Control device, operating device, control method, and work vehicle

Abstract

The control device is a device that controls a drawbar mounted to a main frame of a motor grader, the drawbar generating a motion using at least three actuators, a plurality of the actuators being controlled based on output signals from one operating lever having at least three degrees of freedom, so that a motion of the one operating lever corresponds to a motion of the drawbar.

Description

Technical Field

[0001] This invention relates to control devices, operating devices, control methods, and work vehicles.

[0002] This application claims priority to Japanese Patent Application No. 2021-060559, filed on March 31, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] The working device of a grader consists of a bulldozer blade, a rotary table, a drawbar, and a lifting device, and multiple actuators are provided for positioning them (e.g., Patent Document 1). For example, the actuators that control the movement of the drawbar are the left and right bulldozer blade lifting cylinders and the drawbar moving cylinder. However, in order to achieve the desired angle, three-axis operation across multiple operating levers is required, which presents a problem of complex and difficult operation.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: U.S. Patent Application Publication No. 2020 / 0173135 Summary of the Invention

[0007] The problem that the invention will solve

[0008] The present invention was made in view of the above circumstances, and its object is to provide a control device, operating device, control method, and work vehicle that enable simple operation.

[0009] Methods for solving problems

[0010] To address the aforementioned issues, one aspect of the present invention is a control device that controls a traction rod mounted on the main frame of a grader. The traction rod generates action using at least three actuators. Based on an output signal from an operating lever having at least three degrees of freedom, multiple actuators are controlled so that the action of one of the operating levers corresponds to the action of the traction rod.

[0011] Alternatively, another aspect of the present invention is an operating device comprising the control device and the operating lever.

[0012] Another aspect of the invention is a control method for controlling a traction rod mounted on the main frame of a grader, wherein the traction rod generates action using at least three actuators, and multiple actuators are controlled based on an output signal from an operating lever having at least three degrees of freedom, so that the action of one of the operating levers corresponds to the action of the traction rod.

[0013] Alternatively, another embodiment of the invention is a work vehicle comprising: a main frame; a tow bar mounted on the main frame and constrained thereto by ball bearings; three actuators mounted on the main frame to determine the attitude of the tow bar; an operating lever operated by an operator; and a control device that controls the actuators based on an output signal from the operating lever, the control device controlling the actuators such that the movement of the operating lever corresponds to the movement of the tow bar.

[0014] Invention Effects

[0015] According to various embodiments of the present invention, operation can be simplified. Attached Figure Description

[0016] Figure 1 This is a perspective view showing a basic configuration example of a motorized grader according to an embodiment of the present invention.

[0017] Figure 2 This is a perspective view showing a basic configuration example of the working device of a motorized grader according to an embodiment of the present invention.

[0018] Figure 3 This is a perspective view showing an example of the configuration of an operator operating device according to an embodiment of the present invention.

[0019] Figure 4 It is used for explanation Figure 3 A schematic diagram of the operation example of the joystick 32 shown.

[0020] Figure 5 This is a block diagram illustrating an example of the configuration of a control system according to an embodiment of the present invention.

[0021] Figure 6 It means Figure 5 The flowchart shows an example of the operation of the controller 100.

[0022] Figure 7 It means Figure 5 The system diagram shows an example of the operation of the control system 300.

[0023] Figure 8 It means Figure 5 A flowchart of other action examples of the controller 100 shown.

[0024] Figure 9 It means Figure 5 A system diagram showing other examples of the operation of the control system 300.

[0025] Figure 10 This is a top view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0026] Figure 11 This is a side view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0027] Figure 12 This is a top view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0028] Figure 13 This is a side view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0029] Figure 14 This is a top view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0030] Figure 15 This is a side view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0031] Figure 16 This is a top view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0032] Figure 17 This is a side view illustrating an example of the operation of a motorized grader according to an embodiment of the present invention. Detailed Implementation

[0033] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the same reference numerals are used for the same or corresponding components in each figure, and descriptions are omitted where appropriate.

[0034] [Overview of Operating Machinery]

[0035] Figure 1 This is a perspective view of the working machine 1 as described in the embodiment. Figure 2 This is a perspective view showing a basic configuration example of the working device 10 of the work machinery 1 in the embodiment. The work machinery 1 in the embodiment is, for example, a motorized grader (also simply called a grader). In the following description, the work machinery 1 will be appropriately referred to as a motorized grader 1. Furthermore, the motorized grader 1 is an example of a work vehicle. Figure 1 and Figure 2 They are different models.

