Construction machinery cabin structure

Abstract

This construction machine cabin structure provides improved strength and rigidity by accurately transmitting the lateral load applied to the cabin's roof rails during ROPS standard lateral load testing to the front header, thereby receiving the axial compressive load on the front header. [Solution] The construction machine's cabin 1 comprises a pair of left and right front pillars 3 extending upward from the floor 2, a roof rail 4 extending to the rear of the vehicle body from the top of the front pillars 3, a bent portion 5 connecting the roof rail 4 and the front pillars 3, and a front header 6 connecting the left and right bent portions 5. When viewed from the side of the vehicle body, it has a bent reinforcing member 9 that is bent in a V-shape from the front pillars 3 through the bent portions 5 and along the roof rails 4. The bent reinforcing member 9 has a pillar fixing portion 9a fixed to the front pillars 3, a header fixing portion 9b fixed to the front header 6, and a rail fixing portion 9c fixed to the roof rails 4.

Description

Technical Field

[0001] The present invention relates to a cab structure of construction machinery such as a hydraulic excavator, and particularly to a cab structure of construction machinery that enhances the strength and rigidity when a force is applied to the cab from the side when the vehicle overturns.

Background Art

[0002] As shown in FIG. 1, as a cab structure Cj of construction machinery such as a hydraulic excavator, a pair of left and right front pillars 3 extending upward from the floor 2 of the cab 1, roof rails 4 extending rearward from the top of the front pillars 3 respectively, rear pillars 12 extending downward from the rear ends of the left and right roof rails 4 to the floor 2, a rear header 17 connecting the tops of the left and right rear pillars 12, a bent portion 5 connecting the roof rail 4 and the front pillar 3, and a front header 6 disposed along the vehicle width direction so as to connect the left and right bent portions 5 are known (see Patent Document 1). A boom (not shown) of a hydraulic excavator or the like is disposed on the right side of the cab 1 (opposite to the opening 7 where the operator gets in).

[0003] The cab structure Cj of this type of construction machinery needs to satisfy a rollover protective structure called ROPS (Rollover Protective Structure) that simulates the load received by the cab 1 when the vehicle overturns. In the ROPS standard, as shown in FIG. 1, a side load test in which a side load Fh is applied to the roof rail 4 on the left side (the opening 7 side, which is opposite to the boom) of the cab 1 from the left, a rear load test in which a front load Fr is applied to the rear header 17 of the cab 1 from the rear, and a vertical load test in which a downward vertical load Fv is applied to the ceiling portion 8 of the cab 1 are performed. When the vehicle overturns, since the roof rail 4 on the right side (the boom side: opposite to the opening 7) of the cab 1 is protected by the boom, the side load test from the right side is not performed.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2018-111926 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, when a lateral load Fh is applied from the left to the roof rail 4 on the left side (opening 7 side) of the cabin 1 during the lateral load test shown in Figure 1, there is a large difference in strength and rigidity against the lateral load Fh between the portion of the roof rail 4 to which the front header 6 is attached and the other portions in the longitudinal direction of the roof rail 4. As shown by the dashed line X in Figure 1, the roof rail 4 bends significantly near the former portion, and there is a risk that it will enter the DLV (Deflection Limiting Volume) inside the cabin 1 as defined by the ROPS standard.

[0006] Furthermore, during the vertical load test shown in Figure 1, if a downward vertical load Fv is applied to the ceiling 8 of the cabin 1, the front pillar 3 may buckle and deform at its weak points (parts with high curvature, parts with notches, etc.) as shown by the dashed line Y in Figure 1, potentially entering the DLV (Deflection Limiting Volume) inside the cabin 1 as defined by the ROPS standard.

[0007] Furthermore, Figures 5A and 6A of Patent Document 1 depict a handrail attached to the front pillar of a construction machine cabin that is bent and extended to the roof rail. However, this handrail is attached only to the front pillar and the roof rail, and does not function as a load transmission member that transmits the lateral load to the front header as an axial compressive load when a lateral load is applied to the roof rail during a lateral load test, thus differing from the present invention.

