JP3338541B2 - Extruder die design method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for designing a die of an extruder for extruding tread rubber or the like.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a die of an extruder for extruding a tread rubber or the like, a die is roughly manufactured, and an extruded material is extruded on a trial basis. Then, the dimensions of the extruded material are measured. After comparing with the design value and correcting the location of the deviation, the die is corrected.After that, the extruded material is extruded again on a trial basis, and the dimensions of the extruded material are measured and compared with the design value. Repeat the work of correcting the base until the dimensions of the extruded material are within the tolerance (about 4 to 6 times for those requiring high accuracy)
It was intended to produce a practical base.

[0003]

However, since the manufacturing of the base of such an extruder depends on the intuition and experience of a technician, the above operation is repeated a plurality of times. Labor and time are required, and the operating rate of the extruder is reduced.

[0004]

The inventor of the present invention can solve the above problem by manufacturing a required base while slightly deforming a base manufactured in the past according to the situation. I thought. For this reason, various investigations were performed, and in this investigation, the location where the die gauge was a large value as shown in FIG. 9 was the swell ratio (extruded material gauge / die gauge).
Is also a large value, the swell ratio is plotted on the vertical axis, and the opening ratio of the base (opening gauge / opening area of the base) is plotted on the horizontal axis, and the swell ratio and the opening ratio of the base at a number of different positions in the width direction are graphed. Was expected to show a linear proportional relationship. However, in practice, FIG.
As shown in the figure, the relationship between the swell ratio and the opening ratio of the base was such that the swell ratio had various values even when the opening ratio of the base was the same, and was largely uncoordinated and largely different from expected. For this reason, after further study, the velocity distribution of the extruded material at each position of the die was not a simple shape obtained by a simple theory, but a somewhat uneven shape for such a shape. In addition, such a velocity distribution has an area where the position in the width direction is almost the same.
Even if the opening shapes of the bases are slightly different, they show almost the same tendency.As a result, the ratio between the swell ratio and the opening ratio of the base is almost the same in the width direction position when the opening shapes of the bases are somewhat similar. It has been found that the tendency is almost the same in a certain region.

The present invention has been made on the basis of the above findings, and has as its object to provide a die designing method for an extruder which can design a high-precision die easily and in a short time.

[0006] Such an object is to search for and retrieve an extruded material having a cross-sectional shape similar to that of the extruded material to be extruded this time from among many types of extruded materials extruded in the past, and to select the extruded material having the cross-sectional shape and the extruded material. A step of obtaining dimensional data on the opening shape of the die from which the extruded material is extruded; and dividing the obtained cross-sectional shape of the extruded material and the opening shape of the die into a number of regions in the width direction, and changing the swell ratio in each region. And the step of determining the ratio of the change amount of the die gauge from the dimensional data, the gauge of the extruded material at each of a number of width direction positions on the extruded material this time,
A step of obtaining a die gauge at each position of the die for extruding the extruded material this time from the ratio of the region including these positions.

[0007]

When determining the opening shape of a new die, first, an extruded material having a cross-sectional shape similar to the extruded material to be extruded this time is searched for and taken out from among many types of extruded materials extruded in the past. The dimensional data relating to the cross-sectional shape of the extruded material and the opening shape of the die from which the extruded material is extruded are determined. Next, both the cross-sectional shape of the extruded material and the opening shape of the die obtained by the search are divided into a large number of regions in the width direction, and are divided into a large number of narrow regions. Next, based on the dimensional data, the change amount of the swell ratio in each region, that is, the difference between the swell ratio at one end of each region and the swell ratio at the other end, and the change amount of the base gauge, that is, one end of each region And the difference between the die gauge at the other end and the die gauge at the other end. Next, a number of positions apart in the width direction are set for the current extruded material, and the gauge of the current extruded material at each set position and the ratio of the area including these set positions are used to determine the current extruded material. The die gauge at each set position of the die for pushing out is obtained. And
The opening shape of the base is designed by smoothly connecting the base gauges at the respective set positions thus obtained.
In this way, the opening shape of the base can be determined only by theory without performing the work of extruding with the actual base, measuring the shape of the extruded material, and correcting the base, so that a high-precision base can be easily and quickly provided. Can be designed with

[0008] Even with the structure as described in claim 2, a high-accuracy base can be designed easily and in a short time as described above. Further, with the configuration described in claim 3, the accuracy of the base can be further improved. In addition, according to the structure described in claim 4, it is possible to easily search for and extract an approximated extruded material from many types of extruded materials extruded in the past.

