Electric working machine

Abstract

To improve the efficiency of connection work between a power reception device and an energization cable on the side of a machine body.SOLUTION: A hydraulic shovel 1 energized through a power source cable 100 whose one end is connected to an external power source 200 side includes a machine body 11 having a counter weight 12 at the rear part, an electric motor 20 at the front part of the counter weight, and an energization cable 40 for supplying power to the electric motor, a power reception device 60 to which the other end of the power source cable is connected, and a connection box 50 which is fixed to the upper part of the counter weight and stores a connection part 52 for connecting a wire 61 extending from the power reception device and the energization cable 40 extending from the machine body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric working machine.

Background Art

[0002] Working machines such as hydraulic excavators include a crawler-type lower traveling body and a machine body rotatably provided above the lower traveling body, and perform work by operating a work attachment provided on the machine body. Among such working machines, there is an electric working machine in which an electric motor is mounted on the machine body as a power source.

[0003] Generally, an electric working machine is energized by connecting one end of a power cable to an external power source side and the other end to the machine body side. In a conventional electric working machine, for example, as in Patent Document 1, a slip ring is provided at the upper part of the machine body as a power receiving device for connecting the power cable to the machine body, and the power cable is configured not to be entangled with the electric working machine due to the rotation of the machine body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the electric working machine of Patent Document 1, the connection portion where the energization cable for supplying power to the electric motor and the slip ring are connected is arranged at the upper part inside the power receiving device. Therefore, the energization cable is drawn into the power receiving device from the machine body, and the connection work is performed inside the power receiving device. In such a conventional electric working machine, since the connection portion is in a position difficult for an operator to access, the work of connecting the energization cable to the power receiving device requires a lot of man-hours and is a very complicated work.

[0006] The present invention has been made in view of such a point, and an object thereof is to provide an electric working machine capable of improving the efficiency of the connection work between the power receiving device and the energization cable on the machine body side.

Means for Solving the Problems

[0007] In order to achieve the above object, in the present invention, the connection portion between the power receiving device and the energization cable is separated from the power receiving device and provided at a position that is easily accessible.

[0008] Specifically, in the first invention, an electric working machine energized via a power cable having one end connected to an external power supply side, the machine body having a counterweight at the rear, an electric motor in front of the counterweight, and an energization cable for supplying power to the electric motor, a power receiving device to which the other end of the power cable is connected, and a connection box fixed to the upper part of the counterweight and accommodating a connection portion for connecting a wiring extending from the power receiving device and an energization cable extending from the machine body.

[0009] According to the above configuration, the connection portion for connecting the wiring extending from the power receiving device and the energization cable extending from the machine body is accommodated in the connection box provided at the upper part of the counterweight, so that it is arranged at a position away from the power receiving device and easily accessible to the operator. Therefore, the operator does not need to perform complicated connection work inside the power receiving device, and the connection work can be made more efficient.

[0010] In the second invention, in the first invention, the machine body includes an electric motor cover that can open and close the upper part of the electric motor, and the power receiving device and the connection box are arranged at positions that do not overlap with the electric motor cover in the vehicle body front-rear direction.

[0011] According to the above configuration, since the power receiving device and the connection box are arranged at positions that do not interfere with the opening and closing of the electric motor cover, they do not interfere with the work during the maintenance of the electric motor and its peripheral devices performed by opening the electric motor cover.

[0012] In the third invention, in the first or second invention, the machine body includes, in front of the counterweight, a hydraulic pump arranged side by side with an electric motor in the left-right direction and a hydraulic pump cover that can open and close to cover the upper part of the hydraulic pump, and in the longitudinal direction of the vehicle body, the hydraulic pump cover, the connection box, and the power receiving device are arranged in this order.

[0013] By arranging the hydraulic pump cover, the connection box, and the power receiving device in this order in the front-rear direction, it becomes possible to easily lay the wiring drawn from the power receiving device to the connection box and the energization cable drawn from the connection box into the hydraulic pump cover.

[0014] In the fourth invention, in the third invention, the connection box extends from the counterweight toward the hydraulic pump cover, and is provided with an energization cable inlet for drawing the energization cable into the connection box, and at least the energization cable inlet of the connection box is covered by the hydraulic pump cover above.

