JP2014117723A - Mill for rolling outer diameter shape ring article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ring rolling mill which prevents occurrence of angular speed differences in various parts of work during metal rolling and can roll work having varying outer diameters, instead of straight outer diameters, with good precision.SOLUTION: A ring rolling mill comprises a mandrel 121, a first main roll 111 rolling a part of the periphery of a blank W, a second main roll 112 rolling a part different from the part of the periphery of the blank W rolled by the first main roll 111 and having an outer diameter different from that of the main roll 111, first drive means 130 of rotation-driving the first main roll 111, second drive means 140 of rotation-driving the second main roll 112, outer diameter measurement means 150 of measuring outer diameter dimensions of the part of the blank W rolled by the second main roll 112 and control means 160 of controlling the drive of the first drive means 130 on the basis of the information on measurements obtained by the outer diameter measurement means 150 so as to adjust the number of revolutions of the first main roll 111.

Description

  The present invention relates to a ring rolling mill for rolling a ring having various shapes that are not straight in outer diameter.

  The ring rolling mill is an apparatus that performs rolling of a ring-shaped material to be processed (hereinafter referred to as a workpiece w) using each installed roll. An example of a conventional ring rolling mill device is shown in FIG. This apparatus has a main roll 1 (main roll) that is driven to rotate, a rotatable mandrel 2, and an axial roll 4 that sandwiches a ring material R from above and below. At the time of rolling, the peripheral part (left and right) of the ring material R is sandwiched between the main roll 1 that is rotationally driven and the rotatable mandrel 2 and the wall surface is pressed in the radial direction. The periphery (upper and lower) of R is sandwiched and the upper and lower surfaces thereof are pressed in the axial direction. Thereby, it rolls, rotating the ring material R and expanding the outer diameter.

In such a ring rolling mill, when rolling a workpiece having various shapes that are not straight in outer diameter, for example, a workpiece having a shape as shown in FIG. 3A, an apparatus having the following configuration is conventionally used. Was used. FIG. 4 is a cross-sectional view and a side view of the main part of a conventional ring rolling mill 400 that rolls a workpiece w having various shapes that are not straight in outer diameter. This ring rolling mill has different outer diameters (φD ₁ , φD ₂ ) at the upper and lower portions, a main roll 410 that is rotationally driven at a constant rotational speed (N), a rotatable mandrel 421, and a rotational drive A pair of axial rolls 422 and 423 are provided.

  When rolling, the outer diameter of the lower part becomes larger than the upper part as shown in the target shape product (FIG. 3A, where FIG. 3A is a cross-sectional view of the left half of the target shape product). A work w (FIG. 4A), which is a wasteland, is prepared. The main roll 410 has a large outer diameter portion (upper portion), a smaller outer diameter portion (lower portion), and a mandrel 421 sandwiching the peripheral portion of the prepared rough work w (FIG. 4A), Press the wall in the radial direction. At the same time, the peripheral part (up and down) of the work w, which is a rough ground prepared by the axial rolls 422 and 423, is sandwiched, and the upper and lower surfaces thereof are pressed in the axial direction. Thereby, the workpiece w is rolled while rotating the workpiece w and expanding the outer diameter (FIG. 4B).

However, in the rolling by the conventional ring rolling mill, the angular velocity difference has occurred in various parts of the workpiece during rolling. That is, the outer diameter of the main roll 410 is φD ₁ (upper outer diameter), φD ₂ (lower outer diameter), the rotation speed is N (constant), the outer diameter of the workpiece w is φd ₁ (upper outer diameter), φd ₂ (Lower outer diameter) and the angular velocity of the workpiece w on the workpiece φd ₁ side is ω ₁ , and the angular velocity of the workpiece on the φd ₂ side is ω ₂ , ω ₁ is expressed by the following equation.

また、ω_２は下記の式で表される。

Further, ω ₂ is expressed by the following formula.

従って、下記の式のとおりとなる。

Therefore, the following equation is obtained.

