JPH0428936B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a wrapped V-belt and a manufacturing method thereof. (Prior Art) In general, a wrapped V-belt having a structure in which a belt core having a V-shaped cross section is covered with an outer canvas is widely known (see, for example, Japanese Patent Laid-Open No. 55-94046). The outer covering canvas used for such wrapped V-belts is usually made by cutting a plain weave canvas material in a bias direction inclined with respect to the longitudinal direction to form a plurality of unit bias cloth pieces, and each unit A long bias canvas is formed by repeatedly overlapping and connecting the side edges of the bias cloth pieces, and the bias canvas is cut in the longitudinal direction to a width suitable for wrapping the belt core. For example, as shown in FIG. 6, the outer covering canvas b is wrapped in required ply along the longitudinal direction of the belt core c, and both side edges of the outer covering canvas b are crimped onto the belt core c. A wrapped V-belt a is formed by wrapping the belt core c and polymerizing it on the inside (or outside) of the belt core c to form a so-called bottom-to-bottom (or back-to-back) wrapper. (Problem to be Solved by the Invention) Such a wrapped V-belt has the following characteristics: the overlapping connection portions of the unit bias cloth pieces constituting the outer canvas, the leading edge which is the innermost layer of the outer canvas, and the rear end which is the outermost layer. The thickness of the canvas is thicker in the region where the edge is located, and repeated tensile and compressive stress acts on the belt when the belt runs, so the overlapping connection between the unit bias cloth pieces that make up the outer covering canvas The trailing edge, which is the innermost layer of the outer canvas, is prone to peeling or cracking, and the leading edge, which is the innermost layer of the outer canvas, is prone to cracking, causing premature belt breakage. Note that such peeling and cracking are particularly likely to occur on the inside of the belt. Therefore, as shown in FIG. 6, there is a means for dispersing the stress applied to the trailing edge d by cutting the trailing edge d of the outer covering canvas b in a straight line in a bias direction inclined with respect to the longitudinal direction of the belt. have been taken, but sufficient effects cannot be expected. The present invention was made in view of the above, and an object of the present invention is to provide a wrapped V-belt that disperses the above-mentioned repeated stress and prevents the canvas from peeling off or cracking. The purpose of this invention is to provide a method for manufacturing. (Means for Solving the Problems) In order to achieve the above object, the first invention covers the periphery of a belt core having a V-shaped cross section with an outer covering canvas, and the outer covering canvas is attached to the belt core. Assuming a wrapped V-belt, which is formed by crimping and wrapping both side edges of the outer canvas material in the longitudinal direction of the belt core while overlapping, the outer material canvas has a bias direction that is inclined with respect to the longitudinal direction of the canvas material. A unit bias cloth piece is cut into a predetermined width, and the side edges of the cloth piece are sequentially polymerized and connected, and the winding start edge which becomes the innermost layer and the outermost layer of the above-mentioned outer covering canvas are The trailing edge at the end of the winding is formed in a wavy shape. Further, in the second invention, the periphery of the belt core having a V-shaped cross section is covered with an outer covering canvas, the outer covering canvas is crimped onto the belt core, and both side edges of the outer covering canvas are attached to the belt core. Assuming that the wrapped V-belt is formed by wrapping the belt while overlapping in the longitudinal direction, the outer canvas is made by cutting a unit bias cloth piece into a predetermined width by cutting the canvas material in a bias direction inclined with respect to the longitudinal direction. , the side edges of the pieces of cloth are sequentially polymerized and connected, and the leading edge at the start of winding, which is the innermost layer, and the trailing edge at the end, which is the outermost layer, are formed in a wavy shape, and The unit bias cloth piece is cut into a predetermined width, and the side edge, which is the connecting edge of at least one cloth piece, is formed in a wavy shape at the overlapping connection portion of the cloth pieces. The third invention is to form only one edge or both edges of a rubberized canvas material into a wave shape,
The canvas material is cut in a bias direction inclined with respect to the longitudinal direction to form a plurality of unit bias cloth pieces, and the side edges of the unit bias cloth pieces are overlapped with the side edges of other unit bias cloth pieces. The connections are made sequentially to form a bias canvas, and the bias canvas is cut to a width suitable for wrapping around the belt core surface to form an outer covering canvas. The outer fabric is cut into a wave shape, and the outer fabric is crimped onto the belt core, and the required plies are wrapped around the outer fabric while overlapping both edges of the outer fabric in the longitudinal direction of the belt core. The trailing edge of the outer layer at the end of the winding is cut into a wave shape and joined to form an unvulcanized V-belt. (Function) According to the first invention, among the cloth pieces obtained by cutting unit bias cloth pieces to a predetermined width to cover