Frame structure for construction machine

Abstract

The upper frame of the construction machine comprises: a middle part (11) including a vertical plate (13) extending in the front-back direction; and a side deck (12) including a cross member (18), one end of which is joined to the vertical plate (13) and the other end of which extends leftward or rightward with respect to the vertical plate (13), the upper frame of the construction machine having a reinforcing plate (21) including an upper surface (21u) and a lower surface (21d), one of which is welded to the vertical plate (13) and the other of which is welded to the cross member (18). A welding torch interference avoidance space is provided in which a welding torch (Td) is inserted between the intermediate portion (11) and the side deck (12). As a result, the welding torch (Td) can weld the lower surface (21d) side of the reinforcing plate (21) and the vertical plate (13) without interfering with the intermediate portion (11) and the side deck (12).

Description

Technical Field

[0001] The invention relates to engineering machinery such as construction machinery or agricultural machinery, and in particular to a structure for strengthening an upper frame. Background Art

[0002] As an upper frame of a hydraulic excavator, there is conventionally known an upper frame described in, for example, Patent Document 1. The upper frame described in Patent Document 1 is a frame of an upper revolving body provided on a lower traveling body, and includes a central frame (also referred to as a middle portion) and side frames (also referred to as side decks) provided on both sides of the central frame in the width direction.

[0003] The central frame is formed into an I-shaped cross section by a side portion as a longitudinal plate, an upper surface portion as an upper plate integrally provided at the upper portion of the side portion and extending laterally, and a bottom portion as a bottom plate integrally provided at the lower portion of the side portion and extending laterally. The side frame is composed of a plurality of beams and a frame material. Each beam is arranged in the longitudinal direction along a direction intersecting the central frame, and is integrally provided with the central frame by welding one end of each beam to the side portion of the central frame.

[0004] A plate-shaped reinforcing member is also welded to the welding position between one end of the beam of the side frame and the side portion of the central frame. Specifically, the reinforcing member is attached to the upper portion of one end of the beam, and the upper surface of the reinforcing member is welded to the side portion of the central frame. However, the lower surface of the reinforcing member is not welded to the side portion of the central frame. The beam of the side frame is an L-shaped cross-section with a longitudinal plate on the upper side and a transverse plate on the lower side, and one end of the beam in the left-right direction is welded to the side portion of the central frame. Here, the upper surface side of the transverse plate of the beam of the side frame is welded to the side portion of the central frame, while the lower surface side of the transverse plate of the beam of the side frame is not welded to the side portion of the central frame. The bottom portion of the central frame covers the lower surface of the transverse plate of the beam of the side frame from below.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 2018-053452

[0008] As described above, the lower surface side of the horizontal plate of the beam of the side frame is not welded to the side surface of the center frame in Patent Document 1. When this conventional structure is adopted, if an upward load is applied to the side deck, there is a concern that the strength of the welded portion between the beam and the side surface of the center frame is insufficient.

[0009] On the other hand, when the slewing bearing provided on the bottom plate of the central frame has a large diameter, the bottom plate provided with the slewing bearing will protrude greatly in the left-right direction relative to the longitudinal plate of the central frame and largely cover the side frame, making it difficult to weld the lower surface of the transverse plate of the beam of the side frame to the side surface of the central frame. Summary of the invention

[0010] An object of the present invention is to provide a frame structure of a construction machine capable of improving the workability of welding work and improving the strength against upward loads.

[0011] The frame structure of the engineering machinery of the present invention includes: an upper frame having a middle part and a side deck, the middle part includes a longitudinal plate extending in the front-to-back direction, the side deck includes a cross beam extending in the left-right direction, the cross beam having one end connected to the longitudinal plate and the other end configured to be away from the longitudinal plate; and a reinforcing plate having an upper surface and a lower surface, the reinforcing plate strengthens the connection between the longitudinal plate and the cross beam by being welded to the longitudinal plate and the cross beam respectively; wherein a welding torch entry space is formed between the middle part and the side deck, allowing the welding torch to enter toward the welding portion between the lower surface of the reinforcing plate and the longitudinal plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view showing a frame structure according to the first embodiment of the present invention.

[0013] Figure 2A It is a plan view of the reinforcing plate according to the first embodiment of the present invention.

[0014] Figure 2B It is a horizontal cross-sectional view showing a mounting state of the reinforcing plate according to the first embodiment of the present invention.

[0015] Figure 2C It is a longitudinal sectional view showing a mounting state of the reinforcing plate according to the first embodiment of the present invention.

[0016] Figure 3A It is a front cross-sectional view showing a welded portion of the reinforcing plate according to the first embodiment of the present invention.

[0017] Figure 3B It is a front cross-sectional view showing a welded portion of the reinforcing plate according to the first embodiment of the present invention.

[0018] Figure 4 It is an enlarged perspective view showing a frame structure according to a second embodiment of the present invention.

[0019] Figure 5A It is a plan view of a reinforcing plate according to a second embodiment of the present invention.

[0020] Figure 5B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a second embodiment of the present invention.

[0021] Figure 5C It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a second embodiment of the present invention.

[0022] Figure 6 It is an enlarged perspective view showing a frame structure according to a third embodiment of the present invention.

[0023] Fig. 7A It is a top view showing a reinforcing plate according to a third embodiment.

[0024] Figure 7B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a third embodiment of the present invention.

[0025] Figure 7C It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a third embodiment of the present invention.

[0026] Fig.7D It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a third embodiment of the present invention.

[0027] Figure 8 It is a front cross-sectional view showing a welded portion according to a third embodiment of the present invention.

[0028] Fig. 9A It is a plan view showing a reinforcing plate according to a fourth embodiment of the present invention.

[0029] Fig. 9B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a fourth embodiment of the present invention.

[0030] Fig. 9C It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a fourth embodiment of the present invention.

[0031] Fig.9D It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a fourth embodiment of the present invention.

[0032] Fig. 10A It is a plan view showing a reinforcing plate according to a fifth embodiment of the present invention.

[0033] Fig. 10B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a fifth embodiment of the present invention.

[0034] Fig. 10CIt is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a fifth embodiment of the present invention.

[0035] Fig. 10D It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a fifth embodiment of the present invention.

[0036] Fig.11 It is an enlarged perspective view showing a frame structure according to a sixth embodiment of the present invention.

[0037] Fig. 12A It is a plan view showing a reinforcing plate according to a sixth embodiment of the present invention.

[0038] Fig. 12B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a sixth embodiment of the present invention.

[0039] Fig. 12C It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a sixth embodiment of the present invention.

