Method and system for manufacturing tire components

Abstract

Provided are a method and system for efficiently manufacturing a long tire component formed by joining a plurality of components in a manner that reduces a predetermined quality deviation in the longitudinal direction. A process is continuously performed in which a tire component (R) is conveyed in the longitudinal direction (L) using a conveying device (2) while an X-ray inspection device (3) is used to irradiate a predetermined length range (C) from the surface side of the tire component (R) with X-rays to obtain image data (D) based on X-ray transmittance. Image data (D) of the predetermined length range (C) continuously and without gaps in the longitudinal direction (L) are obtained. Based on the light and dark values ​​in each image data (D), a calculation device (4) is used to calculate the magnitude of the deviation in the longitudinal direction (L) of the distribution of a component (M1) formed of unvulcanized rubber having a greater content of a specific component and the mass of the tire component (R). Based on the magnitude of the deviation, a control device (9) is used to control the rotation speed of a screw (8s) provided in at least one extruder (8) to correct the deviation.

Description

Technical Field

[0001] The present invention relates to a method and system for manufacturing tire components, and more particularly, to a method and system for manufacturing tire components that can efficiently manufacture long tire components formed by joining a plurality of constituent components while reducing variations in predetermined quality in the longitudinal direction. Background Art

[0002] Tires are manufactured using a variety of long tire components. Some of these components are formed by joining together multiple components, such as rubber and reinforcing materials, with different types (combinations). Tire production lines undergo various inspections to assess the quality of these components.

[0003] In the past, as a method for manufacturing while checking the quality of tire components, the following manufacturing method was proposed: the shape, size, etc. of each component in the cross section of the tire component is measured without stopping the production line, and the measurement results are fed back to the extruder of the tire component to reset the appropriate extrusion conditions (see patent document 1). In this proposed manufacturing method, a buffer unit (suspension mechanism) for accumulating tire components is configured in the conveying path of a conveying device such as a belt conveyor for conveying tire components, and a CT scanner is configured on its downstream side. In addition, while the interior of the tire component is inspected by the CT scanner, the portion that meets the inspection range of the tire component is temporarily stopped. On the other hand, the extruder configured on the upstream side of the buffer unit continues to extrude the tire component, and the extruded tire component is temporarily accumulated by the buffer unit. In this way, during the period when the tire component is inspected by the CT scanner in the conveying path, the extrusion of the tire component by the extruder will not be interrupted, thereby avoiding stopping the production line.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 8-86635 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In the manufacturing method proposed in Patent Document 1, in order to accurately determine the magnitude of the predetermined quality deviation in the longitudinal direction of the tire component, the tire component must be seamlessly segmented into multiple sections along the longitudinal direction. Conveyance is temporarily stopped for each section to be inspected using a CT scanner. Consequently, transporting the inspected tire component to the next process via the conveyor path requires considerable time, hindering productivity. On the other hand, if the number of times the tire component's conveyance to the downstream side of the CT scanner is temporarily stopped during inspection by the CT scanner is reduced to increase the intervals between inspection sections, the magnitude of the predetermined quality deviation in the longitudinal direction of the tire component cannot be accurately determined. Consequently, this is not conducive to reducing the predetermined quality deviation in the longitudinal direction of the tire component. Therefore, there is room for improvement in reducing the predetermined quality deviation in the longitudinal direction while manufacturing tire components with high productivity.

[0009] Means for solving problems

[0010] The manufacturing method of the tire component of the present invention manufactures a long tire component with a predetermined quality by joining multiple components composed of unvulcanized rubber extruded by multiple extruders, and is characterized in that in the manufacturing method of the tire component, a process of continuously conveying the tire component in the length direction while irradiating a predetermined length range from the surface side of the tire component with X-rays to obtain image data based on X-ray transmittance of the predetermined length range is continuously performed, the image data of the predetermined length range continuous and without gaps in the length direction is obtained, and based on the light and dark values ​​in each of the obtained image data, the size of the deviation of the tire component of the predetermined quality in the length direction is grasped, and based on the grasped size of the deviation, the rotation speed of the screw of at least one extruder provided in the multiple extruders is controlled to correct the deviation.

[0011] The tire component manufacturing system of the present invention comprises a plurality of extruders for extruding components made of unvulcanized rubber of different types, and manufactures long tire components formed by joining the plurality of components with predetermined quality, and is characterized in that the tire component manufacturing system comprises: a conveying device for conveying the tire components in the length direction; an X-ray inspection device for irradiating a predetermined length range with X-rays from the surface side of the tire components conveyed by the conveying device to obtain image data based on the X-ray transmittance of the predetermined length range; and a computing device for receiving an input input the image data; and a control device, the control device controls the rotation of the screw provided in each of the extruders, the manufacturing system of the tire component is configured to continuously perform the process of obtaining the image data, obtain the image data of the predetermined length range that is continuous and without gaps in the longitudinal direction, calculate the size of the deviation of the tire component in the longitudinal direction of the predetermined quality based on the light and dark values ​​in each of the obtained image data, and control the rotation speed of the screw provided in at least one of the extruders based on the calculated size of the deviation, thereby correcting the deviation.