[0036] In addition, in this embodiment, such as Figure 1 As shown, taking the vehicle body 2 of the motorized grader 1 as the reference, the vehicle width direction is set as the left-right direction, the vertical direction orthogonal to the left-right direction is set as the up-down direction, and the vehicle length direction orthogonal to the left-right and up-down directions is set as the front-back direction.

[0037] like Figure 1As shown, the motorized grader 1 has a vehicle body 2, a cab 3, a running gear 4, and a working device 10. The motorized grader 1 travels at the work site using the running gear 4. The motorized grader 1 performs operations at the work site using the working device 10. The motorized grader 1 can use the working device 10 to perform road construction (cutting and shaping of roadbeds, subgrades, and slopes), road maintenance and repair (cutting and leveling gravel roads), snow removal (removing accumulated snow and compacted snow), and other operations (leveling plaza surfaces, digging ditches, weeding, etc.). Furthermore, the working machinery 1 is not limited to the motorized grader 1 as long as it includes a working device 10 with a drawbar (traction bar, pull rod) that generates action through at least three actuators.

[0038] The cab 3 is supported on the vehicle body 2. Inside the cab 3 is a driver's seat 31 for the operator to sit on and an operator's operating device (not shown) for the operator to operate in order to move the motorized grader 1.

[0039] The running gear 4 supports the vehicle body 2. In this embodiment, the running gear 4 has two rotatable front wheels 5 and four rear wheels 6. The motorized grader 1 can travel on the road surface RS via the front wheels 5 and rear wheels 6 of the running gear 4. Furthermore, the running gear of the work machinery is not limited to wheels; it can also be tracks, etc.

[0040] The working device 10 is supported on the vehicle body 2. For example... Figure 1 as well as Figure 2 As shown, the working device 10 includes a main frame 11, a traction rod 12, a rotary table 13, a bulldozer blade 14, a right bulldozer blade lifting cylinder 15, a left bulldozer blade lifting cylinder 16, a traction rod moving cylinder 17, a lifting device 21, a lifting device 22, a ball bearing 23, a bulldozer blade moving cylinder 24, a power tilting cylinder 25, and a rotary table rotary motor 26. The right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 are three actuators that generate the movement of the traction rod 12. The right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, the traction rod moving cylinder 17, the bulldozer blade moving cylinder 24, and the power tilting cylinder 25 are hydraulic cylinders. Additionally, the rotary table rotary motor 26 is a hydraulic motor. However, it is not limited to hydraulic cylinders or hydraulic motors.

[0041] The main frame 11 is a retaining part that supports the various parts. It consists of two frame parts that are pinned together near the cab 3 and can be bent (hinged).

[0042] The bulldozer blade 14 is supported so that it can move and tilt relative to the drawbar 12 for digging, transporting soil, and shaping. The rotary disc 13 is a large gear with teeth on the inside that holds the bulldozer blade 14 in place and is rotated in the direction of arrow A6 by the rotary disc rotation motor 26. In this case, the bulldozer blade 14 is mounted on the drawbar 12.

[0043] The tow bar 12 is restricted at its end to be able to swing and rotate freely (hereinafter referred to as swing freely) relative to the main frame 11 via a ball bearing 23, supporting the rotating disk 13 and bearing traction force. The ball bearing 23, also known as a ball joint, ball joint, etc., connects the main frame 11 and the tow bar 12. In this case, the tow bar 12 is mounted on the main frame 11 of the motorized grader 1. In addition, the tow bar 12 is restricted by the main frame 11 and a ball bearing 23.

[0044] The middle portion of the right bulldozer blade lifting cylinder 15 is supported relative to the main frame 11 via a lifting device 21, and one end is supported relative to the drawbar 12, extending and retracting in the direction of arrow A1. The middle portion of the left bulldozer blade lifting cylinder 16 is supported relative to the main frame 11 via a lifting device 22, and one end is supported relative to the drawbar 12, extending and retracting in the direction of arrow A2. One end of the drawbar moving cylinder 17 is supported relative to the main frame 11, and the other end is supported relative to the drawbar 12, extending and retracting in the direction of arrow A3. The right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the drawbar moving cylinder 17 control the position and attitude of the drawbar 12.

[0045] One end of the bulldozer blade moving cylinder 24 is connected to the traction rod 12, and the other end is supported on the bulldozer blade 14. It extends and retracts in the direction of arrow A4, laterally transporting the bulldozer blade 14. One end of the power tilting cylinder 25 is connected to the traction rod 12, and the other end is supported on the bulldozer blade 14, causing the cutting angle of the bulldozer blade 14 to change in the rotation direction of arrow A5. The cutting angle is the angle formed between the tip of the cutting edge of the bulldozer blade 14 and the road surface RS when the bulldozer blade 14 contacts the road surface (ground surface) RS.

