JP2758821B2 - Vulcanizing mold for molding solid tires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for vulcanizing and molding a solid tire, which can improve the quality of the tire, save material, and reduce the amount of vulcanized solid tire from the mold. The present invention relates to a vulcanizing mold for molding a solid tire, which can automate take-out and improve productivity.

[0002]

2. Description of the Related Art As shown in FIG. 14, a solid tire is vulcanized and molded in a cavity e of a mold a composed of an upper mold b and a lower mold d with a tire equator as a dividing plane f. A solid tire is formed by charging a raw tire t which has been roughly formed in advance, molding the raw tire t with the mold a, and vulcanizing the raw tire t. The mold a is provided with a large number of air vent holes g so that air remaining inside the mold a can be discharged.

In order to manufacture a solid tire using the mold a, the upper and lower molds are separated from each other, and a raw tire is loaded into a void. Close the upper and lower molds. Bumping (stamping) Vulcanization process Removal Deburring and finishing were performed.

[0004]

However, when the mold a is used, air is left between the mold and the green tire at the time of vulcanization molding, and a bear tends to be generated. Tires have poor appearance.

Therefore, in order to reduce such appearance defects, (1) the number of times of bumping is at least three or more, and efforts are made to eliminate residual air. (2) Provide many air vent holes in the mold. (3) The charged weight of raw rubber as a raw material is made higher than the product weight, and the residual air is crushed by the pressure of the rubber during molding. (4) Raw rubber is rough-finished in advance to the shape of a completed tire to reduce the above-mentioned residual air during preparation. Although such methods have been used, such a treatment has been insufficient to remove poor appearance.

According to the present invention, the space formed between the upper and lower dies is kept airtight and the space is evacuated while the upper and lower dies are being moved toward and away from the upper and lower dies. As a basic rule, it is possible to eliminate the appearance defect of the finished tire and save the material, and it is also possible to adopt it in a multi-stage press that takes out the molded tire by moving the lower mold horizontally. It aims to provide a vulcanization mold for molding solid tires that can promote mass production and automation of tires.

[0007]

SUMMARY OF THE INVENTION The present invention provides a tire equator having a split surface, and the split surface is abutted to form a recess for forming a cavity for forming a tire facing each other and to be capable of moving in and out of contact. A mold and a lower mold are provided, and the space between the upper mold and the lower mold is kept airtight while surrounding the concave portion during the contact and separation of the upper mold and the lower mold, and the movement thereof. Moreover Rutotomoni provided an exhaust port for the vacuum sealing member and the space that can open space, the lower mold, the tire equator
Lower mold body provided with an outer portion of the recess extending from the lower mold body
And an inner portion of the recess is provided and formed on the lower mold body.
The tapered peripheral surface that can fit into the upper opening tapered hole
A vulcanizing mold for molding a solid tire, comprising a lower clip ring having the same.

[0008] The tapered hole and the tapered peripheral surface are
Provide an airtight device to keep airtight in the mated state
CanCanYou.

[0009]

With the above construction, the space between the upper and lower dies can be kept airtight and the space can be evacuated during the contact and separation of the upper and lower dies, and the movement. .

Thus, when a conventional mold is used,
Air that tends to remain between the molding surface of the mold and the green tire as a molded product can be discharged to a state almost completely, so that occurrence of poor appearance such as a bear can be reduced.

Moreover, (1) the number of times of bumping work conventionally performed three or more times can be reduced. (2) It is not necessary to provide an air vent hole for preventing the bear in the mold, thereby reducing the generation of burrs and reducing the finishing step after vulcanization. (3) Prevention of pre-forming for rough finishing of a green tire into a shape close to a mold for preventing bears is eliminated. Thus, the molding process becomes easy and economical production can be achieved.

Further, conventionally, in order to prevent the above-mentioned bear, the material weight is made larger than the product weight, and the residual air is crushed and discharged by the pressure of the rubber due to the extra material. Since the molding is performed, it is not necessary to input an extra material to crush the remaining air, so that the input material can be reduced, and the material yield can be improved.