[0012] Effects of the Invention

[0013] According to the present invention, since the image data obtained by irradiating a predetermined length range from the surface of the tire component while the tire component is conveyed in the longitudinal direction is used, there is no need to stop the conveyance of the tire component to determine the predetermined quality. Furthermore, the image data for the predetermined length range can be obtained without gaps in the longitudinal direction, and the predetermined quality can be determined with high precision based on the shading in each piece of the obtained image data. This facilitates rapid and high-precision determination of the magnitude of the deviation in the predetermined quality of the tire component in the longitudinal direction. Based on the magnitude of this highly precisely determined deviation, the screw speed of at least one of the multiple extruders is controlled to correct the deviation in the predetermined quality in the longitudinal direction. This facilitates reducing the deviation in the predetermined quality of the tire component in the longitudinal direction and producing the tire component with high productivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is an explanatory diagram illustrating an embodiment of a tire member manufacturing system in a side view.

[0015] Figure 2 This is an enlarged example Figure 1 An explanatory diagram of the terahertz wave measurement device and the surrounding area of ​​the profile sensor.

[0016] Figure 3 This is shown in a plan view. Figure 2 Illustration of the illustrated range.

[0017] Figure 4 This is an enlarged example Figure 1 An explanatory diagram of the periphery of an X-ray inspection device.

[0018] Figure 5 This is shown in a plan view. Figure 4 Illustration of the illustrated range.

[0019] Figure 6 This is an explanatory diagram illustrating a tire member in a cross-sectional view.

[0020] Figure 7 It will Figure 6 An explanatory diagram showing a tire component of FIG. 1 with a portion thereof cut away and illustrated in a plan view.

[0021] Figure 8 It is an explanatory diagram illustrating the distribution of the cross-sectional area of ​​the constituent members and tire components in the longitudinal direction.

[0022] Figure 9 is exemplified by Figure 1 An explanatory diagram of image data obtained by an X-ray inspection device.

[0023] Figure 10 This is an example Figure 6 A coordinate diagram of X-ray transmission radiation at positions in the width direction of a tire member.

[0024] Figure 11 3 is a graph illustrating the distribution of the widthwise dimension of the component M1 in the longitudinal direction.

[0025] Figure 12 This is a graph illustrating the distribution of the mass of the tire component in the longitudinal direction.

[0026] Figure 13 This is an explanatory diagram illustrating another embodiment of the tire component manufacturing system in a side view. DETAILED DESCRIPTION

[0027] Hereinafter, a tire member manufacturing method and a tire member manufacturing system according to the present invention will be described based on the embodiments shown in the drawings.

[0028] Figures 1 to 5 The embodiment of the tire member manufacturing system 1 shown in the figure manufactures a tire member R formed by joining a plurality of components M1 to M5 while maintaining a predetermined quality.

[0029] In this embodiment, the manufacturing Figure 6 、 Figure 7 The long tire component R is formed by joining together multiple components M (M1 to M5) as shown. The tire component R is a tread rubber formed by joining together multiple components M1 to M5 made of unvulcanized rubber, extruded by multiple extruders 8 (8a to 8e). The tire component R is not limited to tread rubber and may also be various well-known components used in tire manufacturing, such as sidewall rubber, that are mainly made of rubber.

[0030] The constituent components M1 to M5 are different types of unvulcanized rubber, and may include, for example, the same type of raw rubber with different compounding ingredients, the same type of raw rubber with the same compounding ingredient in different proportions, different types of raw rubber with different compounding ingredients, or different types of raw rubber with the same compounding ingredient in different proportions.

[0031] The types of the constituent members M can be multiple and are not limited to 5, and can be, for example, 2 or more and 8 or less. The size of the tire member R is not particularly limited, and can be, for example, several meters or more and several hundred meters or less in length, 10 mm or more and 2000 mm or less in width, and 0.3 mm or more and 100 mm or less in thickness (maximum thickness).

[0032] exist Figure 6 、 Figure 7 In the illustrated tire component R, sheet-like constituent components M2 and M3 are stacked up and down, and a constituent component M4 is stacked thereon. At both ends in the width direction, a constituent component M5 is stacked to cover both ends in the width direction of the constituent components M2 and M3. Moreover, in the width direction center of the tire component R, the constituent component M1 penetrates the tire component R in the vertical direction (thickness direction). The constituent components M1, M4, and M5 are exposed on the surface of the tire component R, and the constituent components M1, M2, and M5 are exposed on the back surface, which contacts the conveying device 2 and places the tire component R on the conveying device 2. If the tire component R is a qualified product, each constituent component M1 to M5 is approximately Figure 6 The illustrated cross-sectional shape extends over the entire length in the longitudinal direction L. In the drawings, boundaries between the constituent members M are indicated by dotted lines.

