JP5566588B2 - Unvulcanized rubber extruder - Google Patents

Description

  The present invention relates to an unvulcanized rubber extruder for extruding an unvulcanized rubber member made of at least two types of unvulcanized rubber.

The tread of a pneumatic tire for a motorcycle has different contact positions with respect to the road surface during straight traveling and cornering, and the performance required for straight traveling and the performance required for cornering of a motorcycle pneumatic tire are generally different. Is.
Therefore, in order to improve the performance during straight traveling and cornering, treads for pneumatic tires for two-wheeled vehicles using different rubber types in the width direction have been developed.

As a tread of this type of pneumatic tire for a motorcycle, the first rubber disposed in the center portion in the tire width direction, the second rubber disposed on both sides of the first rubber, and the both sides of the second rubber are disposed. There is a seven-part tread composed of a third rubber and a fourth rubber disposed at the end of the tread. The center side emphasizes wear resistance, and both sides emphasize grip.
Such a tread in which four types of rubber are arranged in the tire width direction is manufactured using a multilayer extruder (see, for example, Patent Document 1) that can extrude four types of rubber.

In the head body of the multilayer extruder, four unvulcanized rubber extrusion ports from which unvulcanized rubber is extruded are arranged vertically. For example, the fourth rubber, the first rubber, and the second rubber are sequentially arranged from the upper side. The rubber and the third rubber are extruded.
On the unvulcanized rubber extrusion port side of the head main body, a flow path forming bracket in which a plurality of flow paths for guiding the plurality of types of rubber to the base side are formed. A base for extruding the unvulcanized rubber in a strip shape with a predetermined extruded cross-sectional shape is attached to the end face of the flow path forming metal fitting on the unvulcanized rubber extrusion side.

In addition, the unvulcanized tread is extruded from the die with the width direction being horizontal in order to be rolled up after being continuously extruded from the die in a band shape and conveyed by a conveyor.
That is, in the head body of the extruder, the unvulcanized rubber extrusion ports are arranged in the vertical direction, but an unvulcanized tread in which a plurality of types of unvulcanized rubber are arranged in the lateral direction is extruded from the die. Become.
Japanese Patent Laid-Open No. 06-210699

  By the way, when a plurality of rubber types are used for the tread, it is necessary to ground the rubber corresponding to the inclination of the vehicle body on the road surface, and therefore it is necessary to accurately position the rubber, that is, the rubber boundary position. If the rubber boundary position is different, the required rubber will not contact the road surface and the tire performance as designed cannot be achieved.

However, the conventional example has the following problems.
Due to the relationship between the extruder and peripheral devices, there are restrictions on the size of the flow path forming bracket, more specifically, the size in the rubber extrusion direction. In some cases, the rubber flow path must be bent sharply before the base.

  For example, as shown in FIG. 12A, if two adjacent channels are in the same direction as the extrusion direction of unvulcanized rubber extruded from the base immediately before the base (position facing the base). The boundary between the two unvulcanized rubbers A and B is linearly formed in the middle of the two flow paths, so that there is no problem, but the two flow paths adjacent to each other are formed from the base immediately before the base. FIG. 12B shows a direction crossing the extrusion direction of the unvulcanized rubber to be extruded, in particular, a direction approaching each other when viewed from the unvulcanized rubber extrusion side of the base (as viewed from the front of the base). Thus, the boundary between one unvulcanized rubber A and the other unvulcanized rubber B is not formed in a straight line in the middle of the two flow paths, and a part of one unvulcanized rubber A is not There is a problem that the boundary line is greatly bent due to a large wrap around the vulcanized rubber B side.

  In consideration of the above facts, the present invention provides a boundary between two unvulcanized rubbers adjacent to each other when one unvulcanized rubber member made of a plurality of unvulcanized rubbers is extruded. An object of the present invention is to provide an unvulcanized rubber extruder that can suppress wraparound.

The invention according to claim 1 is an unvulcanized rubber extruder for extruding a band-shaped unvulcanized rubber member made of a plurality of types of unvulcanized rubber from an opening of a die, and comprising an unvulcanized rubber Extruder having a plurality of extruder main bodies for extruding and an unvulcanized rubber extrusion port connected to the unvulcanized rubber discharge side of the extruder main body and discharging unvulcanized rubber extruded from the extruder main body A flow path comprising a head body and a plurality of flow paths that are connected to the unvulcanized rubber discharge side of the extrusion head body and guide the unvulcanized rubber extruded from the unvulcanized rubber extrusion port toward the base. A partition wall is formed between the adjacent channels on the side of the die of the flow channel forming die, and the flow channel is formed at the portion facing the die. Extending in a direction crossing the extrusion direction of the unvulcanized rubber extruded from the In the direction intersecting with the width direction of the unvulcanized rubber, the wall wall extends in a direction intersecting with the direction of extrusion of the unvulcanized rubber extruded from the die of the channel. A notch is formed at the end of the partition wall on the channel outlet side.