[0013] As described above, by providing the above-described structure, the present invention can improve the finished appearance of a finished tire, reduce the number of materials, and increase productivity when vulcanizing and molding a solid tire.

Further , the lower mold is formed by a lower mold body and a lower clip ring having a tapered peripheral surface fitted into the tapered hole, so that the lower mold moves in a direction orthogonal to the pressing direction. Can be adopted as a mold for a multi-stage press that requires a large amount of tires, which can more effectively promote mass production and automation of tires.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, a vulcanizing mold 1 for molding a solid tire (hereinafter referred to as a vulcanizing mold 1 for molding) is a tire equator C
Are formed by an upper mold 3 and a lower mold 4 having a split surface 2.

As shown in FIG. 3, the solid tire T formed by the molding and vulcanizing mold 1 is fitted with a rim J and has a base rubber made of hard rubber having a JISA hardness of, for example, 70 to 90 degrees. The layer B and the tread rubber layer D formed of rubber having a TISA hardness of, for example, 55 to 70 ° are formed integrally with the base rubber layer B, forming a tread surface TR disposed radially outside the base rubber layer B.

The upper mold 3 and the lower mold 4 are formed such that recesses 5 and 6 which can form the contour of the solid tire 1 when the split surfaces 2 abut against each other face each other. The two recesses 5 and 6 form a void 7 for forming a solid tire by abutting. Further, the lower mold 4 is shown in FIG.
As shown, outside the recess 6 extending from the tire equator
Lower mold body 11 and lower clip ring 12 capable of forming a part
And both are a tapered hole 18 and a tapered peripheral surface 19.
It is fitted through.

The upper mold 3 and the lower mold 4 can be moved so that one or both of them can be moved toward and away from each other. The movement is performed by mounting the upper and lower molds 3 and 4, for example, on a press machine. Thereby, it is possible to join with a strong pressure, and to separate the two molds 3 and 4. Further upper mold 3
A seal 9 is provided between the lower mold 4 and the lower mold 4 to keep the space A between the two molds 3 and 4 airtight.

In the present embodiment, the sealing member 9 includes a skirt 13 which surrounds the peripheral surface of the peripheral wall 3A of the upper die 3 and is hermetically attached by welding or the like, and a peripheral surface 4A of the lower die 4. And a sealing member 14 made of elastic rubber which is in airtight contact with the inward surface 13A of the skirt 13, and the sealing member 14 is always kept at the time of relative movement of the upper and lower dies 3, 4 up and down. The space A formed between the upper and lower molds 3 and 4 is kept in contact with the skirt and is always shut off from the outside air.

Further, one or both of the upper mold 3 and the lower mold 4 communicates with the inlet side of the exhaust pump P and the space A
There is provided an exhaust port 10 which opens at. Therefore, space A is
Even when the upper and lower molds are separated from each other, the exhaust can be performed by driving the exhaust pump P, and the space A can be maintained in a state close to a vacuum.

Further, even when the space A is close to a vacuum, the upper and lower dies 3, 4 can be relatively moved in a direction of joining or separating the upper and lower dies 3, 4, for example. This is done by attaching to a press device.

Next, using the vulcanizing mold 1 for molding, the solid tire T is changed to a tire size of T500-8 LUG.
The manufacturing procedure will be described with reference to the case where.

(1) Loading of Material The material M is obtained by fitting a base rubber material and a tread rubber material in and out in the radial direction and forming a substantially rectangular cross section without rough finishing. It is loaded into the internal space with the mold 4 largely separated. It should be noted that the weight of the material M can be reduced to near the finished weight due to little generation of waste such as burrs as described later, and the weight of the material M is reduced by about 2.3% as compared with the case where a conventional mold is used. Can.

(2) The upper and lower dies 3, 4 are approached and stopped in the approach state.

(3) The air present in the space A of the mold is evacuated through the exhaust hole 10 so that the space A is close to a vacuum.

(4) Bumping While maintaining the vacuum state, the upper and lower dies 3, 4 are brought into and out of contact with each other, and as shown in FIG. Solid tire T
O is formed.

