JP2007160830A - Forming apparatus for polygonal bead core for pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the cost for the production of a polygonal bead core with a taper angle for a pneumatic tire. <P>SOLUTION: An apparatus F for forming the polygonal bead core for a pneumatic tire is provided with a forming member M having a forming face S for prescribing a position of a wire for forming the polygonal bead core in which a base with a cross sectional shape being a polygonal shape in a forming groove 34 with a taper angle. The forming member M provides a first forming member 40 with a first forming face 41a and a second forming member 50 with a second forming face 52a. The forming face S has a first forming face 41a inclined at a same angle with a taper angle for adjusting the base and a second forming face 52a for adjusting a side face to be connected to the edge part of the base in a sectional shape. The first and the second forming members 40 and 50 respectively are possible to relatively move by a position arranging member A for changing a length of the base of the bead core without changing the taper angle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a polygonal bead core provided in a tire such as a heavy duty radial tire for large construction vehicles, trucks, buses, etc., and a polygonal bead core having a predetermined taper angle is formed by laminated wires. More specifically, the present invention relates to a forming apparatus including a variable forming portion that can change the length of a forming surface that defines the length of the bottom side of a polygonal bead core.

In order to ensure high durability, a heavy load radial tire employs a bead core having a hexagonal cross section and a base having a predetermined taper angle. This hexagonal bead core is formed by winding a wire in a spiral shape while forming a forming surface having a forming surface inclined at an angle equal to the taper angle of the bead core, while being defined on the forming surface. (See, for example, Patent Document 1).
JP-A-11-58551

In the conventional forming apparatus, the forming part has a forming surface in which the length of the bottom side of the bead core cannot be changed. For this reason, for example, when forming hexagonal bead cores having the same rim diameter and different numbers of wires constituting the base, or different base lengths, the formation surface defining the base length is used. Since it is necessary to use separate forming parts having different lengths, the number of forming parts as many as the types of bead cores to be formed must be prepared, which increases the cost for manufacturing the bead core, and the forming parts. The space for storing was also increasing.
Furthermore, from the viewpoint of cost reduction, it is desirable to suppress the decrease in accuracy of the forming surface as much as possible, and it is desirable to increase the range of changing the length of the base.

  This invention is made | formed in view of such a situation, and the invention of Claims 1-3 aims at reducing the cost of the polygonal bead core with a taper angle with which a tire is equipped. The invention described in claim 2 further aims to maintain the forming surface in a highly accurate state over a long period of time, and the invention described in claim 3 further provides the first forming member in the axial direction of the bead core. The purpose is to increase the range of changing the length of the base while downsizing.

  The invention according to claim 1 is an apparatus for forming a polygonal bead core for a tire, comprising a forming part having a forming surface that defines a position of a wire forming a polygonal bead core having a polygonal cross-sectional shape and a taper angle at the bottom. The forming surface includes a first forming surface that is inclined at the taper angle so as to define the bottom side, and a second forming surface that defines a side side continuous with an end of the bottom side in the cross-sectional shape, The forming unit includes a first forming member having the first forming surface and a second forming member having the second forming surface, and the first forming member and the second forming member change the taper angle. This is an apparatus for forming a polygonal bead core for a tire that is relatively movable so that the length of the base can be changed without any change.

  According to this, since the polygonal bead cores having different base lengths can be formed by relatively moving the first and second forming members, a forming part is prepared for each bead core having different base lengths. There is no need.

  According to a second aspect of the present invention, in the tire polygonal bead core forming apparatus according to the first aspect, the first forming wall having the first forming surface in the first forming member includes a plurality of radially penetrating holes. A plurality of second openings penetrating in the axial direction of the bead core are formed in a second forming wall provided with a first partition wall in the circumferential direction and having the second forming surface in the second forming member. A second partition is provided in the circumferential direction, and the second partition and the first partition pass through the first opening and the second opening, respectively.

