JP2022162744A - Curvature radius instrumentation system and bending roll using it - Google Patents

Abstract

To provide a bending roll which can carry out molding operation efficiently and precisely by using a curvature radius instrumentation system.SOLUTION: This invention uses a curvature instrumentation system which, measures a plate thickness t of a circular-arcuate metal plate W, an inner arc length L3 during bending molding (of a part actually undergoing bending molding), an outer arc length L4 during molding matching with the inner arc length L3, an outer arc length L2 (after spring back) after molding matching with the outer arc length L4, and calculates the inner arc length L1 after molding as an inner arc length (L3 + L4 - L2) from the measurement result, then calculates a curvature radius r=(L1. t)/(L2 - L1), to measure the curvature radius r while bend-molding the metal plate W with a bending roll, and makes a control to adjust the vertical directions of a top roll 1 on the basis of the measurement result, thus enabling molding operation efficiently and precisely.SELECTED DRAWING: Figure 4

Description

The present invention relates to a curvature radius measuring system for measuring the radius of curvature of a plate-like portion formed in an arc shape, and a bending roll for bending a metal plate using the system.

The bending roll includes an upper roll and a pair of lower rolls parallel to the upper roll, and the metal plate is reciprocated by rotating the lower rolls while holding the metal plate between the upper roll and the lower rolls. This is a device that bends while moving.

In such a bending roll, in the middle of bending and forming the metal plate, the forming is temporarily interrupted and the radius of curvature of the metal plate is measured. Setting values such as roll positions are corrected so as to obtain an arc-shaped or pipe-shaped product having a desired radius of curvature after completion of molding.

Here, the measurement of the radius of curvature of the metal plate during forming has conventionally been carried out by an operator bringing an arc-shaped R gauge having a target radius of curvature of the product into contact with the inner or outer surface of the metal plate. In many cases, this measurement operation contributes to a reduction in the efficiency of the overall molding operation.

On the other hand, in Patent Document 1, for example, the thickness of the object to be measured and the length (arc length) along the circumferential direction of the mutually corresponding portions of the concave arc surface and the convex arc surface are measured, and from the measurement result A curvature radius measurement system has been proposed for geometrically calculating the curvature radius of a plate-like portion.

Then, in the bending roll using this curvature radius measuring system, the curvature radius of the metal plate is measured while the metal plate is being bent. The radius measurement operation can be automated to improve the efficiency of the overall molding operation.

Japanese Unexamined Patent Application Publication No. 2020-51832

However, in the conventional curvature radius measuring system described above, since the arc lengths of the concave arc surface and the convex arc surface of the object to be measured are measured by a distance sensor such as a measuring roller, the following is required when using the bending roll. There are some difficulties.

That is, in order to install distance sensors for measuring the arc lengths of the concave arc surface and the convex arc surface of the metal plate in the process of forming in the bending roll, distance sensors must be installed inside the concave arc surface and outside the convex arc surface of the metal plate. A support mechanism is required to move and support the metal plate to a position corresponding to the change in shape due to the molding of the metal plate. In particular, the distance sensor on the inner side of the concave arc surface is supported by the support mechanism from the outside in the width direction of the metal plate. It becomes a thing, and the durability and maintainability tend to be low.

Here, if the upper roll is used as a distance sensor for measuring the arc length of the concave arc surface of the metal plate, the problem of the measuring device as described above does not occur. However, in that case, since the radius of curvature is calculated by measuring the arc length during bending of the metal plate (at the part that is actually bent), the change in the radius of curvature due to springback after bending The subsequent bending is controlled without taking account of the bending accuracy of the product.

Therefore, the first object of the present invention is to provide a curvature radius measuring system suitable for use in bending rolls, and a bending roller capable of performing efficient and highly accurate forming work using the curvature radius measuring system. A second task is to provide rolls.

