JPH0441048B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stitching device for a tire molding machine that presses a band-shaped rubber member wound around a molding drum of the tire molding machine.

Traditionally, stitching devices for tire molding machines include a stitching roll that rotates around a rotating shaft parallel to the axis of the molding drum and rolls on a rubber band member as the molding drum rotates, and a stitching roll that is rotatable. A device is known that includes a supporting member that is supported axially and a moving means that moves the supporting member in the axial direction of the forming drum. However, in such a device, although the crimping locus of the stitching roll becomes a spiral shape on the band-shaped rubber member when crimping the band-shaped rubber member,
Since the axis of rotation of the stitching roll is always parallel to the forming drum, a thrust force in the moving direction of the stitching roll acts on the rubber band member due to frictional resistance, and as a result, the rubber band member There are problems in that unnecessary deformation, gauge changes, elongation, etc. occur. In addition, in the case where a pair of the above stitching rolls are installed and each stitching roll is used to press one end side in the width direction and the other end side in the width direction of the band-shaped rubber member, the thrust force of both stitching rolls is If the balance is lost, the band-shaped rubber member is pulled to one side and moves on the forming drum, resulting in the problem that the balance of the thrust force must be adjusted in a complicated manner. Moreover, even when the balance of the thrust force is adjusted in this way, the balance of the thrust force is lost because the stitching roll flies a small distance when it crosses the deformed part of the band-shaped rubber member mentioned above. There is also the problem that while the band-shaped rubber member moves on the forming drum, the part of the band-shaped rubber member that has blown off is not crimped.

This invention was made in view of the above-mentioned problems, and an object of the present invention is to reduce as much as possible the thrust force acting on the band-shaped rubber member during crimping with a simple structure.

This purpose is to use a stitching roll that rolls on a band-shaped rubber member due to the rotation of a forming drum;
A support member that rotatably supports the stitching roll, a bracket that rotatably supports the support member about the rotation axis, and a moving means that moves the bracket in the axial direction of the forming drum, The rotation axis is substantially parallel to the normal line to the forming drum at the contact point between the stitching roll and the forming drum, and is located on the center plane in the width direction of the stitching roll, and is located on the axis of the stitching roll. The centering can be achieved by being offset by a predetermined amount from the pivot axis on a plane that includes the axis of the stitching roll and is perpendicular to the normal line.

That is, when the belt-shaped rubber member is crimped by moving the bracket along with the stitching roll in the axial direction of the molding drum while rotating the forming drum, the stitching roll receives the reaction force of the thrust force acting on the belt-shaped rubber member. As a result, a moment with at least a predetermined amount between the rotation axis of the support member and the axis of the stitching roll acts on the stitching roll and the support member, and these stitching rolls and the support member Rotates around the rotation axis of the member. As a result, when the thrust force approaches zero as much as possible and the reaction force of the thrust force received by the stitching roll becomes zero,
The stitching roll and support member stop rotating.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

