JP2020090060A - Bead core manufacturing apparatus and bead core manufacturing method - Google Patents

Abstract

To provide a bead core manufacturing technique for the stable production of a bead core having a constant outer circumference diameter.SOLUTION: The bead core manufacturing apparatus for manufacturing a bead core by winding a bead wire in which a wire is coated with rubber comprises: feeder means for feeding the wire; a rubber extruder for coating the wire with rubber to form a bead wire; winding means for winding the bead wire on a rotation axis; rewind circumference diameter measurement means for measuring the outer circumference diameter of the wound bead wire; and tension adjustment means for adjusting the tension of the wire upstream of the rubber extruder. The tension adjustment means is configured to adjust the tension of the wire based on the outer circumference diameter of the wound bead wire measured by the rewind circumference diameter measurement means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bead core manufacturing apparatus that forms a bead wire in which a wire is covered with rubber, and manufactures a bead core using the bead wire, and a bead core manufacturing method using the bead core manufacturing apparatus.

The bead portion of the pneumatic tire is provided with an annular bead core for fitting with the rim. This bead core is usually manufactured by coating the outer circumference of a wire with rubber to form a bead wire, and then winding the bead wire in an annular shape.

FIG. 4 is a diagram for explaining rubber coating by a conventional bead core manufacturing apparatus. As shown in FIG. 4, first, the unwound wire W is passed through a die plate (not shown) of the rubber extruder 2. Then, in the rubber extruder 2, the rubber G is coated around the wire W. Thereby, the bead wire BW is formed. After that, the bead wire BW is aligned with the groove portion provided in the winding drum (not shown), and the bead wire BW is sequentially wound up to manufacture the bead core.

At this time, if the rubber coating on the bead wire is uneven, the bead cores cannot be stably aligned, and a bead core of stable quality cannot be manufactured.

Therefore, it has been proposed to adjust the temperature of the wire in advance to maintain a constant amount of rubber coated on the wire (for example, Patent Document 1).

JP, 2005-138467, A

However, although the above-mentioned technique is applied to control the coating amount of the rubber on the wire to be a constant amount, variations may occur in the outer diameter of the bead core produced, and There is a need for additional techniques to produce stable bead cores.

Therefore, an object of the present invention is to provide a bead core manufacturing technique capable of stably manufacturing a bead core whose outer peripheral diameter is kept constant.

The present inventor has conducted extensive studies on the solution of the above problems, found that the above problems can be solved by the invention described below, and completed the present invention.

The invention according to claim 1 is
A bead core manufacturing apparatus for manufacturing a bead core by winding a bead wire coated with rubber on a wire,
Sending means for sending out the wire,
A rubber extruder for forming a bead wire by coating the wire with rubber,
Winding means for winding the bead wire on a rotating shaft,
A winding outer diameter measuring means for measuring the winding outer diameter of the bead wire wound up,
It comprises a tension adjusting means for adjusting the tension of the wire upstream of the rubber extruder,
The bead core manufacturing apparatus is characterized in that the tension adjusting means is configured to adjust the tension of the wire based on the winding outer diameter of the bead wire measured by the winding outer diameter measuring means. ..

The invention according to claim 2 is
The bead core manufacturing apparatus according to claim 1, wherein the winding outer diameter measuring means is one of a laser sensor and a CCD camera sensor.

The invention according to claim 3 is
The tension adjusting means includes a tension controller,
The bead core manufacturing apparatus according to claim 1 or 2, wherein the tension controller adjusts the tension of the wire.

The invention according to claim 4 is
4. The tension adjusting means is an adjusting means for adjusting the tension of the wire based on the relationship between the winding outer peripheral diameter and the tension which has been measured in advance. The bead core manufacturing apparatus according to item 1.

The invention according to claim 5 is
The bead core according to claim 4, wherein the tension adjusting means is an adjusting means that adjusts the tension of the wire by changing the tension of the wire by 40 N to 120 N with respect to a change amount of the winding outer diameter of the bead wire of 1 mm. It is a manufacturing device.