Next, the operation of the unvulcanized rubber extruder according to claim 1 will be described.
Since the unvulcanized rubber extruder according to claim 1 includes a plurality of extruder main bodies, different unvulcanized rubber can be extruded for each extruder main body.
An extrusion head main body is provided so as to connect the unvulcanized rubber discharge portions of a plurality of extruder main bodies to each other, and different unvulcanized rubber is extruded from unvulcanized rubber extrusion ports provided in the extrusion head main body. be able to.

The unvulcanized rubber extruded from the extrusion head body passes through the flow path formed in the flow path forming mold and travels toward the die.
The unvulcanized rubber that has passed through the flow path is discharged from the base, but on the base side of the flow path forming mold, unvulcanized rubber extruded from the base between the adjacent flow paths. Since the partition wall extending along the direction is formed, the unvulcanized rubber on both sides of the partition wall flows along the partition wall extending along the extrusion direction of the unvulcanized rubber in the vicinity of the partition wall. The unvulcanized rubber member can be extruded on the base side of the partition wall so that the uncured rubber boundary line on both sides is clearly formed on the extension line of the unvulcanized rubber extrusion side of the partition wall. it can.
As a result, it is possible to efficiently extrude a belt-shaped unvulcanized rubber member in which the boundary between two unvulcanized rubbers adjacent to each other is prevented from wrapping around one unvulcanized rubber side.
Further, since the flow path extends in a direction opposite to the extrusion direction of the unvulcanized rubber extruded from the die at a portion facing the die, the unvulcanized rubber is extruded from the die immediately before the die. It flows in a direction crossing the extrusion direction of the unvulcanized rubber.
If the flow of two unvulcanized rubbers adjacent to each other flows in a direction that intersects the extrusion direction of the unvulcanized rubber extruded from the base immediately before the base, The direction of the flow of the vulcanized rubber changes abruptly, and the boundary line between the two unvulcanized rubbers tends to deviate greatly from the intermediate position between the two flow paths.
In the unvulcanized rubber extruder according to the first aspect, since the partition wall is formed at a portion where the flow direction of the unvulcanized rubber changes abruptly, the effect of the invention is remarkably exhibited.
Furthermore, by forming a notch at the end of the partition wall on the channel outlet side, one unvulcanized rubber and the other unvulcanized rubber adjacent to each other are joined on the upstream side of the opening, and one unvulcanized rubber is joined. The vulcanized rubber and the other unvulcanized rubber can be bonded more reliably.

According to a second aspect of the present invention, in the unvulcanized rubber extruder according to the second aspect, the partition wall is a flow of the unvulcanized rubber flowing through one of the flow paths adjacent to each other at a portion facing the base. The direction and the flow direction of the unvulcanized rubber flowing through the other flow path are formed at portions facing each other.

Next, the operation of the unvulcanized rubber extruder according to claim 2 will be described .
In the portion facing the base, at the portion where the flow direction of the unvulcanized rubber flowing through one of the flow paths adjacent to each other and the flow direction of the unvulcanized rubber flowing through the other flow path face each other, Since the boundary position of the unvulcanized rubber is the most easily displaced due to rubber pressure fluctuation or the like, it is best to provide a partition wall here because the effect of the invention can be maximized.

According to a third aspect of the present invention, in the unvulcanized rubber extruder according to the first or second aspect, an interval between the partition wall and the base is 0.5 mm or less.

Next, the operation of the unvulcanized rubber extruder according to claim 3 will be described .
By setting the distance between the partition wall and the base to be 0.5 mm or less, it is possible to prevent the boundary between two unvulcanized rubbers adjacent to each other from greatly turning toward one unvulcanized rubber side.

According to a fourth aspect of the present invention, in the unvulcanized rubber extruder according to the first or second aspect, the partition wall and the base are in contact with each other.

Next, the operation of the unvulcanized rubber extruder according to claim 4 will be described .
By bringing the partition wall and the base into contact with each other, it is possible to reliably suppress the boundary between two unvulcanized rubbers adjacent to each other from greatly turning toward one unvulcanized rubber side.

According to a fifth aspect of the present invention, in the unvulcanized rubber extruder according to any one of the first to fourth aspects, the partition wall is thinner on the base side and the unvulcanized rubber than on the base side. It is characterized in that the upstream side in the flow direction is formed thick.

Next, the operation of the unvulcanized rubber extruder according to claim 5 will be described .
By forming the partition wall thick on the upstream side and thin on the base side, the shape of the belt-shaped unvulcanized rubber member (so-called contour) is not affected, and the strength of the partition wall can be secured. I can do it.

