Work machine

Abstract

To provide a work machine which enables an operator to directly open / close a door of a driver's cab while enabling the door of the driver's cab to be opened / closed by remote operation.SOLUTION: In a wheel loader 1 having a driver's cab 3 in which a door 34 openable / closable by remote operation is mounted on an entrance 3A, in a state where both holdings at a close position and an open position of the door 34 are released, an opening / closing driving device 5 opens / closes the door 34 by a rotation torque of an electric motor 51 by energizing the electric motor 51 on the basis of an operation signal from a remote operation switch 4, and in a state where both holdings at the close position and the open position of the door 34 are released and an operation signal is not output from the remote operation switch 4, the energization to the electric motor 51 is blocked, and the door 34 is openable / closable by an inertial force.SELECTED DRAWING: Figure 8A

Description

Technical Field

[0001] The present invention relates to a work machine including a cab provided with a door that can be opened and closed remotely.

Background Art

[0002] In medium to large-sized vehicles of work machines such as wheel loaders and hydraulic excavators, in particular, the cab is provided at a high position from the ground. When an operator boards or exits the cab, generally, a lifting device composed of a ladder or stairs is used. At this time, the operator directly operates the door of the cab to open and close it while going up or down the lifting device. In recent years, work machines that can open and close the door of the cab by remote operation have appeared before and after the operator uses the lifting device, that is, in a state where the operator is away from the door of the cab and stands on the ground.

[0003] For example, Patent Document 1 discloses a work vehicle including a ladder as a lifting device, a cab having an openable and closable door disposed above the ladder, an actuator provided in the cab to open the door, an operation unit configured to be operable by an operator, and a controller that controls the driving of the actuator. The controller controls the driving of the actuator based on an operation signal received from the operation unit so that the door opens while the operation unit is receiving an operation by the operator.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the work vehicle described in Patent Document 1, when the operator is not operating the operation unit, that is, when no operation signal is output from the operation unit to the controller, the door is fixed in that position. Therefore, in the case of an electrical system failure or when the operator must make an emergency escape from the cab, the door hinders the operator's boarding and exiting operations to and from the cab, causing inconvenience.

[0006] Therefore, an object of the present invention is to provide a work machine that can open and close the cab door by remote control and can also be directly opened and closed by the operator.

Means for Solving the Problems

[0007] To achieve the above object, the present invention provides a cab provided on a main body frame constituting a vehicle body, with a rotatable door attached to an entrance / exit, a first holding device provided in the cab for holding the door in a closed position, a second holding device provided in the cab for holding the door in an open position, an electric motor, a speed reducer for reducing the rotational speed of the electric motor, and an output shaft for outputting the rotational torque of the electric motor transmitted via the speed reducer, and an opening / closing drive device for opening and closing the door by the rotational torque output by the output shaft, and an operating device for outputting an operation signal for opening and closing the door to the opening / closing drive device. In a work machine provided with these components, when the door is released from both the holding by the first holding device and the holding by the second holding device, the opening / closing drive device energizes the electric motor based on the operation signal from the operating device and operates the door to open and close by the rotational torque. When the door is released from both the holding by the first holding device and the holding by the second holding device and no operation signal is output from the operating device, the energization of the electric motor of the opening / closing drive device is cut off, and the door can be opened and closed by inertial force.

Effects of the Invention

[0008] According to the present invention, the door of the driver's cab can be opened and closed by remote control, but the operator can also open and close the door directly. Problems, configurations, and effects other than those described above will become clear from the following description of the embodiment. [Brief explanation of the drawings]

[0009]

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Figure 8A

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Figure 15A

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Embodiments for Carrying Out the Invention

[0010] Hereinafter, as an aspect of a working machine according to an embodiment of the present invention, for example, a wheel loader that performs a loading operation of excavating a work object such as earth and sand or minerals and loading the work object into a loading destination such as a dump truck or a hopper will be described.

[0011] <Configuration of Wheel Loader 1> First, the configuration of the wheel loader 1 will be described with reference to FIGS. 1 to 5.

[0012] FIG. 1 is an external side view showing a configuration example of a wheel loader 1 according to an embodiment of the present invention. FIG. 2 is a perspective view when the wheel loader 1 shown in FIG. 1 is viewed from above diagonally from the left rear side.

[0013] The wheel loader 1 is an articulated working machine that steers by the body bending in the vicinity of the center. A front frame 1A constituting the front part of the body and a rear frame 1B constituting the rear part of the body are connected to be rotatable in the left - right direction by a center joint 10, and the front frame 1A bends in the left - right direction with respect to the rear frame 1B by a steering operation.

[0014] Four wheels 11 are provided on the body. Two wheels 11 are provided as front wheels 11A on both the left and right sides of the front frame 1A, and the remaining two wheels 11 are provided as rear wheels 11B on both the left and right sides of the rear frame 1B. In FIGS. 1 and 2, only the left front wheel 11A and rear wheel 11B among the four wheels 11 are shown. A hydraulically - driven working device 2 is attached to the front part of the front frame 1A.

[0015] The working device 2 includes a lift arm 21 rotatably attached to the front frame 1A in the vertical direction, two lift arm cylinders (not shown) for driving the lift arm 21, a bucket 22 rotatably attached to the tip of the lift arm 21 in the vertical direction, a bucket cylinder 23 for driving the bucket 22, and a bell crank 24 rotatably connected to the lift arm 21 to form a link mechanism between the bucket 22 and the bucket cylinder 23.

[0016] On the rear frame 1B, there are provided a cab 3 for an operator to board, a machine room 12 for housing various devices necessary for driving the wheel loader 1 inside, and a counterweight 13 for maintaining the balance with the working device 2 so that the body does not tip over. In the rear frame 1B, the cab 3 is arranged at the front part, the counterweight 13 is arranged at the rear part, and the machine room 12 is arranged between the cab 3 and the counterweight 13.

[0017] Here, regarding the configuration of the driver's cab 3, in addition to FIGS. 1 and 2, FIGS. 3 to 5 will be referred to for explanation.