  According to this, since the first and second formation surfaces are constituted by the wall surfaces of the first and second partition walls penetrating the first and second openings, respectively, for example, on the formation surface of one formation member, the other Since the forming surface is not used to enable relative movement of the first and second forming members as in the case of moving the forming member, wear of the forming surface by members other than wires is prevented. Thus, a decrease in accuracy of the formation surface is prevented.

  According to a third aspect of the present invention, in the tire polygon bead core forming apparatus according to the second aspect, the first opening is a slit opened in the axial direction.

  According to this, it is possible to form bead cores having different base lengths by utilizing the vicinity of the open end of the slit.

According to invention of Claim 1, the following effect is show | played. That is, since a polygonal bead core having different base lengths can be formed by the same forming portion, the cost of the bead core is reduced, and the storage space of the forming portion is also reduced.
According to invention of Claim 2, in addition to the effect of the invention of the cited claim, there exists the following effect. That is, since the formation surface can be maintained in a highly accurate state over a long period of time, a bead core having a high polygonal shape accuracy can be formed at a low cost.
According to the invention of claim 3, since the length of the slit can be fully utilized when changing the base, a bead core having a large change range of the base is formed while the first forming member is downsized in the axial direction. can do. And since the change range of the length of a base becomes large, since the kind of bead core formed can be increased, it contributes to cost reduction.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
Referring to FIG. 1, a tire 1 having a tapered beaded polygonal bead core B formed by a forming apparatus F (see FIG. 2) to which the present invention is applied is a pneumatic radial tire formed mainly of rubber. , A pair of bead portions 2 that are fitted to the rim R of the wheel, a tread portion 3 that is in contact with the road surface, and a pair of sides that extend radially outward of the tire 1 from each bead portion 2 and continue to the tread portion 3. A wall portion 4 and a toroidal carcass 5 are provided. The carcass 5 is provided so as to wrap around the bead core B and the stiffener 6 from the inside to the outside through the tread portion 3 and the sidewall portion 4 and to wind up radially outward.

  The annular bead core B and the stiffener 6 that fix the tire 1 to the rim R are embedded in the bead portion 2 so as to be in close contact with each other and surrounded by the folded portion 5 a of the carcass 5. For example, the cross-sectional shape of the bead core B formed by stacking metal (for example, steel) wires W is a hexagon in this embodiment, but may be a polygon other than a hexagon such as a quadrangle. Here, the cross-sectional shape of the bead core B is a shape of a circumscribed contour line (two-dot chain line shown in FIG. 1B) of the bead core B in a cross section.

In the specification and claims, terms relating to the bead core B are defined as follows.
The cross section is a cross section along a plane including the central axis of the bead core (corresponding to the meridian surface of the tire), and the bottom of the cross section of the bead core is a polygonal side that is the cross section of the bead core. The taper angle is an angle formed by the base with respect to the central axis in the cross section, the axial direction is the direction in which the central axis extends, and the radial direction and the circumferential direction are centered on the central axis, respectively. Radial direction and circumferential direction.

The bead core B forming apparatus F will be described below with reference to FIGS.
Referring to FIGS. 2 and 3, a forming device F in which a single wire W supplied from a wire supply device (not shown) is spirally wound and arranged in a laminated state to form a bead core B is as follows. A rotating shaft 11 driven and rotated by the motor 10, a support disk 12 rotating integrally with the rotating shaft 11, a formed body 30 supported by the support disk 12 and movable in the radial direction of the rotating shaft 11, and a formed body And an actuator 20 for moving 30. The formed body 30 is composed of a predetermined number of a plurality of segments 31 in this embodiment divided in the circumferential direction of the rotating shaft 11.

