Road paving machine

Abstract

Provided is a road paving machine (100) capable of expanding a range in which a paving material (PV) can be laid. A road paving machine (100) is an asphalt finisher (100) including 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) and receives a paving material (PV). The conveyor (CV) feeds the paving material (PV) in the hopper (2) behind the tractor (1). The screw (SC) spreads the paving material (PV) fed by the conveyor (CV) behind the tractor (1). The screed (3) is configured to expand and contract in a vehicle width direction, and levels the paving material (PV) spread by the screw (SC) behind the screw (SC). The side plate 41 includes a pivoting shaft (41r) along an up-down direction, and a side plate front end portion (41a) provided to pivot inward in the vehicle width direction from a position along a vehicle length direction with the pivoting shaft (41r) as a center.

Description

BACKGROUND OF THE INVENTIONField of the Invention

[0001] The present disclosure relates to a road paving machine.Description of Related Art

[0002] In the related art, a screed device used for a road paving vehicle such as an asphalt finisher, and that smooths a paving surface is known (for example, Japanese Patent No. 3218301).

[0003] The screed device described in Japanese Patent No. 3218301 includes a screed that is towed by a main body to level an asphalt heating mixture and to finish a paving surface to be smooth, and a pair of side plates provided on both side portions of the screed to be openable and closable, and that expands a paving width by being opened.SUMMARY OF THE INVENTION

[0004] However, the side plate of the screed device in the related art is opened and closed between a position extending from both side portions of the screed in the traveling direction and a position extending from both side portions of the screed toward the outside in the vehicle width direction. Therefore, for example, in a bending portion of the construction range such as a curve of a road, the side plate is an obstacle, so that a range in which the asphalt heating mixture is not leveled in the construction range is generated.

[0005] The present disclosure provides a road paving machine capable of expanding a range in which a paving material can be laid.

[0006] According to an embodiment of the present disclosure, there is provided a road paving machine including a tractor, a hopper installed in front of the tractor, and that receives a paving material, a conveyor that feeds the paving material in the hopper behind the tractor, a screw that spreads the paving material fed by the conveyor behind the tractor, a screed configured to expand and contract in a vehicle width direction where the paving material spread by the screw is leveled behind the screw, and a side plate attached to a distal end of the screed, in which the side plate includes a pivoting shaft along an up-down direction, and a side plate front end portion provided to pivot inward in the vehicle width direction from a position along a vehicle length direction with the pivoting shaft as a center.

[0007] According to the above aspect of the present disclosure, for example, it is possible to provide a road paving machine capable of suppressing an obstacle to construction caused by a side plate attached to a distal end of a screed in a bending portion in a construction range and expanding a range in which a paving material can be laid.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a side view of an asphalt finisher. Fig. 2 is a top view of the asphalt finisher. Fig. 3 is an enlarged view of a side plate front end portion of the asphalt finisher. Fig. 4 is a diagram illustrating a configuration example of a control system of the asphalt finisher. Fig. 5 is a flowchart illustrating an operation of a pivoting control unit illustrated in Fig. 4. Fig. 6 is an enlarged view of a right side plate of the asphalt finisher illustrated in Fig. 2. Fig. 7 is an enlarged view of a right side plate of the asphalt finisher illustrated in Fig. 2. Fig. 8 is an enlarged view corresponding to Fig. 6 of an asphalt finisher in the related art. Fig. 9 is an enlarged view corresponding to Fig. 7 of the asphalt finisher in the related art. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment for performing the invention will be described with reference to the drawings.

[0010] Fig. 1 is a side view of an asphalt finisher 100 that is an example of a road paving 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, a direction of the hopper 2 viewed from the tractor 1 (+X direction) will be referred to as the front, and a direction of the screed 3 viewed from the tractor 1 (-X direction) will be referred to as the rear.

[0011] The tractor 1 is a mechanism for moving the asphalt finisher 100. In the illustrated example, the tractor 1 rotates a rear wheel 5 using a rear wheel traveling hydraulic motor and moves the asphalt finisher 100 by rotating a front wheel 6 using a front wheel traveling hydraulic motor. The rear wheel traveling hydraulic motor and the front wheel traveling hydraulic motor rotate by receiving a supply of hydraulic oil from a hydraulic pump. However, the front wheel 6 may be a driven wheel.

[0012] The asphalt finisher 100 may be a crawler type asphalt finisher. In this case, the combination of the rear wheel 5 and the front wheel 6 is replaced with the combination of the left crawler and the right crawler.

[0013] The hopper 2 is a mechanism for receiving a paving material PV. In the illustrated example, the hopper 2 is installed in front of the tractor 1 and is configured to be opened and closed in a 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 a loading platform of a dump truck when the hopper 2 is in a fully open state.

[0014] The dump truck is an example of a transport vehicle that transports the paving material PV. Figs. 1 and 2 illustrate that the hopper 2 is in a fully open state. When the paving material PV in the hopper 2 decreases during construction, an operator of the asphalt finisher 100 closes the hopper 2 and collects the paving material PV near an inner wall of the hopper 2 at a central portion of the hopper 2. This is to enable a conveyor CV which is at the central portion of the hopper 2 to feed the paving material PV behind the tractor 1.

[0015] The paving material PV fed behind the tractor 1 by the conveyor CV is spread in the vehicle width direction at the rear of 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 a left extension screw SCL and a right extension screw SCR are connected to each other.

[0016] For the sake of clarity, Figs. 1 and 2 omit to illustrate the paving material PV in the hopper 2. In addition, the paving material PV spread by the screw SC is illustrated by a coarse dot pattern, and the newly constructed pavement body NP leveled by the screed 3 is illustrated by a fine dot pattern.

[0017] 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 is capable of expanding and contracting in the vehicle width direction and includes a left rear screed 31L and a right rear screed 31R.

[0018] Specifically, the rear screed 31 is expanded and contracted by a screed expanding and contracting cylinder 7 installed in the screed 3. More specifically, the screed expanding and contracting cylinder 7 includes a left screed expanding and contracting cylinder 7L and a right screed expanding and contracting cylinder 7R. The left rear screed 31L is expanded and contracted by the left screed expanding and contracting cylinder 7L, and the right rear screed 31R is expanded and contracted by the right screed expanding and contracting cylinder 7R.

