JP2002066640A - Bending roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bending roll capable of preventing a barreled deformation of the pipe generated at the time of a roll bending work and producing a long steel pipe with a small diameter. SOLUTION: An apparatus to produce the pipe through the bending work by driving each roll of two or three bending rolls 2A, 2B provided coutacllessly in the vicinity of a core roll 1, with a metallic plate 6 fed in between the bending rolls, is provided with a back up roll 3 provided so as to pressure contact the core roll 1 to counteract a reaction force affecting the core roll 1 by the metallic plate 6 at the time of bending said plate 6, a detecting means 5 to detect the top end position and the thickness of the metallic plate 6 on the core roll 1, a moving means 4 which maintains the evacuation position till the end of the roll bending by evacuating the back up roll 3 only by the thickness of the metallic plate 6 before the metallic plate 6 is engaged between the back up roll 3 and the core roll 1 based on the detecting means 5 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of pipes by bending a metal plate by rolling, and more particularly to the manufacture of small-diameter and long pipes.

[0002]

2. Description of the Related Art There are two types of pipe production: a continuous production method using electric resistance welding and a production method using a bending roll device using roll bending. The former has a large and expensive manufacturing machine and is suitable for mass production. In the latter, on the other hand, the production machine is inexpensive but not suitable for mass production. Here, in order to manufacture a thin and long pipe, in the conventional method of manufacturing by electric resistance welding, generally,
Forming and welding can be performed for a plate having a thickness of 0.01 times or more the pipe diameter to be welded, but a plate having a thickness less than 0.01 times is generally not suitable for production by this method.

[0003] On the other hand, in the case of using a bending roll device, it is easy to form a thin pipe. However, when processing a long pipe with a long diameter using the bending roll device, the core roll itself becomes longer. Direction, the deflection near the center of the roll increases, and the roll pushing amount in this portion decreases. For this reason, when a metal plate is molded into a pipe shape, as shown in FIG. 6, the product pipe becomes a barrel shape with a gap at the center in the longitudinal direction, and becomes prominent when a long pipe is molded. Therefore, for example, 1
In many cases, it is difficult to mold a long pipe of 0 times or more by this method. For such a barrel-shaped deformation, starting with a bending roll device described in JP-A-08-117869, providing a crown on a core roll, or providing a backup roll on a pressing roll and intentionally bending in the width direction, There has been an attempt to solve the above problem by keeping a constant interval between the core roll and the pressing roll. In the bending roll device described in JP-A-9-70622, the backup roll 3
There is proposed a device having a step corresponding to the plate thickness.

[0004]

A conventional core roll is provided with a crown, or a backup roll is provided on a pressing roll to be deliberately deflected in the width direction so that a constant interval is maintained between the core roll and the pressing roll. However, even if it is attempted to eliminate the barrel-shaped deformation, if a small-diameter and long pipe as a workpiece is to be formed, the core roll deflection becomes too large and cannot be sufficiently compensated by the above technique. For example, a long pipe having a diameter of 50 mm and a length of 2000 mm could not be formed by roll bending. In the bending roll device described in Japanese Patent Application Laid-Open No. 9-70622, as shown in FIG. 7, there is a backup roll 3 in which a step 31 corresponding to the thickness of the plate 60 is provided. Backup roll 3
It is necessary to change the height of the step 31, and it is necessary to replace the backup roll 3 depending on the thickness of the plate 60, which is inconvenient, inferior in productivity, and accurately positions the tip of the workpiece at the step. Therefore, it is necessary to precisely control the rotational contact position of the backup roll and the like, and when the workpiece slips or the like, the tip position cannot be accurately positioned at the step. A bending roll in which two or three bending rolls are provided in a non-contact manner in the vicinity of the core roll and in the vicinity thereof, and a metal plate is fed between the bending rolls and the rolls are driven to perform a bending process, is capable of bending the tip. In the case of the bending roll described above, it is necessary to consider the fact that, in addition to the above, the tip portion is likely to be separated from the core roll. Then, in this invention, it is proposed in view of the above-mentioned situation, and it is providing the bending roll which can manufacture a small diameter long pipe.

[0005]

According to a first aspect of the present invention, there is provided a bending roll comprising: a core roll;
In a device for producing pipes by providing a bending roll with three or three bending rolls and feeding a metal plate between them to drive the rolls, when the metal plate is bent, the reaction force exerted on the core roll when the metal plate is bent A backup roll provided in contact with the core roll in the direction of canceling, a detecting means for detecting a tip position of the metal plate on the core roll, and a metal plate biting between the backup roll and the core roll based on the detecting means. And moving means for retracting the backup roll by the thickness of the metal plate and maintaining the retracted position until the roll bending is completed.

