JP4537624B2 - Tread ring joint amount verification method and verification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a tread ring joint amount test method and a test apparatus for testing a joint amount when a cut surface of a tread rubber sheet cut into a predetermined size is brought into contact with each other to form an annular tread ring.
[0002]
[Prior art]
In the tire manufacturing process, as shown in FIG. 8A, an annular tread ring is formed by winding a tread rubber sheet a cut to a certain size on a forming drum and jointing the cut surfaces a1 and a2 with each other. Is forming. At this time, in order to increase the joining strength at the joint portion j, both ends of the tread rubber sheet a are cut in a sword-like shape in a vertical plane in the length direction.
[0003]
However, even in such a case, for example, when the joint amount is insufficient due to the length variation of the tread rubber sheet a (shown in FIG. 8B), the thickness and the joint area at the joint portion j are reduced. A sufficient strength cannot be secured. On the contrary, when the joint amount is excessive (shown in FIG. 8C), the thickness at the joint portion j is locally increased, which is disadvantageous for uniformity.
[0004]
Therefore, in order to determine whether or not the joint amount is appropriate, conventionally, for example, a method of measuring an uneven state on the surface of the joint portion j using a laser displacement meter or the like has been employed.
[0005]
[Problems to be solved by the invention]
However, this method has a problem that since the unevenness variation is small, the measurement error increases, and as a result, the determination accuracy and reliability of the joint amount cannot be sufficiently secured.
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a tread ring joint amount test method and a test apparatus that have a simple configuration and that can accurately and reliably determine the joint amount.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the first invention according to claim 1 is characterized in that a rubber sheet piece of a fixed size obtained by cutting a strip-shaped tread rubber sheet continuously extruded from an extruder is wound on a molding drum, and A tread ring joint amount test method for verifying a joint amount of tread rings that are jointed by matching cut surfaces.
The strip-shaped tread rubber sheet extruded from the extruder is wound on a molding drum with a piece of a rubber sheet that is cut in a slanted manner in a vertical plane in the length direction, and both cut surfaces are formed. While forming a tread ring by butting together,
Along with the cutting, a first cutting mark Ma separating the length A from the upper end of the cut surface on the tread rubber sheet on the extruder side to be cut, and a length from the upper end of the cut surface to the rubber sheet piece to be cut With a second cutting mark Mb separating the distance B,
Measure the circumferential length C between the first and second cutting marks Ma ′, Mb ′ in the tread ring,
In addition, a non-defective product is determined when the difference S−C between the reference length S determined by the distances A and B and the length C is within a specified range.
[0008]
A second invention according to claim 5 is a tread ring joint amount testing device,
A cutting device that inclines and cuts a strip-shaped tread rubber sheet extruded from the extruder in a vertical plane in the length direction, and rolls a piece of the cut rubber sheet and butts the cut surfaces together. And a forming drum that forms a tread ring by jointing,
Along with the cutting, a first cutting mark Ma separating the length A from the upper end of the cut surface to the tread rubber sheet on the extruder side to be cut, and a distance B from the upper end of the cutting surface to the side of the rubber sheet to be cut. Marking means for attaching the second cutting mark Mb;
Measuring means for measuring a circumferential length C between the first and second cut marks Ma ′ and Mb ′ in the tread ring;
It is characterized in that there is provided a judging means for judging a non-defective product when the difference S−C between the reference length S determined by the distances A and B and the length C is within a specified range.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the tread ring joint amount test method according to the first invention of the present application will be described together with an embodiment of the tread ring joint amount test apparatus according to the second invention, using an example shown in the drawings.
[0010]
In FIG. 1, a tread ring joint amount verification device 1 (hereinafter referred to as a verification device 1) includes a cutting device 3 that cuts a belt-like tread rubber sheet G extruded from an extruder 2, and a rubber sheet that is cut in a fixed size. A forming drum 4 for winding a piece GA to form a tread ring GB, a marking means 5 for attaching the first and second cutting marks Ma and Mb to the tread rubber sheet G together with the cutting, and the above-described tread ring GB Measuring means 6 for measuring a circumferential length C between the first and second cutting marks Ma, Mb.
[0011]
In the present embodiment, the extruder 2 has a known structure in which a head 2A is provided at the front end of a screw-type extruder main body and is continuously extruded by molding rubber into a predetermined cross-sectional shape. The
[0012]
The tread rubber sheet G from the extruder 2 is supplied to the molding drum 4 through the accumulator 10 and the servicer 11.
