JP2003011245A - Method for detecting degree of joint of tread ring and inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out the judgement of a degree of joint of a tread ring with high precision and reliability. SOLUTION: A tread ring is formed by winding rubber sheet pieces obtained by cutting a tread rubber sheet on a molding drum and joining the rubber sheet pieces together. Further, a first cut mark Ma which is remote by a distance A from the upper end of a cut area is put on the tread rubber sheet of the extruder side, and a second cut mark Mb which is way off by a distance B is put on the rubber sheet piece side, following a cutting operation. A length C in the peripheral direction between the first and the second cut mark Ma and Mb on the tread ring is measured. Then when the difference S-C between a reference length S set by the distances A and B and the length C falls within a specified range, the molded tread ring is judged as a conforming article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tread ring joint amount test method for testing the joint amount when the cut surfaces of tread rubber sheets that have been cut into a constant size are butted against each other and jointed to form an annular tread ring,
And the verification device.

[0002]

2. Description of the Related Art In a tire manufacturing process, as shown in FIG. 8 (A), a tread rubber sheet a, which has been cut to a certain size, is wound around a molding drum, and cut surfaces a1 and a2 thereof are butted against each other and joined. To form an annular tread ring. At this time, both ends of the tread rubber sheet a are cut so as to be inclined like a sword in a vertical plane in the longitudinal direction in order to increase the joint strength at the joint j.

However, even in such a case, when the joint amount is insufficient due to the variation in the length of the tread rubber sheet a (shown in FIG. 8 (B)), the thickness and joint at the joint j It will not be possible to secure sufficient strength such as the area being reduced. On the contrary, when the joint amount is excessive (shown in FIG. 8C), the thickness at the joint j is locally increased, which is disadvantageous to the uniformity.

Therefore, in order to determine whether or not this joint amount is appropriate, a method of measuring the unevenness of the surface of the joint j using a laser displacement meter or the like has been conventionally used.

[0005]

However, this method has a problem that the fluctuation of the unevenness is small and thus the measurement error is large, and as a result, the accuracy and reliability of the determination of the joint amount cannot be sufficiently secured. .

Therefore, an object of the present invention is to provide a tread ring joint amount verification method and a verification device, which have a simple structure and can judge the joint amount with high accuracy and reliability.

[0007]

In order to achieve the above-mentioned object, the first aspect of the present invention, which is claim 1, is a rubber sheet piece of a fixed size obtained by cutting a strip-shaped tread rubber sheet continuously extruded from an extruder. Is a joint amount verification method of a tread ring which is wound on a molding drum and which tests the joint amount of tread rings jointed by abutting cut surfaces against each other, wherein a belt-shaped tread rubber sheet extruded from the extruder is cut. By the device, a tread ring is formed by winding a fixed-size slicing rubber sheet piece inclined and cut in a vertical plane in the length direction on a forming drum, and forming a tread ring by abutting both cut surfaces and joining them. At the same time as the cutting, a first cutting mar that separates a distance A in the length direction from the upper end of the cutting surface on the tread rubber sheet on the extruder side to be cut. Ma and a second cutting mark Mb which is separated from the upper end of the cutting surface by a distance B in the length direction from the upper end of the cutting surface, and the first and second cutting marks Ma ′, Mb ′ on the tread ring are provided. It is characterized in that the circumferential length C between them is measured, and when the difference SC between the reference length S determined by the distances A and B and the length C is within a specified range, it is judged as a non-defective product. There is.

A second aspect of the present invention is a joint amount verification device for a tread ring, wherein a belt-shaped tread rubber sheet extruded from the extruder is tilted in a vertical plane in the longitudinal direction. A cutting device for slicing and a molding drum for forming a tread ring by winding a piece of rubber sheet of a fixed size and jointing the cut surfaces with each other are sewn together with the cutting. The tread rubber sheet on the extruder side has a first cutting mark Ma that is separated from the upper end of the cutting surface by a distance A in the length direction, and a second cutting mark Mb that is separated from the upper end of the cutting surface by a distance B on one side of the rubber sheet to be cut. And a first marking mark M on the tread ring.
measuring means for measuring the circumferential length C between a'and Mb ',
The reference length S determined by the distances A and B and the length C
And a determination means for determining a non-defective product when the difference S-C from the specified range is within a specified range.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a tread ring joint amount test method, which is the first invention of the present application, will be described below.
A tread ring joint amount verification device according to a second aspect of the present invention will be described with reference to an illustrated example together with an embodiment.