The invention according to claim 6 is
Further, on the downstream side of the rubber extruder, a temperature measuring means for measuring the temperature of the rubber in the rubber extruder is provided,
On the upstream side of the rubber extruder, temperature adjusting means for adjusting the temperature of the wire is provided,
6. The temperature adjusting unit is configured to adjust the temperature of the wire based on the temperature of the rubber measured by the temperature measuring unit. The bead core manufacturing apparatus according to item.

The invention according to claim 7 is
A bead core manufacturing method for manufacturing a bead core using the bead core manufacturing apparatus according to any one of claims 1 to 6.
A feeding process for feeding the wire,
A forming step of forming a bead wire by coating the wire with rubber using a rubber extruder;
A winding step of winding the bead wire on a rotating shaft,
A winding outer diameter measuring step of measuring a winding outer diameter of the bead wire wound up,
Comprises a tension adjusting step of adjusting the tension of the wire upstream of the rubber extruder,
The bead core manufacturing method is characterized in that the tension adjusting step adjusts the tension of the wire based on the winding outer diameter of the bead wire measured in the winding outer diameter measuring step.

According to the present invention, it is possible to provide a bead core manufacturing technique capable of stably manufacturing a bead core whose outer peripheral diameter is kept constant.

It is a typical side view of a bead core manufacturing device concerning one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of a wound bead core. It is a typical side view of a bead core manufacturing device concerning other embodiments of the present invention. It is a figure explaining the coating|cover of the rubber by the conventional bead core manufacturing apparatus.

Hereinafter, a bead core manufacturing apparatus according to the present invention will be specifically described based on embodiments.

[1] Process leading to the present invention Prior to describing the embodiments of the present invention, the process leading to the completion of the present invention will be described in order to facilitate understanding of the present invention.

As described above, in the case of the conventional bead core manufacturing apparatus, there is variation in the outer diameter of the manufactured bead core, even though the coating amount of rubber is controlled to be a constant amount when forming the bead wire. There was something to do.

The present inventor conducted various experiments and studies in order to find out what causes the variation in the outer peripheral diameter. As a result, it was found that the change in the tension of the wire during winding on the winding drum causes the variation in the outer diameter.

That is, the bead wire formed by coating the wire with rubber is wound around the winding drum, but since the number of rotations of the winding drum is constant, as the winding outer diameter increases as the winding progresses, The winding speed is increased and the wire tension is increased. Due to the increased tension, the bead wire on the winding drum is reduced and the bead wire on the take-up drum receives pressure from the bead wire in the upper layer to flatten the bead wire. I understood.

Therefore, the present inventor arranges the winding outer diameter measuring means, for example, in the vicinity of the winding drum, and at the time of winding the bead wire, always measures the winding outer diameter and responds to the measurement result. By appropriately adjusting the tension applied to the wire, it was thought that the variation of the outer diameter of the winding could be suppressed, and the specific constitution was examined to complete the present invention. Hereinafter, description will be made based on specific embodiments.

[2] First Embodiment 1. Outline of First Embodiment A bead core manufacturing apparatus according to the first embodiment adjusts a winding outer diameter measuring means for measuring a winding outer diameter of a bead wire, and a tension applied to the wire according to the measurement result. The bead core manufacturing apparatus is provided with a tension adjusting means.

2. Basic configuration of bead core manufacturing apparatus according to first embodiment First, the basic configuration of the bead core manufacturing apparatus according to the first embodiment will be described. FIG. 1 is a schematic side view of a bead core manufacturing apparatus according to the first embodiment.

As shown in FIG. 1, in the bead core manufacturing apparatus of the first embodiment, the wire W wound on a reel is unwound and sent out to the rubber extruder 2, and the wire W is sent out. This is the same as the conventional bead core manufacturing apparatus in that it includes a rubber extruder 2 that coats the rubber G to form the bead wire BW, and a winding means 1 that winds the bead wire BW in an annular shape on a rotating shaft. ..

