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, includes a tractor 1, a hopper 2, a conveyor CV, a screw SC, a screed 3, and a side plate 41. The hopper 2 is installed in front of the tractor 1 to receive a pavement material PV. The conveyor CV feeds the pavement material PV in the hopper 2 to the rear of the tractor 1. The screw SC lays and spreads the pavement material PV fed by the conveyor CV behind the tractor 1. The screed 3 is expandable and contractible in the vehicle width direction, and lays and levels the pavement material PV laid and spread by the screw SC behind the screw SC. The side plate 41 includes a turning shaft 41r along the up-down direction, and a side plate front end portion 41a provided so as to be rotatable about the turning shaft 41r from a position along the vehicle length direction toward the vehicle-width-direction inner side.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to road machinery.

Background Art

[0002] Conventionally, a screed device that finishes a paving surface smoothly and is used in road paving vehicles such as asphalt finishers is known (for example, Patent Document 1).

[0003] The screed device described in Patent Document 1 includes a screed that is towed by a main body to spread an asphalt heating mixture and finish the paving surface smoothly, and a pair of side plates that are provided on both sides of the screed so as to be openable and closable, and the paving width is expanded by opening.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the side plates of the conventional screed device described above open and close between a position extending in the traveling direction from both side portions of the screed and a position extending outward in the vehicle width direction from both side portions of the screed. Therefore, for example, at a bent portion of the construction range such as a curve of a road, there is a range where the side plate becomes an obstacle and the asphalt heating mixture cannot be spread evenly over the construction range.

[0006] The present disclosure provides a road machine capable of expanding the laying range of paving materials.

Means for Solving the Problems

[0007] 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, an extendable and retractable screed in the vehicle width direction for leveling the paving material spread by the screw to the rear of the screw, and a side plate attached to the distal end of the screed, wherein the side plate includes a rotation axis extending in the vertical direction and a front end portion of the side plate provided rotatably inward in the vehicle width direction from a position along the vehicle length direction around the rotation axis.

Advantages of the Invention

[0008] 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, for example, 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

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings.

[0011] 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.

[0012] 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 receive the supply of hydraulic oil from a hydraulic pump and rotate. However, the front wheels 6 may be driven wheels.

[0013] 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.

[0014] 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 fully open.

[0015] The dump truck is an example of a transport vehicle for transporting paving material PV. FIGS. 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.

[0016] 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.

[0017] In addition, in FIGS. 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.

[0018] 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 be expanded and contracted in the vehicle width direction, and includes a left rear screed 31L and a right rear screed 31R.

[0019] 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. And 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.

[0020] 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. An end leveling device may be disposed at the end of the rear screed 31.

[0021] 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. The side plate 41 is arranged, for example, along a guide line GD as a boundary of the road to be constructed, and prevents the paving material PV spread by the screw SC from spreading in the vehicle width direction beyond the guide line GD.

[0022] A footboard 32 is attached behind the screed 3. Specifically, the footboard 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 footboard 32 includes a central footboard 32C attached behind the front screed 30, a left footboard 32L attached behind the left rear screed 31L, and a right footboard 32R attached behind the right rear screed 31R.

[0023] A mold board 42 is attached to the front of the screed 3. The mold board 42 is configured to be able to adjust the amount of the paving material PV staying in front of the screed 3. The mold board 42 is configured to be expandable and contractible in the vehicle width direction as the screed 3 expands and contracts, for example. The paving material PV reaches under the screed 3 through a 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.

[0024] 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.

[0025] FIG. 3 is a schematic enlarged view of the side plate 41 in the asphalt finisher 100 shown in FIG. 2. In FIG. 3, among the pair of side plates 41 attached to the left and right distal ends of the screed 3 that can expand and contract in the vehicle width direction (Y-axis direction) shown in FIG. 2, the left side plate 41L attached to the left end of the left rear screed 31L is shown enlarged. Here, the distal end of the screed 3 means the left end of the left rear screed 31L and the right end of the right rear screed 31R that are separated from the front screed 30 in the vehicle width direction respectively.

