JP2023007766A - work machine - Google Patents

Abstract

To improve stability and convenience of turning.SOLUTION: A work machine includes a steering device and a control device. The steering device includes a first traveling device and a second traveling device for supporting a machine body on the left side and right side, respectively, of the machine body and an operation member for operating traveling and steering of the machine body and drives each traveling device according to an operating state of the steering member to cause the machine body to move straight or turn. When it is determined whether the machine body is stable or not and it is determined that the operation member is operated by a maximum amount to either the left or right side and that the machine body is stable, the control device drives the first traveling device and the second traveling device at the same driving speed in different direction or drives the first traveling device and the second traveling device in different directions so that an absolute value of a difference in driving speed between the first traveling device and the second traveling device becomes smaller than or equal to a threshold value, thereby allowing a zero turn for causing the machine body to turn with a minimum turning radius approximate to zero; and when it is determined that the operation member is operated by an amount smaller than the maximum amount or that the machine body is not stable, the control device inhibits the zero turn.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a work machine that turns left and right by driving traveling devices provided on the left and right sides of the machine body.

As a work machine that turns left and right by driving traveling devices provided on the left and right sides of the machine body, for example, work machines disclosed in Patent Documents 1 and 2 are known.
In the work machines disclosed in Patent Documents 1 and 2, left and right crawler-type traveling devices are driven in accordance with the operation of operating members such as a steering lever and a mode switching switch to turn the machine body left and right. Also, by switching the driving speed and driving direction of the left and right traveling devices, it is possible to execute a plurality of types of turns with different turning radii of the body.

JP-A-2004-74883 Japanese Patent No. 3883484

Depending on the location where the work machine works or travels, it may be desirable to turn the work machine with a very small turning radius. In this case, for example, among the left and right traveling devices, the traveling device on the inner side of the turn located closer to the center of turning is driven in the opposite direction to the driving direction of the traveling device on the outer side of the turning, which is positioned farther from the center of turning. The driving speed of the inner traveling device is set to be equal to or lower than the driving speed of the traveling device on the outer side of the turn. As the drive speed of the travel device on the inner side of the turn approaches the drive speed of the travel device on the outer side of the turn, the turning radius of the work implement becomes smaller.

However, when the left and right traveling gears are driven to turn the work equipment with a very small turning radius, the frictional force between the traveling gears and the road surface increases, causing the machine to shake and the machine to sway. By being shaken, the phenomenon that the frictional force between the traveling device and the road surface is released is repeated. Therefore, if the machine is not in a stable state before turning, the shaking and vibration of the machine will be amplified while the work equipment is turning with a very small turning radius, and the machine will become unstable. There was a risk that it would cause discomfort to the driver, or that the aircraft could become inoperable.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a working machine capable of improving turning stability and convenience.

The technical means of the present invention for solving the above technical problems are characterized by the following points.
A work machine according to one aspect of the present invention includes a first traveling device that supports the machine body so as to be able to travel on the left side of the machine body, a second traveling device that supports the machine body so that the machine body can travel on the right side of the machine body, and and an operating member for operating traveling and steering, wherein the first traveling device and the second traveling device are respectively driven according to the operating state of the operating member, and the A steering device that causes the aircraft to move straight or turn, and a control device that determines whether or not the aircraft is in a stable state, wherein the control device controls whether the operation member is positioned to the left or right to the maximum amount. When it is determined that the vehicle body is in a stable state, the steering device drives the first travel device and the second travel device in different directions at the same drive speed, or The first traveling device and the second traveling device are driven in different directions so that the absolute value of the difference between the driving speed of the traveling device and the driving speed of the second traveling device is equal to or less than a predetermined threshold value, and the driving speed is zero. If it is determined that the operation member is not operated to the left or right by the maximum amount or if the aircraft is not in a stable state, the zero turn is prohibited. do.

Further, in one aspect of the present invention, the work machine includes an operation detection unit that detects an operation state of the operation member, and the steering device detects power output from a prime mover provided in the machine body to the Transmission to at least one of the first traveling device and the second traveling device according to the operating state of the operating member to drive the traveling device, and the control device permits the zero turn, the operating member The steering device is controlled based on the operation state of to execute the zero turn.

Further, in one aspect of the present invention, when the control device determines that the operation member is operated to the left or right by the maximum amount and that the aircraft is not in a stable state, , of the first traveling device and the second traveling device, the traveling device positioned farther from the turning center of the machine body is driven by the steering device, and the traveling device located closer to the turning center of the machine body is driven on the inside of turning. The traveling device is driven by the steering device in a driving direction opposite to the traveling device on the outside of the turn at a driving speed lower than that of the traveling device on the outside of the turn.

Further, in one aspect of the present invention, when the operating member is operated to either the left or the right by an amount smaller than a maximum amount, the control device controls the operation of the first travel device based on the operating state of the operating member. Of the second traveling devices, a turning outer traveling device located far from the turning center of the fuselage is driven by the steering device, and a turning inner traveling device located near the turning center of the fuselage is driven by the turning outer traveling device. It is driven by the steering device in a driving direction opposite to the turn outer traveling device at a driving speed which is a predetermined ratio lower than the driving speed of the traveling device.

Further, in one aspect of the present invention, of the first traveling device and the second traveling device, the driving speed of the traveling device on the inner side of the turn located near the turning center of the fuselage becomes 0, or At least one of the traveling devices is driven by the steering device so as to be slower than the driving speed of the outer traveling device located far from the turning center of the fuselage at a turning radius larger than the turning radius at the zero turn. and a second turn mode in which the zero turn can be executed. When the first turn mode is selected by the mode selection unit, the steering device is controlled based on the operation state of the operation member to perform the other turn, and the second turn mode is selected by the mode selection unit. When it is determined that the turn mode is selected, the operation member is operated to the left or right by the maximum amount, and the aircraft is in a stable state, the zero turn is permitted, and based on the operation state of the operation member The steering device is controlled to execute the zero turn.

Further, in one aspect of the present invention, when the first turn mode is selected by the mode selection unit, the control device controls the steering device based on the operation state of the operation member to perform the turn of
In one aspect of the present invention, as the first turn mode, a super pivot turn mode in which the aircraft can perform a pivot turn, a pivot turn mode in which the aircraft can perform a pivot turn, or the A gentle turning mode in which the body can make a gentle turning can be selected by the mode selection unit.

Further, in one aspect of the present invention, the work machine includes a speed detection unit that detects the speed of the machine body, and the control device detects that the machine body is in a stable state when the speed of the machine body is equal to or lower than a predetermined speed. If the speed of the aircraft is higher than the predetermined speed, it is determined that the aircraft is not in a stable state.
Further, in one aspect of the present invention, each of the first traveling device and the second traveling device is composed of a crawler belt type traveling device, and the steering device is adapted to control the driving speed of the first traveling device and the second traveling device. and a continuously variable transmission for steplessly changing the drive speed of the traveling device, and the control device controls the speed change of the continuously variable transmission to control the speed of the first traveling device and the second traveling device. The driving speed and driving direction are changed respectively.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the working machine which improved the stability and the convenience of turning.

It is a figure which shows the power transmission structure with which a working machine is equipped. FIG. 3 is a control block diagram of a travel system of the working machine; FIG. 4 is a characteristic diagram of turn modes executed by the work machine; 4 is a flow chart showing a turning motion of the working machine; FIG. 5 is a flow chart showing the details of the zero-turn mode process of FIG. 4; FIG. 1 is an overall side view of a working machine; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.
6 is a side view of work machine 100. FIG.
In this embodiment, the working machine 100 is a self-drawable combine harvester. In addition, the work machine according to the present invention is not limited to a combine harvester, and may be configured by other work machines such as a tractor, a track loader, or a backhoe.

As shown in FIG. 6, the work machine 100 includes a machine body 2 and a traveling device 1 that supports the machine body 2 so as to be able to travel. The traveling device 1 comprises a first crawler belt type traveling device 1L provided on the lower left side of the machine body 2 and a second crawler belt type traveling device 1R provided on the lower right side of the machine body 2 (see FIG. 1). ). The first travel device 1L and the second travel device 1R support the body 2 so that it can travel.
A reaping device 3 is connected to the front part of the machine body 2 so as to be vertically movable. The reaping device 3 is a multi-row reaping reaping device. A driver's seat 4 in which a driver rides is provided on the right front part of the body 2. - 特許庁A control stand 6 is provided between the driver's seat 4 and the reaping work device 3. - 特許庁The control table 6 is provided with a plurality of operation members (reference numerals omitted in FIG. 6) that can be operated by the driver seated in the driver's seat 4 .