すなわち、ローリング過程中、ワークのφｄ_１側（小径側）の角速度は、φｄ_２側（大径側）の角速度よりも大きくなる。

That is, during the rolling process, the angular velocity on the φd ₁ side (small diameter side) of the workpiece becomes larger than the angular velocity on the φd ₂ side (large diameter side).

  Therefore, during the rolling process, the flow of the workpiece meat occurs not only in the radial direction but also in the axial direction from the large diameter side to the small diameter side of the workpiece. As a result, the conventional ring rolling mill has a problem that the following defective products are likely to occur.

That is, although the upper outer diameter (φa) is equal to the upper outer diameter (φA) of the target shape product, the lower outer diameter (φb) is smaller than the lower outer diameter (φB) of the target shape product (FIG. 3A). (FIG. 3 (b)), the thickness (h) of the lower flange portion is smaller than the thickness (H) of the flange portion of the target shape product (FIG. 3 (c)), and the inner diameter (φC ₁ , φC ₂ ) is the target shape. In addition to the inner diameter (φC) of the product, the upper inner diameter (φC ₁ ) and the lower inner diameter (φC ₁ , φC ₂ ) are different (FIG. 3 (d)), the wall thickness (FIG. 3 (e)), the small outer diameter ( Defects (FIGS. 3 (b) to (f)) such as makules or cabs (FIG. 3 (f)) in which the meat of the upper outer diameter) and the large outer diameter (lower outer diameter) overlap are generated (a There is a problem that it is difficult to obtain a rolling product of a predetermined dimension shape.

  In the invention of Patent Document 1, the rolling surface of the main roll 10 is composed of a sleeve upper body 16, a sleeve intermediate body 15, and a sleeve lower body 12 having different outer diameters. Then, by making the sleeve upper body 16 and the sleeve lower body 12 rotatable, friction due to a difference in peripheral speed generated between each rolled surface and the surface of the ring material R is reduced during rolling.

  However, in the invention of Patent Document 1, friction due to the peripheral speed difference generated between each rolling surface and the surface of the ring material R cannot be completely eliminated, and there is still room for improvement. In addition, Patent Document 1 mentions that the sleeve upper body 16 and the sleeve lower body 12 are rotated at an optimum rotation speed, but no specific configuration for realizing the rotation is disclosed.

Japanese Patent Publication No. 07-014537

  The present invention has been made in view of the above points. During rolling, a difference in angular velocity is prevented from occurring in various parts of the work, and an outer diameter is not straight but a work having various shapes is rolled with high accuracy. An object of the present invention is to provide a ring rolling mill.

  The ring rolling mill of the present invention has two main rolls that are driven to rotate, and a rotatable mandrel. The main roll and the mandrel sandwich a peripheral portion of a ring-shaped material to be processed, and the wall surface has a radius. It has a pair of axial rolls that are rotated by pressing in the direction and sandwiches the peripheral part of the ring material to be processed with the pair of axial rolls, and presses the upper and lower surfaces in the axial direction. A rolling ring mill that rolls, together with the mandrel, a first main roll that rolls a part of the periphery of the ring-shaped material to be processed, and the mandrel and the peripheral portion of the ring-shaped material to be processed A second part having an outer diameter different from that of the first main roll, wherein a part different from the part being rolled by the first main roll is rolled at a constant rotational speed. Main roll, first drive means for rotationally driving the first main roll, second drive means for rotationally driving the second main roll, and the second of the ring-shaped material to be processed In order to adjust the rotation speed of the first main roll based on the outer diameter measuring means for measuring the outer diameter dimension of the portion rolled by the main roll, and the measurement information measured by the outer diameter measuring means, A ring rolling mill comprising: control means for controlling driving of the first drive means.

  Further, the control means uses the measurement information measured by the outer diameter measuring means, and the angular velocity of the portion of the ring material to be processed that is rolled by the first main roll and the second main roll. The calculation unit for obtaining the rotation speed of the first main roll when the angular velocity of the portion to be rolled becomes equal, and the first main roll to rotate at the rotation speed obtained by the calculation unit. And a control unit that controls the driving of the driving means.

