WORKING MACHINE AND CONTROL METHOD FOR WORKING MACHINE

Abstract

A wheel loader (10) includes a body (1), a working device (3), a ride damper unit (25), an IMU (24), and a controller (26). The body (1) can travel. The working device (3) is attached to the body (1). The ride damper unit (25) can dampen vibrations of the working device (3). The IMU (24) detects the information regarding the vibration of the body (1). The controller (26) controls the ride damper unit (25) based on the vibration information detected by the IMU (24).

Description

TECHNICAL AREA

[0001] The present invention relates to a working machine and a control method for a working machine. STATE OF THE ART

[0002] A construction machine, such as a wheel loader, can operate with a bucket full of earth, sand, or similar material. Because the mass of the machine increases in such a case, vibrations are amplified during operation.

[0003] For this reason, a configuration for reducing vibrations during travel is disclosed, in which an accumulator is connected to a cylinder that drives a working device (see, for example, patent document 1). For example, in patent document 1, a valve is provided between the cylinder and the accumulator; the cylinder and the accumulator are connected during travel by switching the valve on and off, and the connection between the cylinder and the accumulator is interrupted during charging. LIST OF ATTACKS Patent document

[0004] Patent Document 1: US 3,122,246 Brief description of the invention

[0005] However, since the valve is operated manually in the configuration described in patent document 1, an operator must actuate the valve to open it before or during the journey, which makes the operator's job more difficult.

[0006] One objective of the present disclosure is to provide a working machine and a control method for a working machine that can easily stabilize the behavior during travel. SOLUTION TO THE PROBLEM

[0007] A working machine according to a first aspect of the present disclosure includes a working machine body, a working device, a damping unit, a vibration information detection sensor, and a control unit. The working machine body is movable. The working device is attached to the working machine body. The damping unit can dampen vibrations of the working device. The vibration detection sensor detects information regarding the vibration of the working machine body. The control unit controls the damping unit based on the vibration information detected by the vibration information detection sensor.

[0008] A control method for a working machine according to a second aspect of the present disclosure is a control method for a working machine that includes a working machine body configured for driving and a working device attached to the working machine body, and includes a step for detecting vibration information and a step for damping control. The step for detecting vibration information serves to detect information regarding the vibration of the working machine body. The step for damping control serves to control the damping unit, which dampens the vibration of the working device based on the vibration information. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0009] According to the present disclosure, it is possible to provide a working machine and a control method for a working machine that can easily stabilize the behavior during travel. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a side view of a wheel loader. Fig. Figure 2 is a block diagram illustrating a system configuration of the wheel loader. Fig. Figure 3 is a view to illustrate detection by an IMU. Fig. Figure 4 is a block diagram illustrating a configuration of a wheel loader control unit. Fig. Figure 5 is a view showing an example of a vibration waveform of acceleration. Fig. Figure 6 is a view to explain the determination of the state transition of the wheel loader. Fig. Figure 7 is a flowchart to explain the control of the suspension damper by the control unit. DESCRIPTION OF VERSIONS (Overview of the wheel loader)

[0010] A wheel loader, as an example of a construction machine, is described below with reference to the drawings. In the following description, the terms "front," "rear," "right," "left," "top," and "bottom" refer to orientations in relation to the forward view from the driver's seat. A "vehicle width direction" is synonymous with a "left-right direction."

[0011] Fig. Figure 1 is a side view illustrating the general configuration of a wheel bearing 10 according to the present embodiment.

[0012] The wheel loader 10 includes a body 1 (an example of the body of a working machine) and a working attachment 3. The body 1 includes a vehicle frame 2, a pair of front tires 4, a cab 5, an engine compartment 6, a pair of rear tires 7, and a steering cylinder 8.

[0013] The vehicle body frame 2 is of an articulated type and includes a front frame 11, a rear frame 12, and a coupling shaft section 13. The front frame 11 is positioned in front of the rear frame 12. The coupling shaft section 13 is located in the center of the vehicle's width and pivotally connects the front frame 11 and the rear frame 12. The pair of front tires 4 are mounted on the left and right sides of the front frame 11. The pair of rear tires 7 are mounted on the left and right sides of the rear frame 12.