According to a second aspect of the present invention, in the apparatus for manufacturing a pipe, a bending roll is formed by pressing a backup roll on the surface of an elastic body against a core roll and feeding a metal plate to a contact portion thereof. In the direction to cancel the reaction force that the metal plate exerts on the core roll,
A backup roll provided in contact with the core roll,
Detecting means for detecting the tip position of the metal plate on the core roll,
Before the metal plate bites between the backup roll and the core roll based on the detection means, a moving means for retracting the backup roll by the thickness of the metal plate and maintaining the retracted position until the end of roll bending is provided. And

[0007] In the bending roll according to the third aspect, in addition to the above, the moving means of the backup roll may include:
An operation of re-detecting the thickness of the metal plate when the metal plate after the retreat movement is engaged by the detecting means based on the detection means and correcting the movement of the backup roll position is added.

Here, in the inventions according to the first to third aspects, it is particularly advantageous to use a long and small diameter core roll having a width of at least 10 times the diameter of the portion where the metal plate is fed and bent. is there. Further, it is preferable to have a means for causing a part or all of the surface of the core roll to have magnetism during feeding and bending of the metal plate. In the bending roll, it is advantageous to provide a belt that is driven synchronously with the core roll on the circumference of the core roll and between the contact portions of the backup roll.

Further, a seventh aspect of the present invention is a method for bending a metal plate into a roll shape using the bending roll according to any one of the first to sixth aspects, wherein the core roll and the core roll are bent. A state in which the bending roll or the backup roll starts to bite the metal plate, the backup roll comes into pressure contact with the core roll until the tip of the metal plate passes through the detecting means, and then the backup roll is retracted by the thickness of the metal plate. A roll bending method of a metal plate, wherein the backup roll and the core roll start biting the metal plate and finish the roll bending while maintaining the above conditions.

Here, when the metal plate is bent, the backup roll is provided so as to be in contact with the core roll in a direction to cancel the reaction force exerted on the core roll by the metal plate, thereby canceling the deflection of the core roll. The product can be prevented from becoming barrel-shaped. Detecting means for detecting the leading end position of the metal plate on the core roll, and retracting the backup roll to the core roll by the thickness of the metal plate when the metal plate enters between the backup roll and the core roll based on the detecting means. By having a moving means to move, after the metal plate is roll-bent, when the metal plate reaches the position of the backup roll, the backup roll is separated from the core roll by the thickness of the metal plate, and continues The backup roll can prevent the core roll from bending with the same pressure regardless of the presence or absence of the metal plate. Therefore, it is possible to manufacture a long and small-diameter core roll having a width whose roll diameter is 10 times or more. Further, at least the core roll is magnetized at the time of bending, whereby the metal plate is magnetically attached to the core roll, and the metal plate can be processed so as to follow the core roll. The tip can be inserted well in the middle. In addition, by providing a belt that is driven synchronously with the core roll between the contact portions of the backup roll, the metal plate can be similarly inserted between the core roll and the backup roll so that smooth bending can be performed. Works.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a bending roll according to the present invention will be described with reference to the drawings. 1 and 2 show an embodiment in which two bending rolls and a backup roll are provided in the vicinity of a core roll in a non-contact manner, where (a) is a side view, (b) is a front view, and (c). FIG. 2 is a plan view, and FIG. 2 is an explanatory view showing the operation of the backup roll. The bending roll according to the first embodiment includes a core roll 1 serving as a center of a bending process for feeding a metal plate 6 and two bending rolls 2A and 2B provided below the core roll 1 and the core roll 1.
The metal plate 6 is fed in between to drive each roll to perform bending. Above the core roll 1, a backup roll 3 is provided so as to be able to move up and down so as to come into contact with the core roll 1, and the metal on the core roll 1 is provided on the entry side of the metal plate 6 of the backup roll 3. Detecting means 5 for detecting the tip position of the plate 6 is provided.

The core roll 1 is composed of a core roll 1 normally used as a bending roll, for example, a core roll 1 made of an appropriate metal such as iron, and is rotatably supported by a housing 9. On the other hand, the bending rolls 2A and 2B are appropriately made of metal such as iron, and can be moved with respect to the core roll 1 by a roll moving device (not shown) in the housing 9.
The metal plate 6 can be bent. And it is rotatable by an appropriate power source such as the motor 10.

