JP2018052317A - Method for manufacturing pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pneumatic tire in which stud pins can be positioned at respective appropriate positions with respect to respective holes for the sud pins embedded therein.SOLUTION: A pneumatic tire comprises rubber protruding parts: each of which is inserted in each of holes for respective embedding stud pins; each of which protrudes from a bottom surface of the hole; each of which is spaced apart from a side wall of hole for the embedding stud pin, and shorter than a depth of the hole for the embedding stud pin; and each of which extends cylindrically in a direction that the hole for the embedding stud pin extends. On the other hand, a cylindrical elongated hole extends inside the stud pin from an end surface of a lower flange of each of the stud pins, and is closed in the middle. When the stud pin is inserted into the hole for the embedding stud pin, the rubber protruding part and the elongated hole are engaged with each other to cause the rubber protruding part to position the stud pin, and to guide the positioned stud pin into the hole for the embedding stud pin.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a method for manufacturing a pneumatic tire equipped with stud pins.

Conventionally, in snowy and snowy road tires, stud pins are attached to the tread portion of a pneumatic tire so that a grip can be obtained on the road surface on ice.
Generally, a stud pin is embedded in a pin embedding hole (hereinafter also simply referred to as a hole) provided in a tread portion. When the stud pin is embedded in this hole, the stud pin is tightly embedded in the hole by inserting the stud pin into the hole whose hole diameter is expanded. This prevents the stud pin from falling out of the hole due to braking / driving force or lateral force received from the road surface during the rolling of the pneumatic tire.

On the other hand, when the stud pin embedded in the hole falls out of the pneumatic tire, the stud pin falls off while rotating with respect to the hole. Therefore, to prevent the stud pin from falling off, the stud pin should not rotate with respect to the hole. Is preferred.
For example, there is a technique that can suppress the rotation of the stud pin by providing curved concave portions on the side surfaces of the upper flange and the lower flange of the stud pin, and the tread rubber entering the curved concave portion. Known (Patent Document 1).

International Publication No. 2015/114413

While various techniques for preventing the stud pin embedded in the hole from falling out of the pneumatic tire have been studied in this way, the technique for efficiently embedding the stud pin in the stud pin embedding hole of the pneumatic tire is sufficient. Not considered.
When trying to embed the stud pin in the hole, it is necessary to expand the hole using a mounting device and insert the stud pin positioned at the appropriate position of the expanded hole straight in the depth direction of the hole. is there. However, when the stud pin gripped with the tip of the mounting device is moved to the hole position, when the stud pin is loosened and the stud pin is pushed into the hole, the stud pin is slightly displaced with respect to the hole. Or a stud pin may incline slightly with respect to the depth direction of a hole. For this reason, a stud pin cannot be embedded in a hole, and the production efficiency of stud pin attachment may fall. In addition, even if the stud pin can be embedded in the hole in this state (the stud pin has not failed to be embedded), the excess stress due to the inappropriate position and orientation of the stud pin with respect to the hole is treaded. By receiving from rubber, the stud pin may easily fall out of the hole, and the grip performance of the stud tire on the road surface on ice is likely to deteriorate.

  Therefore, the present invention provides a pneumatic tire that can be inserted straight in the depth direction of the hole by positioning the stud pin at an appropriate position with respect to the hole when the stud pin is embedded in the stud pin embedding hole. It aims to provide a method.

One embodiment of the present invention is a method for manufacturing a pneumatic tire equipped with stud pins. The stud pin used in the manufacturing method includes a chip configured to contact a road surface, and a trunk portion extending in one direction configured to be attached to the stud pin embedding hole, The first end surface in the extending direction of the body portion is provided with a chip embedding hole provided so as to fix the chip, and the body portion is opposite to the first end surface of the body portion. A columnar long hole extending from the second end surface toward the first end surface and closing in the middle is provided.
The production method is as follows:
A stud pin embedding hole is provided in the tread rubber, and the stud pin embedding hole protrudes from a bottom surface of the stud pin embedding hole and is spaced apart from a side wall of the stud pin embedding hole. Producing a studded pneumatic tire provided with a rubber protrusion extending in a columnar shape and extending along the extending direction of the stud pin embedding hole.
The stud pin is inserted into the stud pin embedding hole by gripping the outer periphery of the stud pin with a stud pin mounting jig and expanding the side wall of the stud pin embedding hole at the tip of the stud pin mounting jig. And a step of.
When the stud pin is inserted into the stud pin embedding hole, the rubber projecting portion engages with the elongated hole of the stud pin, so that the rubber projecting portion positions the stud pin and embeds the stud pin. Guide into the hole.