[0014] The pair of articulated cylinders 8 is hydraulically actuated. The pair of articulated cylinders 8 is arranged side-by-side in the vehicle width direction on the left and right sides of the coupling shaft section 13. Each articulated cylinder 8 has one end attached to the front frame 11 and the other end attached to the rear frame 12. The angle of the front frame 11 relative to the rear frame 12 is adjusted by extending and retracting the articulated cylinders 8.

[0015] The working device 3 is attached to the body 1. The working device 3 is used for various types of work (e.g., loading and unloading earth and sand, and the like). The working device 3 is driven by hydraulic oil from a hydraulic pump 64, which will be described later. The working device 3 includes a boom 14, a bucket 15, a lifting cylinder 16, a bucket cylinder 17, and an angle lever 18. The boom 14 is mounted on the front frame 11. The bucket 15 is mounted at a distal tip end of the boom 14.

[0016] The lifting cylinder 16 and the bucket cylinder 17 are hydraulic cylinders. One end of the lifting cylinder 16 is attached to the front frame 11, and the other end is attached to the boom 14. The boom 14 pivots up and down by extending and retracting the lifting cylinder 16. One end of the bucket cylinder 17 is attached to the front frame 11, and the other end is connected to the bucket 15 via a bell crank 18. The bucket 15 pivots up and down by extending and retracting the bucket cylinder 17.

[0017] The cab 5 is positioned on the rear frame 12. A steering wheel 55 for changing the direction of travel of the wheel loader 10, an implement control lever 56 for operating the implement 3, various pedals, various switches, a display device and the like are arranged inside the cab 5 (see Fig. 2).

[0018] The engine compartment 6 is located on the rear frame 12 at the rear of the cabin 5. The engine compartment 6 houses an engine 31, which will be described later. A counterweight 6a is located in the rear section of the engine compartment 6. The counterweight 6a is located at a rear end section of the rear frame 12. (System configuration of the wheel loader)

[0019] Fig. Figure 2 is a block diagram that schematically illustrates a system configuration of the wheel loader 10.

[0020] The wheel loader 10 includes a drive unit 21, a brake unit 22, an operating unit 23, an IMU 24 (an example of a vibration information detection sensor), a travel damper unit 25 (an example of a damping unit) and a control unit 26. (Driving Unit 21)

[0021] The driving unit 21 includes a motor 31, a hydrostatic transmission (HST) 32, a transfer case 33, an axle 34, a front tire 4 and a rear tire 7.

[0022] Motor 31, for example, is a diesel engine. The HST 32 includes a pump 32a, a motor 32b, and a hydraulic circuit 32c.

[0023] Pump 32a is a variable displacement swashplate pump. The angle of the swashplate of pump 32a can be changed by an electromagnet 32d. Driven by motor 31, pump 32a delivers hydraulic oil. The hydraulic oil delivered from pump 32a is conveyed via hydraulic circuit 32b to motor 32c. Motor 32b is a swashplate pump. The angle of the swashplate of motor 32b can be changed by an electromagnet 32e.

[0024] Hydraulic circuit 32c is connected to pump 32a and motor 32b. Hydraulic circuit 32c includes a first drive circuit 32c1 and a second drive circuit 32c2. When hydraulic oil is directed from pump 32a to motor 32b via the first drive circuit 32c1, motor 32b is driven in one direction (e.g., forward). When hydraulic oil is directed from pump 32a to motor 32b via the second drive circuit 32c2, motor 32b is driven in the opposite direction (e.g., reverse). Note that the delivery direction of the hydraulic oil to the first drive circuit 32c1 or the second drive circuit 32c2 can be changed by the solenoid 32d.

[0025] The motor 32b is connected to the transfer case 33 via a drive shaft 35. The drive shaft 35 is equipped with a vehicle speed sensor 36. The vehicle speed sensor 36 detects the speed (hereinafter referred to as vehicle speed) of the body 1. The vehicle speed sensor 36 detects the vehicle speed based on the rotational speed of the drive shaft 35. The vehicle speed sensor 36 transmits a detection signal indicating the vehicle speed to the control unit 26.