[0015] According to the above configuration, by configuring the connection box to extend toward the front hydraulic pump side, it is possible to prevent the connection box from protruding to the rear of the machine body. Also, by extending the connection box toward the hydraulic pump side and configuring at least the energization cable inlet to be covered by the hydraulic pump cover, it becomes unnecessary to perform detailed waterproof treatment on the energization cable, and waterproofing can be achieved by sealing only the connection box, so it can be protected with a simple configuration, thus improving waterproofness and assemblability.

[0016] In the fifth invention, in the fourth invention, the front end portion of the connection box is located below the hydraulic pump cover and behind the hydraulic pump.

[0017] According to the above configuration, it is possible to prevent water from entering the connection box and to arrange the connection box at a position that does not interfere with the maintenance work of the hydraulic pump.

[0018] In the sixth invention, in any one of the first to fifth inventions, the connection box has an openable and closable opening that opens upward at a position not overlapping the power receiving device in the vertical direction, and the connection part is configured to be exposed from the opening.

[0019] According to the above configuration, since the operator can easily visually recognize the connection part from the opening provided in the connection box, the connection work of the energized cable becomes easier and the work can be made more efficient. In addition, since the opening can be opened and closed, the connection part can be protected by closing it normally.

[0020] The seventh invention is an electric working machine energized via a power cable having one end connected to the external power supply side, and includes an electric motor, a machine body having an energized cable for supplying power to the electric motor, a power receiving device to which the other end of the power cable is connected, and a connection part for connecting the wiring extending from the power receiving device and the energized cable extending from the machine body, and the connection part is arranged outside the power receiving device.

[0021] According to the above configuration, the connection part for connecting the wiring extending from the power receiving device and the energized cable extending from the machine body is arranged outside the power receiving device, so it is at a position away from the power receiving device and easily accessible to the operator. Therefore, the operator does not need to perform complicated connection work inside the power receiving device, and the connection work can be made more efficient.

[0022] The eighth invention includes a connection box for housing the connection part, the connection box has an openable and closable opening that opens upward at a position not overlapping the power receiving device in the vertical direction, and the connection part is configured to be exposed from the opening.

[0023] According to the above configuration, it is possible to protect the connection part by the connection box, and since the operator can easily visually recognize the connection part from the opening provided in the connection box, the connection work of the energized cable becomes easy and the work can be made efficient. Since the opening can be opened and closed, the connection part can be protected by closing it normally.

Effect of the Invention

[0024] As described above, according to the present invention, it becomes possible to improve the efficiency of the connection work between the power receiving device and the cable on the machine body side.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0026] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0027] For convenience of explanation, in some of the drawings, the traveling direction of the electric working machine is indicated by arrows with the front-rear direction of the vehicle body as the longitudinal direction, the left-right direction as viewed from the operator boarding the electric working machine as the lateral direction of the vehicle body, and the up-down direction of the electric working machine as the vertical direction. Unless otherwise specified, the description will be made according to the directions indicated by these arrows.

[0028] As shown in FIG. 1, the electric working machine according to an embodiment of the present invention is, for example, an electric hydraulic excavator 1, and includes a crawler-type lower traveling body 10 and a machine body 11 rotatably mounted on the lower traveling body 10. One end of a power cable 100 is connected to the external power supply 200 side and the other end is connected to the machine body 11 side, and it operates by being energized through the power cable 100.

[0029] The machine body 11 includes a counterweight 12 at the rear, a machine room 13 in front of the counterweight 12, a cab 14 in front of the machine room 13, a boom 15 that can swing in the vertical direction and is attached adjacent to the cab 14, and a work attachment 17 attached to the tip side of the boom 15 via an arm 16.

[0030] As shown in FIG. 2, the upper part of the machine room 13 is covered with a cover. Inside the machine room 13, an electric motor 20 that is a power source of the hydraulic excavator 1 and a hydraulic pump 30 arranged side by side with the electric motor 20 in the left-right direction are accommodated. The upper part of the electric motor 20 is covered with an openable and closable electric motor cover 21. The electric motor cover 21 has a rotation fulcrum at the rear end, and by pulling up the front end upward to open it, it becomes possible to perform maintenance on the electric motor 20 and its peripheral devices accommodated inside the machine room 13. Also, the upper part of the hydraulic pump 30 is covered with an openable and closable hydraulic pump cover 31, and by opening the hydraulic pump cover 31, it is possible to perform maintenance on the hydraulic pump 30 and its peripheral devices accommodated inside the machine room 13.