A prime mover 5 that is a driving source of the work machine 100 is provided inside the machine body 2 . The prime mover 5 consists of an engine. Alternatively, other prime movers such as electric motors may be used. A threshing device 7 is mounted on the left rear portion of the machine body 2 . A grain recovery tank 9 including a screw type unloader 8 is mounted on the right side of the threshing device 7 .
The reaping work device 3 includes a lifting device 11, a clipper-type reaper 12, a frame 13, a grain culm conveying device (not shown), and the like. The frame 13 is supported by the front part of the body 2 so that it can swing vertically. The grain culm conveying device conveys harvested grain culms toward a feed chain (not shown) of the threshing device 7 . A hydraulic cylinder 15 is provided in the lower part of the body 2 . The hydraulic cylinder 15 raises and lowers the entire reaping work device 3 .

FIG. 1 is a diagram showing a power transmission structure provided in work machine 100. As shown in FIG.
A hydraulic continuously variable transmission (HST) 21, 22, 23 is provided on one side surface of the transmission case 20 shown in FIG. The first continuously variable transmission 21 drives the first traveling device 1L, the second continuously variable transmission 22 drives the second traveling device 1R, and the third continuously variable transmission 23 drives the reaping device 3. That is, the continuously variable transmissions 21 and 22 are transmissions for traveling, and the continuously variable transmission 23 is a transmission for work. In addition, in FIG. 1, the first traveling device 1L is shown on the right side of the second traveling device 1R for the sake of convenience.

Each of the continuously variable transmissions 21, 22, 23 includes axial plunger type variable displacement hydraulic pumps (hereinafter referred to as "variable displacement pumps") P1, P2, P3 and constant displacement hydraulic motors (hereinafter referred to as "constant displacement pumps"). motors") M1, M2 and M3, and port blocks 21c, 22c and 23c for hydraulic control.
An input shaft 24 is provided substantially in the center of the transmission case 20 . Power from the prime mover 5 is transmitted via a belt to one end of an input shaft 24 protruding from the transmission case 20 on the side opposite to the continuously variable transmissions 21 to 23 .

Power input from the prime mover 5 to the input shaft 24 via the belt is transmitted from the counter gear G1 to the pump shafts 21a, 22a of the continuously variable transmissions 21, 22 via the gears G2, G3. Further, power input from the prime mover 5 to the input shaft 24 is transmitted from the counter gear G1 to the pump shaft 23a of the continuously variable transmission 23 via the gear G4. That is, the variable displacement pumps P1, P2, and P3 are driven by the power of the prime mover 5. As shown in FIG.

By changing the angles of the swash plates provided in the variable displacement pumps P1, P2, and P3, it is possible to change the discharge direction and discharge amount of hydraulic oil from the variable displacement pumps P1, P2, and P3. Hydraulic fluid discharged from the variable displacement pumps P1, P2 and P3 rotates the corresponding constant displacement motors M1, M2 and M3. By changing the discharge direction and discharge amount of hydraulic oil from the variable displacement pumps P1, P2, P3, the corresponding constant displacement motors M1, M
2. It is possible to switch the direction of rotation of the motor shafts 21b, 22b, and 23b of M3 and to continuously change the speed from 0 (zero).

The speed change output from the motor shaft 21b of the first continuously variable transmission 21 is transmitted to the gear type first auxiliary transmission mechanism 25, the first intermediate shaft 26, the second intermediate shaft 27, the gear reduction mechanism 28, and the axle 29. As the axle 29 rotates, the first travel device 1L is driven. Further, the speed change output from the motor shaft 22b of the second continuously variable transmission 22 is transmitted to the gear type second auxiliary transmission mechanism 30, the first intermediate shaft 31, the second intermediate shaft 27, the gear reduction mechanism 32, and the axle 33. The rotation of the axle 33 drives the second travel device 1R. The work machine 100 is provided with the steering device 10 including such mechanical parts 21, 22, 24 to 33, 1L, and 1R.

Each of the sub-transmission mechanisms 25 and 30 is configured to be able to shift from a neutral state to two stages of a low speed stage and a high speed stage. The power changed by the first continuously variable transmission 21 is switched between two stages, a high speed stage and a low speed stage, by the first auxiliary transmission mechanism 25 . The power shifted by the second continuously variable transmission 22 is switched between two stages, a high speed stage and a low speed stage, by the second auxiliary transmission mechanism.
The gear reduction mechanisms 28 and 32 are loosely supported by the second intermediate shaft 27 . The first intermediate shaft 26 is supported by the left and right side walls of the transmission case 20 , and the first intermediate shaft 31 is loosely fitted and supported by the first intermediate shaft 26 . Between the first intermediate shaft 26 and the first intermediate shaft 31, a hydraulically operated multi-plate linear clutch 34 is provided. The straight traveling clutch 34 is turned on and off by the hydraulic pressure of the working oil.

When the machine body 2 is caused to travel straight ahead, the first continuously variable transmission 21 and the second continuously variable transmission 22 are set in the same driving state (the angle of the swash plate of the variable displacement pumps P1 and P2, the angle of the swash plate of the variable displacement pumps P1 and P2 , and the rotation direction and rotation speed of the constant displacement motors M1 and M2 are the same or substantially the same), and the straight traveling clutch 34 is engaged (connected state). As a result, the first intermediate shaft 26 and the first intermediate shaft 31 are integrated, the axles 29 and 33 rotate in the same direction at the same speed, and the left and right traveling devices 1L and 1R also rotate in the same direction and at the same speed. , the airframe 2 moves straight.

When turning the machine body 2 left and right, the straight traveling clutch 34 is disengaged (disengaged), and the first continuously variable transmission 21 and the second continuously variable transmission 22 are driven in different driving states, or the first At least one of the continuously variable transmission 21 and the second continuously variable transmission 22 is driven.
An inwardly expanding brake 35 is attached to the first intermediate shaft 26 . For example, when the working machine 100 (body 2) is parked, the motor 5 is stopped and the brake 35 is applied.

When the straight traveling clutch 34 is not engaged or disengaged, there is no pressure in an oil passage (not shown) for supplying operating oil to the straight traveling clutch 34 . At this time, a friction plate (not shown) is elastically pressed by a spring provided inside the rectilinear clutch 34, and the rectilinear clutch 34 is lightly connected. Therefore, if the brake 35 is applied while the straight traveling clutch 34 is not being engaged or disengaged, the braking action is applied not only to the first intermediate shaft 26 but also to the first intermediate shaft 31, and the first traveling device 1L and the first traveling device 1L are affected. The second travel device 1R is braked.

The speed change output from the motor shaft 23b of the third continuously variable transmission 23 is transmitted to the reaping work device 3 via gears G12 and G13, the PTO shaft 36, a reaping clutch (not shown), a belt (not shown), and the like. be done. As a result, the reaping work device 3 is driven.
FIG. 2 is a control block diagram of a traveling system of work machine 100. As shown in FIG.
The work machine 100 also has an electrical configuration of a work system for controlling the reaping work device 3 and the threshing work device 7, etc. However, since this configuration is the same as a known configuration, the present embodiment Illustration and description are omitted here.

Work machine 100 is provided with control device 50 . The control device 50 is composed of an electronic control unit (ECU) including a CPU and a memory. Components other than the control device 50 and the detection units 62 to 65 shown in FIG.
The work machine 100 and the steering device 10 are provided with a main shift lever 37, an auxiliary shift lever 38, a steering lever 39, a mode selection switch (mode selection portion) 40, and an accelerator lever 41 as operating members. These operation members 37 to 41 are installed on the operation table 6 (FIG. 6) or the like.

The main shift lever 37 can be operated to swing from a neutral position in the forward direction and the rearward direction. The main shift lever 37 is biased by an elastic member such as a spring so as to remain stationary at a neutral position when not operated. A potentiometer 42 detects the operating state of the main shift lever 37 (whether or not it is operated, the direction of operation, and the amount of operation).
The sub-transmission lever 38 can be swung forward from the neutral position in the high-speed direction and backward in the low-speed direction. The auxiliary shift lever 38 is urged by an elastic member such as a spring so as to rest at a neutral position in an unoperated state. The operating state (whether or not it is operated and the direction of operation) of the auxiliary shift lever 38 is detected by a switch mechanism 43 . The switch mechanism 43 has, for example, a plurality of electrical fixed contacts and movable contacts. By switching, an electric signal corresponding to the contact state is output from the switch mechanism 43 .

