KR101720207B1

KR101720207B1 - Tractor for loop using a foaming rotational molding and method for manufacturing the same

Info

Publication number: KR101720207B1
Application number: KR1020150147488A
Authority: KR
Inventors: 김학선
Original assignee: 유한회사 가야미
Priority date: 2015-10-22
Filing date: 2015-10-22
Publication date: 2017-03-27

Abstract

Disclosed are a tractor loop using foaming rotational molding and a manufacturing method thereof. The method includes: a mold installation step (S10) of installing an insert in a mold (200); a primary material injecting step (S20) of injecting a polyethylene (PE) material for exterior formation into the mold (200); a mold rotating and heating step (S30) of heating the mold (200), which has gone through the primary material injecting step (S20), at 200-280C while rotating the mold for 20-30 minutes; a primary exterior formation and cooling step (S40) of forming an exterior frame by melting and forming the polyethylene material in the rotated and heated mold; a secondary material injecting step (S50) of depositing the polyethylene material, melted through the primary exterior formation and cooling step, on the wall surface of the mold and then injecting a foaming material for secondary foaming formation; a gas foaming formation step (S60) of forming an inner foaming insulating layer by foaming the foaming material by injecting gas through a gas inlet; a cooling step (S70) of cooling the mold completed with the gas foaming formation; and a separation step (S80) of separating a formed object, formed into a tractor loop through the cooling step (S70), from the mold. The sandwich type tractor loop, having a strong and light structure, is manufactured through the foaming rotational mold able to be partially open or closed to sequentially perform the primary exterior formation and the secondary foaming formation. The tractor loop is capable of showing excellent insulating and soundproof effects.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop for a tractor,

The present invention relates to a loop for a tractor by foam rotary molding and a method of manufacturing the same, and more particularly, to a method for manufacturing a loop for a tractor by rotationally forming a foam rotary molding die capable of opening and closing in order to sequentially perform primary- The present invention relates to a loop for a tractor and a method of manufacturing the same by a foam rotary molding which forms a uniform thickness and shape of a high strength and lightweight structure.

Tractor penetration has been increasing due to the mechanization of agriculture. However, due to the environmental problems that are emerging in recent years and due to the enforcement of environmental regulations, tractors for agricultural machines are also required to lighten frames and bodies to solve environmental regulation problems and increase fuel efficiency .

The weight reduction of the equipment is one of the ways to overcome the environmental regulation problem as well as the increase of the energy efficiency without a big change of the equipment with the development of the soot reduction exhaust engine as a solution to solve the environmental problem.

Therefore, in order to minimize the weight of the conventional tractor, a lightweight FRP as shown in Fig. 1 is applied to the loop of the tractor.

FIG. 1 is a rear view showing a structure of a FRP loop for a tractor according to the related art, and FIG. 2 is an enlarged view of a portion broken by a shock, which is a problem of a conventional FRP loop for a tractor.

The conventional FRP loop is mainly damaged by vibrations and impacts caused by irregular road surfaces due to the characteristics of a tractor traveling on a farm road. As can be seen from FIG. 2, cracks easily occur at the corners, It is becoming a burden on farmers.

In addition, due to the vibration generated when the tractor is operated, the noise generated in the conventional thin tractor loop makes the working environment poor. Particularly, when the part is broken, the vibration is caused by the collision of the damaged parts, And it became a factor to hinder the work efficiency.

In addition, because of the nature of farm machinery that must be operated for a long period of time under the hot sun, it is very important to insulate the solar radiation to block the heat. Conventional FRP has insufficient heat insulation effect and the heat is transferred to the driver's seat. There is a problem in that it is insufficient to protect workers.

In addition, FRP is not recyclable and has a very harsh returning characteristic that takes more than 100 years to decompose from nature in the case of disposal, which causes pollution of the natural environment.

1. Korean Patent Laid-Open No. 10-2003-0088670 (November 20, 2003)

It is an object of the present invention to overcome the above problems and to provide a sandwich structure using polyethylene (PE) material having a long life and excellent hygiene due to no corrosion at all, and a loop for a tractor by foam rotary molding which realizes high strength and light weight, Method.

It is another object of the present invention to provide a tractor loom for foam rotary molding, which has a multi-layered structure made of plastic so as to have a heat insulation effect, a noise generation prevention function and a noise intake prevention function, And a manufacturing method thereof.

Another object of the present invention is to provide a loop for a tractor by foam rotary molding which can easily manufacture a tractor loop which is a large-sized molded product having a complicated shape by foam rotary molding, and a manufacturing method thereof.