The invention according to claim 6 is the unvulcanized rubber extruder according to claim 5 , wherein the partition wall is set to a thickness of 0.1 to 0.5 mm on the base side. It is characterized by that.

Next, the operation of the unvulcanized rubber extruder according to claim 6 will be described .
If the thickness of the partition wall on the base side exceeds 0.5 mm, the shape of the strip-shaped unvulcanized rubber member will be affected. If the thickness of the partition wall on the base side is less than 0.1 mm, the partition wall may be deformed or chipped. Therefore, it is preferable to set the thickness of the partition wall on the base side within a range of 0.1 to 0.5 mm.

The invention described in claim 7 is the unvulcanized rubber extruder according to any one of claims 1 to 6, a plurality of the unvulcanized rubber extruding ports are arranged in a vertical direction, a plurality of The outlet side of the flow path is arranged in the lateral direction.

Next, the operation of the unvulcanized rubber extruder according to claim 7 will be described .
In the unvulcanized rubber extruder according to claim 7, a plurality of unvulcanized rubbers are extruded from the extruder body in a longitudinal direction, and a plurality of unvulcanized rubbers are laterally extruded on the outlet side of the flow path. Extruded side by side.

  Each of the unvulcanized rubber extruded from the plurality of unvulcanized rubber extrusion ports arranged in the vertical direction has a limited space so as to be arranged in the horizontal direction through the plurality of channels arranged on the outlet side in the horizontal direction. When the flow direction is changed, the flow directions of the two unvulcanized rubbers adjacent to each other immediately before the die may be opposite to each other. In such a configuration, the effect of the present invention is achieved. Especially can be demonstrated.

The invention according to claim 8 is the unvulcanized rubber extruder according to any one of claims 1 to 7 , wherein the longitudinal end portion of the partition wall is formed in the flow path forming mold. It is connected to the other site | part different from the part in which the said partition wall is formed.

Next, the operation of the unvulcanized rubber extruder according to claim 8 will be described .
By connecting the end of the partition wall in the longitudinal direction to another part of the flow path forming mold different from the part where the partition wall is formed, the partition wall can be reinforced and deformation of the partition wall can be suppressed. Can do.

The invention according to claim 9 is the unvulcanized rubber extruder according to any one of claims 1 to 8 , wherein the belt-shaped unvulcanized rubber member is used in a tread of a pneumatic tire for a motorcycle. It is characterized by being used.

Next, the operation of the unvulcanized rubber extruder according to claim 9 will be described .
In the unvulcanized rubber extruder according to claim 9, a strip-shaped unvulcanized rubber member used for a tread of a pneumatic tire for a motorcycle is extruded.

  As described above, when the unvulcanized rubber extruder of the present invention extrudes an unvulcanized rubber member composed of a plurality of unvulcanized rubbers, the boundary between two unvulcanized rubbers adjacent to each other is It has the outstanding effect that it can suppress going around to one unvulcanized rubber side.

Before describing the present invention, a reference example of an unvulcanized rubber extruder will be described with reference to the drawings.
As shown in FIG. 1, the unvulcanized rubber extruder 10 is provided so as to connect the four extruder main bodies 12, 14, 16, 18 and the distal ends of the extruder main bodies 12, 14, 16, 18. And an extrusion head 20.
Each extruder body 12, 14, 16, 18 is provided with an unvulcanized rubber supply hopper (not shown), and four types of unvulcanized rubbers A, B, C, and D having different compounding compositions are not added. It is continuously supplied from the vulcanized rubber supply hopper to each extruder main body 12, 14, 16, 18 and kneaded by a screw (not shown) that is rotationally driven inside each extruder main body 12, 14, 16, 18; It is guided toward the extrusion head 20 while self-heating to lower the plasticity and increase the fluidity. In addition, the structure of each extruder main body 12, 14, 16, 18 is the same structure as a conventional product.

Here, before describing the configuration of the unvulcanized rubber extruder 10 in detail, the strip-shaped unvulcanized rubber member 19 extruded by the unvulcanized rubber extruder 10 will be described based on the cross-sectional view of FIG. .
As shown in the cross-sectional view of FIG. 2, the belt-shaped unvulcanized rubber member 19 serves as a tread for a pneumatic tire for a motorcycle, and includes an unvulcanized rubber B and a tread for forming a center portion of the tread. To form an unvulcanized rubber C for forming the outer portion of the center portion in the tread width direction, an unvulcanized rubber D for forming an outer portion of the unvulcanized rubber C in the tread width direction, and an end portion of the tread. The unvulcanized rubber A is composed of four types of unvulcanized rubber, and is extruded and widened in the horizontal direction. In addition, in the strip | belt-shaped unvulcanized rubber member 19 shown in FIG. 2, a lower surface becomes a belt side and an upper surface becomes a tread surface side.