[0040] Fig.12D It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a sixth embodiment of the present invention.

[0041] Fig.13 It is a front cross-sectional view showing a welded portion according to a sixth embodiment of the present invention.

[0042] Fig.14 It is a perspective view showing a frame structure according to a seventh embodiment of the present invention.

[0043] Fig.15A It is a plan view showing a reinforcing plate according to a seventh embodiment of the present invention.

[0044] Fig. 15B It is a horizontal cross-sectional view showing a mounting state of a reinforcing plate according to a seventh embodiment of the present invention.

[0045] Fig. 15C It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a seventh embodiment of the present invention.

[0046] Fig.15D It is a longitudinal sectional view showing a mounting state of a reinforcing plate according to a seventh embodiment of the present invention. DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 11 is an overall perspective view showing the structure of an upper frame as one embodiment of the present invention. The upper frame 10 is a frame of an upper rotating body of a construction machine, and is mounted on a lower traveling body via a slewing bearing (not shown). The construction machine is a construction machine, an agricultural machine, or a machine that performs other operations. The upper frame 10 of this embodiment is mounted on a hydraulic excavator, for example.

[0048] The upper frame 10, which is substantially rectangular, comprises: a middle portion 11, which is arranged in the middle portion in the width direction of the upper frame; and side decks 12, which are arranged on both sides of the width direction of the upper frame. The middle portion 11 includes: a pair of longitudinal plates 13, which extend in the front-rear direction of the upper frame and are arranged facing each other; and a bottom plate 15, which connects the lower end edges of the longitudinal plates 13 to each other.

[0049] The vertical plate 13 is a steel plate extending in the vertical direction. The vertical dimension of the vertical plate 13 is set to be smaller at the front end 13b and the rear end 13d, larger in the middle of the front-back direction, and even larger at the top 13c. In other words, the vertical dimension of the vertical plate 13 is set to gradually decrease as it goes from the top 13c to the front or back.

[0050] The bottom plate 15 is a steel plate extending in the front-rear direction and the width direction of the upper frame (hereinafter referred to as the front-rear direction and the width direction). A slewing bearing (not shown) is provided in the central area of ​​the bottom plate 15. The outer diameter of the slewing bearing may be smaller than the distance between the pair of longitudinal plates 13, 13, or may be larger than the distance between the pair of longitudinal plates 13, 13.

[0051] A boom foot pin mounting hole 13f is formed through the top 13c. The boom of the excavator is connected to the boom foot pin mounting hole 13f by a pin not shown. A boom cylinder mounting hole 13g is formed through the front end 13b. The boom cylinder that moves the boom is connected to the boom cylinder mounting hole 13g by a pin not shown.

[0052] The side deck 12 includes a frame material 14 extending in the front-to-back direction and cross beams 16 and 18 extending in the width direction (left-right direction). A plurality of cross beams 16 and 18 are arranged at intervals in the front-to-back direction. In addition, different cross-sectional shapes are selected for the cross beams 16 and 18 according to their front-to-back direction positions or the equipment (not shown) placed on the cross beams 16 and 18. In the present embodiment, the cross beam 18 arranged in the front-to-back direction central part of the upper frame 10 is composed of a beam longitudinal plate 22 and a beam upper plate 24 extending in the front-to-back direction from the upper edge of the beam longitudinal plate 22. One end of the cross beam 18 is welded to the longitudinal plate 13 of the middle part 11. The other end of the cross beam 18 is arranged at a position away from the longitudinal plate 13 and is welded to the frame material 14. The frame material 14 is, for example, a D-shaped tube with a D-shaped cross section, or a C-shaped tube with a C-shaped cross section (not shown).

[0053] The reinforcing plate 21 as a reinforcing member extends between the transverse beam 18 and the longitudinal plate 13 and is welded. The reinforcing plate 21 reinforces the connection between the transverse beam 18 and the longitudinal plate 13. The reinforcing plate 21 of the first embodiment is installed in an inclined posture with the middle part 11 side at the bottom and the deck 12 side at the top. That is, the reinforcing plate 21 includes an inclined portion that is inclined upward from the longitudinal plate 13 toward the outside in the left-right direction.

[0054] FIG. 2 is a diagram showing a reinforcing plate and a welding portion, wherein: Figure 2A is a top view showing only the reinforcing plate 21, Figure 2B 2 is a horizontal cross-sectional view showing the state of the reinforcement plate 21 when viewed from the beam upper plate 24. Figure 2C This is a longitudinal sectional view when the above-mentioned installation state is viewed from the side deck 12 side along the extending direction of the cross beam 18 .

[0055] First, the longitudinal plate 13 is supplemented with the following description: Figure 2B As shown in FIG. 1 , the single longitudinal plate 13 is formed by arranging two steel plates 13d and 13g having different thicknesses in a front-to-back manner and joining the edges of the two plates together by welding. Figure 2C As shown in FIG. 1 , the welding trace is a weld bead 13k (welding seam) extending in the vertical direction. Figure 2B As shown, the weld bead 13k is provided on the outer side surface of the longitudinal plate 13 (the surface on the side of the side deck 12), and the outer side surfaces in the width direction of the longitudinal plate 13 are aligned to form a single surface. In contrast, a stepped joint 13j exists on the inner side surface of the longitudinal plate 13 (the surface where the longitudinal plates 13, 13 face each other). The joint 13j can be welded.

[0056] The cross beam 18 of the first embodiment is a so-called channel steel, which includes a pair of parallel beam longitudinal plates 22, 22 and a beam upper plate 24 that connects the upper edges of the beam longitudinal plates 22, 22, and is in a downwardly open posture. One end of the cross beam 18 is welded to the longitudinal plate 13 at a position intersecting with the weld bead 13k. Specifically, the beam upper plate 24 intersects with the weld bead 13k, and the beam longitudinal plates 22, 22 are arranged in front and rear with respect to the weld bead 13k. Since the two side surfaces of the beam longitudinal plate 22 face the front-rear direction, it is also called the front side surface or the rear side surface.

[0057] Reference Figure 2AThe reinforcing plate 21 is a flat steel plate and is provided with a slit 23. When the middle portion 11 side is one edge 25 and the side deck 12 side is the other edge 27, the slit 23 starts from the other edge 27 and extends from the other edge 27 to the one edge 25 and ends in the middle without reaching the one edge 25. In the first embodiment, two slits 23, 23 are arranged in parallel, and the interval between the slits 23, 23 corresponds to the interval between the beam longitudinal plates 22, 22. The reinforcing plate 21 of this embodiment has a constant overall plate thickness. However, in order to realize the V-shaped groove or other grooves described later, one edge 25 is chamfered and its plate thickness is set to be thinner toward the end.