[0018] FIG. 3 shows the exterior of the driver's cab 3 when the door 34 is in the fully closed position. FIG. 4 shows the exterior of the driver's cab 3 when the door 34 is in the fully closed position or a position rotated approximately 90° from the fully open position. FIG. 5 shows the exterior of the driver's cab 3 when the door 34 is in the fully open position. In the following description, the closed position where the door 34 is completely closed is referred to as the "fully closed position", and the open position where the door 34 cannot be opened further is referred to as the "fully open position".

[0019] As shown in FIGS. 4 and 5, the driver's cab 3 includes a floor plate portion 30 attached to the rear frame 1B, a ceiling portion 31 covering the upper part of the floor plate portion 30, a plurality of pillars 32 extending vertically between the floor plate portion 30 and the ceiling portion 31, a plurality of windows 33 attached between the plurality of pillars 32, and a door 34 provided at the entrance / exit 3A on one side (left or right) so as to be openable and closable. In the central part of the driver's cab 3, a driver's seat 35 on which an operator sits is provided.

[0020] In this embodiment, four pillars 32 are erected in the driver's cab 3. Of the four pillars 32, two are arranged as a pair of front pillars 32A on the left and right sides in front of the driver's seat 35, and the remaining two are arranged as a pair of rear pillars 32B on the left and right sides behind the driver's seat 35. In FIGS. 1 to 5, only the front pillar 32A and the rear pillar 32B arranged on the left side among the four pillars 32 are shown.

[0021] The plurality of windows 33 include a front window 33A protruding to the front side of the driver's cab 3 between the pair of front pillars 32A, and a rear window 33B protruding to the rear side of the driver's cab 3 between the pair of rear pillars 32B. The entrance / exit 3A is provided between the front pillar 32A and the rear pillar 32B arranged on the left side, that is, on the left side of the driver's cab 3.

[0022] The door 34 has a window formed in at least the area above the central position, and is attached to the rear pillar 32B arranged on the left side via a pair of hinges 36. The door 34 rotates horizontally between the fully closed position shown in FIG. 3 and the fully open position shown in FIG. 5 with these pair of hinges 36 as the rotation center. The "fully open position" is a position rotated approximately 180° with the pair of hinges 36 arranged on the rear pillar 32B as the rotation center with respect to the "fully closed position". Note that FIG. 4 shows the state of the door 34 at a position rotated approximately 90° from the fully closed position or the fully open position as an example of the state of the door 34 during opening and closing.

[0023] In addition, in this embodiment, the entrance / exit 3A and the door 34 are provided on the left side of the driver's cab 3, but depending on the specifications of the vehicle body, they may be provided on the right side or both the left and right sides. This door 34 can be directly opened and closed manually by the operator or opened and closed by remote control.

[0024] Below the door 34 side on the left side of the driver's cab 3, a step 1C protruding outward (left side) from the rear frame 1B is provided. And below the step 1C, a lifting device 14 having a plurality of tread plates 140 arranged at a predetermined interval in the vertical direction is provided. The operator uses the step 1C and the lifting device 14 when boarding or exiting the driver's cab 3.

[0025] <Opening and Closing Drive Mechanism of Door 34> Next, the opening and closing drive mechanism of the door 34 will be described with reference to FIGS. 6 to 10.

[0026] FIG. 6 is a diagram showing the arrangement of the remote operation box 40. FIG. 7 is a diagram showing the inside of the remote operation box 40. FIG. 8A is a diagram showing a configuration example of the rotation mechanism of the door 34. FIG. 8B is a diagram showing a configuration example of the internal mechanism of the speed reducer 52. FIG. 9 is a diagram showing the position of the door drive unit 7 in the cab 3 and the routing of the first wire cable 81 and the second wire cable 82, as viewed from the cab 3 towards the door 34 side. FIG. 10 is a diagram showing the state of rotation of the door 34, as viewed from above the peripheral portion of the door 34 in the cab 3.

[0027] When the operator wants to open and close the door 34 by remote operation, the operator operates the remote operation switch 4 as an operation device for remote operation. In the present embodiment, as shown in FIGS. 6 and 7, the remote operation switch 4 is housed in a lockable remote operation box 40.

[0028] The remote operation box 40 includes a box-shaped main body 401 having an opening 401A formed on one side surface, and a door 402 attached to the main body 401 so as to be openable and closable via a hinge 400A at a position closing the opening 401A. A lock 402A for locking is attached to the door 402. Therefore, the operator who can operate the remote operation switch 4 is limited to a person having a key corresponding to the lock 402A.

[0029] The remote operation box 40 is arranged in the space S formed below step 1C with the door 402 (opening 401A) facing the front side of the vehicle body. Thereby, the operator can access the remote operation switch 4 in the remote operation box 40 in a state of standing on the ground and in a stable posture without difficulty.

[0030] When the operator operates the remote control switch 4, the remote control switch 4 outputs an operation signal for opening and closing the door 34 to the opening and closing drive device 5. As shown in FIG. 8A, the opening and closing drive device 5 includes an electric motor 51 serving as a drive source, a speed reducer 52 that reduces the rotational speed of the electric motor 51, and an output shaft 53 that outputs the rotational torque of the electric motor 51 transmitted via the speed reducer 52. The opening and closing drive device 5 drives the door 34 to open and close by the rotational torque output by the output shaft 53.

[0031] The electric motor 51 rotates in one direction (forward rotation) based on the open operation signal output from the remote control switch 4, and rotates in the other direction (reverse rotation) based on the close operation signal output from the remote control switch 4. On the other hand, the electric motor 51 stops when no operation signal is output from the remote control switch 4.

[0032] As shown in FIG. 8B, the speed reducer 52 is a spur gear type configured by combining a plurality of spur gears 520 with different numbers of teeth. In the present embodiment, the speed reducer 52 is configured by meshing a first spur gear 520A assembled to the rotating shaft 510 of the electric motor 51 and a second spur gear 520B assembled to the output shaft 53.