In order to solve the above-mentioned first problem, the present invention provides an article having a plate-like portion formed in an arc shape by bending and having a constant plate thickness in a cross section in a predetermined direction. In a curvature radius measuring system for measuring the radius of curvature of a shaped portion, a circle between the plate thickness t in a cross section in a predetermined direction of the plate portion and any two third reference points on the concave arc surface during bending. A length L3 along the circumferential direction, and a length L4 along the circumferential direction between two _fourth reference points on the convex arc surface facing each of the _third reference points in the plate thickness direction. and the length L2 along the circumferential direction between the _two second reference points on the convex arc surface after bending corresponding to each of the fourth reference points, and from the measurement results, the After calculating the length L ₁ along the circumferential direction between the two first reference points on the concave arc surface after bending corresponding to each third reference point as (L ₃ + L ₄ - L ₂ ) _{. _ _}

That is, the curvature radius measuring system of the present invention measures the arc lengths of the concave arc surface and the convex arc surface during bending (of the portion actually undergoing bending) of the object to be measured, and after bending (springback occurs). By measuring the arc length of the convex arc surface after bending and calculating the arc length of the concave arc surface after bending, it is possible to measure the radius of curvature after bending. This makes it more suitable for use with bending rolls than conventional radius of curvature measurement systems because it does not require a measuring device to measure the arc length of the concave arc surface.

In order to solve the second problem, the present invention comprises an upper roll and a pair of lower rolls arranged on both front and rear sides below the upper roll, and between the upper roll and each lower roll A curvature radius measuring system configured as described above while bending a metal plate in a bending roll that bends the metal plate while reciprocating the metal plate by rotating the respective lower rolls while holding the metal plate. was used to measure the radius of curvature of the metal plate during forming, and based on the measurement results, the relative positions of the upper roll and the lower rolls in the subsequent forming operation were controlled.

According to the above configuration, it is possible to eliminate the measuring work using the R gauge in the middle of molding, and to perform the molding work efficiently and with high accuracy. Moreover, compared with the case of using a conventional radius of curvature measurement system, the overall structure is simple and low cost, and problems of durability and maintainability of the measuring device for measuring the arc length are less likely to occur.

Further, in the bending roll having the above configuration, as the curvature radius measuring system, the length L3 along the circumferential direction between the two _third reference points is measured using the upper roll, and the two A length L4 along the circumference between the _fourth reference point is measured using a first measuring roller in contact with the metal plate between the pair of lower rolls, and between the two second reference points The length L2 along the circumferential direction of is measured using a _second measuring roller that contacts the metal plate at a position facing the first measuring roller with one of the lower rolls interposed therebetween. be able to.

The curvature radius measurement system of the present invention measures the arc lengths of the concave arc surface and the convex arc surface during bending and the arc length of the convex arc surface after bending of the object to be measured, and from the measurement results after bending Since the method calculates the radius of curvature and does not require a measuring device for measuring the arc length of the concave arc surface after bending, it can be effectively applied particularly to bending rolls.

Further, the bending roll of the present invention performs measurement by the above curvature radius measurement system while bending a metal plate, and controls subsequent bending based on the measurement result. It is possible to perform the forming work more efficiently and accurately than when measuring using an R gauge during bending, and the overall structure is simple and low compared to the case of using a conventional curvature radius measurement system. This is advantageous in terms of cost as well as durability and maintainability of the measuring device for measuring the arc length.

Front view of the bending roll of the embodiment Right side view of Fig. 1 Left side view of Fig. 1 Schematic explanatory view of measurement work by the curvature radius measurement system of the embodiment in the bending roll of FIG. Explanatory drawing of the measuring device that performs the measuring work of FIG. Flowchart of a bending roll control method using the curvature radius measurement system of the embodiment

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 to 3, this bending roll includes an upper roll 1, a pair of lower rolls 2 arranged parallel to the upper roll 1 on both front and rear sides below the upper roll 1, and each lower roll 2. Equipped with a motor case 3 containing a rotationally driven motor (not shown), left and right upper frames 4 and 5 supporting both ends of the upper roll 1, and a lower frame 6 supporting both ends of each lower roll 2. ing. In addition, each lower roll 2 is supported by backup rolls (not shown) from both front and rear sides thereof at its axial central portion. Then, the upper roll 1 is moved to a position in the front-rear direction according to the molding conditions, and the metal plate is held between the upper roll 1 and the lower rolls 2, and the lower rolls 2 are rotationally driven to form the metal plate. is bent while reciprocating. 1 to 3 omit the illustration of a measuring device of a curvature radius measuring system, which will be described later.

Each of the upper frames 4 and 5 is formed in a substantially gate shape, and each leg is formed by a bearing portion 6a provided on the upper surface of the lower frame 6 and a support plate 7 fixed to the front and rear surfaces of the lower frame 6. A support shaft 8 extending in the front-rear direction is passed through the bearing portion 6a and support plates 7 in the front-rear direction. The support shaft 8 is fixed to the bearing portion 6 a of the lower frame 6 and the support plate 7 , and the legs of the upper frames 4 and 5 are slidable relative to the support shaft 8 .

