Work machinery

Abstract

To provide a work machine capable of reducing the movable space of a steering operation device.SOLUTION: A steering operation device 42 is operated to drive a steering actuator by an operator. The steering operation device 42 includes a joystick 43 and a first electric lever 60. The joystick 43 receives the operation by the operator. The first electric lever 60 has a first body part 61, and a first lever part 62 capable of inclining to the first body part 61. The first electric lever 60 outputs the inclination angle of the first lever part 62 to the first body part 61. The joystick 43 and the first body part 61 integrally take action.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to work machines. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2020-26230 (Patent Document 1) discloses a steering device for operating an articulated work vehicle. The joystick lever is configured to be rotatable relative to a base member or a support. A lever angle sensor detects the angle of the joystick lever relative to the support. A body frame angle sensor detects the rotation angle of the front frame relative to the rear frame. A controller controls an electromagnetic pilot valve based on the detected values ​​of the lever angle sensor and the body frame angle sensor. The electromagnetic pilot valve adjusts the pilot oil pressure supplied to the hydraulic valve. The hydraulic valve adjusts the flow rate of oil supplied to the steering cylinder according to the input pilot oil pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-26230 Summary of the Invention [Problem to be solved by the invention]

[0004] Steering operation devices that use an electric lever to detect joystick operation instead of a pilot valve that supplies pilot oil pressure to a hydraulic valve are being devised. An electric signal corresponding to the joystick operation is output from the electric lever to a controller, and the controller controls the steering actuator in response to the received electric signal.

[0005] The wires connected to the steering operation device can be deformed by joystick operation, and it is necessary to provide a space for movement for these wires. It is therefore desirable to reduce this space in order to reduce the size of the steering operation device.

[0006] The present disclosure proposes a work machine that can reduce the movable space of a steering operation device. [Means for solving the problem]

[0007] A work machine according to the present disclosure includes a body frame, a steering actuator, and a steering operation device. The body frame has a rear frame and a front frame rotatably connected to the rear frame. The steering actuator changes the angle of the front frame relative to the rear frame. The steering operation device is operated by an operator to operate the steering actuator. The steering operation device includes a joystick and at least one electric lever. The joystick accepts operations by the operator. The electric lever has a main body portion and a lever portion that is tiltable relative to the main body portion. The electric lever outputs the tilt angle of the lever portion relative to the main body portion. The joystick and the main body portion operate integrally. [Effects of the Invention]

[0008] According to the work machine of the present disclosure, it is possible to reduce the movable space of the steering operation device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a wheel loader as an example of a work machine based on an embodiment. FIG. [Figure 2] FIG. 2 is a perspective view showing the structure around the driver's seat in the cab. [Figure 3] FIG. 1 is a schematic plan view of a wheel loader in a bent state. [Figure 4]3 is a schematic diagram showing a link mechanism that transmits the current vehicle body bending angle to a steering operation device. FIG. [Figure 5] FIG. 2 is a perspective view showing the configuration of a steering operation device. [Figure 6] 10A and 10B are perspective views of the joystick from different angles. [Figure 7] FIG. 2 is a cross-sectional view of a steering operation device. [Figure 8] FIG. 2 is a plan view of the steering operation device. [Figure 9] FIG. 2 is a front view of the steering operation device with the joystick in a neutral position. [Figure 10] FIG. 2 is a front view of the steering operation device with the joystick tilted to the left. [Figure 11] FIG. 2 is a front view of the steering operation device with the joystick tilted to the right. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed description thereof will not be repeated.

[0011] <Overall configuration of wheel loader 1> In the embodiment, a wheel loader 1 will be described as an example of a work machine. Fig. 1 is a side view of a wheel loader 1 as an example of a work machine based on the embodiment.

[0012] As shown in Fig. 1, the wheel loader 1 comprises a body frame 2, a work implement 3, a traveling device, a cab 5, and an engine hood 6. The body frame 2, the cab 5, etc. make up the body (work machine body) of the wheel loader 1. The work implement 3 and the traveling device are attached to the body of the wheel loader 1.

[0013] The traveling gear allows the body of the wheel loader 1 to travel, and includes the traveling wheels 4, 7. The wheel loader 1 is a wheeled vehicle equipped with the traveling wheels 4, 7 as rotating bodies for traveling on both the left and right sides of the body. The wheel loader 1 is self-propelled by driving the traveling wheels 4, 7 to rotate, and can perform desired work such as excavating and loading earth and sand using the work implement 3.

[0014] In this specification, the direction in which the wheel loader 1 travels straight ahead is referred to as the fore-and-aft direction of the wheel loader 1. In the fore-and-aft direction of the wheel loader 1, the side on which the work implement 3 is arranged relative to the body frame 2 is referred to as the front direction, and the side opposite the front direction is referred to as the rear direction. The left-and-right direction of the wheel loader 1 is the direction perpendicular to the fore-and-aft direction when the wheel loader 1 is viewed from above on flat ground. Looking forward, the right and left sides of the left-and-right direction are the right direction and the left direction, respectively. The up-and-down direction of the wheel loader 1 is the direction perpendicular to the plane defined by the fore-and-aft direction and the left-and-right direction. In the up-and-down direction, the side with the ground is the bottom side, and the side with sky is the top side.

[0015] In the drawings, the X direction indicated by a double-headed arrow in Fig. 1 is the front-to-back direction. The XF direction is the front direction, and the XR direction is the rear direction. The Y direction shown in the drawings described later is the left-to-right direction. The YL direction is the left direction, and the YR direction is the right direction.