[0033] When the electric motor 51 is energized and rotates, the first spur gear 520A rotates with the rotation of the rotating shaft 510. Subsequently, the second spur gear 520B meshing with the first spur gear 520A rotates with the rotation of the first spur gear 520A. Then, the output shaft 53 rotates with the rotation of the second spur gear 520B.

[0034] The number of teeth of the second spur gear 520B arranged on the output side is formed to be larger than the number of teeth of the first spur gear 520A arranged on the input side. Therefore, the rotational speed of the second spur gear 520B is slower than that of the first spur gear 520A. Thereby, the speed reducer 52 can reduce the rotational speed of the electric motor 51.

[0035] In addition, in this embodiment, the speed reducer 52 is configured by combining two spur gears 520 (a first spur gear 520A and a second spur gear 520B) with different numbers of teeth. However, the present invention is not limited to this. Depending on the specifications required for the opening / closing drive device 5, it may be configured by combining three or more spur gears 520 with different numbers of teeth.

[0036] Further, in this speed reducer 52, unlike a worm speed reducer having a self-locking function (a function that makes rotation from the output side, i.e., the spur gear side, impossible), it is possible to rotate a plurality of spur gears 520 from the output side.

[0037] Therefore, when the electric motor 51 is in a stopped state (when not energized) and the output shaft 53 is manually forced to rotate, since the plurality of spur gears 520 of the speed reducer 52 rotate from the output side, that is, since the second spur gear 520B rotates and the first spur gear 520A also rotates, the electric motor 51 can be easily rotated. Thus, in the wheel loader 1, by taking advantage of the characteristics of the spur gear type speed reducer 52, it is possible to open and close the door 34 by both the driving force of the electric motor 51 and the inertial force acting on the door 34.

[0038] As shown in FIGS. 8A and 9, the opening / closing drive device 5 is disposed on the frame 70 together with a second servo motor 602 described later, and is attached to the upper end portion of a rear pillar 32B disposed on the left side of the cab 3 as a door drive unit 7. As shown in FIG. 8A, in the opening / closing drive device 5, the speed reducer 52 is disposed at the upper end portion of the electric motor 51, and the tip end portion of the output shaft 53 protrudes upward from the speed reducer 52.

[0039] In addition, a bracket 341 is attached to the upper end portion inside the door 34 by a plurality of bolts. Then, the bracket 341 and the output shaft 53 of the opening / closing drive device 5 are connected by a connecting member 37.

[0040] The connecting member 37 includes a plate-shaped rotating plate 371 attached to the tip of the output shaft 53 and rotating with the rotation of the output shaft 53, and a rod-shaped connecting rod 372 connecting the rotating plate 371 and the bracket 341. The rotating plate 371 includes a disk-shaped base 371A formed with a fitting hole into which the output shaft 53 is fitted, and an extending portion 371B extending outward from a part of the base 371A.

[0041] The bracket 341 includes a portion to be attached 341A attached to the inside of the door 34, and a plate portion 341B projecting horizontally from the lower end portion of the portion to be attached 341A and extending toward the rear pillar 32B side.

[0042] The connecting rod 372 of the connecting member 37 is rotatably connected horizontally to the tip of the extending portion 371B of the rotating plate 371 and the tip of the plate portion 341B of the bracket 341, respectively. That is, the connecting rod 372 constitutes a link mechanism between the rotating plate 371 and the bracket 341.

[0043] As shown in FIG. 10, first, in the fully closed position where the door 34 closes the entrance / exit 3A, the connecting member 37 is in a state where the tip of the extending portion 371B points to the right side of the driver's cab 3 (the side facing the entrance / exit 3A), and the bracket 341 is in a state where the plate portion 341B projects toward the inside of the driver's cab 3.

[0044] Subsequently, when the door 34 is opened about 90° from the fully closed position, the connecting member 37 is in a state where the tip of the extending portion 371B points to the front side of the driver's cab 3, and the bracket 341 is in a state where the plate portion 341B projects toward the front of the vehicle body.

[0045] Then, when the door 34 is further opened from the position where it is opened about 90° to the fully open position where it is opened about 180°, the connecting member 37 is in a state where the tip of the extending portion 371B points to the entrance / exit 3A side, and the bracket 341 is in a state where the plate portion 341B projects toward the left side of the vehicle body.

[0046] When the door 34 opens, the rotary plate 371 rotates counterclockwise as viewed from the ceiling portion 31 side of the cab 3 along with the rotation of the output shaft 53 of the opening / closing drive device 5. Then, the tip of the extending portion 371B pushes out the connecting rod 372 toward the left side of the vehicle body. As a result, the bracket 341 is gradually pushed out from the left side to the rear of the vehicle body, and the door 34 rotates counterclockwise as viewed from the ceiling portion 31 side of the cab 3 from the fully closed position to the fully open position about a pair of hinges 36 disposed on the rear pillar 32B.

[0047] On the other hand, when the door 34 closes, the rotary plate 371 rotates clockwise as viewed from the ceiling portion 31 side of the cab 3 along with the rotation of the output shaft 53 of the opening / closing drive device 5. Then, the tip of the extending portion 371B pulls the connecting rod 372 toward the inside of the cab 3. As a result, the bracket 341 is gradually pulled back from the rear of the vehicle body toward the inside of the cab 3, and the door 34 rotates clockwise as viewed from the ceiling portion 31 side of the cab 3 from the fully open position to the fully closed position about a pair of hinges 36 disposed on the rear pillar 32B.

[0048] In the present embodiment, the opening / closing drive device 5, the connecting member 37, and the bracket 341 related to the opening and closing drive of the door 34 are collectively arranged at the upper end portion and the peripheral portion of the rear pillar 32B disposed on the left side of the cab 3, that is, in the vicinity of the ceiling portion 31 in the upper left rear of the driver's seat 35. Thereby, for example, compared with the case where it is disposed on the floor plate portion 30 around the driver's seat 35, a wider space through which the operator's feet pass can be secured when the operator enters and exits the cab 3, so that the operator can easily enter and exit the cab 3.

