Electric construction machinery and its manufacturing method

Abstract

To perform various types of manufacturing at low cost according to customer needs.SOLUTION: The present invention comprises a base plate that extends in the horizontal direction, an extension plate that is removably attached to the base plate and extends further rearward from a rear end of the plate, a battery unit that is provided across the base plate and the extension plate, a protector provided to cover a lower part of the battery unit from the rear and width direction, and a rear cover provided to cover an upper part of the battery unit from the top, rear, and width direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electric construction machine and a manufacturing method thereof. [Background technology]

[0002] Patent Document 1 discloses an electric hydraulic excavator as an example of an electric construction machine. The electric hydraulic excavator is equipped with an electric motor driven by a battery instead of the engine of a conventional hydraulic excavator. A battery unit having multiple batteries is provided at the rear of the upper rotating body of the electric hydraulic excavator. Patent Document 2 discloses a construction machine in which a rear bracket for attaching a counterweight is fixed integrally to the rear end of a rotating plate of an upper rotating body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-1933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-40706 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, electric construction machinery such as those described above may be manufactured in two types: a large-capacity type and a compact type, based on customer needs. The large-capacity type has a battery unit with a larger capacity, enabling long-term operation. The compact type has a battery unit with a smaller size, resulting in a smaller upper rotating body. Providing rotating plates for these two types requires that each be manufactured separately, which increases manufacturing costs.

[0005] The present invention has been made in view of the above problems, and aims to provide an electric construction machine and a method for manufacturing the same that can manufacture various types of electric construction machines at low cost according to customer needs. [Means for solving the problem]

[0006] An electric construction machine according to one aspect of the present invention includes a base plate extending in a horizontal direction; The battery unit comprises an extension plate that is detachably attached to the base plate and extends further rearward from the rear end of the base plate, a battery unit that straddles the base plate and the extension plate, a protector that covers the lower part of the battery unit from the rear and width directions, and a rear cover that covers the upper part of the battery unit from above, from the rear, and width directions.

[0007] A manufacturing method for an electric construction machine according to one aspect of the present invention includes the steps of selecting one battery unit to be mounted on a base plate from among battery units of a plurality of sizes; determining whether an extension plate is necessary; and, if it is determined that the extension plate is necessary, attaching an extension plate to the rear of the base plate so that the extension plate extends rearward beyond the base plate; and, if the extension plate is not attached, installing the battery unit on the base plate, and, if the extension plate is attached, installing the battery unit so that it straddles both the base plate and the extension plate. [Effects of the Invention]

[0008] According to the electric construction machine and the manufacturing method thereof of the above aspect, various types can be manufactured at low cost according to the needs of the customer. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a large-capacity shovel according to an embodiment of the present invention. [Figure 2]FIG. 2 is a plan view of a rotating plate that constitutes an upper rotating body of the large-capacity excavator according to the embodiment of the present invention. [Figure 3] FIG. 2 is a plan view showing a state in which a large-capacity battery unit is mounted on a swivel plate that constitutes an upper swivel body of a large-capacity excavator according to an embodiment of the present invention. [Figure 4] FIG. 4 is a left side view of FIG. 3. [Figure 5] FIG. 2 is a plan view of a rotating plate that constitutes an upper rotating body of the compact excavator according to the embodiment of the present invention. [Figure 6] FIG. 1 is a plan view showing a state in which a compact battery unit is mounted on a swivel plate that constitutes an upper swivel body of a compact excavator according to an embodiment of the present invention. [Figure 7] FIG. 7 is a left side view of FIG. 6. [Figure 8] 3 is a flowchart showing the steps of a method for manufacturing an electric hydraulic excavator according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described in detail below with reference to Figures 1 to 7. There are two types of electric hydraulic excavators, which are an example of electric construction machines: a large-capacity excavator 200A and a compact excavator 200B. Below, the configuration of the large-capacity excavator 200A will be described, followed by a description of the configuration of the compact excavator 200B.

[0011] <Large capacity excavator> 1, the large-capacity excavator 200A includes a lower traveling body 210 and an upper rotating body 220. Hereinafter, the direction in which gravity acts when the large-capacity excavator 200A is installed on a horizontal surface will be referred to as the up-down direction.

