JP4044572B2 - Elastic crawler and tensile band manufacturing method - Google Patents

Description

  The present invention relates to a method of manufacturing an elastic crawler and a tensile belt used in various crawler type traveling devices.

An endless elastic crawler is attached to an agricultural machine such as a combine and a construction work machine such as a backhoe. A tensile belt including a plurality of steel cords is embedded in the elastic crawler along the circumferential direction. The tensile band is manufactured, for example, by winding a steel cord covered with rubber in a spiral shape. However, the position of the steel cord is likely to be disturbed during manufacturing, and the cause of delamination due to the presence of air between layers, etc. It was. For this reason, there is known a tensile band in which the adjacent surfaces of the tensile body covered with steel cords with rubber are flat crimping surfaces that are crimped to each other and the steel cords are arranged in an orderly manner by crimping these crimping surfaces together. (For example, refer to Patent Document 1).
JP 2001-253374 A

However, in the tensile band of Patent Document 1, a steel cord is passed through an extruder so that the steel cord is covered with rubber to form a tensile member having a rectangular cross section. The thickness of the surrounding coating rubber cannot be made constant. When such a tensile body is wound on the winding drum, the steel cords are undulated in the circumferential direction and the pitch in the width direction (drum axis direction) is disturbed, and the steel cords are arranged with high accuracy. I can't. Therefore, if such a tensile band is used for an elastic crawler, strength reduction and delamination due to non-uniform tension is inevitable, and the progress of rust when the steel cord is exposed to damage is accelerated. Therefore, the elastic crawler may be cut.
The present invention has been made in view of the above problems of the prior art, and an elastic crawler in which cutting is prevented by embedding a tensile band in which steel cords (tensile core wires) are arranged with high precision, and a method for manufacturing the tensile band The purpose is to provide.

In order to achieve the above object, the present invention takes the following technical means.
That is, the present invention is a method for producing a tensile band including the following steps (a) to (c). (A) A state in which a large number of tensile core wires arranged in a row are passed between rolls of a calender device, and the core wires are integrally covered with rubber so that the multiple tensile core wires are arranged at predetermined intervals in the width direction. In the first step (b) of obtaining the strip-shaped material embedded in the step, the strip-shaped material is cut along the longitudinal direction of the strip so that the thickness of the coating rubber from the cut surface to the tensile core is constant. Second step of obtaining a cord-like material in which several tensile strength core wires are embedded (c) winding the cord-like material spirally around a drum in a state where the side surfaces of the cord-like material are in close contact with each other According to the third step of forming an endless belt-like tensile band

In the method for producing the tensile band of the present invention, the tensile cores are temporarily lined up at predetermined intervals by a calendar device, instead of passing the tensile cores through an extruder and covering the rubber with a conventional extruder. After obtaining the strip-shaped material embedded in the state, the strip-shaped material is cut into a cord-shaped material with rubber around the tensile core, and this is wound around a winding drum.
When rubber is coated on the tensile core with the calendar device, the thickness of the coated rubber in the thickness direction is constant. By cutting this strip-shaped material formed by the calendar device into a cord-shaped material with a constant coating rubber thickness from the cut surface to the tensile core, not only the upper and lower sides of the cord-shaped material but also the width direction left and right The coating rubber thickness is also constant. If the cord-like material formed in this way is wound up spirally around the winding drum, the thickness of the covering rubber around the tensile core wire in the tensile band will be constant vertically and horizontally. Therefore, there is no undulation in the circumferential direction of the tensile strength core wires and no disturbance in the pitch in the width direction, and the tensile strength core wires can be arranged in a precise and orderly manner. Thereby, the tension applied to the tensile band becomes uniform.

  In the second step of the manufacturing method, if the strip material is cut along the longitudinal direction of the cord so that the tensile core wire is eccentric in the cross section of the cord-like material after cutting, the coated rubber on the left and right sides of the tensile core wire Thickness accuracy can be improved.

  Furthermore, if a tensile strength core wire with a cord for preventing breakage is wound around it, it is possible to prevent the tensile strength core wire composed of a large number of fibers from being scattered, and the tension applied to the tensile band is more uniform. become.

  In addition, if the tensile band with the tensile cores arranged in an orderly manner is used for an elastic crawler, the tension on the tensile band becomes uniform and the tensile core line is not exposed. Can be prevented.

  As described above, according to the present invention, it is possible to obtain a tensile band in which the tensile cores are arranged with high accuracy by winding the cord-like material having a constant coating rubber thickness around the tensile core. The cutting of the elastic crawler can be prevented by using.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the manufacturing method of the tensile band 1 of the present embodiment, a plurality of steel cords 2 (tensile core wires) are integrally covered with a rubber 3 by a calendar device to form a band-shaped material 4 shown in FIG. Step) After cutting the strip-shaped material 4 along the longitudinal direction of the strip to obtain the cord-shaped material 5 shown in FIG. 1B (second step), the cord material 5 is spirally wound around a winding drum. The strip-shaped tensile band 1 shown in FIG. 1C is obtained (third step). Therefore, the steel cord is not passed through an extruder or the like and wound around a winding drum as in the prior art, but the tensile band 1 is obtained after going through a process of cutting the strip material 4 once. is there.

  As shown in FIG. 1 (b), the cord-shaped material 5 is formed by covering the first and second steel cords 2 </ b> A and 2 </ b> B having a diameter of about 2 to 3 mm with rubber 3. The first and second steel cords 2A and 2B are in a state of being deviated (eccentric) to one side as a whole in the cord-shaped material 5 having a rectangular cross section whose upper, lower, left and right wall surfaces are flat. The cord-like material 5 is formed so that the upper and lower sides are 7 to 9 mm and the left and right sides are 4 to 6 mm. The tensile band 1 winds the cord-like material 5 in a spiral shape (one piece) The cord-shaped material 2 is wound around the circumferential direction while shifting the position in the width direction) to form a seamless structure. The steel cord 2 of the present embodiment employs a combination of several steel filaments combined with several bundles, but is composed of other filaments such as nylon and tetron. Nylon cords, tetron cords, other aramid fiber cords, glass fiber cords, and other cords may be employed.

  FIG. 2 shows an outline of a calendar apparatus for forming a strip-shaped material 4 by coating a steel cord 2 with a rubber 3. The steel cords 2 wound around the plurality of reels 31 are arranged in a horizontal row by the guide rollers 32, and subsequently passed between the calender rollers 33, and the steel cords 2 arranged in the width direction are attached to the steel cords 2 arranged in the width direction. The rubber 3 is integrally coated to form a band-shaped material 4 (rubber sheet) having a width of about 1.5 m, and the band-shaped material 4 is wound around the supply drum 34. Since the rubber 3 is covered with the calendar device, the thickness of the covering rubber attached to the top and bottom of the strip-shaped material 4 is constant. Then, the strip material 4 is cut and divided along the longitudinal direction of the strip so that the thickness of the covering rubber from the cut surface to the steel cord 2 is constant by the process shown in FIG. For example, 60 cord-shaped materials 5 having 2 embedded therein are obtained.

  3A and 3B show an outline of the dividing / winding device. As shown in the drawing, a supply drum 34, first to fourth pulleys 38, 39, 40, 41 and a take-up drum 42 are attached to a plate-like support member 36 fixed to the installation table 35. The belt-like material 4 wound around the supply drum 34 is wound around the winding drum 42 via each pulley. Further, the third pulley 40 is driven to rotate by a motor 43. The strip-shaped material 4 drawn out from the supply drum 34 is installed between the second pulley 39 and the third pulley 40 via the first and second pulleys 38 and 39 and has a cutter 44 having a required number of teeth. Is divided into several pieces to form the cord-shaped material 5 described above (see FIG. 1B). The divided cord-like material 5 reaches the fourth pulley 41 via the third pulley 40 while being arranged in the horizontal direction. The winding drum 42 is installed in the same number as the number of the divided cord-like materials 5 by changing the position thereof, and one cord-like material separated by the fourth pulley 41 in the drum installation direction. 5 is wound around the respective winding drums 42 in a spiral manner to obtain the tensile band 1 shown in FIG.

  A cross-sectional view of the cord material 5 is shown in FIG. In the drawing, the left and right side wall surfaces have cut surfaces 5a and 5b. When the strip material 4 is cut, the cut surfaces 5a (cut surfaces 5b) of the respective cord-shaped materials 5 and the cut surfaces 5a (cut surfaces 5b) are cut. ) To the nearest steel cord 2A (2B), the coating rubber thickness k2 (coating rubber thickness k3) is constant in the circumferential direction and the width direction. In order to cut in this way, a little force is applied from the opposite side so as not to move one side of the belt-shaped material 4, and it is performed at a position close to the steel cord 2A (2B). In this way, stable cutting is possible, and the dimensional accuracy of the thickness of the coated rubber can be improved.

  The first steel cord 2A closest to one cut surface 5a (left cut surface) is close to the one cut surface 5a, and the second steel cord 2B, which is different from this, The steel cord 2A is positioned away from the other cut surface 5b (right cut surface) with a required interval k1. Therefore, when the coating rubber thickness from the first steel cord 2A to one cut surface 5a is k2, and the coating rubber thickness from the second steel cord 2B to the other cut surface 5b is k3, the first rubber cord The second steel cord is arranged so as to satisfy k2 <k3, and as a whole is eccentric from the central portion in the width direction of the cord-like material to one side. Further, the coating rubber thickness k2 of this embodiment is extremely thin and close to 0 mm, and the interval k1 between the first and second steel cords is the same as the coating rubber thickness k3. The coated rubber thickness k2 is preferably 0 to 0.3 mm, and the coated rubber thickness k3 is preferably 0.6 to 2.0 mm.

  As shown in FIG. 4, the cord-like material 5 on the winding drum 42 is in a state where one cut surface 5a of the cord-like material 5 is directed in the same direction (the base end side of the winding drum 30). The winding drum 42 is spirally wound from the proximal end portion toward the distal end portion. When the coating rubber thickness k2 is 0 mm or very thin as in the present embodiment and the interval k1 = coating rubber thickness k3, all the steel cords 2A, 2B of the formed tensile band 1 are arranged at almost equal intervals. On the other hand, when the covering rubber thickness k2 is sufficient and the interval k1 = the covering rubber thickness k3, the steel cords 2A and 2B that are formed as a set of two formed tensile bands 1 are arranged at equal intervals. Become. Side surface 5 a of the cord-like material 5. In order to bring the 5b into close contact with each other, a lateral load is applied by a guide, and the adjacent cord-shaped material 5 can be wound while applying pressure to the mutually facing cut surfaces 5a and 5b (wall surfaces). . In addition, the cord-shaped material 5 may be supplied in a state of being inclined with respect to the axial direction of the winding drum 42.

  Further, when winding around the take-up drum 42, it can be stably taken up by pressing it inwardly with a long pressing roller (not shown) in the axial direction. By performing the surface treatment with good moldability, the removal of the tensile band 1 can be performed smoothly without causing deformation of the mold. Further, as shown in FIG. 5, if a circumferential interval is provided between the winding start end 5s and the winding end end 5e, there is no difference in rigidity when the tensile band 1 is embedded in the elastic crawler, and the end peeling is eliminated. Can be prevented.

  In addition, the tensile band 1 is not limited to the said form, For example, what is shown to FIGS. 6-8 may be used. FIG. 6 shows a case where the cord-like material 5 is pressure-bonded and joined to the rubber sheet 6. The rubber sheet 6 is attached in advance to the winding drum 42, and the cord-like material 5 is spiraled on the rubber sheet 6. The tensile belt 1 is manufactured by winding it into a shape. FIG. 7 shows a fabric (fabric) sheet, that is, a canvas 7 covered with a tensile belt 1. A canvas 7 wider than the tensile belt 1 is attached on a winding drum 42, and the canvas After the cord-like material 5 is wound on the sheet 7, it is folded so as to be wrapped around the left and right edges of the canvas 7, and the left and right edges are overlapped and joined together. In FIG. 8, the rubber sheet 8 is attached on the winding drum 42, and the cord-like material 5 is wound on the rubber sheet 8, and then the canvas 9 is placed on the rubber sheet 8 and the canvas 9. Wrapped to produce.

  In the manufacturing method of the tensile band 1 of the present embodiment, the steel cord 2 (strength core wire) is temporarily used by a calender device, instead of passing the tensile core wire through an extruder and coating the rubber as in the conventional method. ) Are embedded in a state where they are arranged at predetermined intervals, and then the strip material 4 is cut into a cord-like material 5 with a rubber 3 around the steel cord 2, and this is taken up as a winding drum. Take up around 42. When the rubber cord 3 is coated on the steel cord 2 with a calendar device, the thickness of the coated rubber in the thickness direction is constant. By cutting the strip-like material 4 to obtain a cord-like material 5 having a uniform coating rubber thickness from the cut surface to the steel cord 2, not only the upper and lower sides of the cord-like material 5 but also the left and right coating rubbers in the width direction. The thickness is also constant.

  If the cord-shaped material 5 formed in this way is wound up around the winding drum 37 in a spiral manner, as a result, the thickness of the covering rubber around the steel cord 2 in the tensile band 1 becomes constant vertically and horizontally. Therefore, there is no undulation in the circumferential direction of the steel cords and no disturbance in the pitch in the width direction, and the steel cords 2 can be arranged accurately and orderly. Thereby, the tension applied to the tensile band 1 becomes uniform. For example, an improvement in driving width accuracy is recognized as compared with a conventional type using a cord-like material formed by an extruder.

  When the tensile band 1 manufactured as described above is vulcanized, for example, the tensile band 1 may be positioned between the upper and lower molds arranged between the upper and lower presses, and pressurized and heated (see FIG. Not shown). The tensile belt 1 is embedded in the crawler body of an elastic crawler including an endless belt-like crawler body and a lug group formed by a plurality of lugs integrally formed on the outer peripheral surface of the crawler body with a predetermined lug pattern. Can be used. Such an elastic crawler is used by being mounted on various crawler type traveling devices. For example, when the tensile belt 1 is embedded in an elastic crawler containing a core metal, the core metal is placed on a base rubber (inner peripheral rubber). The rubber sheet is placed on the rubber sheet, and vulcanized through the tensile band 1 vulcanized between the rubber sheet and the tread rubber (outer peripheral rubber). In this elastic crawler, the crawler body is composed of a base rubber, a rubber sheet, and a tread rubber, and the tensile belt 1 is embedded in the crawler body.

  FIGS. 10A and 10B illustrate a crawler type traveling device equipped with an elastic crawler 10 in which the tensile body 1 is used. The crawler type traveling device 12 of FIG. 10A is used by being wound around the pneumatic tires 11 arranged at the front and rear, and the crawler type traveling device 16 of FIG. 10B is provided at the front and rear of the airframe. The sprocket 13 and the idler 14, and the rolling wheels 15 arranged between the sprocket 13 and the idler 14 are used as a traveling unit of an agricultural machine, a construction work machine, or the like.

  If the tensile band 1 in which the steel cords 2 are arranged in an orderly manner is used for the elastic crawler 10, the tension on the tensile band 1 becomes uniform, and furthermore, the steel cord 2 is not exposed, so that the occurrence of rust can be suppressed. . Thereby, cutting of the elastic crawler 10 can be prevented. Further, since the driving width accuracy is improved, when the tensile belts 1 are embedded on the left and right in the width direction of the elastic crawler 10, the width dimensions of the respective tensile belts 1 are the same, and other reinforcing cords (bias cords, When embedding a canvas or the like, the tensile band 1 can be embedded with high accuracy with respect to the reinforcing cord.

  In addition, this invention is not limited to the said embodiment. For example, as shown in FIGS. 9B and 9C, a cord-like material 5 including one steel cord 2 may be used. The cord-shaped material 5 in FIG. 9B is eccentric in the width direction, and the coating rubber thickness k2 on one cut surface side is 0 to 0.3 mm, and the coating rubber thickness on the other cut surface side. k3 is set to 0.6 to 2.0 mm. The cord-shaped material 5 in FIG. 9 (c) is eccentric in the width direction and the thickness direction, and the coating rubber thickness k5 from the lower wall surface 5c to the steel cord 2 is 0.4 to 1.5 mm. The coating rubber thickness k6 from the wall surface 5d to the steel cord 2 is 0.4 to 3.0 mm.

  In order to decenter the steel cord 2 in the width direction, it may be performed at the time of cutting as described above. However, in order to decenter in the vertical direction, the amount of rubber applied to the top and bottom of the steel cord 2 may be adjusted in calendar processing. . Further, at the time of cutting, three strips (see FIG. 11A) or more steel cords 2 were embedded by dividing the belt-shaped material 4 by widening the interval between teeth provided on the cutter. The cord-shaped material 5 can also be used. As shown in FIG. 11 (b), a loosening prevention cord 22 may be wound around the steel cord 2. In this way, it is possible to prevent the steel cord 2 from being loosened, and since the tension applied to the tensile band 1 becomes more uniform, it is possible to reliably prevent the elastic crawler from being cut.

  The present invention is applied to the manufacturing method of the tensile band 1 including the above steps, and it is of course possible to include necessary steps other than the steps. For example, the belt-shaped material obtained by the calendar device can be divided into two parts to reduce the width of the belt-shaped material and then cut. In this case, a pulley having a short axial length can be used by reducing the width of the belt-shaped material, and the structure of the pulley support portion can be simplified. Moreover, the slide amount of the steel cord to be wound can be reduced.

(A) is a perspective view of a strip-shaped material, (b) is a perspective view of a cord-shaped material obtained by cutting the strip-shaped material, and (c) is a tensile band obtained by winding the cord-shaped material. It is a perspective view. It is a schematic diagram of a calendar apparatus. (A) is a front view of a winding device that cuts a strip-shaped material and winds it up, and (b) is a side view thereof. It is sectional drawing which shows the state in which a cord-shaped raw material is wound up with a winding drum. It is a schematic diagram of a tensile belt. It is sectional drawing which shows other embodiment of a tension belt. It is sectional drawing which shows other embodiment of a tension belt. It is sectional drawing which shows other embodiment of a tension belt. (A) is a cross-sectional view of a cord-like material including two steel cords eccentric in the width direction, and (b) is a cross-sectional view of a cord-like material including one steel cord eccentric in the width direction. (C) is a cross-sectional view of a cord-like material including one steel cord eccentric in the width direction and the vertical direction. (A), (b) is a side view which shows the example of a crawler type traveling apparatus, respectively. (A) is a perspective view of a cord-like material including three steel cords, and (b) is a cross-sectional view of a steel cord provided with a cord for preventing breakage.

Explanation of symbols

1 Tensile band 2 Steel cord (Tensile core wire)
3 Rubber 4 Band-shaped material 5 Code-shaped material 6 Rubber sheet 7 Canvas 10 Elastic crawler 30 Winding drum 35 Supply drum 36 Molding machine

Claims (4)

A method for producing a tensile band, comprising the following steps (a) to (c).
(A) A state in which a large number of tensile core wires arranged in a row are passed between rolls of a calender device, and the core wires are integrally covered with rubber so that the multiple tensile core wires are arranged at predetermined intervals in the width direction. (B) by cutting the strip material along the longitudinal direction of the strip so that the coating rubber thickness from the cut surface to the tensile core is constant, Second step of obtaining a cord-like material in which several tensile strength core wires are embedded (c) Winding the cord-like material spirally around a drum in a state where the side surfaces of the cord-like material are in close contact with each other According to the third step of forming an endless belt-like tensile band   2. The production of a tensile band according to claim 1, wherein in the second step, the band-shaped material is cut along the longitudinal direction of the band so that the tensile core wire is decentered inside a cross-section of the cord-shaped material after being cut. Method.   The manufacturing method of the tensile belt of Claim 1 or 2 with which the code | cord | chord for scattering prevention is wound around the said tensile strength core wire.   An endless belt-like crawler body made of an elastic body, a lug group composed of a plurality of lugs integrally formed with a predetermined lug pattern on the outer peripheral surface of the crawler body, and embedded in the crawler body along the circumferential direction An elastic crawler comprising a tensile band manufactured by the manufacturing method according to claim 1.

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