ROAD MACHINE AND HOpper CONTROL SYSTEM FOR ROAD MACHINE

Abstract

The invention relates to a road machine and a hopper control system of the road machine, which can reduce the burden of an operator related to the operation of a hopper. An asphalt rolling machine (100) is provided with: a tractor (1); a hopper (2) provided in front of the tractor (1) and receiving paving material (PV); a conveyor (CV) for supplying the paving material (PV) in the hopper (2) to the rear of the tractor (1); a screw (SC) that spreads the paving material (PV) supplied by the conveyor (CV) behind the tractor (1); a leveling machine (3) for uniformly spreading the paving material (PV) spread by the screw (SC) behind the screw (SC); an object detection device (space recognition device (51)) for detecting objects around the asphalt rolling machine (100); and a controller (50) for controlling the opening and closing of the hopper (2) on the basis of the positional relationship between the vehicle and the asphalt rolling machine (100) detected by the object detection device.

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2023-213673 filed on December 19, 2023. The entire contents of the Japanese application are incorporated herein by reference.

[0002] The present invention relates to a road machine and a hopper control system for a road machine. Background Art

[0003] Conventionally, there has been known a road machine (see Patent Document 1) having a hopper for receiving paving materials transported by a dump truck. This road machine is configured to receive paving materials from the dump truck's cargo box into the hopper in the fully open state while the rear wheels of the dump truck are in contact with a push roller located at the front end of the road machine (in the state of receiving the vehicle or the docking state). The hopper is configured to open and close according to the operation of the operator.

[0004] Patent Document 1: International Publication No. 2017 / 010541

[0005] However, in the above structure, if the operator of the road machine forgets to keep the hopper in the fully open state, the driver of the dump truck cannot bring the rear wheels of the dump truck into contact with the push roller. This is because the cargo box of the dump truck may come into contact with the hopper wing. Therefore, the operation of the hopper by the operator of the road machine is an important operation that cannot be forgotten in terms of smoothly replenishing the paving materials. Moreover, this operation of the hopper that cannot be forgotten by the operator of the road machine may be a burdensome task.

[0006] Therefore, there is a need to provide a road machine that can reduce the burden on the operator related to the operation of the hopper. Summary of the Invention

[0007] The road machine according to an embodiment of the present invention includes: a tractor; a hopper provided in front of the tractor and receiving the paving materials from a vehicle transporting the paving materials; a conveyor that supplies the paving materials in the hopper to the rear of the tractor; a screw that spreads the paving materials supplied by the conveyor behind the tractor; a finisher that levels the paving materials spread by the screw behind the screw; an object detection device that detects objects around the road machine; and a control device that controls the opening and closing of the hopper based on the positional relationship between the vehicle and the road machine detected by the object detection device.

[0008] Advantages of the Invention

[0009] The above road machine can reduce the burden on the operator related to the operation of the hopper. Brief Description of the Drawings

[0010] Figure 1 It is a side view of an asphalt screed and a dump truck during construction.

[0011] Figure 2 It is a top view of an asphalt screed and a dump truck during construction.

[0012] Figure 3 It is a block diagram showing a structural example of a hopper control system.

[0013] Figure 4 It is a flowchart of an example of hopper opening processing.

[0014] Figure 5 It is a flowchart of an example of hopper closing processing.

[0015] Figure 6 It is a side view of an asphalt screed and a dump truck during construction.

[0016] Figure 7 It is a top view of an asphalt screed and a dump truck during construction.

[0017] Figure 8 It is a schematic diagram showing another structural example of a hopper control system.

[0018] In the figures: 1 - tractor, 2 - hopper, 2P - push roller, 2PL - left push roller, 2PR - right push roller, 2W - hopper wing, 2WL - left hopper wing, 2WR - right hopper wing, 3 - leveling machine, 3A - leveling arm, 5 - rear wheel, 6 - front wheel, 7 - hopper cylinder, 7L - left hopper cylinder, 7R - right hopper cylinder, 30 - front - side leveling machine, 31 - rear - side leveling machine, 31L - left rear - side leveling machine, 31R - right rear - side leveling machine, 32 - pedal, 32C - central pedal, 32L - left pedal, 32R - right pedal, 41 - side plate, 41L - left side plate, 41R - right side plate, 42 - plow plate, 42L - left plow plate, 42R - right plow plate, 43 - holding plate, 43L - left holding plate, 43R - right holding plate, 50 - controller, 50a - hopper control section, 51 - space recognition device, 51B - rear camera, 51F - front camera, 51L - left camera, 51R - right camera, 53 - information acquisition device, 55 - display device, 56 - sound output device, 60 - power supply device, 61 - diesel engine, 62 - generator, 65 - main pump, 100 - asphalt leveling machine, 200 - dump truck, 201 - cargo box, 202 - front wheel, 202L - left front wheel, 202R - right front wheel, 203 - rear front wheel, 203EL - left outer rear front wheel, 203ER - right outer rear front wheel, 203IL - left inner rear front wheel, 203IR - right inner rear front wheel, 204 - rear rear wheel, 204EL - left outer rear rear wheel, 204ER - right outer rear rear wheel, 204IL - left inner rear rear wheel, 204IR - right inner rear rear wheel, 205 - tipping cylinder, 300 - management device, CV - conveyor, FR - frame, HC - hopper control device, HL - first oil circuit, HV - hopper slide valve, NP - newly - installed paving body, PV - paving material, RB - roadbed, SC - screw, SCL - left extended screw, SCR - right extended screw, SYS - hopper control system, ZN1 - first range, ZN2 - second range, ZN2L - second left range, ZN2R - second right range, ZN3 - third range. Detailed implementation manners

[0019] Figure 1 FIG. 6 is a side view of an asphalt leveling machine 100 and a dump truck 200, which are examples of road machinery according to an embodiment of the present invention. The road machinery may be a base paver, a joint paver, a multi - functional asphalt paver, etc. The dump truck 200 is an example of a transport vehicle for supplementing (feeding) paving material PV into the hopper 2 of the asphalt leveling machine 100. Figure 2 FIG. 7 is a top view of the asphalt leveling machine 100 and the dump truck 200, corresponding to Figure 1 Specifically, Figure 1 FIG. 8 is a side view of the asphalt leveling machine 100 and the dump truck 200 during construction (during the laying of paving material PV).Figure 2 This is a top view of an asphalt paver 100 and a dump truck 200 during construction (during the period of laying paving material PV).