[0012] <Undercarriage> The lower running structure 210 has a pair of crawler tracks 211. These crawler tracks 211 are driven by a hydraulic motor (not shown) for traveling, causing the lower running structure 210 to travel. The traveling direction of the lower running structure 210 is referred to as the front-to-rear direction, the forward side of the traveling direction (the normal forward direction, the side where the blade 212 described below is provided) is referred to as the front, and the rear side of the traveling direction, which is opposite to the forward side, is referred to as the rear. Furthermore, the right side when looking in the forward direction is referred to as the "right", and the left side is referred to as the "left". A pair of crawler tracks 211 is provided on the left and right. A blade 212 serving as a blade extending in the vehicle width direction (hereinafter simply referred to as the width direction) of the lower traveling body 210 is provided at the front of the lower traveling body 210. The height position of the blade 212 can be adjusted by being driven by a hydraulic cylinder.

[0013] <Upper rotating body> The upper rotating body 220 is provided on the lower traveling body 210. The upper rotating body 220 is connected to the lower traveling body 210 via a swing circle 215. The swing circle 215 has an annular shape centered on a swing axis O extending in the vertical direction. The swing circle 215 enables the upper rotating body 220 to swing around the swing axis O (see FIG. 2) relative to the lower traveling body 210. The upper rotating body 220 includes a work implement 221, a rotating frame 10 (see Figures 2 to 4), an operating space 30, a rotating motor 38 (see Figure 3), a large-capacity battery unit 40A (see Figures 3 and 4), a large protector 50A, and an exterior panel 60.

[0014] <Work equipment> As shown in Fig. 1, the work implement 221 has a boom 222, an arm 223, and a bucket 224. The work implement 221 performs various tasks such as excavation by driving the boom 222, the arm 223, and the bucket 224 by their respective hydraulic cylinders. Hereinafter, the width direction of the upper rotating body 220 when the work implement 221 is facing forward of the large-capacity excavator 200A will be simply referred to as the "width direction." Furthermore, the direction toward the center in the width direction will be referred to as the "inner side in the width direction," and the direction from the center in the width direction toward the left side (one side in the width direction) or right side (the other side in the width direction) will be referred to as the "outer side in the width direction."

[0015] <Swivel frame> As shown in FIG. 2, the swivel frame 10 has a base plate 20, a horizontal partition plate 21, a front vertical partition plate 22, a front reinforcing plate 23, a front bracket 24, a rear vertical partition plate 25, a mounting block 26, a rear bracket 27, and an extension plate 28.

[0016] <Base plate> The base plate 20 is a plate-shaped member extending horizontally. That is, the base plate 20 extends in the front-rear and width directions. The base plate 20 may be made of a single steel plate, or may be made by welding a plurality of steel plates together. The lower surface of the base plate 20 is fixed onto a swing circle 215 shown in FIG. 1. As a result, the revolving frame 10 is supported from below by the swing circle 215.

[0017] <Horizontal divider plate> The horizontal partition plate 21 is a plate-like member that protrudes upward from the upper surface of the base plate 20 and extends across the width. The horizontal partition plate 21 extends with the width direction as its longitudinal direction. The horizontal partition plate 21 is provided near the center of the base plate 20 in the front-to-rear direction, away from the front and rear ends of the base plate 20. The horizontal partition plate 21 extends across both ends of the base plate 20 in the width direction, i.e., across both the left and right ends.

[0018] Here, the area on the base plate 20 that is forward of the horizontal partition plate 21 is referred to as the front area F. The area on the base plate 20 that is rearward of the horizontal partition plate 21 is referred to as the rear area R. In other words, the area on the base plate 20 is divided by the horizontal partition plate 21 into a front area F on the forward side and a rear area R on the rear side.

[0019] <Front vertical partition plate> The front vertical partition plates 22 are plate-like members that protrude from the upper surface of the base plate 20 and extend in the front-to-rear direction. A pair of front vertical partition plates 22 are provided on the upper surface of the base plate 20, spaced apart from each other in the width direction, in front of the horizontal partition plates 21. The rear end of the front vertical partition plate 22 is connected to the surface of the horizontal partition plate 21 that faces forward. The pair of front vertical partition plates 22 are provided so as to approach each other from the rear end, which is the connection point with the horizontal partition plate 21, toward the front.

