JP7391786B2 - Construction machinery engine hood - Google Patents

Description

The present invention relates to an engine hood for a construction machine, and particularly to an engine hood for a construction machine that can reduce weld volume without reducing rigidity and has excellent appearance quality.

Conventionally, engine hoods for construction machinery are made by directly assembling multiple reinforcing materials by CO2 welding or spot welding to a thin sheet molded panel (hood body) formed to cover the opening of the engine room, and then attaching the thin sheet molded panel itself that becomes the hood body. The structure used reinforcing materials to increase the rigidity of the structure. For this reason, the welding volume was large, the number of man-hours increased, and the cost of auxiliary materials such as welding wire and CO2 gas also increased.

Due to the large weld volume, weld burn, weld distortion, and spot welding impressions become noticeable, requiring a large amount of finishing work to correct them, and the distortions and impressions cannot be completely removed, resulting in a decrease in appearance quality. was inviting. In addition, in order to ensure the rigidity necessary for opening and closing the engine hood, a large number of reinforcing materials were attached to the thin molded panel, which increased the weight and reduced the operability of opening and closing the hood.

Note that, as an engine hood for construction machinery, Patent Document 1 discloses an engine hood that prevents the engine hood main body from opening unexpectedly from a first open position to a second open position, but the hood opening/closing mechanism Unlike the present invention, the structure of the engine hood itself is not disclosed.

Japanese Patent Application Publication No. 2012-144204

An object of the present invention, which was created in consideration of the above circumstances, is to provide an engine hood for construction machinery that can reduce the weld volume without reducing rigidity and has excellent appearance quality.

According to the present invention, which has been devised to achieve the above object, there is provided an engine hood which is attached to the opening of the engine room of a construction machine so as to be openable and closable, and which includes a cover member forming an outer shell of the engine hood, and an inner side of the cover member. The structural member consists of a base frame formed into a frame shape to match the opening of the engine room, and a space frame consisting of a plurality of U-shaped bent members attached to the base frame. The cover member has a cover formed in a U-shape in cross section to cover the opening of the engine room, and a flange formed along the circumferential direction at the edge of the cover, An engine hood for a construction machine is provided, wherein the engine hood is bonded to a space frame of a structural member by a mastic adhesive, and a flange of the cover member is bonded to a base frame of the structural member by a structural adhesive. .

In the engine hood for construction machinery according to the present invention, the base frame of the structural member includes a hinge for allowing the cover member to open and close with respect to the opening of the engine room, and a hinge for locking the closed cover member in the closed state. A locking member may be attached.

In the engine hood of a construction machine according to the present invention, the cover of the cover member is configured by joining a plurality of flat panels and folded panels, and these flat panels and folded panels have flanges projecting inwardly of the cover. The flange portions may be spot welded together in a state where the flange portions are placed together.

In the engine hood of a construction machine according to the present invention, the flange of the cover member is joined to the base frame of the structural member by a structural adhesive, and also by at least one of welding, hemming, and rivets. They may be joined by two.

In the engine hood for construction machinery according to the present invention, the material of the cover member is different from that of the structural member having a specific gravity smaller than that of the structural member, and the flange of the cover member is attached to the base frame of the structural member. In addition to being joined by adhesive, they may also be joined by at least one of a hemming joint and a rivet.

According to the engine hood for a construction machine according to the present invention, the weld volume can be reduced without reducing the rigidity, and the engine hood for the construction machine can be realized with excellent appearance quality.