[0020] The asphalt paver 100 mainly includes a tractor 1, a hopper 2, and a leveling machine 3. Hereinafter, for convenience, the direction of the hopper 2 observed from the tractor 1 (+X direction) is defined as the front, and the direction of the leveling machine 3 observed from the tractor 1 (-X direction) is defined as the rear. Also, the +Z direction is defined as vertically upward, and the -Z direction is defined as vertically downward.

[0021] The tractor 1 is a mechanism for moving the asphalt paver 100. In the illustrated example, the tractor 1 uses a hydraulic motor for rear-wheel travel to rotate the rear wheels 5, and uses a hydraulic motor for front-wheel travel to rotate the front wheels 6 to move the asphalt paver 100. The hydraulic motor for rear-wheel travel and the hydraulic motor for front-wheel travel receive the supply of working oil from a hydraulic pump and rotate. The rear wheels 5 and the front wheels 6 can be replaced with crawlers.

[0022] The controller 50 is a control device for controlling the asphalt paver 100. In the illustrated example, the controller 50 is composed of a microcomputer including a CPU, a volatile storage device, a non-volatile storage device, etc., and is mounted on the tractor 1. Various functions of the controller 50 are realized by the CPU executing a program stored in a non-volatile storage medium.

[0023] The hopper 2 is a mechanism for receiving the paving material PV. In the illustrated example, the hopper 2 is provided on a frame FR constituting the lower front side of the tractor 1, and includes hopper wings 2W. The hopper wings 2W are configured to be able to open and close in the Y-axis direction (width direction, vehicle width direction) by a hopper cylinder 7. Specifically, the hopper wings 2W include a left hopper wing 2WL that can open and close to the left by a left hopper cylinder 7L and a right hopper wing 2WR that can open and close to the right by a right hopper cylinder 7R. The controller 50 can open the hopper wings 2W by contracting the hopper cylinder 7 and close the hopper wings 2W by extending the hopper cylinder 7.

[0024] Normally, the asphalt paver 100 keeps the hopper wings 2W in a fully open state (a state of being opened to the maximum extent) to receive the paving material PV from the cargo box 201 of the dump truck 200. In the illustrated example, the paving material PV is an asphalt mixture, also known as "asphalt composite material". In Figure 1 and Figure 2 , the hopper wings 2W are in a fully open state. In addition, in Figure 2In [the figure], in order to make a part of the conveyor CV visible, the illustration of the paving material PV accommodated in the hopper 2 is omitted. The paving material PV accommodated in the hopper 2 is conveyed to the rear of the tractor 1 by the conveyor CV located at the center of the bottom of the hopper 2. When the paving material PV in the hopper 2 decreases, the hopper wings 2W close, and the paving material PV near the inner wall of the hopper 2 gathers at the center of the bottom of the hopper 2. This is to enable the conveyor CV to convey the paving material PV to the rear of the tractor 1. In addition, if the operator of the asphalt finisher 100 forgets to close the hopper wings 2W, the supply of the paving material PV to the center of the bottom is insufficient, and further the supply of the paving material PV to the rear of the tractor 1 is insufficient, which may cause poor construction. Therefore, the controller 50 can be configured to automatically close the hopper 2 when a specified hopper closing condition is satisfied.

[0025] The paving material PV conveyed to the rear of the tractor 1 is spread in the vehicle width direction behind the tractor 1 and in front of the finisher 3 by the screw SC. In the illustrated example, the screw SC is in a state where the left extended screw SCL and the right extended screw SCR are connected. And, in Figure 1 and Figure 2 the paving material PV spread by the screw SC is represented by a sparse dot pattern, and the newly laid paving body NP leveled by the finisher 3 is represented by a dense dot pattern.

[0026] A push roller 2P that can rotate around an axis extending in the vehicle width direction is provided at the front end of the frame FR. The push roller 2P is configured to contact the rear wheels (rear rear wheels 204) of the dump truck 200 and be able to rotate together with the rear wheels (rear rear wheels 204) of the dump truck 200. In the illustrated example, the push roller 2P includes a left push roller 2PL that contacts the left rear wheels (left outer rear rear wheels 204EL and left inner rear rear wheels 204IL) of the dump truck 200 and a right push roller 2PR that contacts the right rear wheels (right outer rear rear wheels 204ER and right inner rear rear wheels 204IR) of the dump truck 200.

[0027] When the asphalt finisher 100 advances in the case where the push roller 2P is in contact (docked) with the rear wheels (rear rear wheels 204) of the dump truck 200, the dump truck 200 preferably stops in a neutral state without stepping on the brake at a position several centimeters in front of the asphalt finisher 100. Then, the advancing asphalt finisher 100 causes the push roller 2P to contact the rear wheels (rear rear wheels 204) of the stopped dump truck 200, pushes the dump truck 200 forward, and advances together with the dump truck 200. In addition, when docking, when the asphalt finisher 100 stops, the dump truck 200 can reverse at a low speed until the rear wheels (rear rear wheels 204) contact the push roller 2P.

[0028] The leveling machine 3 is a mechanism for spreading paving material PV evenly. In the illustrated example, the leveling machine 3 includes a front-side leveling machine 30 and a rear-side leveling machine 31. The leveling machine 3 is a floating leveling machine towed by a tractor 1 and is connected to the tractor 1 via a leveling arm 3A. The rear-side leveling machine 31 includes a left rear-side leveling machine 31L configured to be able to extend and retract to the left and a right rear-side leveling machine 31R configured to be able to extend and retract to the right. In Figure 1 and Figure 2 , the leveling machine 3 is in a state of maximum elongation (widening).

[0029] Side plates 41 are installed at the distal ends of the rear-side leveling machine 31. In the illustrated example, a left side plate 41L is installed at the left end of the left rear-side leveling machine 31L, and a right side plate 41R is installed at the right end of the right rear-side leveling machine 31R.

[0030] A pedal 32 is installed at the rear of the leveling machine 3. Specifically, the pedal 32 is installed at the rear of the leveling machine 3 so that a worker can walk back and forth in the vehicle width direction without stepping on the newly laid paving body NP behind the leveling machine 3. In the illustrated example, the pedal 32 includes a central pedal 32C installed at the rear of the front-side leveling machine 30, a left pedal 32L installed at the rear of the left rear-side leveling machine 31L, and a right pedal 32R installed at the rear of the right rear-side leveling machine 31R.