  In that case, it is preferable that the height dimension of the rubber protrusion from the bottom surface is 40% or more of the depth dimension of the stud pin embedding hole.

  It is preferable that the central axis of the rubber protrusion passes through the center of the bottom surface.

  The diameter of the elongated hole is preferably larger than the diameter of the rubber protrusion.

The step of producing the studded pneumatic tire includes vulcanizing a green tire using a tire mold,
The tire mold is
A tread surface corresponding portion corresponding to the tread surface of the studded pneumatic tire;
A mold pin fixed to the tread surface corresponding part and corresponding to the stud pin embedding hole,
The mold pin is provided with a columnar recess that extends in a columnar shape from the tip surface of the mold pin toward the base of the mold pin and closes in the middle.
It is preferable that the depth dimension of the columnar recess from the tip surface is smaller than the dimension of the protrusion height of the mold pin from the surface of the tread surface corresponding part.

  According to the method for producing a pneumatic tire described above, when the stud pin is embedded in the stud pin embedding hole, the stud pin can be positioned at an appropriate position with respect to the hole and inserted straight in the depth direction of the hole. it can.

It is a tire sectional view showing an example of a section of a tire of this embodiment. It is an appearance perspective view of the tire of this embodiment. It is a partial plane development view of a tread pattern which developed an example of a tread pattern of a tire of this embodiment on a plane. (A) is a figure which shows an example of the stud pin of this embodiment, (b) is a figure which shows an example of the bottom face of the lower flange of the stud pin shown to (a). It is a figure which shows an example of the cross section of the hole along the depth direction of the hole for stud pin embedding provided in the tread rubber of the tire of this embodiment. It is a figure explaining an example of the mold corresponding | compatible part around the hole for stud pin embedding in the tire metal mold | die for manufacturing the tire of this embodiment. It is a figure explaining an example of a mode when the stud pin of this embodiment is embedded in the hole for stud pin embedding. It is a figure explaining another example of a mode when the stud pin of this embodiment is embedded in the hole for stud pin embedding.

(Whole tire description)
Hereinafter, the stud tire of this embodiment will be described. FIG. 1 is a tire cross-sectional view showing an example of a cross section of a studable tire (hereinafter referred to as a tire) 10 of the present embodiment. FIG. 2 is an external perspective view of the tire 10.
The tire 10 is a studded tire in which a stud pin can be embedded in a stud pin embedding hole provided in a tread rubber.
The tire 10 is, for example, a passenger car tire. Passenger car tires are tires defined in Chapter A of JATMA YEAR BOOK 2012 (Japan Automobile Tire Association Standard). In addition, the present invention can also be applied to small truck tires defined in Chapter B and truck and bus tires defined in Chapter C.
The numerical value of the dimension of each pattern element specifically explained below is a numerical example in a passenger car tire, and the tire is not limited to these numerical examples.

  The tire circumferential direction C (see FIG. 2) described below refers to the direction of rotation of the tread surface (both rotational directions) when the tire 10 is rotated around the tire rotation axis Axis (see FIG. 2). The tire radial direction R means a radial direction extending orthogonally to the tire rotational axis Axis, and the tire radial direction outer side means a side away from the tire rotational axis Axis in the tire radial direction R. The tire width direction W refers to a direction parallel to the tire rotation axis direction Axis, and the outer side in the tire width direction refers to both sides of the tire 10 away from the tire equator line CL (see FIGS. 1 and 3).

(Tire structure)
The tire 10 includes a carcass ply layer 12, a belt layer 14, and a bead core 16 as a skeleton material. The tire 10 mainly includes a tread rubber 18, a side rubber 20, a bead filler rubber 22, a rim cushion rubber 24, and an inner liner rubber 26 around these skeleton materials.

  The carcass ply layer 12 includes carcass ply materials 12a and 12b in which organic fibers are covered with rubber, which are wound between a pair of annular bead cores 16 to form a toroidal shape. In the tire 10 shown in FIG. 1, the carcass ply layer 12 is composed of carcass ply materials 12a and 12b, but may be composed of one carcass ply material. A belt layer 14 composed of two belt members 14a and 14b is provided outside the carcass ply layer 12 in the tire radial direction. The belt layer 14 is a member in which a rubber is coated on a steel cord disposed at a predetermined angle, for example, 20 to 30 degrees with respect to the tire circumferential direction C, and the width of the lower belt material 14a in the tire width direction. Is wider than the width of the upper belt material 14b. The inclination directions of the steel cords of the two layers of belt members 14a and 14b are inclined in different directions from the tire circumferential direction C toward the tire width direction W. For this reason, belt material 14a, 14b is a crossing layer, and controls expansion of carcass ply layer 12 by the filled air pressure.

