Control system of construction machine, control method of construction machine, and construction machine

Abstract

The present application provides a control system of a construction machine, the control system having a work device, a traveling device, and a parking brake, wherein a controller that outputs a control command for controlling the parking brake based on at least an operation state of the work device is provided.

Description

Control systems for construction machinery, control methods for construction machinery, and construction machinery Technical Field

[0001] This invention relates to control systems for construction machinery, control methods for construction machinery, and construction machinery itself.

[0002] This application claims priority based on Japanese Patent Application No. 2021-026006 filed on February 22, 2021, the contents of which are incorporated herein by reference. Background Technology

[0003] Patent Document 1 describes a parking brake device with the following holding function: When the brake pedal is operated and the vehicle speed is below the stop speed, the parking brake is automatically controlled to a braking state. According to this structure, the parking brake can be automatically switched to a braking state without the operator operating it. Furthermore, in this parking brake device, the parking brake, which is held in a braking state, is released when the accelerator pedal is operated with the gear lever not in the neutral position and the engine speed is above a predetermined speed corresponding to the load of the cargo loaded on the fork. According to this structure, when releasing the parking brake on an uphill slope while the vehicle is loaded with cargo, the rollback of the industrial vehicle can be prevented.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-309256 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] According to the parking brake holding function described in Patent Document 1, it is possible to avoid operating the parking brake, for example, when temporarily stopping on a slope, without continuously pressing the brake pedal. However, the parking brake device described in Patent Document 1 has the following problem: the parking brake is not controlled according to the operator's intention, thus reducing the operability of the construction machinery.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a control system for construction machinery, a control method for construction machinery, and construction machinery that can prevent the reduction of the operability of construction machinery.

[0010] Technical solutions for solving the problem

[0011] To address the aforementioned problems, one aspect of the present invention provides a control system for construction machinery, the construction machinery comprising a working device, a traveling device, and a parking brake, wherein a controller is included, the controller outputting control commands to control the parking brake based at least on the operating state of the working device.

[0012] In addition, one aspect of the present invention provides a control method for construction machinery, the construction machinery having a working device, a traveling device, and a parking brake, wherein the method includes at least the step of outputting a control command to control the parking brake based on the operating state of the working device.

[0013] In addition, one aspect of the present invention provides an engineering machine that includes a working device, a traveling device, a parking brake, and a controller that outputs control commands to control the parking brake based at least on the operating state of the working device.

[0014] Invention Effects

[0015] According to various methods of the present invention, it is possible to prevent a decrease in the operability of engineering machinery. Attached Figure Description

[0016] Figure 1 is a side view of the engineering machinery illustrating the implementation method.

[0017] Figure 2 is a schematic block diagram showing the structure of the control system according to the implementation method.

[0018] Figure 3 is a flowchart illustrating an example of the controller's operation in an implementation method.

[0019] Figure 4 is a flowchart illustrating an example of the controller's operation in an implementation method.

[0020] Figure 5 is a schematic block diagram showing another structure of the control system of the implementation method. Detailed Implementation

[0021] (First Implementation)

[0022] Hereinafter, the first embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that, for the first embodiment and the second embodiment, the same or corresponding structures in each figure are referred to by the same reference numerals or by reference numerals with the English letters "a" or "b" appended to the end of the same numbers, and the description is appropriately omitted.

[0023] In this embodiment, a local coordinate system is established for the construction machinery 1, and the positional relationships of each part are explained with reference to the local coordinate system. In the local coordinate system, the first axis extending in the left-right direction (vehicle width direction) of the construction machinery 1 is designated as the X-axis, the second axis extending in the front-back direction of the construction machinery 1 is designated as the Y-axis, and the third axis extending in the up-down direction of the construction machinery 1 is designated as the Z-axis. The X-axis is orthogonal to the Y-axis. The Y-axis is orthogonal to the Z-axis. The Z-axis is orthogonal to the X-axis. The +X direction is the right direction, and the -X direction is the left direction. The +Y direction is the front direction, and the -Y direction is the rear direction. The +Z direction is the up direction, and the -Z direction is the down direction.

[0024] [Overview of Construction Machinery]

[0025] Figure 1 is a side view of the construction machinery 1 according to the embodiment. The construction machinery 1 according to the embodiment is, for example, a wheel loader. In the following description, the construction machinery 1 will be appropriately referred to as a wheel loader 1.

[0026] As shown in Figure 1, the wheel loader 1 has a vehicle body 2, a cab 3, a running gear 4, and a working device 10. The wheel loader 1 travels at the work site via the running gear 4. The wheel loader 1 performs operations at the work site using the working device 10. The wheel loader 1 can perform excavation, loading, transportation, and snow removal operations using the working device 10. It should be noted that the construction machinery 1 only needs to have the working device 10 and the running gear 4; for example, it can be configured as a dump truck, forklift, or motorized grader.

[0027] The cab 3 is supported by the vehicle body 2. Inside the cab 3 is a driver's seat 31 for the operator and an operator's operating device (not shown) for the operator to operate in order to move the wheel loader 1.

[0028] The running gear 4 supports the vehicle body 2. In this embodiment, the running gear 4 has rotatable wheels 5. The wheel loader 1 can travel on the road surface RS using the wheels 5 of the running gear 4. It should be noted that in Figure 1, only the left front wheel 5F and the rear wheel 5R are shown. It should also be noted that the running gear of construction machinery is not limited to wheels, but can also be tracks, etc.

[0029] The working device 10 is supported on the vehicle body 2. The working device 10 includes a bucket 12 as an example of a working tool, a boom 11 that changes the position and posture of the bucket 12, a boom cylinder 13, a bucket cylinder 14, a crank 15, and a connecting rod (not shown).

