Work machine, system of work machine, and control method of work machine

Abstract

A vehicle body (1) is capable of running. A vehicle speed sensor (24) detects a vehicle speed of the vehicle body (1). A brake operation device (51A) outputs a brake signal of the vehicle body by being operated by an operator. An object sensor (25) detects an object behind the vehicle body (1). An automatic brake device (45) brakes the vehicle body (1) by automatic braking based on a detection result of the object sensor (25). A controller (26) cancels the operation of the automatic brake device (45) based on the vehicle speed and the brake signal after an automatic brake command to brake the vehicle body (1) by the operation of the automatic brake device (45) is output.

Description

Technical Field

[0001] This disclosure relates to work machinery, systems for work machinery, and methods for controlling work machinery. Background Technology

[0002] Previously, in wheel loaders, which are examples of construction machinery, automatic braking systems have been proposed that detect obstacles behind and stop automatically. For example, Japanese Patent Application Publication No. 2019-31823 (Patent Document 1) discloses a technology in which, even if the construction machinery stops automatically, it can be deactivated by operating an emergency brake release switch and move again.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-31823 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in the release of the emergency brake release switch as in Patent Document 1, it is difficult to respond when the operator performs an unintentional action such as starting the working machinery at the moment the automatic brake control is released.

[0008] One object of this disclosure is to provide a machine, a system for a machine, and a method for controlling a machine that can easily and appropriately respond to automatic braking control even when the machine has performed actions that are not intended by the operator.

[0009] Furthermore, Patent Document 1 does not consider the false detection of objects (obstacles) by the working machinery during high-speed operation in the automatic braking control.

[0010] Another object of this disclosure is to provide a working machine, a system for a working machine, and a control method for a working machine that can easily and appropriately respond to false detections of objects traveling at high speeds in automatic braking control.

[0011] Methods for solving problems

[0012] This disclosure discloses a work-operated machine and a system thereof, comprising a vehicle body, a vehicle speed sensor, a braking operating device, an object sensor, an automatic braking device, and a controller. The vehicle body is capable of movement. The vehicle speed sensor detects the vehicle speed. The braking operating device outputs a braking signal to the vehicle body upon operator input. The object sensor detects objects behind the vehicle body. Based on the detection results from the object sensor, the automatic braking device brakes the vehicle body automatically. After outputting an automatic braking command indicating that the vehicle body is braked by the automatic braking device, the controller releases the automatic braking device based on the vehicle speed and the braking signal.

[0013] The present disclosure discloses a control method for a work machinery comprising: a vehicle body capable of travel; a braking operation device that outputs a braking signal to the vehicle body by being operated by an operator; and an automatic braking device that brakes the vehicle body automatically based on the detection of an object behind the vehicle body. The control method for the work machinery includes the following steps.

[0014] It outputs an automatic braking command to brake the vehicle body through the operation of the automatic braking device. After outputting the automatic braking command, it releases the automatic braking device based on the vehicle speed and braking signal.

[0015] Another type of work machinery and its system disclosed herein include a vehicle body, a vehicle speed sensor, a forward / reverse switching device, an object sensor, an automatic braking device, a release device, and a controller. The vehicle body is capable of movement. The vehicle speed sensor detects the vehicle speed. The forward / reverse switching device switches the vehicle's direction of travel. The object sensor detects objects behind the vehicle body. The automatic braking device brakes the vehicle body automatically based on the detection result from the object sensor. The release device outputs a release signal that temporarily disables the automatic braking device upon operator input. When the automatic braking device is engaged while the vehicle body is in motion, the controller releases the automatic braking device based on the reverse operation signal indicating the forward / reverse switching device, the vehicle speed detected by the vehicle speed sensor, and the release signal output from the release device.

[0016] Another control method for the working machinery disclosed herein is as follows: the working machinery has: a vehicle body capable of travel; and an automatic braking device that brakes the vehicle body automatically based on the detection result of an object behind the vehicle body, wherein the control method for the working machinery includes the following steps.

[0017] The automatic braking system operates while the vehicle is in motion. The automatic braking system is deactivated based on an operation signal indicating that the vehicle is traveling in reverse, the vehicle speed, and a release signal that temporarily disables the automatic braking system based on the operator's action.

[0018] Invention Effects

[0019] According to one aspect of this disclosure, a working machine, a system for a working machine, and a control method for a working machine are capable of easily and appropriately responding to automatic braking control even when the working machine performs actions unintentionally by the operator.

[0020] According to another aspect of this disclosure, there is a work machine, a system for the work machine, and a control method for the work machine that can easily and appropriately respond to false detections of objects traveling at high speeds in automatic braking control. Attached Figure Description

[0021] Figure 1 This is a side view showing the structure of a wheel loader according to one embodiment of the present disclosure.

[0022] Figure 2 It means Figure 1 A block diagram of the braking system of a wheel loader.

[0023] Figure 3 It means Figure 2 The hydraulic circuit diagram of the braking device structure.

[0024] Figure 4 It is a diagram showing the configuration and position of the forward / reverse switching device, the release device, the accelerator, and the brake pedal.

[0025] Figure 5 This is a flowchart illustrating a control method for a wheeled loader according to one embodiment of the present disclosure. Detailed Implementation

[0026] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0027] In the specification and accompanying drawings, the same reference numerals are used to denote the same constituent elements or corresponding constituent elements, and repeated descriptions are avoided. Furthermore, in the accompanying drawings, structures are sometimes omitted or simplified for ease of explanation.

[0028] <Structure of Wheel Loader 100>

[0029] use Figure 1 The structure of the wheel loader 100 of this embodiment will be described.

[0030] Figure 1 This is a side view showing the structure of a wheeled loader 100 (an example of a work machine) according to one embodiment of the present disclosure. Figure 1As shown, the wheel loader 100 in this embodiment has a vehicle body (body) 1 and an object sensor 25. The vehicle body 1 is capable of movement. The vehicle body 1 has a running gear 2 and a working device 3. The working device 3 is disposed on the running gear 2. The running gear 2 has a body frame 10, a pair of front tires 4, a cab 5, an engine compartment 6, a pair of rear tires 7, and a steering cylinder 9. The wheel loader 100 uses the working device 3 to perform sand loading operations, etc.

