JPH0818383B2 - Tire code topping method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a topping method for tire cords.
More specifically, the present invention relates to a topping method that can effectively reduce or prevent loss of down time that occurs when lots of cord sheets having different density standards are changed and deterioration of the quality of an organic fiber cord caused by a high temperature rubber substance.

[Conventional technology]

Tire topping sheets are roughly classified into two types: tire cord fabrics (also called woven fabrics) coated with rubber and parallel cord sheets such as those found in steel tire cords coated with rubber. However, in recent years, as the engine performance of automobiles has improved, the performance requirements for tires have become more sophisticated. Above all, there is a great demand for the development of a topping sheet that is light, thin, free of foreign matter, and highly flat. It is becoming expensive. By the way, in terms of a highly flat topping sheet, a weft-free topping sheet such as a steel tire cord has already been put into practical use, but the method using this steel cord makes the tire heavy because the material specific gravity is high, and further Is also hard and has poor riding comfort, so examples of using steel tire cords for carcass are limited to some large vehicles such as trucks and buses where riding comfort is not so important. ing. Therefore, it is generally used as a belt material in the passenger car field, which has a large market.

As described above, the steel tire cord has various problems and has not yet reached an important position as a carcass material for passenger cars. Therefore, while it is expected that a topping coat using an organic fiber cord and having excellent flatness is expected, such a topping sheet has not been realized at present.

[Problems to be solved by the invention]

The same applicant as the present invention proposes various methods for producing a topping sheet using a parallelized organic fiber cord that does not use a weft as a base material in order to solve the problems of the above-described conventional technology ( For example, August 18, 1986
Japanese Patent Application No. 61-191692, which was filed as a "method for manufacturing a topping sheet for tires" on the day). However, when a plurality of organic fiber cords are arranged in parallel in the case of carrying out this method, the arrangement density of organic fiber cords (hereinafter referred to as a yarn pitch) is obtained by using a fixed reed or a grooved roll having a constant reed blade interval. )
Is prescribed. Therefore, there is no problem in continuously producing parallelized organic fiber cords having a constant yarn pitch, but when switching lots of yarn feeding cord sheets with different yarn pitch standards, it is possible to remove new or old reeds or the like. Also, it takes a long time to insert the cord into the newly installed reed, and the device must be stopped during that time.

When the apparatus is stopped for a long time, the portion of the continuous organic fiber cord that is in contact with the high temperature rubber-like object receives excessive heat history, which causes physical property changes such as abnormal shrinkage. Therefore, this portion must be discarded as a loss, which is one of the reasons for inhibiting the progress of the weftlessness in the organic fiber topping sheet. For this reason, it is urgently required to provide a rational reed density varying method together with a rational cord joining method that can be performed in a short time.

Therefore, the inventors of the present invention have earnestly studied to provide a method of changing the code pitch in a short time, which is useful for lot switching, and arrived at the present invention.

That is, the present invention is a tire using a cord density control method that is easy to operate and can extremely reduce the stop loss time at the time of switching when supplying cord sheets having different density standards in the density control of the organic fiber cord group. The purpose is to provide a method of code topping.

[Means for solving problems]

An object of the present invention is to perform a lot switching operation in which lots of organic fiber cords having different pitch standards are subjected to a lot switching operation by pitch-controlling the cords using a reed of a variable density type. Reached by the tire cord topping method.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing an example of an apparatus for carrying out the tire cord topping method of the present invention.

As shown in FIG. 1, the sheet end of the newly-supplied dip cord 12 pulled out from the beam or bobbin 1 and preliminarily put in the preparation reed 14 having the same pitch as the guide reed 2 has a coarse pitch guide reed 2. In the front of the above, the cords are jointed together by the cord end device and the cord joint device 13 for each cord at a time, and then guided through the guide reed 2 to the front variable density reed 4. At this time, in order to smoothly pass through the cord joint having the increased apparent fineness, the reed pitch of the front density varying reed 4 is changed so as to be equal to or larger than the apparent fineness of the cord joint. After the cord joining portion has passed, the reed pitch of the front variable density reed 4 is immediately reset to the pitch of the new cord standard. The dip cord sheet group 12 passing through the front density varying reed 4 is pulled out at a constant speed by the feed roll 5, and then guided to the rear density varying reed 4'provided immediately in front of the calender roll 6. At this time, the cord In order to smoothly pass through the joint, the reed pitch of the rear-density variable reed 4'is variably manipulated so as to be equal to or greater than the apparent fineness of the cord joint. After passing through the cord joining portion, the reed pitch of the rear density varying reed 4'is immediately reset to the pitch of the new cord standard.

