Working machine

Abstract

The present invention provides a working machine that can improve the degree of freedom of design around a telescopic arm and the reliability of the arm when it is extended or retracted. The working machine comprises: an actuator for extension and retraction, which moves a first arm relative to a second arm in the extension and retraction direction; an electric drive source, which is arranged on a movable part of the actuator for extension and retraction; a first force-applying mechanism, which applies force to a first fixed pin to maintain the connection state between the actuator for extension and retraction and the first arm; a first connecting mechanism, which switches the connection state between the actuator for extension and retraction and the first arm based on the power of the electric drive source; a second force-applying mechanism, which applies force to a second fixed pin to maintain the connection state between the first arm and the second arm; a second connecting mechanism, which switches the connection state between the first arm and the second arm based on the power of the electric drive source; and a clutch, which is arranged on a power transmission path from the electric drive source and transmits the power of the electric drive source to the first connecting mechanism and the second connecting mechanism in a manner that can be freely disconnected and connected.

Description

Technical Field

[0001] The present invention relates to a working machine equipped with a telescopic arm. Background Art

[0002] Conventionally, there is known a mobile crane having a telescopic arm, wherein a plurality of arm elements of the telescopic arm are arranged in a nested manner (also referred to as "telescopic manner") and overlapped (for example, see Patent Document 1). The telescopic arm is configured to be telescopic in sections by, for example, a telescopic actuator arranged inside the innermost arm element.

[0003] Specifically, in a telescopic arm, inner and outer adjacent arm elements are connected to each other by an arm connecting pin (hereinafter referred to as a "B pin"). If the connection by the B pin is released, the inner arm element can move in the telescopic direction relative to the outer arm element. The movable arm element is connected to the movable part of the telescopic actuator by a cylinder connecting pin (hereinafter referred to as a "C pin"). The telescopic actuator is composed of, for example, a hydraulic cylinder having a piston rod part and a cylinder part, and the cylinder part plays the role of a movable part to extend and retract the arm element.

[0004] In addition, the insertion and extraction actions of the B pin and the C pin are exclusively controlled by the pin insertion and extraction actuator arranged in the movable part of the telescopic actuator, and the connection state between the arm elements performed by the B pin and the connection state between the cylinder and the arm performed by the C pin cannot be released at the same time (the so-called "interlocking").

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-96928 Summary of the invention

[0008] Problems to be solved by the invention

[0009] However, in the past, hydraulic actuators were used as pin insertion and extraction actuators, and pipes and hydraulic circuits were provided around the telescopic arm to supply hydraulic oil to the actuators. Therefore, the design of the periphery of the telescopic arm was limited in space, which may restrict the miniaturization and weight reduction of the telescopic arm.

[0010] In addition, the viscosity of the hydraulic oil changes depending on the ambient temperature, etc., so the operating time is unstable, especially in a low-temperature environment, which has a great impact and causes poor operation.

[0011] An object of the present invention is to provide a working machine capable of improving the degree of freedom in designing the periphery of a telescopic arm and the reliability when the arm is extended or retracted.

[0012] Means for solving problems

[0013] The working machine involved in the present invention comprises:

[0014] A telescopic arm having a first arm and a second arm that overlap in a telescopic manner;

[0015] an actuator for extension and retraction, causing the first arm to move relative to the second arm in an extension and retraction direction;

[0016] An electrical drive source, provided at a movable portion of the telescopic actuator;

[0017] a first fixing pin connecting the telescopic actuator and the first arm;

[0018] a first urging mechanism for urging the first fixing pin to maintain a connection state between the telescopic actuator and the first arm;

[0019] a first connection mechanism that operates based on the power of the electric drive source to insert and remove the first fixing pin, thereby switching the connection state and non-connection state between the telescopic actuator and the first arm;

[0020] a second fixing pin connecting the first arm and the second arm;

[0021] a second urging mechanism for urging the second fixing pin to maintain the connection between the first arm and the second arm;

[0022] a second connection mechanism that operates based on the power of the electric drive source to insert and remove the second fixing pin, thereby switching the connection state and the non-connection state between the first arm and the second arm; and

[0023] The clutch is disposed in a power transmission path from the electric drive source to the first connection mechanism and the second connection mechanism, and transmits the power of the electric drive source to the first connection mechanism and the second connection mechanism in a manner that can be freely disconnected and connected.

[0024] Effects of the Invention

[0025] According to the present invention, it is possible to improve the degree of freedom in designing the periphery of a telescopic arm and the reliability when the arm is telescoped. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a figure which shows the state of the mobile crane which concerns on one Embodiment of this invention at the time of traveling.

[0027] Figure 2 It is a figure which shows the state of a mobile crane at the time of operation.

[0028] Figure 3A to Figure 3C This is a schematic diagram for explaining the structure and extension operation of the telescopic arm.

[0029] Figure 4A to Figure 4C This is a schematic diagram for explaining the structure and extension operation of the telescopic arm.

[0030] Figure 5 It is an oblique view of the telescopic device as a whole.

[0031] Figure 6 This is a perspective view of the pin insertion and extraction actuator.

[0032] Figure 7 This is a plan view of the pin insertion and extraction actuator as viewed from the + side in the Z direction.

[0033] Figure 8 This is a side view of the pin insertion / extraction actuator as viewed from the + side in the Y direction.

[0034] Fig. 9 It is a perspective view showing a state where the pin insertion / extraction actuator is engaged with the B-pin holding portion.

[0035] Fig.10 This is a front view of the state where the pin insertion / extraction actuator and the B-pin holding portion are engaged, as viewed from the - side in the X direction.

[0036] Fig.11 This is a diagram showing the internal structure of the pin insertion and extraction actuator.

[0037] Fig.12 This is a diagram showing the internal structure of the pin insertion and extraction actuator.

[0038] Fig.13 This is a diagram showing the internal structure of the pin insertion and extraction actuator.

[0039] Fig.14 It is a diagram schematically showing the structure of the pin insertion and extraction actuator.

[0040] Fig.15A , Fig. 15B It is a figure which shows the extracted state of a cylinder connection module and the extracted state of an arm connection module.

[0041] Figures 16A to 16C This is a schematic diagram for explaining the operation and function of the locking mechanism.

[0042] Figures 17A to 17C This is a schematic diagram for explaining the operation of the cylinder connection module.

[0043] Figures 18A to 18C It is a schematic diagram for explaining the operation of the arm connection module.

[0044] Fig.19 This is a timing chart showing an example of control of the telescopic arm during the extension operation.

[0045] Fig. 20This is a timing chart showing an example of control of the telescopic arm during the extension operation to which the motor assist process is applied. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0047] In this embodiment, a mobile crane 1 is described as an example of a working machine according to the present invention.

[0048] <Mobile crane>

[0049] Figure 1 It is a figure which shows the state of the mobile crane 1 which concerns on one Embodiment of this invention at the time of traveling. Figure 2 It is a figure which shows the state of the mobile crane 1 at the time of operation. Figure 1 , Figure 2 The illustrated mobile crane 1 is a so-called rough terrain crane including an upper slewing body 10 and a lower traveling body 20 .

[0050] The upper revolving body 10 includes a revolving frame 11 , a cab 12 , a lifting cylinder 13 , a boom 14 , a hook 15 , a bracket 16 , a telescopic arm 30 , a counterweight CW, a hoisting device (a winch, not shown), and the like.

[0051] The revolving frame 11 is rotatably supported by the lower traveling structure 20 via a revolving support body (not shown). The revolving frame 11 is provided with a cab 12, a lifting cylinder 13, a bracket 16, a telescopic arm 30, a counterweight CW, a lifting device (not shown), and the like.

[0052] The operator's cabin 12 is disposed, for example, at the front of the revolving frame 11. The operator's cabin 12 includes a seat for an operator, various measuring instruments, an operation unit used during crane operation and driving, a display unit, and a sound output unit.

[0053] The up-and-down cylinder 13 is installed between the revolving frame 11 and the telescopic arm 30. By extending and retracting the up-and-down cylinder 13, the telescopic arm 30 is up-and-down within a predetermined up-and-down angle range (for example, 0° to 84°).

[0054] When the lift is increased, the mast 14 is rotatably mounted on the front end (arm head) of the telescopic boom 30. The mast 14 can protrude forward of the telescopic boom 30 by rotating forward.

[0055] The hook 15 is a hook-shaped lifting device having a main hook and an auxiliary hook. The hook 15 is mounted on a steel cable 19, which is hung on a pulley at the front end of the telescopic arm 30 or the front end of the lifting rod 14. The hook 15 is raised or lowered as the lifting device (not shown) lifts or pulls out the steel cable 19.

[0056] The counterweight CW is mounted on the rear portion of the revolving frame 11. The counterweight CW has a plurality of unit weights, and can be set so that different weights can be obtained by combining the unit weights.

[0057] The telescopic arm 30 is rotatably mounted on the bracket 16 via a support shaft (pin, reference numeral omitted). The telescopic arm 30 includes a plurality of arm elements including a front arm 31, an intermediate arm 32, and a base arm 33, and these arm elements are arranged in a nested overlapping manner (so-called "telescopic structure"). Figure 5 ) is extended and retracted, and the front arm 31 and the middle arm 32 of the plurality of arm elements slide relative to the base arm 33 in the extension direction. On the other hand, the base arm 33 cannot move in the extension direction. By sequentially extending from the arm element arranged on the inner side (i.e., the front arm 31), the telescopic arm 30 is extended and retracted from Figure 1 The contraction state shown is Figure 2 The elongated state shown undergoes state transition.

[0058] In addition, a boom head (reference numeral omitted) having a pulley (reference numeral omitted) is disposed at the front end of the front boom 31. In addition, a working attachment such as a bucket may be mounted on the boom head. In addition, in the telescopic boom 30, the number of sections of the intermediate boom 32 is not particularly limited.

[0059] The lower traveling structure 20 includes a vehicle frame 21 , wheels 22 , 23 , outriggers OR1 , OR2 , an engine (not shown), and the like.

[0060] The driving force of the engine is transmitted to the wheels 22 and 23 through a transmission mechanism (not shown). The wheels 22 and 23 are rotated by the driving force of the engine, so that the mobile crane 1 travels. In addition, the steering angle (travel direction) of the wheels 22 and 23 changes with the operation of a steering wheel (not shown) provided in the cab 12.

[0061] During traveling, the outriggers OR1 and OR2 are stored in the vehicle body frame 21. During operation (when the upper swing body 10 is in motion), on the other hand, the outriggers OR1 and OR2 protrude in the horizontal and vertical directions to lift and support the entire vehicle body and stabilize its posture.

[0062] As described above, the mobile crane 1 is a self-propelled crane using the wheels 22 and 23 as the travel portion of the lower travel structure 20, and the travel operation and the crane operation can be performed in one operator's cab.

[0063] Furthermore, as the mobile crane, in addition to the rough terrain crane, there can be mentioned, for example, an all-terrain crane, a truck crane, or a loading-type truck crane (also referred to as a "ship crane").

[0064] <Telescopic arm>

[0065] Figure 3A to Figure 3C as well as Figure 4A to Figure 4C It is a schematic diagram for explaining the structure and extension operation of the telescopic arm 30 . Figure 3A to Figure 3C as well as Figure 4A to Figure 4C The right side of the figure is the base end side of the telescopic arm 30, and the left side of the figure is the front end side of the telescopic arm 30. Here, for the sake of simplicity of description, the telescopic arm 30 consisting of one section of the intermediate arm 32 is illustrated.