[0058] The outer edge shape of the reinforcing plate 21 is set as follows: one edge 25 is a straight line shape, and the other edge 27 is a non-straight line shape, for example, the part near the slit 23 is farthest from the one edge 25, and the part farther from the slit 23 is closer to the one edge 25. In the following description, the outer edge between the slits 23 and 23 is also referred to as a notch edge 29. Alternatively, as a modified example not shown in the figure, the reinforcing plate 21 can also be set to a quadrilateral shape by setting the outer edge on the opposite side of the one edge 25 to a straight line shape.

[0059] The beam longitudinal plate 22 is inserted into the slit 23, and the reinforcing plate 21 and the beam longitudinal plate 22 are welded along the slit 23. In addition, one edge 25 of the reinforcing plate 21 is arranged below the other edge 27, and the reinforcing plate 21 is welded to the middle part 11 and the side deck 12 in an inclined posture. One edge 25 forms a V-shaped groove with the outer side surface of the longitudinal plate 13 on the upper surface 21u side, and is welded to the outer side surface of the longitudinal plate 13 on the upper surface 21u side of the reinforcing plate 21. In addition, one edge 25 forms a V-shaped groove with the surface of the middle part 11 on the lower surface 21d side, and is welded to the outer side surface of the longitudinal plate 13 on the lower surface 21d side. Figure 2B , Figure 2C As shown, the welding traces are an upper surface side weld bead 25u and a lower surface side weld bead 25d extending in the front-rear direction.

[0060] Figure 3A , Figure 3B 2 is a front cross-sectional view showing the welded portion between the middle portion and the side deck, and shows the state viewed in the front-rear direction of the upper frame. Regarding the inclined reinforcing plate 21, the lower surface 21d of the reinforcing plate 21 faces the bottom plate 15, and the upper surface 21u of the reinforcing plate 21 faces the longitudinal plate 13. Figure 3A , Figure 3B As shown, a torch interference avoidance space is provided between the middle portion 11 and the side decks 12 to prevent the welding torches Td and Tu from interfering with the middle portion 11 and the side decks 12 .

[0061] Specifically, if Figure 3A As shown in the figure, a welding torch interference avoidance space is defined between the lower surface 21d (inclined portion) of the reinforcing plate 21 and the bottom plate 15, and the welding torch Td is inserted into the space. The distal end of the welding torch Td reaches the butt joint between the outer side surface of the longitudinal plate 13 and the lower surface 21d of the reinforcing plate 21, and the lower surface side weld bead 25d is generated by welding the two. The lower surface side weld bead 25d is formed to cover the weld bead 15u of the outer side surface of the longitudinal plate 13 and the upper surface of the bottom plate 15 that already exists, and is integrated with a part or all of the weld bead.

[0062] In addition, if Figure 3B As shown, a welding torch interference avoidance space is also defined between the upper surface 21u of the reinforcing plate 21 and the longitudinal plate 13, and the welding torch Tu can be inserted into the space. The distal end of the welding torch Tu reaches the butt joint between the outer side surface of the longitudinal plate 13 and the upper surface 21u of the reinforcing plate 21, and the upper surface side weld bead 25u is generated by welding the two.

[0063] The welding torch interference avoidance space is a space larger than the outer diameter of the distal end of the welding torch Td and Tu, and can allow at least the distal end portion of the welding torch Td and Tu to enter and exit, and preferably, can allow the entire welding torch Td and Tu to enter and exit. In other words, the welding torch interference avoidance space is formed between the middle portion 11 and the side deck 12 to form the lower surface side weld bead 25d and the upper surface side weld bead 25u. The welding torch entry space allows the welding torch Td and Tu to enter toward the welded portion between the lower surface of the reinforcing plate 21 and the longitudinal plate 13.

[0064] like Figure 3A As shown in FIG. 1 , the beam longitudinal plate 22 at one end of the horizontal beam 18 is formed with notches 22u, 22d and a tongue 22t protruding toward the middle portion 11 between the notches 22u, 22d. The tongue 22t is directed toward the longitudinal plate 13 at an inclination angle α. By passing the welding torch Td through the notch 22d, the lower surface side weld bead 25d can extend forward and backward through the notch 22d, and the welding length ( Figure 2C 3, by passing the welding torch Tu through the notch 22u, the upper surface side weld bead 25u can pass through the notch 22u and extend forward and backward, thereby ensuring the welding length ( Figure 2B ). Furthermore, since the tongue portion 22t of the beam longitudinal plate 22 is welded while being inserted into the slit 23 of the reinforcing plate 21, the welding length of the beam longitudinal plate 22 and the reinforcing plate 21 can be ensured. Figure 3B The other side of the reinforcing plate 21 including the other edge 27 is welded to the beam longitudinal plate 22. Specifically, it is welded to the center portion of the horizontal beam 18 in the vertical direction.

[0065] The first embodiment includes two beam longitudinal plates 22, but the notch 22u may be omitted when there is only one beam longitudinal plate 22 as in the second embodiment described later. Figure 3B 2 shows a case where the notch 22u is not provided. In the case where there is one beam longitudinal plate 22, the welding torches Tu and Td only need to be inserted into the respective welding torch interference avoidance spaces on the front side and the rear side of the beam longitudinal plate 22. The inclination angle α of the reinforcing plate 21 relative to the extending direction of the horizontal beam 18 is a predetermined value within a range of 20° to 70°.

[0066] According to the first embodiment, since the lower surface side of the reinforcing plate 21 and the longitudinal plate 13 are welded by the lower surface side weld bead 25d, even if the upward load F is applied to the cross beam 18 as shown in FIG3, the lower surface side weld bead 25d supports the upward load F, and can prevent the welded portion of the reinforcing plate 21 and the longitudinal plate 13 from cracking from the root of the fracture of the lower surface side of the reinforcing plate 21. In particular, when the diameter of the slewing bearing provided on the bottom plate 15 is larger than the distance between the longitudinal plates 13, 13, since the upward load F is larger than before, the practical benefit of the first embodiment is greater.

[0067] The reinforcing plate 21 is arranged below the neutral axis Va of the cross beam 18. If arranged below, the cross beam 18 has a larger cross-sectional inertia moment, thereby ensuring the rigidity of the upper frame 10. Figure 1 The actual benefit is greater when a box or other heavy objects are mounted on the cross beams 16, 18, 16. Although one side and the other side of the reinforcing plate 21 are located below the neutral axis Va, as a modification not shown in the figure, the other side of the reinforcing plate 21 may also coincide with the neutral axis Va or be arranged above the neutral axis Va. The neutral axis described in this specification refers to a position where no stress intensity is generated in the cross section when a bending moment is generated in the cross beam.

