Construction machinery and control method of construction machinery

Abstract

A wheel loader (10) comprises a vehicle body (1), a rear detection unit (71) and a controller (26). The vehicle body (1) comprises a vehicle body frame (2), front tires (4) and rear tires (7), and a working device (3) arranged in front of the vehicle body frame (2). The rear detection unit (71) detects an obstacle (S) when the vehicle travels backward by driving the vehicle body frame (2), the front tires (4) and the rear tires (7). The controller (26) determines whether a first control is effective or ineffective based on the detection of the obstacle (S), the backward traveling state, and the scooping operation state of the working device (3), and when the first control is ineffective, the first control is made effective based on the scooping operation state.

Description

Technical Field

[0001] The invention relates to an engineering machine and a control method for the engineering machine. Background Art

[0002] In a wheel loader as an example of a construction machine, a collision suppression system has been proposed that detects an obstacle behind and suppresses a collision when the wheel loader moves backward (for example, see Patent Document 1).

[0003] For example, in Patent Document 1, the vehicle body is decelerated or an alarm is issued based on the distance to the obstacle.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: (Japan) Utility Model Registration No. 3219005 Summary of the invention

[0007] In a wheel loader, sometimes a scooping operation of pushing up soil on an inclined ground is performed. In this case, in a conventional collision suppression system, the ground is detected as an obstacle when the vehicle is moving backward and an obstacle alarm is output, which is very cumbersome for the operator.

[0008] In order to avoid this, it is conceivable to set the system so that the shoveling operation is determined to be performed and the output of the obstacle alarm is stopped during the shoveling operation.

[0009] However, since the separation from the shoveling operation is not taken into consideration, the ground may be mistakenly detected as an obstacle when descending from the pile of earth and sand after the shoveling operation, and an obstacle alarm may be output.

[0010] An object of the present disclosure is to provide a construction machine and a control method of the construction machine that can issue an alarm in consideration of the deviation of a scooping operation.

[0011] (Technical solutions to problems)

[0012] The construction machine of this embodiment includes a vehicle body, a rear detection unit, and a control unit. The vehicle body includes a traveling body and a working device arranged in front of the traveling body. The rear detection unit detects an object when traveling backward by driving the traveling body. The control unit determines whether the first control is valid or invalid based on the detection of the object, the traveling state toward the rear, and the scooping operation state of the working device, and when the first control is invalid, the first control is valid based on the scooping operation state.

[0013] The control method of the construction machine of this embodiment comprises a control determination step and a control validation step. In the control determination step, the validity or invalidity of the first control is determined based on the detection of an object when the traveling body of the vehicle body having the traveling body and the working device is driven to travel backward, the traveling state to the rear, and the scooping operation state of the working device. In the control validation step, when the first control is invalid, the first control is validated based on the scooping operation state.

[0014] (Effects of the Invention)

[0015] According to the present disclosure, it is possible to provide a construction machine and a control method of the construction machine that can issue an alarm in consideration of the deviation of the scooping work. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a side view of the wheel loader according to the first embodiment of the present disclosure.

[0017] Figure 2 Yes means Figure 1 A block diagram of the structure of the drive system, brake system, operating system, notification system and detection system of a wheel loader.

[0018] Figure 3 Yes means Figure 2 Block diagram of the structure of the controller.

[0019] Figure 4 Yes means Figure 1 Diagram of the transfer of the working state of the wheel loader.

[0020] Figure 5 It is used to illustrate Figure 1 Side view of the wheel loader's automatic braking function based on obstacle detection.

[0021] Figure 6 It is used to illustrate Figure 1 Side view of a wheel loader during shoveling operation.

[0022] Figure 7 It is used to illustrate Figure 1 Flowchart of the control actions of the wheel loader.

[0023] Figure 8 This is a block diagram showing the configuration of a drive system, a brake system, an operation system, a notification system, and a detection system of a wheel loader according to a second embodiment of the present disclosure.

[0024] Fig. 9 Yes means Figure 8 A diagram showing the relationship between the invalidation and the return from invalidation to validation of the first control of the wheel loader with respect to the tilt angle.

[0025] Fig.10 Yes means Figure 1 Side view of a wheel loader midway down a dirt pile.

[0026] Fig.11 This is a block diagram showing the configuration of a drive system, a brake system, an operation system, and a notification system of a wheel loader according to a modified example of the embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] Hereinafter, a wheel loader as an example of the construction machine of the present disclosure will be described with reference to the drawings.

[0028] <Structure>

[0029] (Overview of wheel loaders)

[0030] Figure 1 Schematic diagram showing the structure of a wheel loader 10 (an example of construction machinery) according to the present embodiment. The wheel loader 10 according to the present embodiment includes a vehicle body frame 2, a working device 3, a pair of front tires 4 (an example of wheels), a cabin 5, an engine compartment 6, a pair of rear tires 7 (an example of wheels), and a steering cylinder 9 on a vehicle body 1. In the following description, "front", "rear", "right", "left", "up", and "down" indicate directions based on the state of the front viewed from the driver's seat. In addition, "vehicle width direction" is synonymous with "left-right direction". Figure 1 In FIG. 1 , the front-rear direction is indicated by X, the front direction is indicated by Xf, and the rear direction is indicated by Xb. In addition, the vehicle body frame 2, the front tire 4, and the rear tire 7 correspond to an example of a running body.

[0031] The wheel loader 10 performs soil loading work and the like using the working implement 3 .

[0032] The vehicle body frame 2 is a so-called articulated type, and includes a front frame 11, a rear frame 12, and a connecting shaft 13. The front frame 11 is disposed in front of the rear frame 12. The connecting shaft 13 is provided at the center in the vehicle width direction, and connects the front frame 11 and the rear frame 12 so that they can swing with each other. A pair of front tires 4 are mounted on the left and right of the front frame 11. In addition, a pair of rear tires 7 are mounted on the left and right of the rear frame 12.

[0033] The working device 3 is pumped by the working device pump 35b (see Figure 2 ) is driven by hydraulic oil. The working device 3 is swingably mounted on the front part of the front frame 11. The working device 3 has a boom 14, a bucket 15, a lifting cylinder 16 (an example of a boom cylinder), a bucket cylinder 17 (an example of an actuator), and a rocker arm 18 (an example of a secondary link).

[0034] The base end of the boom 14 is rotatably mounted to the front portion of the front frame 11 via a boom pin 14a. The front end of the boom 14 is rotatably mounted to the rear portion of the bucket 15. The rear portion of the bucket 15 is the opposite side of the opening 15b. The front end of the cylinder rod 16a of the lift cylinder 16 is rotatably mounted between the base end and the front end of the boom 14. The cylinder body of the lift cylinder 16 is rotatably mounted to the front frame 11.

[0035] One end of the rocker arm 18 is rotatably mounted on the front end of the cylinder rod 17a of the bucket cylinder 17. The other end of the rocker arm 18 is rotatably mounted on the rear part of the bucket 15. The rocker arm 18 is rotatably supported between the two ends by a rocker arm bracket 14d near the center of the boom 14. The cylinder body of the bucket cylinder 17 is rotatably mounted on the front frame 11. The telescopic force of the bucket cylinder 17 is converted into a rotational motion by the rocker arm and transmitted to the bucket 15.

[0036] The bucket 15 is rotatably mounted to the front end of the boom 14 by a bucket pin 15a so as to be open toward the front. The bucket 15 rotates relative to the boom 14 by the extension and contraction of the bucket cylinder 17, and performs a tilting action (see arrow J) and a discharge action (see arrow K). Here, the tilting action of the bucket 15 refers to an action of tilting by rotating the opening 15b and the claw 15c of the bucket 15 toward the cabin 5. The discharge action of the bucket 15 refers to an action of tilting by rotating the opening 15b and the claw 15c of the bucket 15 away from the cabin 5, which is opposite to the tilting action.

