JP2016210090A - Mold for tire vulcanization and tire vulcanizing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for tire vulcanization and a tire vulcanizing method which can prevent the occurrence of vertical positional deviation of a tread segment during closing operation and can prevent the occurrence of crushing of the tread segment.SOLUTION: In a mold for tire vulcanization, a side plate is provided with a projection part projecting from its outer peripheral edge to the radial outside, a projecting locking part formed in the axial inside of the projection part, and an inclined surface inclined radially inward from a tip in the radial outside of the projecting part to the radial inside, a sector shoe is provided with an inclined surface, having the same inclination angle as that of the inclined surface of the side plate, from a tip in the axial outside of the radially inside end surface of the sector shoe to the radial outside and the axial outside, and in closing operation, while the inclined surface of the side plate and the inclined surface of the sector shoe are rubbed together, the sector shoe decreases in diameter, whereby the side plate and the sector shoe abut on each other and the side plate and the tread segment abut on each other.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a tire vulcanization mold and a tire vulcanization method used for vulcanization molding of an unvulcanized tire.

  In the manufacturing process of a pneumatic tire, in recent years, an unvulcanized tire vulcanizing mold (hereinafter, also simply referred to as “mold”) having a split mold mold in which a tread segment is divided along a circumferential direction is used. Vulcanization molding of vulcanized tires is widely performed (for example, Patent Documents 1 and 2).

  FIG. 4 is a cross-sectional view schematically showing a conventional tire vulcanization mold. Since the cross section of the tire vulcanization mold is symmetrical, only the left half is shown in FIG. As shown in FIG. 4, a conventional tire vulcanizing mold 1 includes an actuator 2 supported by an upper plate 6, a sector shoe 3 slidably attached along a slope 2b of the actuator 2, A tread segment 7 fitted in the sector shoe 3 and a pair of upper and lower side plates 8 and 9 attached to the upper and lower platen plates 4 and 5 are provided.

  In vulcanization molding of an unvulcanized tire using the tire vulcanizing mold 1, first, after setting the unvulcanized tire T in the tire vulcanizing mold 1, the upper plate 6 is lowered. . Then, by bringing the lower surface of the sector shoe 3 into contact with the lower platen plate 5 and further lowering the plate 6, the sector shoe 3 slides along the inclined surface 2 b of the actuator 2. The tread segment 7 is reduced in diameter toward the inner side in the radial direction.

  When the upper plate 6 is further lowered, the upper end portion 7a and the lower end portion 7b of the tread segment 7 whose diameter is reduced come into contact with the outer peripheral surfaces of the upper and lower side plates 8, 9, and the tire vulcanizing mold 1 is used. Is closed. In this state, a bladder (not shown) is inflated, and vulcanization molding is performed by pressing the unvulcanized tire T against the molding surfaces of the tread segment 7 and the upper and lower side plates 8 and 9 while heating.

JP 2010-155410 A

  However, each part constituting the tire vulcanizing mold 1 has processing tolerances, variations in assembly accuracy, and the like. Therefore, during the above-described closing operation, each tread with respect to the upper and lower side plates 8, 9 is used. There was a risk that the appearance of the tire after vulcanization would deteriorate due to a shift in the positional relationship of the segments 7 in the vertical direction.

  Further, as described above, the upper end portion 7a and the lower end portion 7b of the tread segment 7 are in contact with the side plates 8 and 9, and thus directly receive the tightening force of the closing operation. In general, since the tread segment 7 is made of aluminum and the side plates 8 and 9 are made of iron, the upper end portion 7a and the lower end portion 7b of the tread segment 7 that are directly subjected to the tightening force are easily deformed. As a result, a gap is generated between the tread segment 7 and the side plates 8 and 9, which causes overspewing of the vulcanized tire and causes deterioration in appearance.

  As described above, when the appearance of the tire after vulcanization is deteriorated, reworking or disposal is required, which causes a reduction in production efficiency in the manufacturing process of the pneumatic tire.

  Therefore, the present invention prevents the occurrence of vertical displacement of the tread segment during the closing operation, and prevents the upper end portion and the lower end portion of the tread segment from being crushed, thereby stabilizing a tire having a good appearance. It is an object of the present invention to provide a tire vulcanization mold and a tire vulcanization method that can be manufactured in this manner.

