Inspection jig and inspection method for stud pin, and manufacturing method for stud tire

Abstract

To provide an inspection jig and inspection method for stud pins which can accurately and rapidly grasp the shapes of a large number of stud pins using image data, and a manufacturing method for a stud tire.SOLUTION: A large number of stud pins 14 are arranged in an upright state on a transparent plate 4 placed between triangle pole-shaped prisms 3 arranged in parallel on an inspection stage 12. Light is irradiated onto the upper surface of each pin 14 from an upper lighting unit 12a to acquire image data of the upper surface of each pin 14. Light is irradiated onto the bottom surface of each pin 14 from a lower lighting unit 12c to acquire image data of the bottom contour of each pin 14. Light from the lower lighting unit 12c is irradiated from the side surface of each pin 14 via one prism 3 adjacent to each pin 14, and reflected by the other adjacent prism 3 toward a camera device 10 to acquire image data of the side contour of each pin 14. A calculation unit 13 determines whether the shape of the pin 14 grasped on the basis of each image data satisfies an allowable range of a reference shape.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to a stud pin inspection jig and inspection method, and a stud tire manufacturing method, and more particularly to a stud pin inspection jig and inspection method, and a stud tire manufacturing method that can accurately and quickly grasp the shapes of a large number of stud pins using image data. [Background technology]

[0002] A large number of stud pins are driven into the tread surface of a studded tire. The shape of the stud pins has a significant effect on tire performance (such as driving performance on ice). Furthermore, if there is variation in the shape of the stud pins, the stud pins cannot be stably installed on the tread surface as designed, and they may come off the tire while driving (see, for example, Patent Document 1). Furthermore, this is also detrimental to ensuring the desired tire performance. For this reason, it is important to know the shape of the stud pins in advance, use stud pins with appropriate shapes, and eliminate stud pins with inappropriate shapes.

[0003] For example, about 200 to 250 stud pins are driven into one studded tire for a passenger car. Furthermore, the stud pins have a complex shape, and the shape varies depending on the specifications. Therefore, there is a limit to measuring the dimensions of each stud pin manually. It is also possible to grasp the shape of the stud pin based on image data of the stud pin acquired by a camera device using a known inspection device equipped with a camera device. However, since image data must be acquired from multiple directions in order to grasp the shape of the stud pin with high accuracy, it is difficult to grasp the shape of a large number of stud pins accurately and quickly. Therefore, some ingenuity is required to grasp the shape of a large number of stud pins accurately and quickly. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-25387 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a stud pin inspection jig and inspection method, as well as a stud tire manufacturing method, that are capable of quickly and accurately grasping the shapes of a large number of stud pins using image data. [Means for solving the problem]

[0006] In order to achieve the above object, the stud pin inspection jig of the present invention comprises an inspection stage on which an object to be inspected is placed, a camera device arranged above the inspection stage, a calculation unit to which image data of the object to be inspected acquired by the camera device is input, an upper illumination unit arranged above the inspection stage, and a lower illumination unit arranged below the inspection stage, and the shape of the object to be inspected is grasped based on the image data input to the calculation unit, and it is judged whether the grasped shape of the object to be inspected satisfies a preset tolerance range of a reference shape.The inspection jig for stud pins is used in inspection equipment which comprises an inspection stage on which an object to be inspected is placed, a camera device arranged above the inspection stage, a calculation unit to which image data of the object to be inspected acquired by the camera device is input, an upper illumination unit arranged above the inspection stage, and a lower illumination unit arranged below the inspection stage, and the shape of the object to be inspected is grasped based on the image data input to the calculation unit, and it is judged whether the grasped shape of the object to be inspected satisfies a tolerance range of a preset reference shape.The inspection jig has a plurality of triangular prisms arranged in parallel on the inspection stage and a transparent plate arranged between each of the prisms, and a number of stud pins are arranged in an upright state on the transparent plate, and light is irradiated from the bottom side of each of the stud pins by the lower illumination unit to illuminate the bottom ring of each of the stud pins. the lower illumination unit irradiates light onto the top surface of each of the stud pins through the other prism adjacent to each of the stud pins, the light reflected from each of the stud pins is reflected towards the camera device by the other prism adjacent to each of the stud pins, and image data of the side contour of each of the stud pins is acquired by the camera device; the upper illumination unit irradiates light onto the top surface of each of the stud pins, and image data of the top surface of each of the stud pins is acquired by the camera device; the upper illumination unit irradiates light onto the side surface of each of the stud pins through the other prism adjacent to each of the stud pins, the light reflected from each of the stud pins is reflected towards the camera device by the other prism, and image data of the side surface of each of the stud pins is acquired by the camera device.

