Road machine

Abstract

To provide a road machine capable of expanding a range in which a paving material can be laid.SOLUTION: An asphalt finisher 100 which is a road machine comprises a tractor 1, a hopper 2, a conveyor CV, a screw SC, a screed 3, a mold board 42, and a side plate 41. The hopper 2 is installed at the front of the tractor 1 and receives a paving material PV. The conveyor CV feeds the paving material PV in the hopper 2 to the rear of the tractor 1. The screw SC spreads the paving material PV fed by the conveyor CV at the rear of the tractor 1. The screed 3 is extendable in a vehicle width direction and levels the paving material PV spread by the screw SC at the rear of the screw SC. The mold board 42 is installed at the front of the screed 3 and adjusts an amount of the paving material PV accumulated at in front of the same. The side plate 41 is installed at a distal end of the screed 3 with a front edge thereof positioned to the side of the mold board 42.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to road machinery.

Background Art

[0002] Conventionally, an asphalt finisher is known that spreads an asphalt mixture on a paved surface while moving in the laying direction and compresses the asphalt mixture with a screed (for example, Patent Document 1).

[0003] The screed of the asphalt finisher described in Patent Document 1 is provided with a left widener and a right widener on the left and right sides of the screed body, respectively, and the left and right positions of the outer end of the widener can be adjusted by expanding and contracting the piston rod of the hydraulic cylinder.

[0004] The left and right side plates constituting the outer end of the widener prevent the asphalt mixture held in front of the screed from spreading outside the left and right outer ends of the widener.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the above conventional asphalt finisher, the front end portions of the left and right side plates constituting the outer end of the widener extend forward from the front ends of the left and right wideners. Therefore, for example, at a bent portion of the construction range such as a curve of a road, there is a range where the front end portion of the side plate becomes an obstacle and the asphalt mixture cannot be evenly spread over the construction range.

[0007] The present disclosure provides a road machine capable of expanding the laying range of paving materials.

Means for Solving the Problem

[0008] One aspect of the present disclosure provides a road machine including a tractor, a hopper installed in front of the tractor for receiving paving material, a conveyor for feeding the paving material in the hopper to the rear of the tractor, a screw for spreading the paving material fed by the conveyor to the rear of the tractor, a screed that is expandable and contractible in the vehicle width direction for leveling the paving material spread by the screw to the rear of the screw, a mold board attached to the front part of the screed for adjusting the amount of the paving material staying in front, and a side plate attached to the distal end of the screed with the front end positioned laterally of the mold board.

Advantages of the Invention

[0009] According to the above aspect of the present disclosure, for example, it is possible to provide a road machine that suppresses the side plate attached to the distal end of the screed from becoming an obstacle to construction, such as at a bent portion of the construction range, and can expand the range where the paving material can be laid.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

[0012] FIG. 1 is a side view of an asphalt finisher 100 which is an example of a road machine according to an embodiment of the present disclosure. FIG. 2 is a top view of the asphalt finisher 100. In the illustrated example, the asphalt finisher 100 is a wheel-type asphalt finisher, and mainly includes a tractor 1, a hopper 2, and a screed 3. Hereinafter, the direction of the hopper 2 viewed from the tractor 1 (+X direction) is defined as the front, and the direction of the screed 3 viewed from the tractor 1 (-X direction) is defined as the rear.

[0013] The tractor 1 is a mechanism for moving the asphalt finisher 100. In the illustrated example, the tractor 1 rotates the rear wheels 5 using a hydraulic motor for rear-wheel travel and rotates the front wheels 6 using a hydraulic motor for front-wheel travel to move the asphalt finisher 100. The hydraulic motor for rear-wheel travel and the hydraulic motor for front-wheel travel are rotated by receiving the supply of hydraulic oil from a hydraulic pump. However, the front wheels 6 may be driven wheels.

[0014] The asphalt finisher 100 may be a crawler-type asphalt finisher. In this case, the combination of the rear wheels 5 and the front wheels 6 is replaced with a combination of a left crawler and a right crawler.

[0015] The hopper 2 is a mechanism for receiving the paving material PV. In the illustrated example, the hopper 2 is installed in front of the tractor 1 and is configured to be able to open and close in the vehicle width direction (Y-axis direction) by a hopper cylinder. The asphalt finisher 100 usually receives the paving material PV (for example, an asphalt mixture) from the loading platform of a dump truck when the hopper 2 is in the fully open state.

[0016] The dump truck is an example of a transport vehicle for transporting paving material PV. Figures 1 and 2 show the hopper 2 in a fully open state. When the paving material PV in the hopper 2 decreases during construction, the operator of the asphalt finisher 100 closes the hopper 2 and collects the paving material PV near the inner wall of the hopper 2 at the center of the hopper 2. This is to enable the conveyor CV at the center of the hopper 2 to feed the paving material PV behind the tractor 1.

[0017] The paving material PV fed behind the tractor 1 by the conveyor CV is spread in the vehicle width direction behind the tractor 1 and in front of the screed 3 by the screw SC. In the illustrated example, the screw SC is in a state where the left extension screw SCL and the right extension screw SCR are connected.

[0018] In addition, in Figures 1 and 2, for clarity, the illustration of the paving material PV in the hopper 2 is omitted. Also, the paving material PV spread by the screw SC is shown by a coarse dot pattern, and the newly laid paving body NP leveled by the screed 3 is shown by a fine dot pattern.

[0019] The screed 3 is a mechanism for leveling the paving material PV. In the illustrated example, the screed 3 includes a front screed 30 and a rear screed 31. The front screed 30 includes a left front screed 30L and a right front screed 30R. The rear screed 31 is a screed that can expand and contract in the vehicle width direction, and includes a left rear screed 31L and a right rear screed 31R.

[0020] Specifically, the rear screed 31 is expanded and contracted by a screed expansion and contraction cylinder 7 installed in the screed 3. More specifically, the screed expansion and contraction cylinder 7 includes a left screed expansion and contraction cylinder 7L and a right screed expansion and contraction cylinder 7R. Then, the left rear screed 31L is expanded and contracted by the left screed expansion and contraction cylinder 7L, and the right rear screed 31R is expanded and contracted by the right screed expansion and contraction cylinder 7R.

[0021] Further, the screed 3 is a floating screed towed by the tractor 1 and is connected to the tractor 1 via a leveling arm 3A. The leveling arm 3A includes a left leveling arm 3AL disposed on the left side of the tractor 1 and a right leveling arm 3AR disposed on the right side of the tractor 1. Note that an end paving leveling device may be disposed at the end of the rear screed 31.

[0022] A side plate 41 is attached to the distal end of the rear screed 31. In the illustrated example, a left side plate 41L is attached to the left end of the left rear screed 31L, and a right side plate 41R is attached to the right end of the right rear screed 31R.

