KR950005007B1 - Dipper stick and dipper stick manufacturing method - Google Patents

Abstract

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Description

Excavator deflector made of polymer composite and its manufacturing method

1 is a side view of a typical excavator equipped with a deflector.

2A and 2B are respectively a perspective view and an enlarged perspective view of a composite material differential according to the present invention;

3 is an exploded perspective view before RTM molding of a composite differential according to the present invention.

4A and 4B are cross-sectional perspective views taken along the line A-A of FIG. 2 to illustrate cross-sectional shapes of different embodiments of an internal filler made of urethane foam and reinforcing fibers.

5 is a schematic illustration showing a state in which the filament is wound on the bushing holder pipe to form the bushing holder of FIG.

Figure 6 is a schematic illustration of the RTM molding method which is the final molding method of the composite resin material differential according to the present invention.

* Explanation of symbols for the main parts of the drawings

1: excavator 2: boom

3: bucket 4: dipper cylinder

5: Bucket cylinder 5´: Auxiliary connector (LINK)

10: Differential 10´: Lug Flange

11: outer surface part 12: reinforcing fiber

13,14,15,16: Bushing holder 17,18,19,20: Insertion hole

21: Internal filler 21´: Urethane foam

22 bushing holder pipe 23 fiber filament

24,25: Resin tank 26,27: Transfer control part

28: mold 28´: cavity

29: temperature control unit

The present invention relates to a dipstick which is a part of an excavator working device, and manufactured by forming a fiber reinforced plastic, ie, fiber reinforced plastic (FRP), in a simple process compared to the dipstick, which was made of a conventional structural steel, but improved in strength. The present invention relates to a dipstick made of a polymer composite material (hereinafter referred to as a "composite material") capable of reducing its own weight and doubling the digging force, and a method for producing the dipstick.

As shown in FIG. 1, the deflector 10 includes a boom 2 for supporting the excavation load of the excavator 1, which is a construction heavy equipment, and an excavating bucket 3 for direct excavation. And a working cylinder for providing an excavation force directly to the bucket 3 by expanding and contracting by hydraulic control from an oil pressure control unit (not shown) provided in the excavator 1. Dipper cylinder (4) and bucket cylinder (5) are connected and installed. Therefore, the deflector 10 is repeatedly moved up and down in accordance with the expansion and contraction movement of the cylinders 4 and 5 during the excavation operation, and thus the repetitive movement with the excavating bucket 3 is most severely performed. As a result, the dipstick must be designed and made of a material having sufficient strength to withstand the digging load and to withstand the abrasion and impact caused by repeated digging movements.

Conventional differentials have typically been designed and manufactured using structural materials such as structural steel, for example SS41, so as to satisfy the conditions described above. However, the conventional differential made of structural steel in this way, first, as described in Table 1, the specific gravity of structural steel is 7.9 g / cm 3, which is quite heavy. Because it is constructed, it is vulnerable to the impact from the outside, and has a problem that the wear resistance to repeated excavation and red soil work and the corrosion resistance to the environment such as air or moisture are relatively weak. Moreover, the most important problem with this conventional forced deflector is that due to the heavy weight, it is necessary to increase its own and hydraulic forces relative to the excavating capacity in order to support it, thereby increasing the engine specification.

In order to solve the problems of the conventional structural steel differentials, the present inventors have tried to develop a diffusive having a sufficient strength while supporting a predetermined digging force while reducing the weight. Was developed.

Therefore, the object of the present invention is to reduce the weight of the car body with sufficient strength and to reduce the size of the vehicle body for the digging capacity, and to use the smaller engine size. It is to provide a differential for the excavator.

It is another object of the present invention to provide a method for manufacturing an excavator defferstick made of a composite material having the above characteristics.