[0068] In addition, the outer edge 15f of the bottom plate 15 is located directly below the reinforcing plate 21. Alternatively, as a modified example, the bottom plate 15 may extend beyond the longitudinal plate 13 and greatly extend to the side deck 12 side. The outer edge 15g of the bottom plate 15 of the modified example is located outside in the width direction relative to the reinforcing plate 21. The portion of the bottom plate 15 extending outside the longitudinal plate 13 constitutes the facing portion of the present invention. The facing portion faces the lower surface of the reinforcing plate 21.

[0069] As shown in Figure 2 to Figure 4As shown in the various figures, in the present embodiment, the following technical idea is possessed: the reinforcing plate 21 for reinforcing the joint between the cross beam 18 and the longitudinal plate 13 is tilted upward toward the left and right sides with the welding portion between the reinforcing plate 21 and the longitudinal plate 13 as the lower end, so that the welding torch Td can easily approach and access the welding portion. As a result, even if a part (opposing portion) of the bottom plate 15 protrudes downward, the weld bead 15u (welding portion) can be easily and stably formed. Furthermore, in order to allow the welding torch Td to more easily enter such a welding portion, a welding torch interference avoidance space is formed by forming a notch portion 22u in the beam longitudinal plate 22. The welding torch interference avoidance space is formed at a position that is at least above the lowermost end portion of the cross beam 18. Furthermore, in order to allow the welding torches Tu and Td to each easily enter and to suppress a decrease in the rigidity of the beam longitudinal plate 22, a space is provided between the upper and lower notches. Figure 3A By welding the tongue portion 22 t as shown to the reinforcing plate 21 , it is possible to improve the bonding strength among the vertical plate 13 , the horizontal beam 18 , and the reinforcing plate 21 .

[0070] Next, a second embodiment of the present invention will be described. Figure 4 is an enlarged perspective view showing the frame structure of the second embodiment, which corresponds to Figure 1 FIG5 is a diagram showing a reinforcing plate according to a second embodiment. Figure 5A , Figure 5B , Figure 5C Corresponds to Figure 2A , Figure 2B , Figure 2C 3 is applied to the second embodiment by replacing the reference numeral 21 with the reference numeral 31, and the outer edge 15g is located outside in the width direction relative to the reinforcing plate 31. With respect to the second embodiment, the same reference numerals are attached to the common configurations with the above-mentioned embodiment and the description thereof is omitted, and the different configurations are described below.

[0071] like Figure 4 As shown, the cross beam 18 of the second embodiment is formed into an inverted L-shaped cross section, in other words, it is composed of a beam upper plate 24 and a beam longitudinal plate 22. The beam upper plate 24 is provided with a through hole 24h for mounting and fixing a box or equipment not shown. Thus, the cross beam 18 supports the box, etc. from below. Figure 5A As shown, the reinforcing plate 31 of the second embodiment is substantially isosceles triangular in shape, and a slit 23 is formed at the other edge 27 farthest from the one edge 25. The reinforcing plate 31 is welded to the middle portion 11 and the side deck 12 at an inclined posture of an inclined angle α, similarly to the reinforcing plate 21 in FIG. 3 .

[0072] The upper frame of the second embodiment can also improve the strength against the upward load F shown in FIG. 3 and improve the strength against the reverse downward load P, similarly to the above-described embodiment.

[0073] In addition, as a modified example not shown in the figure, the slit 23 may be divided by a virtual straight line extending along the slit 23. Figure 5A The reinforcing plate 31 shown in FIG. 1 and at least one of the two reinforcing plates after being divided is as shown in FIG. Figure 3B As shown, it is welded to at least one of the front side surface and the rear side surface of the beam longitudinal plate 22.

[0074] Next, a third embodiment of the present invention will be described. Figure 6 3 is an enlarged perspective view showing the frame structure of the third embodiment. Figure 1 FIG. 7 is a diagram showing the reinforcing plate and the welding position. Fig. 7A This is a top view showing only the reinforcing plate. Figure 7B 2 is a horizontal plan view showing the state of the reinforcement plate when viewed from the beam upper plate 24. Figure 7C and Fig.7D This is a longitudinal sectional view when the above-mentioned installation state is viewed from the side deck 12 side along the extending direction of the cross beam 18 . Figure 8 2 is a front cross-sectional view showing the welded portion between the middle portion and the side deck, and shows the state when viewed along the front-rear direction of the upper frame. Regarding the third embodiment, the same reference numerals are attached to the common configurations with the above-mentioned embodiment and the description thereof is omitted, and the different configurations are described below. In the third embodiment, a reinforcing plate 34 is provided instead of the above-mentioned reinforcing plates 21 and 31. The reinforcing plate 34 is basically the same shape as the above-mentioned reinforcing plate 21 (FIG. 2).

[0075] like Fig. 7A As shown, the slit 23 extends straight toward the one edge 25 starting from the other edge 27 of the reinforcing plate 34 and terminates midway between the other edge 27 and the one edge 25. No slit is formed in the dot-dash line portion extending from the terminal 23f of the slit 23 further to the one edge 25 in the same direction as the extending direction of the slit 23. The lower edge of the beam longitudinal plate 22 described later abuts against the dot-dash line portion.

[0076] Figure 7C The cross-sectional view is in Figure 8 The middle figure is a diagram in which one end portion of the beam 18 is viewed in a cross section along the arrow direction at cc. Fig.7D The cross-sectional view is in Figure 8 The cross beam 18 of the third embodiment is a so-called channel steel, which includes a pair of parallel beam longitudinal plates 22, 22 and a beam upper plate 24 that connects the upper edges of the beam longitudinal plates 22, 22, and is in a downwardly open posture.

[0077] The bottom plate 15 extending in the front-to-back direction includes a weld bead 15k (welded seam) at a front-to-back position different from the front-to-back position of the weld bead 13k. The weld bead 15k extends in the width direction and integrates the front bottom plate member and the rear bottom plate member. In addition, the front-to-back positions of the weld beads 13k and 15k overlap with the front-to-back position of the reinforcing plate 34.