[0023] A tread plate 32 is attached behind the screed 3. Specifically, the tread plate 32 is attached behind the screed 3 so that an operator can move back and forth in the vehicle width direction without stepping on the newly paved surface NP behind the screed 3. In the illustrated example, the tread plate 32 includes a center tread plate 32C attached behind the front screed 30, a left tread plate 32L attached behind the left rear screed 31L, and a right tread plate 32R attached behind the right rear screed 31R.

[0024] A mold board 42 is attached to the front of the screed 3. The mold board 42 is provided so as to be able to move up and down by, for example, a hydraulically driven mold board lifting device 57 (see FIG. 4), and is configured to be able to adjust the gap between the lower end of the mold board 42 and the roadbed BS under the control of the controller 50. Thereby, the mold board 42 is configured to be able to adjust the amount of paving material PV staying in front of the screed 3. The paving material PV reaches under the screed 3 through the gap between the lower end of the mold board 42 and the roadbed BS. In the illustrated example, the mold board 42 includes a left mold board 42L disposed in front of the left rear screed 31L and a right mold board 42R disposed in front of the right rear screed 31R.

[0025] A screw SC is arranged in front of the mold board 42, and a retaining plate 43 is arranged in front of the screw SC. Specifically, the retaining plate 43 includes a left retaining plate 43L arranged in front of the left extension screw SCL and a right retaining plate 43R arranged in front of the right extension screw SCR. Note that the retaining plate 43 may be omitted.

[0026] FIG. 3 is a schematic enlarged view of the front end of the side plate 41 in the asphalt finisher 100 shown in FIG. 2. In FIG. 3, the front end of the left side plate 41L attached to the left end of the left rear side screed 31L among the side plates 41 attached to the left and right distal ends of the extendable screed 3 shown in FIG. 2 is enlarged and shown. Here, the distal end of the screed 3 means the left end of the left rear side screed 31L and the right end of the right rear side screed 31R separated from the front side screed 30 in the vehicle width direction, respectively.

[0027] The right side plate 41R attached to the right end of the right rear side screed 31R also has the same configuration as the left side plate 41L shown in FIG. 3. Therefore, hereinafter, the configuration of the left side plate 41L will be described in detail, and the description of the right side plate 41R will be omitted as appropriate. Note that in FIG. 3, the paving material PV staying in front of the mold board 42 is shown by a coarse dot pattern, and the paving material PV leveled through the gap between the mold board 42 and the roadbed BS is shown by a fine dot pattern.

[0028] The front end portion of the side plate 41 is attached to the distal end of the mold board 42 via an attachment member, for example, as shown in FIG. 3. Specifically, the front end portion of the left side plate 41L is attached to the left end of the left mold board 42L, and the front end portion of the right side plate 41R is attached to the right end of the right mold board 42R.

[0029] The front end 41a of the side plate 41 is located on the side of the mold board 42. In other words, for example, in the vehicle length direction (X-axis direction), the position of the front end 41a of the side plate 41 is aligned with the position of the front end of the mold board 42. That is, the front end 41a of the side plate 41 and the front end of the mold board 42 are located on the same plane (YZ plane) perpendicular to the vehicle length direction (X-axis direction), for example. In short, the side plate 41 does not have a portion protruding forward of the mold board 42, for example.

[0030] The rear end portion of the side plate 41 is attached to the distal end of the screed 3, for example, as shown in FIG. 2. Specifically, the rear end portion of the left mold board 42L is attached to the left end of the left rear screed 31L, and the rear end portion of the right mold board 42R is attached to the right end of the right rear screed 31R. The side plate 41 is arranged, for example, along the guide line GD as the boundary of the road to be constructed, and the paving material PV spread by the screw SC and passing under the mold board 42 is prevented from spreading in the vehicle width direction (Y-axis direction) beyond the guide line GD.

[0031] The asphalt finisher 100 may include, for example, as shown in FIG. 3, a paving material detection device 44 that detects the position of the outer edge PVE in the vehicle width direction (Y-axis direction) of the paving material PV staying in front of the mold board 42. The paving material detection device 44 can be constituted by, for example, a monocular camera, a stereo camera, an infrared camera, LiDAR, a millimeter wave radar, a laser radar, a laser scanner, a distance image camera, a laser range finder, an ultrasonic sensor, or a combination thereof. The paving material detection device 44 can be attached, for example, via a mounting arm to the front end portion of the side plate 41.

[0032] However, the paving material detection device 44 may be attached to the mold board 42, the retaining plate 43, or a part of the tractor 1. Further, the paving material detection device 44 may be attached to both the left side plate 41L and the right side plate 41R, or may be attached to either one of the left side plate 41L and the right side plate 41R. The same applies when the paving material detection device 44 is attached to the mold board 42 or the like. Further, the paving material detection device 44 may be attached to, for example, the front screen 30.

[0033] When the paving material detection device 44 includes, for example, a stereo camera, LiDAR, a millimeter wave radar, or an ultrasonic sensor, it may detect the height of the paving material PV staying in front of the mold board 42. Further, when the paving material detection device 44 includes, for example, a stereo camera or LiDAR, it may detect the three-dimensional shape of the paving material PV staying in front of the mold board 42.

[0034] The detection range DR of the paving material detection device 44 is, for example, a region in front of the mold board 42 including the front end 41a of the side plate 41 or the distal end of the mold board 42. Further, the detection range DR may include the distal end of the screw SC. Further, the detection range DR may be, for example, a region that does not include the front end 41a of the side plate 41 and the distal end of the mold board 42. Further, a plurality of paving material detection devices 44 may be used to detect the height or three-dimensional shape of the paving material PV staying in front of the mold board 42 in a plurality of regions including a region including the distal end of the mold board 42 or the front end 41a of the side plate 41 and other regions.

[0035] A travel speed sensor S1, a controller 50, an object detection device 51, an in-vehicle display device 52, a steering device 53, and a screen expansion and contraction device 54 are attached to the tractor 1.

[0036] The traveling speed sensor S1 is configured to be able to detect the traveling speed of the asphalt finisher 100. In the illustrated example, the traveling speed sensor S1 is a wheel speed sensor and is configured to be able to detect the rotational angular velocity and rotational angle of the rear wheel 5, and thus the traveling speed and traveling distance of the asphalt finisher 100.

[0037] The controller 50 is a control device that controls the asphalt finisher 100. In the illustrated example, the controller 50 is composed of a microcomputer including a CPU, a volatile memory device, a non-volatile memory device, etc. Each function of the controller 50 is realized by the CPU executing a program stored in the non-volatile memory device. However, each function of the controller 50 may not only be realized by software, but also by hardware, or by a combination of hardware and software.

[0038] The object detection device 51 is an example of an information acquisition device that acquires information around the asphalt finisher 100, and is configured to acquire information about features within a predetermined range of the road to be constructed and output the acquired information to the controller 50. That is, the object detection device 51 is configured to monitor a predetermined range of the road to be constructed. The predetermined range on the road is, for example, a range including the boundary line of the road, which is located in front of the screed 3. In the illustrated example, the predetermined range on the road is a range having a front-rear width and a left-right width larger than the width of the paving formwork, for example, a range of 2 meters square.