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

Figures 2a and 2b is an overall perspective view of the composite material disperstick according to the present invention and the enlarged perspective view of the main portion of the lug flange portion, Figures 3 and 4 are exploded perspective view and Figure 2a before the final molding of the differential according to the present invention Is a cross-sectional perspective view taken along line AA. According to these figures, the diffusive 10 of the present invention has a box-like structure having an outer surface portion 11 composed of a composite material to have a normal shape, which can be seen in FIGS. 2 and 3. As described above, the outer surface 11 and the outer surface 11 formed by the resin transfer molding (RTM) method described below using a composite material such as FRP are supported and applied to the outer surface 11. The urethane is located inside the outer surface 11 so as to absorb it during an external impact, and is urethane foamed in advance with a urethane foam and then molded into the outer surface 11 during the RTM process. It consists of an internal filler 21 made of foam and reinforcing fibers. In addition, a U-shaped lug flange (lugflange) so that one end of the cylinders (4, 5) can be inserted into the cylinder connection portion of the differential (10), that is, the portion connected to the differential cylinder (4) and the bucket cylinder (5). , 10 ', 10' are provided with grooves 30, respectively, and the lug flanges 10 ', 10' have pipe-shaped bushing holders 13 for inserting the connecting pins 4 ', respectively. It is provided. In addition, the deflector 10 has a pipe-shaped steel tube outer surface for inserting a connecting pin into the connection part with the boom 2, the connection part with the bucket 3, and the connection part with the auxiliary connector 5 '. The filament winding method is provided with bushing holders 14, 15, and 16 reinforced with carbon fibers or glass fibers up to 10 mm thick. The bushing holders 13, 14, 15, and 16 are all manufactured in advance by the filament winding method described below, and then integrally formed with the outer surface 11 of the box-shaped structure during the RTM method.

In addition, when the box-shaped structure of the deflector 10 is completed, a shock and memo-proof plate composed of a porous rubber plate and a polyethylene laminated plate is covered with a bucket connection portion of the deflector to increase abrasion resistance and impact resistance against repetitive movement during excavation. The fastener can be fixed to the deflector 10.

The inner filler 21 of the urethane foam is shown in Figures 4a and 4b, as shown in Figure 4a and 4b, + reinforcement fibers 12 made of glass fiber, aramid fiber or carbon fiber in the shape of + or lattice of urethane foam It is wound around the molded body 21 'to improve the strength and impact resistance of the internal filler 21. This will be explained in detail later.

The differential 10 of the composite material according to the present invention having the above configuration is manufactured through the following manufacturing process.

That is, the bushing holders 13, 14, 15 and 16 of the composite material and the inner filler 21 of the urethane foam are first molded and manufactured. As shown in FIG. 5, the bushing holders 13, 14, 15, and 16 have a continuous fiber impregnated with a resin on a pipe-shaped bushing holder pipe 22 in a filament winding method. Winding densely and then curing at room temperature to manufacture. The bushing holder may be composed of an internal structural steel bushing holder pipe 22 serving as a mandrel and a fiber 23 wound thereon and cured together with a resin as necessary, or after the upper mold is finished. 22) is taken out and consists only of the composite material fiber filament (23). One embodiment of the filament winding method for the bushing holder 13, 14, 15, 16 is the same as the first embodiment. In this embodiment, a bushing holder comprising an internal structural steel bushing holder pipe 22 and an external fiber filament 23 is provided. As another filament winding method, a spiral winding method at any angle may be used.

Example 1

In order to reduce the weight of the bushing holder, the Japanese Nippon Carbion Co. Z 303 LBO (tensile strength: 400㎏f / ㎠, modulus of elasticity 50msi) is impregnated with unsaturated polyester resin or vinyl ester resin for room temperature curing, and then densely wound using a filament winding machine manufactured by Korea Institute of Machinery and Materials. Cured. At this time, the winding conditions were 10 kgf tensile force and 90 ° winding hoop winding method (Hoop Winding) was used, the curing conditions were natural curing at room temperature (25 ℃) for 3 hours.

According to the above embodiment, the bushing holder having sufficient strength could be provided. In addition, the length of the bushing holder is formed by making the bushing holder 13 fitted to the lug flanges 10 'and 10' shorter than the other bushing holders 14, 15 and 16.

