Work machine

Abstract

To provide a work machine capable of preventing a working unit from contacting a member other than the working unit by restricting a rotational range of the working unit.SOLUTION: An electric shovel as a work machine comprises an electric motor, a working unit rotated by the electric motor, and a regulating member that regulates rotation of the working unit.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine. [Background technology]

[0002] BACKGROUND ART A construction machine that includes a bucket as an operating part (working part) and an electric motor that rotates and drives the bucket is known as a conventional technique (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-88834 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, an electric motor (specifically, the output shaft of the electric motor) is capable of infinite rotation. Therefore, in the configuration of Patent Document 1, the bucket is driven to rotate (turn) infinitely. However, if the bucket is driven to rotate infinitely, there is a risk that, for example, the bucket may unintentionally come into contact with a member other than the bucket inside the construction machine, causing damage to the member.

[0005] The present invention has been made to solve the above problems, and its object is to provide a work machine that can limit the rotation range of the working unit and prevent the working unit from coming into contact with members other than the working unit. [Means for solving the problem]

[0006] A work machine according to one aspect of the present invention includes an electric motor, a working unit that is rotated by the electric motor, and a restricting member that restricts the rotation of the working unit. [Effects of the Invention]

[0007] According to the above configuration, the rotation range of the working unit can be limited, and the working unit can be prevented from coming into contact with a member other than the working unit. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a right side view showing a schematic configuration of an electric shovel, which is an example of a work machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram schematically illustrating the configuration of an electrical system of the electric shovel. [Figure 3] FIG. 2 is a right side view showing the configuration of a working unit provided in the electric shovel. [Figure 4] FIG. 4 is a right side view of the working unit in a position different from that shown in FIG. 3. [Figure 5] FIG. 10 is a perspective view showing a configuration of a restricting member against which the working part comes into contact; [Figure 6] 10 is a flowchart showing a flow when rotation stop control of the electric motor that rotates the working unit is executed. [Figure 7] FIG. 10 is a left side view showing the configuration of the working unit in the first modified example. [Figure 8] FIG. 8 is a left side view of the working unit in a first modified example in a posture different from that of FIG. 7. [Figure 9] FIG. 10 is a right side view showing the configuration of the working unit in a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes an embodiment of the present invention with reference to the drawings.

[0010] [1. General configuration of the work machine] 1 is a right side view showing a schematic configuration of an electric shovel 1, which is an example of a work machine according to an embodiment of the present invention. The electric shovel 1 includes a machine body 2 and a working unit 3.

[0011] Here, the directions used in the description of this embodiment are defined as follows: When the machine body 2 moves straight in one direction, one side of the direction is referred to as the "front" and the other side as the "rear." For example, in the direction in which the machine body 2 moves straight in one direction, the side on which the working unit 3 is located is referred to as the "front," and the opposite side is referred to as the "rear." Furthermore, when moving from rear to front, the left side is referred to as the "left" and the right side is referred to as the "right." Furthermore, the direction of gravity, which is perpendicular to the front-to-rear and left-to-right directions, is referred to as the up-down direction, and the upstream side of the direction of gravity is referred to as the "up" and the downstream side is referred to as the "down." In the drawings, the front is indicated by the symbol "F," the rear by the symbol "B," the right by the symbol "R," the left by the symbol "L," the up by the symbol "U," and the down by the symbol "D," as necessary.

[0012] The working unit 3 includes a boom 31, an arm 32, and an attachment 33. The boom 31, the arm 32, and the attachment 33 can be independently driven to perform various types of work.

[0013] The boom 31 is rotated by a boom electric motor 31M. The arm 32 is rotated by an arm electric motor 32M. The attachment 33 is rotated by an attachment electric motor 33M. The boom electric motor 31M, arm electric motor 32M, and attachment electric motor 33M are each configured by a synchronous motor, an induction motor, or the like. Note that the configurations of the boom electric motor 31M, arm electric motor 32M, and attachment electric motor 33M are not limited to the types of motors described above.

[0014] Furthermore, the boom electric motor 31M, the arm electric motor 32M, and the attachment electric motor 33M each have a built-in brake mechanism (not shown) used to slow down or stop the drive (rotation). Note that the brake mechanisms may be provided externally to the boom electric motor 31M, the arm electric motor 32M, and the attachment electric motor 33M, respectively.

[0015] In this embodiment, the boom electric motor 31M, the arm electric motor 32M, and the attachment electric motor 33M are collectively referred to as the electric motor 3M. That is, the electric shovel 1 of this embodiment is equipped with the electric motor 3M, and the working unit 3 is rotated by this electric motor 3M. The configuration of the working unit 3 will be described in detail later.

[0016] The machine body 2 includes a boom support part 21. The boom support part 21 rotatably supports a boom 31. That is, the boom 31 is rotatably connected to the machine body 2 by the boom support part 21. The configuration of the boom support part 21 will be described later.

[0017] [2. Electrical System Configuration] The configuration of the electrical system 5 of the electric shovel 1 will be described with reference to Fig. 2. Fig. 2 is a block diagram that schematically shows the configuration of the electrical system 5 of the electric shovel 1.

[0018] The electric shovel 1 includes an electric system 5, which includes a battery unit 51, an inverter 52, a control device 53, and a sensor 54. In addition to the above-mentioned devices, the electric system 5 also includes an electric motor 3M.

[0019] The battery unit 51 is formed of, for example, a lithium-ion battery, and stores power to be supplied to the electric motors 3M (boom electric motor 31M, arm electric motor 32M, attachment electric motor 33M). The battery unit 51 may be formed by unitizing a plurality of battery cells, or may be formed by a single battery cell. The inverter 52 converts the DC voltage supplied from the battery unit 51 into AC voltage and supplies it to the electric motor 3M. This drives the electric motor 3M.

[0020] The control device 53 is composed of an electronic control unit also called an ECU (Electronic Control Unit). The control device 53 receives operation commands from an operation device (not shown) and electrically controls each part of the electric shovel 1. In particular, the control device 53 controls the rotation of the electric motor 3M. More specifically, based on the rotation command output from the control device 53, an AC voltage is supplied from the inverter 52 to the electric motor 3M.

[0021] Sensor 54 is connected to control device 53. Sensor 54 detects information related to working unit 3 and outputs the detected information to control device 53 as a detection result. Sensor 54 has a first sensor 54a and a second sensor 54b. The configuration of second sensor 54b will be described later.

