Revolving frame and construction machine

Abstract

An outer beam (60) provided in a revolving frame (26) is configured to include: a front wall portion (60A) extending rearward from a central partition plate (44); and an inclined wall portion (60B) extending inward in the width direction and rearward from the front wall portion (60A). A cab support plate (80) that supports a rear portion of a cab (28) is positioned above a boundary portion between the front wall portion (60A) and the inclined wall portion (60B).

Description

Swing frame and construction machine

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

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

[0003] Incidentally, it is preferable that the swing frame can ensure rigidity required for supporting a canopy or a cab. On the other hand, it is not desirable that the swing radius of the swing frame increases in order to ensure the rigidity of the swing frame.

[0004] In consideration of the above facts, an object of the present disclosure is to obtain a swing frame and a construction machine that can suppress an increase in swing radius while ensuring the rigidity required for supporting a cab.

[0005] A swing frame according to a first aspect includes: a base plate; a central partition plate extending in a width direction on the base plate from a peripheral edge portion on one side in the width direction of the base plate to a peripheral edge portion on the other side in the width direction; a pair of front partition plates extending forward from the central partition plate such that a distance therebetween in the width direction decreases toward the front side, the front ends of the pair of front partition plates being connected to each other; a front cab support portion supported by the front partition plates and positioned on an outer side of the front partition plates in the width direction, the front cab support portion rotatably supporting a front portion of the cab about a width direction axis; a pair of outer beams configured to include, on the base plate, a front side wall portion extending along a width-direction outer peripheral edge of the base plate and extending rearward from the central partition plate, and an inclined wall portion extending inward in the width direction and rearward from the front side wall portion; and a pair of rear cab support portions positioned above a boundary between the front side wall portion and the inclined wall portion, the pair of rear cab support portions supporting a rear portion of the cab.

[0006] According to the swing frame of the present disclosure, it is possible to suppress an increase in swing radius while ensuring the rigidity required for supporting a cab.

[0007] This is a side view of the electric excavator according to this embodiment. This is a plan view showing the configuration of the slewing frame and cab base of the electric excavator according to this embodiment. This is a longitudinal cross-sectional view of the slewing frame of the electric excavator according to this embodiment (a cross-sectional view showing the state when cut along line 3-3 in Figure 2). This is a side view showing the configuration of the slewing frame and cab base of the electric excavator according to this embodiment. This is a plan cross-sectional view of the slewing frame of the electric excavator according to this embodiment (a cross-sectional view showing the state when cut along line 5-5 in Figure 4).

[0008] A preferred embodiment of this disclosure will be described below with reference to Figures 1 to 5.

[0009] As shown in Figure 1, the electric excavator 10 as a 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 plane 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, a battery unit 32, 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) are arranged on the rotating frame 26.

[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 3, the slewing frame 26 is composed of a base plate 42 that forms its bottom, a central partition plate 44, a pair of front partition plates 46, a front reinforcing plate 48, a front bush 50 as a swing bracket support, a left cab support 84 and a right cab support 86 as front cab support parts, a left reinforcing rib 52, a right reinforcing rib 54, a pair of inner beams 56, a lateral beam 58, a pair of outer beams 60, a rear beam 62, and a cab support plate 80 as a rear cab support part. 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 5, 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 in a state where it is branched into two 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 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, are narrowed as the central portion of the main body 42A in the front-rear direction moves toward the rear, 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 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 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 partition plate 46 increases from the rear to the front (see Figure 4).

[0032] The front 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 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 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 partition plate 46 by a joint (not shown) such as welding, and together with the pair of front 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 partition plate 46 and the front end of the front reinforcing plate 48 are joined to its outer surface by a joint (not shown) such as welding. In other words, the front parts of the front reinforcing plate 48 are connected to each other via the front bush 50.

[0036] Furthermore, a swing bracket 88, which forms the base of the work implement 18, is pivotally supported on the front bush 50 via a swing bracket pin (not shown) so as to be rotatable around the height direction. The center C1 of the front bush 50 is located to the right in the width direction with respect to the center line CL that passes through the center of the base plate 42 in the width direction and extends in the front-rear direction.