[0016] The body frame 2 includes a front frame 11 and a rear frame 12. The front frame 11 is disposed in front of the rear frame 12. The front frame 11 is connected to the rear frame 12 so as to be able to bend. The front frame 11 is rotatably connected to the rear frame 12 by a connecting shaft 13. The connecting shaft 13, which forms the center of rotation of the front frame 11 relative to the rear frame 12, is an axis that extends in the vertical direction. The connecting shaft 13 is provided in the center of the body frame 2 in the left-right direction. The front frame 11 and the rear frame 12 form the body frame 2 with an articulated structure. The wheel loader 1 is an articulated work machine in which the front frame 11 and the rear frame 12 are connected.

[0017] The front frame 11 and the rear frame 12 are connected by a steering actuator 21. The steering actuator 21 is disposed across the front frame 11 and the rear frame 12. A base end of the steering actuator 21 is attached to the rear frame 12. A tip end of the steering actuator 21 is attached to the front frame 11. A pair of steering actuators 21 are provided, one on the left and one on the right. The steering actuators 21 are disposed side by side on both sides in the left-right direction with the connecting shaft 13 between them.

[0018] As the steering actuator 21 extends and retracts, the front frame 11 moves left and right relative to the rear frame 12 around the connecting shaft 13. The steering actuator 21 is, for example, a hydraulic actuator. The steering actuator 21 is, for example, a hydraulic cylinder. The steering actuator 21 rotates the front frame 11 relative to the rear frame 12. As the steering actuator 21 extends and retracts, the bending angle of the front frame 11 relative to the rear frame 12 changes.

[0019] A work implement 3 and a pair of left and right running wheels (front wheels) 4 are attached to the front frame 11. The work implement 3 is disposed at the front of the vehicle body and is supported by the vehicle body of the wheel loader 1. The work implement 3 includes a boom 14 and a bucket 15. The bucket 15 is disposed at the tip of the work implement 3. The bucket 15 is a working tool for excavating and loading.

[0020] The work implement 3 includes boom cylinders 16. The front frame 11 and the boom 14 are connected by a pair of boom cylinders 16. The base end of the boom cylinder 16 is attached to the front frame 11. The tip of the boom cylinder 16 is attached to the boom 14. The boom cylinder 16 is a hydraulic actuator that moves the boom 14 up and down relative to the front frame 11. As the boom 14 moves up and down, the bucket 15 attached to the tip of the boom 14 also moves up and down.

[0021] The work implement 3 further includes a bell crank 18, a connecting link 19, and a bucket cylinder 17. The bell crank 18 is rotatably supported on the boom 14 at approximately the center of the boom 14. The bucket cylinder 17 connects the bell crank 18 to the front frame 11. The connecting link 19 is connected to the tip of the bell crank 18. The connecting link 19 connects the bell crank 18 to the bucket 15.

[0022] The base end of the bucket cylinder 17 is attached to the front frame 11. The tip end of the bucket cylinder 17 is attached to the base end of a bell crank 18. The bucket cylinder 17 is a hydraulic actuator that moves the bucket 15 up and down relative to the boom 14. The bucket cylinder 17 is an implement cylinder that drives the bucket 15. The bucket 15 is configured to be movable relative to the boom 14. The bucket 15 is configured to be movable relative to the front frame 11.

[0023] An engine hood 6, a cab 5 in which the operator sits, and a pair of left and right running wheels (rear wheels) 7 are attached to the rear frame 12. The engine hood 6 is provided behind the cab 5. The engine hood 6 houses a hydraulic oil tank, an engine, a hydraulic pump, an air cleaner, etc.

[0024] The box-shaped cab 5 is disposed behind the work implement 3. The cab 5 is placed on the body frame 2. The cab 5 is mounted on the rear frame 12. The cab 5 defines an interior space for the operator. A door is provided on the left side of the cab 5, which is opened and closed when the operator enters and leaves the cab 5.

[0025] Fig. 2 is a perspective view showing the structure around the driver's seat 31 inside the cab 5. Inside the cab 5, there are arranged the driver's seat 31 where the operator sits, and operating devices that are operated by the operator to operate the wheel loader 1. The driver's seat 31 is provided in an interior space defined by the cab 5. The operator sits in the driver's seat 31 in the cab 5 to operate the wheel loader 1. As shown in Fig. 2, the driver's seat 31 has a seat cushion 33, a seat back 32, a headrest 34, and a suspension mechanism section 35.

[0026] The seat cushion 33 is provided lying horizontally. The seat cushion 33 is the seat portion on which the operator sits. The seat back 32 is provided so as to rise upward from the rear end of the seat cushion 33. The seat back 32 is the seat portion against which the operator rests. The headrest 34 is attached to the upper end of the seat back 32. The headrest 34 is the seat portion that supports the operator's head.

[0027] The suspension mechanism 35 is provided between the floor surface of the cab 5 and the seat cushion 33 in the vertical direction. The suspension mechanism 35 supports the seat cushion 33 elastically.

[0028] A right armrest 36 and a right console 37 are arranged inside the cab 5. The right armrest 36 and the right console 37 are provided on the right side of the driver's seat 31. A work implement operation lever 38, a dial device 39 and the like are provided on the right console 37. The work implement operation lever 38 is operated to control the operation of the work implement 3. The dial device 39 is operated to control the travel of the wheel loader 1. The dial device 39 may be a vehicle speed limit dial that is operated to specify the maximum vehicle speed at which the wheel loader 1 will travel.