As shown in the cross-sectional view of FIG. 2, the unvulcanized rubber B, the unvulcanized rubber C, and the unvulcanized rubber D of the strip-shaped unvulcanized rubber member 19 are horizontally long and substantially rectangular, and the unvulcanized rubber A is approximately. In this reference example , the boundary line of each unvulcanized rubber member has a substantially straight shape extending in the thickness direction.

Next, the unvulcanized rubber extruder 10 will be described in detail.
As shown in FIG. 3 (B), the extrusion head 20 is a steel extrusion base (hereinafter referred to as a base) located in front of the unvulcanized rubber A, B, C, D (not shown in FIG. 3) in the extrusion direction. ) 21 and the flow paths 22a, 22b, 22c, and 22d of the unvulcanized rubber A, B, C, and D from the extrusion outlets of the respective extruder main bodies 12, 14, 16, and 18 to the base 21 are provided as head bodies. 25, between the flow paths 22a, 22b, 22c, 22d and the base 21, the unvulcanized rubber A, B, C, D each has a strip-shaped unvulcanized rubber member 19 having a predetermined cross-sectional shape. For this purpose, an unvulcanized rubber member forming means 24 is detachably accommodated in the head body 25. The downstream ends of the flow paths 22a, 22b, 22c, and 22d correspond to the unvulcanized rubber extrusion outlet of the present invention.
As shown in FIG. 2 (B), the base 21 is formed with a notch 21a that serves to form the tread tread surface side of the outer contour shape of the strip-shaped unvulcanized rubber member 19. That is, the notch 21a forms a part of an opening through which the unvulcanized rubber A, B, C, D is extruded. The opening through which the unvulcanized rubbers A, B, C, and D are pushed out includes the notch 21a (the part) and an edge 30a (see FIG. 11) of the die holder 30 described later.

As shown in FIGS. 3 (A) and 3 (B), the unvulcanized rubber member forming means 24 is made of steel and connected to the terminal ends (discharge ports) of the flow paths 22a, 22b, 22c, and 22d of the head body 25. A pair of the flow path forming die 32, the base 21, and the base 21 serves to separately form the bottom of the extruded outer contour shape of the band-shaped unvulcanized rubber member 19, and to fix the base 21 The die holder 30 is made of steel, and the die 21 is fixed to the end surface of the flow path forming mold 32 on the unvulcanized rubber extrusion side by the die holder 30.
The band-shaped unvulcanized rubber member 19 is extruded from the base 21 in the direction of arrow F in FIG.

(Flow path forming mold)
The flow path forming mold 32 includes an upper mold 34 disposed on the upper side, a lower mold 36 disposed on the lower side, and a middle mold 38 disposed between the upper mold 34 and the lower mold 36. It consists of three molds.
FIG. 3A is a back view of the flow path forming mold 32 and the die holder 30 as viewed from the back surface (extruder side), and the first flow path 38A is formed on the left and right sides with the center in the width direction as a boundary on the upper side. The second flow path 38B opens at the center in the width direction below the lower side, the third flow path 38C opens at the left and right with the center in the width direction as the boundary, and at the bottom. The fourth flow path 38D is opened to the left and right with the width direction center as a boundary.

FIG. 4 is a front view of the head main body 25 provided at the tip of the extruder main bodies 12, 14, 16, 18 and the openings (unvulcanized rubber extrusion ports) of the flow paths 22a, 22b, 22c, 22d are as follows. It has a horizontally long shape and is arranged in the vertical direction. Only the flow path 22a is divided into two in the width direction.
In addition, the flow paths 22a, 22b, 22c, and 22d of these extruder main bodies 12, 14, 16, and 18 are connected to the back surface of the flow path forming mold 32 and the back die 26 as shown in FIG. The flow path 22a through which the unvulcanized rubber A flows corresponds to the inlet of the first flow path 38A, and the flow path 22b where the unvulcanized rubber B bends corresponds to the inlet of the second flow path 38B. In addition, the flow path 22c through which the unvulcanized rubber C flows faces the inlet of the third flow path 38C, and the flow path 22d through which the unvulcanized rubber D flows faces the inlet of the fourth flow path 38D.

  FIG. 5A is a front view of the flow path forming mold 32 and the die holder 30 as viewed from the surface (rubber discharge side), and a second flow path 38B through which unvulcanized rubber B flows in the center. A third flow path 38C through which the unvulcanized rubber C flows on both sides, a fourth flow path 38D through which the unvulcanized rubber D flows, and a first flow path through which the unvulcanized rubber A flows. 38A is opened and each flow path is arranged in the horizontal direction.

  As shown in the cross-sectional view of FIG. 6A (the cross-sectional view taken along the line AA in FIG. 5A), the first flow path 38A through which the unvulcanized rubber A flows is inclined obliquely downward toward the base 21. Then, it is bent downward on the base side, and is formed parallel to the base 21 (a direction intersecting the rubber extrusion direction) at a portion facing the base 21.