[0008] The present invention, conceived in consideration of the above circumstances, aims to provide a construction machine cabin structure that can accurately transmit the lateral load applied to the roof rails of the cabin to the front header during ROPS standard lateral load tests, thereby receiving it as an axial compressive load on the front header, and thereby improving strength and rigidity. [Means for solving the problem]

[0009] The present invention, devised to achieve the above objective, provides a cabin structure for a construction machine comprising: a pair of left and right front pillars extending upward from the floor of the cabin of the construction machine; roof rails extending to the rear of the vehicle body from the tops of the front pillars; a bent portion connecting the roof rails and the front pillars; and a front header disposed along the vehicle width direction so as to connect the left and right bent portions to each other. The cabin structure is characterized in that, when viewed from the side of the vehicle body, it comprises a bent reinforcing member that is bent in a V-shape from the front pillars through the bent portions and along the roof rails, and the bent reinforcing member has a pillar fixing portion fixed to the front pillars, a header fixing portion fixed to the front header, and a rail fixing portion fixed to the roof rails.

[0010] In the cabin structure of a construction machine according to the present invention, the roof rail is formed hollow, and a rail reinforcing member is provided inside the roof rail along the longitudinal direction of the vehicle body, and a bending reinforcing member may be fixed to the rail reinforcing member.

[0011] In the cabin structure of a construction machine according to the present invention, the bending reinforcing member may have an extended portion that extends from the bending portion beyond the middle of the roof rail toward the rear of the vehicle body.

[0012] In the cabin structure of a construction machine according to the present invention, the construction machine has a boom on the left or right side of the cabin, and the bending reinforcement member may be provided only on the side of the cabin opposite to the boom.

[0013] In the cabin structure of a construction machine according to the present invention, there is a handrail that extends vertically along the front pillar, the upper part of the handrail may be fixed to a bending reinforcement, and the lower part of the handrail may be fixed to the front pillar. [Effects of the Invention]

[0014] According to the construction machine cabin structure of the present invention, a bending reinforcing member is provided that, when viewed from the side of the vehicle body, extends from the front pillar through a bending portion and along the roof rail in a V-shape. Since the bending reinforcing member has a pillar fixing portion fixed to the front pillar, a header fixing portion fixed to the front header, and a rail fixing portion fixed to the roof rail, when a lateral load is applied to the roof rail in a ROPS standard lateral load test, the lateral load applied to the roof rail is accurately transmitted to the front header via the bending reinforcing member and can be received as an axial compressive load on the front header. As a result, deformation of the roof rail due to lateral load is suppressed, and the strength and rigidity of the cabin are improved. [Brief explanation of the drawing]

[0015] [Figure 1] This perspective view shows the deformation that occurs in the cabin frame of a conventional construction machine cabin structure when the lateral load Fh from the ROPS standard lateral load test and the vertical load Fv from the vertical load test are applied. [Figure 2] This is a perspective view showing an overview of the cabin structure of a construction machine according to the first embodiment of the present invention. [Figure 3] Figure 2 is a side view of the cabin structure of the construction machine according to the first embodiment. [Figure 4] This is an explanatory diagram showing a second embodiment of the present invention, where (a) is a perspective view showing the upper part of the cabin structure of a construction machine according to the second embodiment, and (b) is a partial side view of the upper part thereof. [Figure 5] This is a perspective view showing the upper part of the cabin structure of a construction machine according to a third modified embodiment of the present invention. [Figure 6]It is a perspective view showing the upper part of the cab structure of a construction machine according to a fourth modified embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Dimensions, materials, and other specific numerical values shown in such embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals to omit redundant descriptions, and elements not directly related to the present invention are not shown.