[0029] A left armrest 40 and a left console 41 are arranged inside the cab 5. The left armrest 40 and the left console 41 are provided on the left side of the driver's seat 31. The left console 41 is provided between the driver's seat 31 and the door of the cab 5 in the left-right direction. The right console 37 and the left console 41 are provided higher than the seat cushion 33. The right armrest 36 and the left armrest 40 are provided higher than the seat cushion 33. The right armrest 36 and the left armrest 40 have cushioning material made of urethane foam or the like, and are used as armrests for the operator.

[0030] The left console 41 is provided in front of the left armrest 40. A steering operation device 42 is provided on the left console 41. The steering operation device 42 is disposed inside the cab 5. The steering operation device 42 is disposed on the left side of the driver's seat 31. The steering operation device 42 is operated by an operator seated in the cab 5 to rotate the front frame 11 and the rear frame 12. The steering operation device 42 is operated by an operator seated in the driver's seat 31 to operate the steering actuator 21.

[0031] The steering operation device 42 includes a joystick 43. The joystick 43 protrudes upward from the top surface of the left console 41. The joystick 43 has a lever shape. The joystick 43 receives operation from the operator. The operator holds the joystick 43 in his left hand and tilts it left or right to set the angle of bending of the front frame 11 relative to the rear frame 12.

[0032] FIG. 3 is a schematic plan view of the wheel loader 1 in a bent state. The front frame 11 is bent relative to the rear frame 12 by extending and retracting the steering actuator 21 connected to the front frame 11 and rear frame 12. The vehicle body bending angle shown in FIG. 3 is the angle at which the front frame 11 is bent relative to the rear frame 12. When the wheel loader 1 is traveling straight, the vehicle body bending angle is 0 degrees. When one of the left and right steering actuators 21 extends and the other contracts, the vehicle body bending angle becomes an angle greater than 0 degrees. The front frame 11 is bent relative to the rear frame 12 shown in FIG. 3 by the right steering actuator 21 extending and the left steering actuator 21 contracting.

[0033] 4 is a schematic diagram showing a link mechanism that transmits the current vehicle body bending angle to the steering operation device 42. The link mechanism includes a first link member 91 and a second link member 92.

[0034] The first link member 91 and the second link member 92 are rod-shaped members. The front end of the second link member 92 is rotatably connected to a bracket fixed to the front frame 11. The rear end of the second link member 92 and the front end of the first link member 91 are rotatably connected. The rectangle connecting the connecting shaft portion 13, the front end of the second link member 92, the rear end of the second link member 92, and the rear end of the first link member 91 is a parallelogram, and a parallel link is formed. A mechanical link mechanism connects the front frame 11 to the steering operation device 42 inside the cab 5.

[0035] <Configuration of the steering operation device 42> The configuration of the steering operation device 42 of the embodiment will be described in detail below. Fig. 5 is a perspective view showing the configuration of the steering operation device 42. Fig. 6 is a perspective view of the joystick 43 viewed from a different angle. Fig. 7 is a cross-sectional view of the steering operation device 42. Fig. 8 is a plan view of the steering operation device 42.

[0036] The operator operates the joystick 43 to tilt left and right (Y direction). By tilting the joystick 43 to the right (YR direction), the body frame 2 is set to bend so that the front frame 11 tilts rightward relative to the rear frame 12. By tilting the joystick 43 to the left (YL direction), the body frame 2 is set to bend so that the front frame 11 tilts leftward relative to the rear frame 12. The angle of the front frame 11 relative to the rear frame 12 is set according to the angle of tilt of the joystick 43 from the neutral state.

[0037] The joystick 43 has a knob section 44 at its tip. A switch section 45 that is operated by the operator's finger is provided on the knob section 44. The switch section 45 includes, for example, a horn operation button 46 that is pressed to sound the horn. The switch section 45 includes, for example, a speed stage changeover switch 47 that is operated to change the transmission speed stage when the wheel loader 1 is traveling. The speed stage changeover switch 47 has a shift-up button 47U that is pressed to shift up the transmission speed stage, and a shift-down button 47D that is pressed to shift down the transmission speed stage. The switch section 45 includes, for example, a forward / reverse changeover switch 48 that is operated to switch the travel of the wheel loader 1 between forward, reverse, and neutral.

[0038] The steering operation device 42 includes a knob electric wire 49. The knob electric wire 49 extends from the inside to the outside of the joystick 43. One end of the knob electric wire 49 is electrically connected to the switch unit 45. The knob electric wire 49 corresponds to an example of a first electric wire.

[0039] The steering operation device 42 includes a support portion 50. The support portion 50 supports the joystick 43 so that the joystick 43 is movable relative to the support portion 50. The support portion 50 is attached to the left console 41. The joystick 43 rotates relative to the left console 41. A fixing clamp 58 is fixed to the support portion 50.

[0040] The steering operation device 42 includes two electric levers (steering switches). Specifically, the steering operation device 42 includes a first electric lever 60 and a second electric lever 65.

[0041] The first electric lever 60 includes a first main body 61 and a first lever 62 that is tiltable relative to the first main body 61. The first lever 62 has a first core 63C that protrudes from the first main body 61 and a first spacer 63S that surrounds the first core 63C. One end of a first lever electric wire 64 is connected to the first main body 61. The first lever electric wire 64 corresponds to an example of a second electric wire. The first electric lever 60 has a sensor that detects the tilt angle of the first lever 62 relative to the first main body 61. The first electric lever 60 outputs an electric signal that indicates the tilt angle of the first lever 62 relative to the first main body 61 to the outside via the first lever electric wire 64.