[0026] The transfer case 33 distributes the power from the engine 31 to axle 34 at the front and axle 34 at the rear. The pair of front tires 4 is connected to axle 34 at the front. The pair of front tires 4 is rotated by the power distributed to axle 34 at the front. The pair of rear tires 7 is connected to axle 34 at the rear. The pair of rear tires 7 is rotated by the power distributed to axle 34 at the rear. (Brake unit 22)

[0027] The brake unit 22 includes a brake valve 41, a service brake 42, and a parking brake 43. The brake valve 41 is, for example, an electric proportional valve (EPC valve). The amount of hydraulic oil sent to the service brake 42 is adjusted according to the opening degree of the brake valve 41. The opening degree of the brake valve 41 is controlled by the control unit 26. The control unit 26 controls the opening degree of the brake valve 41 according to the amount of actuation of a brake pedal 54, which will be described later.

[0028] The service brake 42 is provided on axle 34 at the front and axle 34 at the rear. The service brake 42 is a hydraulic brake. The braking force of the service brake 42 increases with the increasing degree of opening of the brake valve 41.

[0029] The parking brake 43 is provided on the transfer case 33. For example, a wet multi-stage brake that can switch between a braking state and a non-braking state, a disc brake, or the like can be used as the parking brake 43. (Control unit 23)

[0030] The control unit 23 includes an accelerator pedal 51, an FNR lever 52, a parking switch 53, the brake pedal 54, the steering wheel 55, the implement control lever 56 and an automatic damper switch 57.

[0031] The accelerator pedal 51 is located in cabin 5. The accelerator pedal 51 transmits an actuation signal, indicating the degree of actuation of the accelerator pedal, to the control unit 26. The control unit 26 controls the throttle valve opening degree of the engine 31 based on the received operating signal.

[0032] The FNR lever 52 is located in cabin 5. The FNR lever 52 can be switched to a forward, neutral, or reverse position. The FNR lever 52 transmits an operating signal, indicating its position, to the control unit 26. The control unit 26 engages the forward, neutral, or reverse gear by controlling the electromagnet 32d based on the received operating signal.

[0033] The parking switch 53 is located in cabin 5. The parking switch 53 can be switched to any on or off position. The parking switch 53 transmits an operating signal, indicating its position, to the control unit 26. Based on the received operating signal, the control unit 26 engages or disengages the parking brake 43.

[0034] The brake pedal 54 is located in the cabin 5. The brake pedal 54 transmits an actuation signal, indicating the amount and speed of pedal actuation, to the control unit 26. The control unit 26 controls the opening degree of the brake valve 41 based on the received operating signal.

[0035] The steering wheel 55 is provided in the cabin 5. The steering wheel 55 transmits an actuation signal, specifying the steering wheel direction and the amount of steering wheel movement, to the control unit 26. The control unit 26 extends and retracts the articulated cylinders 8 arranged on the vehicle body frame 2 based on the received operating signal.

[0036] The implement control lever 56 is located in the cab 5. The implement control lever 56 transmits an operating signal, indicating the operating force of the lift cylinder 16 and the bucket cylinder 17, to the control unit 26. The control unit 26 controls the hydraulic pump 64, a lift cylinder control valve 65, and a bucket cylinder control valve 81 based on the received operating signal. The hydraulic pump 64 is driven, and the lift cylinder control valve 65 and the bucket cylinder control valve 81 are controlled, thereby supplying hydraulic oil to the lift cylinder 16 and the bucket cylinder 17 and driving the implement 3.