[0037] The cabin 5 is mounted on the rear frame 12, and a handle for steering operation, a lever for operating the working device 3, various display devices, etc. are arranged inside. The engine compartment 6 is arranged on the rear side of the cabin 5 and on the rear frame 12, and accommodates the engine 31 (see Figure 2 ).

[0038] (Structure related to wheel loader control)

[0039] Figure 2 It is a block diagram showing a configuration related to control of the wheel loader 10 .

[0040] The wheel loader 10 includes a driving system 21 , a braking system 22 , an operating system 23 , a notification system 24 , a detection system 25 , and a controller 26 (an example of a control unit).

[0041] The drive system 21 drives the wheel loader 10. The brake system 22 brakes the wheel loader 10 during travel. The operating system 23 is operated by an operator. Based on the operator's operation of the operating system 23, the drive system 21 and the brake system 22 operate. The notification system 24 notifies the operator based on the operation of the operating system 23 or the detection result of the detection system 25. The detection system 25 detects the driving state, the state of the working device 3, and the obstacle (an example of an object) behind the vehicle body 1. The controller 26 (an example of a control unit) operates the drive system 21, the brake system 22, and the notification system 24 based on the operator's operation of the operating system 23 and the detection of the detection system 25.

[0042] (Drive system 21)

[0043] The drive system 21 includes an engine 31 , an HST 32 , a transmission 33 , an axle 34 , the front tires 4 and the rear tires 7 , and a cylinder drive unit 35 .

[0044] The engine 31 is, for example, a diesel engine, and the driving force generated by the engine 31 drives a pump 32 a of an HST (Hydro Static Transmission) 32 .

[0045] HST32 has a pump 32a, a motor 32b, and a hydraulic circuit 32c connecting the pump 32a and the motor 32b. The pump 32a is a swash plate type variable displacement pump, and the angle of the swash plate can be changed by the solenoid 32d. The pump 32a is driven by the engine 31 to discharge hydraulic oil. The discharged hydraulic oil is sent to the motor 32b through the hydraulic circuit 32c. The motor 32b is a swash plate type pump, and the angle of the swash plate can be changed by the solenoid 32e. The hydraulic circuit 32c has a first drive circuit 32c1 and a second drive circuit 32c2. The motor 32b is driven in one direction (for example, the forward direction) by supplying hydraulic oil from the pump 32a to the motor 32b via the first drive circuit 32c1. The motor 32b is driven in another direction (for example, the backward direction) by supplying hydraulic oil from the pump 32a to the motor 32b via the second drive circuit 32c2. Furthermore, the discharge direction of the hydraulic oil to the first drive circuit 32c1 or the second drive circuit 32c2 can be changed by the solenoid 32d.

[0046] The transmission 33 distributes the output from the engine 31 to the front and rear axles 34 .

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

[0048] The cylinder drive unit 35 includes a power output unit 35a, a work device pump 35b, and a control valve 35c. The power output unit 35a is a PTO (Power Take Off), which outputs the output from the engine 31 and transmits it to the work device pump 35b when the vehicle body 1 is stopped. The work device pump 35b is driven by the power of the engine 31 and discharges hydraulic oil to the control valve 35c. The control valve 35c supplies the hydraulic oil supplied from the work device pump 35b to the lifting cylinder 16 (an example of a boom cylinder) and the bucket cylinder 17 based on the command from the controller 26.

[0049] (Braking system 22)

[0050] The brake system 22 includes a brake valve 41 , a service brake 42 , and a parking brake 43 .

[0051] The brake valve 41 is, for example, an EPC (Electric Proportional Valve) valve, and can adjust the amount of hydraulic oil supplied to the service brake 42 by adjusting the opening degree.

[0052] The service brake 42 is provided on the axle 34. The service brake 42 is a hydraulic brake, and the braking force becomes stronger when the opening degree of the brake valve 41 is large, and the braking force becomes weaker when the opening degree of the brake valve 41 is small.

[0053] As a function of automatic braking, even when a brake pedal 54 described later is not operated, the brake valve 41 is driven by an instruction from the controller 26 and the service brake 42 is activated.

[0054] The parking brake 43 is provided on the transmission device 33. As the parking brake 43, a wet multi-step brake or a disk brake, etc. which can be switched between a braking state and a non-braking state, can be used.

[0055] (Operating System 23)

[0056] The operation system 23 includes an accelerator pedal 51 , an FNR lever 52 (an example of an operation member), a parking switch 53 , a brake pedal 54 , a return switch 55 , an automatic brake release switch 56 , and an engine key unit 57 .

[0057] The accelerator pedal 51 is provided in the cabin 5. The operator operates the accelerator pedal 51 to set the throttle opening. The accelerator pedal 51 generates an opening signal indicating the accelerator pedal operation amount and transmits it to the controller 26. The controller 26 controls the rotation speed of the engine 31 based on the transmitted signal.

[0058] When the accelerator pedal 51 is turned off, fuel supply to the engine 31 is stopped, the swash plate of the pump 32a and the motor 32b is controlled to become a resistance to running, and internal inertia acts to generate a braking force (weak braking force described later).

[0059] The FNR lever 52 is provided in the cabin 5. The FNR lever 52 can be in the forward, neutral or reverse position. An operation signal indicating the position of the FNR lever 52 is sent to the controller 26, and the controller 26 controls the solenoid 32d to switch between forward and reverse.

[0060] The parking switch 53 is provided in the cabin 5, is a switch capable of switching between on and off, and transmits a signal indicating its state to the controller 26. The controller 26 sets the parking brake 43 to the braking state or the non-braking state based on the transmitted signal.

[0061] The brake pedal 54 is provided in the cabin 5. The brake pedal 54 adjusts the opening degree of the brake valve 41. In addition, the brake pedal 54 transmits the operation amount to the controller 26.

[0062] The return switch 55 is operated by an operator in order to return the vehicle body 1 from a stopped state after the vehicle body 1 has stopped by automatic braking described later.

[0063] The automatic brake release switch 56 is set to release the automatic brake function so that the automatic brake function is not activated.

[0064] The engine key unit 57 is set to three positions, namely, an engine start position, an ACC power-on position, and an engine off position, by turning the key. Position information of the engine key unit 57 is transmitted to the controller 26 .

[0065] (Notify system 24)

[0066] The notification system 24 includes an alarm device 61 (an example of a first notification unit), a function OFF notification lamp 62 (an example of a second notification unit), and an automatic brake activation notification lamp 63 .

[0067] The alarm device 61 warns the operator when an obstacle is detected behind the vehicle body 1 based on the detection of the rear detection unit 71 of the detection system 25 described later. The alarm device 61 may have a lamp and light the lamp, for example. In addition, the alarm device 61 is not limited to a lamp, and may have a speaker to sound a sound. In addition, the alarm may be displayed on a display panel such as a monitor.

[0068] The function OFF notification light 62 is lit, for example, when the automatic braking function is suppressed or stopped by the judgment of the controller 26, and notifies the operator. In addition, the function OFF notification light 62 is lit, for example, when the automatic braking release switch 56 is operated by the judgment of the operator and the automatic braking function is turned off, and notifies the operator. In addition, when the function OFF notification light 62 is off, it indicates that the automatic braking function can be activated. In addition, the function OFF notification light 62 may not be limited to a light, but may sound a sound. In addition, the notification may be displayed on a display panel such as a monitor.

[0069] The automatic brake activation notification lamp 63 notifies the operator that the automatic brake is activated and that the return switch 55 needs to be returned. When the return switch 55 is operated and the automatic brake is released, the automatic brake activation notification lamp 63 turns off.