According to an aspect of the present invention, there is provided a tractor loop formed by foam rotary molding, including: an outer skeleton portion of a polyethylene (PE) material; An inner heat-insulating foamed layer of foamed plastic foam deposited inside the outer skeleton portion; And a plurality of engaging members integrally fused with the outer skeleton portion and the inner heat-insulating foam layer.

A tractor loop according to an embodiment of the present invention includes an outer skeleton portion formed by integrally molding an outer surface portion and an inner surface portion and formed with a hollow portion between an outer surface portion and an inner surface portion; Wherein the hollow portion is filled with a foamed plastic foam; And a plurality of coupling members integrally fused to the outer skeleton part and the inner heat-insulating foam layer.

In the present invention, the polyethylene (PE) material constituting the external skeleton part is mixed with 0.5 to 1.5% of an antioxidant and 0.5 to 1.5% of an ultraviolet screening agent to enhance durability.

A method of manufacturing a tractor loop by foam rotary molding according to an embodiment of the present invention includes: a mold mounting step (S10) including a step of inserting an insert into a mold; A first raw material injection step (S20) of injecting a polyethylene (PE) material for external molding into the inside of the mold; A mold rotating and heating step (S30) for rotating the mold in which the primary raw material feeding step (S20) is performed at 200 to 280 DEG C for 20 to 30 minutes; (S40) a primary appearance forming and cooling step of forming an external skeleton by melting and forming a polyethylene material in a rotating and heated mold; A secondary raw material injection step (S50) in which the melted polyethylene material is vapor-deposited on the wall surface of the mold through the primary external shape forming and cooling step (S40), and then the secondary foamed foaming material is charged; A gas foaming molding step (S60) of foaming the foamed material by gas injection through a gas inlet to form an inner foamed insulation layer; A cooling step (S70) of cooling the mold in which the gas foaming is completed; And a demolding step (S80) of separating the molded product formed in the form of a tractor loop from the inside of the mold through the cooling step (S70) from the mold.

In the present invention, the secondary raw material charging step (S50) is characterized in that the foaming material is charged through the foaming material inlet provided on one side of the mold, and the foaming material is EPP (Expanded Polypropylene) .

In the present invention, the gas foaming molding step (S60) may include a step of forming a foamed insulation material for secondary foaming on the polyethylene material deposited on the inner surface of the mold to form an internal foamed insulation layer, .

In the present invention, the heating method of the mold in the heating step (S30) is a heating medium oil circulation system.

The present invention has the effect of improving the working environment of farmers working the tractor for a long time under intense sunlight because the plastic and the foam have a multi-layered structure, excellent heat insulating function, and excellent noise and vibration blocking effect.

Further, according to the present invention, it is possible to produce parts having high strength and light weight by applying the foam of plastic and sandwich structure, and it is possible to constitute a large-sized component having a complicated shape as one body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a rear view showing a structure of a conventional FRP loop for a tractor. FIG.
Fig. 2 is an enlarged view of a portion of the FRP for tractor loop of Fig. 1 broken by impact. Fig.
3 is a perspective view of a tractor loop in accordance with an embodiment of the present invention.
4 is a cross-sectional view taken along line A-A 'of FIG. 3;
5 is a sectional view of a tractor loop according to another embodiment of the present invention;
6 is a schematic configuration view of a rotary die according to an embodiment of the present invention;
7 is an enlarged cross-sectional view of a rotary part according to an embodiment of the present invention;
8 is a block diagram of a manufacturing process according to an embodiment of the present invention.

It is to be understood that the scope of the present invention is not limited to the technical spirit and the construction and operation of the present invention, Or is not limited by the description with reference to the drawings.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 3 is a perspective view of a tractor loop according to an embodiment of the present invention, and FIG. 4 is a sectional view taken along line A-A 'of FIG.

The tractor loop 100 according to the embodiment of the present invention is composed of an outer skeleton part 110, an inner heat-insulating foam layer 120, and a plurality of engaging members 130.

The outer skeleton part 110 forms an outer shape of the tractor loop 100 according to an embodiment of the present invention and is formed to have an appropriate thickness by a polyethylene material.

The low density polyethylene (LDPE), the high density polyethylene (HDPE), and the linear low density polyethylene (LLDPE) may be used as a kind of polyethylene (PE) for producing a tractor loop according to an embodiment of the present invention.