[0007] The stud pin inspection method of the present invention is a method of inspecting stud pins using inspection equipment which comprises placing an object to be inspected on an inspection stage having an upper illumination unit arranged above and a lower illumination unit arranged below, inputting image data of the object to be inspected acquired by a camera device arranged above the inspection stage to a calculation unit, grasping the shape of the object to be inspected based on the image data input to the calculation unit, and determining whether the grasped shape of the object to be inspected satisfies a preset tolerance range of a reference shape, and comprising: arranging a plurality of triangular prisms in parallel on the inspection stage and disposing a transparent plate between each of the prisms; and arranging a number of stud pins in an upright state on the transparent plate as the object to be inspected; irradiating light from the bottom side of each of the stud pins by the lower illumination unit to obtain image data of the bottom contour of each of the stud pins by the camera device; and obtaining an image of each of the front and rear contours of the stud pins through one of the prisms adjacent to each of the stud pins by the lower illumination unit. the upper illumination unit irradiates light onto the side of each of the stud pins through the other prism adjacent to each of the stud pins and image data of the top surface of each of the stud pins is acquired by the camera device; the upper illumination unit irradiates light onto the side of each of the stud pins through the other prism adjacent to each of the stud pins and the light reflected from each of the stud pins is reflected towards the camera device by the other prism and image data of the side surface of each of the stud pins is acquired by the camera device; and the shape of the inspection object is grasped based on at least one of image data of the side contour or image data of the side surface in addition to image data of the bottom surface contour and image data of the top surface.

[0008] The method for manufacturing a studded tire of the present invention, in which a studded tire is manufactured by driving stud pins into each mounting hole formed in the tread surface of a base tire, is characterized in that the stud pins determined by the above-mentioned stud pin inspection method to satisfy the predetermined tolerance range of the reference shape are selected, and the selected stud pins are driven into each of the mounting holes. Effect of the Invention

[0009] According to the stud pin inspection jig and inspection method of the present invention, by arranging a large number of stud pins in an upright position on the transparent plate arranged between a plurality of prisms arranged in parallel on the inspection stage, the camera device can acquire the image data of the bottom surface contour, the image data of the top surface, the image data of the side surface contour and the image data of the side surface of each of the stud pins. The shape of each of the stud pins can be grasped accurately and quickly by performing arithmetic processing by the arithmetic unit based on the image data of the bottom surface contour and the image data of the top surface, as well as on at least one of the image data of the side surface contour or the image data of the side surface. As a result, it is advantageous to grasp the shapes of a large number of stud pins accurately and quickly. Accordingly, it can be accurately and quickly determined whether the shape of each stud pin satisfies the tolerance range of the reference shape set in advance.