[0046] [Traction Rod Control and Input Operation]

[0047] In this embodiment, when controlling the position and attitude of the traction rod 12, the oscillation of the ball bearing 23, which serves as the constraint point of the traction rod 12, and the rotation directions α (indicated by arrow Az), β (indicated by arrow Ay), and γ (indicated by arrow Ax) are defined as rotational movements around the ball bearing 23 along three axes, with the ball bearing 23 as the oscillation point and the rotation center as the origin. The linear motions of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 are then captured as rotational movements around the ball bearing 23. Additionally, an example using a lever with at least three degrees of freedom is the joystick 32. Figure 3 as well as Figure 4 ), the operator input operation when operating the traction rod 12.

[0048] Figure 3 This is a perspective view showing an example of the configuration of an operator operating device according to an embodiment of the present invention.

[0049] Figure 4 It is used for explanation Figure 3 A schematic diagram illustrating an example of the operation of the joystick 32. Figure 3 In the example shown, within the cab 3, a joystick 32 is positioned on the right side of the driver's seat 31, and a joystick 34 is positioned on the left side. In this embodiment, the joystick 32 is used as an input device for controlling the position and orientation of the tow bar 12, and the joystick 34 is used, for example, as an input device for controlling the driving device 4. Figure 4 As shown, the joystick 32 has a lever 32L, which is tiltable at least in the forward and backward direction and the left and right direction, and can rotate about the up and down direction as its rotation axis. Furthermore, the tilting direction is not limited to two directions; for example, it can tilt in all directions. In addition, when the joystick 32 is not operated by the operator, the lever 32L remains in a neutral state (upright state), and has a non-sensitive region that ignores tilting and rotation within a certain range from the neutral state. In this embodiment, the rotation direction αj of the joystick 32 about the up and down axis is set to... Figure 2 The operation input corresponding to the rotation direction α shown is set to the rotation direction βj with the front-back direction as the rotation axis. Figure 2 The operation input corresponding to the rotation direction β shown is to set the rotation direction γj with the left and right directions as the rotation axis to be the same as... Figure 2 The operation input corresponding to the rotation direction γ shown.

[0050] In addition, the control lever 32 also has a slide switch 33. The slide switch 33 is an example of an operating part for operating the bulldozer blade 14 of the motor grader 1. The operator can slide the bulldozer blade 14 left and right by sliding the slide switch 33 left and right.

[0051] The joystick 32 outputs signals representing rotation angles αj, βj, and γj (or signals representing the changes in rotation angles αj, βj, and γj over a predetermined period of time, Δαj, Δβj, and Δγj) based on the operating state of the joystick 32L. Additionally, the joystick 32 outputs a signal representing the amount of sliding of the slide switch 33.

[0052] [Control System Structure]

[0053] Figure 5 This is a block diagram illustrating an example configuration of the control system 300 of the motorized grader 1 according to an embodiment. The control system 300 is an example of an operating device. Figure 2As shown, the motorized grader 1 includes a power source 201, a power take-off (PTO) 202, a travel device 4, a hydraulic pump 203, a hydraulic control valve unit 204, and a controller 100. Additionally, the control system 300 may also include a joystick 32 and a slide switch 33. The controller 100 is an example of a control device, which can be configured using a computer such as a microcomputer, along with its peripheral circuits and peripheral devices, and can perform various functions through a combination of computer hardware and software such as programs executed by the computer.

[0054] Power source 201 generates power to operate the machine tool 1. Examples of power sources 201 include internal combustion engines and electric motors. However, power source 201 is not limited to internal combustion engines and electric motors. Power source 201 may also be a so-called hybrid device that combines an internal combustion engine, a generator-motor, and an energy storage device. Alternatively, power source 201 may not have an internal combustion engine, but may have a configuration that combines an energy storage device and a generator-motor.

[0055] PTO202 transmits at least a portion of the power from power source 201 to hydraulic pump 203. PTO202 distributes the power from power source 201 to travel device 4 and hydraulic pump 203.

[0056] The driving mechanism 4 includes, for example, a transmission, a drive shaft, a brake, and a rear wheel 6. Additionally, the front wheel 5 is driven, for example, by a hydraulic motor (not shown).

[0057] The hydraulic control valve unit 204, under the control of the controller 100, controls the flow rate and direction of the working oil supplied to the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, the traction rod moving cylinder 17, the bulldozer blade moving cylinder 24, the power tilting cylinder 25, and the rotary table rotating motor 26.