The steering lever 39 can be swung from a neutral position, i.e., a straight-ahead position, in a left-turning direction and a right-turning direction. The steering lever 39 is biased by an elastic member such as a spring so as to remain stationary at the straight-ahead position in an unoperated state. A potentiometer 44 detects the operating state of the steering lever 39 (whether or not the steering lever 39 is operated, the direction of operation, and the amount of operation).
Mode selection switch 40 is a switch operated to select a turn mode for turning work implement 100 . An operation knob (reference numeral omitted) of the mode selection switch 40 can be switched between four positions by swinging. The switching position of the mode selection switch 40 is detected by a switch mechanism 45 . The configuration of the switch mechanism 45 is the same as that of the switch mechanism 43 except for the number of fixed contacts, for example.

The slow turning mode can be selected by switching the mode selection switch 40 to the first position P1. The pivot turning mode can be selected by switching the mode selection switch 40 to the second position P2. By switching the mode selection switch 40 to the third position P3, the super pivot turning mode can be selected. The zero turn mode can be selected by switching the mode selection switch 40 to the fourth position P4.

Four turn modes, that is, a slow turning mode, a pivot turning mode, a very pivot turning mode, and a zero turn mode are executed by the working machine 100, so that at least one of the first traveling device 1L and the second traveling device 1R is turned. One side drives and the body 2 turns. The turning radius of the airframe 2 becomes smaller in the order of gentle turn mode, pivot turn mode, super pivot turn mode, and zero turn mode. When the zero turn mode is executed in work implement 100, machine body 2 turns with a minimal turning radius that is close to zero (including zero). The zero-turn mode is also called a minimal turning mode or a high-speed spin turning mode.

The accelerator lever 41 can be swung in an acceleration direction forward from the home position and in a return direction to the home position (opposite to the acceleration direction). The accelerator lever 41 is biased by an elastic member such as a spring so as to rest at the home position in an unoperated state. A potentiometer 46 detects the operation state of the accelerator lever 41 (whether or not it is operated and the amount of operation).

The control device 50 operates the main shift lever 37, the sub shift lever 38, the steering lever 39, the mode selection switch 40, and the accelerator based on electric signals output from the potentiometers 42, 44, 46 and the switch mechanisms 43, 45. The operating state of the lever 41 is detected.
The first valve unit 51 and the first servo cylinder 55 are components for controlling the speed change state of the first continuously variable transmission 21 corresponding to the first travel device 1L. The second valve unit 52 and the second servo cylinder 58 are components for controlling the speed change state of the continuously variable transmission 22 corresponding to the second travel device 1R. The valve units 51 and 52 each include a pair of normally closed electromagnetic on-off valves (not shown) and a pair of normally open electromagnetic on-off valves (not shown).

The first servo cylinder 55 is operated by the hydraulic pressure of hydraulic oil supplied from the first valve unit 51 to change the angle of the swash plate of the variable displacement pump P1 included in the first continuously variable transmission 21 . The second servo cylinder 58 is operated by the hydraulic pressure of hydraulic oil supplied from the second valve unit 52 to change the angle of the swash plate of the variable displacement pump P2 included in the second continuously variable transmission 22 . A potentiometer 56 detects the angle of the swash plate of the variable displacement pump P1.
A potentiometer 59 detects the angle of the swash plate of the variable displacement pump P2. The configuration of the valve units 51, 52 and the servo cylinders 55, 58 is similar to that of known valve units and servo cylinders, such as that disclosed in Cited Document 1, for example.

The constant displacement motor M1 is rotationally driven by hydraulic fluid discharged from the variable displacement pump P1. The constant displacement motor M2 is rotationally driven by hydraulic oil discharged from the variable displacement pump P2. A rotation detection unit 57 detects the rotation speed and rotation direction of the constant capacity motor M1. A rotation detection unit 60 detects the rotation speed and rotation direction of the constant displacement motor M2. The configuration of the continuously variable transmissions 21, 22 including these pumps P1, P2 and motors M1, M2 is the same as that of a known continuously variable transmission such as that disclosed in Patent Document 1, for example.

The third valve unit 53 and the subtransmission cylinder 61 are components for controlling the shift states of the subtransmission mechanisms 25 and 30 . The third valve unit 53 includes a pair of electromagnetic switching valves (not shown). The subtransmission cylinder 61 is operated by the hydraulic pressure of the hydraulic fluid supplied from the third valve unit 53, and shifts the subtransmission mechanisms 25, 30 to high speed, low speed, or neutral through a shift shaft (not shown). switch. The configurations of the third valve unit 53 and the auxiliary transmission cylinder 61 are the same as those of a known valve unit and transmission operation cylinder, such as those disclosed in Cited Document 1, for example.

The control device 50 controls the opening/closing state of the electromagnetic on-off valve of the third valve unit 53 based on the operating state (operating position and operating direction) of the sub-transmission lever 38 detected by the switch mechanism 43, whereby the sub-transmission is performed. By actuating the cylinder 61, the shift states of the auxiliary transmission mechanisms 25 and 30 are switched.
The fourth valve unit 54 is configured to control the on/off state of the straight traveling clutch 34 . The fourth valve unit 54 includes a pair of electromagnetic switching valves (not shown). The linear clutch 34 is engaged (connected state), disengaged (disconnected state), or switched to a neutral state by the hydraulic pressure of hydraulic oil supplied from the fourth valve unit 54 . The configurations of the fourth valve unit 54 and the linear clutch 34 are similar to those of known valve units and linear clutches, such as those disclosed in Cited Document 1, for example.

The control device 50 controls the opening/closing state of the electromagnetic opening/closing valve of the fourth valve unit 54 based on the operating state (operating direction and operating amount) of the steering lever 39 detected by the potentiometer 44, whereby the straight traveling clutch is operated. Switch 34 to on, off, or neutral.
The control device 50 also detects the operating state (operating direction and operating amount) of the main gear shift lever 37 detected by the potentiometer 42, the operating state (operating direction and operating amount) of the steering lever 39 detected by the potentiometer 44. ), the operating state (operating position and operating direction) of the sub-transmission lever 38 detected by the switch mechanism 43, and the angles of the swash plates of the variable displacement pumps P1 and P2 detected by the potentiometers 56 and 59, Feedback control is performed on the open/closed states of the electromagnetic on-off valves of the valve units 51 and 52 .

As a result, the servo cylinders 55 and 58 are actuated to change the angles of the swash plates of the variable displacement pumps P1 and P2 of the continuously variable transmissions 21 and 22, respectively. In accordance therewith, the discharge direction and discharge amount of the hydraulic oil discharged from the variable displacement pumps P1 and P2 are changed, and the drive states (rotation direction and rotation speed) of the constant displacement motors M1 and M2 are also changed. That is, the control device 50 performs continuously variable transmission based on the operation state of the main gear shift lever 37, the sub gear shift lever 38, the steering lever 39, the mode selection switch 40, or the like (the accelerator lever 41 may be included). The speed of the devices 21 and 22 is changed.

Specifically, for example, in a state where the steering lever 39 is in the neutral position, the main gear shift lever 71 is pivotally operated from the neutral position in the forward direction or the reverse direction, and the auxiliary gear lever 38 is moved from the neutral position in the high speed direction or the low speed direction. It is operated to swing in the direction. In this case, the control device 50 determines the target shift positions of the continuously variable transmissions 21, 22 (variable displacement pumps P1, P2 The same value is determined as the target angle of the swash plate of the Then, the control device 50 operates the servo cylinders 53 and 54 by feedback-controlling the valve units 51 and 52 as described above to change the angles of the swash plates of the variable displacement pumps P1 and P2. The angle of the plate is matched with the target shift position (target angle), and the matching state is maintained.

As described above, according to the operation of the accelerator lever 41, the constant capacity motors M1 and M2 are rotationally driven in the same direction at the same speed, and the continuously variable transmissions 21 and 22 are shifted forward or backward. Further, the first travel device 1L and the second travel device 1R are driven in the same direction at the same speed, and the machine body 2 moves forward or backward without turning. The control device 50 controls driving of the prime mover 5 based on the operating state (operating direction and operating amount) of the accelerator lever 41 detected by the potentiometer 46 .