[0066] like Figure 3A to Figure 3C as well as Figure 4A to Figure 4C As shown, the telescopic arm 30 has a structure substantially the same as that of a conventionally known telescopic arm. The telescopic arm 30 has, for example, a symmetrical structure in the width direction of the telescopic axis. A telescopic device A for extending and retracting the telescopic arm 30 is disposed inside the telescopic arm 30 .

[0067] In the telescopic arm 30, the front arm 31 and the intermediate arm 32 are connected by an arm connection pin (hereinafter referred to as "B pin") 315 provided on the front arm 31, and the intermediate arm 32 and the base arm 33 are connected by a B pin 325 provided on the intermediate arm 32. In addition, the front arm 31, the intermediate arm 32, and the base arm 33 are each connected to the telescopic actuator 40 by a cylinder connection pin (hereinafter referred to as "C pin") 150. The front arm 31 or the intermediate arm 32 connected to the telescopic actuator 40 by the C pin 150 becomes an arm element to be telescopic.

[0068] The distal arm 31 has a cylindrical shape and has an internal space capable of accommodating the telescopic device A. The distal arm 31 has a C-pin receiving portion 311 , a B-pin holding portion 314 , and a B-pin 315 at a base end portion.

[0069] The pair of C-pin receiving portions 311 are configured to be respectively engageable with and disengageable from the C-pin 150 (first fixing pin) provided in the pin inserting and extracting actuator 50. The C-pin receiving portions 311 are, for example, disposed coaxially with each other.

[0070] On the base end side of the C pin receiving portion 311, the B pin holding portion 314 is fixed to the frame of the front end arm 31, and holds the B pin 315 (second fixed pin) in a manner that allows it to move forward and backward. A pair of B pins 315 are, for example, coaxially arranged on the B pin holding portion 314, and are forced in opposite directions toward the outer intermediate arm 32 by the force of the force applying member. That is, in normal times when the front end arm 31 is not extended or retracted, the B pin 315 is inserted through the base end side B pin receiving portion 322 or the front end side B pin receiving portion 323 of the intermediate arm 32 by the force of the force applying member, and is maintained in this state.

[0071] The intermediate arm 32 has a cylindrical shape and has an internal space capable of accommodating the distal arm 31. The intermediate arm 32 has a C pin receiving portion 321, a proximal B pin receiving portion 322 and a B pin holding portion 324 at its proximal end, and a distal B pin receiving portion 323 at its distal end.

[0072] The pair of C-pin receiving parts 321 are configured to be respectively engageable with and detachable from the C-pin 150 (first fixing pin). The C-pin receiving parts 321 are, for example, arranged coaxially with each other.

[0073] A pair of proximal B pin receiving parts 322 are provided at the proximal side of the C pin receiving part 321 and are coaxially arranged with each other. A pair of distal B pin receiving parts 323 are provided at the distal end of the intermediate arm 32 and are coaxially arranged with each other. The proximal B pin receiving parts 322 and the distal B pin receiving parts 323 are configured so that the B pin 315 of the distal arm 31 can be inserted and removed.

[0074] The B pin holding portion 324 is fixed to the frame of the intermediate arm 32 at the base end side relative to the base end side B pin receiving portion 322, and holds the B pin 325 (second fixed pin) in a manner that allows it to move forward and backward. A pair of B pins 325B are, for example, coaxially arranged on the pin holding portion 324, and are forced in opposite directions toward the base end arm 33 on the outside by the force of the force applying member. That is, in normal times when the intermediate arm 32 is not extended or retracted, the B pin 325 is inserted through the base end side B pin receiving portion 332 or the front end side B pin receiving portion 333 of the base end arm 33 by the force of the force applying member, and is maintained in this state.

[0075] The base arm 33 has a cylindrical shape and has an internal space capable of accommodating the intermediate arm 32. The base end of the base arm 33 has a base end side B pin receiving portion 332, and the front end of the base arm 33 has a front end side B pin receiving portion 333.

[0076] The pair of proximal B-pin receiving parts 332 are coaxially arranged with each other. The pair of distal B-pin receiving parts 333 are provided at the distal end of the proximal arm 33 and coaxially arranged with each other. The proximal B-pin receiving parts 332 and the distal B-pin receiving parts 333 are configured so that the B-pin 325 of the intermediate arm 32 can be inserted and removed.

[0077] The B pins 315 and 325 are displaced in their own axial directions by the operation of the arm connection module 200 included in the pin insertion and extraction actuator 50 .

[0078] Specifically, the B pin 315 spans and passes through the base end side B pin receiving portion 322 or the front end side B pin receiving portion 323 of the intermediate arm 32. As a result, the front end arm 31 and the intermediate arm 32 are connected to each other, and the connection state is achieved. On the other hand, if the B pin 315 is pulled out from the base end side B pin receiving portion 322 or the front end side B pin receiving portion 323 of the intermediate arm 32, the connection between the front end arm 31 and the intermediate arm 32 is released, and the connection state is achieved.

[0079] The B pin 325 spans and passes through the base end side B pin receiving portion 332 or the front end side B pin receiving portion 333 of the base end arm 33. As a result, the intermediate arm 32 is connected to the base end arm 33, and the connection is in a connected state. On the other hand, if the B pin 325 is pulled out from the base end side B pin receiving portion 332 or the front end side B pin receiving portion 333 of the base end arm 33, the connection between the intermediate arm 32 and the base end arm 33 is released, and the connection is in a non-connected state.

[0080] In the connected state with the intermediate arm 32 via the B pin 315, the front end arm 31 cannot move in the extension direction relative to the intermediate arm 32, and in the unconnected state, the front end arm 31 can move in the extension direction relative to the intermediate arm 32. Similarly, in the connected state with the base end arm 33 via the B pin 325, the intermediate arm 32 cannot move in the extension direction relative to the base end arm 33, and in the unconnected state, the intermediate arm 32 can move in the extension direction relative to the base end arm 33.

[0081] The C pin 150 is displaced in its own axial direction by the operation of the cylinder connection module 100 included in the pin insertion / extraction actuator 50 .

[0082] Specifically, the front arm 31 and the intermediate arm 32 are in either an engaged state in which the C pin 150 is engaged with the C pin receiving parts 311 and 321, or a non-engaged state in which the C pin 150 is disengaged from the C pin receiving parts 311 and 321. In the engaged state, the front arm 31 and the intermediate arm 32 can move in the telescopic direction together with the movable part (the cylinder part 42 in this embodiment) of the telescopic actuator 40. When the intermediate arm 32 moves, the front arm 31 connected to the intermediate arm 32 via the B pin 315 also moves in the telescopic direction.

[0083] Hereinafter, the extending operation of the telescopic arm 30 will be briefly described.

[0084] Figure 3A The telescopic arm 30 is in a fully retracted state. In this state, the front arm 31 is accommodated in the middle arm 32 and is connected to the middle arm 32 by the B pin 315, and cannot be extended in the extension direction (refer to Figure 3C) is moved. In addition, the C pin 150 is engaged with the C pin receiving portion 311 of the front end arm 31, and the front end arm 31 and the cylinder portion 42 are in an engaged state.

[0085] like Figure 3B As shown, the B pin 315 is pulled out from the B pin receiving portion 322 on the base end side of the intermediate arm 32 (see Figure 3B The front arm 31 and the intermediate arm 32 are not connected, and the front arm 31 can move in the extension direction.

[0086] like Figure 3C As shown, as the telescopic actuator 40 is operated, the cylinder portion 42 moves in the extension direction, and the front end arm 31 moves toward the front end side.

[0087] like Figure 4A As shown, after the front end arm 31 moves to a predetermined position, the B pin 315 is inserted through the front end side B pin receiving portion 323 of the intermediate arm 32 (see Figure 4A The front arm 31 and the intermediate arm 32 are connected, and the front arm 31 cannot move in the extension direction.

[0088] like Figure 4B As shown, the engagement between the C-pin receiving portion 311 of the front end arm 31 and the C-pin 150 is released (see Figure 4B The portion surrounded by the dotted line in the middle) is separated from the front end arm 31, and only the cylinder portion 42 can be restored to the retracted state.

[0089] And, if Figure 4C As shown, the cylinder portion 42 is returned to the contracted state, the C-pin receiving portion 321 of the intermediate arm 32 is engaged with the C-pin 150 , and the intermediate arm 32 and the cylinder portion 42 are in the engaged state.

[0090] When the intermediate arm 32 is extended, the same operation as above is performed. When the front end arm 31 or the intermediate arm 32 is contracted, the operation in the opposite direction to the above is performed.

[0091] <Extension device>

[0092] The extension and contraction of the telescopic arm 30 are performed by the telescopic device A built into the telescopic arm 30. Figure 3A In the state shown in FIG. 1 , the telescopic device A is arranged in the internal space of the front end arm 31. The detailed structure of the telescopic device A will be described below.

[0093] Figure 5It is an oblique view of the appearance of the telescopic device A. In the following, the various structural elements constituting the telescopic device A are described using an orthogonal coordinate system (X, Y, Z) based on the state in which they are assembled to the telescopic device A. The common orthogonal coordinate system (X, Y, Z) is also used in the following figures. In the orthogonal coordinate system (X, Y, Z), the X direction coincides with the telescopic direction of the telescopic arm 30. The + side of the X direction is the front end side of the telescopic arm 30, and the - side of the X direction is the base end side of the telescopic arm 30. In the lying state of the telescopic arm 30 with a undulating angle of 0°, the Z direction coincides with, for example, the up and down direction of the mobile crane 1. The Y direction is orthogonal to the X direction and the Z direction, for example, coincides with the width direction of the telescopic arm 30.

[0094] like Figure 5 As shown in FIG. 1 , the telescopic device A includes a telescopic actuator 40 and a pin insertion / extraction actuator 50 . The pin insertion / extraction actuator 50 is disposed on the base end side of the telescopic actuator 40 so as to be movable together with the cylinder portion 42 , for example.

[0095] The telescopic actuator 40 has a piston rod portion 41 (see Figure 3A etc.) and the hydraulic cylinder of the cylinder section 42. The telescopic actuator 40 is moved by the C pin 150 (see Figure 3A The arm element (e.g., the front arm 31 or the middle arm 32) connected to the cylinder part 42 moves in the telescopic direction. The cylinder part 42 has, for example, a cylinder frame 43 with a guide rail. The guide rail (not shown) of the cylinder frame 43 engages with a guide rail groove provided in the telescopic arm 30. Thus, the cylinder part 42 can slide in a stable posture along the telescopic arm 30 in the telescopic direction. In addition, the main structure of the telescopic actuator 40 is substantially the same as that of a known hydraulic cylinder, so a detailed description is omitted.

[0096] Figure 6 to Figure 10 The structure of the pin inserting and extracting actuator 50 is shown. Figure 6 to Figure 8 They are respectively a perspective view of the pin inserting and extracting actuator 50 , a plan view as viewed from the + side in the Z direction, and a side view as viewed from the + side in the Y direction. Fig. 9 , Fig.10 They are respectively a perspective view of a state in which the pin inserting / extracting actuator 50 and the B-pin holding portion 314 are engaged with each other, and a front view as seen from the - side in the X direction.

