Construction machine

Abstract

A revolving frame (26) provided in an electric excavator (10) comprises: a base plate (42); an inner beam (56) extending in the front-rear direction on the base plate (42); and an outer beam (60) positioned on the base plate (42) on the width-direction outer side of the inner beam (56) and extending along an outer peripheral edge portion in the width-direction of the base plate (42). The rear-side height of the inner beam (56) is lower than the height of the outer beam (60).

Description

Construction Machinery

[0001] The present disclosure relates to a construction machine.

[0002] WO 2019 / 146668 discloses a construction machine including a swing frame that supports a battery.

[0003] Incidentally, it is preferable that the swing frame can secure the rigidity required for supporting the battery. On the other hand, an increase in the weight of the swing frame for securing the rigidity of the swing frame is not preferable.

[0004] In consideration of the above facts, an object of the present disclosure is to obtain a construction machine that can suppress an increase in weight while securing rigidity.

[0005] A construction machine according to a first aspect includes a swing frame in an upper swing structure, the swing frame including: a base plate; an inner beam extending in the front-rear direction on the base plate; and an outer beam positioned on the base plate outward of the inner beam in the width direction and extending along a widthwise outer peripheral edge of the base plate, wherein a height of a rear side of the inner beam is lower than a height of the outer beam.

[0006] According to the construction machine of the present disclosure, it is possible to suppress an increase in weight while securing rigidity.

[0007] Fig. 1 is a side view of an electric excavator according to the present embodiment. Fig. 2 is a plan view of a swing frame of the electric excavator according to the present embodiment. Fig. 3 is a side view of the swing frame of the electric excavator according to the present embodiment. Fig. 4 is a cross-sectional plan view of the swing frame of the electric excavator according to the present embodiment (a cross-sectional view showing a state cut along line 4-4 in Fig. 3). Fig. 5 is a vertical cross-sectional view of the swing frame of the electric excavator according to the present embodiment (a cross-sectional view showing a state cut along line 5-5 in Fig. 2).

[0008] An example of a preferred embodiment of the present disclosure will be described below with reference to Figs. 1 to 5.

[0009] As shown in Figure 1, the electric excavator 10, a battery-powered construction machine according to this embodiment, is equipped with a lower traveling body 12 and an upper rotating body 14. In the following, the vertical direction when the electric excavator 10 is installed on a horizontal surface will be referred to as the height direction, and the upper side in the height direction will be indicated by the arrow UP in each figure.

[0010] The lower vehicle 12 is equipped with a pair of tracks 16 on the left and right sides, and these tracks 16 are driven by a hydraulic motor (not shown) that allows the lower vehicle 12 to move. In the following, the direction of travel of the lower vehicle 12 will be referred to as the front-rear direction, and the front side in the direction of travel will be simply referred to as the front side. In each figure, the front side will be indicated by the arrow FR.

[0011] The upper rotating body 14 is equipped with a work implement 18 on its front side, which consists of a boom 20, an arm 22, and a bucket 24. The work implement 18 is capable of performing various operations such as excavation by having the boom 20, arm 22, and bucket 24 each driven by hydraulic cylinders.

[0012] In the following, the width direction of the upper rotating body 14 when the work machine 18 is facing the front of the electric excavator 10 will simply be referred to as the width direction, and the left side in the width direction will be indicated by the arrow LH in each figure. Furthermore, the direction toward the center in the width direction will be referred to as the inner width direction, and the direction toward the right or left from the center in the width direction will be referred to as the outer width direction.

[0013] More specifically, the bottom of the upper rotating body 14 is composed of a rotating frame (revo frame) 26, and a cab 28 on which an operator sits is installed on this rotating frame 26. In addition, the widthwise sides and rear portion of the upper rotating body 14 are covered by a vehicle body cover 30. Furthermore, as shown in Figure 2, the rotating frame 26 is equipped with a battery unit 32 as a battery, a controller 34, a main motor 36, a rotating motor 38, a hydraulic pump (not shown), a hydraulic valve (not shown), a cooling unit (not shown), and a hydraulic oil tank (not shown), etc.