This embodiment shows an example in which a stitching device is applied to tire band forming. In Fig. 1, numeral 1 is a rotatable forming drum that can expand and contract in diameter. A band-shaped rubber member 2 is wrapped around the belt. This band-shaped rubber member 2 consists of a plurality of band-shaped rubber members whose starting ends and terminal ends are joined and overlapped.
Reference numerals 3 and 4 denote a pair of stitching rolls that roll on the band-shaped rubber member 2 when the forming drum 1 is rotating. 5 and 6 are approximately L-shaped support plates, and at the upper end of each support plate 5 and 6,
As shown in FIGS. 2, 3, and 4, a support shaft 7 is attached that is parallel to the axis of the forming drum 1 and loosely fitted within the stitching rolls 3, 4. Bearings 8 and 9 are interposed between the support shaft 7 and the stitching rolls 3 and 4. The support plates 5, 6 and the support shaft 7 described above collectively constitute the support member 1.
0 and 11, and these supporting members 10 and 11
rotatably supports the stitching rolls 3 and 4. An insertion shaft 12 is fixed to the lower end of each support plate 5, 6, and each insertion shaft 12 inserts a bush 1 into a through hole 15 formed in the holding plates 13, 14.
It is rotatably inserted through 6. The axis of each insertion shaft 12, that is, the rotation axis m of the supporting members 10, 11 is approximately parallel to the normal to the forming drum 1 at the contact point between each stitching roll 3, 4 and the forming drum 1, and , are located on the center plane q in the width direction of each stitching roll 3, 4. Further, this axis m includes the axis 1 of the stitching rolls 3 and 4, that is, the axis of the support shaft 7, and is a predetermined distance n from the axis 1 in a plane p perpendicular to the normal line. The shaft center 1 is offset by a distance n from the extension line of the shaft center m. Each holding plate 13, 14 has a vertical plate 17,
18 are fixed and these vertical plates 17,1
8 and the holding plates 13, 14 are each integrally fixed to form brackets 19, 20 to pivotally support the stitching rolls 3, 4. As shown in FIGS. 2 and 4, a pair of stoppers 21 and 22 are attached to each of the holding plates 13 and 14, and between these stoppers 21 and 22 is a projection attached to each of the support plates 5 and 6. 23
is located. Stopper 21, 22 and protrusion 2
3, springs 24 and 25 are interposed to return the protrusion 23 to the neutral position with a force slightly greater than the abrasion resistance between the insertion shaft 12 and the bush 16. As a result, the springs 24, 25
When an external force larger than the elastic force of
When the external force is removed, the support members 10 and 11 can rotate until they come into contact with the spring 2.
It returns to the neutral position by the elastic force of 4 and 25.
The brackets 19 and 20 are fixed to the ends of arms 26 and 27, respectively, as shown in detail in FIG.
Reference numerals 28 and 29 are movable bases installed corresponding to the stitching rolls 3 and 4, and each movable base 28,
A protrusion 30 is formed on the upper surface of 29. The proximal ends of the arms 26 and 27 are rotatably connected to each protrusion 30 via a pin 31. 32
is a screw shaft as a means of movement, and this screw shaft 3
2 extends parallel to the axis of the forming drum 1. The threaded shaft 32 has a right-handed thread on one side and a left-handed thread on the other side, bordering the center in the axial direction, and a moving base 28 is screwed to the right-handed threaded portion, and a moving base 29 is screwed to the left-handed threaded portion. There is. As a result, when the screw shaft 32 rotates, the brackets 19 and 20 move in the axial direction of the forming drum 1 together with the movable tables 28 and 29. Note that 33 is a guide rod parallel to the screw shaft 32 passing through the movable tables 28 and 29. The movable tables 28 and 29 have cylinders 34 and 3 that are substantially parallel to the arms 26 and 27, respectively.
5 are installed and these cylinders 34, 35
The tips of the piston rods 36, 37 are connected to the base ends of the arms 26, 27.

Next, the operation of one embodiment of the present invention will be explained.