FIG. 2 is a perspective view of a cover member forming an outer shell of an engine hood of a construction machine according to an embodiment of the present invention, viewed diagonally from below. FIG. 2 is a perspective view of a structural member disposed inside the cover member of FIG. 1 as viewed obliquely from below. FIG. 1 is a perspective view of an engine hood of a construction machine according to an embodiment of the present invention, viewed diagonally from below. 4 is a sectional view taken along the line IV-IV in FIG. 3. FIG. 4 is a sectional view taken along the line VV in FIG. 3. FIG. 4 is a sectional view taken along the line VI-VI in FIG. 3. FIG. (a) is a sectional view taken along line VII-VII in FIG. 3, and (b) is a sectional view taken along line bb in FIG. 7(a). FIG. 1 is a perspective view of an engine hood of a construction machine according to an embodiment of the present invention, viewed diagonally from above. 9 is a sectional view taken along the line IX-IX in FIG. 8. FIG. (a) is an enlarged view of the portion X in FIG. 8, and (b) is an exploded perspective view thereof. FIG. 4 is a cross-sectional view of part XI in FIG. The case is shown below. FIG. 6 is a sectional view showing a modification of the XII portion in FIG. 5;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely illustrative to facilitate understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements with substantially the same functions and configurations are given the same reference numerals to omit redundant explanation, and elements not directly related to the present invention are omitted from illustration. do.

(Summary of engine hood 1 for construction machinery)
As shown in FIGS. 1 to 3, an engine hood 1 for a construction machine according to an embodiment of the present invention is an engine hood 1 that is attached to an opening of an engine room of a construction machine such as a hydraulic excavator or a wheel loader so as to be openable and closable. The engine hood 1 is composed of a cover member 2 (see FIG. 1) forming the outer shell of the engine hood 1, and a structural member 3 (see FIG. 2) disposed inside the cover member 2.

The structural members 3 shown in FIG. 2 are responsible for the strength and rigidity of the engine hood 1, and include a base frame 4 formed in a frame shape to match the opening of the engine room, and a plurality of structural members attached to the base frame 4. It has a space frame 6 made of a U-shaped bent member 5. On the other hand, the cover member 2 shown in FIG. 1 is in charge of the external design of the engine hood 1, and includes a cover 7 formed in a U-shape in cross section so as to cover the structural member 3 and the opening of the engine compartment. A flange 8 is formed along the circumferential direction at the edge of the cover 7.

As shown in FIG. 4, the cover 7 of the cover member 5 is glued to the space frame 6 of the structural member 3 by means of a mastic adhesive M, and the flange 8 of the cover member 5 is glued to the base of the structural member 3 by means of a structural adhesive S. It is glued to the frame 4. Each component will be explained below.

(Cover member 2)
The cover member 2 shown in FIG. 1 forms the outer shell of the engine hood 1 and is responsible for the external design of the engine hood 1. The cover member 2 includes a cover 7 formed to have a U-shaped cross section so as to cover an opening of an engine room of a construction machine, and a flange 8 formed along the circumferential direction at the edge of the cover 7. The cover 7 includes a top plate portion 7a formed in a rectangular shape so as to cover the opening of the engine room, and a vertical plate portion 7b extending from the four sides of the top plate portion 7a toward the opening of the engine room. , is formed to have a U-shaped cross section (hat cross section shape). A flange 8 is formed along the circumferential direction at the tip of the vertical plate portion 7b.

As shown in FIGS. 8 and 9, the cover 7 of the cover member 2 is configured by joining a plurality of flat panels (top plate portion 7a) and folded panels (vertical plate portion 7b). These flat panel (top plate part 7a) and folded panel (vertical plate part 7b) each have a flange part 7c projecting inward of the cover 7, and when these flange parts 7c are placed together, they can be placed in a spot. Welded. SW is a spot weld. As a result, the impressions of the spot welds SW do not appear on the exterior of the cover 7, improving the appearance quality of the engine hood 1 of the construction machine, and reducing the number of man-hours required to correct the impressions to ensure the appearance quality.

(Structural member 3)
The structural member 3 shown in FIG. 2 is disposed inside the cover member 2 shown in FIG. 1, and is responsible for the strength and rigidity of the engine hood 1. The structural member 3 includes a base frame 4 formed into a frame shape to match the opening of the engine room, and a space frame 6 made of a plurality of U-shaped bending members 5 attached to the base frame 4.

