JP3068154B2 - Tire building drum for two sizes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an initial step of tire molding, that is, a step of bonding a tire inner liner and a carcass ply in order to form a tubular material (hereinafter referred to as a ply band) forming a tire skeleton. The present invention relates to a flat drum that can be enlarged and reduced in diameter for forming a tire used in the step of forming a bead on the ply band.

(Prior Art) As described in JP-A-1-190438, a tire is formed by laminating an inner liner and a carcass ply of a tire on a flat drum in order or by combining an inner liner and a carcass ply. In the formation of a radial tire, it is possible to perform an initial step of forming a ply band by adding a tufer in the middle, expanding the ply band, and setting a bead near its end on the same drum. Is commonly adopted.

In order to set the bead ring on the ply band, it is necessary to increase the diameter of the ply band after positioning the bead ring formed in advance on the ply band. Use what is possible.

This type of forming drum is described in JP-A-60-68929 and JP-B-51-19871 in addition to those described in the above patent gazettes. The former discloses that a plurality of segments constituting a cylindrical drum are movable in a radial direction. This forming drum has a cylindrical ring having a multi-stage piston near the axis thereof, and a plurality of stages of the drum main body are expanded by introducing a pressurized fluid to necessary portions of a plurality of airtight chambers partitioned by each piston. This is a device that performs diameter measurement.

In the latter case, the air cylinder formed of the cylindrical ring in the former device projects axially outward from the inside of the drum to facilitate diameter adjustment and the like.

(Problems to be Solved by the Invention) In the actual tire manufacturing process, tires having the same rim diameter are usually continuously produced, and different types of tires are rarely produced in the same process. This is because in order to manufacture tires having different rim diameters, it is necessary to replace and use molding drums having different diameters, and it is difficult to cope in the same process.

However, it is easily anticipated that establishing a production system to deliver tires of the required size at the required time will be important in the manufacture of a wide variety of tires. Development of a forming drum that can be used together is indispensable.

Therefore, in the case of the device described in Japanese Patent Application Laid-Open No. 60-68929, since the sliding surface is composed of multi-stage pistons, the sliding surface is multiplexed and complicated, so that smooth operation cannot be obtained. It is difficult to accurately adjust to a large number of drums of the same diameter, and furthermore, there is a problem in that the adjustment position is easily shifted during individual use, and tires of constant quality cannot always be produced.

Also, the apparatus described in Japanese Patent Publication No. 51-19871 has the same problem as described above.

Accordingly, an object of the present invention is to provide a forming drum which can be used for forming two sizes of tires having different rim diameters by three-stage expansion and contraction of the drum diameter.

(Means for Solving the Problems) The present invention is directed to a large segment having a fan-shaped cross section arranged at equal intervals on a circumference and an inflatable cylindrical elastic rubber band arranged on the outer surface thereof. A cylindrical drum that constitutes a main part and further includes a small segment having a mountain-shaped cross section between the large segments, and the large segment and the small segment are formed in the radial direction of the cylindrical drum while expanding the cylindrical elastic rubber band. By connecting a slider and a link movably and movably fixed in the axial direction of the rotating shaft by a link, and providing a stopper for adjusting the amount of movement of the slider and the amount of swing of the link in three stages, the peripheral surface of the cylindrical drum is provided. Is a first stage in which a large segment is continuous, a second stage in which the peripheral surface is an alternating continuous series of large segments and small segments, and a small segment in which the peripheral surface is between large segments. Is a two-size combined tire building drum which is fixedly installed in each arrangement where the drum diameter is increased in the order of a third step slightly projecting in the drum radial direction.

(Operation) In the bead set to the ply band bonded on the forming drum, bead rings formed in advance are fitted in gaps from both ends of the ply band and arranged at predetermined positions, and then the forming drum is expanded. The diameter of the ply band is enlarged according to the diameter, and the outer peripheral surface of the ply band is brought into close contact with the inner peripheral surface of the bead ring.

Therefore, the forming drum used in this molding is expanded from the drum diameter A at the time of pasting the ply band to the drum diameter B necessary for bringing the bead ring into close contact with the outer peripheral surface of the ply band, and conversely reduced. What is necessary is just to be able to scale.

