JPS58211438A - Metal mold for tire - Google Patents

Abstract

PURPOSE:To prevent the level difference in tire surface from generating by a structure wherein a tread ring consisting of a circumferentially split mold composed of 7-9 splits is divided at the position near the tread center into the upper and lower half bodies, both of which are slidably equipped to the mold shells of a top force and a bottom force respectively. CONSTITUTION:A tire T to be molded and vulcanized is brought near to the side wall mold 12a of the bottom force B at the state that both the top force A and the bottom force B are open. At the same time, the tread ring half body 15a is slided down along the slide way 16a of the mold shell 11a by means of a driving device 31a in order to couple to the side wall mold 12a. After the tire T having been set to the bottom force B, the mold shell 11 of the top force A is lowered in order to abut the tread ring half body 15 against the outer peripheral surface of the tire and then lowered further until the tread ring half bodies and the mold shell of both the forces are abutted against each other respectively. Next, when respective tread ring guides 26 and 26a are forcibly pressed by means of both the driving devices 31 and 31a, all the tread rings are brought into actuation synchronously, resulting in enabling to be smoothly set without producing any level difference and deformation in the tire surface.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the improvement of tire molds used for molding and vulcanizing tires. The tread ring is divided into two halves and attached so as to be able to slide freely on the sliding surfaces of the upper and lower shells, respectively, and one or two jaws are attached to each of the split molds that make up the tread ring halves. A tread ring guide integral with the entire circumference is abutted and engaged with these jaws, and a drive device is connected to the trend ring guide via a piston rod to close or open the upper mold and the lower mold. It is an object of the present invention to provide a tire mold characterized in that the tread ring half-rest operation is performed synchronously by a drive device.

Conventionally, a tread ring composed of 7 to 9 split molds in the circumferential direction has been used in a container-type tire mold used for forming and curing tires. As shown in the figure, the ring has an integrated structure in the vertical direction in the width direction.

Then, this tread ring 1 was set on the side wall mold of the lower mold B by sliding the sliding surface 5 of the seven-lead shell 4 of the upper mold A down the tapered surface 3 of the actuator 2 integrated therein. Each segment of the split mold constituting the tread ring is pushed back on the outer peripheral surface of the fresh tire that has been shaped, and the upper mold and lower mold come into contact with each other to close the mold.

However, since there is a slight gap between the slide key surface of the upper mold shell and the key surface of the actuator, when the mold closes, the tread ring comes into contact with the outer circumferential surface of the tire in a slightly tilted state. Moreover, since the split molds do not operate synchronously, a slight step 6 is formed on the tire surface at the joint between the shell 4 and the tread ring 1, as shown in FIG.

As described above, the tread ring of conventional tire molds lacks synchronization in the circumferential direction, so when the upper and lower molds are closed, they close in a biased state, which causes the tire to become deformed. This has drawbacks such as overspill, which causes poor appearance, and because the tread ring, which is made up of split molds, is an integral piece in the width direction, the segment blocks are large, making it inconvenient to replace the mold. .

The present inventor has conducted studies to solve the above-mentioned drawbacks in tire molds, and as a result, has arrived at the present invention.

The present invention will be explained below based on FIGS. 3 to 6 showing one embodiment thereof.

Although the present invention is a tire mold that has an upper mold and a lower mold, the structure of the lower mold is the same as that of the upper mold, so a description thereof will be omitted, and only the structure of the upper mold will be described.

Further, in the drawings, the reference numerals relating to each part of the lower mold are indicated by adding a to the reference numeral of the same part in the upper mold.

First, in FIG. 3, A is the upper mold and B is the lower mold.

Reference numeral 11 denotes a mold shell, to which a side wall mold 12 is screwed by a set screw 13.

Reference numeral 15 denotes a half tread ring which is divided into two parts from the tread center of the tread ring 14 which is made up of a plurality of split molds in the circumferential direction, and this half body 15 can freely slide on the conical sliding surface 16 of the mold shell 11. When the tread ring half 15 slides on the slide surface 16 of the mold shell 11, the bolt 17 is attached to the guide groove 19 of the shell 11. 20 is an adjustment collar to make the sliding smooth.