[0010] According to the studded tire manufacturing method of the present invention, the stud pins that are determined to satisfy the preset tolerance range of the reference shape by the stud pin inspection method described above are used in the manufacture of studded tires, and each stud pin will therefore exhibit the set performance, which is advantageous in ensuring the desired tire performance. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 shows an example of a stud pin to be inspected, with FIG. 1(A) being a front view, FIG. 1(B) being a top view, and FIG. 1(C) being a bottom view. [Diagram 2] 1 is an explanatory diagram illustrating an inspection device equipped with an embodiment of a stud pin inspection jig as viewed from the front; FIG. [Diagram 3] 3 is an explanatory diagram illustrating the inspection stage in FIG. 2 as viewed from above. [Figure 4] 4 is an explanatory diagram illustrating an inspection jig mounted on the inspection stage of FIG. 3 in a plan view. [Diagram 5] 5 is an explanatory diagram illustrating the inspection jig in FIG. 4 as viewed from the front. [Figure 6] 5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 7] 5 is an explanatory diagram illustrating the inspection jig in FIG. 4 in an exploded plan view. [Figure 8] 2 is an explanatory diagram illustrating the arrangement plate of FIG. 1 in a plan view. [Figure 9] 9 is a cross-sectional view of FIG. 8 taken along line B-B. [Figure 10] 6 is an explanatory diagram illustrating a step of placing an array plate on the inspection stage of FIG. 5 as seen from the front; [Figure 11] 11 is an explanatory diagram illustrating a state in which the arrangement plate in FIG. 10 is placed on an inspection stage in a plan view. FIG. [Figure 12] 12 is an explanatory diagram illustrating a step of arranging a stud pin on the transparent plate of FIG. 11 as viewed from the front. [Figure 13] 10 is an explanatory diagram illustrating, in a plan view, a state in which each stud pin is arranged on a transparent plate. FIG. [Figure 14] 14 is a cross-sectional view taken along CC in FIG. 13. [Figure 15] FIG. 14 is an explanatory diagram illustrating a state in which the arrangement plate in FIG. 13 is removed. [Figure 16] FIG. 16 is a cross-sectional view taken along the line DD in FIG. [Figure 17] 11 is an explanatory diagram illustrating a step of acquiring image data of the bottom surface contour of a stud pin from a side view. FIG. [Figure 18] 11 is an explanatory diagram illustrating an example of image data of a bottom surface contour of a stud pin. FIG. [Figure 19] 11 is an explanatory diagram illustrating a step of acquiring image data of the upper surface of a stud pin from a side view. FIG. [Figure 20] 11 is an explanatory diagram illustrating image data of the top surface of a stud pin. FIG. [Figure 21] 11 is an explanatory diagram illustrating a step of acquiring image data of a side profile of a stud pin from a side view. FIG. [Figure 22] FIG. 11 is an explanatory diagram illustrating image data of a side profile of a stud pin. [Diagram 23] 11 is an explanatory diagram illustrating a step of acquiring image data of a side surface of a stud pin from a side view. FIG. [Figure 24] FIG. 11 is an explanatory diagram illustrating an example of image data of a side surface of a stud pin. [Diagram 25] 13A and 13B are explanatory diagrams illustrating modified examples of the arrangement plate in cross-sectional view. [Figure 26] 1A to 1C are explanatory diagrams illustrating a process for manufacturing a studded tire in longitudinal cross section of the tire. [Figure 27] FIG. 2 is an explanatory diagram illustrating a manufactured studded tire in longitudinal cross section. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a stud pin inspection jig and inspection method, as well as a studded tire manufacturing method of the present invention will be described based on the embodiments shown in the drawings.

[0013] The present invention is used when inspecting a stud pin as exemplified in FIG. 1. The stud pin 14 has a body portion 14a and a flange-shaped bottom portion 14b, and a tip 14c protrudes upward from the upper surface of the body portion 14a. The upper surface of the body portion 14a is exposed to the tread surface of a studded tire. The lower end portion of the body portion 14a has a smaller diameter and is connected to the bottom portion 14b. The stud pin 14 is not limited to the specifications shown in the figure, and can have various desired specifications. Generally, the bottom portion 14b has a larger shape (larger area) than the body portion 14a in a plan view.

[0014] For inspecting the stud pins 14, an inspection device 10 as exemplified in Figures 2 and 3 is used. An embodiment of the stud pin inspection jig 1 of the present invention is used together with this inspection device 10. This inspection device 10 comprises an inspection stage 12 on which an object to be inspected is placed, a camera device 11 arranged above the inspection stage 12, upper illumination units 12a and 12b arranged above the inspection stage 12, a lower illumination unit 12c arranged below the inspection stage 12, and a calculation unit 13. In the present invention, the object to be inspected is a stud pin 14. Various known types of inspection device 10 can be used. Arrows W, D, and H in the figures indicate the width, depth, and height directions of the inspection device 10, respectively.

[0015] The inspection stage 12 is a frame body with an opening at the center in a plan view, and is movable in the width direction and the depth direction.