Further, for example, while the machine body 2 is moving forward or backward, the steering lever 39 is swung from the neutral position in the left turning direction (or right turning direction). In this case, the control device 50 corrects the target shift position of the first continuously variable transmission 21 (or the second continuously variable transmission 22) corresponding to the operating direction of the steering lever 39 based on the operation amount of the steering lever 39. do.
Specifically, as the amount of operation of the steering lever 39 increases, the control device 50 controls the constant capacity motor M1 of the first continuously variable transmission 21 (or the second continuously variable transmission) corresponding to the operating direction of the steering lever 39. The target shift position of the variable displacement pump P1 of the first continuously variable transmission 21 (or the variable displacement pump P2 of the second continuously variable transmission 22) is corrected in the direction of decelerating the rotational speed of the constant displacement motor M2 of 22). .

The control device 50 operates the servo cylinders 55 and 58 by feedback-controlling the valve units 51 and 52 as described above, and adjusts the angle of the swash plate of the variable displacement pump P1 of the first continuously variable transmission 21 to The target shift position after correction is made to match, the state of matching is maintained, and the state in which the angle of the swash plate of the variable displacement pump P2 of the second continuously variable transmission 22 matches the target shift position is maintained. As a result, the driving speed of the constant displacement motor M1 is reduced to be slower than the driving speed of the constant displacement motor M2, and the continuously variable transmissions 21 and 22 are shifted for left turning. Further, the driving speed of the first traveling device 1L is reduced to become slower than the driving speed of the second traveling device 1R, and the machine body 2 turns leftward.

The speed detector 62 detects the speed of the machine body 2 and the driving speed of the traveling device 1 (1L, 1R). The tilt detection unit 63 is composed of a gyro sensor or the like, and detects the tilt angle and attitude of the body 2 . The elevation position detector 64 detects the elevation height of the reaping work device 3 (FIG. 6). The object detection unit 65 is composed of a lidar, an ultrasonic sensor, or an imaging device (camera), and detects objects around the aircraft 2 . Objects include, for example, road surfaces, structures, people, and obstacles. Based on the detection result of at least one of the detection units 62 to 65, 57, 60, the control device 50 determines whether or not the body 2 is in a stable state.

FIG. 3 is a characteristic diagram of a turn mode executed by work implement 100. As shown in FIG.
In the characteristic diagram of FIG. 3, the operation amount of the steering lever 39 is shown on the horizontal axis. The vertical axis indicates the ratio (inside/outside speed ratio) of the drive speed (output rotation speed) of the travel device located near the turning center to the (output rotation speed). Control data (table data or function data) representing each line L1 to L4 shown in FIG. 3 is stored in the internal memory of the control device 50 in advance.

When the steering lever 39 is swung in the left or right turning direction and the accelerator lever 41 is swung in the acceleration direction to turn the work machine 100 (body 2) left or right, Of the left and right traveling devices 1L and 1R, the traveling device on the inner side of the turn is decelerated by the steering device 10 relative to the traveling device on the outer side of the turning.
When the mode selection switch 40 (FIG. 2) is operated to select one of the slow turning mode, pivot turning mode, super pivot turning mode, and zero turn mode, the control device 50 Execute the selected turn mode.

For example, when the steering lever 39 is swung in the left or right turning direction during execution of any of the turn modes, the control device 50 causes the potentiometers 42 and 44 and the switch mechanism 43 to operate the steering lever 39 to rotate. 39, the operating direction and amount of the main shift lever 37, and the operating position of the auxiliary shift lever 38 are detected. Further, when the accelerator lever 41 is swung in the acceleration direction, the control device 50 detects the amount of operation of the accelerator lever 41 .

Based on the detected operating states of the operating members 37 to 40, the control device 50 controls the traveling device on the outer side of the turn that does not correspond to the operating direction of the steering lever 39 (the traveling device located in the direction opposite to the operating direction of the steering lever 39). device), and the target shift position of the continuously variable transmission (either the first continuously variable transmission 21 or the second continuously variable transmission 22) corresponding to the traveling device. do.

Next, the control device 50 controls the traveling device on the inner side of the turn (position in the operation direction of the steering lever 39) based on the turning mode being executed, the amount of operation of the steering lever 39, and the control data of lines L1 to L4 in FIG. The inside/outside speed ratio is determined between the drive speed Vi of the traveling device on the turning side and the drive speed Vo of the traveling device on the outside of the turn (inside/outside speed ratio=Vi/Vo). Then, the control device 50 multiplies the determined inside/outside speed ratio by the drive speed of the travel device on the outside of the turn to determine the drive speed and the drive direction of the travel device on the inside of the turn.

For example, when the gentle turning mode is being executed, the control device 50 determines the inside/outside speed ratio based on the operation amount of the steering lever 39 and the control data of line L1 in FIG. As indicated by the line L1, in the slow turning mode, as the operation amount of the steering lever 39 increases, the inside/outside speed ratio decreases. The ratio becomes 0.3 (L1 in FIG. 3). That is, in the gentle turning mode, the inner/outer speed ratio is 0.3 or more and less than 1. Further, the driving speed Vi of the traveling device on the inner side of the turn is decelerated to a value that is 0.3 times or more the driving speed Vo of the traveling device on the outer side of the turning and smaller than the driving speed Vo (specifically, 1 times the driving speed Vo). (0.3Vo≦Vi<Vo).

Further, when the pivot turning mode is being executed, the control device 50 determines the inside/outside speed ratio based on the amount of operation of the steering lever 39 and the control data of line L2 in FIG. As indicated by the line L2, in the pivot turning mode, as the amount of operation of the steering lever 39 increases, the inside/outside speed ratio decreases. becomes (L2 in FIG. 3). That is, in the pivot turning mode, the inner/outer speed ratio is 0 or more and less than 1. Further, the drive speed Vi of the travel device on the inner side of the turn is reduced to a value equal to or greater than 0 and smaller than the drive speed Vo of the travel device on the outer side of the turn (0≤Vi<Vo). When the drive speed of the travel device on the inner side of the turn is 0, the travel device is in a stopped state.

Further, when the super pivot turning mode is being executed, the control device 50 determines the inside/outside speed ratio based on the operation amount of the steering lever 39 and the control data of line L3 in FIG. As indicated by the line L3, in the super-stationary turning mode, as the operation amount of the steering lever 39 increases, the inside/outside speed ratio decreases. 0.3 (L3 in FIG. 3). That is, in the super pivot turning mode, the inside/outside speed ratio is -0.3 or more and less than 1. In addition, the drive speed Vi of the travel device on the inside of the turn is reduced to a value that is -0.3 times or more the drive speed Vo of the travel device on the outside of the turn and smaller than the drive speed Vo (-0.3Vo≤Vi<Vo ). When the inside/outside speed ratio is determined to be a negative value (negative value), the travel device on the inside of the turn is driven in the direction opposite to the travel device on the outside of the turn (reverse drive).

Further, when the zero-turn mode is being executed, the control device 50 determines the inside/outside speed ratio based on the operation amount of the steering lever 39 and the control data of line L4 in FIG. As indicated by line L4, in the zero-turn mode, as the amount of operation of the steering lever 39 increases, the inside/outside speed ratio decreases, and when the steering lever 39 is operated by the maximum amount, the inside/outside speed ratio becomes -1. becomes (L4 in FIG. 3). That is, in the zero-turn mode, the inner/outer speed ratio is -1 or more and less than 1. Further, the drive speed Vi of the travel device on the inside of the turn is reduced to a value that is at least -1 times the drive speed Vo of the travel device on the outside of the turn and smaller than the drive speed Vo (-Vo≤Vi<Vo).

As described above, when the control device 50 determines the driving speed and driving direction of the traveling devices 1L and 1R, the control device 50 determines the traveling devices 1L, 1R, 1L, 1L, 1L, 1L, 1L, 1L, 1R based on prestored calculation data (control data such as calculation formulas or tables). Target shift positions of the continuously variable transmissions 21 and 22 corresponding to 1R are determined. Then, the control device 50 feedback-controls the valve units 51 and 52 as described above, operates the servo cylinders 55 and 58, changes the angles of the swash plates of the variable displacement pumps P1 and P2, and adjusts the angle of the swash plates. is matched with the corresponding target shift position, and the matching state is maintained. As a result, hydraulic fluid is discharged from the variable displacement pumps P1 and P2 at a flow rate and pressure corresponding to the target shift position, and the hydraulic fluid is supplied to the constant displacement motors M1 and M2.