As a result, the upper frame 4 on the left side in FIG. 1 is a reversible frame that can move back and forth, and that rotates (overturns) to the left away from one end of the upper roll 1 when removing the formed metal plate. It has become. On the other hand, since the other end of the upper roll 1 extends axially outward, the upper frame 5 on the right side in FIG. is only possible.

A hydraulic cylinder 9 is attached to the upper end of each of the upper frames 4 and 5 with a rod 9a facing downward. The upper roll 1 is moved up and down by the operation of both hydraulic cylinders 9 . The upward movement of the upper roll 1 is restricted by a gate-shaped stopper 11 fixed to the lower frame 6 while straddling the extended portion 1a of the other end of the upper roll 1. As shown in FIG.

The lower frame 6 has a closed end of a two-stage hydraulic cylinder 12 rotatably attached to the lower portion of one end surface thereof. The tip of the rod 12a of the second stage of the hydraulic cylinder 12 is rotatably connected to the upper frame 4 as a tipping frame. By expanding and contracting while moving, the upper frame 4 is turned over and restored.

This bending roll has the above configuration, and while performing the forming work, the measurement is performed by the curvature radius measuring system of the embodiment of the present invention, and based on the measurement result, the vertical position of the upper roll 1 in the subsequent forming work is controlled. By doing so, it is possible to obtain a product having a desired radius of curvature after completion of molding.

As shown in FIG. 4, the curvature radius measuring system of the embodiment has a plate thickness t in the cross section of the metal plate W to be formed in the arc direction, and the thickness t during bending (of the portion actually undergoing bending) The length (inner arc length) L3 along the circumferential direction between the two _third reference points C and C' on the concave arc surface, each of the third reference points C and C' and the plate thickness direction The length (outer arc length) L ₄ along the circumferential direction between the two fourth reference points D and D' on the convex arc surfaces facing each other at 4 and corresponding to each fourth reference point D and D' Measure the length (outer arc length) L2 along the circumferential direction between the _two second reference points B and B' on the convex arc surface after bending, and from the measurement results, each third reference After calculating the length (inner arc length) L1 along the circumferential direction between the two _first reference points A and A' on the concave arc surface after bending corresponding to the points C and C', This is to calculate the radius of curvature r of the concave arcuate surface of the metal plate W after bending.

That is, in such bending, it is considered that the springback after forming shortens the outer arc length by the amount that the inner arc length extends (L ₁ - L ₃ = L ₄ - L ₂ ). can be calculated as (L _{3 +L 4 -L 2 ) .} Regarding the radius of curvature r of the concave arcuate surface after bending, since L ₁ /L ₂ =r/(r+t) is geometrically established, the radius of curvature r is (L ₁ ·t)/(L ₂ − L ₁ ).

Here, the plate thickness t of the metal plate W may be measured using a measuring tool or a known plate thickness meter before starting the forming operation. _In addition, the inner arc length _L3 during bending can be measured using the upper roll ₁ as a distance sensor. Measurement devices can be used, including known distance sensors for measuring distance along.

FIG. 5 shows a measuring device for measuring the arc lengths L ₃ , L ₄ and L ₂ of the metal plate W in the bending rolls of the embodiment. A device for measuring the inner arc length L3 during bending is rotatably attached to a pulley ₁₃ attached to the shaft end of the upper roll 1 and to a stationary upper frame (not shown) via a mount 14. a belt 16 wound between the pulleys ₁₃ and 15; and a pulse encoder 17 for detecting the rotation of the pulley 15 on the upper frame side. It is.

A device for measuring the outer arc length L4 during bending is attached to the lower frame ₆ via a frame 18, and includes an actuator (air cylinder) 19 that extends and contracts in the vertical direction, and an actuator (air cylinder) 19 that is rotatably attached to the upper end of the actuator 19. Equipped with a first measuring roller 20 and a pulse encoder 21 for detecting the rotation of the first measuring roller 20, the actuator 19 presses the first measuring roller 20 against the convex arcuate surface of the metal plate W between the pair of lower rolls 2. _L4 is obtained from the detection result of the pulse encoder 21 in this state.