[0022] The first sensors 54a are respectively disposed near the boom electric motor 31M, near the arm electric motor 32M, and near the attachment electric motor 33M. The first sensor 54a located near the boom electric motor 31M detects the rotation angle of the boom 31. The first sensor 54a located near the arm electric motor 32M detects the rotation angle of the arm 32. The first sensor 54a located near the attachment electric motor 33M detects the rotation angle of the attachment 33. The first sensors 54a are, for example, encoders. In other words, the electric excavator 1 is equipped with the first sensors 54a that detect the rotation angle of the working unit 3 (in this embodiment, the boom 31, the arm 32, and the attachment 33).

[0023] The rotation angle of the working unit 3 detected by the first sensor 54a is output as a detection result to the control device 53. Based on this rotation angle of the working unit 3, the control device 53 performs control related to stopping the rotation of the electric motor 3M (also simply referred to as rotation stop control). The rotation stop control of the electric motor 3M will be described later.

[0024] [3. Work Unit Configuration] The configuration of the working unit 3 will be described with reference to Figures 3 and 4. Figures 3 and 4 are right side views showing the configuration of the working unit 3. Figure 3 illustrates a case in which the boom 31 abuts against a first restricting member 101, which will be described later, and the arm 32 and the attachment 33 abut against a second restricting member 102, which will be described later. Figure 4 illustrates a case in which the boom 31 abuts against the second restricting member 102, and the arm 32 and the attachment 33 abut against the first restricting member 101.

[0025] The boom 31 is made of a hollow metal member that extends while curving in one direction (substantially the vertical direction in FIG. 3). Note that the boom 31 is not limited to the above configuration and may be made of, for example, a solid metal member.

[0026] The boom 31 has a base end rotatably supported by the boom support 21. The base end of the boom 31 is connected to an output shaft 31M1 of a boom electric motor 31M via a boom power transmission unit (not shown). The boom electric motor 31M is fixed to the boom support 21 with the output shaft 31M1 extending in the left-right direction. The boom power transmission unit has a speed reduction mechanism and transmits the rotational power of the output shaft 31M1 of the boom electric motor 31M to the base end of the boom 31 while reducing the speed. Therefore, when the boom electric motor 31M is driven and the output shaft 31M1 of the boom electric motor 31M rotates, the boom 31 rotates relative to the boom support 21. More specifically, the boom 31 rotates about a rotation axis (extending in the left-right direction) located on the same line as the output shaft 31M1 of the boom electric motor 31M. This causes the boom 31 to rotate up and down and fore and aft relative to the machine body 2. The boom 31 may be directly connected to the output shaft 31M1 of the boom electric motor 31M, that is, the boom power transmission unit may be omitted.

[0027] Boom support part 21 is configured to include a plurality of metal plate-like members joined by welding or the like. A regulating member 100 is provided inside boom support part 21. Note that in Figures 3 and 4, a portion of boom support part 21 is not shown in order to clarify the position of regulating member 100 located inside boom support part 21.

[0028] The regulating member 100 is made of a rectangular parallelepiped elastic body (e.g., rubber). The regulating member 100 is fixed to a member located inside the boom support part 21 by a fastening member such as a bolt. This not only firmly fixes the regulating member 100 but also makes it easy to replace the regulating member 100, for example, if the regulating member 100 is damaged. Note that the regulating member 100 is not limited to the above configuration. For example, the regulating member 100 may be made of a metal member, or may be made of a combination of an elastic body and a metal member. Furthermore, the regulating member 100 may be cylindrical or polygonal prism-shaped.

[0029] When the boom 31 is rotated, the boom 31 comes into contact with the regulating member 100. This stops the rotation of the boom 31. That is, the regulating member 100 regulates the rotation of the working unit 3 (boom 31). More specifically, when the boom 31 is rotated in one direction of the rotation (counterclockwise when viewed from the right of the working unit 3) by the drive of the boom electric motor 31M, the first abutment surface 31a of the boom 31 comes into contact with the regulating member 100 (see FIG. 3 in particular). The first abutment surface 31a is a surface extending in the left-right direction at the base end of the boom 31 (the surface located on the rear side in FIG. 3). On the other hand, when the boom 31 is rotated in the other direction of the rotation (clockwise when viewed from the right of the working unit 3) by the drive of the boom electric motor 31M, the second abutment surface 31b of the boom 31 comes into contact with the regulating member 100 (see FIG. 4 in particular). The second contact surface 31b is a surface at the base end of the boom 31 that extends in the left-right direction different from the first contact surface 31a (a surface located on the lower side in FIG. 4).

[0030] In this embodiment, the restricting member 100 that the working unit 3 comes into contact with when the working unit 3 (e.g., the boom 31) is rotated to one side in the rotation direction (counterclockwise when the working unit 3 is viewed from the right in this embodiment) is referred to as the first restricting member 101. That is, the first restricting member 101 restricts the rotation of the working unit 3 to one side in the rotation direction. On the other hand, the restricting member 100 that the working unit 3 comes into contact with when the working unit 3 is rotated to the other side in the rotation direction (clockwise when the working unit 3 is viewed from the right in this embodiment) is referred to as the second restricting member 102. That is, the second restricting member 102 restricts the rotation of the working unit 3 to the other side in the rotation direction. That is, the restricting member 100 in this embodiment has the first restricting member 101 and the second restricting member 102.

[0031] The second sensor 54b is attached via a mounting bracket 54b1 to the upper part of the boom support part 21 (see FIG. 4 in particular). The mounting bracket 54b1 is made of a metal plate-like member that extends substantially in the vertical direction.

[0032] The second sensor 54b is disposed in a position overlapping with the boom 31 that has been rotated slightly to the other side in the rotation direction from the position where it abuts on the first regulating member 101 located inside the boom support part 21, when viewed from the right or left of the working unit 3. The second sensor 54b detects the approach of the boom 31 to the first regulating member 101. That is, the electric excavator 1 is provided with the second sensor 54b that detects the approach of the working unit 3 (the boom 31 in this embodiment) to the regulating member 100 (the first regulating member 101 in this embodiment).

[0033] Information detected by the second sensor 54b (information about the approach of the boom 31 to the first restricting member 101) is output as a detection result to the control device 53. Based on the detection result of this second sensor 54b, the control device 53 performs control to stop rotation of the boom electric motor 31M.

[0034] A rib 31c is provided at the base end of the boom 31. The rib 31c is made of a metal plate-like member having a substantially triangular shape. In this embodiment, two ribs 31c are provided. One rib 31c is provided on one side in the rotation direction of the boom 31 (the rear side in FIG. 3), and the other rib 31c is provided on the other side in the rotation direction of the boom 31 (the front side in FIG. 3). When the rib 31c is provided as in this embodiment, even in a configuration in which a boom electric motor 31M (drive source) is connected to the base end of the boom 31, that is, a configuration in which a large stress is applied to the base end of the boom 31, the stress applied to the boom 31 is efficiently dispersed. In other words, the rib 31c improves the strength of the boom 31.