However, in order to form a tire having a rim diameter larger than the above with the same forming drum, it is necessary to set the drum diameter C at the time of forming the ply band larger than the diameter A and the drum diameter D at the time of bead setting larger than the diameter C by two. Step scaling is further required.

Therefore, in the forming drum according to the present invention, paying attention to the point that there is no problem even if the bead setting in forming a small size tire and the pasting of a ply band in forming a large size tire are performed with the same drum diameter, A three-stage enlargement / reduction system in which the drum diameters B and C are the same has realized a forming drum that can be used in two sizes.

Here, the arrangement of the large and small segments constituting the peripheral surface of the forming drum changes according to the expansion and contraction of the three stages. When the ply band is pasted and formed (the second stage also serves as a bead set), the first stage has a large segment with a fan-shaped cross section, the second stage has a small segment with a large and cross-sectionally mountain-shaped segment, Is characterized in that the drum peripheral surface is always constituted by the series of.

Therefore, in any size, the ply band can be formed on the peripheral surface of the drum without any irregularities, so that air and the like are not sealed in the bonding surface when the respective materials are bonded, so that the post-process can be performed. Adverse effects can be eliminated.

(Example) FIGS. 1 and 2 show cross sections of a tire building drum according to the present invention.

In the drawing, reference numeral 1 denotes a rotary shaft supported by a rotary drive device (not shown), and disk-shaped guide plates 2 are fixed to both ends of the rotary shaft 1, respectively. The small segments 4 having a mountain-shaped cross section are attached so as to be alternately arranged in the circumferential direction, and the large segment 3 and the small segments 4 constitute a cylindrical drum 5 having the rotation shaft 1 as an axis.

Specifically, twelve guide grooves 6 extending radially around the rotation shaft 1 are formed at equal positions on the inner surface of the guide plate 2, and the large segment 3 and the small segment 4 are slid on these guide grooves 6. The large segment 3 and the small segment 4 are movably mounted so as to be movable in the radial direction of the drum.

Further, a slider 7 fixed inside the cylindrical drum 5 along the peripheral surface of the rotating shaft 1 so as to be movable in the axial direction, a short link 8 connecting the slider 7 to the large segment 3 or the small segment 4, and a slightly longer link The link 8a is installed, and the movement of the slider 7 causes the link 8, 8a to swing about the segment side pin as a fulcrum. The large segment 3 or the small segment 4 whose axial movement is restricted by the guide plate 2 is formed in the guide groove. 6 moves outward in the drum radial direction under the guidance of 6.

The inside of the slider 7 is fixed to the slider 7 with stoppers 9a to 9c fixed to the rotating shaft 1 and the stopper 9
The partition chambers 12a to 12g are partitioned by a built-in cylinder 11 composed of a partition wall 10a disposed between a and 9b and partition walls 10b and 10c slidably inside the slider 7 and surrounding a stopper 9c. Then, a predetermined compartment is selected from these compartments 12a to 12g, and the amount of movement of the slider 7 and the amount of swing of the links 8, 8a are adjusted by introducing air into the compartments. The movement of segment 4 is adjusted in three stages.

Here, the inclination angles of the links 8, 8a with respect to the slider 7 are different between the large segment 3 side and the small segment 4 side, that is, the inclination angle of the link 8 connected to the large segment 3 is α, When the inclination angle of the link 8a is β, the relationship is set so that α> β, and the link 8a is configured to be slightly longer than the link 8. This means that the radial movement amount of each segment in accordance with the movement of the slider 7 is smaller than the large segment 3
By this operation, for example, when the diameter of the drum is reduced, care is taken so that the large segment 3 retreats after the small segment 3 retreats, and the intersection of the large segment 3 and the small segment 4 is prevented.

Reference numeral 13 denotes a cylindrical elastic rubber band disposed along the peripheral surface of the cylindrical drum 5 and assists in equalizing the force applied to the ply band in the circumferential direction when the diameter of the drum is enlarged.

Next, three-step expansion and contraction of the drum diameter by moving and fixing the large segment 3 and the small segment 4 were performed at 13 inches and 14 inches.
An example of a forming drum that can be used for forming a tire having a rim diameter of inches will be described.

