JP4685276B2 - Belt forming drum - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a belt forming apparatus capable of preventing the generation of a joint stagger and a decrease in accuracy of joint inspection due to a sword-shaped corner at the tip of a raw belt material falling between belt segments when forming a raw belt of a tire.
[0002]
[Prior art]
When manufacturing a radial tire, as schematically shown in FIG. 7A, a belt forming drum A holding a plurality of circumferentially divided belt segments a so as to be movable in the radial direction is used. A raw belt B is formed in a cylindrical shape by winding a belt-like raw belt material b on a belt forming surface which is a surface.
[0003]
In this belt forming drum A, in order to make the belt forming surface close to a perfect circle when the diameter is increased, the belt segments a tend to be formed narrow and the total number (number of divisions) tends to increase. Further, in order to cope with a plurality of sizes of raw belts B having different diameters, the moving distance of the belt segment a in the radial direction, that is, the diameter expansion amount is formed to be adjustable.
[0004]
On the other hand, as shown in FIG. 7 (B), the belt forming drum A and the raw belt B are developed in a plane, and the raw belt material b has a front end bf and a terminal end br formed of a steel cord (belt cord). ) And is formed into a cylindrical shape by overlapping and jointing the front end portion bf and the end portion br. At this time, a magnet c is embedded in the outer surface of each belt segment a in order to attract and hold the raw belt material b for easy winding.
[0005]
[Problems to be solved by the invention]
However, when the distance d between the belt segments a increases as the diameter increases, the blade tip corner b1 of the raw belt material b is formed on the belt segment a in combination with the narrow width of the belt segment a. It tends to protrude from the gap d. As a result, there is a problem in that the sword-shaped corner b1 is displaced and a joint stagger is generated.
[0006]
In forming the raw belt B, a joint inspection for measuring or determining the joint amount is performed. In this inspection, as proposed in Japanese Patent Application Laid-Open No. 6-23867, the height displacement from the belt forming surface is measured with a laser displacement meter, and the front end bf and the end of the belt material b obtained thereby are measured. The joint amount is calculated from the position detected with the part br. However, the drop of the sword-shaped corner b1 into the interval d causes an error in the measurement of the height displacement, and there is a problem that the inspection accuracy is lowered.
[0007]
Further, in the narrow belt segment a, due to dimensional restrictions, as shown in FIG. 8, a magnet c is embedded in a recess a1 provided on the outer surface, and the surface thereof is fixed and fixed with an adhesive e. However, in such a case, a dent g is formed on the surface due to the chipping of the adhesive e, and the inspection accuracy is similarly lowered.
[0008]
In view of this, the present invention provides a wide belt segment at each position of the sword-shaped corner portion and the obtuse corner portion at the tip of the raw belt material, and a magnet is embedded on the inner surface of the wide belt segment. On the basis of this, an object of the present invention is to provide a belt forming apparatus capable of suppressing the generation of the joint stagger described above and a decrease in accuracy of joint inspection.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the invention of claim 1 of the present application has a belt forming surface capable of expanding and contracting formed by a plurality of belt segments divided in the circumferential direction. A belt-forming drum that forms a cylindrical green belt body by winding a belt-shaped green belt material in which a cord is embedded and overlapping the front end portion and the end portion thereof,
The tip portion and the end portion have a sharp-pointed sharp corner portion and an obtuse corner portion by cutting the raw belt material obliquely with respect to the longitudinal direction,
The plurality of belt segments include a wide belt segment that receives the acute angle portion, a wide belt segment that receives the obtuse angle portion, and a narrow belt segment disposed between the wide belt segments. Including
The wide belt segment is characterized in that a magnet for attracting and holding the steel cord is embedded in the inner surface in the radial direction.
[0010]
According to a second aspect of the present invention, the width WA of the wide belt segment is 1.5 to 3.0 times the width WB of the narrow belt segment.
[0011]
In the invention of claim 3, the wide belt segment is characterized in that a black surface treatment is applied to an outer surface in a radial direction.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a circumferential sectional view schematically showing an enlarged state and a reduced diameter state of a belt forming drum of the present invention, and FIG. 2 is a sectional view in an axial direction including a rotation axis J.
[0013]
In FIG. 1, a belt forming drum 1 includes a plurality of belt segments 2 divided in the circumferential direction, and an expansion and contraction diameter of a belt forming surface S composed of an outer surface 2S by moving the belt segment 2 in a radial direction. And a contracting means 3.
[0014]
Then, on the belt forming surface S in the diameter-expanded state, the raw belt material b is wound and the front end portion bf and the end portion br are overlapped to form the cylindrical raw belt B, and the diameter is reduced. The raw belt B is removed in the state.
[0015]
As is well known, the raw belt material b (shown in FIG. 6) is a belt-like sheet in which steel cords arranged at an angle θ of, for example, 10 to 30 degrees with respect to the longitudinal direction are covered with topping rubber. By being cut diagonally along, a sharp tip-shaped corner portion b1 and an obtuse corner portion b2 are formed at the tip end bf and the end portion br.