  As shown in the sectional view of FIG. 6B (the sectional view taken along the line BB of FIG. 5A), the fourth flow path 38D through which the unvulcanized rubber D flows is inclined obliquely upward toward the base 21. Then, it is bent upward on the base side, and is formed parallel to the base 21 (a direction crossing the rubber extrusion direction) at a portion facing the base 21.

  As shown in the cross-sectional view of FIG. 6C (the cross-sectional view taken along the line CC in FIG. 5A), the third flow path 38C through which the unvulcanized rubber C flows extends horizontally toward the base 21. It is bent upward on the base side, and is formed parallel to the base 21 (a direction intersecting the rubber extrusion direction) at a portion facing the base 21.

  As shown in the sectional view of FIG. 6D (the sectional view taken along the line DD in FIG. 5A), the second flow path 38B through which the unvulcanized rubber B flows is inclined obliquely downward toward the base 21. At the same time, the width of the flow path is gradually narrowed and bent downward on the base side, and the part facing the base 21 is formed parallel to the base 21 (direction intersecting the rubber extrusion direction). .

  In FIG. 5A and FIG. 6, reference numeral 38Aa indicates a first flow path side wall surface of the first flow path 38A formed in parallel with the base 21, and reference numeral 38Ba indicates the second flow path 38B. A portion of the second flow path side wall surface that is formed in parallel with the base 21 is shown. Reference numeral 38Ca denotes a portion of the third flow path side wall surface that is formed in parallel with the base 21 of the third flow path 38C. Shows the fourth channel side wall surface of the portion of the fourth channel 38D formed in parallel with the base 21.

As shown in FIG. 5A and FIG. 9, the middle mold 38 of the flow path forming mold 32 is provided between the first flow path side wall surface 38Aa and the fourth flow path side wall surface 38Da (FIG. 7A). As shown in FIG. 2, the flow direction of the unvulcanized rubber A flowing through one of the flow paths adjacent to each other in the portion facing the base 21 and the flow direction of the unvulcanized rubber D flowing through the other flow path face each other. A first partition wall 40 is formed between the second flow path side wall surface 38Ba and the third flow path side wall surface 38Ca (as shown in FIG. The second partition wall 42 is formed at a portion where the flow direction of the unvulcanized rubber C flowing in one adjacent flow path and the flow direction of the unvulcanized rubber B flowing in the other flow path face each other. The first partition wall 40 and the second flow path side wall surface 38Ba are Longitudinal direction is formed in a linear shape as viewed from the cap side.
5A is a boundary between the third flow path side wall surface 38Ca and the fourth flow path side wall surface 38Da, but actually the third flow path side wall surface 38Ca and the fourth flow path side wall surface. 38 Da is formed continuously, so the boundary 44 cannot be seen.

As shown in FIG. 7, the first partition wall 40 is formed such that the channel side wall surface side (base side) is thick and the base side is thin, and the band-shaped unvulcanized rubber member 19 (not shown in FIG. 7) is formed. It extends toward the extrusion direction (arrow F direction). When the material of the first partition wall 40 is steel, the thickness on the base side is preferably within a range of 0.1 to 0.5 mm. If the thickness of the first partition wall 40 on the base side is thicker than 0.5 mm, the pressure of the unvulcanized rubber is locally reduced at the boundary between the unvulcanized rubber A and the unvulcanized rubber D, The vulcanized rubber A and the unvulcanized rubber D are insufficiently pressure-bonded, or the surface of the extruded strip-shaped unvulcanized rubber member 19 is likely to be depressed at the boundary between the unvulcanized rubber A and the unvulcanized rubber D. A desired cross-sectional shape may not be obtained.
Further, if the thickness of the first partition wall 40 on the base side is less than 0.1 mm, the first partition wall 40 may be deformed or missing.
The first partition wall 40 of the present reference example has a base thickness of 5 mm and a height of 10 mm.

Note that the first partition wall 40 and the second partition wall 42 of the present reference example are both formed with a constant height in the longitudinal direction. Further, the first partition wall 40 of the present reference example has a tip (an end on the arrow F direction side: an end on the flow path outlet side) in contact with the back surface of the base 21. The cross-sectional shape of the second partition wall 42 is the same as the cross-sectional shape of the first partition wall 40, and the tip of the second partition wall 42 is also in contact with the back surface of the base 21.
In this reference example , the longitudinal end portion of the first partition wall 40 and the longitudinal end portion of the second partition wall 42 are portions having high rigidity of the middle mold 38 (see FIG. 9). (A thick portion having a rigidity higher than that of at least the first partition wall 40 and the second partition wall 42) 46, 48, and 50, and the first partition wall 40 and the second partition wall 42 are connected to each other. This is a preferable mode because the first partition wall 40 and the second partition wall 42 are prevented from being deformed. In addition, if the 1st partition wall 40 and the 2nd partition wall 42 can be reinforced, the longitudinal direction edge part of the 1st partition wall 40 and the 2nd partition wall 42 will be the 1st partition wall 40. The first partition wall 40 and the second partition wall 42 may be connected to a portion having rigidity equal to that of the second partition wall 42, or to a portion having lower rigidity than the first partition wall 40 and the second partition wall 42.