[0058] Additionally, the controller 100 receives output signals from the joystick 32, the sliding amount of the slide switch 33, the output signal from the joystick 34, the operating amount of the accelerator pedal 35 located in the cab 3, the output signal from the tow bar rotation angle meter 36, and the output signal from the cylinder length gauge 37. The accelerator pedal 35 is the operator's input device, indicating the output of the power source 201. The tow bar rotation angle meter 36 measures (calculates)... Figure 2The pull rod rotation angle (α, β, γ) is shown, and the measured (calculated) results are output. The pull rod rotation angle meter 36 can be composed of one or more sensors that measure the rotation angle (swing angle) of the shaft of the ball bearing 23, the rotation angle of the pull rod 12 relative to the main frame 11 at multiple points, and a control unit that converts the sensor measurements into the pull rod rotation angle (α, β, γ). The cylinder length meter 37 measures (calculates) the cylinder length L1 of the right bulldozer blade lifting cylinder 15, the cylinder length L2 of the left bulldozer blade lifting cylinder 16, and the cylinder length L3 of the pull rod moving cylinder 17, and outputs the measured (calculated) results. The cylinder length meter 37 can be composed of a control unit that converts the measured values ​​of sensors that measure the cylinder lengths L1, L2, and L3, and multiple sensors that sense the rotation angle of each cylinder, into the cylinder length (L1, L2, L3).

[0059] [Example of a control system's operation]

[0060] Figure 6 It means Figure 5 The flowchart shows an example of the operation of the controller 100. For example, when an input operation is performed by the joystick 32 beyond the insensitive area, it is repeated at a predetermined cycle. Figure 6 The processing is shown.

[0061] like Figure 6 The process begins with the controller 100 first acquiring the attitude (αj, βj, γj) of the joystick 32 (step S101). Next, the controller 100 calculates the attitude change (Δαj, Δβj, Δγj) of the joystick 32 based on the attitude (αj, βj, γj) before one processing cycle and the current attitude (αj, βj, γj) (step S102). Next, the controller 100 acquires the traction rod rotation angle (α, β, γ) output by the traction rod rotation angle meter 36 and sets it as the initial value (α0, β0, γ0) of the traction rod rotation angle (step S103).

[0062] Next, the controller 100 calculates the target values ​​(αt, βt, γt) of the pull rod rotation angle based on the initial values ​​(α0, β0, γ0) and the attitude changes (Δαj, Δβj, Δγj) of the joystick (step S104). The target values ​​(αt, βt, γt) of the pull rod rotation angle are, for example, obtained by multiplying the initial values ​​(α0, β0, γ0) of the pull rod rotation angle by a predetermined coefficient for each component. Furthermore, the predetermined coefficient can be, for example, a value that the operator can adjust within a certain range.

[0063] Next, the controller 100 obtains the pull rod rotation angles (α, β, γ) output by the pull rod rotation angle meter 36 and sets them as the current pull rod rotation angles (αr, βr, γr) (step S105). Next, the controller 100 controls the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the pull rod moving cylinder 17 based on the target values ​​(αt, βt, γt) and the current pull rod rotation angles (αr, βr, γr) (step S106). Next, the controller 100 determines whether the current pull rod rotation angles (αr, βr, γr) have reached the target values ​​(αt, βt, γt) (and whether they are within a specified range from the target values ​​(αt, βt, γt)) (step S107).

[0064] If the current traction rod rotation angle (αr, βr, γr) reaches the target value (αt, βt, γt) of the traction rod rotation angle (if "YES" is selected in step S107), the controller 100 terminates. Figure 6 The process is shown. On the other hand, if the current traction rod rotation angle (αr, βr, γr) does not reach the target value (αt, βt, γt) of the traction rod rotation angle (if "NO" is set in step S107), the controller 100 executes the process after step S105 again.

[0065] Through the above processing, the controller 100 can change the rotation angle (α, β, γ) of the traction lever 12 in a manner corresponding to the change in rotation angle (αj, βj, γj) of the lever 32L of the control lever 32 (Δαj, Δβj, Δγj)). In this case, the traction lever 12 moves in the same direction as the operator's lever rotation operation.

[0066] Figure 7 It means Figure 6 The system diagram shows the action example of the control system 300 corresponding to the action example shown. Figure 7 In the illustrated action example, if the joystick 32 is operated as an operator (S301) (S302), the joystick signal is converted within the controller 100 (S304), and the joystick attitude changes (Δαj, Δβj, Δγj) are calculated. Within the controller 100, based on the joystick attitude changes (Δαj, Δβj, Δγj) and the current traction rod rotation angle (α, β, γ), the target value of the traction rod rotation angle (αt, βt, γt) is calculated (S305).