[0031] It should be noted that in the following description, "front," "rear," "right," "left," "up," and "down" refer to directions based on the view of the front from the operator seat 5s inside the driver's cab 5. Figure 1 In this context, Z represents the forward and backward directions. Zf represents the forward direction, and Zb represents the backward direction.

[0032] The vehicle body frame 10 is a hinged type, comprising a front frame 11, a rear frame 12, and a connecting shaft 13. The front frame 11 is positioned forward of the rear frame 12. The connecting shaft 13 is located at the center of the vehicle body frame 10 in the left-right direction (vehicle width direction), connecting the front frame 11 and the rear frame 12 in a rotatable manner. A pair of front tires 4 are mounted on the left and right sides of the front frame 11. Additionally, a pair of rear tires 7 are mounted on the left and right sides of the rear frame 12.

[0033] The working device 3 is driven by working oil from a working device pump (not shown). The working device 3 has a boom 14, a bucket 15, a lifting cylinder 16, a bucket cylinder 17, and a double boom crank 18. The boom 14 is mounted on the front frame 11. The bucket 15 is mounted on the front end of the boom 14.

[0034] The lifting cylinder 16 and the bucket cylinder 17 are hydraulic cylinders. One end of the lifting cylinder 16 is mounted to the front frame 11, and the other end is mounted to the boom 14. The boom 14 rotates up and down by extending and retracting the lifting cylinder 16. One end of the bucket cylinder 17 is mounted to the front frame 11, and the other end is mounted to the bucket 15 via the boom crank 18. The bucket 15 rotates up and down by extending and retracting the bucket cylinder 17.

[0035] The cab 5 is mounted on the rear frame 12. Inside the cab 5 are a driver's seat 5s for the operator, a steering wheel for steering, levers for operating the working device 3, various switches, display devices, etc. The engine compartment 6 is mounted on the rear frame 12 at the rear of the cab 5, and houses the engine 31.

[0036] Braking System of Wheel Loader 100

[0037] Next, use Figures 2-4 The braking system of the wheel loader 100 in this embodiment will be described.

[0038] Figure 2 It means Figure 1 A block diagram of the braking system of a wheel loader. Figure 3 It means Figure 2 The hydraulic circuit diagram of the braking device structure. Figure 4 It is a diagram showing the configuration and position of the forward / reverse switching device, the release device, the accelerator pedal, and the brake pedal.

[0039] like Figure 2 As shown, the braking system of the wheel loader 100 includes a drive unit 21, a braking unit 22, an operating unit 23, a vehicle speed sensor 24, an object sensor 25, and a controller 26.

[0040] Drive unit 21 drives the wheel loader 100. Braking unit 22 brakes the vehicle body 1. Operating device 23 is operated by the operator. Vehicle speed sensor 24 detects the vehicle speed (travel speed) of the vehicle body 1. Object sensor 25 detects objects (obstacles) around the vehicle body 1. Controller 26 operates drive unit 21 and braking device 22 based on the operator's operation of operating device 23 and the detections by vehicle speed sensor 24 and object sensor 25.

[0041] (Drive device 21)

[0042] like Figure 2 As shown, the drive unit 21 includes an engine 31, an HST 32, a transmission 33, an axle 34, a front tire 4, and a rear tire 7.

[0043] The engine 31 is, for example, a diesel engine, and the driving force generated by the engine 31 drives the pump 32a of the HST (HydroStatic Transmission) 32.

[0044] HST32 includes a pump 32a, a motor 32b, and a hydraulic circuit 32c. Pump 32a is, for example, a swashplate type variable capacity pump, whose swashplate angle can be changed via solenoid 32d. Pump 32a is driven by engine 31 to discharge working oil. The discharged working oil is delivered to motor 32b via hydraulic circuit 32c. Motor 32b is, for example, a swashplate type pump, whose swashplate angle can be changed via solenoid 32e.

[0045] Hydraulic circuit 32c connects pump 32a to motor 32b. Hydraulic circuit 32c has a first drive circuit 32c1 and a second drive circuit 32c2. Working oil is supplied from pump 32a to motor 32b through the first drive circuit 32c1, thereby driving motor 32b in one direction (e.g., forward). Working oil is also supplied from pump 32a to motor 32b through the second drive circuit 32c2, thereby driving motor 32b in another direction (e.g., backward). It should be noted that the discharge direction of working oil to the first drive circuit 32c1 or the second drive circuit 32c2 can be changed via solenoid 32d.

[0046] The transmission 33 distributes the output from the engine 31 to the front and rear axles 34. It should be noted that the driving force generated by the engine 31 can also be distributed to the front and rear axles 34 via the torque converter and transmission.

[0047] A pair of front tires 4 are connected to the front axle 34 and rotate by the output distributed from the engine 31. A pair of rear tires 7 are connected to the rear axle 34 and rotate by the output distributed from the engine 31.

[0048] (Brake device 22)

[0049] like Figure 2 As shown, the braking device 22 performs braking of the vehicle body 1 based on the operation of the brake pedal 51 and performs automatic braking control of the vehicle body 1 based on instructions from the controller 26.

[0050] The braking device 22 includes a brake valve unit 41, brake circuits 42a and 42b (an example of a service brake), a parking brake 43, working oil supply lines 44a and 44b, an EPC (Electric Proportional Valve) valve 46, a shuttle valve unit 47, and an oil tank 48.

[0051] Accumulators, pumps, etc. are connected to the working oil supply lines 44a and 44b, and working oil is supplied to them.

[0052] like Figure 3 As shown, the brake valve unit 41 is operated by the brake pedal 51, which will be described later. The brake valve unit 41 has a rear brake valve 41a and a front brake valve 41b. The rear brake valve 41a and the front brake valve 41b are both three-position switching valves with three ports.

[0053] The first port of the rear brake valve 41a is connected to the working oil supply line 44a via the reservoir 49a. The second port of the rear brake valve 41a is connected to the oil tank 48. The third port of the rear brake valve 41a is connected to the rear shuttle valve 47a of the shuttle valve unit 47.

[0054] In its first state, the rear brake valve 41a connects its first and third ports, connecting the working oil supply line 44a to the rear shuttle valve 47a, supplying working oil to the rear shuttle valve 47a. In its second state, the rear brake valve 41a closes all ports. In its third state, the rear brake valve 41a connects its second and third ports, discharging the working oil between the rear shuttle valve 47a and the rear brake valve 41a into the oil tank 48. In both the second and third states, the rear brake valve 41a stops supplying working oil to the rear shuttle valve 47a.