[0019] In addition, 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 a left side of the tractor 1 and a right leveling arm 3AR disposed on a right side of the tractor 1. An end portion leveling device may be disposed at an end portion of the rear screed 31.

[0020] A side plate 41 is attached to a distal end of the rear screed 31. In the illustrated example, a left side plate 41L is attached to a left end of the left rear screed 31L, and a right side plate 41R is attached to a right end of the right rear screed 31R. For example, the side plate 41 is disposed along a guideline GD as a boundary of a road which is a construction target, and prevents the paving material PV paved by the screw SC from spreading in the vehicle width direction beyond the guideline GD.

[0021] A tread plate 32 is attached behind the screed 3. Specifically, the tread plate 32 is attached behind the screed 3 such that a worker at the rear of the screed 3 can move back and forth in the vehicle width direction without stepping on the newly constructed pavement body NP. In the illustrated example, the tread plate 32 includes a central 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.

[0022] A moldboard 42 is attached to a front portion of the screed 3. The moldboard 42 is configured to be capable of adjusting the amount of the paving material PV staying in front of the screed 3. For example, the moldboard 42 is configured to be expandable and contractible in the vehicle width direction in association with the expansion and contraction of the screed 3. The paving material PV reaches under the screed 3 through a gap between a lower end of the moldboard 42 and a roadbed BS. In the illustrated example, the moldboard 42 includes a left moldboard 42L disposed in front of the left rear screed 31L and a right moldboard 42R disposed in front of the right rear screed 31R.

[0023] The screw SC is disposed in front of the moldboard 42, and a retaining plate 43 is disposed in front of the screw SC. Specifically, the retaining plate 43 includes a left retaining plate 43L disposed in front of the left extension screw SCL and a right retaining plate 43R disposed in front of the right extension screw SCR. The retaining plate 43 may be omitted.

[0024] Fig. 3 is a schematic enlarged view of the side plate 41 in the asphalt finisher 100 illustrated in Fig. 2. In Fig. 3, the left side plate 41L attached to the left end of the left rear screed 31L is enlarged and illustrated among a pair of side plates 41 attached to distal ends on the right and left of the screed 3 that is expandable and contractible in the vehicle width direction (Y-axis direction) illustrated in Fig. 2. Here, the distal end of the screed 3 means a left end of the left rear screed 31L and a right end of the right rear screed 31R, which are each separated from the front screed 30 in the vehicle width direction.

[0025] The right side plate 41R attached to the right end of the right rear screed 31R also has the same configuration as that of the left side plate 41L illustrated 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 appropriately omitted.

[0026] The left side plate 41L includes a pivoting shaft 41r along the up-down direction (Z-axis direction), and a side plate front end portion 41a provided to pivot inward in the vehicle width direction from a position along the vehicle length direction (X-axis direction) with the pivoting shaft 41r as the center. In addition, 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. In addition, although not illustrated in Fig. 3, the asphalt finisher 100 includes, for example, a side plate pivoting mechanism 55 (refer to Fig. 4) that pivots the side plate front end portion 41a.

[0027] For example, as illustrated in Figs. 2 and 3, the pivoting shaft 41r is attached to a front end portion of the distal end of the screed 3. Specifically, for example, the pivoting shaft 41r is attached to each of a front end portion of a left end of the left rear screed 31L and a front end portion of a right end of the right rear screed 31R. For example, the pivoting shaft 41r is fixed to each of the distal ends on the right and left of the screed 3, and pivotably supports each of the side plate front end portions 41a of the left side plate 41L and the right side plate 41R around a rotation axis in the up-down direction.

[0028] A pair of pivoting shafts 41r provided at the distal ends on the right and left of the screed 3 may be provided on the same straight line parallel to the vehicle width direction with the positions in the vehicle length direction aligned. Specifically, in the example illustrated in Fig. 2, the pivoting shaft 41r provided at the right end of the right rear screed 31R may be provided on the right side plate 41R in front of the right rear screed 31R, and the position of the pivoting shaft 41r provided at the left end of the left rear screed 31L in the vehicle length direction may be aligned. In addition, the pivoting shaft 41r for pivoting the side plate front end portion 41a of the left side plate 41L may be provided at the left side plate 41L in front of the left rear screed 31L.

[0029] For example, the side plate front end portion 41a is pivoted from a position along the vehicle length direction (X-axis direction) inward in the vehicle width direction within a predetermined angle range α, by a side plate pivoting mechanism 55 (refer to Fig. 4) which is not illustrated in Fig. 3. Specifically, for example, the side plate front end portion 41a pivots within an angle range α that does not come into contact with the distal end of the screw SC. More specifically, for example, the side plate pivoting mechanism 55 can set a pivotable angle range α of the side plate front end portion 41a. In addition, for example, the moldboard 42 can adjust to be expanded and contracted in the vehicle width direction within a range in which the contact between the side plate front end portion 41a and the screw SC can be prevented.

[0030] For example, the side plate front end portion 41a is pivotably connected to a distal end of the moldboard 42. In the example illustrated in Fig. 3, for example, the side plate front end portion 41a of the left side plate 41L is pivotably connected to the distal end of the moldboard 42 via a pivoting connection portion 42a. For example, the pivoting connection portion 42a has a hinge or a ball joint, and allows the side plate front end portion 41a to pivot with respect to the moldboard 42.

[0031] In addition, for example, the side plate front end portion 41a is provided to pivot outward in the vehicle width direction from a position along the vehicle length direction with the pivoting shaft 41r as the center. For example, the side plate front end portion 41a is pivoted from a position along the vehicle length direction outward in the vehicle width direction within a predetermined angle range β, by the side plate pivoting mechanism 55 (refer to Fig. 4) which is not illustrated in Fig. 3. Specifically, for example, an angle range β of the side plate front end portion 41a is set to a range in which the moldboard 42 connected to the side plate front end portion 41a via the pivoting connection portion 42a can follow.

[0032] The side plate front end portion 41a and the distal end of the moldboard 42 are not connected to each other and may be separated from each other. In this case, for example, the side plate front end portion 41a can be pivoted from a position along the vehicle length direction outward in the vehicle width direction within the angle range β of approximately 90°. In addition, the moldboard 42 and the rear screed 31 may be connected to each other by a support beam in order to ensure the stiffness of the moldboard 42.