[0070] It should be noted that the automatic brake activation notification lamp 63 may not be limited to a lamp, but may also sound a sound. In addition, a display panel such as a monitor may also display the notification.

[0071] As described above, the notification system 24 can appropriately select a light, a sound, a monitor, etc. as a means for notifying the operator of information.

[0072] (Detection system 25)

[0073] like Figure 2 As shown, the detection system 25 includes a rear detection unit 71 , a travel state detection unit 72 , and a work machine state detection unit 73 .

[0074] The rear detection unit 71 detects obstacles behind the vehicle body 1. The rear detection unit 71 is, for example, Figure 1 As shown, the rear end of the vehicle body 1 is installed, but it is not limited to the rear end.

[0075] The rear detection unit 71 includes, for example, a millimeter wave radar. The receiving antenna detects the situation where the radio waves in the millimeter wave band emitted by the transmitting antenna are reflected on the surface of the obstacle and returned, so that the distance to the object can be measured. The detection result of the rear detection unit 71 is sent to the controller 26, and the controller 26 can detect the existence of obstacles within a specified range when retreating. In addition, it is not limited to the millimeter wave radar, and it can also be a camera, etc.

[0076] The traveling state detection unit 72 detects the traveling state of the vehicle body 1. The traveling state detection unit 72 includes a traveling direction sensor 72a and a vehicle speed sensor 72b.

[0077] The driving direction sensor 72a detects the rotation direction of the front tire 4 or the rear tire 7, and detects whether the vehicle body 1 is in the forward or reverse state. The driving direction sensor 72a can be arranged on, for example, the axle 34, but can also be arranged in any structure of the drive system 21 as long as it can detect the driving state of the vehicle body 1. In addition, it is also possible to replace the driving direction sensor 72a, or together with the driving direction sensor 72a, determine whether to move forward or backward based on the position of the FNR lever 52. In this case, the FNR lever 52 is also included in the driving state detection unit 72.

[0078] The work implement state detection unit 73 detects the state of the work implement 3. The work implement state detection unit 73 includes a boom angle sensor 73a (an example of a work implement height detection unit) and a boom bottom pressure sensor 73b.

[0079] The boom angle sensor 73a detects the angle of the boom 14 and outputs the detected value to the controller 26 (an example of a control unit). The boom angle sensor 73a can be constituted by a position sensor and is disposed on the boom pin 14a, for example.

[0080] like Figure 1 As shown, the angle of the boom 14 is an angle θ of a straight line Lb extending from the center of the boom pin 14a toward the center of the bucket pin 15a relative to a horizontal line Lh extending forward from the center of the boom pin 14a. When the straight line Lb is horizontal, the boom angle is set to 0°. When the straight line Lb is located above the horizontal line Lh, the angle θ of the boom 14 is set to a positive value. When the straight line Lb is located below the horizontal line Lh, the angle θ of the boom 14 is set to a negative value.

[0081] In addition, the boom angle sensor 73 a may be a stroke sensor provided in the lift cylinder 16 .

[0082] The boom bottom pressure sensor 73b is installed on the bottom side of the lifting cylinder 16. When pressure is applied to the bottom side of the lifting cylinder 16, the boom 14 rises due to the extension of the pressure cylinder. The boom bottom pressure sensor 73b detects the pressure (bottom pressure) of the hydraulic oil in the oil chamber on the bottom side of the lifting cylinder 16. The boom bottom pressure sensor 73b sends the detected bottom pressure to the controller 26.

[0083] (Controller 26)

[0084] The controller 26 includes a processor and a storage device. The processor is, for example, a CPU (Central Processing Unit). Alternatively, the processor may be a processor different from the CPU. The processor executes processing for controlling the wheel loader 10 according to a program. The storage device includes non-volatile memories such as ROM (Read Only Memory) and volatile memories such as RAM (Random Access Memory). The storage device may also include auxiliary storage devices such as a hard disk or SSD (Solid State Drive). The storage device is an example of a non-transitory computer-readable recording medium. The storage device stores programs and data for controlling the wheel loader 10. The storage device stores, for example, data of threshold values ​​described later.

[0085] Figure 3 It is a block diagram showing the structure of the controller 26.

[0086] The controller 26 includes a control execution determination unit 81, a brake indication unit 82, and a notification indication unit 83. In addition, the controller 26 is not limited to one, and multiple controllers may be provided, and the functions of the control execution determination unit 81, the brake indication unit 82, and the notification indication unit 83 may be separately provided in multiple controllers.

[0087] The control execution determination unit 81 determines the execution of control of the notification system 24 and the brake system 22. The control execution determination unit 81 includes an obstacle determination unit 91, a scooping determination unit 92, a determination unit 93, and a control return determination unit 94.

[0088] The obstacle determination unit 91 determines whether there is an obstacle when moving backward. The obstacle determination unit 91 detects that the vehicle is moving backward by detecting that the front tires 4 or the rear tires 7 are rotating toward the rear through the detection of the driving direction sensor 72a, or that the FNR lever 52 is in the backward position. When the obstacle determination unit 91 receives detection information of an obstacle within a predetermined range from the rear detection unit 71 of the detection system 25 while detecting the vehicle moving backward, it determines that there is an obstacle.

[0089] The lifting determination unit 92 determines whether the work content of the wheel loader 10 during forward movement is a lifting work.

[0090] Specifically, the scooping determination unit 92 determines whether the excavation operation state is in progress, and determines whether the scooping operation state is in progress while maintaining the determination of the excavation operation state.

[0091] Figure 42 is a diagram showing the state transition of the work content. The scooping determination unit 92 determines between the excavation work state W1 and the state W2 other than the excavation work.

[0092] The scooping determination unit 92 determines that the excavation operation state W1 is in the forward movement state when the condition A and the condition B are satisfied.

[0093] The scooping determination unit 92 determines that the vehicle body 1 is traveling forward (advancing state) based on the front tires 4 or the rear tires 7 rotating forward or the FNR lever 52 being in the forward position.

[0094] Condition (A) is that the detection value of the boom bottom pressure sensor 73b, that is, the boom bottom pressure satisfies a first threshold value or more. The first threshold value is stored in the controller 26. It can be seen that when the boom bottom pressure is above a predetermined threshold value, pressure is applied to the lift cylinder 16. That is, during excavation, etc., pressure is applied to the lift cylinder 16 by loading sand and soil into the bucket 15, so it can be determined whether the excavation operation state is in progress by detecting the boom bottom pressure.

[0095] Condition (B) is that the angle θ of the boom 14 detected by the boom angle sensor 73a satisfies a second threshold or less. During excavation, the angle θ of the boom 14 is below the horizontal state, so the second threshold is preferably a negative value. The second threshold is stored in the controller 26 .

[0096] That is, when a pressure greater than a predetermined first threshold is applied to the lift cylinder 16 and the angle θ of the boom 14 falls below a predetermined second threshold, the wheel loader 10 is determined to be in the excavation operation state W1. If the lifting determination unit 92 determines that the excavation operation state W1 is in progress, the excavation flag is set to ON and the boom pressure reduction flag is set to OFF.

[0097] Next, the scooping determination unit 92 determines whether the state is the scooping state W3 or the state other than the scooping state W4 in the excavation state W1. When the excavation flag is on, the scooping determination unit 92 determines that the state is the scooping state W3 if condition (C) is satisfied, and determines that the state is the state other than the scooping state W4 if condition (C) is not satisfied.

[0098] Condition (C) satisfies a state in which the detection value of the boom angle sensor 73a, i.e., the angle θ of the boom 14, is greater than the third threshold value. The third threshold value is, for example, a negative value. The third threshold value is set to be larger than the second threshold value. The third threshold value is stored in the controller 26. In addition, the second threshold value indicates when the position of the bucket 15 is close to the tire contact surface. The second threshold value can be set to, for example, -40°. In addition, the third threshold value indicates the position of the boom 14 when it is intermediate between the horizontal state and the state of the second threshold value. The third threshold value can be set to, for example, -20°. The third threshold value and the second threshold value are set in such a way that the boom 14 under the third threshold value is rotated to a state above the boom 14 under the second threshold value.