Since the bumping operation is performed in the vacuum state, the air remaining between the material M and the space 7 and the material M
Since the air interposed as a porous inside is crushed and exhausted from the exhaust hole 10, a raw tire TO made of a dense rubber in which no bear is generated and no porous exists in the tire is formed.

(5) Vulcanization After the green tire TO is loaded, the lower molds 3 and 4 are heated at about 153 ° C. for 60 minutes to obtain the raw tire T.
O is vulcanized to form a solid tire T. The vulcanization operation itself is performed under substantially the same conditions as the conventional one.

(6) Deburring and finishing operations The upper and lower dies 3, 4 are not provided with air vent holes unlike the conventional dies, and the weight of the material is reduced to a state close to the finished weight. The occurrence of is very small, and the finishing work can be greatly reduced compared to the tire using the conventional mold,
Furthermore, since there is no occurrence of bears, product quality is significantly improved.

The sealing device may be provided with a skirt on the lower mold and a seal on the upper mold, as opposed to the one shown in FIG. 1. Further, the airtightness between the upper and lower molds may be improved. It is also possible to connect the upper and lower molds with, for example, a bellows body, as long as they can be held even during the movement of the molds.

FIG. 4 shows another embodiment formed for a multi-stage press. In this example, the lower mold 4S includes a ring-shaped lower mold body 11 provided with an outer portion 16 of the recess 6 extending from the tire equator C, and an inner portion 17 of the recess 6.
Is provided with the lower clip ring 12.

The lower clip ring 12 has a tapered peripheral surface 19 provided on the outer periphery of the lower die body 11 and capable of fitting into an upwardly open tapered hole 18. An airtight device 21 capable of holding the fitting portion 20 airtight in the above-mentioned fitted state is provided between them. In this embodiment, the inclination angle β of the tapered hole portion 18 with respect to the axis of the lower mold 4S is set to 30 ° or more and 60 ° or less.

In this embodiment, the hermetic device 21 is formed as a seal ring orbiting the tapered peripheral surface 19. The lower mold body 11 and the lower clip ring 12 can be connected to the lower clip ring 12 without using a fixing tool such as a bolt.
Is seated on the fitting surface 20 so as to be able to approach and separate from the lower mold body 11.

The tapered hole 18 and the tapered peripheral surface 19
Of the lower metal mold 4S with respect to the axis center is 30 ° or more and 60 ° or less.

The lower mold 4S thus formed is effective when the vulcanizing mold 1A for molding is used for a multi-stage press.

FIG. 5 schematically shows a two-stage multi-stage press E provided with pressing means PM and PN at the upper portion M and the lower portion N, respectively.

The vulcanizing mold 1A for molding includes an upper section M, a lower section
To a pair of press plates 31, each pressing a mold to N
Interposed between the upper rowDepartmentPressed from above in M
The lower stage is pressed from below. Therefore, upper and lowerDepartment
Solid tires T and T are molded simultaneously in M and N
To produce solid tire T efficiently
Can be done.

However, in the multi-stage press E having the above structure, the pressing means PM is disposed above the vulcanizing mold 1A in the upper section M and above the vulcanizing mold 1A in the lower section N. Since the press plate 31 is immovably fixed to the main body of the multi-stage press E, it is not easy to load the green tire into the mold and to remove the vulcanized solid tire from the mold.

Therefore, it is necessary to move the lower mold 4S from the above-mentioned pressing position at the time of loading the green tire into the mold and taking it out of the mold. Moreover, molding the tire in the high heat condition after vulcanization, the separation step of separating the mold to take out the Desolation of a state in which the lower half thereof is fitted into the lower mold 4S is required.

For this reason, the conveying means 32 and the lower clip ring 1 for moving the lower mold 4S laterally are provided in the multi-stage press E.
A push-up means 33 for pushing up the solid tire 2 together with the vulcanized solid tire T is provided.

As shown in FIG. 5, in this embodiment, the transport means 32 is a roller conveyor, and moves the lower mold 4S together with the press plate 31 disposed therebelow to the position of the push-up means 33. When the lower mold 4S is moved, a robot arm or the like can be used instead of the roller conveyor.