[0026] The right side plate 41R attached to the right end of the right rear 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.

[0027] The left side plate 41L includes a rotation axis 41r along the vertical direction (Z-axis direction), and a side plate front end portion 41a provided so as to be rotatable inward in the vehicle width direction from a position along the vehicle length direction (X-axis direction) around the rotation axis 41r. Further, the left side plate 41L includes, for example, a side plate rear end portion 41p fixed to the distal end of the left rear screed 31L. Also, although not shown in FIG. 3, the asphalt finisher 100 is provided with, for example, a side plate rotation mechanism 55 (see FIG. 4) for rotating the side plate front end portion 41a.

[0028] The pivot shaft 41r is attached to the front end of the distal end of the screed 3, for example, as shown in FIGS. 2 and 3. Specifically, the pivot shaft 41r is attached to the front end of the left end of the left rear screed 31L and the front end of the right end of the right rear screed 31R, respectively. The pivot shaft 41r is fixed to the left and right distal ends of the screed 3, respectively, and rotatably supports the front ends 41a of the respective side plates of the left side plate 41L and the right side plate 41R around the vertical rotation axis.

[0029] In addition, the pair of pivot shafts 41r provided at the left and right distal ends of the screed 3 may be provided on the same straight line parallel to the vehicle width direction with their positions in the vehicle length direction aligned. Specifically, in the example shown in FIG. 2, the pivot shaft 41r provided at the right end of the right rear screed 31R is provided on the right side plate 41R in front of the right rear screed 31R, and the position in the vehicle length direction may be aligned with the pivot shaft 41r provided at the left end of the left rear screed 31L. Further, the pivot shaft 41r for rotating the front end 41a of the side plate of the left side plate 41L may be provided on the left side plate 41L in front of the left rear screed 31L.

[0030] The front end 41a of the side plate is rotated within a predetermined angle range α from the position along the vehicle length direction (X-axis direction) to the inside in the vehicle width direction by a side plate rotation mechanism 55 (see FIG. 4), which is not shown in FIG. 3, for example. Specifically, the front end 41a of the side plate rotates within an angle range α that does not contact the distal end of the screw SC, for example. More specifically, the side plate rotation mechanism 55 can set the rotatable angle range α of the front end 41a of the side plate, for example. Further, the mold board 42 can be adjusted to expand and contract in the vehicle width direction within a range that can prevent contact between the front end 41a of the side plate and the screw SC.

[0031] The front end portion 41a of the side plate is pivotally connected to, for example, the distal end of the mold board 42. In the example shown in FIG. 3, the front end portion 41a of the side plate of the left side plate 41L is pivotally connected to the distal end of the mold board 42 via, for example, a pivot connection portion 42a. The pivot connection portion 42a is constituted by, for example, a hinge or a ball joint, etc., and allows the front end portion 41a of the side plate to pivot with respect to the mold board 42.

[0032] Further, the front end portion 41a of the side plate is pivotally provided, for example, about a pivot axis 41r from a position along the vehicle length direction to the outside in the vehicle width direction. The front end portion 41a of the side plate is pivoted, for example, by a side plate pivoting mechanism 55 (see FIG. 4), which is not shown in FIG. 3, from a position along the vehicle length direction to the outside in the vehicle width direction within a predetermined angle range β. Specifically, the angle range β of the front end portion 41a of the side plate is set within a range that the mold board 42 connected to the front end portion 41a of the side plate via the pivot connection portion 42a can follow.

[0033] Note that the front end portion 41a of the side plate and the distal end of the mold board 42 may not be connected and may be separated from each other. In this case, the front end portion 41a of the side plate can be pivoted, for example, from a position along the vehicle length direction to the outside in the vehicle width direction within an angle range β of approximately 90°. Also, in order to ensure the rigidity of the mold board 42, the mold board 42 and the rear screen 31 may be connected by a support beam.

