JPH0429540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pneumatic tire molding machine, and more particularly to a device for folding back a carcass ply band in a positive molding method.

Generally, the following two methods are employed in tire molding machines. In other words, () this is a method used when molding tires of relatively small size, in which a carcass ply is wrapped around the circumferential surface of a molding drum in a reduced diameter state, a bead wire is supplied and placed around it, and then a bead wire is placed around it. There are two methods: (1) expanding the diameter of the forming drum and folding the carcass ply around the bead wire to form the tire, and (2) the method used when forming especially large tires such as truck and bus tires. After attaching a carcass ply band formed in a separate process to the circumferential surface of the forming drum in a reduced diameter state, the forming drum is expanded in diameter.
Next, the carcass ply band is reduced in diameter to a diameter close to the inner diameter of the bead wire, and bead wires having a smaller diameter than the enlarged outer diameter of the drum are placed at both ends of the drum in the axial direction. This is a so-called positive molding method in which both ends of the carcass ply band are folded back along the tire to mold the tire.

In the latter method, ()
A device such as that disclosed in No. 33977 has been proposed. However, in this device, the bead wire is supported only by a flexible bladder when folding the carcass ply band, so
It is difficult to accurately position the bead wire concentrically with the drum, and misalignment is likely to occur.
If the position of the bead wire is misaligned, wrinkles will occur in the carcass ply band on the inner circumferential side of the bead wire, causing air entrainment, or variations in the position of the edge of the folded carcass ply band may occur, resulting in completion of the carcass ply band. Since defects such as poor uniformity of the manufactured tire occur, careful work by skilled workers is required, which is a factor that hinders improvement in the efficiency of tire molding work.

This invention was made by focusing on these conventional problems, and it does not require careful work by skilled workers, improves work efficiency, and molds product tires with good uniformity. It is an object of the present invention to provide a carcass ply band folding device using a positive molding method.

The present invention is characterized in that a carcass ply band folding device for a tire forming machine folds both ends of a carcass ply band folded at an axial end of a tire forming drum along the inner circumference of a bead wire. The carcass ply band is disposed on the inner circumferential side of the axial end of the tire forming drum, and is temporarily inflated and approaches the end of the tire forming drum in a stoppable manner to spread out wrinkles in the carcass ply band near the bead wire. a bladder mechanism having a bladder membrane that folds back;
It is provided inside the bladder of the bladder mechanism so as to be able to protrude outward in the radial direction, and when protruding comes into contact with the bead wire from the inner circumferential direction via the bladder membrane and the carcass ply band to hold the bead wire in a predetermined position. The present invention provides a carcass ply band folding device for a positive molding method, comprising a bead wire holding mechanism for holding the bead wire and an actuation mechanism for projecting the bead wire holding mechanism into the interior of the bladder when expansion of the bladder membrane is temporarily stopped.

The present invention will be explained below based on the drawings. FIGS. 1 to 8 show an embodiment of the present invention, and first, the configuration of FIG. 1 will be explained. Although the figure shows only one side of the tire building drum 1 in the axial direction, the opposite side has a similar configuration. The tire building drum (hereinafter simply referred to as a drum) 1 is constituted by a plurality of drum segments 2 divided in the circumferential direction, and is capable of expanding and contracting in diameter. In the figure, the drum 1 is in an enlarged diameter state.
Reference numeral 3 denotes a known folding blade plate which is provided so as to be coaxially close to and away from the axial end of the drum 1, and is used to fold in the axial end 4a of the carcass ply band 4 attached to the drum 1 in the radial direction. It is. 5 is a known bead wire transport mechanism that holds the bead wire 6 concentrically with the drum 1 and transports it to the end of the drum 1. This bead wire conveying mechanism 5 includes a support member 7 that supports the inner peripheral surface of the bead wire 6, a pressing plate 8 that contacts one side of the bead wire 6 to press and position the bead wire 6 against the end surface of the drum 1, and the outer peripheral side of the It has an outer ring portion 9 located at the outer ring portion 9 for deforming the bladder, which will be described later. 10 is an annular body provided on the axial end side of the drum 1 so as to be able to approach and separate from the drum 1 concentrically, and 11 is a bladder attached to the outer peripheral surface of the annular body 10. The annular body 10 includes a bladder 11
A plurality of air holes 12 for blowing compressed air into it to inflate it or discharging it to make it deflate.
As shown in FIG. 2, they are provided at a predetermined angle from each other in the circumferential direction, and each air hole 12 is an air pipe with a switching valve (not shown) in the middle, as shown in FIG. 13, it is connected to a compressed air source (not shown). The annular body 10, bladder 11, and air pipe 13 are combined to form a bladder mechanism 14 for folding back the end portion 4a of the carcass ply band 4 radially outward along the inner peripheral surface of the bead wire 6.
It consists of Returning to FIG. 1, reference numeral 15 designates pin members inserted into holes 16 formed in the radial direction between each air hole 12 of the annular body 10 so as to be able to move forward and backward. One end of the pin member 15, that is, the radially outer end of the annular body 10;
A bead wire holding member 17 is attached to the end, and a rotating roller 18 is attached to the other end. pin member 15, bead wire holding member 17,
The rotating rollers 18 are combined to form a bead wire holding mechanism 19. A block 20 is provided so as to be slidable in the axial direction along the inner circumferential surface 10a of the annular body 10, and has an inclined groove 21 having a T-shaped cross section. This block 20 is a piston rod 22a of an air cylinder 22 fixed to the annular body 10.
As is clear from FIG. 2, the block 20 and air cylinder 22 are connected to the tip of the
Each bead wire holding mechanism 19 is provided between each air pipe 13 in correspondence with the bead wire holding mechanism 19 . And the bead wire holding mechanism 1
As is clear from FIG. 1, the ends of the blocks 9 on the rotating roller 18 side are movably inserted into the inclined grooves 21 of the corresponding blocks 20. As a result, the bead wire holding mechanism 19 can protrude or retract radially outward, that is, into the bladder 11 along the inclined groove 21 as the block 20 moves forward or backward. The air cylinder 22 and block 20 together constitute an operating mechanism 23 for operating the bead wire holding mechanism 19.