A detecting device 5 is provided between the bending rolls 2A and 2B and a backup roll 3 to be described later. The detection device 5 uses, for example, a laser position detection device utilizing the reflection of laser light or the like, and detects the tip position of the metal plate 6 and the metal plate 6 in accordance with the position detection.
And also measure the thickness. That is, by measuring the tip position of the metal plate 6 and measuring the thickness of the metal plate 6 in advance, an appropriate retreat timing and retreat amount of the backup roll 3 are obtained. Note that the above-described detection device is a preferable example because both can be obtained at the same time. However, as long as they can be measured, a known detection device, which is not limited to the above-described detection device and device, may be used. .

Above the core roll 1, a backup roll 3 is provided. This backup roll 3
When the metal plate 6 is bent, the metal plate 6 is provided so as to be in contact with the core roll 1 in a direction to cancel the reaction force exerted on the core roll 1 to prevent the core roll 1 from bending, and the object to be molded is formed into a barrel shape. It has the role of preventing it from being formed. The backup roll 3 has an elastic body 30 provided on the surface of the roll as shown in FIG. Here, the elastic body 30 provided on the pressing roll 2 is made of, for example, a rubber material, and its thickness is generally 20 mm to 100 mm in order to have sufficient deformability.
About thickness is provided.

The backup roll 3 includes, for example, a hydraulic cylinder 40 and a support 4 for the backup roll.
1 is provided between the backup roll 3 and the core roll 1 based on the detection device 5 for detecting the tip position of the metal plate 6 on the core roll 1 described above. Immediately before biting, the backup roll 3 can be retracted by the thickness of the metal plate 6 and
Before and after the metal plate 6 is engaged, a cylinder or the like of a moving mechanism can be used to contact the core roll 1 with the same pressure. Here, as described above, the movement amount of the backup roll 3 moves by an amount corresponding to the amount by which the tip position of the metal plate 6 is separated from the surface of the core roll 1.

According to the present invention, the metal plate 6 is supplied from the work table 90 to the core roll 1 from the bending roll 2A, and the tip of the metal plate 6 reaches the bending roll 2B. And between the bending rolls 2A and 2B. When the metal plate 6 is supplied to the core roll 1 and the bending rolls 2A and 2B and the bending is continued, when the tip of the metal plate 6 is positioned at the laser position detecting device 5, the thickness of the metal plate 6 is detected by the laser position detecting device 5. And detect the position. Based on the detected signal, the time required for the metal plate 6 to reach the backup roll 3 and the amount of retreat of the backup roll 3 are calculated based on the rotation speed of the core roll 1, and immediately before the metal plate 6 meshes with the backup roll 3. Then, the backup roll 3 is retracted by the moving means 4 such as a hydraulic cylinder. Thereafter, the position of the backup roll 3 is maintained so as to prevent the core roll 1 from bending. Thereafter, the rotation of each roll is stopped, the backup roll 3 is retracted, the pipe-shaped metal plate 6 is extracted from the core roll 1, and the end is completed through a welding process (not shown).

There is a possibility that the tip of the metal plate 6 is separated from the surface of the core roll 1, that is, the tip of the metal plate 6 is in a state of springback or the like and the tip is in a floating state. is there. However, even in this state,
The surface of the backup roll 3 is made of an elastic material, and is used in a slightly pressed state against the core roll 1 in order to prevent the core roll 1 from bending. Even when the backup roll 3 is retracted, the movement of the elastic member 30 of the backup roll 3 is reduced to such an extent that the recess is reduced, and the tip of the metal plate 6 can be brought into contact with the surface of the core roll 1. However, if the roll bending is continued in this state, the pressure applied to the core roll decreases, and the core roll may be bent. Therefore, when the thickness of the metal plate 6 is measured by the position detecting device 5 in a state where the back surface of the metal plate 6 is in contact with the core roll 1, the thickness of the metal plate 6 can be accurately measured. Then, by adjusting the position of the backup roll 3 again based on this data, the position of the backup roll 3 can be adjusted more accurately, and the deflection of the core roll 1 can be more reliably prevented.

If the tip of the metal plate is in a floating state, it is not possible to obtain an accurate measurement value. Therefore, means for imparting magnetism to the core roll 1 may be provided. For example, as shown in FIG. 3, a configuration in which the permanent magnet 7 is built in the core roll, or a configuration in which an electromagnetic coil is provided in the core roll (not shown) may be used. In these cases, the permanent magnet 7 and the like function to magnetically attach the leading end of the metal plate 6 to the core roll 1, prevent the leading end from being lifted by springback of the metal plate 6, and reduce the leading end position and thickness of the metal plate. Accurate measurement is possible, and it is not necessary to measure the thickness of the metal plate again, and it is not necessary to adjust the retracted position of the backup roll 3.