[0031] As shown in FIG. 3, when the hydraulic pump cover 31 is opened, a live cable 40 that supplies power to the electric motor 20 and a control panel (not shown), a hydraulic pump 30, and a part of a connection box 50 described later are exposed. By configuring the front end portion of the connection box 50 to be located below the hydraulic pump cover 31 and behind the hydraulic pump 30, the inside of the connection box 50 can be protected without degrading the maintainability of the hydraulic pump 30.

[0032] In the machine room 13, the live cable 40 is drawn from the side of the electric motor 20 upward between the electric motor 20 and the hydraulic pump 30. As shown in FIG. 4, inside the machine room 13 on the side of the hydraulic pump 30, a flat fireproof board 32 that shields the hydraulic pump 30 from the high-temperature part of the electric motor is installed above the hydraulic pump 30 inside the machine room 13 in the longitudinal direction of the vehicle body. Also, inside the machine room 13, a rod-shaped beam member 41 extending in the longitudinal direction of the vehicle body is installed above the hydraulic pump 30 on the side of the electric motor 20 with respect to the fireproof board 32.

[0033] The live cable 40 is formed by bundling a plurality of cables 40a and is guided from the front to the rear of the vehicle body while being made to crawl on the beam member 41. The live cable 40 has a plurality of bundled cables 40a separated at the rear end, and each cable 40a is drawn into the connection box 50.

[0034] A connection part 52 that connects the wiring 61 extending from the power receiving device 60 and the live cable 40 extending from the machine body 11 is arranged outside the power receiving device 60 by being housed in the connection box 50. Specifically, as shown in FIG. 5, the connection box 50 is a box-shaped member extending in the longitudinal direction of the vehicle body, and a connection part 52 that connects the wiring 61 extending from the power receiving device 60 and the live cable 40 extending from the machine body 11 is housed in its internal space. The rear part of the connection box 50 is fixed to the upper part of the counterweight 12 and extends forward from the counterweight 12 toward the hydraulic pump cover 31.

[0035] The connection box 50 has a bottom plate portion 50a and a peripheral wall portion 50b that stands upright from the bottom plate portion 50a. The top plate portion 50c that covers the upper part is provided with two openings at intervals in the vehicle body front-rear direction.

[0036] Among the openings provided in the top plate portion 50c, the rear-side opening is a connection opening 51 provided for connecting the power receiving device 60 above the connection box 50. A cylindrical connecting member 70 is screwed to the upper part of the connection opening 51, and the power receiving device 60 is connected above the connection box 50 via the connecting member 70. The wiring 61 extending from the power receiving device 60 is drawn into the connection box 50 through the connecting member 70 and the connection opening 51, and is connected to a connection portion 52 fixed to the front side of the bottom plate portion 50a.

[0037] By connecting the power receiving device 60 above the rear part of the connection box 50, in the vehicle body front-rear direction, the hydraulic pump cover 31, the connection box 50, and the power receiving device 60 are arranged in this order. By being arranged in this way, the wiring 61 drawn from the power receiving device 60 to the connection box 50 and the energization cable 40 drawn from the connection box 50 into the hydraulic pump cover 31 can be laid on a straight line in the vehicle body front-rear direction, so that the laying work becomes easy.

[0038] Below the connection opening 51, a rectangular flat plate-shaped fixing member 12a is attached to the lower part of the bottom plate portion 50a of the connection box 50, and the connection box 50 is screwed to the upper surface of the counterweight 12 via the fixing member 12a.

[0039] Among the openings provided in the top plate portion 50c, the front opening is a connection opening 53 that opens upward at a position that does not overlap the power receiving device 60 in the vertical direction. Further, the connection opening 53 and the coupling opening 51 are provided at different levels, and the connection opening 53 is provided below the position where the coupling opening 51 is provided. The connection opening 53 can be opened and closed by a lid portion 54. Since the connection opening 53 is provided so as to overlap the connection portion 52 in the vertical direction, when the connection opening 53 is opened, the connection portion 52 can be exposed from the connection opening 53. Therefore, during the connection operation, the lid portion 54 can be opened to easily perform the operation, and the connection portion 52 can be protected by closing it when not in operation.

