JPH0429006B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an apparatus for measuring the amount of bending of a section steel.

Shaped steel products are usually cooled after hot rolling, but during these processes, bending occurs due to differences in heat capacity at various parts of the product cross section, uneven cooling, etc. This bending is usually corrected using a roller straightening machine or a press straightening machine.

However, since shaped steel products placed on a flat surface bend due to their own weight, it is difficult to quantitatively determine the amount of bending using ordinary measurement methods.

Therefore, conventionally, the amount of bending has been measured using the following measurement method.

First, if the shaped steel product has a cross-sectional shape that can be rotated 90 degrees, such as H-shaped steel or channel steel, the product is rotated 90 degrees using a crane, etc., and the vertical bend is turned into a horizontal bend. Measure with a water string, etc. after eliminating deflection due to its own weight.

In addition, if the product has a cross-sectional shape that makes it difficult to turn 90 degrees, such as steel sheet piles, the product may be placed on two fulcrums placed at a predetermined interval depending on the length of the product to be measured. Place the product so that the length of each fulcrum is equal and measure the amount of deflection. Next, the product is turned 180 degrees using a crane, etc., and similarly placed on a fulcrum and the amount of deflection at this time is measured. The amount of bending is calculated from the two amounts of deflection obtained in this way.

However, all of the conventional measurement methods described above require the use of equipment such as a crane, making it impossible to perform quick online measurements. In addition, this necessitated off-line sampling inspection, which had the disadvantage of making it difficult to inspect all products and guarantee quality.

In order to improve these drawbacks, the applicant of the present application has already proposed a new method and apparatus for measuring bending in Japanese Patent Application No. 56-43986.

This proposed method and device place a shaped steel to be measured on fulcrums having a predetermined interval, measure the amount of deflection of the shaped steel, and then apply a predetermined load to the shaped steel to be measured. The purpose is to measure the amount of deflection of the shaped steel in the state in which it is bent, and calculate the true amount of bending of the shaped steel to be measured from the two amounts of deflection measured respectively.

The present invention is a further development of the proposed bending measurement configuration described above, in which a section steel placed between fulcrums is pushed up from below to offset the deflection due to its own weight, and the amount of deflection is measured in this state. This is to obtain the bending of the shaped steel.

First, the principle of bending measurement using the apparatus of the present invention will be explained first. As shown in FIG. 1, the shaped steel A to be measured is placed on fulcrums B and B. The weight W and overall length l of this shaped steel A are measured in advance. Further, the section steel A is placed so that the overhang lengths l ₁ and l ₁ protruding from the fulcrums B and B are the same length. The overhang lengths l ₁ and l ₁ are determined in advance, and the fulcrums B and the distance between them l ₂ are adjusted accordingly, and then the section steel A is placed on the fulcrums B and B as described above.

The amount of deflection δ ₁ of section steel A measured at this time is
It consists of the bending amount δ and the deflection amount δco due to its own weight, and δ ₁ = δ + δco holds true. Rewriting this gives δ=δ ₁ − δco.

In the present invention, as shown in FIG. 1b, the shaped steel A to be measured is pushed up from below the center between the fulcrums with a predetermined drag force P, and the amount of deflection δco due to its own weight is offset to 0, and δ=δ ₁ , the amount of deflection at this time δ ₁
Let be the bending amount δ of the section steel.

Here, the amount of deflection δco due to its own weight is theoretically expressed by the following formula.

δco=W/384EIl ₂ ² (5l ₂ ² −24l ₁ ² )... Here, E: Young's modulus (Kg/cm ² ) I: Second moment of area (cm ⁴ ) W: Weight per unit length (Kg/cm 2 ) cm) On the other hand, the amount of push-up δ _P due to the drag force P is theoretically expressed by the following formula.

δ _P = P/48EIl ₂ ³ ... Therefore, in order to offset the amount of deflection δco due to self-weight by the amount of push up δ _P , it is necessary to set δ _P = δco...

By substituting the formula into the equation, P=W/8l ₂ (5l ₂ ² −24l ₁ ² )... can be found. In other words, if we push up the shape steel A with a drag force of W/8l ₂ (5l ₂ ² -24l ₁ ² ), the amount of deflection δco due to its own weight will be canceled out, and if we measure the amount of deflection δ ₁ in this state, this will be the result of the shape steel A. The amount of bending is δ.

If such a measurement method is implemented, there is no need to rotate the section steel A, so online measurement becomes possible.

Next, a specific embodiment of the apparatus of the present invention for realizing the above method will be described based on FIG.

This device includes a weight measuring device (not shown) for measuring the weight of the shaped steel to be measured, a length measuring device 5 for measuring its total length, a fulcrum device 1, a bending amount detector 2, an arithmetic control device 3, and a pushing device 4. It consists of.

The fulcrum device 1 consists of a pair of fulcrums 10, 10, which are movable up and down and movable in the longitudinal direction of the shaped steel A to be measured. The movement and elevation of the fulcrums 10, 10 are controlled by the arithmetic and control device 3, and the distance l ₂ between the fulcrums 10, 10 is input to the arithmetic and control device 3. Furthermore, the weight W measured by the weight measuring device is also input to the arithmetic and control device 3.

