JPS585727B2 - Method and device for producing a variable thickness material having thickness variation in the longitudinal direction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and an apparatus for manufacturing a variable thickness material in which the width is constant and the thickness changes in the longitudinal direction.

There is a great need for a plate material whose thickness gradually changes in the length direction and whose width is constant in general structural members used as cantilever members.

In particular, if it is used in leaf springs as suspension structural members of automobiles, it is expected to have many favorable effects such as weight reduction, material saving, simplification of structure, and smoothing of the shock absorbing effect. Methods and equipment for mass-produced and economical manufacturing have not yet been developed.

Of course, it is already known that it is possible to control the gap between the rolls used to roll a plate material to obtain a desired plate material whose thickness changes in the longitudinal direction. Therefore, a trimming process is necessary to make the final width of the product uniform, and the part where the width is cut off becomes a loss of material, so it is difficult to say that it is economically superior. Met.

The present invention has been made to eliminate the drawbacks of the above-mentioned prior art, and its aims are to:
Using a width direction rolling roll and a thickness direction rolling roll, the roll gap between the width direction rolling rolls is continuously changed, and in the next rolling with the thickness direction rolling roll, the plate width becomes a dog as the plate thickness changes. After reducing the width of the board in advance, the gap between the rolling rolls in the thickness direction is continuously varied based on predetermined conditions to change the thickness of the workpiece, thereby creating a board with a constant width. To manufacture a plate material of a desired shape whose thickness changes in the longitudinal direction without going through a trimming process.

Hereinafter, a detailed explanation will be given based on the drawings showing an example of the present invention.

In FIG. 1, reference numeral 1 denotes a workpiece, which is continuously moved in the direction indicated by arrow A.

A pair of width direction rolling rolls (vertical rolls) 2a and 2b are arranged on the upstream side of the flow of the workpiece 1.

The vertical rolls 2a, 2b are rotatably supported by a frame (not shown) and the roll positions can be adjusted.

This roll position is adjusted by a lowering mechanism 4 including hydraulic cylinders 3a and 3b.

Further, downstream of the vertical rolls 2a, 2b, a pair of thickness direction rolling rolls (horizontal rolls) 5a, 5b are rotatably arranged, and like the vertical rolls 2a, 2b, a rolling roll including hydraulic cylinders 6a, 6b is provided. The roll position is adjusted by a mechanism 7.

These vertical rolls 2a, 2b and horizontal rolls 5a, 5
The roll position b is controlled based on a command from the controller 8.

The controller 8 sets the initial setting values for the board width and board thickness determined from the shape of the product, and the board width function and board thickness function determined from the relationship between the longitudinal position of the product and the board width and board thickness.
The vertical rolls 2a, 2b can be set in advance according to the type of product, and the vertical rolls 2a, 2b can be set according to the set conditions.
and the roll positions of the horizontal rolls 5a and 5b to the workpiece 1.
output as an electrical signal based on the amount of movement.

Explaining this regarding the vertical rolls 2a and 2b, the amount of movement of the workpiece 1 is determined by the detection roller 9, which is brought into contact with the workpiece 1 and rotates as the workpiece moves, and a pulse is generated at each constant rotation angle. The movement amount is detected by a movement amount detection device 12 consisting of an encoder 11 and inputted to the controller 8.

The controller 8 calculates a target roll position corresponding to each longitudinal position of the workpiece 1 from this input, the preset width function, and the initial value, and outputs the result.

The digital output of the controller 8 is converted into an analog signal by D/A converters (digital-to-analog converters) 13a, 13b, and input to servo amplifiers 14a, 14b.

The outputs of differential transformers 15 and 16 are also input to the servo amplifiers 14a and 14b, respectively (these two differential transformers 15 and 16 constitute a roll position measuring device 17). input and said D/
Outputs corresponding to the difference between the inputs from the A converters 13a and 13b are outputted to the servo valves 18 and 19.

As a result, the servo valves 18 and 19 are operated, pressure oil from the hydraulic unit 21 is supplied to the hydraulic cylinders 3a and 3b, and the positions of the vertical rolls 2a and 2b are varied.