[0031] A plow plate 42 is disposed in front of the rear-side leveling machine 31. In the illustrated example, the plow plate 42 is installed on the leveling machine 3 and is configured to be able to move up and down in order to adjust the amount of paving material PV remaining in front of the rear-side leveling machine 31. The paving material PV reaches below the leveling machine 3 through the gap between the lower end of the plow plate 42 and the roadbed RB.

[0032] Specifically, the plow plate 42 includes a left plow plate 42L disposed in front of the left rear-side leveling machine 31L and a right plow plate 42R disposed in front of the right rear-side leveling machine 31R.

[0033] A screw SC is disposed in front of the plow plate 42, and a holding plate 43 is disposed in front of the screw SC. Specifically, the holding plate 43 includes a left holding plate 43L disposed in front of the left extended screw SCL and a right holding plate 43R disposed in front of the right extended screw SCR. Additionally, the holding plate 43 can be omitted.

[0034] A space recognition device 51, a display device 55, and a sound output device 56 are installed on the upper part of the tractor 1.

[0035] The space recognition device 51 is configured to recognize the space around the asphalt paver 100. The space recognition device 51 includes at least one of a monocular camera, a stereo camera, a LIDAR, an ultrasonic sensor, an infrared sensor, a lidar, a millimeter-wave radar, etc. In addition, the space recognition device 51 may include a space recognition device such as a space recognition device installed on the road and not installed on the asphalt paver 100, or may be a space recognition device not installed on the asphalt paver 100. At this time, the space recognition device not installed on the asphalt paver 100 may be connected to the controller 50 via wireless communication or wired communication. In the illustrated example, the space recognition device 51 is a monocular camera capable of photographing the surroundings of the asphalt paver 100.

[0036] In the illustrated example, the space recognition device 51 includes a rear camera 51B for photographing the rear of the asphalt paver 100, a front camera 51F for photographing the front of the asphalt paver 100, a left camera 51L for photographing the left side of the asphalt paver 100, and a right camera 51R for photographing the right side of the asphalt paver 100.

[0037] The display device 55 is a display device installed on the tractor 1 in a manner that can be visually recognized by a person located in front of the asphalt paver 100. In the illustrated example, the display device 55 is a liquid crystal display capable of displaying characters, graphics, etc., and is installed at the upper right end of the tractor 1 so that the driver of the right-steering dump truck 200 can visually recognize it directly or through an external rearview mirror or an internal rearview mirror. Specifically, the display device 55 is installed to protrude to the right from the vehicle width of the tractor 1.

[0038] The sound output device 56 is configured to be able to output sound toward a person located in front of the asphalt paver 100. In the illustrated example, the sound output device 56 is a speaker capable of outputting sound, and is installed at the upper right end of the tractor 1 so that the driver of the right-steering dump truck 200 can easily hear it.

[0039] The dump truck 200 is configured to include a cargo box 201 for loading paving material PV. In the illustrated example, the dump truck 200 is a 10-wheel dump truck with double tires on the rear wheels, and includes front wheels 202, rear front wheels 203, and rear rear wheels 204. The rear front wheels 203 and the rear rear wheels 204 constitute the rear wheels of the dump truck 200. In the illustrated example, as Figure 2 shown, the front wheels 202 include a left front wheel 202L and a right front wheel 202R, the rear front wheels 203 include a left outer rear front wheel 203EL, a left inner rear front wheel 203IL, a right outer rear front wheel 203ER, and a right inner rear front wheel 203IR, and the rear rear wheels 204 include a left outer rear rear wheel 204EL, a left inner rear rear wheel 204IL, a right outer rear rear wheel 204ER, and a right inner rear rear wheel 204IR.

[0040] Next, with reference to Figure 3 the hopper control system SYS that supports the construction of the asphalt paver 100 will be described. Figure 3 is a block diagram showing a structural example of the hopper control system SYS. The hopper control system SYS mainly includes a controller 50, a space recognition device 51, an information acquisition device 53, a display device 55, a sound output device 56, a hopper control device HC, etc. In the illustrated example, the controller 50, the space recognition device 51, the information acquisition device 53, the display device 55, the sound output device 56, and the hopper control device HC receive power supply from a power supply device 60.

[0041] The power supply device 60 converts the AC power generated by a generator 62 driven by a diesel engine 61, which is an example of a drive source, into DC power. The power supply device 60 can receive power supply from a battery (not shown).

[0042] The diesel engine 61 is configured such that its rotating shaft is connected to the rotating shaft of the main pump 65 and can drive the main pump 65.

[0043] The main pump 65 is configured to be able to supply working oil to a hydraulic actuator including a hopper cylinder 7. In the illustrated example, the main pump 65 is a variable capacity type hydraulic pump that can discharge the working oil for expanding and contracting the hopper cylinder 7.

[0044] Figure 3 The thick dotted lines represent power lines, the thin solid lines represent signal lines, the thick solid lines represent the first oil path HL through which the working oil flows, and the double solid lines represent that the diesel engine 61, the generator 62, and the main pump 65 are mechanically connected to each other.

[0045] In addition, the diesel engine 61 can be replaced by other internal combustion engines such as a hydrogen engine. And the drive source can be replaced by a combination of a all-solid-state battery or a lithium-ion battery and an electric motor, etc.

[0046] The controller 50 includes a hopper control section 50a as a functional component. The hopper control section 50a is composed of software, hardware, firmware, or a combination thereof, and controls the display device 55, the sound output device 56, and the hopper control device HC.

[0047] In the illustrated example, the hopper control section 50a determines whether to open or close the hopper wing 2W based on the output of at least one of the space recognition device 51 and the information acquisition device 53. Moreover, when the hopper control section 50a determines that an opening / closing operation is required, it outputs an instruction related to the start of the opening / closing operation to the hopper control device HC. The hopper control device HC is configured to be able to open and close the hopper wing 2W according to an instruction from the hopper control section 50a.

[0048] Specifically, the hopper control device HC is an electromagnetic valve configured to adjust the pilot pressure of the hopper slide valve HV. The hopper slide valve HV is a control valve provided in the first oil passage HL connecting the main pump 65 and the hopper cylinder 7. The electromagnetic valve of the hopper control device HC opens and closes according to an instruction from the controller 50, so that the pilot pressure acting on the pilot port of the hopper slide valve HV can be adjusted, thereby enabling the expansion and contraction of the hopper cylinder 7 to be controlled. In addition, the pilot ports of the hopper slide valve HV include a pilot port on the closing side and a pilot port on the opening side. However, the pilot port of the hopper slide valve HV may be configured to include only the pilot port on the closing side. Moreover, the hopper control device HC may be the hopper slide valve HV as an electromagnetic valve.