However, unlike the conventional bead core manufacturing apparatus, the bead core manufacturing apparatus of the present embodiment further includes a winding outer diameter measuring means 4 for measuring the winding outer diameter of the bead wire BW wound around the winding means 1. A tension adjusting means 5 for adjusting the tension of the wire W is provided upstream of the rubber extruder 2.

Then, in the present embodiment, the measurement result of the winding outer diameter of the winding outer diameter measuring means 4 is fed back to the tension adjusting means 5 to adjust the tension of the wire W (indicated by the broken line). Arrow F1).

With such a configuration, by adjusting the tension of the wire W in accordance with the variation in the winding outer diameter, it is possible to stably manufacture the bead core in which the outer diameter is kept constant.

3. Specific Configuration of Bead Core Manufacturing Apparatus According to this Embodiment Next, a specific configuration of the bead core manufacturing apparatus according to this embodiment will be described. In the following, first, the basic configuration of the present apparatus, which is the same configuration as the conventional bead core manufacturing apparatus, will be described, and then the winding outer diameter measuring means that is a characteristic part of the bead core manufacturing apparatus in the present embodiment The tension adjusting means will be described.

(1) Basic configuration of the bead core manufacturing apparatus according to the present embodiment (a) Feeding means The feeding means 3 unwinds the wire W wound on a reel and held by a creel stand or the like, and the rubber extruder 2 Send to.

(B) Rubber Extruder The rubber extruder 2 forms a bead wire BW by extruding and covering rubber around the fed wire W. At this time, a die plate (not shown) is provided at the tip of the rubber extruder 2 so that the amount of rubber covered is constant.

(C) Winding Means The winding means 1 winds the bead wire BW formed in the rubber extruder 2 on a rotating shaft that rotates at a constant number of rotations to manufacture an annular bead core. A bead former is used as the concrete winding means 1, and a bead core is manufactured by winding the bead wire BW in a plurality of stages while aligning the bead wire BW in a groove portion formed in the circumferential direction on the surface of the bead former. It

FIG. 2 is a schematic cross-sectional view of the bead core wound by the winding means 1. As shown in FIG. 2, the bead core BC has a plurality of rows of bead wires BW in which the wire W is covered with the rubber G in a plurality of rows (in FIG. 2, five rows, in a groove portion provided in the winding means 1). It is manufactured by winding (4 stages).

At this time, as described above, since the winding means 1 is rotating at a constant rotation speed, the winding speed of the bead wire BW on the outer peripheral side is increased, and the tension of the wire W is increased. For this reason, the winding outer diameter of the wound bead wire is reduced, and variations occur in the outer diameter of the manufactured bead core.

(2) Characteristic part of the bead core manufacturing apparatus of the present embodiment (a) Winding outer circumference diameter measuring means In order to address the above problem, in the present embodiment, first, as shown in FIG. The winding outer diameter measuring means 4 is arranged above the means 1 to measure the winding outer diameter of the bead wire BW wound on the winding means 1.

In the present embodiment, the winding outer diameter measuring means is not particularly limited, but a laser sensor, a CCD camera sensor and the like are preferable in consideration of the ease of measurement, the accuracy of the measurement result, the size of the measuring device, and the like.

(B) Tension adjusting means In the present embodiment, the tension adjusting means 5 is provided in addition to the winding outer diameter measuring means 4, and the measurement result of the winding outer diameter measuring means 4 is transferred to the tension adjusting means 5. It is configured to feed back and adjust the tension of the wire W.

Specifically, first, the tension adjusting means that receives the measurement result from the winding outer diameter measuring means compares the measured winding outer diameter with the predicted winding outer diameter. For example, in FIG. 2, in the fourth winding of the bead wire BW, the thickness T4 is predicted to be four times the thickness T1 that is the same thickness as the diameter of the bead wire BW. When the winding outer diameter measured by the winding outer diameter measuring means 4 is smaller than expected, the tension adjusting means decreases the winding outer diameter of the bead wire BW wound because the tension of the wire W has increased. Determine that

Then, the tension adjusting means that determines that the tension of the wire W is increased reduces the tension of the wire W. As a result, even if the winding speed of the bead wire BW increases and the tension increases, the tension of the wire W can be immediately adjusted to keep the tension constant and the bead wire BW can be wound. Bead cores can be manufactured.