[0033] Component M1 is a ground-contacting tread rubber blended with a large amount of carbon black and no silica. Component M1 has a generally rectangular cross-section and is the thickest of the components M. It also has the highest carbon black content (weight ratio) and the lowest specific gravity (density) among the components M. Component M1 has a width dimension of, for example, 0.5 mm to 50 mm.

[0034] Component M2 is an adhesive rubber compounded with carbon black and no or a small amount of silica, and is the thinnest sheet-like member among component M. Component M3 is a bottom tread rubber compounded with carbon black and no or a small amount of silica, and is a thicker sheet-like member than component M2.

[0035] Component M4 is a cap rubber that contains no or a small amount of carbon black, but contains a large amount of silica in place of carbon black. Component M4 is the second thickest component of the components M, after component M1. Its surface has concave and convex portions extending along the longitudinal direction L, and its thickness varies depending on its widthwise position. Component M5 is an end rubber that contains carbon black but no silica. Component M5 forms the inclined surface of the widthwise end face of the tire component R, and its thickness varies depending on its widthwise position.

[0036] The specific gravities (densities) of the components M1 to M5 vary, and their respective specific gravities (average values) are known in advance. Component M4, which contains the most significant amount of silica among the components M, has a higher specific gravity than the other components M1, M2, M3, and M5. Furthermore, each component M may contain other known components depending on the required performance. The term "not contained" does not necessarily mean that the component is completely absent; it also includes the presence of a very small amount.

[0037] This manufacturing system 1 includes a plurality of extruders 8 (8a to 8e), a conveyor device 2, an X-ray inspection device 3, a computing device 4, and a control device 9. In this embodiment, the manufacturing system 1 also includes a terahertz wave measuring device 6, a profile sensor 7, a coiler 10, a cutter 11, a distribution conveyor 12, and a discharge conveyor 13, but these may be arbitrarily provided.

[0038] The monitor 5 is communicatively connected to the computing device 4. An extruder 8 is positioned upstream of the conveyor 2 in the conveying direction. A winder 10 and a discharge conveyor 13 are positioned downstream, sandwiching a distribution conveyor 12 therebetween. In the conveying path of the conveyor 2, a terahertz wave measuring device 6, a profile sensor 7, and an X-ray inspection device 3 are arranged in this order from upstream to downstream in the conveying direction. However, this arrangement is not limited to this and can be modified as appropriate. A cutter 11 is positioned above the conveyor 2 in the conveying path, downstream of the X-ray inspection device 3 in the conveying direction.

[0039] The conveying device 2 conveys the tire member R in the longitudinal direction L. As the conveying device 2 , various known specifications such as a belt conveyor device and a roller conveyor device in which a plurality of rotating rollers are arranged can be adopted.

[0040] The X-ray inspection apparatus 3 includes an irradiating section 3a and a light receiving section 3b. The irradiating section 3a is positioned above the tire member R placed on the conveyor 2, while the light receiving section 3b is positioned below the tire member R. Therefore, the tire member R being conveyed by the conveyor 2 passes between the irradiating section 3a and the light receiving section 3b.

[0041] The irradiation unit 3a irradiates a predetermined length range C of the tire member R, from the surface side (upper side in the figure) of the tire member R being conveyed by the conveyor device 2, with X-rays covering the entire width of the tire member R. The X-rays transmitted through the tire member R are received by the light receiving unit 3b. Then, the X-ray inspection device 3 acquires image data D based on the X-ray transmittance of the predetermined length range C of the tire member R that has been irradiated with X-rays. Various known X-ray inspection devices 3 can be used.

[0042] The irradiation unit 3a irradiates X-rays continuously or intermittently to acquire image data D for each of the predetermined length ranges C that are continuous in the longitudinal direction L. Adjacent predetermined length ranges C in the longitudinal direction L may slightly overlap in the longitudinal direction L, but are not separated in the longitudinal direction L. When irradiating X-rays intermittently, the faster the conveying speed of the tire member R by the conveyor device 2 or the smaller the predetermined length range C, the more frequent the X-ray irradiation. In other words, the slower the conveying speed of the conveyor device 2 or the larger the predetermined length range C, the longer the intermittent X-ray irradiation intervals.

[0043] The size (length) of the predetermined length range C and the conveying speed of the conveyor 2 can be arbitrarily set. For example, the size of the predetermined length range C is approximately 50 mm (5 mm to 1000 mm). Furthermore, the conveying speed of the conveyor 2 is approximately 50 mm / s to 1000 mm / s, for example. Furthermore, the X-ray irradiation intensity (X-ray tube voltage and current) is set to a range that allows for the acquisition of clearer image data D, based on the specifications of the tire member R to be inspected, through prior testing or the like.