[0035] The configuration of the ribs 31c is not limited to the above. For example, two more ribs 31c may be added to the two ribs 31c described above. In this case, one of the two added ribs 31c may be provided on the left side of the base end of the boom 31, and the other of the two added ribs 31c may be provided on the right side of the base end of the boom 31.

[0036] A first restricting member 101 and a second restricting member 102, which come into contact with the arm 32, are provided at the tip of the boom 31 via an angle adjustment member 31d. In the position of the boom 31 shown in Fig. 3, the first restricting member 101 is located rearward of the second restricting member 102. The angle adjustment member 31d is a metal member that makes it possible to adjust the mounting angle of the first restricting member 101 and the second restricting member 102 (located at the tip of the boom 31) that come into contact with the arm 32.

[0037] A pair of left and right arm support parts 31e are attached to the tip of the boom 31 by fastening members such as bolts. Note that in Figures 3 and 4, the right arm support part 31e is not shown in order to clarify the positions of the first restricting member 101 and the second restricting member 102 located at the tip of the boom 31.

[0038] The left and right arm support parts 31e are each made of a metal plate-like member that extends in the direction in which the tip of the boom 31 extends (in FIG. 3, the direction extends upward as it moves forward). The left and right arm support parts 31e rotatably support the arm 32. In other words, the arm 32 is connected to the machine body 2 via the boom 31.

[0039] An arm electric motor 32M is fixed to the left arm support part 31e. A first high-voltage wiring WH1 used for supplying high-voltage power and a first low-voltage wiring WL1 used for supplying low-voltage power are connected to the arm electric motor 32M. For example, driving power is supplied to the arm electric motor 32M via the first high-voltage wiring WH1. Furthermore, power (signals) for controlling a brake mechanism built into the arm electric motor 32M is supplied to the arm electric motor 32M via the first low-voltage wiring WL1.

[0040] The first high-voltage wiring WH1 and the first low-voltage wiring WL1 are respectively attached along the surface of the boom 31. For example, the first high-voltage wiring WH1 is arranged along the left end portion on the other side in the rotation direction of the boom 31. The first low-voltage wiring WL1 is arranged along the left end portion on one side in the rotation direction of the boom 31. Therefore, the first high-voltage wiring WH1 and the first low-voltage wiring WL1 can be attached more easily than when the first high-voltage wiring WH1 and the first low-voltage wiring WL1 are attached inside the boom 31. Furthermore, because the first high-voltage wiring WH1 and the first low-voltage wiring WL1 are arranged apart from each other, electrical noise is prevented from being added to the control power (signal) supplied via the first low-voltage wiring WL1.

[0041] The arm 32 includes an arm main body 32a, a first block 32b, and a second block 32c. The arm main body 32a is a hollow metal member extending in one direction (a direction extending downward as it moves forward in FIG. 3). More specifically, the arm main body 32a is formed by joining multiple metal plate-like members by welding or the like. Specifically, the arm main body 32a includes a pair of left and right arm side plates 32a1, an arm upper plate 32a2, and an arm lower plate 32a3. The left and right arm side plates 32a1 are positioned apart in the left-right direction and extend in the one direction. The arm upper plate 32a2 extends in the left-right direction and is connected to one end of the left and right arm side plates 32a1 (the upper-front end in FIG. 3) by welding. The arm lower plate 32a3 is configured to extend in the left-right direction, and is connected to the other end portions (rear lower end portions in FIG. 3) of the left and right arm side plates 32a1 by welding.

[0042] The first block 32b is connected to the base end of the arm main body 32a by welding. The first block 32b is made of a metal member extending in the left-right direction. The first block 32b is not limited to a specific shape. A reinforcing member corresponding to the rib 31c provided on the boom 31 may be provided at the joint between the arm main body 32a and the first block 32b.

[0043] The first block 32b is rotatably supported by the arm support portion 31e. The first block 32b is coupled to the output shaft 32M1 of the arm electric motor 32M via an arm power transmission portion (not shown). The arm electric motor 32M is fixed to the arm support portion 31e with the output shaft 32M1 extending in the left-right direction. The arm power transmission portion has a speed reduction mechanism and transmits the rotational power of the output shaft 32M1 of the arm electric motor 32M to the first block 32b while reducing the speed. Therefore, when the arm electric motor 32M is driven and the output shaft 32M1 of the arm electric motor 32M rotates, the first block 32b rotates relative to the arm support portion 31e. Specifically, the first block 32b rotates around a rotation axis (extending in the left-right direction) that is aligned with the output shaft 32M1 of the arm electric motor 32M. As a result, the arm 32 rotates up and down and back and forth relative to the boom 31 .

[0044] When the arm 32 is rotated, the arm 32 abuts against the restricting member 100. This stops the rotation of the arm 32. That is, the restricting member 100 restricts the rotation of the working unit 3 (arm 32). More specifically, when the first block 32b is rotated to one side in the rotation direction by the drive of the arm electric motor 32M, the third abutting surface 32b1 of the first block 32b abuts against the first restricting member 101 provided on the boom 31 (see FIG. 4 in particular). The third abutting surface 32b1 is a surface extending in the left-right direction of the first block 32b (the surface located on the upper side in FIG. 4). On the other hand, when the first block 32b is rotated to the other side in the rotation direction by the drive of the arm electric motor 32M, the fourth abutting surface 32b2 of the first block 32b abuts against the second restricting member 102 provided on the boom 31 (see FIG. 3 in particular). The fourth contact surface 32b2 is a surface (a surface located on the lower side in FIG. 3) that extends in the left-right direction of the first block 32b and is different from the third contact surface 32b1.

[0045] The second block 32c is connected to the tip of the arm main body 32a by welding. The second block 32c is made of a metal member extending in the left-right direction. The second block 32c is not limited to a particular shape. The second block 32c is provided with a first restricting member 101 and a second restricting member 102 that come into contact with the attachment 33. In the position of the arm 32 shown in FIG. 3, the first restricting member 101 is located forward of the second restricting member 102.

[0046] Additionally, an attachment support part 32d is attached to the left side of the second block 32c with a fastening member such as a bolt. The attachment support part 32d is made of a metal plate-like member that extends in the direction in which the tip of the arm main body part 32a extends (in FIG. 3, the direction extends downward as it moves to the right). The attachment support part 32d rotatably supports the attachment 33. That is, the attachment 33 is rotatably connected to the arm 32 by the attachment support part 32d.