Then, for example, when the slow turning mode is being executed, the constant displacement motors M1 and M2 are driven in the same direction at different speeds. Of the left and right traveling devices 1L and 1R, the traveling device on the inner side of the turn is driven in the same direction as the traveling device on the outer side of the turning at a driving speed lower than that of the traveling device on the outer side of the turning. As a result, the body 2 slowly turns to the left or right.
Further, when the pivot turning mode is being executed, the constant capacity motors M1 and M2 are driven in the same direction at different speeds, or one of the constant capacity motors corresponding to the traveling device on the inner side of the turn is stopped. In addition, the left and right traveling devices 1L and 1R are also driven in the same direction at different speeds, or the traveling device on the inner side of the turn stops.

At this time, if the operation amount of the steering lever 39 is maximum, the control device 50 sets the inside/outside speed ratio to 0, and sets the driving speed of the traveling device on the inner side of the turn to 0. Further, as described above, the control device 50 determines the driving direction of the traveling device on the outer side of the turn according to the operation direction of the steering lever 39, and determines the driving speed of the traveling device on the outer side of the turning according to the operation amount of the steering lever 39 and the accelerator lever. It is determined according to the operation amount of 41 and the like. Further, the control device 50 determines the target shift positions of the continuously variable transmissions 21 and 22 and performs the speed change of the continuously variable transmissions 21 and 22 .

As a result, the travel device on the outside of the turn is driven at a direction and speed corresponding to the operating direction of the steering lever 39 and the amount of operation of the levers 39 and 41, while the travel device on the inside of the turn is stopped. One of the constant-capacity motors M1 and M2, which corresponds to the traveling device on the outer side of the turn, rotates at a direction and speed corresponding to the operating direction of the steering lever 39 and the amount of operation of the levers 39 and 41. On the other hand, the other constant capacity motor corresponding to the traveling device on the inner side of the turn stops. Therefore, the body 2 makes a pivot turn to the left or right.

Note that even during execution of the pivot turning mode, if the amount of operation of the steering lever 39 is not the maximum amount and the amount of operation is not 0, the control device 50 controls the internal and external speeds of the left and right traveling devices 1L and 1R. Determine the ratio to be a positive value greater than 0 and less than 1. Further, as described above, the control device 50 determines the driving direction and driving speed of the traveling device on the inner side of the turn and the traveling device on the outer side of the turning, respectively, and determines the target shift positions of the continuously variable transmissions 21 and 22. , the continuously variable transmissions 21 and 22 are changed. As a result, the constant capacity motors M1 and M2 are driven in the same direction at different speeds, the left and right traveling devices 1L and 1R are also driven in the same direction at different speeds, and the machine body 2 makes a semi-pivot turn leftward or rightward. do. A semi-pivot turn is a turn in which the turning radius of the body 2 is larger than that of a gentle turn and smaller than that of a pivot turn.

Further, when the super pivot turning mode is being executed, the constant displacement motors M1 and M2 are driven in different directions at different speeds. The left and right traveling devices 1L and 1R are also driven in different directions at different speeds.
At this time, if the operation amount of the steering lever 39 is large to some extent, the control device 50 sets the inner/outer speed ratio to a negative value (negative value) smaller than 0 and equal to or greater than -0.3 based on the operation amount of the steering lever 39. to decide. Further, as described above, the control device 50 determines the driving direction and driving speed of the traveling device on the outer side of the turn and the traveling device on the inner side of the turning, respectively, and determines the target shift positions of the continuously variable transmissions 21 and 22. The gears of the continuously variable transmissions 21 and 22 are changed.

As a result, the travel device on the outside of the turn is driven in the direction corresponding to the operation direction of the steering lever 39, while the travel device on the inside of the turn is slower than the travel device on the outside of the turn in the direction opposite to the travel device on the outside of the turn. Drive at drive speed. Among the constant capacity motors M1 and M2, one of the constant capacity motors corresponding to the travel device on the outer side of the turn rotates in the direction corresponding to the operating direction of the steering lever 39, while the travel device on the inner side of the turn is driven to rotate. The other constant displacement motor corresponding to drives in the opposite direction to the one constant displacement motor at a lower drive speed than the one constant displacement motor. As a result, the aircraft 2 makes a pivot turn to the left or right.

Even during execution of the super pivot turning mode, if the operation amount of the steering lever 39 is small and the operation amount is not 0, the control device 50 sets the inside/outside speed ratio to 0 or more and less than 1. Decide on a positive value. Further, as described above, the control device 50 determines the driving direction and driving speed of the traveling device on the inner side of the turn and the traveling device on the outer side of the turning, respectively, and determines the target shift positions of the continuously variable transmissions 21 and 22. , the continuously variable transmissions 21 and 22 are changed.

As a result, the constant capacity motors M1 and M2 are driven in the same direction at different speeds, or one of the constant capacity motors M1 and M2 is stopped. Further, the left and right traveling devices 1L and 1R are also driven in the same direction at different speeds, or one of the left and right traveling devices 1L and 1R is stopped. Therefore, the body 2 makes a gentle leftward or rightward turn, a semi-pivot turn, or a pivot turn.
Also, when the zero-turn mode is being executed, the constant displacement motors M1 and M2 are driven in different directions at different speeds or at the same speed. The left and right traveling devices 1L and 1R are also driven in different directions at different speeds or at the same speed.

At this time, if the operation amount of the steering lever 39 is maximum, the control device 50 determines the inside/outside speed ratio to be -1. Further, as described above, the control device 50 determines the driving direction and driving speed of the traveling device on the inner side of the turn and the traveling device on the outer side of the turning, respectively, determines the target shift positions of the continuously variable transmissions 21 and 22, and The gears of the continuously variable transmissions 21 and 22 are changed. As a result, the constant capacity motors M1 and M2 are driven in different directions at the same speed, the left and right traveling devices 1L and 1R are also driven in different directions at the same speed, and the machine body 2 moves leftward or rightward to approximately zero. A zero turn is performed with a very small turning radius.

Note that even during execution of the zero-turn mode, if the operation amount of the steering lever 39 is not the maximum amount and the operation amount is not 0, the control device 50 sets the inner/outer speed ratio to be greater than -1 and greater than 1. Decide on a small value. Further, as described above, the control device 50 determines the driving direction and driving speed of the traveling device on the inner side of the turn and the traveling device on the outer side of the turning, respectively, determines the target shift positions of the continuously variable transmissions 21 and 22, and The gears of the continuously variable transmissions 21 and 22 are changed.

As a result, the constant capacity motors M1 and M2 are driven in different directions at different speeds, or driven in the same direction at different speeds, or one of the constant capacity motors M1 and M2 is stopped. The left and right traveling devices 1L and 1R are also driven in different directions at different speeds, or driven in the same direction at different speeds, or one of the left and right traveling devices 1L and 1R is stopped. As a result, the aircraft 2 turns leftward or rightward in gentle turns, quasi-pivot turns, pivot turns, super-pivot turns, or quasi-zero turns. A quasi-zero turn is a turn in which the turning radius of the body 2 is larger than that of a super-pivot turn and smaller than that of a zero turn.

When executing a zero turn, as described above, the control device 50 drives the first traveling device 1L and the second traveling device 1R in different directions at the same driving speed by the steering device 10. There may be a slight difference between the driving speed of 1L and the driving speed of the second travel device 1R. In this case, the control device 50 makes the absolute value of the difference between the actual driving speed of the first row device 1L and the actual driving speed of the second traveling device 1R detected by the rotation detectors 57 and 60 approximate zero. The first traveling device 1L and the second traveling device 1R are driven in different directions so as to be equal to or less than the predetermined threshold value, and the zero turn is executed.

Further, when executing a pivot turn, as described above, the control device 50 drives the traveling device on the outer side of the turn, out of the traveling devices 1L and 1R, at the determined direction and speed. The drive speed is set to 0, but the drive speed of the traveling device on the inner side of the turn may be made slightly faster or slower than 0. In this case, the control device 50 controls the steering device 10 so that the absolute value of the actual driving speed of the travel device on the inner side of the turn detected by the rotation detection units 57 and 60 is equal to or less than a predetermined threshold value close to zero. is used to control the drive of the traveling device inside the turn to execute the pivot turn.