[0044] Image data D acquired by the X-ray inspection apparatus 3 is sequentially input to the computing device 4. Various other data are input to the computing device 4, and various computations are performed using installed programs. A known computer can be used as the computing device 4. The computing device 4 may be provided separately from the X-ray inspection apparatus 3 or may be integrated as part of the X-ray inspection apparatus 3.

[0045] The monitor 5 displays the image data D acquired by the X-ray inspection apparatus 3 and data (image data, etc.) processed by the calculation device 4. As the monitor 5, various known specifications may be adopted.

[0046] The terahertz wave measurement device 6 includes a transmitter 6a that transmits electromagnetic waves (radio waves) at a terahertz frequency (substantially 0.1 THz to 10 THz), and a detector 6b that detects reflected waves that enter and reflect from the interior of the tire member R. In this embodiment, the transmitter 6a and the detector 6b are disposed on the back side (lower side in the figure) of the tire member R placed on the conveyor 2.

[0047] The electromagnetic wave transmitted from the transmitting unit 6a enters the interior of the tire component R and is reflected at the boundary of the constituent component M. The reflected wave reflected at the boundary is detected by the detecting unit 6b. The terahertz wave measuring device 6 calculates the cross-sectional area (cross-sectional shape) of at least one constituent component M that is biased to the back side of the tire component R based on the reflection angle of the reflected wave (the refraction angle at the boundary) and the time from the transmission of the electromagnetic wave to the detection. When the boundary of the constituent component M changes significantly (the unevenness is large), the reflected wave diffuses and the cross-sectional area (cross-sectional shape) of the constituent component M cannot be calculated with high precision. Therefore, in this embodiment, the cross-sectional area (cross-sectional shape) of the flat sheet-like constituent components M2 and M3 is calculated by the terahertz wave measuring device 6. The terahertz wave measuring device 6 can adopt a device of known specifications.

[0048] The profile sensor 7 includes an irradiation unit 7a for irradiating laser light and a light receiving unit 7b for receiving light reflected from the outer surface of the tire member R. In this embodiment, the set of the irradiation unit 7a and the light receiving unit 7b is arranged on the front side (upper side in the figure) and the back side (lower side in the figure) of the tire member R placed on the conveyor 2.

[0049] The laser beam emitted from each irradiation unit 7a is reflected by the outer surface (outer contour surface) of the tire member R. The reflected light is received by the set of light receiving units 7b. The profile sensor 7 calculates the cross-sectional area (cross-sectional shape) of the tire member R based on the reflection angle of the reflected light and the time from laser irradiation to laser reception. The profile sensor 7 can be a profile sensor of known specifications.

[0050] The extruder 8 (8a to 8e) has a cylinder body in which a screw 8s is driven to rotate. The unvulcanized rubber obtained by mixing the raw rubber and various compounding ingredients is conveyed forward while the screw 8s is rotated to a suitable viscosity and extruded from the extrusion head 8H. Extruders 8 of various known specifications can be used. In this embodiment, the tire component R is formed by joining five components M1 to M5, so five extruders 8a to 8e are used. Different types of unvulcanized rubber corresponding to the components M1, M2, M3, M4, and M5 are extruded from each extruder 8a, 8b, 8c, 8d, and 8e. The individual unvulcanized rubbers extruded by the extruders 8a to 8e are joined by the extrusion head 8H and extruded from the extrusion head 8H as an integrated tire component R.

[0051] The control device 9 controls the rotation of the screw 8s of each extruder 8. The control device 9 is communicatively connected to the computing device 4 and receives various data from the computing device 4. The control device 9 uses the various input data to control the rotation speed of the screw 8s of each extruder 8. A well-known computer can be used as the control device 9.

[0052] The winder 10 winds up and temporarily stores the tire member R conveyed by the conveyor 2. The winder 10 has a winding drum that winds up the tire member R together with the inner liner. If the produced tire member R is used immediately in the next step in an extrusion molding direct connection line, the winder 10 is not required.

[0053] The cutter 11 cuts the tire member R placed on the conveyor 2 in a transverse direction. As the cutter 11, a known blade such as a rotary circular blade can be used.

[0054] The distribution conveyor 12 rotates up and down around one end (the upstream end in the conveying direction). When the other end of the distribution conveyor 12 rotates downward, the tire member R conveyed by the conveying device 2 is guided toward the winder 10, and when the other end of the distribution conveyor 12 rotates upward, it is guided toward the discharge conveyor 13.

[0055] The following describes an example of a process for manufacturing a tire component R while understanding the magnitude of the deviation in the longitudinal direction L of the predetermined quality of the tire component R, using the present invention. First, the description will focus on understanding the distribution in the longitudinal direction L of the width dimension of a component M1 formed of unvulcanized rubber having a higher content of a specific component (carbon black) than that of the other components M2 to M5, as the predetermined quality.