Also, instead of the magnet 7, the metal roll 6, which has come out of the bending roll 1, does not float off the roll surface, as shown in FIGS. A belt 8 that is driven in synchronization with the rotation speed of the core roll 1 may be provided between the contact portions between the core roll 1 to prevent the metal plate 6 from floating from the surface of the core roll 1.

FIG. 5 shows a second embodiment in which two backup rolls are provided. FIG. 5 (a) is a side view, FIG. 5 (b) is a front view, and FIG. 5 (c) is a plan view. . The bending roll according to this embodiment includes a core roll 1 that feeds a metal plate 6 and serves as a center of the bending process, two backup rolls 3A and 3B, and a position for detecting the tip position of the metal plate 6 on the core roll 1. The configuration differs from the first embodiment in that the backup rolls 3A and 3B are arranged on one straight line so that the core roll 1 is sandwiched between the backup rolls 3A and 3B. This is the same as in the first embodiment. The same material as that of the first embodiment is used for the material of the core roll 1 and the backup rolls 3A and 3B.

A metal plate 6 serving as a pipe material placed on a work table 90 is supplied from between the core roll 1 and the first backup roll 3A, and the metal plate 6 is subjected to roll bending by the core roll 1 and the backup roll 3A. Is done. next,
When the tip of the metal plate 6 is located at the laser position detection device 5, the laser position detection device 5 detects the thickness and position of the metal plate 6. Based on the detected signal, the metal plate 6 is rotated by the rotation speed of the core roll 1 so that the backup roll 3
B and the retracted amount of the backup roll 3B are calculated, and the metal plate 6 is moved to the backup roll 3B.
Immediately before the engagement, the backup roll 3B is retracted by the moving means 4 such as a hydraulic cylinder. Thereafter, the position of the backup roll 3B is maintained so as to prevent the core roll 1 from bending, and the core roll 1 and the backup roll 3
The roll bending is performed again at B, and the core roll 1 completes one round, thereby completing the roll bending. Thereafter, the rotation of each roll is stopped, and the backup rolls 3A and 3B are retracted,
A metal plate 6 formed into a pipe shape is extracted from the core roll 1 and the end is completed through a welding process (not shown).

(Example 1) In the apparatus of the embodiment shown in FIG. 1, the core roll 1 has a diameter of 50 mm, the bending rolls 2A and 2B have a diameter of 40 mm, the backup roll 3 has a diameter of 100 mm, and is made of urethane rubber. The elastic material portion has a thickness of 50 mm. The metal plate 6 used is made of steel and has a thickness of 0.5 mm and a length of 2 m.
Roll bending was performed at m / min. During bending, the reaction force of the core roll 1 acting on the backup roll 3 is 6
８００800 kfg. Core roll 1 whose leading end is the starting point of biting between core roll 1 and backup roll 3
The backup roll 3 was moved 0.5 mm upward when it reached about 5 mm before the point of contact between the backup roll 3 and the backup roll 3. The movement of the backup roll 3 is completed in about 0.1 second. The time from the start of the movement until the plate completely passes between the core roll 1 and the backup roll 3 is as follows:
Although the pipe diameter is slightly increased, it is only a very small length, so there is no problem when viewed as a molded pipe. The metal plate 6 after the bending process could be formed so that the end portions were substantially in a straight line, and there was almost no gap at the center portion, and the metal plate 6 did not become a barrel shape. When a similar experiment was performed using a bending roll having no backup roll, the bending of the core roll 1 was about 10 mm, and the gap at the center was about 50 to 100 mm. Further, since the backup roll 3 is not retracted beyond the plate thickness, in the case of the present invention, the core roll 1 hardly bends, and the roundness of the thin long pipe can be accurately obtained.

(Embodiment 2) In the apparatus of the embodiment shown in FIG. 5, the core roll 1 has a diameter of 50 mm, the pressing roll 2 has a diameter of 400 mm, and the thickness of the elastic material portion made of urethane rubber is reduced. The metal plate 6 to be used is made of steel and has a thickness of 0.5 mm and a length of 2 m.
At a pressure of 00 mm / min, the pressing force of the pressing roll 2 is about 10
Roll bending was performed at ton. During bending, the reaction force of the core roll 1 acting on the backup roll 3 is 10 t
It was on. When the plate tip reached about 5 mm before the point of contact between the core roll 1 and the backup roll 3, which is the starting point of the engagement between the core roll 1 and the backup roll 3, the backup roll 3 was moved 0.5 mm upward. The movement of the backup roll 3 is completed in about 0.1 second.
From the start of this movement to the time when the plate completely passes between the core roll 1 and the backup roll 3, the pipe diameter is slightly increased, but since it is only a very small length, the pipe after forming is formed. If you look at it, there is no problem. After bending, the metal plate 6 was able to be formed so that its ends were substantially in a straight line, there was almost no gap at the center, and it did not become a barrel shape.