[0016]
The belt segment 2 is a long piece extending in the axial direction, and its outer surface 2S is linear in a cross section in the axial direction in this example. Further, the outer surface 2S is formed in an arc shape having a curvature substantially equal to the radius of the belt forming surface S in the expanded diameter state in a cross section perpendicular to the rotation axis J. The “substantially equal” means that the diameter of the belt forming surface S in the expanded state is adjusted according to the tire size, but this adjustment width is allowed.
[0017]
Next, as shown in FIG. 2, the expansion / contraction means 3 includes a rotating shaft 4, a plurality of slide fittings 5 for attaching the belt segment 2 on the outer surface in the radial direction, and a guide means for one end of each slide fitting 5. A side plate 7 that guides inward and outward in the radial direction via 6, and a wedge that engages with a radial inner edge of each slide fitting 7 via an inclined guide means 9 and advances and retracts the slide fitting 5 in the radial direction by moving back and forth in the axial direction. And a plurality of actuating brackets 10 in the form of a ring. Each actuating bracket 10 is integrally attached to a sliding cylinder 11 that is externally attached to the rotating shaft 4.
[0018]
The slide fitting 5 has a plate shape for attaching the belt segment 2 on the outer surface in the radial direction, and is arranged radially around the rotation axis J.
[0019]
Further, the side plate 7 has a substantially disc shape extending radially outward from the rotary shaft 4 on one end side (left end side in FIG. 2) of the belt segment 2 and is fixed to the rotary shaft 4 so as to be integrally rotatable. The side plate 7 guides one end (the left end in FIG. 2) of the slide fitting 5 inward and outward in the radial direction via the guide means 6.
[0020]
In this example, the guide means 6 is a linear guide, which is a linearly extending rail portion 16 and a block-shaped bearing portion that can move relative to the rail portion 16 by engaging with the rail portion 16. 17. In this example, the rail portion 16 is disposed at a right angle to the rotational axis J and at the one end of the slide fitting 5, and the bearing portion 17 is disposed on the inward surface of the side plate 7. Is illustrated.
[0021]
Further, the outer edge in the radial direction of the wedge-shaped operating metal fitting 10 fixed to the operating metal fitting 10 is engaged with the inner edge in the radial direction of the slide metal fitting 5 through the inclined guide means 9. The inclined guide means 9 is formed by a linear guide comprising a rail portion 16 and a bearing portion 17 as in the case of the guide means 6. In the figure, the case where the bearing portion 17 is arranged on the inner edge in the radial direction of the slide fitting 5 and the rail portion 16 is arranged on the outer edge in the radial direction of the operating fitting 10 is illustrated.
[0022]
The sliding cylinder 11 is supported so as to be able to move forward and backward in the axial direction by being extrapolated to the rotating shaft 4 and to rotate integrally with the rotating shaft 4. In this example, the other end (right end in FIG. 2) of the sliding cylinder 11 is connected with a rod 19A of an advancement / retraction tool 19 that extends in the axial direction, for example, an air cylinder, and is operated by the movement of the rod 19A. The metal fitting 10 can advance and retreat integrally with the sliding cylinder 11.
[0023]
Next, as shown in FIGS. 1 and 3, the belt segment 2 includes a pair of wide belt segments 2 </ b> A that respectively receive the acute corner portion b <b> 1 and the obtuse corner portion b <b> 2 of the raw belt material b, and A narrow belt segment 2B is arranged between the wide belt segments 2A and 2A.
[0024]
In this example, the narrow belt segment 2B has the same configuration as the conventional one, and as shown in FIGS. 4 (A) and 4 (B), the slide fitting is formed on the radially inner surface of the substantially rectangular main body 24. A fitting groove 25 for positioning and fixing 5 is recessed. Further, a concave portion 26 for embedding the magnet is formed on the outer surface 2S, and the surface of the magnet c1 embedded in the concave portion 26 is fixed by being covered with an adhesive e filled in the concave portion 26. .
[0025]
In the narrow belt segment 2B, the reason why the magnet c1 is embedded in the outer surface 2S is that if the magnet is embedded in the inner surface, only the narrow magnet is attached because the fitting groove 25 becomes an obstacle. This is because the adsorption range is remarkably narrowed.
[0026]
The narrow belt segment 2B is arranged in the circumferential direction at equal intervals as in the conventional case. In this example, the narrow belt segment 2B has an angular pitch α of 10 degrees (shown in FIG. 1). The case where it is arranged is illustrated.
[0027]
Further, as shown in FIGS. 5A and 5B, the wide belt segment 2A has a wide body portion 29 in which wing portions 29B are extended on both sides of a central portion 29A corresponding to the body portion 24. Have. A fitting groove 25 for positioning and fixing the slide metal fitting 5 is similarly provided in the inner surface of the central portion 29A.