Thus, the cord sheets arranged in parallel at a predetermined pitch are guided to the calender roll 6, and one or both sides of the cord sheet are covered with the high temperature molten rubber-like material 8 of about 90 to 110 ° C. to be integrated with the rubber. It becomes the primary topping sheet 15. Next, the topping sheet 15 in the high temperature state is cooled to near room temperature by a plurality of cooling drums 7 to become a stabilized topping sheet 15 ', and then a liner 9 for preventing sticking between the unvulcanized rubber sheets is rolled up. It is constructed so that it can be wound into a beam 11 shape.

The variable density type reed used in the tire cord topping method according to the present invention may be a fixed reed in which the reed wing (or reed needle) itself is fixed to the reed frame, or the reed is slidable and movable. It may be a reed, and the point is that the cord group inserted in the reed device can be smoothly passed through the cord joining part and the new lot code sheet without being detached from the reed device before and after the lot switching cord joining part. Any type of reed may be used as long as it has a function of imparting a predetermined pitch. That is, in the former fixed reed system, a zigzag reed system 20 (FIG. 2) in which a zigzag reed 20 composed of small piece divided reeds 21 provided in a zigzag shape is deformed by a widthwise expansion / contraction operation to change the pitch, a straight reed 22 The center in the width direction of the fulcrum
Straight reed angle changing method with variable pitch as 23 and variable pitch (Fig. 3), fan-shaped reed with different pitch between upper side and lower side
There is a fan-shaped reed system (Fig. 4) in which the pitch is changed by using the 24 according to the level of the thread passing portion.

In the latter movable reed system, a reed 25 in which a multi-coil spring 25 and a reed wing 26 are integrally combined is used and a pitch of the so-called spring reed is expanded and contracted to change the pitch (fifth).
Figure) etc. When carrying out the topping method according to the present invention, one of these reeds that best matches the purpose of use may be used. At this time, the supporting method of the reed wing may be one side or both sides, and may be selected according to the purpose of use.

There are two major advantages of using the variable density reed device. First, the first point is the passing effect of the cord splicing part with an increased apparent fineness, and the minimum density state is taken when passing through the splicing part. Can be reached by

Next, the second point is the effect that a predetermined pitch can be given to the newly supplied cord without attaching or detaching the cord sheet.

The code group consisting of a plurality of codes referred to in the present invention is substantially
It is a parallel code string of 100 or more and less than 2000.

The organic fiber cord used in the topping method according to the present invention refers to all fiber cords other than inorganic fibers such as polyamide, polyester, aramid, viscose, rayon and polyoxymethylene fiber, but from the purpose of the present invention. If so, the effect is more remarkable with a material having a disadvantage in heat resistance and heat shrinkage. The form may be multifilament or monofilament, but needless to say, multifilament is preferable from the viewpoint of fatigue resistance and flexibility. The cord is preferably an adhesive-treated cord from the viewpoint of improving the adhesiveness with rubber.

The lots having different pitch standards referred to in the present invention means switching between new and old topping lots of supplied cord sheets having different gaps between adjacent cords, and the length of one cord sheet is not constant. Gourmet 500-2000m
Degree is general. Therefore, how to efficiently perform lot switching is a very important factor as compared with the case of using the cord weave of the tire cord.

Here, it is more preferable that the total number of cords in the cord sheet is the same or similar in the new and old lots in order to enhance the effect of the present invention.

The molten rubber-like material used in the topping method according to the present invention is a generic term for high temperature rubber-like substances in a fluidized state by heating, such as a rubber pellet or a rubber sheet in a fluidized state by being heated, and a code sheet. It is a composite and integrated one. The high temperature referred to herein means a range of about 90 to 100 ° C., and the types of rubber generally used include chloroprene rubber, NBR, SBR and the like, or several types of composite types including these rubbers.

Further, the topping referred to in the present invention refers to an operation of coating a rubber-like material on one side or both sides of a cord sheet, and generally refers to applying a high temperature fluidized rubber-like material using a calender roll machine, In many cases, a four-roll type calender machine is used for coating both sides.

As described above with reference to one example with reference to the drawings, in the present invention, when changing lots having different pitch standards,
By using a reed device of variable density, it is possible to smoothly pass through the cord joints and quickly and effectively respond to the new and old pitch standards.

Therefore, according to the present invention, it is possible to effectively cope with a change in the code pitch within a certain range, and it is possible to shorten the stop loss time of the topping device at the time of lot switching and ensure high quality of the topping sheet.