[0047] An attachment electric motor 33M is fixed to the attachment support part 32d. A second high-voltage wiring WH2 used for supplying high-voltage power and a second low-voltage wiring WL2 used for supplying low-voltage power are connected to the attachment electric motor 33M. For example, driving power is supplied to the attachment electric motor 33M via the second high-voltage wiring WH2. Furthermore, power (a signal) for controlling a brake mechanism built into the attachment electric motor 33M is supplied to the attachment electric motor 33M via the second low-voltage wiring WL2.

[0048] The second high-voltage wiring WH2 is attached along the surface of the boom 31 and the surface of the arm 32. The same applies to the second low-voltage wiring WL2. For example, the second high-voltage wiring WH2 is arranged along the left end portion of the boom 31 on the other side in the rotation direction, and is also arranged along the left end portion of the arm 32 on the other side in the rotation direction. In other words, the second high-voltage wiring WH2 is arranged together with the first high-voltage wiring WH1 on the surface of the boom 31. The second low-voltage wiring WL2 is arranged along the right end portion of the boom 31 on one side in the rotation direction, and is also arranged along the right end portion of the arm 32 on one side in the rotation direction.

[0049] Therefore, the second high-voltage wiring WH2 and the second low-voltage wiring WL2 can be installed more easily than when the second high-voltage wiring WH2 and the second low-voltage wiring WL2 are installed inside the boom 31 and inside the arm 32. Furthermore, since the second high-voltage wiring WH2 and the second low-voltage wiring WL2 are arranged at a distance from each other, electrical noise is prevented from being added to the control power (signal) supplied via the second low-voltage wiring WL2. Furthermore, since the first low-voltage wiring WL1 and the second low-voltage wiring WL2 are also arranged at a distance from each other, electrical noise is reliably prevented from being added to the control power (signal).

[0050] The attachment positions of the first high-voltage wiring WH1, the second high-voltage wiring WH2, the first low-voltage wiring WL1, and the second low-voltage wiring WL2 are not limited to those described above. For example, the first high-voltage wiring WH1 and the first low-voltage wiring WL1 may be attached inside the boom 31, and the second high-voltage wiring WH2 and the second low-voltage wiring WL2 may be attached inside both the boom 31 and the arm 32. This configuration protects the first high-voltage wiring WH1, the second high-voltage wiring WH2, the first low-voltage wiring WL1, and the second low-voltage wiring WL2 from, for example, earth and sand flying from near the attachment 33. It also prevents, for example, a worker from accidentally touching the first high-voltage wiring WH1 or the like and receiving an electric shock.

[0051] The attachment 33 includes an attachment main body 33a and a connecting portion 33b that connects the attachment main body 33a to the attachment support portion 32d. The connecting portion 33b is made of a metal plate-like member that extends in one direction (approximately the front-to-rear direction in FIG. 3). The connecting portion 33b is rotatably supported by the attachment support portion 32d. In other words, the connecting portion 33b is connected to the arm 32.

[0052] In this embodiment, the attachment body 33a is a bucket used for excavating earth and sand, etc. The attachment body 33a may be, for example, a breaker, a grapple, or the like, in addition to a bucket.

[0053] The attachment main body 33a is replaceably attached to the connecting portion 33b. That is, the attachment main body 33a is replaceable with various types. More specifically, the attachment main body 33a and the connecting portion 33b are connected via a connecting shaft 33c. That is, the attachment 33 includes a connecting shaft 33c that connects the attachment main body 33a and the connecting portion 33b. The connecting shaft 33c includes a connecting shaft 33c1. The connecting shaft 33c1 is formed by a metal rod-shaped member that extends in the left-right direction.

[0054] A first mounting hole (not shown) penetrating in the left-right direction is provided at the base end of the attachment main body 33a. A second mounting hole (not shown) penetrating in the left-right direction is provided at the tip end (the side opposite the side connected to the arm 32) of the connecting portion 33b. The connecting shaft 33c1 is inserted from the right (or left) into the first mounting hole and the second mounting hole. The connecting shaft 33c1 then fits into the first mounting hole and the second mounting hole. This attaches the attachment main body 33a to the connecting portion 33b. That is, the attachment main body 33a is connected to the connecting portion 33b.

[0055] The connecting portion 33b is connected to the output shaft 33M1 of the attachment electric motor 33M via an attachment power transmission portion (not shown). The attachment electric motor 33M is fixed to the attachment support portion 32d with the output shaft 33M1 extending in the left-right direction. The attachment power transmission portion has a speed reduction mechanism and transmits the rotational power of the output shaft 33M1 of the attachment electric motor 33M to the connecting portion 33b while reducing the speed. Therefore, when the attachment electric motor 33M is driven and the output shaft 33M1 of the attachment electric motor 33M rotates, the connecting portion 33b rotates relative to the attachment support portion 32d. More specifically, the connecting portion 33b rotates about a rotation axis (extending in the left-right direction) located on the same line as the output shaft 33M1 of the attachment electric motor 33M. This allows the attachment 33 to rotate up and down and back and forth relative to the arm 32. Alternatively, the connecting portion 33b may be directly connected to the output shaft 33M1 of the electric motor 33M for the attachment, that is, the power transmission portion for the attachment may be omitted.

[0056] When the attachment 33 is rotated, the connecting portion 33b of the attachment 33 comes into contact with the restricting member 100. This stops the rotation of the attachment 33. That is, the restricting member 100 restricts the rotation of the working unit 3 (attachment 33). More specifically, when the connecting portion 33b is rotated to one side in the rotation direction by the drive of the attachment electric motor 33M, a fifth contact surface 33b1 of the connecting portion 33b comes into contact with a first restricting member 101 provided on the arm 32 (see FIG. 4 in particular). The fifth contact surface 33b1 is a surface of the connecting portion 33b that extends in the left-right direction and is located on one side (substantially downward in FIG. 3) in a direction (substantially up-down direction in FIG. 3) perpendicular to the one direction (substantially the front-rear direction in FIG. 3).

[0057] On the other hand, when the attachment electric motor 33M is driven to rotate the connecting portion 33b to the other side in the rotation direction, the sixth abutment surface 33b2 of the connecting portion 33b abuts against the second restricting member 102 provided on the arm 32 (see particularly FIG. 3). The sixth abutment surface 33b2 is a surface that extends in the left-right direction and is located on the other side of the connecting portion 33b in the direction perpendicular to the one direction (substantially upward in FIG. 3).

