JPS6330854B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a radial tire.

An example of this type of tire manufacturing method and device is shown in Japanese Patent Publication No. 51-33595.
According to this, an improvement can be seen in that the carcass layer before bead core installation and expansion can be reliably prepared on a rigid drum, but there is no improvement in the problem of bead core installation.

When assembling the carcass layer of a radial tire, the important thing is to wrap the bead core without disturbing the fiber spacing of the carcass cord, which is manufactured under strict control during the raw material process (specifically, the calender process).
Furthermore, the fibers are arranged as densely as possible in the inner peripheral position of the bead core.

However, in the conventional methods including those described above, first, as shown in FIG. 1a, the carcass layer a is
is made smaller than the inner diameter of the bead core to be wrapped in when assembling it into an annular shape, and after installing the bead core b outside it as shown in Fig. 1b, the first
As shown in figure c, the carcass layer a below the bead core
The fibers are expanded outward so as to be brought into close contact with the inner periphery of the bead core b, but the fiber spacing in the carcass layer a prepared at this time destroys the spacing determined in the raw material process, and When the fibers are brought into close contact with the fibers, the fiber density is reduced.

To give a quantitative example, tire size 11R22.5
In the case of bead core inner diameter......576mm Outer diameter of carcass layer before expansion of bead core installation part......536mm Expansion rate......(576-536)/536≒7.5%. The fiber spacing determined in the raw material process for the layers had changed by more than 7%, which translated into an elongation of approximately 126 mm in circumference, which had a major impact on tire quality.

The present invention was proposed in view of the above points, and
It is an object of the present invention to provide a new method and apparatus for manufacturing a radial tire that allows a carcass layer to be assembled around a bead core without stretching the carcass layer or destroying the fiber spacing.

In the present invention, after temporarily elastically deforming the entire area of a cylindrical carcass ply in a standing wave shape inward in the radial direction, a bead core prepared on the outside of the carcass ply is installed at a predetermined position, and then This relates to a radial tire manufacturing method characterized in that the elastic deformation of the carcass ply is released and the carcass ply is crimped onto the inner circumferential surface of the bead core, and the carcass ply is expanded radially outward when the bead core is installed. The carcass ply can be assembled around the bead core without elongating the carcass ply or destroying the fiber spacing controlled in the raw material process. This can contribute to improving tire quality, and even if the same carcass raw material as conventional ones is used, the number of fibers constituting the carcass ply can be increased, so the strength of the carcass ply can be improved. Furthermore, since the entire area of the carcass ply is elastically deformed into a standing wave shape, the bead core can be prepared without being affected by the carcass ply winding process, so the bead core preparation work can be facilitated.

Further, the present invention includes a plyformer made of a plurality of segments installed on a rotating shaft so as to be expandable and contractable in the radial direction, and a pair of bead holders that are disposed outside the plyformer and can be expanded and contracted in the radial direction. In addition, the plurality of segments of the plyformer form an inner cylindrical surface having a diameter smaller than the inner diameter of the bead core by the thickness of the carcass ply wound in the expanded position, and sufficiently smaller than the inner diameter of the bead core in the contracted position. The invention relates to a radial tire manufacturing device characterized in that the radial tire manufacturing device is configured so that the contraction limit positions inward in the radial direction are alternately different, and the carcass ply is manufactured by expanding a plurality of segments of the plyformer. By winding the carcass ply to form a cylindrical carcass ply, and then contracting the segments radially inward, the cylindrical carcass ply can be elastically deformed in a standing wave shape over its entire area, and in this state, By installing the bead core prepared in advance in the bead holder in a predetermined position and then expanding the segments, the carcass ply can be crimped onto the inner circumferential surface of the bead core, which is a simple method that can contribute to improving tire quality. A radial tire manufacturing apparatus having the following configuration can be obtained.

The present invention will be explained below based on illustrated embodiments.
Figure 2 is a diagram specifically showing the radial tire manufacturing method. First, as shown in Figure 2a, each segment of the plyformer is expanded and carcass ply etc. are wrapped around it to form a cylindrical tire. carcass ply 1
form 0. The diameter of the pliformer is set so that the outer diameter after winding the carcass ply is equal to the inner diameter of the bead core to which it is to be tightly attached, so the outer circumferential length of the carcass ply is equal to the inner circumferential length of the bead core.

Subsequently, the entire area of the carcass ply is elastically deformed radially inward by contracting the segments of the plyformer, as shown in FIG. 2b. FIG. 3 shows a carcass ply that has been elastically deformed, and the contracted state of the segments is regulated so as to form a standing wave shape as shown.

In this state, the bead core 1 prepared in the bead holder in advance is placed at a predetermined position outside the carcass ply 10 as shown in FIGS. By returning each segment of the plyformer to its original expanded state and releasing the elastic deformation of the carcass ply 10, the carcass ply 1 is formed on the inner circumferential surface of the bead core 11 as shown in FIG. 2e.
0 can be strongly crimped. Note that the bead core can be prepared without being affected by the carcass ply winding process.