[0056] like Figure 1 As shown in the example, the tire member R extruded from the extruder 8 through the extrusion head 8H is placed on the conveying device 2 arranged in the front and conveyed in the longitudinal direction L. During this conveying process, Figure 2 、 Figure 3 As illustrated, while the tire member R is being conveyed in the longitudinal direction L, the quality inspection of the tire member R is performed using the terahertz wave measuring device 6 and the profile sensor 7 .

[0057] In the terahertz wave measuring device 6, the transmitting unit 6a continuously transmits electromagnetic waves of a terahertz frequency from the back side of the tire member R being transported in the longitudinal direction L toward the tire member R. The reflected waves that enter and reflect the tire member R are detected by the detecting unit 6b. Thus, the cross-sectional shape (cross-sectional area) of the constituent members M2 and M3 is determined in the terahertz wave measuring device 6. Figure 8 As shown, the distribution of the cross-sectional area of ​​the components M2 and M3 in the longitudinal direction L is determined. Since the specific gravity of each component M2 and M3 is known, the distribution of the mass of the components M2 and M3 in the longitudinal direction L is also determined.

[0058] In the profile sensor 7, the irradiation unit 7a continuously irradiates the tire member R being transported in the longitudinal direction L with laser light. The light receiving unit 7b receives the reflected light of the laser light reflected on the outer surface of the tire member R. As a result, the profile sensor 7 grasps the cross-sectional shape (cross-sectional area) of the tire member R. Therefore, as Figure 8 As illustrated, the distribution of the cross-sectional area of ​​the tire member R in the longitudinal direction L is grasped.

[0059] Then, then, Figure 4 、 Figure 5 As illustrated, the X-ray inspection apparatus 3 is used to determine the distribution of the widthwise dimension of the component M1 in the longitudinal direction L while the tire component R is being conveyed in the longitudinal direction L. Therefore, the irradiation unit 3a irradiates a predetermined length range C of the conveyed tire component R with X-rays from the surface side. The X-rays that have passed through the predetermined length range C of the tire component R are sequentially received by the light receiving unit 3b.

[0060] Thus, the X-ray inspection device 3 obtains the X-ray transmittance of the predetermined length range C. Figure 9 The image data D shown in the example is obtained. By continuously performing the process of acquiring image data D in this manner, image data D covering a predetermined length range C that is continuous and seamless in the longitudinal direction L is acquired. Each acquired piece of image data D is sequentially input to the computing device 4, where it is processed and analyzed. The computing device 4 calculates the magnitude (degree of deviation) of the width dimension of the component M1 in the longitudinal direction L based on the shading in the image data D. The calculation process of the computing device 4 is described in detail below.

[0061] X-rays irradiated by the irradiation unit 3a pass through the tire member R and are received by the light receiving unit 3b. The thicker the tire member R, the greater the attenuation of X-rays in the tire member R (the greater the absorption), and therefore the amount of X-rays received by the light receiving unit 3b (the transmitted radiation dose) decreases. Furthermore, when the tire member R contains a high content of components that easily attenuate X-rays (high atomic number and density), the amount of X-rays received by the light receiving unit 3b (the transmitted radiation dose) decreases. Consequently, the resulting image data D becomes darker and closer to black. On the other hand, the thinner the tire member R, the less attenuation of X-rays in the tire member R (the less the absorption), and therefore the amount of X-rays received by the light receiving unit 3b (the transmitted radiation dose) increases. Furthermore, when the tire member R contains a low content of components that easily attenuate X-rays, the amount of X-rays received by the light receiving unit 3b (the transmitted radiation dose) increases. Consequently, the resulting image data D becomes lighter and closer to white.

[0062] Silica is a component that significantly attenuates (absorbs) X-rays compared to carbon black. Therefore, the image data D of a component M containing silica or having a high silica content appears closer to black and darker than that of a component M containing carbon black instead of silica or having a high carbon black content. Thus, the shading of the image data D depends on the thickness and composition of the tire component R at the location through which the X-rays pass.

[0063] like Figure 10 As shown by the dashed line Z in FIG. 1 , the X-ray transmission dose Z of the tire member R varies in the width direction W. Figure 10 To facilitate understanding of the widthwise position of the tire component R, a cross-sectional view of the tire component R is shown below the coordinate graph. The transmission radiation dose Z represents the amount of X-rays received by the back side of the tire component R when X-rays are irradiated from the front side. The transmission radiation dose Z can be calculated based on the thickness, specific gravity, and attenuation coefficient of the tire component R at the position through which the X-rays pass. Widthwise positions with greater transmission radiation dose Z appear darker in color in the image data D.

[0064] Therefore, in Figure 9 In the illustrated image data D, the color is darkest at the thickest position of the component M4 and becomes lighter at the thinnest position. The component M1 is the thickest member, but since it has the smallest specific gravity, the color of the image data D becomes lighter at the position where the component M1 is arranged. At the position where the component M5 is arranged, the color of the image data D becomes lighter as it goes toward the width direction end of the tire component R. Figure 9 In the figure, the arrangement pitch of the oblique lines is changed according to the color density, and the arrangement pitch of the oblique lines is reduced in a relatively dark color portion so that the lines are densely written.