[0040] At the front end of the connection box 50, an energization cable inlet 55 that opens forward is provided in the peripheral wall portion 50b. The energization cable inlet 55 is provided for drawing the energization cable 40 from the machine body 11 into the connection box 50. It is desirable that at least the energization cable inlet 55 of the connection box 50 is covered by the hydraulic pump cover 31 from above.

[0041] As shown in FIG. 6, by arranging the connection box 50 behind the hydraulic pump cover 31, the power receiving device 60 and the connection box 50 are arranged at positions that do not overlap the electric motor cover 21 in the vehicle body front-rear direction. And in this embodiment, the connection box 50 is covered by the hydraulic pump cover 31 from the front end portion provided with the energization cable inlet 55 to the connection opening 53.

[0042] As shown in Fig. 5, the power receiving device 60 has a hollow fixed shaft 62 with its lower end fixed to the connecting member 70 and extending in the vertical direction, and a case 63 rotatably provided on the outer periphery of the fixed shaft 62. The case 63 includes a bottom plate portion 63a through which the connecting member 70 is inserted and the outer periphery of the connecting member 70 is rotatably provided, a cylindrical portion 63b erected on the bottom plate portion 63a and surrounding the outer periphery of the fixed shaft 62, and a top plate portion 63c covering the upper part of the cylindrical portion 63b. A relay cable 100a connected to the power cable 100 is inserted through the top plate portion 63c, and the relay cable 100a is drawn into the case 63.

[0043] Inside the case 63 of the power receiving device 60, a plurality of conductive rings 64 are provided at predetermined intervals in the axial direction on the outer periphery of the fixed shaft 62. On the outer peripheral side of each conductive ring 64, a brush 65 is provided so as to face and contact the conductive ring 64. A relay cable 100a connected to the power cable 100 is connected to the brush 65, and a wiring 61 is connected to the conductive ring 64. The wiring 61 is inserted into the fixed shaft 62 and drawn into the connection box 50 via the connecting member 70.

[0044] With such a configuration, the power supplied from the external power source 200 flows to the brush 65 via the power cable 100 and the relay cable 100a, then from the brush 65 to the conductive ring 64 and flows through the wiring 61, and in the connection box 50, it flows from the wiring 61 to the energizing cable 40 via the connection portion 52, and finally is supplied from the energizing cable 40 to the electric motor 20 and the control panel (not shown) mounted inside the machine body 11.

[0045] (Function and Effect) In the present embodiment configured as described above, the connection portion 52 that connects the wiring 61 extending from the power receiving device 60 and the energization cable 40 extending from the machine body 11 is housed in the connection box 50 provided above the counterweight 12, and thus is disposed outside the power receiving device 60, at a position away from the power receiving device 60 and at a position easily accessible to the operator. Therefore, the operator does not need to perform complicated connection work inside the power receiving device 60, and the connection work can be made more efficient. Further, the power receiving device 60 and the connection box 50 can be disposed at positions that do not obstruct work during maintenance of the electric motor 20, the hydraulic pump 30, and their peripheral devices. Furthermore, by configuring a part of the connection box 50 to be covered with the hydraulic pump cover 31, it becomes possible to protect the inside of the connection box 50 with a simple configuration.

[0046] (Other embodiments) FIG. 7 shows the rear part of the machine body of the electric working machine according to another embodiment of the present invention, and is different from the above embodiment in that the configurations of the power receiving device and the wiring box are different. In the following embodiments, the same parts as those in the above embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0047] In the embodiment shown in FIG. 7, the power receiving device 60A and the connection box 50A are different from the above embodiment in that the power receiving device 60A and the connection box 50A are arranged side by side in the left-right direction. The connection box 50A extends in the left-right direction and is fixed above the counterweight 12 so that the whole is positioned on the counterweight 12. The power receiving device 60A is connected above the connection box 50A so as to be arranged side by side with the connection box 50A in the left-right direction and the whole is positioned on the counterweight 12. Note that the power receiving device 60A may be fixed above the counterweight 12 instead of above the connection box 50A and may be connected to the connection box 50A in the left-right direction.