A tread rubber 18 is provided on the outer side of the belt layer 14 in the tire radial direction, and side rubbers 20 are connected to both ends of the tread rubber 18 to form sidewall portions. The tread rubber 18 is composed of two layers of rubber, and includes an upper layer tread rubber 18a provided on the outer side in the tire radial direction and a lower layer tread rubber 18b provided on the inner side in the tire radial direction. A rim cushion rubber 24 is provided at the inner end of the side rubber 20 in the tire radial direction, and comes into contact with a rim on which the tire 10 is mounted. The bead core 16 is sandwiched between the portion of the carcass ply layer 12 before being wound around the bead core 16 and the portion of the carcass ply layer 12 after being wound around the bead core 16 on the outer side in the tire radial direction of the bead core 16. A bead filler rubber 22 is provided. An inner liner rubber 26 is provided on the inner surface of the tire 10 facing the tire cavity region filled with air surrounded by the tire 10 and the rim.
In addition, the tire 10 includes a belt cover layer 28 that covers the belt layer 14 from the outer side in the tire radial direction of the belt layer 14 and that is formed by covering organic fibers with rubber.

  Although the tire 10 has such a tire structure, the tire structure of the present embodiment is not limited to the tire structure shown in FIG.

(Tread pattern)
FIG. 3 is a plan development view of a part of the tread pattern in which the tread pattern 30 which is an example of the tire 10 is developed on the plane. In FIG. 3, the illustration of the stud pin attached to the tread portion is omitted. As shown in FIG. 3, the tire 10 is designated with a rotational direction X indicating one direction in the tire circumferential direction C. Information on the direction of the rotational direction X is shown in an information display section such as numbers and symbols (for example, arrow symbols) provided on the sidewall surface of the tire 10. The stud pins (see FIG. 4A) are attached to the plurality of stud pin embedding holes 29 shown in FIG.

The tread pattern 30 includes an inclined groove 32, a circumferential communication groove 34, a protruding groove 36, and a sipe 38.
A plurality of the inclined grooves 32 are formed at predetermined intervals in the tire circumferential direction (vertical direction in FIG. 3).
The inclined groove 32 extends in the direction opposite to the tire rotation direction X (downward in FIG. 3) (upward in FIG. 3) and outward in the tire width direction. The inclined groove 32 crosses the tire equator line CL from the position in the vicinity of the tire equator line CL on one side in the tire width direction W across the tire equator line CL, and the other side in the tire width direction W. To the pattern end PE.
The groove width of the inclined groove 32 gradually increases from the starting end in the vicinity of the tire equator line CL. The inclination of the inclined groove 32 with respect to the tire width direction W is the smallest in the vicinity of the tire equator line CL including the starting end, and after traversing the tire equator line CL, the inclination is bent so that the inclination angle with respect to the tire width direction W increases. Proceed in the direction opposite to the tire rotation direction X on the outer side in the direction. Further, the inclination angle gradually decreases as the tire width direction increases. Such inclined grooves 32 are provided on both sides of the tire equator line CL.
The inclined groove 32 provided on one side across the tire equator line CL of the tread portion is displaced with respect to the tire circumferential direction C with respect to the inclined groove 32 provided on the other side. The starting end of the inclined groove 32 provided is not connected to the inclined groove 32 provided on the other side.

  Of the plurality of inclined grooves 32 provided in the tire circumferential direction C, the adjacent inclined grooves 32 communicate with each other through a circumferential communication groove 34. More specifically, the circumferential communication groove 34 extends from one middle of the inclined groove 32 toward the tire circumferential direction C, crosses the inclined groove 32 adjacent to the tire circumferential direction C, and is formed into the adjacent inclined groove 32. On the other hand, it further proceeds to the inclined groove 32 adjacent in the tire circumferential direction C. That is, the start end of the circumferential communication groove 34 is in one of the inclined grooves 32, and the end is in the second inclined groove 32 along the tire circumferential direction C from the inclined groove 32 with the start end. As described above, the circumferential communication groove 34 is provided so as to connect the three inclined grooves 32 adjacent along the tire circumferential direction C. The circumferential communication groove 34 is inclined with respect to the tire circumferential direction C so as to approach the tire equator line CL as it proceeds in the direction opposite to the tire rotation direction X.