[0030] The boom 11 is rotatably supported relative to the vehicle body 2 and moves vertically according to the extension and retraction of the boom cylinder 13. The boom cylinder 13 is an actuator that generates power to move the boom 11; one end is connected to the vehicle body 2, and the other end is connected to the boom 11. When the operator operates the working device operating lever 81, the boom cylinder 13 extends and retracts. This causes the boom 11 to move vertically. The boom cylinder 13 is, for example, a hydraulic cylinder.

[0031] The bucket 12, with a shovel tip 12T, is a working tool used for digging and loading objects such as sand and soil. The bucket 12 is rotatably connected to the boom 11 and to one end of a connecting rod. The other end of the connecting rod is rotatably connected to one end of a crank 15. The central portion of the crank 15 is rotatably connected to the boom 11, and the other end is rotatably connected to one end of a bucket cylinder 14. The other end of the bucket cylinder 14 is rotatably connected to the vehicle body 2. The bucket 12 operates using power generated by the bucket cylinder 14. The bucket cylinder 14 is an actuator that generates power to move the bucket 12. When the operator operates the working device operating lever 81, the bucket cylinder 14 extends or retracts. This causes the bucket 12 to swing. The bucket cylinder 14 is, for example, a hydraulic cylinder.

[0032] [Structure of the Control System]

[0033] Figure 2 is a block diagram showing a structural example of the control system 300 of the wheel loader 1 according to the embodiment. As shown in Figure 2, the wheel loader 1 includes a power source 201, a PTO (Power Take Off) 202, a power transmission device 203, a hydraulic pump 204, a control valve 200, and a controller 100. Furthermore, the control system 300 is a control system for a wheel loader 1 (construction machinery) including a working device 10, a traveling device 4, and a parking brake 207, and at least includes a controller 100. Alternatively, the control system 300 may also include devices for inputting predetermined signals to the controller 100, such as a working device operating lever 81 (e.g., a forward / reverse switching operating device 82), an accelerator operating device 83 (e.g., a speed adjustment device), a brake operating device 84, an operator presence detection sensor 85, a parking brake holding function active / inactive switch 86, a parking brake engagement / release switch 87, and a speed sensor 88.

[0034] Power source 201 generates power to enable the construction machinery 1 to operate. Examples of power sources 201 include an internal combustion engine and an electric motor. It should be noted that power source 201 is not limited to an internal combustion engine and an electric motor. Power source 201 can also be, for example, a so-called hybrid power system that combines an internal combustion engine, a generator-motor, and an energy storage device. Alternatively, power source 201 may have a structure that combines an energy storage device and a generator-motor without an internal combustion engine.

[0035] PTO202 transmits at least a portion of the power from power source 201 to hydraulic pump 204. PTO202 distributes the power from power source 201 to power transmission device 203 and hydraulic pump 204.

[0036] The power transmission device 203 includes a gearbox 205, a drive shaft 206, a parking brake 207, and a control valve 208. The gearbox 205 changes the torque, speed, and direction of rotation of the power generated by the power source 201, outputting it to the drive shaft 206 or cutting off the power generated by the power source 201. The drive shaft 206 transmits the power from the gearbox 205 to the driving device 4. The gearbox 205 is not limited to a structure with multiple gears and multiple clutches. The gearbox 205 may also be an HST (Hydraulic Static) system that includes a hydraulic pump and a hydraulic motor, and converts the power generated by the power source 201 into hydraulic power for transmission.

[0037] Transmission (hydraulic static transmission) or HMT (Hydraulic Mechanical Transmission)

[0038] The transmission 205 can also be a structure that includes an EMT (Electric Mechanical Transmission) with a generator and an electric motor, instead of a hydraulic pump and a hydraulic motor. It should be noted that in this embodiment, the transmission 205 has a structure capable of producing a creep phenomenon (the phenomenon of the construction machinery 1 moving forward or backward at a very low speed when the accelerator operating device 83 described later is not operated).

[0039] The parking brake 207 includes a brake disc 2071 fixed relative to and coaxially rotating with the drive shaft 206, a friction member 2072 for engaging (engaged state) or releasing (released state) the brake disc 2071, and a hydraulic device 2073 for driving the friction member 2072. The hydraulic device 2073 includes a spring 2073s, which engages the friction member 2072 with the brake disc 2071 by spring pressure when no hydraulic pressure is supplied, and releases the friction member 2072 when hydraulic pressure is supplied. The control valve 208 includes a solenoid 2081, which supplies working oil from the hydraulic pump 204 to the hydraulic device 2073 when power is supplied to the solenoid 2081. In this configuration, the parking brake 207 includes a holding unit (hydraulic device 2073 (spring 2073s)) for holding the braking components (brake disc 2071 and friction component 2072) in a braking state, and a brake release unit (hydraulic device 2073 and control valve 208) for releasing the braking state. When no control signal (drive signal of solenoid 2081) is input to the brake release unit, it operates as a negative brake in a braking state. It should be noted that the parking brake 207 is not limited to hydraulic pressure; for example, it can also utilize electricity or air pressure. Furthermore, the parking brake 207 is not limited to a disc brake type; for example, it can also be a drum brake.

[0040] The hydraulic pump 204 is driven by power generated by the power source 201 and sprays working oil. At least a portion of the working oil sprayed from the hydraulic pump 204 is supplied to the boom cylinder 13 and the bucket cylinder 14 via control valve 200, and to the parking brake 207 via control valve 208. The control valve 200 controls the flow rate and direction of the working oil supplied from the hydraulic pump 204 to the boom cylinder 13 and the bucket cylinder 14. The working device 10 is operated by the working oil from the hydraulic pump 204.

