JP6125253B2 - Unvulcanized rubber member cutting apparatus and method - Google Patents

Description

  The present invention relates to an unvulcanized rubber member cutting device used for manufacturing a pneumatic tire and an unvulcanized rubber member cutting method using the unvulcanized rubber member cutting device.

  In the production of pneumatic tires, various unvulcanized rubber members (hereinafter also simply referred to as “rubber members”) are cut to a predetermined length, and both ends of the cut rubber members are jointed to each other. (For example, Patent Documents 1 to 4).

  At this time, generally, both end portions of the unvulcanized rubber member are perpendicular to the longitudinal direction and inclined with respect to the thickness direction so that the joint surface is inclined with respect to the member surface. It has been cut.

  By using an inclined joint surface, it is possible to absorb the imbalance in weight due to the variation in length generated when the rubber member is cut, and the joint operation can be easily performed.

  Conventionally, such a cutting operation is generally performed using a cutter heated by an electric heater or the like, or using an ultrasonic vibration cutter.

  An example of a conventional cut using a heated cutter is shown in FIG. In FIG. 4, an electric heater 9 is set between the cutter blade 1 and the cutter blade holder 8, and the cutter blade 1 is heated to a predetermined temperature. The unvulcanized rubber member G is cut by inclining the heated cutter blade 1 with respect to the unvulcanized rubber member G at a cut angle θ and moving it in the width direction of the unvulcanized rubber member G.

  An example of a conventional cutter blade is shown in FIG. In FIG. 5, reference numeral 1 denotes a cutter blade, 2 denotes a blade edge portion of the cutter blade 1, and 10 denotes an opening provided for setting the cutter blade 1 in a cutter blade holder.

  And when cutting such a rubber member, it is preferable that the cut angle θ is set to a lower angle.

JP 2012-171274 A JP 2002-346975 A JP 2011-005573 A JP 2011-126252 A

  However, if the cut angle is too low, the contact area between the rubber member and the cutter blade increases, leading to an increase in slip resistance, which may cause deformation of the rubber member and cause a defective cut. The occurrence of such cut defects causes joint variations, greatly affects the appearance quality and uniformity of product tires, and the burden of reworking work is large.

  For this reason, the cut angle in the conventional cutting operation is limited to about 25 to 30 °.

  Therefore, the present invention provides a cutting apparatus and a cutting method for an unvulcanized rubber member that can cut an unvulcanized rubber member at an even lower cut angle than before without causing an increase in slip resistance. And

The invention described in claim 1
A cutting device for an unvulcanized rubber member that cuts an unvulcanized rubber member perpendicularly to the longitudinal direction and obliquely with respect to the thickness direction by a cutter blade held by a cutter blade holder,
The cutter blade includes an air introduction port connected to an air pipe and a plurality of air ejection ports formed in the vicinity of the blade edge on the surface, and an air passage that connects the air introduction port and the air ejection port inside. And
The air supplied from the air pipe to the air introduction port is configured to cut the unvulcanized rubber member while being ejected from the air ejection port via the airway.
A heater for heating the cutter blade is attached to the cutter blade holder,
The cutter blade, a copper, a cutting apparatus of the unvulcanized rubber member you characterized by low friction coating is applied to the surface.

The invention described in claim 2
When the thickness of the cutter blade is is 3 to 8 mm, claim 1 to the surface of the cutter blade, wherein said air ejection opening diameter 0.5~2.0mm are provided five or more per side It is a cutting apparatus of the unvulcanized rubber member as described in above.

The invention according to claim 3
Using the unvulcanized rubber member cutting device according to claim 1 or 2 , the cutter blade held by the cutter blade holder allows the unvulcanized rubber member to be perpendicular to the longitudinal direction and to the thickness direction. A method of cutting an unvulcanized rubber member that is cut obliquely,
The unvulcanized rubber member is cut while the air supplied from the air pipe to the air introduction port is ejected from the air ejection port via the airway. It is a cutting method.

The invention according to claim 4
4. The unvulcanized rubber member cutting method according to claim 3 , wherein the unvulcanized rubber member is cut at a cut angle of 15 to 20 [deg.].