  The protruding groove 36 protrudes from the circumferential communication groove 34 in the direction of the tire equator line CL, and is provided so as to be closed before reaching the tire equator line CL.

  The land portion of the tread portion is divided into a center region and a shoulder region by the inclined groove 32 and the circumferential communication groove 34. A plurality of sipes 38 connected to the inclined groove 32 and the circumferential communication groove 34 are provided in both the center region and the shoulder region of the tread portion.

Further, a plurality of stud pin embedding holes 29 are provided in both the center region and the shoulder region of the tread portion.
The groove depths of the inclined groove 32, the circumferential communication groove 34, and the protruding groove 36 are, for example, 8.5 to 10.5 mm, and the maximum width of the groove width is 12 mm. The tread pattern shown in FIG. 3 is an example, and the tread pattern of the tire to which the stud pin of this embodiment is attached is not limited to the form shown in FIG.

(Stud pin)
FIG. 4A is a perspective view showing an example of the stud pin 50 of the present embodiment embedded in a stud pin embedding hole (hereinafter simply referred to as a hole) 29 of the tire 10. FIG.4 (b) is a figure which shows an example of the bottom part of the lower flange of the stud pin 50 shown to Fig.4 (a).

  The stud pin 50 includes a chip 52 and a body portion 54. The body part 54 has a shape extending in one direction, and the body part 54 includes an upper flange 56, a shank part 60, and a lower flange 58 in order along the one direction. When the body portion 54 is embedded in the hole 29 of the tire 10, the body portion 54 is embedded in the tread rubber 18 (FIG. 1) and contacts the tread rubber 18.

  The tip 52 is a portion configured to come into contact with the road surface and has a tip end surface. The chip 52 is made of a super steel alloy such as tungsten carbide. In addition, the chip 52 can be made of a cermet material. The chip 52 is fixed to the upper end surface of the body portion 54. When the stud pin 50 is attached to the tire 10, the tip 52 of the stud pin 50 projects from the tread surface.

The body portion 54 is configured to be embedded in the hole 29 provided in the tread rubber of the tire 10. The body portion 54 is provided around the central axis Z and holds the chip 52.
The upper flange 56 of the body portion 54 is configured such that the chip 52 protrudes from the tread surface when the body portion 54 is embedded in the hole 29. A chip embedding hole provided so as to fix the chip 52 is provided on the upper end surface of the upper flange 56. A part of the chip 52 is embedded in this hole, and the chip 52 is fixed at the upper end of the upper flange 56.
The lower flange 58 is configured to contact the bottom surface of the hole 29 when the body portion 54 is embedded in the hole 29. The lower flange 58 is provided at the end of the upper flange 56 opposite to the end surface that holds the tip 52.
The shank portion 60 is a portion connecting the upper flange 56 and the lower flange 58, and the cross section perpendicular to the central axis Z of the shank portion 60 is narrower than the cross sections of the upper flange 56 and the lower flange 58.
Although the material of the trunk | drum 54 is not restrict | limited in particular, For example, in order to reduce the weight of the stud pin 50, it is comprised with the aluminum alloy etc.
The central axis Z passes through the centroid of a cross section orthogonal to the extending direction of the body portion 54. Therefore, the axial direction of the central axis Z is the extending direction of the body portion 54.
The cross-sectional shape orthogonal to the central axis Z of the upper flange 56 and the lower flange 58 of the stud pin 50 is a circular shape, but an elliptical shape, a polygonal shape, a shape with rounded corners of a polygonal shape, or a side of a polygonal shape The portion may be recessed inwardly.

  The stud pin 50 extends from the bottom portion 58a of the lower flange 58 of the body portion 54 (the bottom surface opposite to the end surface holding the tip 52 of the upper flange 56) 58a to the inside of the stud pin 50 from the end surface side holding the tip 52 ( A columnar long hole 62 extending toward the first side and closing in the middle is provided. Specifically, the elongated hole 62 is a hole along the central axis Z, and the shape of the cross section orthogonal to the central axis Z of this hole is circular. It is preferable that the central axis Z passes through the center of the long hole 62.