Next, the action will be explained.

After attaching the carcass ply band 4 previously formed in another process to the outer periphery of the drum 1 whose diameter has been expanded, the bladder mechanism 14 is brought close to both ends of the drum 1. Next, the folded wing plate 3 is brought close to the end of the drum 1, and both ends 4a, 4a of the carcass ply band 4 are folded inward in the radial direction along the shape of the end of the drum 1. When folded like this,
The carcass ply band 4 is wrinkled due to its diameter reduction, and the wrinkles are not uniform. Next, the bead wire 6 is transferred to the drum 1 by the bead wire conveyance mechanism 5.
It is conveyed to both ends of and pressed into position. This state is the state shown in FIG. bead wire 6
When the bead wire transport mechanism 5 is positioned, the support member 7 of the bead wire conveying mechanism 5 moves back in the direction of the arrow as shown in FIG. next,
A predetermined amount of compressed air is supplied into the bladder 11 through an air pipe 13 and an air hole 12 from a compressed air source (not shown). As a result, the bladder 11 expands to some extent as shown in FIG. 5, contacts both ends 4a, 4a of the carcass ply band 4 from the inside in the radial direction, and lifts the bladder 11 outward in the radial direction so as to spread out the wrinkles. At this time, it is desirable to inflate the bladder 11 to such an extent that it comes into close contact with the carcass ply band 4 so that the carcass ply band 4 is not wrinkled at the inner peripheral portion of the bead wire 6. Therefore, it is best to slowly inflate with low-pressure air. As described above, when the bladder 11 is inflated and the wrinkles of the carcass ply band 4 are removed, the supply of compressed air to the bladder 11 is temporarily stopped. Then, when the piston rod 22a of the air cylinder 22 is projected, the bead wire holding mechanism 19 is guided by the inclined groove 21 of the block 20, moves in the axial direction, and projects into the interior of the bladder 11 from the annular body 10 in the radial direction. As a result, the bead wire holding member 17 of the bead wire holding mechanism 19, as shown in FIG.
It contacts the inner peripheral surface of the beat wire 6 via the bladder membrane 11a of the bladder 11 and the carcass ply band 4, and is positioned and fixed concentrically with the drum 1.
Next, the bead wire conveying mechanism 5 and the folding vane 3 return to a standby position spaced apart from the end of the drum 1, as shown in FIG. however,
As described above, the bead wire 6 is accurately positioned and fixed at a predetermined position by the bead wire holding mechanism 19, so that no displacement occurs.
Further, since the carcass ply band 4 is also in close contact with the bladder 11, it does not wrinkle. In this state, compressed air is supplied to the bladder 11 again and it starts expanding. During the expansion of the bladder 11, the bead wire conveying mechanism 5 is brought close to the drum 1 to a predetermined position, and as shown in FIG. Fold completely outward. When the carcass ply band 4 has been folded back, the bead wire conveyance mechanism 5 is returned to the standby position and the piston rod 22a of the cylinder 22 is moved back. As a result, the movement of the block 20 causes the bead wire holding mechanism 1 to
9 retracts along the inclined groove 21 in the axial direction of the annular body 10 by its own weight. Next, the compressed air in the bladder 11 is discharged, the bladder 11 is completely deflated, and one cycle of the carcass ply band 4 folding operation is completed.

As explained above, according to this invention,
Since the bead wire can be fixed precisely concentrically with the drum until the carcass ply band is completely folded back along the bead wire, wrinkles that can cause air to be drawn into the carcass ply band are less likely to form. Since the variation in the position of the edge of the folded carcass ply band is small, it is possible to obtain a product tire with good uniformity and high quality. Furthermore, since careful work by skilled workers is not required, the efficiency of tire molding work can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a carcass ply band folding device in a positive molding method according to the present invention, FIG. 2 is a sectional view taken along the - arrow in FIG. − arrow cross-sectional view;
4 to 8 are sectional views showing the operating state of the apparatus of FIG. 1, respectively. DESCRIPTION OF SYMBOLS 1... Tire forming drum, 4... Carcass ply band, 6... Bead wire, 11... Bladder, 14... Bladder mechanism, 19... Bead wire holding mechanism, 23... Operating mechanism of bead wire holding mechanism.

Claims (1)

[Claims] 1. In a carcass ply band folding device in a positive molding method in which both ends of a carcass ply band folded at an axial end of a tire forming drum are folded back along the inner circumference of a bead wire,
The carcass ply band is disposed on the axial end side of the tire building drum, and is temporarily and stopably inflated and approached from the radially inner side of the tire forming drum to widen the wrinkles in the carcass ply band near the bead wire, and then the carcass ply band is expanded. a bladder mechanism having a bladder for folding back a band; and a bladder mechanism provided inside the bladder of the bladder mechanism so as to be able to protrude outward in a radial direction; It is characterized by comprising a bead wire holding mechanism that abuts to hold the bead wire in a predetermined position, and an actuation mechanism that causes the bead wire holding mechanism to project into the interior of the bladder when expansion of the bladder temporarily stops. Carcass ply band folding device for positive molding method.