[0097] exist Figure 6 to Figure 10 In order to distinguish a pair of C pins 150, they are indicated as "C pins 150A, 150B". Fig. 9 , Fig.10 In the figure, in order to distinguish a pair of B pins 315, they are represented as "B pins 315A, 315B".

[0098] like Figure 6 to Figure 8As shown in FIG. 1 , the pin insertion and extraction actuator 50 is arranged on the X direction - side (base end side) of the cylinder part 42, and moves in the extension and contraction direction together with the cylinder part 42. The pin insertion and extraction actuator 50 includes an electric motor 51 (electrical drive source), a brake 52, a transmission mechanism 53, a position detection device 54, and a locking mechanism 55 (see FIG. 1 ). Fig.11 ), the cylinder connection module 100 (first connection device) and the arm connection module 200 (second connection device). The transmission mechanism 53 includes a clutch 61, a speed reducer 62 and a torque limiter 63 (see Fig.14 ).

[0099] Each component is arranged in the housing 58 and is unitized. This can realize a compact pin insertion / extraction actuator 50, improve productivity, and improve system reliability. Specifically, the housing 58 includes a box-shaped first housing 581 and a box-shaped second housing 582.

[0100] The inner space of the first housing 581 accommodates the oil cylinder connection module 100. The C pins 150A and 150B of the oil cylinder connection module 100 are arranged so as to be able to advance and retreat from both ends of the first housing 581 in the Y direction. The piston rod portion 41 of the telescopic actuator 40 is inserted into the first housing 581 in the X direction (see Figure 3A The end of the cylinder portion 42 is fixed to the side wall of the first housing 581 on the + side in the X direction.

[0101] The second housing 582 is provided on the Z direction + side of the first housing. The internal space of the second housing 582 accommodates the arm connection module 200. The rack bar 220A for the B pin of the arm connection module 200 is configured to be able to move forward and backward from one end of the second housing 582 in the Y direction, and the rack bar 220B for the B pin is configured to be able to move forward and backward from the other end. In addition, the transmission shaft 56 of the transmission mechanism 53 is inserted into the second housing 582 in the X direction (see Fig.12 ).

[0102] The electric motor 51 is an electrical drive source for operating the oil cylinder connection module 100 and the arm connection module 200. The electric motor 51 is configured as, for example, a rotary motor that outputs a rotary motion using electromagnetic force. As a rotary motor, for example, various electromagnetic motors such as a brushed motor (DC motor), a brushless DC motor, and a stepping motor can be used. The operation of the electric motor 51 is controlled by the control device 70 (see Fig.14 )control.

[0103] The electric motor 51 is supported by the second housing 582 via the transmission mechanism 53. The output shaft (not shown) of the electric motor 51 extends in the X direction. The electric motor 51 is configured such that, for example, a ring gear (not shown) arranged on the outer periphery of the piston rod portion 41 as a mechanical element of the transmission mechanism 53 is meshed with the output shaft of the electric motor 51. By configuring the electric motor 51 in this way, the pin insertion and extraction actuator 50 can be miniaturized in the Y direction and the Z direction.

[0104] The electric motor 51 can also be a flat motor such as a large thin motor or a flat relative motor and can be arranged in the cylinder frame 43. In this case, the structure can be compact, and the cylinder frame 43 can function as a protective cover to reduce the risk of damage caused by interference during the arm extension and retraction operation. In addition, the large outer diameter of the motor is utilized to directly transmit power from the output shaft of the motor to the large diameter gear ring, thereby reducing the reduction ratio and reducing the inertia of the C pin force mechanism 160 or the B pin force mechanism 240 during the insertion operation.

[0105] The electric motor 51 is connected to the upper rotating body 10 (see Figure 1 ) is connected to a power supply device (not shown) arranged on the upper rotating body 10. In addition, the electric motor 51 is connected to a control device 70 arranged on the upper rotating body 10, for example, via a control signal transmission cable. These cables can be connected at the base end of the telescopic arm 30 or the upper rotating body 10 (see Figure 1 ) is used to unwind and reel the wire.

[0106] The wiring space for power supply cables and control signal transmission cables is small and they can be freely routed, so the degree of freedom in designing the telescopic arm 30 is significantly improved compared to the case of providing piping and a hydraulic circuit for a hydraulic actuator.

[0107] In addition, the electric motor 51 has a manual operating unit 511 that can be operated by a manual handle (not shown). The manual operating unit 511 is an operating unit for manually transferring the state of the pin insertion and extraction actuator 50 (specifically, the cylinder connection module 100 and the arm connection module 200). When the motor fails, the manual operating unit 511 is rotated by the manual handle, and the output shaft of the electric motor 51 rotates to transfer the state of the pin insertion and extraction actuator 50, so that the B pins 315, 325 and the C pin 150 can be inserted and removed.

[0108] In the present embodiment, the cylinder connection module 100 and the arm connection module 200 are operated by one electric motor 51. In addition, a motor for the cylinder connection module 100 and a motor for the arm connection module 200 may be provided as the electric motor 51, respectively. For example, when the output shaft of the electric motor 51 is connected to the ring gear (not shown) of the transmission mechanism 53, the configuration of the electric motor 51 is not limited as long as it is the outer periphery of the ring gear, so a plurality of small motors can be easily configured as the electric motor 51. In addition, the required torque can be obtained by increasing or decreasing the number of motors, so it can be realized with one type of motor, and it can also be easily applied to the design of other models.

[0109] The brake 52 applies a braking force to the electric motor 51. The brake 52 is configured as an electromagnetic brake that brakes using electromagnetic force, for example. The operation of the brake 52 is controlled by the control device 70.

[0110] When the electric motor 51 is in a stopped state (non-energized state), the brake 52 restricts the rotation of the output shaft of the electric motor 51. The brake 52 operates, for example, when the cylinder connection module 100 is in an extended state or the arm connection module 200 is in an extended state. Accordingly, when the electric motor 51 is in a stopped state, the extended state of the cylinder connection module 100 and the arm connection module 200 is maintained. Compared with the case where the extended state is maintained by the motor torque, power saving can be achieved, and heating of the electric motor 51 due to the locked state can be prevented.

[0111] In addition, if a predetermined external force is applied to the cylinder connection module 100 or the arm connection module 200 during braking, the brake 52 may also allow the electric motor 51 to rotate (i.e., slide). This can prevent the mechanical elements of the pin insertion and extraction actuator 50 (e.g., the electric motor 51 and various gears) from being damaged due to overload.

[0112] The brake 52 is arranged at a stage before the speed reducer 62 of the transmission mechanism 53. The front stage refers to the upstream side (X direction - side) of the power transmission path in which the power of the electric motor 51 is transmitted to the cylinder connection module 100 or the arm connection module 200, including the upstream side of the electric motor 51. On the other hand, the rear stage refers to the downstream side (X direction + side) of the power transmission path of the electric motor 51. In the present embodiment, the brake 52 is coaxially arranged with the electric motor 51 on the X direction - side (that is, on the opposite side of the transmission mechanism 53 centered on the electric motor 51) than the electric motor 51. By arranging the brake 52 in this way, the actuator 50 for pin insertion and extraction can be miniaturized in the Y direction and the Z direction. In addition, when the brake 52 is arranged at a stage before the speed reducer 62, the brake torque required to maintain the stopped state of the electric motor 51 becomes smaller than when it is arranged at a stage after the speed reducer 62, so the miniaturization of the brake 52 can be achieved.

[0113] In addition, various brake devices such as mechanical and electromagnetic brakes can be applied to the brake 52. In addition, the position of the brake 52 is not limited to the position in the present embodiment.

[0114] The transmission mechanism 53 transmits the power (i.e., rotational motion) of the electric motor 51 to the cylinder connection module 100 and the arm connection module 200. The transmission mechanism 53 is disposed in the second housing 582. The transmission mechanism 53 includes a clutch 61, a speed reducer 62, and a torque limiter 63 (see Fig.14 The transmission mechanism 53 includes, for example, a ring gear (not shown) disposed on the outer periphery of the piston rod portion 41 and a transmission gear meshing with the ring gear, and the clutch 61, the speed reducer 62, and the torque limiter 63 are disposed on a transmission shaft 56 connected to the transmission gear.

[0115] The clutch 61 is arranged in the power transmission path for transmitting the power of the electric motor 51, and transmits the power to the cylinder connection module 100 and the arm connection module 200 in a manner that can be freely disconnected and connected. In the power transmission path, the clutch 61 is arranged, for example, in the front stage of the speed reducer 62 (in this embodiment, between the electric motor 51 and the speed reducer 62). By arranging the clutch 61 in this way, the transmission torque capacity of the clutch 61 can be reduced, and the clutch 61 can be miniaturized.

[0116] For example, an electromagnetic clutch, a mechanical clutch, or a torque diode can be applied to the clutch 61. These structures are well known and thus will be briefly described.

[0117] The electromagnetic clutch is a mechanical element that electromagnetically cuts off or transmits power from the input shaft to the output shaft. When the electromagnetic clutch is applied, the operation of the clutch 61 is controlled by, for example, the control device 70. In addition, when the operation of the clutch 61 is linked to the electric motor 51, it is not necessary to control the clutch 61 separately.

[0118] A mechanical clutch is a mechanical element that transmits power through the mutual meshing of an input shaft and an output shaft. In the case of a mechanical clutch, the clutch 61 is preferably a one-way clutch, which transmits power from the input shaft to the output shaft on the one hand, and cuts off the power from the output shaft to the input shaft on the other hand, and transmits power only in one direction.

[0119] A torque check piece is a mechanical element that transmits power from the input shaft to the output shaft on the one hand, and cuts off power from the output shaft to the input shaft on the other hand.

[0120] When a mechanical clutch and a torque one-way element are used, electrical control by the control device 70 or the like is not necessary.

[0121] The speed reducer 62 reduces the speed of the electric motor 51 and outputs the rotation. The speed reducer 62 is composed of, for example, a planetary gear mechanism housed in a speed reducer box (reference numerals omitted), and the input shaft and the output shaft extend in the X direction. By configuring the speed reducer 62 in this way, the pin insertion and extraction actuator 50 can be miniaturized in the Y direction and the Z direction.

[0122] The torque limiter 63 is an overload protection device, which is arranged in the power transmission path that transmits the power of the electric motor 51, so that the torque acting on the mechanical elements (for example, the electric motor 51) constituting the power transmission path is maintained below a specified value. For example, in the power transmission path, the torque limiter 63 is arranged at the rear stage of the reducer 62. By arranging the torque limiter 63 in this way, the influence of the tolerance and deviation of the torque setting value can be reduced compared to when it is arranged at the front stage of the reducer 62. In addition, for example, in the power transmission path, the torque limiter 63 can also be arranged at the front stage of the reducer 62. In this case, the torque setting value becomes smaller, so the torque limiter 63 can be miniaturized.

[0123] Furthermore, by driving the electric motor 51 all the time, the torque limiter 63 continues to slide, and a predetermined torque can be continuously provided to the cylinder connection module 100 and the arm connection module 200. Therefore, the torque limiter 63 can be used as a substitute for the brake 52 to maintain the withdrawal state of the cylinder connection module 100 and the arm connection module 200. In addition, the electric motor 51 is not in a locked state, so it does not generate heat due to overload.

