WO2024257926A1 - Small electric excavator - Google Patents

Abstract

An aspect of the present disclosure provides a small electric excavator including a lower traveling body, an upper rotating body, and a working device, wherein: the upper rotating body includes a vehicle body frame, a cabin installed on the left side on the vehicle body frame, and a counterweight installed on the rear side of the vehicle body frame; inside the vehicle body frame, with respect to a center line, a MCV and a hydraulic tank are disposed on the left side and a cooling fan, a radiator, an oil cooler, a battery, an electric motor, a hydraulic pump, and electric devices are disposed on the right side; at least one inlet through which cold air is introduced is formed in the vehicle body frame; an outlet through which hot air is discharged is formed in a front surface portion of the vehicle body frame; and the cooling fan is disposed directly behind the outlet so as to be configured in a manner of blowing air inside the vehicle body frame forward.

Description

compact electric excavator

The present disclosure relates generally to small electric excavators. In certain aspects, the present disclosure relates to small electric excavators having a structure and arrangement capable of improving cooling efficiency of internal components. The present disclosure may be applied to large vehicles such as trucks, buses, and construction equipment among other vehicle types. Although the present disclosure may be described with respect to a particular vehicle, the present disclosure is not limited to any particular vehicle.

An excavator is a type of construction machine that performs various tasks, such as digging the ground at construction sites, loading work to transport soil, excavating work to create a foundation, crushing work to dismantle a building, leveling work to prepare the ground, and leveling work to level the ground. Such construction machines may generally include a lower body that functions to move the equipment, an upper swivel body that is swivellably mounted on the lower body, and a work device mounted on the front of the upper swivel body.

Conventional excavators are usually equipped with an engine such as a diesel engine to obtain driving power, and the power of this engine is used to drive a hydraulic pump, and the hydraulic fluid discharged from the hydraulic pump is supplied to a hydraulic actuator such as a hydraulic motor or a hydraulic cylinder, thereby rotating the driving crawler or tires or operating equipment such as a boom, arm, or bucket.

Existing excavators equipped with engines such as diesel engines have the disadvantage of high fuel prices and high fuel consumption, which increases operating costs. In addition, there is a continuing demand for strengthened exhaust gas regulations for construction equipment, increased demand for low-noise equipment, and low maintenance costs.

Accordingly, relatively efficient and eco-friendly small electric excavators are emerging to improve energy efficiency and work performance. However, these small electric excavators have narrow internal spaces, so there is not enough space to accommodate components. Therefore, it is important to efficiently arrange each component. For example, considering the location of the battery module, it is desirable to arrange the cooling device in a direction that does not affect battery cooling. In addition, since small electric excavators require various electric devices (motors, inverters, converters, various ECUs, etc.) other than the battery to be arranged within the frame, it is necessary to manage the heat generation of each component. In existing excavators, the engine was the largest heat source, but in electric excavators, various devices that use hydraulic oil (hydraulic tanks, main control valves (MCVs), hydraulic pumps, etc.) are the largest heat sources. Therefore, in order to efficiently manage the heat of each component placed inside a small electric excavator, it is important to determine how to place the inlet section where cold air flows in and the outlet section where the heated air passes through each component and radiator and is discharged.

The present disclosure is intended to solve the problems of the above-mentioned prior art, and an object of the present disclosure is to provide a small electric excavator having a structure and arrangement capable of improving the cooling efficiency of internal components.

The first aspect of the present disclosure provides a compact electric excavator including a lower body, an upper slewing body, and a work device, wherein the upper slewing body includes a body frame, a cabin installed on the left side of the body frame, and a counterweight installed on the rear of the body frame, and inside the body frame, an MCV and a hydraulic tank are arranged on the left side with respect to a centerline, and a cooling fan, a radiator, an oil cooler, a battery, an electric motor, a hydraulic pump, and electric devices are arranged on the right side, and at least one inlet for introducing cool air is formed in the body frame, an outlet for discharging heated air is formed on the front side of the body frame, and the cooling fan is arranged immediately behind the outlet and configured to blow internal air of the body frame forward.

In some examples, optionally including at least one preferred example, the radiator and the oil cooler may be positioned directly behind the cooling fan, which may be a compact electric excavator.

In some examples, optionally including at least one preferred example, the MCV may be a small electric excavator characterized in that it is arranged on the left front side with respect to the centerline inside the body frame, and ventilation is formed on the lower part of the body frame where the MCV is located so that heat generated from the MCV can be circulated.