[0041] As shown in Figure 2, the wheel loader 1 includes a working device operating lever 81, a forward / reverse switching operating device 82, an accelerator operating device 83, a brake operating device 84, an operator presence detection sensor 85, a parking brake holding function active / inactive switch 86, a parking brake engagement / release switch 87, and a steering device (not shown). These operating devices are operated by the operator to make the wheel loader 1 move.

[0042] The working device operating lever 81 (working device operating device) is an operating device used to operate the working device 10. The operator operates the working device 10 by operating the working device operating lever 81. For example, operating the working device operating lever 81 in the left-right direction outputs a signal to move the boom 11 up or down, and operating it in the forward-backward direction outputs a signal to put the bucket 12 into the scooping or unloading state. The operating state of the working device operating lever 81 is neutral when the operator is not operating it, and it can tilt in the left-right and forward-backward directions (tilting state) depending on the operator's operation. Furthermore, a non-sensitive area is provided on the working device operating lever 81 near the neutral position. The operating state of the working device 10 is non-operating (stopped state; inactive state) when the operating state of the working device operating lever 81 is neutral or the operation amount is within the non-sensitive area. Conversely, the operating state of the working device 10 is operating when the operating state of the working device operating lever 81 is not neutral and the operation amount is not within the non-sensitive area (operating state). In the description of the operation example of the controller 100 described later, the operation state of the working device operating lever 81 is "neutral" (or the working device operating lever 81 is "neutral"), which refers to the combination of the working device operating lever 81 being in a neutral state (the state where the operator does not operate) and the operating amount of the working device operating lever 81 being within the insensitive area (the state where the operator operates but the operating amount is less than a specified size). Furthermore, the information indicating the operation state of the working device 10 can be, for example, information obtained from sensors that detect the angle, length, load, etc., of the working device 10, information indicating the control signal of the actuator that causes the working device 10 to operate, information indicating the operation state of the working device operating lever 81 operated by the operator, and combinations thereof. In this embodiment, the information indicating the operation state of the working device 10 includes at least information indicating the operation state of the working device operating device operated by the operator to cause the working device 10 to operate. It should be noted that multiple working device operating levers 81 may be provided independently, for example, along with levers for operating the boom 11 and levers for operating the bucket 12. The operating lever 81 of the working device electrically detects the operating status (tilting direction and tilting amount) of the lever and outputs a signal indicating the operating status to the controller 100. It should be noted that the operating lever 81 of the working device can also be mechanical or can use a PPC valve (Pressure Proportional Control valve).

[0043] The forward / reverse switching operation device 82 is used to switch the driving state of the wheel loader 1 to forward, neutral, or reverse. In this embodiment, the forward / reverse switching operation device 82 is a lever-type operation device. The forward / reverse switching operation device 82 outputs a signal indicating the forward, neutral, or reverse operating state to the controller 100. It should be noted that the forward / reverse switching operation device 82 is not limited to a lever; for example, a switch can also be used to switch between forward, neutral, and reverse.

[0044] The accelerator operating device 83 is an operating device used to increase or decrease the output of the power source 201. The operator can adjust the speed of the wheel loader 1 by operating the accelerator operating device 83; therefore, the accelerator operating device 83 functions as a speed adjustment device. In this embodiment, the accelerator operating device 83 is a pedal-type operating device. The accelerator operating device 83 outputs a signal indicating the operating status to the controller 100. It should be noted that the accelerator operating device 83 is not limited to a pedal-type operating device; for example, it can also be a dial-type or lever-type operating device.

[0045] The braking operating device 84 is an operating device for operating the braking device, also known as the service brake (or service brake), used to decelerate and stop the wheel loader 1. In this embodiment, the accelerator operating device 83 is a pedal-type operating device. The braking operating device 84 outputs a signal indicating the operating state (operation quantity) to the controller 100. It should be noted that the braking operating device 84 is not limited to a pedal-type operating device.

[0046] The operator presence detection sensor 85 is a sensor that detects whether an operator is present in the cab 3 and outputs a signal indicating the detection result to the controller 100. The operator presence detection sensor 85 can be configured using, for example, a seat belt sensor, a seat (sitting) sensor, a work device locking lever (switch), a sensor that detects the operator's posture and behavior (such as a camera or motion sensor), a door lock release sensor (switch), or a door opening / closing switch.

[0047] The parking brake holding function enable / disable switch 86 is a switch that sets the automatic holding function of the parking brake 207 to be enabled or disabled. It should be noted that, in this embodiment, the automatic holding function of the parking brake 207 is a function whereby the controller 100 automatically sets the parking brake 207 to an engaged state and maintains that engaged state, or releases the maintained engaged state. The parking brake holding function enable / disable switch 86 is a switch that is turned on (enabled) or off (disabled) according to the operator's operation, and outputs a signal indicating the on or off state to the controller 100.

[0048] The parking brake engagement / release switch 87 is used to operate the parking brake 207 in an engaged or released state. When the parking brake engagement / release switch 87 is operated (set) to engage, the parking brake 207 is engaged regardless of whether the automatic holding function of the parking brake 207 is active or inactive. Conversely, when the parking brake engagement / release switch 87 is operated to release, the parking brake 207 is released when the automatic holding function of the parking brake 207 is inactive. Furthermore, when the parking brake engagement / release switch 87 is operated to release, if the automatic holding function of the parking brake 207 is active, on the one hand, the parking brake 207 is engaged when the controller 100 activates the automatic holding function; on the other hand, the parking brake 207 is released when the controller 100 does not activate the automatic holding function.