[0034] The rear end portion 41p of the side plate is attached to, for example, the distal end of the screen 3. Specifically, the rear end portion 41p of the side plate of the left side plate 41L is fixed to the left end of the left rear screen 31L. The rear end portion 41p of the side plate is arranged along the vehicle length direction, and when the front end portion 41a of the side plate is at a position along the vehicle length direction, it is aligned in a straight line with the front end portion 41a of the side plate in the vehicle length direction, that is, in the front - rear direction.

[0035] As shown in FIGS. 1 and 2, a traveling speed sensor S1, a controller 50, an object detection device 51, an in-vehicle display device 52, a steering device 53, and a screed 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 wheels 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, and the like. 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 be realized not only 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 ground objects 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 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 wheels 6, a range located in front of the axle of the rear wheels 5, a range located in front of the screw SC, and the like.

[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 gutter 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 about ground features within a predetermined range regardless of day or night, that is, without the need for 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, even if the position of the object AP changes in the vehicle width direction, the controller 50 can ensure that the object AP is continuously included within the monitoring range of the object detection device 51.

[0051] The mounting member 60 may be provided with at least one of a sensor that detects the amount of expansion and contraction of the telescopic member TA and a sensor that detects 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] In addition, the asphalt finisher 100 may be equipped 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 and right ends 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 (handle) 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 control a pair of left and right crawlers separately. 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 hydraulic oil flowing from a hydraulic pump to a left traveling hydraulic motor for rotating the left crawler, and a right steering electromagnetic control valve that controls the flow rate of hydraulic oil flowing from the hydraulic pump to a 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 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 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 in accordance with a 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 in accordance with a 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 a 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 hydraulic oil flowing from a hydraulic pump to the screed expansion and contraction cylinder 7 and the flow rate of 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 in response to the operation of an expansion and contraction button set (not shown) as an operating 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 in accordance with an 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 the 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 the 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 the 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 the 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 the hydraulic oil in the left screed telescoping cylinder 7L according to the telescoping command from the controller 50, regardless of whether the driver operates the left telescoping button set. Similarly, the right telescoping electromagnetic control valve may be configured to be able to control the inflow and outflow of the hydraulic oil in the right screed telescoping cylinder 7R according to the telescoping command from the controller 50, regardless of whether the driver operates the right telescoping button set.

[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, an angle detection device 44, and a position and attitude detection device 56. 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, and a side plate rotation mechanism 55.

[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 / contraction control unit 50c, and a rotation control unit 50d. Each part of these controllers 50 represents each function of the controller 50 realized by the CPU executing a program stored in a non-volatile memory device, for example. Also, 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 objects 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 the surface on which the end faces in the width direction of the paving body to be laid should be made to 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 the surface on which the left end face of the newly laid paving body NP should be made to coincide, and a right guide line GDR indicating the right guide surface, which is the surface on which the right end face of the newly laid paving body NP should be made to 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 constituting 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 constituting 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 each of the point VL and the point VR. In the example shown in the figure, the coordinate calculation unit 50a is configured to calculate and store the coordinates of each of the point VL and the point VR every 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 each of the point VL and the point VR every 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 each of points VL1 to VL4.

[0072] Similar to Figure 1, Figure 2 also shows how the coordinate calculation unit 50a intermittently calculates and stores the coordinates of point VL and point VR. 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 screeds 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 screeds 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 side plate front end 41a) 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 at the closest position in front of a predetermined part (for example, the left front end point of the side plate front end 41a) 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 portion of the right rear screed 31R (for example, the right front end point of the side plate front end portion 41a) 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 portion of the right rear screed 31R (for example, the right front end point of the side plate front end portion 41a). 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, in each of the left rear screed 31L and the right rear screed 31R, the coordinates of a predetermined portion of the rear screed 31, such as the coordinates of the left front end point and the right front end point of the side plate front end portion 41a, 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 the left front end point and the right front end point of the side plate front end portion 41a of the left rear screed 31L and the side plate front end portion 41a of the right rear screed 31R with respect to the position of the reference point for each of them 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, the steering angle sensor, and the like. Therefore, the coordinate calculation unit 50a can calculate the relative position of each of the point VL, the point VR, the left front end point of the side plate front end portion 41a of the left rear screed 31L, and the right front end point of the side plate front end portion 41a of the right rear screed 31R with respect to the position of the reference point at other time points with respect to the position of the reference point at the first time point.