  The support disk 12 includes the predetermined number of guide portions extending in the radial direction, here six guide rail pairs 13 corresponding to the six segments 31 arranged at equal intervals in the circumferential direction of the rotating shaft 11 in the circumferential direction. Are provided at equal intervals. Each segment 31 is supported so as to be movable in the radial direction with respect to the support disk 12 via a guided portion 32 provided in the segment 31 and guided by being slidably fitted to each guide rail 13a. The

  The hydraulic actuator 20 includes a cylinder 21 that is supported on the outer periphery of the rotating shaft 11 so as to be movable in the axial direction, and an annular piston that is fitted in the cylinder 21 and fixed integrally with the rotating shaft 11. 22, and a link 23 that connects the cylinder 21 and each segment 31. A pair of hydraulic chambers 24 and 25 are formed in a cylinder 21 slidable in an oil-tight manner with respect to the rotating shaft 11 and are partitioned by a piston 22 in sliding contact with the cylinder 21. The hydraulic oil is supplied to and discharged from the annular hydraulic chambers 24 and 25 through oil passages 26 and 27 communicating with the high hydraulic pressure source and the low hydraulic pressure source via the hydraulic control valve.

  When the hydraulic chamber 24 communicates with the high hydraulic pressure source via the oil passage 26 while the hydraulic chamber 25 communicates with the low hydraulic pressure source via the oil passage 27 by the hydraulic control valve, the cylinder 21 moves on the rotating shaft 11. Then, each segment 31 moves radially outward in synchronization. When the cylinder 21 comes into contact with the stopper 28 and stops, the movement of each segment 31 outward in the radial direction is completed, and the formed body 30 occupies the formation position (see the upper half of FIG. 2), which is the diameter expansion position. Thus, formation of a bead core B having a diameter corresponding to the rim R having a predetermined diameter is started. When the hydraulic chamber 24 communicates with the low hydraulic pressure source and the hydraulic chamber 25 communicates with the high hydraulic source by the hydraulic control valve, the cylinder 21 moves on the rotating shaft 11 in the opposite direction, and the segments 31 are synchronized. And move inward in the radial direction. Then, when the cylinder 21 comes into contact with the stopper 29 and stops, the movement of each segment 31 inward in the radial direction is completed, and the formed body 30 moves to the removal position (see the lower half of FIG. 2) which is the reduced diameter position. The formed bead core B can be removed from the formed body 30.

  4 and 5 together, each segment 31 has a partial annular shape (or arc shape) in which a main body 33 to which the link 23 is connected and a wire W wound around the forming body 30 is accommodated. And a forming portion M for forming the forming groove 34. The formation part M is comprised from the 1st formation member 40, the 2nd formation member 50, and the position adjustment part A which adjusts the relative position in the axial direction of the 1st, 2nd formation member 40,50. The first and second forming members 40 and 50 change the length of the base e1 (see also FIG. 1B) in the cross-section of the bead core B without changing the taper angle α through the position adjusting portion A. Can be moved relative to each other in parallel to the axial direction. The formation groove 34 has a trapezoidal cross section substantially corresponding to the shape of the inner portion when the hexagon which is the cross sectional shape of the bead core B is divided into the inner portion and the outer portion in the radial direction.

  In this embodiment, the first forming member 40 provided by being coupled to the main body portion 33 by the bolt 60 has a first forming surface 41a and a third forming surface 43a that define the position of the wire W in the forming groove 34, respectively. The first and third formation walls 41 and 43 and the attachment portion 44 are integrally formed with the first and third formation walls 41 and 43 and the attachment portion 44. Therefore, the first forming member 40 is a member in which the forming member having the first forming wall 41 and the forming member having the third forming wall 43 are integrally formed. On the other hand, the second forming member 50 includes a forming wall 52 having a second forming surface 52a that defines the position of the wire W in the forming groove 34, and an attaching portion 54 for attaching the second forming member 50 to the attaching portion 44. The second forming wall 52 and the attachment portion 54 are integrally formed.