[0014] The battery unit 32 comprises a metal battery case 32A that forms its outer shell and whose outer shape has its longitudinal direction as its width, and a battery module (not shown) housed in the battery case 32A.

[0015] This battery unit 32 is capable of supplying power to the main motor 36 and other components via an inverter (not shown) that converts DC power into AC power of any frequency and outputs it. The main motor 36 is then driven by the AC power output from this inverter.

[0016] The controller 34 is used to control various electronic devices, including the main motor 36.

[0017] The main motor 36 drives the hydraulic pump with its driving force. The hydraulic pump pressurizes the hydraulic fluid flowing into it and supplies this fluid to the hydraulic valve. The pressurized hydraulic fluid then branches off from the hydraulic valve and flows to various hydraulic devices such as hydraulic cylinders. The hydraulic fluid tank stores the hydraulic fluid supplied to the hydraulic pump. The cooling unit cools the hydraulic fluid by exchanging heat with the outside air.

[0018] The slewing motor 38 is capable of transmitting driving force to a swing circle 40 interposed between the lower traveling body 12 and the upper slewing body 14 via a swing pinion (not shown). When the swing circle 40 is driven, the upper slewing body 14 rotates relative to the lower traveling body 12.

[0019] Next, the configuration of the slewing frame 26 will be described. As shown in Figure 2, the slewing frame 26 is composed of a base plate 42 that forms its bottom, a central partition plate 44, a pair of front vertical partition plates 46 as one-sided partition plates, a front reinforcing plate 48, a front bush 50, a left reinforcing rib 52 and a right reinforcing rib 54 as one-sided ribs, a pair of inner beams 56, a horizontal beam 58, a pair of outer beams 60 and a rear beam 62. The slewing frame 26 is composed of these steel members combined together.

[0020] The base plate 42 is plate-shaped and extends in the front-rear and width directions. The base plate 42 may be made of a single steel plate or of multiple steel plates combined together. The lower surface of the base plate 42 is fixed on the swing circle 40, and the slewing frame 26 is supported from below by the swing circle 40 near the center of the base plate 42 (at a predetermined distance forward of the center).

[0021] More specifically, as shown in Figure 4, the base plate 42 is composed of a main body portion 42A that constitutes its main part, and an extension portion 42B that extends forward from the main body portion 42A and is roughly triangular in shape when viewed from the height direction. Furthermore, in the following, the part of the main body portion 42A that is in front of its center in the front-rear direction will be referred to as the front part of the main body portion 42A1, and the part that is in rear of its center in the front-rear direction will be referred to as the rear part of the main body portion 42A2.

[0022] The front part 42A1 of the main body widens from the front to the rear. Furthermore, the front part 42A1 of the main body has a first outer front penetration part 64 formed by the left side of its width direction being penetrated in the height direction, a second outer front penetration part 66 formed by the right side of its width direction being penetrated in the height direction, and a front central penetration part 68 formed by the rear part of its center in the width direction being penetrated in the height direction.

[0023] A hydraulic valve is located on the first outer front through-hole 64, a hydraulic oil tank is located on the second outer front through-hole 66, and a slewing motor 38 is located in front of the front central through-hole 68 when viewed from the height direction (see Figure 2).

[0024] On the other hand, the front portion of the main body rear section 42A2 has a constant width, while the width of the rear portion of the main body rear section is reduced as it moves towards the rear, and remains constant at the rear end of the main body rear section 42A2.

[0025] Furthermore, the rear portion 42A2 of the main body has a first outer rear through-hole 70 formed by the left side of its width direction being penetrated in the height direction, a second outer rear through-hole 72 formed by the right side of its width direction being penetrated in the height direction, and a rear central through-hole 74 formed by the center of its width direction being penetrated in the height direction. The rear central through-hole 74 is open to the rear, and the rear portion 42A2 of the main body is bifurcated at the rear.

[0026] Furthermore, a hydraulic pump and part of the main motor 36 are located on the first outer rear through-hole 70, a controller 34 and part of the cooling unit are located on the second outer rear through-hole 72, and a battery unit 32, a controller 34 and part of the main motor 36 are located on the rear central through-hole 74 (see Figure 2).