The measuring device for the outer arc length L2 after bending consists of an actuator (air cylinder) 22 whose lower end is rotatably attached to the lower frame 6, and a _second measuring device whose upper end is rotatably attached to the actuator 22. A roller 23 and a pulse encoder 24 for detecting the rotation of the second measurement roller 23 are provided. The pulse encoder 24 is connected to the second measuring roller 23 and fixed to an arcuate roller support member 26 extending along the outer circumference of one of the lower rolls 2 via a mount 25 . The roller support member 26 rotatably supports a plurality of guide rollers 27 in contact with the outer peripheral surface of the lower roll 2 . , and moves along the outer circumference of the lower roll 2 together with the guide roller 27 . As a result, the second measuring roller 23 is always stably supported, and the actuator 22 presses the second measuring roller 23 against the convex arcuate surface of the metal plate W at a position facing the first measuring roller 20 with the lower roll 2 interposed therebetween. _L2 can be obtained from the detection result of the pulse encoder 24 in this state.

As described above, this curvature radius measurement system does not require _a measuring device for measuring the inner arc length L1 after bending, so it is more suitable for use in bending rolls than conventional curvature radius measurement systems. It is a thing.

Next, a method for controlling the radius of curvature in the metal plate forming operation with this bending roll will be described. In this embodiment, the sequencer automatically controls the position of the upper roll until the radius of curvature of the metal plate after bending reaches the target value.

FIG. 6 shows a specific processing procedure of the control method of this embodiment. In this control method, before starting the forming of the metal plate, in advance, together with the forming conditions (upper roll position, lower roll rotation distance, etc.), the target value r ₀ of the curvature radius of the concave arc surface after forming and the inner arc during forming A length measurement target value L ₄₀ is set (steps S ₁ , S ₂ , S ₃ ).

Then, after forming is started (step S ₄ ), measurement of the inner arc length L ₃ and the outer arc length L ₄ during forming and the outer arc length L ₂ after forming is started at a predetermined timing at the same time, and L ₄ is Measurement is performed until the measurement target value L ₄₀ is reached (steps S ₅ and S ₆ ). After the measurement of L ₃ , L ₄ and L ₂ is completed, the inner arc length L ₁ after molding and the curvature radius r of the concave arc surface after molding are calculated (steps S ₇ , S ₈ , S ₉ ). It is determined whether or not the calculated radius of curvature r is the target value r ₀ (step S ₁₀ ). Here, it is assumed that the target value _r0 of the radius of curvature has a certain allowable range.

As a result of the determination in step _S10 , if the value of the radius of curvature r is not the target value _r0 , the correction amount for the vertical position of the upper roll is calculated (step _S11 ), and the rotation distance of the lower roll is calculated. If the set value is not reached, the upper roll is moved vertically (steps S ₁₂ , S ₁₃ ), and the above steps S ₅ to S ₁₀ are repeated. _On the other hand, if the rotation distance of the lower roll has not reached the set value in step _S12 when the radius of curvature r is the target value _r0 , steps S5 to _S10 are repeated without moving the position of the upper roll. . Then, regardless of the value of the radius of curvature r, if the rotational distance of the lower roll reaches the set value in step _S12 , the molding is terminated ₍ step S14).

In this bending roll, the above-described control method is applied not only to the initial bending of the metal plate to be formed, but also to the subsequent corrective bending. As a result, the forming work can be performed efficiently and with high precision, and the forming time can be greatly shortened compared to the case where the measurement using the conventional R gauge is performed during the bending forming. In addition, compared with the case of using a conventional curvature radius measuring system, the overall structure is simple and the cost is low, and the durability and maintainability of the measuring device for measuring the arc length are also advantageous.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the meaning described above, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

For example, in the bending roll of the embodiment described above, as a measuring device for the inner arc length L3 during bending _, a device that detects the rotation transmitted from the upper roll by a pulley and a belt is used. It is also possible to use one that presses a measurement roller against the outer peripheral surface of the shaft end of the upper roll and detects the rotation of the measurement roller. _In addition, the measuring device of the outer arc length L4 during bending of the embodiment uses the one that detects the rotation of the first measuring roller pressed against the convex arc surface of the metal plate by the actuator composed of the air cylinder. Instead of the actuator, a spring may be used to press the first measurement roller against the metal plate.

In the bending roll of the embodiment, the vertical position of the upper roll is adjusted to control the radius of curvature of the metal plate. can be adjusted by adjusting the vertical position of the lower roll.