[0124] The torque limiter 63 is, for example, a friction torque limiter which is attached to the output shaft of the clutch 61 (transmission shaft 56 of the transmission mechanism 53 ) and which causes the input side element and the output side element to slide and engage when a torque greater than a predetermined value is generated.

[0125] The position detection device 54 detects the displacement of the C pin 150 and the B pins 315 and 325 based on the output of the electric motor 51 (for example, the rotation of the output shaft). The position detection device 54 detects, for example, the displacement of the C pin 150 or the B pins 315 and 325 from the reference position (refer to Fig.17A as well as Fig.18A ) and the amount of movement (rotation angle).

[0126] The position detection device 54 is composed of an angle sensor such as a rotary encoder or a potentiometer, and outputs information (e.g., a pulse signal or a code signal) corresponding to the rotation amount of the output shaft of the electric motor 51. The rotary encoder detects and outputs the rotation displacement of the input shaft using a built-in encoder wheel. The potentiometer converts the change in the rotation angle into a change in the resistance value and outputs it.

[0127] The output method of the rotary encoder is not particularly limited, and can be either an incremental method that outputs a pulse signal (relative angle signal) corresponding to the rotation amount (rotation angle) from the measurement start position, or an absolute method that outputs a code signal (absolute angle signal) corresponding to the absolute angular position relative to a reference point.

[0128] When the position detection device 54 is configured as an absolute rotary encoder, the absolute positions of the C pin 150 and the B pins 315 and 325 can be detected even when the device is reset from the non-energized state to the energized state.

[0129] The position detection device 54 may be directly provided on the output shaft of the electric motor 51 , or may be provided on a rotating member (eg, a rotating shaft, a gear, etc.) that rotates together with the output shaft of the electric motor 51 .

[0130] In the present embodiment, the position detection device 54 is provided on the transmission shaft 56 at the rear stage (X direction + side) of the transmission mechanism 53 (torque limiter 63), and outputs information corresponding to the rotation amount of the transmission shaft 56. In this case, the position detection device 54 is preferably a rotary encoder capable of obtaining a sufficient resolution for the rotation speed (rotation speed) of the transmission shaft 56.

[0131] In addition, the toothless gear 110 for the C pin of the cylinder connection module 100 and the toothless gear 210 for the B pin of the arm connection module 200 are fixed on the transmission shaft 56, so it can also be said that the detection result of the position detection device 54 is information corresponding to the rotation amount of the toothless gear 110 for the C pin and the toothless gear 210 for the B pin.

[0132] In addition, the position detection device 54 is not limited to the above-mentioned rotary encoder, and may be composed of a limit switch or a proximity sensor, for example. The limit switch is arranged at a stage later than the reducer 62, and is mechanically operated based on the output of the electric motor 51. In addition, the proximity sensor is arranged at a stage later than the reducer 62, opposite to the rotating member that rotates based on the output of the electric motor 51, and outputs a detection signal based on the distance from the above-mentioned rotating member. The detection result of the position detection device 54 is output to the control device 70.

[0133] However, the proximity sensors and limit switches are provided at positions where the insertion and extraction states of the C pin 150 and the B pins 315 and 325 can be detected, and the number thereof needs to be at least the same as the number of the C pin 150 and the B pin rack bars 220A and 220B. In contrast, when a rotary encoder is used, the states of the C pin 150 and the B pins 315 and 325 can be detected by one detection sensor, thereby reducing the number of parts and achieving low cost.

[0134] In addition, the arrangement of the position detection device 54 is not limited to the present embodiment. For example, the position detection device 54 may be arranged at a stage before the speed reducer 62. That is, the position detection device 54 may also obtain information output to the control device 70 based on the rotation of the electric motor 51 before the speed reduction by the speed reducer 62. The position detection device 54 arranged at the stage before the speed reducer 62 can obtain a higher resolution than the position detection device 54 arranged at the stage after the speed reducer 62.

[0135] The control device 70 is, for example, an on-board computer, which has a CPU (Central Processing Unit) as a calculation / control device, a ROM (Read Only Memory) and a RAM (Random Access Memory) as main storage devices, input terminals, output terminals, etc. The control device 70 calculates information related to the position of the C pin 150 or the B pins 315 and 325 based on the output of the position detection device 54. In the calculation, data (table, map, etc.) indicating the correlation between the output of the position detection device 54 and the information related to the position of the C pin 150 and the B pins 315 and 325 (for example, the movement amount from the reference position) is used. This data is stored in, for example, the ROM.

[0136] The control device 70 determines whether the C pin 150 is in an engaged state with the C pin receiving portion 311 or 321 of the front arm 31 or the intermediate arm 32 by, for example, calculation based on the output of the position detection device 54 (for example, Figure 3A shown) or in a non-engaged state (e.g., Figure 4B The state shown in the figure), that is, the connection state of the pin insertion and extraction actuator 50 and the front end arm 31 or the intermediate arm 32 is determined.

[0137] In addition, when the telescopic object is the front arm 31, the control device 70 determines whether the B pin 315 of the front arm 31 and the intermediate arm 32 are in the engaged state through calculation based on the detection result of the position detection device 54 (see Figure 3A , Figure 3C etc.) or in a non-engaged state (refer to Figure 3B ), that is, to determine the connection state between the front end arm 31 and the intermediate arm 32. Similarly, when the telescopic object is the intermediate arm 32, the control device 70 determines the connection state between the intermediate arm 32 and the base end arm 33 by calculation based on the detection result of the position detection device 54.

[0138] Based on the calculation results, the control device 70 performs various controls on the pin insertion / extraction actuator 50, including, for example, operation controls of the electric motor 51, the brake 52, the clutch 61, etc. In addition, when performing various controls on the pin insertion / extraction actuator 50, for example, various sensors provided on the telescopic arm 30 and the telescopic actuator 40 may be used to obtain information indicating the state of the telescopic arm 30 or the telescopic actuator 40.

[0139] Reference Figure 11 to Figure 14 , explaining the cylinder connection module 100 and the arm connection module 200. Figure 11 to Figure 13 It is a diagram showing the internal structure of the pin inserting and extracting actuator 50 . Fig.14 It is a diagram schematically showing the structure of the pin inserting and extracting actuator 50 .

[0140] Figure 11 to Figure 14 Indicates a neutral state, in which the electric motor 51 is in a stopped state, and the cylinder connection module 100 and the arm connection module 200 are not in motion. In the neutral state, the cylinder connection module 100 and the arm connection module 200 are in an inserted state together. For example, the movement of the rack rod 120 for the C pin and the rack rods 220A and 220B for the B pin are mechanically restricted by a stopper (not shown) to maintain the neutral state. In addition, it can also be configured to maintain the neutral state by balancing the force applied by the C pin force mechanism 160 and the force applied by the B pin force mechanism 240.

[0141] in addition, Fig.15A , Fig. 15B Indicates the extracted state of the arm connection module 200 and the extracted state of the cylinder connection module 100. Fig.15A As shown, when the cylinder connection module 100 is in the withdrawn state, the arm connection module 200 remains in the inserted state. Fig. 15B As shown, when the arm connection module 200 is in the withdrawn state, the cylinder connection module 100 is maintained in the inserted state.

[0142] The oil cylinder connection module 100 is operated based on the power (i.e., rotational motion) of the electric motor 51, and in the inserted state (refer to Fig.11 ) and extracted state (refer to Fig.15A ) to transfer states.

[0143] The inserted state of the oil cylinder connection module 100 refers to the following state, that is, the C pin receiving portion 311, 321 of the front arm 31 or the intermediate arm 32 is engaged with the C pin 150, and the respective arm elements are connected to the pin insertion and extraction actuator 50. In this connected state, the front arm 31 and the intermediate arm 32 can move together with the oil cylinder portion 42 and the pin connection actuator 50 (refer to Figure 3B , Fig. 15B wait).

[0144] On the other hand, the withdrawn state of the cylinder connection module 100 refers to the state in which the C pin 150 is disengaged from the C pin receiving portion 311, 321 of the front arm 31 or the intermediate arm 32, and the respective arm elements and the pin connection actuator 50 are separated. In this non-connected state, the cylinder part 42 and the pin connection actuator 50 can be moved independently from the respective arm elements (see Figure 4B , Fig.15A wait).

[0145] The arm connection module 200 is operated based on the power (i.e., rotational motion) of the electric motor 51, and in the inserted state (see Fig.11 ) and extracted state (refer to Fig. 15B ) to transfer states.

[0146] The inserted state of the arm connection module 200 refers to the following state, that is, for example, the B pin 315 is inserted through the base end side B pin receiving portion 322 or the front end side B pin receiving portion 323 of the intermediate arm 32 to connect the front end arm 31 and the intermediate arm 32. In this connection state, the front end arm 31 cannot move relative to the intermediate arm 32 in the extension direction (see Figure 3A , Fig.15A wait).

[0147] On the other hand, the pulled-out state of the arm connection module 200 refers to a state in which, for example, the B pin 315 is disengaged from the base end side B pin receiving portion 322 or the front end side B pin receiving portion 323 of the intermediate arm 32, and the front end arm 31 and the intermediate arm 32 are separated. In this non-connected state, the front end arm 31 can move relative to the intermediate arm 32 in the extension direction (see Figure 3B , Fig. 15B wait).

[0148] like Figure 11 to Figure 14 As shown, the oil cylinder connection module 100 includes a C-pin toothless gear 110, a C-pin rack bar 120, a first gear group 130, a second gear group 140, a C-pin 150, and a C-pin urging mechanism 160. Each mechanical element 110 to 160 is an example of a component of the first connection mechanism. In the following description, the C-pin 150 is represented as "C-pin 150A, 150B" to distinguish it.

[0149] Furthermore, in the present embodiment, the pair of C pins 150A and 150B are incorporated in the cylinder connection module 100 , but the C pins 150A and 150B may be provided independently of the cylinder connection module 100 .

[0150] The C pin missing tooth gear 110 is a substantially circular plate-shaped gear, and a portion of the outer peripheral surface of the C pin missing tooth gear 110 has a tooth portion 111 (see Fig.12The C pin missing gear 110 is externally fixed to the transmission shaft 56 of the transmission mechanism 53 and rotates together with the transmission shaft 56. The C pin missing gear 110 and the B pin missing gear 210 of the arm connection module 200 together constitute the switch gear G (see Fig.14 The power of the electric motor 51 is selectively transmitted to one of the cylinder connection module 100 and the arm connection module 200 through the switch gear G.

[0151] In this embodiment, the C-pin missing tooth gear 110 and the B-pin missing tooth gear 210 that constitute the switch gear G are respectively assembled into the cylinder connection module 100 as the first connection mechanism and the arm connection module 200 as the second connection mechanism, but the switch gear G can also be set independently of the first connection mechanism and the second connection mechanism.

[0152] In addition, the switch gear G can play the role of the C pin missing tooth gear 110 and the B pin missing tooth gear 210, for example, Fig.14 As shown, it can also be composed of one missing tooth gear.