[0020] <Front reinforcement plate> The front reinforcing plate 23 is fixed integrally to the pair of front vertical partition plates 22 at the front portions of the pair of front vertical partition plates 22 .

[0021] <Front bracket> The front bracket 24 is fixed to the front ends of the pair of front vertical partition plates 22 and the front reinforcing plate 23. The front bracket 24 is a cylindrical member that penetrates in the vertical direction. The work implement 221 is supported on the base plate 20 via the front bracket 24.

[0022] <Rear vertical partition plate> The rear vertical partition plate 25 is a plate-like member that protrudes from the upper surface of the base plate 20 in the rear region R of the base plate 20 and extends in the front-to-rear direction. A plurality of front vertical partition plates 22 (three in this embodiment) are provided rearward of the horizontal partition plate 21 and spaced apart in the width direction. The front end of the rear vertical partition plate 25 is connected to the surface of the horizontal partition plate 21 that faces rearward. The horizontal partition plate 21, the front vertical partition plate 22, and the rear vertical partition plate 25 are strength members that form the framework of the revolving frame 10.

[0023] <Placement block> A pair of mounting blocks 26 are provided on the rear region R of the base plate 20, spaced apart in the width direction. The mounting blocks 26 are fixed integrally to the base plate 20 by welding. The mounting blocks 26 are provided in a position closer to the rear and closer to the rear end of the base plate 20 than the horizontal partition plate 21 in the rear region R. The pair of mounting blocks 26 are positioned identically in the front-to-rear direction. The left mounting block 26 is provided further left than the left rear vertical partition plate 25. The right mounting block 26 is provided further right than the right rear vertical partition plate 25. In other words, the pair of mounting blocks 26 are arranged so as to sandwich multiple vertical partition plates from the left and right.

[0024] The upper surface of the mounting block 26 is a flat side mounting surface 26a that extends horizontally, similar to the upper surface of the base plate 20. The heights of the side mounting surfaces 26a of the pair of mounting blocks 26 are the same, i.e., they are located on the same horizontal plane.

[0025] <Rear bracket> The rear bracket 27 is provided at the rearmost end portion of the rear region R of the base plate 20, i.e., at the rear end portion of the base plate 20. The rear bracket 27 is fixed integrally to the base plate 20 by welding. The rear bracket 27 has an upper and lower surface extending horizontally and is plate-shaped with its longitudinal direction extending in the width direction. The lower surface of the rear bracket 27 abuts against the upper surface of the base plate 20.

[0026] The height position of the upper surface of the rear bracket 27 is located lower than the side mounting surfaces 26a of the mounting blocks 26. The widthwise dimension of the rear bracket 27 is smaller than the widthwise spacing between the pair of mounting blocks 26. The rear ends of the multiple rear vertical partition plates 25 are connected to the rear bracket 27. The rear bracket 27 is arranged to fit within the base plate 20 in a plan view. The rear edge of the rear bracket 27 is shaped to follow the rear edge of the base plate 20.

[0027] <Extension plate> The extension plate 28 is provided on the base plate 20 so as to extend further rearward from the rear end of the base plate 20. The extension plate 28 is shaped like a plate with its upper and lower surfaces extending horizontally and its longitudinal direction being the width direction. The lower surface of the extension plate 28 abuts against the upper surface of the rear bracket 27. In other words, a front portion of the lower surface of the extension plate 28 abuts against the rear bracket 27 across the width direction.

[0028] 2 and 4, the extension plate 28 is fixed by bolts 29 that pass through the base plate 20 and the rear bracket 27 from below to above. That is, the extension plate 28 is detachably fixed to the base plate 20 via the rear bracket 27 and the bolts 29. A plurality of bolts 29 (three in this embodiment) that fix the extension plate 28 are provided at intervals in the width direction.

[0029] The upper surface of the extension plate 28 is a rear mounting surface 28a that is entirely flat. The height position of the rear mounting surface 28a is the same as the height position of the side mounting surfaces 26a, that is, the rear mounting surface 28a and the side mounting surfaces 26a are located on the same plane. The rear edge of the extension plate 28 extends in the width direction. The rear edge of the extension plate 28 is located rearward in the width direction of the rear edge of the base plate 20.