[0055] The first port of the front brake valve 41b is connected to the working oil supply line 44b via the reservoir 49b. The second port of the front brake valve 41b is connected to the oil tank 48. The third port of the front brake valve 41b is connected to the front shuttle valve 47b of the shuttle valve unit 47.

[0056] In its first state, the front brake valve 41b connects its first port to its third port, connecting the working oil supply line 44b to the front shuttle valve 47b, supplying working oil to the front shuttle valve 47b. In its second state, the front brake valve 41b closes all ports. In its third state, the front brake valve 41b connects its second port to its third port, discharging the working oil between the front shuttle valve 47b and the front brake valve 41b into the oil tank 48. In both the second and third states, the front brake valve 41b stops supplying working oil to the front shuttle valve 47b.

[0057] The opening of the rear brake valve 41a and the front brake valve 41b is adjusted according to the amount of operation of the brake pedal 51, thereby changing the amount of working oil supplied to the shuttle valve unit 47. For example, when the amount of operation of the brake pedal 51 is large, the amount of working oil supplied to the shuttle valve unit 47 from the rear brake valve 41a and the front brake valve 41b increases.

[0058] Braking circuit 42a is located on the rear axle 34 ( Figure 2 Braking circuit 42a is connected to the rear via shuttle valve 47a. Braking circuit 42b is located on the front axle 34. Figure 2 The braking circuit 42b is connected to the front shuttle valve 47b.

[0059] Braking circuits 42a and 42b are hydraulic brakes. The more working oil supplied from the rear via shuttle valve 47a, or the greater the pressure, the stronger the braking force of braking circuit 42a. The more working oil supplied from the front via shuttle valve 47b, or the greater the pressure, the stronger the braking force of braking circuit 42b.

[0060] EPC valve 46 is connected to the working oil supply line 44b. EPC valve 46 is a three-port solenoid valve. The first port of EPC valve 46 is connected to the working oil supply line 44b. The second port of EPC valve 46 is connected to the oil tank 48. The third port of EPC valve 46 is connected to the shuttle valve unit 47.

[0061] When open, EPC valve 46 connects the first port to the third port, supplying working oil from working oil supply line 44b to shuttle valve unit 47. The opening degree of EPC valve 46 is adjusted based on an instruction from controller 26, thereby changing the amount of working oil supplied to shuttle valve unit 47.

[0062] When EPC valve 46 is in the closed state, it closes the first port and connects the second and third ports, discharging the working oil from the flow path from EPC valve 46 to shuttle valve unit 47 to the oil tank 48. Thus, when EPC valve 46 is in the closed state, it stops supplying working oil from working oil supply path 44b to shuttle valve unit 47.

[0063] In this embodiment, when the controller 26 determines that the wheel loader 100 is traveling in a specified direction (e.g., the rear direction Zb) and there is a high risk of interference with objects in the direction of travel, the controller 26 controls the EPC valve 46 to be in the open state.

[0064] The shuttle valve unit 47 includes a rear shuttle valve 47a and a front shuttle valve 47b. The rear shuttle valve 47a supplies the brake circuit 42a with the working oil of higher pressure, which is supplied via the rear brake valve 41a and the working oil supplied via the EPC valve 46. The front shuttle valve 47b supplies the brake circuit 42b with the working oil of higher pressure, which is supplied via the front brake valve 41b and the working oil supplied via the EPC valve 46.

[0065] With this structure, even when the brake pedal 51 is not operated and no working oil is supplied from the brake valve unit 41, when the EPC valve 46 is opened according to the instruction from the controller 26, working oil will be supplied to the brake circuits 42a and 42b from the rear shuttle valve 47a and the front shuttle valve 47b to implement automatic braking control.

[0066] A brake that switches between braking and non-braking states via brake circuits 42a and 42b is, for example, a wet multi-plate disc brake. A wet multi-plate disc brake mainly consists of multiple discs, plates, pistons, and springs. The multiple discs are integrated with the output shafts of either the front tire 4 or the rear tire 7. The plates and discs are alternately arranged and mounted on a fixed component, without rotation. The pistons are operated by hydraulic pressure supplied to the brake circuits 42a and 42b. Through piston operation, the plates are pressed between the multiple discs. Thus, the wet multi-plate disc brake is engaged, entering the braking state. Conversely, when the supply of hydraulic pressure to the brake circuits 42a and 42b is stopped, the pistons return to their original positions under the restoring force (returning force) of the springs, and the pressing state between the plates and discs is released. Thus, the wet multi-plate disc brake is in the non-braking state.

[0067] EPC valve 46, shuttle valve unit 47, and brake circuits 42a and 42b correspond to an example of an automatic braking device 45 that brakes the vehicle body 1 automatically based on the detection results of object sensor 25.

[0068] like Figure 2 As shown, the parking brake 43 is installed on the transmission 33. As the parking brake 43, for example, a wet multi-stage brake or a disc brake that can switch between braking and non-braking states can be used.

[0069] (Operating device 23)

[0070] like Figure 2 As shown, the operating device 23 is operated by a person sitting in the driver's cab 5 ( Figure 1 The operator operates the device 23 within the device. The operating device 23 includes a brake pedal 51, a release device 52, a forward / reverse switching device 53, and a throttle 54.

[0071] like Figure 4 As shown, the brake pedal 51 is located in the cab 5, in front of the driver's seat 5s. The brake pedal 51 adjusts the opening of the rear brake valve 41a and the front brake valve 41b of the brake valve unit 41 according to the amount of its operation. The amount of operation of the brake pedal 51 is detected, for example, by a brake pressure sensor, a pedal travel sensor, etc. A signal indicating the amount of operation of the brake pedal 51 detected by the brake pressure sensor, pedal travel sensor, etc., is sent to the controller 26. The brake pedal 51 and the brake operation amount detection sensors (brake pressure sensor, pedal travel sensor, etc.) correspond to an example of a brake operation device 51A that outputs a brake signal to the vehicle body 1 when operated by the operator.