[0037] The left cab support section 84 is composed of a support beam 90 and a support plate 92, as shown in Figures 2 to 4. The support beam 90 has a U-shape in cross-section when viewed from the width direction, with an open bottom, and extends outward in the width direction from the front partition plate 46 on the left side in the width direction. The inner end of the support beam 90 in the width direction is joined to the front partition plate 46 on the left side in the width direction by a joint (not shown) such as welding.

[0038] On the other hand, the support plate 92 extends upward and forward from the upper surface of the outer end of the support beam 90 in the width direction, with the plate thickness direction as the width direction, and a through-hole 94 is formed in its upper portion, penetrating in the width direction.

[0039] Furthermore, a pair of support plates 96 are provided on the left side in the width direction of the lower part of the front of the cab 28 so as to sandwich the upper part of the support plate 92. Connecting pins 100 are inserted in the width direction into the through-holes 98 of the support plates 96 and the through-holes 94 of the support plate 92, so that the front part of the cab 28 is supported by the left cab support part 84 so as to be rotatable around the width direction.

[0040] The right cab support portion 86 is configured to include a support beam 102 and a support plate 104. The support beam 102 has a U-shaped cross-section open downward when viewed from the width direction, and extends outward in the width direction from the front partition plate 46 on the right side in the width direction. The inward end of the support beam 102 in the width direction is joined to the front partition plate 46 on the right side in the width direction via a joint portion (not shown) formed by welding or other methods.

[0041] On the other hand, the support plate 104 has its plate thickness direction aligned with the width direction from the upper surface of the outward end of the support beam 102 in the width direction, extends upward and forward, and is formed with a through portion 106 penetrating in the width direction at its upper portion.

[0042] Further, a pair of support plates 108 are provided on the right side in the width direction of the lower portion of the front face of the cab 28 so as to clamp the upper portion of the support plate 104. A connecting pin 100 is inserted in the width direction into the through portion 109 provided in the support plates 108 and the through portion 106 of the support plate 104, so that the front portion of the cab 28 is rotatably supported by the right cab support portion 86 around the width direction.

[0043] It should be noted that the length of the support beam 102 in the width direction is shorter than the length of the support beam 90 in the width direction, and the distance from the center line CL to the support plate 104 is shorter than the distance from the center line CL to the support plate 92.

[0044] As shown in Fig. 5, the left reinforcing rib 52 is in the shape of a triangular plate when viewed in the height direction. The peripheral edge portion on the left side in the width direction is arranged at the boundary between the front partition plate 46 and the central partition plate 44, along the front partition plate 46 on the left side in the width direction and spaced apart from the base plate 42 in the height direction. A part of the left reinforcing rib 52 on the left side in the width direction is clamped between the front partition plate 46 on the left side in the width direction and the central partition plate 44, and is joined to these via a joint portion (not shown) formed by welding or other methods.

[0045] The right reinforcing rib 54 is formed into a substantially triangular plate shape when viewed from the height direction. The peripheral edge portion on the left side in the width direction is arranged at the boundary between the front partition plate 46 and the central partition plate 44, along the front partition plate 46 on the right side in the width direction and spaced apart from the base plate 42 in the height direction. The right reinforcing rib 54 is joined to the front partition plate 46 and the central partition plate 44 on the right side in the width direction via unillustrated joining portions by means such as welding.

[0046] The inner beam 56 is formed into a plate shape that protrudes upward from the upper surface of the base plate 42, has its plate thickness direction aligned with the width direction, and extends rearward from the central partition plate 44. The inner beams 56 are arranged as a pair spaced apart in the width direction. More specifically, one inner beam 56 is arranged between the first outer rear through portion 70 and the rear central through portion 74 on the base plate 42, and the other is arranged between the rear central through portion 74 and the second outer rear through portion 72 on the base plate 42. 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, respectively via unillustrated joining portions by means such as welding.

[0047] Furthermore, as shown also in FIG. 3, the portion of the inner beam 56 near 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 the portion rearward of the rising portion 56A is formed as a general portion 56B having a constant height.

[0048] It should be noted that, at the central portion in the front-rear direction of the inner beam 56, a battery mount 76 that supports the battery unit 32 is provided, the battery mount 76 being formed of 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.

[0049] The horizontal beam 58 is oriented with its thickness in the front-to-back direction and extends 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. It spans the central portions of a pair of inner beams 56 on the rear central penetration portion 74. Both ends of the horizontal beam 58 are supported from below by a portion of a pair of inner land portions 42A3 of the base plate 42. The horizontal beam 58 is joined to the pair of inner beams 56 and the pair of inner land portions 42A3 by welding or other joints (not shown). The height of the upper edge of the horizontal 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 (see Figure 3).