Further, when the work device 1 turns, the control device 50 detects the actual driving speeds of the traveling devices 1L and 1R by the rotation detection units 57 and 60, and the actual driving speeds determine the traveling devices 1L and 1R. PI control or the like may be performed to operate the steering device 10 so as to match the driving speed (target speed) determined.
FIG. 4 is a flowchart showing the turning motion of work implement 100 .

When the control device 50 detects that the mode selection switch 40 has been operated (S1: Yes), the control device 50 executes turn mode selection processing (S2). In the turn mode selection process, the control device 50 detects the post-operation position of the mode selection switch 40 based on the output signal from the switch mechanism 45, and further detects the turn mode corresponding to the post-operation position. , it is determined that the turn mode has been selected.

When the zero-turn mode is not selected (S3: No), when the steering lever 39 is operated (S6: Yes), the control device 50 performs the selected turn mode processing other than the zero-turn mode (slow turning mode). , pivot turning mode, or super pivot turning mode) is executed (S7).
At this time, the control device 50 controls the driving direction and driving speed of the traveling devices 1L and 1R based on the operation states of the steering lever 39, the main gear lever 37, the auxiliary gear lever 38, etc., as described above. 21 and 22 and the inside/outside speed ratio are determined. The control device 50 changes the speed of the continuously variable transmissions 21 and 22 using the valve units 51 and 52, the servo cylinders 55 and 58, and the like. When the accelerator lever 41 is swung in the acceleration direction, the control device 50 controls the continuously variable transmissions 21 and 22 to change the actual driving directions and driving speeds of the traveling devices 1L and 1R to the traveling devices 1L and 1R. Match or substantially match the determined drive direction and drive speed (target speed) of 1R, and make the body 2 turn left or right in gentle turn, semi-pivot turn, pivot turn, or super pivot turn. swirl.

On the other hand, when the zero-turn mode is selected (S3: Yes) and the steering lever 39 is operated (S4: Yes), the control device 50 executes the zero-turn mode process (S5).
FIG. 5 is a flow chart showing the details of the zero-turn mode process.
First, the control device 50 executes a body state determination process (S8). In the machine body state determination process, the control device 50 compares the speed of the machine body 2 detected, for example, by the speed detector 62 (FIG. 2) with a predetermined speed stored in advance. The predetermined speed is set to 0 or a very low speed close to 0.

If the speed of the airframe 2 is faster than the predetermined speed, the control device 50 determines that the airframe 2 is in an unstable state (S9: No), prohibits the zero turn, and records the result in the internal memory (Fig. 5). S10).
On the other hand, if the speed of the aircraft 2 is equal to or less than the predetermined speed, the control device 50 determines that the aircraft 2 is in a stable state because the aircraft 2 is in a stopped state or a substantially stopped state (S9: Yes). Then, the control device 50 confirms the operation amount of the steering lever 39 .

If the steering lever 39 is swung in the left or right turning direction by an operation amount smaller than the maximum amount immediately before the process S4 in FIG. is not the maximum (S11 in FIG. 5: No), the zero turn is prohibited, and the result is recorded in the internal memory (S13).
On the other hand, if the steering lever 39 is swung to the maximum amount in the left or right turning direction immediately before processing S4 in FIG. After confirming that (S11 in FIG. 5: Yes), the zero turn is permitted and the zero turn flag provided in a predetermined storage area of the internal memory is turned on (S12).

Then, when the accelerator lever 41 is swung in the acceleration direction (S14: Yes), the control device 50 confirms whether or not the zero turn flag is turned on. If the zero-turn flag is ON (S15: Yes), the controller 50 executes zero-turn (S16).
At this time, the control device 50 determines the driving direction and the driving speed of the traveling device on the outer side of the turning out of the left and right traveling devices 1L and 1R, based on the operating direction and amount of operation of the steering lever 39, and the like. Further, the control device 50 determines the inside/outside speed ratio to be -1, and multiplies the inside/outside speed ratio by the drive speed of the travel device on the outside of the turn to determine the drive speed of the travel device on the inside of the turn. Further, the control device 50 determines the direction opposite to the driving direction of the traveling device on the outside of the turn as the driving direction of the traveling device on the inside of the turning. Then, the control device 50 drives the traveling device on the outer side of the turn and the traveling device on the inner side of the turning with the determined driving direction and driving speed by the steering device 10, and executes a zero turn to the left or right of the body 2. do. When the zero turn is completed, the control device 50 turns off the zero turn flag (S17).

On the other hand, if the zero turn flag is not turned on (S15: No), the control device 50 executes a turn other than the zero turn (S18).
At this time, the control device 50 determines the driving direction and the driving speed of the traveling device on the outer side of the turning out of the left and right traveling devices 1L and 1R, based on the operating direction and amount of operation of the steering lever 39, and the like. Further, the control device 50 determines the inside/outside speed ratio to be a value somewhat larger than -1. In addition, the control device 50 multiplies the inside/outside speed ratio by the drive speed of the travel device on the outside of the turn to determine the drive speed of the travel device on the inside of the turn. Further, the control device 50 determines the direction opposite to the driving direction of the traveling device on the outside of the turn as the driving direction of the traveling device on the inside of the turning. Then, the control device 50 drives the traveling device on the outer side of the turn and the traveling device on the inner side of the turning by the steering device 10 at the determined driving direction and driving speed, thereby causing the machine body 2 to turn other than zero turn (quasi-zero turn, super-reliable turn). Turn left or turn right by ground turn, pivot turn, quasi-pivot turn, or gentle turn).

More specifically, at this time, for example, the control device 50 operates the traveling device on the outer side of the turning out of the first traveling device 1L and the second traveling device 1R based on the operation state (operation direction and operation amount) of the steering lever 39. The traveling device on the inner side of the turn is driven by the steering device 10, and the traveling device on the inner side of the turn is driven by the steering device 10 at a driving speed lower than the driving speed of the traveling device on the outer side of the turn in a driving direction opposite to that of the traveling device on the outer side of the turning, Execute a quasi-zero turn or a super pivot turn.

Alternatively, the control device 50 drives the traveling device on the outer side of the turn by the steering device 10 based on the operation state of the steering lever 39, and drives the traveling device on the inner side of the turning at a predetermined speed with respect to the driving speed of the traveling device on the outer side of the turning. At a relatively slow drive speed, the steering gear 10 is driven in the drive direction opposite to the travel gear on the outside of the turn to perform a quasi-zero turn or super-pivot turn.
The control device 50 also controls the difference between the driving speed of the traveling device on the outer side of the turn and the driving speed of the traveling device on the inner side of the turning (the traveling device on the outer side of the turning) when executing a quasi-zero turn or a super pivot turn in the above case. The amount by which the drive speed of the traveling device on the inner side of the turn is delayed with respect to the drive speed of the turn) is larger than the threshold value that suppresses the difference between the drive speed of the traveling device on the outer side of the turn and the drive speed of the traveling device on the inner side of the turn when executing zero turn. do.

As another example, in the machine body state determination process of step S3, the control device 50 compares the tilt angle of the machine body 2 detected by the tilt detector 63 (FIG. 2) with a predetermined angle, and determines that the tilt angle of the machine body 2 is If the tilt angle is less than or equal to the predetermined angle, it is determined that the body 2 is in a stable state (S9 in FIG. 5: Yes). : No).

Further, the control device 50 compares the elevation height of the reaping work device 3 (FIG. 6) from the ground detected by the elevation position detector 64 (FIG. 2), for example, with a predetermined height, and determines the elevation height of the reaping work device 3. If the height is less than the predetermined height, the center of gravity of the working machine 100 is low, so it is determined that the machine body 2 is in a stable state (S9 in FIG. 5: Yes), and the lifting height of the reaping work device 3 is the predetermined height If it is greater than or equal to , it may be determined that the machine body 2 is in an unstable state (S9: No) because the center of gravity of the work implement 100 is high.

Further, for example, when the object detection unit 65 ( FIG. 2 ) detects that there is an obstacle in the surroundings with which each part of the work machine 100 comes into contact by performing a zero turn of the work machine 100 , the control device 50 If it is determined that the aircraft 2 is in an unstable state (S9 in FIG. 5: No) and the obstacle is not detected by the object detection unit 65, the control device 50 determines that the aircraft 2 is in a stable state ( S9: Yes) may be done.