  ADVANTAGE OF THE INVENTION According to this invention, the cutting apparatus and cutting method of an unvulcanized rubber member which can cut an unvulcanized rubber member at the cut angle lower than before, without causing increase in slip resistance can be provided.

It is sectional drawing which shows typically the structure of the cutting device of the unvulcanized rubber member which concerns on one embodiment of this invention. It is a figure which shows the cutter blade used for the cutting apparatus of the unvulcanized rubber member which concerns on 1 embodiment of this invention. It is a figure explaining the formation procedure of an airway in the cutter blade used for the cutting device of the unvulcanized rubber member concerning one embodiment of the present invention. It is a figure which shows an example of the conventional cut using the heated cutter. It is a figure which shows an example of the conventional cutter blade.

  Hereinafter, the present invention will be specifically described based on embodiments with reference to the drawings.

  FIG. 1 schematically shows the configuration of an unvulcanized rubber member cutting device according to the present embodiment. FIG. 2 shows a cutter blade used in the cutting device. 2A is a front view of the cutter blade, and FIG. 2B is a cross-sectional view of the cutter blade.

  As shown in FIG. 1 and FIG. 2, in the cutting device according to the present embodiment, a plurality (five pieces per side) of air jets 3 (diameter 1 mm) are provided on the surface in the vicinity of the cutting edge 2 of the cutter blade 1. Is provided. An air inlet 5 is provided on the surface of the cutter blade 1. An airway 4 that connects the air inlet 5 and the air outlet 3 is provided inside the cutter blade 1.

  The cutter blade 1 is made of copper and has a low friction coating 6 on the surface.

  The cutter blade 1 is attached to a cutter blade holder 8, and an air pipe 7 is connected to the air introduction port 5.

  The air is supplied to the inside of the cutter blade 1 from the air introduction port 5 connected to the air pipe 7 by using the cutting device configured as described above, so that the air is discharged from the air outlet 3 via the airway 4. And then discharged to the outside from the air outlet 3.

  By blowing air released from the air outlet 3 toward the rubber member to be cut, the cut angle is set to an angle lower than the conventional limit of 25-30 °, When the cutter blade 1 is moved in the width direction of the rubber member, contact between the cutter blade 1 and the rubber member at a portion other than the blade edge portion 2 is suppressed, and therefore friction generated between the cutter blade 1 and the rubber member. And the increase in slip resistance at the time of cutting is suppressed.

  As a result, it is possible to obtain a rubber member having a good cut section at a low cut angle while sufficiently reducing the occurrence of cut defects due to an increase in resistance. Specifically, it is possible to obtain a rubber member having a good cut section at a cut angle as low as 15 to 20 °.

  And, by using a rubber member having a good cut cross section cut with a cutting angle as low as 15 to 20 ° using the cutting device as described above, the occurrence of joint variation is further suppressed, and the appearance quality and uniformity Can provide a more improved product tire.

  In order to sufficiently suppress the contact between the cutter blade 1 and the rubber member at a portion other than the blade edge portion 2 by the air discharged from the air jet port 3, as described above, the air jet port 3 It is preferable that it is provided in the vicinity of the blade edge part 2 of the cutter blade 1, and it is preferable that five or more per side are provided on both surfaces of the cutter blade 1.

  Moreover, as a diameter of each air jet nozzle 3, 0.5-2.0 mm is preferable and 1 mm is especially preferable.

  And formation of the airway 4 to the cutter blade 1 is performed according to the procedure shown in FIG. First, from the side surface in the thickness direction of the cutter blade 1, drilling is performed in three directions indicated by arrows, and holes having a diameter of 1 to 2 mm are linearly provided. Next, only the portion indicated by the dotted line is filled. Thereby, the airway 4 is formed in the part shown with the continuous line.

  Thereafter, the air jet connected to the airway 4 is drilled in a direction perpendicular to the airway 4 along the airway 4 formed in the blade edge 2 and penetrates a hole having a diameter of about 1 mm at a predetermined interval. An outlet 3 is formed on the surface of the cutter blade 1.

  Considering the processing problems for forming the airway 4 and the durability of the processed cutter blade 1, the thickness of the cutter blade 1 is preferably 3 mm or more, and more preferably 5 mm or more.