[0017] (First Embodiment: Cab Structure C1 of a Construction Machine) As shown in FIGS. 2 and 3, the cab structure C1 of a construction machine according to the first embodiment of the present invention includes a pair of left and right front pillars 3 extending upward from the floor 2 of the cab 1 of the construction machine, roof rails 4 extending rearward from the top of the front pillars 3, rear pillars 12 extending downward from the rear ends of the left and right roof rails 4 to the floor 2, a rear header 17 connecting the tops of the left and right rear pillars 12, a bent portion 5 connecting the roof rail 4 and the front pillar 3, and a front header 6 disposed along the vehicle width direction so as to connect the left and right bent portions 5 to each other.

[0018] As shown in FIGS. 2 and 3, in the cab structure C1 of the construction machine according to the present embodiment, when viewed from the side of the vehicle body, there is provided a bent reinforcing member 9 bent in a U shape along the roof rail 4 via the bent portion 5 from the front pillar 3. The bent reinforcing member 9 has a pillar fixing portion 9a fixed to the front pillar 3, a header fixing portion 9b fixed to the front header 6, and a rail fixing portion 9c fixed to the roof rail 4.

[0019] As shown in Fig. 2, bolt insertion holes are formed in the pillar fixing portion 9a, the header fixing portion 9b, and the rail fixing portion 9c, respectively. Bolts 10 are inserted into these bolt insertion holes, and each bolt 10 is screwed into a screw hole formed in the front pillar 3 (or a nut welded to the front pillar 3, the same applies hereinafter), a screw hole formed in the front header 6, and a screw hole formed in the roof rail 4. Thereby, the bending reinforcement 9 is fixed to the front pillar 3, the front header 6, and the roof rail 4. In Fig. 3, the bolts 10 are omitted.

[0020] The construction machine to which the cab structure C1 according to the present embodiment is applied is a hydraulic excavator or the like, and a working boom (not shown) is disposed to the right of the cab 1 shown in Fig. 2. According to this configuration, when the vehicle overturns, the lateral load applied from the right to the roof rail 4 on the right side (boom side) of the cab 1 is protected by the boom, and a lateral load Fh is applied from the left to the roof rail 4 on the left side (anti-boom side) of the cab 1. Based on this, the bending reinforcement 9 is disposed only on the left side of the cab on the side opposite to the boom. Further, an opening 7 for the operator to get in is formed on the left side of the cab 1 on the side opposite to the boom where the bending reinforcement 9 is disposed.

[0021] As shown in Figs. 2 and 3, this cab structure C1 has a handrail 11 extending in the vertical direction along the front pillar 3. The handrail 11 assists the operator to grab and get into the cab 1 when the operator gets into the cab 1 from the opening 7 provided on the side opposite to the boom of the cab 1. Therefore, the handrail 11 is disposed only on the front pillar 3 on the left side (opening 7 side) of the cab 1 on the side opposite to the boom. The upper portion 11a of the handrail 11 is fixed to the bending reinforcement 9, and the lower portion 11b is fixed to the front pillar 3. Bolts, nuts, welding, etc. are used for the fixing.

[0022] (Function and Effect) As shown in Figures 2 and 3, the cabin structure C1 of the construction machine according to this embodiment includes a bent reinforcing member 9 that is bent in a V-shape from the front pillar 3 through the bent portion 5 to follow the roof rail 4 when viewed from the side of the vehicle body. The bent reinforcing member 9 has a pillar fixing portion 9a fixed to the front pillar 3, a header fixing portion 9b fixed to the front header 6, and a rail fixing portion 9c fixed to the roof rail 4.