The above-mentioned FIG. 1 shows the first stage state in which the drum diameter is the minimum, that is, the drum diameter used when the ply band is pasted and formed in a tire having a rim diameter of 13 inches. In this case, the compartments 12a, 12c and 12e are provided. Air is introduced, and the slider 7 is fixed at a position where the partition 10c hits the stopper 9c. In the first stage drum diameter, as shown in FIG. 2, the peripheral surface of the cylindrical drum 5 is entirely constituted by a series of large segments 3, and the small segments 4 fit inside the large segments 3 in the radial direction. The arrangement makes it possible to provide a drum peripheral surface without irregularities.

FIGS. 3 (a) and 3 (b) show a second drum having an intermediate drum diameter.
The step state, i.e., the diameter of the drum used when pasting and forming the ply band on a tire having a rim diameter of 14 inches and when setting the bead ring on the 13-inch ply band, is indicated in this case by air in the compartments 12d and 12f. And introduced
The slider 7 is fixed at a position where the partition wall 10b hits the stopper 9c. In the drum diameter of the second stage, the peripheral surface of the cylindrical drum 5 has a large segment 3 as shown in FIG.
And the small segments 4 are continuous with each other, and the large segments 3 and the small segments 4 are alternately arranged. In this case as well, a drum peripheral surface without unevenness can be provided.

As described above, in the first and second drum diameters,
Since the drum surface has no irregularities, the inner liner,
Carcass plies and the like can be bonded together without air intrusion and wrinkling.

4 (a) and 4 (b) show the third drum having the largest drum diameter.
The step state, that is, the diameter of the drum used when setting the bead ring on the ply band for the rim having a rim diameter of 14 inches, in this case, introducing air into the compartments 12b and 12g,
The slider 7 is fixed at a position where 10a hits the stopper 9b. In this third stage drum diameter, large segment 3
The small segments 4 are arranged alternately such that the small segments 4 slightly protrude radially outward between the large segments 3 as shown in FIG. In this case, although some irregularities are formed on the peripheral surface of the drum, as described above, since a uniform arc is maintained with the elastic rubber band 13, there is a problem in setting the bead ring to the ply band. Does not occur.

In addition, since the contraction force of the elastic rubber band 13 based on the diameter expansion is increased in the third stage state, in addition to the introduction of the air into the compartment 12b, the air is also supplied to the compartment 12g as described above. Is introduced so that the expanded state can be sufficiently maintained.

(Effect of the Invention) By using a forming drum that can be used for forming tires of different sizes according to the present invention, tires of different sizes can be formed on the same line, so that a finer production system than before can be established. In addition, a tire of constant quality can be produced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a forming drum according to the present invention, FIG. 2 is an end view of the forming drum, FIG. 3 (a) is a sectional view of the forming drum, and FIG. () Is a cross-sectional view of the forming drum, and (b) is an end view. 1 ... rotating shaft 2 ... guide plate 3 ... large segment 4 ... small segment 5 ... cylindrical drum, 6 ... guide groove 7 ... slider, 8, 8a ... link 9a-9c ... stopper , 10a-10c ... Partition wall 11 ... Built-in cylinder, 12a-12g ... Partition chamber 13 ... Elastic band

Claims (1)

(57) [Claims] 1. A main portion of a cylinder is constituted by a large segment having a fan-shaped cross section arranged at equal intervals on the circumference and an inflatable cylindrical elastic rubber band arranged on the outer surface thereof. A cylindrical drum in which small segments having a mountain-shaped cross section are arranged between segments, wherein the large segment and the small segment are movable in a radial direction of the cylindrical drum while expanding a cylindrical elastic rubber band, and By connecting a slider and a link fixedly movably in the axial direction with a link, and providing a stopper for adjusting the amount of movement of the slider and the amount of swing of the link in three stages, the peripheral surface of the cylindrical drum becomes a series of large segments. One stage, the second surface in which the peripheral surface is an alternating series of large segments and small segments, and the peripheral surface slightly projects small segments between the large segments in the drum radial direction. A tire building drum for two sizes, which is fixedly installed in each arrangement in which the diameter of the drum increases in the order of the third stage.