[0099] In addition, the conditions (B) and (C) are set based on the angle of the boom 14, but are not limited thereto, and may be set based on the height of the bucket 15 by detecting the position of the bucket 15. The position of the bucket 15 may be detected by a camera installed in the cabin 5, for example. In addition, the third threshold and the second threshold are set so that the height of the bucket 15 at the third threshold is higher than the height of the bucket 15 at the second threshold.

[0100] In this way, based on the height setting conditions (B) and (C) of the work machine 3 , the height of the work machine 3 at the third threshold value may be set higher than the height of the work machine 3 at the second threshold value.

[0101] If the lifting determination unit 92 determines that the state is the lifting work state W3, the lifting flag is turned on. If the lifting determination unit 92 determines that the condition (C) is not satisfied when the excavation flag is on, the lifting flag is turned off.

[0102] Since the boom 14 is located higher during lifting than during normal excavation, the lifting state W3 and the state W4 other than lifting can be distinguished by detecting the angle θ of the boom 14 in the excavation work state W1 .

[0103] Furthermore, when the excavation flag is on and condition (D) or condition (E) is satisfied, the lifting determination unit 92 regards that the wheel loader 10 is in the state W2 other than the excavation operation and sets the excavation flag to OFF.

[0104] Condition (D) is a state where the boom bottom pressure reduction flag is on. When the detection value of the boom bottom pressure sensor 73b is less than the boom bottom pressure which is a threshold value pre-set based on the angle θ of the boom 14 within a predetermined time, the boom bottom pressure reduction flag is set to on. Here, the boom bottom pressure which is a threshold value pre-set based on the angle θ of the boom 14 is stored in the controller 26.

[0105] Thus, when the boom bottom pressure is less than a threshold value set based on the boom angle within a predetermined time, the scooping determination unit 92 sets the boom pressure reduction flag to ON, determines that the state has shifted to the state W2 other than the excavation operation, and sets the excavation flag to OFF.

[0106] Condition (E) is that the FNR lever 52 is in a position other than forward (F) (reverse (N) or neutral (N)). When the vehicle is not moving forward, the lifting determination unit 92 determines that the vehicle is in a state other than excavation operation W2 and sets the excavation flag to OFF.

[0107] As described above, when the scooping determination unit 92 determines that the excavation operation state W1 is satisfied due to the conditions (A) and (B), and when the condition (C) is further satisfied while maintaining the determined state, it determines that the wheel loader 10 is in the scooping operation state W3 and sets the scooping flag to ON.

[0108] The determination unit 93 determines control of the notification system 24 and the brake system 22 based on the determination result of the scooping determination unit 92 .

[0109] The decision unit 93 determines that the scooping operation is not a scooping operation ( Figure 4 In the case of a state W2 other than the excavation operation and a state W4 other than the shovel operation), the first control is enabled as the control of the notification system 24 and the brake system 22.

[0110] In the first control, when the obstacle determination unit 91 determines that there is an obstacle during the reverse movement, as described later, Figure 5 As shown, the automatic brake is activated and an obstacle presence warning is issued (an example corresponding to object detection). This is because the wheel loader 10 is not performing a shovel operation, so it can be determined that the obstacle detection is not a false detection.

[0111] In addition, when the scooping determination unit 92 determines that the vehicle is in the scooping operation state W3, the decision unit 93 enables the second control as a control of the notification system 24 and the brake system 22. In the second control, the automatic brake is not activated and the alarm is not issued regardless of whether the obstacle determination unit 91 determines that an obstacle exists during reverse operation. In addition, when the second control is enabled, the first control is disabled.

[0112] This is because, as described later Figure 5 As shown, the wheel loader 10 is performing a scooping operation and can determine that the ground surface is erroneously detected as an obstacle.

[0113] The brake instruction unit 82 performs automatic braking control based on the effective control of the first control or the second control of the decision unit 93. The automatic braking in this specification refers to the automatic application of braking force to the vehicle body 1 based on the determination results of the obstacle determination unit 91 and the determination results of the scooping determination unit 92, and is not limited to the braking force formed by the service brake 42 as described later.

[0114] When the decision unit 93 makes the first control effective, if the obstacle determination unit 91 determines that there is an obstacle when moving backward, the brake instruction unit 82 stops the fuel supply to the engine 31 by turning off the accelerator pedal 51. In addition, the brake instruction unit 82 stops the vehicle body 1 by operating the brake valve 41 to drive the service brake 42. On the other hand, when the decision unit 93 makes the second control effective, the automatic braking function is stopped, and the brake instruction unit 82 does not operate the brake valve 41 and does not apply the braking force. That is, in the second control, even if the obstacle determination unit 91 determines that there is an obstacle when moving backward, the braking force is not applied.

[0115] The notification instruction unit 83 instructs the alarm device 61 or the function OFF notification lamp 62 to perform an operation instruction based on the effective control of the first control or the second control of the determination unit 93 .

[0116] When the obstacle determination unit 91 determines that an obstacle exists during reverse travel while the determination unit 93 is activating the first control, the notification instruction unit 83 activates the alarm device 61 to notify the operator of the presence of the obstacle and the activation of automatic braking.

[0117] On the other hand, if the decision unit 93 makes the second control effective, the notification indicator 83 stops the function of the alarm device 61, lights up the function OFF notification lamp 62, and notifies the operator that the automatic braking function is stopped. That is, in the second control, even if the obstacle determination unit 91 determines that there is an obstacle when reversing, no alarm is issued.

[0118] Figure 5 1 is a diagram showing a state in which an obstacle S is detected and the vehicle body 1 is stopped when the vehicle is moving backward. In the first control, the service brake 42 is activated with a preset braking force (also referred to as braking force) to stop the vehicle body 1 so that the vehicle body 1 stops in front of the obstacle S. Figure 5 In FIG. 1 , the stopped vehicle body 1 is indicated by a two-dot chain line.

[0119] It should be noted that the automatic braking based on the set braking force may also be performed by activating the parking brake 43 instead of braking the vehicle body 1 through the service brake 42 as described above. In this case, the decision unit 93 enables the first control as the control of the notification system 24 and the brake system 22, and if the obstacle S is detected during the reverse movement, the brake instruction unit 82 stops the fuel supply to the engine 31 by disconnecting the accelerator pedal 51. In addition, the brake instruction unit 82 controls the parking brake 43 to brake the vehicle body 1.

[0120] Figure 6 2 is a diagram showing a state where the wheel loader 10 is performing a shoveling operation. Figure 6 As shown, a pile of soil M is formed on the ground G, and a wheel loader 10 is placed on the slope i thereof. The inclination angle θ is, for example, an angle between a line L connecting the axes of the front tires 4 and the rear tires 7 and a horizontal line H.

[0121] After the shoveling operation, since the wheel loader 10 descends the slope i, the ground G is detected as an obstacle S when moving backward. Therefore, in the present embodiment, when it is determined that the shoveling operation state W3 is in place, the second control is enabled as control of the notification system 24 and the brake system 22. In the second control, the automatic braking function and the alarm device 61 function are stopped, the function OFF notification lamp 62 is turned on, and the automatic braking and the alarm device 61 are not activated.

[0122] It should be noted that, during the second control, the function of the rear detection unit 71 itself can be turned off, or the rear detection unit 71 can be used for detection, but the controller 26 does not use the detection result. Alternatively, the detection result of the rear detection unit 71 is used to perform the judgment of the obstacle judgment unit 91, but the judgment result is not used.