[0050] Furthermore, the center of the horizontal beam 58 in the width direction is provided with a tapped block having a screw hole that protrudes forward from the horizontal beam 58 and penetrates vertically, and a controller mount 78 for supporting the controller 34 is also provided.

[0051] The outer beam 60 is plate-shaped, protruding upward from the upper surface of the base plate 42 and extending along the outer peripheral edge in the width direction of the rear part 42A2 of the main body.

[0052] More specifically, the outer beam 60 is composed of a front wall portion 60A extending to the rear from the central partition plate 44, an inclined wall portion 60B extending inward in the width direction and to the rear from the front wall portion 60A, and a rear wall portion 60C extending to the rear from the inclined wall portion 60B.

[0053] In other words, the distance in the width direction between the pair of outer beams 60 is longer on the front side than on the rear side. Also, as shown in Figure 3, 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 beams 60 are joined to the base plate 42 by a joint (not shown) such as welding.

[0054] The cab support plate 80 is positioned above the boundary between the front wall portion 60A and the inclined wall portion 60B of the outer beam 60, and supports the rear of the cab 28 via the cab base 110. The cab support plate 80 is joined to the outer beam 60 by a joint (not shown) such as welding (see Figure 2).

[0055] Furthermore, as shown in Figure 5, a controller mount 78 is provided near the cab support plate 80 on the front wall portion 60A on the right side in the width direction, protruding inward in the width direction from the front wall portion 60A.

[0056] In addition, the front side of the controller mount 78 provided on the horizontal beam 58 and the front side of the controller mount 78 provided on the front wall portion 60A are each made of cylindrical tapped blocks with vertically penetrating screw holes, and a controller mount 79 that supports the controller 34 is provided on the base plate 42.

[0057] As shown in Figures 2 and 4, the cab base 110 is U-shaped when viewed from the front and rear, with the lower side open, and includes an upper support portion 112, a pair of legs 114, and a pair of lower support portions 116, and supports the cab 28 from below.

[0058] More specifically, the upper support portion 112 extends in the width direction with the plate thickness direction as the height direction, and this upper support portion 112 is connected to the rear of the cab 28 via a fastening portion (not shown).

[0059] The leg portion 114 is composed of a support piece portion 114A that supports the outer end of the upper support portion 112 in the width direction from below, with the plate thickness direction as the vertical direction, and a vertical piece portion 114B that extends downward from the outer peripheral edge of the support piece portion 114A in the width direction, with the plate thickness direction as the width direction. The support piece portion 114A is connected to the upper support portion 112 via fastening portions 118, including bolts, which are arranged at intervals in the front-rear direction.

[0060] The lower support portion 116 is positioned below the leg portion 114 and is shaped like a rectangular plate when viewed from the height direction, with its main portion extending outward from the leg portion 114 in the width direction. The lower support portion 116 is joined to the lower end of the leg portion 114 by a joint (not shown) such as welding.

[0061] The lower support portion 116 is positioned above the cab support plate 80 and is located on a straight line L1 that extends in the front-rear direction when viewed from the height direction. It is connected to the cab support plate 80 via fastening portions 120, including bolts, which are spaced apart in the front-rear direction. When viewed from the height direction, the front wall portion 60A of the outer beam 60 and the straight line L1 are parallel.

[0062] Furthermore, in this embodiment, the intermediate position in the width direction between the fastening portion 120 on one side in the width direction and the fastening portion 120 on the other side in the width direction, as viewed from the height direction, is located on the center line CL of the base plate 42. Note that the state in which the intermediate position is located on the center line CL also includes, for example, a state in which the intermediate position is located near the center line CL, or a state in which the intermediate position can be considered to be located on the center line CL.

[0063] Furthermore, as described above, the cab 28, which is supported by the slewing frame 26, has its center of gravity G located to the left in the width direction relative to the center line CL when viewed from the height direction.

[0064] 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.

[0065] 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.

[0066] <Effects> Next, the effects of this embodiment will be described.

[0067] 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.

[0068] 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.