[0023] With this configuration, as shown in Figure 2, when a lateral load Fh is applied to the roof rail 4 in a ROPS standard lateral load test simulating a vehicle rollover, the lateral load Fh applied to the roof rail 4 is accurately transmitted to the front header 6 via the bending reinforcement member 9 and can be received as an axial compressive load on the front header 6. As a result, the large deformation of the roof rail 4 due to the lateral load Fh, as shown by the dashed line X in Figure 1, is avoided, and the deformation of the roof rail 4 due to the lateral load Fh is suppressed. Therefore, the strength and rigidity of the cabin 1 against the lateral load Fh are improved.

[0024] Here, a working boom (not shown) is positioned to the right of the cabin 1 (opposite the opening 7) as shown in Figure 2. When the vehicle rolls over, the lateral load applied from the right to the roof rail 4 on the right side of the cabin 1 (boom side, opposite the opening 7) is protected by the boom. Therefore, when the vehicle rolls over, the lateral load Fh is applied to the cabin 1 from the left side (opening 7 side), and the bending reinforcement member 9 is positioned only on the left side of the cabin 1 (opening 7 side), which is opposite the boom. Thus, the strength and rigidity of the cabin 1 against the lateral load Fh when the vehicle rolls over can be effectively increased at low cost while keeping the weight increase to a minimum.

[0025] Furthermore, as shown in Figures 2 and 3, the cabin structure C1 of the construction machine according to this embodiment has a handrail 11 that extends vertically along the front pillar 3, with the upper part 11a of the handrail 11 fixed to the bending reinforcement member 9 and the lower part 11b of the handrail 11 fixed to the front pillar 3. The middle part of the handrail 11 may also be fixed to the front pillar 3.

[0026] With this configuration, as shown in Figure 2, when a downward vertical load Fv is applied to the ceiling 8 of the cabin 1 in the RPOS standard vertical load test, the downward vertical load Fv is transmitted to the handrail 11 via the bending reinforcement 9 and can be received as an axial compressive load on the handrail 11. As a result, the large deformation of the front pillar 3 due to the vertical load Fv, as shown by the dashed line Y in Figure 1, is avoided, and the deformation of the front pillar 3 due to the vertical load Fv is suppressed. Therefore, the strength and rigidity of the cabin 1 against the vertical load Fv are improved.

[0027] Here, as shown in Figure 2, the handrail 11 functions as an assist grip for the occupant to grasp when entering the cabin 1 through the opening 7, and is therefore installed only on the front pillar 3 on the side opposite the boom where the opening 7 is located (the left side of the cabin 1). Since this opening 7 requires a fairly large area for the occupant to enter, the left side of the cabin 1 where the opening 7 is located (the side opposite the boom) tends to have lower strength and rigidity against a downward vertical load Fv compared to the right side where the opening 7 is not located (the boom side).

[0028] Therefore, in this embodiment, as shown in Figure 2, the upper part 11a of the handrail 11, which is arranged along the front pillar 3 only on the left side of the cabin 1 (the side opposite the boom, the side with the opening 7), is fixed to the bending reinforcement member 9, and the lower part 11b of the handrail 11 is fixed to the front pillar 3, thereby accurately reinforcing the left side of the cabin 1, which tends to lack strength and rigidity against the downward vertical load Fv due to the opening 7. The handrail 11, which functions as a reinforcement member, may be a hollow pipe material, but it may also be a solid rod material to further increase the buckling strength.

[0029] Furthermore, as shown in Figure 2, a boom (not shown) is located on the right side of cabin 1 (opposite the opening 7), so there is no opening for the occupants to enter. A reinforcing diagonal member 13 is provided extending from the floor 2 of cabin 1 to the rear pillar 12. The diagonal member 13 increases the strength and rigidity of the right side of cabin 1 (opposite the opening 7), balancing the strength and rigidity of the left and right sides of cabin 1, which may be affected by the presence or absence of the handrail 11 and the opening 7.