(Base frame 4)
As shown in FIGS. 3 and 4, the base frame 4 has a structure in which a square pipe made of steel pipe or the like is bent into a rectangular frame shape to fit the opening of the engine room, or a structure with a square closed cross section made of multiple folded plates, etc. It has a rectangular frame-like structure, and includes a flat plate 4a attached to the bottom surface of a square pipe forming the base frame 4 or the bottom surface of a square closed section, as shown in FIGS. 5 to 7. The flat plate 4a of the base frame 4 is overlapped with the flange 8 of the cover member 2, and is bonded with a structural adhesive S. In addition, as will be described later, the flat plate 4a and the flange 8 are partially joined by spot welding (see spot welds SW in FIGS. 5 to 7) in addition to the structural adhesive S. . The structural adhesive S used is of a heat curing type, and the spot welded portion SW also functions as a temporary fixing until the structural adhesive S hardens. In other words, the temporary fixing function and the strength function are the roles of the spot welded portion SW.

As shown in FIG. 2, the base frame 4 includes a hinge 9 for freely opening and closing the engine hood 1 (cover member 2) with respect to the opening of the engine room, and a hinge 9 for locking the closed engine hood 1 in the closed state. A locking member 10 for the engine hood 1, a steady rest bracket 11 for suppressing the vibration of the closed engine hood 1, a stay bracket 12 for fixing the opening angle to a predetermined angle when the engine hood 1 is opened, etc., have strength, rigidity, and durability. Necessary parts are assembled.

As shown in FIG. 5, the hinge 9 is attached to the bottom surface of the flat plate 4a of the base frame 4 by welding or a structural adhesive, and is subjected to a load each time the engine hood 1 is opened or closed. As shown in FIG. 6, the steady rest bracket 11 is attached to the bottom surface of the flat plate 4a of the base frame 14 by welding or structural adhesive, and is subjected to a load when the engine hood 1 is shaken while the construction machine is operating. .

As shown in FIGS. 10(a) and 10(b), the lock member 10 includes a lock striker 10a and a striker support bracket 10b, and the support bracket 10b is attached to the base frame 4 by welding or a structural adhesive. A striker 10a is fastened to a nut 10c, which is attached to the support bracket 10b by welding, by a bolt 10d inserted through a hole 7d in the cover 7. Each time the engine hood 1 is closed and locked, a load is applied to the striker 10a of the locking member 10 by a mating component, and the load is supported by the base frame 4 via the support bracket 10b.

The stay bracket 12 shown in FIG. 2 is provided with a recessed part 12a that engages with a bent end portion of a stay (not shown) that supports the engine hood 1 when it is opened.The stay bracket 12 shown in FIG. Load is added each time it is fixed. Note that the stay bracket 12 is omitted in FIG. 3 for convenience of drawing. The parts (hinge 9, lock member 10, steady bracket 11, stay bracket 12) that require strength, rigidity, and durability are attached to the base frame 4 of the structural member 3, which has high rigidity and strength.

(Space frame 6)
As shown in FIG. 2, a space frame 6 made of a plurality of U-shaped bent members 5 is attached to the base frame 4. The U-shaped bending member 5 is attached to the side surface of the square pipe or square closed cross section constituting the base frame 4 by welding or a structural adhesive. As shown in FIGS. 3 and 4, the U-shaped bent member 5 has a bent shape that matches the inner surface of the cover member 2, and cooperates with the frame-shaped base frame 4 inside the cover member 2. to construct a three-dimensional framework structure.

As shown in FIGS. 3 and 4, in this embodiment, the space frame 6 includes one U-shaped bending member 5 in the longitudinal direction of the cover member 2, and three in the transverse direction at intervals. However, the number is not limited to these. The U-shaped bending member 5 may be a round pipe as shown in FIG. 11(a), a square pipe as shown in FIG. 11(b), or a channel with a U-shaped cross section as shown in FIG. 11(c). Material (channel steel) may also be used.