[0013]
The accumulator 10 has a storage portion 10A that suspends the tread rubber sheet G from the extruder 2 in a U shape and temporarily stores it. As is well known, the storage unit 10A absorbs the difference between the movement (including speed and timing) of the tread rubber sheet G on the upstream side and the movement on the downstream side, and achieves a smooth operation. For example, FIGS. 6A to 6E show changes in the storage amount.
[0014]
Next, the servicer 11 is arranged so as to be freely connected to the first conveyor unit 11A for receiving and transporting the tread rubber sheet G from the accumulator 10, and to the first conveyor unit 11A via the cutting device 3. It is formed from a second conveyor portion 11B that conveys and affixes the rubber sheet piece GA cut to a predetermined size to the molding drum 4.
[0015]
11 A of said 1st conveyors are belt conveyors, Comprising: It is controlled by the control means which intermittently feeds the tread rubber sheet G for every predetermined length. In this example, the first conveyor unit 11A includes detection means such as detecting the number of rotations of the drive motor m1 with an encoder or detecting the number of rotations of a roller that rolls in contact with the conveyor belt. Thus, the feed length L1 of the tread rubber sheet G from the first conveyor portion 11A to the second conveyor portion 11B, that is, the feed at which the tread rubber sheet G is sent from the upstream side to the downstream side of the cutting device 3 The length L1 is measured.
[0016]
The second conveyor unit 11B includes a conveyor body 13 that is pivotally supported at a pivot point K on the gantry 12 and can be tilted up and down around the pivot point K. The conveyor body 13 is formed of a belt conveyor and is connected to the upper end of a rod of a cylinder 15 that is attached to, for example, a side surface of the gantry 12. It tilts between a position and a position where it waits away from the molding drum 4.
[0017]
And the said cutting device 3 and the marking means 5 are provided in the transfer position between the said 1st, 2nd conveyor parts 11A and 11B.
[0018]
2, the cutting device 3 includes a traveling table 16 that is movable in the width direction above the tread rubber sheet G, and an ultrasonic cutter 17 that is attached to the lower surface of the traveling table 16 and moves together with the traveling table 16. With In this example, the traveling platform 16 includes a screw hole 16A that is screwed into a screw shaft 19A that is horizontally installed, and a guide hole 16B that is guided by a guide shaft 19B that is parallel to the screw shaft 19A. The traveling table 16 can reciprocate in the width direction by the rotation operation of the screw shaft 19A by the drive motor m2.
[0019]
The ultrasonic cutter 17 has a well-known structure, and cuts the tread rubber sheet G in a sword tip shape at a cutting position between the conveyor portions 11A and 11B. The tilt angle can be adjusted.
[0020]
In addition, the marking means 5 includes first and second cutting marks Ma which are marks respectively on the tread rubber sheet G on the side of the extruder 2 to be cut and the rubber sheet piece GA to be cut. , Mb. Here, the “with cutting” may be not only during cutting but also before or after cutting as long as the conveyor parts 11A and 11B are stopped for cutting. However, after cutting, the front end of the tread rubber sheet G and the rear end of the rubber sheet piece GA become free ends and easily deform, so the marking becomes unclear or the marking accuracy is easily lost. During cutting or before cutting is preferred.
[0021]
Further, as shown in FIG. 7A, the first cutting mark Ma is formed on the tread rubber sheet G at a position separated from the upper end of the cutting surface GS by a distance A in the length direction, and the second cutting mark Mb. Is formed in the rubber sheet piece GA at a position separating the distance B from the upper end of the cut surface GS in the length direction. Since the first and second cutting marks Ma and Mb are marks, for example, printing or spraying with ink may be used. However, in order to simplify the apparatus, the first and second cutting marks Ma and Mb may be surface depressions or cuts caused by pressing. May be. Also, as shown in FIG. 3, various mark shapes such as a dot shape (single or plural) or a linear shape can be adopted.
[0022]
In this example, the case where the 1st and 2nd cutting marks Ma and Mb are the dot-shaped dents provided in the rubber | gum surface is illustrated. For this purpose, the marking means 5 includes punch-like markers 21a and 21b in this example for forming marks on a base 20 that can be moved forward and backward toward the surface of the tread rubber sheet G, and a sharp tip at the tread rubber sheet. It is attached toward the G surface. In addition, the said base 20 is attached to the rod end of advance / retreat tools, such as the cylinder 21, for example.