The bending amount detector 2 is movable between the fulcrums 10, 10, and the lower surface of the section steel A is the fulcrum 10, 10.
The amount of deflection is detected by detecting the amount of displacement with respect to the 10 height levels.
This detected value is also input to the arithmetic and control unit 3.

The pushing up device 4 is movable between the supporting points 10 and 10 like the bending amount detector 2, and is
It consists of a push rod 40 that pushes up with a predetermined resistance P, and a load cell 41 that detects the load. The push rod 40 pushes up the section steel A by a suitable drive device. The drag force P to be applied at this time is calculated and output by the arithmetic and control unit 3 according to the above formula. Further, the load actually applied is detected by the load cell 41 and inputted to the arithmetic and control device 3.

The device configured as described above can be installed at any position in the manufacturing flow as long as it is downstream of the device having the function of measuring the length of the shaped steel to be measured. As an example, the operation will be described below when the shaped steel product is placed on a conveyance table that transports it in its longitudinal direction.

First, the length l is measured by the length measuring device 5 located on the upstream side.
The shape steel to be measured whose length has been measured by this method is stopped at the position of this measuring device. This stop may be performed using a stopper or the like.

The length l signal from the length measuring device 5 is transmitted to the arithmetic and control unit 3, where the fulcrum spacing _l2 is calculated from the predetermined overhang length _l1 . The arithmetic and control device 3 moves the fulcrums 10, 10 so that the calculated fulcrum spacing l ₂ is achieved, and then moves the fulcrums 10, 10,
10 is raised to support the section steel, and then moved so that the detector 2 and the push rod 40 are located approximately at the center of the section steel A. Note that it is preferable to make the overhang length l ₁ as small as possible within a range that does not interfere with the measurement work, since this reduces measurement errors.

When the shaped steel A is supported by the fulcrums 10, 10, the weight W is measured and input to the arithmetic and control device 3. Here, the arithmetic and control device 3 calculates P=W/8l ₂ (5l ₂ ² −24l ₁ ² ) and outputs this drag force P to the pushing up device 4. The push-up device 4 pushes the push rod 40 against the section steel A with a drag force P commanded by the arithmetic and control device 3. This actually applied drag force P is the load cell 4
1 and read into the device 3.

As a result, the deflection δco of section steel A due to its own weight is 0.
Therefore, if the bending amount detector 2 detects the deflection amount δ ₁ in this state, this δ ₁ immediately becomes the bending amount δ. This amount of bending δ is displayed externally by appropriate means.

The above operation is shown in the flowchart of FIG.

It should be noted that the bending amount detector 2 may be of a structure in which a contact type sensor and a magnescale or the like are used to contact the sensor from below the section steel A and detect the vertical position of the sensor at that time, but this is not the case. In the example, an optical type as shown in Fig. 4 is used.
It is connected to the arithmetic and control unit 3. In Figure 4, 21
22 is a lifting device that raises and lowers this photodetecting device 21; 23 is a position detecting device that detects the vertical position of the photodetecting device 21; X is a fulcrum 10;
Level 10, α and β, are the lowest ends of the flexure of the section steel A to be measured.

As shown in the figure, the photodetector 21 is composed of a head 24 having an E-shaped cross section, a light emitter 25, and a light receiver 26. The emitter 25 and the receiver 26 are connected to the head 2.
In this embodiment, two sets of this combination are provided. Light is emitted from the emitter 25 and received by the receiver 26, and the beams m ₁ and m ₂ at this time form a measurement level, but the beams m ₁ and m ₂ are arranged so that they are located on the same horizontal line. The horizontal positions of the light emitter 25 and the light receiver 26 are aligned. When the beams m ₁ and m ₂ are interrupted, the light receiver 26 outputs an object detection signal, and this signal is configured to be input to the arithmetic and control unit 3.

Note that in this embodiment, the light receivers 26, 2
Light receiving slits 27, 27 are provided on the front surface of the projector 6, and the slit 27 improves the aperture detection accuracy of the spread of the beam from the projector 25. Further, a touch switch 28 is provided above each of the light emitters 25 and the light receivers 26, so that if a shaped steel to be measured or the like collides with the touch switch 28, this is immediately detected. This touch switch 28 may be connected to the elevating device 22 and configured to make an emergency stop in the event of a collision.

The photodetecting device 21 configured as described above is supported by a lifting device 22, and can be raised and lowered thereby. The lifting device 22 is composed of a pedestal 29, a motor 30, and a pair of linear heads 31.
The linear head 31 is connected to the motor 30 and converts the rotational motion of the motor 30 into linear motion, and has the same function as a rack and pinion. The photodetector 21 is placed on the rod 32 of this linear head 31. The motor 30 is capable of forward and reverse rotation, and is configured to rotate forward or backward in response to an ascending or descending command from the arithmetic processing unit 3.