Furthermore, in the actual control, in order to improve the bending accuracy of the product, _a correction coefficient is introduced into the calculation formula of the inner arc length L1 after bending, and the correction coefficient is adjusted by experimental measurement. You can also

The curvature radius measuring system of the present invention is not limited to the metal plate that is bent by the bending rolls as in the embodiment. Applicable to articles having parts.

1 upper roll 2 lower rolls 4, 5 upper frame 6 lower frames 13, 15 pulley 16 belts 17, 21, 24 pulse encoders 19, 22 actuator (air cylinder)
20 First measurement roller 23 Second measurement roller 26 Roller support member 27 Guide roller 28 Guide member W Metal plate

In order to solve the above-mentioned first problem, the present invention provides an article having a plate-like portion formed in an arc shape by bending and having a constant plate thickness in a cross section in a predetermined direction. In a curvature radius measuring system for measuring the radius of curvature of a shaped portion, the plate thickness t is measured in a cross section of the plate shaped portion in a predetermined direction, and any two third reference points on the concave arc surface during bending are measured. A length L ₃ along the circumferential direction between and a length along the circumferential direction between two fourth reference points on the convex arc surface facing each of the third reference points in the plate thickness direction The length L4 and the length L2 along the circumferential direction between the _{two second} reference points on the convex arc surface after bending are measured at the same timing, and from the measurement results, each of the above -mentioned After calculating the length L ₁ along the circumferential direction between the two first reference points on the concave arc surface facing each of the two reference points in the plate thickness direction as (L ₃ + L ₄ - L ₂ ) _{. _ _}

As shown in FIG. 4, the curvature radius measurement system of the embodiment measures the plate thickness t in the cross section of the metal plate W to be formed in the arc direction, and during bending (actually undergoing bending) The length (inner arc length) L ₃ along the circumferential direction between two third reference points C, C' on the concave arc surface of the part, and each of the third reference points C, C' The length (outer arc length) L4 along the circumferential direction between two _fourth reference points D and D' on the convex arc surface facing each other in the plate thickness direction, and on the convex arc surface after bending The length (outer arc length) L2 along the circumferential direction between the _two second reference points B, B' of is measured at the same timing, and from the measurement results, each of the second reference points B, B' After calculating the length (inner arc length) L1 along the circumferential direction between the two _first reference points A and A' on the concave arc surface facing each other in the plate thickness direction, the metal plate W The radius of curvature r of the concave arcuate surface after bending is calculated.

Claims (3)

In a curvature radius measuring system for measuring the radius of curvature of a plate-shaped portion in a cross-section in a predetermined direction, for an article having a plate-shaped portion formed in a circular arc by bending and having a constant plate thickness in a cross-section in a predetermined direction,
A thickness t in a cross section of the plate-shaped portion in a predetermined direction, a length L3 along the circumferential direction between any two _third reference points on the concave arc surface during bending, and each of the third Length L ₄ along the circumferential direction between each of the three reference points and two fourth reference points on the convex arc surface facing each other in the plate thickness direction, and after bending corresponding to each of the fourth reference points Measure the length L ₂ along the circumferential direction between the two second reference points on the convex arc surface of , and from the measurement results, the concave arc after bending corresponding to each of the third reference points After calculating the length L ₁ along the circumferential direction between the two first reference points on the surface as (L ₃ + L ₄ - L ₂ ), (L ₁ t) / (L ₂ - L ₁ ) to determine the radius of curvature of the concave arcuate surface after bending of the plate-like portion. An upper roll and a pair of lower rolls arranged on both front and rear sides below the upper roll are provided, and the lower rolls are rotationally driven while a metal plate is sandwiched between the upper roll and the lower rolls. Therefore, in the bending roll that bends and forms the metal plate while reciprocating,
While bending the metal plate, measure the radius of curvature of the metal plate during forming using the curvature radius measuring system according to claim 1, and based on the measurement result, the upper roll in the subsequent forming operation. and a bending roll characterized by controlling the relative position of each lower roll. The curvature radius measurement system measures the length L ₃ along the circumferential direction between the two third reference points using the upper roll, and measures the length L 3 along the circumferential direction between the two third reference points. Measure the length L ₄ along the circumferential direction between the pair of lower rolls using a first measuring roller in contact with the metal plate, and the length L 4 along the circumferential direction between the two second reference points ₂ is measured using a second measuring roller that contacts the metal plate at a position facing the first measuring roller with one of the lower rolls interposed therebetween. bending roll.

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