(Mastic adhesive M)
As shown in FIGS. 3 and 4, the space frame 6 of the structural member 3 and the cover 7 of the cover member 2 are joined by a mastic adhesive M. As shown in FIGS. The mastic adhesive M is a foamable elastic adhesive mainly composed of synthetic rubber, and is filled between the cover 7 and the space frame 6 to bond them together. Since the elastic mastic adhesive is interposed between the space frame 6 and the cover 7, variations in the gap between the cover 7 and the space frame 6 that are unavoidable during manufacturing can be absorbed, and the shape of the space frame 6 (skeleton structure) can be adjusted. shape) can be prevented from appearing on the outer surface of the cover 7, and the appearance quality of the engine hood 1 of the construction machine is improved. Furthermore, it is possible to prevent noise caused by direct contact of the cover 7 with the space frame 6 due to vibration during operation of the construction machine. In addition, since multiple parts of the cover 7 are supported by the space frame 6 with the mastic adhesive M at intervals, the tension and rigidity of the cover 7 can be maintained, and so-called drumming (drumming noise) caused by low frequency vibration of the cover 7 can be prevented. be done.

As shown in FIG. 11(a), when the U-shaped bent member 5 constituting the space frame 6 is a round pipe, the amount of mastic adhesive M to be applied is small, so the round pipe 5 is coated in a disc shape. The substitute member 5a may be welded and the mastic adhesive M may be applied to the substitute member 5a (see FIGS. 2, 3, and 4). On the other hand, as shown in FIGS. 11(b) and 11(c), when the U-shaped bent material 5 is a square pipe or channel material, the flat part becomes the application area for the mastic adhesive M, so the basic Although the application allowance member 5a is not necessary, the application allowance member 5a may be provided in the same manner as the round pipe in order to increase the bonding area. Further, when the U-shaped bending member 5 is a round pipe, the adhesive portion of the pipe to the cover 7 may be crushed to ensure an adhesive margin.

(Structural adhesive S)
As shown in FIGS. 5 to 7, the flat plate 4a of the base frame 4 and the flange 8 of the cover member 2 are bonded with a structural adhesive S. As shown in FIGS. The structural adhesive S is an adhesive mainly composed of a one-component curing epoxy resin, and has higher adhesive strength and impact resistance than the mastic adhesive M. The structural adhesive S firmly adheres and fixes the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4.

In this embodiment, the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 are joined not only by the structural adhesive S but also by spot welding. In FIGS. 5 to 7, SW is a spot weld. Specifically, in FIG. 3, the flange 8 of the short side portion of the cover member 2 to which the hinge 9 and the lock member 10, which are subjected to a large load, are attached, and the flat plate 4a are joined by a structural adhesive S and spot welding (FIG. 5). , see spot weld SW in FIG. 6), and the flange 8 on the longitudinal part of the cover member 2, which is not subjected to a very large load, and the flat plate 4a of the base frame 4 are joined only by spot welding (see spot weld SW in FIG. 7). (See section SW). By allowing the structural adhesive S to provide part of the bonding strength between the flange 8 and the flat plate 4a, stress concentration is avoided and stress distribution is achieved, the number of spot welds can be reduced, and the weld volume can be reduced. can.

In addition, in FIG. 3, the flange 8 and the flat plate 4a are joined along the entire circumference with a structural adhesive S, and the parts where the joint strength is insufficient with only the structural adhesive S are joined by spot welding. You may. For example, the flange 8 of the short side portion of the cover member 2 to which the hinge 9 and the locking member 10, which are subjected to a large load, are attached, and the flat plate 4a are joined by a structural adhesive S and spot welding, and the cover is not subjected to a large load. The flange 8 of the longitudinal portion of the member 2 and the flat plate 4a may be bonded together using only the structural adhesive S. As a result, the spot welding portion (spot welding portion SW) becomes the minimum necessary portion in terms of strength, and the welding volume is significantly reduced.