In some examples, optionally including at least one preferred example, the compact electric excavator may be characterized in that a baffle is installed inside the body frame to at least partially block the inflow of air from the left to the right with respect to the centerline.

In some examples, optionally including at least one preferred example, the hydraulic tank is arranged at the left rear side with respect to the centerline inside the body frame, and a third inlet is formed on the lower part of the body frame where the hydraulic tank is located to allow air to be introduced for cooling the hydraulic tank, which may be a small electric excavator.

In some examples, optionally including at least one preferred example, the electric motor, the hydraulic pump and the electric devices are arranged at the right rear side with respect to the centerline inside the body frame, and a first inlet is formed at the rear of the body frame to allow air to be introduced for cooling the electric motor, the hydraulic pump and the electric devices, which may be a small electric excavator.

In some examples, optionally including at least one preferred example, the battery may be disposed behind the radiator and the oil cooler, and a second inlet is formed on the right side of the body frame to introduce air for cooling the battery, which may be a small electric excavator.

In some examples, optionally including at least one preferred example, the compact electric excavator may be characterized in that a fourth inlet is formed on an upper surface of the body frame where the radiator and the oil cooler are located to introduce air for cooling the radiator and the oil cooler.

In some examples, optionally including at least one preferred example, the first inlet may be a small electric excavator, characterized in that it includes a long hole extending horizontally, and an inclined hole extending downwardly from one end of the long hole.

In some examples, optionally including at least one preferred example, the fourth inlet may be formed in an inclined shape with an open rearward direction on the upper surface of the body frame, which may be a small electric excavator.

According to the small electric excavator according to the present disclosure, a radiator and an oil cooler are arranged immediately behind a cooling fan, and the cooling fan is configured to blow internal air of the body frame forward, so that air heated while passing through the radiator can be discharged to the outside without affecting the battery.

According to the small electric excavator according to the present disclosure, a blocking wall is installed inside the body frame to at least partially block the inflow of air from the left to the right with respect to the center line, thereby blocking the air heated while passing through the MCV located at the left front inside the body frame from moving to the radiator and oil cooler located at the right front, thereby preventing the cooling efficiency of the radiator and oil cooler from being reduced.

According to the small electric excavator according to the present disclosure, the first to fourth inlets through which cold air is introduced into the body frame and the outlets through which hot air is discharged are efficiently arranged, thereby improving the cooling efficiency of components arranged inside the body frame.

It should be understood that the effects of the present disclosure are not limited to the effects described above, but include all effects that can be inferred from the detailed description of the present disclosure or the composition of the disclosure described in the claims.

The disclosed aspects, embodiments (including any preferred embodiments), and/or accompanying claims may be suitably combined with one another as would be apparent to one skilled in the art.

Additional features and advantages are set forth in the description, claims and drawings that follow, and in part will be readily apparent to those skilled in the art or may be recognized by practicing the teachings herein.

The example is described in more detail below with reference to the attached drawings.

FIG. 1 is a drawing showing the basic configuration of a small electric excavator according to one aspect of the present disclosure.

FIG. 2 is a front perspective view of the upper swivel body according to one aspect of the present disclosure.

Figure 3 is a rear perspective view of the upper swivel body according to one side of the present disclosure.

Figure 4 is a plan view of the upper swivel body according to one side of the present disclosure.

FIG. 5 is a drawing partially showing the internal space of the upper swivel body according to one aspect of the present disclosure.

FIG. 6 is a cross-sectional view taken along line A-A' of FIG. 2, schematically illustrating air flow inside a body frame according to one side of the present disclosure.

FIG. 7 is a cross-sectional view taken along line B-B' of FIG. 3, schematically illustrating air flow inside a body frame according to one side of the present disclosure.

Figure 8 is a rear perspective view of the upper swivel body according to another aspect of the present disclosure.

The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practice the present disclosure. However, the present disclosure may be implemented in many different forms and is therefore not limited to the aspects set forth herein. In addition, in order to clearly describe the present disclosure in the drawings, parts that are not related to the description are omitted, and similar parts are designated by similar drawing reference numerals throughout the specification.

The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. The terms “comprises,” “comprising,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Although the terms first, second, etc. may be used herein to describe various elements, it will be understood that these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, a first element could be referred to as a second element, and similarly, a second element could also be referred to as a first element.

Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe one element's relationship to another, as illustrated in the drawings. It will be understood that these terms and the terms discussed above are intended to encompass different orientations of the device in addition to the orientations depicted in the drawings. When a component is referred to as being "connected to" or "coupled to" another component, it will be understood that it can be directly connected or coupled to the other component, or that intervening components may be present. In contrast, when an element is referred to as being "directly connected to" or "directly coupled to" another element, no intervening elements are present.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should be further understood that terms used herein should be interpreted to have a meaning consistent with their meaning in the context of this disclosure and related art, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

Hereinafter, one aspect of the present disclosure will be described in detail with reference to the attached drawings.

FIG. 1 is a drawing showing the basic configuration of a small electric excavator according to one aspect of the present disclosure, FIG. 2 is a front perspective view of an upper slewing body according to one aspect of the present disclosure, FIG. 3 is a rear perspective view of an upper slewing body according to one aspect of the present disclosure, FIG. 4 is a plan view of an upper slewing body according to one aspect of the present disclosure, and FIG. 5 is a drawing partially showing an internal space of an upper slewing body according to one aspect of the present disclosure.

As illustrated in FIGS. 1 to 5, a small electric excavator (1000) according to one aspect of the present disclosure comprises a lower body (10), an upper slewing body (20) rotatably supported on the lower body (10), and a boom (31), an arm (32), and an attachment (33) operated by respective cylinders, and a working device (30) supported on the upper slewing body (20).

The lower drive body (10) supports the load of the upper slewing body (20) and the work device (30) and is configured to move the small electric excavator (1000) forward and backward or left and right for work purposes.

The upper swing body (20) is configured to be supported on the lower driving body (10) and is designed to rotate on the lower driving body (10) by a swing device including a swing motor, a swing reduction gear, etc.

The work device (30) is installed to be supported on the upper swivel body (20) and is configured to perform the work of the small electric excavator (1000). At this time, the work may mean various tasks in civil engineering and construction sites. The work device (30) may be configured to include a boom (31), an arm (32), and an attachment (33) operated by each cylinder, and is installed while being supported toward the front of the upper swivel body (20). Therefore, when the upper swivel body (20) rotates, the work device (30) rotates together with the upper swivel body (20).

Meanwhile, the upper swing body (20) includes a body frame (100), a cabin (200), and a counterweight (300).

More specifically, the upper swivel body (20) is configured to include a body frame (100), a cabin (200) installed on the left side of the body frame (100), and a counterweight (300) installed on the rear side of the body frame (100).

The body frame (100) is rotatably installed on the lower driving body (10) by a swivel device. That is, the body frame (100) forms a support structure and constitutes the base of the upper swivel body (20).

The body frame (100) is a supporting structure surrounded by a front portion (100a), a rear portion (100b), a left side portion (100c), a right side portion (100d), an upper portion (100e), and a lower portion (100f). At this time, the rear portion (100b) of the body frame (100) may be in the form of a rear cover. A counterweight (300) is installed at the rear of the body frame, that is, on the lower side of the rear portion (100b). In addition, a cabin (200) may be installed on the body frame (100), and the cabin (200) may preferably be installed on the left side of the centerline (CL) on the body frame (100). An internal space capable of accommodating components is formed inside the body frame (100).

The cabin (200) may be provided with a driver's seat for the operator to sit in. In front of the driver's seat, various handles or pedals for operating or driving the small electric excavator (1000) may be provided.

A counter weight (300) is installed at the rear of the body frame (100). This counter weight (300) is intended to balance the weight with the work device (30) and may be formed of a weight having a convex shape toward the rear.

FIG. 6 is a cross-sectional view taken along line A-A' of FIG. 2, schematically illustrating air flow inside a body frame according to one side of the present disclosure, and FIG. 7 is a cross-sectional view taken along line B-B' of FIG. 3, schematically illustrating air flow inside a body frame according to one side of the present disclosure.

Referring to FIGS. 2 to 7, the small electric excavator (1000) of the present disclosure may include components such as a cooling fan (110), a radiator (120), an oil cooler (130), a main control valve (MCV) 140, an air conditioning system (HAVC) 150, a hydraulic tank (hydraulic tank) 160, an electric motor (electric motor) 170, a hydraulic pump (hydraulic pump) 180, a battery (ESS) 190), and other electric devices. In addition, the other electric devices may include a converter, an inverter, a junction box, a motor drive, and the like. These components of the small electric excavator (1000) may be provided in an internal space of an upper swivel body (20), more specifically, a body frame (100).