[0042] The second electric lever 65 includes a second main body 66 and a second lever 67 that is tiltable relative to the second main body 66. The second lever 67 has a second core 68C that protrudes from the second main body 66 and a second spacer 68S that surrounds the second core 68C. One end of a second lever electric wire 69 is connected to the second main body 66. The second lever electric wire 65 corresponds to an example of a second electric wire. The second electric lever 65 has a sensor that detects the tilt angle of the second lever 67 relative to the second main body 66. The second electric lever 65 outputs an electric signal that indicates the tilt angle of the second lever 67 relative to the second main body 66 to the outside via the second lever electric wire 69.

[0043] The first core portion 63C and the second core portion 68C are made of, for example, a metal material. The first spacer 63S and the second spacer 68S are made of, for example, a metal material.

[0044] The steering operation device 42 includes a movable part 70. When the operator tilts the joystick 43, the movable part 70 moves integrally with the joystick 43 relative to the support part 50. The movable part 70 mainly has a base part 71, a flange part 72, a sleeve part 73, a holding part 74, and a movable clamp 78.

[0045] A first connector 75 is provided on the base portion 71. The first lever electric wire 64 is connected to the first connector 75. A second connector 76 is provided on the base portion 71. The second lever electric wire 69 is connected to the second connector 76.

[0046] The holding portion 74 holds the first body portion 61 of the first electric lever 60 and the second body portion 66 of the second electric lever 65. The first body portion 61 of the first electric lever 60 and the second body portion 66 of the second electric lever 65 move integrally with the movable portion 70. Therefore, the first body portion 61 and the second body portion 66 move integrally with the joystick 43 as the operator tilts the joystick 43. The first body portion 61 and the second body portion 66 rotate relative to the left console 41.

[0047] The first lever electric wire 64 and the second lever electric wire 69 are inserted into the electric wire sleeve 79 and wired through the electric wire sleeve 79. The movable clamp 78 bundles the knob electric wire 49 and the electric wire sleeve 79. The movable clamp 78 bundles the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69. Similarly, the fixed clamp 58 bundles the knob electric wire 49 and the electric wire sleeve 79, and bundles the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69.

[0048] In the path of the knob wire 49, the movable clamp 78 bundles the knob wire 49, the first lever wire 64, and the second lever wire 69 at a position closer to the joystick 43 than the fixed clamp 58. In the path of the first lever wire 64, the movable clamp 78 bundles the knob wire 49, the first lever wire 64, and the second lever wire 69 at a position closer to the first electric lever 60 than the fixed clamp 58. In the path of the second lever wire 69, the movable clamp 78 bundles the knob wire 49, the first lever wire 64, and the second lever wire 69 at a position closer to the second electric lever 65 than the fixed clamp 58.

[0049] The flange portion 72 is fixed to the base portion 71 and to the base end of the joystick 43. The flange portion 72 has a plate-like shape and has a through-hole that penetrates through it in the thickness direction, as shown in Fig. 7. The sleeve portion 73, the frame portion 80, and the transmission member 96 are arranged within the through-hole of the flange portion 72.

[0050] The frame portion 80 is attached to the left console 41. The frame portion 80 has a general hollow cylindrical shape. A cylindrical shaft-shaped transmission member 96 is inserted inside the frame portion 80. The inner bearing 82 supports the transmission member 96 rotatably relative to the frame portion 80. An inner ring of the inner bearing 82 is attached to the outer peripheral surface of the transmission member 96, and an outer ring of the inner bearing 82 is attached to the inner peripheral surface of the frame portion 80.

[0051] One end of the transmission member 96 (the right end in FIG. 7) is connected to the first link member 91 shown in FIG. 4. A mechanical link mechanism is configured that connects the front frame 11 to the steering operation device 42 via the second link member 92, the first link member 91, and the transmission member 96. Via this link mechanism, the current angle of the front frame 11 relative to the rear frame 12, i.e., the current vehicle body bending angle (FIG. 3), is mechanically transmitted from the front frame 11 to the steering operation device 42. The transmission member 96 corresponds to an example of a link.

[0052] The sleeve portion 73 is disposed on the outer periphery of the cylindrical frame portion 80. The outer bearing 81 supports the sleeve portion 73 rotatably relative to the frame portion 80. The inner ring of the outer bearing 81 is attached to the outer periphery of the frame portion 80, and the outer ring of the outer bearing 81 is attached to the sleeve portion 73.

[0053] The joystick 43, flange portion 72, and sleeve portion 73 are configured to operate integrally. The joystick 43 is rotatable relative to the frame portion 80. The transmission member 96 is rotatable relative to the frame portion 80. The joystick 43 and the transmission member 96 are rotatable independently relative to the frame portion 80. Rotation of the joystick 43 relative to the frame portion 80 does not affect the operation of the transmission member 96. Furthermore, rotation of the transmission member 96 relative to the frame portion 80 does not affect the operation of the joystick 43. The outer bearing 81 supports the joystick 43 so that it can rotate relatively to the transmission member 96.

[0054] The transmission member 96 is disposed so as to pass through the connecting portion 100. The transmission member 96 is disposed so that the other end of the transmission member 96 (the left end in FIG. 7 ) abuts against the input portion 110. A bolt 97 passes through the input portion 110 and is fixed to the transmission member 96. The transmission member 96 and the input portion 110 are fitted together and connected together by the bolt 97. A bolt 98 fits between the input portion 110 and the connecting portion 100, thereby further strengthening the connection between the input portion 110 and the transmission member 96.