[0069] Furthermore, in this embodiment, a pair of front partition plates 46 are provided, which extend forward from the central partition plate 44 such that the distance between them in the width direction narrows as they move towards the front, and whose front ends are connected to each other. Therefore, in this embodiment, rigidity against bending in the front-rear direction can be ensured in the front portion of the central partition plate 44 of the swivel frame 26.

[0070] Furthermore, a pair of outer beams 60 are arranged on the base plate 42, extending along the outer peripheral edge of the base plate 42 in the width direction, thereby increasing the rigidity of the slewing frame 26 against bending in the front-rear direction.

[0071] By the way, when supporting the cab 28 with the slewing frame 26, it is preferable that the slewing frame 26 can secure the rigidity necessary to support the cab 28. On the other hand, it is undesirable for the slewing radius of the slewing frame 26 to increase in order to secure the rigidity of the slewing frame 26.

[0072] In this embodiment, the outer beam 60 is composed of a front wall portion 60A extending rearward from the central partition plate 44 and an inclined wall portion 60B extending inward and rearward in the width direction from the front wall portion 60A. The cab support plate 80, which supports the rear of the cab 28, is located above the boundary between the front wall portion 60A and the inclined wall portion 60B. Therefore, in this embodiment, the rigidity of the slewing frame 26 can be ensured at the location where the cab 28 is supported on the slewing frame 26, while reducing the slewing radius of the slewing frame 26.

[0073] Furthermore, in this embodiment, the front portions of a pair of front partition plates 46 are connected by a front bush 50, and the swing bracket 88, which constitutes the base of the work implement 18, is supported by this front bush 50. Therefore, in this embodiment, the load during operation by the work implement 18 can be supported by the pair of front partition plates 46.

[0074] Incidentally, if the area on the slewing frame 26 where the load from the work implement 18 acts and the center of gravity of the cab 28 are offset in the width direction, it is conceivable that an uneven load will be applied to the swing circle 40.

[0075] In this embodiment, when viewed from the height direction, the center C1 of the front bush 50 is located to the right in the width direction relative to the center line CL of the base plate 42, and the center of gravity G of the cab 28 is located to the left in the width direction relative to the center of the base plate. Therefore, in this embodiment, the center of gravity of the upper slewing body 14 is suppressed to be biased in the width direction, and as a result, biased loads acting on the swing circle 40 can be suppressed.

[0076] Furthermore, in this embodiment, when viewed from the height direction, the center C1 of the front bush 50 is located to the right in the width direction relative to the center line CL of the base plate 42, and the midpoint in the width direction between the fastening portion 120 on one side in the width direction and the fastening portion 120 on the other side in the width direction is located on the center line CL. Therefore, in this embodiment, the rear of the cab base 110 and thus the cab 28 can be stably supported relative to the base plate 42 while suppressing the center of gravity of the upper slewing body 14 from being biased in the width direction.

[0077] Furthermore, in this embodiment, the cab support plate 80 supports the cab 28 at multiple fastening points located on a straight line L1 when viewed from the height direction, and the front side wall portion 60A of the outer beam 60 is parallel to the straight line L1. Therefore, in this embodiment, the moment caused by the load acting on the cab 28 in the front-rear direction can be supported by the front side wall portion 60A.

[0078] In addition, in this embodiment, as shown in Figure 4, the support points for the cab 28 on the left cab support portion 84 and the right cab support portion 86 are located above the pair of front partition plates 46. Therefore, in this embodiment, the load received by the left cab support portion 84 and the right cab support portion 86 from the cab 28 can be supported by the entire pair of front partition plates 46 in the height direction.

[0079] 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. However, 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.

[0080] As described above, the slewing frame 26 according to this embodiment and the electric excavator 10 equipped therewith can suppress an increase in the slewing radius while ensuring the rigidity necessary to support the cab 28.