[0009]

An embodiment of the present invention will be described below with reference to the drawings. 1, 2 and 3, reference numeral 11 denotes control means such as a CPU for performing an arithmetic operation based on a program. The control means 11 is connected to an input means 12 such as a keyboard and a display means such as a display and a printer. 13 is connected. Reference numeral 14 denotes a storage unit such as a hard disk or a magneto-optical disk. The storage unit 14 is also connected to the control unit 11. The storage means 14 has an existing extruded material Z such as tread rubber actually extruded, an existing die K extruded from the existing extruded material Z, and an existing extruded material Z.
, Such as dimensional data of the cross-sectional shape of the existing extruded material Z (coordinates at many points of the outer shape),
The dimension data of the opening shape of the existing base K (coordinates at many points of the opening), the material (rubber type) of the existing extruded material Z, the extruded form (single-layer, two-layer extrusion), and the like are stored. Are for many types extruded in the same extruder in the past. Here, the coordinates at many points of the outer shape of the existing extruded material Z are, for example, formed by forming a number of cutouts at equal distances in the width direction in the existing base K and extruding the existing extrusion K from the existing base K. After forming a number of ridges corresponding to the notches on the material Z, the positions of these ridges are determined while moving the measuring device 21 of the laser beam cutting method over the entire width in the width direction of the existing extruded material Z. It can be obtained by detecting.

Next, when the standard (design value) of the new extruded material S to be extruded as shown in FIG. 4 is determined, a new die U for extruding the new extruded material S as shown in FIG. In the case of performing such a design, first, a large number of set positions G which are equidistant in the width direction are set on the outer shape of the new extruded material S, and the coordinates of these set positions G are set. And the extrusion conditions determined by the standard are input from the input means 12 to the control means 11. This allows
The control means 11 searches for an existing extruded material Z whose extrusion conditions conform to the standard of the new extruded material S from among the many types of existing extruded materials Z stored in the storage means 14 and takes out a plurality of the extruded materials. The plurality of existing extruded materials Z and the new extruded materials S are individually compared to determine the difference in their shapes, and the degree of approximation between each of the existing extruded materials Z and the new extruded materials S is determined. Then, based on these degrees of approximation, control means
11 is a new extruded material S from the plurality of existing extruded materials Z.
In the order of approximation (from the one with the largest degree of approximation), several pieces, for example, two pieces are selected. At this time, the dimensional data related to the two selected existing extruded materials Z, that is, the coordinates at each point of the existing extruded material Z and the coordinates at each point of the opening of the existing base K are stored from the storage means 14 to the control means. Take out to 11. If the search is performed based on the degree of approximation as described above, the existing extruded material Z that is similar can be easily and reliably extracted from the many types of existing extruded material Z.

Next, the control means 11 divides the cross-sectional shape of the extracted extruded material Z into a large number of regions B in the width direction with a point at which coordinates are known as boundaries, and also changes the shape of the opening of the existing base K. Like the existing extruded material Z, it is divided into a number of regions C in the width direction, and the sectional shape of the existing extruded material Z and the opening shape of the existing die K are divided into a number of narrow regions B and C, respectively. Next, the control means 11 calculates the swell ratio at one end and the other end of each region based on the dimensional data, and then calculates the difference between the two swell ratios in each region, that is, the amount of change in the swell ratio. Ask. At the same time, the control means 11 calculates the opening ratio of the base (the value obtained by dividing the base gauge by the base opening area) at one end and the other end of each region based on the dimensional data, and then calculates the opening ratio of each base in each region. The difference between the ratios, that is, the amount of change in the aperture ratio is obtained by calculation. Here, the opening ratio of the base is a value obtained by dividing the base gauge by the opening area of the base as described above. However, since the base area of the base is a constant value, the opening ratio is the base of the base gauge itself. It can be thought that it is just a dimension. After that, the control means 11 uses these values to determine the ratio between the amount of change in the swell ratio and the amount of change in the aperture ratio (base gauge) in each region. Here, FIG. 6 is a graph of the ratio in a certain region Bn, Cn. In this graph, a point P is a plot of a swell ratio and an aperture ratio at one end (left end) of the certain region Bn, Cn. The point Q is a plot of the swell ratio and the opening ratio at the other end (right end) of the certain regions Bn and Cn. ) Is the ratio in the areas Bn and Cn, and the inclination of such a straight line differs for each of the above-mentioned many areas. FIG. 7 shows the ratio (slope of the straight line) in the regions Bo and Co, and FIG. 8 shows the ratio (slope of the straight line) in the regions Bp and Cp.

Next, based on the coordinates of the set position G of the new extruded material S, the control means 11 searches the areas B and C including the set position G. Next, the gauge of the new die U required to obtain the gauge of the new extruded material S at each set position G is obtained. At this time, the ratio (trend) is substantially the same in the width direction position as described above. In the case of (the same area), the conditions are almost the same under the condition that the opening shapes of the mouthpieces are similar. Therefore, the coordinates of each set position G on the new extruded material S and the area including these set positions G The base gauges at the respective set corresponding positions H of the new base U for extruding the new extruded material S can be obtained by calculation using the ratios in the above. Here, such calculation is performed by the control means.
11 is performed. Specifically, after assuming that the gauge of the new base U at each setting corresponding position H is an appropriate value, the gauge of the new extrusion member S at each setting position G is calculated based on this value. Then, the obtained value is compared with the gauge at each set position G of the new extrusion member S, and if different, the gauge of the new mouthpiece U is slightly shifted from the appropriate value and the calculation is performed again. Then, such calculation is repeated many times, convergence calculation is performed until the difference falls within the allowable value, and the gauge of the new base U at each setting corresponding position H is obtained. Such calculation is also performed for the selected (two) existing extruded materials Z and the existing base K. Next, the gauges at the same setting corresponding position H of these two new bases U are synthesized for each setting corresponding position H while taking into account the degree of approximation of the existing extruded material Z as a basis, and the new gauge at each setting corresponding position H is synthesized. Find the final base gauge of base U. Then, the opening shape of the new base U is designed by smoothly connecting the base gauges at the respective setting corresponding positions H thus obtained. Each stage of the above-described design is appropriately displayed on the display unit 13 by transmitting a signal from the control unit 11 to the display unit 13. As described above, the opening shape of the new base U can be determined only by theory without performing the operations of actual extrusion with the base, measurement of the shape of the extruded material, and correction of the base. The design can be performed in a short time, and when the design is actually performed using the present embodiment, a new die S within the tolerance is designed by a single calculation for a new extruded material Z requiring high accuracy. I was able to.