  On the other hand, it is known from the conventional knowledge that a temperature of 170 to 230 ° C. is preferable for the cutting edge portion 2 of the cutter blade 1 at the time of cutting. In order to efficiently heat to such a temperature, the cutter blade As 1, it is preferable to use a copper cutter blade 1 having excellent thermal conductivity. However, copper cannot be said to be a material with excellent wear resistance, and it cannot be said that the coefficient of friction is low.

  Therefore, as described above, the copper cutter blade 1 having the surface provided with the low-friction coating 6 is employed. Specific examples of the low-friction coating include DLC (Diamond Like Carbon) coating. Since DLC is excellent in wear resistance and has a low coefficient of friction, the above-described weaknesses in the copper cutter blade can be eliminated.

  However, even if it is such a cutter blade 1, if thickness exceeds 8 mm, it will become difficult to heat the blade edge | tip part 2 to the temperature of 170-230 degreeC mentioned above.

  Using the side wall sticking device of the molding machine, each cutter blade formed with the thickness shown in Table 1 and the number of air outlets is set in the cutter blade holder, and the side wall rubber is used as an unvulcanized rubber member. And cut at a cut angle of 15 °. Since the ignition temperature of this sidewall rubber is about 350 ° C., the temperature of the cutter blade holder was set to 300 ° C.

  While evaluating the state of the cut cross section in each visually, the blade edge | tip temperature of the cutter blade was measured using the non-contact-type thermometer.

  The results are shown in Table 1.

  From the results of Table 1, when no air outlet was provided (Comparative Example 1), a good cut cross section was not obtained, but the blade thickness was 5 to 8 mm and five air outlets were provided. When the cutter blade was used (Examples 3 to 5), the cutting edge temperature was preferably heated to 180 to 200 ° C., and it was confirmed that a good cut section was obtained while the cut angle was as low as 15 °.

  When the number of air jets is as small as three (Example 1), the cutting edge temperature was preferably heated to 200 ° C., but since the unvulcanized rubber member was in contact with the cutter during cutting, Example 3 Even excellent cut cross sections such as ˜5 were not obtained.

  Further, when the thickness of the cutter blade is too thick as 10 mm (Example 2), since the blade edge temperature is as low as 150 ° C., as in Example 1, up to excellent cut sections like Examples 3-5. It was not obtained.

  While the present invention has been described based on the embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above-described embodiments within the same and equivalent scope as the present invention.

DESCRIPTION OF SYMBOLS 1 Cutter blade 2 Cutting edge part 3 Air outlet 4 Airway 5 Air inlet 6 Low friction coating 7 Air piping 8 Cutter blade holder 9 Electric heater 10 Opening part G Unvulcanized rubber member θ Cut angle

Claims (4)

A cutting device for an unvulcanized rubber member that cuts an unvulcanized rubber member perpendicularly to the longitudinal direction and obliquely with respect to the thickness direction by a cutter blade held by a cutter blade holder,
The cutter blade includes an air introduction port connected to an air pipe and a plurality of air ejection ports formed in the vicinity of the blade edge on the surface, and an air passage that connects the air introduction port and the air ejection port inside. And
The air supplied from the air pipe to the air introduction port is configured to cut the unvulcanized rubber member while being ejected from the air ejection port via the airway.
A heater for heating the cutter blade is attached to the cutter blade holder,
The cutter blade, a copper, cutting device of the unvulcanized rubber member you characterized by low friction coating is applied to the surface. When the thickness of the cutter blade is is 3 to 8 mm, claim 1 to the surface of the cutter blade, wherein said air ejection opening diameter 0.5~2.0mm are provided five or more per side The unvulcanized rubber member cutting device described in 1. Using the unvulcanized rubber member cutting device according to claim 1 or 2 , the cutter blade held by the cutter blade holder allows the unvulcanized rubber member to be perpendicular to the longitudinal direction and to the thickness direction. A method of cutting an unvulcanized rubber member that is cut obliquely,
The unvulcanized rubber member is cut while the air supplied from the air pipe to the air introduction port is ejected from the air ejection port via the airway. Cutting method. The method for cutting an unvulcanized rubber member according to claim 3 , wherein the unvulcanized rubber member is cut at a cut angle of 15 to 20 °.

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