JP2022018888A - Engine hood for construction machine - Google Patents

Abstract

To provide an engine hood for a construction machine that is able to reduce a welding volume without decreasing rigidity and excellent in appearance quality.SOLUTION: An engine hood for a construction machine is composed of: a cover member 2 forming an outer shell for an engine hood 1; and a structure member 3 disposed inside the cover member 2. The structure member 3 has: a base frame 4 formed in a frame shape so as to match an opening of an engine room; and a space frame 6 composed of a plurality of U-shaped bent materials 5 mounted on the base frame 4. The cover member 2 has: a cover 7 having a U-shaped cross-section so as to cover the opening of the engine room; and a flange 8 circumferentially formed along an edge part of the cover 7. The cover 7 of the cover member 2 is attached to the space frame 6 of the structure member 3 by means of a mastic adhesive M. The flange 8 of the cover member 2 is attached to the base frame 4 of the structure member 3 by means of an adhesive S for structure.SELECTED DRAWING: Figure 4

Description

The present invention relates to an engine hood of a construction machine, and more particularly to an engine hood of a construction machine which can reduce the welding volume without reducing the rigidity and has excellent appearance quality.

Conventionally, the engine hood of construction machinery is a thin plate molded panel itself that becomes the hood body by directly assembling multiple reinforcing materials by CO2 welding or spot welding to a thin plate molded panel (hood body) formed so as to cover the opening of the engine room. It was a structure that enhances the rigidity of the engine with a reinforcing material. For this reason, the welding volume is large, the man-hours are increased, and the cost of auxiliary materials such as welding wire and CO2 gas is also high.

Due to the large welding volume, welding burns, welding distortions, and spot welding indentations become prominent, and a large amount of finishing man-hours are required to correct them. In addition, distortions and indentations cannot be completely removed, resulting in deterioration in appearance quality. Was invited. Further, in order to secure the rigidity required for opening and closing the engine hood, a large number of reinforcing materials are attached to the thin plate molded panel, which increases the weight and causes a decrease in the hood opening / closing operability.

As the engine hood of a construction machine, Patent Document 1 discloses a hood opening / closing mechanism that prevents the engine hood main body from unexpectedly opening from the first open position to the second open position. The structure of the engine hood itself as in the present invention is not disclosed.

Japanese Unexamined Patent Publication No. 2012-144204

An object of the present invention, which was devised in consideration of the above circumstances, is to provide an engine hood for a construction machine, which can reduce the welding volume without lowering the rigidity and has excellent appearance quality.

According to the present invention, which was devised to achieve the above object, it is an engine hood that can be opened and closed in an opening of an engine room of a construction machine, and is inside a cover member forming an outer shell of the engine hood and inside the cover member. The structural member is composed of a base frame formed in a frame shape according to the opening of the engine room, and a space frame made of a plurality of U-shaped bending 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 the edge of the cover. Provided are engine hoods for construction machinery, characterized in that they are adhered to the structural member space frame by a mastic adhesive and the cover member flange is attached to the structural member base frame by a structural adhesive. ..

In the engine hood of a construction machine according to the present invention, the base frame of the structural member has a hinge for opening and closing the cover member with respect to the opening of the engine room, and the closed cover member for locking in the closed state. The lock member of the above may be attached.

In the engine hood of a construction machine according to the present invention, the cover of the cover member is formed by joining a plurality of flat panels and bent panels, and these flat panels and bent panels are flanges protruding inward of the cover. It may have portions and be spot-welded in a state where these flange portions are in contact with each other.

In the engine hood of a construction machine according to the present invention, in addition to the flange of the cover member being joined to the base frame of the structural member by a structural adhesive, at least one of welding, hemming coupling and rivet. It may be joined by one.

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

According to the engine hood of a construction machine according to the present invention, the welding volume can be reduced without lowering the rigidity, and the engine hood of the construction machine having excellent appearance quality can be realized.