[0067] Within the controller 100 (S303), based on the deviation between the current traction rod rotation angle (α, β, γ) and the target value of the traction rod rotation angle (αt, βt, γt), the extension and retraction speeds ΔV1, ΔV2, and ΔV3 of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 are calculated.

[0068] (S306).

[0069] Next, as the cylinder body and working device operate (S308), the hydraulic valves of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the drawbar moving cylinder 17 are controlled based on the extension and retraction speeds ΔV1, ΔV2, and ΔV3 (S309). Here, the right bulldozer blade lifting cylinder extends and retracts (S310), the left bulldozer blade lifting cylinder extends and retracts (S311), and the drawbar moving cylinder extends and retracts (S312), and the drawbar 12 rotates (S313). In addition, the current rotation angle is re-detected by the drawbar rotation angle gauge 36 (S314).

[0070] In addition, the processing in module S315 is executed in a shorter cycle than the processing in module S307.

[0071] Through the above processing, the control system 300 can change the rotation angle (α, β, γ) of the traction lever 12 in a manner corresponding to the change in rotation angle (αj, βj, γj) of the lever 32L of the control lever 32 (Δαj, Δβj, Δγj)). In this case, the traction lever 12 moves in the same direction as the operator's lever rotation operation.

[0072] Next, refer to Figure 8 Other action examples will be explained. Figure 8 It means Figure 5 A flowchart of other examples of actions of the controller 100 shown. For example, in the case where an input operation is performed by the joystick 32 beyond the insensitive area, the operation is repeated at a predetermined cycle. Figure 8 The processing is shown.

[0073] like Figure 8The process begins with the controller 100 first acquiring the attitude (αj, βj, γj) of the joystick 32 (step S201). Next, the controller 100 calculates the attitude change (Δαj, Δβj, Δγj) of the joystick 32 based on the attitude (αj, βj, γj) before the first processing and the current attitude (αj, βj, γj) (step S202). Next, the controller 100 acquires the tow lever rotation angle (α, β, γ) output by the tow lever rotation angle meter 36 and sets it as the initial value (α0, β0, γ0) of the tow lever rotation angle (α0, β0, γ0) (step S203). Alternatively, the initial value (α0, β0, γ0) of the tow lever rotation angle can be calculated based on the current length (L1, L2, L3) of each cylinder instead of using the tow lever rotation angle meter 36. In this case, the tow lever angle and cylinder length are pre-calibrated.

[0074] Next, the controller 100 calculates the target values ​​(Δα, Δβ, Δγ) of the pull rod rotation angle based on the initial values ​​(α0, β0, γ0) and the attitude changes (Δαj, Δβj, Δγj) of the joystick (step S204). The target values ​​(Δα, Δβ, Δγ) of the pull rod rotation angle are, for example, values ​​obtained by multiplying each component based on the initial values ​​(α0, β0, γ0) and the attitude changes (Δαj, Δβj, Δγj) of the pull rod rotation angle by a predetermined coefficient. Furthermore, the predetermined coefficient can be, for example, a value that the operator can adjust within a certain range.

[0075] Next, the controller 100 obtains the current length (L1, L2, L3) of each cylinder and sets it as the initial length value (L1o, L2o, L3o) of each cylinder (step S205). Next, the controller 100 calculates the target value (ΔL1, ΔL2, ΔL3) of the length change of each cylinder based on the initial value (α0, β0, γ0) of the traction rod rotation angle and the target value (Δα, Δβ, Δγ) of the traction rod rotation angle (step S206).

[0076] In step S206, the controller 100 uses a rotation matrix and a coordinate transformation matrix to calculate the target values ​​(ΔL1, ΔL2, ΔL3) of the length changes of each cylinder in a manner corresponding to the target values ​​(Δα, Δβ, Δγ) of the traction rod rotation angle. In this embodiment, the mechanism of the traction rod 12 is classified as a model of a three-degree-of-freedom (DOF) parallel mechanism in terms of mechanical kinematics. In a three-DOF parallel mechanism, there are cylinder lengths (L1, L2, L3) of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17, for which the desired posture (α, β, γ) of the traction rod 12 is achieved. Therefore, if the lengths of each cylinder are adjusted simultaneously, the posture (α, β, γ) of the traction rod 12 can be controlled. That is, the cylinder extension / retraction amount required for angular rotation can be calculated based on the three-axis angle signal of the lever input angle of the control lever 32. In addition, by using a rotation matrix, the changes in the coordinates of the constraint points of each cylinder on the traction rod 12 can be calculated. Furthermore, since the coordinates of the constraint points on both sides of the vehicle body do not change, it is possible to calculate the length of each cylinder after the traction rod 12 is rotated.