[0055] In the cross-sectional view shown in FIG. 7, the input unit 110 has an L-shape. The L-shaped input unit 110 has a first side extending in the up-down direction (the up-down direction in FIG. 7) and a second side extending in the front-rear direction (the X direction; the left-right direction in FIG. 7). The first side of the input unit 110 is connected to the transmission member 96 by a bolt 97. Two elongated holes 111 and 112 are formed in the second side of the input unit 110. The elongated holes 111 and 112 are formed so as to penetrate the plate-shaped input unit 110 in the thickness direction. Referring also to FIG. 8, the elongated holes 111 and 112 extend in the front-rear direction (the X direction). The elongated holes 111 and 112 extend in a direction perpendicular to the left-right direction (the Y direction), which is the direction in which the operator tilts the joystick 43.

[0056] The first lever portion 62 of the first electric lever 60 is disposed in the elongated hole 111. The second lever portion 67 of the second electric lever 65 is disposed in the elongated hole 112. The steering operation device 42 has two electric levers (the first electric lever 60 and the second electric lever 65). Two elongated holes 111, 112, the same number as the number of electric levers, are formed in the input portion 110. The lever portions of each electric lever are disposed in different elongated holes.

[0057] The first electric lever 60 and the second electric lever 65 are arranged side by side in the front-to-back direction (X direction), which is a direction perpendicular to the left-to-right direction (Y direction) in which the operator tilts the joystick 43. The first electric lever 60, the second electric lever 65, and the joystick 43 are arranged side by side in this order in the front-to-back direction (X direction). The first electric lever 60 and the second electric lever 65 are arranged away from the joystick 43 in the front-to-back direction (X direction).

[0058] In the plan view from above shown in Fig. 8, the slots 111 and 112 have an elongated shape with a longitudinal direction in the front-rear direction (X direction) and a lateral direction in the left-right direction (Y direction). The peripheries of the slots 111 and 112 shown in Fig. 8 are closed curves.

[0059] The distance between the outer peripheral surface of the first lever portion 62 (first spacer 63S) and the periphery of the elongated hole 111 is maximum in the front-rear direction (X direction) and minimum in the left-right direction (Y direction). The distance between the first lever portion 62 (first spacer 63S) and the periphery of the elongated hole 111 in the front-rear direction (X direction) is greater than the distance between the first lever portion 62 (first spacer 63S) and the periphery of the elongated hole 111 in the left-right direction (Y direction).

[0060] The distance between the outer peripheral surface of the second lever portion 67 (second spacer 68S) and the periphery of the elongated hole 112 is maximum in the front-rear direction (X direction) and minimum in the left-right direction (Y direction). The distance between the second lever portion 67 (second spacer 68S) and the periphery of the elongated hole 112 in the front-rear direction (X direction) is greater than the distance between the second lever portion 67 (second spacer 68S) and the periphery of the elongated hole 112 in the left-right direction (Y direction).

[0061] The peripheries of the long holes 111, 112 do not necessarily have to be closed curves. The long holes 111, 112 may be long, narrow gaps extending in the front-to-rear direction (X direction). The long hole 111 may extend to the edge of the input section 110 and open to the edge of the input section 110. The long hole 112 may extend to the edge of the input section 110 and open to the edge of the input section 110. The long holes 111 and 112 may be connected to each other.

[0062] The first spacer 63S of the first lever portion 62 has a hollow cylindrical shape. The second spacer 68S of the second lever portion 67 has a hollow cylindrical shape. The first spacer 63S and the second spacer 68S extend in the up-down direction. The first spacer 63S passes through the elongated hole 111. The second spacer 68S passes through the elongated hole 112. The first spacer 63S and the second spacer 68S pass through the plate-shaped input portion 110 in the thickness direction. The axial lengths of the first spacer 63S and the second spacer 68S are greater than the thickness of the plate-shaped input portion 110.

[0063] <Steering operation of wheel loader 1> The operation of changing the direction of travel of the traveling wheel loader 1 by operating the steering operation device 42 described above to change the bending angle of the vehicle body of the wheel loader 1 (FIG. 3) will be described below.

[0064] When an operator seated in the driver's seat 31 tilts the joystick 43 to the left or right at his / her hand, the first body part 61 of the first electric lever 60 and the second body part 66 of the second electric lever 65 tilt to the left or right together with the joystick 43.

[0065] Meanwhile, the transmission member 96 rotates with the longitudinal direction (X direction) as its axis in accordance with the current vehicle body bending angle. The input unit 110, which is connected to the transmission member 96, moves left and right integrally with the transmission member 96 as the transmission member 96 rotates. Slots 111 and 112 are formed in the input unit 110. The first lever unit 62 is disposed in the slot 111. The second lever unit 67 is disposed in the slot 112. The input unit 110, which moves left and right, presses the first lever unit 62 and the second lever unit 67 left and right. The input unit 110 inputs the current vehicle body bending angle, transmitted by the transmission member 96, to the first lever unit 62 and the second lever unit 67. By pressing the first lever unit 62, the input unit 110 changes the angle at which the first lever unit 62 is inclined relative to the first main body unit 61. The input portion 110 changes the angle at which the second lever portion 67 is inclined relative to the second main body portion 66 by pressing the second lever portion 67 .

