JP2010076309A - Method for manufacturing rubber crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a method which can efficiently manufacture a high-quality rubber crawler. <P>SOLUTION: A mold cavity is formed between the lower mold U<SB>1</SB>in which a plurality of segments are arranged and fixed/held in the shape of a circle and the upper mold U<SB>2</SB>which is engaged with the lower mold U<SB>1</SB>. Inner rubber 3b, a reinforcement 4, a core material 5, and an outer rubber sheet 3d are wound around in the mold cavity, and mold clamping is carried out after molding. Next, the rubber crawler is manufactured by carrying out pressurization, vulcanization, and demolding. In this process, the core material 5 is formed by at least two layers of adhesive rubber sheets 5b and 5c which are wound onto the outer surface of the inner rubber 3b and a steel cord 5a which is held between the adhesive rubber sheets 5b and 5c and wound spirally around the mold U<SB>1</SB>. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a rubber crawler to be mounted on a construction machine such as a hydraulic excavator, an agricultural machine such as a combine or tractor, or other crawler type vehicles, and attempts to realize efficient production of the rubber crawler. To do.

  A crawler-type vehicle is constructed by winding a belt-like body endlessly between a sprocket type drive wheel connected to a drive means such as a hydraulic motor and a driven wheel arranged at an interval from the drive wheel. A crawler is attached and rotated by a drive wheel to allow the aircraft to travel.

  The rubber crawler is gentle on the road surface (does not damage the soil in fields, etc., and rarely damages the road surface on asphalt or concrete roads), has low vibration and low noise, and can reduce the contact pressure. Therefore, since it can run stably on snow and sand, it does not have mechanical joints compared to steel ones, so there is no mud clogging and there is no need for troublesome maintenance like an iron shoe. In recent years, this type of crawler tends to be frequently used, such as a metal reinforcement type in which a core metal is embedded and fixed in a rubber layer together with a core body, and a ply reinforcement type in which only a reinforcement layer is provided without a core metal. Existing.

As a vulcanization molding method, a laminated body is configured by placing a core and a reinforcing material between sheet-like inner rubber and outer rubber, and this is placed in a cavity formed by a lower mold and an upper mold. Vulcanization and joining method (basically using a flat mold) that pressurizes and vulcanizes to form a belt-like vulcanized molded body, and further joins the vulcanized molded body by overlapping the end portions thereof. A circular integrated vulcanization system in which crawler components are placed on a circular inner mold that also serves as a molding drum, and an outer mold is superimposed on the inner mold, and pressure and vulcanization are performed under predetermined conditions. Patent Document 1 is referred to as a prior art regarding this point.
Japanese Patent Laid-Open No. 11-1797

  Among the above vulcanization molding methods, the circular integrated vulcanization method does not require a joining process such as a vulcanization joining method in which the end faces of the vulcanized moldings are overlapped and vulcanized and joined, and the joining vulcanization method. In contrast to the above, there is an advantage that efficient production can be achieved, but the following problems remain.

  In other words, the steel cord forming the core body had an adhesive rubber coating layer formed on its surface using an extruder for the purpose of improving the adhesion to the rubber constituting the crawler, but the coating speed was When manufacturing products with a maximum circumference of about 30 m / min, a long circumference, and a large number of cores (steel cord layers) driven, a core body molding process (a process of winding a steel cord in a spiral) In some cases, a time lag may occur between the vulcanization and demolding processes (the cycle time of the core molding process exceeds the cycle time of the vulcanization and demolding processes).

  The subject of this invention exists in the place which proposes the manufacturing method which can eliminate the time lag between the processes which had arisen when manufacturing a rubber crawler by applying a circular integrated vulcanization system.

The present invention forms a mold cavity between a lower mold in which a plurality of segments are arranged and fixedly held in a circular shape and an upper mold fitted to the lower mold, and an inner rubber and a reinforcing material are formed in the mold cavity. In the production of a rubber crawler by rotating and molding the core and the outer rubber sheet and then pressing, vulcanizing, and demolding,
The core body is sandwiched between at least two adhesive rubber sheets wound around the outer surface of the inner rubber and the adhesive rubber sheet, and is wound around the inner mold in a spiral shape. It is a method of manufacturing a rubber crawler characterized by being formed of a steel cord.

  As the steel cord, a steel cord that has been subjected to a dipping treatment with a rubber paste in a stage before being wound around the inner mold can be applied. Further, the reinforcing material is applied to both a core metal (core rubber-containing rubber crawler) or a reinforcing ply layer (core metal-less rubber crawler).

  By placing an adhesive rubber sheet before and after the molding process to form the core body, the steel cord will be sandwiched between them, so it is necessary to provide a separate rubber coating layer on the outer surface of the steel cord There is no time lag between the molding process for forming the core body and the vulcanization and demolding processes, and an improvement in productivity can be expected by increasing the processing speed.

  When the steel cord is wound in a spiral shape, the steel cord is subjected to a dipping process using rubber glue, whereby the adhesive strength with the rubber layer constituting the crawler can be further improved.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
FIG. 1 is an external perspective view showing a part of a rubber crawler with a core metal in cross section. In the figure, reference numeral 1 denotes a driving wheel (or driven wheel) of the vehicle, and 2 denotes a wheel disposed between the driving wheel 1 and the driven wheel. Among the rollers 2, the roller 2 located at the lower side functions on the grounding side to transmit the load of the machine body to the rubber crawler so that the grounding portion of the crawler is securely grounded. 2 (not shown) functions so that the tension of the rubber crawler is always kept constant between the driving wheel 1 and the driven wheel. A rubber crawler 3 is wound between the driving wheel 1 and the driven wheel, and a land portion (a grounding portion) such as a lug is formed on the outer peripheral side 3a thereof.

  Reference numeral 4 denotes a core bar embedded and fixed in the rubber layer of the crawler 3. A plurality of the core bars 4 are arranged around the crawler 3 at intervals, blades 4b and 4c extending toward the width end of the base portion 4a, and toward the inner peripheral side of the crawler 3 at the center of the base portion 4a. A pair of protrusions 4d and 4e projecting from each other, and a path for passing the driving wheel 1 and the driven wheel is defined between the protrusions 4d and 4e.

  Reference numeral 5 denotes a core body which is disposed on the outer peripheral side of the core metal 4 and is embedded and fixed in the rubber layer together with the core metal 4. The core body 5 is composed of a plurality of steel cords 5a extending in a direction along the crawler 3 and wound in a spiral shape along the width direction. 6 is provided adjacent to the outside of the protrusions 4d and 4e, and is a flat surface on which the rolling wheels roll. 7 is a path through which the driving wheel 1 and the driven wheel pass, and passes between the inner peripheral side and the outer peripheral side of the crawler 3. It is a meshing hole. The protrusion of the drive wheel 1 fits into the meshing hole 7.

  FIG. 2 shows an external perspective view of a lower mold of a vulcanization mold suitable for use in the present invention, and FIG. 3 shows a stacking state of components disposed in a mold cavity of the vulcanization mold. .

To produce the structure rubber crawler 3 as displayed above掲図1 in accordance with the present invention, FIG. 2, the inner circumferential surface of the rubber crawler inner mold U ₁ in the vulcanization mold as shown in FIG. 3 The inner rubber 3b to be formed is disposed, and the core metal 4 and the intermediate rubber 3c are sequentially disposed. Then, an adhesive rubber sheet (treat rubber) 5b is disposed on the intermediate rubber 3c and the steel cord 5a is wound in a spiral shape, and then the adhesive rubber sheet 5c is disposed thereon to correspond to the core body 5. forming a portion was molded by further match the inner mold U ₁ the upper die U ₂ After placing the outer rubber 3d forming the outer peripheral surface of the rubber crawler 3 on the adhesive rubber sheet 5c, the desired condition Vulcanize and demold under

  When winding the steel cord, as shown in FIG. 4, it is also possible to pass the steel cord 5a through the storage tank M storing the rubber paste and to perform the dipping treatment. In this case, the shoreline constituting the steel cord Since the rubber paste enters the inside, the adhesion strength to the rubber is further increased and the steel cord can be prevented from being deteriorated.

  As for the dipping process, it is preferable to use a continuous line as shown in the drawing from the viewpoint of efficiency. However, a batch-type facility that performs a dipping process on the steel cord 5a in advance may be applied, and this point is limited. Not.

  Moreover, although it does not correspond to a dipping process, after tracking the winding of the steel cord 5a (spiral winding), a rubber paste can be applied to the surface using a brush or the like.

  FIG. 5 is an external perspective view showing a section of another embodiment of the rubber crawler according to the present invention (core rubberless type rubber crawler), and FIGS. 6 and 7 are rubber crawlers shown in FIG. It is the figure which showed typically the metal mold | die suitable for manufacture of (FIG. 6 is an external appearance perspective view, FIG. 7 is sectional drawing).

  In manufacturing the coreless rubber crawler, as shown in FIG. 7, guide protrusions 8 are disposed in the inner recesses h, and at least one reinforcing ply layer is provided between the core body 5 and the outer rubber 3d. 9 is installed.

  As the reinforcing ply layer 9, for example, a bias layer in which a steel cord is inclined or crossed at an angle of 38 to 60 °, more preferably at an angle of 52 ° with respect to the rotation direction of the rubber crawler can be used. A 90 ° ply layer can also be added.

  In order to manufacture a rubber crawler having a size of 450 × 43 × 110 KN (W × L × P) (K: tread pattern, N: guide shape), steel cord (strength: 1000 kg per piece, wire diameter: 3. 16 mm (outer diameter after coating: 4.35 mm, 88 shots) with adhesive rubber coating (thickness: 0.595 mm) and spiral winding, and dip treatment according to the present invention Comparison survey on the time required to complete molding, vulcanization, and demolding when using spiral winding (using a rubber sheet with a thickness of 1.3 mm as the adhesive rubber sheet) (The conditions in the other steps are the same).

  As a result, in the conventional method in which the spiral winding was performed with the steel cord covered with the adhesive rubber, it took about 14 minutes to manufacture one product, whereas the steel cord was dipped. In the case where the treatment is performed, it takes about 7 minutes, and according to the present invention, it was confirmed that there is no restriction on the line speed and the production efficiency is remarkably improved.

  A rubber crawler with stable quality can be manufactured efficiently.

It is the external appearance perspective view which showed embodiment of the rubber crawler according to this invention. It is an external appearance perspective view of an inner type. It is the figure which showed the cross section of the vulcanization die. It is the figure which showed the dipping processing point of the steel cord. It is the external appearance perspective view which showed other embodiment of the rubber crawler according to this invention. It is an external appearance perspective view of an inner type. It is the figure which showed the cross section of the vulcanization die.

Explanation of symbols

1 Drive Wheel 2 Rolling Wheel 3 Rubber Crawler 4 Core Bar (Reinforcing Material)
5 Core body 6 Flat surface 7 Mating hole 8 Guide protrusion 9 Reinforcement ply layer (reinforcement material)
U ₁ inner mold U ₂ outer mold

Claims (4)

A mold cavity is formed between a lower mold in which a plurality of segments are arranged and fixed and held in a circular shape, and an upper mold fitted to the lower mold, and an inner rubber, a reinforcing material, a core body, and Each of the outer rubber sheets is wound and molded, and then clamped. Then, in producing a rubber crawler by pressing, vulcanizing, and demolding,
The core was sandwiched between at least two layers of an adhesive rubber sheet wound around the outer surface of the inner rubber and the adhesive rubber sheet, and was wound in a spiral around the inner mold A method of manufacturing a rubber crawler, characterized by being formed of a steel cord.   The rubber crawler manufacturing method according to claim 1, wherein the steel cord is subjected to a dipping process using a rubber paste in a stage before being wound around the inner mold.   The rubber crawler manufacturing method according to claim 1, wherein the reinforcing material is a cored bar.   The rubber crawler manufacturing method according to claim 1, wherein the reinforcing material is a reinforcing ply layer.

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