JPS6366650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a long V-belt with row edge cogs.

Conventional methods for manufacturing this type of belt include, for example, the drum method, in which a rubber cog-equipped matrix is wrapped around the surface of the drum, and the belt components, including a V-core rubber sheet, are sequentially wrapped around it to form an unvulcanized belt. The method used was to mold a body, fit a cylindrical jacket onto its surface, and then vulcanize it in a vulcanizing can. However, in this process, the length of the folded belt, which involves cutting an open cog-equipped matrix to a predetermined length and winding it endlessly around the drum surface, is rarely divisible accurately by the cog pitch. I have often experienced the occurrence of cog pitch deviation in the cog shape of the belt at the joint portion, even though there is no particular problem in terms of quality.

In recent years, the use of low-edge V-belts for general industrial use has been considered, and the demand for long V-belts with good flexibility and low-edge cogs has been increasing. As an alternative to this method, there is a press vulcanization method that progressively vulcanizes an unvulcanized belt molded body using a flat cog-equipped mold. has been adopted.

In progressive vulcanization in the press vulcanization method, a cooling device is used at the vulcanization boundary of the belt molding to eliminate problems such as the generation of air bubbles, volume overflow, and outflow of rubber from the belt molding at both ends of the press. It is considered to be in a semi-vulcanized state, and from the second time onwards after the sequential feeding operation following the first press vulcanization, the vulcanized cog belt forming part and the unvulcanized belt forming part are partially overlapped in the same press. It is necessary to vulcanize it. The cog portion of this folding master mold is fitted into the cog portion located at the end of the already vulcanized belt. In general, the belt length is not necessarily divisible by the cog pitch of the mold, and the continuous molding of the cog parts of the initial vulcanization zone and the final vulcanization zone of an endless belt molded body is usually In the case of , look at the occurrence of the fraction of the cog. If this unvulcanized endless belt molded product with cog fractions is molded and vulcanized using a mold with cogs, the cog part of the belt will not match the cog part of the mold during final vulcanization, and the molding vulcanization work will be forced. However, there were still problems that needed to be solved, such as the cog part of the belt being destroyed. One way to eliminate this problem is to remove the unvulcanized endless belt, which was molded integrally with the matrix on the drum together with the matrix, even if some fraction occurs, and sequentially vulcanize it in a separate press vulcanizer. There is also a way to remove the matrix.
In this case, the problem of the belt cog being destroyed can be solved, but extra work is required to remove the mother molds one by one, and the heat and pressure during vulcanization make it impossible to reuse the mother molds, resulting in waste. As a result, new economic problems have arisen, such as the increased cost of belts.

This invention aims to eliminate and improve the drawbacks inherent in the various belt vulcanization methods described above, and its basic principle is to use the progressive press vulcanization method as the main method, but to adjust the cog pitch of the matrix during the final press vulcanization. When the belt cog pitch that has already been vulcanized and sent to one end (the belt cog pitch that was vulcanized before the final press vulcanization) is put together, the belt cog pitch at the other end (the belt cog pitch that was press vulcanized first) will be the same as the mother mold. In most cases, the belt does not fit correctly into the cog pitch, but we are concerned that the cog part of the belt will be destroyed if press vulcanization is performed forcibly as it is, so By using an elastic master mold with elasticity as the mold and vulcanizing it, the length of the final belt cog forming area left unvulcanized during belt cog forming is Accordingly, an elastic matrix mold was used to expand and contract, and even with a long belt, the cog accuracy was quite good, and the vulcanization work was simplified.

Hereinafter, with reference to drawings, we will explain two or three specific examples of a method for manufacturing a V-belt with a long row edge cog, which is characterized in that a stretchable elastic matrix mold is used only during the press vulcanization work that accompanies final cog forming. I will explain.