[0066] Both the tilt angle of the joystick 43 from the neutral state and the current vehicle body bending angle are mechanically input to the first electric lever 60 and the second electric lever 65. By tilting the joystick 43 from the neutral state, the first body portion 61 of the first electric lever 60 and the second body portion 66 of the second electric lever 65 move left and right together with the joystick 43, changing the tilt angle of the first lever portion 62 relative to the first body portion 61 and changing the tilt angle of the second lever portion 67 relative to the second body portion 66. The input unit 110 presses the first lever portion 62 of the first electric lever 60 and the second lever portion 67 of the second electric lever 65 left and right in accordance with the current vehicle body bending angle, changing the tilt angle of the first lever portion 62 relative to the first body portion 61 and changing the tilt angle of the second lever portion 67 relative to the second body portion 66.

[0067] When the set angle of the front frame 11 relative to the rear frame 12 by operating the joystick 43 differs from the current angle of the front frame 11 relative to the rear frame 12 fed back to the steering operation device 42, the first lever portion 62 is positioned at an incline relative to the first main body portion 61, and the second lever portion 67 is positioned at an incline relative to the second main body portion 66. An electric signal indicating the inclination angle of the first lever portion 62 relative to the first main body portion 61 is output to the outside via the first lever electric wire 64. An electric signal indicating the inclination angle of the second lever portion 67 relative to the second main body portion 66 is output to the outside via the second lever electric wire 69.

[0068] These electrical signals are input to a controller (not shown). In response to the input electrical signals, the controller generates a control signal that commands the angle of the front frame 11 relative to the rear frame 12. The controller outputs this control signal to the steering actuator 21 to control the steering actuator 21. More specifically, the controller extends and contracts the left and right steering actuators 21 so as to bring the vehicle body bending angle closer to the set angle of the front frame 11 relative to the rear frame 12.

[0069] For example, when the wheel loader 1 is traveling straight ahead, the angle of the front frame 11 relative to the rear frame 12 is zero degrees, and at this time the input portion 110 does not tilt the first lever portion 62 or the second lever portion 67 left or right.

[0070] From this state, when the operator tilts the joystick 43 to the right, the first body portion 61 of the first electric lever 60 and the second body portion 66 of the second electric lever 65 move integrally with the joystick 43. Because it takes time for the steering actuator 21 to move in response to the operation of the joystick 43, the angle of the front frame 11 relative to the rear frame 12 remains at zero degrees. The angle of tilt of the joystick 43 from the neutral state is the angle difference between the current angle of the front frame 11 relative to the rear frame 12 and the set angle of the front frame 11 relative to the rear frame 12. The angle of tilt of the joystick 43 from the neutral state is the tilt angle of the first lever portion 62 relative to the first body portion 61, and the tilt angle of the second lever portion 67 relative to the second body portion 66.

[0071] The controller receives the electrical signals indicating these tilt angles and extends the left steering actuator 21 and contracts the right steering actuator 21, bending the front frame 11 to the right relative to the rear frame 12. This changes the body bending angle of the wheel loader 1. The body bending angle increases from zero degrees and approaches the set angle of the front frame 11 relative to the rear frame 12.

[0072] The current vehicle body bending angle is fed back to the steering operation device 42 via a mechanical link mechanism. When the front frame 11 bends to the right relative to the rear frame 12 and the vehicle body bending angle changes, the input unit 110 presses the first lever portion 62 and the second lever portion 67, causing the first lever portion 62 and the second lever portion 67 to tilt to the right. The tilt angle of the first lever portion 62 relative to the first main body portion 61 decreases, and the tilt angle of the second lever portion 67 relative to the second main body portion 66 decreases.

[0073] Control is performed to adjust the amount of extension and contraction of the steering actuator 21 until the vehicle body bending angle becomes equal to the set angle of the front frame 11 relative to the rear frame 12.

[0074] When the vehicle body bending angle becomes equal to the set angle of the front frame 11 relative to the rear frame 12, the first lever portion 62 stops tilting relative to the first main body portion 61, and the second lever portion 67 stops tilting relative to the second main body portion 66. The tilt angle of the first lever portion 62 relative to the first main body portion 61 output from the first electric lever 60 becomes zero, and the tilt angle of the second lever portion 67 relative to the second main body portion 66 output from the second electric lever 65 becomes zero. Upon receiving these electrical signals indicating a tilt angle of zero, the controller stops the extension and contraction of the steering actuator 21 and maintains the extension and contraction amount of the steering actuator 21 at that time. This stops the bending movement of the front frame 11 relative to the rear frame 12, and the vehicle body bending angle is maintained at the set angle.

[0075] Fig. 9 is a view from the front of the steering operation device 42 with the joystick 43 in a neutral state. Fig. 10 is a view from the front of the steering operation device 42 with the joystick 43 tilted to the left (YL direction). Fig. 11 is a view from the front of the steering operation device 42 with the joystick 43 tilted to the right (YR direction).

[0076] The joystick 43 can be tilted left or right by the operator. The support part 50 is fixed to the left console 41 and does not move even when the joystick 43 is tilted. The joystick 43 moves relative to the support part 50. The first body part 61 of the first electric lever 60 and the second body part 66 of the second electric lever 65 move integrally with the joystick 43.

[0077] The knob electric wire 49 is electrically connected to a switch portion 45 (FIG. 6) provided on the knob portion 44 at the tip of the joystick 43, and extends from the inside to the outside of the joystick 43. The knob electric wire 49 moves relative to the support portion 50 as the joystick 43 tilts left or right. The electric wire sleeve 79 accommodates a first lever electric wire 64 connected to the first main body portion 61 of the first electric lever 60, and a second lever electric wire 69 connected to the second main body portion 66 of the second electric lever 65. The first lever electric wire 64 moves relative to the support portion 50 as the first main body portion 61 moves left or right. The second lever electric wire 69 moves relative to the support portion 50 as the second main body portion 66 moves left or right.