[0072] The release device 52 is a device that outputs a release signal that temporarily disables the operation of the automatic braking device 45; it can be a switch, button, etc. The release device 52 can also be an automatic braking control cancellation switch. It should be noted that the temporary disabling of automatic braking by the automatic braking control cancellation switch restores the automatic braking to active status when the switch operation is terminated; therefore, it differs from the automatic braking release described in this disclosure. The release device 52 is located inside the driver's cab 5. Figure 4 As shown, the release device 52 can also be configured on the control panel 61 located to the side of the driver's seat 5s. For example, any one of the multiple switches 63 configured on the control panel 61 can be set as the release device 52. An armrest 62 can also be configured between the driver's seat 5s and the control panel 61.

[0073] like Figure 2 As shown, the operator operates the release device 52 to temporarily deactivate (disable) the automatic braking device 45. The operator's operation sends a release signal from the release device 52 to the controller 26. Upon receiving the release signal, the controller 26 closes the EPC valve 46, temporarily deactivating the automatic braking device 45.

[0074] The forward / reverse switching device 53 is located inside the driver's cab 5. For example... Figure 4 As shown, the forward / reverse switching device 53 can be a lever 64 protruding from the steering column, or it can be a lever protruding from the floor of the cab 5.

[0075] like Figure 2 As shown, the operator switches and sets the driving direction of the vehicle body 1 by operating the forward / reverse switching device 53. The forward / reverse switching device 53 is, for example, an FNR lever. The FNR lever 53 can be in a forward (F), neutral (N), or reverse (R) position. An operation signal indicating the position of the FNR lever 53 is sent to the controller 26, which switches the driving direction to forward, neutral, or reverse by controlling the solenoid 32d.

[0076] As a position detection sensor for detecting the position of the FNR lever 53, a potentiometer can be used, or separate switches can be provided for the forward, backward, and neutral positions. Alternatively, both the potentiometer and the switch can be configured to detect even if one of them is misoperated.

[0077] like Figure 4 As shown, the throttle 54 is located in the cab 5, in front of the driver's seat 5s. The operator operates the throttle 54 to set the throttle opening. The throttle 54 generates an opening signal indicating the amount of throttle operation and sends it to the controller 26. The controller 26 controls the rotational speed of the engine 31 based on the sent signal.

[0078] It should be noted that a starting device for initiating automatic braking control is also located within the cab 5. This starting device is, for example, a key switch. The operator can switch from an off state to an on state by inserting the key into the key switch. This sends an operation signal indicating the on or off state from the key switch to the controller 26. When an on-state operation signal is received, the controller 26 starts the engine 31 and initiates automatic braking control. Conversely, when an off-state operation signal is received, the controller 26 stops the engine 31.

[0079] (Vehicle speed sensor 24)

[0080] like Figure 2 As shown, the vehicle speed sensor 24 detects the vehicle speed of the vehicle body 1. The vehicle speed sensor 24 detects the vehicle speed of the vehicle body 1, for example, by detecting the rotational speed of the transmission output shaft, and generates a signal indicating the detected vehicle speed. The vehicle speed sensor 24 sends the vehicle speed signal to the controller 26.

[0081] The vehicle speed sensor 24 can also detect the vehicle speed of the vehicle body 1 by detecting the rotational speed of the front tire 4 or the rear tire 7. Alternatively, the vehicle speed sensor 24 can also be an IMU (Inertial Measurement Unit) that detects the acceleration of the vehicle body 1. In this case, the vehicle speed is calculated based on the product of the accelerations of the vehicle body 1 detected by the IMU.

[0082] (Object sensor 25)

[0083] like Figure 2 As shown, the object sensor 25 detects objects around the vehicle body 1. The object sensor 25 detects objects located in the driving direction of the wheel loader 100. Specifically, the object sensor 25 is a rear detection unit that detects objects in the rear direction Zb of the vehicle body 1 when the wheel loader 100 is traveling in the rearward direction Zb.

[0084] When the object sensor 25 is a rear detection unit, the rear detection unit 25 is, for example, as shown in the example below. Figure 1 It is shown to be installed at the rear end of the vehicle body 1, but it can also be installed outside the rear end.

[0085] Object sensor 25 may be, for example, a LiDAR (Light Detection and Ranging) sensor that acquires information about an object by emitting laser light. Object sensor 25 may also be a Radar (Radio Detection and Ranging) sensor that acquires information about an object by emitting radio waves. Radar may also be, for example, a millimeter-wave radar that detects the reflection of millimeter-wave radio waves emitted from a transmitting antenna on the surface of an object. Object sensor 25 may also be a vision sensor including a camera. Object sensor 25 may also be an infrared sensor.

[0086] Information detected by object sensor 25 is sent to controller 26, which determines whether an object exists in the direction of travel of vehicle body 1. Additionally, controller 26 calculates the distance to the detected object. Based on the distance to the detected object, controller 26 can also determine whether the risk of interference between vehicle body 1 and the object is high.

[0087] (Controller 26)

[0088] Figure 2 The controller 26 shown includes a processor, main memory, and storage. The processor is, for example, a CPU (Central Processing Unit). The main memory includes, for example, non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory).

[0089] The controller 26 and the operating device 23 can be mounted on the wheel loader 100 or separately disposed on the exterior of the wheel loader 100. When the controller 26 and the operating device 23 are separately disposed on the exterior of the wheel loader 100, they can also be wirelessly connected to the drive unit 21, braking unit 22, vehicle speed sensor 24, object sensor 25, etc. The controller 26 can also be stored on a server located away from the wheel loader 100. Furthermore, since the operating device 23 is located away from the wheel loader 100, the operator can remotely operate the wheel loader 100 from a remote location without being inside the cab 5 of the wheel loader 100.

[0090] The controller 26 reads the program stored in the memory and expands it in the main memory, executing the prescribed processing according to the program. The controller 26 can also be divided into a collision detection controller and an HST controller. The collision detection controller and the HST controller can also have different CPUs. Furthermore, the program can be distributed to the controller 26 via a network.

[0091] <Control Method of Wheel Loader 100>

[0092] Next, the main use Figure 5 The control method of the wheel loader 100 in this embodiment will be described.

[0093] Figure 5 This is a flowchart illustrating a control method for a wheeled loader according to one embodiment of the present disclosure. For example... Figure 5 As shown, in step S1, automatic braking control is initiated. Automatic braking control is initiated, for example, by setting the aforementioned starting device to the ON state.