[0077] Next, the controller 100 obtains the current length (L1, L2, L3) of each cylinder (step S207) and calculates the current length change (ΔL1r, ΔL2r, ΔL3r) of each cylinder (step S208). Next, the controller 100 controls the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 based on the target length change values ​​(ΔL1, ΔL2, ΔL3) and the current length changes (ΔL1r, ΔL2r, ΔL3r) of each cylinder (step S209). Next, the controller 100 determines whether the current length change (ΔL1r, ΔL2r, ΔL3r) of each cylinder has reached the target length change values ​​(ΔL1, ΔL2, ΔL3) of each cylinder (step S210).

[0078] If the condition is met (in the case of "YES" in step S210), controller 100 terminates. Figure 8 The process is shown. On the other hand, if the condition is not met (in the case of "NO" in step S210), the controller 100 executes the process after step S207 again.

[0079] Through the above processing, the controller 100 can change the rotation angle (α, β, γ) of the traction lever 12 in a manner corresponding to the change in rotation angle (αj, βj, γj) of the lever 32L of the control lever 32 (Δαj, Δβj, Δγj)). In this case, the traction lever 12 moves in the same direction as the operator's lever rotation operation.

[0080] Figure 9 It means and Figure 8The system diagram of the control system 300 corresponding to the shown action example is shown. Figure 9 In the illustrated action example, if the joystick 32 is operated as an operator (S401) (S402), then the joystick signal is converted within the controller 100 (S404), and the joystick attitude changes (Δαj, Δβj, Δγj) are calculated. Within the controller 100, based on the joystick attitude changes (Δαj, Δβj, Δγj) and the current traction rod rotation angle (α, β, γ), the target value of the traction rod rotation angle (Δα, Δβ, Δγ) is further calculated (S405).

[0081] Within the controller 100 (S403), the extension and retraction amounts ΔL1, ΔL2, and ΔL3 of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 are further calculated based on the current traction rod rotation angle (α, β, γ), the target value of the traction rod rotation angle (Δα, Δβ, Δγ), and the cylinder length (L1, L2, L3) (406).

[0082] Next, as the cylinder and working device operate (S408), the hydraulic valves of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the drawbar moving cylinder 17 are controlled based on the extension amounts ΔL1, ΔL2, and ΔL3 (S409). Here, the right bulldozer blade lifting cylinder extends and retracts (S410), the left bulldozer blade lifting cylinder extends and retracts (S411), and the drawbar moving cylinder extends and retracts (S412), and the drawbar 12 rotates (S413). In addition, the current rotation angle is re-detected by the drawbar rotation angle gauge 36 (S414). In addition, the current cylinder length (L1, L2, L3) is re-detected by the cylinder length gauge 37 (S415).

[0083] In addition, the processing in module S416 is executed in a shorter cycle than the processing in module S407.

[0084] Through the above processing, the control system 300 can change the rotation angle (α, β, γ) of the traction lever 12 in a manner corresponding to the change in rotation angle (αj, βj, γj) of the lever 32L of the control lever 32 (Δαj, Δβj, Δγj)). In this case, the traction lever 12 moves in the same direction as the operator's lever rotation operation.

[0085] [Operational Example of a Motorized Grader]

[0086] Next, refer to Figures 10-17 The operation example of motorized grader 1 will be explained. Figures 10-17 These are top and side views illustrating an example of the operation of a motorized grader according to an embodiment of the present invention.

[0087] Figure 10This is a top view of the motorized grader 1, showing its driving posture. Figure 11 This is a side view of the motorized grader 1 in its driving posture. To achieve this driving posture, the bulldozer blade 14 needs to be moved upwards. In this situation, the operator... Figure 4 The control lever 32 shown can be rotated around the left-right axis (rotation in the γj direction) so that the traction lever 12 does not rotate around the front-back axis. Figure 2 The traction rod 12 is lifted at an angle (in the β direction), making operation easy.

[0088] Assuming that the three operating levers, each with a cylinder length corresponding to the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the tow rod moving cylinder 17, are in a driving posture, if the tow rod 12 is slightly raised using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16, the tow rod 12 will tilt. Therefore, the tow rod moving cylinder 17 is used for adjustment. In addition, if the tow rod 12 is slightly raised using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16, the tow rod 12 will tilt. Therefore, the adjustment operation using the tow rod moving cylinder 17 needs to be repeated multiple times.