[0030] <Driving space> As shown in Fig. 1, the operating space 30 is provided in a portion of the rotating frame 10 above the front region F of the base plate 20. The operating space 30 is a space where an operator rides and operates the large-capacity excavator 200A. The operating space 30 is provided in a portion of the upper part of the upper rotating body 220 that is closer to the left.

[0031] The driving space 30 includes a floor panel 31 , a driver's seat 32 , an operating lever 33 , an operating pedal 34 , and a canopy 35 . The floor panel 31 extends horizontally and forms the floor surface of the driving space 30. The floor panel 31 is disposed above the front region F of the base plate 20. The operator's seat 32 is a portion where an operator sits when operating the large-capacity excavator 200 A. The rear portion of the operator's seat 32 is located above the rear region R of the base plate 20.

[0032] The operating lever 33 is a lever operated by the operator and is provided in front of the driver's seat 32. A plurality of operation pedals 34 are provided in the front part of the floor panel 31. The canopy 35 is provided to cover the driving space 30 from above.

[0033] <Slewing motor> As shown in Figures 2 and 3, the swing motor 38 is provided at a position on the base plate 20 between the pair of front vertical partition plates 22 so as to penetrate the base plate 20. The swing motor 38 is a hydraulically driven motor. The rotation shaft of the swing motor 38 extends in the vertical direction, and the central axis of the rotation shaft is the swing axis O. When the swing motor 38 is driven hydraulically, the driving force of the swing motor 38 is transmitted to the swing circle 215 via a swing pinion (not shown). This drives the upper swing body 220 to swing relative to the lower traveling body 210.

[0034] <Large-capacity battery unit> 3 and 4 is a power source for the large-capacity excavator 200A. The large-capacity battery unit 40A is provided in the rear region R of the base plate 20. The large-capacity battery unit 40A has a large-capacity battery unit main body 41A, a side flange 42, and a rear flange 44.

[0035] The large-capacity battery unit body 41A is configured by arranging multiple battery modules, each functioning as a battery, vertically, front-to-back, left-to-right, and has an overall rectangular parallelepiped shape that extends in the front-to-back, width, and up-to-down directions.

[0036] A pair of side flanges 42 are provided so as to protrude from the lower portion of the large-capacity battery unit main body 41A to both the left and right sides (both sides in the width direction). The side flanges 42 extend rearward from the front end of the large-capacity battery unit main body 41A. The lower surfaces of the side flanges 42 extend horizontally, similar to the bottom surface of the large-capacity battery unit 40A. The lower surfaces of the side flanges 42 are located on the same plane as the lower surface of the large-capacity battery unit 40A. The lower surface of the left side flange 42 is placed in contact with the left side mounting surface 26a. The lower surface of the right side flange 42 is placed in contact with the right side mounting surface 26a. The pair of side flanges 42 are fixed to the mounting block 26 via bolts 43 that pass through the side flanges 42 and the side mounting surface 26a from top to bottom.

[0037] The rear flanges 44 are provided so as to protrude horizontally from the rear surface of the large-capacity battery unit main body 41A. A pair of rear flanges 44 are provided with a gap in the width direction. The lower surfaces of the rear flanges 44 extend horizontally, similar to the bottom surface of the large-capacity battery unit 40A. The lower surfaces of the rear flanges 44 are located on the same plane as the lower surface of the large-capacity battery unit 40A. The lower surfaces of the pair of rear flanges 44 are placed in contact with the rear mounting surface 28a, which is the upper surface of the extension plate 28. The pair of rear flanges 44 are fixed to the rear bracket 27 via bolts 45 that pass through the rear flanges 44 and the extension plate 28 from top to bottom.

[0038] In this state where the large-capacity battery unit 40A is fixed to the revolving frame 10, the large-capacity battery unit main body 41A is disposed so as to straddle the base plate 20 and the extension plate .