[0094] If the controller 26 receives an operation signal indicating an on state from the starting device, it will begin automatic braking control. The state in which automatic braking control is started (on state) means that the controller 26 can automatically control the opening and closing of the EPC valve 46 based on the detection results of the forward / reverse switching device 53 and the detection results of the object sensor 25.

[0095] In step S2, during automatic braking control, the controller 26 acquires information about the driving direction of the wheel loader 100 and information about objects (obstacles). The controller 26 obtains information about the driving direction of the wheel loader 100 from the forward / reverse switching device 53. The forward / reverse switching device 53 is, for example, an FNR lever, and the controller 26 acquires a signal indicating the position of the FNR lever in forward, neutral, or reverse position. The controller 26 obtains information from the object sensor 25 regarding the presence of an object in the driving direction (rearward direction Zb) of the vehicle body 1.

[0096] In step S3, the controller 26 determines whether the risk of interference between the vehicle body 1 and the object is high in the vehicle body 1's travel direction (rearward direction Zb). The controller 26 performs this determination based on information about the vehicle body 1's travel direction and the object's information.

[0097] If the controller 26 determines that the risk of interference between the wheel loader 100 and an object in the direction of travel is low, it repeatedly acquires travel direction information and object information (step S2) and determines interference with the object (step S3). On the other hand, if the controller 26 determines that the risk of interference between the vehicle body 1 and an object in the direction of travel is high, the controller 26 outputs an automatic braking command to brake the vehicle body 1. Specifically, the controller 26 outputs a command to open the EPC valve 46 as an automatic braking command.

[0098] In step S4, the automatic braking device 45 is activated by controlling the EPC valve 46 to be in the open state. Specifically, by opening the EPC valve 46, working oil is supplied from the rear shuttle valve 47a and the front shuttle valve 47b to the braking circuits 42a and 42b to perform the braking action.

[0099] The operating state of the automatic braking device 45 refers to the state in which the braking force of the braking circuits 42a and 42b is exerted. An example of the operating state of the automatic braking device 45 is when, in the case of a wet multi-plate disc brake, the plates are clamped between the multiple discs and pressed down. As a result, the vehicle body 1 is braked.

[0100] The opening degree of EPC valve 46 is adjusted by a command current output from controller 26 to EPC valve 46. In this example, the command current is preset to a predetermined value. It should be noted that the command current can also be adjusted based on the distance to the detected object. For example, controller 26 can also calculate the deceleration required to stop the object near its location based on the distance to the detected object, and send an opening command (command current) to EPC valve 46 to achieve the opening degree required to achieve that deceleration.

[0101] In this way, the controller 26 performs automatic braking control based on the detection results of objects in the driving direction. In automatic braking control, the controller 26 automatically controls the driving through the braking device 22 based on the detection results of objects by the object sensor 25. Thus, even without the operator operating the brake pedal 51, automatic braking control can be implemented to exert braking force and bring the vehicle body 1 to a stop near the object.

[0102] (An example of automatic braking device disengagement)

[0103] When the automatic braking device 45 is activated via automatic braking control as described above, the operator may sometimes wish to deactivate the automatic braking device 45 for normal use or to get closer to an object. Therefore, the automatic braking device 45 is deactivated when the prescribed deactivation conditions are met. It should be noted that normal use refers to use with the automatic braking control deactivated.

[0104] In this embodiment, after the automatic braking device 45 is activated, in step S5, the controller 26 determines whether the release conditions for releasing the automatic braking device 45 are met. These release conditions are met when the operator wants to use the wheel loader 100 normally, for example, when the wheel loader 100 is stopped, the operator is operating the brake pedal 51, and the forward / reverse switching device 53 is in a state other than reverse (i.e., forward or neutral). Additionally, the release conditions are met when the operator wants to move the wheel loader 100 closer to an object, for example, when the wheel loader 100 is stopped, the operator is operating the brake pedal 51, and the release device 52 is pressed and held.

[0105] The controller 26 determines whether the wheel loader 100 should stop based on the detection results of the vehicle speed sensor 24. The controller 26 determines that the wheel loader 100 should stop if the vehicle speed of the wheel loader 100 detected by the vehicle speed sensor 24 is, for example, below a specified speed and continues for more than a specified time.

[0106] The controller 26 determines whether the operator is operating the brake pedal 51 based on detection results from, for example, a brake pressure sensor or a pedal travel sensor. The controller 26 determines that the brake pedal 51 is being operated if the brake pressure detected by the brake pressure sensor is, for example, above a specified pressure and remains above a specified time.

[0107] The controller 26 determines whether the forward / backward switching device 53 is in a state other than backward based on the operation signal output from the forward / backward switching device 53. If the controller 26 receives a forward or neutral operation signal from the forward / backward switching device 53, it determines that the forward / backward switching device 53 is in a state other than backward.

[0108] The controller 26 determines whether the release device 52 has been pressed and held based on the release signal output from the release device 52. If the controller 26 receives a release signal from the release device 52 for a specified period of time or more, it determines that the release device 52 has been pressed and held.

[0109] Based on the above, when the operator wants to use the wheel loader 100 normally, the controller 26 disengages the automatic braking device 45 based on, for example, the vehicle speed of the vehicle body 1 detected by the vehicle speed sensor 24, the braking signal output from the braking operation device 51A, and the operation signal of the forward / reverse switching device 53. Furthermore, when the operator wants to bring the wheel loader 100 closer to an object, the controller 26 disengages the automatic braking device 45 based, for example, the vehicle speed of the vehicle body 1 detected by the vehicle speed sensor 24, the braking signal output from the braking operation device 51A, and the release signal output from the release device 52.

[0110] If the release condition is not met, the controller 26 continues to operate the automatic braking device 45 while repeatedly performing the determination in step S5. On the other hand, if the release condition is met, the controller 26 controls the EPC valve 46 to close.

[0111] In step S6, as described above, the automatic braking device 45 is deactivated by controlling the EPC valve 46 to the closed state. Specifically, by closing the EPC valve 46, the supply of working oil to the brake circuits 42a and 42b is blocked, and the automatic braking device 45 is deactivated.