Here, seam welding, hemming connection, or rivets may be used instead of spot welding. That is, the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 shown in FIG. They may be joined by either one of them. Since the welding surfaces of the flange 8 and the flat plate 4a are flat, they are suitable for seam welding. By seam welding, the welding area and range can be increased compared to spot welding, and the bonding volume of the structural adhesive S can be reduced compared to spot welding. Also, while spot welding is held at a pinpoint, seam welding can be held at a line.

In order to reduce the weight, the cover member 2 is made of a different material (aluminum, resin, etc.) that has a specific gravity smaller than that of the structural member 3 (base frame 4) (e.g., iron, steel, etc.). You can also use it as In this case, since welding is not possible, the flange 8 of the cover member 2 is joined to the flat plate 4a of the base frame 4 not only by the structural adhesive S but also by at least one of a hemming joint and a rivet.

As shown in FIG. 7(b), a predetermined gap G is formed along the circumferential direction between the inner surface of the cover 7 of the cover member 2 and the side surface of the base frame 4 of the structural member 3. This is to absorb manufacturing variations in the cover 7 and the base frame 4 and to avoid a situation where they come into contact and interfere. If the corner of the side surface of the base frame 4 comes into contact with the inner surface of the cover 7, the ridgeline of the corner of the base frame 4 will appear on the outer surface of the cover 7, deteriorating the appearance quality, but this can be avoided by the gap G. are doing.

As shown in FIG. 7(b), a weather strip 13 is provided in the circumferential direction at the overlapping portion of the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 in order to watertight the opening of the engine room of the construction machine. It is installed along. The weather strip 13 is attached to cover the indentations of the spot welds SW shown in FIGS. 5 to 7, and also has the function of hiding the indentations and improving the appearance quality.

(action/effect)
According to the engine hood 1 for a construction machine according to the present embodiment having the above-described configuration, as shown in FIGS. The flange 8 of the cover member 2 and the base frame 4 of the structural member 3 are firmly joined with a structural adhesive S, and the cover 7 of the cover member 2 is divided into and the space frame 6 of the structural member 3 are elastically joined with the mastic adhesive M, so the welding volume can be reduced without reducing the rigidity of the hood 1 as a whole, and the engine hood 1 of the construction machine has an excellent appearance quality. realizable.

Conventional engine hoods for construction machinery have a structure in which multiple reinforcing materials (strength members) are welded to a thin plate molded panel (hood body) that affects the appearance quality. However, in the engine hood 1 of the construction machine according to the present embodiment, the cover member 2 is responsible for appearance quality, and the structural member 3 is responsible for strength and rigidity. Since the functions are divided, the welding volume for joining the cover member 2 and the structural member 3 can be significantly reduced. In addition, since structural adhesive S and mastic adhesive M are used differently depending on the function required for the joint, stress concentration on spot welds SW can be alleviated, and the number of welded parts can be reduced to the necessary minimum. can.

In this way, since the welding volume can be reduced, the amount of heat input during welding is significantly reduced, welding distortion, welding burn, and spot welding impressions can be reduced, and the appearance quality is improved. Additionally, the number of finishing steps required to correct welding distortion, welding burns, and spot welding indentations can be reduced, and manufacturing costs can be reduced. In addition, since the engine hood 1 is divided into a cover member 2 that carries the design and a structural member 3 disposed inside the cover member 3 and these are joined using a structural adhesive S and a mastic adhesive M, thin plate forming is possible. Compared to conventional products that ensure rigidity by welding multiple reinforcing materials to the panel (hood body), the weight of the engine hood 1 can be significantly reduced while ensuring the required rigidity, making it possible to open and close the hood 1. Improves operability.