[0049] The information acquisition device 53 is configured to be able to acquire information and output the acquired information to the controller 50. The information acquisition device 53 includes, for example, at least one of a communication device, a positioning device, a traveling speed sensor, a steering angle sensor, a paving thickness sensor, a paving width sensor, and the like. The communication device controls communication with external devices such as the communication device mounted on the dump truck 200. The traveling speed sensor detects the traveling speed of the asphalt paver 100. The steering angle sensor detects the steering angle of the asphalt paver 100. The paving thickness sensor detects the height of the roadbed RB and the height of the newly installed paving body NP and calculates the paving thickness. The paving width sensor detects the extension amount of the rear leveling machine 31 and calculates the paving width. In addition, the information acquisition device 53 may be an input device such as a touch panel or a switch.

[0050] Next, refer to Figure 4 An example of the process (hereinafter referred to as the "hopper opening and closing process") in which the hopper control unit 50a controls the hopper control device HC to open and close the hopper 2 will be described. Figure 4 It is a flowchart of an example of the process (hereinafter referred to as the "hopper opening process") in which the hopper control unit 50a controls the hopper control device HC to open the hopper 2. The hopper opening process is an example of the hopper opening and closing process. In Figure 4 the example shown, the hopper control unit 50a repeatedly executes this hopper opening process at a prescribed control cycle during the operation of the asphalt paver 100. The hopper control unit 50a starts executing the hopper opening process, for example, when the power supply device 60 receives power supply or when the diesel engine 61 starts operating. In addition, the hopper control unit 50a may be configured to start executing this hopper opening process when a prescribed operation via an input device such as an operation of a switch is performed. Moreover, the hopper control unit 50a may be configured to stop executing this hopper opening process when a prescribed operation via an input device such as an operation of a switch is performed.

[0051] First, the hopper control unit 50a determines whether the hopper opening condition is satisfied (step ST1). In the illustrated example, the hopper control unit 50a determines that the hopper opening condition is satisfied when at least one of the space recognition device 51 and the information acquisition device 53 acquires information related to the approach of the dump truck 200 to the asphalt paver 100. In addition, the hopper opening condition may include that the hopper 2 is not in the fully open state as one of the hopper opening conditions.

[0052] For example, when the hopper control unit 50a detects from the image acquired by the front camera 51F as the space recognition device 51 that the dump truck 200 has entered the specified range, i.e., the first range ZN1, in front of the asphalt paver 100, it is regarded as having acquired information related to the approach of the dump truck 200 to the asphalt paver 100, and it is determined that the hopper opening condition is satisfied. That is, the space recognition device 51 can be configured to function as an object detection device.

[0053] Alternatively, when the hopper control unit 50a detects based on the output of the ultrasonic sensor as the space recognition device 51 that the distance DS1 between the asphalt paver 100 and the dump truck 200 is shorter than the specified first distance, it can be regarded as having acquired information related to the approach of the dump truck 200 to the asphalt paver 100, and it is determined that the hopper opening condition is satisfied. At this time, the distance DS1 is, for example, the distance between the ultrasonic sensor installed at the front end of the frame FR and the rear wheel 204 of the dump truck 200. Moreover, the ultrasonic sensor is arranged at the same position in the traveling direction of the asphalt paver 100 as the position of the push roller 2P. That is, the distance DS1 is the distance between the push roller 2P and the rear wheel 204.

[0054] Alternatively, when the hopper control unit 50a detects from the information two received by the communication device as the information acquisition device 53 that the dump truck 200 has entered the first range ZN1, it can be determined that the hopper opening condition is satisfied. The information received by the communication device as the information acquisition device 53 includes, for example, the output of a positioning device such as a GNSS receiver mounted on the dump truck 200. At this time, the hopper control unit 50a can detect the situation where the dump truck 200 has entered the first range ZN1 based on the output of the positioning device as the information acquisition device 53 mounted on the asphalt paver 100 and the output of the positioning device mounted on the dump truck 200. At this time, the controller 50 can be configured to calculate the distance between the asphalt paver 100 and the dump truck 200, and when this distance is shorter than the specified first distance, it is determined that the hopper opening condition is satisfied.

[0055] When it is determined that the hopper opening condition is not satisfied (the "No" in step ST1), the hopper control unit 50a does not open the hopper 2, but ends the current hopper opening process.

[0056] On the other hand, when it is determined that the hopper opening condition is satisfied (Yes in step ST1), the hopper control unit 50a determines whether there is an object within the opening / closing range of the hopper 2 (step ST2). In the illustrated example, the hopper control unit 50a determines whether there is an object within a second range ZN2, which is an example of the opening / closing range of the hopper 2, based on the image acquired by the front camera 51F serving as the space recognition device 51. The opening / closing range of the hopper 2 is, for example, a preset space range including the space between the hopper wings 2W in the fully closed state (the state of being closed to the maximum extent) and the hopper wings 2W in the fully open state. Specifically, the second range ZN2 includes a second left range ZN2L, which is an example of the opening / closing range of the left hopper wing 2WL, and a second right range ZN2R, which is an example of the opening / closing range of the right hopper wing 2WR.

[0057] Moreover, when it is determined that there is no object within the opening / closing range of the hopper 2 (No in step ST2), the hopper control unit 50a operates the hopper control device HC to open the hopper 2 (step ST3). In the illustrated example, the hopper control unit 50a outputs a current command to the electromagnetic valve serving as the hopper control device HC. The electromagnetic valve serving as the hopper control device HC that has received the current command adjusts the pilot pressure acting on the pilot port on the opening side of the hopper slide valve HV by adjusting the flow path area of the oil path through which the pilot oil flows, and operates the hopper slide valve HV in such a manner as to contract the hopper cylinder 7 (in such a manner that the working oil flows out from the bottom oil chamber of the hopper cylinder 7) to bring the hopper 2 into the fully open state. After bringing the hopper 2 into the fully open state, the hopper control unit 50a may output a command to at least one of the display device 55 and the sound output device 56. At this time, the display device 55 that has received the command may display character information such as "Can reverse" or "Please dock" or an image conveying the gist thereof, and prompt the driver of the dump truck 200 to reverse the dump truck 200. Alternatively, the sound output device 56 that has received the command may output an alarm or sound information such as "Can reverse" or "Please dock", and prompt the driver of the dump truck 200 to reverse the dump truck 200.