[0039] The range located in front of the screed 3 is, for example, a range located in front of the hopper 2, a range located in front of the axle of the front wheel 6, a range located in front of the axle of the rear wheel 5, a range located in front of the screw SC, etc.

[0040] Features within a predetermined range include, for example, the roadbed BS and an object AP outside the roadbed BS. The object AP is a feature used to determine the position of the end face in the width direction of the pavement to be laid. In the examples shown in FIGS. 1 and 2, the object AP is a paving formwork having a predetermined thickness (height), and includes a left object APL on the left side of the asphalt finisher 100 and a right object APR on the right side of the asphalt finisher 100.

[0041] Specifically, the left object APL includes a first left object APL1 and a second left object APL2, and the right object APR includes a first right object APR1 and a second right object APR2. The object AP may be an L-shaped side groove block, a curb block, or a cut step portion of an existing pavement. The cut step portion of the existing pavement means a step portion between the surface of the cut portion and the surface of the uncut portion formed when cutting an old pavement to lay a new pavement.

[0042] The object AP may be a feature with almost no thickness, such as a line drawn on the ground, a tape attached to the ground, or a thread stretched along the ground. Information about the feature includes, for example, the height of the feature, the color of the surface of the feature, or the reflectivity of the surface of the feature. In FIG. 1, for clarity, the illustration of the left object APL is omitted.

[0043] In the illustrated example, the object detection device 51 is a stereo camera configured to monitor a predetermined range. Note that the object detection device 51 may be a monocular camera, LiDAR, millimeter wave radar, laser radar, laser scanner, distance image camera, laser range finder, ultrasonic sensor, or a combination thereof, etc., configured to monitor a predetermined range.

[0044] Also, the stereo camera as the object detection device 51 is preferably configured to have an automatic exposure adjustment function. With this configuration, the object detection device 51 can acquire information on ground features within a predetermined range regardless of day or night, that is, without requiring special lighting or the like. In the illustrated example, the object detection device 51 includes a left object detection device 51L installed on the left side of the asphalt finisher 100 and a right object detection device 51R installed on the right side of the asphalt finisher 100.

[0045] The left object detection device 51L is configured to be able to monitor the ground on the left side of the asphalt finisher 100. In the illustrated example, the left object detection device 51L is a stereo camera that monitors the left monitoring range ZL (the range surrounded by the dashed-dotted line in FIG. 2) on the ground on the left side of the asphalt finisher 100.

[0046] The right object detection device 51R is configured to be able to monitor the ground on the right side of the asphalt finisher 100. In the illustrated example, the right object detection device 51R is a stereo camera that monitors the right monitoring range ZR (the range surrounded by the dashed-dotted line in FIG. 2) on the ground on the right side of the asphalt finisher 100.

[0047] The object detection device 51 may be attached to the asphalt finisher 100 via an attachment member 60. The attachment member 60 is a member used to attach the object detection device 51 to the asphalt finisher 100. In the illustrated example, the attachment member 60 includes a left attachment member 60L and a right attachment member 60R. In the example shown in FIG. 2, the left object detection device 51L is attached to the left front end of the tractor 1 via the left attachment member 60L, and the right object detection device 51R is attached to the right front end of the tractor 1 via the right attachment member 60R. Note that the left object detection device 51L may be attached to other parts of the asphalt finisher 100, such as the left front end of the hopper 2, via the left attachment member 60L. Similarly, the right object detection device 51R may be attached to other parts of the asphalt finisher 100, such as the right front end of the hopper 2, via the right attachment member 60R.

[0048] Further, the object detection device 51 may be configured to monitor the expansion and contraction state of the rear screen 31. For example, the object detection device 51 may additionally include a stereo camera configured to monitor the end of the left rear screen 31L and a stereo camera configured to monitor the end of the right rear screen 31R. In this case, the object detection device 51 may be disposed on the screen 3. For example, the object detection device 51 may be disposed on the rear screen 31. Further, when an end leveling device is disposed at the end of the rear screen 31, the object detection device 51 may be disposed on the end leveling device.

[0049] Also, in the example shown in FIG. 2, the object detection device 51 is attached to the attachment member 60 so as to face vertically downward, but may be attached to the attachment member 60 so as to face other directions such as obliquely downward. Also, in the example shown in FIG. 2, the left attachment member 60L is composed of a telescopic member TA that can expand and contract in the width direction and a rotating member SB that is rotatably connected to the distal end of the telescopic member TA. The rotating member SBa represented by a broken line in FIG. 2 shows the state when the rotating member SB rotates. The same applies to the right attachment member 60R.

[0050] In this way, the attachment member 60 is configured to be able to move the monitoring range of the object detection device 51 by the telescopic member TA and the rotating member SB. This is to enable it to cope with changes in the paving width and the like. In this case, the controller 50 may be configured to be able to control the rotation of the rotating member SB and the expansion and contraction of the telescopic member TA so that the object detection device 51 follows the object AP. Thereby, the controller 50 can ensure that the object AP is continuously included within the monitoring range of the object detection device 51 even when the position of the object AP changes in the vehicle width direction.

[0051] The mounting member 60 may be provided with at least one of a sensor for detecting the amount of expansion and contraction of the telescopic member TA and a sensor for detecting the amount of rotation (rotation angle) of the rotating member SB. Note that at least one of the telescopic member TA and the rotating member SB may be omitted. For example, the mounting member 60 may be configured to be non-telescopic and non-rotatable. That is, the mounting member 60 may be a rod-shaped member that is non-telescopic and non-rotatable. Further, the object detection device 51 may be directly attached to the asphalt finisher 100 without passing through the mounting member 60.

[0052] Further, the asphalt finisher 100 may be provided with a steering angle sensor configured to detect the steering angle of the asphalt finisher 100, a screed expansion and contraction amount sensor configured to detect the amount of expansion and contraction of the rear screed 31, and the like.

[0053] The in-vehicle display device 52 is configured to be able to display information regarding the asphalt finisher 100. In the illustrated example, the in-vehicle display device 52 is a liquid crystal display installed in front of the driver's seat 1S. However, the in-vehicle display device 52 may include a display device installed at at least one of the left end portion and the right end portion of the screed 3.

[0054] The steering device 53 is configured to be able to steer the asphalt finisher 100. In the illustrated example, the steering device 53 is configured to expand and contract a front wheel steering cylinder installed near the front axle. Specifically, the steering device 53 includes a steering electromagnetic control valve that controls the flow rate of the hydraulic oil flowing from the hydraulic pump to the front wheel steering cylinder and the flow rate of the hydraulic oil discharged from the front wheel steering cylinder.