[0048] Even in such a configuration, since the connection part 52 is arranged at a position away from the power receiving device 60A and at a position easily accessible to the operator, it is possible to improve the efficiency of the wiring work. Further, unlike the above-described embodiment, by extending the connection box 50A in the left-right direction and arranging the whole on the counterweight 12, it is possible to prevent the connection box 50A from protruding to the rear of the machine body 11 and also to prevent interference with the front hydraulic pump cover 31 and the electric motor cover 21. The connection box 50A can be configured such that the lid portion 54 covering the connection part 52 is exposed on the counterweight 12 without being covered by the hydraulic pump cover 31. Therefore, access to the connection part 52 becomes easier, and it is possible to improve workability with a simple configuration.

[0049] In the above-described embodiment, a large hydraulic excavator is taken as an example, but the present invention is not limited thereto. As another embodiment, for example, it can also be applied to a small swing-type electric working machine. A small swing-type electric working machine may be equipped with a counterweight formed in an arc shape so as to cover the outer periphery of the machine room. However, it is possible to arrange the power receiving device and the connection box on such an arc-shaped counterweight, and the present invention can be applied regardless of the shape of the counterweight.

[0050] In the above-described embodiment, the power receiving device and the connection box are arranged on the counterweight, but the positions where the power receiving device and the connection box are arranged are not limited thereto. For example, they may be arranged at other positions on the upper surface of the machine body excluding the counterweight.

Explanation of Reference Numerals

[0051] 1 Hydraulic excavator (electric working machine) 10 Lower traveling body 11 Machine body 12 Counterweight 20 Electric motor 21 Electric motor cover 30 Hydraulic pump 31 Hydraulic pump cover 40 Energizing cable 41 Beam member 50 Connection box 52 Connection part 53 Connection opening 54 Cover part 55 Power cable inlet 60 Power receiving device 61 Wiring 100 Power cable 200 External power supply

Claims

1. An electric working machine that is energized via a power cable having one end connected to an external power source side, a machine body having a counterweight at the rear, an electric motor in front of the counterweight, and a power supply cable for supplying power to the electric motor; a power receiving device to which the other end of the power cable is connected; and a connection box fixed to the upper part of the counterweight and accommodating a connection part for connecting wiring extending from the power receiving device and the power supply cable extending from the machine body. The electric working machine is characterized by comprising these components.

2. The machine body includes an electric motor cover that can open and close to cover the upper part of the electric motor, and the power receiving device and the connection box are arranged at positions that do not overlap with the electric motor cover in the vehicle body front-rear direction. The electric working machine according to Claim 1 is characterized by this.

3. The machine body includes a hydraulic pump arranged side by side with the electric motor in the left-right direction and a hydraulic pump cover that covers the upper part of the hydraulic pump in front of the counterweight, and in the vehicle body front-rear direction, the hydraulic pump cover, the connection box, and the power receiving device are arranged in this order. The electric working machine according to Claim 1 or 2 is characterized by this.

4. The connection box extends from the counterweight toward the hydraulic pump cover, and is provided with a power supply cable inlet for drawing the power supply cable into the connection box. At least the power supply cable inlet of the connection box is covered by the hydraulic pump cover from above. The electric working machine according to Claim 3 is characterized by this.

5. The front end of the connection box is located below the hydraulic pump cover and behind the hydraulic pump. The electric working machine according to Claim 4 is characterized by this.

6. The connection box has an openable opening that opens upward at a position not overlapping the power receiving device in the vertical direction, and the connection part is configured to be exposed from the opening. The electric working machine according to any one of claims 1 to 5, characterized in that.

7. An electric working machine that is energized through a power cable having one end connected to an external power source side, A machine body having an electric motor and a power supply cable for supplying power to the electric motor, A power receiving device to which the other end of the power cable is connected, A connection part that connects the wiring extending from the power receiving device and the power supply cable extending from the machine body, and is provided with The electric working machine, characterized in that the connection part is disposed outside the power receiving device and on the upper surface of the machine body.

8. A connection box for housing the connection part is provided, The connection box has an opening that allows the connection part to be exposed. The electric working machine according to claim 7, characterized in that.

Images