[0153] In the following description, the cylinder connection module 100 is in the inserted state (refer to Fig.11 ) to the withdrawn state (refer to Fig.15A ) when the state is transferred, the rotation direction of the C pin with the missing tooth gear 110 ( Fig.14 The R1 direction in the figure is called the "positive direction". When the state is transferred from the withdrawn state to the inserted state, the rotation direction of the C pin with the toothless gear 110 ( Fig.14 The R2 direction in the image is called the “reverse direction”.

[0154] Among the convex portions constituting the tooth portion 111 of the C-pin missing-tooth gear 110 , the convex portion provided at the positive end portion of the C-pin missing-tooth gear 110 is a positioning tooth (not shown).

[0155] The C-pin rack bar 120 is, for example, a shaft member extending in one direction, and is arranged along the Y direction on the lower side (Z direction − side) of the C-pin toothless gear 110 .

[0156] The surface of the C-pin rack rod 120 on the side close to the C-pin toothless gear 110 (Z direction + side) has an input side rack portion 121, and the surface of the C-pin rack rod 120C on the side away from the C-pin toothless gear 110 (Z direction - side) has two output side rack portions 122 and 123.

[0157] Only when the cylinder connection module 100 is inserted from the state (refer to Fig.11 ) to the withdrawn state (refer to Fig.15A ) When the state is transferred, the input side rack portion 121 meshes with the tooth portion 111 of the C-pin toothless gear 110.

[0158] Specifically, in the inserted state of the oil cylinder connection module 100, the first end surface (not shown) of the input side rack portion 121 on the positive side in the Y direction abuts against the positioning teeth (not shown) in the tooth portion 111 of the C pin toothless gear 110, or faces each other in the Y direction with a small gap. In this state, if the C pin toothless gear 110 rotates in the R1 direction, the positioning teeth press the first end surface to the positive side in the Y direction, and the C pin rack bar 120 moves to the positive side in the Y direction. In addition, the tooth portion 111 formed in the reverse direction relative to the positioning teeth sequentially meshes with the input side rack portion 121. Accordingly, as the C pin toothless gear 110 rotates in the R1 direction, the C pin rack bar 120 moves to the positive side in the Y direction.

[0159] In addition, from Fig.11 In the inserted state of the cylinder connection module 100 shown, when the C-pin toothless gear 110 rotates in the R2 direction, the input-side rack portion 121 does not mesh with the tooth portion 111 of the C-pin toothless gear 110 .

[0160] Thus, along with the rotation of the C-pin toothless gear 110, the C-pin rack bar 120 moves in its own longitudinal direction (Y direction). The C-pin rack bar 120 is located closest to the Y direction - side (refer to Fig.11 ), in the pulled-out state, it is located closest to the + side in the Y direction (refer to Fig.15A ).

[0161] That is, if the C-pin toothless gear 110 rotates in the R1 direction in the inserted state (neutral state) of the cylinder connection module 100, the C-pin rack bar 120 moves to the Y direction + side and transfers to the extracted state. On the other hand, if the C-pin toothless gear 110 rotates in the R2 direction in the extracted state of the cylinder connection module 100, the C-pin rack bar 120 moves to the Y direction - side and transfers to the inserted state.

[0162] The output-side rack portions 122 and 123 mesh with the first gear group 130 and the second gear group 140 , respectively.

[0163] The first gear train 130 includes, for example, a driving gear 131, an intermediate gear 132, and a driven gear 133. Each gear element is composed of a spur gear.

[0164] Specifically, the drive gear 131 meshes with the output-side rack portion 122 of the C-pin rack bar 120 and the intermediate gear 132. The intermediate gear 132 meshes with the drive gear 131 and the driven gear 133. The driven gear 133 meshes with the intermediate gear 132 and the pin-side rack portion 151 of one C pin 150A.

[0165] When the cylinder connection module 100 is in the inserted state, the driving gear 131 meshes with the end portion of the output side rack portion 122 of the C pin rack bar 120 on the + side in the Y direction or a portion close to the end portion. In addition, the driven gear 133 meshes with the end portion of the pin side rack portion 151 of one C pin 150A on the - side in the Y direction.

[0166] The second gear train 140 includes, for example, a driving gear 141 and a driven gear 142. Each gear element is composed of a spur gear.

[0167] Specifically, the driving gear 141 meshes with the output-side rack portion 123 of the C-pin rack bar 120 and the driven gear 142. The driven gear 142 meshes with the driving gear 141 and the pin-side rack portion 151 of the other C pin 150B.

[0168] When the cylinder connection module 100 is in the inserted state, the driving gear 141 meshes with the end portion of the output side rack portion 123 of the C pin rack bar 120 on the positive side in the Y direction or a portion close to the end portion. In addition, the driven gear 142 meshes with the end portion of the pin side rack portion 151 of the other C pin 150B on the positive side in the Y direction.

[0169] In the first gear group 130, the driving gear 131 and the driven gear 133 are connected via the intermediate gear 132, whereas in the second gear group 140, the driving gear 141 and the driven gear 142 are directly connected. Therefore, the rotation direction of the driven gear 133 in the first gear group 130 and the rotation direction of the driven gear 142 in the second gear group 140 are opposite.

[0170] The pair of C pins 150A and 150B are arranged coaxially with each other in the Y direction, for example. Preferably, the C pins 150A and 150B are symmetrical about the center of the piston rod 41 of the telescopic actuator 40. This can prevent bending stress from being generated in the piston rod 41 and reduce the dimension in the height direction (Z direction).

[0171] In addition, the C pins 150A and 150B can be arranged symmetrically in the telescopic direction (X direction), for example, they can be arranged at positions deviated from each other in the Z direction, or they can be set at an eccentric position relative to the piston rod portion 41 (for example, the Z direction - side of the piston rod portion 41).

[0172] In the following, the tip ends of the C pins 150A and 150B refer to the ends on the sides away from each other, and the base ends refer to the ends on the sides approaching each other.

[0173] The C pins 150A and 150B have a pin-side rack portion 151 on their outer circumferential surfaces. The pin-side rack portion 151 of one C pin 150A meshes with the driven gear 133 of the first gear train 130 , while the pin-side rack portion 151 of the other C pin 150B meshes with the driven gear 142 of the second gear train 140 .

[0174] The C pins 150A and 150B each move in their own axial direction (Y direction) along with the rotation of the driven gears 133 and 142. Specifically, the C pin 150A on one side moves to the - side of the Y direction when the cylinder connection module 100 changes state from the inserted state to the extracted state, and moves to the + side of the Y direction when the cylinder connection module 100 changes state from the extracted state to the inserted state. The C pin 150B on the other side moves to the + side of the Y direction when the cylinder connection module 100 changes state from the inserted state to the extracted state, and moves to the - side of the Y direction when the cylinder connection module 100 changes state from the extracted state to the inserted state. That is, in the above-mentioned state transition, the C pins 150A and 150B move in opposite directions in the Y direction.

[0175] The C-pin urging mechanism 160 urges the C-pins 150A and 150B in a direction away from each other. The C-pin urging mechanism 160 is composed of, for example, a pair of compression coil springs. In the present embodiment, the C-pin urging mechanism 160 is disposed on the base end side of the C-pins 150A and 150B and urges the C-pins 150A and 150B toward the tip end side.

[0176] When the electric motor 51 rotates in the R1 direction, the cylinder coupling module 100 is pulled out (see Fig.15A ), the electric motor 51 stops, and the oil cylinder connection module 100 is automatically reset to the inserted state by the force applied by the C pin force applying mechanism 160. However, when the brake 52 is in positive motion, the oil cylinder connection module 100 does not automatically reset to the inserted state, but remains in the withdrawn state.

[0177] In addition, the C-pin force applying mechanism 160 may directly apply force to the C-pins 150A and 150B, or may apply force through other components. In addition, the C-pin force applying mechanism 160 may be omitted, and the oil cylinder connection module 100 may be transferred from the withdrawn state to the inserted state based on the power of the electric motor 51. Even in this case, from the perspective of fault protection, it is preferable to provide the C-pin force applying mechanism 160 in the structure so as to reset to the insertion state on the safe side when the motor fails.

[0178] like Figure 11 to Figure 13 As shown, the arm connection module 200 includes a B pin toothless gear 210, a pair of B pin rack bars 220A, 220B, and a synchronous gear 230 (see Fig.14) and a force applying mechanism 240 for the B pin. Each mechanical element 210 to 240 is an example of a structural component of the second connection mechanism. In the following description, in order to distinguish the B pin 315, it is represented as "B pins 315A, 315B". In addition, the arm connection module 200 is described as acting on the B pin 315, but the same is true for the case where it acts on the B pin 325.

[0179] The B pin missing tooth gear 210 is a gear in the shape of a substantially circular wheel plate, and has a tooth portion 211 on a portion of the outer peripheral surface. The B pin missing tooth gear 210 is externally fixed to the transmission shaft 56 at a position closer to the + side in the X direction than the C pin missing tooth gear 110, and rotates together with the transmission shaft 56. As described above, the B pin missing tooth gear 210 and the C pin missing tooth gear 110 of the oil cylinder connection module 100 together constitute the switch gear G (refer to Fig.14 ).

[0180] In the following description, the arm connection module 200 is in the inserted state (refer to Fig.11 ) to the withdrawn state (refer to Fig. 15B ) The rotation direction of the B pin with missing teeth gear 210 when the state is transferred ( Fig.14 The R2 direction in the figure is called the “positive direction”, and the rotation direction of the B pin with the toothless gear 210 when the state is transferred from the pulled-out state to the inserted state ( Fig.14 The R1 direction in the image is called “reverse”.

[0181] Among the convex portions constituting the tooth portion 211 of the B pin missing-tooth gear 210 , the convex portion provided at the positive end portion of the B pin missing-tooth gear 210 is a positioning tooth (reference numeral omitted).

[0182] That is, the rotation direction R2 of the B-pin toothless gear 210 when the arm connection module 200 is transferred from the inserted state to the removed state is opposite to the rotation direction R1 of the C-pin toothless gear 110 when the cylinder connection module 100 is transferred from the inserted state to the removed state.

[0183] The pair of B-pin rack bars 220A and 220B are, for example, unidirectionally extending shaft members, and are arranged parallel to each other in the Y direction on the upper side (Z direction + side) of the B-pin toothless gear 110. In addition, the B-pin rack bars 220A and 220B are connected in the X direction by the synchronous gear 230 (see Fig.14 ) is the center configuration.

[0184] The B-pin rack bars 220A and 220B each have an engagement portion 221 that engages with the engagement piece 314a of the B-pin holding portion 314. The engagement piece 314a is provided at both ends of the B-pin holding portion 314 in the Y direction (near the B-pins 315A and 315B), for example.

[0185] The B-pin rack bar 220B has a driving side rack portion 222 on the surface close to the B-pin toothless gear 210. In addition, the B-pin rack bars 220A and 220B have synchronization side rack portions 223 on the surfaces facing each other in the X direction (see FIG. Fig.14 The synchronous side rack parts 223 are respectively meshed with the synchronous gears 230.

[0186] Only when the arm connection module 200 is removed from the inserted state (refer to Fig.11 ) to the withdrawn state (refer to Fig. 15B ) When the state is transferred, the driving side rack portion 222 meshes with the tooth portion 211 of the B pin toothless gear 210.