Further, the calculation unit is configured such that the rotation speed of the first main roll is N _X1 , the diameter is D ₁ , the rotation speed of the second main roll is N _X2 , the diameter is D ₂ , and the ring-shaped material to be processed When the outer diameter of the portion rolled by the second main roll is d _x2 , the angular velocity of the portion rolled by the first main roll of the ring-shaped material to be processed and the first It can comprise so that the rotation speed of the said 1st main roll when the angular velocity of the part rolled with 2 main rolls may become equal may be calculated | required.

  Further, the first main roll and the second main roll may be arranged adjacent to each other in the vertical direction and have center lines on the same straight line.

  Furthermore, the first driving means has a first shaft for rotating the first main roll, and the second driving means is a second axis for rotating the second main roll. The first shaft can be configured to penetrate through the inside of the second shaft.

  The first driving means has a first shaft for rotating the first main roll, and the second driving means is a second axis for rotating the second main roll. The first axis and the second axis can be configured to be adjacent to each other in the vertical direction.

  This suppresses the occurrence of a difference in angular velocity at various parts of the workpiece during rolling, and can accurately roll a workpiece having various shapes in which the outer diameter is not straight.

The side view of the principal part of the ring rolling mill 100 which is 1st Example of this invention, and the conceptual diagram of a control and a drive system. The side view of the main roll part of the ring rolling mill 100 which is 1st Example of this invention, and the 1st and 2nd drive means part. Sectional drawing of the main roll part of the ring rolling mill 100 which is 1st Example of this invention. The side view of the principal part of the ring rolling mill 200 which is 2nd Example of this invention. Sectional drawing of the left half part from the center of the defect goods produced by the rolling by the workpiece | work of a target shape and the conventional ring rolling mill. The cross section and side view of the principal part of the conventional ring rolling mill 400 which rolls the workpiece | work w of the shape from which an outer diameter is not straight but changes variously.

  The configuration of the ring rolling mill 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1A to 1C. FIG. 1A is a side view of a main part of a ring rolling mill 100 according to a first embodiment of the present invention and a conceptual diagram of a control and drive system, and a main roll of the ring rolling mill 100 according to the first embodiment of the present invention. FIG. 1C is a cross-sectional view of the main roll portion of the ring rolling mill 100 according to the first embodiment of the present invention.

  Referring to FIGS. 1A to 1C, a ring rolling mill 100 according to a first embodiment of the present invention is a rotationally driven variable speed main roll 111 and a rotationally driven having a smaller outer diameter than the variable speed main roll 111. Constant-speed main roll 112, rotatable mandrel 121, a pair of axial rolls 122 and 123 driven by axial roll motors 122 (a) and 123 (a) (not shown), a motor 131, and a reducer 132. A first driving means 130 having a shaft 133 and a key 133 (a), a second driving means 140 having a motor 141, a speed reducer 142, a shaft 143 and a key 143 (a), and a workpiece w. A control provided with an outer diameter measuring means 150 for measuring the outer diameter of the portion rolled to the constant-speed main roll 112, a calculation unit 161, and a control unit 162 Means 160.

  The variable speed main roll 111 and the constant speed main roll 112 will be described with reference to FIGS. 1A and 1B.

  The variable speed main roll 111 and the constant speed main roll 112 are rotationally driven in the same direction, and are used for rolling the workpiece w together with a rotatable mandrel 121 and a pair of rotationally driven axial rolls 122 and 123. .

The variable speed main roll 111 and the constant speed main roll 112 are installed so that they are adjacent to each other in the vertical direction and their center lines are located on the same straight line. In this embodiment, the variable speed main roll 111 is installed at the upper part, and the constant speed main roll 112 is installed at the lower part. Among these, the diameter φD ₁ of the variable speed main roll 111 installed in the upper part is set larger than the diameter φD ₂ of the constant speed main roll 112 installed in the lower part. Thereby, the workpiece | work w whose outer diameter of a lower side is larger than an upper side can be rolled. The size of [phi] D ₁ and [phi] D _2, depending on the shape of the target shape article can be appropriately changed.

