JP3788766B2 - Die-cutting method for vulcanized tire and vulcanization molding machine for tire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for punching a vulcanized tire having lug grooves on the surface of a tire tread from a vulcanization molding machine and a vulcanization molding machine for a tire.
[0002]
[Prior art]
In recent years, as the demand for wear resistance and durability on tires has increased in the market, the rigidity of the belt placed inside the tread of the tire has increased in response to the demand, and the rigidity of the crown part has also increased as compared with the conventional structure Yes, it is difficult to die. Therefore, when a vulcanized tire is die-cut from a vulcanization molding machine, problems such as tread cracking and chipping of the product tire cannot be ignored.
[0003]
For this reason, conventionally, as a method of reducing or preventing the product die-cutting resistance after vulcanization at the time of vulcanization of a tire, application of a split mold type vulcanization molding machine is known.
[0004]
As shown in FIG. 4, the split mold type vulcanization molding machine can approach and separate the lower mold 22 having a molding surface that mainly molds the lower side wall portion of the unvulcanized tire, and the lower mold 22. The upper mold 23 having a molding surface for mainly molding the upper sidewall portion of the unvulcanized tire, and the tread of the unvulcanized tire that is disposed between the molds of the lower mold and the upper mold and can be expanded and contracted. And a plurality of sector molds 24 having a molding surface for mainly molding the part. In taking out the product tire, as shown in FIG. 4 (a), after the upper mold 23 is removed by lifting means (not shown), as shown in FIG. The diameter of 24 was increased, and then the product tire was taken out by lifting means (not shown).
[0005]
In addition, in order to facilitate die cutting, a special mold type vulcanization molding machine (not shown) that can operate the groove forming bone corresponding to the circumferential groove in the radial direction is applied. I came.
[0006]
Furthermore, as shown in FIG. 5, the lower mold 32 having a molding surface that mainly molds the lower sidewall portion of the unvulcanized tire and the lower half of the tread portion, and the lower mold 32 can be approached and separated. In the case of using a full mold type vulcanization molding machine provided with an upper mold 33 having a molding surface for mainly molding an upper sidewall portion of an unvulcanized tire and an upper half of a tread portion, an upper mold When the upper mold 33 is pulled out by lifting 33 vertically, and then the lower mold 32 is pulled out by lifting the vulcanized tire M, the groove of the tread treading portion that becomes the resistance to punching is shallowed, Or countermeasures such as increasing the wall surface angle of the groove with respect to the die-cutting direction to reduce the resistance have been taken.
[0007]
[Problems to be solved by the invention]
However, in order to make it easy to perform die-cutting, the above-mentioned split mold type vulcanization molding machine and special mold type vulcanization molding machine are applied. Compared to the above, since it is necessary to add an operating device for divided segments, it becomes extremely expensive.
[0008]
Further, when using a full mold type vulcanization molding machine, it is necessary to change the design of the original pattern of the tire, and it is inevitable that the original performance and appearance of the tire are inferior.
[0009]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for die-cutting a vulcanized tire that can be easily die-cut without requiring an additional device such as an operating device for a divided segment or a design change of a tire pattern, and the method Another object of the present invention is to provide an inexpensive tire vulcanization molding machine that can be used in the manufacturing process.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventor has intensively studied about die-cutting of tires having lug groove patterns adopted for construction vehicle tires and the like, and can solve the above-mentioned problems by adopting the following configuration. As a result, the present invention has been completed.
[0011]
That is, the method for die-cutting a vulcanized tire according to the present invention includes a lower mold having a molding surface for mainly molding a lower sidewall portion of an unvulcanized tire and a lower half of a tread portion, and the lower mold From a full mold vulcanization molding machine comprising an upper mold having a mold surface for mainly molding an upper side wall portion of the unvulcanized tire and an upper half of the tread portion. In a method of die-cutting a vulcanized tire having
The upper mold is lifted and pulled out while rotating so that the lug groove molding bone formed on the tread mounting surface of the upper mold engages with the lug groove of the vulcanized tire, and then the lower mold is pulled out. The vulcanized tire is lifted and pulled out while rotating so that the lug groove molding bone formed on the tread mold attaching surface of the mold mold and the lag groove of the vulcanized tire are engaged with each other It is.
[0012]
Moreover, the vulcanization molding machine for tires of the present invention is a vulcanization molding machine for tires that is used in the above-described method for punching vulcanized tires.
At least one pair of slide guides that are slidably engaged with each other at an inclination with respect to the horizontal direction are provided on the outer surface of the lower mold and the outer surface of the upper mold, and the slide guides with respect to the horizontal direction The sliding surface is substantially equal to the angle of the lug groove molding bone.
[0013]
In the tire vulcanization molding machine according to the present invention, a cylindrical lifting device for lifting the vulcanized tire is coaxial with the lower mold and the upper mold at the radially inner end of the vulcanized tire. Preferably, at least one insertion hole for a rod for imparting rotation to the vulcanized tire is formed on the side surface of the cylindrical suspension and on the upper portion of the vulcanized tire.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
In a preferred example of the tire vulcanization molding machine 1 of the present invention schematically shown in FIG. 1, the upper and lower halves are full molds, which mainly consist of a lower mold 2 and an upper mold 3.
[0015]
On the inner mold surfaces of the lower mold 2 and the upper mold 3, a plurality of lug groove molded bones are arranged in an annular shape. The lower mold 2 is fixed with the mold surface opened upward, and the upper mold 3 is supported so as to be movable up and down with the mold surface opened downward. Further, the upper mold 3 is supported so as to be freely rotatable around the vertical center axis.
[0016]
On the lower mold 2 and the upper mold 3, a pair of slide guides 4a, 4b, and 5 that are slidably engaged with an inclination with respect to the horizontal direction are provided to project. The sliding surfaces between the projecting slide guides 4a, 4b and 5 are substantially equal to the angle of the lug groove molding bone with respect to the horizontal direction. That is, as shown in FIG. 2, the angle α formed by the sliding surfaces of the slide guides 4a and 4b with respect to the horizontal direction and the angle β formed by the lug groove 6 (lug groove forming bone) of the tire M in the vulcanization molding machine. To be substantially equal.
[0017]
The slide guides 4a, 4b and 5 may be attached by bolts or the like, and the attachment method is not particularly limited. The pair of slide guides 4a, 4b and 5 may be provided at only one place, but may be provided at two or more places in consideration of the balance when the upper mold 3 is rotated and lifted.
[0018]
In the die-cutting method of the present invention, the lower mold 2 and the upper mold 3 are combined and vulcanized and molded with a green tire interposed therebetween, and then die-cut as follows.
[0019]
First, as shown in FIG. 1, the upper mold 3 is rotated while rotating so that the lug groove molding bone formed on the tread mold attaching surface of the upper mold 3 and the lug groove 6 of the vulcanized tire are engaged with each other. lift. By using the tire vulcanization molding machine 1 of the present invention shown in the figure for the lifting, the upper mold 3 is lifted while sliding the sliding surface between the slide guides 4a, 4b and 5 described above, so that the lug groove The upper mold 3 is smoothly pulled out by rotating in the pulling direction so that the molded bone and the lug groove 6 of the vulcanized tire M are engaged with each other. As a result, the pull-out resistance is reduced as compared with the case where the upper mold 3 is lifted without rotating, and the die-cutting is facilitated.
[0020]
Next, as shown in FIG. 3, the lug groove molding bone formed on the tread mold attaching surface of the lower mold 2 and the lug groove 6 of the vulcanized tire M are rotated in the pulling direction so as to engage with each other. Lift the vulcanized tire M. At this time, at least one insertion hole 8 for a rod for imparting rotation to the vulcanized tire M may be drilled on the side surface of the cylindrical hanger 7 and above the vulcanized tire M. preferable. In this way, when the vulcanized tire M is taken out from the lower mold 2, the rod 9 is inserted into the insertion hole 8, and at the same time as lifting the tire, the rod 9 is easily rotated by human power or the like. be able to. Since the vulcanized tire M is pulled out while rotating in the pulling direction with respect to the lower mold 2, the pulling resistance is reduced, and the vulcanized tire M can be easily taken out. If a plurality of rod insertion holes 8 are formed in the side surface of the cylindrical hanger 7 at appropriate intervals, it is not necessary to move around the vulcanization molding machine in order to insert the rod 9.
[0021]
In the full mold vulcanization molding machine of the present invention, a known structure may be appropriately adopted except that the conventional full mold vulcanization molding machine is provided with slide guides 4a, 4b and 5 and insertion holes 8. it can.
[0022]
【The invention's effect】
As described above, according to the present invention, it is easy to take out a vulcanized tire from a mold even with an inexpensive full-mold vulcanization molding machine, and prevent tread cracking and chipping of a product tire. can do. In addition, the degree of freedom in pattern design is expanded.
[Brief description of the drawings]
FIG. 1 is a perspective view showing die cutting of a vulcanized tire according to the present invention.
FIG. 2 is an explanatory diagram showing a relationship between a slide guide and a tire lug groove.
FIG. 3 is a perspective view showing lifting of a vulcanized tire from a lower mold according to the present invention.
FIG. 4 is an explanatory view showing die removal from a conventional split mold type vulcanization molding machine.
FIG. 5 is an explanatory view showing die removal from a conventional full mold vulcanization molding machine.
[Explanation of symbols]
1 Tire vulcanization molding machine 2, 22, 32 Lower mold 3, 23, 33 Upper mold 4a, 4b, 5 Slide guide 6 Lug groove 7 Cylindrical hanger 8 Insertion hole 9 Rod 24 Sector mold M Tire