In the present embodiment, the lower clip ring 12 is formed with a blind operating hole 22 which is opened on the lower surface with its axis centered. The operation hole 22 has an opening 22A at the bottom thereof and a large-diameter large-diameter portion 22B connected to the operation hole 22 via a step surface 23. The lifting tool 34 appears and disappears.

As shown in FIG. 6, the push-up means 33 has a base 35 provided with a linear operating tool F1 such as a hydraulic cylinder for raising and lowering the push-up tool 34. The lower clip ring 12 can be pushed up by entering the hole 22.

The push-up device 34 has a locking piece 36 which can be protruded and retracted toward the peripheral wall of the large-diameter portion 22B when it enters the operation hole 22, and when the locking piece 36 is protruded. , By lowering the lifting tool 34,
The locking piece 36 comes into contact with the step surface 23, and the lower clip ring 12 can be lowered. The engagement piece 36 is moved up and down by the operation of the linear actuator F2 as shown in FIG.

The operation of the vulcanizing mold 1A when the vulcanizing mold 1A is used in the multi-stage press E shown in FIG. 5 will be described.

A description will be given from the stage where the solid tire is loaded in a vulcanized state in the vulcanizing mold 1A for molding which is attached to the upper portion M and the lower portion N, respectively.

As shown in FIG. 7 (A), the vulcanizing mold 1A for molding in the upper stage M lifts the upper mold 3 and the lower mold 4
S is moved to the position of the lifting means 33 by the transport means 32 together with the press plate 31.

Next, as shown in FIG.
Then, the lower clip ring 12 is lifted up by the tip thereof together with the vulcanized solid tire T and separated from the lower mold body 11 as shown in FIG. After that,
The solid tire T is detached from the lower clip ring 12 using an appropriate clamp not shown. After the removal is completed, the lower clip ring 12 is joined to the lower mold body 11 by fitting the tapered peripheral surface 19 and the tapered hole portion 18 by lowering the push-up device 34 and airtight. The tool 21 hermetically seals the fitting surface 20.

The lower die 4S is loaded with a raw tire for the next cycle, and the lower die 4S is moved below the upper die 3 and the upper die 3 is lowered, so that the raw tire is lowered. Complete loading.

As described above, the vulcanizing mold for molding 1A of this embodiment includes, in addition to the seal 9 capable of sealing the space between the upper mold 3 and the lower mold 4S in an airtight manner, Although the mold 4S is formed so as to be able to be divided into the lower mold body 11 and the lower clip ring 12 for work, an airtight device 21 for maintaining airtightness is provided on the fitting surfaces 20 of both. Therefore, when molding and vulcanizing the raw cover, the finished appearance can be enhanced and the material can be saved.

Further, since the fitting surface 20 has an upwardly open taper, the lower die body 1 of the lower clip ring 12 is formed.
1 can be easily and accurately performed.

FIGS. 9A and 9B show the lower part N.
As shown in FIG. 5, the upper mold 3 is clamped immovably, and the lower mold 4S is moved downward with the pressing means PN.
, And is moved to the position of the push-up means 33 by the transfer means 32 having the transfer surface height aligned.

Thereafter, the solid tire T which has been molded and vulcanized is taken out and loaded with a raw tire in the same procedure as the above-mentioned operation procedure in the upper section M, and the raw tire is loaded by the transport means 32. Go again.

As described above, since the green tires are simultaneously loaded into the upper portion M and the lower portion N, the two tires can be simultaneously molded and vulcanized, so that the production efficiency is increased, and the lower mold is further improved. Since the 4S is moved from the position of the pressing means PM and PN to another position to unload and load the tire, manufacturing can be automated and labor saving can be promoted.

Such an operation can be achieved by providing an airtight device 21 on the fitting surface 20 between the lower mold body 11 and the lower clip ring 12.

[0056]

【Concrete example】

A) Test 1 The tire size is T500-8 LUG, and the material weight is reduced step by step using the molding and vulcanizing mold 1 according to the above configuration to investigate the appearance defect and the state of the porous material generated inside the solid tire T. (Samples A to F) and a conventional product formed using the conventional mold a shown in FIG. 14 was also investigated and compared. Table 1 shows the test results.