[0081] The rotation control unit 50d controls the side plate rotation mechanism 55 so that, for example, for each of the left side plate 41L and the right side plate 41R, the orientation of the front end portion 41a of the side plate is aligned with the guide line GD as the boundary of the construction range where the paving material PV is to be laid.

[0082] Specifically, the rotation control unit 50d acquires, for example, the coordinates of the points VL and VR on the guide line GD calculated by the coordinate calculation unit 50a. Also, the rotation control unit 50d acquires, for example, for the front end portions 41a of each of the left side plate 41L and the right side plate 41R, the coordinates of the left front end point and the right front end point calculated by the coordinate calculation unit 50a.

[0083] Furthermore, the rotation control unit 50d controls the side plate rotation mechanism 55 so that, for example, the coordinates of the left front end point and the right front end point are aligned with the points VL of the left guide line GDL and the point VR of the right guide line GDR, respectively. The side plate rotation mechanism 55 rotates the front end portions 41a of each of the left side plate 41L and the right side plate 41R under the control of the rotation control unit 50d.

[0084] Also, the rotation control unit 50d may acquire, for example, the construction information including the coordinates of the boundary of the construction range stored in advance in the non-volatile storage device of the controller 50, and the dimensional information of each part of the asphalt finisher 100. Also, the rotation control unit 50d may acquire, for example, the position and orientation information of the asphalt finisher 100 detected by the position and orientation detection device 56, and the angle of the front end portion 41a of the side plate with respect to the vehicle length direction (X-axis direction) detected by the angle detection device 44.

[0085] In this case, the rotation control unit 50d can control the orientation of the front end portion 41a of the side plate based on, for example, the acquired construction information, dimensional information, position and orientation information, and the angle of the front end portion 41a of the side plate. Specifically, the rotation control unit 50d controls the side plate rotation mechanism 55 so as to align the orientation of the front end portion 41a of the side plate with the guide line GD as the boundary of the construction range where the paving material PV is to be laid, based on, for example, the above-mentioned various information.

[0086] The angle detection device 44 is constituted by, for example, a rotary encoder, resolver, potentiometer, stroke sensor, etc., and detects the rotation angles α, β (see FIG. 3) of the front end portion 41a of the side plate with respect to the vehicle length direction of the asphalt finisher 100, and outputs the detected angles to the controller 50.

[0087] The position and orientation detection device 56 is mounted on, for example, the asphalt finisher 100 and detects the position and orientation information of the asphalt finisher 100. The position and orientation detection device 56 is, for example, a GNSS compass using a global navigation satellite system, and detects the position information of the asphalt finisher 100 in a coordinate system such as the ITRF coordinate system or WGS84 coordinate system and the position and orientation information including the azimuth in the vehicle length direction, and outputs the detected information to the controller 50.

[0088] The side plate rotation mechanism 55 is constituted by, for example, a motor and a speed reducer, or a hydraulic cylinder and a link mechanism. The side plate rotation mechanism 55 rotates the front end portion 41a of the side plate at a predetermined angle around the rotation axis 41r along the vertical direction of the asphalt finisher 100 from the position facing forward along the vehicle length direction, under the control of the rotation control unit 50d of the controller 50.