[0065] Therefore, in Figure 9The image data D contains dark and light areas, with the light areas existing in multiple locations (the thinnest location of component M4, the location of component M1, and the location of component M5). Therefore, simply by looking at the light and dark areas in the image data D, it is difficult to identify which light area is where component M1 is located. However, when the thickness of the same type of unvulcanized rubber varies, the change in the transmittance Z is gradual, similar to the change in thickness, so the change in light and dark in the image data D is gentle. On the other hand, in different types of unvulcanized rubber, the transmittance Z varies significantly due to the differences in the ingredients contained, so the change in light and dark in the image data D is rapid.

[0066] Therefore, in this embodiment, it is pre-learned Figure 10 The amount of light transmitted Z in the width direction W of the tire member R is exemplified by utilizing the difference in the amount of light transmitted Z. That is, the amount of light transmitted Z of each component M is known in advance, such as Figure 9 As shown in the example, a reference range is set for the difference in the amount of transmitted radiation Z between the components M adjacent to each other in the width direction W. In other words, the reference range is set so that if the variation in the amount of transmitted radiation Z in the width direction W falls within the reference range, the components M1 and M4 are substantially adjacent to each other in the width direction W.

[0067] The range of differences in shading of the image data D corresponding to the set reference range is then stored in the computing device 4 as a determination reference. The computing device 4 calculates the magnitude of the shading difference in the width direction W for each piece of image data D. When the computing device 4 detects a position where this difference falls within the determination reference, it determines that the detected widthwise position is the boundary between the components M1 and M4. If a single component M1 in the tire component R extends in the longitudinal direction L, the boundary between the components M1 and M4 is detected at two locations separated by a gap in the width direction W, and the gap in the width direction W between these boundaries is calculated as the widthwise dimension of the component M1.

[0068] The results, such as Figure 11 As illustrated, the magnitude of the variation in the widthwise dimension of the constituent member M1 in the tire member R in the longitudinal direction L is calculated. Figure 11 The Mc on the vertical axis represents the design value of the width dimension of the component M1. In the manufactured tire component R, it is possible to understand to what extent the width dimension of the component M1 varies in the longitudinal direction L. Figure 11 The case where the width direction dimension is zero means that the component M1 is interrupted in the middle of the length direction L. Therefore, according to Figure 11 The data can be used to understand the continuity of the component M1 with respect to the longitudinal direction L.

[0069] In this embodiment, X-rays are irradiated from the irradiation section 3a to a predetermined length range C of the tire member R so as to cover the entire width of the tire member R. However, the widthwise position at which the component M1 is arranged in the tire member R is known in advance. Therefore, the widthwise range to which X-rays are irradiated can also be set to a narrower range that includes the widthwise position known in advance as the position at which the component M1 is arranged.

[0070] If the calculated deviation in the longitudinal direction L of the widthwise dimension of the component M1 falls within a pre-set allowable range, the portion of the tire component R that falls within the predetermined length range C is determined to be a qualified portion. The qualified portion of the tire component R conveyed by the conveyor device 2 is then guided to the winder 10 by the distribution conveyor 12 and wound up. In the case of an extrusion molding line directly connected to the production line, the qualified portion of the tire component R is conveyed intact to the next process.

[0071] If the calculated deviation in the longitudinal direction L of the widthwise dimension of the component M1 falls outside the permissible range, the predetermined length range C (the defective portion) that meets the requirements is cut off by the cutter 11 on the conveyor 2. Then, when the cut predetermined length range C (the defective portion) is conveyed to the downstream end of the conveyor 2 in the conveying direction, the distribution conveyor 12 rotates toward the discharge conveyor 13. Thus, the cut predetermined length range C (the defective portion) is placed on the discharge conveyor 13 and conveyed, and removed from the production line.

[0072] When the deviation in the longitudinal direction L of the width dimension of the component M1 is too large, the possibility of it falling outside the allowable range increases. Therefore, the control device 9 controls the rotational speed of the screw 8s of at least one of the multiple extruders 8 based on the size of the deviation in the width dimension of the component M1 calculated and grasped as described above. For example, the rotational speed of the screw 8s of the extruder 8a that extrude the unvulcanized rubber that forms the component M1 is controlled to correct the deviation in its width dimension and bring it closer to the design value Mc. If the width dimension of the component M1 is too small relative to the design value Mc, the rotational speed of the screw 8s of the extruder 8a is increased. If the width dimension is too large relative to the design value Mc, the rotational speed of the screw 8s of the extruder 8a is reduced. Not limited to the extruder 8a, the rotational speed of the screw 8s of the extruder 8 that has a greater impact on the variation in the width dimension of the component M1 can also be controlled preferentially.