The invention described in claim 1
A tire vulcanization mold having a pair of upper and lower side plates and a sector shoe to which a tread segment is attached, and configured to contact the side plate and the tread segment in a closing operation. ,
In each of the pair of upper and lower side plates,
A protruding portion that protrudes radially outward from the outer periphery;
A convex locking part formed on the inner side in the axial direction of the projecting part and projecting inward in the axial direction;
An inclined surface that is inclined inward in the axial direction from the distal end on the radially outer side of the projecting portion toward the locking portion inward in the radial direction;
The sector shoe is provided with an inclined surface having the same inclination angle as that of the inclined surface of the side plate from the distal end on the axially outer side of the radially inner end surface of the sector shoe toward the radially outer side and the axially outer side. And
In the closing operation, the sector shoe is reduced in diameter while the inclined surface of the side plate and the inclined surface of the sector shoe are rubbed together, and the convex locking portion contacts the radially inner end surface of the sector shoe. In addition, the tire vulcanization mold is configured such that the side plate and the tread segment come into contact with each other.

The invention described in claim 2
The tire vulcanization mold according to claim 1, wherein the tread segment is made of aluminum, and the sector shoe and the side plate are made of iron.

The invention according to claim 3
The tire vulcanization mold according to claim 1 or 2, wherein an inclination angle of the inclined surface of the side plate is 15 to 45 °.

The invention according to claim 4
4. The length of contact between the inclined surface of the side plate and the inclined surface of the sector shoe in the closed state is 20 to 50 mm. 5. This is a tire vulcanization mold.

The invention described in claim 5
A tire vulcanization method for vulcanizing and molding an unvulcanized tire using the tire vulcanization mold according to any one of claims 1 to 4,
In the closing operation of the tire vulcanizing mold, the sector shoe is reduced in diameter while rubbing the inclined surface of the side plate and the inclined surface of the sector shoe, and the convex locking portion is connected to the sector shoe. The tire vulcanizing method is characterized in that the side plate and the tread segment are brought into contact with each other at a radial inner end surface thereof.

  According to the present invention, it is possible to prevent the occurrence of positional deviation in the vertical direction of the tread segment during the closing operation, and to prevent the upper end portion and the lower end portion of the tread segment from being crushed, thereby stabilizing a tire having a good appearance. Thus, a tire vulcanization mold and a tire vulcanization method that can be manufactured are provided.

It is sectional drawing which shows typically the open state of the metal mold | die for tire vulcanization | cure which concerns on one embodiment of this invention. It is sectional drawing which shows typically the closed state of the metal mold | die for tire vulcanization | cure which concerns on one embodiment of this invention. It is sectional drawing which shows typically closing operation | movement of the metal mold | die for tire vulcanization | cure which concerns on one embodiment of this invention. It is sectional drawing which shows the conventional metal mold | die for tire vulcanization typically.

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

1. 1 is a cross-sectional view schematically showing an open state of a tire vulcanization mold according to the present embodiment, and FIG. 2 is a schematic view of the closed state. FIG. FIG. 3 is a cross-sectional view schematically showing the closing operation of the tire vulcanization mold according to the present embodiment. The tire vulcanization mold has a substantially cylindrical shape as a whole, and a plurality of tread segments 7 and sector shoes 3 in FIGS. 1 to 3 are arranged in the circumferential direction.

  As shown in FIGS. 1 to 3, the tire vulcanization mold 1 according to the present embodiment includes a sector shoe 3 in which a tread segment 7 is fitted and a pair of upper and lower side plates 8 and 9, as in the past. The side plates 8 and 9 and the tread segment 7 are configured to come into contact with each other in the closing operation.

  The sector shoe 3 is slidably attached along the slope of the actuator 2 attached to the upper plate 6. The side plates 8 and 9 are attached to the upper and lower plates 6 and 10 via the platen plates 4 and 5, respectively. Note that B in FIG. 3 is a bladder, and 2c is a jacket to which a heating medium is supplied.