[0016] The camera device 11 may employ various known digital cameras or similar cameras capable of acquiring image data of the stud pin 14. Various known lighting devices such as incandescent lamps (light bulbs), fluorescent lamps, and LEDs may be used for the upper lighting units 12a, 12b and the lower lighting unit 12c. In this embodiment, annular lighting devices are employed for the upper lighting units 12a, 12b. The upper lighting units 12a, 12b can move up and down individually to approach and move away from the inspection stage 12. A single upper lighting unit may be used instead of separate upper lighting units 12a, 12b. The imaging systems such as these lighting units and cameras can be made to use telecentric optical systems to reduce measurement errors.

[0017] Image data of the stud pin 14 acquired by the camera device 11 is input to the calculation unit 13. Various known computers can be used as the calculation unit 13. The calculation unit 13 performs calculation processing using the input data and stored data. The reference shape and tolerance range (allowable dimensional range) of the stud pin 14 are input to the calculation unit 13. The calculation unit 13 calculates the shape of the stud pin 14 based on the input image data. In this way, the shape of the stud pin 14 is grasped. The calculation unit 13 then judges whether the grasped shape of the stud pin 14 satisfies the tolerance range of the reference shape that is set in advance.

[0018] 1 has a plurality of triangular prisms 3 arranged on an inspection stage 12, a transparent plate 4 arranged between each of the prisms 3, a holding plate 2, a pressing portion 5, a positioning guide 6, and an alignment plate 7. The holding plate 2, the positioning guide 6, and the alignment plate 7 may be provided as desired.

[0019] The inspection jig 1 will be described in detail below. As illustrated in Fig. 4 to Fig. 6, a holding plate 2, a prism 3, a transparent plate 4, a pressing portion 5, and a positioning guide 6 are placed on an inspection stage 12. As illustrated in Fig. 7, the holding plate 2 is a frame body with an opening at the center in a plan view, similar to the inspection stage 12. The holding plate 2 is fixed to a predetermined position on the inspection stage 12 with screws or the like.

[0020] Each of the prisms 3 arranged in parallel has a cross section of a right-angled triangle (right-angled isosceles triangle). The inclined surface is a reflecting surface 3a, and the two perpendicular surfaces are transmitting surfaces 3b. The reflecting surface 3a reflects the incident light, and the transmitting surface 3b transmits the incident light. The reflecting surface 3a has, for example, an aluminum deposition layer, and is coated with magnesium fluoride or the like as a protective layer. The transmitting surface 3b has a known AR coating (anti-reflection coating). Each prism 3 is installed on the holding plate 2 with one transmitting surface 3b facing downward. In this embodiment, there are four prisms 3 arranged in parallel, but three or more are preferable. The number of prisms 3 is set appropriately according to the size of the inspection stage 12.

[0021] A large number of stud pins 14 are arranged upright on the transparent plate 4 disposed between each of the prisms 3. The transparent plate 4 is made of glass or a highly transparent resin (polycarbonate). In this embodiment, since there are four prisms 3, three transparent plates 4 are provided. For example, it is also possible to arrange the transparent plates 4 between the prisms 3 by disposing the prisms 3 at intervals on one transparent plate 4.

[0022] Each prism 3 and each transparent plate 4 extends in the width direction and spans the openings of the inspection stage 12 and the holding plate 2. Both longitudinal ends of each transparent plate 4 protrude in the width direction beyond both longitudinal ends of each prism 3.

[0023] The holding parts 5 are disposed on both longitudinal ends of each transparent plate 4 and fixed to the holding plate 2 with screws or the like. As a result, each holding part 5 is installed at a predetermined position on the inspection stage 12. Both longitudinal ends of each transparent plate 4 are sandwiched vertically between the holding parts 5 and the holding plate 2 and installed at a predetermined position on the inspection stage 12.

[0024] The positioning guide 6 is fixed to the four corners of the inspection stage 12 in plan view with screws or the like. In this embodiment, a block body with a portion cut out is used as the positioning guide 6. The positioning guide 6 may have various forms as long as it can position the arrangement plate 7 at a predetermined position on the inspection stage 12. The positioning guide 6 can also be fixed to the holding plate 2.