[0027] Furthermore, in the rear portion 42A2 of the main body, the portion between the first outer rear through-hole 70 and the rear central through-hole 74, and the portion between the second outer rear through-hole 72 and the rear central through-hole 74, have a width that narrows towards the rear as the front portion approaches, while the width of the rear portion remains constant.

[0028] In the following, the portion of the base plate 42 between the first outer rear through portion 70 and the rear central through portion 74, and the portion between the second outer rear through portion 72 and the rear central through portion 74 will be referred to as the inner land portion 42A3, and the portion of the first outer rear through portion 70 that is on the outer side in the width direction and the portion of the second outer rear through portion 72 that is on the outer side in the width direction will be referred to as the outer land portion 42A4.

[0029] The central partition plate 44 is a plate-like structure that protrudes upward from the upper surface of the base plate 42, with its thickness oriented in the front-to-back direction and extending in the width direction, and is located at the boundary between the front part 42A1 and the rear part 42A2 of the main body. The end of the central partition plate 44 reaches the outer peripheral edge of the base plate 42 in the width direction. The central partition plate 44 is joined to the base plate 42 by a joint (not shown) such as welding.

[0030] The front vertical partition plate 46 is plate-shaped and protrudes from the upper surfaces of the front part 42A1 of the main body and the extension part 42B. It extends forward from the part of the central partition plate 44 that is wider than the widthwise center, such that the distance between them in the widthwise direction narrows as they move towards the front.

[0031] The front vertical partition plate 46 is joined at its front end to the front bush 50, at its rear end to the central partition plate 44, and at its lower end to the base plate 42 by welding or other means (not shown). The height of the upper edge of the front vertical partition plate 46 increases from the rear to the front (see Figure 3).

[0032] The front vertical partition plate 46 on the left side in the width direction is located between the first outer front through-hole 64 and the front central through-hole 68, and the front vertical partition plate 46 on the right side in the width direction is located between the second outer front through-hole 66 and the front central through-hole 68.

[0033] As shown in Figure 2, the front reinforcing plate 48 is plate-shaped such that, when viewed from the height direction, its outer peripheral edge in the width direction extends along the pair of front vertical partition plates 46, while its rear peripheral edge is curved in a forward-convex shape to avoid the slewing motor 38.

[0034] This front reinforcing plate 48 is joined to the upper end of the front vertical partition plate 46 by a joint (not shown) such as welding, and together with the pair of front vertical partition plates 46 and a part of the base plate 42, it forms a closed-section structure whose cross-section when viewed from the front-rear direction is a closed section.

[0035] The front bush 50 is cylindrical with its height direction as the axial direction, and the front end of the front vertical partition plate 46 and the front end of the front reinforcing plate 48 are joined to its outer surface by welding or other means (not shown).

[0036] Furthermore, a swing bracket pin (not shown), which constitutes part of the work implement 18, is pivotally supported on the front bush 50 so as to be rotatable around the height direction, and the work implement 18 is supported by the front bush 50. The center of the front bush 50 is located to the right in the width direction with respect to the center line CL, which passes through the center in the width direction of the base plate 42 and extends in the front-rear direction.

[0037] The left reinforcing rib 52 is shaped like a triangular plate when viewed from the height direction, and its left peripheral edge in the width direction is positioned along the left front vertical partition plate 46 in the width direction, with a gap in the height direction between it and the base plate 42, at the boundary between the front vertical partition plate 46 and the central partition plate 44.

[0038] This left-side reinforcing rib 52 is sandwiched between the left-side front vertical partition plate 46 and the central partition plate 44, with a portion of its widthwise side being sandwiched between them, and is joined to them by a joint (not shown) such as welding. In other words, the left-side reinforcing rib 52 is interposed between the right-side surface in the widthwise direction of the left-side front vertical partition plate 46 and the front surface of the central partition plate 44, and is welded to them.