[0089] The side plate rotation mechanism 55 is attached to, for example, at least one of the distal end of the rear side screed 31 and the side plate 41. The side plate rotation mechanism 55 rotates, for example, the front end portion 41a of the side plate in the vehicle width direction inward and outward from the position facing forward along the vehicle length direction. In this case, the side plate rotation mechanism 55 can include, for example, one hydraulic cylinder disposed inside or outside the side plate 41, or two hydraulic cylinders respectively disposed inside and outside the side plate 41.

[0090] FIG. 5 is a flowchart for explaining the operation of the rotation control unit 50d of the controller 50. In the illustrated example, when construction is started, the controller 50 starts the processing flow of angle control of the front end portion 41a of the side plate shown in FIG. 6. 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.

[0091] More specifically, when the pressure of the hydraulic oil in the rod side oil chamber of the lift cylinder 8 falls below a predetermined value, 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 construction has started. Note that the controller 50 may determine that construction has started by any other arbitrary method. Further, the controller 50 may be configured to start the processing flow of angle control of the front end portion 41a of the side plate at another timing.

[0092] When the rotation control unit 50d starts the processing flow shown in FIG. 5, for example, it acquires the coordinates of the points VL and VR on the guide line GD, the coordinates of the left front end point of the left side plate 41L, and the coordinates of the right front end point of the right side plate 41R (processing P1). Also, in this processing P1, the rotation control unit 50d may acquire, for example, the aforementioned construction information, dimension information, position and attitude information, and the angle of the front end portion 41a of the side plate.

[0093] FIG. 6 is a schematic enlarged view showing an enlarged view of the right side plate 41R of the asphalt finisher 100 shown in FIG. 2 and the bent portion of the roadbed BS which is the construction range. Hereinafter, the right side plate 41R will be described. Regarding the left side plate 41L, since it is the same as the right side plate 41R, the description will be omitted.

[0094] The left, center, and right views in FIG. 6 respectively show the positional relationship between the front end portion 41a of the side plate and the bent portion BP of the roadbed BS which is the construction range at times t = t1, t2, and t3. Time t2 is the time when a predetermined time has elapsed from time t1, and time t3 is the time when a predetermined time has elapsed from time t2. Further, in FIG. 6, the roadbed BS which is the construction range is shown by diagonal hatching, and the construction direction Dpv of the asphalt finisher 100 is shown by an arrow.

[0095] After the end of the above-described process P1, the rotation control unit 50d determines, for example, as shown in FIG. 5, whether or not the direction of the boundary of the construction range has changed (process P2). In the example shown in FIG. 6, the asphalt finisher 100 aligns the right front end point Pfr of the front end portion 41a of the right side plate 41R with the right guide line GDR as the boundary of the roadbed BS which is the construction range shown by the broken line, and lays the paving material PV on the roadbed BS while moving in the construction direction Dpv.

[0096] At time t1, the direction of the right guide line GDR on the front side of the right front end point Pfr of the front end portion 41a of the side plate is the same as the direction of the right guide line GDR on the rear side of the right front end point Pfr. In this case, the rotation control unit 50d determines in process P2 shown in FIG. 5 that the direction of the boundary of the construction range has not changed (NO), and executes the end determination process P4 described later without executing the process P3 of rotating the front end portion 41a of the side plate.

[0097] After the elapse of time t1, the right front end point Pfr of the front end portion 41a of the side plate moves on the right guide line GDR and reaches the bent portion BP of the right guide line GDR. In this case, the direction of the right guide line GDR changes on the front side and the rear side of the right front end point Pfr of the front end portion 41a of the side plate. Therefore, in the process P2 shown in FIG. 5, the rotation control unit 50d determines that the direction of the boundary of the construction range has changed (YES), and executes the process P3 of rotating the front end portion 41a of the side plate.

[0098] In this process P3, the rotation control unit 50d controls, for example, the side plate rotation mechanism 55 to rotate the front end portion 41a of the side plate, and aligns the orientation of the front end portion 41a of the side plate with the orientation of the right guide line GDR on the front side of the right front end point Pfr.