[0055] The electromagnetic control valve for steering is configured to be able to control the inflow and outflow of hydraulic oil in the front-wheel steering cylinder according to the rotation of the steering wheel SH (handwheel) as an operating device. Note that the electromagnetic control valve for steering may be configured to be able to control the inflow and outflow of hydraulic oil in the front-wheel steering cylinder according to the operation of an input switch, which is an operating device different from the steering wheel SH, regardless of the movement of the steering wheel SH.

[0056] Also, the electromagnetic control valve for steering may be configured to be able to control the inflow and outflow of hydraulic oil in the front-wheel steering cylinder according to a steering command from the controller 50, regardless of the rotation of the steering wheel SH. That is, the controller 50 may be configured to be able to automatically steer the asphalt finisher 100 regardless of whether the driver operates the steering wheel SH.

[0057] When the asphalt finisher 100 is a crawler-type asphalt finisher, the steering device 53 is configured to be able to separately control a pair of left and right crawlers. Note that the crawler-type asphalt finisher has a left operation lever, which is an operating device for operating the left crawler, and a right operation lever, which is an operating device for operating the right crawler, instead of the steering wheel SH.

[0058] Specifically, the steering device 53 includes a left steering electromagnetic control valve that controls the flow rate of the hydraulic oil flowing from the hydraulic pump to the left traveling hydraulic motor for rotating the left crawler, and a right steering electromagnetic control valve that controls the flow rate of the hydraulic oil flowing from the hydraulic pump to the right traveling hydraulic motor for rotating the right crawler. The left steering electromagnetic control valve is configured to be able to control the inflow and outflow of the hydraulic oil in the left traveling hydraulic motor according to the operation amount (tilt angle) of the left operation lever. Similarly, the right steering electromagnetic control valve is configured to be able to control the inflow and outflow of the hydraulic oil in the right traveling hydraulic motor according to the operation amount (tilt angle) of the right operation lever.

[0059] Note that the left steering electromagnetic control valve may be configured to control the inflow and outflow of hydraulic oil in the left traveling hydraulic motor according to the steering command from the controller 50, regardless of whether the driver operates the left operation lever. Similarly, the right steering electromagnetic control valve may be configured to control the inflow and outflow of hydraulic oil in the right traveling hydraulic motor according to the steering command from the controller 50, regardless of whether the driver operates the right operation lever.

[0060] The screed expansion and contraction device 54 is configured to be able to expand and contract the rear screed 31 in the vehicle width direction (Y-axis direction). In the illustrated example, the screed expansion and contraction device 54 is configured to expand and contract the screed expansion and contraction cylinder 7 installed in the screed 3. Specifically, the screed expansion and contraction device 54 includes a screed expansion and contraction electromagnetic control valve that controls the flow rate of the hydraulic oil flowing from the hydraulic pump to the screed expansion and contraction cylinder 7 and the flow rate of the hydraulic oil discharged from the screed expansion and contraction cylinder 7.

[0061] The screed expansion and contraction electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic oil in the screed expansion and contraction cylinder 7 according to the operation of an expansion and contraction button set (not shown) as an operation device provided near the in-vehicle display device 52. The expansion and contraction button set typically includes a left expansion and contraction button set for expanding and contracting the left rear screed 31L and a right expansion and contraction button set for expanding and contracting the right rear screed 31R.

[0062] The screed expansion and contraction electromagnetic control valve may be configured to control the inflow and outflow of hydraulic oil in the screed expansion and contraction cylinder 7 according to the expansion and contraction command from the controller 50, regardless of the operation of the expansion and contraction button set. That is, the controller 50 may be configured to be able to automatically expand and contract the rear screed 31 regardless of whether the driver operates the expansion and contraction button set.

[0063] Specifically, the screed telescoping device 54 includes a left telescoping electromagnetic control valve that controls the flow rate of hydraulic oil flowing to the left screed telescoping cylinder 7L for telescoping the left rear screed 31L from a hydraulic pump, and a right telescoping electromagnetic control valve that controls the flow rate of hydraulic oil flowing to the right screed telescoping cylinder 7R for telescoping the right rear screed 31R from the hydraulic pump. The left telescoping electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic oil in the left screed telescoping cylinder 7L according to the operation content of the left telescoping button set. Similarly, the right telescoping electromagnetic control valve is configured to be able to control the inflow and outflow of hydraulic oil in the right screed telescoping cylinder 7R according to the operation content of the right telescoping button set.

[0064] Note that the left telescoping electromagnetic control valve may be configured to be able to control the inflow and outflow of hydraulic oil in the left screed telescoping cylinder 7L according to the telescoping command from the controller 50, regardless of whether the left telescoping button set is operated by the driver. Similarly, the right telescoping electromagnetic control valve may be configured to be able to control the inflow and outflow of hydraulic oil in the right screed telescoping cylinder 7R according to the telescoping command from the controller 50, regardless of whether the right telescoping button set is operated by the driver.

[0065] Next, referring to FIG. 4, a configuration example of the control system of the asphalt finisher 100 will be described. FIG. 4 is a block diagram showing a configuration example of the control system mounted on the asphalt finisher 100 of FIG. 1.

[0066] The control system of the asphalt finisher 100 includes, for example, a controller 50, a left object detection device 51L, a right object detection device 51R, a traveling speed sensor S1, and a paving material detection device 44. The control system of the asphalt finisher 100 also includes, for example, an in-vehicle display device 52, a steering device 53, a screed telescoping device 54, a conveyor drive device 55, a screw drive device 56, and a mold board lifting device 57.

[0067] In the example shown in FIG. 4, the controller 50 includes a coordinate calculation unit 50a, a steering control unit 50b, a screed expansion and contraction control unit 50c, a paving material retention amount control unit 50d, and a machine learning unit 50e. Each part of the controller 50 represents each function of the controller 50 realized by the CPU executing a program stored in a non-volatile memory device, for example. Further, as described above, each part of the controller 50 shown in FIG. 4 may be realized by hardware, for example, or may be realized by a combination of hardware and software.

[0068] The coordinate calculation unit 50a is configured to calculate the coordinates on the boundary line of the construction target range based on the information about the ground features acquired by the object detection device 51. The guide line GD shown by the thick broken line in FIG. 2 is an example of the boundary line of the road to be constructed, and is a virtual line indicating the guide surface. The guide surface is a virtual surface recognized as a surface on which the end faces in the width direction of the paving body to be laid should coincide. In the example shown in FIG. 2, the guide line GD includes a left guide line GDL indicating the left guide surface, which is a surface on which the left end face of the newly laid paving body NP should coincide, and a right guide line GDR indicating the right guide surface, which is a surface on which the right end face of the newly laid paving body NP should coincide.