In order to enhance durability, the exterior skeleton part 110 is exposed to intense sunlight. To improve the durability of the exterior skeleton part 110, 0.5 to 1.5% of an antioxidant is added to polyethylene (PE) 0.5 to 1.5% of a blocking agent is added to the mixture to further enhance its durability.

A plurality of troughs 113 are formed in the front and rear direction on the surface of the outer surface 111 of the skeleton part 110 so that the rainwater collects on the rainy surface and flows downward in the rain direction.

That is, when the tractor loop 100 is installed, it is installed to be inclined rearward so that rainwater flows along the troughs 113 and flows down to the rear side, thereby obscuring the view of the operator.

The inner heat-insulating foam layer 120 is deposited on the inside of the skeleton part 110 to form an integral body.

The inner heat-insulating foam layer 120 is made of foamed plastic foam to have an appropriate thickness to maximize the heat insulation effect.

Therefore, even if you work under the sun for a long time, the worker is protected by preventing the heat of sunlight from being transmitted to the lower part.

The joining member 130 is inserted into the mold 200 during molding according to the present invention and integrally fused to the outer skeleton part 110 and the inner heat-insulating foam layer 120 and is provided at a plurality of corners.

The coupling member 130 may be formed as various parts that can be easily coupled to a column or a wall surface provided around the driver's seat of the tractor.

FIG. 5 is a cross-sectional view of a tractor loop 100 according to another embodiment of the present invention, in which the shape of the external skeleton portion 110 is formed to be double.

That is, the outer skeleton part 110 is a rotational molded product of polyethylene, and the outer surface part 111 and the inner surface part 112 are integrally formed and the hollow part 115 is formed therebetween.

The hollow portion 115 is filled with a foamed plastic foam to form an inner heat-insulating foam layer 120. The hollow portion 115 is divided into a plurality of A coupling member 130 is provided.

In order to easily mold the outer skeleton 110 constituting the skeleton, the tractor loop 100 having the above-described structure has a complicated structure and a very large size, .

6 is a schematic configuration diagram of a rotary die according to an embodiment of the present invention.

As described above, the tractor loop 100 has a complicated structure, which is not uniform in shape, but is a molded article having a very large size. Therefore, the tractor loop 100 is structurally inadequate for molding by a stationary mold.

That is, in order to uniformly form the outer skeleton portion 110 when the outer skeleton portion 110 and the inner heat-insulating foamed layer 120 are integrally formed, the polyethylene resin is uniformly distributed on the inner wall surface of the metal mold, It should be deposited in one thickness.

Accordingly, after the polyethylene material is injected into the mold, the mold is rotated while being heated to a temperature higher than the melting temperature, and is uniformly diffused and deposited on the inner wall surface of the mold, followed by cooling and solidification to form the outer skeleton portion 110.

The rotary molding method applied to the production of the tractor loops of the present invention has large molding, differential molding, compounding, surface treatment, insert molding, hollow body double wall molding, graphic & logo molding, free coloring and various formability .

In other words, it is possible to mold a large molding that can commercialize a large injection product with an inexpensive mold cost, to mold a mold that can be molded integrally with a complex shape, and to perform a multi-purpose composite product molding It is possible.

In addition, it is possible to increase the value of the product by variously treating the surface of the mold surface, insert molding can be easily performed by simply attaching the metal insert to the necessary part, and the urethane foam can be introduced into the double- It is possible to make hollow body double wall molding to increase coldness and strength.

In addition, it is possible to form graphic & logo which design graphic design on the surface of the product. Also it is possible to easily change the color even in the production of small lot, free coloring to freely choose the color and it is possible to use polyethylene (PE), crosslinked polyethylene ), Thermoplastic engineering plastics such as polypropylene (PP), polycarbonate (PC), and nylon fluorine resin.

FIG. 6 shows an embodiment of the present invention in which four molds are formed so as to form a single set, and a plurality of moldings can be obtained at the same time. However, two molds may be paired if necessary.

The inner mold 210 and the outer mold 220 are combined to form a single molded product by opening and closing the inner and outer molds 210 and 220, respectively.

FIG. 7 is an enlarged cross-sectional view of a rotary mold according to an embodiment of the present invention, in which a foam material inlet 240 is provided on one side of a mold 200 for introducing a foam material, A gas injection port 230 is provided.

The polyethylene material is melted and molded inside the mold 200 when the mold 200 is rotated and heated after putting a polyethylene material for external appearance molding into the mold 200. The outer skeleton 110 ).