[0123] The control return determination unit 94 determines whether to return the first control from invalid to valid based on information related to the shoveling operation state, including vehicle speed, position of the FNR lever 52 (an example of an operating member), travel distance, braking state of the parking brake, or key position.

[0124] The control return determination unit 94 obtains the vehicle speed from the detection value sent from the vehicle speed sensor 72b. The control return determination unit 94 obtains the position of the FNR lever 52 (an example of an operating member) from the operation information sent from the FNR lever 52. The control return determination unit 94 obtains the travel distance by using the vehicle speed signal sent from the vehicle speed sensor 72b to the controller 26 and the calculation of the timer included in the controller 26. The control return determination unit 94 obtains the braking state of the parking brake 43 from the ON / OFF signal sent from the parking switch 53. The control return determination unit 94 obtains the position of the key from the position information sent from the engine key unit 57.

[0125] The control return determination unit 94 determines a return to the first control effective position when any one of the following conditions (1) to (6) is satisfied based on the acquired information.

[0126] (1) The vehicle speed is higher than a predetermined speed and the FNR lever 52 is in the reverse position

[0127] (2) A predetermined time or longer has passed since the FNR lever 52 was placed in the retracted position.

[0128] (3) After the FNR lever 52 is placed in the reverse position, the vehicle has traveled a predetermined distance or more.

[0129] (4) The FNR lever 52 moves from the rearward position to the neutral position or from the rearward position to the forward position

[0130] (5) Parking brake

[0131] (6) The key is in the OFF position

[0132] When any one of the above conditions (1) to (3) is satisfied, it is considered that the wheel loader 10 is in a state of descending from the sand pile after the shoveling operation, and therefore, the control return determination unit 94 determines to return the first control to be effective instead of the second control as the control of the notification system 24 and the brake system 22. In addition, when any one of the conditions (4) to (6) is satisfied, it is considered that the wheel loader 10 has stopped for some reason, and therefore, the control return determination unit 94 determines to return the first control to be effective instead of the second control as the control of the notification system 24 and the brake system 22.

[0133] When the control return determination unit 94 determines that the return is the first control effective, the determination unit 93 makes the first control effective as the control of the notification system 24 and the brake system 22 instead of the second control.

[0134] Thus, after determining the shoveling operation state and disabling the first control, returning to the first control being enabled is determined based on conditions different from the determination of the shoveling operation state, thereby preventing the ground from being erroneously detected as an obstacle when descending from the pile of earth after the shoveling operation.

[0135] <Action>

[0136] Next, the control operation of the wheel loader 10 according to the present embodiment will be described.

[0137] Figure 7 This is a flowchart showing the control operation of the wheel loader 10 according to the present embodiment.

[0138] First, in step S10 (an example of a control determination step), the determination unit 93 of the controller 26 enables the first control as control of the notification system 24 and the brake system 22. In the first control, when the obstacle determination unit 91 determines that an obstacle exists during reverse travel, automatic braking is activated and an alarm is sounded.

[0139] Next, in step S20 (an example of a scooping determination step), the scooping determination unit 92 of the controller 26 determines whether the vehicle body 1 is in the scooping operation state W3. If it is determined in step S20 that the vehicle body 1 is not in the scooping operation state, the control returns to step S10 and the first control is maintained.

[0140] On the other hand, when it is determined in step S20 that the scooping work state W3 is in progress, the control proceeds to step S30.

[0141] In step S30 (an example of a stop step), the decision unit 93 invalidates the first control and validates the second control as control of the notification system 24 and the brake system 22. In the state where the second control is validated, the automatic braking function and the alarm device 61 function are stopped, and the function OFF notification lamp 62 is lit. Therefore, even if it is determined that an obstacle exists during reverse travel, the automatic braking and the alarm device 61 are not activated.

[0142] Next, in step S40, the control return determination unit 94 determines whether any one of the above-mentioned conditions (1) to (6) is satisfied based on the information related to the shoveling operation state, and determines whether to return the first control to effective as the control of the notification system 24 and the braking system 22.

[0143] In step S40, if it is determined that any one of conditions (1) to (6) is not satisfied and the first control is not returned to effective, step S40 is repeated until any one of conditions (1) to (6) is satisfied. In step S40, if the control return determination unit 94 determines that any one of conditions (1) to (6) is satisfied, control proceeds to step S50.

[0144] Then, in step S50 , the decision unit 93 returns the first control to be effective as the control of the notification system 24 and the brake system 22 .

[0145] Thus, even when descending a slope after shoveling, the automatic braking function and the alarm device 61 function are stopped, and erroneous detection of the ground surface G as an obstacle can be reduced.

[0146] Furthermore, since the automatic braking function can be stopped, it is possible to prevent a situation in which the ground is detected after the shoveling operation and the vehicle cannot descend from the pile of sand and soil M.

[0147] (Implementation Method 2)

[0148] Next, a wheel loader 10 according to a second embodiment of the present disclosure will be described.

[0149] In the wheel loader 10 of the first embodiment, whether or not the shoveling operation state is in progress is determined based on the detection of the working device state detection unit 73, but in the wheel loader 10 of the second embodiment, whether or not the shoveling operation state is in progress is determined based on the tilt state of the vehicle body 1. In addition, unlike the wheel loader 10 of the first embodiment, which determines the condition for returning to the first control to be effective, in the wheel loader 10 of the second embodiment, the return to the first control to be effective is determined based on the tilt state of the vehicle body 1.

[0150] Figure 8 This is a block diagram showing the configuration of the drive system 21, brake system 22, operation system 23, notification system 24, and detection system 125 of the wheel loader 10 of the second embodiment. Compared with the detection system 25 of the first embodiment, the detection system 125 of the wheel loader 10 of the second embodiment does not include the travel state detection unit 72 and the work implement state detection unit 73, but includes a vehicle body angle sensor 74 (an example of a tilt state detection unit).

[0151] The body angle sensor 74 detects the tilt state of the vehicle body 1. The body angle sensor 74 detects whether the vehicle body 1 is in a tilt state by detecting the angle of the vehicle body 1. In addition, an IMU (Inertial Measurement Unit) may be used instead of the body angle sensor 74, or the tilt state of the wheel loader 10 may be determined based on a detection image of a camera provided inside or outside the vehicle body. In addition, any configuration that can detect the tilt state of the wheel loader 10 is not limited to these configurations.

[0152] In the second embodiment, the scooping determination unit 92 determines whether the scooping operation state is in progress based on the detection value of the vehicle body angle sensor 74. The scooping determination unit 92 determines that the scooping operation state is in progress when the inclination angle detected by the vehicle body angle sensor 74 is greater than or equal to a predetermined threshold value θ1 (an example of a fourth threshold value, for example, 20°). Figure 5 ) is the angle at which the front side of the wheel loader 10 is lifted relative to the horizontal.

[0153] In the second embodiment, the control return determination unit 94 determines the return to the first control effective position when the inclination angle detected by the vehicle body angle sensor 74 is less than the predetermined threshold value θ2 (an example of the fifth threshold value, for example, 10°). This is because it is considered that the vehicle body 1 is in a state of descending from the inclined surface where the shovel operation is performed. In addition, the predetermined threshold value θ2 is set smaller than the predetermined threshold value θ1.

[0154] Fig. 9 : is a diagram showing the relationship between the invalidation of the first control of the tilt angle and the return to the valid position. Fig. 9 As shown, the threshold value θ2 for determining the end of the shoveling operation and the descending from the soil pile and determining the return to the first control to be effective is set smaller than the threshold value θ1 for determining the shoveling operation state and invalidating the first control.

[0155] For example, if the threshold θ1 and the threshold θ2 are set to the same value, then Fig.10 As shown in FIG. 1 , since the first control is set to return to the position halfway down the soil pile after the shoveling operation, the ground surface G is mistakenly detected as an obstacle.