〔Example〕

Next, examples of the present invention will be described in comparison with comparative examples.

Example 1 Nylon 66 fiber 1,260d / 2 (new twist: Z
39T / D / twist: S35T / D) Adhesive liquid dip cord (apparent diameter 0.6mmφ) is used, and the cord pitch is 1.1 each for new and old.
When switching lots of 6mm / 1.60mm cord sheets with a total number of 1,200 cords with different pitch standards, first of all, the cord sheet end of the new reed and the guide reed that were preliminarily placed in the reed with the same pitch as the guide reed The ends of the code sheets of the old lot, which were cut at the front, are adhesively vulcanized with a cord joint device using unvulcanized rubber as a medium, and joined so that the code sheets of the new and old lots are continuous in units of one cord. A continuous cord sheet with an apparent maximum diameter of 1.1 mmφ was obtained. Next, when introducing to the front zigzag reed, which is composed of fixed small reeds with a needle diameter of 1.1 mmφ, inter-center pitch of 2.3 mm, and needle gap of 1.3 mm, operate the expansion mechanism to expand the angle of the zigzag reed and increase the apparent pitch. It was made rough and passed through the joint, and then the angle of the zigzag reed was immediately shortened and reset to a code pitch of 1.16 mm. Hereinafter, the passage of the joint portion to the rear zigzag reed and the resetting of the cord pitch were performed in the same manner as in the front zigzag reed to obtain a rubber topping sheet having predetermined cord pitch and cord physical properties. By adopting one type of zigzag reed, a series of these operations could be performed by one person without the operation of attaching and detaching the cord.
For this reason, it was possible to transfer from the sheet edge cut of the old lot to the rear density variable reed of the joint in about 12 minutes.

Comparative Example 1 When switching a new lot and an old lot with the same material and code standard as in Example 1, a new method is used by the same method as in Example 1 above.
After connecting the old cords, the fixed density reeds at the two front and rear locations were replaced with reeds of the specified density, and then the cords were manually inserted into the two front and rear reeds. It took about 50 minutes from the cutting of the sheet edge of the lot to the passage of the rear fixed density reed of the joint. In the reed insertion operation, it is necessary to attach a pitch holding machine such as an adhesive tape in advance in order to hold the pitch of the cord sheet. The quality of the topping sheet was deteriorated due to the suspension. At present, the method of inserting the cord into the fixed density reed is only manual method, and it is indispensable to secure a skilled worker in order to perform it accurately and quickly. It is common to use two people and it is inefficient.

Comparative Example 2 With respect to the same code standard as in Example 1 and Comparative Example 1,
Switching between the new and old lots was carried out in the batch method with no cord joining, as in the case of the steel cord. After cutting the code sheet of the old lot after the topping process, first remove the density fixed reeds at the two front and back used at the time of the old lot from the reed holding table, and place the density fixed reeds for the new lot at the predetermined positions. I put it on. Next, while pulling out the cord sheet end of the new lot that was put on the reed and taped on the prepared reed with the same pitch as the preliminary guide reed,
The front density fixed reed, the feed roll, and the rear density variable reed were installed in this order, but it took about 70 minutes from the end of the topping process of the old lot to the normal start of the new lot.
This is because, in addition to passing several reeds and rolls, it is necessary to guide the path from the calender roll to the winding beam.

〔The invention's effect〕

Since the present invention adopts a variable density reed as a reed device for determining the cord pitch, it is easy to operate when switching lots of organic fiber cords having different density standards, and the switching stop loss time can be significantly shortened. In addition, the quality improvement effect of the topping sheet can be expected.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an example of an apparatus for carrying out a tire cord topping method according to the present invention, and FIGS. 2 to 5 are examples of reeds used in the apparatus shown in FIG. FIG. 4A is a schematic front view showing a state in which (a) shows a state for obtaining a coarse yarn pitch, and (b) shows a state for obtaining a dense yarn pitch. 1: beam or bobbin, 2: guide reed, 3: leveling roll, 4,
4 ': variable density reed, 5: feed roll, 6: calendar roll, 7: cooling drum, 8: molten rubber, 9: liner, 10: press roll, 11: beam, 12: dip code, 13: code Joint device, 14: Preparation reed, 15, 15 ':
Topping sheet.

Claims (1)

[Claims] 1. When switching topping lots of a group of organic fiber cords having a plurality of pitch standards different from each other, the cords are pitch-controlled by using a reed device of a variable density system and coated with rubber. Tire code topping method.