As shown in FIG. 2, a hinge is attached to the base frame 4 of the structural member 3 to allow the engine hood 1 (cover member 2) to be opened and closed with respect to the opening of the engine compartment, and to open and close the engine hood 1 in a closed state. A locking member 10 for locking, a steadying bracket 11 for suppressing swinging of the closed engine hood 1, and a stay bracket 12 for fixing the opening angle to a predetermined angle when the engine hood 1 is opened are attached. In this way, parts that require strength, rigidity, and durability are supported by the base frame 4 of the structural member 3, so the support rigidity of the hinge 9, lock member 10, steady rest bracket 11, and stay bracket 12 is improved. , durability is increased.

As shown in FIGS. 8 and 9, the cover 7 of the cover member 2 is composed of a plurality of flat panels (top plate portion 7a) and folded panels (vertical plate portion 7b) joined together. The plate portion 7a) and the folded panel (vertical plate portion 7b) each have a flange portion 7c protruding inward of the cover 7, and these flange portions 7c are spot welded together. . As a result, the impressions of the spot welds SW do not appear on the appearance of the cover 7, improving the appearance quality of the engine hood 1 of the construction machine, and reducing the number of man-hours required to correct the impressions.

(Modified example)
FIG. 12 is a sectional view showing a modification of the XII portion in FIG. The base frame 4 in this modification has a rectangular frame-like structure with a square closed cross section by combining a pair of bent plates. An upper joint part 4b and a lower joint part 4c are formed in each of the bent plates constituting the base frame 4, and the upper joint parts 4b are joined by spot welding (spot welding part SW), and the lower joint part 4b is joined by spot welding (spot welding part SW). 4c are joined together by spot welding. Further, the flange 8 of the cover member 2 is overlapped with the lower joint portion 4c, and these are spot welded together. Note that instead of spot welding, seam welding, hemming, rivets, or the like may be used for joining. This modification has the same structure as the previous embodiment in other respects, and has the same effects as the previous embodiment.

Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the embodiments described above, and various modifications within the scope of the claims are possible. It goes without saying that modifications and modifications also fall within the technical scope of the present invention.

INDUSTRIAL APPLICATION This invention can reduce a welding volume without reducing rigidity, and can be utilized for the engine hood of a construction machine with excellent appearance quality.

1 Engine hood 2 Cover member 3 Structural member 4 Base frame 5 U-shaped bent member 6 Space frame 7 Cover 7a Flat panel (top plate part of cover)
7b Folding panel (vertical plate part of cover)
8 Flange 9 Hinge 10 Lock member M Mastic adhesive S Structural adhesive SW Spot welding part

Claims (5)

An engine hood that can be freely opened and closed over an opening in an engine room of a construction machine,
Consisting of a cover member forming the outer shell of the engine hood, and a structural member disposed inside the cover member,
The structural member has a base frame formed in a frame shape to match the opening of the engine room, and a space frame made of a plurality of U-shaped bent members attached to the base frame,
The cover member has a cover formed in a U-shape in cross section so as to cover the opening of the engine room, and a flange formed along the circumferential direction at an edge of the cover,
a cover of the cover member is glued to a space frame of the structural member by mastic adhesive;
An engine hood for a construction machine, wherein a flange of the cover member is bonded to a base frame of the structural member using a structural adhesive. A hinge for allowing the cover member to open and close with respect to an opening of an engine room and a locking member for locking the closed cover member in a closed state are attached to the base frame of the structural member. The engine hood for a construction machine according to claim 1, characterized in that: . The cover of the cover member is constructed by joining a plurality of flat panels and folded panels, and these flat panels and folded panels each have a flange portion projecting inward of the cover, and these flange portions are connected to each other. The engine hood for a construction machine according to claim 1 or 2, wherein the engine hood is spot-welded in a folded state. The flange of the cover member is bonded to the base frame of the structural member by a structural adhesive and also by at least one of welding, hemming, and rivets. An engine hood for a construction machine according to claim 1. The material of the cover member is a different material from the structural member having a specific gravity smaller than that of the structural member, and the flange of the cover member is bonded to the base frame of the structural member with a structural adhesive. The engine hood for a construction machine according to claim 1, further comprising a hemming joint and a rivet.

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