[0058] According to the above configuration, even if the working unit 3 is rotated, the rotation of the working unit 3 can be restricted (stopped) at the position where the working unit 3 hits the restricting member 100. In other words, the rotation range of the working unit 3 can be limited. This makes it possible to set the rotation range of the working unit 3 to a range that excludes members other than the working unit 3 (for example, members other than the working unit 3 inside the electric excavator 1). Therefore, even if the working unit 3 is rotated, it is possible to prevent the working unit 3 from coming into contact with the above members. As described above, by restricting the rotation range of the working unit 3, it is possible to prevent the working unit 3 from coming into contact with members other than the working unit 3.

[0059] From the viewpoint of restricting the rotation range of the working unit 3 on both sides of the rotation direction (counterclockwise when viewed from the right in this embodiment) and the rotation range on the other side of the rotation direction (clockwise when viewed from the right in this embodiment), the following configuration is desirable. That is, as in this embodiment, it is desirable that the regulating member 100 has a first regulating member 101 that regulates the rotation of the working unit 3 on one side of the rotation direction, and a second regulating member 102 that regulates the rotation of the working unit 3 on the other side of the rotation direction.

[0060] In a configuration in which the working unit 3 has an arm 32 and an attachment 33 including a connecting portion 33b connected to the arm 32, the following configuration is desirable from the viewpoint of limiting the rotation range of the attachment 33 with a small number of parts by effectively utilizing the connecting portion 33b. That is, as in this embodiment, it is desirable that the connecting portion 33b come into contact with the restricting member 100 when the attachment 33 is rotated.

[0061] Here, the details of the configuration of the regulating member 100 will be described with reference to Fig. 5. Fig. 5 is a perspective view showing the configuration of the regulating member 100. Note that in Fig. 5, directions other than the directions of the electric excavator 1 described above (front-rear direction, left-right direction, and up-down direction) are indicated by dashed arrows for the purpose of explaining the configuration of the regulating member 100. That is, in Fig. 5, the F1-B1 direction and the L1-R1 direction, which are orthogonal to each other, and the U1-D1 direction, which is perpendicular to the F1-B1 direction and the L1-R1 direction, are indicated by dashed arrows.

[0062] As described above, the regulating member 100 is made of a rectangular parallelepiped elastic body. More specifically, the regulating member 100 has a flat surface portion 100a, an attachment surface portion 100b that is parallel to the flat surface portion 100a and spaced apart in one direction (the U1-D1 direction in FIG. 5), and a side surface portion 100c that is connected to the peripheral edge of the flat surface portion 100a and the peripheral edge of the attachment surface portion 100b.

[0063] When attaching the regulating member 100, the regulating member 100 is attached in a direction such that the attachment surface 100b comes into contact with the portion to which the regulating member 100 is attached. For example, in the case of the regulating member 100 provided on the second block 32c of the arm 32 (see FIGS. 3 and 4), the regulating member 100 is attached (fixed) so that the attachment surface 100b comes into contact with the second block 32c. Furthermore, the regulating member 100 is positioned so that, when the working unit 3 abuts against the regulating member 100, the flat surface 100a is parallel to the portions of the working unit 3 that abut against the regulating member 100 (for example, the fifth abutment surface 33b1 of the attachment 33). Therefore, for example, when the attachment 33 is rotated and the attachment 33 (particularly the connecting portion 33b) hits the regulating member 100 (the first regulating member 101 or the second regulating member 102), the attachment 33 hits the flat surface portion 100a of the regulating member 100. That is, the working unit 3 (for example, the attachment 33) hits the flat surface portion 100a of the regulating member 100.

[0064] When the working part 3 hits the flat part 100a, the impact stress applied to the regulating member 100 is alleviated compared to when the working part 3 hits a corner (not shown) of the regulating member 100. From this perspective, it is desirable that the regulating member 100 has the flat part 100a on which the working part 3 hits, as in this embodiment.

[0065] As described above, in this embodiment, the regulating member 100 is made of an elastic material, and therefore the planar portion 100a of the regulating member 100 is made of an elastic material.

[0066] From the viewpoint of reliably mitigating the impact stress applied to the regulating member 100 when the working part 3 hits the regulating member 100, it is desirable that the flat surface part 100a be made of an elastic material as in this embodiment.

[0067] As described above, the regulating member 100 is attached in a replaceable manner. Therefore, by replacing the regulating member 100 with one having a different size, shape, etc., the rotation range of the working unit 3 can be easily adjusted.

[0068] [4. Electric motor rotation stop control] The rotation stop control of the electric motor 3M will be described below. As an example, the rotation stop control of the boom electric motor 31M will be described below with reference to Fig. 6. Fig. 6 is a flowchart showing the flow when the rotation stop control of the boom electric motor 31M is executed. In step S0, it is assumed that the rotation angle of the boom 31 is within a predetermined range and that the boom 31 is rotated toward one side of the rotation direction (counterclockwise when viewing the working unit 3 from the right in this embodiment).

[0069] In step S1, the first sensor 54a (see FIG. 2) located near the boom electric motor 31M detects the rotation angle of the boom 31. As described above, the first sensor 54a outputs the detected rotation angle of the boom 31 to the control device 53. Once the rotation angle of the boom 31 is output to the control device 53, the process proceeds to the next step S2.

[0070] In this embodiment, the rotation angle of the boom 31 means the rotation angle relative to the machine body 2. Furthermore, the rotation angle of the arm 32 means the rotation angle relative to the boom 31, and the rotation angle of the attachment 33 means the rotation angle relative to the arm 32.

[0071] In step S2, the control device 53 determines whether the rotation angle of the boom 31 output from the first sensor 54a is outside a predetermined range. In this embodiment, the predetermined range is set, for example, between 90 degrees above the horizontal and 20 degrees below the horizontal, and is stored in the control device 53. If the rotation angle of the boom 31 is outside the predetermined range (Yes in step S2), the process proceeds to the next step S3. If the rotation angle of the boom 31 is not outside the predetermined range, that is, if it is within the predetermined range (No in step S2), the process returns to step S1.

[0072] In step S3, the control device 53 starts a first rotation stop control for the boom electric motor 31M. In this embodiment, in the first rotation stop control, the control device 53 outputs a rotation command to the inverter 52 (see FIG. 2) to stop the generation of rotational power in the boom electric motor 31M (the output shaft 31M1 of the boom electric motor 31M). This stops the rotation of the boom electric motor 31M. At this time, the boom 31 is separated from the first restricting member 101 located in the boom support section 21. In other words, the boom 31 is not in contact with the first restricting member 101. Therefore, the control device 53 executes the following when the rotation angle of the working unit 3 detected by the first sensor 54a falls outside a predetermined range before the working unit 3 (the boom 31 in this embodiment) comes into contact with the restricting member 100 (the first restricting member 101 in this embodiment). That is, the control device 53 executes the following to stop the rotation of the electric motor 3M (the boom electric motor 31M in this embodiment). When the first rotation stop control is started, the process proceeds to the next step S4.