Meanwhile, the small electric excavator (1000) has a narrow internal space and does not have enough space to accommodate the parts. Therefore, it is important to efficiently arrange each part. In particular, considering the location of the battery (190), it is desirable to form an air flow in a direction that does not affect battery cooling. In addition, in the small electric excavator (1000), parts such as the MCV (140), the hydraulic tank (160), and the hydraulic pump (180) that use hydraulic oil are the largest heat sources, so it is important to efficiently perform heat management of these parts.

Referring to FIGS. 6 and 7, inside the body frame (100), an MCV (140), an HVAC (150), and a hydraulic tank may be arranged on the left side based on the center line (CL), and a cooling fan (110), a radiator (120), an oil cooler (130), a battery (190), an electric motor (170), a hydraulic pump (180), and other electric devices may be arranged on the right side.

In addition, one or more inlets (102, 103, 104, 105) for introducing cold air may be formed in the body frame (100), and an outlet (106) for introducing hot air through internal components may be formed at the front portion (100a) of the body frame (100) based on the centerline (CL).

At this time, the cooling fan (110) is for cooling the heat generated from the components constituting the small electric excavator (1000) with air, and can be placed right behind the outlet (106). This cooling fan (110) blows the internal air of the body frame (100) to force it to flow forward, thereby causing the internal air to flow out to the outside through the outlet (106).

Meanwhile, the radiator (120) and oil cooler (130) constituting the heat exchanger may be placed immediately behind the cooling fan (110). The radiator (120) is an element for releasing heat of cooling water for an electric device such as an electric motor (170), and the oil cooler (130) is an element for cooling hydraulic oil returning to the hydraulic tank (160) from a hydraulic device such as a work device (30).

These radiators (120) and oil coolers (130) can be arranged in a row laterally at the rear of the cooling fan (110) and can be positioned downstream in the flow of cooling air by the cooling fan (110). That is, since the radiator (120) and oil cooler (130) are arranged immediately behind the cooling fan (110) and the cooling fan (110) is configured to blow the internal air of the body frame (100) forward, the air heated while passing through the radiator (120) can be discharged to the outside without affecting the battery (190).

The MCV (140) is for controlling the direction of hydraulic oil discharged from the hydraulic pump (180) to operate the work device (30), and may be placed on the left front side and the lower part of the cabin (200) based on the centerline (CL) inside the body frame (100). A ventilation (101) may be formed on the lower part (100f) of the body frame (100) where the MCV (140) is positioned so that heat generated from the MCV (140) can be circulated by natural convection. That is, the ventilation (101) may be positioned on the lower side of the MCV (140).

The temperature of the MCV (140) can be raised to about 90° by the oil, and the air flowing in through the ventilation (101) can become hot as it passes through the MCV (140). In this way, if the air that becomes hot as it passes through the MCV (140) passes through the radiator (120) and the oil cooler (130), a problem may occur in which the cooling efficiency of the radiator (120) and the oil cooler (130) decreases.

Accordingly, as illustrated in FIGS. 5 and 6, a blocking wall (107) may be installed inside the body frame (100) to at least partially block the inflow of air from the left to the right with respect to the centerline (CL). That is, the blocking wall (107) blocks air heated while passing through the MCV (140) located at the left front inside the body frame (100) from moving to the radiator (120) and oil cooler (130) located at the right front, thereby preventing the cooling efficiency of the radiator (120) and oil cooler (130) from being reduced.

The hydraulic tank (160) is a hydraulic oil storage tank for supplying hydraulic oil to the hydraulic pump (180) and can be placed on the left rear side based on the center line (CL) inside the body frame (100).

A third inlet (104) may be formed on the lower surface (100f) of the body frame (100) where the hydraulic tank (160) is located to allow air to be introduced for cooling the hydraulic tank (160). That is, the third inlet (104) may be located on the lower side of the hydraulic tank (160).

Referring to FIGS. 6 and 7, the electric motor (170), the hydraulic pump (180), and the electric devices may be placed on the right rear side with respect to the centerline (CL) inside the body frame (100).

