JPH0123783Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a press mold for forming a V-belt, and more particularly to a flat plate mold used when press-forming and vulcanizing a long cogged V-belt or the like.

Generally, a press curing device using a flat mold is used for long V-belts, and the outline of this is shown in Fig. 3.
A pair of pulleys P whose center distance can be adjusted,
The upper plate 2 is suspended between P and on the surface side of the belt molded body 1.
, a middle plate 3 is arranged on the bottom side, and a lower plate 4 is arranged on the downward surface side of the belt molded body 1, and plate-shaped molds 5, 6, 6, and 7 are equipped on the belt holding surface of each plate. Vulcanization is performed in the press vulcanizer 10 while sequentially feeding the unvulcanized belt molded body 1. A cooling device, more specifically a cooling fluid supply pipe 8, is provided in the width direction of the mold at both front and rear ends located on the longitudinal side of the belt molded body of each of the molds 5, 6, 6, 7. During vulcanization, it plays the role of preventing the rubber from flowing from the boundary in the vulcanized part of the belt molded body and preventing the generation of sponge at the boundary.
As shown in an enlarged view of a part of the cooling section in FIG. 4, there is a step h (however, h = Thickness of the unvulcanized belt molded body - distance between the top of the cog of the lower mold and the maximum approach of the upper mold), and if this part is vulcanized as it is, the tensile rope of the belt will not line up properly. Moreover, variations in belt thickness occur, resulting in unfavorable results in terms of quality.

The steps h that occur here vary depending on the shape of the belt, but generally the larger the pushing distance, the more noticeable they are.
After the press marks, the cracks are generated every time on the insertion side (the rear end side of the mold) of the unvulcanized belt molded body.

The present invention was proposed to address the above-mentioned problems, and involves forming a taper at the lower edge in the mold width direction perpendicular to the longitudinal direction of the belt molded object in the cooling section near both front and rear ends of the upper plate mold. By doing so, it is possible to prevent the occurrence of extreme steps on the surface side of the unvulcanized belt molded body that occur at the lower edge portion of the upper sheet metal mold, and to improve the above-mentioned variations in the belt rope arrangement and belt thickness. This is the purpose.

Hereinafter, a specific example of a plate-shaped mold used for molding and curing a long cogged V-belt will be described in more detail with reference to the accompanying drawings.

Figure 1 is a rear end view of the plate-shaped mold according to the present invention.
Upper plate mold 1 in contact with the surface side of the unvulcanized belt molded body
5 has a smooth surface 20, while the lower plate mold 16 in contact with the back side of the belt molded body has a cog surface in which protrusions 21 and grooves 22 extending in the width direction of the mold are alternately provided at predetermined intervals. Furthermore, both the upper and lower sheet metal molds 15,1
Partition walls 23, 23 are protruded on both left and right sides of 6 to prevent rubber from flowing out during vulcanization. And an upper plate mold 15 in contact with the surface side of the belt molded body 11
A taper 24 is formed in the cooling section 18 near both front and rear ends of the belt molded body over the entire length of the lower edge portion in the mold width direction perpendicular to the longitudinal direction of the belt molded article. FIG. 2 is an enlarged longitudinal cross-sectional view centered on the rear end cooling part of the pair of molds 15 and 16, and shows the unvulcanized belt molded body 11.
is fitted into the molds 15 and 16 and vulcanized at a predetermined temperature and pressure to form a cog part. Distance H when the sheet metal mold approaches the maximum above the top
It is molded to be thicker by h.

Therefore, in the conventional upper plate mold 5 shown in FIGS. 3 and 4 lacking a tapered part, a step h occurs on the surface side of the unvulcanized belt molded product at the edge part on the lower surface side of the mold. In the case of the upper plate mold 15 of the present invention provided with the taper 24, the occurrence of an extreme step h is suppressed, and a gentle slope is formed in a portion corresponding to the surface of the unvulcanized belt molded body.

The method of applying the taper differs depending on the type of belt, but basically, the taper is formed from a position approximately half of the length l corresponding to the cooling section 18 to the end of the upper plate mold 15 where it rises by an amount h. It is desirable that the slope of the taper be chamfered up to 2h/l and the taper slope 2h/l be in the range of 0.05 to 0.40. Also, the edge part 19 is r=1~8m/
It is desirable to provide a radius of m.

The above example is about a plate-shaped mold used when vulcanizing a wide sleeve-shaped unvulcanized belt molded body, but the present invention is for vulcanizing an endless wide unvulcanized belt molded body. First, V-cuts are made to a predetermined width to form individual endless belt moldings, and the same method can be applied to a mold used when press vulcanizing a plurality of belts simultaneously with cog molding.

As described above, the present invention has a slight modification in which a taper is formed at the lower edge in the width direction of the mold in the front and rear cooling parts of the upper plate mold used in the press vulcanization method. By suppressing the occurrence of an extreme step at the boundary of the vulcanized part and making the step a gentle taper,
In addition, the taper part provided at the end of the mold to form a tapered part in a part of the belt molding is located on the side of the thin rubber layer above the tensile rope embedded in the belt molding. By forming it on the end of the upper sheet metal mold, and on the thicker rubber layer side below the tensile rope, it extends in the width direction of the belt to serve as an escape allowance for the flow of the rubber material. By disposing a lower plate mold with a cog surface consisting of a collection of cog grooves, the flow of the rubber material around the tensile rope, which is the most important component of the V-belt, is suppressed as much as possible, and the Variations in the belt tensile rope arrangement and belt thickness are improved, and significant effects such as improved belt life and stable quality can be expected.

[Brief explanation of drawings]

Figure 1 is a rear end view of a mold in which the present invention was implemented, Figure 2 is an enlarged vertical sectional view centered on the rear end cooling section of the mold, and Figure 3 is a press process using a conventional mold. FIG. 4 is a longitudinal cross-sectional view of the sulfurization apparatus, and is a partially enlarged view centered on the right end of the mold including the cooling section in FIG. 3. In the figure, 11 is an unvulcanized belt molded body, 15 is an upper plate mold, 16 is a lower plate mold, 18 is a cooling part, 19 is an edge part, 20 is a smooth surface, 21 is a protrusion, 22 is a groove, 24 indicates taper.

Claims (1)

[Scope of utility model registration request] In a pair of molds consisting of an upper mold with a smooth surface and a lower mold with a cog surface, which constitute a plate-shaped mold for vulcanization molding of a V-belt with cogs, both molds are located on the longitudinal side of the belt molded object. A cooling device is provided at both the front and rear ends of the mold, and a cog-equipped V with a taper extending perpendicularly to the longitudinal direction of the belt molded body is provided at the lower edge of the front and rear ends of the upper plate mold located on the belt surface side. Press mold for belt forming.