[0023]
Here, as shown in FIG. 4, when the thickness of the tread rubber sheet G changes from t1 to t2, the position of the upper end of the cut surface GS also changes. Accordingly, in order to avoid the influence on the distances A and B due to the thickness change, the markers 21a and 21b are preferably inclined at the same angle as the ultrasonic cutter 17, but the profile of the tread rubber sheet G surface is complicated. In this case, it is preferable to advance and retract the markers 21a and 21b substantially at right angles to the tread rubber sheet G as in this example in order to eliminate the influence of the profile.
[0024]
Next, the measuring means 6 measures the circumferential length C between the first and second cut marks Ma ′ and Mb ′ in the tread ring GB wound on the forming drum 4.
As this measuring means 6, in this example, as shown in FIG. 5, a CCD camera 22 for photographing the joint portion J including the first and second cutting marks Ma ′ and Mb ′, and the CCD camera 22 are sent. The thing provided with the image processing means 23 which processes the image data which comes is illustrated.
[0025]
The CCD camera 22 is attached to a lifting / lowering base 24B of a lifting / lowering tool 24 using, for example, a ball screw mechanism 24A, and photographs the joint portion J from above at a substantially right angle. The elevator 24B is provided with illumination 25 such as a fluorescent lamp before and after the CCD camera 22.
[0026]
The image processing means 23 recognizes the first and second cut marks Ma ′ and Mb ′ in the image, and measures the number of pixels between the first and second cut marks Ma ′ and Mb ′. Then, the circumferential length C is calculated by converting the number of pixels into a distance. Strictly speaking, the circumferential length C needs to be measured by an arc along the outer surface of the tread ring GB. However, the circumferential length C is smaller than the radius of the tread ring GB. It can be approximated by being sufficiently small. Therefore, in this example, the sum A + B of the distances is in the range of 30 to 50 mm.
[0027]
The first and second cut marks Ma ′ and Mb ′ can be recognized by so-called pattern matching in which a pattern in an image is automatically recognized by comparison with a registered mark shape. At this time, in order to surely distinguish the cut marks Ma and Mb from the patterns on the surface of the tread rubber sheet G, it is preferable to use a special mark shape such as a + character.
[0028]
In this embodiment, the determination means for determining a non-defective product when the length C measured by the measurement means 6 and the reference length S and the difference S−C determined by the distances A and B are within a specified range. 7 is provided.
[0029]
Here, if the length of the rubber sheet piece GA does not vary substantially until it is wound on the molding drum 4, the reference length S is determined as the sum of the distances A + B. Can do.
[0030]
However, in reality, after cutting, due to extrusion distortion, the rubber sheet piece GA may shrink (shrink) on the second conveyor portion 11B, and the length may vary. In such a case, before winding the drum, the length L2 of the rubber sheet piece GA is measured on the second conveyor portion 11B by the measuring means 9 (shown in FIG. 1), and the length L2 and the first The reference length S is determined as the following expression (1) from the feed length L1 from one conveyor section 11A.
S = (A + B) × (L2 / L1) --- (1)
When the rubber sheet piece GA is attached to the molding drum 4, the second conveyor unit 11B and the molding drum 4 are controlled in synchronization, that is, the entire operation such as the driving speed and timing is controlled in synchronization. The length variation does not substantially occur.
[0031]
As the measurement means 9, the front end (downstream side end) and the rear end (upstream side end) of the rubber sheet piece GA waiting on the second conveyor unit 11B are photographed, and the length L2 is determined from the image. Those having a CCD camera and image processing means for measurement can be suitably employed.
[0032]
In the present embodiment, the determination means 7 determines that the joint amount is appropriate and the tread ring GB is non-defective when the difference SC is within a specified range of 0 to 3.0 mm. . However, the specified range can be set according to the thickness and length of the tread rubber sheet G, the sword tip angle at the time of cutting, or the specified range can be set as a relative length with respect to the length L1 or the like. Good.
[0033]
In the present embodiment, the determination means 7 increases the value L1 when the difference S-C is larger than the specified range, and conversely when the difference S-C is smaller than the range, the value L1 is increased. A control device 7A (shown in FIG. 1) that performs feedback control to be reduced is included. In other words, the determination means 7 reflects the result of the failure determination in the next or subsequent cuts, and adjusts the cut length to greatly reduce the incidence of defective joint products that require rework. Can do.
[0034]
The control device 7A controls the drive motor m1 of the first conveyor unit 11A and adjusts the feed length L1 from the conveyor unit 11A.