[0033] For example, the side plate rear end portion 41p is attached to the distal end of the screed 3. Specifically, the side plate rear end portion 41p of the left side plate 41L is fixed to the left end of the left rear screed 31L. The side plate rear end portion 41p is disposed along the vehicle length direction, and when the side plate front end portion 41a is located along the vehicle length direction, the side plate rear end portion 41p and the side plate front end portion 41a are aligned in a straight line in the vehicle length direction, that is, the front-rear direction.

[0034] As illustrated in Figs. 1 and 2, the tractor 1 is provided with a traveling speed sensor S1, a controller 50, an object detection device 51, a vehicle-mounted display device 52, a steering device 53, and a screed expanding and contracting device 54.

[0035] The traveling speed sensor S1 is configured to detect a traveling speed of the asphalt finisher 100. In the illustrated example, the traveling speed sensor S1 is a wheel speed sensor and is capable of detecting the rotation angular speed and the rotation angle of the rear wheel 5 and the traveling speed and the traveling distance of the asphalt finisher 100.

[0036] The controller 50 is a control device that controls the asphalt finisher 100. In the illustrated example, the controller 50 includes a microcomputer including a CPU, a volatile storage device, a non-volatile storage device, and the like. Each function of the controller 50 is realized by the CPU executing a program stored in the non-volatile storage device. However, each function of the controller 50 is not only realized by software but may be realized by hardware, or may be realized by a combination of hardware and software.

[0037] The object detection device 51 is an example of an information acquisition device that acquires information on the surroundings of the asphalt finisher 100 and is configured to be capable of acquiring information related to a feature within a predetermined range of the road which is the construction target and outputting the acquired information to the controller 50. That is, the object detection device 51 is configured to use the predetermined range of the road which is the construction target as a monitoring target. The predetermined range on the road is, for example, a range that is positioned in front of the screed 3 and that includes a boundary line of the road. In the illustrated example, the predetermined range on the road is a range that has a front-rear width and a right-left width which are larger than the width of a paving mold and for example, is a range of 2 meters square.

[0038] The range positioned in front of the screed 3 is, for example, a range positioned in front of the hopper 2, a range positioned in front of an axle of the front wheel 6, a range positioned in front of an axle of the rear wheel 5, a range positioned in front of the screw SC, and the like.

[0039] The feature within the predetermined range includes, for example, the roadbed BS and an object AP outside the roadbed BS. The object AP is a feature used in order to determine the position of the end surface in the width direction of the pavement body to be laid. In the examples illustrated in Figs. 1 and 2, the object AP is a paving mold that has 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.

[0040] 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 rim stone block, a cutting step portion of an existing pavement body, or the like. The cutting step portion of the existing pavement body means a step portion that is formed when an old pavement body is cut and a new pavement body is laid and that is between a surface of a cut portion and a surface of an uncut portion.

[0041] The object AP may be a feature that has almost no thickness, such as a line drawn on the ground, a tape attached to the ground, and a thread stretched along the ground. The information related to a feature includes, for example, the height of the feature, the color of the surface of the feature, the reflectance of the surface of the feature, or the like. For the sake of clarity, Fig. 1 omits illustrating the left object APL.

[0042] In the illustrated example, the object detection device 51 is a stereo camera configured to be capable of monitoring the predetermined range. The object detection device 51 may be a monocular camera, a LiDAR, a millimeter wave radar, a laser radar, a laser scanner, a distance image camera, a laser range finder, an ultrasound sensor, a combination thereof, or the like, which is configured to be capable of monitoring the predetermined range.

[0043] In addition, the stereo camera, which is the object detection device 51, is desirably configured to have an automatic exposure adjustment function. With the configuration, the object detection device 51 can acquire information related to a feature within the predetermined range, regardless of day or night, that is, without requiring special lighting. 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.

[0044] The left object detection device 51L is configured 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 a left monitoring range ZL (a range surrounded by a one-dot chain line in Fig. 2) on the ground on the left side of the asphalt finisher 100.

[0045] The right object detection device 51R is configured 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 a right monitoring range ZR (a range surrounded by a one-dot chain line in Fig. 2) on the ground on the right side of the asphalt finisher 100.

[0046] 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 in order 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 illustrated in Fig. 2, the left object detection device 51L is attached to a left front end portion of the tractor 1 via the left attachment member 60L, and the right object detection device 51R is attached to a right front end portion of the tractor 1 via the right attachment member 60R. The left object detection device 51L may be attached to another portion of the asphalt finisher 100, such as a left front end portion of the hopper 2, via the left attachment member 60L. Similarly, the right object detection device 51R may be attached to another portion of the asphalt finisher 100, such as a right front end portion of the hopper 2, via the right attachment member 60R.

[0047] In addition, the object detection device 51 may be configured to monitor an expansion and contraction state of the rear screed 31. For example, the object detection device 51 may additionally include a stereo camera configured to monitor an end portion of the left rear screed 31L and a stereo camera configured to monitor an end portion of the right rear screed 31R. In this case, the object detection device 51 may be disposed at the screed 3. For example, the object detection device 51 may be disposed at the rear screed 31. In addition, in a case where the end portion leveling device is disposed at the end portion of the rear screed 31, the object detection device 51 may be disposed at the end portion leveling device.

[0048] In addition, the object detection device 51 is attached to the attachment member 60 to face vertically downward in the example illustrated in Fig. 2, but may be attached to the attachment member 60 to face another direction such as obliquely downward. In addition, in the example illustrated in Fig. 2, the left attachment member 60L includes an expanding and contracting member TA that is capable of expanding and contracting in the width direction and a pivoting member SB that is pivotably connected to a distal end of the expanding and contracting member TA. A pivoting member SBa represented by a broken line in Fig. 2 indicates a state when the pivoting member SB has pivoted. The same applies to the right attachment member 60R.

[0049] As described above, the attachment member 60 is configured to move a monitoring range of the object detection device 51 with the expanding and contracting member TA and the pivoting member SB. This is to enable response to a change in a paving width or the like. In this case, the controller 50 may be configured to control the pivoting of the pivoting member SB such that the object detection device 51 follows the object AP or may be configured to control the expansion and contraction of the expanding and contracting member TA. Accordingly, the controller 50 can continuously include the object AP within the monitoring range of the object detection device 51 even when the position of the object AP changes in the vehicle width direction.