[0024]

According to the bending roll of the present invention,
It has become possible to stably produce small-diameter long pipes, which could not be formed conventionally. According to the invention described in claims 1 to 4 and claim 7, since the deflection of the core roll can be prevented beforehand, the finished product can prevent so-called barrel-shaped deformation, and can mold a small-diameter, long pipe. I can do it.
According to the third aspect of the present invention, in addition to the above, the backup roll is controlled in accordance with the spring back of the workpiece and the floating state of the metal plate even if the metal plate floats from the core roll. Since the backup roll position is controlled again after biting, the back-up roll can reliably prevent the core roll from bending, and can improve the properties of the end portion of the product. According to the fifth or sixth aspect of the present invention, it is possible to prevent the leading end of the metal plate from being lifted up on the surface of the core roll during feeding and bending of the metal plate, and to press the metal plate itself against the core roll. It is possible to produce a pipe with a good finish with good penetration into the part and the backup roll.

[Brief description of the drawings]

FIG. 1 shows an embodiment in which two bending rolls and a backup roll are provided in a non-contact manner in a backup roll according to the present invention, (a) is a side view, (b) is a front view,
(C) is a plan view.

FIG. 2 is an explanatory diagram showing an operation of a backup roll according to the present invention.

FIG. 3 is an explanatory view showing an embodiment in which a permanent magnet is provided on a core roll of the bending roll of the present invention.

FIG. 4 is a perspective view of an embodiment in which a belt is provided between two backup rolls according to the present invention.

FIG. 5 is an explanatory view of an embodiment in which two backup rolls according to the present invention are provided, (a) is a side view, (b) is a front view,
(C) is a plan view.

FIG. 6 is a perspective view of a conventional barrel-shaped pipe formed by roll bending.

FIG. 7 is an explanatory view of a conventional example in which a step corresponding to a plate thickness is provided on a backup roll.

[Explanation of symbols]

 1 core roll 10 motor 2A, 2B bending roll 3, 3A, 3B backup roll 30 elastic body 4 moving means 40 hydraulic cylinder 41 support 5 detection device 6 metal plate 7 permanent magnet 8 belt 9 housing

Claims (7)

[Claims] An apparatus for producing a pipe in which two or three bending rolls are provided in the vicinity of a core roll in a non-contact manner, and a metal plate is fed between the rolls and each roll is driven to perform a bending process. When bending the plate, a backup roll provided to cancel the reaction force exerted on the core roll by the metal plate and to be brought into pressure contact with the core roll; and a detecting means for detecting a tip position and a thickness of the metal plate on the core roll; Before the metal plate bites between the backup roll and the core roll based on the detection means, a moving means for retracting the backup roll by the thickness of the metal plate and maintaining the retracted position until the end of roll bending is provided. Bending roll to do. 2. An apparatus for manufacturing a pipe by pressing a pressing roll on the surface of an elastic body against a core roll and feeding a metal plate to a contact portion thereof to perform a bending process. In bending the metal plate, the metal plate is pressed against the core roll. A backup roll provided to cancel the applied reaction force and press contact with the core roll; a detection unit for detecting a tip position and a thickness of the metal plate on the core roll; and a backup roll and the core roll based on the detection unit. A bending roll provided with moving means for retracting the backup roll by the thickness of the metal plate before the metal plate bites and maintaining the retracted position until the roll bending is completed. 3. The bending roll according to claim 1, wherein the back-up roll moving means detects again the metal plate thickness at the time when the retracted and moved metal plate bites, based on the detecting means, and determines the backup roll position. A bending roll characterized by adding a movement correcting operation. 4. The bending roll according to claim 1, wherein a long and small diameter core roll having a width of at least 10 times the diameter is used. 5. The method according to claim 1, wherein a part or all of the surface of the core roll is provided with means for causing magnetism during the feeding and bending of the metal plate. Bending roll. 6. The bending roll according to claim 1, wherein a belt that is driven synchronously with the core roll is provided on the circumference of the core roll between the contact portions of the backup roll. 7. A method of bending a metal plate into a roll using the bending roll according to claim 1, wherein the core roll and the bending roll or the backup roll bite the metal plate. Starting, the backup roll comes into pressure contact with the core roll until the tip of the metal plate passes through the detecting means, and then, while maintaining the state in which the backup roll is retracted by the thickness of the metal plate, the backup roll and the core roll are brought into contact with the metal. A method for forming a metal plate into a roll, comprising: starting to bite the plate and ending the roll bending.