[0049] <Holding mechanism of door 34> Next, the holding mechanism of the door 34 will be described with reference to FIGS. 11 to 14 in addition to FIGS. 8A and 9.

[0050] FIG. 11 is a view showing the first holding device 61. FIG. 12 is a view showing a configuration example of the doorknob 343 and the second holding device 62. FIG. 13 is an enlarged view showing the periphery of the second latch 622 of the second holding device 62 in FIG. 12. FIG. 14 is a view for explaining the basic mechanisms of the first holding device 61 and the second holding device 62.

[0051] The door 34 is held by the first holding device 61 in the fully closed position and by the second holding device 62 in the fully open position, respectively. Therefore, the door 34 is in a state where it can rotate horizontally about a pair of hinges 36 according to an external force or an inertial force during opening and closing (hereinafter simply referred to as a "rotatable state"), but is fixed to the cab 3 in both the fully closed position and the fully open position.

[0052] As shown in FIG. 11, the first holding device 61 includes a first striker 611 that protrudes from the front pillar 32A disposed on the left side of the cab 3 toward the rear pillar 32B, and a first latch 612 provided at the lower end side of a portion of the edge of the door 34 that faces the front pillar 32A in the fully closed position. A notch 612A into which the first striker 611 is fitted is formed in the first latch 612.

[0053] When the door 34 rotates from the fully open position in the closing direction to the fully closed position, the first striker 611 is fitted into the notch 612A of the first latch 612 and is held by the front pillar 32A. On the other hand, when the door 34 is rotated in the opening direction from the fully closed position, it is necessary to release the fitting between the first striker 611 and the first latch 612 in order to make the door 34 held in the fully closed position by the first holding device 61 rotatable.

[0054] At the lower end of the inner surface of the door 34, there is provided a first operation lever 342 for releasing the fitting of the first striker 611 and the first latch 612, that is, for releasing the holding of the door 34 in the fully closed position, when the operator manually opens the door 34 from inside the driver's cab 3. Further, as shown in FIG. 12, at the lower end of the outer surface side of the door 34, there are provided a door knob 343 for releasing the fitting of the first striker 611 and the first latch 612 when the operator manually opens the door 34 from the outside of the driver's cab 3, and a locking device 344 for locking the door knob 343, respectively.

[0055] Furthermore, on the plate portion 341B of the bracket 341 attached to the upper end of the inner surface of the door 34, there is disposed a first servo motor 601 for releasing the fitting of the first striker 611 and the first latch 612 when the door 34 is opened by remote operation. That is, this first servo motor 601 corresponds to a first actuator that drives the first holding device 61 that holds the door 34 to a state where the holding of the door 34 is released. As shown in FIGS. 8A, 9, and 11, one end of a first wire cable 81 is connected to the first servo motor 601.

[0056] As shown in FIGS. 9 and 11, the first wire cable 81 led out from the first servo motor 601 is routed along the outer edge of the door 34 so as not to obstruct the operator's view, and the other end is connected to the first latch 612. That is, the first servo motor 601 and the first latch 612 of the first holding device 61 are connected by the first wire cable 81.

[0057] As shown in FIG. 12, the second holding device 62 includes a second striker 621 that protrudes from the lower part of the outer surface of the door 34 (at the upper right position of the locking device 344 in FIG. 12), and a second latch 622 provided at the lower rear side of the rear pillar 32B. As shown in FIG. 13, the second latch 622 is formed with a notch 622A into which the second striker 621 is fitted.

[0058] When the door 34 rotates in the opening direction from the fully closed position to the fully open position, the second striker 621 is fitted into the notch 622A of the second latch 622 and is held on the left side surface of the cab 3. On the other hand, when the door 34 is rotated in the closing direction from the fully open position, it is necessary to release the fitting between the second striker 621 and the second latch 622 in order to make the door 34, which is held in the fully open position by the second holding device 62, rotatable.

[0059] As shown in FIGS. 8A and 9, on the frame 70, a second servo motor 602 for releasing the fitting between the second striker 621 and the second latch 622 when closing the door 34 by remote operation is disposed on one side of the electric motor 51 (the rear pillar 32B side in FIGS. 8A and 9). This second servo motor 602 corresponds to a second actuator that drives the second holding device 62 that holds the door 34 to a state where the holding of the door 34 is released. One end of a second wire cable 82 is connected to the second servo motor 602.

[0060] As shown in FIGS. 9 and 13, the second wire cable 82 led out from the second servo motor 602 is routed along the extending direction of the rear pillar 32B so as not to obstruct the operator's view, and the other end is connected to the second latch 622. That is, the second servo motor 602 and the second latch 622 of the second holding device 62 are connected by the second wire cable 82.

[0061] Also, as shown in FIGS. 8A and 9, a second operation lever 602A for releasing the fitting between the second striker 621 and the second latch 622 when the operator manually closes the door 34 from inside and outside the cab 3 is attached to one end portion of the second wire cable 82 on the side of the position of the second latch 622 rather than the connection portion with the second servo motor 602.

[0062] Since the mechanisms of the first holding device 61 and the second holding device 62 are basically the same, they will be described together with reference to FIG. 14. In the following description, "the first striker 611 and the second striker 621" may be collectively referred to as "strikers 611, 621", and "the first latch 612 and the second latch 622" may be collectively referred to as "latches 612, 622".

[0063] When the strikers 611, 621 are fitted into the latches 612, 622, as shown on the left side of FIG. 14, the strikers 611, 621 push a region on one side of the notches 612A, 622A of the latches 612, 622 (the region having the surface facing the strikers 611, 621). As a result, the latches 612, 622 rotate in one direction (counterclockwise in FIG. 14) about the rotation axis C, and the strikers 611, 621 are fitted into the notches 612A, 622A.