[0039] That is, the rear portion of the large-capacity battery unit main body 41A is placed on the rear mounting surface 28a, which is the upper surface of the extension plate 28. The back surface of the large-capacity battery unit main body 41A is disposed along the rear end of the extension plate 28 in a plan view. The position of the front surface of the large-capacity battery unit main body 41A is the same as the position of the front end of the mounting block 26. The widthwise spacing of the large-capacity battery unit main body 41A, i.e., the spacing between the pair of side surfaces of the large-capacity battery unit 40A, is the same as the spacing between the widthwise inner sides of the pair of mounting blocks 26. The rear portion of the large-capacity battery unit 40A protrudes rearward beyond the base plate 20 in a plan view, and this protruding portion is supported by the extension plate 28. A first front-rear length LA, which is the dimension of the large-capacity battery unit main body 41A in the front-rear direction, is a large dimension that extends from the center of the rear region R of the base plate 20 in the front-rear direction to the rear end of the extension plate 28.

[0040] <Other devices> Other devices (all not shown) for operating the large-capacity excavator 200A are provided on the swivel frame 10. DC power supplied from the large-capacity battery unit 40A is converted to AC power by an inverter and supplied to the electric motor. When the electric motor rotates, the hydraulic pump is driven and hydraulic oil stored in the oil tank is discharged. The discharged hydraulic oil is distributed to various hydraulic devices via hydraulic valves, thereby operating the large-capacity excavator 200A. After completing its work in each hydraulic device, the hydraulic oil is cooled in the oil cooler of the cooling unit and then returned to the oil tank.

[0041] <Large protector> As shown in Figures 1 and 4, a pair of large protectors 50A are provided at both corners of the rear and lower part of the upper rotating body 220, spaced apart in the width direction. The large protectors 50A are formed of a high-strength material such as steel. The large protectors 50A are fixed integrally to both corners of the rear end of the base plate 20. The large plate is fixed to the base plate 20 via supports (not shown). The large protectors 50A and the extension plate 28 are not in contact with each other, and a gap is formed between them.

[0042] <Exterior panel> The exterior panel 60 is a cover that forms the outer shape of the upper rotating body 220. Inside the exterior panel 60, various devices including the large-capacity battery unit 40A of the upper rotating body 220 are housed. The exterior panel 60 has a large rear cover 61A, a left cover 62, and a right cover 63. The large rear cover 61A forms the rear of the exterior panel 60 and covers the large-capacity battery unit 40A protruding rearward from the base plate 20 from behind and above. The large rear cover 61A is fixed to the base plate 20 via a support (not shown). The large rear cover 61A and the extension plate 28 are not in contact with each other, and a gap is formed between them. The left cover 62 forms the left side of the exterior panel 60. The right cover 63 forms the right side of the exterior panel 60.

[0043] 3, the rear edge of the upper rotating body 220 defined by the large rear cover 61A of the exterior panel 60 and the large protector 50A forms an arc centered on the rotation axis O in a plan view. The radius of this arc is set to be the first rotation radius RA. In the large-capacity excavator 200A, the first rotation radius RA is also set to be large in accordance with the size of the large-capacity battery unit 40A.

[0044] <Compact excavator> Next, the compact excavator 200B will be described with reference to Figures 5 to 7. In the description of the compact excavator 200B, the same components as those of the large-capacity excavator 200A will be given the same reference numerals and description thereof will be omitted.

[0045] As shown in Fig. 5, the revolving frame 10 of the compact excavator 200B does not have the extension plate 28, unlike the large-capacity excavator 200A. Therefore, the upper surface of the rear bracket 27 is exposed in the revolving frame 10 alone. The revolving frame 10 of the compact excavator 200B has the same structure as the revolving frame 10 of the large-capacity excavator 200A, except that it does not have the extension plate 28.

[0046] As shown in Fig. 6, the compact excavator 200B has a compact battery unit 40B instead of the large-capacity battery unit 40A of the large-capacity excavator 200A. The compact battery unit 40B has a compact battery unit main body 41B. The compact battery unit main body 41B is configured by integrally arranging a plurality of battery modules, each functioning as a battery, vertically, front-to-back, and left-to-right. The compact battery unit main body 41B has an overall rectangular parallelepiped shape that extends in the front-to-rear, width, and vertical directions.