[0069] Specifically, the coordinate calculation unit 50a calculates the coordinates on the guide line GD based on the information about the object AP acquired by the object detection device 51. More specifically, the coordinate calculation unit 50a calculates the coordinates of the point VL that constitutes the left guide line GDL based on the information about the left object APL acquired by the left object detection device 51L, and calculates the coordinates of the point VR that constitutes the right guide line GDR based on the information about the right object APR acquired by the right object detection device 51R.

[0070] The coordinate calculation unit 50a intermittently calculates and stores the coordinates of the point VL and the point VR, respectively. In the illustrated example, the coordinate calculation unit 50a is configured to calculate and store the coordinates of the point VL and the point VR, respectively, each time the asphalt finisher 100 advances by a predetermined distance (for example, 15 cm). Note that the coordinate calculation unit 50a may be configured to calculate and store the coordinates of the point VL and the point VR, respectively, each time a predetermined time elapses.

[0071] Figure 1 shows how the coordinate calculation unit 50a intermittently calculates and stores the coordinates of point VL. In Figure 1, point VL0 corresponds to the point VL derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at the current time. Also, point VL1 corresponds to the point VL derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain past time. The same applies to points VL2 to VL4. Also, point VL11 corresponds to the point VL to be derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain future time. The same applies to points VL12 to VL14. That is, at the current time, the coordinate calculation unit 50a has already calculated and stored the coordinate values of point VL0 and points VL1 to VL4 respectively.

[0072] Similar to Figure 1, Figure 2 also shows how the coordinate calculation unit 50a intermittently calculates and stores the coordinates of points VL and VR respectively. In Figure 2, point VR0 corresponds to the point VR derived by the coordinate calculation unit 50a based on the output of the right object detection device 51R at the current time. The same applies to point VL0. Also, point VR1 corresponds to the point VR derived by the coordinate calculation unit 50a based on the output of the right object detection device 51R at a certain past time. The same applies to points VR2 to VR4. Also, point VL1 corresponds to the point VL derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain past time. The same applies to points VL2 to VL4. Also, point VR11 corresponds to the point VR to be derived by the coordinate calculation unit 50a based on the output of the right object detection device 51R at a certain future time. The same applies to points VR12 to VR14. Also, point VL11 corresponds to the point VL to be derived by the coordinate calculation unit 50a based on the output of the left object detection device 51L at a certain future time. The same applies to points VL11 to VL14.

[0073] The steering control unit 50b is configured to be able to automatically steer the asphalt finisher 100 regardless of the operation on an operating device such as a travel speed dial. Note that the steering control unit 50b may be configured to be able to control the travel speed of the asphalt finisher 100 when automatically steering the asphalt finisher 100. Also, the steering control unit 50b may be omitted.

[0074] The screed expansion / contraction control unit 50c is configured to be able to automatically expand and contract the left and right rear screeds 31 that can be expanded and contracted regardless of the operation on an operating device such as an expansion / contraction button set. Note that the screed expansion / contraction control unit 50c may be configured to be able to automatically expand and contract the rear screed 31 according to the travel speed and steering angle of the asphalt finisher 100 when the asphalt finisher 100 is automatically steered.

[0075] In the illustrated example, the screed expansion / contraction control unit 50c generates an expansion / contraction command for the screed expansion cylinder 7 based on the coordinates on the boundary line calculated and stored by the coordinate calculation unit 50a. The expansion / contraction command is, for example, a command regarding the expansion / contraction speed, a command regarding the expansion / contraction amount, or a combination thereof.

[0076] Specifically, the screed expansion / contraction control unit 50c executes feedforward control of the expansion / contraction amount of the rear screed 31. More specifically, the screed expansion / contraction control unit 50c expands and contracts the left screed expansion cylinder 7L so that the coordinates of a predetermined part (for example, the left front end point) of the left rear screed 31L match the left target coordinates. The left target coordinates are an example of the target coordinates and are, for example, the coordinates of a point VL that is at the closest position in front of a predetermined part (for example, the left front end point) of the left rear screed 31L.

[0077] Further, the screed expansion / contraction control unit 50c expands and contracts the right screed expansion / contraction cylinder 7R so that the coordinates of a predetermined part (e.g., the right front end point) of the right rear screed 31R match the right target coordinates. The right target coordinates are another example of the target coordinates, and are, for example, the coordinates of a point VR that is at the closest position in front of a predetermined part (e.g., the right front end point) of the right rear screed 31R. Further, the screed expansion / contraction control unit 50c may be configured to determine the expansion / contraction speed according to the traveling speed of the asphalt finisher 100 detected by the traveling speed sensor S1.

[0078] Note that the coordinates of a predetermined part of the rear screed 31, such as the coordinates of the left front end point of the left rear screed 31L and the coordinates of the right front end point of the right rear screed 31R, can be calculated by the coordinate calculation unit 50a in the same manner as the coordinates of the points VL and VR.

[0079] Specifically, the coordinate calculation unit 50a can calculate the relative position of the object detection device 51 with respect to the position of a reference point, such as the center point of the tractor 1, based on the expansion / contraction amount of the expansion / contraction member TA that positions the object detection device 51. Similarly, the coordinate calculation unit 50a can calculate the relative position of each of the left front end point of the left rear screed 31L and the right front end point of the right rear screed 31R with respect to the position of the reference point based on the expansion / contraction amount of the rear screed 31.

[0080] Further, the coordinate calculation unit 50a can calculate the relative position of the reference point at a second time point with respect to the position of the reference point at a first time point based on the outputs of the traveling speed sensor S1 and a steering angle sensor or the like. Therefore, the coordinate calculation unit 50a can calculate the relative position of each of the points VL, VR, the left front end point of the left rear screed 31L, and the right front end point of the right rear screed 31R at another time point with respect to the position of the reference point at the first time point.

[0081] Further, the screed expansion / contraction control unit 50c may control, for example, the distal end of the screw SC and the distal end of the mold board 42 at a predetermined interval. Specifically, the screed expansion / contraction control unit 50c acquires, for example, the coordinates of the distal end of the screw SC and the coordinates of the distal end of the mold board 42, and maintains the interval between the distal end of the screw SC and the distal end of the mold board 42 at a predetermined threshold value or more. This predetermined interval prevents the screw SC from colliding with the side plate 41 and facilitates the adjustment of the position of the outer edge PVE of the paving material PV in the vehicle width direction.

[0082] The paving material retention amount control unit 50d controls at least one of, for example, the conveyor CV, the screw SC, and the mold board 42 so that the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 is aligned with the distal end of the mold board 42 as shown in FIG. 3. In other words, the paving material retention amount control unit 50d controls at least one of the conveyor CV, the screw SC, and the mold board 42 so that the position of the outer edge PVE of the paving material PV in the vehicle width direction is aligned with the position of the distal end of the mold board 42.