Note that limit switches 33 and 33 are provided at upper and lower positions of the pedestal 29, and limit the lifting range of the rod 32, that is, the lifting range of the photodetector 21. When this limit switch 33 is connected to the motor 30 and turned on, the motor 3
0 may be configured to cause an emergency stop.

In this embodiment, the position detection device 23 uses a linear magnet scale, and its magnetic head 34
is connected to the lower end of the head 24 via a connecting rod 35. This magnescale 23 is adjusted so that when the beams m ₁ and m ₂ are located at the fulcrum level X of the section steel A, the vertical position signal S = 0, and the lower the head 24 is, the more S increases. It is set to be large. The output of this Magnescale 23 is input to the arithmetic and control unit 3.

The arithmetic and control device 3 inputs the position signal S from the position detection device 23 that changes every moment, and also inputs the detection signals of the lowest ends α and β of the bending part from the light receivers 26 and 26, and detects α and β. The position signal at the time is read and the deflection amount δ ₁ , that is, the bending amount δ is output. At this time, the deflection amounts δ ₁ 〓 and δ ₁ 〓 at the lower ends of both edges α and β of the section steel A may be determined and the average value δ ₁ may be taken as shown in the following formula.

δ ₁ = δ ₁ 〓 + δ ₁ 〓/2 The reason for this is that the cross-sectional shape and dimensions of the section steel are generally not completely symmetrical, and there is a slight left-right imbalance, and the position where the drag force P is applied is in the direction of the section width. This is because the lower end positions of both edges may not be the same on the left and right sides due to this influence.

Next, the operation of this bend amount detector 2 will be explained.

First, a normal rotation drive command is output from the arithmetic and control unit 3 to the motor 30, and the motor 30 starts rotating in the normal direction and the photodetecting device 21 starts moving upward. Assuming that the lowest end α is now below β, when α comes to the beam _m1 position, the light receiver 26 outputs an α detection signal to the arithmetic and control unit 3 in order to block the light. The device 3 stores the signal S from the position detection device 23 at this time as the deflection amount δ ₁ 〓 in its internal memory. Subsequently, β is detected by the other light receiver 26, and the arithmetic and control unit 3 similarly records the deflection amount δ ₁ 〓 in its internal memory.
Remember. Next, the average value is calculated from these δ ₁ 〓 and δ ₁ 〓 to obtain the deflection amount δ ₁ , that is, the bending amount δ, and output it. Next, the arithmetic and control unit 3 outputs stop and reverse commands to the motor 30, and when the photodetector 21 returns to its original position, it is stopped and the measurement is completed.

The bend amount detector configured as described above can perform measurements with extremely high accuracy.

As explained above, according to the measuring device of the present invention, it is possible to measure the amount of bending of the shaped steel without turning it, so continuous measurement within the line is possible, and the bending amount of all products can be measured. There are effects such as being able to perform inspections.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram explaining the principle of bending measurement by the device of the present invention, Fig. 2 is a front view showing an embodiment of the device of the present invention, Fig. 3 is a flowchart showing its operation, and Fig. 4 is the amount of bending. It is a front view showing one example of a detector. In the figure, 1 is a fulcrum device, 2 is a bending amount detector, 3 is an arithmetic control device, 4 is a push-up device, 10 is a fulcrum,
40 is a push rod, 41 is a load cell, 21 is a photodetector, 22 is a lifting device, 23 is a position detection device, 2
4 is the head, 25 is the emitter, 26 is the receiver, 27
28 is a touch switch, 29 is a stand, 30 is a motor, 31 is a linear head, 32
33 is a limit switch, 24 is a magnetic head, and 35 is a connecting rod.

Claims (1)

[Scope of Claims] 1. A pair of measuring instruments for measuring the weight and total length of the shaped steel to be measured, and a pair of measuring instruments on which the shaped steel to be measured is placed, which is movable in the longitudinal direction of the shaped steel and can be raised and lowered in the vertical direction. A push-up device that pushes up the shaped steel to be measured with arbitrary force between the fulcrums, and the measured values of the weight and total length of the shaped steel to be measured detected by each of the measuring instruments are input, and the fulcrum spacing is determined based on that. It has an arithmetic control device that sets the fulcrum and raises and lowers the fulcrum, and also controls the pushing force of the pushing up device, and a bending amount measuring device that measures the bending amount of the shaped steel to be measured. The left and right protrusion lengths l ₁ from the fulcrum on which the steel is placed are determined in advance to be equal lengths, the weight W and the total length of the section steel are measured, and the total length and the left and right protrusion lengths l ₁ are determined. Based on this, set the fulcrum spacing l ₂ and place the shaped steel to be measured on these fulcrums so that the left and right protrusion length l ₁ is the determined length above, and calculate based on the formula below. Pushing up the shaped steel to be measured with a drag force P corresponding to the deflection due to its own weight W, canceling out the deflection due to its own weight W, and measuring the amount of bending of the shaped steel to be measured in this state,
An apparatus for measuring the amount of bending of a shaped steel, characterized in that it measures the bending of a shaped steel to be measured. P=W/8l ₂ (5l ₂ ² −24l ₁ ² )