[0073] In step S4, the control device 53 determines whether the boom 31 (rotation of the boom 31) has stopped. In this embodiment, this determination is made based on the rotation angle of the boom 31 output from the first sensor 54a. For example, if the rotation angle of the boom 31 is the same as the rotation angle of the boom 31 a predetermined time ago (for example, one second), it is determined that the boom 31 has stopped. On the other hand, if the rotation angle of the boom 31 is different from the rotation angle of the boom 31 a predetermined time ago, it is determined that the boom 31 is rotating (not stopped). If the boom 31 has stopped (Yes in step S4), the first rotation stop control is ended (see step S5). If the boom 31 is rotating, i.e., if the boom 31 has not stopped (No in step S4), the process proceeds to step S6.

[0074] In step S6, the control device 53 determines whether or not an emergency stop command for the boom 31 has been issued. In this embodiment, the emergency stop command is issued when the second sensor 54b (see FIGS. 2 and 4) detects that the boom 31 is approaching the first restricting member 101 (see FIGS. 3 and 4) located within the boom support section 21. If an emergency stop command for the boom 31 has been issued (Yes in step S6), the process proceeds to the next step, S7. If an emergency stop command for the boom 31 has not been issued (No in step S6), the process returns to step S3.

[0075] In step S7, the control device 53 starts the second rotation stop control for the boom electric motor 31M. In this embodiment, in the second rotation stop control, the brake mechanism built into the boom electric motor 31M is activated. This stops the rotation of the boom electric motor 31M. At this time, the boom 31 is separated from the first regulating member 101 located in the boom support section 21. In other words, the boom 31 is not in contact with the first regulating member 101. Therefore, the control device 53 executes the following based on the detection result of the second sensor 54b (approach of the boom 31 to the first regulating member 101) before the working unit 3 (the boom 31 in this embodiment) comes into contact with the regulating member 100 (the first regulating member 101 in this embodiment). That is, the control device 53 executes the following to stop the rotation of the electric motor 3M (the boom electric motor 31M in this embodiment). Once the second rotation stop control is started, the process proceeds to the next step S8.

[0076] In step S8, similarly to step S4, the control device 53 determines whether or not the boom 31 (rotation of the boom 31) has stopped. The processing in step S8 is similar to the processing in step S4, and therefore a description thereof will be omitted here.

[0077] As described above, in this embodiment, the first restricting member 101 (placed inside the boom support section 21) is provided so that the boom 31 hitting the first restricting member 101 hits the boom 31 as it rotates to one side of the rotation direction (counterclockwise when the boom 31 is viewed from the right in this embodiment). Therefore, even if at least one of the first rotation stop control and the second rotation stop control is executed, if the boom 31 continues to rotate due to, for example, the inertia of the boom 31, the boom 31 hits the first restricting member 101, and the rotation of the boom 31 is stopped.

[0078] If the boom 31 (rotation of the boom 31) has stopped (Yes in step S8), the second rotation stop control is ended (see step S9), and the first rotation stop control is ended (see step S5). If the boom 31 is rotating, that is, if the boom 31 has not stopped (No in step S8), the process returns to step S7.

[0079] As described above, in this embodiment, the first sensor 54a is arranged near the boom electric motor 31M, as well as near the arm electric motor 32M and the attachment electric motor 33M. Therefore, the first rotation stop control described above is also applicable to the arm electric motor 32M and the attachment electric motor 33M.

[0080] Furthermore, if the second sensor 54b is disposed in a position overlapping with the boom 31 that has been slightly rotated to one side in the rotation direction from the position where it abuts on the second restricting member 102 in the boom support section 21 when viewed from the right or left of the working unit 3, the following becomes possible. That is, the second rotation stop control can be applied to the boom 31 that is rotated toward the other side in the rotation direction (clockwise when viewed from the right of the working unit 3 in this embodiment). Furthermore, in order to apply the second rotation stop control to the arm 32 and the attachment 33, a configuration may be adopted in which the second sensor 54b is added.

[0081] From the viewpoint of limiting the rotation range of the working unit 3 by controlling the rotation of the electric motor 3M (e.g., the boom electric motor 31M) in accordance with the rotation angle of the working unit 3 (e.g., the boom 31), the following configuration is desirable. That is, as in the present embodiment, the electric excavator 1 is desirably equipped with a first sensor 54a that detects the rotation angle of the working unit 3 and a control device 53 that controls the rotation of the electric motor 3M. Furthermore, when limiting the rotation range of the working unit 3, it is desirably to prevent the working unit 3 from hitting a regulating member 100 (e.g., a first regulating member 101 located inside the boom support part 21) and to avoid the work by the working unit 3 being hindered by the restriction on the rotation range of the working unit 3. From this viewpoint, as in the present embodiment, it is desirably that the control device 53 stops the rotation of the electric motor 3M when the rotation angle of the working unit 3 falls outside a predetermined range before the working unit 3 hits the regulating member 100.

[0082] In a configuration in which the electric excavator 1 is equipped with a second sensor 54b that detects the approach of the working unit 3 (the boom 31 in this embodiment) to the regulating member 100, the following configuration is desirable from the viewpoint of reliably limiting the rotation range of the working unit 3 while preventing the working unit 3 from hitting the regulating member 100. That is, as in this embodiment, it is desirable that the control device 53 stop the rotation of the electric motor 3M (the boom electric motor 31M in this embodiment) based on the detection result of the second sensor 54b before the working unit 3 hits the regulating member 100.

[0083] The first rotation stop control and the second rotation stop control may be configured in reverse. That is, as the first rotation stop control, the brake mechanism built into the boom electric motor 31M may be activated. As the second rotation stop control, the control device 53 may output a rotation command to stop the generation of rotational power in the boom electric motor 31M.

[0084] In the present embodiment, a configuration has been described in which sensors 54 (first sensor 54a, second sensor 54b) are provided separately from the regulating member 100, but the present invention is not limited to this configuration. For example, the sensor 54 may be built into the regulating member 100 itself. In this case, the sensor 54 may be, for example, a contact sensor that detects stress (impact stress) applied to the regulating member 100 and detects that the working unit 3 has hit the regulating member 100, i.e., that the working unit 3 has come into contact with the regulating member 100. Furthermore, the control device 53 may be configured to execute at least one of first rotation stop control and second rotation stop control based on the detection result output from the contact sensor. This prevents the working unit 3 from continuing to press against the regulating member 100, which could damage the regulating member 100.