8A is a front view of the upper mold 34, FIG. 8B is a rear view of the upper mold 34, and FIG. 8C is a side view of the upper mold 34. This is a groove for forming one flow path 38A.
9A is a front view of the middle mold 38, FIG. 9B is a rear view of the middle mold 38, FIG. 9C is a side view of the middle mold 38, and reference numeral 39B is the second flow. It is a groove | channel for forming the path | route 38B, and the code | symbol 39C is a groove | channel for forming the 3rd flow path 38C.

  10A is a front view of the lower mold 36, FIG. 10B is a back view of the lower mold 36, and FIG. 10C is a side view of the lower mold 36. It is a groove | channel for forming 3 flow path 38C, and code | symbol 39D is a groove | channel for forming 4th flow path 38D.

(Function)
Next, the operation of the unvulcanized rubber extruder 10 will be described.
First, when the unvulcanized rubbers A, B, C, and D are fed from the extruder main bodies 12, 14, 16, and 18 toward the extrusion head 20, as shown in FIG. The unvulcanized rubber B flows into the second flow path 38B through the flow path 22b, and the unvulcanized rubber C flows into the third flow path 38C through the flow path 22c. The unvulcanized rubber D flows into the fourth flow path 38D via the flow path 22d.

  The unvulcanized rubber A flows through the first flow path 38A and is pushed out of the base 21 in the direction of arrow F, and the unvulcanized rubber B flows through the second flow path 38B and flows from the base 21 to the arrow F. The unvulcanized rubber C is pushed out in the direction, flows in the third flow path 38C and is pushed out from the base 21 in the direction of arrow F, and the unvulcanized rubber D flows in the fourth flow path 38D through the base. 21 is pushed in the direction of arrow F. The unvulcanized rubber A, the unvulcanized rubber B, the unvulcanized rubber C, and the unvulcanized rubber D have their cross-sectional shapes shown in FIG. A strip-shaped unvulcanized rubber member 19 is continuously obtained.

  As shown in FIG. 7 (B), the unvulcanized rubber B at the center changes its direction after the flow direction becomes parallel to the base 21 at the position of the second flow path side wall surface 38Ba facing the base 21. The direction of flow of the unvulcanized rubber C adjacent to the center unvulcanized rubber B toward the extrusion direction of the vulcanized rubber member 19 (arrow F direction) is also at the position of the third channel side wall surface 38Ca facing the base 21. After being parallel to the base 21, the direction is changed and the strip-shaped unvulcanized rubber member 19 is directed in the direction of extruding (direction of arrow F) (see also FIG. 11. The vulcanized rubber flows from the back side of the drawing toward the front side, and the reference numeral 92 indicates that the unvulcanized rubber flows from the front side of the drawing toward the back side.

  The unvulcanized rubber B and the unvulcanized rubber C are flowing in directions facing each other along the channel side wall surface immediately before going in the extrusion direction, but the second channel side wall surface 38Ba and the third channel side Since the second partition wall 42 is disposed between the wall surface 38Ca and the unvulcanized rubber B and the unvulcanized rubber C are not in contact with each other on the upstream side of the base 21, as shown by the arrows. Since the direction changes to the extrusion direction (arrow F direction), the boundary line SL1 between the unvulcanized rubber B and the unvulcanized rubber C continues on the extension line of the second partition wall 42 in the unvulcanized rubber extrusion direction. As shown in FIG. 2, a part of one unvulcanized rubber does not wrap around to the other unvulcanized rubber side, and is the same as the longitudinal direction of the second partition wall 42 as shown in FIG. In addition, the boundary line SL1 can be substantially linear.

  In addition, as shown in FIG. 7A, the unvulcanized rubber A is not strip-shaped when the direction of flow is parallel to the base 21 at the position of the first flow path side wall surface 38Aa facing the base 21. The unvulcanized rubber D adjacent to the unvulcanized rubber A toward the extrusion direction (arrow F direction) of the vulcanized rubber member 19 also flows in the direction of the base 21 at the position of the fourth flow passage side wall surface 38Da facing the base 21. The direction of the belt-shaped unvulcanized rubber member 19 is changed in the direction of the arrow F in the direction of arrow F.