When the assembly of the carcass ply 10 and bead core 11 is completed, the carcass gripping device of the transfer retracts radially inward to grip the carcass ply and then each segment of the plyformer, as shown in Figure 2f. contracts, and thus the assembly of carcass ply 10 and bead core 9 is passed to the transfer, and due to the movement of the transfer,
It is transferred to the first stage manufacturing equipment for the next process, where a cylindrical carcass layer is assembled.

Next, an example of a radial tire manufacturing apparatus used in the above method will be specifically explained.

Here, the apparatus A in FIG. 4 will be explained using a first-stage manufacturing apparatus used in a two-stage manufacturing method as an example, but it can also be applied to a drum apparatus employed in a first-stage manufacturing method. Of course.

FIG. 4 is a plan view of the whole, in which A is a first stage manufacturing device used in a two-stage manufacturing method equipped with a known drum device, B is a known stitcher device, C is a known material supply device, and D is a known stitching device. is a former that assembles inner liner, carcass ply, bead core, etc.
E is a known material supply device, and F is a transfer that is movable between the former D and the first-stage manufacturing device A to transfer assemblies such as carcass plies and bead cores; , transfer F are arranged coaxially.

The above-mentioned first stage manufacturing device A, stitcher device B,
Since each of the material supply devices C and E is well known, a detailed explanation thereof will be omitted, and the configurations of the former D and transfer F will be described below.

As shown in FIG. 5, the former D consists of a plyformer 21 and a bead holder 22, which are arranged on a rotatable shaft 20 so as to rotate together with the same shaft 20.

The plymer 21 includes a sleeve 23, a disk 24 provided at both ends of the sleeve 23 and projecting outward in the radial direction, a groove 25 provided in the disk,
A plurality of fan-shaped segments 26 with magnets 26a embedded in the outer surface, and a guide 2 that protrudes from the segments 26 and is guided by fitting into the groove 25.
7. It is composed of a stopper 28 that restricts the movement of the guide 27 in the radial direction, and a fluid pressure cylinder 29 installed between the segments 26 and the sleeve 23.
In the radially outward position regulated by The grooves 25 and the guides 2 are arranged so that the inner diameter of the bead core is sufficiently smaller than the inner diameter of the bead core in the inner position, that is, the retracted position, and the grooves 25 and the guides 2
7. A stopper 28 is constructed.

Therefore, if the segment 26 that has moved inward in the radial direction is moved inward first, and then the adjacent segments 26 are moved inward, the adjacent segments will overlap at the contraction limit position. This time difference in movement can be achieved by controlling the timing of fluid supply to the hydraulic cylinder 29.

As shown in FIG. 6, the plyformer 21 has a width sufficiently larger than the thickness of the bead core near the bead core setting position at both ends of each segment 26, so that it can protrude outward from the segment 26. A beadlock device 30 may be provided, which beadlock device 30 may be provided in the segment 2.
A segment 32 having an elastic body 31 stored in a recess 6, a pin 33 protruding from the segment 32 and sliding through a hole provided in the segment 26 as a guide, and a hydraulic cylinder 34 installed between the segments 26 and 32. The elastic body 3
The curvature of the outer surface of segment 1 is preferably the same as the curvature of segment 26 and, when stored in the recess of segment 26, the outer surface of segment 26.

The bead holder 22 is arranged at the shaft end on the opposite shaft support side of the plyformer 21, and is composed of a holder 35 for the left bead core and a holder 36 for the right bead core.
5 and 36 are made up of a plurality of fan-shaped pieces, and are attached to the radially outer position of the hub 37 fixed to the shaft 20 together with air bags 38 and 39 that are inflated and deflated separately;
The bead core is guided by the outer periphery of the bub 37, and the bead core installation seating surface is made slightly larger than the inner diameter of the bead core at the expansion limit, and at the contraction limit, the inner diameter of the bead core and the carcass ply wound on the plywood atom 21 are guided. It is becoming much smaller.

After the foamer structured as above is wrapped with carcass ply, inner liner, etc.
By folding inward in the radial direction, the entire carcass ply is elastically deformed into a cylindrical body with a regular wave-shaped surface as shown in Figure 3, and its outer diameter is made smaller than the inner diameter of the bead core. Can be done.

After deploying the bead core in place, segment 26
The carcass ply is crimped onto the inner circumferential surface of the bead core by expanding the segments 32 in the case shown in FIG. 6 and further expanding the segments 32.

When taking out the assembled carcass ply and bead core structure outside the former, the segments 26, 32 and the holders 35, 36 of the bead holder 21 are contracted inward to reduce their outer diameters, and then taken out by the transfer F. Can be done.