[0025] The arrangement plate 7 shown in Figures 8 and 9 is used to easily arrange a large number of stud pins 14 in an upright state on the transparent plate 4. The arrangement plate 7 is formed with a large number of pin holes 8a into which the stud pins 14 are inserted one by one in an upright state, and also has prism holes 8b corresponding to each prism 3. In this embodiment, four rectangular prism holes 8b corresponding to the four prisms 3 penetrate the arrangement plate 7 from top to bottom. A large number of pin holes 8a are arranged in a row at intervals in the width direction between each of the prism holes 8b, and penetrate the arrangement plate 7 from top to bottom.

[0026] In plan view, each pin hole 8a is slightly larger than a stud pin 14, and each prism hole 8b is slightly larger than a prism 3. The shape of the pin holes 8a in plan view is determined according to the shape of the stud pin 14 (bottom portion 14b) in plan view, and each stud pin 14 inserted into each pin hole 8a is arranged to face the same direction in plan view.

[0027] 10 and 11 , the alignment plate 7 is positioned and installed at a predetermined position on the inspection stage 12 using the positioning guides 6. In this embodiment, the four corners of the alignment plate 7 function as positioning portions 9 and engage with the positioning guides 6.

[0028] When the four corners of the array plate 7 are engaged with the corresponding positioning portions 9 and the array plate 7 is placed at a predetermined position on the inspection stage 12, each of the pin holes 8a is positioned above the transparent plate 4 between the corresponding prisms 3, and each of the prism holes 8b is positioned above the corresponding prism 3 without contacting the prism 3. In this embodiment, as illustrated in Fig. 12, the position of the upper surface of the array plate 7 when placed on the inspection stage 12 using the positioning guides 6 is higher than the apex of each of the prisms 3.

[0029] Next, an example of a procedure for grasping the shape of the stud pin 14 using the inspection jig 1 will be described.

[0030] As shown in Fig. 11, after placing the inspection jig 1 on the inspection stage 12, the stud pins 14 are inserted into each of the pin holes 8a as shown in Fig. 12. As a result, as shown in Figs. 13 and 14, the stud pins 14 inserted into each of the pin holes 8a are arranged in a row in an upright state on the transparent plate 4 between the prisms 3. Each of the stud pins 14 faces the same direction in a plan view.

[0031] 14, in this embodiment, the position of the top surface of the array plate 7, which is positioned on the inspection stage 12 by the positioning guides 6, is higher than the apexes of the prisms 3. In other words, the prisms 3 do not protrude from the top surface of the array plate 7. This is advantageous in avoiding the problem of the stud pins 14 coming into contact with the prisms 3 and damaging them when inserting the stud pins 14 into the pin holes 8a.

[0032] After the required number of stud pins 14 have been inserted into the pin holes 8a and arranged on the transparent plate 4, the arrangement plate 7 is moved upward and removed from the inspection stage 12. As a result, a large number of stud pins 14 are arranged in an upright state on the transparent plate 4 and arranged between each of the prisms 3, as shown in Figs.

[0033] Next, image data M1 of the bottom surface contour of the stud pin 14, image data M2 of the top surface of the stud pin, image data M3 of the side surface contour of the stud pin 14, and image data M4 of the side surface of the stud pin 14 are obtained as image data of each stud pin 14. The order in which the image data M1 to M4 are obtained does not matter.

[0034] To obtain image data M1 of the bottom contour of the stud pins 14, light is applied from the bottom side of each stud pin 14 by the downward illumination unit 12c, as shown in Figure 17. This allows the camera device 11 to obtain image data M1 of the bottom contour of each stud pin 14, as shown in Figure 18.

[0035] To obtain image data M2 of the top surfaces of the stud pins 14, light is irradiated onto the top surface of each stud pin 14 by the upper illumination unit 12b, as shown in Figure 19. In this way, image data M2 of the top surface of each stud pin 14 is obtained by the camera device 11, as shown in Figure 20. By appropriately adjusting the vertical position of the upper illumination unit 12b relative to the stud pins 14 and irradiating light, it is possible to obtain image data M2 in which the outer edges of the stud pins 14 clearly stand out.