[0037] The automatic damper switch 57 is provided in the cabin 5. For example, the automatic damper switch 57 can be displayed on a screen and can also be a physical switch. The automatic damper switch 57 can be switched to any on or off state. The automatic damper switch 57 transmits an operating signal, indicating its state, to the control unit 26. The control unit 26 puts the automatic damper control into an operating or out-of-service state based on the received operating signal. In the operating state of the automatic damper control, as described later, the control unit 26 automatically puts a damper function of the damper unit 25 into an on or off state. (IMU 24)

[0038] The IMU 24 is an inertial measurement unit. The IMU 24 is located on the rear frame 12, as shown in Fig. Figure 1 illustrates this. The IMU 24 includes an accelerometer and a gyroscope. The IMU 24 measures acceleration and angular velocity along an X-axis, a Y-axis, and a Z-axis, as shown in Figure 1. Fig. Figure 3 illustrates this. Here, the X-axis points forward towards body 1, the Y-axis to the right towards body 1, and the Z-axis downward towards body 1. From the acceleration and the angular velocity on the X-axis, the Y-axis, and the Z-axis, a pitch angle pθ, a yaw angle yθ, and a roll angle rθ are calculated.

[0039] The IMU 24 outputs a recognition signal to the control unit 26, which includes the acceleration and angular velocity on the X-axis, the Y-axis and the Z-axis, as well as information on the pitch angle pθ, the yaw angle yθ and the roll angle rθ. (Damping unit 25)

[0040] The travel damper unit 25 includes a hydraulic circuit 61, an on / off valve 62, an accumulator 63, the hydraulic pump 64, the lifting cylinder control valve 65 and a hydraulic oil tank 66.

[0041] The hydraulic circuit 61 is connected to the pair of lifting cylinders 16, the on / off valve 62 and the lifting cylinder control valve 65.

[0042] The on / off valve 62 is arranged between each of the lifting cylinders 16 and the accumulator 63. The on / off valve 62 is a two-position switching valve that can be switched to an open position X (open state) or a closed position Y (closed state). The position of the on / off valve 62 is controlled by the control unit 26.

[0043] When the on / off valve 62 is in the open position X, it causes each of the lifting cylinders 16 and the accumulator 63 to communicate with each other. This connects the lifting cylinders 16 and the accumulator 63, and the wheel loader 10's ride damping function is switched on (an example of the first state). When the on / off valve 62 is in the closed position Y, it blocks each of the lifting cylinders 16 and the accumulator 63. This disconnects each of the lifting cylinders 16 and the accumulator 63, and the wheel loader 10's ride damping function is switched off (an example of the second state).

[0044] The accumulator 63 is connected to the hydraulic circuit 61 via an on / off valve 62. When the on / off valve 62 is in the open position X, the accumulator 63 is connected to each of the lifting cylinders 16 via the hydraulic circuit 61. In this case, the accumulator 63 acts as a damping mechanism that reduces the vibration of each lifting cylinder 16.

[0045] When the on / off valve 62 is in the closed position Y, the connection between the accumulator 63 and the lifting cylinder 16 is disconnected by the on / off valve 62. In this case, the accumulator 63 does not function as a damping mechanism to reduce the vibration of each of the lifting cylinders 16.

[0046] The hydraulic pump 64 is driven by the motor 31. The hydraulic pump 64 supplies each of the lifting cylinders 16 with hydraulic oil stored in the hydraulic oil tank 66 via the lifting cylinder control valve 65 and the hydraulic circuit 61. The hydraulic pump 64 supplies the bucket cylinder 17 with hydraulic oil stored in the hydraulic oil tank 66 via the bucket cylinder control valve 81. (Control unit 26)

[0047] The control unit 26 includes a processor and a storage device. The processor is, for example, a central processing unit (CPU). Alternatively, the processor can be a different type of processor than the CPU. The processor performs the processing to control the wheel loader 10 according to a program stored in the storage device. The storage device includes non-volatile memory such as read-only memory (ROM) and volatile memory such as random-access memory (RAM). The storage device can be a hard disk or additional storage such as a solid-state drive (SSD). The storage device is an example of a non-transient, computer-readable recording medium.

[0048] Fig. Figure 4 is a block diagram illustrating the configuration of control unit 26. Fig. However, in section 4, a basic system configuration regarding the driving unit 21 is omitted.

[0049] The control unit 26 includes a ride control unit 71, a calculation unit 72, a vibration control unit 73, and a ride damper control unit 74. The processor executes the program stored in the storage device and thereby implements functions of the ride control unit 71, the calculation unit 72, the vibration control unit 73, and the ride damper control unit 74.

