. To describe the fine movement adjuster 35, the bracket 2 of the holder 26c of the laser displacement meter 26 is described.
A bolt 26e threaded through 6d is screwed onto the support bracket 22b of the mounting board 22. By adjusting the screwing depth of the bolt 26e, the reference scale S ₂ and the laser displacement meter 26 are adjusted. It seems that the distance can be adjusted.
Instead of the laser displacement meter 25, the laser displacement meter 25 is provided with the light emitting portion and the light receiving portion on both sides of the arrangement area of the rod-shaped material to be measured W, similarly to the laser dimension measuring device 23, to measure the bending in the y-axis direction. Good.

Each of the reference scales S ₁ and S ₂ is formed in a long plate shape having a substantially rectangular cross section, and is supported by a plurality of support bases 3 and 4, respectively, and the reference surface of the reference scale S ₁ is supported. Is opposed to the laser displacement meter 24 in the x-axis direction, and the reference surface of the reference scale S ₂ is opposed to the laser displacement meter 26 in the y-axis direction. A plurality of support bases 3 (four in this embodiment) are provided upright on the upper surface of the base 1 at regular intervals along the longitudinal direction thereof, and the support base 3 has a shallow recess with a width substantially equal to the size of the reference scale S _{1 at} the upper end. Grooves 3a are formed, and the reference scale S ₁ is detachably fitted in a manner to be passed to the concave grooves 3a of each support base 3.

A plurality of support bases 4 of the standard scale S ₂ are fixed on the upper surface of the base 1 at regular intervals along the longitudinal direction thereof, and each of them is provided with a U-shaped support groove 4a into which the standard scale S ₂ is fitted. The bracket is fixed to the base 1 by screwing. The reference scale S ₂ is inserted in the support groove 4a of each support base 4 so that the reference scale S ₂ can be inserted and removed.

The mounting table 5 for the rod-shaped material to be measured W is composed of a fixed portion 5a and a movable portion 5b. The fixed portion 5a has an insertion hole 5c having a rectangular cross section at its upper end, and a bracket provided at the lower end is fixed by screws. It is fixed to the base 1. On the other hand, movable part 5b
Is also formed in an inverted L shape in a side view, and the vertical portion is slidably fitted into the insertion hole 5c of the fixed portion 5a from above, and the horizontal portion is bent toward the measurement head portion 2 side. It is extended in the orthogonal direction. A stopper 5d for preventing the measured material from falling is provided at the tip of the horizontal portion.

A bolt 5 which is slidably fitted into the insertion hole 5c and protrudes downward from the lower end of the vertical portion is attached to a bracket 5e provided on one side surface of the fixing portion 5a by screwing from the lower side to the upper side. The tip of 5f is brought into contact, and the vertical position of the movable portion 5b can be finely adjusted by rotating the bolt 5f.

Next, the bending measurement operation will be described. The control unit drives the motor M to move the bending measurement head unit 2 toward one end of the base 1, and mounts the reference scales S ₁ and S ₂ on the support bases 3 and 4, respectively. This reference surface of the reference scale S ₁ and the laser displacement meter 24, also the reference surface of the reference scale S ₂ is s position opposing the laser displacement meter 26 and her husband. Further, the rod-shaped material W to be measured is placed on the plurality of mounting tables 5. The motor M is driven by the control unit and the laser dimension measuring device 2
3. Operate the laser displacement gauges 24, 25, 26. A predetermined number of laser beams are emitted from the light emitting portion 31 of the laser dimension measuring device 23 in parallel at substantially regular intervals, and the rod-shaped material to be measured W is measured.
The laser beam that is not blocked by is incident on the photoelectric converter 32b of the light receiving unit 32 and is detected.

The control unit determines the rod-shaped measured material W from the number of detected signals.
Is calculated and the center point O _j of the rod-shaped material W to be measured is calculated.
Position (x-axis direction position) is calculated. Displacement of the distance between this and the synchronization with the reference plane of this and measuring standard S ₁ by the laser displacement meter 24, bending positional deviation of the measuring head 2 relative to the scale S ₁ in other words is also measured sequentially, the measured material The x-coordinate of the center point O of W is calculated by correcting the positional deviation.

Similarly, also in the y-axis direction, the laser displacement meter 2
The displacement value of No. 5 and the displacement value of the laser displacement meter 26 are given to the control unit, which causes the distance from the reference surface of the scale S ₂ to the measured material W to be the distance between the laser displacement meters 25 and 26. Is known, the center point of the rod-shaped measuring material W in which the positional deviation due to the bending of the reference surface and the bending of the linear guide 28 is corrected is determined based on these values.

[0034] (1) slope compensation current of the measured material W, the scale S ₁ to the rod-shaped object to be measured material W as shown in FIG. 4
Is curved in the x-axis direction, measurement is performed from the measurement point n ₀ to the measurement points n _i (the length L between them) at regular intervals a, and a bar shape from the reference line Q at the measurement points n ₀ is measured. deviation of the measured material W is zero, deviation xn _i of the rod-shaped object to be measured material W from the reference line Q at the measurement point n _i, the deviation of the measured material W with respect to the reference line at the measurement point n _i xn _i (= Δx ). Between the center O ₀ of the measured material W at the measurement point n _0, a straight line connecting the center point O _i of the measured material W and the correction line ML in the final measurement point n _i, this correction line ML and the reference line Q The reference line Q is rotated by the angle θ formed by.