As a result of this positional variation, when the inputs from the differential transformers 15, 16 match the inputs from the D/A converters 13a, 13b, the servo valves 18, 19 are stopped, and the vertical rolls 2a, 2b are stopped. The position is adjusted to the value specified by the controller 8.

That is, servo amplifiers 14a, 14b and servo valve 1
8 and 19 constitute a control mechanism 22 that controls the operation of the rolling down mechanism 4 based on the output of the controller 8 and the output of the roll position measuring device 17.

Although the vertical rolls 2a and 2b have been described above, the same applies to the horizontal rolls 5a and 5b, and the movement amount of the workpiece 1 is detected by the movement amount detection device 28 consisting of the detection roller 26 and the encoder 27. The controller 8 uses the detection result of this movement amount, the workpiece movement amount preset in the controller 8, and the horizontal roll 5a.
, 5b with the roll position (thickness function) and the initial value of the roll position, the target roll position is calculated, and the result is converted into an analog signal by D/A converters 29a and 29b.

Based on this analog signal and the output of a roll position measuring device 33 consisting of differential transformers 31 and 32, a control mechanism 37 consisting of servo amplifiers 34a and 34b and servo valves 35 and 36 controls the hydraulic cylinders 6a and 6b. The rolling down mechanism 7 is controlled, and the roll gap between the horizontal rolls 5a and 5b is controlled in accordance with the command from the controller 8.

Further, load cells 47 and 48 are attached to the lowering mechanisms 4 and 7 for detecting the biting of the workpiece 1 into the vertical rolls 2a and 2b and the horizontal rolls 5a and 5b, and the output thereof is shown in FIG. As shown in FIG. 3, the signals are sent to electromagnetic valves 42 and 43 via timers 39 and 41, respectively.

The electromagnetic valves 42 and 43 are connected to the movement amount detection device 12,
Air cylinders 44, 4 that move 28 between an operating position in contact with the workpiece 1 and an inoperative position away from the workpiece 1.
The load cell 37 is for controlling the operation of the load cell 37.
．． After a predetermined period of time has elapsed since 38 detected the biting and the tip of the workpiece 1 has passed the movement amount detection position, the movement amount detection devices 12 and 28 are moved to the operating position.

Next, a method for manufacturing a product having a constant plate width and a plate thickness that varies in the longitudinal direction using the apparatus configured as described above will be explained, taking as an example the production of a tapered leaf for an automobile suspension spring.

First, from the shape of the taper leaf to be manufactured, we calculate the thickness function that represents the relationship between the longitudinal position of one tapered leaf (one period) and the thickness, and the initial value of the thickness (usually the thinnest part). (plate thickness).

Next, when a predetermined material (work material 1 before rolling) is subjected to rolling according to the plate thickness function described above, the amount by which the width of the material will increase and the thickness direction The intermediate material required to make the width of the product the same at all positions in the longitudinal direction by correcting the increase calculated by calculating the amount of width return in rolling Find the shape of the latter one (namely, the material with variable width).

In other words, the width function and the initial value of the width (usually is the width of the board at the narrowest part).

In addition, the width return amount mentioned above refers to the width of the workpiece 1 during rolling in the width direction.
This is the amount by which the width increases as the plate thickness increases at both side edges and returns to its original size during rolling in the thickness direction.

Preparation for rolling is completed by setting the conditions such as the plate thickness function, initial plate thickness value, plate width function, and initial plate width value obtained as described above in the controller 8.

However, if the width or thickness of the workpiece 1 is considerably larger than the initial value of the width or the initial value of the thickness, the roll gap between the vertical rolls 2a, 2b or the horizontal rolls 5a, 5b is set from the beginning to the initial value of the width or thickness. If it is impossible to bite the workpiece 1 into each roll by setting it to the initial value,
First, each roll gap is set to a value larger than each initial value, and after the workpiece 1 is bitten by each roll, it is detected by the load cells 47 and 48 attached to the rolling mechanisms 4 and 7. It is necessary to quickly shift the gap between each roll to its initial value.

When the preparation for rolling is completed, the workpiece 1 is transferred to the vertical roll 2a.
, 2b.