It is a perspective view of the cover member forming the outer shell of the engine hood of the construction machine which concerns on one Embodiment of this invention as seen from diagonally below. It is a perspective view which looked at the structural member arranged inside the cover member of FIG. 1 from diagonally below. It is a perspective view which looked at the engine hood of the construction machine which concerns on one Embodiment of this invention from diagonally below. FIG. 3 is a sectional view taken along line IV-IV of FIG. FIG. 3 is a sectional view taken along line VV of FIG. FIG. 3 is a sectional view taken along line VI-VI of FIG. (A) is a sectional view taken along line VII-VII of FIG. 3, and (b) is a sectional view taken along line bb of FIG. 7 (a). It is a perspective view which looked at the engine hood of the construction machine which concerns on one Embodiment of this invention from diagonally above. FIG. 8 is a sectional view taken along line IX-IX of FIG. (A) is an enlarged view of the portion X in FIG. 8, and (b) is an exploded perspective view thereof. 4 is a cross-sectional view of the XI portion of FIG. 4, where (a) is a case where a round pipe is used for the space frame, (b) is a case where a square pipe is used for the space frame, and (c) is a channel cross-sectional material for the space frame. Is used. It is sectional drawing which shows the modification of the XII part of FIG.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in the embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and the drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate explanations, and elements not directly related to the present invention are not shown. do.

(Outline of engine hood 1 of construction machinery)
As shown in FIGS. 1 to 3, the engine hood 1 of a construction machine according to an embodiment of the present invention is an engine hood 1 that can be opened and closed in an opening of an engine room of a construction machine such as a hydraulic excavator or a wheel loader. It 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) arranged inside the cover member 2.

The structural member 3 shown in FIG. 2 is responsible for the strength and rigidity of the engine hood 1, and includes a base frame 4 formed in a frame shape according to the opening of the engine room and a plurality of members attached to the base frame 4. It has a space frame 6 made of a U-shaped bending member 5. On the other hand, the cover member 2 shown in FIG. 1 is in charge of the exterior design of the engine hood 1, and includes a cover 7 formed in a U-shaped cross section so as to cover the structural member 3 and the opening of the engine room. It has a flange 8 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 adhered to the space frame 6 of the structural member 3 by the mastic adhesive M, and the flange 8 of the cover member 5 is the base of the structural member 3 by the structural adhesive S. It is adhered to the frame 4. Hereinafter, each component will be described.

(Cover member 2)
The cover member 2 shown in FIG. 1 forms the outer shell of the engine hood 1 and is in charge of the exterior design of the engine hood 1. The cover member 2 has a cover 7 formed in a U-shape in cross section so as to cover the opening of the engine room of the construction machine, and a flange 8 formed along the circumferential direction at the edge of the cover 7. The cover 7 has 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. , It is formed in a U-shaped cross section (hat cross-sectional shape). A flange 8 is formed at the tip of the vertical plate portion 7b along the circumferential direction.

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 bent panels (vertical plate portion 7b). These flat panels (top plate portion 7a) and bent panels (vertical plate portion 7b) each have a flange portion 7c protruding inward of the cover 7, and the flange portions 7c are spot-welded to each other. It is welded. SW is a spot welded portion. As a result, the indentation of the spot welded portion SW does not appear on the appearance of the cover 7, the appearance quality of the engine hood 1 of the construction machine is improved, and the man-hours for correcting the indentation to ensure the appearance quality can be reduced.

(Structural member 3)
The structural member 3 shown in FIG. 2 is arranged 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 has a base frame 4 formed in a frame shape in accordance with 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 a steel pipe or the like is bent into a rectangular frame shape according to an opening of an engine room, or a square closed cross section is formed by a plurality of folded plates or the like. It has a rectangular frame-like structure, and as shown in FIGS. 5 to 7, it is provided with 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 cross section. The flat plate 4a of the base frame 4 is overlapped with the flange 8 of the cover member 2 and adhered by the structural adhesive S. Further, as will be described later, the flat plate 4a and the flange 8 are partially joined by spot welding (see the spot welded portion SW in FIGS. 5 to 7) in addition to the structural adhesive S. .. A heat-curable structural adhesive S is used, and the spot weld SW also functions as a temporary fixing until the structural adhesive S is cured. That is, the temporary fixing function + the strength function plays the role of the spot welded portion SW.