Correspondingly, the measurement points n _{0 to} n _i
The shift amount of each central point O _{0 to} O _i position is converted from the shift amount with respect to the reference line Q to the shift amount with respect to the correction line ML. This conversion may be performed by correcting the positional deviation amount of each of the center points O _{0 to} O _i corresponding to the length of the correction line ML from the center point so that the deviation amount Δx with respect to the length L is obtained. The large bend value and the small bend value are sequentially calculated based on the measurement data on which the inclination correction is performed.

(2) Calculation of large bend value In FIG. 5, the horizontal axis represents the correction line ML, and the vertical axis represents each measurement point n.
₀~ N_iCenter point O for each ₀~ O_iTheory showing the amount of deviation
It is a clear view, and the first measurement point O of the rod-shaped measured material W ₀And the
Later measurement point O_iCorrect the correction line ML connecting
Center point O after going₀~ O_iThe deviation amount of xn₁′, Xn
₂′… Xn_iIt is shown as'. Maximum deviation during this period
Is obtained as xmax ′, and this is set as a large bending value.

(3) Calculation of small bending amount The small bending amount is within a predetermined distance P as shown in FIG.
Each measurement point n₀~ N _FourAt the first measurement point n₀When
Last measurement point n_FourCenter point xn at and₀'~ Xn_Four′
A new correction line ML₁Figure as above
As shown in FIG. 6A, the same correction as that shown in FIG.
The maximum deviation amount Xmax 'within the range of the distance P is calculated,
This is a small bend value SB₁And

FIG. 6 (a) is an explanatory diagram showing the small bend value with the correction line on the horizontal axis and the shift amount on the vertical axis, and the small bend value SB ₁ between the measurement points n _{0 to} n _4. Is required. Figure 6
Similarly, in (b), the measurement points are shifted by one, and measurement points n _{1 to} n
The small bend value SB ₂ between ₅ and FIG. 6C shows the small bend value SB ₃ between the measurement points n ₂ to n ₆ . The process of tilt correction in the y-axis direction and the calculation of the large bend value and the small bend value are substantially the same as those in the x-axis direction described above.

In the above-described embodiment, two orthogonal directions are used.
That is, the case of measuring the bending in the x-axis direction and the y-axis direction has been described, but the present invention is not limited to this.
It is also applicable to direction bending measurement. Further, in the above-described embodiment, the distance between the bending measurement head portion 2 and the rod-shaped measured material W,
Also, a case has been described in which the distance between the bending measurement head unit 2 and the reference planes of the reference scales S ₁ and S ₂ is performed simultaneously. For example, first, the deviation between the reference scales of the reference scales S ₁ and S ₂ is measured. However, in the actual bending measurement, the reference scales S ₁ and S of the rod-shaped material W to be measured are used.
₂ does not measure the distance to the laser dimension measuring device 23,
The measurement may be performed by operating only the laser displacement meter 25.

[0040]

As described above, according to the first aspect of the present invention, the bending measuring head portion can simultaneously measure the bending in two directions and the outer diameter without moving the material to be measured during the measurement operation. Therefore, the work efficiency is extremely high.

According to the second aspect of the invention, at the same time as the distance between the bending measuring head and the material to be measured, the bending measuring head and the first and second
Since it is possible to measure the dimensions of the standard scale at the same time, even if there is a bending, installation, or assembly error of the standard scale, this can be corrected and a high measurement accuracy can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a bending measuring apparatus according to the present invention.

FIG. 2 is a diagram illustrating the principle of a laser dimension measuring device.

FIG. 3 is a diagram illustrating the principle of a laser displacement meter.

FIG. 4 is an explanatory diagram showing inclination correction of a rod-shaped material to be measured W.

FIG. 5 is an explanatory diagram showing a manner of calculating a large bend of the rod-shaped measured material W.

FIG. 6 is an explanatory diagram showing a mode of calculating a small bend of the rod-shaped measured material W.

FIG. 7 is a schematic front view of a conventional device.

FIG. 8 is a schematic plan view and a partially enlarged view of a conventional device.

[Explanation of symbols]

1 Base 2 Bending Measuring Head 3, 4 Support 5 Mounting Table 23 Laser Dimension Measuring Device 24, 25, 26 Laser Displacement Meter W Rod-like Measuring Material S ₁ , S ₂ Standard Scale

Claims (2)

[Claims] 1. An apparatus for measuring the bending of a rod-shaped measured material by measuring a distance between the rod-shaped measured material arranged along a reference line and the reference line, wherein the rod-shaped measured material has different circumferential directions. A bend comprising: first and second rangefinders facing each of the two busbars; and a moving table on which the first and second rangefinders are mounted and which moves parallel to the reference line. measuring device. 2. An apparatus for measuring the bending of a rod-shaped measured material by measuring a distance between the rod-shaped measured material arranged along a reference line and the reference line, wherein the rod-shaped measured material has different circumferential directions. First and second rangefinders facing the two busbars respectively; first and second scales respectively constituting the reference lines;
The 3rd and 4th rangefinders which measure the distance between the 2nd rangefinder and the 1st and 2nd standard scales, and the 1st-4th rangefinders are attached, and the 1st and 1st. A bend measuring device, comprising: a movable table that moves in parallel with the second reference scale.