[0050] The attachment member 60 may include at least one of a sensor that detects an expansion and contraction amount of the expanding and contracting member TA, and a sensor that detects a pivoting amount (pivoting angle) of the pivoting member SB. At least one of the expanding and contracting member TA and the pivoting member SB may be omitted. For example, the attachment member 60 may be configured to be incapable of expanding and contracting and to be incapable of pivoting. That is, the attachment member 60 may be a rod-shaped member that is incapable of expanding and contracting and that is incapable of pivoting. In addition, the object detection device 51 may be directly attached to the asphalt finisher 100 without via the attachment member 60.

[0051] In addition, a steering angle sensor configured to detect a steering angle of the asphalt finisher 100, a screed expansion and contraction amount sensor configured to detect an expansion and contraction amount of the rear screed 31, and the like may be attached to the asphalt finisher 100.

[0052] The vehicle-mounted display device 52 is configured to be capable of displaying information related to the asphalt finisher 100. In the illustrated example, the vehicle-mounted display device 52 is a liquid crystal display installed in front of the driver's seat 1S. However, the vehicle-mounted display device 52 may include a display device installed at least one of a left end portion and a right end portion of the screed 3.

[0053] The steering device 53 is configured 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 close to a front axle. Specifically, the steering device 53 includes a steering electromagnetic control valve that controls the flow rate of a 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.

[0054] The steering electromagnetic control valve is configured to be capable of controlling the inflow and outflow of the hydraulic oil in the front wheel steering cylinder in accordance with the rotation of a steering wheel SH (handle), which is a manipulation device. The steering electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the front wheel steering cylinder in response to an operation of an input switch which is a manipulation device different from the steering wheel SH, regardless of the movement of the steering wheel SH.

[0055] In addition, the steering electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the front wheel steering cylinder in accordance with 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 capable of automatically steering the asphalt finisher 100 regardless of the presence or absence of an operation of the steering wheel SH by a driver.

[0056] In a case where the asphalt finisher 100 is a crawler type asphalt finisher, the steering device 53 is configured to be capable of controlling each of a pair of right and left crawlers. The crawler type asphalt finisher includes a left operation lever that is a manipulation device for operating the left crawler and a right operation lever that is a manipulation device for operating the right crawler, instead of the steering wheel SH.

[0057] Specifically, the steering device 53 includes a left steering electromagnetic control valve that controls the flow rate of a hydraulic oil flowing from the 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 a 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 control the inflow and outflow of the hydraulic oil in the left traveling hydraulic motor in accordance with a manipulated variable (inclination angle) of the left operation lever. Similarly, the right steering electromagnetic control valve is configured to control the inflow and outflow of the hydraulic oil in the right traveling hydraulic motor in accordance with a manipulated variable (inclination angle) of the right operation lever.

[0058] The left steering electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the left traveling hydraulic motor in accordance with a steering command from the controller 50, regardless of the presence or absence of an operation of the left operation lever by the driver. Similarly, the right steering electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the right traveling hydraulic motor in accordance with a steering command from the controller 50, regardless of the presence or absence of an operation of the right operation lever by the driver.

[0059] The screed expanding and contracting device 54 is configured to be capable of expanding and contracting the rear screed 31 in the vehicle width direction (Y-axis direction). In the illustrated example, the screed expanding and contracting device 54 is configured to expand and contract the screed expanding and contracting cylinder 7 installed in the screed 3. Specifically, the screed expanding and contracting device 54 includes a screed expanding and contracting electromagnetic control valve that controls the flow rate of a hydraulic oil flowing from the hydraulic pump to the screed expanding and contracting cylinder 7 and the flow rate of the hydraulic oil discharged from the screed expanding and contracting cylinder 7.

[0060] The screed expanding and contracting electromagnetic control valve is configured to control the inflow and outflow of the hydraulic oil in the screed expanding and contracting cylinder 7 in response to an operation of an expansion and contraction button set (not illustrated), which is a manipulation device provided close to the vehicle-mounted 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.

[0061] The screed expanding and contracting electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the screed expanding and contracting 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 capable of automatically expanding and contracting the rear screed 31 regardless of the presence or absence of the operation of the expansion and contraction button set by the driver.

[0062] Specifically, the screed expanding and contracting device 54 includes a left expanding and contracting electromagnetic control valve that controls the flow rate of a hydraulic oil flowing from the hydraulic pump to the left screed expanding and contracting cylinder 7L for expanding and contracting the left rear screed 31L and a right expanding and contracting electromagnetic control valve that controls the flow rate of a hydraulic oil flowing from the hydraulic pump to the right screed expanding and contracting cylinder 7R for expanding and contracting the right rear screed 31R. The left expanding and contracting electromagnetic control valve is configured to control the inflow and outflow of the hydraulic oil in the left screed expanding and contracting cylinder 7L in accordance with operation content of the left expansion and contraction button set. Similarly, the right expanding and contracting electromagnetic control valve is configured to control the inflow and outflow of the hydraulic oil in the right screed expanding and contracting cylinder 7R in accordance with operation content of the right expansion and contraction button set.

[0063] The left expanding and contracting electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the left screed expanding and contracting cylinder 7L in accordance with an expansion and contraction command from the controller 50, regardless of the presence or absence of an operation of the left expansion and contraction button set by the driver. Similarly, the right expanding and contracting electromagnetic control valve may be configured to control the inflow and outflow of the hydraulic oil in the right screed expanding and contracting cylinder 7R in accordance with an expansion and contraction command from the controller 50, regardless of the presence or absence of an operation of the right expansion and contraction button set by the driver.

[0064] Next, a configuration example of a control system of the asphalt finisher 100 will be described with reference to Fig. 4. Fig. 4 is a block diagram illustrating a configuration example of the control system mounted on the asphalt finisher 100 of Fig. 1.

[0065] For example, the control system of the asphalt finisher 100 includes 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 posture detection device 56. In addition, for example, the control system of the asphalt finisher 100 includes the vehicle-mounted display device 52, the steering device 53, the screed expanding and contracting device 54, and the side plate pivoting mechanism 55.

[0066] In the example illustrated 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, and a pivoting control unit 50d. For example, each part of the controller 50 represents each function of the controller 50 realized by the CPU executing a program stored in the non-volatile storage device. In addition, for example, each part of the controller 50 illustrated in Fig. 4 may be realized by hardware as described above, or may be realized by a combination of hardware and software.