[0156] Therefore, by setting the threshold value θ2 to be smaller than the threshold value θ1, it is possible to reduce the occurrence of false detections.

[0157] In addition, if you use Figure 7The control operation of the wheel loader 10 according to the second embodiment will be described. In step S20, when the tilt angle detected by the vehicle body angle sensor 74 is greater than the predetermined threshold value θ1, the lifting determination unit 92 determines that the vehicle is in the lifting operation state, and the control proceeds to step S30. On the other hand, when the tilt angle is less than the predetermined threshold value θ1, the lifting operation state is determined not to be in the lifting operation state, and the control returns to step S10.

[0158] In addition, in step S40, when the tilt angle detected by the vehicle body angle sensor 74 is less than the predetermined threshold value θ2, the control return determination unit 94 regards that the return condition is satisfied and determines to return to the first control effective position, and the control proceeds to step S50. On the other hand, when the tilt angle detected by the vehicle body angle sensor 74 is greater than the predetermined threshold value θ2, the return condition is regarded as not satisfied and the control of step S40 is repeated, and step S40 is repeated until the return condition is satisfied.

[0159] <Features> (1)

[0161] The wheel loader 10 (an example of a construction machine) of the present embodiment includes a vehicle body 1, a rear detection unit 71, and a controller 26 (an example of a control unit). The vehicle body 1 includes a vehicle body frame 2, front tires 4 and rear tires 7 (an example of a traveling body), and a working device 3 arranged in front of the vehicle body frame 2. The rear detection unit 71 detects an obstacle (an example of an object) when the vehicle body frame 2, the front tires 4 and the rear tires 7 are driven to travel backward. The controller 26 determines whether the first control is valid or invalid based on the detection of the obstacle, the traveling state to the rear, and the scooping operation state of the working device 3. When the first control is invalid, the first control is made valid based on the scooping operation state.

[0162] Thus, when an obstacle is detected, it is determined that the scooping operation state exists, and the first control for taking measures to reduce the collision can be invalidated. If it is not necessary to invalidate the first control, the first control can be returned from invalidation to validity.

[0163] Therefore, even when descending from a pile of sand and soil after shoveling, the first control is not made effective, thereby preventing the ground surface G from being detected as an obstacle, thereby reducing alarms due to false detection. (2)

[0165] The wheel loader 10 (an example of a construction machine) of the present embodiment further includes an alarm device 61 (an example of a first notification unit). The alarm device 61 notifies that an obstacle is detected behind the vehicle body 1 by the rear detection unit 71. The controller 26 enables the second control when the first control is invalid. The first control executes the notification of the alarm device 61. The second control executes the change of the notification of the alarm device 61. The change of the notification includes stopping the notification, suppressing the volume of the notification, or changing the output method of the notification.

[0166] Thus, when the first control is invalid, it is possible to stop issuing the alarm, suppress the alarm level, change from sound to light, and the like. (3)

[0168] In the wheel loader 10 (an example of a construction machine) of the present embodiment, information related to the shoveling operation state includes the vehicle speed, the position of the FNR lever 52 (an example of an operating member), and the travel distance. When the first control is invalid, the controller 26 makes the first control valid in any of the following cases: the vehicle speed is higher than a predetermined speed and the FNR lever 52 is configured in the reverse position; a predetermined time has passed since the FNR lever 52 was configured in the reverse position; and a predetermined distance has been traveled since the FNR lever 52 was configured in the reverse position.

[0169] This shows that the vehicle is in a state of descending from the pile of sand and soil after the shoveling operation, and therefore, the first control corresponding to the detection of the obstacle can be returned to the effective position. (4)

[0171] In the wheel loader 10 (an example of a construction machine) of the present embodiment, the information related to the shoveling operation state includes the position of the FNR lever 52 (an example of an operating member), the braking state of the parking brake 43, or the ON / OFF state of the engine key 57 (an example of a key). When the first control is invalid, the controller 26 enables the first control in any of the following cases: the FNR lever 52 moves from the reverse position to the neutral position or from the reverse position to the forward position, the parking brake 43 is applied, or the engine key 57 is in the OFF state.

[0172] This shows that the work vehicle has stopped for some reason, and therefore the first control corresponding to the detection of the obstacle can be returned to being effective. (5)

[0174] The wheel loader 10 (an example of a construction machine) of the present embodiment includes a driving state detection unit 72 and a working device state detection unit 73. The driving state detection unit 72 detects the driving state of the vehicle body 1. The working device state detection unit 73 detects the state of the working device 3. Information related to the shoveling operation state includes the driving state and the state of the working device 3. The controller 26 determines whether it is the shoveling operation state based on the state of the working device 3 when moving forward.

[0175] Thus, it is possible to determine whether the scooping operation state is in progress based on the travel state of the vehicle body 1 and the state of the work implement 3 . (6)

[0177] In the wheel loader 10 (an example of construction machinery) of the present embodiment, the working device 3 has a boom 14, a bucket 15, and 16 (an example of a boom cylinder). The boom 14 is movably mounted on the front portion of the vehicle body frame 2. The bucket 15 is connected to the boom 14 in a manner of being configured with an opening toward the front, and is driven relative to the boom 14. 16 drives the boom 14. The working device state detection unit 73 includes a boom bottom pressure sensor 73b and a boom angle sensor 73a. The boom bottom pressure sensor 73b detects the bottom pressure of 16. The boom angle sensor 73a detects the angle of the boom 14. The controller 26 determines whether it is in the shoveling operation state based on the bottom pressure of 16 and the angle of the boom 14.

[0178] In this way, by detecting the angle θ of the boom 14 and the bottom pressure of the boom 16 , it is possible to determine whether the wheel loader 10 is in the scooping operation state. (7)

[0180] In the wheel loader 10 (an example of a construction machine) of the present embodiment, the controller 26 determines that the state is an excavation operation when the bottom pressure of the lift cylinder 16 is greater than a first threshold and the angle of the boom 14 is less than a second threshold, and determines that the state is a shoveling operation when the angle of the boom 14 is greater than a third threshold when the state is an excavation operation. The third threshold is located above the second threshold.

[0181] In this way, by detecting the angle of the boom 14 and the bottom pressure of the boom 16, it is determined whether the wheel loader 10 is in the excavation operation state, and if it is determined to be in the excavation operation state, it can be determined whether the excavation operation is a shoveling operation based on the angle of the boom 14. This is because the boom 14 is located at an upper position during shoveling compared to normal excavation, so in the excavation operation state, it is possible to distinguish between the shoveling operation state and the state other than the shoveling operation. (8)

[0183] In the wheel loader 10 (an example of a construction machine) of the present embodiment, the driving state detection unit 72 detects the rotation direction of the front tires 4 or the rear tires 7 provided on the vehicle body 1, or the position set by the FNR lever 52 capable of setting the forward or reverse direction of the vehicle body 1. The controller 26 determines the forward direction based on the detection of the driving state detection unit 72.

[0184] This makes it possible to determine whether or not the scooping operation is in progress when the vehicle body 1 is moving forward. (9)

[0186] The wheel loader 10 (an example of a construction machine) of the present embodiment further includes a vehicle body angle sensor 74 (an example of an inclination state detection unit). The vehicle body angle sensor 74 detects the inclination state of the vehicle body 1. The information related to the scooping operation state includes the inclination state. When the inclination angle of the vehicle body 1 is greater than or equal to the fourth threshold value, the controller 26 determines that it is in the scooping state.