[0047] The width and height dimensions of the compact battery unit main body 41B are the same as those of the large-capacity battery unit main body 41A. However, the second front-rear length LB, which is the front-rear dimension of the compact battery unit main body 41B shown in Fig. 6, is smaller than the first front-rear length LA, which is the front-rear dimension of the battery unit main body of the large-capacity battery unit 40A shown in Fig. 3. In other words, only the front-rear length dimension of the compact battery unit main body 41B is smaller than that of the large-capacity battery unit main body 41A.

[0048] As a result, the rear surface of the compact battery unit main body 41B is substantially contained within the base plate 20 in a plan view, as shown in Fig. 6. As shown in Fig. 7, legs 46 extending downward are provided at the rear portion of the bottom surface of the compact battery unit 40B. The lower ends of the legs 46 abut against the upper surface of the rear bracket 27, thereby supporting the rear portion of the compact battery unit main body 41B. The legs 46 are fixed by bolts 47 that penetrate the base plate 20 and the rear bracket 27 from below to above. Furthermore, the provision of the legs 46 maintains the horizontal position of the compact battery unit main body 41B.

[0049] As shown in FIG. 7, the compact excavator 200B is equipped with a small protector 50B instead of the large protector 50A of the large-capacity excavator 200A. A pair of small protectors 50B are provided at both corners of the rear and lower part of the upper revolving body 220, spaced apart in the width direction. The small protectors 50B are formed of a high-strength material such as steel. The small protectors 50B are fixed integrally to both corners of the rear end of the base plate 20. The small protector 50B is slightly smaller in size than the large protector 50A. In other words, the small protector 50B has a compact shape that can cover the compact battery unit 40B.

[0050] As shown in Figures 6 and 7, the exterior panel 60 of the compact excavator 200B has a small rear cover 61B instead of the large rear cover 61A of the large-capacity excavator 200A. The small rear cover 61B forms the rear of the exterior panel 60 and covers the compact battery unit main body 41B, which fits on the base plate 20, from behind and above. The small rear cover 61B is slightly smaller in shape than the large rear cover 61A. In other words, the small rear cover 61B has a compact shape that can cover the compact battery unit 40B.

[0051] 6, the rear edge of the upper swing body 220, which is defined by the small rear cover 61B of the exterior panel 60 and the small protector 50B, forms an arc shape centered on the swing axis O in a plan view. The radius of this arc is defined as the second swing radius RB. In the compact excavator 200B, the second swing radius RB also increases in accordance with the size of the compact battery unit 40B. In other words, the second swing radius RB is smaller than the first swing radius RA.

[0052] <Manufacturing method for electric hydraulic excavators> Next, a method for manufacturing the large-capacity excavator 200A and the compact excavator 200B as the electric hydraulic excavator described above will be described with reference to the flowchart shown in FIG.

[0053] First, the size of the battery unit (large-capacity battery unit 40A, compact battery unit 40B) to be mounted on the revolving frame 10 is selected (step S1). That is, depending on the customer's needs, it is decided whether to manufacture a large-capacity excavator 200A or a compact excavator 200B, and accordingly, it is decided whether to mount the large-capacity battery unit 40A or the compact battery unit 40B.

[0054] Next, it is determined whether the extension plate 28 is required for the revolving frame 10 (step S2). If it is determined in step S1 that the large-capacity battery unit 40A is to be mounted, it is determined that the extension plate 28 is required (step S2: Yes). On the other hand, if it is determined in step S1 that the compact battery unit 40B is to be mounted, it is determined that the extension plate 28 is not required (step S2: No).

[0055] If it is determined in step S2 that the extension plate 28 is necessary, the extension plate 28 is attached to the base plate 20 (step S3).

[0056] Next, the large-capacity battery unit 40A or compact battery unit 40B is installed on the revolving frame 10 (step S4). That is, if the extension plate 28 is attached to the base plate 20 in step S3, the large-capacity battery unit 40A is installed so as to straddle the base plate 20 and the extension plate 28. On the other hand, if the extension plate 28 is not attached, the small-sized compact battery unit 40B is installed after step S2 so as to fit on the base plate 20. In either case, the base plate 20 and the strength members integrally provided on the base plate 20 have the same structure.

[0057] In this way, after installing the large-capacity battery unit 40A or the compact battery unit 40B, other components can be sequentially attached, thereby selectively manufacturing either the large-capacity excavator 200A or the compact excavator 200B.