[0081] The following are additional notes relating to this disclosure. (Note 1) A slewing frame comprising: a base plate; a central partition 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 of the base plate; a pair of front partition plates extending forward from the central partition plate such that the distance between them in the width direction narrows towards the front, and their front ends are connected; a front cab support portion supported by the front partition plate and located on the widthwise outer side of the front partition plate, supporting the front of the cab so as to be rotatable around the width direction; a pair of outer beams extending on the base plate along the widthwise outer peripheral edge of the base plate and extending rearward from the central partition plate, and comprising a front wall portion and an inclined wall portion extending inward in the width direction and rearward from the front wall portion; and a pair of rear cab support portions located above the boundary between the front wall portion and the inclined wall portion, and supporting the rear of the cab. (Note 2) The swing frame as described in Note 1, further comprising a swing bracket support portion that supports the swing bracket constituting the base of the work machine and connects the front portions of the pair of front partition plates, wherein, when viewed from the height direction, the center of the swing bracket support portion is located to the right in the width direction with respect to a center line that passes through the center in the width direction of the base plate and extends in the front-rear direction, and when viewed from the height direction, the center of gravity of the cab is located to the left in the width direction with respect to the center line. (Note 3) The swing frame as described in Note 1, further comprising: a swing bracket support portion that supports the swing bracket constituting the base of the work machine and connects the front portions of the pair of front partition plates; and a cab base that supports the rear portion of the cab relative to the pair of rear cab support portions, wherein, when viewed from the height direction, the center of the swing bracket support portion is located to the right in the width direction with respect to a center line that passes through the center in the width direction of the base plate and extends in the front-rear direction, and the intermediate position in the width direction between the fastening point between the cab base and the rear cab support portion on one side in the width direction and the fastening point between the cab base and the rear cab support portion on the other side in the width direction is located on the center line.(Note 4) The rear cab support portion supports the cab at a plurality of fastening points located on the same straight line when viewed from the height direction, and the front wall portion and the straight line are parallel when viewed from the height direction, the slewing frame described in any of Notes 1 to 3. (Note 5) The position of the support point of the cab at the front cab support portion is located above the pair of front partition plates, the slewing frame described in any of Notes 1 to 4. (Note 6) A construction machine comprising an upper slewing body having the slewing frame described in any of Notes 1 to 5 and a battery unit supported by the slewing frame, and a lower traveling body that rotatably supports the upper slewing body.

[0082] The disclosure of Japanese Patent Application No. 2025-054464, filed on 27 March 2025, is incorporated herein by reference in its entirety.

Claims

1. A slewing frame comprising: a base plate; a central partition 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 of the base plate; a pair of front partition plates extending forward from the central partition plate such that the distance between them in the width direction narrows towards the front, and their front ends are connected; a front cab support portion supported by the front partition plate and located on the widthwise outer side of the front partition plate, supporting the front of the cab so as to be rotatable around the width direction; a pair of outer beams extending on the base plate along the widthwise outer peripheral edge of the base plate and including a front wall portion extending rearward from the central partition plate and an inclined wall portion extending inward in the width direction and rearward from the front wall portion; and a pair of rear cab support portions located above the boundary between the front wall portion and the inclined wall portion, supporting the rear of the cab.

2. The swing frame according to claim 1, further comprising a swing bracket support portion that supports a swing bracket constituting the base of the work machine and connects the front portions of the pair of front partition plates, wherein, when viewed from the height direction, the center of the swing bracket support portion is located to the right in the width direction with respect to a center line that passes through the center in the width direction of the base plate and extends in the front-rear direction, and when viewed from the height direction, the center of gravity of the cab is located to the left in the width direction with respect to the center line.

3. The swing frame according to claim 1, further comprising: a swing bracket support portion that supports a swing bracket constituting the base of the work machine and connects the front portions of the pair of front partition plates; and a cab base that supports the rear portion of the cab relative to the pair of rear cab support portions, wherein, when viewed from the height direction, the center of the swing bracket support portion is located to the right in the width direction with respect to a center line that passes through the center in the width direction of the base plate and extends in the front-rear direction, and the intermediate position in the width direction between the fastening point between the cab base and the rear cab support portion on one side in the width direction and the fastening point between the cab base and the rear cab support portion on the other side in the width direction is located on the center line.

4. The slewing frame according to claim 1, wherein the rear cab support portion supports the cab at a plurality of fastening points located on the same straight line when viewed from the height direction, and the front wall portion and the straight line are parallel when viewed from the height direction.

5. The slewing frame according to claim 1, wherein the position of the support point of the cab in the front cab support portion is located above the pair of front partition plates.

6. A construction machine comprising: an upper rotating body having a rotating frame according to any one of claims 1 to 5 and a battery unit supported by the rotating frame; and a lower traveling body that rotatably supports the upper rotating body.

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