  Here, the first, second, and third formation surfaces 41a, 43a, and 52a constitute the formation surface S of the formation portion M that defines the position of the wire W within the formation groove 34. The first forming surface 41a is inclined at the same angle as the taper angle α so as to define the base e1 in the cross-sectional shape of the bead core B. The second and third formation surfaces 43a and 52a have a cross-sectional shape of the bead core B, and a pair of first and second side edges e2 and e3 that rise radially outward from both ends of the bottom edge e1 in the axial direction (see FIG. 1 (see also B)).

  The position adjusting portion A is composed of both mounting portions 44, 54 and bolts 61 and nuts 62 as connecting means for connecting the first and second forming members 40, 50 with the mounting portions 44, 54. 44 and 54 are coupled by bolts 61 and nuts 62 so that the second forming member 50 can be adjusted in the axial direction with respect to the first forming member 40. The bolt 61 inserted through the attachment portion 44 is inserted through a long hole 54 a provided in the attachment portion 54 and extending in the axial direction. The position of the second forming member 50 in the axial direction is adjusted between the second forming member 50 and the first forming member 40 within the range of the length of the long hole 54a in the axial direction. Therefore, in this embodiment, the first forming member 40 is a fixed forming member that cannot move with respect to the main body 33, and the second forming member 50 is a movable forming member that can move with respect to the fixed forming member. is there.

  The first forming wall 41 is provided with first slits 45 constituting a plurality of first openings penetrating radially outward with the first partition wall 46 interposed therebetween. On the other hand, the second forming wall 52 is provided with second slits 55 constituting a plurality of second openings penetrating in the axial direction with the second partition wall 56 interposed therebetween in the circumferential direction. The first slit 45 is open in the axial direction, and the second slit 55 is open in the radial direction. Therefore, a first forming wall 41 having a plurality of first slits 45 and first partition walls 46 alternately arranged in the circumferential direction, and a second having a plurality of second slits 55 and second partition walls 56 alternately arranged in the circumferential direction. The forming wall 52 has a comb-teeth shape.

  The first and second slits 45 and 55 are arranged so that the second partition walls 56 and the first partition walls 46 are alternately arranged in the circumferential direction, and the opposing surfaces in the circumferential direction of the partition walls 46 and 56 are substantially in contact with each other. Inserted into. For this reason, the first formation surface 41a is constituted by a surface of each first partition wall 46 that does not penetrate the second slit 55 and faces outward in the radial direction. The second formation surface 52a In the second partition wall 56, the portion that penetrates the first slit 45 is constituted by a surface that faces the third formation surface 43 a in the axial direction. On the other hand, the second forming member 50 is in contact with the surface 46a facing inward in the radial direction in each first partition wall 46. Accordingly, the first, second, and third formation surfaces 41a, 52a, and 43a are surfaces that only the wire W comes into contact with.

Then, as shown in FIG. 5, by moving the second forming member 50 in the direction away from the third forming surface 43a in the axial direction, it becomes possible to form a bead core B having a longer base e1. Further, as shown by a two-dot chain line in FIG. 5, the second forming surface 52a is moved to the vicinity of the open end of the first slit 45 or to the vicinity of the end of the first forming surface 41a in the axial direction. B can be formed.
On the other hand, by moving the second forming member 50 in the direction approaching the third forming surface 43a, the bead core B having a shorter base e1 can be formed.

Next, a method for forming the forming apparatus F will be described.
As shown in FIG. 4, the position adjusting unit is adjusted to the length of the bottom side e <b> 1 (see FIG. 1B) of the bead wire W set corresponding to the width of the rim R (see FIG. 1A). A position in the axial direction of the second forming member 50 with respect to the first forming member 40 is set through A. Each segment 31 is driven by the actuator 20 (see FIG. 2), and the formation body 30 occupies the formation position. After the end portion of the wire W is fixed to the forming body 30, the wire W is supplied from the wire supply device while rotating the forming body 30 via the rotating shaft 11 and the support disk 12 driven by the motor 10.