  Further, during rolling, the rotation speed of the variable speed main roll 111 is changed. On the other hand, the constant speed main roll 112 is rotated in a state where the rotation speed is kept constant.

  Next, the first driving means 130 and the second driving means 140 will be described with reference to FIGS. 1A to 1C.

  The first driving means 130 is a part that rotationally drives the variable speed main roll 111. The first driving means 130 includes a motor 131, a speed reducer 132 that reduces the rotational speed of the motor 131 and increases the torque and outputs it, and a shaft that rotates via the speed reducer 132 by driving the motor 131. 133 and a key 133 (a) installed in a keyway provided in the variable speed main roll 111 and the shaft 133 and transmitting the rotation of the shaft 133 to the variable speed main roll 111.

  The second driving means 140 is a part that rotationally drives the constant speed main roll 112. The second driving means 140 includes a motor 141, a speed reducer 142 that decelerates the rotational speed of the motor 141 and outputs an increased torque, and a shaft that rotates via the speed reducer 142 by driving the motor 141. 143, and a key 143 (a) that is installed in a keyway provided in the constant speed main roll 112 and the shaft 143 and transmits the rotation of the shaft 143 to the constant speed main roll 112.

  Of these, the shaft 133 is designed to be longer in the axial direction than the shaft 143 and smaller in diameter than the shaft 143. The shaft 133 is installed in a cylindrical cavity having a diameter larger than that of the shaft 133 provided from one end to the other end of the shaft 143 in the axial direction. Accordingly, when the shaft 133 and the shaft 143 are installed in the ring rolling mill 100, the shaft 133 is partially covered by the shaft 143.

  A keyway is provided on the outer periphery of the shaft 143, and the key 143 (a) is installed here. The key 143 (a) is received in a corresponding key groove provided in the constant speed main roll 112. A keyway is also provided on the outer periphery of the shaft 133 that is not covered by the shaft 143, and the key 133 (a) is installed here. The key 133 (a) is received in a corresponding key groove provided in the variable speed main roll 111.

  Thus, when the motors 131 and 141 are driven, the shaft 133 and the shaft 143 rotate without interfering with each other because the diameter of the cavity in the shaft 143 is larger than the diameter of the shaft 133. Therefore, the variable-speed main roll 111 and the constant-speed main roll 112 can be separately rotated via the keys 133 (a) and 143 (a) installed on the shafts 133 and 143. Moreover, since it can be separately driven to rotate, the variable speed main roll 111 and the constant speed main roll 112 can also be driven to rotate at different rotational speeds.

  Next, the outer diameter measuring means 150 will be described with reference to FIG. 1A.

The outer diameter measuring means 150 is a part that constantly measures the outer diameter φd _{2 of the} part rolled by the constant speed main roll of the workpiece w during rolling. And the outer diameter measurement means 150 outputs measurement information at any time.

  For example, the outer diameter measuring means 150 is pressed against the outer peripheral surface of the portion rolled by the constant-speed main roll 112, and can be moved according to the diameter of the workpiece w and the amount of movement of the measuring roll. You may comprise by the outer diameter measuring device etc. which measure the change of the magnitude | size of a diameter.

  Next, the control means 160 will be described with reference to FIG. 1A.

  The control means 160 is a part that controls the first drive means 130 in order to adjust the rotation speed of the variable speed main roll 111 based on the measurement information from the outer diameter measurement means 150. The control unit 160 includes a calculation unit 161 and a control unit 162.

  Based on the measurement information from the outer diameter measuring means 160, the calculation unit 161 makes the angular velocity of the portion of the workpiece w rolled by the variable speed main roll 111 equal to the angular velocity of the portion rolled by the constant speed main roll 112. In this case, the rotation speed of the variable speed main roll 111 is obtained.