As shown in FIG. 7, the transfer F also includes a pair of left and right bead gripping devices F ₁ and F ₂ for gripping the bead core prepared in the bead holder 22 of the former D and setting it in a fixed position, and a bead core. a carcass gripping device F ₃ that grips from the outside between both bead cores of the carcass ply, and
It consists of a truck part _F4 for reciprocating between the former D position and the first stage manufacturing equipment A, and the truck part _F4 is a pedestal 42 equipped with wheels 41 that runs on a track 40.
An annular body 43 is installed on the pedestal 42 coaxially with the former D and the first stage manufacturing device A, the annular body 43 forms cylindrical guide surfaces at both ends thereof, and a bead gripping device F ₁ , F ₂ respective sleeves 44
is slidably mounted. Further, the ring body 43 has protrusions at a plurality of locations outward in the radial direction, and a plurality of sets of fluid pressure cylinders 45 for moving the bead gripping devices F ₁ and F ₂ in the axial direction are mounted on the protrusions, Furthermore, it guides the fan-shaped segment 46 of the carcass gripping device F ₃ in the radial direction and is equipped with its drive.

The bead gripping device _F1 includes a sleeve 44 that slides on the cylindrical surface of the ring body 43, a plurality of sets of arms 47 swingably attached to the sleeve 44, a magnet 48 provided at the tip of each arm, and a magnet 48 provided at the tip of each arm. The other end of the arm 47 is connected to the sleeve 44, and one end of the hydraulic cylinder 49 is connected to the sleeve 44.
The hydraulic cylinder 45 is connected to a protrusion 50 protruding from the annular body 44 at its other end.

When the arm 47 swings inward in the radial direction due to the extension of the cylinder 49, the radially inward position of the magnet 48 is set to the metal wire portion of the bead core, and the magnet 48 is positioned so as not to come into contact with the material wound on the former D. It is being done.

The bead gripping device F ₂ has the same configuration as F ₁ , and thus the bead gripping devices F ₁ and F ₂ can be positioned at any axial direction on the ring body 43, and the arm 47 can be swung at any position. I'm starting to be able to do it.

Furthermore, the carcass gripping device F ₃ includes a plurality of fan-shaped segments 46 movably mounted in the radial direction inside the ring body 43, a fluid pressure cylinder 51 that moves the segments in the radial direction, and an inner peripheral surface of the segments 46. Consisting of an embedded magnet 52, the segment 46 is adapted to approximately correspond to the outside diameter of the cylindrical carcass formed on the former D at the limit of its radial inward travel.

The transfer F configured as described above uses _the bead gripping devices F ₁ and F ₂ to install the bead core 11 in a predetermined position as shown in FIG. The structure is grasped and transferred from Former D to the first stage manufacturing equipment.

The above-mentioned embodiment is applied to the manufacture of tires using carcass plies containing steel cords, and the magnets 26a and transfer wires embedded in the outer surface of the segments 26 constituting the ply former 21 of former D. The magnet 52 constituting the carcass gripping device _F3 of F is
These act to elastically deform the carcass ply in a standing wave shape in the radial direction and to suction and grip the carcass ply. When using a carcass ply with a textile coat, a so-called finger ply is used instead of these magnets. Devices similar to down devices are placed on both sides of the former D, and vacuum suction means is used in place of the magnet 52.

[Brief explanation of the drawing]

1a to d are diagrams showing a conventional tire manufacturing method step by step; FIGS. 2a to 2f are diagrams showing a step by step example of an example of the tire manufacturing method according to the present invention; FIG. 4 is an overall plan view of the tire manufacturing apparatus according to the present invention, FIG. 5 is a cross-sectional view showing the specific structure of the former, and FIG. 6 is a diagram showing another embodiment of the former. FIG. 7 is a partially cutaway sectional view showing a specific structure of the transfer. 10: carcass ply, 11: bead core,
D: former, 20: rotating shaft, 21: preformer, 22: bead holder, 26: segment, 29: hydraulic cylinder, 35, 36: holder, 38, 39: air bag.

Claims (1)

[Claims] 1. After temporarily elastically deforming the entire area of a cylindrical carcass ply in a standing wave shape radially inward, a bead core prepared outside the carcass ply is installed at a predetermined position. A method for manufacturing a radial tire, comprising: then releasing the elastic deformation of the carcass ply to press the carcass ply to the inner circumferential surface of the bead core. 2. A plyhomer consisting of a plurality of segments installed on a rotating shaft so as to be expandable and contractable in the radial direction;
A pair of bead holders are arranged on the outside of the plyformer and are expandable and retractable in the radial direction, and in the expanded position, the plurality of segments of the plyformer are extended by the thickness of the carcass ply wound from the inner diameter of the bead core. A radial tire manufactured by forming an inner cylindrical surface with a small diameter, which is sufficiently smaller than the inner diameter of the bead core at the retracted position, and whose radially inward retracting limit positions are alternately different. Device.