[0035]
Thus, in the present embodiment, the first and second cutting marks Ma and Mb are attached at the time of cutting, the length between the cutting marks Ma and Mb at that time (ie, A + B), and the first and second measured after the joint. Since only the length C between the cutting marks Ma ′ and Mb ′ is compared, a numerical value calculation process can be easily performed. Further, the lengths A + B, C, etc. can be easily measured, and the joint amount can be accurately represented, so that the determination of the joint amount can be performed with high accuracy and high reliability. In addition, since the configuration is simple, an increase in apparatus cost can be suppressed. In addition, since the feedback of the determination result is easy, the occurrence rate of joint failure can be greatly reduced.
[0036]
As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.
[0037]
【The invention's effect】
Since the present invention is configured as described above, the determination of the joint amount can be performed with high accuracy and high reliability. In addition, since the configuration is simple, an increase in apparatus cost can be suppressed to a low level, and the determination result can be easily fed back, so that the joint failure rate can be greatly reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a tread ring joint amount verification apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing a main part of the cutting device together with marking means.
FIGS. 3A and 3B are plan views illustrating cutting marks. FIGS.
FIG. 4 is a schematic diagram showing another example of marking means.
FIG. 5 is a side view showing an example of measuring means.
6A to 6E are diagrams schematically illustrating the flow of a tread rubber sheet.
FIG. 7 is a diagram illustrating determination means.
FIGS. 8A to 8C are diagrams illustrating the problems of the prior art.
[Explanation of symbols]
2 Extruder 3 Cutting device 4 Molding drum 5 Marking means 6 Measuring means 7 Judging means 7A Control device G Tread rubber sheet GA Rubber sheet piece GB Tread ring GS Cut surface

Claims (7)

A tread ring that tests the joint amount of a tread ring that is obtained by winding a piece of a sized rubber sheet cut from a belt-like tread rubber sheet that is continuously extruded from an extruder, on a molding drum, and joining the cut surfaces to each other. The joint amount test method of
The strip-shaped tread rubber sheet extruded from the extruder is wound on a molding drum with a piece of a rubber sheet that is cut in a slanted manner in a vertical plane in the length direction, and both cut surfaces are formed. While forming a tread ring by butting together,
Along with the cutting, a first cutting mark Ma separating the length A from the upper end of the cut surface on the tread rubber sheet on the extruder side to be cut, and a length from the upper end of the cut surface to the rubber sheet piece to be cut With a second cutting mark Mb separating the distance B,
Measure the circumferential length C between the first and second cutting marks Ma ′, Mb ′ in the tread ring,
A tread ring joint amount verification method, wherein a non-defective product is determined when a difference S-C between a reference length S determined by the distances A and B and the length C is within a specified range. The tread ring joint amount test method according to claim 1, wherein the specified range is 0 to 3.0 mm. 3. The tread ring joint amount test method according to claim 1, wherein the reference length S is A + B. The reference length S is determined by measuring the feed length at which the tread rubber sheet is fed from the upstream side to the downstream side of the cutting device at the time of cutting, the value being L1, and the value of the rubber sheet piece measured before drum winding being L2. When
S = (A + B) × (L2 / L1)
The tread ring joint amount testing method according to claim 1, wherein the tread ring joint amount is testing. A tread ring that tests the joint amount of a tread ring that is obtained by winding a piece of a sized rubber sheet cut from a belt-like tread rubber sheet that is continuously extruded from an extruder, on a molding drum, and joining the cut surfaces to each other. The joint amount testing device of
A cutting device that inclines and cuts a strip-shaped tread rubber sheet extruded from the extruder in a vertical plane in the length direction, and rolls a piece of the cut rubber sheet and butts the cut surfaces together. And a forming drum that forms a tread ring by jointing,
Along with the cutting, the first cut mark Ma separating the length A from the upper end of the cut surface to the tread rubber sheet on the extruder side to be cut, and the distance B from the upper end of the cut surface to one side of the rubber sheet to be cut. Marking means for attaching the second cutting mark Mb;
Measuring means for measuring a circumferential length C between the first and second cut marks Ma ′ and Mb ′ in the tread ring;
A tread ring joint amount characterized by comprising a judging means for judging a non-defective product when a difference S-C between the reference length S determined by the distances A and B and the length C is within a specified range. Test device. The reference length S is assumed to be A + B, or the feed length of the tread rubber sheet sent from the upstream side to the downstream side of the cutting device at the time of cutting is measured, and the value is measured before L1 and drum winding. When the value of the rubber sheet piece is L2,
S = (A + B) × (L2 / L1)
The tread ring joint amount test apparatus according to claim 5, wherein The determination means includes a control device that performs feedback control to increase the value L1 when the difference S−C is larger than the specified range and to decrease the value L1 when the difference SC is smaller than the range. The tread ring joint amount test apparatus according to claim 6, further comprising:

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