As shown in FIG. 2, the base frame 4 has a hinge 9 for opening and closing the engine hood 1 (cover member 2) with respect to the opening of the engine room, and the closed engine hood 1 is locked in the closed state. The strength, rigidity, and durability of the lock member 10, the steady rest bracket 11 that suppresses the runout of the closed engine hood 1, and the stay bracket 12 that fixes the opening angle to a predetermined angle when the engine hood 1 is opened, etc. The 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 structural adhesive, and a load is applied each time the engine hood 1 is opened and closed. As shown in FIG. 6, the steady rest bracket 11 is attached to the bottom surface of the base frame 14 flat plate 4a by welding or structural adhesive, and a load is applied by shaking the engine hood 1 during the operation of the construction machine. ..

As shown in FIGS. 10A and 10B, the lock member 10 has 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 structural adhesive. The striker 10a is fastened to the nut 10c welded to the support bracket 10b by a bolt 10d through which the hole 7d of the cover 7 is inserted. A load is applied to the striker 10a of the lock member 10 by the mating component each time the engine hood 1 is closed and locked, and the load is supported by the base frame 4 via the support bracket 10b.

The stay bracket 12 shown in FIG. 2 has a recessed portion 12a in which a bent portion at the tip of a stay (not shown) that supports the engine hood 1 when opened is engaged with the stay bracket 12, and the engine hood 1 is opened at a predetermined angle. A load is applied each time it is fixed with. In FIG. 3, the stay bracket 12 is omitted for the convenience of drawing. The parts (hinge 9, lock member 10, steady rest bracket 11, stay bracket 12) that require strength, rigidity, and durability are attached to the base frame 4 of the structural member 3 having high rigidity and strength.

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

As shown in FIGS. 3 and 4, in the present embodiment, the U-shaped bending member 5 constituting the space frame 6 is one in the longitudinal direction of the cover member 2 and three in the lateral direction at intervals. Although they are arranged, the number is not limited to these. The U-shaped bending member 5 may be a round pipe as shown in FIG. 11A, a square pipe as shown in FIG. 11B, or a channel having a U-shaped cross section as shown in FIG. 11C. The material (grooved steel) may 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 the mastic adhesive M. The mastic adhesive M is an elastic adhesive having foamability containing synthetic rubber as a main component, and is filled between the cover 7 and the space frame 6 to bond them. Since an elastic mastic adhesive is interposed between the space frame 6 and the cover 7, the shape (framework) of the space frame 6 absorbs the variation in the gap between the cover 7 and the space frame 6 which is unavoidable in manufacturing. The shape) can be prevented from coming out to the outer surface of the cover 7, and the appearance quality of the engine hood 1 of the construction machine is improved. Further, during the operation of the construction machine, it is possible to prevent noise caused by the cover 7 coming into direct contact with the space frame 6 due to vibration. Further, since a plurality of locations of the cover 7 are supported by the space frame 6 by the mastic adhesive M at intervals, the tension rigidity of the cover 7 can be maintained and so-called drumming (drumming noise) due to low frequency vibration of the cover 7 is prevented. Will be done.

As shown in FIG. 11A, when the U-shaped bending member 5 constituting the space frame 6 is a round pipe, the application allowance of the mastic adhesive M is small, so that the round pipe 5 is coated with a disk shape. The substitute member 5a may be welded and the mastic adhesive M may be applied to the coating margin 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 bending material 5 is a square pipe or a channel material, the flat surface portion serves as a coating allowance for the mastic adhesive M, which is basic. The coating allowance member 5a is not required, but the coating allowance member 5a may be provided in the same manner as the round pipe in order to increase the adhesive area. Further, when the U-shaped bending member 5 is a round pipe, the pipe bonding portion with respect to the cover 7 may be crushed to secure the bonding 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 joined by a structural adhesive S. The structural adhesive S is an adhesive containing a one-component curable epoxy resin as a main component, 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 the present embodiment, the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 are joined by spot welding in addition to being joined by the structural adhesive S. In FIGS. 5 to 7, SW is a spot welded portion. Specifically, in FIG. 3, the flange 8 of the short portion of the cover member 2 to which the hinge 9 to which a large load is applied and the lock member 10 are attached and the flat plate 4a are joined by structural adhesive S and spot welding (FIG. 5). , See the spot weld SW in FIG. 6), the flange 8 of the longitudinal portion of the cover member 2 to which a large load is not applied and the flat plate 4a of the base frame 4 are joined only by spot welding (spot welding in FIG. 7). See section SW). By assigning a part of the joint strength between the flange 8 and the flat plate 4a to the structural adhesive S, stress concentration can be avoided, stress distribution can be achieved, the number of spot welds can be reduced, and the welding volume can be reduced. can.