[0078] The joystick 43, the first main body 61, and the second main body 66 are configured to operate integrally. The knob electric wire 49 connected to the joystick 43, the first lever electric wire 64 connected to the first main body 61, and the second lever electric wire 69 connected to the second main body 66 form the same movement system. As shown in Figs. 9 to 11, the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69 move in the same manner.

[0079] The portions of the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69 between the portion bound by the fixed clamp 58 and the portion bound by the movable clamp 78 move left and right significantly. The movement of other portions of the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69 is relatively small. The movable space that needs to be secured for the movement of the knob electric wire 49, the first lever electric wire 64, and the second lever electric wire 69 only needs to be large enough to accommodate the movement of the portions between the portion bound by the fixed clamp 58 and the portion bound by the movable clamp 78. This makes it possible to reduce the movable space.

[0080] <Action and effect> Although some of the description overlaps with the above description, the characteristic configuration and effects of the work machine of this embodiment can be summarized as follows.

[0081] 5, 7 and 8, the steering operation device 42 includes a joystick 43 and a first electric lever 60. The joystick 43 receives an operation from the operator to set the angle of the front frame 11 relative to the rear frame 12 of the wheel loader 1. The first electric lever 60 has a first main body portion 61 and a first lever portion 62 that can be tilted relative to the first main body portion 61. The first electric lever 60 outputs the tilt angle of the first lever portion 62 relative to the first main body portion 61. The joystick 43 and the first main body portion 61 operate integrally.

[0082] If the joystick 43 and the first main body 61 move independently, two separate moving spaces are required for these separate movements, resulting in a large moving space being required. However, by moving the joystick 43 and the first main body 61 integrally, it is possible to combine the moving spaces into one. Therefore, the moving space of the steering operation device 42 can be reduced.

[0083] As shown in FIG. 6, the joystick 43 has a switch unit 45 that is operated by the operator's finger. As shown in FIGS. 5 to 7, the steering operation device 42 includes a knob electric wire 49 that is electrically connected to the switch unit 45 and extends from the inside to the outside of the joystick 43, and a first lever electric wire 64 that has one end connected to a first main body 61 of a first electric lever 60. By operating the joystick 43 and the first main body 61 together, the knob electric wire 49 and the first lever electric wire 64 can be made to be in the same movement system. As shown in FIGS. 9 to 11, the knob electric wire 49 and the first lever electric wire 64 can be made to move in the same way. Since the movement spaces for the movements of the knob electric wire 49 and the first lever electric wire 64 can be unified into one, the movement space of the steering operation device 42 can be reduced.

[0084] 5, and 9 to 11, the steering operation device 42 includes a clamp that bundles the knob electric wire 49 and the first lever electric wire 64. Because the knob electric wire 49 and the first lever electric wire 64 are in the same movement system and move in the same way, it is possible to bundle both the knob electric wire 49 and the first lever electric wire 64 at the same clamp position. This allows the configuration of the steering operation device 42 to be simplified.

[0085] 5, 7 to 11, the steering operation device 42 includes a support part 50 that supports the joystick 43 so that it can move relatively. As shown in FIGS. 5, 9 to 11, the clamp that binds the knob electric wire 49 and the first lever electric wire 64 includes a fixed clamp 58 and a movable clamp 78. The fixed clamp 58 is fixed to the support part 50. The movable clamp 78 moves relatively to the support part 50 together with the joystick 43 as the operator tilts the joystick 43.

[0086] The fixed clamp 58 bundles the knob electric wire 49 and the first lever electric wire 64 and fixes them to the support part 50, and the movable clamp 78 bundles the knob electric wire 49 and the first lever electric wire 64 at a position separated from the fixed clamp 58. By bundling the knob electric wire 49 and the first lever electric wire 64 with clamps at two locations, the movable spaces of the knob electric wire 49 and the first lever electric wire 64 can be reliably combined into one.

[0087] 5, and 9 to 11, in the path of the knob electric wire 49, the movable clamp 78 bundles the knob electric wire 49 and the first lever electric wire 64 at a position closer to the joystick 43 than the fixed clamp 58. By arranging the fixed clamp 58 and the movable clamp 78 in this way, the movable space for the movement of the knob electric wire 49 and the first lever electric wire 64 is defined in the portion between the movable clamp 78 and the fixed clamp 58. This makes it possible to clearly define the position of the movable space that needs to be secured.

[0088] As shown in FIG. 7 , the transmission member 96 mechanically transmits the current angle of the front frame 11 relative to the rear frame 12 to the steering operation device 42. The steering operation device 42 includes an input unit 110. The input unit 110 is connected to the transmission member 96. The input unit 110 inputs the current vehicle body bending angle transmitted by the transmission member 96 to the first lever unit 62 of the first electric lever 60. Operation of the joystick 43 by the operator is input to the first main body unit 61, and movement of the vehicle body of the wheel loader 1 is fed back and input to the first lever unit 62. The first electric lever 60 can output the angle difference between the set value of the angle of the front frame 11 relative to the rear frame 12 and the current vehicle body bending angle. By appropriately controlling the steering actuator 21 based on this angle difference, the angle of the front frame 11 relative to the rear frame 12 can be easily adjusted to the set value.