[0064] In addition, in the fitting of the strikers 611, 621 and the latches 612, 622 due to the opening and closing operation of the door 34, even if no external force is applied to the door 34 until the strikers 611, 621 and the latches 612, 622 are fitted, the door 34 rotates due to the inertia (weight) of the door 34, and the strikers 611, 621 and the latches 612, 622 are fitted as if they were respectively sucked in from the side of the first latch 612 to the first striker 611 or from the side of the second striker 621 to the second latch 622.

[0065] Subsequently, when releasing the fitting of the strikers 611, 621 and the latches 612, 622, as shown on the right side of FIG. 14, the latches 612, 622 rotate in the other direction (clockwise in FIG. 14) about the rotation axis C, and the region on one side pushes out the strikers 611, 621 within the notches 612A, 622A. As a result, the strikers 611, 621 come out of the notches 612A, 622A, and the strikers 611, 621 and the latches 612, 622 are in a separated state.

[0066] In addition, when releasing the engagement between the strikers 611 and 621 and the latches 612 and 622, it is necessary to rotate the latches 612 and 622 by an external force. When the door 34 is opened and closed by remote control, the driving forces of the first servo motor 601 and the second servo motor 602 respectively serve as external forces. When the door 34 is opened and closed manually, the operating forces of the first operating lever 342, the door knob 343, and the second operating lever 602A respectively serve as external forces.

[0067] <Opening and closing operation of door 34> Next, the opening and closing operation of the door 34 will be described with reference to FIGS. 15 and 16.

[0068] FIG. 15A is a diagram for explaining the movement of each device when the door 34 is moved from the fully closed position to the open position by remote control. FIG. 15B is a diagram for explaining the movement of each device when the door 34 is moved from the fully open position to the closed position by remote control. FIG. 16A is a diagram for explaining the movement of each device when the door 34 is opened manually from outside the cab 3. FIG. 16B is a diagram for explaining the movement of each device when the door 34 is opened manually from inside the cab 3. FIG. 16C is a diagram for explaining the movement of each device when the door 34 is closed from the fully open position manually.

[0069] When the door 34 is moved from the fully closed position to the open position by remote control, as shown in FIG. 15A, the operator switches the remote control switch 4 from the neutral position (remote control stop position) to the open position. Then, the remote control switch 4 outputs an open operation signal to the electric motor 51 and the first servo motor 601 respectively. [[ID=??]] [[ID=??]]

[0070] [[ID=??]] It seems there are some tags with "??" in the original that might be incorrect or incomplete. I've translated based on what was provided as accurately as possible.The first servo motor 601 is energized based on the opening operation signal output from the remote operation switch 4, and drives in the direction of pulling the other end of the first wire cable 81. Along with this, the first latch 612 rotates in the direction of pushing out the first striker 611 held in the notch 612A to the outside. As a result, the fitting between the first striker 611 and the first latch 612, that is, the holding of the door 34 by the first holding device 61 is released.

[0071] In this embodiment, when an opening operation signal is output from the remote operation switch 4, the first servo motor 601 is used as the first actuator that drives the first holding device 61 in a state of holding the door 34 to a state of releasing the holding of the door 34. However, the present invention is not limited to this, and for example, an electromagnetic magnet or the like may be used. Further, the first actuator does not necessarily have to be an electric actuator, and a mechanical actuator may be used.

[0072] Note that the first holding device 61 is configured such that the first latch 612 can operate by driving the first servo motor 601 even when the door 34 is locked by a locking device 344 described later, that is, even when the first latch 612 does not come off from the first striker 611 even if the door knob 343 is operated. Thereby, even when the door 34 is locked by the locking device 344, the operator can open the door 34 by the remote operation switch 4 from the ground without accessing the locking device 344 provided on the door 34 using the lifting device 14.

[0073] However, as described above, since the remote operation switch 4 is housed in the remotely operable lock box 40, the operator who can operate the remote operation switch 4 is limited to those who have a key that can unlock the lock 402A. That is, those who can open the locked door 34 of the driver's cab 3 are limited to those who have a key for unlocking the door 34 of the driver's cab 3 (a key corresponding to the locking device 344) or a key for unlocking the door 402 of the remote operation box 40 (a key corresponding to the lock 402A).

[0074] The electric motor 51 is energized based on the opening operation signal output from the remote operation switch 4, and rotates in a counterclockwise direction when viewed from the ceiling portion 31 side of the driver's cab 3. Along with this, the connecting member 37 pushes the bracket 341 outward of the driver's cab 3. As a result, the door 34 performs an opening operation toward the rear of the vehicle body around a pair of hinges 36 disposed on the rear pillar 32B, and is held by the second holding device 62 at the fully open position.

[0075] During the opening operation of the door 34 by remote operation, if the operator switches the remote operation switch 4 from the open position to the neutral position, the opening operation signal is no longer output from the remote operation switch 4. In this case, that is, in a state where the holding of the door 34 by the first holding device 61 is released and no opening operation signal is output from the remote operation switch 4, the power supply to the electric motor 51 is cut off, and the door 34 can perform an opening operation due to inertial force.

[0076] When the door 34 is closed from the fully open position by remote operation, as shown in FIG. 15B, the operator switches the remote operation switch 4 from the neutral position to the closed position. Then, the remote operation switch 4 outputs a closing operation signal to the electric motor 51 and the second servo motor 602, respectively.

[0077] The second servo motor 602 is energized based on the closing operation signal output from the remote operation switch 4, and drives in a direction to pull the other end of the second wire cable 82. Along with this, the second latch 622 rotates in a direction to push the second striker 621, which was held in the notch 622A, outward. As a result, the engagement between the second striker 621 and the second latch 622, that is, the holding of the door 34 by the second holding device 62 is released.

[0078] In this embodiment, when a closing operation signal is output from the remote operation switch 4, the second servo motor 602 is used as the second actuator that drives the second holding device 62 that holds the door 34 to a state where the holding of the door 34 is released. However, the present invention is not limited to this, and for example, an electromagnetic magnet or the like may be used. Further, the second actuator does not necessarily have to be an electric actuator, and a mechanical actuator may be used.