[0036] To obtain image data M3 of the side profile of the stud pins 14, the downward illumination unit 12c irradiates light from the side of each stud pin 14 through one prism 3 adjacent to each stud pin 14, as shown in the example of Figure 21. The light is reflected towards the camera device 11 by the other prism 3 adjacent to each stud pin 14.

[0037] More specifically, light from the downward illumination unit 12c is transmitted through the lower transmitting surface 3b of one of the prisms 3 and reflected by the reflective surface 3a, and then transmitted through the other transmitting surface 3b to irradiate the side surface of each stud pin 14. This light is reflected by the reflective surface 3a of the other prism 3 towards the camera device 11. In this way, image data M3 of the side profile of each stud pin 14, as shown in FIG. 22, is acquired by the camera device 11.

[0038] To obtain image data M4 of the side surface of the stud pins 14, the upper illumination unit 12a irradiates light from the side surface of each stud pin 14 through the other prism 3 adjacent to each stud pin 14, as shown in Figure 23. The light reflected from each stud pin 14 is then reflected towards the camera device 11 by the other prism 3. In this way, image data M4 of the side surface of each stud pin 14, as shown in Figure 24, is obtained by the camera device 11.

[0039] More specifically, light from the upper illumination unit 12a is reflected by the reflective surface 3a of the other prism 3, and the light is irradiated from the side surface of each stud pin 14. The light is reflected by the side surface of each stud pin 14, and is further reflected by the reflective surface 3a of the other prism 3 towards the camera device 11.

[0040] The calculation unit 13 calculates and grasps the shape of the stud pin 14 based on at least one of the side profile image data M3 and the side profile image data M4, in addition to the bottom profile image data M1 and the top surface image data M2. That is, the three-dimensional shape of the stud pin 14 is calculated using image data of at least three directions of the stud pin 14. Since only the top surface of the stud pin 14 is exposed from the tread surface 16 of the studded tire 18, it is generally sufficient to determine the outline of the side shape of the stud pin 14. Since the side profile image data M3, which does not contain unnecessary information, is suitable for grasping the outline of the side shape of the stud pin 14, it is preferable to calculate and grasp the shape of each stud pin 14 based on the bottom profile image data M1, the top surface image data M2 and the side profile image data M3.

[0041] Next, the calculation unit 13 judges whether the grasped shape of the stud pin 14 satisfies a preset tolerance range for a reference shape. For example, it judges whether the height of the body portion 14a and the bottom portion 14b, the outer edge shape (the distance between opposing outer edges and the arrangement, etc.), the height of the tip 14c, the outer edge shape (the distance between opposing outer edges and the arrangement, etc.), the amount of misalignment, etc. are within the tolerance range for the reference values. If all of the reference values ​​are within the tolerance range, the stud pin 14 is judged to be a good stud pin, and otherwise the stud pin 14 is judged to be a defective stud pin.

[0042] According to the inspection jig 1 and the stud pin inspection method using this inspection jig 1 described above, by arranging a large number of stud pins 14 in an upright position on a transparent plate 4 placed between a number of prisms 3 arranged in parallel on the inspection stage 12, it is possible to obtain image data M1 of the bottom contour, image data M2 of the top surface, image data M3 of the side contour and image data M4 of the side of each stud pin 14 by the camera device 11. In other words, image data can be quickly obtained from three orthogonal directions of the stud pin 14, which has a complex shape. Moreover, image data of a large number of stud pins 14 can be obtained at one time.

[0043] Then, by performing calculations using the calculation unit 13 based on at least one of the image data M3 of the side profile or the image data M4 of the side in addition to the image data M1 of the bottom profile and the image data M2 of the top surface, the shape of each stud pin 14 can be grasped quickly and accurately. This is advantageous for accurately and quickly grasping the shapes of a large number of stud pins 14. Accordingly, it can be determined quickly and accurately whether the shape of each stud pin 14 satisfies the tolerance range of a preset reference shape.

[0044] The inspection jig 1 in this embodiment is equipped with an alignment plate 7, but if the alignment plate 7 is not equipped, the positioning guide 6 will also be unnecessary. If the alignment plate 7 is not used, the stud pins 14 are arranged in an upright state directly on the transparent plate 4 between the prisms 3. However, since arranging the stud pins 14 in an upright state directly on the transparent plate 4 requires a considerable amount of effort, by using the alignment plate 7 as in this embodiment, a large number of stud pins 14 can be quickly arranged in an upright state.