[0050] The driving control unit 71 determines, based on the detection signal received from the vehicle speed sensor 36, whether or not a journey should take place. The driving control unit 71 determines that the vehicle should move if the speed is greater than a predetermined threshold, and determines that it should not move if the vehicle speed is equal to or less than the predetermined threshold.

[0051] The processing unit 72 calculates the frequency and amplitude of the acceleration vibration in the Z-axis direction from the detection signal input by the IMU 24. Acceleration in the Z-axis direction can also be described as acceleration in an up-down direction. Fig. Figure 5 is a diagram showing the change in acceleration over time in the Z-axis direction. The vertical axis represents the amplitude, and the horizontal axis represents time. The processing unit 72 calculates an amplitude A and a frequency f from the detection signal, as shown in Fig. 5 shown. The frequency f is the reciprocal of one period T in Fig. 5.

[0052] The vibration determination unit 73 determines, based on the calculated amplitude and frequency, whether or not vibrations are generated in the wheel loader 10. Fig. Figure 6 is a state transition diagram illustrating a vibration state of the wheel loader 10. In a case where condition (1) is met, vibration detection unit 73 determines that the wheel loader 10 has transitioned from a vibration-free state M1 to a vibrating state M2. The case where condition (1) is met occurs when the amplitude A is greater than a predetermined threshold and the frequency f is greater than a predetermined threshold. That is, vibration detection unit 73 determines that a vibration is generated in body 1 when the amplitude A of the acceleration is greater than the predetermined threshold and the frequency f of the acceleration is greater than the predetermined threshold. Fig. Figure 5 shows +A0 and -A0 as predetermined threshold values ​​of the amplitude A. If the amplitude A is greater than the predetermined threshold, this means that the upward amplitude is greater than +A0 and the downward amplitude is less than -A0, as in, for example, Fig. Figure 5 shows that the determination that the amplitude in condition (1) is greater than the predetermined threshold can be adjusted accordingly. For example, if the upward amplitude is greater than +A0 and the downward amplitude is less than -A0, and is repeated a predetermined number of times (or for a predetermined time), the amplitude A can be determined to be greater than the predetermined threshold. The amplitude A can be determined to be greater than the predetermined threshold if the upward amplitude is greater than +A0 and the downward amplitude is less than -A0. The determination that the frequency in condition (1) is greater than the predetermined threshold can be adjusted accordingly.The period T can be obtained, for example, from the time at which the amplitude reaches its maximum and the time at which it reaches its minimum, or from the time at which the amplitude exceeds the predetermined threshold and the time at which it falls below the predetermined threshold. If the frequency f obtained from this period T is continuously greater than a predetermined threshold over a predetermined time, it can be determined that the frequency f is greater than the predetermined threshold.

[0053] On the other hand, if condition (1) is not met, the vibration detection unit 73 determines that the wheel loader 10 maintains the vibration-free state M1 and no vibration is generated. That is, the vibration detection unit 73 determines that no vibration is generated in the wheel loader 10 if the amplitude A is equal to or less than the predetermined threshold or the frequency f is equal to or less than the predetermined threshold.

[0054] In a case where condition (2) is satisfied after it has been determined that body 1 is in vibration state M2, the vibration determination unit 73 determines that the state of body 1 has transitioned from vibration state M2 to non-vibration state M1 and no further vibration is being generated. The case where condition (2) is satisfied is a case where the state in which condition (1) is not satisfied persists for a predetermined threshold time or longer.

[0055] When the vibration detection unit 73 determines that the wheel loader 10 is in vibration state M2, the suspension control unit 74 switches the on / off valve 62 to the open position X and activates the suspension function of the wheel loader 10. When the vibration detection unit 73 determines that the wheel loader 10 is in vibration-free state M1, the suspension control unit 74 switches the on / off valve 62 to the closed position Y and deactivates the suspension function of the wheel loader 10.