the periphery of a belt core body having a V-shaped cross section, the winding start edge and Since the trailing edge of the winding end of the outermost cloth piece is formed in a wavy shape, the range over which repeated stress acts when the V-belt runs is increased compared to the case where the V-belt is running in a straight line. The applied stress is distributed over a relatively wide range. In other words, since the leading edge of the innermost layer of cloth at the beginning of winding and the trailing edge of the outermost layer of cloth at the end of winding are formed in a wavy shape, the part where stress is applied has a wavy shape in the longitudinal direction of the belt. The width corresponds to the height, and stress is dispersed. According to the second aspect of the present invention, the side edge, which is the connection edge of at least one of the cloth pieces, is formed in a wave shape at the overlapping connection portion of the cloth pieces obtained by cutting the unit bias cloth piece into a predetermined width. Therefore, when the V-belt runs, not only the stress that acts on the leading edge of the winding start, which is the innermost layer, and the trailing edge of the winding, which is the outermost layer, but also the stress that acts on the overlapping joint of the cloth pieces of the predetermined width. distributed over a relatively wide area. According to the third invention, only one end edge or both end edges of the rubberized canvas material forming the unit bias cloth piece are formed into a wave shape, and also before and after wrapping the outer covering canvas around the belt core. The wrapped V-belt of the second aspect of the invention can be easily produced because the leading edge at the start of winding, which is the innermost layer, and the trailing edge, which is the outermost layer, at the end of winding are wave-shaped. (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. In Figure 1, 1 is an endless wrapped V
The belt is composed of a belt core body 2 having a V-shaped cross section, and an outer covering canvas 3 that covers the belt core body 2. As is well known, the belt core 2 includes a cushion rubber layer 4 forming the bottom rubber and the cushion rubber layer 4.
The pile tension body layer 5 is composed of a core cord 6 and an adhesive rubber layer 7 in which the core cord 6 is buried. The outer covering canvas 3 has a width surrounding the belt core 2, and is made up of unit bias cloth pieces 8 made by cutting a rubberized plain weave canvas (canvas material) in a bias direction inclined with respect to the longitudinal direction. Bias canvas 15 formed by sequentially connecting (see Figure 2)
It was formed by Side edge 9 of each unit bias cloth piece 8 located at the mutually overlapping connection part of the unit bias cloth pieces 8, 8
are connected by slightly overlapping the side edges of the bias cloth pieces 8 while keeping them straight (not shown), or by connecting the side edges 9 of both bias cloth pieces 8, 8 or one of the bias cloth pieces 8. , as shown in FIG. 1, are connected in a zigzag waveform with slight overlap. The outer covering canvas 3 is wound in required plies in the longitudinal direction of the belt core 2, and wraps around the belt core 2 and extends both side edges of the outer covering canvas 3 along the longitudinal direction of the belt core 2, that is, the belt core 2. It is arranged so that it is polymerized parallel to the edge of the core body 2 and is crimped. In addition, among the leading edge 10 of the innermost layer and the trailing edge 11 of the outermost layer of the outer covering canvas 3, that is, the unit bias cloth piece 8, which is the lowermost edge of the unit bias cloth piece 8, the unit bias cloth piece 8, which is the edge at which the winding starts, is made to a predetermined width. The leading edge 10 of the cut piece of cloth and the trailing edge 11 of the piece of cloth formed by cutting the unit bias cloth piece 8 to a predetermined width, which is the uppermost edge of the winding end, are also the side edges of the bias cloth piece 8. Similar to 9,
Each is cut into a zigzag waveform. Note that the leading edge 10 and trailing edge 11 of the outer covering canvas 3 are as follows:
Although the outer covering canvas 3 may be cut in a waveform in a direction perpendicular to the length direction, it is preferable to cut in a waveform in an oblique direction from the viewpoint of stress distribution. The waveforms of the side edge 9 of the bias cloth piece 8, the leading edge 10 and the trailing edge 11 of the outer covering canvas 3 may be triangular waveforms as shown in FIG. 3a, or sine waves as shown in FIG. 3b. The shape may be either a random wave shape as shown in FIG. Next, a method for manufacturing the wrapped V-belt 1 will be explained based on FIG. 2. The canvas material A serving as the outer covering canvas 3 is a plain-woven canvas whose warp and warp yarns are, for example, blended yarns obtained by appropriately blending cotton, nylon, or thermoplastic fibers such as polyester fibers with cotton. This canvas material A is
As is well known, wrought rubber containing chloroprene rubber or natural rubber is rubbed in using a calender.
Both sides of the material are friction surfaces. The side edges 9, 9 of the canvas material A are formed in a wave shape on both sides. The canvas material A thus rubberized is bias-cut in a direction inclined at 45 degrees with respect to the longitudinal direction to form a plurality of unit bias cloth pieces 8 (see FIG. 2b). Next, the side edges 9 of the unit bias cloth pieces 8 are slightly overlapped and connected to form an overlapping connection 12, and this is repeated to form the bias canvas 15.