  As described above, the elongated hole 62 extending from the bottom 58a of the lower flange 58 of the stud pin 50 is provided by engaging the elongated hole 62 with a columnar rubber protrusion provided in the hole 29 of the tire 10 described later. This is because the misalignment of the stud pin 50 with respect to the hole 29 is suppressed and the direction of the central axis Z of the stud pin 50 is matched with the depth direction of the hole 29. As a result, the stud pin 50 can be positioned at an appropriate position with respect to the hole 29 and inserted straight in the depth direction of the hole 29. As a result, the stud pin 50 embedded in the hole 29 can be prevented from falling out of the hole 29.

  The dimension H2 (see FIG. 4A) from the bottom 58a of the lower flange 58 to the closed end of the elongated hole 62 is from the bottom 58a of the lower flange 58 to the end face of the upper flange 56 that holds the chip 52. It is preferably 40% or more of the length dimension H1 (see FIG. 4A), more preferably 50% or more. The length dimension H <b> 2 of the elongated hole 62 may be a dimension that allows the entire rubber protrusion 29 a described later to enter the elongated hole 62. Of course, the dimension H2 is less than 100% of the dimension H1.

FIG. 5 is a diagram illustrating an example of a cross section of the hole 29 along the depth direction of the stud pin embedding hole 29 provided in the tread rubber 18 of the tire 10 of the present embodiment.
As shown in FIG. 5, the hole 29 is provided with a rubber protrusion 29a. The rubber protrusion 29a protrudes from the bottom surface 29b of the hole 29, is spaced from the side wall 29c of the hole 29, is shorter than the depth D1 of the hole 29, and extends in a column shape along the extending direction of the hole 29. When the stud pin 50 is mounted in the hole 29, the rubber protruding portion 29a engages with the long hole 62 provided in the stud pin 50 described above.

FIG. 6 is a diagram for explaining an example of a die-corresponding portion around the hole 29 of a tire mold for vulcanizing and manufacturing a studded pneumatic tire having the hole 29 provided in the tread rubber. . The mold 70 includes a tread surface corresponding portion 72 and a mold pin 74.
The tread surface corresponding portion 72 is a portion corresponding to the tread surface of the tire 10 that forms the tread surface of the tire 10.
The mold pin 74 is a part that forms the hole 29 of the tire 10. The mold pin 74 is fixed to the tread surface corresponding portion 72 with a screw or the like.
The mold pin 74 is provided with a columnar recess 74c that extends in a columnar shape from the protruding end surface 74a of the mold pin 74 toward the base 74b of the mold pin 74 and closes in the middle.
The columnar recess 74c is a portion corresponding to the rubber protrusion 29a described above. The dimension D2 (see FIG. 6) of the depth from the front end surface 74a of the columnar recess 74c is smaller than the dimension H4 of the protruding height of the mold pin 74 from the surface of the tread surface corresponding part 72. For this reason, when the tire 10 is produced using the tire mold 70, the height dimension H3 of the rubber protrusion 29a is smaller than the depth dimension D1 of the hole 29. The depth dimension D2 is preferably 40% or more, and more preferably 50% or more of the protrusion height dimension H4 of the mold pin 74. The depth dimension D2 is a dimension corresponding to the height dimension H3 of the rubber protrusion 29a so that the rubber protrusion 29a described above is formed.

(Tire making method)
A method for producing a pneumatic tire equipped with the stud pin of this embodiment will be described below.
First, the studded tire 10 to which the above-described stud pin 50 is not attached is manufactured. That is, the studded tire 10 has a large number of mold pins 74 as shown in FIG. 6 and vulcanizes the green tire using a tire mold having irregularities corresponding to the tread pattern 30 as shown in FIG. Produced. Specifically, as shown in FIG. 5, the tire 10 in which the stud pin embedding hole 29 is provided in the tread rubber and the rubber protruding portion 29 a is provided in the hole 29 is manufactured.

Next, as shown in FIG. 7, the stud pin 50 is brought close to the hole 29 while the outer periphery of the stud pin 50 is gripped by the tip claw 64 of the stud pin mounting jig. Further, the side wall of the hole 29 is expanded when the tip claw 64 of the stud pin mounting jig enters the hole 29. FIG. 7 is a diagram illustrating an example of a state when the stud pin 50 according to the present embodiment is embedded in the hole 29.
In FIG. 7, when the tip claw 64 enters the hole 29, the hole 29 expands, and the stud pin 50 sandwiched and held between the tip claw 64 attempts to enter the hole 29 from now on. Indicates the state.