[0056] It should be noted that, although the acceleration in the Z-axis direction is used to determine the vibration in the description above, the pitch angle pθ input by the IMU 24 can also be used. The computation unit 72 calculates the frequency and amplitude of the vibration at the pitch angle pθ. If the calculated amplitude of the pitch angle pθ is greater than a predetermined threshold and the frequency of the pitch angle pθ is greater than a predetermined threshold, the vibration determination unit 73 determines that a vibration is being generated.

[0057] The determination can be performed for both the acceleration in the up-down direction and the pitch angle, and if condition (1) is met for either, the generation of a vibration can be determined. That is, if the amplitude A of the acceleration is greater than a predetermined threshold A0 and the frequency f of the acceleration is greater than the predetermined threshold, or if the amplitude of the pitch angle pθ is greater than the predetermined threshold and the frequency of the pitch angle pθ is greater than the predetermined threshold, the vibration determination unit 73 determines that a vibration is generated. The acceleration or the pitch angle in the up-down direction corresponds, for example, to information regarding vibration. (Control process)

[0058] Next, a control process of the wheel loader 10 according to the present embodiment will be described. Fig.Figure 7 is a flowchart showing a control process of the wheel loader 10 according to the present embodiment.

[0059] First, in step S10, the control unit 26 determines whether the automatic damper switch 57 is in the ON state or not. If the automatic damper switch 57 is in the OFF state in step S10, the control process ends. If the automatic damper switch 57 is in the ON state in step S10, the control process continues with step S11.

[0060] Next, in step S11, the driving control unit 71 of the control unit 26 determines, based on the recognition signal received from the vehicle speed sensor 36, whether a journey should take place or not.

[0061] If in step S11 it is determined that a journey should take place, the computation unit 72 of the control unit 26 receives a recognition signal from the IMU 24 in step S12. Step S12 corresponds to an example of the step for acquiring vibration information.

[0062] Next, in step S13, the computation unit 72 of the control unit 26 calculates the frequency and amplitude of the vibration of the up-and-down acceleration, which is included in the detection signal from the IMU 24. It should be noted that, as described above, the frequency and amplitude of the vibration can be calculated at the pitch angle pθ.

[0063] Next, in step S14, the vibration detection unit 73 of the control unit 26 determines whether condition (1) (the amplitude is greater than the predetermined threshold and the frequency is greater than the predetermined threshold) is met or not. If condition (1) is met in step S14, the vibration detection unit 73 of the control unit 26 determines that body 1 is in vibration state M2.

[0064] Next, in step S15, the damper control unit 74 of the control unit 26 sets the on / off valve 62 to the open position X and activates the damper function of the wheel loader 10. Step S15 corresponds to an example of the damper control step.

[0065] Next, in step S16, the vibration detection unit 73 of the control unit 26 determines whether condition (2) (condition (1) is not continuously met for a predetermined time or longer) is met or not. If condition (2) is met, the vibration detection unit 73 of the control unit 26 determines that body 1 has transitioned from vibration state M2 to non-vibration state M1.

[0066] If, in step S16, it is determined that condition (2) is met, the damping control unit 74 of the controller 26 switches the on / off valve 62 to the closed position Y in step S17, thereby switching the damping function of the wheel loader 10 to the off state, and the controller terminates. Step S17 corresponds to an example of the damping control step.

[0067] It should be noted that if in step S11 it is determined that no travel is taking place, the control continues with step S16 and the travel damper control unit 74 of the control unit 26 moves the on / off valve 62 to the closed position Y and puts the travel damper function of the wheel loader 10 into the off state, and the control ends.

[0068] If condition (1) is not met in step S14, it is determined that the wheel loader 10 is in the vibration-free state M1, and the travel damper control unit 74 of the control 26 sets the on / off valve 62 to the closed position Y and puts the travel damper function of the wheel loader 10 into the off state, and the control ends.

[0069] If condition (2) in step S16 is not met, it is determined that the wheel loader 10 maintains vibration state M2, and the control ends.