[0083] Specifically, the paving material retention amount control unit 50d executes, for example, feedforward control and feedback control for controlling the position of the outer edge PVE of the paving material PV. More specifically, the paving material retention amount control unit 50d increases or decreases the supply amount of the paving material PV fed forward to the front of the mold board 42 so that the position coordinates of the outer edge PVE of the paving material PV in the vehicle width direction are aligned with the position coordinates of the distal end of the mold board 42, which is the target value. Further, the paving material retention amount control unit 50d increases or decreases the passing amount of the paving material PV passing under the mold board 42 so that the position coordinates of the outer edge PVE of the paving material PV in the vehicle width direction are aligned with the position coordinates of the distal end of the mold board 42, which is the target value.

[0084] More specifically, the paving material retention amount control unit 50d acquires, for example, the position of the distal end of the mold board 42 from the paving material detection device 44. Further, the paving material retention amount control unit 50d may acquire the position of the end of the rear screed 31 from, for example, the screed expansion / contraction control unit 50c or the object detection device 51, and may also acquire the position of the distal end of the mold board 42 from the positional relationship between the side plate 41 and the mold board 42 stored in the nonvolatile memory device.

[0085] In addition, the paving material retention amount control unit 50d acquires, for example, the position of the outer edge PVE in the vehicle width direction of the paving material PV detected by the paving material retention amount control unit 50d. Further, the paving material retention amount control unit 50d controls the supply amount of the paving material PV fed forward of the mold board 42 and the passing amount of the paving material PV passing below the mold board 42 based on the position of the distal end of the mold board 42 and the position of the outer edge PVE of the paving material PV.

[0086] Specifically, the paving material retention amount control unit 50d controls, for example, at least one of the feeding speed of the paving material PV by the conveyor CV, the rotation speed of the screw SC, and the gap between the mold board 42 and the roadbed BS. Thereby, the paving material retention amount control unit 50d controls at least one of the supply amount of the paving material PV fed forward of the distal end portion of the mold board 42 and the passing amount of the paving material PV moving rearward of the mold board 42 through the gap between the mold board 42 and the roadbed BS.

[0087] For example, assume that the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 is located inside the mold board 42 in the vehicle width direction from the distal end. In this case, the paving material retention amount control unit 50d executes at least one of control to increase the supply amount of the paving material PV and control to decrease the passing amount of the paving material PV. Thereby, the outer edge PVE of the paving material PV can be moved outward in the vehicle width direction and brought closer to the distal end of the mold board 42.

[0088] Specifically, the control for increasing the supply amount of the paving material PV includes, for example, at least one of the control for increasing the feeding speed of the paving material PV by the conveyor CV and the control for increasing the rotation speed of the screw SC. Further, the control for decreasing the passing amount of the paving material PV includes, for example, at least one of the control for decreasing the gap between the mold board 42 and the roadbed BS and the control for decreasing the traveling speed of the tractor 1.

[0089] On the other hand, assume that the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 is located outside the vehicle width direction from the distal end of the mold board 42. In this case, the paving material stay amount control unit 50d executes, for example, at least one of the control for decreasing the supply amount of the paving material PV and the control for increasing the passing amount of the paving material PV. Thereby, the outer edge PVE of the paving material PV can be moved inward in the vehicle width direction and brought closer to the distal end of the mold board 42.

[0090] Specifically, the control for decreasing the supply amount of the paving material PV includes, for example, at least one of the control for decreasing the feeding speed of the paving material PV by the conveyor CV and the control for decreasing the rotation speed of the screw SC. Further, the control for increasing the passing amount of the paving material PV includes, for example, at least one of the control for increasing the gap between the mold board 42 and the roadbed BS and the control for increasing the traveling speed of the tractor 1.

[0091] The paving material stay amount control unit 50d can increase or decrease the feeding speed of the paving material PV by the conveyor CV, for example, by outputting a control command to the conveyor drive device 55 that drives the conveyor CV. Further, the paving material stay amount control unit 50d can increase or decrease the rotation speed of the screw SC, for example, by outputting a control command to the screw drive device 56 that rotates the screw drive device 56.

[0092] Further, the paving material retention amount control unit 50d can increase or decrease the gap between the mold board 42 and the roadbed BS, for example, by outputting a control command to a mold board lifting device 57 that raises and lowers the mold board 42. Further, the paving material retention amount control unit 50d can increase or decrease the traveling speed of the tractor 1, for example, by outputting a control command to a traveling electromagnetic control valve that controls the direction and flow rate of the hydraulic oil supplied to the rear-wheel traveling hydraulic motor and the front-wheel traveling hydraulic motor.

[0093] Note that the paving material retention amount control unit 50d does not necessarily have to align the outer edge PVE of the paving material PV with the distal end of the mold board 42. The paving material retention amount control unit 50d may control at least one of the conveyor CV, the screw SC, and the mold board 42 so as to align the outer edge PVE of the paving material PV with the inner edge in the vehicle width direction of the front end 41a of the side plate 41, for example.

[0094] Further, as described above, when the paving material detection device 44 detects the height of the paving material PV staying in front of the mold board 42, the controller 50 may include a machine learning unit 50e. The machine learning unit 50e learns, for example, the relationship between the control amounts of the conveyor CV, the screw SC, and the mold board 42, the detection result of the paving material detection device 44, and the position of the outer edge PVE of the paving material PV.

[0095] FIG. 5 is a diagram for explaining an example of the learned model of the machine learning unit 50e shown in FIG. 4. As the machine learning used for generating the learned model of the machine learning unit 50e, for example, machine learning using a deep neural network (DNN) is used, and deep learning (deep neural network) is applied.

[0096] The machine learning unit 50e generates a teacher data set, for example, during the control of the conveyor CV, screw SC, paving material detection device 44, etc. by the paving material retention amount control unit 50d. At this time, the machine learning unit 50e uses, for example, the respective control amounts of the conveyor CV, screw SC, and mold board 42 stored in the non-volatile storage device, the detection result of the paving material detection device 44, and the position of the outer edge PVE of the paving material PV to generate a teacher data set. The machine learning unit 50e generates a learned model by performing machine learning using the generated teacher data set.

[0097] The learned model of the machine learning unit 50e outputs the control amounts of the conveyor CV, screw SC, and mold board 42 from the output layer (nth layer) by inputting the detection result of the paving material detection device 44 into the input layer (0th layer) of the neural network, for example. These are control amounts for aligning the outer edge PVE of the paving material PV with the distal end of the mold board 42.

[0098] FIG. 6 is a flowchart for explaining the operation of the paving material retention amount control unit 50d of the controller 50. In the illustrated example, the controller 50 starts the processing flow of the paving material retention amount control shown in FIG. 6 when the construction is started. Specifically, the controller 50 determines whether the screed 3 has been lowered toward the roadbed BS based on the output of a pressure sensor that acquires the pressure of the hydraulic oil in the lift cylinder 8 (see FIG. 1) for lifting the screed 3.