In FIG. 1, a tread ring joint amount verification device 1 (hereinafter referred to as a verification device 1) comprises a cutting device 3 for cutting a strip-shaped tread rubber sheet G extruded from an extruder 2 and a constant cutting device. A molding drum 4 for winding the rubber sheet piece GA to form a tread ring GB,
Marking means 5 for attaching first and second cutting marks Ma, Mb to the tread rubber sheet G along with the cutting, and a circumferential length C between the first and second cutting marks Ma, Mb in the tread ring GB. And a measuring means 6 for measuring

In the present embodiment, the extruder 2 has a well-known structure in which a screw type extruder main body is provided at the front end thereof with a head 2A for molding rubber into a predetermined sectional shape and continuously extruding it. Is used.

Further, the tread rubber sheet G from the extruder 2 is constructed so as to be supplied to the forming drum 4 through the accumulator 10 and the servicer 11.

The accumulator 10 has a storage portion 10A for suspending the tread rubber sheet G from the extruder 2 in a U shape and temporarily storing it. As is well known, the storage section 10A absorbs a 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 to achieve a smooth operation. For example, FIGS. 6A to 6E show changes in the storage amount.

Next, the servicer 11 receives the tread rubber sheet G from the accumulator 10 and conveys it to the first conveyor portion 11A via the cutting device 3 so as to be freely connectable to the first conveyor portion 11A. And a second conveyor section 11B which conveys and affixes the cut and cut rubber sheet pieces GA to the forming drum 4.

The first conveyor section 11A is a belt conveyor, and is controlled by a control means for intermittently feeding the tread rubber sheet G every predetermined length. This first
In this example, the conveyor section 11A of the
The number of rotations of 1 is detected by an encoder, or the number of rotations of a roller that rolls in contact with a conveyor belt is detected by an encoder, whereby the first conveyor section 11A to the second conveyor section are provided. The feeding length L1 of the tread rubber sheet G to 11B is
The feed length L1 at which the tread rubber sheet G is fed from the upstream side to the downstream side of the cutting device 3 is measured.

Further, the second conveyor section 11B includes a gantry 1
The upstream end is pivotally supported at a pivot point K on the upper end of the conveyor 2, and a conveyor main body 13 that can tilt up and down around the pivot point K is provided. The conveyor main body 13 is composed of a belt conveyor, and is connected to the upper end of a rod of a cylinder 15 attached to, for example, a side surface of the gantry 12. By the expansion / contraction operation of the rod, the tip approaches the molding drum 4 and the rubber sheet piece GA is attached. It tilts between a position and a position where it stands apart from the molding drum 4.

Then, the first and second conveyor sections 11
At the connecting position between A and 11B, the cutting device 3 and
Marking means 5 is provided.

As shown in the enlarged view of FIG. 2, the cutting device 3 has a traveling base 16 which is movable in the width direction above the tread rubber sheet G, and an ultrasonic wave which moves integrally with the mounting traveling base 16 on the lower surface thereof. It includes a cutter 17. In the present example, the traveling table 16 includes a screw hole 16A screwed into a horizontally extending screw shaft 19A, and a guide hole 16B guided by a guide shaft 19B parallel to the screw shaft 19A.
Then, the traveling base 16 can reciprocate in the width direction by the rotation operation of the screw shaft 19A by the drive motor m2.

Further, the ultrasonic cutter 17 has a well-known structure, and cuts the tread rubber sheet G at a cutting position between the conveyor portions 11A and 11B while inclining it in a sword-like shape. The tilt angle can be adjusted.

The marking means 5 cuts the tread rubber sheet G on the side of the extruder 2 which is cut along with cutting.
The first and second cutting marks Ma and Mb, which are marks, are formed on the rubber sheet piece GA to be cut. Here, “with cutting” may mean 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 are easily deformed, so that marking becomes unclear or marking accuracy is easily impaired. During cutting or before cutting is preferable.

As shown in FIG. 7A, the first cut mark Ma is formed on the tread rubber sheet G at a position separated from the upper end of the cut surface GS by a distance A in the lengthwise direction.
The second cut mark Mb is formed on the rubber sheet piece GA at a position separated from the upper end of the cut surface GS by a distance B in the length direction. Since the first and second cutting marks Ma and Mb are marks, they may be printed or sprayed with ink, for example. However, for the sake of simplifying the device, they are dents or cuts on the surface caused by pressing. May be. As for the shape of the mark, as shown in FIG. 3, various shapes such as a dot shape (may be single or plural) or a linear shape can be adopted.