[0058] On the other hand, when it is determined that there is an object within the opening / closing range of the hopper 2 (Yes in step ST2), the hopper control unit 50a notifies the outside of the current situation (step ST4). In the illustrated example, the hopper control unit 50a determines that the hopper wing 2W cannot be opened because there is an object within the second range ZN2. Moreover, the hopper control unit 50a determines that if the dump truck 200 continues to reverse, the cargo box 201 of the dump truck 200 may come into contact with the hopper wing 2W that is not in the fully open state, and outputs an instruction to at least one of the display device 55 and the sound output device 56. The received display device 55 displays, for example, character information such as "Reverse prohibited" or "Please stop" or an image conveying the gist thereof, and urges the driver of the dump truck 200 to stop the dump truck 200. Alternatively, the received sound output device 56 outputs an alarm or sound information such as "Reverse prohibited" or "Please stop", and urges the driver of the dump truck 200 to stop the dump truck 200. This is to prevent the cargo box 201 of the dump truck 200 from coming into contact with the hopper wing 2W that is not in the fully open state. In addition, the hopper control unit 50a may be configured to urge the driver of the dump truck 200 to move the dump truck 200 forward as needed.

[0059] Thus, when the hopper control unit 50a determines that there is an object within the opening / closing range of the hopper 2, it does not operate the hopper control device HC, that is, does not automatically open the hopper 2, and ends the current hopper opening process. This is to avoid contact between the hopper 2 and the object.

[0060] In addition, the controller 50 may be configured to be able to distinguish the dump truck 200 from objects other than the dump truck 200 by performing various image processes on the images acquired by the front camera 51F. The image process includes, for example, image recognition processes such as deep learning. At this time, when the hopper control unit 50a determines that there is an object other than the dump truck 200 within the first range ZN1, it does not automatically open the hopper 2 and ends the current hopper opening process. This structure has the effect of suppressing the automatic opening of the hopper 2 in response to an object other than the dump truck 200.

[0061] Further, the controller 50 can be configured to distinguish a person from objects other than a person by performing various image processing operations on the images acquired by the space recognition device 51. Also, the worker can wear an armband or a safety helmet with a prescribed mark drawn thereon. This is to make it easier to be recognized by the image recognition processing. That is, this is to enable the controller 50 to detect the position of the worker by finding an image of the prescribed mark. At this time, when it is determined that a person exists within the first range ZN1 or the second range ZN2, the hopper control unit 50a can perform the same processing as when it is determined that an object other than a person exists, or can perform processing different from when it is determined that an object other than a person exists. The processing different from when it is determined that an object other than a person exists is, for example, an emergency stop of the dump truck 200 or an emergency stop of the asphalt paver 100. This is to reliably prevent contact between a person and the dump truck 200 or the asphalt paver 100. At this time, the asphalt paver 100 can be configured to be able to cause the dump truck 200 to make an emergency stop.

[0062] In addition, the controller 50 can be configured to detect objects such as the dump truck 200 or a person existing around the asphalt paver 100 based on the outputs of other object detection devices (space recognition devices) such as a stereo camera, a millimeter-wave radar, an ultrasonic sensor, a lidar, an infrared sensor, or a LIDAR, and can also be configured to calculate the distance between the detected object and the asphalt paver 100.

[0063] Also, the step of determining whether an object exists within the opening and closing range of the hopper 2, i.e., step ST2, can be omitted or can be incorporated into the step of determining whether the hopper opening condition is satisfied, i.e., step ST1. At this time, the hopper control unit 50a can open the hopper 2 when it is determined that the hopper opening condition is satisfied.

[0064] Further, the controller 50 may be configured to calculate the reliability (a value indicating the accuracy of the recognition result) of the recognition result that the object approaching the asphalt paver 100 is the dump truck 200 based on the output of at least one of the space recognition device 51 and the information acquisition device 53. Moreover, the controller 50 may be configured to automatically open the hopper 2 when the reliability is equal to or higher than the first threshold. And the controller 50 may be configured to, when the reliability is equal to or higher than the second threshold and lower than the first threshold, after automatically opening the hopper 2, convey to the operator of the asphalt paver 100 the gist that the object approaching the asphalt paver 100 may be the dump truck 200 through sound output or image display. This structure has the effect of suppressing the situation where the hopper 2 is placed in the fully open state and the paving material PV in the hopper 2 is unnecessarily cooled even if the paving material PV based on the dump truck 200 is not replenished. Alternatively, the controller 50 may be configured to, when the reliability is lower than the second threshold, instead of automatically opening the hopper 2, convey to the operator the gist that the object approaching the asphalt paver 100 may be the dump truck 200 or the gist that an object other than the dump truck 200 is approaching the asphalt paver 100. This structure has the effect of suppressing the situation where the hopper 2 is placed in the fully open state and the paving material PV in the hopper 2 is unnecessarily cooled even if the paving material PV based on the dump truck 200 is not replenished. And at this time, the controller 50 may output an alarm to the sound output device 56. This is to draw attention to the object approaching the asphalt paver 100.

[0065] Further, the controller 50 may be configured to be able to discriminate whether an object other than the dump truck 200 is a moving object such as a person or an animal or a stationary object. Moreover, the controller 50 may be configured to issue an alarm toward the moving object when it is determined that the object other than the dump truck 200 is a moving object. This structure has the effect of making a moving object that has not noticed the presence of the asphalt paver 100 notice the presence of the asphalt paver 100 and urging the moving object to leave a specified range in front of the asphalt paver 100. And the controller 50 may be configured to issue an alarm toward the operator of the asphalt paver 100 when it is determined that the object other than the dump truck 200 is a stationary object, and may also cause the asphalt paver 100 to stop urgently as needed. This is to prevent the asphalt paver 100 from coming into contact with the stationary object. In addition, this process can also be used in the case where it is determined that the object other than the dump truck 200 is a moving object.

[0066] Through this hopper opening process, even if the operator of the asphalt paver 100 does not manually perform the opening operation of the hopper 2, the controller 50 can automatically bring the hopper 2 into the fully open state before the dump truck 200 comes into contact with the asphalt paver 100. Therefore, the controller 50 can suppress the contact between the cargo box 201 of the dump truck 200 and the hopper wing 2W.