[0079] The electric motor 51 is energized based on the closing operation signal output from the remote operation switch 4 and rotates in a clockwise direction when viewed from the ceiling portion 31 side of the driver's cab 3. Accordingly, the connecting member 37 pulls the bracket 341 toward the inside of the driver's cab 3. As a result, the door 34 closes toward the front of the vehicle body about a pair of hinges 36 disposed on the rear pillar 32B and is held by the first holding device 61 at the fully closed position.

[0080] During the closing operation of the door 34 by remote operation, if the operator switches the remote operation switch 4 from the closed position to the neutral position, the closing operation signal is no longer output from the remote operation switch 4. In this case, that is, when the holding of the door 34 by the second holding device 62 is released and the closing operation signal is not output from the remote operation switch 4, the power supply to the electric motor 51 is cut off, and the door 34 can be closed by inertial force.

[0081] As described above, when the holding of the door 34 by both the first holding device 61 and the second holding device 62 is released, the opening / closing drive device 5 energizes the electric motor 51 based on the operation signal from the remote operation switch 4 and performs an opening / closing operation by the rotational torque of the electric motor 51.

[0082] Further, when the holding of the door 34 by both the first holding device 61 and the second holding device 62 is released and no operation signal is output from the remote operation switch 4, the power supply to the electric motor 51 is cut off, and the door 34 can be opened and closed by inertial force.

[0083] Note that when the door 34 is released from the holding by both the first holding device 61 and the second holding device 62, and a closing operation signal or an opening operation signal is output from the remote operation switch 4, the closing operation signal or the opening operation signal is also input to the first servo motor 601 that drives the first holding device 61, or the second servo motor 602 that drives the second holding device 62. Therefore, although the first latch 612 or the second latch 622 rotates based on the closing operation signal or the opening operation signal, in this case, since it is a so-called idling operation, it does not affect the rotation of the door 34.

[0084] When the operator manually opens the door 34 in the fully closed position from the outside of the driver's cab 3, as shown in Fig. 16A, the operator releases the locked state of the door 34 by the locking device 344 (the state where the first latch 612 does not disengage from the first striker 611 even when the door knob 343 is operated), and then pulls the door knob 343 forward. Along with this, the first latch 612 rotates in a direction to push out the first striker 611 held in the notch 612A outward. Thereby, the engagement between the first striker 611 and the first latch 612, that is, the holding of the door 34 by the first holding device 61 is released. Therefore, the door knob 343 is operable to release the holding of the door 34 held in the fully closed position by the first holding device 61.

[0085] Note that the locking device 344 is a device for locking the door 34 of the driver's cab 3. Therefore, the operator can lock (lock) and unlock (unlock) the door 34 using a key.

[0086] Subsequently, the operator pulls the door 34 forward. Along with this, since the output shaft 53 is forcibly rotated counterclockwise via the connecting member 37, the plurality of spur gears 520 of the speed reducer 52 rotate from the output side. Thereby, the door 34 becomes rotatable and opens toward the rear of the vehicle body by inertia or an external force around the rear pillar 32B, and is held by the second holding device 62 at the fully open position.

[0087] When the other party manually opens the door 34 in the fully closed position from the inside of the driver's cab 3, as shown in FIG. 16B, the operator tilts the first operation lever 342 backward. Along with this, the first latch 612 rotates in a direction to push out the first striker 611 that was held in the notch 612A outward. As a result, the engagement between the first striker 611 and the first latch 612, that is, the holding of the door 34 by the first holding device 61 is released. Therefore, the first operation lever 342, like the door knob 343, can operate the first holding device 61 to release the holding of the door 34 held in the fully closed position by the first holding device 61.

[0088] Subsequently, the operator pushes the door 34 outward. Along with this, since the output shaft 53 is forcibly rotated counterclockwise as viewed from the ceiling portion 31 side of the driver's cab 3 via the connecting member 37, the plurality of spur gears 520 of the speed reducer 52 rotate from the output side (from the second spur gear 520B). As a result, the door 34 becomes rotatable and opens by inertia or an external force toward the fully open position.

[0089] When the door 34 in the fully open position is manually closed from both the inside and outside of the driver's cab 3, as shown in FIG. 16C, the operator tilts the second operation lever 602A upward. Along with this, the second latch 622 rotates in a direction to push out the second striker 621 that was held in the notch 622A outward. As a result, the engagement between the second striker 621 and the second latch 622, that is, the holding of the door 34 by the second holding device 62 is released. Therefore, the second operation lever 602A can operate the second holding device 62 to release the holding of the door 34 held in the fully open position by the second holding device 62.

[0090] Subsequently, the operator pulls the door 34 forward. Along with this, the output shaft 53 is forced to rotate clockwise as viewed from the ceiling portion 31 side of the cab 3 via the connecting member 37, so that the plurality of spur gears 520 of the speed reducer 52 rotate from the output side (from the second spur gear 520B). As a result, the door 34 becomes rotatable and opens due to inertial force or external force toward the fully closed position.

[0091] In this way, in the wheel loader 1, both the remote operation by the remote control switch 4 and the manual operation using the door knob 343, the first operation lever 342, and the second operation lever 602A can release the holding of the door 34 by the first holding device 61 and the holding of the door 34 by the second holding device 62, and the door 34 can be opened and closed by both the driving force of the electric motor 51 and the inertial force or external force acting on the door 34.

[0092] Therefore, the operator can usually open and close the door 34 electrically by remote control, but in the case of an electrical system failure or when the operator must make an emergency escape from the cab 3, the operator can open and close the door 34 manually.

[0093] <Modification Example> Next, the wheel loader 1 according to a modification example of the present embodiment will be described with reference to FIGS. 17 to 21. In FIGS. 17 to 21, components common to those described for the wheel loader 1 according to the embodiment are denoted by the same reference numerals and their description is omitted.

[0094] FIG. 17 is a diagram showing a configuration example of the driver's seat 35 and its peripheral portion in the modification example. FIG. 18 is a sequence circuit diagram showing the connection configuration between each remote control switch 4, 38 and each drive device 51, 601, 602. FIG. 19 is a table showing the relationship between the operations of each remote control switch 4, 38 and the detection content of the belt mounting sensor 350 and the operations of each drive device 51, 601, 602.