Here, the diameter of the variable speed main roll 111 is φD ₁ , the rotation speed is N _x1 , the diameter of the constant speed main roll 112 is φD ₂ , the rotation speed is N _x2, and the roll is rolled by the variable speed main roll 111 of the workpiece w. portion of the outer diameter at any point .phi.d _{x1 that,} the rotational speed n _x1, and ₁ angular velocity omega, .phi.d _x2 outer diameter at any point of the portion to be rolled by a constant speed main roll _112, rotation speed Mathematical formula for obtaining the rotational speed N _x1 of the variable speed main roll 111 when ω ₁ and ω ₂ are equal to each other, where n _x2 and angular velocity are ω ₂ .

  First, at the time of rolling, a portion of the workpiece w that is rolled by the variable speed main roll 111 is sandwiched between the variable speed main roll 111 and the rotatable mandrel 121 and is rotated by the variable speed main roll 111. Therefore, at the time of rolling, the peripheral speeds of the variable speed main roll 111 and the portion of the workpiece w that is rolled onto the variable speed main roll 111 are equal. The peripheral speed (m / s) is obtained by diameter (unit m) × π × rotational speed ÷ 60. Therefore, when the calculation formulas of the respective peripheral speeds are put together, the following formula 1 is obtained.

  Further, during rolling, the peripheral speed between the portion of the workpiece rolled by the constant speed main roll 112 and the constant speed main roll 112 is also equal for the same reason. Therefore, when formulas for calculating the respective peripheral speeds are put together, the following formula 2 is obtained.

  Then, from Equation 1 and Equation 2, the following Equation 3 is obtained.

Here, the angular velocity is obtained by 2π × rotational speed. Therefore, ω ₁ = ω ₂ that holds _true, is when the _n x1 ₌ n _x2. Therefore, when this is reflected in the above Equation 3, the following Equation 4 is obtained.

Moreover, the relationship of the following formula 5 is established among φD ₁ , φd _x1 , φD ₂ , and φd _x2 .

  When the formula 5 is modified and substituted into the formula 4, the following formula 6 is obtained.

In Equation 6, the value of N _x2 is constant and known because it is the rotation speed of the constant speed main roll 12. The diameter [phi] D ₁ of the variable speed main roll 111, the value of the diameter [phi] D ₂ of the constant-speed main roll 112 is also constant and known. Therefore, if the value of the outer diameter φd _x2 of the part of the work w rolled on the constant speed main roll 112 is determined, the value of N _x1 can be obtained.

The arithmetic unit 161 can obtain the rotational speed N _x1 of the variable speed main roll 111 when ω ₁ and ω ₂ are equal using Equation 6. That is, it is possible to obtain the value of N _x1 by receiving the measurement information by the outer diameter measuring means 150 and substituting the value of φd _x2 into Equation 6. Then, information about the obtained value of N _x1 is output.

  The control unit 162 is a part that controls the first driving unit 130 so that the variable speed main roll 111 rotates at the rotation speed obtained by the calculation unit 161.

Specifically, the control unit receives information on the rotation speed obtained by the calculation unit 161 and sends a control signal to control the driving of the motor 131. Thereby, the variable speed main roll 111 can be rotated at the rotation speed obtained by the calculation unit 161, that is, at the rotation speed when ω ₁ = ω ₂ .

  Next, the operation of the ring rolling mill 100 according to the first embodiment of the present invention will be described.

  First, a workpiece w (FIG. 1A (a)), which is a wasteland having a lower outer diameter compared to the upper portion, is prepared as in the shape product to be created (target shape product). Then, the peripheral part (left and right) of the work w is sandwiched between the variable speed main roll 111 and the constant speed main roll 112, and the peripheral part (up and down) of the work w is sandwiched between the pair of axial rolls 122 and 123. Here, the motors 131 and 141 and the unillustrated axial roll motors 122 (a) and 123 (a) are driven. As a result, the shafts 133 and 143 rotate. The rotation is transmitted to the variable speed main roll 111 and the constant speed main roll 112 via the keys 133 (a) and 143 (a), and the variable speed main roll 111 and the constant speed main roll 112 are rotated. Further, the pair of axial rolls 122 and 123 also rotate. Accordingly, the wall surface of the peripheral part (left and right) of the work w is pressed in the radial direction by the variable speed main roll 111 and the mandrel 120, and the peripheral part (upper and lower) of the work w is pressed by the pair of axial rolls 122 and 123. Press the upper and lower surfaces in the axial direction. Thereby, it rolls, rotating the whole workpiece | work w and expanding the outer diameter (FIG. 1A (b)).