In this example, the first and second cutting marks Ma,
The case where Mb is a dot-shaped recess formed on the rubber surface is illustrated. To that end, the marking means 5
Base 2 that can move back and forth toward the surface of the tread rubber sheet G
0, a punch-shaped marker 21 in this example for mark formation
a and 21b, the sharp tip of which is tread rubber sheet G
It is attached toward the surface. The base 20 is attached to the rod end of an advancing / retreating tool such as a cylinder 21.

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. Therefore, in order to avoid the influence of the thickness change on the distances A and B, the marker 21
It is preferable to incline a and 21b at the same angle as the ultrasonic cutter 17, but when the profile of the surface of the tread rubber sheet G is complicated, as in this example, the markers 21a and 2b are used.
It is preferable to move 1b forward and backward substantially at right angles to the tread rubber sheet G in order to eliminate the influence of the profile.

Next, the measuring means 6 includes the first and second parts of the tread ring GB wound on the forming drum 4.
The circumferential length C between the cutting marks Ma ′ and Mb ′ of is measured. As the 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 ′, Mb ′, and the CCD
An example including an image processing unit 23 for processing image data sent from the camera 22 will be exemplified.

The CCD camera 22 is attached to a lift table 24B of a lift tool 24 using, for example, a ball screw mechanism 24A and the joint portion J is photographed from above at a substantially right angle. The elevator table 24B is provided with illuminations 25 such as fluorescent lamps before and after the CCD camera 22.

The image processing means 23 recognizes the first and second cutting marks Ma 'and Mb' in the image and measures the number of pixels between the first and second cutting marks Ma 'and Mb'. . Then, by converting this number of pixels into a distance,
The circumferential length C is calculated. The circumferential length C
Strictly speaking, it is necessary to measure with an arc along the outer surface of the tread ring GB.
Can be approximated by being sufficiently smaller than the radius of the tread ring GB. Therefore, in this example, the sum A + B of the distances is set in the range of 30 to 50 mm.

As the recognition of the first and second cutting marks Ma 'and Mb', it is possible to detect the pattern in the image by so-called pattern matching in which the pattern is automatically recognized by comparing it with the registered mark shape. At this time, the cutting marks Ma, Mb
Is preferably a special mark shape such as a + character in order to be surely distinguished from the patterns on the surface of the tread rubber sheet G.

Further, in the present embodiment, the length C measured by the measuring means 6 and the distances A and B are further added.
When the difference between the reference length S and the difference S-C determined by the above is within a specified range, the determination means 7 is provided for determining a non-defective product.

Here, when the length of the rubber sheet piece GA does not substantially change before being wound on the molding drum 4, the reference length S is the sum of the distances A +.
It can be defined as B.

However, in practice, after cutting, the rubber sheet piece GA may shrink (shrink) on the second conveyor section 11B due to the distortion of extrusion, and the length may fluctuate. is there. In this case, the length L2 of the rubber sheet piece GA is measured by the measuring means 9 (shown in FIG. 1) on the second conveyor section 11B before winding the drum, and the length L2 and the The reference length S is determined by the following equation (1) from the length L1 of the sheet fed from the conveyor unit 11A of No. 1 S = (A + B) × (L2 / L1) --- (1) When the rubber sheet piece GA is attached to the forming drum 4, the second conveyor section 11B and the forming drum 4 are synchronously controlled, that is, Since the entire operation such as the driving speed and the timing is controlled in synchronization with each other, the length variation does not substantially occur.

As the measuring 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 section 11B are photographed, and the length is taken from the image. A device having a CCD camera for measuring the height L2 and an image processing means can be suitably adopted.

In the present embodiment, the judging means 7 judges that the joint amount is proper and the tread ring GB is a good product when the difference SC is within the specified range of 0 to 3.0 mm. Is going. However, this specified range can be set according to the thickness and length of the tread rubber sheet G, or the angle of the sword at the time of cutting, and the specified range can be set as a relative length with respect to the length L1 or the like. Good.

Further, in the present embodiment, the judging 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 is increased. Control device 7A for performing feedback control for reducing the value L1
(Shown in FIG. 1). That is, the judging means 7 reflects the judgment result of the rejection in the next or subsequent cutting and adjusts the cutting length, thereby significantly reducing the incidence of defective joints requiring repair. You can

The controller 7A controls the drive motor m1 of the first conveyor section 11A to adjust the delivery length L1 from the conveyor section 11A.