[0187] During the shoveling operation, the vehicle body 1 is placed at an inclined location such as a pile of sand and soil, and therefore, by detecting the inclination, it can be determined whether the shoveling operation is in progress. (10)

[0189] In the wheel loader 10 (an example of a construction machine) of this embodiment, the information on the lifting work state includes the tilt state. When the first control is invalid, the controller 26 validates the first control when the tilt angle of the vehicle body 1 is less than or equal to a fifth threshold value which is smaller than the fourth threshold value.

[0190] In this way, the fourth threshold value of the inclination angle for determining whether it is a shoveling operation state and the fifth threshold value of the inclination angle for returning the first control for performing the action to reduce the collision are changed, and the fifth threshold value is set smaller than the fourth threshold value, thereby reducing the situation of false detection in the middle of descending from the pile of earth. (11)

[0192] The wheel loader 10 (an example of a construction machine) of the present embodiment further includes a driving state detection unit 72 that detects the driving state of the vehicle body 1. The controller 26 detects an object behind the vehicle body 1 when moving backward. The driving state detection unit 72 detects the rotation direction of the front tires 4 or the rear tires 7 provided on the vehicle body 1, or the position set by the FNR lever 52 that can set the forward or reverse movement of the vehicle body 1. The controller 26 determines to move backward based on the detection of the driving state detection unit 72.

[0193] This makes it possible to detect that the main vehicle body 1 is moving backward. (12)

[0195] In the wheel loader 10 (an example of a construction machine) of this embodiment, the controller 26 enables the second control when the first control is invalid. The first control drives the automatic brake to automatically brake the vehicle body 1. The second control suppresses the braking force of the automatic brake or stops the automatic brake.

[0196] Thereby, for example, when the vehicle body 1 is placed on a slope during shoveling work, it is possible to prevent the automatic brake from being activated and stop the vehicle body 1 . (13)

[0198] The wheel loader 10 (an example of a construction machine) of the present embodiment further includes a function OFF notification lamp 62 (an example of a second notification unit) which notifies the operator of the suppression of the braking force of the automatic brake or the stop of the automatic brake. When the controller 26 suppresses the braking force of the automatic brake or stops the automatic brake, it notifies the operator through the function OFF notification lamp 62.

[0199] This allows the operator to recognize that automatic braking is being suppressed or stopped. (14)

[0201] In the wheel loader 10 (an example of a construction machine) of the present embodiment, the working device 3 includes a boom 14, a bucket 15, a bucket cylinder 17 (an example of an actuator), and a rocker arm 18 (an example of a secondary link). The boom 14 is swingably mounted on the front portion of the vehicle body frame 2. The bucket 15 is connected to the boom 14 in a manner of being arranged with an opening facing forward, and is driven relative to the boom 14. The bucket cylinder 17 drives the bucket 15. The rocker arm 18 is mounted on the boom 14, and transmits the driving force of the bucket cylinder 17 to the bucket 15.

[0202] Thus, in the wheel loader 10 having the front loading structure, it is possible to reduce the number of alarms caused by false detection of the ground surface G as an obstacle S and activation of the alarm device 61 during and after the shoveling operation. (15)

[0204] The control method of the wheel loader 10 (an example of a construction machine) of the present embodiment includes step S10, step S30 (an example of a control determination step), and steps S40 and S50 (an example of a control validation step). In steps S10 and S30, the validity or invalidity of the first control is determined based on the detection of an object when traveling backwards, the traveling state when traveling backwards, and the scooping operation state of the working device 3 by driving the traveling body of the vehicle body 1 having the vehicle body frame 2, the front tires 4 and the rear tires 7 (an example of a traveling body) and the working device 3. In steps S40 and S50, when the first control is invalid, the first control is validated based on the scooping operation state.

[0205] Thus, by determining that the scooping operation state is in progress, the first control for taking measures to mitigate a collision when an obstacle is detected can be invalidated, and when the first control does not need to be invalidated, the first control can be returned from invalidation to validity.

[0206] Therefore, even when descending from the pile of earth and sand after the shoveling operation, the first control is not made effective, so that the ground surface G can be prevented from being detected as an obstacle, and the alarm due to false detection can be reduced.

[0207] <Other Implementation Methods>

[0208] As mentioned above, one embodiment of the present invention has been described, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention.

[0209] (A)

[0210] In the above embodiment, the automatic braking function is stopped in the second control, but it is not limited to stopping. The opening of the brake valve 41 may be set smaller than that in the first control and the control may be performed in a manner of starting with a weaker braking force than that in the automatic braking. This weak braking corresponds to an example of suppression of the automatic braking. At this time, the suppression of the automatic braking may also be notified by the function OFF notification lamp 62.

[0211] It should be noted that the weak braking force can also be generated by the operator's control when the accelerator pedal 51 is turned off instead of adjusting the opening of the brake valve 41. When the operator turns off the accelerator pedal 51, the fuel supply to the engine 31 is stopped, and the swash plate of the control pump 32a and the motor 32b becomes a resistance to travel, so that the weak braking force is activated. That is, the brake instruction unit 82 can also stop the fuel supply to the engine 31, and the swash plate of the control pump 32a and the motor 32b becomes a resistance to travel.

[0212] In addition, the weak braking force can be activated not only by the control when the accelerator pedal is disconnected, but also by the control when the FNR lever 52 is operated in a neutral position. When the FNR lever 52 is in the neutral position, the controller 26 controls the solenoids 32d and 32e to move in a manner such that the swash plate of the pump 32a and the motor 32b becomes a resistance to travel. That is, the brake instruction unit 82 can also stop the fuel supply to the engine 31 and control the swash plate of the pump 32a and the motor 32b to become a resistance to travel.

[0213] Thus, the braking force acts to generate a weak braking force. In addition, the neutral position can obtain a greater braking force than simply disconnecting the accelerator pedal 51.

[0214] (B)

[0215] In the above embodiment, the HST 32 is used in the drive system 21 , but the drive system 21 is not limited to the HST and may be a torque converter. Fig.11 This is a block diagram showing a configuration in which the drive system 21 is provided with a torque converter 132 and a transmission 133 . Fig.11 Although a modification of the configuration of the second embodiment is described, a configuration in which the torque converter 132 and the transmission 133 are provided in the drive system 21 may be applied to the first embodiment.

[0216] The driving force from the engine 31 is transmitted to the transmission 133 via the torque converter 132. The transmission 133 changes the speed of the rotational driving force of the engine 31 transmitted via the torque converter 132 and transmits it to the axle 34. The transmission 133 is provided with a parking brake 43.

[0217] In the case of a torque converter, in order to generate the weak braking force described in (A) above, the opening of the brake valve 41 may be set small as described above. In addition, although the braking force is weaker than that of the HST, it is also possible to perform control by only turning the accelerator pedal 51 off. It should be noted that, in the case of generating the set braking force, the opening of the brake valve 41 may be increased or the parking brake 43 may be used as in the above embodiment.

[0218] Furthermore, the present invention is not limited to HST, and HMT (Hydro Mechanical Transmission) may also be used.

[0219] (C)

[0220] In the above embodiment, in the second control, the automatic brake is not activated, and the alarm device 61 is not activated, but, for example, only the alarm device 61 may be operated. In addition, only the automatic brake may be activated, or both the automatic brake and the alarm device 61 may be activated. When both are activated, unlike the first control, in the second control, the braking force of the automatic brake or the alarm level of the alarm device 61 may be suppressed.

[0221] (D)

[0222] Although the wheel loader 10 of the above embodiment has the function of automatic braking, it may not have the function of automatic braking. In this case, in the first control, the automatic braking is not activated, and the alarm device 61 is activated. In addition, in the second control, the alarm device 61 is not activated.

[0223] In the first control, the volume of the alarm may be changed according to the distance from the vehicle body 1 to the obstacle.

[0224] (E)

[0225] In the above embodiment, as an example of changing the notification of the alarm device 61, in the second control, the alarm of the alarm device 61 is stopped, but the present invention is not limited to this, and the volume of the alarm may be suppressed or the output method of the alarm may be changed. Changing the output method of the alarm means, for example, changing the notification based on sound to the notification based on light.