The first step is to attach a rubber sleeve 12 to the surface.
The outer peripheral surface of the cylindrical drum 11 coated with
An unvulcanized V-core rubber sheet 1 of a constant thickness in which short fiber groups 2 are oriented is wrapped endlessly so that the short fibers 2 are perpendicular to the circumferential direction of the cylindrical drum 11, and then the lower cushion is wrapped. After wrapping the tensile rope 4 in a spiral shape under a constant tension on the rubber sheet 3a, the upper cushion rubber sheet 3b is formed.
an upper core rubber sheet 5 in which two groups of short fibers are also oriented perpendicularly to the circumferential direction.
The outer circumferential surface of the unvulcanized belt is covered with at least one sheet of rubberized elastic canvas 6 to form an endless sleeve-shaped unvulcanized belt molded body 10 whose partial perspective view is shown in FIG. .

Next, in the second step, as shown in FIG. 3 and FIG. The belt molded body 1 is suspended between
An upper plate 22 is disposed on the front side of the belt molded body 10, a middle plate 23 is arranged on the bottom side of the belt molded body 10, and a lower plate 24 is arranged on the downward facing surface side of the belt molded body, and a metal mold 25 is placed on the belt clamping surface of each plate. , 26, 26, 27 and is in contact with the surface side of the belt.
The surfaces 5 and 27 have smooth surfaces 28, while the molds 26 and 26 in contact with the bottom side of the belt have cog surfaces alternately provided with protrusions 29 and grooves 30 extending in the width direction of the mold at predetermined intervals. Furthermore, edges 31 are provided on both left and right sides of the metal molds 25, 26, 26, and 27 to prevent rubber from flowing out during vulcanization. In addition, a cooling device 32, more specifically a cooling fluid supply pipe, is provided in the width direction (direction perpendicular to the edge 31) at both front and rear ends of each mold, and during vulcanization, the vulcanized portion of the belt molded body is This device 32 suppresses extreme volume overflow, generation of sponging, and outflow of the rubber constituting the belt molded body at the boundary between the belt molded body and the unvulcanized portion.

The belt molded body 10 suspended between a pair of flat pulleys 21, 21 is placed on both upper and lower sides of a metal mold 26, 26, which is provided with a cog surface and is equipped on the middle plate 23 at two places, on the forward side and the return side. The metal molds 25 and 27 having smooth surfaces 28 provided on the disks 22 and 24 sandwich and press the belt molded body 10, and at a predetermined temperature and pressure, the belt molded body 10 is molded into a cog. At the same time, vulcanization progresses, and at this time, the cooling device 32 installed in each metal mold is used to prevent the generation of air bubbles and increase the volume at the boundary between the vulcanized and unvulcanized parts of the belt molded body. over) phenomenon. The vulcanized belt molded body is progressively fed from the vulcanization area of the metal mold, and the semi-vulcanized belt cog part is moved again to the front cog of the metal mold by the action of the cooling device 32 at the rear part of the vulcanized part. The semi-vulcanized part is heated and pressurized again to be cured together with the next part, and this process is repeated one after another until the last vulcanized zone of the belt molded body is left unvulcanized. The second step ends with the sulfur remaining in the sulfur state. (Thus, since the vulcanization process is proceeding at the same time in the upper and lower parts of the endless belt molded body, two unvulcanized zones are left as a result.) In the third step shown in FIG. 5, the final vulcanized region of the unvulcanized belt molded body left unvulcanized in the second step is vulcanized. That is, an upper plate 41 arranged on the front side of the belt molded body 10 and a lower plate 42 arranged on the bottom side.
Each of the belt clamping surfaces has a metal mold 44 having a smooth surface 43 and an elastic matrix having elasticity and having a cog surface in which protrusions 45 and grooves 46 extending in the width direction of the mold are alternately arranged at predetermined intervals. Using a two-stage press vulcanizer equipped with a mold 47 and having raised edges (not shown) on both sides to prevent rubber from flowing out, the two remaining unvulcanized belt molded parts are brought to a predetermined temperature. , vulcanized under pressure.