[0049] The parking brake engagement / release switch 87 is a switch that is turned on or off according to the operator's operation, for example, outputting a signal indicating the on or off state to the controller 100. Alternatively, the parking brake engagement / release switch 87 may also be configured to engage when disengaged, thus forming the next circuit. That is, the parking brake engagement / release switch 87 connects one end of the switch to a DC power supply and the other end to one end of a switch (mechanical or semiconductor switch) not shown in the controller 100. Furthermore, the other end of the switch in the controller 100 is connected to one end of a solenoid 2081, and the other end of the solenoid 2081 is connected to the ground wire of the DC power supply. In this case, when the parking brake engagement / release switch 87 is disengaged (engaged operation), the power supplied to the solenoid 2081 is cut off, and the parking brake 207 is operated in the engaged state. In addition, when the parking brake engagement / release switch 87 is turned on (release operation), the power supplied to the solenoid 2081 operates the parking brake 207 to a released state or an engaged state according to the on or off state of the switch in the controller 100.

[0050] In addition, the vehicle speed sensor 88 detects the speed of the wheel loader 1. The vehicle speed sensor 88 outputs a signal (vehicle speed signal) indicating the speed of the wheel loader 1 to the controller 100.

[0051] [Controller Structure]

[0052] The controller 100 shown in Figure 2 is constructed using, for example, an FPGA (Field Programmable Gate Array) or microcomputer having a processor, main storage device, auxiliary storage device, input / output device, etc., and its peripheral circuits or peripheral devices. The controller 100 is a functional structure composed of hardware or a combination of hardware and software, including an acquisition unit 101, a determination unit 102, and a parking brake control unit 103.

[0053] The acquisition unit 101 repeatedly acquires the output signals of the working device operating lever 81, the forward / backward switching operating device 82, the accelerator operating device 83, the brake operating device 84, the operator presence detection sensor 85, the parking brake holding function active / inactive switch 86, the parking brake engagement / release switch 87, and the vehicle speed sensor 88 at a predetermined cycle.

[0054] The determination unit 102 determines whether each output signal acquired by the acquisition unit 101 meets the prescribed conditions. Based on each output signal acquired by the acquisition unit 101, the determination unit 102 performs processes such as determining and setting whether the automatic holding function of the parking brake 207 is enabled or disabled, and determining whether the parking brake 207 is in an engaged state or a released state when the automatic holding function is enabled.

[0055] The parking brake control unit 103 outputs a control command to control the parking brake 207 to either an engaged or released state based on the determination result of the determination unit 102.

[0056] [Example of controller actions]

[0057] Figures 3 and 4 are flowcharts illustrating examples of the operation of the controller 100 according to the embodiment. Figure 3 shows the process when the controller 100 determines and sets the automatic holding function of the parking brake 207 to be active or inactive. Figure 4 shows the process when the controller 100 determines and instructs the parking brake 207 to be in an engaged or released state. The processes shown in Figure 3 and Figure 4 are repeated sequentially at the same or different intervals. It should be noted that in this example of operation, the state in which the parking brake 207 is kept engaged under the control of the controller 100 is referred to as the automatic holding state of the brake. In addition, the parking brake engagement / release switch 87 is set to release.

[0058] When the process shown in FIG3 begins, firstly, the determination unit 102 determines whether the automatic holding function is effective (step S101). If the automatic holding function is not effective (=ineffective) (in the case of "No" in step S101), the determination unit 102 determines whether the operator presence detection sensor 85 detects the presence of the operator (step S102). If the operator presence detection sensor 85 detects the presence of the operator (in the case of "Yes" in step S102), the determination unit 102 determines whether the parking brake holding function effective / ineffective switch 86 is set to effective (step S103). If the parking brake holding function effective / ineffective switch 86 is set to effective (in the case of "Yes" in step S103), the determination unit 102 sets the automatic holding function to effective (step S104) and ends the process shown in FIG3. On the other hand, if the operator presence detection sensor 85 does not detect the presence of the operator (in the case of "No" in step S102), or if the parking brake holding function effective / ineffective switch 86 is set to ineffective (in the case of "No" in step S103), the determination unit 102 ends the process shown in FIG3.

[0059] On the other hand, when the automatic hold function is active (in the case of "Yes" in step S101), the determination unit 102 simultaneously determines whether the above-mentioned brake automatic hold state is in effect (step S101).

[0060] S105), and determine whether the operation amount of the braking operation device 84 is greater than the specified threshold (step).

[0061] (S106). If the brake is in automatic hold mode (if "Yes" in step S105), the determination unit 102 ends the process shown in FIG3. If the brake is not in automatic hold mode (if "No" in step S105), or if the operation amount of the brake operation device 84 is greater than a predetermined threshold (if "Yes" in step S106), the determination unit 102 determines whether the parking brake hold function enable / disable switch 86 is set to disable (step S107). If the parking brake hold function enable / disable switch 86 is set to enable (if "No" in step S107), the determination unit 102 determines whether the operator presence detection sensor 85 detects the presence of the operator (step S108). If the parking brake holding function enable / disable switch 86 is set to disable (if "Yes" in step S107), or if the operator presence detection sensor 85 does not detect the presence of the operator (if "Yes" in step S108), the determination unit 102 disables the automatic holding function (step S109) and ends the process shown in FIG3. On the other hand, if the operation amount of the brake operation device 84 is less than the predetermined threshold (if "No" in step S106), or if the operator presence detection sensor 85 detects the presence of the operator (if "No" in step S108), the determination unit 102 ends the process shown in FIG3.