In the present embodiment, the tension adjusting means is not particularly limited, but a tension controller or the like is preferable in consideration of ease of adjusting tension, size, and the like.

The tension adjustment using the tension controller is based on the relationship between the measured winding outer diameter and the tension in advance according to the change amount (mm) of the winding outer diameter measured by the winding outer diameter measuring means. Then, it is preferable to operate the tension controller to adjust the tension (N) of the wire.

In the case of manufacturing a general bead core, it is preferable to change the wire tension by 40 N to 120 N with respect to a change amount of the winding outer diameter of the bead wire of 1 mm, and more preferably 60 N to 100 N.

[3] Second Embodiment (1) Outline of Second Embodiment Although the bead core manufacturing apparatus of the second embodiment has the same basic configuration as that of the first embodiment, rubber is used. It is different in that it further has temperature adjusting means for measuring the temperature of the rubber extruded from the extruder and adjusting the temperature of the pre-rubber-coated wire based on the measured temperature.

In the first embodiment in which the tension of the wire is adjusted in accordance with the change in the winding outer diameter, if there is a temperature difference between the wire and the extruded rubber, defective adhesion with rubber will occur during formation of the bead wire. As a result, there may be a case where the bead core is broken.

Therefore, the present inventor further comprises not only the tension control means but also a temperature adjusting means for adjusting the temperature of the wire before the rubber coating upstream of the extruder to the temperature of the rubber in the rubber extruder, whereby the outer diameter of the bead core is It was found that not only the variation of the above can be suppressed, but also the problem of rubber sticking can be remarkably improved, and a bead core of more stable quality can be manufactured.

(2) Temperature Adjusting Means FIG. 3 is a schematic side view of the bead core manufacturing apparatus according to the second embodiment. The temperature adjusting means is installed in the vicinity of the extrusion port of the rubber extruder 2 and measures the temperature of the extruded rubber (not shown), and the temperature adjusting section 6 installed upstream of the rubber extruder 2. Composed of.

In the temperature adjusting means of the present embodiment, the temperature adjusting unit 6 performs feedback control for heating the wire before rubber coating to a predetermined temperature based on the temperature of the rubber measured by the temperature measuring unit (broken line arrow F2). ). The temperature adjusting unit 6 is preferably installed immediately before the rubber extruder 2 in order to avoid a decrease in the temperature of the heated wire.

The temperature at which the wire is adjusted is preferably 5° C. or less, more preferably 3° C. or less, and even more preferably approximately the same as the temperature of the extruded rubber.

Hereinafter, the present invention will be described more specifically based on Examples.

[1] Experiment 1
1. Experimental Method In this experiment, a bead core was manufactured using a bead core manufacturing apparatus (Example 1) having a tension adjusting means and a conventional bead core manufacturing apparatus (Comparative Example 1), and the quality and process capability index of the manufactured product were measured. evaluated.

(1) Example As an example, a bead wire (diameter: 1.2 mm) coated with rubber having a thickness of 0.3 mm was coated on a wire (diameter: 1.2 mm) manufactured by Kiss Wire Co., using a bead core manufacturing apparatus equipped with the tension adjusting means shown in FIG. : 1.5 mm) and corresponding to the change amount (mm) of the winding outer diameter measured by the winding outer diameter measuring means, based on the relationship between the winding outer diameter and the tension measured in advance. Then, the bead wire was wound around the winding means while adjusting the tension of the wire by operating the tension controller to manufacture 100 bead cores (Example 1).

(2) Comparative Example On the other hand, as a comparative example, a bead core was manufactured in the same manner as in the example, except that a conventional bead core manufacturing apparatus having no tension adjusting means was used (Comparative Example 1).

2. Evaluation content (1) Variation in outer diameter of bead core The outer diameter of each bead core manufactured was measured, and the average value Ave and standard deviation σ thereof were calculated.