[0067] The coordinate calculation unit 50a is configured to calculate coordinates on the boundary line of the construction target range based on information related to a feature acquired by the object detection device 51. The guideline GD indicated by the thick broken line in Fig. 2 is an example of a boundary line of the road which is the construction target, and is an imaginary line indicating a guide surface. The guide surface is an imaginary surface recognized as a surface to match an end surface of a laid pavement body in the width direction. In the example illustrated in Fig. 2, the guideline GD includes a left guideline GDL that represents a left guide surface which is a surface to match a left end surface of the newly constructed pavement body NP, and a right guideline GDR that represents a right guide surface which is a surface to match a right end surface of the newly constructed pavement body NP.

[0068] Specifically, the coordinate calculation unit 50a calculates the coordinates on the guideline GD based on information related to the object AP acquired by the object detection device 51. More specifically, the coordinate calculation unit 50a calculates the coordinates of a point VL configuring the left guideline GDL based on information related to the left object APL acquired by the left object detection device 51L and calculates the coordinates of a point VR configuring the right guideline GDR based on information related to the right object APR acquired by the right object detection device 51R.

[0069] The coordinate calculation unit 50a intermittently calculates and stores the coordinates of each of the point VL and the point VR. In the illustrated example, the coordinate calculation unit 50a is configured to calculate and store the coordinates of each of the point VL and the point VR each time the asphalt finisher 100 advances by a predetermined distance (for example, 15 cm). The coordinate calculation unit 50a may be configured to calculate and store the coordinates of each of the point VL and the point VR each time a predetermined time elapses.

[0070] Fig. 1 illustrates a state where the coordinate calculation unit 50a intermittently calculates and stores the coordinates of the point VL. In Fig. 1, a point VL0 corresponds to the point VL derived by the coordinate calculation unit 50a based on an output of the left object detection device 51L at the present time point. In addition, the 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 time point in the past. The same applies to the point VL2 to the point VL4. In addition, the 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 time point in the future. The same applies to the point VL12 to the point VL14. That is, at the present time point, the coordinate calculation unit 50a has already calculated and stored a coordinate value of each of the point VL0 and the point VL1 to the point VL4.

[0071] Similar to Fig. 1, Fig. 2 also illustrates a state where the coordinate calculation unit 50a intermittently calculates and stores coordinates of each of the point VL and the point VR. In Fig. 2, a point VR0 corresponds to the point VR derived by the coordinate calculation unit 50a based on an output of the right object detection device 51R at the present time point. The same applies to the point VL0. In addition, a point VR1 corresponds to the point VR derived by the coordinate calculation unit 50a based on an output of the right object detection device 51R at a certain time point in the past. The same applies to the point VR2 to the point VR4. In addition, the 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 time point in the past. The same applies to the point VL2 to the point VL4. In addition, a point VR11 corresponds to the point VR to be derived by the coordinate calculation unit 50a based on an output of the right object detection device 51R at a certain time point in the future. The same applies to the point VR12 to the point VR14. In addition, the 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 time point in the future. The same applies to the point VL11 to the point VL14.

[0072] The steering control unit 50b is configured to be capable of automatically steering the asphalt finisher 100 regardless of an operation of a manipulation device such as a traveling speed dial. The steering control unit 50b may be configured to control the traveling speed of the asphalt finisher 100 when automatically steering the asphalt finisher 100. In addition, the steering control unit 50b may be omitted.

[0073] The screed expansion and contraction control unit 50c is configured to be capable of automatically expanding and contracting the right and left rear screeds 31 that can expand and contract regardless of an operation of a manipulation device such as the expansion and contraction button set. The screed expansion and contraction control unit 50c may be configured to be capable of automatically expanding and contracting the rear screed 31 depending on the traveling speed and the steering angle of the asphalt finisher 100 when automatically steering the asphalt finisher 100.

[0074] In the illustrated example, the screed expansion and contraction control unit 50c generates an expansion and contraction command with respect to the screed expanding and contracting cylinder 7 based on coordinates on a boundary line calculated and stored by the coordinate calculation unit 50a. The expansion and contraction command is, for example, a command related to an expansion and contraction speed, a command related to an expansion and contraction amount, a combination thereof, or the like.

[0075] Specifically, the screed expansion and contraction control unit 50c executes feed-forward control of the expansion and contraction amount of the rear screed 31. More specifically, the screed expansion and contraction control unit 50c expands and contracts the left screed expanding and contracting cylinder 7L so that the coordinates of a predetermined position of the left rear screed 31L (for example, a left front end point of the side plate front end portion 41a) match the left target coordinates. The left target coordinates are an example of the target coordinates, and are, for example, coordinates of the point VL that is located at a position closest to the front with respect to a predetermined position of the left rear screed 31L (for example, a left front end point of the side plate front end portion 41a).

[0076] In addition, the screed expansion and contraction control unit 50c expands and contracts the right screed expanding and contracting cylinder 7R so that the coordinates of a predetermined position 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, coordinates of the point VR that is located at a position closest to the front with respect to a predetermined position of the right rear screed 31R (for example, a right front end point of the side plate front end portion 41a). In addition, the screed expansion and contraction control unit 50c may be configured to determine an expansion and contraction speed depending on the traveling speed of the asphalt finisher 100 detected by the traveling speed sensor S1.

[0077] In addition, in each of the left rear screed 31L and the right rear screed 31R, the coordinates of a predetermined position 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, similar to the coordinates of the point VL and the point VR.

[0078] 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 and contraction amount of the expanding and contracting member TA performing positioning of the object detection device 51 or the like. Similarly, the coordinate calculation unit 50a can calculate the relative positions of the left front end point and the right front end point for each 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 a reference point, based on the expansion and contraction amount of the rear screed 31.

[0079] In addition, the coordinate calculation unit 50a can calculate a 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 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 at another time point with respect to the position of the reference point at the first time point for 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.

[0080] For example, the pivoting control unit 50d controls the side plate pivoting mechanism 55 so that the direction of the side plate front end portion 41a for each of the left side plate 41L and the right side plate 41R is aligned with the guideline GD as the boundary of the construction range where the paving material PV is to be laid.