In the above-described embodiment, the ratio between the amount of change in the swell ratio and the amount of change in the base gauge in each area is obtained from the dimensional data, and these ratios are used to set the corresponding positions H of the new base U. In the present invention, the base gauge is obtained, but from the dimensional data,
In each area, the difference between the value obtained by subtracting the base gauge from the gauge of the extruded material and the base gauge is used to determine the ratio between the amount of change in the base gauge and the amount of change in the base gauge. The base gauge at each setting corresponding position may be obtained. In this case, the same effect as in the above-described embodiment can be obtained. In the above-described embodiment, the number of the existing extruded materials Z to be searched and taken out is set to several (two) in order to make the new die U highly accurate. However, in the present invention, the degree of approximation is the highest. One existing extruded material may be taken out. Further, in the above-described embodiment, the opening ratio of the base is determined for each region based on the dimensional data. However, in the present invention, the numerical value of the base gauge itself can be used instead of the opening ratio. . Further, in the present invention, when taking out the approximate existing extruded material, it is performed without taking into account the material of the extruded material, and after taking out the approximated existing extruded material, the coefficient considering the material in the gauge of this existing extruded material is used. May be used as the gauge of the existing extruded material. By doing so, the number of existing extruded materials to be searched can be increased, and existing extruded materials that are more similar in shape can be taken out, thereby further improving accuracy.

[0014]

As described above, according to the present invention, a high-accuracy base can be designed easily and in a short time.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention, in which a part is shown by a block.

FIG. 2 is a sectional view of an existing extruded material.

FIG. 3 is a front view showing an opening shape of an existing base.

FIG. 4 is a sectional view of a new extruded material.

FIG. 5 is a front view showing an opening shape of a new base.

FIG. 6 is a graph showing a ratio in a region Bn.

FIG. 7 is a graph showing a ratio in a region Bo.

FIG. 8 is a graph showing a ratio in a region Bp.

FIG. 9 is a graph showing an approximate relationship between a base gauge and a swell ratio.

FIG. 10 is a graph showing a relationship between a swell ratio and an opening ratio of a base.

[Explanation of symbols]

 Z: Existing extruded material S: New extruded material K: Existing base B, C ... Area G: Set position U: New base

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (4)

(57) [Claims] An extruded material having a cross-sectional shape similar to the extruded material to be extruded this time is searched for and taken out of a large number of extruded materials extruded in the past, and the extruded material is extruded in a sectional shape and extruded material. A step of obtaining dimensional data relating to the opening shape of the die, and dividing the obtained cross-sectional shape of the extruded material and the opening shape of the die into a number of regions in the width direction, and changing the swell ratio in each region and the die gauge. The step of obtaining the ratio of the amount of change from the dimensional data, the gauge of the extruded material at each of a number of widthwise positions on the extruded material this time, and the ratio of the region including these positions, Obtaining a die gauge at each position of the die for extruding the extruded material. 2. An extruded material having a cross-sectional shape similar to the extruded material to be extruded this time is searched for and taken out of a large number of extruded materials extruded in the past. A step of obtaining dimensional data relating to the opening shape of the die, and dividing the obtained cross-sectional shape of the extruded material and the opening shape of the die into a number of regions in the width direction, and in each region, from the gauge of the extruded material to the die gauge. A step of calculating the ratio of the amount of change in the value obtained by dividing the subtracted value by the die gauge to the amount of change in the die gauge from the dimensional data, and a number of positions in the width direction on the extruded material at this time. Extruded material gauge and, from the ratio of the area including each of these positions, the step of obtaining a die gauge at each position of the die to extrude the extruded material this time, Cap design method of the extruder, characterized in that was example. 3. The past extruded materials to be retrieved and retrieved are set to several pieces, and, based on these several extruded materials, the cap gauges for extruding the present extruded material are respectively obtained. 2. The method according to claim 1, wherein the synthesis is performed while considering the degree of approximation. 4. A die design for an extruder according to claim 1, wherein the difference between the shapes of the extruded material extruded in the past and the extruded material extruded this time is determined as an approximation degree, and the search is performed based on the approximation degree. Method.