[0058] <Action and effect> According to this embodiment, two types of excavators, a large-capacity excavator 200A and a compact excavator 200B, can be manufactured while sharing the same base plate 20 and the same strength members integrally provided on the base plate 20. That is, when manufacturing an excavator with a large-capacity battery unit 40A that can operate for a long time, an extension plate 28 can be attached to the base plate 20 and a large-capacity battery unit 40A that spans the base plate 20 and the extension plate 28 can be installed. Furthermore, when manufacturing a compact excavator 200B that is easy to maneuver, a compact battery unit 40B can be installed so that it fits on the base plate 20 without attaching the extension plate 28 to the base plate 20.

[0059] Here, the revolving frame 10 is a key component of the upper revolving body 220, and therefore has been meticulously designed for strength. If a revolving frame 10 suitable for each of the large-capacity excavator 200A and the compact excavator 200B were to be individually designed, consideration would be required depending on the weight and size of each, making the design process complicated. Furthermore, it would be necessary to manufacture the revolving frame 10 for each of the large-capacity excavator 200A and the compact excavator 200B from scratch, which would increase manufacturing costs and make inventory management complicated.

[0060] In contrast to this, in this embodiment, the base plate 20 and strength members (horizontal partition plate 21, front vertical partition plate 22, front reinforcing plate 23, rear vertical partition plate 25, and rear bracket 27) that are common to the large-capacity excavator 200A and the compact excavator 200B can be used, so the above-mentioned inconvenience does not occur. Therefore, various types of electric hydraulic excavators can be manufactured at low cost in accordance with customer needs.

[0061] Furthermore, in the large-capacity excavator 200A, the large-capacity battery unit 40A is placed on the pair of side mounting surfaces 26a, as well as on the rear mounting surface 28a of the extension plate 28, which is flush with the side mounting surfaces 26a. This allows the large-capacity battery unit 40A to be stably supported on the revolving frame 10.

[0062] Furthermore, because the large protector 50A and the large rear cover 61A are not in direct contact with the extension plate 28, when an external force is applied to the rear of the upper rotating body 220, for example, the external force can be prevented from being directly applied to the extension plate 28 via the large protector 50A and the large rear cover 61A. This allows the extension plate 28 to stably and reliably support the heavy large-capacity battery unit 40A.

[0063] Furthermore, because the extension plate 28 is fixed to the rear bracket 27, the load of the large-capacity battery unit 40A received by the extension plate 28 is transmitted to the base plate 20 via the rear bracket 27. On the other hand, in the compact excavator 200B, the rear portion of the bottom surface of the compact battery unit 40B is supported by the rear bracket 27, so the load is also transmitted to the base plate 20 via the rear bracket 27. In other words, whether the large-capacity battery unit 40A or the compact battery unit 40B is used, the behavior of the load transmission to the base plate 20 is the same. Therefore, the strength design of the entire revolving frame 10, which is based on the base plate 20, can be standardized.

[0064] Furthermore, because the rear bracket 27 is connected to strength members such as the horizontal partition plate 21 via the rear vertical partition plate 25, it is possible to prevent the rear of the revolving frame 10 from being bent when the large-capacity battery unit 40A is installed via the rear bracket 27. In other words, because the rear bracket 27 is directly connected to the strength members that form the framework of the revolving frame 10, even if a load from the large-capacity battery unit 40A is applied to the rear bracket 27, the load can be supported by the entire strength member. This allows for stable support of the large-capacity battery unit 40A.

[0065] <Other embodiments> Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the technical idea of ​​the invention.

[0066] In the embodiment, an electric hydraulic excavator is manufactured by selecting from two types of battery units, a large-capacity battery unit 40A and a compact battery unit 40B. However, this is not limited to this, and one battery unit may be selected from three or more types of battery units of multiple sizes, and the presence or absence of an extension plate 28 may be determined depending on the size of the selected battery unit. Furthermore, if an extension plate 28 is provided, an extension plate 28 of a size corresponding to the size of the battery unit selected from the multiple sizes of extension plates 28 may be used.

[0067] Furthermore, for example, the large-capacity excavator 200A may be converted into a compact excavator 200B by removing the large-capacity battery unit 40A and the extension plate 28 and instead providing a compact battery unit 40B. Conversely, the compact excavator 200B may be converted into a large-capacity excavator 200A by removing the compact battery unit 40B and instead providing the extension plate 28 and the large-capacity battery unit 40A.