[0081] Specifically, for example, the pivoting control unit 50d acquires the coordinates of the point VL and the point VR on the guideline GD calculated by the coordinate calculation unit 50a. In addition, for example, the pivoting control unit 50d acquires the coordinates of the left front end point and the right front end point calculated by the coordinate calculation unit 50a for each of the side plate front end portions 41a of the left side plate 41L and the right side plate 41R.

[0082] Furthermore, for example, the pivoting control unit 50d controls the side plate pivoting mechanism 55 so that each of the coordinates of the left front end point and the right front end point is aligned with each of the point VL of the left guideline GDL and the point VR of the right guideline GDR. The side plate pivoting mechanism 55 pivots each of the side plate front end portions 41a of the left side plate 41L and the right side plate 41R under the control of the pivoting control unit 50d.

[0083] In addition, for example, the pivoting control unit 50d may acquire 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 dimension information on each part of the asphalt finisher 100. In addition, for example, the pivoting control unit 50d may acquire the position and posture information on the asphalt finisher 100 detected by the position and posture detection device 56 and the angle of the side plate front end portion 41a with respect to the vehicle length direction (X-axis direction) detected by the angle detection device 44.

[0084] In this case, for example, the pivoting control unit 50d can control the direction of the side plate front end portion 41a based on the acquired construction information, dimension information, position and posture information, the angle of the side plate front end portion 41a, and the like. Specifically, for example, the pivoting control unit 50d controls the side plate pivoting mechanism 55 based on each piece of the above-described information, so that the direction of the side plate front end portion 41a is aligned with the guideline GD as the boundary of the construction range where the paving material PV is to be laid.

[0085] For example, the angle detection device 44 includes a rotary encoder, a resolver, a potentiometer, a stroke sensor, or the like, detects the rotation angles α and β (refer to Fig. 3) of the side plate front end portion 41a with respect to the vehicle length direction of the asphalt finisher 100, and outputs the rotation angles to the controller 50.

[0086] For example, the position and posture detection device 56 is mounted on the asphalt finisher 100 and detects the position and posture information on the asphalt finisher 100. For example, the position and posture detection device 56 is a GNSS compass using a global navigation satellite system, and detects the position information on the asphalt finisher 100 in a coordinate system such as an ITRF coordinate system or a WGS84 coordinate system and position and posture information including the direction in the vehicle length direction, and outputs the information to the controller 50.

[0087] The side plate pivoting mechanism 55 includes, for example, a motor and a speed reducer, or a hydraulic cylinder and a link mechanism. For example, the side plate pivoting mechanism 55 pivots the side plate front end portion 41a about the pivoting shaft 41r along the up-down direction of the asphalt finisher 100 by a predetermined angle from a position facing forward along the vehicle length direction under the control of the pivoting control unit 50d of the controller 50.

[0088] For example, the side plate pivoting mechanism 55 is attached to the distal end of the rear screed 31 and at least one of the side plates 41. For example, the side plate pivoting mechanism 55 pivots the side plate front end portion 41a from a position facing the front along the vehicle length direction inward and outward along the vehicle width direction. In this case, for example, the side plate pivoting mechanism 55 can include one hydraulic cylinder disposed at the inside or the outside of the side plate 41, or two hydraulic cylinders disposed at each of the inside and the outside of the side plate 41.

[0089] Fig. 5 is a flowchart illustrating an operation of the pivoting control unit 50d of the controller 50. In the illustrated example, the controller 50 starts the processing flow of the angle control of the side plate front end portion 41a illustrated in Fig. 6 when the construction is started. Specifically, the controller 50 determines whether or not the screed 3 is lowered toward the roadbed BS based on the output of a pressure sensor that acquires a pressure of the hydraulic oil in the lift cylinder 8 (refer to Fig. 1) for lifting the screed 3.

[0090] More specifically, the controller 50 determines that the lift cylinder 8 is expanded and the screed 3 is lowered toward the roadbed BS in a case where the pressure of the hydraulic oil in a rod-side oil chamber of the lift cylinder 8 falls below a predetermined value, and determines that the construction is started. The controller 50 may determine that the construction is started by any other method. In addition, the controller 50 may be configured to start the processing flow of the angle control of the side plate front end portion 41a at another timing.

[0091] When the processing flow illustrated in Fig. 5 is started, for example, the pivoting control unit 50d acquires the coordinates of the point VL and the point VR on the guideline 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). In addition, in the processing P1, for example, the pivoting control unit 50d may acquire the above-described construction information, dimension information, position and posture information, and the angle of the side plate front end portion 41a.

[0092] Fig. 6 is a schematic enlarged view illustrating by enlarging the bending portion of the right side plate 41R of the asphalt finisher 100 illustrated in Fig. 2 and the roadbed BS which is a construction range. Hereinafter, the right side plate 41R will be described, and since the left side plate 41L is the same as the right side plate 41R, the description thereof will be omitted.

[0093] Each of the left, center, and right views of Fig. 6 illustrates the positional relationship between the side plate front end portion 41a and the bending portion BP of the roadbed BS, which is the construction range, at the times t = t1, t2, and t3. The time t2 is a time when a predetermined time has elapsed from the time t1, and the time t3 is a time when a predetermined time has elapsed from the time t2. In addition, in Fig. 6, the roadbed BS, which is the construction range, is indicated by hatching with oblique lines, and the construction direction Dpv of the asphalt finisher 100 is indicated by an arrow.

[0094] After the above-described processing P1 is ended, for example, the pivoting control unit 50d determines whether or not the direction of the boundary of the construction range is changed, as illustrated in Fig. 5 (processing P2). In the example illustrated in Fig. 6, the asphalt finisher 100 aligns the right front end point Pfr of the side plate front end portion 41a of the right side plate 41R with the right guideline GDR as the boundary of the roadbed BS which is the construction range indicated by a broken line, and lays the paving material PV on the roadbed BS while moving in the construction direction Dpv.

[0095] At time t1, the direction of the right guideline GDR on the front side of the right front end point Pfr of the side plate front end portion 41a is the same as the direction of the right guideline GDR on the rear side of the right front end point Pfr. In this case, the pivoting control unit 50d determines that the direction of the boundary of the construction range is not changed (NO) in the processing P2 illustrated in Fig. 5, and executes the end determination processing P4 described later without executing the processing P3 of pivoting the side plate front end portion 41a.