  However, in the present embodiment, unlike the conventional case, protrusions 8c and 9c are formed on the pair of upper and lower side plates 8 and 9, respectively. The projecting portions 8c and 9c project radially outward from the outer peripheral edges of the side plates 8 and 9, and projecting shapes projecting inward in the axial direction on the inner sides in the axial direction of the projecting portions 8c and 9c. The locking portions 8a and 9a are formed. The locking portions 8a and 9a are formed in an annular shape along the outer peripheries of the disk-shaped side plates 8 and 9.

  In addition, inclined surfaces 8b and 9b are formed on the inner sides in the axial direction of the tip portions of the respective protrusions 8c and 9c. The inclined surfaces 8b and 9b are predetermined to the above-described locking portions 8a and 9a from the radially outer tips of the protruding portions 8c and 9c toward the radially inner side (the molding surface side of the side plates 8 and 9), respectively. It is inclined at an inclination angle θ1.

  In the present embodiment, the sector shoe 3 is provided with inclined surfaces 3f and 3g. The inclined surfaces 3f and 3g are inclined from the outer ends of the radially inner end surfaces 3d and 3e of the sector shoe 3 toward the radially outer side and the axially outer side, and the inclined surfaces 8b of the side plates 8 and 9 described above. 9b has the same inclination angle θ2 as the inclination angle θ1 of 9b.

  The tread segment 7 is preferably made of aluminum, and the upper and lower side plates 8 and 9 and the sector shoe 3 are preferably made of iron.

2. Tire vulcanization method using tire vulcanization mold according to the present embodiment Next, a tire vulcanization method using the tire vulcanization mold according to the present embodiment will be described.

  First, in the tire vulcanization mold 1 in the open state as shown in FIG. 3A, the unvulcanized tire is tired so that the bladder B is disposed in the lumen of the unvulcanized tire (not shown). After setting inside the vulcanizing mold 1, the upper plate 6 is lowered to start the mold closing operation.

  Then, as shown in FIG. 3B, after the lower surface of the sector shoe 3 is brought into contact with the lower platen plate 5, the upper plate 6 is further lowered to bring the sector shoe 3 along the inclination of the actuator 2. The diameter is reduced toward the inside in the radial direction by sliding.

  At this time, as shown in FIG. 2, before the tread segment 7 comes into contact with the side plates 8 and 9, the inclined surfaces 8b and 9b of the side plates 8, 9 and the inclined surfaces 3f and 3g of the sector shoe 3 , The sector shoe 3 is reduced in diameter while the inclined surfaces are rubbed against each other, so that the sector shoe 3 and the side plates 8 and 9 move while being positioned with respect to each other, so that the tread segment with respect to the side plates 8 and 9 moves. 7 can be appropriately prevented from being displaced in the vertical direction.

  Then, the diameter of the sector shoe 3 is further reduced, and the end surfaces 3d, 3e on the radially inner side of the sector shoe 3 are brought into contact with the locking portions 8a, 9a of the side plates 8, 9, and the side plates 8, 9 are brought into contact with each other. And the upper end 7a and the lower end 7b of the tread segment 7 are brought into contact with each other. As a result, the mold is closed and the closing operation is completed.

  When this mold is closed, in the present embodiment, not only the tread segment 7 and the side plates 8 and 9 are brought into contact as in the prior art, but also the end face 3d on the radially inner side of the sector shoe 3, 3e and the locking portions 8a and 9a of the side plates 8 and 9 are also in contact with each other. As a result, the tightening force applied to the upper end portion 7a and the lower end portion 7b of the tread segment 7 is also distributed to the sector shoe 3 to prevent the upper end portion 7a and the lower end portion 7b of the tread segment 7 from being crushed by an excessive tightening force. be able to.

  After the mold is in a closed state (see FIG. 3C), a heated and pressurized medium is supplied to the bladder B to expand the unvulcanized tire set inside the mold to the side plate 8. 9 and 9 and the vulcanized tire is heated and vulcanized while being pressed against the molding surface of the tread segment 7.