Further, in FIG. 3, the flange 8 and the flat plate 4a are joined by the structural adhesive S over the entire circumference along the circumferential direction, and the portion where the joining strength is insufficient only by the structural adhesive S is joined by spot welding. You may. For example, the flange 8 on the short side of the cover member 2 to which the hinge 9 and the lock member 10 to which a large load is applied are joined to the flat plate 4a by the structural adhesive S and spot welding, and the cover to which a large load is not applied is joined. The flange 8 at the longitudinal portion of the member 2 and the flat plate 4a may be joined only with the structural adhesive S. As a result, the spot welded portion (spot welded portion SW) becomes the minimum necessary portion in terms of strength, and the welding volume is significantly reduced.

Here, seam welding, hemming coupling, or rivets may be used instead of spot welding. That is, in addition to being joined by the structural adhesive S, the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 shown in FIG. 3 are at least any of spot welding, seam welding, hemming coupling, and rivets. It may be joined by one or the other. 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 are increased as compared with spot welding, and the bonding volume of the structural adhesive S can be reduced as compared with spot welding. Also, spot welding can be held pinpoint, while seam welding can be held in line.

Further, in order to reduce the weight of the material of the cover member 2, the material (aluminum, resin, etc.) different from that of the structural member 3 having a smaller specific gravity than the material of the structural member 3 (base frame 4) (for example, iron, steel, etc.) May be. 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 by at least one of a hemming bond and a rivet in addition to being joined by the structural adhesive S.

As shown in FIG. 7B, 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 of the cover 7 and the base frame 4 and to avoid a situation in which they come into contact with each other and interfere with each other. If the corners of the side surface of the base frame 4 come into contact with the inner surface of the cover 7, the ridges of the corners of the base frame 4 will appear on the outer surface of the cover 7, and the appearance quality will deteriorate, but this is avoided by the gap G. is doing.

As shown in FIG. 7B, a weather strip 13 is provided in the circumferential direction at the overlapping portion between the flange 8 of the cover member 2 and the flat plate 4a of the base frame 4 in order to stop the opening of the engine room of the construction machine. It is installed along. The weather strip 13 is mounted so as to cover the indentations of the spot welded portions SW shown in FIGS. 5 to 7, and also has a function of hiding the indentations and improving the appearance quality.

(Action / effect)
According to the engine hood 1 of the construction machine according to the present embodiment having the above configuration, as shown in FIGS. 1 to 3, the engine hood 1 of the construction machine is the cover member 2 which bears the appearance design, and the cover member 2 thereof. It is divided into a structural member 3 which is arranged on the side and bears strength and rigidity, and the flange 8 of the cover member 2 and the base frame 4 of the structural member 3 are firmly joined with the structural adhesive S to firmly join the cover 7 of the cover member 2. And the space frame 6 of the structural member 3 are elastically joined with the mastic adhesive M, so that the welding volume can be reduced without lowering the rigidity of the entire hood 1, and the engine hood 1 of the construction machine having excellent appearance quality can be obtained. realizable.

The engine hood of a conventional construction machine has a structure in which a plurality of reinforcing materials (strength members) are welded to a thin plate molded panel (hood body) that affects the appearance quality, and is a spot to disperse the stress of the welded part. The number of welded parts increased and the welding volume had to be increased. However, in the engine hood 1 of the construction machine according to the present embodiment, the cover member 2 which is responsible for the appearance quality and the structural member 3 which is responsible for the strength and rigidity are used. 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 the structural adhesive S and the mastic adhesive M are used properly depending on the location according to the function required for joining, the stress concentration on the spot welded portion SW can be alleviated and the welded portion is minimized. can.