[0099] Specifically, the rotation control unit 50d calculates, for example, the rotation direction and rotation angle of the front end portion 41a of the side plate so that the coordinates of the right front end point Pfr of the front end portion 41a of the side plate acquired from the coordinate calculation unit 50a match the coordinates of the point VR on the right guide line GDR. Further, the rotation control unit 50d may calculate, for example, the rotation direction and rotation angle for aligning the orientation of the front end portion 41a of the side plate with the orientation of the right guide line GDR based on the construction information, position and attitude information, and information such as the rotation angle acquired as described above. Furthermore, the rotation control unit 50d outputs a control command to the side plate rotation mechanism 55 so as to rotate the front end portion 41a of the side plate at the calculated direction and angle.

[0100] As a result, after the right front end point Pfr of the front end portion 41a of the side plate reaches the bent portion BP, the front end portion 41a of the side plate rotates inward in the vehicle width direction from the position facing the front in the construction direction Dpv along the vehicle length direction. Thereafter, the rotation control unit 50d increases, for example, the rotation angle of the front end portion 41a of the side plate so as to move the right front end point Pfr on the right guide line GDR (time t2). As a result, at time t3, the orientation of the front end portion 41a of the side plate becomes substantially equal to the orientation of the right guide line GDR on the front side of the bent portion BP, and the front end portion 41a of the side plate and the right guide line GDR become substantially parallel to each other.

[0101] After that, the rotation control unit 50d executes the end determination process P4 shown in FIG. 5. In this process P4, for example, when an operation to stop the construction is performed by the driver or the operator, the rotation control unit 50d determines the end (YES) of the construction and ends the processing flow shown in FIG. 5. On the other hand, for example, when an operation to end the construction has not been performed by the driver or the operator, the rotation control unit 50d determines that the construction has not ended (NO) and repeats the above-described process P1.

[0102] After the elapse of the time t3 shown in FIG. 6, while the right rear screed 31R is contracted by the screed expansion / contraction control unit 50c, the tractor 1 is moved forward, so that the side plate front end portion 41a of the right side plate 41R moves along the right guide line GDR. As a result, for example, on the roadbed BS that is one step lower than the area outside the guide line GD that is the boundary of the construction range, the paving material PV can be sufficiently spread evenly up to the vicinity of the bent portion BP of the right guide line GDR.

[0103] FIG. 7 is an enlarged view showing a modified example of FIG. 6. In FIG. 6, the right side plate 41R is moved along the inside of the right guide line GDR, but in FIG. 7, the right side plate 41R is moved along the outside of the right guide line GDR. More specifically, in FIG. 6, the right front end point Pfr of the side plate front end portion 41a of the right side plate 41R is arranged on the right guide line GDR and moved along the right guide line GDR.

[0104] On the other hand, in FIG. 7, the left front end point Pfl of the side plate front end portion 41a of the right side plate 41R is arranged on the right guide line GDR and moved along the right guide line GDR. Also in this modified example, while preventing the paving material PV from protruding outside the roadbed BS that is the construction range, the paving material PV can be sufficiently spread evenly up to the vicinity of the bent portion BP of the right guide line GDR.

[0105] Next, while comparing with a conventional asphalt finisher having the same configuration as the conventional asphalt finisher described in the above-mentioned Patent Document 1, the operation of the asphalt finisher 100 as a road machine according to the present embodiment will be described.

[0106] FIG. 8 and FIG. 9 are respectively schematic enlarged views of a conventional asphalt finisher corresponding to FIGS. 6 and 7 of the asphalt finisher 100 according to the present embodiment. The conventional asphalt finisher is different from the asphalt finisher 100 according to the present embodiment in that it does not have a front end portion 41a of a side plate that is rotatably provided from a position along the vehicle length direction to the inside in the vehicle width direction.