[0039] The right-side reinforcing rib 54 is shaped like a roughly triangular plate when viewed from the height direction, and its left peripheral edge in the width direction is positioned along the front vertical partition plate 46 on the right side in the width direction, with a gap in the height direction between it and the base plate 42, at the boundary between the front vertical partition plate 46 and the central partition plate 44.

[0040] This right-side reinforcing rib 54 is joined to the front vertical partition plate 46 and the central partition plate 44 on the right side in the width direction by a joint (not shown) such as welding. In other words, the right-side reinforcing rib 54 is interposed between the right-side surface of the front vertical partition plate 46 on the right side in the width direction and the front surface of the central partition plate 44, and is welded to them.

[0041] The inner beam 56 protrudes upward from the upper surface of the base plate 42, is formed in a plate shape having a plate thickness direction as a width direction and extending rearward from the central partition plate 44. This inner beam 56 is formed as a pair spaced apart in the width direction, more specifically, disposed between the first outer rear through portion 70 and the rear central through portion 74 of the base plate 42, and between the rear central through portion 74 and the second outer rear through portion 72, respectively. The front end portion of the inner beam 56 is joined to the central partition plate 44, and the lower end portion thereof is joined to the base plate 42 through unillustrated joining portions formed by welding or the like, respectively.

[0042] Furthermore, as shown in Fig. 5, a portion of the inner beam 56 in the vicinity of the central partition plate 44 is formed as a rising portion 56A whose height decreases from a height approximately equal to that of the central partition plate 44 toward the rear side, and a portion on the rear side of the rising portion 56A is formed as a general portion 56B having a constant height.

[0043] It should be noted that, at the central portion in the front-rear direction of the inner beam 56, a battery mount 76 serving as a battery support portion for supporting the battery unit 32 is provided, the battery mount 76 being configured by a tapped block provided with a screw hole that protrudes outward in the width direction from the inner beam 56 and penetrates in the vertical direction.

[0044] As shown in Fig. 2 and Fig. 5, the lateral beam 58 is formed in a plate shape having a plate thickness direction as the front-rear direction and extending in the width direction along the front peripheral edge of the battery case 32A of the battery unit 32 when viewed from the height direction, and is bridged between the central portions of the pair of inner beams 56 on the rear central through portion 74. Both end portions of the lateral beam 58 are supported from below by a part of the pair of inner land portions 42A3 of the base plate 42, and the lateral beam 58 is joined to the pair of inner beams 56 and the pair of inner land portions 42A3 through unillustrated joining portions formed by welding or the like. The height of the upper edge of the lateral beam 58 is set to be approximately the same as the height of the upper edge of the general portion 56B of the inner beam 56.

[0045] Further, as shown in Fig. 4, a controller mount 78 that supports the controller 34 is provided at the center in the width direction of the transverse beam 58, said controller mount 78 being formed of a tapped block that projects forward from the transverse beam 58 and is provided with a screw hole penetrating in the vertical direction.

[0046] The outer beam 60 is formed as a plate-shaped member that projects upward from the upper surface of the base plate 42 and extends along the widthwise outer peripheral edge of the main body rear portion 42A2.

[0047] More specifically, the outer beam 60 includes a front side wall portion 60A extending rearward from the central partition plate 44, an inclined wall portion 60B extending inward in the width direction and rearward from the front side wall portion 60A, and a rear side wall portion 60C extending rearward from the inclined wall portion 60B.

[0048] That is, the distance in the width direction between the pair of outer beams 60 is longer on the front side than on the rear side. Further, the height of the upper edge of the general portion 56B of the inner beam 56 is lower than the height of the upper edge of the outer beam 60. The outer beam 60 is joined to the base plate 42 at a joining portion (not shown) formed by welding or the like.

[0049] Further, as also shown in Fig. 2, a cab support plate 80 that supports a rear portion of the cab 28 is disposed on the upper side at the boundary between the front side wall portion 60A and the inclined wall portion 60B of the outer beam 60, and this cab support plate 80 is joined to the outer beam 60 at a joining portion (not shown) formed by welding or the like.

[0050] Furthermore, a controller mount 78 is provided near the cab support plate 80 on the front side wall portion 60A on the right side in the width direction, in a state of projecting inward in the width direction from the front side wall portion 60A.