At the start of rolling, the outer diameter measuring means 150 starts measuring the outer diameter φd _x2 of the portion to be rolled by the constant speed main roll 112. Then, the measured information is output to the calculation unit 161.

Receiving this measurement information, the calculation unit 161 substitutes the value of φd _x2 measured by the outer diameter measuring means 150 into the above formula 6. Thereby, the rotation of the variable speed main roll 111 when the angular velocity ω _{1 of the} part of the work w rolled by the variable speed main roll 111 and the angular speed ω _{2 of the} part rolled by the constant speed main roll 112 become equal. The number N _x1 is obtained. Then, information on the rotation speed N _x1 is output to the control unit 162.

Receiving information about the rotation speed N _x1 , the controller 162 sends a control signal to control the driving of the motor 131. As a result, the variable speed main roll 111 is rotated at a rotation speed of N _{× 1} .

The feedback loop of rolling, measurement of the outer diameter φd _{× 2} , calculation based on the measurement information, and drive control of the motor 131 based on the calculation result is always repeated during the rolling and continues until the rolling is finished.

Due to this feedback loop, the variable speed main roll 111 is rotating at a rotational speed N _{x1 in} which ω ₁ and ω ₂ are equal during rolling. Therefore, the work w also rotates without causing each speed difference at various places.

  Thereby, the workpiece | work w of the target shape without the defect (FIG.3 (b)-(f)) which has arisen conventionally can be obtained (FIG.1A (c)).

  In this way, the ring rolling mill 100 according to the first embodiment of the present invention prevents a difference in angular velocity from occurring in various parts of the work during rolling, and the work has a shape in which the outer diameter is not straight and changes in various ways. w can be rolled with high accuracy.

  A ring rolling mill 200 according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a side view of a main roll portion and first and second driving means portions of a ring rolling mill 200 according to the second embodiment of the present invention. In the following description, the description of the same parts as in the first embodiment will be omitted, and different points will be mainly described.

  Similar to the ring rolling mill 100 according to the first embodiment, the ring rolling mill 200 according to the second embodiment of the present invention has a variable speed main roll 211, a constant speed main roll 212, and a mandrel 221 (not shown). A first driving means 230 including a pair of axial rolls 222 and 223 (not shown) that are rotationally driven, a motor 231, a speed reducer 232, a shaft 233, and a key 233 (a) (not shown). A second drive means 240 including a motor 241, a speed reducer 242, a shaft 243, a key 243 (a) (not shown), an outer diameter measuring means 250 (not shown), and a calculation unit 261 ( Control means 260 (not shown) provided with a control unit 262 (not shown).

  Furthermore, in this embodiment, the shaft 233 is designed to have the same diameter as the shaft 243. One end of the shaft 233 is installed in the output portion of the speed reducer 232, and the other end is installed in the variable speed main roll 211. The shaft 243 has one end installed in the output portion of the speed reducer 242 and the other end installed in the constant speed main roll 212.

  Thereby, the shaft 233 and the shaft 243 rotate without interfering with each other when the motors 231 and 241 are driven. Therefore, the variable speed main roll 211 and the constant speed main roll 212 can be separately rotated via the keys 233 (a) and 243 (a) installed on the shafts 233 and 243. Moreover, since it can rotate separately, the variable speed main roll 211 and the constant speed main roll 212 can also be rotationally driven at different rotation speeds. As described above, the structure of the shaft and the key portion is not limited to that shown in the first embodiment, and a structure such as the shafts 233 and 243 and the keys 233 (a) and 243 (a) of the present embodiment is adopted. You can also.