[0107] As shown in FIG. 8, for example, at time t1, the conventional asphalt finisher arranges the side plate 41 inside the roadbed BS along the right guide line GDR and moves it in the construction direction Dpv. After that, when the right front end point Pfr of the side plate 41 reaches the bent portion BP of the right guide line GDR, by advancing the tractor 1 while contracting the right rear screed 31R, the right front end point Pfr can be moved along the right guide line GDR at times t2 and t3.

[0108] However, as described above, the conventional asphalt finisher does not have a front end portion 41a of a side plate that is rotatably provided from a position along the vehicle length direction to the inside in the vehicle width direction. Therefore, when the right rear screed 31R is contracted at times t2 and t3, a non-constructible area UR where the paving material PV cannot be spread evenly expands in the vicinity of the bent portion BP of the right guide line GDR.

[0109] Also, as shown in FIG. 9, in the asphalt finisher of the conventional example, for example, at time t1, the side plate 41 is arranged outside the roadbed BS along the right guide line GDR and moved in the construction direction Dpv. After that, at times t2 and t3, even if the left front end point Pfl of the side plate 41 crosses the bent portion BP of the right guide line GDR, the side plate 41 is still moved in the construction direction Dpv to spread the paving material PV up to the vicinity of the bent portion BP.

[0110] However, the asphalt finisher of this conventional example does not have a side plate front end portion 41a that is rotatable from a position along the vehicle length direction to the inside in the vehicle width direction as described above. Therefore, for example, at time t3, as shown by the dark dot hatching, the amount of the paving material PV that protrudes outside beyond the right guide line GDR, which is the boundary of the roadbed BS as the construction range, increases.

[0111] On the other hand, the asphalt finisher 100 as the road machine of the present embodiment includes, as described above, a tractor 1, a hopper 2 installed in front of the tractor 1 to receive the paving material PV, and a conveyor CV that feeds the paving material PV in the hopper 2 to the rear of the tractor 1. The asphalt finisher 100 further includes a screed SC that spreads the paving material PV fed by the conveyor CV behind the tractor 1, and a screed 3 that is expandable and contractible in the vehicle width direction to level the paving material PV spread by the screed SC behind the screed SC. Furthermore, the asphalt finisher 100 includes a side plate 41 attached to the distal end of the screed 3. The side plate 41 includes a rotation axis 41r along the vertical direction and a side plate front end portion 41a that is rotatable from a position along the vehicle length direction to the inside in the vehicle width direction around the rotation axis 41r.

[0112] With such a configuration, the asphalt finisher 100 as the road machine of the present embodiment can evenly spread the paving material PV up to the vicinity of the bent portion BP even when, for example, as shown in FIGS. 6 and 7, the guide line GD as the boundary of the road to be constructed bends inward in the vehicle width direction. More specifically, for example, as shown in FIGS. 6 and 7, the front end portion 41a of the side plate can be rotated inward in the vehicle width direction about the rotation shaft 41r so that the right front end point Pfr or the left front end point Pfl of the front end portion 41a of the side plate moves along the guide line GD. As a result, the paving material PV can be evenly spread up to the vicinity of the bent portion BP of the guide line GD that bends inward in the vehicle width direction. Therefore, according to the asphalt finisher 100 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 in the bent portion of the roadbed BS, which is the construction range, and to expand the range where the paving material PV can be laid.

[0113] Further, in the asphalt finisher 100 as the road machine of the present embodiment, the rotation shaft 41r is provided at the distal end of the screed 3.

[0114] With such a configuration, the asphalt finisher 100 of the present embodiment can bend the side plate 41 at the position of the screed 3 by rotating the front end portion 41a of the side plate about the rotation shaft 41r. Therefore, compared with the case where the rotation shaft 41r is provided at the distal end of the mold board 42, the length of the rotatable front end portion 41a of the side plate can be ensured. Therefore, it is possible to more effectively suppress the front end portion 41a of the side plate from becoming an obstacle to construction in the bent portion of the roadbed BS, which is the construction range, and to further expand the range where the paving material PV can be laid.