[0073] As described above, since image data D is obtained by irradiating a predetermined length range C with X-rays from the surface side of the tire member R while being conveyed by the conveyor device 2 along the longitudinal direction L, it is not necessary to stop the conveyance of the tire member R in order to determine the widthwise dimension of the component M1. Furthermore, image data D can be obtained for the predetermined length range C that is continuous and seamless in the longitudinal direction L, and the computing device 4 can accurately determine the widthwise dimension of the component M1 based on the shading in each piece of image data D. This facilitates rapid and highly accurate determination of the deviation in the widthwise dimension of the component M1 along the longitudinal direction L (i.e., the continuity of the component M1 along the longitudinal direction L). Furthermore, by controlling the rotational speed of the screw 8s as described above based on the magnitude of the highly accurately determined deviation in the widthwise dimension of the component M1, this deviation can be reduced, thereby facilitating the production of the tire member R with high productivity.

[0074] In the above embodiment, the longitudinal distribution of component M1, formed of unvulcanized rubber having a higher content of carbon black as a specific component than that of the unvulcanized rubber forming other components M, is examined as an example. This specific component is not limited to carbon black and may be another component depending on the purpose. Furthermore, the specific component to be inspected is not limited to component M1 and may also be another component M.

[0075] Next, the case of grasping the distribution of the mass of the tire member R in the longitudinal direction L as the predetermined quality inspected by the X-ray inspection device 3 will be described. The distribution can be grasped by the magnitude of the deviation in the longitudinal direction L of the widthwise dimension of the component M1 described above, instead of or in addition to it.

[0076] The aforementioned image data D is acquired in advance under the same conditions for a plurality of tire member R samples. Furthermore, mass data per unit length is acquired for each sample. By using these image data D and mass data as training data for machine learning, a prediction model (computer program) is generated based on the image data D acquired as the inspection target for estimating the mass per unit length of a predetermined length range C corresponding to the image data D, and the model is stored in the computing device 4.

[0077] As described above, the shading in the image data D varies depending on the thickness and components of the tire member R. Therefore, the shading distribution is correlated with the mass per unit length of the portion of the tire member R corresponding to the image data D (predetermined length range C). Therefore, for example, the image data D is subdivided into a plurality of microregions, and the correlation between the shading degree and position of each microregion and the mass per unit length corresponding to the image data D is obtained through machine learning, thereby generating an estimation model. Various well-known machine learning methods, such as deep learning using neural networks, can be used.

[0078] When estimating the mass of each predetermined length range C of the conveyed tire member R, image data D sequentially acquired by the X-ray inspection device 3 is input to the estimation model and processed by the calculation device 4. Thus, the mass of each predetermined length range C is estimated and calculated.

[0079] The results, such as Figure 12 As illustrated, the magnitude of the variation in the mass (mass per unit length) of the tire member R in the longitudinal direction L is calculated. Figure 12 The vertical axis Ra represents the permissible range of the mass (mass per unit length) of the tire component R. Figure 12 , in the manufactured tire member R, it is possible to understand to what extent its mass varies in the longitudinal direction L. Figure 12 When the medium quality is within the allowable range Ra, the predetermined length range C that meets the requirements is determined as a qualified portion. When it is outside the allowable range Ra, the predetermined length range C that meets the requirements is determined as a defective portion.

[0080] In this embodiment, as in the previous embodiment, the predetermined length range C corresponding to the conforming portion is guided to the coiler 7 by the distribution conveyor 9. The predetermined length range C corresponding to the reject portion is cut by the cutter 8 on the conveyor device 2, guided by the distribution conveyor 9 to the discharge conveyor 10, and removed from the production line.

[0081] If the mass deviation of the tire component R in the longitudinal direction L is too large, the possibility of it falling outside the allowable range Ra increases. Therefore, the control device 9 controls the rotational speed of the screw 8s of at least one of the multiple extruders 8 based on the magnitude of the mass deviation of the tire component R calculated and grasped as described above. By performing this control, the mass deviation of the tire component R in the longitudinal direction L is corrected, and the mass is maintained within the allowable range Ra.

[0082] In this embodiment, the widthwise position and widthwise dimensions of component M1 are determined using the X-ray inspection device 3, and the cross-sectional shape of the tire component R is determined using the profile sensor 7. Therefore, the cross-sectional area and mass of component M1 can also be determined. Furthermore, the cross-sectional area and mass of components M2 and M3 are determined using the terahertz wave measurement device 6. Therefore, by subtracting the cross-sectional area (mass) of components M1, M2, and M3 from the determined cross-sectional area (mass) of tire component R, the combined cross-sectional area (mass) of components M4 and M5 can be determined. Since the cross-sectional area (mass) of component M5 is significantly smaller than that of component M4, the cross-sectional area (mass) of component M4 can also be roughly determined. Therefore, based on the magnitude of the deviation in the determined cross-sectional area (mass) of each component M2, M3, and M4 in the longitudinal direction L, similar to the correction of the deviation in the widthwise dimension of component M1 described above, the control device 9 can be used to control the rotational speed of the screw 8s of at least one of the multiple extruders 8 to correct for the deviation in each cross-sectional area (mass). As a result, the variation in the mass of the tire member R in the longitudinal direction L is corrected.