  As a result, the ring rolling mill 200 according to the second embodiment of the present invention also prevents a difference in angular velocity from occurring in various parts of the work during rolling, and the work w having various shapes that are not straight and variously changed. It can be rolled with high accuracy.

  The first to second embodiments of the ring rolling mill of the present invention have been described above. However, the present invention is not limited to the above embodiments, and can be implemented with various modifications. For example, the vertical positional relationship between the variable-speed main roll and the constant-speed main roll can be appropriately changed as necessary, and the diameter size and the magnitude relationship between the variable-speed main roll and the constant-speed main roll are also appropriately determined. Can be changed.

DESCRIPTION OF SYMBOLS 100 Ring rolling mill 111 Variable speed main roll 112 Constant speed main roll 121 Mandrel 122, 123 Axial roll 122 (a), 123 (a) Axial roll motor 130 First drive means 131 Motor 132 Reducer 133 Shaft 133 (a ) Key 140 Second driving means 141 Motor 142 Reducer 143 Shaft 143 (a) Key 150 Outer diameter measuring means 160 Control means 161 Calculation part 162 Control part

Claims (6)

While having two main rolls to be rotated and a rotatable mandrel, the main roll and the mandrel sandwich the peripheral part of the ring-shaped material to be processed, press the wall surface in the radial direction, and perform rolling. A ring rolling mill having a pair of axial rolls that are driven to rotate, sandwiching a circumferential portion of the ring-shaped material to be processed by the pair of axial rolls, and pressing the upper surface and the lower surface in the axial direction for rolling. ,
Along with the mandrel, a first main roll that rolls a part of the periphery of the ring-shaped material to be processed,
Along with the mandrel, a part different from the part rolled by the first main roll of the peripheral part of the ring-shaped material to be processed is rolled at a constant rotational speed, and has an outer diameter different from that of the first main roll. A second main roll having
First driving means for rotationally driving the first main roll;
Second driving means for rotationally driving the second main roll;
An outer diameter measuring means for measuring an outer diameter of a portion of the ring-shaped material to be processed that is rolled by the second main roll;
Control means for controlling the driving of the first driving means in order to adjust the rotational speed of the first main roll based on the measurement information measured by the outer diameter measuring means. Ring rolling mill. The control means includes
Using the measurement information measured by the outer diameter measuring means, the angular velocity of the portion of the ring-shaped material to be processed that is rolled by the first main roll and the angular velocity of the portion that is rolled by the second main roll. And a calculation unit for obtaining the rotation speed of the first main roll when
2. The ring rolling mill according to claim 1, further comprising: a control unit that controls driving of the first driving unit so that the first main roll rotates at the number of rotations obtained by the calculation unit. The calculation unit is configured such that the rotation speed of the first main roll is N _X1 , the diameter is D ₁ , the rotation speed of the second main roll is N _X2 , the diameter is D ₂ , and the first ring of the workpiece ring-shaped material is When the outer diameter of the portion rolled by the main roll No. ₂ is d _x2 , the angular velocity of the portion rolled by the first main roll of the ring-shaped material to be processed and the second The ring rolling mill according to claim 2, wherein the number of rotations of the first main roll when the angular velocity of the portion rolled by the main roll becomes equal is obtained.

  The ring according to any one of claims 1 to 3, wherein the first main roll and the second main roll are arranged adjacent to each other in the vertical direction and have centerlines on the same straight line. Rolling mill.   The first driving means has a first shaft for rotating the first main roll, and the second driving means is a second shaft for rotating the second main roll. The ring rolling mill according to claim 4, wherein the first shaft is installed through the second shaft.   The first driving means has a first shaft for rotating the first main roll, and the second driving means is a second shaft for rotating the second main roll. 5. The ring rolling mill according to claim 4, wherein the first shaft and the second shaft are adjacent to each other in a vertical direction.

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