After the molding of the primary skeleton part 110 is completed through the primary exterior molding and cooling steps, the foaming material for the secondary foaming foam is put into the mold, and the mold 200 can be partly opened and closed A foam material inlet 240 is provided.

The foam material inlet 240 can be opened / closed at will by the opening / closing cap 241.

Therefore, it is possible to sequentially perform the first external appearance molding operation and the second foam molding operation by allowing the entire mold to be opened and closed partially without opening.

Further, a gas inlet 230 for injecting a high-pressure gas into the foam material for secondary foaming foam injected into the mold to perform the foaming action is provided.

And the foaming material is foamed by gas injection through the gas inlet 230 to form the inner foamed insulation layer 120.

The foamed material is mainly used as a cushioning material, a thermal insulation material, a shock-absorbing material or the like due to its easy shape and light weight, absorbs impact, and has high heat insulation performance. The foamed material is injected into a mold having a molding space, .

EPP (Expanded Polypropylene) can be used as the foamed resin. The EPP is foamed with a physical gas pressure without using a chemical foaming agent.

Therefore, the molding space of the foamed resin is provided by a plurality of dies that are relatively moved so that the foamed resin is supplied to form a molded body.

In addition, it is also possible to provide a heating means for heating the mold so as to melt the polyethylene, and a cooling means for cooling the mold to cool the mold so as to maintain the shape, Means are provided.

In the present invention, the heating medium is circulated through the inner circulation duct of the mold so that the temperature can be easily controlled, so that the mold is heated.

In addition, the cooling means allows cooling to be achieved through a cooling water line formed to circulate conventional cooling water.

The mold temperature at the time of melt depositing the resin on the inner surface of the mold should be higher than the melting temperature of the ethylenic copolymer usually by 80 to 170 DEG C, and therefore the preferable mold temperature is about 200 to 280 DEG C.

The adhesion and the melting time are not particularly limited and can be suitably selected according to the size of the molded body and the thickness of the molded body. In the present invention, the heating is performed for 20 to 30 minutes.

8 is a block diagram of the manufacturing process according to the embodiment of the present invention.

The method of manufacturing a tractor loop according to an embodiment of the present invention includes a mold setting step S10, a first raw material applying step S20, a mold rotation / heating step S30, a first outer shaping / cooling step (S40), a secondary raw material injection step (S50), a gas foaming molding step (S60), a cooling step (S70), and a demolding step (S80).

The mold mounting step S10 includes a step of preparing inserts for forming the engaging member 130 in the mold 200 in a state where the mold is open.

The engaging member 130 inserted into the mold 200 has a nut or a bolt, which facilitates the attachment to the tractor.

In the first raw material input step S20, an amount suitable for forming the external skeleton part 110 is accurately metered by injecting a polyethylene (PE) material for external appearance molding into the mold 200 .

In the mold rotation and heating step S30, after the polyethylene material is charged through the first raw material applying step S20, the mold 200 is rotated for 20 to 30 minutes while being heated to 200 to 280 ° C .

In the heating step (S30), it is preferable to apply a heating medium oil circulation method in which a relatively precise temperature can be controlled, but the heating method of the mold can be variously adopted.

The polyethylene material is melted and deposited on the inner wall surface of the mold 200 through the mold rotation and heating step S30 so as to be deposited while rotating the mold 200 to form a uniform thickness .

A first step of molding the outer skeleton part 110 by melting and molding the polyethylene material inside the mold 200 rotated and heated through the mold rotating and heating step S30, So that the shape is maintained. The primary appearance forming and cooling step S40 for forming the external skeleton part 110 may include forming a plurality of troughs 113 in the front and back direction on the surface of the external surface part 111 of the external skeleton part 110 .

The step S50 of injecting the secondary raw material is a step of injecting a foaming material for secondary foaming after the melted polyethylene material is vapor-deposited on the wall surface of the mold through the first external appearance forming and cooling step (S40).

In the second raw material input step S50, the mold 200 is partially opened to partially open the second raw material. In the present embodiment, the plug 200 of the foam material inlet 240 provided at one side of the mold 200 (241) is opened, and an appropriate amount of foam material for a secondary foamable mold is introduced.

In the secondary raw material input step S50, the foamed material is introduced through the foamed material inlet 240 provided on one side of the mold 200, and the foamed material is made of general-purpose plastic [EPP (Expanded Polypropylene)] do.

After the foam material for secondary foamable foam is introduced, the cap 241 is closed to close the mold 200, and the process proceeds to the foaming process.