[0078] contrast Figure 7C , Fig.7D And refer to Figure 8 , the lower edge of the beam longitudinal plate 22 is set at a relatively high position (second lower edge) at one end of the cross beam 18 and is set at a relatively low position (first lower edge) in the central area of ​​the extension direction (left-right direction) of the cross beam 18. The lower edges of these beam longitudinal plates form a step 26 (connected by the step 26) at their continuous position. In this way, at one end of the cross beam 18, approximately the lower half of the beam longitudinal plate 22 is cut off. Moreover, a welding torch interference avoidance space is ensured in the front-to-back direction range of the cutout, and the welding torch Td can be inserted into the space. That is, the welding torch interference avoidance space is formed on the lower surface side of the reinforcing plate 34 between the longitudinal plate 13 in the middle part and the step 26. At this time, the welding torch interference avoidance space is formed at a position at least above the lowermost end of the cross beam 18. In addition, the upper surface 34u of the reinforcing plate abuts against the lower edge of the cut-out beam longitudinal plate 22. Specifically, referring to Fig. 7A The dotted line portion on the upper surface of the reinforcing plate abuts against the lower edge of the beam longitudinal plate 22. This abutting state is shown in FIG. Figure 7C sectional view. In addition, the lower edge of the beam longitudinal plate 22 and the reinforcing plate 34 are welded to each other at the abutting portion. The welding mark is a weld bead 33u. The weld bead 33u extends along the upper surface of the reinforcing plate 34. In addition, the weld bead 33u extends along the surface of the beam longitudinal plate 22 on the opposite side to the other beam longitudinal plate 22 that is paired with it.

[0079] Fig.7D The cross-sectional view of FIG. 2 shows the slit 23 of the reinforcing plate 34 and the beam longitudinal plate 22 inserted into the slit 23. The slit 23 receives the beam longitudinal plate 22. The cross section is Figure 8 The cross section is a cross section when the cross section dd is observed along the arrow direction. The reinforcing plate 34 and the beam longitudinal plate 22 are welded to each other at the slit 23. The welding mark is the weld bead 33d described above. The weld bead 33d extends along the lower surface of the reinforcing plate 34. In addition, the weld bead 33d extends along the surface on the opposite side of the inner surface of the beam longitudinal plate 22 (the so-called outer surface) of the two surfaces of the beam longitudinal plate 22 facing each other.

[0080] The reinforcing plate 34 extends from one end of the beam 18 to the central region in the extending direction beyond the step 26. However, the reinforcing plate 34 is less than half the length of the beam 18 and is slightly spaced from the other end of the beam 18.

[0081] According to the third embodiment, Figure 8 As shown, since a welding torch interference avoidance space is provided between the middle portion 11 and the side deck 12, the welding torch Td can be inserted into the space, and the lower surface side of the reinforcing plate 34 can be welded to the longitudinal plate 13. Therefore, the lower surface side of the reinforcing plate 34 is welded to the longitudinal plate 13, and the strength against the upward load F (FIG. 3) applied to the cross beam 18 is increased.

[0082] Furthermore, since the reinforcing plate 34 extends across the lower edges of the front beam longitudinal plate 22 and the rear beam longitudinal plate 22 at one end of the cross beam 18 , one end of the cross beam 18 is firmly welded to the longitudinal plate 13 , thereby improving the strength of one end of the cross beam 18 .

[0083] According to the third embodiment, similarly to the above-described embodiments, the reinforcing plate 34 is disposed below the neutral axis Va. Therefore, even if a heavy object such as a box is placed on the upper surface of the beam 18, the beam 18 can reliably support the downward load applied from the heavy object.

[0084] In addition, due to the torch interference avoidance space, the lower side of the beam longitudinal plate 22 is cut out at one end of the cross beam 18 and is considered to be insufficient in strength. However, as described above, the strength of the welded portion is improved, and Figure 7C As shown, the cross member 18 is formed as a closed cross section based on the reinforcing plate 34, which eliminates the lack of strength caused by forming a cutout.

[0085] In addition, as a modified example not shown in the figure, it is also possible to Fig. 7A The dashed lines extending straight from the slits 23 and 23 shown in FIG. 2 divide the reinforcing plate 34, and at least one of the three reinforcing plates after division is formed as shown in FIG. Figure 7B As shown, it is welded to at least one of the front side surface and the rear side surface of the beam longitudinal plate 22.

[0086] In addition, as a modified example not shown in the figure, Fig. 7A The position of the other edge 27 shown in the figure is changed to the position of the terminal 23f of the slit 23, and the other edge 27 is brought close to the one edge 25 to realize a reinforcing plate without the slit 23. The reinforcing plate of this modified example has a dotted line portion as shown in FIG. Figure 7C As shown in the cross-sectional view of FIG. 2 , the reinforcing plate of the modified example does not exceed the step 26, so the central area and the other end of the beam 18 are separated by a certain distance from each other in the extending direction of the beam 18.

[0087] Next, a fourth embodiment of the present invention will be described. FIG. 9 is a diagram showing a reinforcing plate according to the fourth embodiment. Fig. 9A , Fig. 9B , Fig. 9C , Fig.9D Corresponding to the above-mentioned FIG. 7 Fig. 7A , Figure 7B , Figure 7C , Fig.7D The above-mentioned Figure 8 The fourth embodiment is applied by replacing reference numeral 34 with reference numeral 35. Regarding the fourth embodiment, the same reference numerals are given to the same configurations as those in the above-mentioned embodiment, and the description thereof is omitted. The different configurations are described below.

[0088] As shown in the drawings of Fig. 9, the fourth embodiment includes a reinforcing plate 35 instead of the reinforcing plate 34. The reinforcing plate 35 is in a strip shape, and the other side portion including the other edge 27 is formed to be tapered toward the far end. The two reinforcing plates 35 are welded to the middle portion 11 and the side deck 12 in a posture parallel or substantially parallel to the neutral axis Va of the beam 18, similarly to the reinforcing plates 34 described above.

[0089] The reinforcing plate 35 of the fourth embodiment is Fig. 7A The modification of the reinforcing plate 34 of the third embodiment shown in FIG. 1 is a modification of the reinforcing plate 34 of the third embodiment, in which the plate portion including the notch edge 29 is removed from the reinforcing plate 34 and the plate portion including the slits 23, 23 remains. Therefore, the reinforcing plate 35 of the fourth embodiment can also achieve improved strength against the upward load F shown in FIG. 3 and improved strength against the reverse downward load P, as the reinforcing plate 34 of the third embodiment.