First, a plurality of layers of rubber bands are wound around the forming drum 1 while rotating the forming drum 1 in an enlarged diameter state to form a cylindrical band-like rubber member 2. Next, by rotating the screw shaft 32, the movable tables 28 and 29 are synchronously moved toward the axial center of the band-shaped rubber member 2, and when the stitching rolls 3 and 4 come into contact with each other, the screw shaft 32 rotates. stop. Next, actuate the cylinders 34 and 35 to remove the piston rod 3.
6,37 can be retracted. As a result, arm 2
6 and 27 swing, and the stitching rolls 3 and 4 are brought into pressure contact with the band-shaped rubber member 2 at a predetermined pressure. At the same time, since the forming drum 1 is rotated, the stitching rolls 3 and 4 roll on the band-shaped rubber member 2, and crimping of the band-shaped rubber member 2 is started. Next, the screw shaft 32 is rotated at a constant speed, and the movable tables 28 and 29 are moved away from each other in the axial direction of the forming drum 1.
Therefore, the stitching rolls 3 and 4 roll in a spiral shape from the axial center to both axial ends on the band-shaped rubber member 2, and the pitch angle of the trajectory is determined by the rotational speed of the forming drum 1 and the movable table 28. , 29. As a result, the rubber band members constituting the rubber band member 2 are successively crimped together, and the air remaining between them is pushed out toward both ends in the axial direction. At this time, as mentioned above, since the stitching rolls 3 and 4 move in the axial direction of the band-shaped rubber member 2, the band-shaped rubber member 2 receives a thrust force from the stitching rolls 3 and 4 toward both ends in the axial direction, and , the stitching rolls 3 and 4 receive the reaction force of this thrust force. However, as described above, the axis l of the stitching rolls 3 and 4 is offset by a predetermined amount n from the axis m of the supporting members 10 and 11 on the plane p including the axis l. The moment when the predetermined amount n is at least the arm length (actually, the arm length is the shortest distance between the crimping point of the stitching rolls 3 and 4 on the band-shaped rubber member 2 and the axis m) is applied to the stitching rolls 3 and 4. 4 and the support members 10, 11, and the support members 10, 1
1 is supported by brackets 19 and 20 so as to be rotatable about the axis m, so that both the stitching rolls 3 and 4 and the supporting members 10 and 11 are rotated about the axis m in the direction in which the reaction force acts. Rotate. As a result, the thrust force approaches zero as much as possible, and when the widthwise center plane q of the stitching rolls 3, 4 is inclined by an angle equal to the pitch angle, the thrust force becomes zero. As a result, the rotation of the stitching rolls 3 and 4 and the support members 10 and 11 is stopped. In this way, the stitching rolls 3 and 4 roll on the band-shaped rubber member 2 while swinging so that the thrust force becomes zero, so that the stitching rolls 3 and 4 roll on the band-shaped rubber member 2.
No unnecessary deformation, misalignment, or elongation occurs during crimping.
Furthermore, there is no need to adjust the balance of the thrust force on the rubber band member 2, and furthermore, the stitching rolls 3, 4 do not fly a minute distance over the rubber band member 2 during crimping. Note that when crimping a band-shaped rubber member 2 with a contour such as a tread band, the stitching rolls 3 and 4 are oscillated so that the thrust force becomes zero, but the oscillation angle in this case is based on the contour. Since it is affected by the inclination angle, it is not the same as the pitch angle mentioned above. The stitching rolls 3 and 4 may generate self-excited vibrations while crimping the band-shaped rubber member 2, but if this self-excited vibration becomes larger than a predetermined value, the protrusion 23 will move against the stopper 2.
1 and 22 to restrict the expansion of self-excited vibration. Next, when the stitching rolls 3 and 4 reach both axial ends of the band-shaped rubber member 2, the threaded shaft 32
The rotation of the brackets 19 and 20 is stopped, and the axial movement of the brackets 19 and 20 is stopped. As a result, the stitching rolls 3 and 4 are oscillated again, and the center plane q in the width direction thereof becomes perpendicular to the axis of the band-shaped rubber member 2. As a result,
It is also possible to uniformly press both ends of the band-shaped rubber member 2 in the axial direction. When the band-shaped rubber member 2 is crimped in this way, the cylinders 34 and 35 are actuated to project the piston rods 36 and 37,
The stitching rolls 3 and 4 are separated from the band-shaped rubber member 2. At this time, stitching roll 3,
4 is held in the neutral position by the elastic force of the springs 24 and 25, so that it is in a proper posture when starting the next compression bonding of the band-shaped rubber member. next,
After stopping the rotation of the forming drum 1, the forming drum 1 is reduced in diameter. Next, the band-shaped rubber member 2 that has been crimped is
(band) is taken out and transported to the next process. The above is one cycle of operation of one embodiment of this invention,
This cycle is repeated thereafter. In the above embodiment, the stitching rolls 3 and 4 are held in the neutral position using the springs 24 and 25, but the springs 24 and 25 are not necessarily required.

As explained above, according to the present invention, the thrust force acting on the band-shaped rubber member during crimping can be reduced as much as possible. For this reason, deformation, elongation, and gauge changes of the band-shaped rubber member during crimping,
It is possible to prevent separation of the joint portions at the beginning and end, and also to prevent displacement in the axial direction. Moreover, since the structure is simple, it can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention, FIG. 2 is a plan view of the vicinity of the stitching roll,
3 is a view in the direction of the - arrow in FIG. 2, and FIG. 4 is a sectional view in the direction of the - arrow in FIG. 1... Molding drum, 2... Band-shaped rubber member, 3,
4... Stitching roll, 10, 11... Support member, 19, 20... Bracket, 32... Moving means (screw shaft).

Claims (1)

[Claims] 1 A stitching device for a tire molding machine that presses a band-shaped rubber member wrapped around a forming drum of a tire-molding machine, which comprises a stitching roll that rolls on the band-shaped rubber member as the forming drum rotates, and a stitching roll that rotates the stitching roll. a support member that is rotatably supported, a bracket that supports the support member so as to be rotatable about the rotation axis, and a moving means that moves the bracket in the axial direction of the forming drum; is substantially parallel to the normal line to the forming drum at the point of contact between the stitching roll and the forming drum, and is located on the center plane in the width direction of the stitching roll, and the axis of the stitching roll is A stitching device for a tire molding machine, characterized in that the stitching device is offset by a predetermined amount from the rotation axis on a plane that includes the axis of the roll and is perpendicular to the normal line.