[0112] The state in which the automatic braking device 45 is disengaged refers to the state in which the braking force of the braking circuits 42a and 42b is not exerted. An example of the state in which the automatic braking device 45 is not engaged is when, in the case of a wet multi-plate disc brake, the plates are not pressed between the discs.

[0113] Thus, the controller 26 disengages the automatic braking device 45 when the release conditions are met. Therefore, the vehicle body 1 can be moved for normal use of the wheel loader 100 or to bring the wheel loader 100 close to an object that has become an obstacle.

[0114] (Another example of automatic braking device disengagement)

[0115] In the aforementioned automatic braking control, the automatic braking device 45 sometimes operates based on false detection of objects in the driving direction of the vehicle body 1. In such cases, it may be desirable to release the automatic braking device 45 according to the operator's intention and continue driving. Therefore, the automatic braking device 45 is released when the prescribed release conditions are met.

[0116] In this embodiment, after the automatic braking device 45 is activated, in step S5, the controller 26 determines whether the release condition for releasing the automatic braking device 45 is met. If the automatic braking device 45 is activated due to the aforementioned false detection while the vehicle body 1 is traveling at high speed, the release condition is, for example, the following three conditions are met: the vehicle body 1 is traveling at high speed, the forward / reverse switching device 53 is in a reverse state (i.e., the travel direction is backward), and the release device 52 has been briefly pressed.

[0117] The controller 26 determines whether the wheel loader 100 is traveling at high speed based on the detection results of the vehicle speed sensor 24. If the vehicle speed of the vehicle body 1 detected by the vehicle speed sensor 24 is, for example, above a predetermined threshold (e.g., 10 km / h), the controller 26 determines that the vehicle body 1 is traveling at high speed. The vehicle speed used in the above determination is, for example, the vehicle speed at the time when the release device 52 is pressed.

[0118] The controller 26 determines whether the forward / reverse switching device 53 is in a reverse state based on the operation signal output from the forward / reverse switching device 53. When the controller 26 receives a reverse operation signal from the forward / reverse switching device 53, the forward / reverse switching device 53 is in a reverse state, and it is determined that it is moving in the reverse direction.

[0119] The controller 26 determines whether the release device 52 has been pressed based on the release signal output from the release device 52. The controller 26 determines that the release device 52 has been pressed briefly based on the change in the waveform of the release signal output from the release device 52. For example, the controller 26 determines that the release device 52 has been pressed briefly based on the acquisition of the rising edge (or falling edge) of the waveform of the release signal when the release signal switches from off to on.

[0120] As described above, when it is desired to deactivate the automatic braking device 45 that has been activated due to the aforementioned false detection, the controller 26 deactivates the automatic braking device 45 based on, for example, the vehicle speed of the vehicle body 1 detected by the vehicle speed sensor 24, the reverse operation signal indicating the forward / reverse switching device 53, and the deactivation signal output from the deactivation device 52.

[0121] If the release condition is not met, the controller 26 continues to operate the automatic braking device 45 while repeatedly performing the determination in step S5. On the other hand, if the release condition is met, the controller 26 controls the EPC valve 46 to close.

[0122] In step S6, as described above, the automatic braking device 45 is deactivated by controlling the EPC valve 46 to the closed state. Specifically, by closing the EPC valve 46, the supply of working oil to the brake circuits 42a and 42b is blocked, and the automatic braking device 45 is deactivated.

[0123] The state in which the automatic braking device 45 is disengaged refers to the state in which the braking force of the braking circuits 42a and 42b is not exerted. An example of the state in which the automatic braking device 45 is not engaged is when, in the case of a wet multi-plate disc brake, the plates are not pressed between the discs.

[0124] Thus, the controller 26 releases the automatic braking device 45 when the release conditions are met. Therefore, the automatic braking device 45, which is based on the false detection of the aforementioned object, can be released according to the operator's instructions, allowing the vehicle body 1 to continue driving.

[0125] <Effect>

[0126] Next, the effects of this embodiment will be explained.

[0127] When the wheel loader 100 stops by executing automatic braking control, it is sometimes desirable to disengage the automatic braking device 45 based on automatic braking control in order to use the wheel loader 100 normally or to bring the wheel loader 100 closer to an object (obstacle). However, immediately after disengaging the automatic braking, the wheel loader 100 sometimes performs actions unintentionally by the operator due to creeping, sliding, etc. In addition, when the automatic braking device 45 is disengaged unintentionally due to a malfunction of sensors, etc., sometimes the operator does not have time to perform a braking operation. Furthermore, it is desirable to be able to easily disengage the automatic braking device 45 when it is desired to bring the wheel loader 100 closer to an object, etc.

[0128] In this embodiment, such as Figure 2 As shown, the controller 26 outputs an automatic braking command to brake the vehicle body 1 by operating the automatic braking device 45 (step S4), and then releases the operation of the automatic braking device 45 based on the vehicle speed and braking signal of the vehicle body 1 (step S6). Thus, after outputting the automatic braking command to brake the vehicle body 1, the vehicle body 1 can be driven for normal use of the wheel loader 100 or to bring the wheel loader 100 close to an object that is an obstacle.

[0129] Furthermore, the release condition for disengaging the automatic braking device 45 includes the operator operating the brake operating device 51A. Therefore, even if unintentional actions such as creeping or sliding occur at the moment the automatic braking device 45 is disengaged, the operator can immediately operate the brake operating device 51A to perform braking. Thus, in terms of automatic braking control, even if the wheel loader 100 performs an unintentional action by the operator, it is easy to respond appropriately.

[0130] Furthermore, the conditions for disengaging the automatic braking device 45 are the vehicle speed of the wheel loader 100 and the operator's operation of the brake operating device 51A. Therefore, the automatic braking device 45 can be disengaged through a simple operation such as operating the brake operating device 51A.

[0131] In addition, in this embodiment, such as Figure 2As shown, the controller 26 deactivates the automatic braking device 45 based on vehicle speed, braking signal, and the operation signal of the forward / reverse switching device 53. Therefore, the automatic braking device 45 can also be deactivated based on the driving direction of the wheel loader 100 after its activation has been deactivated.

[0132] In addition, in this embodiment, such as Figure 2 As shown, the controller 26 releases the automatic braking device 45 based on vehicle speed, braking signal, and the operation signal of the forward / reverse switching device 53. Because this makes the release conditions for automatic braking multiple (dualized), even if a sensor or the like malfunctions, the automatic braking device 45 can be prevented from being unintentionally released.