[0089] Figure 12 This is a top view of a motorized grader 1 showing its trenching posture. Figure 13 This is a side view of the motorized grader 1 in the trenching posture. When moving to the trenching posture, the right side of the drawbar 12 needs to be lowered after the bulldozer blade 14 is moved upwards. In this case, the operator first... Figure 4 The control lever 32 shown is rotated around the left-right axis (rotation in the γj direction), so that the traction lever 12 can be rotated without rotating around the front-back axis. Figure 2 The traction rod 12 is tilted and raised in the β direction. Next, the operator... Figure 4 The control lever 32 shown is rotated around its circumference in the front-rear direction (rotation in the βj direction), thereby lowering the right side of the traction lever 12. In this case, the traction lever 12 is also prevented from rotating around its front-rear axis during rotation in the γj direction ( Figure 2 The traction rod 12 is tilted in the β direction, making it easy to operate.

[0090] Assuming that when the three operating levers of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17 are in a trenching posture, when the traction rod 12 is lifted, if the traction rod 12 is slightly raised using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16, the traction rod 12 will tilt. Therefore, the traction rod moving cylinder 17 is used for adjustment. In addition, if the traction rod 12 is slightly raised using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16, the traction rod 12 will tilt. Therefore, the operation of adjusting using the traction rod moving cylinder 17 needs to be repeated multiple times.

[0091] Figure 14 This is a top view of the motorized grader 1, showing the maximum (MAX) or minimum (MIN) shoulder extension posture. Figure 15 This is a side view of a motorized grader 1 showing the maximum (MAX) or minimum (MIN) shoulder extension position. When moving to the maximum (MAX) or minimum (MIN) shoulder extension position, it is necessary to lower the tow bar 12 without tilting it about the front and rear axles, while simultaneously sliding the tow bar 12 to its maximum, for example, to the right. In this situation, the operator first... Figure 4 The control lever 32 shown can be rotated about the left-right axis (rotation in the γj direction) and about the up-down axis (rotation in the αj direction), thereby preventing the traction lever 12 from rotating about the front-back axis. Figure 2 The traction rod 12 is lowered at an angle (in the β direction), and at the same time, the traction rod 12 can slide to its maximum extent from the right side. In addition, by moving the slide switch 33, the bulldozer blade 14 can slide to the right.

[0092] Assuming that the three operating levers, each with a cylinder length of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17, are used to achieve the maximum extension (MAX) of the shoulder, (1) firstly, the traction rod 12 is raised to a certain degree using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16 (because the right side of the traction rod 12 is lowered by the operation in (2)). (2) The traction rod moving cylinder 17 is used for maximum extension. (3) Since the traction rod 12 is tilted, the bulldozer blade lifting cylinder 16 is used to adjust it to lower the left side so that the traction rod 12 becomes horizontal. (4) The bulldozer blade 14 is placed on the ground and its height is adjusted using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16. (5) Next, the bulldozer blade 14 is slid to the right using the bulldozer blade moving cylinder 24. Compared to this embodiment, the operation becomes more complicated.

[0093] Figure 16 This is a top view of a motorized grader 1, showing its ground leveling operation posture. Figure 17 This is a side view of a motorized grader 1 in a ground leveling operation posture. In this posture, the height of the tow bar 12 needs to be fine-tuned while the machine is moving. In this situation, the operator visually observes the leveled ground surface to confirm the leveling depth. Figure 4 The control lever 32 shown can be rotated about the left-right axis (rotation in the γj direction) to prevent the traction lever 12 from rotating about the front-back axis. Figure 2 By tilting the traction rod 12 in the β direction, the ground can be visually inspected again to ensure it is flat.

[0094] Assuming that the ground leveling operation posture is formed by using three operating levers of the lengths of the right bulldozer blade lifting cylinder 15, the left bulldozer blade lifting cylinder 16, and the traction rod moving cylinder 17, (1) first, the operator visually confirms the ground leveling depth, (2) the traction rod 12 is lowered parallel to the ground using the right bulldozer blade lifting cylinder 15 and the left bulldozer blade lifting cylinder 16, (3) for example, if the left side is lowered too much, the left bulldozer blade lifting cylinder 16 is used to raise the left side to adjust it to be parallel, (4) the operator moves to the ground leveling area for visual inspection. Compared with this embodiment, the operation is more complicated.

[0095] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific configuration is not limited to the above embodiments, and design changes are also included without departing from the spirit of the invention. Furthermore, in the above embodiments, part or all of the program executed by a computer can be distributed via a computer-readable recording medium or communication line.