Therefore, the positioning of the tread ring half body 15 is performed by connecting the tread ring side guide 21 connected to the head of the half body 15 with the molded dowel hole 2 formed in the head of the shell 11.
2, and another side guide 23 formed outward of the tread ring half body 15 is fitted to the shell 11.
This can be done accurately and easily by fitting into the mold dowel groove 24 of.

The plurality of split half bodies C constituting this tread ring 14 have a shape as shown in FIG. It is formed by connecting and forming.

Then, the tread ring guide 26, which is integrated around the entire circumference, is brought into contact with the position of the jaw part 25 of the tread ring half body 15 such as the half body C, and the jaw part 25 is engaged with the recessed part to form the tread ring guide. The bolt 27 and set screw 28 are screwed into the elongated hole 29 provided in the hole 26.

FIG. 5 is a sectional view of the body showing how the trend ring guide 26 is fitted to the half body C and the mold shell 11.

The elongated hole 29 is formed so that the tread ring half 15 fixed to the mold shell 11 is connected to the slide surface 16 of the mold shell 11.
This is a hole through which the stop bolt 27 slides so that the tread ring guide 26, which is snap-fitted to the jaw portion 25, can follow the movement of the tread ring guide 26 when the tread ring guide 26 slides.

30 is an adjustment collar fitted in order to make finger movements smoother.

Reference numeral 31 denotes a cylinder or spring-type drive device, which is connected to the tread ring guide 26 by a piston rod 32, and applies pressure evenly to the tread ring guide 26 when the upper and lower molds are closed, so that the tread can be tightened. The entire ring 14 is operated synchronously.

Therefore, it is preferable that two to four driving devices 31 be connected to the tread ring guide 26, which is integrally formed around the entire circumference.

Next, to explain the operation of the tire mold consisting of the upper mold A and the lower mold B having the above structure, first, with the upper mold A and the lower mold B open, the tire T to be molded and vulcanized is heated. At the same time as the mold shell lla of the lower mold B approaches the side wall mold 12a, the drive device 31 of the lower mold B
a to gradually lower the tread ring cow body 15a of the lower mold B by sliding it on the slide surface 16a of the mold shell 11a, and then pre-shave the bladder (not shown), and at the same time as the pre-shaving is completed. The head tread ring side guide 21a of the tread ring cow body 15a is inserted into the mold knock hole 22a of the mold shell lla, and 2
The tread ring side guide 3a is placed on the bottom of the mold knock groove 24a to connect the tread ring 15a and the mold shell Ila.

Mold shell 11a of Kottolet link half body 15a
When sliding onto the slide surface 16a, the set screw 18a slides along the guide groove 19a of the mold shell lla, and the mold shell lla and the trend ring half body 15a
Tighten after connecting with.

After setting the tire T to the lower mold in this way, the upper mold A is next set.
Perform the descent.

First, the mold shell 11 is gradually lowered, and the tread ring half 15 is inserted into the mold knock hole 22 of the shell 11.
Fit the tread ring side guide 21 and the tread ring side guide 23 into the mold knock groove 24.

Furthermore, a tread ring half 1 is attached to the outer peripheral surface of the tire T.
The tread ring half 15a and the mold shell lla of the lower mold B, which were previously set in contact with the tire T, are brought into contact with those of the upper mold A.

Thereafter, by strongly pressing the respective tread ring guides 26.26a with the driving devices 31.31a of the upper mold A1 and the lower mold B, all the tread rings operate synchronously.
As shown in FIG. 6, the tire T can be smoothly set in the mold along the circumferential surface of the tire T without causing any step or deformation to the tire surface.

After vulcanizing the tire T in this state, first, begin to bleed air from the Prada 33, move the upper die A upward, and then slide the tread ring half 15a of the lower die B together with the tire. side wall mold 1
After separating it from 2a, the molded tire is removed by lifting only the tire T upward and removing it from the lower mold.

The structure and operation of the tire mold of the present invention have been explained above, and its features and effects include: 1. The tread ring, which consists of 7 to 9 split molds in the circumferential direction, is divided into upper and lower halves near the tread center. As a result, each half-tread ring is slidably screwed onto the mold shells of the upper and lower molds, so when setting the tire, the half-tread ring does not follow the outer circumference of the tire smoothly, and there are no steps on the tire surface. etc. will not occur.