[0067] Next, another example of the hopper opening / closing process will be described with reference to Figures 5 to 7 FIGs. Figure 5 FIG. 6 is a flowchart of an example of a process in which the hopper control unit 50a controls the hopper control device HC to close the hopper 2 (hereinafter referred to as "hopper closing process"). The hopper closing process is an example of the hopper opening / closing process. In the example shown in Figure 5 FIG. 6, the hopper control unit 50a repeatedly executes this hopper closing process at a predetermined control cycle during the operation of the asphalt paver 100. The hopper control unit 50a starts executing the hopper closing process, for example, when the hopper 2 is in the fully open state. In addition, the hopper control unit 50a may be configured to start executing this hopper closing process when a predetermined operation such as an operation of a switch is performed via an input device. Further, the hopper control unit 50a may be configured to stop executing this hopper closing process when a predetermined operation such as an operation of a switch is performed via an input device or the like.

[0068] Figure 6 FIG. 7 is a side view of the asphalt paver 100 and the dump truck 200 when the hopper closing process is being executed. Figure 7 FIG. 8 is a top view of the asphalt paver 100 and the dump truck 200 when the hopper closing process is being executed, corresponding to Figure 6 FIG. 7. In Figure 6 FIGs. Figure 7 7 and 8, the cargo box 201 of the dump truck 200 is lifted by the tipping cylinder 205, so that the paving material PV loaded in the cargo box 201 is replenished into the hopper 2. In addition, the state in which the cargo box 201 is lifted by the tipping cylinder 205 is also referred to as the state in which the cargo box 201 is dumped. The dump truck 200 maintains the state in which the cargo box 201 is dumped until all the paving material PV loaded in the cargo box 201 is replenished into the hopper 2. Further, when all the paving material PV loaded in the cargo box 201 is replenished into the hopper 2, the dump truck 200 starts moving forward and separates from the asphalt paver 100.

[0069] Figure 6 and Figure 7 The hopper closing process described with reference to FIGs. 7 and 8 is executed, for example, when the dump truck 200 replenishes the paving material PV from the cargo box 201 into the hopper 2 of the asphalt paver 100 while the hopper 2 is in the fully open state, which is different from the above-described hopper opening process executed when the hopper 2 is not in the fully open state.

[0070] In the process of closing the hopper, the hopper control unit 50a also first determines whether the hopper closing condition is satisfied (step ST11). In the illustrated example, the hopper control unit 50a determines that the hopper closing condition is satisfied when at least one of the space recognition device 51 and the information acquisition device 53 acquires information related to the detachment of the dump truck 200 from the asphalt paver 100. Specifically, when the hopper control unit 50a detects, based on the image acquired by the front camera 51F as the space recognition device 51, that the dump truck 200 has exited from within the specified range, i.e., the third range ZN3, in front of the asphalt paver 100, it is regarded as having acquired information related to the detachment of the dump truck 200 from the asphalt paver 100 and determines that the hopper closing condition is satisfied. Additionally, typically, the third range ZN3 is a range smaller than the first range ZN1 in Figure 1 and Figure 2 but it can be the same range as the first range ZN1 or a range larger than the first range ZN1.

[0071] Alternatively, when the hopper control unit 50a detects, based on the output of the ultrasonic sensor as the space recognition device 51, that the distance DS2 between the asphalt paver 100 and the dump truck 200 has exceeded the specified second distance, it can be regarded as having acquired information related to the detachment of the dump truck 200 from the asphalt paver 100 and determines that the hopper closing condition is satisfied. At this time, the distance DS2 is, for example, the distance between the ultrasonic sensor installed at the front end of the frame FR and the rear wheel 204 of the dump truck 200. Moreover, the ultrasonic sensor is configured such that its position in the traveling direction of the asphalt paver 100 is the same as the position of the push roller 2P. That is, the distance DS2 is the distance between the push roller 2P and the rear wheel 204. Additionally, typically, the specified second distance is less than the specified first distance related to the Figure 1 and Figure 2 but it can be the same as the specified first distance or greater than the specified first distance.

[0072] Alternatively, when the operator of the asphalt paver 100 operates the specified hopper closing switch, the hopper control unit 50a can determine that the hopper closing condition is satisfied.

[0073] In addition, regarding the hopper closing condition, as one of the hopper closing conditions, it can include the case where the hopper 2 is not in the fully closed state.

[0074] When it is determined that the hopper closing condition is satisfied (Yes in step ST11), the hopper control unit 50a determines whether there is an object within the opening and closing range of the hopper 2 (step ST12). In the illustrated example, the hopper control unit 50a determines whether there is an object within the second range ZN2 based on the image acquired by the front camera 51F as the space recognition device 51.

[0075] Moreover, when it is determined that there is no object within the opening / closing range of the hopper 2 (No in step ST12), the hopper control unit 50a operates the hopper control device HC to close the hopper 2 (step ST13). In the illustrated example, the hopper control unit 50a outputs a current command to the electromagnetic valve serving as the hopper control device HC. The electromagnetic valve serving as the hopper control device HC that has received the current command adjusts the pilot pressure acting on the closing-side pilot port of the hopper spool valve HV by adjusting the flow path area of the oil passage through which the pilot oil flows, and operates the hopper spool valve HV in such a manner as to extend the hopper cylinder 7 (in such a manner that the working oil flows into the bottom-side oil chamber of the hopper cylinder 7) to bring the hopper 2 into a fully closed state.

[0076] On the other hand, when it is determined that there is an object within the opening / closing range of the hopper 2 (Yes in step ST12), the hopper control unit 50a does not operate the hopper control device HC, that is, does not automatically close the hopper 2, and ends the current hopper closing process. This is to reliably prevent contact between the hopper wing 2W and the object. Further, the hopper control unit 50a may output an alarm to the sound output device 56. This is to alert attention to the object existing within the opening / closing range of the hopper 2.

[0077] In addition, the step of determining whether there is an object within the opening / closing range of the hopper 2, that is, step ST12, may be omitted or may be incorporated into the step ST11 of determining whether the hopper closing condition is satisfied. In this case, the hopper control unit 50a can close the hopper 2 when it is determined that the hopper closing condition is satisfied. Further, the hopper control unit 50a may determine whether there is an object inside the hopper 2. The object is, for example, a person working inside the hopper 2 or paving material PV existing inside the hopper 2 in an amount equal to or more than a specified amount. In this case, the hopper control unit 50a can determine whether there is an object inside the hopper 2 based on, for example, an image acquired by the front camera 51F serving as the space recognition device 51. Moreover, when it is determined that there is an object inside the hopper 2, the hopper control unit 50a may not operate the hopper control device HC, that is, may not automatically close the hopper 2, and ends the current hopper closing process. In other words, the hopper control unit 50a can be configured to operate the hopper control device HC to close the hopper 2 only when it is determined that there is no object inside the hopper 2. Further, the step of determining whether there is an object inside the hopper 2 may be incorporated into the step ST11 of determining whether the hopper closing condition is satisfied.