[0070] If the on / off valve 62 is already in the open position X in step S15, the control unit 26 does not need to actuate the on / off valve 62. If the on / off valve 62 is already in the closed position Y in step S17, the control unit 26 does not need to actuate the on / off valve 62. (Characteristics and the like) (1) The wheel loader 10 of the present embodiment includes the body 1, the working tool 3, the damping unit 25, the IMU 24, and the control unit 26. The body 1 can move. The working tool 3 is attached to the body 1. The damping unit 25 can dampen vibrations of the working tool 3. The IMU 24 detects information regarding the vibration of the body 1. The control unit 26 controls the damping unit 25 based on the vibration information detected by the IMU 24. This allows the control unit of the suspension unit 25 to operate automatically based on the vibration information detected by the IMU 24. Therefore, it is possible to easily stabilize the driving behavior of the wheel loader 10. (2) In the wheel loader 10 of the present embodiment, the control unit 26 can switch the suspension unit 25 between an activated suspension operating state, in which the function to dampen the vibration of the working implement 3 is exercised, and an deactivated suspension operating state, in which the function to dampen the vibration of the working implement 3 is not exercised. If it is determined that the body 1 is vibrating based on the vibration information, the control unit 26 switches the suspension unit 25 to the activated suspension operating state. This allows the damping unit 25 to be automatically switched to the damping operating state when, based on the information about the vibration detected by the IMU 24, it is determined that the body 1 is in vibration state M2. (3) The wheel loader 10 of the present embodiment further includes the pair of lifting cylinders 16, which drive the working implement 3. The shock absorber unit 25 includes the on / off valve 62 and the accumulator 63. The accumulator 63 is connected to the lifting cylinders 16 via the on / off valve 62. When the on / off valve 62 is in the open position X, the shock absorber unit 25 is switched to the switched-on shock absorber operating state, and when the on / off valve 62 is in the closed position Y, the shock absorber unit 25 is switched to the switched-off shock absorber operating state. The control unit 26 controls the on / off valve 62 based on information regarding the vibrations. This allows the state of the damping unit 25 to be switched between the damping unit being switched on, in which the function to dampen the vibration of the working device 3 is exercised, and the damping unit being switched off, in which the function to dampen the vibration of the working device 3 is not exercised. (4) In the wheel loader 10 of the present embodiment, the information relating to the vibration is the acceleration generated on the body 1. The control unit 26 determines that the body 1 vibrates when the amplitude of the acceleration is greater than the predetermined threshold and the frequency of the acceleration is greater than the predetermined threshold. By detecting the acceleration generated in body 1 in this way, it can be determined whether body 1 vibrates or not. (5) In the wheel loader 10 of the present embodiment, the information regarding the vibration is the pitch angle generated at the body 1. The control unit 26 determines that the body 1 vibrates when the amplitude of the pitch angle is greater than the predetermined threshold and the frequency of the pitch angle is greater than the predetermined threshold. By detecting the tilt angle generated in body 1 in this way, it can be determined whether body 1 is vibrating or not. (6) The control method for the wheel loader 10 of the present embodiment is a control method for a working machine that includes the mobile body 1 and the work attachment 3 mounted on the body 1, and includes steps S12 and S14. In step S12, information regarding the vibration of the body 1 is acquired. In step S14, the travel damping unit 25, which dampens the vibrations of the work attachment 3, is controlled based on the information regarding the vibration. This allows the control of the travel damper unit 25 to be carried out automatically based on the vibration information acquired in step S12. Therefore, it is possible to easily stabilize the driving behavior of the wheel loader 10. (Other embodiments)