[0085] 5. Modified working unit Below, a modification of the working unit 3 described above will be described.

[0086] [5-1. First Modified Example] A first modified example of the working unit 3 will be described with reference to FIGS. 7 and 8. FIGS. 7 and 8 are left side views showing the configuration of the working unit 3 in the first modified example. FIG. 7 illustrates a case in which the attachment 33 abuts against a first restricting member 101. FIG. 8 illustrates a case in which the attachment 33 abuts against a second restricting member 102 (a recess 32e of the arm 32, which will be described later). The working unit 3 shown in FIGS. 7 and 8 has the same configuration as the working unit 3 shown in FIGS. 3 and 4, except for the configuration of the arm 32 (particularly the arm main body 32a and the attachment support portion 32d). That is, the attachment 33 shown in FIGS. 7 and 8 includes an attachment main body 33a, a connecting portion 33b, and a connecting shaft 33c (connecting shaft 33c1). 7 and 8, for convenience, the base end portion of the arm 32 is not shown, but the base end portion of the arm 32 has the same configuration as the base end portion of the arm 32 shown in FIGS. 3 and 4.

[0087] In the first modified example, the arm main body 32a is configured to include a metal plate-like member extending in one direction (the front-to-rear direction in FIGS. 7 and 8) and in a direction perpendicular to the one direction (the up-down direction in FIGS. 7 and 8). Note that, hereinafter, the direction perpendicular to the one direction may also be referred to as the perpendicular direction.

[0088] A recess 32e is formed at the end of the arm main body 32a on one side in the orthogonal direction (downward in FIGS. 7 and 8). The recess 32e is shaped to fit the outer peripheral surface of the connecting shaft 33c1 of the connecting shaft portion 33c, and is recessed toward the other side in the orthogonal direction (upward in FIGS. 7 and 8).

[0089] A first restricting member 101 is attached to the left side surface of the arm main body 32a. In the first modified example, the first restricting member 101 includes a base 101a made of a rectangular parallelepiped metal member and a buffer member 101b made of a flat elastic body (e.g., rubber). The buffer member 101b is attached to at least one of the multiple surfaces of the base 101a with an adhesive or the like. In the first modified example, the buffer member 101b is attached to one of the multiple surfaces of the base 101a (the front surface in FIGS. 7 and 8).

[0090] The attachment 33 (particularly the connecting portion 33b) is rotatably connected to the left side of the tip of the arm main body 32a. That is, in the first modified example, the arm main body 32a and the attachment support portion 32d are integrally formed. That is, the arm main body 32a is configured to include the attachment support portion 32d. In addition, an attachment electric motor 33M is fixed to the right side of the tip of the arm main body 32a.

[0091] When the attachment 33 is rotated to one side in the rotation direction by the drive of the attachment electric motor 33M, the fifth abutment surface 33b1 of the connecting portion 33b abuts against the first restriction member 101 attached to the arm 32 (see FIG. 7 in particular). As in the cases shown in FIGS. 3 and 4, in the first modified example, the one side in the rotation direction means the clockwise direction when the working unit 3 is viewed from the left, i.e., the counterclockwise direction when the working unit 3 is viewed from the right. The other side in the rotation direction means the counterclockwise direction when the working unit 3 is viewed from the left, i.e., the clockwise direction when the working unit 3 is viewed from the right.

[0092] On the other hand, when the attachment 33 is rotated to the other side in the rotation direction by the drive of the attachment electric motor 33M, the connecting shaft 33c1 of the connecting shaft portion 33c comes into contact with the recess 32e formed in the arm 32 (see FIG. 8 in particular). Therefore, in the first modified example, the recess 32e functions to limit the rotation range of the attachment 33 rotating to the other side in the rotation direction. That is, the recess 32e constitutes the second restricting member 102 that restricts the rotation of the working unit 3 to the other side in the rotation direction. That is, in the first modified example, the second restricting member 102 includes the recess 32e.

[0093] When the attachment 33 includes an attachment main body 33a, a connecting portion 33b, and a connecting shaft 33c, the following configuration is desirable from the viewpoint of limiting the rotation range of the attachment 33 with a small number of parts by effectively utilizing the connecting portion 33b and the connecting shaft 33c. That is, as in the first modified example, when the attachment 33 is rotated to one side in the rotation direction (clockwise when viewed from the left of the working unit 3 in the first modified example), it is desirable that the connecting portion 33b abuts against the first restricting member 101. In addition, when the attachment 33 is rotated to the other side in the rotation direction (counterclockwise when viewed from the left of the working unit 3 in the first modified example), it is desirable that the connecting shaft 33c abuts against the second restricting member 102.

[0094] By changing the length (depth of recess 32e) of recess 32e in the orthogonal direction (the vertical direction in FIGS. 7 and 8), the rotation range of attachment 33 (particularly the rotation range when attachment 33 rotates to the other side of the rotation direction) can be easily adjusted. Furthermore, as described above, recess 32e is formed in a shape that follows the outer circumferential surface of connecting shaft 33c1. This increases the contact area between recess 32e and connecting shaft 33c1 when connecting shaft 33c1 abuts against recess 32e, thereby mitigating impact stress applied to recess 32e and connecting shaft 33c1. Therefore, from the perspectives of facilitating adjustment of the rotation range of attachment 33 and mitigating impact stress applied to arm 32 and connecting shaft 33c, it is desirable that second restricting member 102 include recess 32e with which connecting shaft 33c abuts, as in the first modified example.

[0095] [5-2. Second Modified Example] A second modified example of working unit 3 will be described with reference to Fig. 9. Fig. 9 is a right side view showing the configuration of working unit 3 (arm 32) in the second modified example. The working unit 3 shown in Fig. 9 has the same configuration as the working unit 3 shown in Figs. 3 and 4, except for the configuration of arm 32 (particularly arm main body 32a).

[0096] In the second modified example, the arm main body 32a is formed of a hollow metal member extending in one direction (the front-to-rear direction in FIG. 9), similar to the arm main body 32a shown in FIGS. 3 and 4. However, the arm main body 32a of the second modified example becomes thinner toward one side of the one direction (the front in FIG. 9). More specifically, the pair of left and right arm side plates 32a1 are spaced apart in the left-to-right direction. The left and right arm side plates 32a1 become shorter in length (width) in a direction perpendicular to the one direction (the up-down direction in FIG. 9) toward one side of the one direction. The arm upper plate 32a2 inclines toward one side of the one direction (downward in FIG. 9). The arm upper plate 32a2 is connected to one end (the upper end in FIG. 9) of the left and right arm side plates 32a1. The arm lower plate 32a3 is inclined toward one side in one direction and toward the other side in a direction perpendicular to the one direction (upward in FIG. 9). The arm lower plate 32a3 is connected to the other ends (lower ends in FIG. 9) of the left and right arm side plates 32a1.