[0030] (Second Embodiment) Figures 4(a) and 4(b) show a cabin structure C2 of a construction machine according to a second embodiment of the present invention. The cabin structure C2 of the construction machine according to the second embodiment has the same configuration as the first embodiment shown in Figures 2 and 3, except that the roof rail 4 of the cabin 1 is formed hollow, a rail reinforcing member 14 is provided inside the roof rail 4 along the longitudinal direction of the vehicle body, and a bending reinforcing member 9 is fixed to the rail reinforcing member 14. For this reason, the same reference numerals are used for components similar to those in the first embodiment, and their descriptions are omitted.

[0031] The rail reinforcement members 14 shown in Figures 4(a) and 4(b) are formed extending from the front of the roof rail 4 to the rear of the middle of the vehicle in the longitudinal direction (to the rear in this embodiment) and are fixed to the roof rail 4 by welding or bolts. The bending reinforcement member 9 is fixed to this rail reinforcement member 14. Specifically, a bolt 10 inserted through the bolt insertion hole of the rail fixing portion 9c of the bending reinforcement member 9 passes through a through hole formed in the roof rail 4 and is screwed into a threaded hole formed in the rail reinforcement member 14, thereby fastening the bending reinforcement member 9 together with the rail reinforcement member 14 and the roof rail 4. Note that the bolt 10 is omitted in Figure 4(b).

[0032] According to the cabin structure C2 of the construction machine as described in this second embodiment, when the vehicle rolls over and a lateral load Fh is applied to the middle of the roof rail 4 shown in Figure 4(a), the lateral load Fh is transmitted to the bending reinforcement 9 via the rail reinforcement 14, and then from the bending reinforcement 9 to the front header 6. As a result, the lateral load Fh can be received as an axial compressive load on the front header 6. Therefore, deformation of the roof rail 4 due to the lateral load Fh during vehicle rollover is effectively suppressed, and the strength and rigidity of the cabin 1 are improved.

[0033] (Third embodiment) Figure 5 shows a cabin structure C3 of a construction machine according to a third embodiment of the present invention. The cabin structure C3 of the construction machine according to the third embodiment has the same configuration as the second embodiment shown in Figures 4(a) and 4(b), except that the bending reinforcing member 9 has an extension portion 9d that extends from the bending portion 5 beyond the middle of the roof rail 4 toward the rear of the vehicle body, and the extension portion 9d is fixed to the rail reinforcing member 14. For this reason, the same reference numerals are used for components that are the same as in the second embodiment and their descriptions are omitted.

[0034] As shown in Figure 5, a rail reinforcing member 14 is provided inside the hollow roof rail 4, extending in the longitudinal direction of the vehicle body. The rail reinforcing member 14 is formed to extend from the front of the roof rail 4 to the rear of the middle of the vehicle in the longitudinal direction (to the rear in this embodiment) and is fixed to the roof rail 4 by welding or bolts. On the other hand, the bending reinforcing member 9 has an extension portion 9d that extends from the bending portion 5 beyond the middle of the roof rail 4 toward the rear of the vehicle body (to the rear in this embodiment). The extension portion 9d is fastened together with the rail reinforcing member 14 and the roof rail 4 by bolts 15.

[0035] More specifically, as shown in Figure 5, the extended portion 9d of the bending reinforcement member 9 has multiple bolt insertion holes formed at intervals, the roof rail 4 has multiple through holes formed to match the positions of the bolt insertion holes, and the rail reinforcement member 14 has multiple screw holes formed to match the positions of the bolt insertion holes in the extended portion 9d, the bolts 15 inserted through the bolt insertion holes in the roof rail 4 pass through the through holes in the roof rail 4 and are screwed into the screw holes in the rail reinforcement member 14, thereby fastening the extended portion 9d of the bending reinforcement member together with the rail reinforcement member 14 and the roof rail 4. The rearmost part of the extended portion 9d is fastened to the rear pillar 12 by bolts 16. Note that welding or the like may be used instead of bolts 15 and 16.