[0078] Further, the hopper control unit 50a can be configured to close the hopper 2 step by step. This is because when the amount of paving material PV in the hopper 2 is large, it is sometimes difficult to fully close the hopper 2. That is, even if working oil is to flow into the bottom oil chamber of the hopper cylinder 7 to extend the hopper cylinder 7, the pressure in the bottom oil chamber will increase and the working oil will be discharged through the safety valve. At this time, the hopper control unit 50a can be configured, for example, to gradually increase the extension amount of the hopper cylinder 7 according to the passage of time since the moment when the dump truck 200 has completed the replenishment of the paving material PV to the asphalt paver 100. In addition, the moment when the dump truck 200 has completed the replenishment of the paving material PV to the asphalt paver 100 can be, for example, the moment when it is determined that the hopper closing condition is satisfied, or a moment different from the moment when it is determined that the hopper closing condition is satisfied (for example, the moment when the controller 50 detects that the cargo box 201 of the dump truck 200 has become empty based on the output of the space recognition device 51 or the like). Alternatively, the hopper control unit 50a can be configured to gradually increase the extension amount of the hopper cylinder 7 according to the increase in the traveling distance of the asphalt paver 100 or the increase in the rotation speed of the conveyor CV since the moment when it is determined that the hopper closing condition is satisfied. And the time interval between each stage and the extension amount of the hopper cylinder 7 at each stage can be determined according to the paving thickness or paving width, etc.

[0079] Through this hopper closing process, even if the operator of the asphalt paver 100 does not manually perform the closing operation of the hopper 2, the controller 50 can start the function of automatically closing the hopper 2 when the dump truck 200 detaches from the asphalt paver 100. Therefore, even if the operator of the asphalt paver 100 does not manually perform the closing operation of the hopper 2, the controller 50 can automatically keep the hopper 2 in a fully closed state when the dump truck 200 and the asphalt paver 100 are separated from each other. Therefore, the controller 50 can prevent the paving material PV existing in the hopper 2 from being unnecessarily cooled.

[0080] Next, refer to Figure 8 Another structural example of the hopper control system SYS will be described. Figure 8 FIG. is a schematic diagram showing another structural example of the hopper control system SYS. The hopper control system SYS is a system for controlling the hopper 2 of one or more asphalt pavers 100. In the present embodiment, the hopper control system SYS mainly consists of an asphalt paver 100, a dump truck 200, and a management device 300. The asphalt paver 100, the dump truck 200, and the management device 300 constituting the hopper control system SYS can each be one or more. And the communication with the dump truck 200 can be omitted. In Figure 8 In the example shown, the hopper control system SYS includes one asphalt paver 100, one dump truck 200, and one management device 300.

[0081] Typically, the management device 300 is a fixed terminal device, such as a server computer installed in a management center or the like located at a position far from the construction site. The management device 300 can be a mobile computer (e.g., a mobile terminal device such as a laptop computer, a tablet computer, or a smart phone).

[0082] The management device 300 can be equipped with a monitor and an operation device for remote operation. At this time, the operator can use the operation device for remote operation and operate the asphalt paver 100. The operation device for remote operation is connected to the controller 50 mounted on the asphalt paver 100 through a wireless communication network such as a short-range wireless communication network, a mobile phone communication network, or a satellite communication network.

[0083] In Figure 8 In the hopper control system SYS shown, the hopper control unit 50a can be implemented by the control device in the management device 300 instead of the controller 50 of the asphalt paver 100.

[0084] At this time, the controller 50 of the asphalt paver 100 can send at least one of the output of the space recognition device 51 and the output of the information acquisition device 53 to the management device 300.

[0085] In addition, the space recognition device 51 can include a space recognition device installed on the road and not installed on the asphalt paver 100, or can be a space recognition device not installed on the asphalt paver 100. At this time, the space recognition device not installed on the asphalt paver 100 can be connected to the controller 50 through wireless communication or wired communication, or can be connected to the management device 300.

[0086] In this way, for the hopper control system SYS, regardless of whether the hopper control unit 50a is installed in the management device 300 or in the controller 50, the opening and closing of the hopper 2 can be controlled according to the positional relationship between the asphalt paver 100 and the dump truck 200. Therefore, the hopper control system SYS has the effect of being able to reduce the burden on the operator of the asphalt paver 100 related to the operation of the hopper 2.

[0087] As described above, as Figure 2As shown in the figure, an asphalt paver 100, which is an example of a road machine according to an embodiment of the present invention, includes: a tractor 1; a hopper 2 provided in front of the tractor 1 and receiving paving material PV from a vehicle (dump truck 200) transporting the paving material PV; a conveyor CV supplying the paving material PV in the hopper 2 to the rear of the tractor 1; a screw SC spreading the paving material PV supplied through the conveyor CV behind the tractor 1; a leveling machine 3 leveling the paving material PV spread by the screw SC behind the screw SC; an object detection device (space recognition device 51) detecting objects around the asphalt paver 100; and a control device (controller 50) controlling the opening and closing of the hopper 2 according to the positional relationship between the dump truck 200 and the asphalt paver 100 detected by the object detection device.

[0088] This structure has the effect of being able to reduce the burden on the operator related to the operation of the hopper 2. For example, this structure has the effect that by automatically opening the hopper 2 when the dump truck 200 enters a specified range in front of the asphalt paver 100, the operator's operation of opening the hopper 2 can be omitted, thereby reducing the burden on the operator related to the opening operation of the hopper 2. Therefore, this structure can, for example, suppress problems such as: when constructing at night or in other situations where it is difficult to obtain a clear view, the driver of the dump truck 200 misses the closed state of the hopper 2 and the cargo box 201 contacts the hopper 2. Or, this structure has the effect that by automatically closing the hopper 2 when the dump truck 200 exits a specified range in front of the asphalt paver 100, the operator's operation of closing the hopper 2 can be omitted, thereby reducing the burden on the operator related to the closing operation of the hopper 2. And, this structure has the effect of being able to suppress the hopper 2 being placed in a fully open state and the paving material PV in the hopper 2 being unnecessarily cooled. And, this structure has the effect that by automating the opening and closing operation of the hopper 2, the burden on the operator related to the opening and closing operation of the hopper 2 can be reduced and the operator can engage in other operations, so the accuracy of the overall construction work can be improved. And, this structure has the effect of being able to automate the opening and closing operation of the hopper 2 more reliably and at an appropriate timing compared to the case of automating the opening and closing operation of the hopper 2 by grasping the amount of paving material PV in the hopper 2. This is because in the case of operating at night or when the hopper 2 gets dirty, it may be difficult to grasp the amount of the black paving material PV based on an image. In contrast, in night operations, by detecting the illuminated taillight of the dump truck 200, it is relatively easy to grasp the positional relationship between the dump truck 200 and the asphalt paver 100 based on an image or the like.