[0057]

[Table 1]

As a result of the test, Sample D showed no defective appearance and no porous inside of the completed solid tire, and the use of the mold of the present invention reduced the weight of the sample D by a few percent compared to the conventional product. It was confirmed that it could be done.

In the test, FIG. 10 shows the relationship between the material weight and the product weight, and FIG. 11 shows the relationship between the material weight and the burr weight.

FIG. 12 shows the change in the tire outer diameter DT and FIG. 13 shows the change in the tire total width W for the samples A to D and the conventional product. Regarding the samples A, B, C and D, it was confirmed that the variation was substantially small and the accuracy of the finished tire could be maintained.

B) Test 2 Based on the results of Test 1 described above, the distribution of appearance defects during mass production was examined for Sample D, which is the limit of weight loss that does not cause appearance defects and no porous inside, and the conventional example. . Table 2 shows the results of the investigation.

[0062]

[Table 2]

C) Comprehensive Evaluation Table 3 shows a comprehensive evaluation based on Test 1 and Test 2.
As described above, by producing using the molding of the present application, a vulcanization mold, it is possible to suppress the occurrence of appearance defects such as a bear, and further, without generating a porous in the completed tire,
It has been confirmed that the roundness of the tire can be reduced by increasing the homogeneity.

[0064]

[Table 3]

[0065]

As described above, the solid tire molding and vulcanizing mold of the present invention comprises a sealing member for maintaining a space between the upper mold and the lower mold, and an exhaust hole for evacuating this space. By using the molding and vulcanizing molds, the appearance and the internal quality of the solid tire can be improved, the material can be reduced, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention in a state where upper and lower dies are separated from each other.

FIG. 2 is a cross-sectional view showing a state where a lower mold abuts on the upper mold.

FIG. 3 is a cross-sectional view showing a solid tire manufactured by a molding and vulcanizing mold of the present invention.

FIG. 4 is a sectional view showing another embodiment.

FIG. 5 is a front view schematically showing a multi-stage press using the mold.

FIG. 6 is a sectional view showing an example of the push-up means.

FIG. 7 is a front view schematically showing the operation of the upper stage of the multi-stage press.

FIG. 8 is a sectional view showing the operation of the lower mold.

FIG. 9 is a cross-sectional view schematically illustrating a lower stage operation of the multi-stage press.

FIG. 10 is a graph showing the relationship between material weight and product weight.

FIG. 11 is a graph showing the relationship between material weight and burr weight.

FIG. 12 is a graph showing a relationship between a material weight and an outer diameter of a completed tire.

FIG. 13 is a graph showing a relationship between a material weight and a total width of a completed tire.

FIG. 14 is a sectional view showing a conventional mold.

[Explanation of symbols]

 2 Split surface 3 Upper mold 4 Lower mold 5, 6 Recess 7 Empty space 9 Sealing tool 10 Exhaust port 11 Lower mold body 12 Lower clip ring 16 Outer part 17 Inner part 18 Taper hole 19 Tapered peripheral surface 21 Airtight device A Space C Tire equator β Tilt angle

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 30:00

Claims (2)

(57) [Claims] An upper mold and a lower mold which are provided with a concave surface forming a cavity for forming a tire by facing the equator of the tire and making contact with the divided surface. A seal that surrounds the recess during the contact and separation of the upper mold and the lower mold, and the movement thereof, keeps the space between the upper mold and the lower mold airtight, and opens the space. ingredients and Rutotomo provided an exhaust port for the space in the vacuum
The lower mold is located outside the recess extending from the tire equator.
The lower mold body provided with the
Upwardly open tapered hole formed in the lower mold body
A lower clip ring having a tapered peripheral surface that can be fitted to the part
A vulcanizing mold for molding solid tires, comprising: (2) The tapered hole and the tapered peripheral surface are
Provide an airtight device to keep airtight in the mated state
The solid tire according to claim 1, wherein
Vulcanizing mold for shapes.