[0089] 5, 7 and 8, the steering operation device 42 has a first electric lever 60 and a second electric lever 65. The joystick 43, a first body 61 of the first electric lever 60, and a second body 66 of the second electric lever 65 move integrally. The steering operation device 42 has a plurality of electric levers for redundancy, which improves the reliability of the steering operation device 42. By moving the plurality of bodies of the plurality of electric levers and the joystick 43 integrally, the movable space of the steering operation device 42 can be significantly reduced.

[0090] In the above description of the embodiment, the wheel loader 1 is given as an example of a work machine, but the present invention is also applicable to other types of work machines such as articulated dump trucks and motor graders.

[0091] <Additional Notes> The above description includes the following additional features.

[0092] (Appendix 1) a vehicle body frame having a rear frame and a front frame rotatably connected to the rear frame; a steering actuator for changing the angle of the front frame relative to the rear frame; a steering operation device that is operated by an operator to operate the steering actuator, The steering operation device is a joystick that accepts operator operations; At least one electric lever having a main body and a lever that is tiltable relative to the main body, and that outputs a tilt angle of the lever relative to the main body; A work machine in which the joystick and the main body operate integrally.

[0093] (Appendix 2) The joystick has a switch portion that is operated by an operator's finger, The work machine described in Appendix 1, wherein the steering operation device further includes a first electric wire electrically connected to the switch unit and extending from the inside to the outside of the joystick, and a second electric wire having one end connected to the main body unit.

[0094] (Appendix 3) 3. The work machine according to claim 2, wherein the steering operation device further includes a clamp that bundles the first electric wire and the second electric wire.

[0095] (Appendix 4) the steering operation device further includes a support portion that supports the joystick so that the joystick can move relatively; The work machine described in Appendix 3, wherein the clamp includes a movable clamp that moves relative to the support part integrally with the joystick in response to an operator's operation to tilt the joystick, and a fixed clamp that is fixed to the support part.

[0096] (Appendix 5) The work machine according to claim 4, wherein the movable clamp bundles the first electric wire and the second electric wire together at a position in the path of the first electric wire that is closer to the joystick than the fixed clamp.

[0097] (Appendix 6) a link that mechanically transmits a current angle of the front frame relative to the rear frame to the steering operation device, The work machine according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the steering operation device further includes an input unit connected to the link and inputting the current angle transmitted by the link to the lever unit.

[0098] (Appendix 7) the at least one electric lever comprises a plurality of electric levers; 7. The work machine according to any one of claims 1 to 6, wherein the joystick and the main body portions of the electric levers operate integrally.

[0099] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0100] 1 Wheel loader, 2 Body frame, 3 Work equipment, 4, 7 Traveling wheels, 5 Cab, 11 Front frame, 12 Rear frame, 13 Connecting shaft portion, 14 Boom, 15 Bucket, 21 Steering cylinder, 31 Driver's seat, 40 Left armrest, 41 Left console, 42 Steering operation device, 43 Joystick, 44 Knob portion, 45 Switch portion, 46 Horn operation button, 47 Speed ​​change switch, 47D Shift down button, 47U Shift up button, 48 Forward / reverse change switch, 49 Knob electric wire, 50 Support portion, 58 Fixing clamp, 60 First electric lever, 61 First main body portion, 62 First lever portion, 63C First core portion, 63S First spacer, 64 First lever electric wire, 65 Second electric lever, 66 Second main body portion, 67 Second lever portion, 68C Second core portion, 68S Second spacer, 69 Second lever wire, 70 Movable portion, 71 Base portion, 72 Flange portion, 73 Sleeve portion, 74 Holding portion, 75 First connector, 76 Second connector, 78 Movable clamp, 79 Wire sleeve, 80 Frame portion, 81 Outer bearing, 82 Inner bearing, 91 First link member, 92 Second link member, 96 Transmission member, 97, 98 Bolts, 100 Connecting portion, 110 Input portion, 111, 112 Long holes, X Front-rear direction, Y Left-right direction.

Claims

1. a vehicle body frame having a rear frame and a front frame rotatably connected to the rear frame; a steering actuator for changing the angle of the front frame relative to the rear frame; a steering operation device that is operated by an operator to operate the steering actuator, The steering operation device is a joystick that accepts operator operations; at least one electric lever having a main body and a lever that is tiltable relative to the main body, and that outputs a tilt angle of the lever relative to the main body; A work machine in which the joystick and the main body operate integrally.

2. The joystick has a switch portion that is operated by an operator's finger, 2. The work machine according to claim 1, wherein the steering operation device further includes: a first electric wire electrically connected to the switch portion and extending from the inside to the outside of the joystick; and a second electric wire having one end connected to the main body portion.

3. The work machine according to claim 2 , wherein the steering operation device further includes a clamp that bundles the first electric wire and the second electric wire together.

4. the steering operation device further includes a support portion that supports the joystick so that the joystick can move relatively; 4. The work machine according to claim 3, wherein the clamp includes a movable clamp that moves integrally with the joystick relative to the support portion in response to an operation of tilting the joystick by an operator, and a fixed clamp that is fixed to the support portion.

5. The work machine according to claim 4 , wherein the movable clamp bundles the first electric wire and the second electric wire together at a position on the path of the first electric wire that is closer to the joystick than the fixed clamp.

6. a link that mechanically transmits a current angle of the front frame relative to the rear frame to the steering operation device, 6. The work machine according to claim 1, wherein the steering operation device further includes an input unit connected to the link and inputting the current angle transmitted by the link to the lever unit.

7. the at least one electric lever comprises a plurality of electric levers; The work machine according to claim 1 , wherein the joystick and the plurality of main body portions of the plurality of electric levers operate integrally.

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