  FIG. 8 is a diagram for explaining another example of a state when the stud pin 50 of the present embodiment is embedded in the hole 29. The state of the stud pin 50 shown in FIG. 8 is a state in which time has elapsed from the state of the stud pin 50 shown in FIG. Specifically, FIG. 8 shows a state in which the stud pin 50 is loosened and the rod 66 pushes the stud pin 50 toward the bottom surface 29 b of the hole 29 to push the stud pin 50 into the hole 29. Yes. As shown in FIG. 8, when the holding of the stud pin 50 is loosened and the rod 66 pushes the stud pin 50 into the hole 29, the elongated hole 62 is already in engagement with the rubber protrusion 29a. That is, when the stud pin 50 gripped by the tip claw 64 of the mounting device for implantation moves toward the hole 29, the grip of the stud pin 50 is loosened after the elongated hole 62 and the rubber protruding portion 29a are engaged. The stud 66 is pushed into the hole 29 by the rod 66. Therefore, the rubber protrusion 29 a and the stud pin 50 are engaged with each other so that the rubber protrusion 29 a positions the stud pin 50 and guides it in the hole 29. For this reason, the stud pin 50 is inserted straight in the depth direction of the hole 29 along the rubber protruding portion 29 a while maintaining a state where the stud pin 50 is positioned at an appropriate position with respect to the hole 29.

  As mentioned above, although the manufacturing method of the pneumatic tire of this invention was demonstrated, this invention is not limited to the said embodiment, Of course, in the range which does not deviate from the main point of this invention, you may make a various improvement and change. It is.

DESCRIPTION OF SYMBOLS 10 Pneumatic tire 12 Carcass ply layer 14 Belt layers 14a and 14b Belt material 16 Bead core 18 Tread rubber 18a Upper layer tread rubber 18b Lower layer tread rubber 20 Side rubber 22 Bead filler rubber 24 Rim cushion rubber 26 Inner liner rubber 28 Belt cover layer 29 Stud pin Filling hole 29a Rubber protrusion 29b Bottom surface 29c Side wall 29d Expansion part 30 Tread pattern 32 Inclined groove 34 Circumferential communication groove 36 Projection groove 50 Stud pin 52 Tip 54 Body part 56 Upper flange 58 Lower flange 58a Bottom part 60 Shank part 62 Long hole 64 Tip claw 66 Rod

Claims (5)

A method for producing a pneumatic tire fitted with stud pins,
The stud pin includes a tip configured to come into contact with a road surface, and a trunk portion extending in one direction configured to be fitted in the stud pin embedding hole, and extending the trunk portion. A first end surface in the direction of orientation includes a chip embedding hole provided so as to fix the chip, and the body portion has a second end surface opposite to the first end surface of the body portion. From, a columnar elongated hole extending toward the first end surface and closing in the middle is provided,
A stud pin embedding hole is provided in the tread rubber, and the stud pin embedding hole protrudes from a bottom surface of the stud pin embedding hole and is spaced apart from a side wall of the stud pin embedding hole. Producing a studded pneumatic tire provided with a rubber protrusion extending in a columnar shape and extending along the extending direction of the stud pin embedding hole.
The stud pin is inserted into the stud pin embedding hole by gripping the outer periphery of the stud pin with a stud pin mounting jig and expanding the side wall of the stud pin embedding hole at the tip of the stud pin mounting jig. And comprising the steps of:
When the stud pin is inserted into the stud pin embedding hole, the rubber projecting portion engages with the elongated hole of the stud pin, so that the rubber projecting portion positions the stud pin and embeds the stud pin. A method for producing a pneumatic tire, characterized in that the pneumatic tire is guided in a hole.   The method for producing a pneumatic tire according to claim 1, wherein a height dimension of the rubber protruding portion from the bottom surface is 40% or more of a depth dimension of the stud pin embedding hole.   The pneumatic tire manufacturing method according to claim 1, wherein a central axis of the rubber protruding portion passes through a center of the bottom surface.   The method for producing a pneumatic tire according to claim 1, wherein a diameter of the elongated hole is larger than a diameter of the rubber protrusion. The step of producing the studded pneumatic tire includes vulcanizing a green tire using a tire mold,
The tire mold is
A tread surface corresponding portion corresponding to the tread surface of the studded pneumatic tire;
A mold pin fixed to the tread surface corresponding part and corresponding to the stud pin embedding hole,
The mold pin is provided with a columnar recess that extends in a columnar shape from the tip surface of the mold pin toward the base of the mold pin and closes in the middle.
The dimension of the depth from the said front end surface of the said columnar recessed part is small compared with the dimension of the protrusion height of the said mold pin from the surface of the said tread surface corresponding | compatible part. Method for producing a pneumatic tire.

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