On the other hand, the inner filler 21 of the urethane foam is filled with urethane in a urethane foam mold having an internal volume of 70% to 80% of the volume of the finished product in the same shape and then foamed. After foaming, the molded urethane foam is taken out, divided into four quarters in the longitudinal direction, and then wound on four quartered urethane foams 21 'with reinforcing fibers 12 made of glass fibers, aramid fibers or carbon fibers, respectively. At this time, the method of winding the reinforcing fiber 12 is wrapped in the longitudinal direction of the urethane foam (21 ') equally as shown in Figures 4a and 4b by laminating the front (4a degree), or two sides of the inside The bay is laminated and wrapped (4b degrees). The four fillers (21 ′) made of the reinforcing fibers laminated to the reinforcing fibers 21 are combined again, and then the reinforcing fibers (12) made of glass fiber, aramid fiber or carbon fiber are placed thereon. Wrap to obtain + or cross section of grid. Thereafter, as shown in FIG. 3, holes 17, 18, 19, and 20 for inserting bushing holders 13, 14, 15, and 16 into the inner filler 21, and U-shaped lug flanges 10 '. The groove 30 for forming is processed by the punching operation. As a result, the internal filler 21 having the perspective structure of FIG. 3 and the cross-sectional structure of FIG. 4 was obtained. However, the holes for the bushing holder and the grooves for the lug flange can be molded simultaneously with the foaming of the urethane foam by the mold shape during the foaming of the urethane foam.

The bushing holders 13, 14, 15, and 16 and the inner filler 21 of the urethane foam are completed through the above-described process, respectively, and then into the holes 17, 18, 19, and 20 of the inner filler 21, respectively. Insert the bushing holder in to make the primary assembly.

The RTM process as shown in FIG. 6 is then performed on the one assembly to finalize the deflective 10 of the box-like structure. One embodiment of the RTM method is the same as in Example 2.

Example 2

As shown in FIG. 6, the RTM apparatus is generally connected to the resins A and B resin tanks 24 and 25 and the feed adjusting units 26 and 27 to control the resin transfer. ) And a mold 28 consisting of upper and lower molds in communication with the control units 26 and 27, and a temperature control unit 29 for controlling the molding temperature of the mold 28. Between the upper and lower portions of the mold 28 is provided a cavity 28 ^* of a shape conforming to the actual external shape and the specification of the difficut 10. In the RTM process for final molding of the differential of the present invention, first, the primary assembly formed by inserting the bushing holders 13, 14, 15, and 16 into the urethane foam filler 21 is formed in the cavity of the mold 28. And a liquid resin such as the above-mentioned vinyl ester or unsaturated ester and additives such as a conventional catalyst, accelerator, promoter, gel delay agent, etc., from each tank 24, 25. 26, 27), and flowed into the mold 28 using a resin transfer pressure 5Bar at a reduced pressure inside the mold for 5 to 10 minutes, and then heated to the mold 28 under reduced pressure for 30-40 minutes. Curing was added to form the finished finished product 10. At this time, the composite material transferred into the mold is densely filled in the gap between the bushing holders 13, 14, 15, and 16 and the insertion holes 17, 18, 19, and 20 disposed in the urethane filler 21. The outer surface portion 11 is formed on the filler 21 by being coated with a predetermined thickness. In addition, each material constituting the RTM molded part of the composite diffractive material is made of DERAKANE 411-45, a vinyl ester resin manufactured by Dow Chemical, USA, and a glass fiber mat, manufactured by Vetrotex, USA. Can be used. As for the viscosity of the said DERAKANE resin, 400-500 mPa.s, suitably 450 mPa.s was effective. In addition, the resin conveyance pressure at the time of shaping | molding normally uses 5 Bar, and pressure reduction is used inside a mold. This reduced pressure was very advantageous because it facilitated the transfer of the resin into the mold 28 and the impregnation of the composite material with the reinforcing fibers 12 wound on the urethane foam 21 'in the mold 28.

Methyl ethyl ketone peroxide (MEKP), such as Butanox LPT from AKZO, the catalyst, diethylaniline, dimethylaniline or dimethylacetoacetamide as promoter, cobalt naphthenate as promoter, 2,4 as gel delay Pentaedione was used.

As a result of Example 2, it was possible to obtain a diffuser of a composite material having a very beautiful surface, excellent strength and light weight. The strength and weight characteristics of this composite diffraction are as follows in Table 1 and Table 2, which are compared with the strength and weight of a diffraction manufactured to the same standard as SS41, which is a conventional structural steel. It can increase about 3 times compared to the structural steel, and can reduce the weight by 50% for the small diffusive and up to 60% for the large deficit. Compared to the weight ratio, it is possible to achieve a weight loss of up to 6.8% of the red soil weight for a single excavation and 13.9% for a large one, and ultimately a smaller body size and proportionate to the weight loss ratio. Engine capacity could provide the same amount of digging force. In other words, when the same weight body and the engine of the same capacity, the composite material differentiator of the present invention can bring up to 6.8% -13.9% of the digging ability compared to the conventional manufacturing of the structural steel Means that.