[0051] In addition, on each of the front side of the controller mount 78 provided on the transverse beam 58 and the front side of the controller mount 78 provided on the front side wall portion 60A, a controller mount 79 that supports the controller 34 is provided on the base plate 42, said controller mount 79 being formed of a cylindrical tapped block provided with a screw hole penetrating in the vertical direction.

[0052] The rear beam 62 is a plate-like shape with its thickness direction oriented in the front-to-back direction and extending in the width direction. It is positioned along the rear peripheral edge of the base plate 42 so as to straddle the rear central penetration portion 74, and is joined to the base plate 42 by a joint (not shown) such as welding.

[0053] Furthermore, the rear beam 62 is provided with tapped blocks on both sides in the width direction, each having a screw hole that protrudes rearward from the rear beam 62 and penetrates vertically, as well as a battery mount 82 that supports the battery unit 32.

[0054] <Effects> Next, the effects of this embodiment will be described.

[0055] In this embodiment, as shown in Figure 2, the base plate 42, which constitutes a part of the slewing frame 26 of the electric excavator 10, extends in the front-rear and width directions, and various components of the battery unit 32 can be arranged on the base plate 42.

[0056] Furthermore, a central partition plate 44 is positioned on the base plate 42, extending in the width direction from one peripheral edge in the width direction to the other peripheral edge in the width direction of the base plate 42. This central partition plate 44 divides the base plate 42 into a front part 42A1 and a rear part 42A2 of the main body, and also increases the rigidity of the slewing frame 26 against bending in the width direction.

[0057] Furthermore, a pair of inner beams 56 extending from the central partition plate 44 toward the rear are arranged on the base plate 42 at intervals in the width direction, and these inner beams 56 increase the rigidity of the slewing frame 26 against bending in the front-rear direction.

[0058] Furthermore, a pair of outer beams 60 extend along the outer peripheral edge of the base plate 42 in the width direction, and are located on the outer side of the inner beam 56 in the width direction. These outer beams 60, like the inner beam 56, increase the rigidity of the slewing frame 26 against bending in the front-rear direction.

[0059] Incidentally, the slewing frame 26 is supported by the swing circle 40 near the center of the base plate 42, and it is conceivable that the effect of bending moments caused by impacts when the electric excavator 10 travels on rough roads will be greater on the outer periphery of the slewing frame 26 than on the central side. In other words, it is preferable that the rigidity of the slewing frame 26 is higher on the outer periphery than on the central side.

[0060] On the other hand, from the standpoint of the weight of the slewing frame 26, it is preferable to reduce the weight of the components that make up the slewing frame 26.

[0061] In this embodiment, the height of the rear portion of the inner beam 56 is lower than the height of the outer beam 60. Therefore, in this embodiment, the rigidity of the slewing frame 26 can be ensured by the outer beam 60, while the weight of the inner beam 56, which contributes less to the rigidity of the slewing frame 26 compared to the outer beam 60, can be reduced.

[0062] Furthermore, in this embodiment, a rear central penetration portion 74 is formed in the base plate 42 that penetrates in the height direction between a pair of inner beams 56 and is open to the rear, thereby reducing the weight of the base plate 42 while ensuring a maintenance hole in the base plate 42.

[0063] Incidentally, if the base plate 42 has a rear central through-hole 74 that is open at the rear, the rear of the base plate 42 will be in a bifurcated state, and it is conceivable that the left and right portions of the base plate 42 in the width direction will exhibit different behaviors when the electric excavator 10 is running.

[0064] In this embodiment, a horizontal beam 58 is provided on the rear central through-hole 74 that connects the inner beams 56 in the width direction, allowing the movement of one side of the slewing frame 26 and the other side to be synchronized when the electric excavator 10 is traveling.

[0065] Furthermore, in this embodiment, the distance in the width direction between the pair of outer beams 60 is longer on the front side than on the rear side. Therefore, by ensuring the distance between the outer beams 60 at the center of the pivot frame 26 in the front-rear direction, it is possible to reduce the pivot radius of the pivot frame 26 while ensuring the rigidity of the pivot frame 26 against bending in the front-rear direction.