[0133] In addition, in this embodiment, such as Figure 2 As shown, the controller 26 disengages the automatic braking device 45 when the forward / reverse switching device 53 selects a position other than reverse. Therefore, after the automatic braking device 45 is disengaged, the wheel loader 100 can be used normally while avoiding interference with objects behind it.

[0134] In addition, in this embodiment, such as Figure 2 As shown, the controller 26 releases the automatic braking device 45 based on the release signal output from the release device 52. This temporarily disables the automatic braking device 45, allowing the wheel loader 100 to approach the object further.

[0135] In addition, in this embodiment, such as Figure 2 As shown, when the controller 26 receives a release signal output from the release device 52 for a specified period of time, it releases the operation of the automatic braking device 45. This prevents the automatic braking device 45 from being released due to operator error.

[0136] In addition, in this embodiment, such as Figure 2 As shown, if the controller 26 continuously achieves a vehicle speed below a predetermined speed for a specified period of time, the automatic braking device 45 is deactivated. Therefore, the automatic braking device 45 can be deactivated only when the vehicle speed reliably falls below the predetermined speed.

[0137] In addition, in this embodiment, such as Figure 2 As shown, if the controller 26 receives a braking signal for a specified period of time or longer, the automatic braking device 45 is released from operation. This prevents the automatic braking device 45 from being released due to malfunction of the braking operation device 51A.

[0138] In this embodiment, such as Figure 2As shown, the controller 26 outputs an automatic braking command to brake the vehicle body 1 through the operation of the automatic braking device 45 (step S4), and then releases the operation of the automatic braking device 45 when the release condition is met (step S5) (step S6). Thus, even if the automatic braking device 45 operates based on the false detection of an object in the driving direction of the vehicle body 1, the operation of the automatic braking device 45 can be released, allowing the vehicle body 1 to continue driving.

[0139] Furthermore, the release condition for disengaging the automatic braking device 45 includes operator operation of the release device 52. Therefore, the automatic braking device 45 can be disengaged according to the operator's intention, allowing the vehicle body 1 to continue driving. Thus, it is easy to appropriately handle false detections of objects traveling at high speeds during automatic braking control.

[0140] Furthermore, in this embodiment, when the vehicle body 1 is reversing at a speed exceeding a predetermined threshold, the controller 26 releases the automatic braking device 45 based on a release signal. This allows the vehicle body 1 to continue reversing without stopping, thus improving work efficiency.

[0141] Furthermore, in this embodiment, the controller 26 releases the automatic braking device 45 based on changes in the waveform of the release signal. Therefore, the automatic braking device 45 can be released by a short press of the release device 52.

[0142] <Postscript>

[0143] The above description includes the following features.

[0144] (Note 1)

[0145] A type of work machinery, wherein,

[0146] The operating machinery includes:

[0147] The vehicle body, which enables it to move;

[0148] A vehicle speed sensor that detects the vehicle speed;

[0149] A braking operating device that outputs a braking signal to the vehicle body by being operated by an operator;

[0150] An object sensor that detects objects behind the vehicle body;

[0151] An automatic braking device that, based on the detection results of the object sensor, brakes the vehicle body automatically; and

[0152] The controller, after outputting an automatic braking command to brake the vehicle body through the operation of the automatic braking device, releases the operation of the automatic braking device based on the vehicle speed and the braking signal.

[0153] (Note 2)

[0154] According to the operating machinery described in Appendix 1, wherein,

[0155] The operating machinery also has a forward / reverse switching device, which switches the vehicle's travel direction.

[0156] The controller deactivates the automatic braking device based on the vehicle speed, the braking signal, and the operation signal of the forward / reverse switching device.

[0157] (Note 3)

[0158] According to the operating machinery described in Appendix 2, wherein,

[0159] The controller deactivates the automatic braking device based on the vehicle speed and the braking signal, and when the forward / reverse switching device selects a position other than reverse.

[0160] (Note 4)

[0161] According to the operating machinery described in Appendix 1, wherein,

[0162] The operating machinery also includes a release device that outputs a release signal that temporarily disables the operation of the automatic braking device.

[0163] The controller deactivates the automatic braking device based on the vehicle speed, the braking signal, and the release signal.

[0164] (Note 5)

[0165] According to the operating machinery described in Appendix 4, wherein...

[0166] The controller releases the automatic braking device based on the vehicle speed and the braking signal, and if the release signal is received after a specified period of time.

[0167] (Note 6)

[0168] The operating machinery according to any one of Appendix 1 to Appendix 5, wherein,

[0169] The controller disengages the automatic braking device if the vehicle speed remains below a specified speed for a specified period of time.

[0170] (Note 7)

[0171] The operating machinery according to any one of Appendix 1 to Appendix 6, wherein,

[0172] When the braking signal is braking pressure, the controller releases the automatic braking device if the braking pressure has been maintained at a specified pressure for a specified time or more.

[0173] (Postscript 8)

[0174] A system for operating machinery, wherein,

[0175] The system of the operating machinery includes:

[0176] The vehicle body, which enables it to move;

[0177] A vehicle speed sensor that detects the vehicle speed;

[0178] A braking operating device that outputs a braking signal to the vehicle body by being operated by an operator;

[0179] An object sensor that detects objects behind the vehicle body;

[0180] An automatic braking device that, based on the detection results of the object sensor, brakes the vehicle body automatically; and

[0181] The controller, after outputting an automatic braking command to brake the vehicle body through the operation of the automatic braking device, releases the operation of the automatic braking device based on the vehicle speed and the braking signal.

[0182] (Note 9)

[0183] A control method for a work machinery, the work machinery comprising: a vehicle body capable of travel; a braking operation device that outputs a braking signal to the vehicle body by being operated by an operator; and an automatic braking device that automatically brakes the vehicle body based on the detection result of an object behind the vehicle body, wherein...

[0184] The control method for the operating machinery includes the following steps:

[0185] Output an automatic braking command that causes the vehicle body to brake through the operation of the automatic braking device; and

[0186] After the automatic braking command is output, the automatic braking device is deactivated based on the vehicle speed and the braking signal.

[0187] The embodiments disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the invention is not defined by the foregoing description, but by the technical solutions, and is intended to include all equivalent meanings and modifications within that scope.