The trailing cog portion 7a of the final vulcanized belt vulcanized in the second step is fitted into the front cog portion of the elastic matrix mold 47, and the leading cog portion of the first vulcanized belt is fitted into the elastic matrix mold 47. They are fitted into the rear cog portions 7b of the mold 47 (the cog portions of the belt are in a semi-vulcanized state with the cooling device 32), and the upper plate 41 is lowered and pressed toward the lower plate 42 to form a belt molded body. The unvulcanized area, represented by the remaining length (l) out of 10, is finally vulcanized.

In this way, the semi-vulcanized cog portion is completely vulcanized by heating and pressurizing again. Even in this invention, especially in the third step (see Figure 5), for most belt sizes, the length (l) of the remaining unvulcanized area cannot be divided by the cog pitch of the master mold, and a fraction occurs. Since this master mold is made of an elastic body that has elasticity, the part of the master mold where the remaining unvulcanized belt molding part fits freely expands and contracts, and absorbs fractions extremely easily. .

In other words, if the length (l) of the remaining unvulcanized part is short, the master mold is shrunk, and if it is long, the master mold is expanded to correspond to the length of the unvulcanized zone, and the part is cog-molded. Vulcanize at the same time.

The above-mentioned elastic matrix mold may be one that satisfies physical properties such as hardness of 70 to 80° (JIS standard), 100% modulus of 100 kg/cm ² or less, and elongation at cutting of 200% or more. It is not limited to those made of rubber.

In the final step, the full-length molded and vulcanized belt molded body is cut into a V-shape with a constant width to obtain a long row-edge cog-equipped V-belt 10' in which seven cogs are connected in series as shown in FIG.

The belt manufacturing method detailed above is an embodiment in which a wide endless belt molded body is press-cured with cog forming, and then the wide sleeve-shaped belt molded body is cut into rounds to manufacture a plurality of V-belts with cogs. However, prior to vulcanization, a wide endless belt molded body is V-cutted to a predetermined width, and each endless belt molded body is made into an independent endless belt molded body, and multiple belts are cog-formed at the same time. A V-belt with cogs can also be obtained by press vulcanization, and a specific example of the manufacturing method will be described below with reference to the drawings.

In addition, since this example uses almost all the steps disclosed in the previous examples, the details of the overlapping work steps will be omitted and the explanation will be continued. shall be.

First, in the first step, a V-core rubber sheet 1 is placed on the outer peripheral surface of the cylindrical drum 11 centered at the point shown in FIG.
The molding process of the wide sleeve-shaped unvulcanized belt molded body 10, which is formed by winding various belt constituent materials including the following in a laminated manner, is the same. At this point, as a second step, the sleeve-shaped unvulcanized belt molded body 10 is cut into rings of a predetermined width, and then both sides are skived into a substantially inverted trapezoid shape using a skiving machine to create a plurality of independent pieces. Endless unvulcanized V-belt molded body 1
Forms 0A. The next third step is basically the same as the one explained above with reference to FIG. 3, but as shown in FIGS. 7 and 8, there are two V-groove pulley 21A, 2
A plurality of unvulcanized V-belt molded bodies 10A between 1A,
10A are suspended at the same time, and an upper plate 22A, a middle plate 23A, and a lower plate 24A are arranged facing the front and bottom parts of the V-belt molded body 10A, respectively, and a mold 25A, 26
The configuration for equipping A, 26A, 27A is the same, but the metal molds 25A, 27A at this time have a plurality of arch surfaces 28A having smooth surfaces at equal intervals in the mold width direction, and each arch surface 28A Correspondingly, an inverted trapezoidal groove 33 is formed in the molds 26A, 26A, and the bottom of the inverted trapezoidal groove 33 has a cog surface in which protrusions 29A and grooves 30A are alternately provided at predetermined intervals. Further, a cooling device 32A, more specifically a cooling fluid supply pipe, is provided at both front and rear ends of each mold, extending in the width direction of the mold.

The endless unvulcanized V-belt molded body 10A is fitted and clamped in a metal mold, and is sequentially vulcanized with cog forming by applying a predetermined temperature and pressure. It moves sequentially,
The length (l) of the last vulcanized zone of belt molded body 10A
Leave only the unvulcanized state and move on to the next step.