[0045] It is preferable to arrange three or more prisms 3 in parallel as in this embodiment. When three or more prisms 3 are arranged in parallel, the prisms 3 other than the prisms 3 arranged in parallel on the outermost side can be used more effectively. Specifically, if the prism 3 on the left side shown in Fig. 21 is a prism other than the prisms 3 arranged in parallel on the outermost side, it can be used when acquiring image data M3 of the side profile of the stud pin 14 arranged to the right of this prism 3, as shown in Fig. 21. This prism 3 can also be used when acquiring image data M4 of the side of the stud pin 14 arranged to the left of this prism 3, as shown in Fig. 23.

[0046] As described above, if each prism 3 is placed on one transparent plate 4 and the transparent plate 4 is arranged between each prism 3, the configuration of the inspection jig 1 can be simplified. On the other hand, as illustrated in FIG. 16 of this embodiment, if each prism 3 is not placed on the transparent plate 4 but the transparent plate 4 is arranged between each prism 3, the bottom surface of the stud pin 14 placed on each transparent plate 4 will be higher than the lower surface of the prism 3. This makes the position of the bottom surface of the stud pin 14 clear in the image data M3 of the side profile and the image data M4 of the side. That is, the boundary between the bottom surface of the stud pin 14 and the upper surface of the transparent plate 4 becomes clear in the image data M3 of the side profile and the image data M4 of the side. If the position of the bottom surface of the stud pin 14 is clear, there is an advantage that the shape of the stud pin 14 can be calculated with high accuracy easily based on the bottom surface.

[0047] 25, the arrangement plate 7 can also be designed so that the top surface of each prism hole 8b is blocked. That is, each prism hole 8b is not a through hole that passes vertically through the arrangement plate 7, but is open only downward. Use of this arrangement plate 7 is even more advantageous in avoiding the problem of the stud pins 14 coming into contact with the prisms 3 and damaging the prisms 3 when inserting the stud pins 14 into each pin hole 8a.

[0048] Next, an example of a procedure for manufacturing a studded tire will be described.

[0049] A base tire 15 as shown in Fig. 26 is manufactured by a known method. A large number of installation holes 17 are formed in the tread surface 16 of this base tire 15. Stud pins 14 are driven into each installation hole 17 by a known driving device. Note that arrow C in Figs. 26 and 27 indicates the circumferential direction of the studded tire 18 (base tire 15) to be manufactured.

[0050] Here, stud pins 14 that are determined to satisfy the preset tolerance range of the reference shape (good stud pins 14) are selected by the above-mentioned inspection method for the stud pins 14. These selected stud pins 14 are driven into the respective installation holes 17.

[0051] As shown in Figure 27, once the stud pin 14 has been driven in, the bottom portion 14b is embedded in the installation hole 17, the top surface of the body portion 14a is exposed on the tread surface 16, and the tip 14c protrudes outward from the tread surface 16. A studded tire 18 of desired specifications is manufactured by driving stud pins 14 of preset specifications into each installation hole 17 in a preset driving state. Each stud pin 14 used in a studded tire 18 is a non-defective product and will therefore exhibit the set performance. This is therefore advantageous in ensuring the desired tire performance. [Explanation of symbols]

[0052] 1 Inspection fixture 2 Retaining Plate 3. Prism 3a Reflective surface 3b Transparent surface 4 Transparent plate 5 Presser section 6 Positioning guide 7 Array Plate 8a Pin hole 8b Prism hole 9 Positioning part 10 Inspection Equipment 11 Camera equipment 12 Inspection Stage 12a, 12b Upper lighting section 12c Lower lighting section 13 Arithmetic section 14 Stud pin 14a Body 14b Bottom section 14c Chip 15 Base tire 16 Tread surface 17 Installation hole 18 Studded tires