  As described above, in the present embodiment, it is possible to appropriately prevent the positional relationship in the vertical direction of the tread segment 7 from being shifted, and to prevent the upper end portion and the lower end portion of the tread segment from being crushed. Therefore, a tire having a good appearance can be manufactured stably.

  In addition, since the constituent members such as the sector shoe 3 and the side plates 8 and 9 can be closely adhered to each other, heat from the jacket 2c of the actuator 2 is efficiently transmitted to the side plates 8 and 9 and the tread segment 7. In addition, the heating efficiency at the time of vulcanization molding can be improved as compared with the prior art, and the vulcanization time can be shortened.

3. Preferred Aspect In the present embodiment, it is more preferable to adopt the following aspect.

  That is, it is preferable to set the inclination angle θ1 of the inclined surfaces of the side plates 8 and 9 within a range of 15 to 45 ° with respect to the horizontal direction. When the inclination angle θ1 is less than 15 °, there is a case where the inclined surfaces cannot be properly brought into contact with each other during the closing operation of the mold and the contact portion is scraped, so-called galling occurs. The effect of regulating the vertical position of the segment 7 may be reduced.

  Moreover, it is preferable to set the overlap amount 1 (refer FIG. 2) which is the length which each inclined surface contacts in the range of 20-50 mm. When the overlap amount l is less than 20 mm, the mechanical strength of the tip portions of the projecting portions 8c and 9c is insufficient, so that the tip portions of the projecting portions 8c and 9c may be damaged and cannot be aligned. If it exceeds 50 mm, the effect of the present invention is saturated and only the equipment cost is increased, which is not preferable.

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

DESCRIPTION OF SYMBOLS 1 Tire vulcanizing mold 2 Actuator 2b Actuator slope 2c Jacket 3 Sector shoe 3d, 3e End surface 3f of sector shoe in the radial direction 3f 3g Slope of sector shoe 4, 5 Platen plate 6, 10 Plate 7 Tread segment 7a Upper end portion of tread segment 7b Lower end portion of tread segment 8, 9 Side plate 8a, 9a Side plate locking portion 8b, 9b Side plate inclined surface 8c, 9c Side plate protrusion B Bladder T Unvulcanized tire l Over Lapping amount θ1 Inclination angle of side plate inclination surface θ2 Inclination angle of sector shoe inclination surface

Claims (5)

A tire vulcanization mold having a pair of upper and lower side plates and a sector shoe to which a tread segment is attached, and configured to contact the side plate and the tread segment in a closing operation. ,
In each of the pair of upper and lower side plates,
A protruding portion that protrudes radially outward from the outer periphery;
A convex locking part formed on the inner side in the axial direction of the projecting part and projecting inward in the axial direction;
An inclined surface that is inclined inward in the axial direction from the distal end on the radially outer side of the projecting portion toward the locking portion inward in the radial direction;
The sector shoe is provided with an inclined surface having the same inclination angle as that of the inclined surface of the side plate from the distal end on the axially outer side of the radially inner end surface of the sector shoe toward the radially outer side and the axially outer side. And
In the closing operation, the sector shoe is reduced in diameter while the inclined surface of the side plate and the inclined surface of the sector shoe are rubbed together, and the convex locking portion contacts the radially inner end surface of the sector shoe. In addition, the tire vulcanization mold is configured such that the side plate and the tread segment come into contact with each other.   The tire vulcanization mold according to claim 1, wherein the tread segment is made of aluminum, and the sector shoe and the side plate are made of iron.   The tire vulcanization mold according to claim 1 or 2, wherein an inclination angle of the inclined surface of the side plate is 15 to 45 °.   4. The length of contact between the inclined surface of the side plate and the inclined surface of the sector shoe in the closed state is 20 to 50 mm. 5. Tire vulcanization mold. A tire vulcanization method for vulcanizing and molding an unvulcanized tire using the tire vulcanization mold according to any one of claims 1 to 4,
In the closing operation of the tire vulcanizing mold, the sector shoe is reduced in diameter while rubbing the inclined surface of the side plate and the inclined surface of the sector shoe, and the convex locking portion is connected to the sector shoe. The tire vulcanizing method is characterized in that the side plate and the tread segment are brought into contact with each other on the radially inner end face of the tire.

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