[0028]
Further, concave portions 30A and 30B for embedding magnets are formed on the groove bottom of the fitting groove 25 and the inner surface of the wing portion 29B. In this example, the case where the magnets c2 are embedded in two rows in the width direction is illustrated in the wing portion 29B, but one wide magnet may be embedded. The magnet c3 embedded in the central portion 29A is narrower than the magnet c1 of the belt segment 2B, but since the magnet c2 of the wing portion 29B is adjacent, a wide adsorption range is secured as a whole.
[0029]
As described above, since the wide belt segment 2A is used, the sharp corner b1 in the raw belt material b is also formed by the wide belt segment even when the diameter d is increased and the interval d between the belt segments is widened. 2A can be prevented from protruding from above 2A and falling into the interval d, or misalignment due to poor suction of the corner portion b1. As a result, it is possible to suppress the occurrence of the above-described joint stagger and the decrease in accuracy of joint inspection.
[0030]
From this point of view, the width WA of the wide belt segment 2A is preferably as wide as possible, but conversely, if it is too wide, the distance d between the belt segments 2A and 2B is increased when the diameter is expanded. As compared with the distance d between 2B, it becomes too wide and tends to impair the uniformity of the raw belt B. Accordingly, the width WA of the wide belt segment 2A is preferably 1.5 to 3.0 times the width WB of the narrow belt segment.
[0031]
In addition to the pair of wide belt segments 2A, other wide belt segments 2A may be mixed, but it is preferable not to add them to improve the roundness of the belt forming surface S.
[0032]
Further, in the wide belt segment 2A, the magnets c2 and c3 are embedded in the inner surface thereof, so that the outer surface 2A is smooth without irregularities, and accordingly, the measurement accuracy of the height displacement by the laser displacement meter at the time of joint inspection, or The detection accuracy of the front end portion bf and the end portion br can be increased.
[0033]
Further, since the laser displacement meter measures the height displacement by reflection of light, there is a risk of erroneous measurement if the reflecting surface is a silver metal color. Therefore, in this example, black surface treatment is performed on the outer surface 2S of the wide belt segment 2A to prevent erroneous measurement. Examples of such surface treatment include alumite and Teflon treatment. Conventionally, since the adhesive is exposed on the surface, even when the surface treatment is performed, unevenness cannot be sufficiently prevented from being sufficiently prevented.
[0034]
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.
[0035]
【The invention's effect】
As described above, in the present invention, a wide belt segment is arranged at each position of the tip of the raw belt material at the tip of the blade and the obtuse corner, and a magnet is embedded in the inner surface of the wide belt segment. I wear it. Therefore, it is possible to suppress the occurrence of a joint stagger when the front end portion and the end portion of the raw belt material are joined, and a decrease in accuracy of joint inspection.
[Brief description of the drawings]
FIG. 1 is a circumferential sectional view schematically showing a belt forming drum according to an embodiment of the present invention.
FIG. 2 is a sectional view in an axial direction including a rotation axis J of a belt forming drum.
FIG. 3 is a development view schematically showing an arrangement of belt segments in a plane.
4A and 4B are a perspective view and a cross-sectional view in the width direction showing a narrow belt segment, respectively.
5A and 5B are a perspective view and a cross-sectional view in the width direction showing a wide belt segment, respectively.
FIG. 6 is a plan view schematically showing a raw belt material.
7A is a sectional view in the circumferential direction showing a conventional belt forming drum, and FIG. 7B is a development view schematically showing the arrangement of the belt segments in a plane.
FIG. 8 is a cross-sectional view illustrating one of the conventional problems.
[Explanation of symbols]
2A Wide belt segment 2B Narrow belt segment b Raw belt material bf Tip portion br End portion b1 Sharp corner portion b2 Obtuse corner portion B Raw belt c2, c3 Magnet S Belt molding surface

Claims (3)

A belt-shaped surface that can be expanded and contracted is formed by a plurality of belt segments divided in the circumferential direction, and a belt-shaped raw belt material in which a steel cord is embedded is wound on the belt-shaped surface and the tip thereof A belt forming drum that forms a cylindrical green belt by overlapping a portion and a terminal portion,
The tip portion and the end portion have a sharp-pointed sharp corner portion and an obtuse corner portion by cutting the raw belt material obliquely with respect to the longitudinal direction,
The plurality of belt segments include a wide belt segment that receives the acute angle portion, a wide belt segment that receives the obtuse angle portion, and a narrow belt segment disposed between the wide belt segments. Including
The wide belt segment has a belt forming drum in which a magnet for attracting and holding the steel cord is embedded in an inner surface in a radial direction. The belt forming drum according to claim 1, wherein a width WA of the wide belt segment is 1.5 to 3.0 times a width WB of the narrow belt segment. The belt forming drum according to claim 1 or 2, wherein the wide belt segment has a black surface treatment applied to an outer surface in a radial direction thereof.

Images