[0090] Next, the fifth embodiment of the present invention will be described. FIG10 is a diagram showing a reinforcing plate according to the fifth embodiment. Fig. 10A , Fig. 10B , Fig. 10C , Fig. 10D Corresponding to the above-mentioned FIG. 7 Fig. 7A , Figure 7B , Figure 7C , Fig.7D The above-mentioned Figure 8 By replacing the reference numeral 34 with the reference numeral 36h, the fifth embodiment is applied. Regarding the fifth embodiment, the same reference numerals are given to the same configurations as those in the above-mentioned embodiment, and the description thereof is omitted. The different configurations are described below.

[0091] As shown in the drawings of FIG. 10 , the fifth embodiment includes three reinforcing plates 36h, 36i, and 36j instead of the reinforcing plate 34 described above. The central reinforcing plate 36i has one edge 25, the other edge 27, the notch edge 29, the front edge 36l, and the rear edge 36m as the outline. The front edge 36l and the rear edge 36m extend parallel to each other, and the interval between them corresponds to the pair of beam longitudinal plates 22, 22. The reinforcing plate 36h arranged on the front side of the reinforcing plate 36i has one edge 25, the other edge 27, and the rear edge 36k as the outline. The reinforcing plate 36j arranged on the rear side of the reinforcing plate 36i has one edge 25, the other edge 27, and the front edge 36n as the outline.

[0092] Reference Fig. 10B The central reinforcing plate 36i is arranged between a pair of beam longitudinal plates 22, 22. The other reinforcing plate 36h is arranged on the opposite side of the central reinforcing plate 36i with respect to one beam longitudinal plate 22. The remaining reinforcing plate 36h is arranged on the opposite side of the central reinforcing plate 36i with respect to the other beam longitudinal plate 22.

[0093] The front edge 361 and the rear edge 36m of the central reinforcing plate 36i are welded to the inner surfaces facing each other in the pair of beam longitudinal plates 22, 22. The rear edge 36k of the front reinforcing plate 36h and the front edge 36n of the rear reinforcing plate 36h are welded to the outer surfaces of the pair of front and rear beam longitudinal plates 22, 22, respectively.

[0094] Reference Fig. 10A The reinforcing plates 36h, 36i, and 36j of the fifth embodiment are Fig. 7A The modification of the reinforcing plate 34 of the third embodiment shown in FIG. 1 divides the reinforcing plate 34 by extending the slits 23, 23 from the other edge 27 to the one edge 25. Therefore, the reinforcing plates 36h, 36i, and 36j of the fifth embodiment can also achieve improved strength against the upward load F shown in FIG. 3 and improved strength against the reverse downward load P, as in the reinforcing plate 34 of the third embodiment.

[0095] Next, a sixth embodiment of the present invention will be described. Fig.11 is an enlarged stereoscopic view showing the frame structure of the sixth embodiment. Figure 1 FIG12 is a diagram showing the reinforcing plate and the welding position. Fig. 12A This is a diagram showing only the reinforcing plate. Fig. 12B 2 is a horizontal plan view showing the state of the reinforcement plate when viewed from the beam upper plate 24. Fig. 12C and Fig.12D This is a longitudinal sectional view when the above-mentioned installation state is viewed from the side deck 12 side along the extending direction of the cross beam 18 . Fig.13It is a front cross-sectional view showing the welding part between the middle part and the side deck, showing the state when viewed along the front-rear direction of the upper frame. Regarding the sixth embodiment, the same symbols are attached to the common structures with the above-mentioned embodiments and their descriptions are omitted, and the different structures are described below.

[0096] In the sixth embodiment, a reinforcing plate 37 is provided instead of the reinforcing plate 34 ( Figures 6 to 8 ) The reinforcing plate 37 is a modified example of the reinforcing plate 34 described above, and has a partially common shape.

[0097] The reinforcing plates 34, 35, 36h, 36i, and 36j described above have dimensions that are slightly longer than the length of one end of the entire length of the cross beam 18. In contrast, the reinforcing plate 37 of the sixth embodiment is a reinforcing plate that has the same dimensions as the entire length of the cross beam 18. Fig.13 As shown, the other edge 27 of the reinforcing plate 37 is in contact with the frame material 14 , and is preferably welded to the frame material 14 .

[0098] Specifically, refer to Fig. 12A , the dimension from one edge 25 to the notch edge 29 is smaller than the distance from the longitudinal plate 13 to the step 26, and in this respect, the reinforcing plate 37 is common to the reinforcing plate 34. However, the dimension from one edge 25 to the other edge 27 of the reinforcing plate 37 is much larger than the dimension from one edge 25 to the other edge 27 of the reinforcing plate 34. In addition, the slit 23 of the reinforcing plate 37 is much longer than the slit 23 of the reinforcing plate 34. The slit depth dimension from the starting end (the other edge 27) of the slit 23 to the terminal end 23f of the slit 23 is larger than the dimension from one edge 25 to the notch edge 29. Moreover, the entire central area of ​​the extending direction of the beam longitudinal plate 22 is inserted into the long slit 23 of the reinforcing plate 37.

[0099] The reinforcing plate 37 extends from one end of the beam 18 to the other end beyond the step 26. As a modified example of the fifth embodiment not shown in the figure, the reinforcing plate may be about half the total length of the beam 18, and may extend from one end of the beam 18 to the central area in the extending direction beyond the step 26, and may be spaced apart from the other end of the beam 18 by a certain distance. Alternatively, as another modified example, the reinforcing plate is set to be a length that is a certain degree shorter than the total length of the beam 18, and extends from one end of the beam 18 to the other end, but the other edge 27 is spaced apart from the frame material 14 by a certain distance via a gap.

[0100] According to the reinforcing plate 37 of the sixth embodiment, the cross beam 18 is reinforced from one end to the other end at the lower side relative to the neutral axis Va. Therefore, it is possible to improve the strength against the upward load F shown in FIG. 3 and improve the strength against the reverse downward load P. In addition, as a modified example not shown in the figure, the slit 23 may be extended from the other edge 27 to the one edge 25 and the reinforcing plate 37 may be extended as shown in FIG. Fig. 10A As shown in the figure, the reinforcing plates are divided into three pieces, and the three reinforcing plates are welded to the cross beam 18 and the longitudinal plate 13.

[0101] Next, a seventh embodiment of the present invention will be described. Fig.14 FIG. 15 is a perspective view showing a frame structure of the seventh embodiment. FIG. 16 is a view showing a reinforcing plate and a welding portion. Fig.15A This is a top view showing only the reinforcing plate. Fig. 15B 2 is a horizontal plan view showing the state of the reinforcement plate when viewed from the beam upper plate 24. Fig. 15C and Fig.15D This is a longitudinal sectional view of the installation state when viewed from the side deck 12 along the extending direction of the cross beam 18. Figure 8 The seventh embodiment can be applied by replacing reference numeral 34 with reference numeral 35. Regarding the seventh embodiment, the same reference numerals are given to the same configurations as those in the above-mentioned embodiment, and the description thereof is omitted. The different configurations will be described below.