Biting of the workpiece 1 is detected by the load cell 47, and after a certain period of time has elapsed since the generation of the detection signal, the movement amount detection device 12 is moved to the operating position.

At this time, since the tip of the workpiece 1 has already passed the movement amount detection position, the detection roller 9 is brought into gentle contact with the upper surface of the workpiece 1 from a direction substantially perpendicular to it.

When the detection roller 9 comes into contact with the workpiece 1, the encoder 1
1 starts generating a pulse, which is input to the controller 8.

In the controller 8, the target roll positions of the vertical rolls 2a, 2b are calculated moment by moment from this pulse input, the width function set in advance in the controller 8, and its initial value, and based on the result, the vertical rolls 2a, 2b are 2b's position adjustment (as a result, gap control) is started.

That is, since the position adjustment of the vertical rolls 2a, 2b is always started after the detection roller 9 comes into contact with the workpiece 1, at least the vertical rolls 2a, 2 at the tip of the workpiece
The part with a length corresponding to the distance between b and the detection roller 9 is not part of the product.

Therefore, the detection roller 9 should be moved as far as possible to the vertical rolls 2a, 2b.
It is desirable to place it in a position close to .

After the gap control by the controller 8 is started, the vertical rolls 2a and 2b repeatedly approach and separate from each other periodically, and as shown in the left end of FIGS. 4 and 5, the material has a constant width and thickness. After passing through the vertical rolls 2a and 2b, the intermediate material 1' becomes an intermediate material 1'' whose width is periodically reduced along the longitudinal direction, as shown in the center of FIG.

At this time, the plate thickness of the intermediate material 1'' increases slightly in the portion where the plate width is reduced, but the amount is relatively small.

In other words, the effect of reducing the board width is mostly manifested as an elongation of the material 1' in the longitudinal direction.

When the tip of the intermediate material 1'' is bitten by the horizontal rolls 5a and 5b, the load cell 48 detects this, and when a certain period of time has elapsed since the generation of this detection signal, the movement amount detection device 28 is set to the operating position by the air cylinder 45. be moved to.

As a result, the detection roller 26 detects the workpiece 1 (semi-finished product 1'')
(i.e., a plurality of consecutive tapered leaves, which are plate thickness changeable materials), and the encoder 27 starts generating pulses.

The roll gap control of the horizontal rolls 5a, 5b based on the plate thickness function (hereinafter referred to as plate thickness adjustment) is the same as the roll gap control of the vertical rolls 2a, 2b (hereinafter referred to as plate width adjustment) based on the plate width function. It starts when the movement amount detected by the movement amount detection device 12 from the moment when the movement amount of the intermediate material 1'' becomes exactly equal to the distance between the axes of the vertical rolls 2a, 2b and the horizontal rolls 5a, 5b. .

After that, based on the command from the controller 8, the horizontal roll 5a
, 5b are periodically approached and separated, and the intermediate material 1'' is made into a semi-finished product 1'' whose plate thickness changes along the longitudinal direction as shown at the right end of FIG.

If the board thickness is reduced, the board width will naturally increase, but as mentioned above, the board width of the intermediate material 1" has been reduced by an amount corresponding to this increase in board width, so the semi-finished product 1" The width of ' is the same at all positions in the longitudinal direction, as shown at the right end of FIG.

This semi-finished product 1''' is placed at the right end of Figure 5 along the two-dot chain line
If you cut it at the position shown by , C, you will get a single taper product.
You will get a leaf.

The above is an overview of the manufacturing method for taper leaves, but in reality, when adjusting the plate width and plate thickness independently, the accumulated dimensional errors in the longitudinal direction of the workpiece 1 The starting point of the board width change and the starting point of the board thickness change on the material 1 will shift with each adjustment cycle, and there is a risk that the uniformity of the board width of the semi-finished product 1'' will be impaired. It is desirable to repeat the adjustment cycles while forcibly matching the start or end points of the board width adjustment cycle and the board thickness adjustment cycle on the workpiece 1 for each adjustment cycle.

This point will be explained in more detail based on FIG.

Each horizontal line in FIG. 6 indicates the position of the workpiece 1 at each stage of the rolling process.

In addition, each symbol indicates the following.

WS: Board width adjustment starting point (position on workpiece 1).