[0097] Therefore, in the second modified example, the section modulus of the cross section perpendicular to one direction in the arm main body 32a is greater at the base end side (rear side in FIG. 9) than at the tip end side (front side in FIG. 9). Therefore, with the configuration of the arm 32 (arm main body 32a) of the second modified example, stress applied to the base end of the arm 32 is efficiently dispersed without providing a reinforcing member corresponding to the rib 31c of the boom 31 shown in FIGS. 3 and 4. In other words, the strength of the arm 32 is improved with a reduced number of parts. However, even in the arm 32 of the second modified example, the above-mentioned reinforcing member may be provided (particularly at the joint between the arm main body 32a and the first block 32b).

[0098] Furthermore, in a configuration in which the arm electric motor 32M (drive source) is connected to the base end of the arm 32, stress is smaller at the tip end of the arm 32 than at the base end of the arm 32. Therefore, with the configuration of the arm 32 (arm main body 32a) of the second modified example, the strength of the tip end of the arm 32 is ensured while the weight of the arm 32 is reduced.

[0099] [6. Supplementary Information] In the present embodiment, for example, a configuration has been described in which the restricting member 100 that limits the rotation range of the boom 31 is disposed at a location separate from the boom 31, but the present invention is not limited to the above configuration. For example, the restricting member 100 that limits the rotation range of the boom 31 may be disposed on the boom 31 itself. The same applies to the restricting member 100 that limits the rotation of the arm 32 and the restricting member 100 that limits the rotation range of the attachment 33.

[0100] The electric shovel 1 may be configured to include a control unit that allows an operator to ride on and control the electric shovel 1.

[0101] In this embodiment, an electric shovel 1 has been described as an example of a work machine, but the work machine is not limited to the electric shovel 1 and may be a construction machine such as a hydraulic excavator or a wheel loader. The work machine may also be an agricultural machine such as a combine harvester or a tractor.

[0102] [7. Notes] The electric shovel 1 described in this embodiment can also be expressed as a work machine described in the following supplementary notes.

[0103] The work machine in Appendix (1) is An electric motor; a working unit rotated by the electric motor; and a restricting member that restricts the rotation of the working unit.

[0104] The work machine of supplementary note (2) is the work machine of supplementary note (1), The regulating member is a first restricting member that restricts rotation of the working unit in one direction of the rotation direction; and a second restricting member that restricts the rotation of the working unit on the other side of the rotation direction.

[0105] The work machine of supplementary note (3) is the work machine of supplementary note (2), The working unit includes: Arm and an attachment pivotally connected to the arm; the attachment includes a connecting portion connected to the arm, The connecting portion comes into contact with the restricting member when the attachment is rotated.

[0106] The work machine of supplementary note (4) is the work machine described in supplementary note (3), The attachment is an attachment main body portion connected to the connecting portion; a connecting shaft portion that connects the attachment main body portion and the connecting portion, When the attachment is rotated to one side in the rotation direction, the connecting portion comes into contact with the first restricting member, The connecting shaft comes into contact with the second restricting member when the attachment is rotated to the other side in the rotation direction.

[0107] The work machine of supplementary note (5) is the work machine according to supplementary note (4), The second restricting member includes a recess against which the connecting shaft abuts.

[0108] The work machine of supplementary note (6) is a work machine according to any one of supplementary notes (1) to (5), The restricting member has a flat surface against which the working portion comes into contact.

[0109] The work machine of supplementary note (7) is the work machine according to supplementary note (6), The planar portion is formed of an elastic body.

[0110] The work machine of supplementary note (8) is a work machine according to any one of supplementary notes (1) to (7), a first sensor that detects the rotation angle of the working unit; a control device that controls the rotation of the electric motor, The control device stops the electric motor when the rotation angle of the working unit falls outside a predetermined range before the working unit hits the restricting member.

[0111] The work machine of supplementary note (9) is the work machine according to supplementary note (8), a second sensor that detects the working unit approaching the regulating member; The control device stops the electric motor based on the detection result of the second sensor before the working part hits the regulating member.

[0112] Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these, and the invention can be expanded or modified without departing from the spirit of the invention. [Industrial Applicability]

[0113] The present invention can be used in work machines such as construction machines and agricultural machines. [Explanation of symbols]

[0114] 1. Electric shovel (work machine) 3 Working section 3M Electric Motor 32 Arm 32e recess 33 Attachment 33a Attachment body 33b Connection part 33c Connecting shaft part 53 Control device 54a First sensor 54b Second sensor 100 Regulatory member 100a flat part 101 first restricting member 102 second restricting member

Claims

1. An electric motor; a working unit rotated by the electric motor; a restricting member that restricts the rotation of the working unit.

2. The regulating member is a first restricting member that restricts rotation of the working unit in one direction of the rotation direction; The work machine according to claim 1 , further comprising: a second restricting member that restricts rotation of the working unit on the other side of the rotation direction.

3. The working unit includes: Arm and an attachment pivotally connected to the arm; the attachment includes a connecting portion connected to the arm, The work machine according to claim 2 , wherein the connecting portion abuts against the restricting member when the attachment is rotated.

4. The attachment is an attachment main body portion connected to the connecting portion; a connecting shaft portion that connects the attachment main body portion and the connecting portion, When the attachment is rotated to one side in the rotation direction, the connecting portion comes into contact with the first restricting member, The work machine according to claim 3 , wherein the connecting shaft abuts against the second restricting member when the attachment is rotated to the other side in the rotation direction.

5. The work machine according to claim 4 , wherein the second restricting member includes a recess against which the connecting shaft portion abuts.

6. The work machine according to claim 1 , wherein the regulating member has a flat surface against which the working portion abuts.

7. The work machine according to claim 6 , wherein the flat surface portion is formed of an elastic material.

8. a first sensor that detects a rotation angle of the working unit; a control device that controls the rotation of the electric motor, 8. The work machine according to claim 1, wherein the control device stops the electric motor when the rotation angle of the working unit falls outside a predetermined range before the working unit comes into contact with the regulating member.

9. a second sensor that detects the working unit approaching the regulating member; The work machine according to claim 8 , wherein the control device stops the electric motor based on the detection result of the second sensor before the working part comes into contact with the regulating member.

Images