[0096] After time t1 has elapsed, the right front end point Pfr of the side plate front end portion 41a moves on the right guideline GDR and reaches the bending portion BP of the right guideline GDR. In this case, the direction of the right guideline GDR changes between the front side and the rear side of the right front end point Pfr of the side plate front end portion 41a. Therefore, the pivoting control unit 50d determines that the direction of the boundary of the construction range is changed (YES) in the processing P2 illustrated in Fig. 5, and executes the processing P3 of pivoting the side plate front end portion 41a.

[0097] In the processing P3, for example, the pivoting control unit 50d controls the side plate pivoting mechanism 55 to pivot the side plate front end portion 41a, and aligns the direction of the side plate front end portion 41a with the direction of the right guideline GDR on the front side of the right front end point Pfr.

[0098] Specifically, for example, the pivoting control unit 50d calculates the rotation direction and the rotation angle of the side plate front end portion 41a so that the coordinates of the right front end point Pfr of the side plate front end portion 41a acquired from the coordinate calculation unit 50a match the coordinates of the point VR on the right guideline GDR. In addition, for example, the pivoting control unit 50d may calculate the rotation direction and the rotation angle for aligning the direction of the side plate front end portion 41a with the direction of the right guideline GDR, based on the information such as the construction information, the position and posture information, and the rotation angle acquired as described above. Furthermore, the pivoting control unit 50d outputs a control command to the side plate pivoting mechanism 55 so as to pivot the side plate front end portion 41a in the calculated direction and angle.

[0099] As a result, after the right front end point Pfr of the side plate front end portion 41a reaches the bending portion BP, the side plate front end portion 41a pivots inward in the vehicle width direction from a position facing the front in the construction direction Dpv along the vehicle length direction. Thereafter, for example, the pivoting control unit 50d increases the pivoting angle of the side plate front end portion 41a so that the right front end point Pfr moves on the right guideline GDR (time t2). As a result, at time t3, the direction of the side plate front end portion 41a is substantially equal to the direction of the right guideline GDR on the front side of the bending portion BP, and the side plate front end portion 41a and the right guideline GDR are substantially parallel to each other.

[0100] Thereafter, the pivoting control unit 50d executes the end determination processing P4 illustrated in Fig. 5. In the processing P4, for example, in a case where the operation of stopping the construction is performed by the driver or the operator, the pivoting control unit 50d determines that the construction is ended (YES), and ends the processing flow illustrated in Fig. 5. On the other hand, for example, the pivoting control unit 50d determines that the construction is not ended (NO) in a case where the operation of ending the construction is not performed by the driver or the operator, and repeats the above-described processing P1.

[0101] After the time t3 illustrated in Fig. 6 has elapsed, the tractor 1 is moved forward while the right rear screed 31R is contracted by the screed expansion and contraction control unit 50c, so that the side plate front end portion 41a of the right side plate 41R moves along the right guideline GDR. As a result, for example, the paving material PV can be sufficiently leveled up to the vicinity of the bending portion BP of the right guideline GDR in the roadbed BS that is lower by one stage than the region outside the guideline GD, which is the boundary of the construction range.

[0102] Fig. 7 is an enlarged view illustrating a modification example of Fig. 6. In Fig. 6, the right side plate 41R is moved along the inside of the right guideline GDR, but, in Fig. 7, the right side plate 41R is moved along the outside of the right guideline 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 disposed on the right guideline GDR and moved along the right guideline GDR.

[0103] 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 disposed on the right guideline GDR and is moved along the right guideline GDR. Also in this modification example, the paving material PV can be sufficiently leveled up to the vicinity of the bending portion BP of the right guideline GDR while preventing the paving material PV from protruding outward of the roadbed BS which is the construction range.

[0104] Hereinafter, the operation of the asphalt finisher 100 as the road paving machine of the present embodiment will be described while making a comparison with the asphalt finisher in the related art having the same configuration as that of the asphalt finisher in the related art described in the above-described Japanese Patent No. 3218301.

[0105] Each of Figs. 8 and 9 is a schematic enlarged view of the asphalt finisher in the related art corresponding to Figs. 6 and 7 of the asphalt finisher 100 of the present embodiment. The asphalt finisher in the related art is different from the asphalt finisher 100 of the present embodiment in that the asphalt finisher in the related art does not include the side plate front end portion 41a provided to pivot inward in the vehicle length direction from a position along the vehicle width direction.

[0106] As illustrated in Fig. 8, in the asphalt finisher in the related art, for example, at time t1, the side plate 41 is disposed inside the roadbed BS along the right guideline GDR and is moved in the construction direction Dpv. Thereafter, when the right front end point Pfr of the side plate 41 reaches the bending portion BP of the right guideline GDR, the tractor 1 is moved forward, while the right rear screed 31R is contracted, so that the right front end point Pfr can be moved along the right guideline GDR at the time t2 and the time t3.

[0107] However, the asphalt finisher in the related art does not include the side plate front end portion 41a provided to pivot inward in the vehicle width direction from a position along the vehicle length direction, as described above. Therefore, when the right rear screed 31R is contracted at the time t2 and the time t3, the construction-impossible region UR where the paving material PV cannot be leveled is expanded in the vicinity of the bending portion BP of the right guideline GDR.

[0108] In addition, as illustrated in Fig. 9, in the asphalt finisher in the related art, for example, at time t1, the side plate 41 is disposed outside the roadbed BS along the right guideline GDR and is moved in the construction direction Dpv. Thereafter, even when the left front end point Pfl of the side plate 41 crosses the bending portion BP of the right guideline GDR at the times t2 and t3, the side plate 41 is moved in the construction direction Dpv as it is, and the paving material PV is leveled to the vicinity of the bending portion BP.

[0109] However, the asphalt finisher in the related art does not include the side plate front end portion 41a provided to pivot inward in the vehicle width direction from a position along the vehicle length direction, as described above. Therefore, for example, at time t3, as indicated by the dark dots and hatching, the paving material PV that protrudes outward beyond the right guideline GDR, which is the boundary of the roadbed BS as the construction range, increases.