[0089] And, as Figure 1 and Figure 2As shown, the controller 50 can be configured to open the hopper 2 when the distance DS1 between the dump truck 200 in front of the asphalt paver 100 and the asphalt paver 100 becomes equal to or less than a specified distance. Typically, the controller 50 is configured to keep the hopper 2 fully open. Also, the specified distance can be a preset fixed value, or can be dynamically set according to at least one of the reverse speed of the dump truck 200, the forward speed of the asphalt paver 100, and the maximum opening speed of the hopper 2 (the maximum contraction speed of the hopper cylinder 7).

[0090] This structure has the effect of reliably keeping the hopper 2 fully open at an appropriate timing.

[0091] Also, as Figure 6 and Figure 7 shown, the controller 50 can be configured to close the hopper 2 when there is no dump truck 200 within a specified range in front of the asphalt paver 100, i.e., the third range ZN3.

[0092] This structure has the effect of being able to close the hopper 2 for as long a period as possible. Also, this structure has the effect of keeping the hopper 2 closed throughout the entire period except during the period when the paving material PV is replenished into the hopper 2 by the dump truck 200, thereby being able to suppress unnecessary cooling of the paving material PV in the hopper 2. Additionally, this structure has the effect of, for example, automatically closing the hopper 2 even after the operator has manually opened the hopper 2 for visual inspection of the paving material PV in the hopper 2, thereby being able to reduce the burden on the operator related to the closing operation of the hopper 2.

[0093] Also, the controller 50 can be configured to start controlling the automatic closing of the hopper 2 when the replenishment of the paving material PV from the dump truck 200 to the asphalt paver 100 is completed.

[0094] This structure has the effect of being able to start controlling the automatic closing of the hopper 2 at an appropriate timing. At this time, when the distance DS2 between the asphalt paver 100 and the dump truck 200 exceeds the specified distance, the controller 50 can determine that the replenishment of the paving material PV from the dump truck 200 to the asphalt paver 100 is completed and start controlling the automatic closing of the hopper 2.

[0095] Also, the controller 50 can be configured to close the hopper 2 in stages. For example, the controller 50 can be configured to gradually increase the extension amount of the hopper cylinder 7 according to an increase in the travel distance of the asphalt paver 100 or an increase in the number of rotations of the conveyor CV from the moment when it is determined that the hopper closing condition is satisfied. Also, the extension amount of the hopper cylinder 7 at each stage can be determined according to the paving thickness or paving width, etc.

[0096] This structure has the effect of being able to effectively bring the hopper 2 close to a fully closed state. If the amount of paving material PV in the hopper 2 is large, even if the hopper cylinder 7 is extended to close the hopper 2 and working oil is to flow into the bottom oil chamber of the hopper cylinder 7, the pressure in the bottom oil chamber will increase and the working oil will be discharged through the safety valve. However, this structure can suppress the discharge of the working oil through the safety valve while bringing the hopper 2 into a fully closed state by closing the hopper 2 in stages. Moreover, this structure has the effect of being able to suppress the unnecessary cooling of the paving material PV in the hopper 2 by bringing the hopper 2 into a fully closed state as quickly as possible.

[0097] Moreover, the hopper control system SYS for supporting the construction of the asphalt paver 100 according to the embodiment of the present invention has: an object detection device that detects an object around the asphalt paver 100; and a control device that controls the opening and closing of the hopper 2 based on the positional relationship between the vehicle (dump truck 200) detected by the object detection device and the asphalt paver 100. The object detection device may be a device such as the space recognition device 51 mounted on the asphalt paver 100, or a device that is not mounted on the asphalt paver 100, such as a device provided on the road. Moreover, the control device may be the controller 50 mounted on the asphalt paver 100, or the control device in the management device 300 provided in the management center.

[0098] Similar to the asphalt paver 100 according to the embodiment of the present invention, this structure has the effect of being able to reduce the burden on the operator related to the operation of the hopper 2.

[0099] The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, nor is it limited to the embodiments described later. The above or later embodiments can be applied with various modifications, replacements, etc. within the scope not departing from the present invention. Moreover, the respective features described with reference to the above or later embodiments can be appropriately combined as long as they are not technically contradictory.

Claims

1. A road machine comprising: Tractor; a hopper disposed in front of the tractor and receiving the paving material from a vehicle transporting the paving material; a conveyor for supplying the paving material in the hopper to the rear of the tractor; a screw that spreads the paving material supplied by the conveyor behind the tractor; a leveler, which evenly spreads the paving material spread by the screw behind the screw; an object detection device to detect objects around the road machinery; and The control device controls the opening and closing of the hopper according to the positional relationship between the vehicle and the road machine detected by the object detection device.

2. The road machine according to claim 1, wherein: The control device opens the hopper when the distance between the road machine and the vehicle located in front of the road machine becomes equal to or smaller than a predetermined distance.

3. The road machine according to claim 1, wherein: The control device closes the hopper when the vehicle is not present within a predetermined range in front of the road machine.

4. The road machine according to claim 1, wherein: The control device starts the control of automatically closing the hopper when the vehicle completes replenishment of the road paving material to the road machine.

5. The road machine according to claim 4, wherein: The control device closes the hopper in stages.

6. A hopper control system for a road machine, which supports construction performed by the road machine, the road machine comprising: a tractor; a hopper provided in front of the tractor and receiving the paving material from a vehicle transporting the paving material; a conveyor supplying the paving material in the hopper to the rear of the tractor; a screw spreading the paving material supplied by the conveyor behind the tractor; and a screed spreading the paving material spread by the screw behind the screw, the hopper control system for the road machine having: Object detection devices to detect objects around the road machinery; and The control device controls the opening and closing of the hopper according to the positional relationship between the vehicle and the road machine detected by the object detection device.

Images