Therefore, in the above-mentioned overlapping connection, the wave-shaped side edge 9 of the unit bias cloth piece 8 and the wave-shaped side edge 9 of the other unit bias cloth piece 8 are connected. They will be slightly polymerized and bonded. In the above embodiment, the side edges 9 of the canvas material A are formed in a wave shape on both sides, but only one side is formed in the above-mentioned wave shape, and the side edge 9 of one unit bias cloth piece 8 at the overlapping joint is Only the edge 9 may have a wavy shape, and furthermore, both side edges 9 of the canvas material A may be left in the straight shape formed at the time of weaving. They may be polymerized and connected to each other. Next, the bias canvas 15 is cut in the longitudinal direction so as to be slightly wider than the circumferential length of the preformed belt core 2 to form the outer covering canvas 3 (see FIG. 2 d).
reference). As shown in FIG. 1, the belt core 2 is composed of a cushion rubber layer 4 and a pile tension layer 5 formed on the cushion rubber layer 4, and the pile tension body layer 5 is formed in a spiral shape. A core cord 6 such as a wound polyester cord is embedded within an adhesive rubber layer 7. Before wrapping the outer canvas 3 around the belt core 2, first, the leading edge 10, which is the winding start edge, of the outer canvas 3 is inclined at 45 degrees with respect to the longitudinal direction of the canvas. For example, the third
Cut into a wave shape as shown in the figure (see Figure 2e). Note that the tip edge 10 of the outer covering canvas 3 may be cut in a direction perpendicular to the longitudinal direction of the canvas. The procedure for wrapping the outer canvas 3 around the belt core 2 is, for example, by wrapping it between two pulleys of the belt core 2 and fixing the leading edge 10 of the outer canvas 3 to the belt core 2. Transfer the belt core 2 and attach the outer covering canvas 3 to the belt core 2 using a pressure roller or the like.
The belt core 2 is wrapped in the outer covering canvas 3, and the bottom side (or back) of the belt core 2 is wrapped around the belt core 2 along its longitudinal direction, and both edges are simultaneously pressed against the belt core 2 side. The edges of the outer covering canvas 3 are slightly overlapped along the edge 2a of the belt core 2 (see FIG. 2 f). Then, in the same manner, after winding the required ply (one ply or several plies) of the outer covering canvas 3 around the belt core 2, the trailing edge 11, which is the end edge of the winding, is wound in the longitudinal direction of the canvas in the same manner as the leading edge 10. They are cut and bonded in a wave shape as shown in FIG. 3 in a bias direction (or perpendicular direction) that is inclined to the opposite direction (see FIG. 1). Thus, as is well known, a large number of unvulcanized V-belts wrapped with the outer covering canvas 3 are placed in a known vulcanization mold, placed in a vulcanization can, and vulcanized. After completion of vulcanization, remove from the vulcanization can. After cold setting, it is taken out from the vulcanization mold to form the desired wrapped V-belt. Next, tests were carried out on the wrapped V-belt of the present invention shown in FIG. 1 and the conventional wrapped V-belt shown in FIG. A comparative test will be explained based on FIGS. 4 and 5. In the test, as shown in Fig. 4, both the driving pulley 20 and the driven pulley 21 had the same pitch diameter of 95.25.
mm, a load W of 68 kg is applied to the driven pulley 21, and the belt 1 is run at a rotation speed of 4800 rpm.
The time until cracks appear (crack initiation time) and the time until the belt can no longer be used (endurance life) were measured. The wrapped V-belt used in the test has a height H of 10.3 in Figure 5.
m/m, top width B is 16.7 m/m, belt angle D
is 40 degrees, the total length of the belt is 42 inches, and the wave shape of the side edge of the cloth piece constituting the outer covering canvas of the wrapped V-belt according to Example 1 of the present invention is a triangular wave shape, the height of the wave crest is 2 mm, and the pitch is 3 mm. , the leading edge 10 and the trailing edge 11 are both formed into a wave shape in the bias direction. In Example 2 of the present invention, a unit bias cloth piece is cut into a predetermined width, and only the side edge, which is the connecting edge of one cloth piece, is formed in a wave shape in the bias direction at the overlapping connection portion of the cloth pieces. The other points are the same as Example 1 of the present invention. A comparative example is
Only the rear edge, which is the outermost layer, of the outer covering canvas is formed into a wave shape in the bias direction. Each unit bias cloth piece is cut into a predetermined width, and there is only one overlapping connection portion between the cloth pieces. The test results are shown in the table below.