(Same hereafter) WE: Board width adjustment end point TS: Board thickness adjustment start point TE: Board thickness adjustment end point Furthermore, numbers such as ■, ■ indicate the order in which each of the above points are determined, and solid line arrows The determination is made by the movement amount detection device 1.
The broken line arrow indicates that the determination is made based on the output of the movement amount detection device 28.

As is clear from FIG. 6, after the board thickness adjustment start point TS1 for the first cycle is determined based on the board width adjustment start point WS1 for the first cycle, ■ the board width adjustment start point for the first cycle. The board width adjustment end point WE1 of the first cycle is determined based on WS1, and furthermore, ■ this board width adjustment end point WE1
The board width adjustment start point WS2 for the second cycle is determined based on the .

However, in FIG. 6, the interval between the board width adjustment end point WE1 and the board width adjustment start point WS2 is shown wide for ease of understanding, but in reality, it is sufficient to arbitrarily set a minute amount. It is also possible to make it almost zero.

Subsequently, a board thickness adjustment end point TE1 is determined based on the board thickness adjustment start point TS1, and a board width adjustment start point WS2 is determined.
A board thickness adjustment start point TS2 for the second cycle is determined based on , and a board width adjustment end point WE2 is determined similarly based on the board width adjustment start point WS2.

By repeating the same process ν, it is possible to repeat the board width adjustment cycle and the board thickness adjustment cycle an arbitrary number of times.

Moreover, the starting points of the plate thickness adjustment cycle are TS1, TS2,...
・ is the starting point of each board width adjustment cycle ws1, ws2, ・
Since it is determined based on ..., the plate thickness adjustment starting point TS
1, TS2, ... Board width adjustment starting point ws1, ws2,
There is no risk that errors for ... will accumulate.

Another method for avoiding error accumulation is shown in FIG.

The method shown in FIG. 7 is similar to the method shown in FIG. 6 in that the plate thickness adjustment start point TS1 of the first cycle is determined based on the plate width adjustment start point WS1 of the first cycle. The plate thickness adjustment start point TS2 of the second cycle is determined based on the plate thickness adjustment end point TE1 of the first cycle,
Furthermore, the sixth point is set at the point where the second cycle sheet width adjustment end point WE2 is determined based on this sheet thickness adjustment start point TS2.
The methods shown in the figure are different.

That is, in the first cycle, the movement amount detection device 2 from the moment when plate thickness adjustment starts until the moment when plate width adjustment ends.
The detected value L of 8 is stored in the controller 8, and from the second cycle onward, when the detected value of the movement amount detecting device 28 from the moment the plate thickness adjustment is started becomes equal to the stored value L. , the board width adjustment is forced to end.

In other words, in the method shown in Fig. 7, from the second cycle onwards, the board width adjustment end points WE2, WE3, ... are determined based on the board thickness adjustment start points TS2, TS3, ... (as a result, Board width adjustment starting point ws3, ws4,
... also indirectly serves as the plate thickness adjustment starting point TS2, TS3,...
), the amount of movement detection device 2
Since each adjustment start point and end point will be determined based on the result of detecting the amount of movement of the semi-finished product 1″′ in step 8,
The advantage is that the dimensional accuracy of the semi-finished product 1'' in the longitudinal direction is improved.

An example of specific data when rolling is performed while correcting discrepancies in the longitudinal direction of the workpiece between plate width adjustment and plate thickness adjustment at each adjustment cycle as described above is as follows. .

Material: Thickness 20.5mm, width 100.5mm, length 390
0mm, Material: SUP9 spring steel Rolling temperature: 900℃ Maximum rolling force: Width direction rolling roll 21 tons Thickness direction rolling roll 228 tons Product dimensions: As shown in Figure 8 (However, the product has a width of 100 m.
m taper leaf) Product dimensional accuracy: Thickness ±0.07mm or less Width ±0.
20 mm or less From the above data, it will be easy to see how the present invention is suitable for manufacturing products such as tapered leaves whose width is constant and whose thickness varies in the longitudinal direction.