  Referring to FIG. 5, the wire W is first wound so as to be in contact with the first and second forming surfaces 41a and 52a (the wire W1a in FIG. 5), and then the position is regulated by the first forming surface 41a. Thus, the wire is wound spirally so as to come into contact with the wound wire W while being moved in the axial direction on the first forming surface 41a toward the third forming surface 43a. In a state where the position of the wire W is in contact with the first and third forming surfaces 41a and 43a (the wire W1b in FIG. 5), the first row constituting the bottom of the bead core B is formed. Here, at least one of the wire supply device and the forming device F is configured to be movable in the axial direction.

Subsequently, the wire W is spirally wound toward the second formation surface 52a directly on the first row of wires W from the state where the position is regulated by the third formation surface 43a (wire W2b in FIG. 5). The second row is formed in a state where the position of the wire W is in contact with the second forming surface 52a (the wire W2a in FIG. 5). Thereafter, the third column and the fourth column are sequentially formed in the same manner. The winding of the wire W formed with the position restricted by the forming surface S is up to the fourth row, and thereafter, the winding is continued directly on the two wires W directly below, A bead core B having a hexagonal cross-section is formed by the wires W formed by forming the seventh row of the row, the sixth row and the outermost row, and being wound and arranged in a stacked state, and the forming step is completed. .
Next, each segment 31 is driven by the actuator 20 (see FIG. 2), the formation body 30 occupies the removal position, and the bead core B is removed from the formation portion M.

  Further, when forming the bead core B having the same diameter of the rim R and the minimum inner diameter of the bead core B and the longer base e1, the second forming member is formed through the position adjusting portion A as shown in FIG. 50 is moved to a predetermined position in a direction away from the third forming surface 43a, and then the first forming member 40 and the second forming member 50 are fixed by the bolt 61 and the nut 62, whereby the two forming members 40, 50 are fixed. The position in the axial direction is set. In the same manner as described above, the wire W is spirally wound around the forming portion M and arranged in a stacked state, and the bead core B is formed.

Next, operations and effects of the embodiment configured as described above will be described.
The forming surface S of the forming unit M of the forming apparatus F defines a first forming surface 41a that is inclined at a taper angle α to define the base e1, and a side e2 that is continuous with one end of the base e1 in the cross-sectional shape of the bead core B. The second forming surface 52a and the third forming surface 43a defining the side e3 continuous with the other end of the base e1, and the forming portion M includes the first forming member 40 having the first forming surface 41a. A second forming member 50 having a second forming surface 52a, and the first and second forming members 40, 50 can change the length of the base e1 of the bead core B without changing the taper angle α. Since the polygonal bead core B having a different length of the base e1 can be formed by relatively moving the first and second forming members 40 and 50, the relative length of the base e1 can be increased. There is no need to prepare the forming portion M for each bead core B having a different length. As a result, since the polygonal bead core B with the base e1 having different lengths can be formed by the same forming portion M, the cost of the bead core B is reduced, and the storage space for the forming portion M is also reduced.

  In the first forming wall 41 having the first forming surface 41a, a plurality of first slits 45 penetrating radially outward are provided in the circumferential direction with the first partition wall 46 interposed therebetween, and a second forming surface 52a is provided. The second forming wall 52 is provided with a plurality of second slits 55 penetrating in the axial direction with the second partition wall 56 sandwiched in the circumferential direction. The first slit 45 and the second slit 55 include the second partition wall 56 and the second partition wall 56. When the first partition wall 46 penetrates, the first and second formation surfaces 41a and 52a are constituted by the wall surfaces of the second and first partition walls 56 and 46 that penetrate the first and second slits 45 and 55, respectively. Therefore, the forming surface S is used to enable relative movement of the first and second forming members 40 and 50, for example, when the other forming member is moved on the forming surface of one forming member. Therefore, the wear of the forming surface S by members other than the wire W is prevented, and the accuracy of the forming surface S is improved. Reduction is prevented. As a result, since the formation surface S can be maintained in a highly accurate state for a long period of time, the bead core B having a high accuracy of the shape of a polygon (here, a hexagon) can be formed at a low cost.