As described above, in the present embodiment, the first and second cutting marks Ma and Mb are added at the time of cutting, the length between the cutting marks Ma and Mb at that time (that is, A + B), and the first measured after the joint. Since only the length C between the cut marks Ma ′ and Mb ′ of 1 and 2 is compared, the numerical value arithmetic processing can be performed easily. Further, since the lengths A + B, C, etc. can be easily measured and the joint amount is accurately represented, the joint amount can be determined accurately and highly reliably. Further, since the structure is simple, it is possible to suppress an increase in device cost to a low level. Further, since it is easy to feed back the determination result, it is possible to significantly reduce the incidence of joint failure.

Although a particularly preferred embodiment of the present invention has been described above in detail, the present invention is not limited to the illustrated embodiment and can be modified into various modes.

[0037]

Since the present invention is constructed as described above,
The joint amount can be determined with high accuracy and reliability. Further, since the structure is simple, it is possible to suppress an increase in the cost of the apparatus to a low level, and since it is easy to feed back the determination result, it is possible to significantly reduce the occurrence rate of joint defects.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a tread ring joint amount verification device of the present invention.

FIG. 2 is a sectional view showing a main part of a cutting device together with a marking means.

FIGS. 3A and 3B are plan views illustrating cut marks.

FIG. 4 is a schematic view showing another example of the marking means.

FIG. 5 is a side view showing an example of measuring means.

6 (A) to (E) are diagrams schematically illustrating the flow of a tread rubber sheet.

FIG. 7 is a diagram illustrating a determination unit.

8A to 8C are diagrams for explaining the problems of the conventional technology.

[Explanation of symbols]

2 extruder 3 cutting device 4 molding drum 5 Marking means 6 Measuring means 7 Judgment means 7A control device G tread rubber sheet GA rubber sheet piece GB tread ring GS cut surface

Claims (7)

[Claims] Claim: What is claimed is: 1. A tread ring joint amount in which a constant-sized piece of rubber sheet obtained by cutting a strip-shaped tread rubber sheet continuously extruded from an extruder is wound on a molding drum and the cut surfaces are butted against each other. A method for certifying the joint amount of a tread ring, in which a belt-shaped tread rubber sheet extruded from the extruder is cut by a cutting device, and is cut to a predetermined length in a vertical plane in a longitudinal direction. Wind the piece on the forming drum,
A tread ring is formed by abutting and jointing both cut surfaces with each other, and at the same time as the cutting, a tread rubber sheet on the extruder side to be cut is separated from the upper end of the cut surface by a distance A in the longitudinal direction.
Cutting mark Ma and a second cutting mark M that is separated from the upper end of the cutting surface by a distance B in the length direction from the rubber sheet piece to be cut.
b, the circumferential length C between the first and second cutting marks Ma ′, Mb ′ in the tread ring is measured, and the reference length S determined by the distances A, B, and A tread ring joint amount test method, characterized in that a non-defective product is judged when the difference S-C from the length C is within a specified range. 2. 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. 4. The reference length S is a rubber sheet piece measured by measuring 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, and measuring the value L1 before winding the drum. When the value of is set to L2, it is S = (A + B) * (L2 / L1), The joint amount test method of the tread ring in any one of Claims 1-3 characterized by the above-mentioned. 5. A joint amount of a tread ring formed by winding a constant-sized piece of rubber sheet obtained by cutting a belt-shaped tread rubber sheet continuously extruded from an extruder, and winding the piece on a molding drum and abutting the cut surfaces against each other. Is a joint amount verification device of the tread ring for verifying, a cutting device for inclining the belt-shaped tread rubber sheet extruded from the extruder in a vertical plane in the longitudinal direction and sizing, A cutting drum is formed by winding a piece of rubber sheet and forming a tread ring by joining both cut surfaces to each other by abutting the cut surfaces, and at the same time as the cutting, the tread rubber sheet on the extruder side to be cut has a cut surface upper end. First distance A from the distance A
Marking mark Ma, and a marking means for marking one side of the rubber sheet to be cut with a second cutting mark Mb separating a distance B from the upper end of the cutting surface, and the first and second cutting marks Ma ′ in the tread ring, Measuring means for measuring the circumferential length C between Mb ', a reference length S defined by the distances A and B, and the length C
And a determination means for determining a non-defective product when the difference S-C from the specified range is within a specified range. 6. The reference length S is A + B, or 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 is measured and the value is L.
1, the value of the rubber sheet piece measured before winding the drum is L2
Then, S = (A + B) × (L2 / L1) is set, and the joint amount test device for the tread ring according to claim 5, wherein 7. The feedback control for increasing the value L1 when the difference S−C is larger than the specified range and decreasing the value L1 when the difference S−C is smaller than the range. The joint amount verification device for a tread ring according to claim 6, further comprising a control device for performing.