Claims

1. An inspection jig for stud pins for use in an inspection device comprising an inspection stage on which an object to be inspected is placed, a camera device arranged above the inspection stage, a calculation unit to which image data of the object to be inspected acquired by the camera device is input, an upper illumination unit arranged above the inspection stage, and a lower illumination unit arranged below the inspection stage, wherein the shape of the object to be inspected is grasped based on the image data input to the calculation unit, and it is determined whether the grasped shape of the object to be inspected satisfies a tolerance range of a preset reference shape, The inspection stage includes a plurality of triangular prisms arranged in parallel, and transparent plates arranged between the prisms, As the inspection object, a number of stud pins are arranged in an upright state on the transparent plate, light is irradiated from a bottom surface side of each of the stud pins by the downward illumination unit, and image data of a bottom surface contour of each of the stud pins is acquired by the camera device; light is irradiated from a side of each of the stud pins by the downward illumination unit through one of the prisms adjacent to each of the stud pins, the light is reflected by the other prism adjacent to each of the stud pins towards the camera device, and image data of the side contour of each of the stud pins is acquired by the camera device; light is irradiated onto an upper surface of each of the stud pins by the upward illumination unit, and image data of the upper surface of each of the stud pins is acquired by the camera device; A stud pin inspection jig in which light is irradiated from the side of each of the stud pins through the other prism adjacent to each of the stud pins by the upward lighting unit, and the light reflected from each of the stud pins is reflected by the other prism toward the camera device, so that image data of the side of each of the stud pins is acquired by the camera device.

2. an arrangement plate having a large number of pin holes into which the stud pins are inserted one by one and having prism holes corresponding to the prisms; and a positioning guide for positioning the arrangement plate at a predetermined position on the inspection stage, 2. A stud pin inspection jig as described in claim 1, wherein when the alignment plate is placed on the inspection stage using the positioning guide, each of the pin holes is positioned above the transparent plate between each of the prisms, and each of the prism holes is positioned above a corresponding prism without contacting the prism.

3. 3. A stud pin inspection jig as described in claim 2, wherein the position of the upper surface of the alignment plate when the alignment plate is placed on the inspection stage using the positioning guide is set at a position higher than the apex of each of the prisms.

4. 4. A stud pin inspection jig as claimed in claim 3, wherein the upper surface of each of said prism holes is blocked.

5. A method for inspecting stud pins using inspection equipment, comprising the steps of: placing an object to be inspected on an inspection stage having an upper illumination unit above and a lower illumination unit below, inputting image data of the object to be inspected acquired by a camera device arranged above the inspection stage into a calculation unit, grasping the shape of the object to be inspected based on the image data inputted to the calculation unit, and judging whether or not the grasped shape of the object to be inspected satisfies a tolerance range of a preset reference shape, A plurality of triangular prisms are arranged in parallel on the inspection stage, a transparent plate is placed between each of the prisms, and a number of stud pins are arranged in an upright state on the transparent plate as the inspection objects; using the downward illumination unit to irradiate light from the bottom side of each of the stud pins, and acquiring image data of the bottom contour of each of the stud pins using the camera device; said downward illumination unit irradiates light from the side of each of said stud pins through one of said prisms adjacent to each of said stud pins, and the light is reflected by the other of said prisms adjacent to each of said stud pins towards said camera device, thereby obtaining image data of the side contour of each of said stud pins by said camera device; said upper illumination unit irradiates light onto an upper surface of each of said stud pins, and said camera device acquires image data of the upper surface of each of said stud pins; said upper illumination unit irradiates light from the side of each of said stud pins through the other of said prisms adjacent to each of said stud pins, and the light reflected from each of said stud pins is reflected by the other of said prisms towards said camera device, thereby acquiring image data of the side surface of each of said stud pins by said camera device; A stud pin inspection method in which the shape of the object to be inspected is grasped based on image data of the bottom surface contour and image data of the top surface, as well as image data of at least one of the side surface contour image data and the side surface image data.

6. A method for manufacturing a studded tire by driving stud pins into respective installation holes formed in the tread surface of a base tire, comprising the steps of: A method for manufacturing a studded tire, comprising the steps of: selecting the stud pins that are determined to satisfy a preset tolerance range for the reference shape by the stud pin inspection method according to claim 5; and driving the selected stud pins into the respective installation holes.

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