Claims (3)

A lower mold having a molding surface for mainly molding a lower sidewall portion of the unvulcanized tire and a lower half of the tread portion, and an upper sidewall of the unvulcanized tire that is close to and away from the lower mold. In a method of die-cutting a vulcanized tire having a lug groove pattern from a full mold vulcanization molding machine provided with an upper mold having a molding surface that mainly molds the upper half of the upper part and the tread part,
The upper mold is lifted and pulled out while rotating so that the lug groove molding bone formed on the tread mounting surface of the upper mold engages the lug groove of the vulcanized tire, and then the lower mold is pulled out. The vulcanized tire is lifted and pulled out while being rotated so that the lug groove molding bone formed on the tread attaching surface of the mold mold and the lag groove of the vulcanized tire are engaged with each other. Die-cutting method for sulfurized tires. In the vulcanization molding machine for tires used for the die cutting method of the vulcanized tire according to claim 1,
At least one pair of slide guides that are slidably engaged with each other at an inclination with respect to the horizontal direction are provided on the outer surface of the lower mold and the outer surface of the upper mold, and the slide guides with respect to the horizontal direction A tire vulcanization molding machine characterized in that the sliding surface and the angle of the lug groove molding bone are substantially equal. A cylindrical suspension for lifting the vulcanized tire is disposed coaxially with the lower mold and the upper mold at the radially inner end of the vulcanized tire, and is provided on the side surface of the cylindrical suspension. The vulcanization molding machine for tires according to claim 2, wherein at least one insertion hole for a rod for imparting rotation to the vulcanized tire is formed in an upper portion of the vulcanized tire.

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