[0188] Explanation of reference numerals in the attached figures:

[0189] 1 Vehicle body, 2 Running gear, 3 Working device, 4 Front tire, 5 Cab, 5S Driver's seat, 6 Engine compartment, 7 Rear tire, 9 Steering cylinder, 10 Body frame, 11 Front frame, 12 Rear frame, 13 Connecting axle, 14 Boom, 15 Bucket, 16 Lifting cylinder, 17 Bucket cylinder, 18 Double boom crank, 21 Drive unit, 22 Braking unit, 23 Operating device, 24 Vehicle speed sensor, 25 Object sensor, 26 Controller, 31 Engine, 32a Pump, 32b Motor, 32c Hydraulic circuit, 32c1 First drive circuit, 32c2 Second drive circuit, 32d, 32e Solenoids, 33 Transmission unit, 34 Axle, 41 Brake valve unit, 41a Rear brake valve, 41b Front brake valve, 42a, 42b Brake circuit, 43 Parking brake, 44a, 44b working oil supply lines, 45 automatic braking device, 46 EPC valve, 47 shuttle valve unit, 47a rear shuttle valve, 47b front shuttle valve, 48 oil tank, 49a, 49b reservoirs, 51 brake pedal, 51A brake operating device, 52 release device, 53 forward / reverse switching device, 54 throttle, 61 control panel, 62 handrail, 63 switch, 100 wheel loader.

Claims

1. A type of operating machinery, wherein, The operating machinery includes: The vehicle body, which enables it to move; A vehicle speed sensor that detects the vehicle speed; A braking operating device that outputs a braking signal to the vehicle body by being operated by an operator; An object sensor that detects objects behind the vehicle body; An automatic braking device that brakes the vehicle body automatically based on the detection results of the object sensor; as well as The controller, after outputting an automatic braking command to brake the vehicle body through the operation of the automatic braking device, releases the operation of the automatic braking device based on the vehicle speed and the braking signal.

2. The operating machinery according to claim 1, wherein, The operating machinery also has a forward / reverse switching device, which switches the vehicle's travel direction. The controller deactivates the automatic braking device based on the vehicle speed, the braking signal, and the operation signal of the forward / reverse switching device.

3. The operating machinery according to claim 2, wherein, The controller deactivates the automatic braking device based on the vehicle speed and the braking signal, and when the forward / reverse switching device selects a position other than reverse.

4. The operating machinery according to claim 1, wherein, The operating machinery also includes a release device that outputs a release signal that temporarily disables the operation of the automatic braking device. The controller deactivates the automatic braking device based on the vehicle speed, the braking signal, and the release signal.

5. The operating machinery according to claim 4, wherein, The controller releases the automatic braking device based on the vehicle speed and the braking signal, and if the release signal is received after a specified period of time.

6. The operating machinery according to claim 1, wherein, The controller disengages the automatic braking device if the vehicle speed remains below a specified speed for a specified period of time.

7. The operating machinery according to claim 1, wherein, When the braking signal is braking pressure, the controller releases the automatic braking device if the braking pressure has been maintained at a specified pressure for a specified time or more.

8. A system for a work-related machine, wherein, The system of the operating machinery includes: The vehicle body, which enables it to move; A vehicle speed sensor that detects the vehicle speed; A braking operating device that outputs a braking signal to the vehicle body by being operated by an operator; An object sensor that detects objects behind the vehicle body; An automatic braking device that brakes the vehicle body automatically based on the detection results of the object sensor; as well as The controller, after outputting an automatic braking command to brake the vehicle body through the operation of the automatic braking device, releases the operation of the automatic braking device based on the vehicle speed and the braking signal.

9. A control method for a work machinery, the work machinery comprising: a vehicle body capable of travel; a braking operation device that outputs a braking signal to the vehicle body by being operated by an operator; and an automatic braking device that brakes the vehicle body automatically based on the detection result of an object behind the vehicle body, wherein... The control method for the operating machinery includes the following steps: Output an automatic braking command that causes the vehicle body to brake through the operation of the automatic braking device; and After the automatic braking command is output, the automatic braking device is deactivated based on the vehicle speed and the braking signal.

10. A type of operating machinery, wherein, The operating machinery includes: The vehicle body, which enables it to move; A vehicle speed sensor that detects the vehicle speed; A forward / reverse switching device that switches the vehicle's driving direction; An object sensor that detects objects behind the vehicle body; An automatic braking device that brakes the vehicle body automatically based on the detection results of the object sensor; The release device outputs a release signal that temporarily disables the operation of the automatic braking device upon operator intervention; as well as The controller, when the automatic braking device is in operation while the vehicle is in motion, releases the operation of the automatic braking device based on a reversing operation signal indicating the forward / reverse switching device, the vehicle speed detected by the vehicle speed sensor, and a release signal output from the release device.

11. The operating machinery according to claim 10, wherein, When the vehicle body reverses at a speed exceeding a predetermined threshold, the controller releases the automatic braking device based on the release signal.

12. The operating machinery according to claim 11, wherein, The controller releases the automatic braking device based on changes in the waveform of the release signal.

13. A system for a work-related machine, wherein, The system of the operating machinery includes: The vehicle body, which enables it to move; A vehicle speed sensor that detects the vehicle speed; A forward / reverse switching device that switches the vehicle's driving direction; An object sensor that detects objects behind the vehicle body; An automatic braking device that brakes the vehicle body automatically based on the detection results of the object sensor; The release device outputs a release signal that temporarily disables the operation of the automatic braking device upon operator intervention; as well as The controller, when the automatic braking device is in operation while the vehicle is in motion, releases the operation of the automatic braking device based on a reversing operation signal indicating the forward / reverse switching device, the vehicle speed detected by the vehicle speed sensor, and a release signal output from the release device.

14. A control method for a work machine, the work machine comprising: a vehicle body capable of travel; and an automatic braking device that brakes the vehicle body automatically based on the detection result of an object behind the vehicle body, wherein, The control method for the operating machinery includes the following steps: The automatic braking device is activated while the vehicle body is in motion; and The automatic braking device is deactivated based on an operation signal indicating that the vehicle body is traveling in reverse, the vehicle body speed, and a release signal that temporarily disables the operation of the automatic braking device based on the operator's operation.

Images