[0096] As described above, the controller 100 of this embodiment is a control device that controls the drawbar mounted on the main frame of a grader. The drawbar is operated by at least three actuators. The control device controls multiple actuators based on output signals from an operating lever having at least three degrees of freedom, so that the operation of the operating lever corresponds to the operation of the drawbar. Furthermore, the drawbar is constrained by the main frame and a ball bearing, and the rotation of the operating lever's axis corresponds to the rotation of the axis centered on the ball bearing of the drawbar. The operating lever also has an operating section that operates the movement of the bulldozer blade mounted on the drawbar. Furthermore, when the operating section slides left and right, the bulldozer blade slides left and right. Furthermore, the tilt of the operating lever corresponds to the tilt of the drawbar. Additionally, the control system 300 of this embodiment is an operating device that includes both a control device and an operating lever. Furthermore, the motorized grader 1 of this embodiment includes: a main frame; a drawbar mounted on the main frame and limited thereto by ball bearings; three actuators mounted on the main frame and determining the attitude of the drawbar; an operating lever operated by an operator; and a control device that controls the actuators based on output signals from the operating lever, the control device being a work vehicle that controls the actuators so that the movement of the operating lever corresponds to the movement of the drawbar. These features simplify operation.

[0097] Industrial availability

[0098] According to various embodiments of the present invention, operation can be simplified.

[0099] Explanation of reference numerals in the attached figures

[0100] 1…Motorized grader (operating vehicle), 11…Main frame, 12…Tether rod, 14…Bulldozer blade, 15…Right bulldozer blade lifting cylinder (actuator), 16…Left bulldozer blade lifting cylinder (actuator), 17…Tether rod moving cylinder (actuator), 23…Ball bearing, 100…Controller (control device), 300…Control system (operating device), 32…Joint lever (operating lever), 33…Slide switch.

Claims

1. A control device that is a device that controls a drawbar mounted to a main frame of a grader, characterized by, the drawbar generating a motion with at least three actuators, a plurality of the actuators being controlled based on output signals from one operating lever having at least three degrees of freedom, so that a motion of one operating lever corresponds to a motion of the drawbar, the operating lever having a shape extending in an up-down direction, and a slide switch that slides in a left-right direction in a surface thereof being installed on a side facing an operator on a front end side in an up direction, the drawbar being restrained by the main frame and one ball bearing, an operation input to the operating lever in a rotation direction about an axis in the up-down direction being made to correspond to a rotation direction about an axis in the up-down direction with the ball bearing of the drawbar as a center, a slide operation input to the slide switch installed to the operating lever in the left-right direction being made to correspond to a movement in the left-right direction of a blade installed to the drawbar.

2. The control device according to claim 1, characterized by, an inclination of the operating lever corresponding to an inclination of the drawbar.

3. An apparatus operable to, provided with: the control device according to claim 1 or 2; and the operating lever.

4. A control method that is a method of controlling a drawbar mounted to a main frame of a grader, characterized by, the drawbar generating a motion with at least three actuators, a plurality of the actuators being controlled based on output signals from one operating lever having at least three degrees of freedom, so that a motion of one operating lever corresponds to a motion of the drawbar, the operating lever having a shape extending in an up-down direction, and a slide switch that slides in a left-right direction in a surface thereof being installed on a side facing an operator on a front end side in an up direction, the drawbar being restrained by the main frame and one ball bearing, an operation input to the operating lever in a rotation direction about an axis in the up-down direction being made to correspond to a rotation direction about an axis in the up-down direction with the ball bearing of the drawbar as a center, a slide operation input to the slide switch installed to the operating lever in the left-right direction being made to correspond to a movement in the left-right direction of a blade installed to the drawbar.

5. A work vehicle characterized by, provided with: a main frame; a drawbar mounted to the main frame, restrained to the main frame by a ball bearing; three actuators mounted to the main frame, determining a posture of the drawbar; one operating lever operated by an operator; and a control device that controls the actuators based on output signals from the operating lever, the control device controlling the actuators so that a motion of the operating lever corresponds to a motion of the drawbar, the operating lever having a shape extending in an up-down direction, and a slide switch that slides in a left-right direction in a surface thereof being installed on a side facing an operator on a front end side in an up direction, the drawbar being restrained by the main frame and one ball bearing, an operation input to the operating lever in a rotation direction about an axis in the up-down direction being made to correspond to a rotation direction about an axis in the up-down direction with the ball bearing of the drawbar as a center, ​ The left-right sliding operation input of the sliding switch mounted on the operating rod corresponds to the left-right movement of the bulldozer blade mounted on the traction rod.

Images