(2) Process capability index Then, the process capability index Cpk for the outer diameter of the bead core was calculated using the set value and the two-sided standard. The higher the number, the more consistent the process can be controlled.

3. Experimental Results Table 1 shows the experimental results.

From the results shown in Table 1, in the bead core manufacturing apparatus of Example 1, by measuring the winding outer diameter and adjusting the tension in accordance with the amount of change, the standard deviation and the process capability index values are shown. In addition, it was confirmed that a bead core with a small outer diameter and a stable outer diameter can be obtained. On the other hand, in Comparative Example 1, a large variation was found in the outer diameter.

[2] Experiment 2
1. Experimental Method An experiment was conducted using a bead core manufacturing apparatus (Example 2) equipped with a tension adjusting means and a bead core manufacturing apparatus (Example 3) further equipped with a temperature adjusting means upstream of the rubber extruder in addition to the tension adjusting means. A bead wire was formed in the same manner as in Example 1 and the rate of occurrence of defective rubber was evaluated.

As the temperature adjusting means, an apparatus configured to adjust the temperature of the pre-rubber coated wire to the temperature of the rubber extruded from the rubber extruder was used.

2. Experimental Results Table 2 shows the experimental results.

From Table 2, it was confirmed that the occurrence rate of the defective bead wire sticking with rubber can be greatly reduced by providing the temperature adjusting means.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the above embodiment. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

1 Winding Means 2 Rubber Extruder 3 Feeding Means 4 Winding Outer Diameter Measuring Means 5 Tension Adjusting Means 6 Temperature Adjusting Parts BC Bead Core BW Bead Wires F1, F2 Feedback Control G Rubber W Wires T1, T2, T3, T4 Thickness

Claims (7)

A bead core manufacturing apparatus for manufacturing a bead core by winding a bead wire coated with rubber on a wire,
Sending means for sending out the wire,
A rubber extruder for forming a bead wire by coating the wire with rubber,
Winding means for winding the bead wire on a rotating shaft,
A winding outer diameter measuring means for measuring the winding outer diameter of the bead wire wound up,
It comprises a tension adjusting means for adjusting the tension of the wire upstream of the rubber extruder,
The bead core manufacturing apparatus, wherein the tension adjusting means is configured to adjust the tension of the wire based on the winding outer diameter of the bead wire measured by the winding outer diameter measuring means. The bead core manufacturing apparatus according to claim 1, wherein the winding outer diameter measuring means is one of a laser sensor and a CCD camera sensor. The tension adjusting means includes a tension controller,
The bead core manufacturing apparatus according to claim 1, wherein the tension controller adjusts the tension of the wire. 4. The tension adjusting means is an adjusting means for adjusting the tension of the wire based on a relationship between a measured winding outer diameter and a tension in advance. The bead core manufacturing apparatus according to item 1. The bead core according to claim 4, wherein the tension adjusting means is an adjusting means that adjusts the tension of the wire by changing the tension of the wire by 40 N to 120 N with respect to a change amount of the winding outer diameter of the bead wire of 1 mm. Manufacturing equipment. Further, on the downstream side of the rubber extruder, a temperature measuring means for measuring the temperature of the rubber in the rubber extruder is provided,
On the upstream side of the rubber extruder, temperature adjusting means for adjusting the temperature of the wire is provided,
6. The temperature adjusting unit is configured to adjust the temperature of the wire based on the temperature of the rubber measured by the temperature measuring unit. The bead core manufacturing apparatus according to item. A bead core manufacturing method for manufacturing a bead core using the bead core manufacturing apparatus according to any one of claims 1 to 6.
A feeding process for feeding the wire,
A forming step of forming a bead wire by coating the wire with rubber using a rubber extruder;
A winding step of winding the bead wire on a rotating shaft,
A winding outer diameter measuring step of measuring a winding outer diameter of the bead wire wound up,
Comprises a tension adjusting step of adjusting the tension of the wire upstream of the rubber extruder,
The bead core manufacturing method, wherein the tension adjusting step adjusts the tension of the wire based on the winding outer diameter of the bead wire measured in the winding outer diameter measuring step.

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