Further, the control device 50 may determine whether or not the aircraft 2 is in a stable state based on stability conditions other than those described above. Furthermore, the control device 50 may determine whether the stable state of the aircraft 2 is appropriate based on whether two or more of the stability conditions described above are appropriate.
In addition, the control device 50 evaluates the stability of the aircraft 2 in a plurality of stages based on the stability conditions as described above, and determines the turn to be executed instead of the zero turn in processing S17 based on the evaluation results. good too. In this case, for example, the control device 50 may increase the turning radius of the body 2 by increasing the inside/outside speed ratio as the stability of the body 2 decreases. Further, for example, when the stability of the body 2 is too low, the control device 50 may prevent the turning of the body 2 by the steering device 10 .

In the above-described embodiment, the operation knob is swung to switch to four positions, and the mode selection switch can select any of the slow turning mode, pivot turning mode, super pivot turning mode, and zero turn mode. 40 is used, but instead of this, other types of operation units, such as push-button type, dial type, lever type, or soft keys displayed on a touch panel, may be used as mode selection units. Also, the number of executable turn modes other than the zero turn mode is not limited to the above three, and one, two, or four or more may be provided.

Further, instead of the main shift lever 37, the sub shift lever 38, the steering lever 39, or the accelerator lever 41, other types of operation members such as a push button type, a dial type, a handle type, or a touch panel capable of displaying soft keys can be used. may be used. Also, an operation member such as a joystick that serves as both a steering lever and an accelerator lever may be used.
In the above-described embodiment, the driving speed of the first traveling device 1L on the left side of the machine body 1 and the driving speed of the second traveling device 1R on the right side are controlled by the first continuously variable transmission 21 and the second continuously variable transmission 22. , but it is not limited to this configuration.

As another example, a single continuously variable transmission, multiple clutches corresponding to each turn, multiple brake mechanisms corresponding to each traveling device, multiple actuators, multiple solenoid valves, etc. may be provided. good. In this case, the speed change of the single continuously variable transmission, the on/off of each clutch, and the braking and braking of each brake mechanism are controlled via electromagnetic valves and actuators to control the driving speed of the first traveling device and the second traveling device. A plurality of turns including a zero turn may be realized by varying the drive speed of each traveling device.

Alternatively, a continuously variable transmission for running, a continuously variable transmission for turning, a plurality of clutches for turning, a plurality of actuators, an electromagnetic valve, etc. are provided, and the speed change of each continuously variable transmission and each clutch is performed. The driving speed of the first traveling device and the driving speed of the second traveling device may be changed by controlling the on/off of the power supply via the solenoid valve and the actuator, thereby realizing a plurality of turns including zero turns. .
In the above-described embodiment, the same control device 50 permits/prohibits zero turn and controls the traveling devices 1L and 1R, but instead permits/prohibits zero turn and controls the traveling devices 1L and 1R. It may be configured to be performed by separate controllers.

In the above-described embodiment, the speed detection unit 62 detects the speed of the machine body 2, but instead of this, for example, the control device 50 detects the rotation speeds of the constant capacity motors M1 and M2 detected by the rotation detection units 57 and 60. You may calculate the speed of the body 2 based on. Alternatively, a driving speed detection unit that detects the actual driving speed of the traveling devices 1L and 1R is provided, and the controller 50 detects the driving speed of the traveling devices 1L and 1R detected by the driving speed detecting unit, and detects the driving speed of the machine body 2. Velocity may be calculated.
In the above-described embodiment, the crawler belt type traveling devices 1L and 1R are used, but instead of this, a wheeled traveling device may be used, or a traveling device combining wheels and crawlers may be used. good too.

The working machine 100 of the present embodiment described above has the following configuration, and has an effect.
The work machine 100 of this embodiment includes a first traveling device 1L that supports the machine body 2 so that it can travel on the left side of the machine body 2, and a second traveling device 1R that supports the machine body 2 so that it can travel on the right side of the machine body 2. , operating members 37, 38, 39, 41 (main gearshift lever 37, auxiliary gearshift lever 38, steering lever 39, accelerator lever 41) for operating the traveling and steering of the body 2, and The steering device 10 drives the first traveling device 1L and the second traveling device 1R according to the operating states of the operating members 37, 38, 39, and 41, respectively, so as to cause the body 2 to go straight or turn. and a control device 50 for determining whether or not the body 2 is in a stable state. is in a stable state, the steering device 10 drives the first traveling device 1L and the second traveling device 1R in different directions at the same driving speed, or at the driving speed of the first traveling device 1L. The first traveling device 1L and the second traveling device 1R are driven in different directions so that the absolute value of the difference from the driving speed of the second traveling device 1R is equal to or less than a predetermined threshold value, and a minimal turn close to zero is achieved. A zero turn for turning the machine body 2 with a radius is permitted, and the zero turn is prohibited when the operation member 39 is operated to the right or left by an amount smaller than the maximum amount or when the machine body 2 is judged not to be in a stable state.

According to the above, in the working machine 100, when the operating member 39 (steering lever 39) is operated to the maximum amount only when the machine body 2 is in a stable state, a zero turn in which the machine body 2 turns with a minimal turning radius is permitted. Therefore, it is possible to improve the safety during execution of the zero turn and improve the convenience of turning.
In this embodiment, the work machine 100 includes operation detection units 42, 43, 44, and 46 (potentiometers 42, 44, and 46, and a switch mechanism 43) that detect the operation states of the operation members 37, 38, 39, and 41. The steering device 10 directs the power output from the prime mover 5 provided on the body 2 to the first travel device 1L and the second travel device 1R in accordance with the operating states of the operating members 37, 38, 39, and 41. When the control device 50 permits the zero turn, the control device 50 controls the steering device 10 based on the operating states of the operating members 37, 38, 39, 41, and Execute zero turn. As a result, only when the aircraft 2 is in a stable state, the control device 50 permits the zero turn and the zero turn can be executed when the operating member 39 (steering lever 39) is operated by the maximum amount.

In this embodiment, when the control device 50 determines that the operation member 39 (steering lever 39) is operated to the left or right by the maximum amount and the machine body 2 is not in a stable state, the operation members 37, 38, 39, 41, of the first traveling device 1L and the second traveling device 1R, the turning outer traveling device located far from the turning center of the machine body 2 is driven by the steering device 10, and the turning center of the machine body 2 is driven. The turning inner traveling device located near the center is driven by the steering device 10 at a driving speed slower than the driving speed of the turning outer traveling device in a driving direction opposite to that of the turning outer traveling device. As a result, when the machine body 2 is not in a stable state, when the operation member 39 is operated by the maximum amount, the machine body 2 turns with a turning radius larger than the zero turn, so the shaking and vibration of the machine body 2 during the turning are reduced. As a result, the safety and convenience of turning in work machine 100 can be improved.

In this embodiment, when the operating member 39 (steering lever 39) is operated left or right by an amount smaller than the maximum amount, the control device 50 controls the operating state of the operating members 37, 38, 39, and 41 based on the operating states. Of the first traveling device 1L and the second traveling device 1R, the turning outer traveling device located far from the turning center of the machine body 2 is driven by the steering device 10, and the turning inner traveling device positioned near the turning center of the machine body 2 is driven. The traveling device is driven by the steering device 10 in a driving direction opposite to that of the traveling device on the outside of the turn at a driving speed that is slower than the driving speed of the traveling device on the outside of the turn by a predetermined ratio (inside/outside speed ratio). As a result, when the operating member 39 (steering lever 39) is operated by an amount less than the maximum amount, the machine body 2 turns with a turning radius larger than the zero turn, thereby reducing shaking and vibration of the machine body 2 during the turning. As a result, the safety and convenience of turning in work machine 100 can be improved.