[0062] In the processing shown in Figure 3, when the "automatic hold function is active," if the brake is not in an automatic hold state (i.e., the brake is released) and ("parking brake hold function active / inactive switch 86 is inactive" or "no operator is present"), or if the operation amount of the brake operating device 84 is greater than a predetermined threshold and ("parking brake hold function active / inactive switch 86 is inactive" or "no operator is present"), the controller 100 will set the automatic hold function to inactive. Conversely, if the "automatic hold function is inactive," and "an operator is present" and "parking brake hold function active / inactive switch 86 is active," the controller 100 will set the automatic hold function to active.

[0063] Next, when the process shown in FIG4 begins, the determination unit 102 first determines whether the automatic holding function is effective (step S201). If the automatic holding function is not effective (=ineffective) (in the case of "No" in step S102), the parking brake control unit 103 controls the parking brake 207 to the released state (step S213) and ends the process shown in FIG4. However, if the parking brake 207 has already been controlled to the released state, the parking brake control unit 103 omits the process of controlling it to the released state and ends the process shown in FIG4.

[0064] On the other hand, if the automatic brake holding function is active (if "Yes" in step S201), the determination unit 102 determines whether the brake is in automatic holding mode (step S202). If the brake is not in automatic holding mode (if "No" in step S202), the determination unit 102 determines whether the accelerator operating device 83 is operated (step S203). If the accelerator operating device 83 is not operated (if "Yes" in step S203), the determination unit 102 determines whether the operation amount of the brake operating device 84 is greater than a predetermined threshold (step S204). If the operation amount of the brake operating device 84 is greater than the predetermined threshold (if "Yes" in step S204), the determination unit 102 determines whether the vehicle speed is approximately zero (= whether it is less than the predetermined threshold) (step S205). If the vehicle speed is approximately zero (if "Yes" in step S205), the determination unit 102 determines whether the forward / reverse switching operating device 82 has been operated to "forward" (step S206). When the forward / backward switching operation device 82 is operated to "forward" (in the case of "yes" in step S206), the determination unit 102 determines whether the operating state of the working device operating lever 81 is "neutral" (in step S206).

[0065] (S207). When the working device operating lever 81 is in the "neutral" state (= the working device operating lever 81 is not operated, or the operation amount of the working device operating lever 81 is within the insensitive area) (when "yes" is in step S207), the parking brake control unit 103 outputs a control command to control the parking brake 207 to the engaged state (stop the drive signal to the solenoid 2081) (step S208), and ends the process shown in FIG4.

[0066] On the other hand, when the brake is in an automatic holding state (if "Yes" in step S202), the determination unit 102 determines whether to operate the brake operating device 84 (step S209). If the brake operating device 84 is not operated (if "Yes" in step S209), the determination unit 102 determines whether the operating state of the working device operating lever 81 is "neutral" (step S210). If the working device operating lever 81 is "neutral" (if "Yes" in step S210), the determination unit 102 determines whether to operate the accelerator operating device 83 (step S211). If the accelerator operating device 83 is operated (if "Yes" in step S211), the determination unit 102 determines whether the forward / backward switching operating device 82 is not "neutral" (step S212). If the forward / backward switching operating device 82 is not "neutral" (if "Yes" in step S212), the parking brake control unit 103 controls the parking brake 207 to the released state (step S212).

[0067] S213), and end the process shown in Figure 4.

[0068] On the other hand, when the braking operation device 84 is operated (in the case of "No" in step S209), the determination unit 102 determines whether to operate the forward / backward switching operation device 82 to "backward".

[0069] (Step S214). When the forward / backward switching operation device 82 is operated to "backward" (when "yes" is in step S214), the parking brake control unit 103 controls the parking brake 207 to the released state (step S213) and ends the process shown in FIG4.

[0070] On the other hand, when the accelerator operating device 83 is operated (in step S203 if "No"), when the operation amount of the brake operating device 84 is less than the predetermined threshold (in step S204 if "No"), when the vehicle speed is approximately not zero (in step S205 if "No"), or when the forward / reverse switching operating device 82 is not operated to "forward" (in step S204 if "No"), the following conditions apply:

[0071] If the following conditions are met: (1) the working device operating lever 81 is not "neutral" in step S206; (2) the working device operating lever 81 is not "neutral" in step S207; (3) the working device operating lever 81 is not "neutral" in step S210; (4) the accelerator operating device 83 is not operated (5) the forward / backward switching operating device 82 is not "neutral" in step S212; or (5) the forward / backward switching operating device 82 is not operated to "backward" in step S214. Then the determination unit 102 ends the process shown in FIG4.

[0072] In the processing shown in Figure 4, when the brake is not in automatic hold mode, the controller 100 controls the parking brake 207 to be engaged when: the automatic hold function is active, the accelerator operating device 83 is not operated, the operation amount of the brake operating device 84 is greater than the specified threshold, the vehicle speed is approximately zero, the forward / reverse switching operating device 82 is operated to "forward," and the working device operating lever 81 is in "neutral." On the other hand, when the brake is in automatic hold mode, the controller 100 engages the parking brake 207 when: the automatic hold function is inactive, or the brake operating device is not operated.

[0073] When the following conditions are met: 84”, “working device operating lever 81 is in the “neutral” state”, “accelerator operating device 83 is operated”, “forward / reverse switching operating device 82 is in a state other than “neutral””, or “brake operating device 84 is operated”, and “forward / reverse switching operating device 82 is operated to the “reverse” state”, the controller 100 controls the parking brake 207 to be released.