[0226] (F)

[0227] In addition, the braking force control may also include, in addition to the service brake 42 and the parking brake 43, a means for changing the braking force as appropriate.

[0228] (G)

[0229] The determination condition of the scooping operation state in the first embodiment described above may be combined with the return condition in the second embodiment, and conversely, the determination condition of the scooping operation state in the second embodiment may be combined with the return condition in the first embodiment.

[0230] In addition, the determination conditions of the scooping operation state of the first embodiment and the second embodiment may be combined, and the return conditions of the first embodiment and the second embodiment may be combined. For example, as the return condition, the condition that the inclination angle is less than or equal to the threshold value θ2 is added as condition (7) to conditions (1) to (6), and the return condition may be satisfied when any one of conditions (1) to (7) is satisfied.

[0231] (H)

[0232] In the above embodiment, the function OFF notification lamp 62 is always lit in the second control, but the function OFF notification lamp 62 may be lit only when an obstacle is detected during reverse travel.

[0233] (I)

[0234] The wheel loader according to the above-described embodiment may be operated by an operator riding on the wheel loader, or may be unmanned.

[0235] (J)

[0236] In the above-mentioned embodiment, the wheel loader is used as an example of the construction machine for explanation, but the construction machine is not limited to the wheel loader and may be a bulldozer, a forklift, or the like.

[0237] Industrial Applicability

[0238] According to the construction machine and the control method of the construction machine disclosed in the present invention, an effect of being able to issue an alarm in consideration of the deviation in the scooping operation is achieved, and the construction machine and the control method of the construction machine are useful for a wheel loader and the like.

[0239] Description of Reference Numerals

[0240] 1 Vehicle body

[0241] 2 Body frame

[0242] 3 Working device

[0243] 4 Front tires

[0244] 7 Rear tire

[0245] 26 Controller

[0246] 71 Rear detection unit

Claims

1. A construction machine, characterized in that: have: A vehicle body having a traveling body and a working device arranged in front of the traveling body; a rear detection unit that detects an object when the vehicle travels rearward by the driving of the traveling body; a control unit that determines whether a first control is effective or ineffective based on the detection of the object, the state of traveling toward the rear, and the scooping operation state of the working device, and when the first control is ineffective, makes the first control effective based on the scooping operation state; The information related to the shoveling operation state includes vehicle speed, position of an operating component or travel distance, The control unit enables the first control when the first control is invalid, in any one of the following cases: when the vehicle speed is higher than a predetermined speed and the operating member is placed in the reverse position, when a predetermined time has passed after the operating member is placed in the reverse position, or when the vehicle has traveled a predetermined distance after the operating member is placed in the reverse position. The first control is to drive an automatic brake for automatically braking the vehicle body, or to control a first notification unit for notifying that the rear detection unit has detected an object behind the vehicle body.

2. The construction machine according to claim 1, wherein: The control unit enables the second control when the first control is invalid. The first control performs notification of a situation in which an object is detected behind the vehicle by the first notification unit. The second control executes a change in notification of the first notification unit, The change of the notification includes stopping the notification, suppressing the volume of the notification, or changing the output method of the notification.

3. The construction machine according to claim 1, wherein: The information related to the shoveling operation state includes the position of the operating member, the braking state of the parking brake, or the ON / OFF state of the key. When the first control is invalid, the control unit enables the first control in any of the following cases: the operating member moves from the rearward position to the neutral position or from the rearward position to the forward position, the parking brake is applied, or the key is in the OFF state.

4. The construction machine according to any one of claims 1 to 3, wherein: Also available: A driving state detection unit, which detects the driving state of the vehicle body; a working device state detection unit, which detects the state of the working device; The control unit determines whether the working device is in the scooping operation state based on the state of the working device when the working device is moving forward.

5. The construction machine according to claim 4, wherein: The working device comprises: A large arm movably mounted on the front portion of the traveling body; A bucket connected to the boom with an opening facing forward and driven relative to the boom; A boom cylinder, which drives the boom, The working device state detection unit further comprises: A boom bottom pressure sensor, which detects the bottom pressure of the boom cylinder; A boom angle sensor, which detects the angle of the boom, The control unit determines whether the scooping operation state is in the state based on the bottom pressure of the boom cylinder and the angle of the boom.

6. The construction machine according to claim 5, wherein: The control unit determines that the excavation operation state is in the case where the bottom pressure of the boom cylinder is greater than a first threshold value and the angle of the boom is less than a second threshold value, and determines that the excavation operation state is in the case where the angle of the boom is greater than a third threshold value when the excavation operation state is determined. The third threshold is located above the second threshold.

7. The construction machine according to claim 4, wherein: The driving state detection unit detects the rotation direction of the wheels provided on the vehicle body or the position set by the operating member capable of setting the forward or reverse movement of the vehicle body. The control unit determines to move forward based on the detection by the traveling state detection unit.

8. The construction machine according to claim 1, wherein: The vehicle body further includes an inclination state detecting unit for detecting the inclination state of the vehicle body. The information related to the shoveling operation state includes the tilt state, The control unit determines that the scooping operation state is in the state when the inclination angle of the vehicle body is equal to or greater than a fourth threshold value.

9. The construction machine according to claim 8, wherein: The information related to the shoveling operation state includes the tilt state, The control unit enables the first control when the inclination angle of the vehicle body is equal to or smaller than a fifth threshold value that is smaller than the fourth threshold value while the first control is invalid.

10. The construction machine according to claim 1, wherein: The vehicle further comprises a driving state detection unit for detecting the driving state of the vehicle body. The control unit detects an object behind the vehicle body when the vehicle moves backward. The driving state detection unit detects the rotation direction of the wheels provided on the vehicle body or the position set by the operating member capable of setting the forward or reverse movement of the vehicle body. The control unit determines reverse movement based on the detection by the traveling state detection unit.

11. The construction machine according to claim 1, wherein: The control unit enables the second control when the first control is invalid. The first control is to drive the vehicle body to automatically brake so as to perform automatic braking. The second control performs suppression of the braking force of the automatic braking or stops the automatic braking.

12. The construction machine according to claim 11, wherein: further comprising a second notification unit configured to notify that the braking force of the automatic braking is suppressed or the automatic braking is stopped, When the control unit suppresses the braking force of the automatic braking or stops the automatic braking, the control unit notifies the operator through the second notifying unit.

13. The construction machine according to any one of claims 1 to 3 and 8 to 10, wherein: The engineering machinery is a wheel loader, The working device comprises: A large arm, which is swingably mounted on the front part of the traveling body; A bucket connected to the boom with an opening facing forward and driven relative to the boom; an actuator that drives the bucket; A secondary link is mounted on the boom and transmits the driving force of the actuator to the bucket.

14. A control method for engineering machinery, characterized in that: have: A control determination step of determining whether a first control is effective or ineffective by detecting an object when traveling backward, a traveling state toward the rear, and a scooping operation state of the working device based on driving of a traveling body of a vehicle body having a traveling body and a working device; A control enabling step of enabling the first control based on the shoveling operation state when the first control is invalid; The information related to the shoveling operation state includes vehicle speed, position of an operating component or travel distance, In the control enabling step, when the first control is invalid, the first control is enabled in any one of the following cases: when the vehicle speed is higher than a predetermined speed and the operating member is configured in the reverse position, when a predetermined time has passed after the operating member is configured in the reverse position, or when the vehicle has traveled a predetermined distance after the operating member is configured in the reverse position. The first control is to execute driving of an automatic brake for automatically braking the vehicle body, or to execute notification control of a first notification unit that notifies that an object has been detected behind the vehicle body.

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