[0102] The seventh embodiment is basically the same as the fourth embodiment ( FIG. 9 ) described above, but is different from the fourth embodiment in that the horizontal beam 18 has one beam longitudinal plate 22. Fig. 15C and Fig.15D As shown, the horizontal beam 18 of the second embodiment is formed in an inverted L-shaped cross section, in other words, it is composed of one beam upper plate 24 and one beam vertical plate 22 .

[0103] The reinforcing plate 35 is arranged at one end of the horizontal beam 18. Furthermore, the step 26 and the beam longitudinal plate 22 are inserted into the slit 23 of the reinforcing plate 35. The upper surface 35u of the reinforcing plate 35 abuts against the lower edge of one end of the beam longitudinal plate 22. The reinforcing plate 35 is welded to the beam longitudinal plate 22 along the abutting portion and the slit 23. In addition, one edge 25 of the reinforcing plate 35 is welded to the outer side surface of the longitudinal plate 13 on the lower surface 35d side. This welding mark is the lower surface side weld bead 25d.

[0104] According to the reinforcing plate 35 of the seventh embodiment, as in the various embodiments described so far, the welding portion between the longitudinal plate 13 and the cross beam 18 is reinforced, and the strength of the upper frame against the upward load F (Figure 3) applied to the side deck 12 and the reverse downward load P applied to the side deck 12 is improved.

[0105] The embodiments of the present invention are described above with reference to the accompanying drawings, but the present invention is not limited to the illustrated embodiments. Various modifications or deformations may be added to the illustrated embodiments within the same scope as the present invention or within an equal scope. For example, a part of the configuration may be extracted from the first embodiment described above and another part of the configuration may be extracted from the other embodiments described above and these extracted configurations may be combined. For example, after the second embodiment, the reinforcing plate extends in the horizontal direction without being tilted. However, various configurations of the embodiments after the second embodiment may also be applied to the tilted reinforcing plate of the first embodiment.

[0106] The frame structure of the engineering machinery involved in the present invention includes: an upper frame, having a middle part and a side deck, the middle part includes a longitudinal plate extending in the front-to-back direction, the side deck includes a cross beam extending in the left-right direction, the cross beam has one end connected to the longitudinal plate and the other end configured to be away from the longitudinal plate; and a reinforcing plate, having an upper surface and a lower surface, the reinforcing plate strengthens the connection between the longitudinal plate and the cross beam by being welded to the longitudinal plate and the cross beam respectively; wherein a welding torch entry space is formed between the middle part and the side deck, allowing the welding torch to enter toward the welding portion between the lower surface of the reinforcing plate and the longitudinal plate.

[0107] According to such a structure, a welding torch can be inserted into the welding torch entry space, and the lower surface side of the reinforcing plate can be welded to the longitudinal plate of the middle part. Therefore, it is possible to improve the strength of the welding portion between the reinforcing plate and the longitudinal plate of the middle part from the lower surface side of the reinforcing plate, and even if an excessive upward load is repeatedly applied to the cross beam, its strength can be maintained. In addition, even if the middle part has a bottom plate and the bottom plate of the middle part is connected to the lower edge of the longitudinal plate of the middle part, it is possible to ensure a welding torch entry space between the bottom plate of the middle part and the reinforcing plate.

[0108] The posture of the reinforcing plate is not limited, but as one aspect of the present invention, the middle portion may also include a bottom plate integrated with the lower edge of the longitudinal plate, the bottom plate having an opposing portion facing the lower surface of the reinforcing plate, the reinforcing plate including an inclined portion inclined upward from the longitudinal plate toward the outside in the left-right direction, and the welding torch entry space is formed between the inclined portion and the opposing portion of the bottom plate.

[0109] According to such a structure, the inclined portion of the reinforcing plate receives the upward load and the downward load applied to the cross beam, thereby improving the strength of the welded portion between the side deck and the middle portion. In addition, by inserting the welding torch into the space between the inclined portion and the opposing portion of the bottom plate, which becomes narrower as it goes inward, the distal end of the welding torch can reach the intersection of the lower surface of the reinforcing plate and the longitudinal plate.

[0110] As a preferred aspect of the present invention, a portion of the reinforcing plate located on the opposite side in the left-right direction with respect to the welded portion between the reinforcing plate and the vertical plate is welded to a center portion of the horizontal beam in the up-down direction.

[0111] According to such a structure, it is possible to avoid the stress caused by the bending moment of the horizontal beam from being concentrated on the welded portion between the vertical plate and the reinforcing plate.

[0112] The shape of the cross beam is not particularly limited. As another aspect of the present invention, the cross beam may include a beam longitudinal plate and a beam upper plate extending from the upper edge of the beam longitudinal plate toward at least one of the front and rear, the first lower edge of the beam longitudinal plate in the central region of the cross beam in the left-right direction is arranged at a position lower than the second lower edge of the beam longitudinal plate at one end of the longitudinal plate side of the cross beam, the beam longitudinal plate has a step connecting the first lower edge and the second lower edge, the reinforcing plate is welded to the beam longitudinal plate along the second lower edge, and the welding torch entry space is formed between the longitudinal plate in the middle portion and the step on the lower surface side of the reinforcing plate.

[0113] According to such a structure, the lower end of the longitudinal plate side of the cross beam is cut away, thereby forming a space for the welding torch to enter. Therefore, the lower surface side of the reinforcing plate and the longitudinal plate in the middle portion can be welded easily and stably, and the strength of the welded portion can be improved.

[0114] There is no particular limitation on the length of the reinforcing plate in the long side direction of the cross beam. As one aspect of the present invention, the reinforcing plate may be disposed only at one end of the cross beam, and may be spaced apart from the central portion of the cross beam in the extending direction. In other words, the outer end of the reinforcing plate in the left-right direction may be disposed closer to the longitudinal plate side than the central portion of the cross beam in the left-right direction.

[0115] As another aspect of the present invention, the reinforcing plate may extend from one end of the cross beam to the central region in the extending direction of the cross beam, and may be spaced apart from the other end of the cross beam. In other words, the end of the reinforcing plate on the outer side in the left-right direction may be arranged in the central region of the cross beam in the left-right direction, or may be arranged on the outer side in the left-right direction of the central region and closer to the inner side than the end of the cross beam on the outer side in the left-right direction.