[0187] Specifically, in the inserted state of the arm connection module 200, the first end surface (not shown) of the driving side rack portion 222 on the positive side in the Y direction abuts against the positioning teeth (not shown) in the tooth portion 211 of the B pin toothless gear 210, or faces each other in the Y direction with a small gap therebetween. In this state, if the B pin toothless gear 210 rotates in the R2 direction, the positioning teeth press the first end surface to the positive side in the Y direction, and the B pin rack bar 220B on one side moves to the positive side in the Y direction.

[0188] When one B-pin rack bar 220B moves to the + side in the Y direction, the synchronization gear 230 rotates and the other B-pin rack bar 220A moves to the − side in the Y direction (ie, the opposite side to the B-pin rack bar 220B).

[0189] In addition, from Fig.11 In the inserted state of the arm connection module 200 shown, when the B-pin missing-tooth gear 210 rotates in the R1 direction, the driving-side rack portion 222 does not mesh with the tooth portion 211 of the B-pin missing-tooth gear 210 .

[0190] Thus, along with the rotation of the B pin toothless gear 210, the B pin rack bars 220A and 220B move in their own longitudinal direction (Y direction). The B pin rack bar 220B on one side is located closest to the Y direction - side (refer to Fig.11 ), in the pulled-out state, it is located closest to the + side in the Y direction (refer to Fig. 15B ). In addition, the other B-pin rack bar 220A is located closest to the positive side in the Y direction when the arm connection module 200 is inserted (see Fig.11 ), in the pulled-out state, it is located closest to the Y direction - side (refer to Fig. 15B ).

[0191] As the rack bar 220B for B pin moves in the Y direction, the locking piece 314a of the B pin holding portion 314 contacts the engagement portion 221 of the rack bar 220B for B pin. Furthermore, the member supporting the B pin 315B of the B pin holding portion 314 moves in the Y direction, so that the B pin 315B switches to the inserted state or the extracted state.

[0192] Similarly, as the other B-pin rack bar 220A moves in the Y direction, the other locking piece 314a of the B-pin holding portion 314 comes into contact with the engaging portion 221 of the B-pin rack bar 220A. Furthermore, the member supporting the B-pin 315A of the B-pin holding portion 314 moves in the Y direction, so that the B-pin 315A is transferred to the inserted state or the withdrawn state.

[0193] In the above-mentioned state transition, the B pins 315A and 315B move in opposite directions to each other in the Y direction.

[0194] Furthermore, movement of one B-pin rack bar 220B to the + side in the Y direction and movement of the other B-pin rack bar 220A to the − side in the Y direction are restricted by contact with a stopper (not shown) provided on the housing 58 , for example.

[0195] The B-pin urging mechanism 240 urges the B-pin rack bars 220A and 220B in a direction away from each other. The B-pin urging mechanism 240 is composed of, for example, a pair of compression coil springs. In the present embodiment, the B-pin urging mechanism 240 is built into the B-pin rack bars 220A and 220B, and urges the B-pin rack bars 220A and 220B toward the front end side.

[0196] When the electric motor 51 rotates in the R2 direction, the arm connection module 200 is pulled out (see Fig. 15B ), the action of the electric motor 51 stops, and the arm connection module 200 is automatically reset to the inserted state by the force applied by the B pin force applying mechanism 240 (refer to Fig.11 However, when the brake 52 is in positive operation, the arm connection module 200 does not automatically return to the inserted state but remains in the withdrawn state.

[0197] In addition, the B-pin force applying mechanism 240 may directly apply force to the B-pin rack rods 220A and 220B, or may apply force through other components. In addition, the B-pin force applying mechanism 240 may be omitted, and the arm connection module 200 may be transferred from the withdrawn state to the inserted state based on the power of the electric motor 51. Even in this case, from the perspective of fault protection, it is preferable to provide the B-pin force applying mechanism 240 in the structure so as to reset to the insertion state on the safe side when the motor fails.

[0198] The locking mechanism 55 can prevent the cylinder connection module 100 (for example, the rack bar 120 for the C pin) or the arm connection module 200 (for example, the rack bars 220A and 220B for the B pin) from being acted on by an external force other than the power from the electric motor 51, thereby preventing the cylinder connection module 100 and the arm connection module 200 from being simultaneously transferred to the withdrawn state. That is, the locking mechanism 55 prevents the operation of the other connection mechanism when at least one of the connection mechanisms of the arm connection module 200 and the cylinder connection module 100 is in operation.

[0199] Reference Figures 16A to 16C , explaining the locking mechanism 55. Fig.16A The figure shows the situation when the cylinder connection module 100 and the arm connection module 200 are in the inserted state (neutral position). Fig. 16B , Fig. 16C The arm connection module 200 is shown in FIG. 1 and FIG. 2 respectively when the arm connection module 200 is transferred from the inserted state to the extracted state. Figures 16A to 16C In FIG. 1 , the C-pin missing gear 110 of the cylinder connection module 100 and the B-pin missing gear 210 of the arm connection module 200 are shown as a switch gear G formed integrally.

[0200] like Fig.16A As shown in FIGS. 1 and 1 , the lock mechanism 55 includes a first convex portion 551 , a second convex portion 552 , and a cam member 553 (lock-side rotation member).

[0201] The first protrusion 551 is integrally provided on the C-pin rack bar 120 of the cylinder connection module 100. Specifically, the first protrusion 551 is provided at a position adjacent to the input-side rack portion 121 of the C-pin rack bar 120.

[0202] The second protrusion 552 is integrally provided on the rack bar 220B for B pins of the arm connection module 200. Specifically, the second protrusion 552 is provided at a position adjacent to the driving side rack portion 222 of the rack bar 220B for B pins.

[0203] The cam member 553 is a plate-like member having a substantially crescent shape and has a first cam receiving portion 553a at one end in the circumferential direction and a second cam receiving portion 553b at the other end.

[0204] The cam member 553 is externally fixed on the transmission shaft 56 at a position offset in the X direction from the position where the switch gear G is externally fixed. In the present embodiment, the cam member 553 is externally fixed between the C pin toothless gear 110 and the B pin toothless gear 210. That is, the cam member 553 is coaxially arranged with the switch gear G, and rotates with the transmission shaft 56 as the center axis together with the switch gear G as the transmission shaft 56 rotates.

[0205] In addition, the cam member 553 may be provided integrally with the switch gear G. In addition, the cam member 553 may be provided integrally with at least one of the C-pin missing-tooth gear 110 and the B-pin missing-tooth gear 210 .

[0206] like Fig. 16B As shown in FIG. 1 , when the tooth portion G1 of the switch gear G is meshed with the drive side rack portion 222 of the B pin rack bar 220B, the first cam receiving portion 553a of the cam member 553 is located closer to the positive side in the Y direction than the first convex portion 551. That is, the first cam receiving portion 553a and the first convex portion 551 are opposed to each other with a small gap in the Y direction. In this state, even if an external force ( Fig. 16B The external force Fa) acts on the C-pin rack rod 120 toward the + side of the Y direction and is also absorbed by the gap.

[0207] If a larger external force Fa is applied to the C-pin rack bar 120 toward the + side in the Y direction, the C-pin rack bar 120 moves from Fig. 16B In this state, the first protrusion 551 abuts against the first cam receiving portion 553a, and the C-pin rack bar 120 is prevented from moving to the positive side in the Y direction.

[0208] In addition, if Fig. 16C As shown in FIG. 1 , when the tooth portion G1 of the switch gear G is meshed with the input side rack portion 121 of the C pin rack bar 120, the second cam receiving portion 553b of the cam member 553 is located closer to the positive side in the Y direction than the second convex portion 552. That is, the second cam receiving portion 553b and the second convex portion 552 are opposed to each other with a small gap in the Y direction. In this state, even if an external force (positive side in the Y direction) is applied to the B pin rack bar 220B, the positive side in the Y direction will be Fig. 16C The external force Fb) in the gap will also be absorbed by the gap.

[0209] If a larger external force Fb is applied to the B-pin rack bar 220B toward the + side in the Y direction, the B-pin rack bar 220B moves from Fig. 16C The position indicated by the two-dot chain line in the middle moves to the position indicated by the solid line toward the + side in the Y direction. In this state, the second protrusion 552 abuts against the second cam receiving portion 553b, and the B-pin rack bar 220B is prevented from moving toward the + side in the Y direction.

[0210] <Operation of the Cylinder Connection Module 100 and the Arm Connection Module 200>

[0211] Reference Figures 17A to 17C as well as Figures 18A to 18C , an example of the operation of the cylinder connection module 100 and the arm connection module 200 will be described. Figures 17A to 17C as well as Figures 18A to 18CThe operation shown is, for example, an operation of pulling out the cylinder connection module 100 and the arm connection module 200 when the front arm 31 is extended.

[0212] Hereinafter, the rotation of the electric motor 51 when the arm connection module 200 is transferred from the inserted state to the extracted state is referred to as “forward rotation”, and the rotation of the electric motor 51 when the cylinder connection module 100 is transferred from the inserted state to the extracted state is referred to as “reverse rotation”.

[0213] Figures 17A to 17C It is a schematic diagram for explaining the operation of the cylinder connection module 100 . Figures 17A to 17C 1 shows the operation of the cylinder connection module 100 when it is transferred from the inserted state to the withdrawn state. Figures 17A to 17C In FIG. 1 , the C pin missing tooth gear 110 and the B pin missing tooth gear 210 are shown as an integrally formed switch gear G. Figures 17A to 17C In the embodiment, the locking mechanism 55 is omitted.

[0214] like Fig.17A As shown, in the contracted state before the front arm 31 is extended, the cylinder connection module 100 is in a neutral state. That is, the C pin 150 is engaged with the C pin receiving portion 311 of the arm 31, and the front arm 31 and the cylinder connection module 100 are in a connected state.

[0215] When the cylinder connection module 100 is shifted from the inserted state to the withdrawn state, the power of the electric motor 51 is transmitted to the C pins 150A and 150B via the following first and second paths.

[0216] The first path is the C pin missing tooth gear 110 → the C pin rack bar 120 → the first gear group 130 → one C pin 150A. The second path is the C pin missing tooth gear 110 → the C pin rack bar 120 → the second gear group 140 → the other C pin 150B.

[0217] like Fig. 17B As shown in FIG. 1 , if the electric motor 51 is reversed, the C pin gear 110 rotates in the R1 direction. As the C pin gear 110 rotates, the C pin rack bar 120 moves to the + side in the Y direction ( Figures 17A to 17C Along with this, in the first path, through the first gear group 130, one C pin 150A moves to the Y direction - side ( Figures 17A to 17C In the second path, the other C pin 150B moves to the + side (in the Y direction) through the second gear group 140. Figures 17A to 17C That is, when the cylinder connection module 100 is transferred from the inserted state to the withdrawn state, the C pin 150A on one side and the C pin 150B on the other side are displaced in a direction approaching each other.

[0218] Finally, if Fig. 17C As shown, the C pins 150A and 150B are completely separated from the C pin receiving portion 311, and the cylinder connection module 100 is disconnected from the front arm 31. The cylinder connection module 100 automatically transitions from the withdrawn state to the inserted state based on the urging force of the C pin urging mechanism 160.