The electric motor (170) is configured to generate power for driving a small electric excavator (1000) using the electric energy of the battery (190), and the hydraulic pump (180) is configured to provide pressure for driving each component of the small electric excavator (1000) using the power generated from the electric motor (170). That is, the hydraulic pump (180) is driven by the power from the electric motor (170) and discharges a flow rate to drive the working device (30) and the lower travel body (10). For example, the hydraulic pump (180) provides pressure to the boom cylinder, the arm cylinder, and the attachment cylinder to drive the boom (31), the arm (32), and the attachment (33). At this time, the hydraulic pump (180) can receive hydraulic pressure from the hydraulic tank (160) and provide pressure to the working device (30).

The electric devices may include a converter, an inverter, a junction box, a motor drive, etc. These electric devices may be arranged on the right rear side with respect to the center line (CL) inside the body frame (100), preferably above the electric motor (170) and the hydraulic pump (180). A converter is a device that changes the shape of a signal or energy. Such a converter may include a DC/DC converter that converts a DC power of a certain voltage into a DC power of a different voltage. An inverter is a device that converts a DC power into an AC power. That is, the inverter converts the DC power of the battery (190) into an AC power of a certain voltage required to drive the electric motor (170). The junction box controls the power transmitted to the battery (190) and controls the power stored in the battery (190) to be transmitted to peripheral components. That is, the junction box controls the power of the battery (190) to be transmitted to the converter, the inverter, etc. The motor drive is an electronic control device that controls an electric motor (170) and can perform torque control, speed control, position control, etc. of the electric motor (170).

Meanwhile, referring to FIGS. 6 and 7, a first inlet (102) may be formed in the rear portion (100b) of the body frame (100) to allow air to be introduced for cooling the electric motor (170), the hydraulic pump (180), and the electric devices arranged at the rear inside the body frame (100). The first inlet (102) may include one or more long holes (102a) extending in a horizontal direction. The cold air introduced through the first inlet (102) may sequentially pass through the electric motor (170), the hydraulic pump (180), the electric devices, the radiator (120), and the oil cooler (130) arranged at the rear, and then be discharged to the outside through the cooling fan (110).

In this way, as the first inlet (102) is formed in the rear portion (100b) of the body frame (100), the electric motor (170), the hydraulic pump (180), and the electric devices located at the rear can be efficiently cooled.

Referring to FIGS. 6 and 7, the battery (190) may be placed in the center right of the centerline (CL) inside the body frame (100). More specifically, the battery (190) may be placed behind the radiator (120) and the oil cooler (130), and in front of the electric motor (170) and the hydraulic pump (180), and may be placed toward the right side (100d) of the body frame (100).

A second inlet (103) may be formed on the right side (100d) of the body frame (100) to allow air to be introduced for cooling the battery (190). The cold air introduced through the second inlet (103) may sequentially pass through the battery (190), radiator (120), and oil cooler (130) and then be discharged to the outside through the cooling fan (110).

Meanwhile, since the first inlet (102), the second inlet (103), and the third inlet (104) described above have a long distance to the cooling fan (110) positioned at the front, the cold air introduced through the first inlet (102), the second inlet (103), and the third inlet (104) passes through several parts before reaching the radiator (120) and the oil cooler (130), and thus the cooling efficiency of the radiator (120) and the oil cooler (130) may not be good.

That is, referring to FIGS. 3 to 5 and FIG. 7, in order to increase the cooling efficiency of the radiator (120) and oil cooler (130) positioned at the rear of the cooling fan (110), a fourth inlet (105) may be formed on the upper surface (100e) of the body frame (100) where the radiator (120) and oil cooler (130) are positioned to allow air to be introduced for cooling the radiator (120) and oil cooler (130).

Since the cold air flowing in through the fourth inlet (105) can directly affect the radiator (120) and the oil cooler (130), the cooling efficiency of the radiator (120) and the oil cooler (130) can be increased.

For example, the fourth inlet (105) may be formed in an inclined shape with the rear end open on the upper surface (100e) of the body frame (100). When the fourth inlet (105) is formed in an inclined shape with the rear end open, hot air blown forward by the cooling fan (110) and discharged through the outlet (106) formed in the front end (100a) can be prevented from entering the fourth inlet (105) again and lowering the cooling efficiency.

Figure 8 is a rear perspective view of the upper swivel body according to another aspect of the present disclosure.