  The unvulcanized rubber A and the unvulcanized rubber D are flowing in directions facing each other along the channel side wall surface portion immediately before going in the extrusion direction, but the first channel side wall surface 38Aa and the fourth channel side Since the first partition wall 40 is disposed between the wall surface 38Da and the upstream side of the base 21, the unvulcanized rubber A and the unvulcanized rubber D do not come into contact with each other as shown by arrows. Since the direction changes in the extrusion direction (arrow F direction), the boundary line SL2 between the unvulcanized rubber A and the unvulcanized rubber D is continuously on the extension line of the first partition wall 40 in the unvulcanized rubber extrusion direction. As shown in FIG. 2, a part of one unvulcanized rubber does not greatly wrap around to the other unvulcanized rubber side, and is the same as the longitudinal direction of the first partition wall 40. The boundary line SL2 can be substantially linear.

In addition, in the channel side wall surface portion immediately before the base 21 (immediately before the flow of the unvulcanized rubber C, D changes in the extrusion direction (arrow F direction)), the flow direction of the unvulcanized rubber C (illustrated by a dotted arrow) And the direction in which the unvulcanized rubber D flows (illustrated by dotted arrows) are substantially the same direction, so that if the discharge pressures of the unvulcanized rubber C and the unvulcanized rubber D are the same, the third Since the boundary between the unvulcanized rubber C and the unvulcanized rubber D (reference numeral SL3 in FIG. 2) is formed in a substantially straight line at an intermediate position between the flow path 38C and the fourth flow path 38D, Immediately before, it is not necessary to provide a partition wall between the third flow path 38C and the fourth flow path 38D.

  The boundary position between the unvulcanized rubber C and the unvulcanized rubber D can be shifted in the width direction by changing the discharge pressure of the unvulcanized rubber C and the discharge pressure of the unvulcanized rubber D. Various strip-shaped unvulcanized rubber members 19 having different boundary positions between the unvulcanized rubber C and the unvulcanized rubber D can be molded. For example, if the discharge pressure of the unvulcanized rubber C is made higher than the discharge pressure of the unvulcanized rubber D, the boundary position between the unvulcanized rubber C and the unvulcanized rubber D is set to the outside in the width direction of the belt-shaped unvulcanized rubber member 19. Can be displaced.

[Other reference examples ]
In addition, when the front-end | tip of the 1st partition wall 40 and the front-end | tip of the 2nd partition wall 42 leave | separate from the back surface of the nozzle | cap | die 21, the boundary of the unvulcanized rubber which mutually adjoins across the partition wall will shift | deviate from a regular position. End up. The distance between the partition wall tip and the base 21 is preferably 0.5 mm or less, and most preferably the partition wall tip is brought into contact with the base 21.

In the above reference example , an example of extruding a band-shaped unvulcanized rubber member that becomes a tread of a pneumatic tire for a motorcycle has been shown. However, the unvulcanized rubber extruder changes the flow path, the base 21 and the like other than the tread. It is also possible to extrude the belt-shaped unvulcanized rubber member.

[Embodiment]
In the middle mold 38 of the above reference example , the second partition wall 42 is formed at a certain height. However, in the present embodiment shown in FIG. 13, the second partition wall 42 is provided on the channel outlet side. A notch 52 is formed at the end of (arrow F direction side) from the end of arrow D direction toward the notch 21a of the base 21 indicated by a two-dot chain line, and the portion facing the opening (base 21) The height of the second partition wall 42 in the portion seen from the opening when viewed from the front is lower than the other portion (the back portion of the base 21).

Thereby, as shown in FIG. 14, the unvulcanized rubber B and the unvulcanized rubber C have an arrow B on the upstream side (the lower side in the drawing) of the opening. Since joining is performed by a flow as indicated by “and arrow C”, the unvulcanized rubber B and the unvulcanized rubber C are more reliably joined.
Here, the notch 52 is formed in the second partition wall 42, but the notch may be formed in the first partition wall 40.