[0219] Figures 18A to 18C It is a schematic diagram for explaining the operation of the arm connection module 200 . Figures 18A to 18C 2 shows the operation of the arm connection module 200 when it is transferred from the inserted state to the pulled-out state. Figures 18A to 18C In FIG. 1 , the C pin missing tooth gear 110 and the B pin missing tooth gear 210 are shown as an integrally formed switch gear G. Figures 18A to 18C In the embodiment, the locking mechanism 55 is omitted.

[0220] like Fig.18A As shown, in the contracted state before the front arm 31 is extended, the cylinder connection module 100 and the arm connection module 200 are in a neutral state. That is, the front arm 31 is connected to the intermediate arm 32 by the B pin 315 and cannot move relative to the intermediate arm 32 in the extension direction.

[0221] When the arm connection module 200 changes state from the inserted state to the pulled-out state, the power of the electric motor 51 is transmitted via the B-pin toothless gear 210 → one B-pin rack bar 220B → the synchronous gear 230 → the other B-pin rack bar 220A.

[0222] like Fig.18B As shown in FIG. 1 , if the electric motor 51 rotates forward, the B pin toothless gear 210 rotates in the R2 direction. As the B pin toothless gear 210 rotates, the B pin rack bar 220B on one side moves to the + side in the Y direction ( Figures 18A to 18C In addition, the synchronous gear 230 rotates, and the B pin on the other side receives the rotation of the synchronous gear 230 and moves to the - side in the Y direction ( Figures 18A to 18C That is, when the arm connection module 200 is transferred from the inserted state to the withdrawn state, the B-pin rack bar 220B on one side and the B-pin rack bar 220A on the other side are displaced in a direction toward each other. Accordingly, the B-pin holding portion 314 connected to the B-pin rack bars 220A and 220B also contracts, and the B-pin 315 held in the B-pin holding portion 314 is slowly pulled out from the B-pin receiving portion 322.

[0223] Finally, if Fig. 18CAs shown, the B pins 315A and 315B are completely separated from the B pin receiving portion 322, and the front arm 31 and the intermediate arm 32 are in a disconnected state. The arm connection module 200 automatically transitions from the withdrawn state to the inserted state based on the urging of the B pin urging mechanism 240.

[0224] <Control during telescopic movement>

[0225] Fig.19 1 is a timing diagram showing an example of control of the telescopic arm 30 during the extension operation. For simplicity, the case of extending the front arm 31 from the fully retracted state is described. In addition, the insertion state and the withdrawal state of the B pin 315 correspond to the insertion state and the withdrawal state of the arm connection module 200, and the insertion state and the withdrawal state of the C pin 150 correspond to the insertion state and the withdrawal state of the cylinder connection module 100. The switching of the electric motor 51, the brake 52 and the clutch 61 to ON (start) / OFF (close) is controlled by the control device 70.

[0226] Fig.19 The interval T0 to T1 in the figure is the contracted state at the initial stage of the extension operation, and the cylinder connection module 100 and the arm connection module 200 are in the neutral state (refer to Fig.17A , Fig.18A That is, the front arm 31 is connected to the intermediate arm 32 via the B pin 315 and cannot move in the extension direction relative to the intermediate arm 32. In addition, the C pin 150 is engaged with the C pin receiving portion 311 of the front arm 31, and the front arm 31 and the cylinder portion 42 are in a connected state.

[0227] The states of the mechanical elements in the interval T0 to T1 are as follows.

[0228] Electric motor 51: OFF

[0229] Clutch 61: OFF

[0230] Brake 52: OFF

[0231] C pin 150 (cylinder connection module 100): inserted

[0232] B pin 315 (arm connection module 200): inserted

[0233] When the control device 70 receives the operator's extension operation of the telescopic arm 30 (timing T1), the clutch 61 is controlled to be in the ON state (connected state), and the electric motor 51 is rotated forward. The B pin 315 gradually shifts from the inserted state to the withdrawn state.

[0234] The states of the mechanical elements in the interval T1 to T2 are as follows.

[0235] Electric motor 51: ON (start)

[0236] Clutch 61: ON (start)

[0237] Brake 52: OFF

[0238] C pin 150 (cylinder connection module 100): inserted

[0239] B pin 315 (arm connection module 200): inserted state → extracted state (extracting action)

[0240] At this time, if the B pin 315 is hooked on the base end side B pin receiving portion 322 of the intermediate arm 32 and is difficult to be pulled out, the rotating elements in the power transmission path from the electric motor 51 to the arm connection module 200 cannot rotate smoothly, resulting in overload. In addition, a large current flows through the electric motor 51, which may cause heat or burnout.

[0241] In this embodiment, the torque limiter 63 is arranged on the power transmission path, and the load applied to the mechanical elements in the power transmission path is kept below a predetermined value, thereby preventing damage to the mechanical elements caused by the difficulty in withdrawing the B pin 315 when withdrawing the B pin 315.

[0242] The control device 70 determines the state of the B pin 315 based on the detection result of the position detection device 54, and if the B pin 315 is transferred to the withdrawn state (timing T2), the clutch 61 is maintained in the ON (start) state to stop the electric motor 51. In addition, the brake 52 is turned on (start) to maintain the withdrawn state of the B pin 315.

[0243] The timing of turning off the electric motor 51 and turning on the brake 52 are appropriately controlled by the control device 70. For example, by turning off the electric motor 51 after turning on the brake 52, the pulled-out state of the B pin 315 can be reliably maintained.

[0244] At timing T2, the B pin 315 is completely separated from the base end side B pin receiving portion 322, and the front end arm 31 and the intermediate arm 32 are in a non-connected state. Although not shown in the figure, in the interval T2 to T3, the control device 70 controls the telescopic actuator 40 to move the cylinder part 42 in the extension direction. Along with this, the front end arm 31 connected to the cylinder part 42 through the cylinder connection module 100 moves in the extension direction.

[0245] The states of the mechanical elements in the interval T2 to T3 are as follows.

[0246] Electric motor 51: OFF

[0247] Clutch 61: ON (start)

[0248] Brake 52: ON (start)

[0249] C pin 150 (cylinder connection module 100): inserted

[0250] B pin 315 (arm connection module 200): pulled out

[0251] When the front end arm 31 moves to a predetermined position and becomes extended (timing T3), the control device 70 controls the clutch 61 and the brake 52 to be OFF. The arm connection module 200 is reset to the neutral state by the force applied by the B pin force applying mechanism 240. Along with this, the B pin 315 is transferred from the withdrawn state to the inserted state and is inserted through the front end side B pin receiving portion 323.

[0252] The states of the mechanical elements in the interval T3 to T4 are as follows.

[0253] Electric motor 51: OFF

[0254] Clutch 61: OFF

[0255] Brake 52: OFF

[0256] C pin 150 (cylinder connection module 100): inserted

[0257] B pin 315 (arm connection module 200): pulled out state → inserted state (insertion action)

[0258] In this way, during the insertion of the B pin 315, the B pin urging mechanism 240 is used to reset to the neutral state. In this case, if the power transmission path from the electric motor 51 to the arm connection module 200 is connected, the electric motor 51 rotates in the opposite direction to the rotation direction during the withdrawal action along with the insertion of the B pin 315. In addition, the rotating elements including the electric motor 51 will not stop at the neutral position due to the inertial force, and there is a possibility that the thrust that causes the switch gear G to rotate in the direction of withdrawing the C pin 150 may be generated due to overrunning.

[0259] In this regard, in the present embodiment, the clutch 61 is disposed in the power transmission path, and when the B pin urging mechanism 240 is reset to the neutral state, the power transmission from the arm connection module 200 to the electric motor 51 is cut off. Therefore, it is possible to prevent the C pin 150 from temporarily shifting to the withdrawn state during the insertion operation of the B pin 315, thereby preventing the operation from becoming unstable.

[0260] When the B pin 315 is completely engaged with the front end B pin receiving portion 323 (timing T4), the control device 70B transfers the C pin 150 to the withdrawn state in order to return the telescopic actuator 40 to the contracted state. That is, at timing T5, the control device 70 controls the clutch 61 to the ON (started) state (connected state) and reverses the electric motor 51. The C pin 150 gradually transfers from the inserted state to the withdrawn state.

[0261] The states of the mechanical elements in the interval T5 to T6 are as follows.

[0262] Electric motor 51: ON (start)

[0263] Clutch 61: ON (start)

[0264] Brake 52: OFF

[0265] C pin 150 (cylinder connection module 100): inserted state → extracted state (extraction action)

[0266] B pin 315 (arm connection module 200): inserted

[0267] At this time, if the C pin 150 is hooked on the C pin receiving portion 311 of the front arm 31 and is difficult to be pulled out, the rotating elements in the power transmission path from the electric motor 51 to the cylinder connection module 100 cannot rotate smoothly, resulting in overload. In addition, a large current flows through the electric motor 51, which may cause heat or burnout.

[0268] In this embodiment, the torque limiter 63 is disposed on the power transmission path, and the load applied to the mechanical elements in the power transmission path is kept below a predetermined value, thereby preventing damage to the mechanical elements caused by the difficulty in withdrawing the C pin 150 during withdrawal.

[0269] The control device 70 determines the state of the C pin 150 based on the detection result of the position detection device 54, and if the C pin 150 is transferred to the withdrawn state (timing T6), the clutch 61 is maintained in the ON (activated) state to stop the electric motor 51. In addition, the brake 52 is turned on (activated) to maintain the withdrawn state of the C pin 150.

[0270] At timing T6, the C pin 150 is completely separated from the C pin receiving portion 311 of the front arm 31, and the cylinder connection module 100 is disconnected from the front arm 31. Although not shown in the figure, in the interval T6 to T7, the control device 70 controls the telescopic actuator 40 to move the cylinder part 42 in the contraction direction. At this time, the cylinder part 42 is in a state of being disconnected from the front arm 31, the intermediate arm 32, and the base arm 33, so the cylinder part 42 moves alone in the contraction direction.

[0271] The states of the mechanical elements in the interval T6 to T7 are as follows.

[0272] Electric motor 51: OFF

[0273] Clutch 61: ON (start)

[0274] Brake 52: ON (start)

[0275] C pin 150 (cylinder connection module 100): pulled out

[0276] B pin 315 (arm connection module 200): inserted

[0277] When the telescopic actuator 40 is in the contracted state (timing T7), the control device 70 controls the clutch 61 and the brake 52 to the OFF state. The hydraulic cylinder connection module 100 is reset to the neutral state by the force applied by the C pin force applying mechanism 160. Along with this, the C pin 150 is transferred from the withdrawn state to the inserted state and is engaged with the C pin receiving portion 321 of the intermediate arm 32. In addition, the B pin holding portion 324 of the intermediate arm 32 is engaged with the B pin rack bars 220A and 220B.

[0278] The states of the mechanical elements in the interval T7 to T8 are as follows.

[0279] Electric motor 51: OFF

[0280] Clutch 61: OFF

[0281] Brake 52: OFF

[0282] C pin 150 (cylinder connection module 100): withdrawn state → inserted state (insertion action)

[0283] B pin 315 (arm connection module 200): inserted

[0284] In this way, during the insertion of the C pin 150, the C pin urging mechanism 160 is used to reset to the neutral state. In this case, if the power transmission path from the electric motor 51 to the oil cylinder connection module 100 is connected, the electric motor 51 rotates in the opposite direction to the rotation direction during the withdrawal action along with the insertion of the C pin 150. In addition, the rotating elements including the electric motor 51 will not stop at the neutral position due to the inertial force, and there is a possibility that the thrust that causes the switch gear G to rotate in the direction of withdrawing the B pin 325 may be generated due to overrunning.