[0036] According to the cabin structure C3 of the construction machine as described in this third embodiment, when the vehicle rolls over and a lateral load Fh is applied to the middle of the roof rail 4 as shown in Figure 5, the lateral load Fh is transmitted to the front header 6 via the extended portion 9d of the bending reinforcement member 9 and the rail reinforcement member 14, and can be received as an axial compressive load on the front header 6. Furthermore, since the extended portion 9d of the bending reinforcement member 9 and the rail reinforcement member 14 overlap in the vehicle width direction, the bending rigidity against the lateral load Fh is improved compared to the second embodiment. Therefore, deformation of the roof rail 4 due to the lateral load Fh during vehicle rollover is effectively suppressed, and the strength and rigidity of the cabin 1 are improved.

[0037] (Fourth Embodiment) Figure 6 shows a cabin structure C4 of a construction machine according to the fourth embodiment of the present invention. In the cabin structure C4 of the construction machine according to the fourth embodiment, the rail reinforcement member 14 of the third embodiment shown in Figure 5 is omitted to reduce weight and cost when the necessary strength and rigidity against lateral load Fh can be secured by forming an extension 9d on the bending reinforcement member 9 and fixing the extension 9d to the roof rail 4 with bolts 15 or welding. Since the configuration is the same as the third embodiment except for the omission of the rail reinforcement member 14, the same reference numerals are used for components that are the same as in the third embodiment and their descriptions are omitted.

[0038] Although preferred embodiments of the present invention have been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to the embodiments described above, and that various modifications or alterations within the scope of the claims also fall within the technical scope of the present invention. [Industrial applicability]

[0039] The present invention can be used in the cabin structure of construction machinery such as hydraulic excavators, to enhance the strength and rigidity when a lateral force is applied to the cabin during a vehicle rollover. [Explanation of Symbols]

[0040] 1 Cabin 2 floors 3 Front pillar 4 Roof rails 5. Flexed section 6 Front Header 9. Bending reinforcement 9a Pillar fixing part 9b Header fixing part 9c Rail fixing part 9d Extension 11 Handrail 11a Top of the handrail 11b Lower part of the handrail 14 Rail reinforcement C1 Cabin structure of construction machinery (first embodiment) C2 Cabin structure of construction machinery (second embodiment) C3 Cabin structure of construction machinery (third embodiment) C4 Cabin structure of construction machinery (fourth embodiment)

Claims

1. A construction machine cabin structure comprising: a pair of left and right front pillars extending upward from the floor of the cabin of the construction machine; roof rails extending towards the rear of the vehicle body from the tops of the front pillars; a bent portion connecting the roof rails to the front pillars; and a front header disposed along the width direction of the vehicle so as to connect the left and right bent portions to each other. A cabin structure for a construction machine, characterized in that, when viewed from the side of the vehicle body, it is provided with a bent reinforcing member that is bent in a V-shape from the front pillar through the bent portion to follow the roof rail, and the bent reinforcing member has a pillar fixing portion fixed to the front pillar, a header fixing portion fixed to the front header, and a rail fixing portion fixed to the roof rail.

2. The cabin structure of a construction machine according to claim 1, characterized in that the roof rail is formed hollow, a rail reinforcing member is provided inside the roof rail along the longitudinal direction of the vehicle body, and the bending reinforcing member is fixed to the rail reinforcing member.

3. The cabin structure for a construction machine according to claim 1 or 2, characterized in that the bending reinforcing member has an extension that extends from the bending portion beyond the middle of the roof rail toward the rear of the vehicle body.

4. The cabin structure for a construction machine according to claim 1 or 2, characterized in that the construction machine has a boom to the left or right of the cabin, and the bending reinforcement is provided only on the side of the cabin opposite to the boom.

5. The cabin structure for a construction machine according to claim 4, characterized in that it has a handrail extending vertically along the front pillar, the upper part of the handrail being fixed to the bending reinforcement, and the lower part of the handrail being fixed to the front pillar.

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