[0095] The wheel loader 1 according to this modification example includes a ground remote operation switch 4 as a ground operation unit that can be operated from the ground and a cab remote operation switch 38 as a cab operation unit that can be operated from within the cab 35, as an operation device that outputs an operation signal for opening and closing the door 34 to the opening and closing drive device 5. Note that the ground remote operation switch 4 is the remote operation switch 4 described in the embodiment, but in this modification example, it is referred to as the ground remote operation switch 4 for the purpose of distinguishing it from the cab remote operation switch 38.

[0096] As shown in FIG. 17, the cab remote operation switch 38 is provided at a position on the door 34 side (left side) of the front console 39 installed in front of the driver's seat 35 within the cab 3. By arranging the cab remote operation switch 38 for opening and closing the door 34 near the door 34 in this way, the operability of the operator when entering and leaving the cab 3 is improved.

[0097] In this modification example, the operator can remotely operate the door 34 from within the cab 3. However, for example, when the operator is performing maintenance work while not seated on the driver's seat 35 within the cab 3, if the operator accidentally touches the cab remote operation switch 38, the door 34 may open and close unintentionally.

[0098] Therefore, within the cab 3, a switch-type belt wearing sensor 350 that detects whether a seat belt is worn is provided as a seating detection device that detects whether the operator is seated on the driver's seat 35.

[0099] Note that the seating detection device does not necessarily have to be a sensor that detects the wearing state of the seat belt. For example, it may be a sensor that detects the pressure applied to the seat surface of the driver's seat 35, or a switch provided at a position where the operation cannot be performed unless the operator is seated on the driver's seat 35 in a correct posture.

[0100] As shown in FIG. 18, when the operator wears the seat belt, the belt wearing sensor 350 turns ON and switches to the connection position α that enables the operation of the remote operation switch 38 for the driver's cab. As a result, the remote operation switch 38 for the driver's cab, the first servo motor 601, the second servo motor 602, and the electric motor 51 are electrically connected to each other, and the first servo motor 601, the second servo motor 602, and the electric motor 51 each acquire the operation signal output from the remote operation switch 38 for the driver's cab.

[0101] At this time, since the connection between the remote operation switch 4 for the ground and the first servo motor 601, the second servo motor 602, and the electric motor 51 is cut off respectively, the operation of the remote operation switch 4 for the ground becomes invalid.

[0102] On the other hand, when the operator does not wear the seat belt, the belt wearing sensor 350 turns OFF and switches to the connection position β (shown by the broken line in FIG. 18) that enables the operation of the remote operation switch 4 for the ground. As a result, the remote operation switch 4 for the ground, the first servo motor 601, the second servo motor 602, and the electric motor 51 are electrically connected to each other, and the first servo motor 601, the second servo motor 602, and the electric motor 51 each acquire the operation signal output from the remote operation switch 4 for the ground.

[0103] At this time, since the connection between the remote operation switch 38 for the driver's cab and the first servo motor 601, the second servo motor 602, and the electric motor 51 is cut off respectively, the operation of the remote operation switch 38 for the driver's cab becomes invalid.

[0104] The specific correlation between the operation of the remote operation switch 38 for the driver's cab, the operation of the remote operation switch 4 for the ground, the detection state of the belt wearing sensor 350, and the driving states of the electric motor 51, the first servo motor 601, and the second servo motor 602 is as shown in FIG. 19.

[0105] That is, when the belt wearing sensor 350 detects that the seat belt is worn, the operation of the remote control switch 38 for the driver's cab becomes effective, and the operation of the remote control switch 4 for the ground becomes ineffective. On the other hand, when the belt wearing sensor 350 does not detect that the seat belt is worn, the operation of the remote control switch 38 for the driver's cab becomes ineffective, and the operation of the remote control switch 4 for the ground becomes effective.

[0106] Thereby, for example, it is possible to prevent a situation in which another operator different from the operator accidentally operates the ground remote control switch 4 without noticing the operator sitting in the driver's seat 35, and the door 34 suddenly opens and closes for the operator sitting in the driver's seat 35.

[0107] Note that the system configuration related to the switching between the effective and ineffective operations of the ground remote control switch 4 and the switching between the effective and ineffective operations of the remote control switch 38 for the driver's cab does not necessarily need to be realized by constructing a sequence circuit, and may be realized by using the controller 9, for example.

[0108] FIG. 20 is a functional block diagram showing the functions of the controller 9. FIG. 21 is a flowchart showing the flow of processing executed in the controller 9.

[0109] The controller 9 is configured such that a CPU, a RAM, a ROM, an input I / F, and an output I / F are connected to each other via a bus. Then, the ground remote control switch 4, the remote control switch 38 for the driver's cab, and the belt wearing sensor 350 are connected to the input I / F, and the first servo motor 601, the second servo motor 602, and the electric motor 51 are connected to the output I / F.

[0110] In such a hardware configuration, the CPU reads out a control program (software) stored in a recording medium such as a ROM or an optical disk and expands it on the RAM, and by executing the expanded control program, the control program and the hardware cooperate to realize the functions of the controller 9.

[0111] As shown in FIG. 20, the controller 9 includes a data acquisition unit 91, a seating state determination unit 92, a valid / invalid selection unit 93, and a signal output unit 94.

[0112] In the controller 9, as shown in FIG. 21, first, the data acquisition unit 91 acquires, as data, the operation signal output from the ground remote operation switch 4, the operation signal output from the cab remote operation switch 38, and the signal output from the belt wearing sensor 350 (step S901).

[0113] Subsequently, the seating state determination unit 92 determines whether the operator is wearing the seat belt, that is, whether the operator is seated on the driver's seat 35, based on the signal from the belt wearing sensor 350 acquired in step S901 (step S902).