It is a side view which shows schematic structure of an unvulcanized rubber extruder. (A) is sectional drawing of the unvulcanized rubber member extrusion-molded with the unvulcanized rubber extruder, (B) is a front view of a nozzle | cap | die. (A) is the reverse view seen from the extruder main body side of the unvulcanized rubber member formation means, (B) is sectional drawing which shows the principal part of an extrusion head. It is a front view of a head body. (A) is the front view seen from the unvulcanized rubber extrusion side of an unvulcanized rubber member formation means, (B) is sectional drawing which shows the principal part of an extrusion head. (A) is the sectional view on the AA line of the extrusion head shown in FIG. 5, (B) is sectional drawing on the BB line of the extrusion head shown in FIG. 5, (C) is the extrusion head shown in FIG. FIG. 6D is a cross-sectional view taken along the line C-C of FIG. 5, and (D) is a cross-sectional view taken along the line D-D of the extrusion head shown in FIG. 5. It is the EE sectional view taken on the line of the 1st partition wall shown in FIG. 5, (B) is the FF sectional view taken on the line of the 2nd partition wall shown in FIG. (A) is a front view of the upper mold, (B) is a back view of the upper mold, and (C) is a side view of the upper mold. (A) is a front view of a middle mold, (B) is a back view of the middle mold, and (C) is a side view of the middle mold. (A) is a front view of a lower mold, (B) is a back view of the lower mold, and (C) is a side view of the lower mold. It is the enlarged front view which expanded a part of extrusion head shown in FIG. (A) is sectional drawing of the unvulcanized rubber member in which the boundary of rubber is appropriate, (B) is sectional drawing of the unvulcanized rubber member in which the boundary of rubber is inappropriate. It is a perspective view of the principal part of the inside metal mold concerning an embodiment . It is a GG sectional view taken on the line of the middle mold shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Unvulcanized rubber extruder A Unvulcanized rubber B Unvulcanized rubber C Unvulcanized rubber D Unvulcanized rubber 12 Extruder main body 14 Extruder main body 16 Extruder main body 18 Extrusion head 19 Band-shaped unvulcanized rubber member 21 Base 22a Flow path (unvulcanized rubber extrusion port of the present invention)
22b Flow path (unvulcanized rubber extrusion port of the present invention)
22c flow path (unvulcanized rubber extrusion port of the present invention)
22d channel (unvulcanized rubber extrusion port of the present invention)
25 Extrusion head body 32 Flow path forming mold 38A First flow path (flow path of the present invention)
38B 2nd flow path (flow path of the present invention)
38C 3rd flow path (flow path of the present invention)
38D 4th flow path (flow path of the present invention)
40 1st partition wall 42 2nd partition wall 46 A part higher in rigidity than the partition wall (another part different from the part where the partition wall is formed)
48 Parts with higher rigidity than the partition wall (other parts different from the part where the partition wall is formed)
50 Parts with higher rigidity than the partition wall (other parts different from the part where the partition wall is formed)
52 Notch

Claims (9)

An unvulcanized rubber extruder for extruding a strip-shaped unvulcanized rubber member made of a plurality of types of unvulcanized rubber from an opening of a die,
A plurality of extruder bodies for extruding unvulcanized rubber;
An extrusion head body connected to the unvulcanized rubber discharge side of the extruder body, and having an unvulcanized rubber extrusion port for discharging unvulcanized rubber extruded from the extruder body; and
A flow path forming mold that is connected to the unvulcanized rubber discharge side of the extrusion head body and includes a plurality of flow paths that guide the unvulcanized rubber extruded from the unvulcanized rubber extrusion port toward the base. Have
On the base side of the flow path forming mold, a partition wall is formed between the flow paths adjacent to each other,
The flow path extends in a direction crossing the extrusion direction of the unvulcanized rubber extruded from the base at a portion facing the base.
The partition wall extends in a direction intersecting a width direction of the unvulcanized rubber on a wall surface of the flow path extending in a direction intersecting with an extrusion direction of the unvulcanized rubber extruded from the die of the flow path. Formed into
An unvulcanized rubber extruder, in which a notch is formed at an end of the partition wall on the channel outlet side.   The partition wall is a portion where the flow direction of the unvulcanized rubber flowing through one of the adjacent flow paths and the flow direction of the unvulcanized rubber flowing through the other flow path face each other at a portion facing the base. The unvulcanized rubber extruder according to claim 1, wherein the unvulcanized rubber extruder is formed.   The unvulcanized rubber extruder according to claim 1 or 2, wherein an interval between the partition wall and the die is 0.5 mm or less.   The unvulcanized rubber extruder according to claim 1 or 2, wherein the partition wall and the base are in contact with each other.   The unvulcanized rubber extruder according to any one of claims 1 to 4, wherein the partition wall is formed so that the base side is thin and the upstream side in the flow direction of the unvulcanized rubber is thicker than the base side. .   The unvulcanized rubber extruder according to claim 5, wherein the partition wall has a thickness on the base side set in a range of 0.1 to 0.5 mm.   The unvulcanized rubber according to any one of claims 1 to 6, wherein the plurality of unvulcanized rubber extrusion ports are arranged in a vertical direction, and the outlet sides of the plurality of flow paths are arranged in a horizontal direction. Rubber rubber extruder.   The longitudinal direction edge part of the said partition wall is connected with the other site | part different from the part in which the said partition wall is formed in the said flow-path formation metal mold | die. The unvulcanized rubber extruder according to item 1.   The unvulcanized rubber extruder according to any one of claims 1 to 8, wherein the belt-shaped unvulcanized rubber member is used for a tread of a pneumatic tire for a motorcycle.

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