The gas foaming molding step S60 is a step of foaming the foamed material by gas injection through the gas inlet 230 to form the inner foamed insulation layer 120 such that the inner foamed insulation layer 120 covers the outer skeleton part 110 So that the gas foaming molding is performed while being integrally welded to the inner surface.

In the gas foaming step S60, a foaming material for a secondary foaming foam is deposited on the polyethylene material deposited on the inner surface of the mold 200 to form an internal foam insulation layer 120, and the rotation mold 200 is stopped Lt; / RTI >

The cooling step S70 is a step of cooling the metal mold 200 having completed the gas foaming process through the gas foaming molding step S60 so that the final shape of the molded product is finally obtained.

The demolding step S80 is a step of removing the molded product manufactured in the form of the tractor loop 100 from the inside of the mold 200 through the cooling step S70 by separating the molded product from the mold 200, .

As described above, according to the embodiment of the present invention, the plastic and foam are formed in a multi-layered structure, so that the heat insulating function is excellent and the noise and vibration shielding effect is excellent, so that the working environment of the farmers working the tractor for a long time under intense sunlight is improved. , It is possible to produce parts having high strength and light weight by applying the foam of the sandwich structure and to make the loops of the tractor easily by constituting one large body of complex parts having a shape.

It will be apparent to those skilled in the art that the concepts and embodiments of the invention set forth herein may be used as a basis for modifying or designing other structures for carrying out the same purposes of the present invention It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims and their equivalents. And various changes, substitutions, and alterations can be made without departing from the scope of the invention.

100: Tractor Loop
110: outer skeleton part 111: outer surface part
112: inner surface 113:
115: hollow
120: Inner adiabatic foam layer
130:
200: Mold
210: inner mold 220: outer mold
230: gas inlet 240: foam material inlet
241: Plug

Claims

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In the tractor loop 100,
An outer skeleton portion 110 formed by integrally molding an outer surface portion 111 and an inner surface portion 112 and formed with a hollow portion 115 between the outer surface portion 111 and the inner surface portion 112;
The hollow portion 115 is filled with an expanded foamed plastic foam 120; And
A plurality of joining members (130) integrally fused to the outer skeleton part (110) and the inner heat - insulating foam layer (120);
Lt; / RTI >
In order to increase the durability of the polyethylene (PE) material constituting the external skeleton part 110, 0.5 to 1.5% of an antioxidant and 0.5 to 1.5% of an ultraviolet screening agent are mixed,
Wherein a plurality of troughs (113) are formed on the surface of the outer surface (111) of the outer skeleton part (110) in the longitudinal direction.

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A method of manufacturing a tractor loop by foam rotary molding,
(S10) including a step of installing an insert for forming a coupling member (130) inside the mold (200);
A first raw material injection step (S20) of injecting a polyethylene (PE) material for external molding into the inside of the mold (200);
A mold rotating and heating step (S30) for rotating the mold 200 having the primary raw material applying step (S20) while heating it at 200 to 280 DEG C for 20 to 30 minutes;
A primary appearance forming and cooling step (S40) in which the outer skeleton part 110 is formed by melting and forming a polyethylene material inside the rotated and heated metal mold 200;
A secondary raw material injection step (S50) in which the melted polyethylene material is vapor-deposited on the wall surface of the mold through the primary external shape forming and cooling step (S40), and then the secondary foamed foaming material is charged;
A gas foaming molding step (S60) of foaming the foamed material by gas injection through a gas inlet (230) to form an internal foamed insulation layer (120);
A cooling step (S70) of cooling the metal mold 200 in which gas foaming is completed;
A demolding step (S80) of separating the molded product formed in the shape of the tractor loop (100) from the inside of the mold (200) through the cooling step (S70) from the mold (200);
Lt; / RTI >
In the secondary material input step S50, the foamed material is introduced through the foamed material inlet 240 provided at one side of the mold 200. The foamed material is a general plastic (EPP (Expanded Polypropylene)
In the gas foaming step S60, a foaming material for a secondary foaming foam is deposited on the polyethylene material deposited on the inner surface of the mold 200 to form an internal foam insulation layer 120, and the rotation mold 200 is stopped Lt; / RTI >
The heating method of the mold in the heating step S30 is a heating medium oil circulation system,
The primary appearance forming and cooling step S40 for forming the external skeleton part 110 includes the steps of forming a plurality of troughs 113 in the front and rear direction on the surface of the external surface part 111 of the external skeleton part 110 Wherein the method comprises the steps of:

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