[0074] Through the above processing, when the controller 100 (brake control device of construction machinery) controls the parking brake 207 in the construction machinery 1 equipped with the working device 10, the traveling device 4, and the parking brake 207, the parking brake control unit 103 outputs a control command to control the parking brake 207 based at least on the operating state of the working device 10. According to this structure, the parking brake control unit 103 can control the parking brake 207 to be engaged or released, for example, when at least the working device 10 is in a non-operating state (stopped state). In this case, it is possible to prevent the parking brake from automatically engaging and holding, or automatically releasing from a held engaged state, during the operation of the working device 10. Accordingly, it is possible to prevent the automatic holding function from operating or releasing unintentionally during the operation of the working device 10, thus preventing a decrease in the operability of the working device, such as a decrease in operability due to the use of the automatic holding function of the parking brake.

[0075] It should be noted that the processing shown in Figures 3 and 4 is an example and can be modified appropriately. For example, the determination in step S206 (determining whether the forward / backward switching operation device 82 is in the "forward" position) can be omitted. In addition, the determination in step S214 (determining whether the forward / backward switching operation device 82 is in the "backward" position) can also be omitted or replaced by determining whether the position ("forward", "backward", or "neutral") changes from the position when the brake is engaged. Furthermore, when the parking brake control unit 103 controls the parking brake 207 to be engaged (step S206), it can further output a predetermined control command (second control command) by, for example, cutting off the power transmission from the transmission 205 to the wheels 5 (driving device 4).

[0076] It should be noted that in the above processing, when the working device 10 is in a non-operating state, when the accelerator operating device 83 (vehicle speed adjustment device) of the construction machinery 1 is in a non-operating state, the speed of the construction machinery 1 is approximately zero (less than the specified threshold), the operation amount of the brake operating device 84 of the construction machinery 1 is greater than the specified threshold, and the forward / reverse switching operating device 82 of the construction machinery 1 is operated to the forward state, the parking brake control unit 103 outputs a control command to control the parking brake 207 to the engaged state.

[0077] In addition, when an operator of the operating device 10 is present and the holding function of the parking brake 207 is set to an active state (when the parking brake holding function active / inactive switch 86 is set to active), the parking brake control unit 103 sets the automatic holding function to active and outputs a control command to control the parking brake 207 to an engaged state when the specified conditions are met.

[0078] In addition, when the working device 10 is in a non-operating state, and the accelerator operating device 83 (vehicle speed adjustment device) of the construction machinery 1 is in an operating state and the brake operating device 84 of the construction machinery 1 is in a non-operating state, the parking brake control unit 103 outputs a control command to control the parking brake 207 to the release state.

[0079] In addition, when the parking brake 207 is controlled to be engaged, when the forward / reverse switching operation device 82 (forward / reverse switching device) of the construction machinery 1 is operated to reverse, the parking brake control unit 103 outputs a control command to control the parking brake 207 to be released.

[0080] [The Role and Effects of the Implementation Method]

[0081] As described above, according to this embodiment, it is easy to avoid the automatic holding function from operating or disengaging in accordance with the operator's intention during the operation of the working device 10. Therefore, it is easy to prevent the reduction in the operator's sense of operation due to the use of the automatic holding function of the parking brake.

[0082] In the operation of construction machinery, there are situations where, in order to fine-tune the position of the working device, it is desirable to quickly start the construction machinery after temporarily stopping it and fine-tuning the working device. In this case, according to the parking brake device described in Patent Document 1, if the vehicle speed is below the stopping speed during the temporary stop, the parking brake is automatically controlled to a braking state. For example, after the operator finishes fine-tuning the position of the working device, they want to reduce the amount of operation of the braking device and, for example, want to use the creep phenomenon to quickly start the construction machinery, but if the parking brake is in a braking state, the construction machinery cannot be started as the operator wishes. In contrast, according to this embodiment, during the operation of the working device 10, the automatic holding function of the parking brake 207 is not activated. Therefore, the operator can depress the braking device 84 to stop the construction machinery 1, and at the same time (or from just before stopping) operate the working device 10 (bucket or fork, etc.) to fine-tune it. After the fine-tuning is completed, the amount of operation of the braking device 84 is reduced, for example, using the creep phenomenon to quickly start the construction machinery 1.

[0083] Furthermore, during the operation of construction machinery, when only the working device is activated while the machine is idle, there are instances where the following operation is performed to accelerate the working device's operation: the accelerator operating device is activated to increase the engine (hydraulic pump) speed, thereby increasing the oil supply to the working device. In this case, according to the parking brake device described in Patent Document 1, the parking brake, which is held in a braking state, is released when the engine speed reaches a predetermined speed corresponding to the load of the cargo loaded on the fork. In this situation, even if the operator does not intend to move forward when the accelerator operating device is activated, the construction machinery may unintentionally move forward when the brake is released. In contrast, in this embodiment, the automatic holding function of the parking brake 207 is not released during the operation of the working device 10. Therefore, when only the working device 10 is in operation during standby parking, and the working device 10 is operated by increasing the speed of the power source 201 by operating the accelerator operating device 83 to increase the oil supply to the working device 10 in order to speed up the operation of the working device 10, it is possible to prevent the construction machinery 1 from moving forward unintentionally even though the operator does not expect it to move forward, because the parking brake 207 is released.

[0084] (Second Implementation)

[0085] Hereinafter, the second embodiment of the present invention will be described with reference to FIG5. FIG5 is a block diagram showing a structural example of the control system of the wheel loader 1a according to the second embodiment. The control system 300a shown in FIG5 is a control system of the wheel loader 1a including a working device 10, a traveling device 4, and a parking brake 207, and includes at least a controller 100a (or at least a controller 100a and a controller).