As described above, since the welding volume can be reduced, the amount of heat input to the weld is significantly reduced, welding strain, welding burn, and spot welding indentation can be reduced, and the appearance quality is improved. In addition, the finishing man-hours for correcting welding distortion, welding burn, and spot welding indentation can be reduced, and the manufacturing cost can be reduced. Further, since the engine hood 1 is divided into a cover member 2 that bears the design and a structural member 3 disposed inside thereof and these are joined by a structural adhesive S and a mastic adhesive M, a thin plate is formed. Compared to the conventional product that secures 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, and the hood 1 can be opened and closed. Operability is improved.

As shown in FIG. 2, the base frame 4 of the structural member 3 has a hinge for opening and closing the engine hood 1 (cover member 2) with respect to the opening of the engine room, and the closed engine hood 1 is in a closed state. A lock member 10 for locking, a steady rest bracket 11 for suppressing the runout 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, since the parts that require strength, rigidity, and durability are supported by the base frame 4 of the structural member 3, the support rigidity of the hinge 9, the lock member 10, the steady rest bracket 11, and the stay bracket 12 is improved. , Increases durability.

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 bent panels (vertical plate portion 7b), and these flat panels (top plate portion 7b) are joined. The plate portion 7a) and the bent panel (vertical plate portion 7b) each have a flange portion 7c projecting inward of the cover 7, and the flange portions 7c are spot-welded to each other in a state of being in contact with each other. .. As a result, the indentation of the spot welded portion SW does not appear on the appearance of the cover 7, the appearance quality of the engine hood 1 of the construction machine is improved, and the man-hours for correcting the indentation can be reduced.

(Modification example)
FIG. 12 is a cross-sectional view showing a modified example of the XII portion of 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 portion 4b and a lower joint portion 4c are formed on each of the bent plates constituting the base frame 4, and the upper joint portions 4b are joined by spot welding (spot welded portion SW) to form a lower joint portion. 4c are joined by spot welding. Further, the flange 8 of the cover member 2 is superposed on the lower joint portion 4c, and these are spot-welded together. Instead of spot welding, seam welding, hemming coupling, rivets, or the like may be used for joining. In this modification, other configurations are the same as those of the previous embodiment, and the same functions and effects as those of the previous embodiment are exhibited.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various modifications in the scope of claims are described. It goes without saying that the modified examples also belong to the technical scope of the present invention.

INDUSTRIAL APPLICABILITY The present invention can reduce the welding volume without reducing the rigidity, and can be used for an engine hood of a construction machine having excellent appearance quality.

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

Claims (5)

An engine hood that can be opened and closed in the opening of the engine room of construction machinery.
It consists of a cover member forming the outer shell of the engine hood and a structural member arranged inside the cover member.
The structural member has a base frame formed in a frame shape in accordance with the opening of the engine room, and a space frame made of a plurality of U-shaped bending 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 the edge of the cover.
The cover of the cover member is adhered to the space frame of the structural member by a mastic adhesive.
An engine hood of a construction machine, wherein the flange of the cover member is adhered to a base frame of the structural member by a structural adhesive. A hinge for opening and closing the cover member with respect to the opening of the engine room and a lock member for locking the closed cover member in the closed state are attached to the base frame of the structural member. The engine hood of the construction machine according to claim 1, wherein the engine hood is characterized by the above. The cover of the cover member is configured by joining a plurality of flat panels and bent panels, and these flat panels and bent panels have flange portions protruding inward of the cover, and these flange portions are connected to each other. The engine hood of a construction machine according to claim 1 or 2, wherein the engine hood is spot-welded in a joined state. The flange of the cover member is bonded to the base frame of the structural member by at least one of welding, hemming bond and rivet in addition to being bonded by a structural adhesive. The engine hood of the construction machine according to claims 1 to 3. The material of the cover member is different from that of the structural member having a smaller specific gravity than the structural member, and the flange of the cover member is joined to the base frame of the structural member by a structural adhesive. The engine hood of a construction machine according to claim 1 to 3, further comprising being joined by at least one of a hemming bond and a rivet.

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