[0099] More specifically, the controller 50 determines that the lift cylinder 8 has extended and the screed 3 has been lowered toward the roadbed BS, and determines that the construction has started when the pressure of the hydraulic oil in the rod side oil chamber of the lift cylinder 8 falls below a predetermined value. Note that the controller 50 may determine that the construction has started by any other arbitrary method. Also, the controller 50 may be configured to start the processing flow of the paving material retention amount control at another timing.

[0100] When the paving material retention amount control unit 50d starts the processing flow shown in FIG. 6, it outputs control commands to the conveyor drive device 55, the screw drive device 56, and the mold board lifting device 57 to drive the conveyor CV, rotate the screw SC, and adjust the gap between the mold board 42 and the roadbed BS (processing P1).

[0101] As a result, the paving material PV is fed from the central part of the hopper 2 to the rear of the tractor 1 by the conveyor CV, and spread by the screw SC behind the tractor 1 and in front of the screed 3. The outer edge in the vehicle width direction of the paving material PV spread in front of the screed 3 reaches the distal end of the mold board 42 as shown in FIG. 3.

[0102] Next, the paving material retention amount control unit 50d determines, for example, whether the position P_mbd of the distal end of the mold board 42 and the position P_pve of the outer edge PVE of the paving material PV in the vehicle width direction match (processing P2). Here, the paving material retention amount control unit 50d determines that the position P_mbd and the position P_pve match (YES) when the difference between the position P_mbd and the position P_pve is equal to or less than a predetermined threshold value, and continues to feed the paving material PV to maintain the supply amount of the paving material PV (processing P3).

[0103] Thereafter, the paving material retention amount control unit 50d determines whether to end the feeding of the paving material PV (processing P4). In this processing P4, the paving material retention amount control unit 50d determines to end the feeding of the paving material PV (YES) when, for example, an operation to stop the feeding of the paving material PV is performed by the driver or the operator, and ends the processing flow shown in FIG. 6. On the other hand, the paving material retention amount control unit 50d determines to continue the feeding of the paving material PV (NO) when, for example, an operation to stop the feeding of the paving material PV is not performed by the driver or the operator, and repeats the above-mentioned processing P2.

[0104] For example, due to changes in the viscosity of the paving material PV, unevenness of the roadbed BS, fluctuations in the traveling speed of the tractor 1, etc., the difference between the position P_mbd of the distal end of the mold board 42 shown in FIG. 3 and the position P_pve of the outer edge PVE of the paving material PV in the vehicle width direction may exceed the threshold value. In that case, the paving material retention amount control unit 50d determines, for example, in the above-described process P2, that the position P_mbd and the position P_pve do not match (NO), and adjusts the supply amount of the paving material PV, etc. (process P5).

[0105] Here, for example, as described above, it is assumed that the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 is located inside the vehicle width direction from the distal end of the mold board 42. In this case, in this process P5, the paving material retention amount control unit 50d executes at least one of the control to increase the supply amount of the paving material PV and the control to decrease the passing amount of the paving material PV as described above. Thereafter, the paving material retention amount control unit 50d repeats the above-described process P2.

[0106] Also, for example, as described above, it is assumed that the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 is located outside the vehicle width direction from the distal end of the mold board 42. In this case, in this process P5, the paving material retention amount control unit 50d executes at least one of the control to decrease the supply amount of the paving material PV and the control to increase the passing amount of the paving material PV as described above. Thereafter, the paving material retention amount control unit 50d repeats the above-described process P2.

[0107] As described above, the controller 50 can align the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 with the distal end of the mold board 42.

[0108] Hereinafter, the operation of the asphalt finisher 100 as a road machine according to the present embodiment will be described while comparing it with the conventional asphalt finisher described in the above-described Patent Document 1.

[0109] In the conventional asphalt finisher described in the aforementioned Patent Document 1, the front ends of the left and right side plates that constitute the outer end of the widener extend forward from the front ends of the left and right wideners. Therefore, for example, at a bent portion of the construction range such as a curve of a road, the front end of the side plate may become an obstacle. Specifically, when the front end of the side plate arranged along the outer edge in the width direction of the road, which is the construction range, reaches the bent portion, it is necessary to contract the widener so that the front end of the side plate does not exceed the outer edge of the construction range. As a result, at the bent portion of the construction range, a range where the asphalt mixture cannot be spread evenly near the outer edge in the width direction of the construction range is generated.

[0110] On the other hand, as described above, the asphalt finisher 100 as a road machine according to the present embodiment includes the tractor 1, the hopper 2 installed in front of the tractor 1 to receive the paving material PV, and the conveyor CV that feeds the paving material PV in the hopper 2 to the rear of the tractor 1. Further, the asphalt finisher 100 includes a screw SC that spreads the paving material PV fed by the conveyor CV behind the tractor 1, and a screed 3 that is stretchable in the vehicle width direction and levels the paving material PV spread by the screw SC behind the screw SC. Furthermore, the asphalt finisher 100 includes a mold board 42 that is attached to the front portion of the screed 3 and adjusts the amount of the paving material PV staying in the front, and a side plate 41 that is attached to the distal end of the screed 3 and has a front end located on the side of the mold board 42.

[0111] With such a configuration, the asphalt finisher 100 as the road machinery of the present embodiment can spread the paving material PV over the entire road width up to the bent portion even when, for example, as shown in FIG. 2, the guide line GD as the boundary of the road to be constructed is bent. More specifically, in the example shown in FIG. 2, it is not necessary to contract the left rear screed 31L until the left mold board 42L located laterally of the tip of the left side plate 41L reaches the bent portion of the left guide line GDL. Thereby, the range where the paving material PV cannot be spread evenly in the vicinity of the bent portion of the left guide line GDL can be substantially eliminated. Therefore, according to the asphalt finisher 100 as the road machinery of the present embodiment, it is possible to suppress the side plate 41 attached to the distal end of the screed 3 from becoming an obstacle to construction at the bent portion or the like of the construction range, and to expand the range where the paving material PV can be laid. Further, since the side plate 41 does not have a portion protruding in front of the mold board 42, the degree of freedom in construction by the asphalt finisher 100 can be improved, and damage to the object AP outside the roadbed BS can be prevented.

[0112] Further, the asphalt finisher 100 as the road machinery of the present embodiment further includes a controller 50 as a control device. The controller 50 controls at least one of the conveyor CV, the screw SC, and the mold board 42 to align the outer edge PVE in the vehicle width direction of the paving material PV staying in front of the mold board 42 with the distal end of the mold board 42.

[0113] With such a configuration, the asphalt finisher 100 as the road machinery of the present embodiment can prevent, for example, as shown in FIG. 3, the paving material PV staying in front of the mold board 42 from spreading outward in the vehicle width direction beyond the front end 41a of the side plate 41. Thereby, in the side plate 41, the portion protruding in front of the mold board 42 can be eliminated, and the range where the paving material PV can be laid can be expanded.