[0086] 100b). Alternatively, the control system 300a may also include a device for inputting a predetermined signal to the controller 100a (or controller 100a and controller 100b), such as a work device operating lever 81b (as an example of a work device operating device), a forward / reverse switching operating device 82b, an accelerator operating device 83b (as an example of a vehicle speed adjustment device), a brake operating device 84b, and an operator presence detection sensor 85b. In the first embodiment, the operator in the cab 3 operates the wheel loader 1 by operating the work device operating lever 81, the forward / reverse switching operating device 82, the accelerator operating device 83, and the brake operating device 84, etc., within the cab 3. In contrast, in the second embodiment, the work device operating lever 81b and the forward / reverse switching operating device are provided in an operator's cab 80 separate from the wheel loader 1a.

[0087] 82b. Accelerator operating device; 83b. Braking operating device; 84b. Operator presence detection sensor.

[0088] 85b, parking brake holding function effective / ineffective switch 86b, and parking brake engagement / release switch 87b, etc., the operator in the control room 80 remotely operates the wheel loader 1a by operating the working device control lever 81b, forward / reverse switching control device 82b, accelerator control device 83b, brake control device 84b, etc. in the control room 80.

[0089] It should be noted that a controller 100b and a communication device 110b are installed in the operator's cab 80, and a communication device 110a is installed on the wheel loader 1a. The controller 100b and controller 100a transmit and receive prescribed information via wireless signal 89 through the communication devices 110b and 110a. It should be noted that the controller 100b and controller 100a transmit and receive image information, location information, distance measurement information, various monitoring information, and other information for remote operation; however, the structures for acquiring and outputting such information are omitted from the illustration for simplicity. Furthermore, the acquisition unit combining the acquisition unit 101b of the controller 100b and the acquisition unit 101a of the controller 100a has the same function as the acquisition unit 101 shown in FIG. 1.

[0090] Furthermore, the combined action of controllers 100a and 100b is the same as the action of controller 100 shown in FIG1 as described with reference to FIG3.

[0091] According to this embodiment, similar to the first embodiment, it is easy to avoid the automatic holding function being unintentionally activated or deactivated during remote operation of the working device 10. Therefore, it is easy to prevent the decrease in the operability of construction machinery, such as the decrease in operability due to the use of the automatic holding function of the parking brake.

[0092] [Modifications of this embodiment or other embodiments]

[0093] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the specific structure is not limited to the above embodiments, and may include design changes that do not depart from the spirit of the invention.

[0094] In addition, in the above embodiments, part or all of the program executed by the computer can be published via a computer-readable recording medium or communication line.

[0095] Industrial availability

[0096] According to various methods of the present invention, it is possible to prevent a decrease in the operability of engineering machinery.

[0097] Explanation of reference numerals in the attached figures

[0098] 1. Wheel loader (construction machinery), 2. Vehicle body, 3. Cab, 4. Running gear, 5. Wheels, 6. Tires, 10. Working device, 11. Boom, 12. Bucket (working tool), 12T shovel tip, 13. Boom cylinder, 14. Bucket cylinder, 15. Crank, 100, 100a, 100b controller, 101.

[0099] 101a, 101b Acquisition Unit, 102 Judgment Unit, 103 Parking Brake Control Unit, 81, 81b Working Device Operating Lever, 82, 82b Forward / Reverse Switching Operating Device, 83, 83b Accelerator Operating Device

[0100] (Vehicle speed adjustment device), 84, 84b Brake operating device, 85, 85b Operator presence detection sensor, 86, 86b Parking brake holding function active / inactive switch, 87, 87b Parking brake engagement / release switch, 88 Vehicle speed sensor, 207 Parking brake, 300, 300a Control system

Claims

1. A control system for engineering machinery comprising a working device, a traveling device, and a parking brake, characterized in that, The system includes: a working device operating device operated by an operator to activate the working device; a vehicle speed adjustment device operated by an operator to adjust the speed of the construction machinery; a brake operating device operated by an operator to operate the brake device of the construction machinery; and a controller that outputs control commands to control the parking brake based at least on the operating state of the working device. The controller determines whether the parking brake is in an automatic holding state or a released state based on the operating state of the vehicle speed adjustment device or the brake operating device. The automatic holding state is a state in which the parking brake is kept engaged under the control of the controller, and the released state is a state not in the automatic holding state. Even when the parking brake is in the automatic holding state, if the operating state of the brake operating device meets the conditions for automatically releasing the parking brake, and if the working device operating device that activates the working device is operated by the operator and the operation amount is not within the insensitive area near the neutral position, the parking brake will not be released, and the automatic holding state will be maintained.

2. The control system according to claim 1, wherein, The controller receives a signal indicating the operating status from the operating device of the working device, determines the operating status of the operating device of the working device based on the signal, and outputs a control command to control the parking brake to either an engaged or released state when it is determined that at least the operating device of the working device is in a non-operating state.

3. The control system according to claim 2, wherein, It also includes: a vehicle speed sensor that detects the speed of the construction machinery; for the controller, receiving a vehicle speed signal from the vehicle speed sensor and a signal indicating the operating status from the braking operation device; when it is determined that the working device operation device is in a non-operating state, when it is determined that the vehicle speed adjustment device is in a non-operating state, and when it is determined that the vehicle speed is less than a predetermined threshold, and when it is determined that the braking operation device is in an operating state, outputting a control command to control the parking brake to an engaged state.

4. The control system according to claim 1, wherein, It also has a forward / reverse switching operation device, which is operated by the operator to switch the driving state of the construction machinery to forward, neutral or reverse. The controller also receives a signal indicating the operation state from the forward / reverse switching operation device, and outputs the control command when it determines that the forward / reverse switching operation device has been operated to the forward or reverse state.

5. The control system according to claim 1, wherein, It also has a forward / reverse switching operation device, which is operated by the operator to switch the driving state of the construction machinery to forward, neutral or reverse. The controller also receives a signal indicating the operation state from the forward / reverse switching operation device, and outputs the control command when it determines that the forward / reverse switching operation device has been operated to the forward state.