[Table] However, the above test results are the average value of 5 tests. As is clear from the table above, it can be seen that Examples 1 and 2 of the present invention are significantly superior to the conventional examples and comparative examples in terms of time until cracking and durability. (Effects of the Invention) According to the first invention, after a piece of cloth is obtained by cutting a unit bias cloth piece to a predetermined width to cover the periphery of a belt core body having a V-shaped cross section, the winding start edge which becomes the innermost layer and the outermost layer Since both the trailing edges of the winding ends of the cloth strips are formed in a wavy shape, the leading edges and trailing edges of the cloth strips are formed in a wavy shape, compared to the conventional method using cloth strips cut straight in the bias direction. The applied external stress is dispersed over a relatively wide range, thereby suppressing the occurrence and growth of cracks, and preventing premature breakage of the belt caused by the cracks. Further, according to the second invention, in addition to the leading edge and the trailing edge, at least one side edge of the overlapping connection portion of the cloth pieces formed by cutting the unit bias cloth piece to a predetermined width is similarly formed. Since it is shaped like a wave, the stress applied to the polymerization joint is also dispersed over a relatively wide range. According to the third invention, the tip edge of a cloth piece obtained by cutting a unit bias cloth piece to a predetermined width and the end edge of the outermost layer of the unit bias fabric, which is the end edge of the winding start edge of the innermost layer. A wrapped V-belt that can easily disperse stress at the trailing edge of a piece of cloth cut into a predetermined width and at the overlapping joint between pieces of cloth made by cutting a unit bias cloth piece into a predetermined width. It becomes possible to manufacture.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention.
The figure is a partially cutaway perspective view of the wrapped V-belt of the present invention, and Figure 2 shows its manufacturing method, in which figure a is a perspective view of a canvas material, figure b is a perspective view of a unit bias cloth piece, Figure c is a perspective view of a piece of bias cloth, figure d is an explanatory diagram showing the manufacturing procedure of the outer covering canvas, figure e
1 is a perspective view of the outer covering canvas, FIG. is a cross-sectional dimensional drawing of the wrapped V-belt used in the test. FIG. 6 is a perspective view of a conventional wrapped V-belt. 1...wrapped V-belt, 2...belt core,
3... Outer covering canvas, 8... Unit bias cloth piece, 9...
...Side edge, 10...Top edge, 11...Rear edge, 1
2... Connection section, 15... Bias canvas.

Claims (1)

[Scope of Claims] 1. A belt core having a V-shaped cross section is covered with an outer covering canvas, and the outer covering canvas is crimped onto the belt core, and both side edges of the outer covering canvas are attached to the belt core. In a wrapped V-belt formed by overlapping and wrapping in the longitudinal direction, the outer covering canvas is formed by cutting a unit bias cloth piece into a predetermined width by cutting a canvas material in a bias direction inclined with respect to the longitudinal direction, and cutting the piece of cloth into a predetermined width. The side edges of the outer canvas are sequentially overlapped and connected, and the leading edge at the start of winding, which is the innermost layer, and the trailing edge at the end, which is the outermost layer, are formed in a wavy shape. Wrapped V-belt. 2 Covering the periphery of the belt core having a V-shaped cross section with an outer covering canvas, pressing the outer covering canvas onto the belt core, and polymerizing both side edges of the outer covering canvas in the longitudinal direction of the belt core. In the wrapped V-belt, the outer covering canvas is formed by cutting a unit bias cloth piece into a predetermined width by cutting a canvas material in a bias direction inclined with respect to the longitudinal direction, and the side edge of the cloth piece is cut into a predetermined width. It is constructed by sequentially polymerizing and connecting the outer covering canvas, and the leading edge at the start of winding, which is the innermost layer, and the trailing edge at the end, which is the outermost layer, are formed in a wave shape, and the unit bias cloth pieces are formed into a predetermined width. 1. A wrapped V-belt characterized in that a side edge, which is a connecting edge of at least one of the cut cloth pieces, is formed in a wave shape at the overlapping connection portion of the cut cloth pieces. 3. Forming only one edge or both edges of a rubberized canvas material into a wave shape, and cutting the canvas material in a bias direction inclined with respect to the longitudinal direction to form a plurality of unit bias cloth pieces. , Form a bias canvas by sequentially overlapping and connecting the side edges of the unit bias cloth piece with the side edges of other unit bias cloth pieces, and cut the bias canvas to a width suitable for wrapping around the belt core surface. The outer canvas is formed by cutting the leading edge of the outer canvas, which is the innermost layer of the winding start, into a wave shape, and the outer canvas is crimped onto the belt core, and the edges of both sides of the outer canvas are cut into a wave shape. The required amount of ply is wound around the belt core while polymerizing the parts in the longitudinal direction of the belt core, and the trailing edge of the winding end, which is the outermost layer, is cut into a wave shape and joined to form an unvulcanized V-belt. A method for manufacturing a wrapped V-belt, characterized by: