JP4633438B2 - Mandrel-less elastic crawler and its manufacturing method - Google Patents

Description

  The present invention relates to a coreless elastic crawler used for various crawler type traveling devices and a method for manufacturing the same.

Crawler type traveling devices are widely used in transport vehicles, agricultural machines, and the like, and endless elastic crawlers are mounted on these crawler type traveling devices. The elastic crawler includes a crawler main body made of an elastic body, a drive protrusion protruding from the inner peripheral surface of the crawler main body, and a plurality of lugs provided on the outer peripheral surface of the crawler main body. Of these, the drive protrusion engages with the sprocket of the traveling device to transmit the drive force to the elastic crawler and has a function of preventing the wheel from coming off, as shown in FIG. 7 (a). In order to prevent the protrusions 30 from being worn, deformed, etc., a reinforcing core member 31 is embedded therein (see, for example, Patent Document 1).
JP-A-9-301229

However, in the elastic crawler of Patent Document 1, both end portions 31a of the reinforcing core member 31 are exposed on the side surfaces of the drive protrusions 30 in the crawler width direction, so that the vehicle-side rolling wheels are exposed by repeatedly rubbing against the side surfaces. When the rubber peels off from around the reinforcing core member 31 and grows, the reinforcing core member 31 falls off.
Further, in the other elastic crawler 40 shown in FIG. 7B, since the reinforcing core material 41 is brought into contact with the mold for positioning, a part 41a of the reinforcing core material 41 is located on the crawler circumferential side surface of the drive protrusion 42. Exposed. When the driving sprocket on the vehicle side repeatedly hits the side surface, like the elastic crawler, the rubber is peeled off from the exposed portion, and the reinforcing core member 41 falls off.
In view of the above-described problems of the prior art, an object of the present invention is to provide a method for manufacturing a cored bar-less elastic crawler in which a reinforcing core material is prevented from falling off.

In order to achieve the above object, the present invention takes the following technical means. That is, the unvulcanized rubber is vulcanized in the inner space of the mold, and the crawler body, the drive protrusions that are embedded on the inner peripheral surface of the crawler body and the reinforcing core material is embedded, and the outer peripheral surface of the crawler body. A method of manufacturing a cored bar-less elastic crawler for molding a lug to be provided, wherein a positioning member extending into the internal space is formed of an upper mold and a lower mold for molding the drive protrusion, The upper die is erected on the inner surface of the upper die, and the upper die is divided according to the shape of the drive protrusion, and is constituted by a plurality of divided dies that can move in a direction substantially perpendicular to the outer surface of the drive protrusion. The positioning member is erected on each of the inner surfaces of the plurality of split molds in a direction along the moving direction, and the front end of the positioning member is located on the front end side of the drive protrusion and the crawler circumferential side surface side. at least From the deviation or the other side is brought into contact with the reinforcing core, the unvulcanized rubber was vulcanized in a condition in which the reinforcing core material was determined positional relationship so as not to be exposed from the driving projection, after vulcanization, the divided The positioning member is removed by moving the mold in a direction substantially perpendicular to the outer surface of the driving projection with which the inner surface of the divided mold contacts .

According to the manufacturing method of the coreless elastic crawler described above, the position of the positioning member standing on the inner surface of the mold is brought into contact with the reinforcing core material, and the positional relationship is determined so that the reinforcing core material is not exposed from the drive protrusion. Since the unvulcanized rubber is vulcanized in such a state, the reinforced core material is completely covered with the rubber material of the drive protrusion after vulcanization molding. Accordingly, the reinforcing core material is not exposed on the crawler width direction side surface or the crawler circumferential side surface, so that the rubber is not peeled off even when the vehicle-side wheel or the drive sprocket repeatedly hits the drive protrusion. Thereby, dropping of the reinforcing core material can be prevented.
Further, if the positioning member is brought into contact with the crawler circumferential side surface side of the drive projection, the crawler circumferential position of the reinforcing core can be easily determined, and further, the positioning member can be brought into contact with the tip side. The reinforcing core material can be made more stable. In addition, regarding the shape of the positioning member, for example, a cylindrical shape (pin shape) or a plate shape extending in the crawler width direction can be used.

  In addition, the positional relationship between the drive protrusion and the reinforcing core can be determined by changing the length dimension, the number, and the arrangement of the positioning members, but the positioning member is the crawler circumferential side surface of the drive protrusion. It is preferable that the rubber thickness after vulcanization for covering the reinforcing core material is set to 1 mm or more. In this case, a rubber thickness of 1 mm or more can be secured on the crawler circumferential side surface of the drive protrusion, so that the reinforcing core material is not exposed at this portion, and the rubber is prevented from peeling off by the sprocket, and the reinforcing core material is prevented from falling off. Can be increased.

  In addition, if the positioning core is provided with a positioning hole that allows the distal end of the positioning member to be inserted and removed, and the positional relationship is determined by inserting the distal end of the positioning member into the positioning hole, the reinforcing core material is further stabilized. Vulcanization molding can be performed in the state.

  Further, the positioning member may be brought into contact with the reinforcing core member from the side corresponding to the portion of the driving protrusion that does not contact the driving sprocket on the vehicle side. In this way, in the elastic crawler after vulcanization molding, the molding hole of the positioning member does not come in the portion of the drive projection where the drive sprocket on the vehicle side contacts. For this reason, when a drive sprocket engages with a drive protrusion, it does not contact the molding hole, and cracks starting from the molding hole and growth thereof can be prevented. Thereby, dropping of the reinforcing core material can be prevented.

The present invention also includes a crawler body made of an endless belt-like rubber-like elastic body, and a plurality of drive protrusions integrally projected from the inner peripheral surface of the crawler body in a state of being arranged at regular intervals in the crawler circumferential direction. , A lug group formed in a predetermined lug pattern on the outer peripheral surface of the crawler body, and a tensile body embedded in the crawler body along the circumferential direction of the crawler. to the metal core-less elastic crawler reinforcing core is embedded, the reinforcing core the respective drive projections when vulcanized with the crawler body to be positioned inside of the drive projection, said drive projection constituting the mold upper mold of for molding the, the multiple split each inner surface movable in a direction substantially perpendicular to the outer surface of the to be divided the drive projections corresponding to the shape of the driving projection While being erected in a direction along the moving direction, out of the distal end side and the crawler circumferential direction side surface side of the drive projection, the molded hole of the positioning member abuts the driving projection from at least either one side, in the driving projection It is characterized in that the drive sprocket on the vehicle side is arranged at a portion where it does not contact.

  According to the above-described coreless elastic crawler of the present invention, since the molding hole of the positioning member formed on the drive protrusion is disposed at a portion where the drive sprocket on the vehicle side does not contact with the drive protrusion, the drive sprocket is driven. When engaged with the protrusion, the molded hole is not contacted, cracks starting from the molded hole and its growth can be prevented, and the reinforcing core material can be prevented from falling off.

  As described above, according to the present invention, since the unvulcanized rubber is vulcanized in a state where the positional relationship is determined such that the reinforcing core material is not exposed from the drive protrusion, the reinforcing core material is completely covered with the rubber material. Can be prevented from falling off.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a cross-sectional view in the crawler circumferential direction according to an embodiment when the coreless elastic crawler 1 is vulcanized using a mold, and FIG. 2 is a crawler width of the molded coreless elastic crawler 1 FIG. As shown in FIG. 2, the coreless elastic crawler 1 (hereinafter simply referred to as an elastic crawler) is configured as a coreless without a cored bar, and includes a plurality of cores at regular intervals in the crawler circumferential direction. The crawler main body 3 with the driving protrusions 2 provided thereon, the lug group 4 formed in a predetermined lug pattern on the outer peripheral surface 3a of the crawler main body 3, and the crawler main body 3 embedded in the circumferential direction. A tensile core 5 is provided, and a reinforcing core member 6 is embedded in the drive projection 2.

  Among these, the crawler main body 3 is formed in an endless belt shape having a substantially constant thickness by a rubber elastic body, and the crawler main body 3 has an inner peripheral surface 3b at a central portion in the crawler width direction (left-right direction in FIG. 2). The driving protrusion 2 made of a rubber elastic body made of the same material as the crawler body 3 is provided so as to protrude over the entire circumference of the crawler body 3. The elastic crawler 1 is a crawler traveling device (not shown) mainly composed of drive sprockets and idlers provided before and after the airframe, and a plurality of wheels arranged between the drive sprockets and idlers. It is used by being wound around the outer periphery. In the drive sprocket, a pair of rotationally driven disks are arranged opposite to each other in the left-right direction, and left and right drive pins 50 (indicated by phantom lines in FIG. 1) are arranged in the circumferential direction on the outer peripheral side between the disks. The elastic crawler 1 is driven along the rotational direction when the drive pin 50 is engaged with the drive protrusion 2.

  The driving projection 2 has a function of preventing the falling of the rolling wheels that roll on the inner peripheral surface 3b of the crawler body 3 in addition to transmitting the driving force to the elastic crawler 1 as described above. The tensile body 5 is configured by juxtaposing steel cords and the like extending along the crawler circumferential direction. Further, the plurality of lugs 4 formed on the outer peripheral surface 3a of the crawler body 3 are formed in a single letter shape extending in the crawler width direction. Further, as shown in FIGS. 1 and 2, the reinforcing core member 6 embedded in the drive protrusion 2 has a cylindrical shape, and is arranged with the crawler width direction as the longitudinal direction. The reinforcing core member 6 is provided to increase the rigidity of the drive protrusion 2 and is vulcanized and bonded inside the drive protrusion 2 to increase the adhesive force with the rubber material.

  As a result, the drive protrusion 2 is less likely to fall in the crawler width direction, and the function of preventing the wheel from coming off is improved. The reinforcing core member 6 is completely embedded in the driving projection 2 by being disposed at a predetermined position when the elastic crawler 1 is vulcanized, and both end surfaces 6a and side surfaces 6b thereof are exposed on the outer surface of the driving projection 2. Not done. In particular, the thickness of the rubber material covering the reinforcing core member 6 on the crawler circumferential side surface (hereinafter simply referred to as the circumferential side surface) 2a of the drive protrusion 2 is 1 mm or more.

  The manufacturing method according to the present embodiment is a pre-process for vulcanization molding of rubber materials constituting the inner peripheral surface side such as the driving projection 2 and the outer peripheral surface side such as the lug 4 on the upper and lower sides of the end and linear tensile body 5. The end portion of the tensile body 5 is overlapped, and the post-process includes filling the unvulcanized rubber around the overlapped portion, pressurizing and heating, and connecting them in an endless manner. Among these, the pre-process is to vulcanize the unvulcanized rubber in the inner space N of the mold, and to mold the drive protrusion 2 and the plurality of lugs 4 in which the crawler body 3 and the reinforcing core material 6 are embedded. FIG. 1 shows a state in which the upper die 7 is removed after the vulcanization molding is completed, and the drive projection 2 is vulcanized and molded with two upper dies 7A and 7B as shown in FIG. A tensile body 5, a reinforcing core member 6 and unvulcanized rubber are arranged between the upper molds 7A and 7B and a lower mold (not shown), and the upper and lower molds are closed. An elastic crawler 1 is manufactured by vulcanizing vulcanized rubber. Note that these upper and lower molds are temperature-controlled at a predetermined temperature by a heater, a thermocouple or the like.

  The two upper molds 7A and 7B can move obliquely upward in the crawler circumferential direction with respect to the drive protrusion 2, and positioning pins 9 (positioning members) are provided upright on the inner surface 8 thereof. The positioning pins 9 are provided to support the reinforcing core member 6 at a predetermined position in the internal space N, and the two positioning pins 9 arranged at a predetermined interval in the crawler width direction are driven. The upper molds 7 </ b> A and 7 </ b> B are vertically erected vertically so as to correspond to the front and rear circumferential side surfaces 2 a of the protrusion 2. The positioning pin 9 has a cylindrical shape having a required diameter and a length dimension of 1 mm or more.

  The inner surface 8 of the upper mold 7 is composed of a top end flat surface 8a, a first inclined surface 8b, and a second inclined surface 8c from the top corresponding to the shape of the peripheral side surface of the drive protrusion 2, and of these, the first inclined surface 8b A positioning pin 9 is attached in the vicinity of the lower end. Therefore, the positioning pin 9 comes into contact with the reinforcing core member from the side corresponding to the portion of the driving protrusion 2 where the vehicle-side driving sprocket does not contact. If it does in this way, in the elastic crawler 1 after vulcanization molding, as shown in FIG. 1, the molding hole 10 of the positioning pin 9 does not exist in the part which the drive pin 50 (drive sprocket) contacts. For this reason, when the drive pin 50 is engaged with the drive protrusion 2, it does not come into contact with the molding hole 10, and a crack starting from the molding hole 10 and its growth can be prevented. Then, four positioning pins 9 are arranged with respect to the drive protrusion 2, and the position of the reinforcing core member 6 is determined by each positioning pin 9 during vulcanization molding.

  In the stage before vulcanization, the distal ends 9a of the two positioning pins 9 on the one peripheral side surface 2a side of the drive protrusion 2 and the distal ends 9a of the two positioning pins 9 on the other peripheral side surface 2a side of the reinforcing core member 6 are respectively connected. It contacts the side surface 6b from two diagonal directions on the crawler inner peripheral side. Accordingly, the reinforcing core member 6 is positioned by stopping the positional deviation in the crawler circumferential direction and the positional deviation in the crawler thickness direction, and the mutual positional relationship between the reinforcing core member 6 and the drive protrusion 2 is determined. It becomes. The four positioning pins 9 are not exposed from the peripheral side surface 2a of the drive protrusion 2 due to the relationship between the contact angle to the reinforcing core member 6, the arrangement thereof, and the length dimension, and the peripheral side surface of the same. The rubber thickness t after vulcanization covering the reinforcing core member 6 in 2a is configured so as to be 1 mm or more. In addition, the positional relationship between the drive protrusion 2 and the reinforcing core member 6 can be determined by changing the length dimension, the number of positioning pins 9 and the configuration depending on the arrangement. Thus, a rubber thickness of 1 mm or more is secured on the peripheral side surface 2a of the drive protrusion 2. Further, since the positioning pins 9 are inserted into the drive protrusions 2 after vulcanization, the molding holes 10 from which the positioning pins 9 have been removed are provided in total on the front and rear peripheral side surfaces 2a of the drive protrusions 2 where the upper mold 7 is raised. One is formed.

  The forming procedure of the elastic crawler 1 will be described. First, lug rubber on the outer peripheral surface side, which is a component of the elastic crawler 1, inner peripheral rubber on the inner peripheral surface side, reinforcing core member 6, and driving protrusion rubber constituting the driving protrusion. The tensile body 5 and the like are placed on the inner surface of the lower mold (not shown). Then, the molding material is confined by the lower mold and the upper molds 7A and 7B, and the upper molds 7A and 7B are lowered to a predetermined position. In this state, the molding material is pressurized and heated to a predetermined temperature to vulcanize the unvulcanized rubber. After the vulcanization is completed, the upper molds 7A and 7B are lifted and separated so as to be separated obliquely upward in the crawler circumferential direction. At that time, the positioning pins 9 are removed from the driving projections 2 together with the upper molds 7A and 7B. Thereafter, the vulcanized elastic crawler 1 is taken out.

  According to the manufacturing method of the coreless elastic crawler 1, the tip 9 a of the positioning pin 9 erected on the inner surface 8 of the mold 7 is brought into contact with the reinforcing core member 6, and the reinforcing core member 6 is moved from the drive protrusion 2. Since the unvulcanized rubber is vulcanized in a state where the positional relationship is not exposed, the reinforcing core member 6 is completely covered with the rubber material of the drive protrusion 2 after vulcanization molding. Accordingly, since the reinforcing core member 6 is not exposed to the crawler width direction side surface or the crawler circumferential direction side surface, the rubber does not peel off even when the vehicle-side wheel and the drive sprocket repeatedly hit the drive protrusion 2. . Thereby, dropping of the reinforcing core member 6 can be prevented. Moreover, the elastic crawler 1 can be molded in a state where the position of the reinforcing core member 6 is securely fixed, and the reinforcing core member 6 is not displaced.

  Further, since the rubber thickness t of 1 mm or more is secured on the peripheral side surface 2a of the driving protrusion 2, the reinforcing core member 6 is not exposed at this portion, and the peeling of the rubber by the driving sprocket is effectively prevented and reinforced. The drop prevention effect of the core material 6 can be enhanced. In addition, according to the coreless elastic crawler 1, the molding hole 10 of the positioning pin 9 formed in the driving projection 2 is disposed in a portion where the driving sprocket on the vehicle side in the driving projection 2 does not contact. When 50 (driving sprocket) engages with the driving protrusion 2, it does not come into contact with the forming hole 10, and cracks starting from the forming hole 10 and growth thereof can be prevented. Thereby, dropping of the reinforcing core material can be prevented.

  FIG. 3 is an explanatory view showing a second embodiment of the method for manufacturing the coreless elastic crawler 1 according to the present invention. The present embodiment is different from the first embodiment in that the positioning pin 11 is configured to be able to contact the reinforcing core member 6 from three directions. In addition, the structure of the part which is common in 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits the description (Hereinafter, 3rd-5th embodiment is also the same.). Two positioning pins 11 are erected on the inner surface of the upper mold on the front and rear circumferential side surfaces 2a side and the front end 2b side of the driving projection 2 with a required interval, and these six positioning pins 11 are respectively used as reinforcing cores. The reinforcing core member 6 is positioned by contacting the side surface 6 b of the member 6. Accordingly, as shown in FIGS. 1 (a) and 1 (b), the drive projection 2 after vulcanization molding is formed with two molding holes 12 at the front end 2b and two molding holes 12 at each of the front and rear circumferential surfaces 2a. Thereby, the reinforcement core material 6 can be arrange | positioned in an internal space in the state stabilized before the vulcanization | cure.

Figure 4 is an explanatory view showing a manufacturing how the metal core-less elastic crawler 1 according to a reference example. This reference example is different from the first embodiment in that the positioning pin 13 is configured to contact the reinforcing core member 6 from the crawler thickness direction (the vertical direction in FIG. 4B). The erection direction of the positioning pin 13 provided on the inner surface 18a of the upper mold 18 is not perpendicular to the inner surface 18a but the crawler thickness direction. Accordingly, the upper mold 18 is one that moves up and down in the crawler thickness direction with respect to the drive protrusion 2.

Figure 5 is an explanatory view showing a manufacturing how the metal core-less elastic crawler 1 according to a reference example. The difference between this reference example and the above reference example is that the positioning member 14 erected on the inner surface 19a of the upper mold 19 has a plate shape extending in the crawler width direction. One positioning member 14 is provided for each of the front and rear circumferential side surfaces 2a of the drive projection 2, and as shown in FIG. 5A, the positioning member 14 is provided on each of the front and rear circumferential side surfaces 2a of the vulcanized drive projection 2. A forming hole 15 extending in the crawler width direction is formed. If such a positioning member 14 is used, the manufacturing cost of the upper mold can be reduced, and the durability of the positioning member 14 is improved.

In each of the above-described embodiments, the reinforcing core member 6 is positioned by the tip of the positioning member (pin) coming into contact with the cylindrical reinforcing core member, but the tip portion is in point contact with the side surface 6 b of the reinforcing core member 6. Therefore, the displacement of the reinforcing core material 6 may occur due to the fluctuation of the molding material. In this case, as in the third embodiment of the method for manufacturing the coreless elastic crawler 1 according to the present invention shown in FIG. 6, the positioning hole 17 that allows the distal end 16 a of the positioning member 16 to be inserted and removed is formed in the reinforcing core member 6. The positional relationship may be determined by inserting the tip 16a into the positioning hole 17.

  The positioning member 16 of the present embodiment has a plate shape extending in the crawler width direction, and is erected on the front end 2 b side of the drive protrusion 2 on the inner surface 20 a of the upper mold 20. A positioning hole 17 extending in the crawler width direction in which the tip 16 a of the positioning member 16 can be inserted and removed is formed in the side surface 6 b of the reinforcing core member 6. Thereby, vulcanization molding can be performed in a state where the reinforcing core member 6 is more stabilized. The present invention is not limited to the above embodiments. For example, the number, shape, and arrangement of the positioning members may be changed, and the reinforcing core member 6 having various shapes such as a cylindrical shape may be employed, and various resins and metals may be employed as the constituent material of the reinforcing core member 6. it can.

It is explanatory drawing which represented the manufacturing method which concerns on this invention in the crawler circumferential cross section. It is a crawler width direction sectional view of a vulcanized elastic crawler. (A) is explanatory drawing showing the manufacturing method which concerns on 2nd Embodiment in the crawler circumferential cross section, (b) is the crawler width direction sectional drawing of the drive protrusion. (A) is the crawler inner peripheral side top view of the drive protrusion of the elastic crawler shape | molded with the manufacturing method which concerns on a reference example , (b) is explanatory drawing which represented the same manufacturing method in the AA sectional view. (A) is the crawler inner peripheral side top view of the drive protrusion of the elastic crawler shape | molded with the manufacturing method which concerns on a reference example , (b) is explanatory drawing which represented the same manufacturing method in the AA sectional view. (A) is the crawler inner peripheral side top view of the drive protrusion of the elastic crawler shape | molded with the manufacturing method which concerns on 3rd Embodiment, (b) is explanatory drawing showing the same manufacturing method in the AA sectional view. is there. (A) is a perspective view of the drive protrusion of the elastic crawler of a prior art, (b) is a circumferential direction sectional view of the other conventional elastic crawler.

Explanation of symbols

2 Driving Protrusion 2a Circumferential Side 6 Reinforcement Core 7 Upper Mold 9, 11, 13, Positioning Pins 14, 16 Positioning Member

Claims (6)

Unvulcanized rubber is vulcanized in the inner space of the mold, and is provided on the crawler main body, the drive protrusion in which the reinforcing core material is embedded and the outer peripheral surface of the crawler main body. A manufacturing method of a coreless elastic crawler that molds a lug,
A positioning member extending into the inner space is erected on the inner surface of the upper mold among the upper mold and the lower mold for molding the drive protrusion,
The upper mold is constituted by a plurality of divided molds that are divided in accordance with the shape of the drive protrusion and are movable in a direction substantially perpendicular to the outer surface of the drive protrusion,
The positioning member is erected in a direction along the moving direction on each of the inner surfaces of the plurality of split molds,
The front end of the positioning member is brought into contact with the reinforcing core member from at least one of the front end side and the crawler circumferential side surface side of the driving protrusion, and the reinforcing core member is not exposed from the driving protrusion. The unvulcanized rubber is vulcanized in a state where the positional relationship is determined, and after vulcanization , the split mold is moved in a direction substantially perpendicular to the outer surface of the drive projection with which the inner face of the split mold contacts. A method of manufacturing a coreless elastic crawler, characterized by removing the core.   2. The mandrel-less elastic crawler according to claim 1, wherein the positioning member is configured such that a rubber thickness after vulcanization covering the reinforcing core member on a crawler circumferential side surface of the driving protrusion is 1 mm or more. Method.   The method of manufacturing a cored bar-less elastic crawler according to claim 1, wherein the positioning member has a cylindrical shape or a plate shape extending in the crawler width direction.   A positioning hole for allowing the distal end of the positioning member to be inserted and removed is provided in the reinforcing core member, and the positional relationship is determined by inserting the distal end of the positioning member into the positioning hole. The manufacturing method of the core metal-less elastic crawler of description.   The mandrel-less elastic crawler according to any one of claims 1 to 4, wherein the positioning member is in contact with the reinforcing core member from a side corresponding to a portion of the drive projection that does not contact a drive sprocket on the vehicle side. Method. A crawler body made of an endless belt-like rubber-like elastic body, a plurality of drive protrusions integrally projected from the inner peripheral surface of the crawler body in a state of being arranged at regular intervals in the crawler circumferential direction, and an outer periphery of the crawler body A lug group formed in a predetermined lug pattern on the surface, and a tensile body embedded in the crawler body along the circumferential direction of the crawler, and a reinforcing core material embedded in each drive projection In the coreless elastic crawler,
To position the reinforcing core material within the said drive projection of the respective drive projections when vulcanized with the crawler body, constituting the mold upper mold of for molding the driving projection, said drive A plurality of split molds that are divided in accordance with the shape of the protrusion and are movable in a direction substantially perpendicular to the outer surface of the drive protrusion, are erected on the inner surface of each of the divided molds in a direction along the movement direction, The molding hole of the positioning member that comes into contact with the drive projection from at least one of the front end side and the crawler circumferential side surface side is arranged in a portion where the drive sprocket on the vehicle side of the drive projection does not contact. A coreless elastic crawler.

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