[0114] If it is determined in step S902 that the operator is seated (step S902 / YES), the valid / invalid selection unit 93 validates the operation signal from the cab remote operation switch 38 acquired in step S901 and invalidates the operation signal from the ground remote operation switch 4 acquired in step S901 (step S903).

[0115] Next, if the operation signal from the cab remote operation switch 38 acquired in step S901 is an open operation signal (step S904 / open), the signal output unit 94 outputs an open operation signal to the electric motor 51 and the first servo motor 601 respectively (step S905), and the processing in the controller 9 ends.

[0116] On the other hand, if the operation signal from the cab remote operation switch 38 acquired in step S901 is a close operation signal (step S904 / close), the signal output unit 94 outputs a close operation signal to the electric motor 51 and the second servo motor 602 respectively (step S906), and the processing in the controller 9 ends.

[0117] Also, when it is determined in step S902 that the operator is not seated (step S902 / NO), the valid / invalid selection unit 93 invalidates the operation signal from the cab remote operation switch 38 acquired in step S901, and validates the operation signal from the ground remote operation switch 4 acquired in step S901 (step S907).

[0118] Next, when the operation signal from the ground remote operation switch 4 acquired in step S901 is an open operation signal (step S908 / open), the signal output unit 94 outputs an open operation signal to the electric motor 51 and the first servo motor 601 respectively (step S909), and the processing in the controller 9 ends.

[0119] On the other hand, when the operation signal from the ground remote operation switch 4 acquired in step S901 is a close operation signal (step S908 / close), the signal output unit 94 outputs a close operation signal to the electric motor 51 and the second servo motor 602 respectively (step S910), and the processing in the controller 9 ends.

[0120] The embodiments of the present invention have been described above. Note that the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of a given embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a given embodiment. Furthermore, it is possible to add, delete, or replace a part of the configuration of a given embodiment with another configuration.

[0121] For example, in the above embodiment, the wheel loader 1 is described as an example of one aspect of the working machine. However, the present invention is not limited thereto. For example, any working machine provided with a cab that can rotate horizontally, such as a hydraulic excavator, and having a cab provided on the main body frame is not particularly limited.

Explanation of Reference Numerals

[0122] 1: Wheel loader (working machine) 1B: Rear frame (main body frame) 1C: Step 3: Cab 3A: Entrance / exit 4: Remote control switch, ground-based remote control switch (operating device, ground-based operating unit) 5: Opening / closing drive device 32, 32B: Rear pillar 34: Door 35: Driver's seat 37: Connecting member 38: Cab remote control switch (operating device, cab operating unit) 51: Electric motor 52: Reducer 53: Output shaft 61: First holding device 62: Second holding device 81: First wire cable 82: Second wire cable 341: Bracket 342: First operation lever 343: Door knob 350: Belt wearing sensor (seating detection device) 601: First servo motor (first actuator) 602: Second servo motor (second actuator) 602A: Second operation lever

Claims

1. A cab provided on a main frame constituting a vehicle body, with a rotatable door attached to an entrance / exit, a first holding device provided in the cab for holding the door in a closed position, a second holding device provided in the cab for holding the door in an open position, an opening / closing drive device having an electric motor, a speed reducer for reducing the rotational speed of the electric motor, and an output shaft for outputting the rotational torque of the electric motor transmitted through the speed reducer, and driving the door to open and close by the rotational torque output by the output shaft, an operating device for outputting an operation signal for opening and closing the door to the opening / closing drive device, in a working machine comprising: when the door is released from both the holding by the first holding device and the holding by the second holding device, the opening / closing drive device energizes the electric motor based on the operation signal from the operating device and operates the door to open and close by the rotational torque, when the door is in a state where it is released from both the holding by the first holding device and the holding by the second holding device and the operation signal is not output from the operating device, the energization of the electric motor of the opening / closing drive device is cut off, and the door can be opened and closed by inertial force A working machine characterized by this.

2. In the working machine according to Claim 1, a first actuator that drives the first holding device that holds the door to a state of releasing the holding of the door when an opening operation signal for opening the door is output from the operating device, a first wire cable having one end connected to the first holding device and the other end connected to the first actuator, a second actuator that drives the second holding device that holds the door to a state of releasing the holding of the door when a closing operation signal for closing the door is output from the operating device, a second wire cable having one end connected to the second holding device and the other end connected to the second actuator, comprising: A working machine characterized by this.

3. In the working machine according to Claim 2, a bracket attached to the upper end portion inside the door, a connecting member connecting the bracket and the output shaft of the opening / closing drive device, comprising: The door is rotatably provided on a rear pillar standing behind the entrance / exit in the cab. The opening and closing drive device is attached to the upper end of the rear pillar, The first actuator is attached to the bracket, The first wire cable is arranged along the outer edge of the door, The second actuator is attached to the upper end of the rear pillar together with the opening and closing drive device, The second wire cable is arranged along the rear pillar A working machine characterized by this.

4. In the working machine according to claim 2, On the outside of the door, a doorknob is provided that can operate the first holding device to release the holding of the door held in the closed position by the first holding device, Inside the door, a first operation lever is provided that can operate the first holding device to release the holding of the door held in the closed position by the first holding device, Inside the driver's cab, A second operation lever is provided that can operate the second holding device to release the holding of the door held in the open position by the second holding device A working machine characterized by this.

5. In the working machine according to claim 1, Below the door side of the driver's cab, A step projecting outward from the main body frame is provided, The operating device, Includes a ground operating part arranged below the step and operable from the ground A working machine characterized by this.

6. In the working machine according to claim 5, The operating device, Further includes a cab operating part arranged on the door side in front of the driver's seat provided in the cab and operable from inside the cab A working machine characterized by this.

7. In the working machine according to claim 6, Equipped with a seating detection device for detecting whether an operator is seated on the driver's seat, The operating device, When the seating detection device detects that the operator is seated, the operation in the cab operating part becomes effective, and the operation in the ground operating part becomes ineffective, When the seating detection device does not detect that the operator is seated, the operation in the cab operating part becomes ineffective, and the operation in the ground operating part becomes effective A working machine characterized by this.

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