[0068] In the manufacturing method for the large-capacity excavator 200A and the compact excavator 200B of the embodiment, if it is decided to install a large-capacity battery unit 40A, it is determined that the extension plate 28 is necessary, and the extension plate 28 is attached to the base plate 20. However, this is not limited to this, and even if it is decided to install a large-capacity battery unit 40A, it may be determined that the extension plate 28 is not necessary, and the extension plate 28 may not be provided on the base plate 20. In this case, it is sufficient to mount the large-capacity battery unit 40A directly on the base plate 20.

[0069] In the embodiment, an electric hydraulic excavator has been described as an example of an electric construction machine, but the present invention is not limited to this. For example, the present invention may be applied to an electric excavator or other electric construction machine in which the working implement 221 and other components are all driven electrically. [Explanation of symbols]

[0070] 10...Swivel frame 20...Base plate 21...Horizontal partition plate 22...Front vertical partition plate 23...Front reinforcement plate 24...Front bracket 25...Rear vertical partition plate 26...Mounting block 26a...Side mounting surface 27...Rear bracket 28...Extension plate 28a...Rear mounting surface 29...Bolt 30...Driver's space 31...Floor panel 32...Driver's seat 33...Operating lever 34...Operating pedal 35...Canopy 38...Swivel motor 40A...Large capacity battery unit 40B...Compact battery unit 41A...Large capacity battery unit main body 41B...Compact battery unit main body 42...Side flange 43...Bolt 44...Rear flange 45...Bolt 46...Leg 47...Bolt 50A...Large protector 50B...Small protector 60...Exterior panel 61A...Large rear cover 61B...Small rear cover 62...Left cover 63...Right cover 200A...Large capacity excavator 200B...Compact excavator 210...Undercarriage 211...Crawler 212...Blade 215...Swing circle 220...Upper rotating body 221...Work implement 222...Boom 223...Arm 224...Bucket F...Front region R...Rear region O...Slewing axis LA...First fore-and-aft length LB...Second fore-and-aft length RA...First swing radius RB...Second swing radius

Claims

1. a base plate extending horizontally; an extension plate detachably attached to the base plate and extending further rearward from the rear end of the base plate; a battery unit provided across the base plate and the extension plate; a protector provided to cover a lower portion of the battery unit from the rear and width directions; a rear cover provided to cover an upper portion of the battery unit from above, from behind, and in the width direction; Electric construction machinery equipped with

2. a pair of mounting blocks are provided on the base plate and spaced apart in the width direction, and the upper surfaces of the mounting blocks serve as side mounting surfaces extending horizontally; The upper surface of the extension plate is a rear support surface extending horizontally, The electric construction machine according to claim 1, wherein a lower surface of the battery unit is placed on the pair of side mounting surfaces and the rear mounting surface.

3. 3. The electric construction machine according to claim 1, wherein the protector and the rear cover are supported by the base plate at a distance from the extension plate.

4. a rear bracket provided integrally with the base plate at a rear portion of the base plate and having an upper surface extending horizontally; 4. The electric construction machine according to claim 1, wherein the extension plate is fixed to an upper surface of the rear bracket, and is thereby detachably attached to the base plate via the rear bracket.

5. a horizontal partition plate that protrudes from an upper surface of the base plate, extends in the width direction, and divides the top of the base plate into a front region on a front side and a rear region on a rear side; a rear vertical partition plate that protrudes from an upper surface of the base plate, extends in the front-rear direction, has a front end connected to the horizontal partition plate, and has a rear end connected to the rear bracket; The electric construction machine according to claim 4, further comprising:

6. selecting one battery unit to be mounted on the base plate from among a plurality of sizes of battery units; determining whether an extension plate is required; a step of attaching an extension plate to a rear portion of the base plate when it is determined that the extension plate is necessary, the extension plate extending rearward from the base plate; a step of installing the battery unit on the base plate when the extension plate is not attached, and installing the battery unit so as to straddle the base plate and the extension plate when the extension plate is attached; A method for manufacturing an electric construction machine, comprising:

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