[0071] Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above and various modifications can be made without departing from the spirit of the invention. (A) In the above embodiment, the pitch angle pθ is calculated by the IMU 24 and input into the control unit 26; however, the control unit 26 can also calculate the pitch angle pθ from the acceleration and angular velocity of the X-axis, Y-axis and Z-axis input by the IMU 24. (B) In the above embodiment, the determination of whether or not a journey takes place is based on the detection signal from the vehicle speed sensor 36; however, the present invention is not limited to this. The determination of whether or not a journey should take place can be made based on the operating signal input from the accelerator pedal 51 or the operating signal from the FNR lever 52. (C) In the above embodiment, the control unit 26 determines that the body 1 is in vibration state M2 when the amplitude of the acceleration is greater than the predetermined threshold and the frequency of the acceleration is greater than the predetermined threshold; however, the present invention is not limited thereto. For example, the control unit 26 can determine that the body 1 is in vibration state M2 when at least one of the following is fulfilled: the amplitude of the acceleration is greater than the predetermined threshold, and the frequency of the acceleration is greater than the predetermined threshold. In the embodiment described above, the control unit 26 determines that the body 1 is in vibration state M2 when the amplitude of the pitch angle is greater than the predetermined threshold and the frequency of the pitch angle is greater than the predetermined threshold; however, the present invention is not limited to this. For example, the control unit 26 can determine that the body 1 is in vibration state M2 when at least one of the following conditions is met: the amplitude of the pitch angle is greater than the predetermined threshold, and the frequency of the pitch angle is greater than the predetermined threshold. (D) In ​​the embodiment above, the wheel loader 10 is provided with the IMU 24; however, the present invention is not limited to the IMU. For example, if vibration is determined using acceleration in the up-down direction, an accelerometer can be provided instead of the IMU. If vibration is determined using pitch angle, an angle sensor can be provided instead of the IMU. (E) In the embodiment above, the IMU 24 is provided on the rear frame 12, but the present invention is not limited thereto. For example, the IMU 24 may be provided on the front frame 11, but is preferably located at a position less affected by the operation of the working device 3. (F) In the embodiment above, the wheel loader 10 includes the pair of lifting cylinders 16, but the present invention is not limited thereto. The wheel loader 10 can include one or more lifting cylinders 16. (G) In the above embodiment, the wheel loader 10 was described as an example of the working machine, but the examples of the working machine include, in addition to the wheel loader, a hydraulic excavator and a backhoe, which include wheels, or the like. (H) In the embodiment above, the wheel loader 10 incorporates the HST 32 as a transmission, but the present invention is not limited thereto. For example, a hydromechanical transmission (HMT), a torque converter (T / C), or the like can be used as the transmission. Commercial applicability

[0072] The working machine and the control method for the working machine of the present disclosure have an effect of slightly stabilizing the behavior during travel and are useful, for example, for a wheel loader and the like. Reference symbol list 1 Bodywork 3 Work equipment 10 wheel loaders 24 IMU 25 Driving damper unit 26 Control QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 3,122,246

[0004]

Claims

[1] Working machine, comprising: a working machine body configured for driving; a tool that is attached to the body of the machine; a damping unit that can dampen vibrations of the work equipment; a vibration information detection sensor that detects information regarding the vibration of the working machine body; and a control unit which controls the damping unit based on the information regarding vibration detected by the vibration information detection sensor. [2] Working machine according to claim 1, wherein the control unit is configured to switch the damping unit between a first state in which a function to dampen vibrations of the working equipment is exercised, and a second state in which a function to dampen vibrations of the working equipment is not exercised, and The control system switches the damping unit to the first state when it determines, based on information regarding vibration, that the working machine body is vibrating. [3] Working machine according to claim 2, further comprising: a hydraulic cylinder that drives the working device, including the damping unit: an on / off valve; and an accumulator that is connected to the hydraulic cylinder via the on / off valve, the damping unit is in the first state when the on / off valve is open, the damping unit is in the second state when the on / off valve is closed, and The control unit controls the on / off valve based on the vibration information. [4] Working machine according to claim 2, wherein the information regarding the vibrations is the acceleration generated in the working machine body and The control unit determines that the working machine body vibrates when at least one of the following conditions is met: an amplitude of the acceleration is greater than a predetermined threshold, and a frequency of the acceleration is greater than a predetermined threshold. [5] Working machine according to claim 2, wherein the information regarding the vibrations is a pitching angle that is generated in the working machine body, and The control system determines that the working machine body vibrates when at least one of the following conditions is met: the amplitude of the pitch angle is greater than a predetermined threshold, and the frequency of the pitch angle is greater than a predetermined threshold. [6] Control method for a working machine comprising a working machine body configured for driving and a working device attached to the working machine body, wherein the control method comprises: Acquiring information regarding the vibration of the working machine body; and Controlling a damping unit that dampens the vibrations of the work equipment based on information regarding the vibrations.

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