[0115] Further, the asphalt finisher 100 as a road machine according to the present embodiment further includes a mold board 42 that is attached to the front portion of the screed 3 and is expandable and contractible in the vehicle width direction to adjust the amount of paving material PV staying forward. And the front end portion 41a of the side plate is rotatably connected to the distal end of the mold board 42.

[0116] With such a configuration, the asphalt finisher 100 as a road machine according to the present embodiment can expand and contract the mold board 42 according to the rotation of the front end portion 41a of the side plate. Also, a gap is prevented from being formed between the front end portion 41a of the side plate and the mold board 42. Therefore, the amount of paving material PV staying inside the front end portion 41a of the side plate in the vehicle width direction can be adjusted more reliably by the mold board 42.

[0117] Also, in the asphalt finisher 100 as a road machine according to the present embodiment, the front end portion 41a of the side plate is provided so as to be rotatable outward in the vehicle width direction.

[0118] With such a configuration, the asphalt finisher 100 as a road machine according to the present embodiment can align the direction of the front end portion 41a of the side plate with the direction of the guide line GD even when the guide line GD, which is the boundary of the roadbed BS as the construction range, bends outward in the vehicle width direction. As a result, the paving material PV can be sufficiently spread evenly up to the vicinity of the bent portion of the guide line GD that bends outward in the vehicle width direction. Therefore, according to the asphalt finisher 100 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 in the bent portion of the roadbed BS, which is the construction range, and to expand the range where the paving material PV can be laid.

[0119] Further, the asphalt finisher 100 as a road machine according to the present embodiment further includes a side plate rotation mechanism 55 that rotates the front end portion 41a of the side plate, and a controller 50 as a control device that controls the side plate rotation mechanism 55. The controller 50 controls the side plate rotation mechanism 55 so that the orientation of the front end portion 41a of the side plate matches the guide line GD that is the boundary of the roadbed BS, which is the construction range where the paving material PV is laid.

[0120] With such a configuration, the asphalt finisher 100 according to the present embodiment can automatically align the orientation of the front end portion 41a of the side plate with the guide line GD that is the boundary of the construction range by controlling the side plate rotation mechanism 55 with the controller 50.

[0121] 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 in, for example, a bent portion of the construction range, and can expand the layable range of the paving material PV.

[0122] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions etc. 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.

Explanation of Signs

[0123] 1 Tractor 2 Hopper 3 Screed 41 Side plate 41a Front end portion of side plate 41r Rotation shaft 42 Mold board 50 Controller (control device) 55 Side plate rotation mechanism 100 Asphalt finisher (road machinery) BS roadbed (construction area) CV conveyor GD guide line (boundary) GDR right guide line (boundary) GDL left guide line (boundary) PV paving material SC screw

Claims

1. A tractor, a hopper installed in front of the tractor for receiving 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 to the rear of the tractor, a screed that is expandable and contractible in the vehicle width direction for leveling the paving materials spread by the screw to the rear of the screw, and a side plate attached to the distal end of the screed, wherein the side plate includes a rotation axis along the vertical direction and a front end portion of the side plate that is rotatably provided inward in the vehicle width direction from a position along the vehicle length direction around the rotation axis, a road machine.

2. The rotation axis is provided at the distal end of the screed, The road machine according to Claim 1.

3. The road machine further includes a mold board that is attached to the front portion of the screed and is expandable and contractible in the vehicle width direction for adjusting the amount of the paving materials staying in the front, wherein the front end portion of the side plate is rotatably connected to the distal end of the mold board, The road machine according to Claim 2.

4. The front end portion of the side plate is rotatably provided outward in the vehicle width direction, The road machine according to Claim 1.

5. A side plate rotation mechanism for rotating the front end portion of the side plate, and a control device for controlling the side plate rotation mechanism so that the orientation of the front end portion of the side plate is aligned with the boundary of the construction range where the paving materials are laid, The road machine according to any one of Claims 1 to 4.

Images