Referring to FIGS. 7 and 8, the first inlet (102) may include one or more long holes (102a) in a horizontal direction, and an inclined hole (102b) extending obliquely from one end of the long hole (102a). That is, in order to improve the cooling efficiency of the hydraulic tank (130) and the hydraulic pump (180) arranged at the rear inside the body frame (100), an inclined hole (102b) extending from the long hole (102a) may be further formed, and it is preferable that the inclined hole (102b) be formed to be inclined downward in order to increase the amount of air flowing into the hydraulic tank (130) and the hydraulic pump (180).

In this way, the small electric excavator of the present disclosure efficiently manages the heat generation of hydraulic devices such as the MCV, hydraulic tank, and hydraulic pump that use hydraulic oil, which is the largest heat source, while at the same time arranging internal components and various cooling devices (cooling fan, radiator, oil cooler, inlet, outlet) so as not to affect the cooling of the battery, thereby improving the overall cooling efficiency of the small electric excavator.

It should be understood that the present disclosure is not limited to the embodiments described above and illustrated in the drawings. Rather, those skilled in the art will recognize that many changes and modifications can be made within the scope of the present disclosure and the appended claims. In the drawings and specification, aspects have been disclosed for illustrative purposes only and not for purposes of limitation, and the scope of the concepts of the present disclosure is set forth in the claims that follow.

Description of the sign

1000 compact electric excavator

10 Lower body

20 upper swivel

30 Working Devices

31 boom

32 Aam

33 Attachment

100 body frame

100a front

100b rear

100c left side

100d right side

100e top surface

100f lower part

101 Ventilation

102 1st inlet

103 2nd inlet

104 3rd inlet

105 4th inlet

106 outlet

107 barrier

110 Cooling Fan

120 radiator

130 Oil Cooler

140 MCV

150 HAVC

160 hydraulic tank

170 electric motor

180 hydraulic pump

190 battery

200 cabins

300 counter weight

CL centerline

Claims (10)

A small electric excavator comprising a lower body, an upper slewing body and a working device, The upper swivel body includes a body frame, a cabin installed on the left side of the body frame, and a counterweight installed on the rear of the body frame. Inside the above body frame, the MCV and hydraulic tank are placed on the left side of the center line, and the cooling fan, radiator, oil cooler, battery, electric motor, hydraulic pump, and electrical devices are placed on the right side. The above body frame is formed with one or more inlets through which cold air is introduced, and an outlet through which hot air is discharged is formed at the front of the body frame. A small electric excavator, wherein the cooling fan is positioned immediately behind the outlet and configured to blow the internal air of the body frame forward. In the first paragraph, A compact electric excavator, characterized in that the radiator and the oil cooler are positioned immediately behind the cooling fan. In the second paragraph, A compact electric excavator, characterized in that the MCV is positioned on the left front side with respect to the centerline inside the body frame, and ventilation is formed on the lower part of the body frame where the MCV is positioned so that heat generated from the MCV can circulate. In the third paragraph, A compact electric excavator, characterized in that a blocking wall is installed inside the body frame to at least partially block the inflow of air from the left to the right based on the center line. In the second paragraph, A compact electric excavator, characterized in that the hydraulic tank is arranged at the left rear side based on the centerline inside the body frame, and a third inlet is formed on the lower part of the body frame where the hydraulic tank is located to allow air to be introduced for cooling the hydraulic tank. In the second paragraph, A compact electric excavator characterized in that the electric motor, hydraulic pump and electric devices are arranged on the right rear side with respect to the center line inside the body frame, and a first inlet is formed at the rear of the body frame to allow air to flow in for cooling the electric motor, hydraulic pump and electric devices. In the second paragraph, A compact electric excavator, characterized in that the battery is placed behind the radiator and the oil cooler, and a second inlet is formed on the right side of the body frame to allow air to flow in for cooling the battery. In the second paragraph, A compact electric excavator, characterized in that a fourth inlet is formed on the upper surface of the body frame where the radiator and oil cooler are located to allow air to flow in for cooling the radiator and oil cooler. In Article 6, The above first inlet is, A small electric excavator characterized by comprising a long hole extending horizontally, and an inclined hole extending downwardly from one end of the long hole. In Article 8, A small electric excavator, characterized in that the fourth inlet is formed in an inclined shape with an open rear end on the upper surface of the body frame.

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