  By opening the first slit 45 in the axial direction of the bead core B, it is possible to form the bead core B having a different length of the base e1 by using the first slit 45 up to the vicinity of the open end. As a result, since the length of the first slit 45 can be sufficiently utilized in changing the base e1, the bead core B having a large change range of the length of the base e1 can be formed while reducing the size of the first forming member 40 in the axial direction. can do. And since the change range of the length of the base e1 becomes large, since the kind of bead core B formed can be increased, it contributes to cost reduction.

Hereinafter, an embodiment in which a part of the configuration of the above-described embodiment is changed will be described with respect to the changed configuration.
The first forming member 40 may be a movable forming member, and the second forming member 50 may be a fixed forming member.
The first forming member 40 may be integrally formed with the main body portion 33. In addition, the first forming member 40 may be composed of separate members of the forming member having the first forming wall 41 and the forming member having the third forming wall 43. In this case, the first, second, second The three forming members may be movable relative to each other in the axial direction. At this time, the minimum inner diameter of the bead core B may be changed at the same time when the length of the base e1 is changed.
The first opening or the second opening may be a long hole into which the partition walls 46 and 56 can be inserted instead of the slits 45 and 55.
The position adjusting unit A may be configured by an actuator that relatively moves the first forming member 40 and the second forming member 50 in the axial direction.
The direction of relative movement between the first and second forming members 40 and 50 may be parallel to the radial direction.
The formed body 30 may be supported by the support disk 12 so as not to move. Furthermore, the formation body 30 and the formation part M may each be one annular shape, without being comprised from several segments.

(A) is principal part sectional drawing in the meridian of a tire provided with the bead core shape | molded by the forming apparatus with which this invention was applied, (B) is an enlarged view of the bead core on the right side of (A). FIG. 4 is a schematic cross-sectional view taken along the line II-II of FIG. 3 of the forming apparatus to which the present invention is applied. . It is a figure of the principal part by the III arrow of Drawing 2, and the upper half shows the state where a formation part occupies a formation position, and the lower half shows the state where a formation part occupies a removal position. It is a principal part expanded arrow view of the formation part of the formation apparatus of FIG. It is an expanded sectional view of the formation part of FIG. It is a figure corresponding to FIG. 5 when forming the bead core from which the length of a base differs by the formation apparatus of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tire, 2 ... Bead part, 34 ... Formation groove, 40, 50 ... 1st formation member, 41a, 43a, 52a ... Formation surface, 45, 55 ... Slit, 46, 56 ... Partition, F ... Formation apparatus, B ... Bead core, W ... Wire, α ... Taper angle, M ... Forming part, A ... Position adjusting part.

Claims (3)

In an apparatus for forming a polygonal bead core for a tire, comprising a forming portion having a forming surface that defines a position of a wire that forms a polygonal bead core having a polygonal cross-sectional bottom and a taper angle.
The forming surface has a first forming surface that is inclined at the taper angle so as to define the base, and a second forming surface that defines a side that is continuous with the end of the base in the cross-sectional shape, The portion includes a first forming member having the first forming surface and a second forming member having the second forming surface, and the first forming member and the second forming member change the taper angle. The apparatus for forming a polygonal bead core for a tire is characterized in that it can be moved relative to each other so that the length of the bottom side can be changed.   In the first forming member, a first forming wall having the first forming surface is provided with a plurality of first openings penetrating in a radial direction with a first partition wall interposed therebetween in the circumferential direction. A second forming wall having a second forming surface is provided with a plurality of second openings penetrating in the axial direction of the bead core with a second partition in the circumferential direction, and the first opening and the second opening have The apparatus for forming a polygonal bead core for a tire according to claim 1, wherein the second partition wall and the first partition wall penetrate each other. The apparatus for forming a polygonal bead core for tire according to claim 2, wherein the first opening is a slit that opens in the axial direction.

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