[0116] As another aspect of the present invention, the reinforcing plate may extend from one end of the cross beam to the other end, or may be welded to a frame material coupled to the other end of the cross beam. In other words, the reinforcing plate may be configured to extend from the one end of the cross beam in the left-right direction to the other end along the left-right direction.

[0117] Regarding the front-to-back direction of the upper frame, the size of the reinforcing plate is not particularly limited. As one aspect of the present invention, the reinforcing plate may extend across the front and rear sides of the lower edge of the beam longitudinal plate at one end of the cross beam. In other words, the reinforcing plate may be configured to extend along the front-to-back direction across the front and rear sides of the lower edge of the beam longitudinal plate at the one end of the cross beam.

[0118] The shape of the reinforcing plate is not particularly limited. As one aspect of the present invention, the reinforcing plate may have a slit for inserting the longitudinal plate of the beam in the central region of the extending direction of the beam, and the longitudinal plate of the beam in the central region of the extending direction of the beam may be welded to the reinforcing plate at the slit. In other words, the reinforcing plate may have a slit for receiving the longitudinal plate of the beam of the beam, and the longitudinal plate of the beam of the beam may be welded to the reinforcing plate at the slit.

[0119] There is no particular limitation on the configuration of the reinforcing plate. As a preferred aspect of the present invention, two beam longitudinal plates of the cross beam may be provided at intervals in the front-rear direction of the engineering machinery, the upper plate of the cross beam may be integrated with the upper edge of the front beam longitudinal plate and the upper edge of the rear beam longitudinal plate, and the reinforcing plate may extend across the front beam longitudinal plate and the rear beam longitudinal plate. In other words, the cross beam may have at least two beam longitudinal plates arranged at intervals in the front-rear direction of the engineering machinery, the upper plate of the cross beam may connect the upper edge of the front beam longitudinal plate with the upper edge of the rear beam longitudinal plate of the at least two beam longitudinal plates, and the reinforcing plate may be configured to extend across the front beam longitudinal plate and the rear beam longitudinal plate.

[0120] In addition, it may be that, when viewed along the front-to-back direction, the cross beam has a cut-off shape on the lower end side of the one end portion joined to the longitudinal plate so as to include an area where the reinforcing plate is connected to the longitudinal plate, and the welding torch entry space is formed by the cut-off portion of the cross beam at an upper position relative to the lowermost end portion of the cross beam.

[0121] As described above, according to the present invention, the lower surface side of the reinforcing plate and the middle portion can be welded, and the strength of the upper frame against the upward load can be improved.

[0122] The present invention can be advantageously utilized in vehicles or other machines.

Claims

1. A frame structure of an engineering machinery, characterized in that include: an upper frame having a middle portion and a side deck, the middle portion including a longitudinal plate extending in the front-rear direction, the side deck including a cross beam extending in the left-right direction, the cross beam having one end connected to the longitudinal plate and the other end disposed away from the longitudinal plate; and A reinforcing plate having an upper surface and a lower surface, wherein the reinforcing plate is welded to the longitudinal plate and the transverse beam respectively to strengthen the connection between the longitudinal plate and the transverse beam; wherein, A welding torch entry space is formed between the middle portion and the side deck, and a welding torch can be inserted toward a welded portion between the lower surface of the reinforcing plate and the vertical plate.

2. The frame structure of the engineering machinery according to claim 1, characterized in that: The middle portion further includes a bottom plate integrally connected to the lower edge of the longitudinal plate, the bottom plate having an opposing portion facing the lower surface of the reinforcing plate, The reinforcing plate includes an inclined portion that is inclined upward from the longitudinal plate toward the outer side in the left-right direction. The torch entry space is formed between the inclined portion and the opposing portion of the bottom plate.

3. The frame structure of the engineering machinery according to claim 2, characterized in that: A portion of the reinforcing plate located on the opposite side in the left-right direction with respect to the welded portion between the reinforcing plate and the vertical plate is welded to a center portion of the horizontal beam in the up-down direction.

4. The frame structure of engineering machinery according to claim 1, characterized in that: The cross beam includes a beam longitudinal plate and a beam upper plate extending from an upper edge of the beam longitudinal plate toward at least one of the front and rear. The first lower edge of the beam longitudinal plate in the central area of ​​the horizontal beam in the left-right direction is arranged at a position lower than the second lower edge of the beam longitudinal plate at one end of the horizontal beam on the longitudinal plate side, and the beam longitudinal plate has a step connecting the first lower edge and the second lower edge. The reinforcing plate is welded to the beam longitudinal plate along the second lower edge. The torch entry space is formed between the vertical plate and the step in the middle portion on the lower surface side of the reinforcing plate.

5. The frame structure of the engineering machinery according to claim 4, characterized in that: The outer end portion of the reinforcing plate in the left-right direction is arranged closer to the vertical plate than the center portion of the horizontal beam in the left-right direction.

6. The frame structure of engineering machinery according to claim 4, characterized in that: The left-right outer end of the reinforcing plate is arranged in the left-right central region of the cross beam, or arranged outside the central region in the left-right direction and closer to the inside than the left-right outer end of the cross beam.

7. The frame structure of engineering machinery according to claim 4, characterized in that: The reinforcing plate is arranged to extend from the one end portion in the left-right direction of the cross beam to the other end portion along the left-right direction.

8. The frame structure of engineering machinery according to claim 4, characterized in that: The reinforcing plate is arranged to extend in the front-rear direction across the front and rear sides of the lower edge of the beam longitudinal plate at the one end portion of the horizontal beam.

9. The frame structure of engineering machinery according to claim 6, characterized in that: The reinforcing plate has a slit for receiving the longitudinal plate of the beam of the cross beam, The beam longitudinal plate of the cross beam is welded to the reinforcing plate at the slit.

10. The frame structure of an engineering machine according to any one of claims 4 to 9, characterized in that: The cross beam has at least two beam longitudinal plates which are arranged at intervals in the front-rear direction of the construction machine. The upper plate of the horizontal beam connects the upper edge of the front beam longitudinal plate and the upper edge of the rear beam longitudinal plate of the at least two beam longitudinal plates. The reinforcing plate is arranged to extend across the front beam longitudinal plate and the rear beam longitudinal plate.

11. The frame structure of an engineering machine according to any one of claims 1 to 10, characterized in that: When viewed in the front-rear direction, the cross beam has a cut-away shape at the lower end side of the one end portion joined to the longitudinal plate so as to include a region where the reinforcing plate is connected to the longitudinal plate. The torch entry space is formed by a cut-away portion of the beam above the lowermost end of the beam.

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