[0083] Figure 13 In the embodiment of the manufacturing system 1 illustrated, a group of a terahertz wave measuring device 6, a profile sensor 7, and an X-ray inspection device 3 are arranged at two locations separated in the longitudinal direction L of the conveyor 2. That is, in this embodiment, Figure 1 In the manufacturing system 1 shown as an example, a group of a terahertz wave measuring device 6 , a profile sensor 7 , and an X-ray inspection device 3 are added to the downstream side of the conveying device 2 in the conveying direction.

[0084] The group of terahertz wave measuring devices 6, profile sensors 7, and X-ray inspection devices 3 located upstream of the conveyor device 2 in the conveying direction functions similarly to the previous embodiment. Specifically, this group inspects the quality of the tire component R and provides feedback on the inspection results for the control device 9 to control the rotational speed of the screw 8s. Meanwhile, the group located downstream in the conveying direction inspects the quality of the tire component R and simply determines whether the inspection results meet the acceptable range.

[0085] Description of Reference Numerals

[0086] 1 Manufacturing System

[0087] 2 Conveying device

[0088] 3 X-ray inspection equipment

[0089] 3a Irradiation area

[0090] 3b Light receiving part

[0091] 4 Computing device

[0092] 5 Monitor

[0093] 6 Terahertz wave measurement device

[0094] 6a Sending Department

[0095] 6b Detection Department

[0096] 7 Profile Sensor

[0097] 7a Irradiation section

[0098] 7b Light receiving part

[0099] 8 (8a~8e) extruder

[0100] 8s screw

[0101] 8H Extrusion Head

[0102] 9 Control device

[0103] 10 Coiler

[0104] 11 Cutting Machine

[0105] 12 Distribution Conveyor

[0106] 13 Discharge conveyor

[0107] R tire components

[0108] M1, M2, M3, M4, M5 components

[0109] C Predetermined length range

[0110] D Image data

Claims

1. A method for manufacturing a tire component, wherein a long tire component is formed by joining a plurality of components made of unvulcanized rubber extruded from a plurality of extruders to produce the tire component with predetermined quality. In the manufacturing method of the tire component, a process is continuously performed to obtain image data based on X-ray transmittance of a predetermined length range of the tire component by irradiating the predetermined length range of the tire component from the surface side of the tire component while conveying the tire component in the length direction, and the image data of the predetermined length range continuous and without gaps in the length direction are obtained. Based on the light and dark values ​​in each of the obtained image data, the size of the deviation of the tire component of the predetermined quality in the length direction is grasped. Based on the grasped size of the deviation, the rotation speed of the screw of at least one extruder provided in the multiple extruders is controlled to correct the deviation.

2. The method for manufacturing a tire component according to claim 1, As the predetermined quality, the distribution in the longitudinal direction of the width dimension of a specific component formed of unvulcanized rubber having a higher content of a specific component than that of the unvulcanized rubber forming the other components is grasped, The specific component is carbon black.

3. The method for manufacturing a tire component according to claim 1 or 2, As the predetermined quality, the distribution of the mass of the tire member in the longitudinal direction is grasped.

4. The method for manufacturing a tire component according to claim 1 or 2, The distribution of the cross-sectional area of ​​the tire member in the longitudinal direction is determined by irradiating the tire member conveyed in the longitudinal direction with laser light and receiving reflected light from the outer surface of the tire member.

5. The method for manufacturing a tire component according to claim 1 or 2, By transmitting electromagnetic waves of a terahertz frequency toward the tire component from the back side of the tire component being transported along the length direction, and detecting the reflected waves that enter and reflect the tire component, the distribution of the cross-sectional area of ​​at least one of the constituent components biased on the back side of the tire component in the length direction is grasped.

6. A tire component manufacturing system comprising a plurality of extruders for extruding components made of unvulcanized rubber of different types, and manufacturing a long tire component formed by joining the plurality of components to achieve a predetermined quality. The tire component manufacturing system includes: a conveying device that conveys the tire component in a longitudinal direction; an X-ray inspection device that irradiates a predetermined length range of the tire component from the surface side of the tire component being conveyed by the conveying device with X-rays to obtain image data based on X-ray transmittance of the predetermined length range; a computing device to which the image data is input; and a control device that controls the rotation of a screw provided in each of the extruders. The manufacturing system of the tire component is constructed by continuously performing the process of obtaining the image data, obtaining the image data of the predetermined length range that is continuous and without gaps in the longitudinal direction, calculating the size of the deviation of the tire component of the predetermined quality in the longitudinal direction based on the light and dark values ​​in each of the obtained image data, and controlling the rotational speed of the screw provided in at least one of the extruders based on the calculated size of the deviation using the control device, thereby correcting the deviation.

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