It should be noted that in the embodiment described in detail above, the vertical rolls 2a, 2b and the horizontal rolls 5a, 5b are all independently variable in their axis positions, and each pair of rolls 2a, 2b or 5a is , 5b are arranged so that not only the relative distance between the axes but also the absolute axial center position can be measured by two differential transformers 15, 16 or 31, 32, respectively. ,2
b and the two horizontal rolls 5a, sb can be moved symmetrically with respect to the center line of the workpiece 1, which has the advantage that there is no risk of bending the workpiece 1.

However, if the amount of reduction in board width or board thickness is small, it is also possible to fix the axial center position of one vertical roll or horizontal roll, and in short, it is sufficient that the roll gap can be controlled as a result, and in this case For this purpose, it is sufficient to measure the distance between the axes of each roll, and only one measuring device such as a differential transformer is required.

Further, hydraulic cylinders 3a, 3 are used as roll position measuring devices.
It is also possible to use a device that indirectly measures the roll position by measuring piston positions such as pistons b, 6a, and 6b.

Further, in the above embodiment, a circuit for correcting the change in the roll gap due to the deflection of the roll portion due to the rolling pressure is not shown, but the rolling load is measured using, for example, the load cells 47 and 48, and based on this, the controller 8 It is also possible to modify the command value of to maintain the actual roll gap at the desired value.

Furthermore, a circuit is provided that actually measures the width and thickness of the workpiece 1 and automatically corrects the coefficient of the function set in the controller 8 or the command value of the controller 8 itself based on the measurement results. It is also possible to improve the accuracy of the product.

In addition to the mechanism using a hydraulic cylinder as the driving source as described above, it is also possible to use a mechanism that uses an electro-hydraulic pulse motor or the like to rotate a gap adjustment screw, thereby changing the roll gap. A non-contact type using an image sensor or the like can be used as the movement amount detection device, and various alternative means can be adopted for other components without departing from the spirit of the present invention. Of course, it is possible to do so.

Although the present invention is mainly applied to hot rolling, it can also be applied to cold rolling depending on the amount of rolling reduction, and furthermore, one or both of the vertical rolls and horizontal rolls has multiple stages. It can be similarly applied to multi-high rolling mills.

) As is clear from the above description, the present invention reduces the width of the workpiece using the width direction rolling rolls on the upstream side to produce a material with a variable width, and then applies the material on the downstream side to the material with a variable width. A method for manufacturing a plate thickness-variable material having a constant plate width and a desired plate thickness change in the longitudinal direction by oval rolling in the thickness direction with a thickness direction rolling roll, the method comprising: (a) the thickness direction; a step of setting a plate thickness function representing the relationship between the longitudinal position and the plate thickness of the desired thickness-changeable material in a roll gap control device of the rolling rolls; To,
The plate width of the plate width variable material, which is given a plate width change in advance so as to offset the plate width change that occurs when rolling according to the plate thickness function and make the width of the plate width variable material constant over the entire length. (c) a step of starting rolling; and (d) a step of setting a width function representing the relationship between the widthwise variable material and the longitudinal position of the widthwise variable material; (e) calculating the roll gap of the rolling rolls in the width direction from time to time based on the longitudinal movement amount of the plate width variable material and the plate width function; a step of controlling the roll gap of the width direction rolling rolls based on the results; (f) a step of detecting the longitudinal movement amount of the plate thickness-variable material on the exit side of the thickness direction rolling rolls; (g) From the moment when the longitudinal movement amount of the plate width variable material after the start of roll gap control of the width direction rolling rolls becomes equal to the distance between the axes of the width direction rolling rolls and the thickness direction rolling rolls, the plate Calculating the roll gap of the thickness direction rolling rolls based on the longitudinal movement amount of the thickness variable material and the plate thickness function, and controlling the roll gap of the thickness direction rolling rolls based on the result of the calculation. The present invention provides a method for manufacturing a plate material having a change in thickness in the longitudinal direction, the method comprising the steps of:

Furthermore, the apparatus for carrying out this method includes (a) a pair of width direction rolling rolls arranged on the upstream side of the flow of the workpiece, and (b) a pair of width direction rolling rolls arranged on the downstream side. directional rolling rolls; (c) a rolling mechanism for changing the roll gap between each pair of rolls; and (d) a rolling mechanism disposed on the exit side of the width direction rolling roll and the thickness direction rolling roll, respectively, to form the workpiece. a movement amount detection device that detects first and second movement amounts of the material; A board width function is set that represents the relationship between the board width of a board width variable material to which a board width change is given in advance to be constant over the length of the board width and the longitudinal position of the board width variable material, and the board width function and the above-mentioned (f) a controller for widthwise rolling rolls that calculates a momentary target roll gap of the widthwise rolling rolls based on the widthwise rolling distance and outputting the result as an electric signal; A plate thickness function representing the relationship between the position and the plate thickness is set, and the first movement amount from the time when the controller for the width direction rolling roll starts emitting an electric signal representing the target roll gap is the widthwise rolling roll. and the distance between the axes of the thickness direction rolling rolls, the momentary target roll gap of the thickness direction rolling rolls is calculated based on the plate thickness function and the second movement amount. , a thickness direction rolling roll controller that outputs this as an electric signal, (g) a roll gap measuring device that measures the roll gap between the width direction rolling roll and the thickness direction rolling roll, and (h) the roll gap. The actual roll gap obtained by the measuring device is compared with the target roll gap outputted from the controller, and the rolling mechanism is operated so as to make the difference zero, and each of the width direction rolling roll and the thickness direction rolling roll is It is configured to include a control mechanism that controls the roll gap.

Therefore, according to the present invention, the following effects can be obtained.

(1) A board whose thickness changes in the longitudinal direction and whose width remains constant can be manufactured at low cost without a trimming process.

(2) It has excellent productivity and extremely high material yield, making it possible to supply variable thickness materials such as tapered leaves in large quantities at low cost.

(3) The start timing of roll gap control for the rolls in the width direction and the start time of roll gap control for the rolls in the thickness direction are matched based on the actual measured value of the amount of movement of the workpiece itself, so both directions The roll gap control is effectively prevented from shifting in the longitudinal direction of the workpiece, and a variable thickness material with high dimensional accuracy not only in the thickness direction but also in the width direction can be obtained.

(4) Since the roll gap control criteria are given by the plate width function and the plate thickness function, changes in product shape can be easily handled and setup changes are also easy.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are detailed explanatory diagrams of a movement amount detecting device in the apparatus shown in FIG. 1, respectively. 4 and 5 are a plan view and a front view, respectively, showing changes in shape of a workpiece processed by the apparatus shown in FIG. 1. FIG. FIG. 6 and FIG. 7 are explanatory diagrams each showing a method of avoiding cumulative errors in an actual case of the present invention. FIG. 8 is a drawing showing an example of the dimensions of a tapered leaf manufactured by an apparatus according to an embodiment of the present invention. 1...Work material, 1'...Material, 1''.
...Intermediate material, 1''' ...Semi-finished product, 2
a, 2b... Width direction rolling roll (vertical roll)
, 3a, 3b, 6a, 6b... hydraulic cylinder,
4, 7... Lowering mechanism, 5a, 5b...
Thickness direction rolling roll (horizontal roll), 8...controller, 9, 26...detection roller, 11,
27... Encoder, 12, 28...
Movement amount detection device, 13a, 13b, 29a, 29b...
--D/A converter, 14a, 14b, 34a, 34
b... Servo amplifier, 15, 16, 31, 32
...Differential transformer, 17, 33... Roll position measuring device, 18, 19, 35, 36...
・Servo valve, 22, 37... control mechanism.

Claims (1)