6. The control system according to any one of claims 1 to 5, wherein, When the holding function of the parking brake is set to the active state, the controller outputs the control command to control the parking brake to the engaged state.

7. The control system according to any one of claims 1 to 5, wherein, It also has an operator presence detection sensor to detect whether an operator is operating the working device. The controller receives a signal indicating the detection result from the operator presence detection sensor and outputs a control command to control the parking brake to the engaged state when it determines that the presence of an operator is detected.

8. The control system according to any one of claims 1 to 5, wherein, When the parking brake is engaged, the controller also outputs a second control command to cut off the transmission of power to the driving device.

9. The control system according to claim 3, wherein, When the controller determines that the operating device of the working device is in a non-operating state, and when it determines that the vehicle speed adjustment device is in an operating state and the braking operation device is in a non-operating state, it outputs a control command to release the parking brake.

10. The control system according to claim 4 or 5, wherein, When the parking brake is engaged, the controller outputs a control command to release the parking brake when the forward / reverse switching device is operated to reverse.

11. A control method for engineering machinery equipped with a working device, a traveling device, and a parking brake, characterized in that, The construction machinery also includes: a working device operating device operated by an operator to activate the working device; a vehicle speed adjusting device operated by an operator to adjust the vehicle speed of the construction machinery; a braking operating device operated by an operator to operate the braking device of the construction machinery; a controller that outputs a control command to control the parking brake based at least on the operating state of the working device; and a step of outputting the control command to control the parking brake based at least on the operating state of the working device, wherein in the step of outputting the control command to control the parking brake, a decision is made based on the operating state of the vehicle speed adjusting device or the braking operating device. The parking brake is either in an automatic holding state or a released state. The automatic holding state is when the parking brake is kept engaged under the control of the controller. The released state is when the parking brake is not in the automatic holding state. Even if the operation of the brake operating device meets the conditions for automatically releasing the parking brake, the parking brake will not be released and the automatic holding state will be maintained if the operating device that actuates the working device is operated by the operator and the operation amount is not in the insensitive area near the neutral position.

12. The control method according to claim 11, wherein, The information indicating the operational state of the working device includes at least information indicating the operational state of the working device operating device operated by the operator to make the working device operate. The control method further includes: receiving a signal indicating the operational state from the working device operating device; determining the operational state of the working device operating device based on the signal; receiving a signal indicating the operational state from a speed adjustment device operated by the operator to adjust the speed of the construction machinery; receiving a speed signal from a speed sensor that detects the speed of the construction machinery; and receiving a signal indicating the operational state from a braking operating device operated by the operator to operate the braking device of the construction machinery. The control command is a control command output when it is determined that at least the working device operating device is in a non-operating state, to control the parking brake to an engaged state or a released state. Furthermore, when it is determined that the working device operating device is in a non-operating state, and when it is determined that the speed adjustment device is in a non-operating state, and the speed is less than a predetermined threshold, and the braking operating device is in an operating state, the control command is output to control the parking brake to an engaged state.

13. The control method according to claim 11 or 12, wherein, When the holding function of the parking brake is set to the active state, the control command is output to control the parking brake to the engaged state.

14. The control method according to claim 12, wherein, If the operating device of the working device is determined to be in a non-operating state, and the vehicle speed adjustment device is determined to be in an operating state and the braking operation device is determined to be in a non-operating state, the control command is output to control the parking brake to be in a released state.

15. An engineering machinery, characterized in that, It comprises: a working device; a traveling device; a parking brake; a working device operating device operated by an operator to activate the working device; a speed adjustment device operated by an operator to adjust the speed of the construction machinery; a brake operating device operated by an operator to operate the brake device of the construction machinery; and a controller that outputs control commands to control the parking brake based at least on the operating state of the working device. The controller determines whether the parking brake is in an automatic holding state or a released state based on the operating state of the speed adjustment device or the brake operating device. The automatic holding state is a state in which the parking brake is kept engaged by the controller, and the released state is a state in which the parking brake is not in the automatic holding state. When the parking brake is in the automatic holding state, even if the operating state of the brake operating device meets the conditions for automatically releasing the parking brake, and the working device operating device that activates the working device is operated by the operator and the operation amount is not within the insensitive area near the neutral position, the parking brake is not released and the automatic holding state is maintained.

16. The engineering machinery according to claim 15, wherein, The information indicating the operational state of the working device includes at least information indicating the operational state of the working device operating device operated by the operator to make the working device operate. The controller also receives signals indicating the operational state from the working device operating device, determines the operational state of the working device operating device based on the signals, receives signals indicating the operational state from a speed adjustment device operated by the operator to adjust the speed of the construction machinery, receives a speed signal from a speed sensor that detects the speed of the construction machinery, and receives signals indicating the operational state from a braking device operated by the operator to operate the braking device of the construction machinery. If it is determined that at least the working device operating device is in a non-operating state, the controller outputs the control command to control the parking brake to an engaged or released state. Furthermore, if it is determined that the working device operating device is in a non-operating state, and the speed adjustment device is in a non-operating state, and the speed is less than a predetermined threshold, and the braking device is in an operating state, the controller outputs the control command to control the parking brake to an engaged state.

17. The engineering machinery according to claim 15 or 16, wherein, When the holding function of the parking brake is set to the active state, the control command is output to control the parking brake to the engaged state.

18. The engineering machinery according to claim 16, wherein, If the operating device of the working device is determined to be in a non-operating state, and the vehicle speed adjustment device is determined to be in an operating state and the braking operation device is determined to be in a non-operating state, the control command is output to control the parking brake to be in a released state.

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