[0066] Furthermore, in this embodiment, a battery mount 76 for supporting the battery unit 32 is provided on the inner beam 56, and the battery unit 32 is supported on the inner beam 56. The horizontal beam 58 extends along the front peripheral edge of the battery case 32A of the battery unit 32. Therefore, in this embodiment, the battery case 32A can function together with the inner beam 56 and the horizontal beam 58 as a reinforcing part of the base plate 42. As a result, in this embodiment, the capacity of the battery unit 32 can be increased while reducing the height dimension of the cross-sections of the inner beam 56 and the horizontal beam 58.

[0067] Furthermore, in this embodiment, a rear beam 62 is provided that connects the rear ends of the pair of outer beams 60 to the rear ends of the pair of inner beams 56. The pair of inner beams 56, the lateral beam 58, and the rear beam 62 form a rigid frame structure, and this rigid frame structure can support the pair of outer beams 60.

[0068] Furthermore, in this embodiment, the height of the portion of the inner beam 56 on the central partition plate 44 side is higher than the height of the other portions of the inner beam 56. Therefore, while ensuring the rigidity of the slewing frame 26 in the portion of the inner beam 56 on the central partition plate 44 side, it is possible to secure space for arranging the battery unit 32, etc., above the other portions of the inner beam 56.

[0069] Furthermore, in this embodiment, a pair of front vertical partition plates 46 are provided, extending forward from the portion to the left and the portion to the right of the widthwise center of the central partition plate 44. The rear portion of the front vertical partition plate 46 on the left side in the widthwise direction is connected to the central partition plate 44 by a left reinforcing rib 52, and the rear portion of the front vertical partition plate 46 on the right side in the widthwise direction is connected to the central partition plate 44 by a right reinforcing rib 54.

[0070] Therefore, in this embodiment, rigidity against bending in the front-to-back direction and rigidity against bending in the width direction can be ensured in the front portion of the central partition plate 44 in the swivel frame 26.

[0071] In addition, in this embodiment, a first outer rear penetration portion 70 is formed in the left side of the base plate 42 in the width direction, between the inner beam 56 and the outer beam 60, and penetrates in the height direction.

[0072] On the other hand, a second outer rear penetration portion 72 is formed between the inner beam 56 and the outer beam 60 in the right side portion of the base plate 42 in the width direction, and penetrates in the height direction. Therefore, in this embodiment, maintenance holes can be secured on both sides of the base plate 42 in the width direction while reducing weight.

[0073] Furthermore, in this embodiment, the width of the base plate 42 narrows as it moves towards the rear, in the portion between the rear central through portion 74 and the first outer rear through portion 70, and in the portion between the rear central through portion 74 and the second outer rear through portion 72.

[0074] Therefore, in this embodiment, the portion between the rear central through-hole 74 and the first outer rear through-hole 70, and the portion between the rear central through-hole 74 and the second outer rear through-hole 72, can be made lighter in the portion reinforced by the horizontal beam 58 and the battery case 32A, while the cross-sectional area of ​​the remaining portion when viewed from the front-rear direction can be secured, thereby ensuring the rigidity of the base plate 42.

[0075] In the above-described embodiment, the electric excavator 10 was equipped with a cab 28. However, depending on the specifications of the electric excavator 10, a configuration in which a canopy is mounted on the electric excavator 10 instead of the cab 28 may be adopted.

[0076] Furthermore, in the above-described embodiment, the slewing frame 26 was equipped with a left-side reinforcing rib 52 and a right-side reinforcing rib 54, but depending on the specifications of the electric excavator 10, the slewing frame 26 may be configured to be equipped with at least one of these.

[0077] As described above, the slewing frame 26 according to this embodiment and the electric excavator 10 equipped therewith can suppress weight increase while ensuring rigidity.