[0114] Further, the asphalt finisher 100 as a road machine according to the present embodiment further includes a paving material detection device 44 that detects the position P_pve of the outer edge PVE of the paving material PV. Then, the controller 50 as a control device controls at least one of the supply amount of the paving material PV fed forward of the mold board 42 and the passing amount of the paving material PV passing below the mold board 42 based on the position P_mbd of the distal end of the mold board 42 and the position P_pve of the outer edge PVE of the paving material PV detected by the paving material detection device 44.

[0115] With such a configuration, the asphalt finisher 100 as a road machine according to the present embodiment can control the supply amount or the passing amount of the paving material PV by the controller 50 to align the outer edge PVE of the paving material PV with the distal end of the mold board 42. Thereby, in the side plate 41, the portion protruding in front of the mold board 42 can be eliminated, and the range where the paving material PV can be laid can be expanded.

[0116] Also, in the asphalt finisher 100 as a road machine according to the present embodiment, the paving material detection device 44 may detect the height of the paving material PV staying in front of the mold board 42.

[0117] With such a configuration, the asphalt finisher 100 as a road machine according to the present embodiment can more accurately grasp the state of the paving material PV staying in front of the mold board 42, which changes depending on the state such as the viscosity of the paving material PV. As a result, for example, the controller 50 can perform feedforward control to align the outer edge PVE of the paving material PV with the distal end of the mold board 42 regardless of the variation in the state of the paving material PV. Thereby, in the side plate 41, the portion protruding in front of the mold board 42 can be eliminated, and the range where the paving material PV can be laid can be expanded.

[0118] Further, in the asphalt finisher 100 as the road machine of the present embodiment, a controller 50 as a control device has a machine learning unit 50e. The machine learning unit 50e learns the relationship between the control amounts of the conveyor CV, the screw SC, and the mold board 42, the detection result of the paving material detection device 44, and the position of the outer edge PVE of the paving material PV. The learned machine learning unit 50e outputs the above control amounts for aligning the position P_pve of the outer edge PVE of the paving material PV with the position P_mbd of the distal end of the mold board 42 by inputting the detection result of the paving material detection device 44.

[0119] With such a configuration, the asphalt finisher 100 as the road machine of the present embodiment can align the outer edge PVE of the paving material PV with the distal end of the mold board 42 with higher accuracy by the controller 50. Thereby, in the side plate 41, the portion protruding forward of the mold board 42 can be eliminated, and the range in which the paving material PV can be laid can be expanded.

[0120] Further, in the asphalt finisher 100 as the road machine of the present embodiment, the controller 50 as a control device may control the distal end of the screw SC and the distal end of the mold board 42 at a predetermined interval.

[0121] With such a configuration, the asphalt finisher 100 as the road machine of the present embodiment can cope with fluctuations in the state of the paving material PV, fluctuations in the state of the construction target, speed changes of the tractor 1, and other disturbances, and more easily align the outer edge PVE of the paving material PV with the distal end of the mold board 42. Specifically, the interval between the distal end of the screw SC and the distal end of the mold board 42 can be made to act as a buffer against the above disturbances, and the deviation between the outer edge PVE of the paving material PV and the distal end of the mold board 42 can be suppressed. Also, it is possible to prevent the screw SC from colliding with the side plate 41.

[0122] As described above, according to the present embodiment, for example, it is possible to provide an asphalt finisher 100 as a road machine that suppresses the side plate 41 attached to the distal end of the screed 3 from becoming an obstacle to construction, such as a bent portion of the construction range, and can expand the laying range of the paving material PV.

[0123] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions can be applied to the above-described embodiments without departing from the scope of the present invention. Also, the features described separately can be combined as long as there is no technical contradiction.

[0124] For example, in the above-described embodiment, a road machine including a side plate attached to the distal end of the screed and having a front end located laterally of the mold board has been described. However, the present invention can also be applied to a road machine including a side plate having a front end located in front of the mold board.

[0125] That is, in the conventional asphalt finisher described in Patent Document 1 mentioned above, an operator needs to manually adjust the supply amount of the asphalt mixture fed from the hopper to the paved surface by the conveyor and the auger. Therefore, for example, if an inexperienced operator makes a mistake in adjusting the supply amount of the asphalt mixture, there is a risk that the asphalt mixture will spill out from the inside to the outside of the side plate.

[0126] On the other hand, the road machine according to the present disclosure includes a configuration having a control device that controls at least one of a conveyor, a screw, and a mold board to align the outer edge in the vehicle width direction of the paving material staying in front of the mold board with the distal end of the mold board. Thereby, the supply amount of the asphalt mixture can be maintained within an appropriate range, and it is possible to prevent the paving material from spilling out from the inside to the outside of the side plate.

[0127] In the above-described embodiment, an example in which the controller as the control device aligns the outer edge in the width direction of the paving material and the distal end of the mold board has been described. However, the outer edge in the width direction of the paving material and the distal end of the mold board may be aligned by manual operation of the operator.

Explanation of Signs

[0128] 1 Tractor 2 Hopper 3 Screed 41 Side Plate 42 Mold Board 44 Paving Material Detection Device 50 Controller (Control Device) 50e Machine Learning Unit 100 Asphalt Finisher (Road Machinery) CV Conveyor PV Paving Material PVE Outer Edge SC Screw

Claims

1. A tractor, a hopper installed in front of the tractor to receive paving materials, a conveyor for feeding the paving materials in the hopper to the rear of the tractor, a screw for spreading the paving materials fed by the conveyor at the rear of the tractor, a screed that can expand and contract in the vehicle width direction to level the paving materials spread by the screw at the rear of the screw, a moldboard attached to the front part of the screed to adjust the amount of the paving materials staying in front, and a side plate attached to the distal end of the screed with the front end located laterally of the moldboard. A road machine.

2. The road machine according to claim 1, further comprising a control device that controls at least one of the conveyor, the screw, and the moldboard to align the outer edge in the vehicle width direction of the paving materials staying in front of the moldboard with the distal end of the moldboard. The road machine according to claim 1.

3. The road machine further comprises a paving material detection device for detecting the position of the outer edge of the paving materials, wherein the control device controls at least one of the supply amount of the paving materials fed in front of the moldboard and the passing amount of the paving materials passing under the moldboard based on the position of the distal end of the moldboard and the position of the outer edge of the paving materials detected by the paving material detection device. The road machine according to claim 2.

4. The paving material detection device detects the height of the paving materials staying in front of the moldboard. The road machine according to claim 3.

5. The control device has a machine learning unit that learns the relationship between the control amounts of the conveyor, the screw, and the moldboard, the detection result of the paving material detection device, and the position of the outer edge of the paving materials. The learned machine learning unit outputs a control amount for aligning the position of the outer edge of the paving materials with the position of the distal end of the moldboard by inputting the detection result of the paving material detection device. The road machine according to claim 3 or claim 4.

6. The road machine according to claim 3, wherein the control device controls the distal end of the screw and the distal end of the moldboard to a predetermined interval.

Images