In this embodiment, of the first traveling device 1L and the second traveling device 1R, the driving speed of the traveling device located closer to the turning center of the machine body 2 is set to 0, or Another turn in which at least one of the running gears is driven by the steering device 10 to be slower than the drive speed of the farther outer turning gear, causing the machine body 2 to turn with a turning radius greater than the turning radius at the zero turn. The first turn mode (super pivot turn mode, pivot turn mode, or gentle turn mode) in which (quasi-zero turn, super pivot turn, pivot turn, quasi pivot turn, gentle turn) can be executed, and zero turn A mode selection unit 40 (mode selection switch 40) capable of selecting one of the executable second turn modes (zero turn mode) is provided. When the turn mode is selected, the steering device 10 is controlled based on the operating states of the operating members 37, 38, 39, 41 to execute another turn, and the mode selector 40 selects the second turn mode. If it is selected, the operation member 39 (steering lever 39) is operated to the left or right by the maximum amount, and it is determined that the airframe 2 is in a stable state, the zero turn is permitted, and the operation members 37, 38, 39, The steering device 10 is controlled based on the operation state of 41 to execute a zero turn.

As described above, only when the second turn mode (zero turn mode) is selected by the mode selection unit 40 (mode selection switch 40) and the airframe 2 is in a stable state, the operation member 39 (steering lever 39) is moved to the maximum amount. When manipulated, zero turns are allowed. Therefore, the zero turn can be stably executed according to the user's intention, and the safety and convenience of turning in the work implement 1 can be further improved.

In this embodiment, the control device 50 controls the steering device 10 based on the operating states of the operating members 37, 38, 39, and 41 when the first turn mode is selected by the mode selection unit 40 (mode selection switch 40). to perform another turn (quasi-zero turn, super-pivot turn, pivot turn, semi-pivot turn, gentle turn). As a result, in work machine 100, a turn different from the zero turn can be executed according to the user's intention, and the convenience of turning can be further improved.

In this embodiment, as the first turn mode, a super pivot turn mode in which the machine body 2 can execute a pivot turn, a pivot turn mode in which the machine body 2 can execute a pivot turn, or a gentle turn of the machine body 2 can be performed. An executable slow turning mode can be selected by the mode selection unit 40 (mode selection switch 40). As a result, the user selects one of the gentle turning mode, pivot turning mode, super pivot turning mode, and second turn mode (zero turn mode) using the mode selection unit 40, and the work machine 100 makes a gentle turn, A pivot turn, a super pivot turn, a zero turn, and the like can be executed, and the convenience of turning can be further improved.

In this embodiment, the work machine 100 includes a speed detection unit 62 that detects the speed of the machine body 2, and the control device 50 determines that the machine body 2 is in a stable state if the speed of the machine body 2 is equal to or lower than a predetermined speed. If the speed of the body 2 is higher than the predetermined speed, it is determined that the body 2 is not in a stable state. As a result, when the operating member 39 (steering lever 39) is operated by the maximum amount while the machine body 2 is stopped or the speed of the machine body 2 is slow, a zero turn is permitted. The frictional force between the traveling devices 1L, 1R and the road surface is evenly and gradually increased to reduce shaking and vibration of the machine body 2, thereby further improving safety.

In the present embodiment, the first traveling device 1L and the second traveling device 1R are each composed of a track-type traveling device, and the steering device 10 controls the driving speed of the first traveling device 1L and the driving speed of the second traveling device 1R. The control device 50 controls the speed change of the continuously variable transmissions 21 and 22 to control the first traveling device 1L and the second traveling device 1R. change the driving speed and driving direction of each. As a result, the driving speed of the first traveling device 1L and the driving speed of the second traveling device 1R are controlled with high accuracy, and the work machine 100 can reliably perform slow turning, pivot turning, super pivot turning, and zero turn. can do.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all changes within the meaning and range of equivalents of the claims.

1 traveling device 1L first traveling vehicle body 1R second traveling device 2 body 5 motor 10 steering device 21 first continuously variable transmission (continuously variable transmission)
22 second continuously variable transmission (continuously variable transmission)
37 Main shift lever (operating member)
39 steering lever (operating member)
40 Mode selection switch (mode selection part)
41 accelerator lever (operating member)
42, 44, 46 potentiometer (operation detector)
43 Switch mechanism (operation and detection unit)
50 control device 62 speed detector 100 working machine

Claims (9)

a first running device that supports the body so that it can run on the left side of the body;
a second travel device supporting the fuselage on the right side of the fuselage so that the fuselage can travel;
and an operating member for operating the traveling and steering of the body, wherein the first traveling device and the second traveling device are driven according to the operating state of the operating member. a steering device for straightening or turning the aircraft,
A control device that determines whether the aircraft is in a stable state,
The control device is
When it is determined that the operating member is operated to the left or right by the maximum amount and the machine body is in a stable state, the steering device steers the first travel device and the second travel device in different directions in the same direction. The first traveling device and the second traveling device are driven at the driving speed or so that the absolute value of the difference between the driving speed of the first traveling device and the driving speed of the second traveling device is equal to or less than a predetermined threshold value. drive the device in different directions to allow a zero turn turning the vehicle with a very small turning radius approaching zero;
A working machine that prohibits the zero turn when the operating member is operated to either the left or right by an amount smaller than the maximum amount or when the machine body is determined not to be in a stable state. An operation detection unit that detects an operation state of the operation member,
The steering device transmits power output from a prime mover provided in the airframe to at least one of the first traveling device and the second traveling device according to the operating state of the operating member, driving the traveling device,
2. The working machine according to claim 1, wherein when the control device permits the zero turn, the control device controls the steering device based on the operating state of the operating member to execute the zero turn. When the control device determines that the operation member is operated to the left or right by the maximum amount and the machine body is not in a stable state, the controller controls the first travel device and the second traveling device based on the operation state of the operation member. Of the two traveling devices, the turning outer traveling device located far from the turning center of the fuselage is driven by the steering device, and the turning inner traveling device located near the turning center of the fuselage is driven by the turning outer traveling device. The work machine according to claim 1 or 2, wherein the steering device drives the work machine in a driving direction opposite to that of the turning outer traveling device at a driving speed slower than the driving speed. The control device selects one of the first traveling device and the second traveling device based on the operating state of the operating member when the operating member is operated to either the left or the right by an amount less than a maximum amount. A turning outer travel device positioned far from the turning center of the machine body is driven by the steering device, and a turning inner traveling device positioned near the turning center of the machine body is driven at a predetermined speed with respect to the driving speed of the turning outer traveling device. The work machine according to any one of claims 1 to 3, wherein the work machine is driven by the steering device in a driving direction opposite to that of the turning outer traveling device at a relatively slow driving speed. Of the first traveling device and the second traveling device, the driving speed of the traveling device located near the turning center of the fuselage on the inner side of the turning is set to 0, or the driving speed of the traveling device located far from the turning center of the fuselage is set to zero. At least one of the running gears is driven by the steering device so as to be slower than the driving speed of the outer running gears, so that another turn can be performed in which the machine body turns with a turning radius greater than the turning radius at the zero turn. a mode selection unit capable of selecting any one of a first turn mode and a second turn mode in which the zero turn can be executed,
The control device is
when the first turn mode is selected by the mode selection unit, the steering device is controlled based on the operation state of the operation member to execute the another turn;
When it is determined that the second turn mode is selected by the mode selection unit, the operation member is operated to the left or right by the maximum amount, and the aircraft is in a stable state, the zero turn is permitted, and the The working machine according to any one of claims 1 to 4, wherein the steering device is controlled based on the operating state of the operating member to execute the zero turn. 6. The control device according to claim 5, wherein, when the first turn mode is selected by the mode selection unit, the control device controls the steering device based on the operating state of the operating member to execute the another turn. Work machine as described. As the first turn mode, a super pivot turn mode in which the aircraft can perform a pivot turn, a pivot turn mode in which the aircraft can perform a pivot turn, or a slow turn mode in which the aircraft can perform a slow pivot turn. The work machine according to claim 5 or 6, wherein a turning mode can be selected by the mode selection section. A speed detection unit that detects the speed of the aircraft,
The controller determines that the aircraft is in a stable state if the speed of the aircraft is less than or equal to a predetermined speed, and determines that the aircraft is not in a stable state if the speed of the aircraft is greater than the predetermined speed. The work machine according to any one of claims 1 to 7. the first traveling device and the second traveling device each comprise a crawler belt type traveling device,
The steering device includes a continuously variable transmission for steplessly changing the driving speed of the first traveling device and the driving speed of the second traveling device,
9. The control device according to any one of claims 1 to 8, wherein the control device changes the driving speed and the driving direction of the first traveling device and the second traveling device by controlling the speed change of the continuously variable transmission. The working machine described in .

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