The next fourth step is a vulcanization operation involving cog formation of the belt molded body left unvulcanized as shown in FIG. A metal mold 44 having
A and an inverted trapezoidal groove 53 are provided, and this inverted trapezoidal groove 53
The remaining unvulcanized belt is produced using a two-stage press vulcanizer equipped with an elastic matrix mold 47A that has elasticity and has a cog surface with alternating protrusions 45A and grooves 46A formed on the bottom of the belt. The molded part was vulcanized with cog molding similar to that already explained with reference to FIG. 5, and the cog 7 shown in FIG.
To obtain a long V-belt 10A' with a continuous row edge cog.

As described in detail above, the present invention leaves a final unvulcanized zone of length (l) and presses the belt using a die mold with a cog surface without considering the presence of the cog portion of the belt. The curing process is continued, and the unvulcanized zone that remains is subjected to a press curing process that involves cog formation. ) By arranging the press vulcanization process using a master mold with elastic cogs that can correspond to It is possible to obtain a long V-belt with raised cog groups in an orderly manner without significantly damaging the shape of the parts, reducing the amount of scrap of an elastic mother mold with cogs, and without requiring particularly complicated work. did it.

It should be noted that the very slight deviation of the cog part of the belt obtained by the final vulcanization process according to the vulcanization method of the present invention compared to other parts is due to this cog function exclusively due to the bending property of the V-belt. Since this was desired, there was no functional defect, and even when it was wrapped around a small diameter pulley, it was able to run without causing early abdominal cracks.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing the form of an unvulcanized belt molded body, Figure 2 is a partial perspective view of an endless unvulcanized belt molded body, and Figure 3 is a press vulcanization process involving cog forming work. 4 is an enlarged cross-sectional view taken along line A-A in FIG. 3 (however, the unvulcanized belt molded body is not shown), and FIG. 5 is an elastic A side view showing the vulcanization process using a press vulcanizer equipped with a matrix mold (however, only the mold part is shown cut away), FIG. 6 is a partial perspective view of a V-belt with a long row edge cog, and FIG.
The figures are a diagram corresponding to FIG. 3 showing another embodiment, and a diagram corresponding to FIG. 8.
The figure is an enlarged cross-sectional view taken along the line B-B of FIG. 7 (however, the group of unvulcanized V-belt molded bodies is not shown), FIG. 9 is a view corresponding to FIG. 5 showing another example, and FIG. 10
The figure is a diagram corresponding to FIG. 6 obtained by another example. In the figure, 1 is an unvulcanized V-core rubber sheet, 4 is a tensile rope, 5 is an upper core rubber sheet, 7 is a cog part of the belt, 10, 10A is an endless unvulcanized belt molded body, 1
0', 10A' are V-belts with long row edge cogs, 21, 21A are pulleys, 25, 25A, 2
6, 26A, 27, 27A, 44, 44A are metal molds, 29, 45, 29A, 45A are protrusions,
30, 46, 30A, 46A are grooves, 47, 47
A shows an elastic matrix mold.

Claims (1)

[Claims] 1. A first step of forming an endless unvulcanized belt molded body by winding belt constituent materials including a V-core rubber sheet in a laminated manner, and then forming a smooth surface on the surface side of the unvulcanized belt molded body. A mold with cogs formed at a constant pitch on the bottom side is arranged respectively, and the endless unvulcanized belt molded body is sequentially fed between the pair of molds and press-processed with cog forming. In the curing step, the second step is to leave the final press-cured area of the belt molded body unvulcanized during the progressive feeding, and then the area left unvulcanized is removed from the belt surface side. A mold with a smooth surface is placed on the bottom side of the belt, and a mold is placed on the bottom side of the belt to absorb the fractions generated during cog molding, depending on the length (l) of the area left unvulcanized. and a third step of press vulcanization accompanied by cog forming by sandwiching it between a mold equipped with a stretchable elastic matrix having a cog whose length is adjusted, the first step or the third step. A method for producing a long cog-equipped V-belt, characterized in that a V-shaped belt cutting step is subsequently added.