[Scope of Claims] 1. The width of the workpiece is reduced by an upstream width direction rolling roll to produce a material with a variable width, and then the material is subjected to a thickness direction rolling roll on the downstream side. A method for producing a material with variable thickness having a constant width and a desired thickness change in the longitudinal direction by rolling in the thickness direction, the method comprising: rolling gap control device for the thickness direction rolling rolls; a step of setting a plate thickness function that expresses the relationship between the longitudinal position of the plate thickness change material and the plate thickness, and applying rolling processing according to the plate thickness function to the roll gap control device of the width direction rolling roll. The width of the variable width material and the longitudinal position of the variable width material are given a width change in advance so as to offset the change in width that occurs when the width of the material is changed to make the width of the variable thickness material constant over the entire length. a step of setting a sheet width function representing the relationship between the following steps: a step of starting rolling; a step of detecting the amount of movement in the longitudinal direction of the sheet width variable material on the exit side of the width direction rolling roll; a step of calculating the roll gap of the widthwise rolling rolls from time to time based on the longitudinal movement amount and the plate width function, and controlling the roll gap of the widthwise rolling rolls based on the result of the calculation; a step of detecting the amount of longitudinal movement of the material with variable thickness on the exit side of the widthwise rolling roll; and a step of detecting the amount of longitudinal movement of the material with variable thickness after the start of the roll gap control of the widthwise rolling roll. From the moment when the distance between the axes of the rolling roll and the thickness direction rolling roll becomes equal,
Calculation of the roll gap of the thickness direction rolling rolls is started based on the longitudinal movement amount of the plate thickness changing material and the plate thickness function, and the roll gap of the thickness direction rolling rolls is calculated based on the result of the calculation. 1. A method for manufacturing a plate material having a thickness change in the longitudinal direction, the method comprising: controlling the thickness of the plate material in the longitudinal direction. 2. A patent in which roll gap control between the width direction rolling roll and the thickness direction rolling roll is periodically performed multiple times for one workpiece, and a plurality of sheets with varying thicknesses are continuously manufactured. The manufacturing method according to claim 1. 3 The plate thickness function and the plate width function are each set as a function for one cycle, and are returned to the initial state every time the previous cycle of rolling is completed, and are repeatedly applied to continuously produce a plurality of plates with varying thicknesses. and after the second cycle, the roll gap control start timing of the widthwise rolling rolls is first determined, and after the start of the roll gap control of the widthwise rolling rolls, the width-variable material is rolled in the widthwise direction. 3. The manufacturing method according to claim 2, wherein the roll gap control of the thickness direction rolling roll is started when the roll moves by a distance equal to the distance between the axes of the thickness direction rolling roll. 4 The plate thickness function and the plate width function are each set as a function for one cycle, and are returned to the initial state every time the previous cycle of rolling is completed, and are repeatedly applied to continuously produce a plurality of plates with varying thicknesses. The method of claim 1, wherein the roll gap control start time of the thickness direction roll is determined based on the roll gap control end time of the previous cycle of the thickness direction roll itself after the second cycle. The manufacturing method according to scope 1. 5. A device for producing a variable thickness material having a constant width and a desired change in thickness in the longitudinal direction by rolling, including a pair of widthwise rolling rolls disposed on the upstream side of the flow of the workpiece. a pair of thickness rolls disposed on the downstream side; a rolling mechanism for changing the roll gap between each pair of rolls; and a roll-down mechanism on the exit side of the width roll and thickness roll a movement amount detection device that is respectively arranged to detect the entire first and second movement amount of the workpiece; and a movement amount detection device that detects the entire first and second movement amount of the workpiece; A board width function is set that expresses the relationship between the board width of the board width variable material and the position in the longitudinal force direction of the board width variable material, which is given a board width change in advance so that the width of the board is constant over the entire length. calculating a momentary target roll gap of the width direction rolls based on the width function and the first movement amount;
A width direction rolling roll controller outputs the result as an electric signal, and a plate thickness function representing the relationship between the longitudinal position of the plate thickness changing material and the plate thickness is set, and the width direction rolling roll controller outputs the result as an electric signal. From the moment when the first movement amount from when the electric signal representing the gap starts to be emitted becomes equal to the distance between the axes of the width direction roll and the thickness direction roll, the plate thickness function and the a controller for the thickness direction rolls that calculates a momentary target roll gap of the thickness direction rolls based on the second movement amount and outputs the calculated value as an electric signal; a roll gap measuring device for measuring the roll gap between the rolls and the rolling roll; and a device that compares the actual roll gap obtained by the roll gap measuring device with the target roll gap output from the controller and sets the difference to zero. 1. An apparatus for producing a material with variable thickness that changes in thickness in the longitudinal direction, comprising a control mechanism that operates a rolling mechanism and controls gaps between the rolls of the width direction rolling roll and the thickness direction rolling roll.