2. One or two jaws are connected to each side of the split mold forming the tread ring.

3. The tread ring guide, which is integrated all around the chin, is in contact with the chin, and the drive device is connected to the piston rod at several points to tighten the guide, so the entire tread ring can be operated synchronously. , it can be placed evenly along the outer circumference of the tire.

4. The sliding surfaces of the mold shell and the tread ring are conical, and the tread ring side guide is fitted into the mold dowel hole of the shell, so the tread ring can be positioned accurately.

5. Since the upper and lower mold shells are in contact with each other when the mold is closed, the press tightening force is received by the dowel holes and dowel grooves of the mold shell, and the aluminum tread ring is not tightened. The tread ring will not be damaged because it is not subjected to force.

6. Since the seam between the tread ring and the sidewall mold is a tapered surface, the upper mold,
Since the lower mold and the tread ring do not have a sliding structure, it is possible to prevent mold locking (defects in engagement).

7. When connecting the tread ring guide to the jaw part of the tread ring and the mold shell with a set screw,
Since this is done within the elongated hole provided in the guide, the position of the tread ring guide does not change due to the sliding of the tread ring which is capable of sliding the set screw within the elongated hole.

8. Since the driving device can be installed inside the container, the device can be installed in a press that cannot be attached to the outside, such as a press before split molds.

9. Since the tread ring is divided into two parts, the upper mold and the lower mold, the sliding surface of the ring with the mold shell is small, which allows the shell to be thicker, increasing the rigidity of the mold. .

10. Since the upper sidewall mold and the tread ring do not have sliding surfaces, mold skidding can be prevented.

11. The tread ring side guide fits into the dowel hole and the dowel groove to hold the tread ring and mold shell, so even if the finishing accuracy of the clearance between the tread ring and mold shell is rough, the positioning of both is accurate. can be done.

12. Since the tread ring is a split type and is constructed from two halves, it is easy to handle, and the mold can be easily replaced.

The tire mold of this invention has great industrial value.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway sectional view showing a conventional tire mold;
The figure is a partially enlarged sectional view, FIG. 3 is a partially cutaway sectional view showing the tire mold of the present invention when opened, and FIG. 4 is a partially cutaway view of the half mold constituting the tire mold of the present invention. 5 is an explanatory view showing the contact state of the mold shell, tread ring, and tread ring guide; FIG. 6 is a partially cutaway sectional view showing the tire mold of the present invention when the tire is loaded and closed. . 11, lla...mold shell, 12.12a.
...Side wall mold, 14...Tread ring, 15.15a...Tread ring half-closed, 16.16a
...Sliding surface, 25.25a...Jaw portion, 261.26a...Tread ring guide, 31.3
1a...Drive device, A...Upper mold, B...Lower mold,
C...Half-split type, T...Tire, Patent applicant: Sumitomo Rubber Industries, Ltd., Patent attorney, Chuwa 1) Akira

Claims (2)

[Claims] (1) In a tire mold consisting of a pair of upper and lower molds,
Sidewall molds are screwed onto the shells of both types, and the tread ring, which is made up of multiple split molds in the circumferential direction, is divided into upper and lower parts near the tread center. The tread ring is slidably screwed onto the sliding surface of the shell, and a tread ring guide integral with the entire circumference is abutted and engaged with the jaws formed in one or two joints on each split mold forming the tread ring. A tire mold characterized in that a plurality of drive devices are linked to the guide so that the same devices can synchronously close and open an upper mold and a lower mold. (2) In the tread ring half-rest that slides on the sliding surfaces of the upper and lower shells, the head of each split mold that makes up this is a tapered surface, and the head has one or two protrusions. A shaped tread ring side guide is provided, and when the upper mold and the lower mold are closed, the guide fits into the mold dowel hole drilled in the shell head of the upper mold and the lower mold, and the tapered surface of the head is fitted into the side wall mold. 2. The tire mold according to claim 1, wherein the tire mold comes into contact with the tapered surface of the tire mold.