[0078] The following are additional notes relating to this disclosure. (Note 1) A construction machine comprising: an upper rotating body equipped with a rotating frame, wherein the rotating frame comprises: a base plate; an inner beam extending in the front-rear direction on the base plate; and an outer beam located on the base plate outside the width direction of the inner beam and extending along the outer periphery of the base plate in the width direction, wherein the height of the rear side of the inner beam is lower than the height of the outer beam. (Note 2) The construction machine according to Note 1, further comprising: a central partition plate on the base plate extending in the width direction from the periphery of the base plate on one side in the width direction to the periphery on the other side in the width direction, wherein the inner beam and the outer beam extend rearward from the central partition plate. (Note 3) The construction machine according to Note 1, wherein the inner beams are arranged in pairs with a gap between them in the width direction, and the base plate has an inner through-hole formed therein in the height direction between the pair of inner beams and open to the rear, and the machine further comprises a transverse beam connecting the inner beams in the width direction on the inner through-hole. (Note 4) The construction machine according to Note 3, wherein the machine further comprises a battery support portion provided on the inner beam and supporting a battery, and the transverse beam extends along the front peripheral edge of the battery. (Note 5) The construction machine according to Note 3 or Note 4 referencing Note 3, wherein the base plate has an outer through-hole formed therein in the height direction between the inner beam and the outer beam, and the width of the portion of the base plate between the inner through-hole and the outer through-hole narrows towards the rear. (Note 6) The outer beams are arranged in pairs with a gap in the width direction, and the distance in the width direction between the pair of outer beams is longer at the front than at the rear, as described in any of Notes 1 to 5. (Note 7) The construction machine described in Note 6, further comprising a rear beam connecting the rear ends of the pair of outer beams and the rear ends of the pair of inner beams. (Note 8) The construction machine described in Note 7, wherein the height of the inner beam on the side with the central partition plate is higher than the height of the rest of the inner beam.(Note 9) A construction machine as described in any of Notes 1 to 8, further comprising: a one-sided partition plate extending forward from one side in the width direction from the width direction center of the central partition plate; and a one-sided rib connecting the rear portion of the one-sided partition plate to the central partition plate.

[0079] The disclosure of Japanese Patent Application No. 2025-054463, filed on 27 March 2025, is incorporated herein by reference in its entirety.

Claims

1. A construction machine comprising an upper rotating body equipped with a rotating frame, wherein the rotating frame comprises a base plate, an inner beam extending in the front-rear direction on the base plate, and an outer beam located on the base plate outside the width direction of the inner beam and extending along the outer periphery of the base plate, wherein the height of the rear side of the inner beam is lower than the height of the outer beam.

2. The construction machine according to claim 1, further comprising a central partition plate on the base plate, extending in the width direction from one peripheral edge in the width direction of the base plate to the other peripheral edge in the width direction, wherein the inner beam and the outer beam extend toward the rear from the central partition plate.

3. The construction machine according to claim 1, wherein the inner beams are arranged in pairs with a gap between them in the width direction, and the base plate has an inner penetration portion that penetrates in the height direction between the pair of inner beams and is open to the rear, and the machine further comprises a transverse beam that connects the inner beams in the width direction on the inner penetration portion.

4. The construction machine according to claim 1, wherein the outer beams are arranged in pairs with a gap between them in the width direction, and the distance in the width direction between the pair of outer beams is longer at the front than at the rear.

5. The construction machine according to claim 4, referencing claim 3, further comprising a battery support portion provided on the inner beam and supporting a battery, wherein the transverse beam extends along the front peripheral edge of the battery.

6. The construction machine according to claim 4, referencing claim 3, further comprising a rear beam connecting the rear ends of the pair of outer beams and the rear ends of the pair of inner beams.

7. The construction machine according to claim 6, wherein the height of the inner beam on the side with the central partition plate is higher than the height of the other parts of the inner beam.

8. The construction machine according to claim 1, further comprising: a one-sided partition plate extending forward from one side in the width direction beyond the widthwise center of the central partition plate; and a one-sided rib connecting the rear portion of the one-sided partition plate to the central partition plate.

9. The construction machine according to claim 3, wherein an outer through-hole is formed in the base plate between the inner beam and the outer beam, and the width of the portion of the base plate between the inner through-hole and the outer through-hole narrows towards the rear.

Images