TABLE 1

TABLE 2

As described above, the composite material differential according to the present invention can reduce its own weight by 50% -60%, and in the case of the excavated toby, it can achieve a weight reduction of 6.8-13.9% by practically 6.8%- It offers the advantage of improving digging capacity up to 13.9%. In addition, since the composite material of the present invention is a composite material such as FRP, which is its main material, has excellent corrosion resistance, abrasion resistance, and elastic force superior to structural angles, accordingly, it is excellent in corrosion resistance, impact resistance, and earthquake resistance of the differential. It provides the advantage of providing an excavator that can be useful in the poor working conditions such as port dredging.

Claims (12)

In the excavator differential, an outer surface portion 11 made of a high strength composite material and an inner filler material 21 made of urethane foam 21 'and reinforcing fibers 12 are integrally disposed in the outer surface portion 11. Box-shaped structure, the box-shaped structure is connected to the bucket (3), the connection with the spring (2), the differential cylinder (4) and the bucket cylinder (5) and the connecting pin (5 ′) at the connecting pin ( 4 ') a differential of an excavator made of a composite material characterized in that the bushing holders (13, 14, 15, 16) for fitting 4') are integrally provided. The method of claim 1, wherein the bushing holder (13, 14, 15, 16) is made of a fiber filament (23) of the composite material cured by winding the filament on the metal bushing holder pipe (22), or after curing, The deflector of the composite material excavator comprising the fiber filament 23 of the composite material from which the bushing holder pipe 22 is removed. 2. The excavator's differential according to claim 1, wherein the composite material comprises a vinyl ester or an unsaturated ester and a glass fiber mat. The method according to claim 1, wherein the deflector of the composite material is provided with the impact and abrasion prevention plate made of a porous rubber plate and a polyethylene epoxy laminated plate covered with a connection portion of the bucket of the differential (10). In the manufacturing method of the deflector of the excavator of the composite material of claim 1, the bushing holder (13, 14, 15, 16) by the filament winding method, an internal filler made of urethane foam and reinforcing fibers (21) ), The bushing holder (13, 14, 15, 16) to the inner filler 21 to form a primary assembly and the primary assembly in the mold 28 of the resin trans-molding machine ( 28 ') and the liquid resin is transferred to the mold 28 to manufacture and complete the box-shaped structure of the diffraction. The hoop winding of claim 5, wherein the winding of the composite filament 23 with respect to the bushing holder pipe 22 in the filament winding step for manufacturing the bushing holders 13, 14, 15, and 16 is carried out. A method for producing a deflector of an excavator made of a composite material, characterized in that it is carried out in a spiral winding manner at any angle or in any manner. The method of claim 5, wherein the manufacturing step of the internal filler (21) is a step of injecting a urethane foam into a mold and foam molding, the step of dividing the molded urethane foam (21 ') in the longitudinal direction into four quarters, The step of laminating the reinforcing fibers 12 on the molded urethane foam 21 ′, and the step of laminating the reinforcing fibers 12 on the re-combination of the urethane foams 21 ′ laminated with the reinforcing fibers 12. A method for producing a deflector of an excavator made of a composite material, characterized in that consisting of. 8. The method according to claim 7, wherein the reinforcing fiber (12) is made of glass fiber, aramid fiber or carbon fiber. The method according to claim 7, wherein in the laminating step of the reinforcing fiber 12 to the quartered urethane foam 21 ', only two sides of the inside of the urethane foam 21' are laminated or the whole of four sides are laminated. A method for producing a deflector of an excavator made of a composite material. 10. The method of claim 7, wherein the mold for molding the urethane foam has an internal volume of 70% -80% of the volume of the differential (10). The composite material excavator according to claim 5, wherein the material used in the resin transfer molding step for producing the box-shaped structure is a fiberglass mat reinforcement and a vinyl ester resin or an unsaturated ester resin. The manufacturing method of the difficile of. The method according to claim 5, wherein the resin transfer molding step uses a conveying pressure of 5 Bar or less, or uses a reduced pressure inside the mold.