[0285] In this regard, in the present embodiment, a clutch 61 is disposed in the power transmission path, and when the C-pin urging mechanism 160 is reset to the neutral state, the power transmission from the cylinder connection module 100 to the electric motor 51 is cut off. Therefore, it is possible to prevent the B pin 325 from temporarily shifting to the withdrawn state during the insertion operation of the C-pin 150, thereby preventing the operation from becoming unstable.

[0286] When the C pin 150 is completely engaged with the C pin receiving portion 321 of the intermediate arm 32 (timing T8), the neutral state is maintained. When the intermediate arm 32 is extended, the same operation as above is performed. When the front end arm 31 or the intermediate arm 32 is contracted, the operation in the opposite direction to the above is performed.

[0287] Here, usually, lubricating oil is applied to the mechanical elements constituting the pin insertion and extraction actuator 50 so that the extraction and insertion of the B pin 315 and the C pin 150 can be smoothly performed. In this case, if the viscosity of the lubricating oil increases due to the ambient temperature or aging, it may hinder the insertion and extraction of the B pin 315 and the C pin 150. In particular, the insertion of the B pin 315 and the C pin 150 is performed by applying force, so there is a risk that the high-viscosity lubricating oil will become resistance and the action time will become unstable.

[0288] Therefore, in this embodiment, when the C pin 150 is reset to the inserted state due to the urging of the C pin urging mechanism 160 and when the B pin 315 is reset due to the urging of the B pin urging mechanism 240 , the control device 70C performs motor assist processing to activate the electric motor 51 .

[0289] Fig. 20 It is a timing chart for explaining the extension operation of the telescopic arm 30 to which the motor assist process is applied.

[0290] like Fig. 20 As shown, when the B pin 315 is inserted in the interval T3 to T4, the control device 70 reverses the electric motor 51 for a short time (for example, 0.01 to 0.5 seconds). In addition, when the C pin 150 is inserted in the interval T7 to T8, the control device 70 forwards the electric motor 51. According to this, the state where the C pin 150 or the B pin 315 becomes difficult to move due to the viscosity of the lubricating oil is released by the power of the electric motor 51, and the subsequent reset to the neutral state by the force applied by the C pin force mechanism 160 or the B pin force mechanism 240 can be smoothly performed.

[0291] The motor-assisted processing may be always performed during the insertion of the B pin 315 and the C pin 150, or may be performed only when a specified condition is satisfied. The specified condition includes the ambient temperature (e.g., below -10°C), the usage time, etc. In addition, the operator may manually set whether to perform the motor-assisted processing. In addition, the motor-assisted processing may be selectively performed on the B pin 315 and the C pin 150.

[0292] Furthermore, the control device 70 can determine the start timing and driving time of the electric motor 51 in the motor assist process according to the ambient temperature. Thus, since the appropriate motor assist process is performed, it is possible to prevent the generation of thrust in the direction of pulling away the C pin 150 or the B pins 315, 325 due to overrunning.

[0293] Thus, the mobile crane 1 (working machine) according to the present embodiment comprises: a telescopic arm 30 having a first arm (e.g., a front arm 31) and a second arm (e.g., an intermediate arm 32) overlapped in a telescopic manner; a telescopic actuator 40 for moving the first arm in a telescopic direction relative to the second arm; an electric motor 51 (electrical drive source) provided in a cylinder portion 42 (movable portion) of the telescopic actuator 40; a C pin 150 (a first fixed pin) for connecting the telescopic actuator 40 and the first arm; a C pin urging mechanism 160 (a first urging mechanism) for urging the C pin 150 to maintain the connection state between the telescopic actuator 40 and the first arm; and a cylinder connection mechanism 100 (a first connection mechanism) for operating by power based on the electric motor 51 to insert and remove the C pin 150, thereby cutting The telescopic actuator 40 switches the connection state and the non-connection state with the first arm; the B pins 315 and 325 (the second fixed pins) connect the first arm and the second arm; the B pin force mechanism 240 (the second force mechanism) applies force to the second fixed pins 315 and 325 to maintain the connection state of the first arm and the second arm; the arm connection module 200 (the second connection mechanism) is actuated based on the power of the electric motor 51 to insert and remove the B pins 315 and 325, thereby switching the connection state and the non-connection state of the first arm and the second arm; and the clutch 61 is arranged in the power transmission path from the electric motor 51 to the cylinder connection module 100 and the arm connection module 200, and transmits the power of the electric motor 51 to the cylinder connection module 100 and the arm connection module 200 in a manner that can be freely disconnected and connected.

[0294] Specifically, the clutch 61 cuts off the power of the electric motor 51 (electric drive source) at least when the C pin 150 (first fixed pin) is reset by the force of the C pin force mechanism 160 (first force mechanism) and / or when the B pins 315, 325 (second fixed pin) are reset by the force of the B pin force mechanism 240 (second force mechanism).

[0295] According to the mobile crane 1, the cylinder connection module 100 and the arm connection module 200 are both electric, so there is no need to provide a hydraulic circuit in the internal space of the telescopic arm 30 as in the conventional structure. Therefore, the space originally used for the hydraulic circuit can be effectively utilized, and the degree of freedom in the design of the internal space of the telescopic arm 30 is increased.

[0296] In addition, a clutch 61 is arranged in the power transmission path. Since the power transmission from the cylinder connection module 100 or the arm connection module 200 to the electric motor 51 is cut off when the C-pin force mechanism 160 or the B-pin force mechanism 240 is used to reset to the neutral state, it is possible to prevent the B pin 315, 325 or the C pin 150 from temporarily shifting to the withdrawal state during the insertion action of the C pin 150 or the B pin 315, 325, thereby preventing the action from becoming unstable.

[0297] Therefore, according to the mobile crane 1, it is possible to improve the degree of freedom in designing the periphery of the telescopic boom 30 and the reliability when the boom is extended or retracted.

[0298] The mobile crane 1 also includes a speed reducer 62 that reduces the driving speed of the electric motor 51 (electrical drive source) and outputs the speed, and the clutch 61 is disposed between the electric motor 51 and the speed reducer 62. This can reduce the transmission torque capacity of the clutch 61 and make the clutch 61 compact.

[0299] In the mobile crane 1, the clutch 61 is composed of an electromagnetic clutch, a mechanical clutch, or a torque one-way element. According to this, the transmission / interruption of the power from the electric motor 51 can be easily switched by appropriately selecting from general clutches as needed.

[0300] As mentioned above, the invention made by the present inventors has been specifically described based on the embodiments. However, the present invention is not limited to the above-mentioned embodiments, and can be modified within the scope not departing from the gist thereof.

[0301] For example, the electric motor 51 may be a hollow motor having a hollow stator arranged on the inside and a rotor arranged on the outside, which is arranged on the outer periphery of the piston rod portion 41, and the transmission gear (not shown) of the transmission mechanism 53 meshes with the gear provided on the rotor.

[0302] The arrangement of the electric motor 51 shown in the embodiment is an example, and the electric motor 51 may be arranged so that the output shaft (not shown) extends in the Y direction or the Z direction.

[0303] The electric motor 51 is not limited to a rotary motor, and a linear motor (a direct-acting actuator) that outputs a linear motion can also be applied.

[0304] In addition, the working machine according to the present invention is not limited to a mobile crane, and can also be applied to other working machines (for example, an aerial work vehicle) equipped with a telescopic arm.

[0305] The embodiments disclosed this time are illustrative in all respects and should not be construed as limiting. The scope of the present invention is indicated by the claims rather than the above description, and includes all modifications within the meaning and scope equivalent to the claims.

[0306] The disclosure contents of the specification, drawings, and abstract contained in Japanese application No. 2019-151521 filed on August 21, 2019 are incorporated herein by reference in their entirety.

[0307] Description of Reference Numerals

[0308] 1 Mobile crane (working machine)

[0309] 30 Telescopic arm

[0310] 31 Front arm

[0311] 311 C pin receiving part

[0312] 314 B pin retaining part

[0313] 315, 315A, 315B B pin

[0314] 32 Intermediate arm

[0315] 321 C pin receiving part

[0316] 322 Base end side B pin receiving portion

[0317] 323 Front end side B pin receiving part

[0318] 324 B pin retaining part

[0319] 325 B pin

[0320] 33 Base arm

[0321] A Telescopic device

[0322] 40 Telescopic actuator

[0323] 41 Piston rod

[0324] 42 Cylinder part (movable part)

[0325] 50-pin plug-in / plug-out actuator

[0326] 51 Electric motor (electrical drive source)

[0327] 52 Brake

[0328] 53 Transmission mechanism

[0329] 54 Position detection device

[0330] 55 Locking mechanism

[0331] 56 Transmission shaft

[0332] 61 Clutch

[0333] 62 reducer

[0334] 63 Torque limiter

[0335] 100 Cylinder connection module (1st connection mechanism)

[0336] 110 C pin with missing teeth gear

[0337] 120 C pin rack rod

[0338] 130 1st gear set

[0339] 140 2nd gear set

[0340] 150, 150A, 150B C pin

[0341] 160 C pin force applying mechanism (first force applying mechanism)

[0342] 200 Arm connection module (second connection mechanism)

[0343] 210 B pin with missing teeth gear

[0344] 220A, 220B B pin rack rod

[0345] 230 Synchronous gear

[0346] 240 B pin force applying mechanism (second force applying mechanism)

Claims

1. A working machine comprising: A telescopic arm having a first arm and a second arm that overlap in a telescopic manner; an actuator for extension and retraction, causing the first arm to move relative to the second arm in an extension and retraction direction; An electrical drive source, provided at a movable portion of the telescopic actuator; a first fixing pin connecting the telescopic actuator and the first arm; a first urging mechanism for urging the first fixing pin to maintain a connection state between the telescopic actuator and the first arm; a first connection mechanism that operates based on the power of the electric drive source to insert and remove the first fixing pin, thereby switching the connection state and non-connection state between the telescopic actuator and the first arm; a second fixing pin connecting the first arm and the second arm; a second urging mechanism for urging the second fixing pin to maintain the connection between the first arm and the second arm; a second connection mechanism that operates based on the power of the electric drive source to insert and remove the second fixing pin, thereby switching the connection state and the non-connection state between the first arm and the second arm; as well as The clutch is disposed in a power transmission path from the electric drive source to the first connection mechanism and the second connection mechanism, and transmits the power of the electric drive source to the first connection mechanism and the second connection mechanism in a manner that can be freely disconnected and connected.

2. The working machine according to claim 1, wherein: The clutch cuts off the power of the electric drive source at least when the first fixing pin is returned to its original position by the urging force of the first urging mechanism and / or when the second fixing pin is returned to its original position by the urging force of the second urging mechanism.

3. The working machine according to claim 1 or 2, wherein: The working machine includes a speed reducer that reduces the driving speed of the power of the electric drive source and outputs the power of the electric drive source. The clutch is arranged between the electric drive source and the speed reducer.

4. The working machine according to claim 1, wherein: The clutch is composed of an electromagnetic clutch, a mechanical clutch or a torque one-way member.

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