[0110] On the other hand, the asphalt finisher 100 as the road paving machine of 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 behind the tractor 1, as described above. In addition, the asphalt finisher 100 includes the screw SC that spreads the paving material PV fed by the conveyor CV at the rear of the tractor 1, and the screed 3 that can be expanded and contracted in the vehicle width direction where the paving material PV spread by the screw SC is leveled behind the screw SC. Furthermore, the asphalt finisher 100 includes the side plate 41 attached to the distal end of the screed 3. The side plate 41 includes a pivoting shaft 41r along the up-down direction and a side plate front end portion 41a provided to pivot inward in the vehicle width direction from a position along the vehicle length direction with the pivoting shaft 41r as the center.

[0111] With such a configuration, for example, the asphalt finisher 100 as the road paving machine of the present embodiment can sufficiently level the paving material PV up to the vicinity of the bending portion BP even in a case where the guideline GD as the boundary of the road which is the construction target is bent inward in the vehicle width direction as illustrated in Figs. 6 and 7. More specifically, for example, as illustrated in Figs. 6 and 7, the side plate front end portion 41a can be pivoted inward in the vehicle width direction with the pivoting shaft 41r as the center, so that the right front end point Pfr or the left front end point Pfl of the side plate front end portion 41a moves along the guideline GD. As a result, the paving material PV can be sufficiently leveled up to the vicinity of the bending portion BP of the guideline GD that is bent inward in the vehicle width direction. Therefore, according to the asphalt finisher 100 of the present embodiment, it is possible to suppress an obstacle to construction caused by the side plate 41 attached to the distal end of the screed 3 in the bending portion of the roadbed BS, which is the construction range, and to expand a range in which the paving material PV can be laid.

[0112] In addition, in the asphalt finisher 100 as the road paving machine of the present embodiment, the pivoting shaft 41r is provided at the distal end of the screed 3.

[0113] 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 pivoting the side plate front end portion 41a with the pivoting shaft 41r as the center. Therefore, the length of the pivotable side plate front end portion 41a can be ensured as compared to a case where the pivoting shaft 41r is provided at the distal end of the moldboard 42. Therefore, it is possible to more effectively suppress an obstacle to construction caused by the side plate front end portion 41a in the bending portion of the roadbed BS, which is the construction range, and to further expand the range in which the paving material PV can be laid.

[0114] In addition, the asphalt finisher 100 as the road paving machine of the present embodiment further includes the moldboard 42 that is attached to a front portion of the screed 3 and is capable of expanding and contracting in the vehicle width direction to adjust the amount of the paving material PV staying in front of the screed 3. The side plate front end portion 41a is pivotably connected to the distal end of the moldboard 42.

[0115] With such a configuration, the asphalt finisher 100 as the road paving machine of the present embodiment can expand and contract the moldboard 42 in response to the pivoting of the side plate front end portion 41a. In addition, a gap is prevented from being formed between the side plate front end portion 41a and the moldboard 42. Therefore, the amount of the paving material PV that stays inside the side plate front end portion 41a in the vehicle width direction can be more reliably adjusted by the moldboard 42.

[0116] In addition, in the asphalt finisher 100 as the road paving machine of the present embodiment, the side plate front end portion 41a is provided to pivot outward in the vehicle width direction.

[0117] With such a configuration, the asphalt finisher 100 as the road paving machine of the present embodiment can align the direction of the side plate front end portion 41a with the direction of the guideline GD even in a case where the guideline GD, which is the boundary of the roadbed BS as the construction range, is bent outward in the vehicle width direction. As a result, the paving material PV can be sufficiently leveled up to the vicinity of the bending portion of the guideline GD bent outward in the vehicle width direction. Therefore, according to the asphalt finisher 100 of the present embodiment, it is possible to suppress an obstacle to construction caused by the side plate 41 attached to the distal end of the screed 3 in the bending portion of the roadbed BS, which is the construction range, and to expand a range in which the paving material PV can be laid.

[0118] In addition, the asphalt finisher 100 as the road paving machine of the present embodiment further includes the side plate pivoting mechanism 55 that pivots the side plate front end portion 41a, and the controller 50 that is a control device for controlling the side plate pivoting mechanism 55. The controller 50 controls the side plate pivoting mechanism 55 so that the direction of the side plate front end portion 41a is aligned with the guideline GD as the boundary of the roadbed BS which is a construction range where the paving material PV is to be laid.

[0119] With such a configuration, the asphalt finisher 100 of the present embodiment can control the side plate pivoting mechanism 55 by the controller 50 to automatically align the direction of the side plate front end portion 41a with the guideline GD as the boundary of the construction range.

[0120] As described above, according to the present embodiment, for example, it is possible to provide the asphalt finisher 100 as the road paving machine capable of suppressing an obstacle to construction caused by the side plate 41 attached to the distal end of the screed 3 in the bending portion of the construction range and expanding the range in which the paving material PV can be laid.

[0121] Hereinbefore, the preferable embodiment of the present invention has been described in detail. However, the present invention is not limited to the embodiment described above. Various modifications, substitutions, or the like can be applied to the embodiment described above without departing from the scope of the present invention. In addition, the features described separately can be combined as long as there is no technical contradiction.Brief Description of the Reference Symbols

[0122] 1 tractor 2 hopper 3 screed 41 side plate 41a side plate front end portion 41r pivoting shaft 42 moldboard 50 controller (control device) 55 side plate pivoting mechanism 100 asphalt finisher (road paving machine) BS roadbed (construction range) CV conveyor GD guideline (boundary) GDR right guideline (boundary) GDL left guideline (boundary) PV paving material SC screw

Claims

1. A road paving machine (100) comprising: a tractor (1); a hopper (2) installed in front of the tractor (1), and that receives a paving material (PV); a conveyor (CV) that feeds the paving material (PV) in the hopper (2) behind the tractor (1); a screw (SC) that spreads the paving material (PV) fed by the conveyor (CV) behind the tractor (1); a screed (3) configured to expand and contract in a vehicle width direction where the paving material (PV) spread by the screw (SC) is leveled behind the screw (SC); and a side plate (41) attached to a distal end of the screed (3), wherein the side plate (41) includes a pivoting shaft (41r) along an up-down direction, and a side plate front end portion (41a) provided to pivot inward in the vehicle width direction from a position along a vehicle length direction with the pivoting shaft (41r) as a center.

2. The road paving machine (100) according to claim 1, wherein the pivoting shaft (41r) is provided at the distal end of the screed (3).

3. The road paving machine (100) according to claim 2, further comprising: a moldboard (42) attached to a front portion of the screed (3), and configured to expand and contract in the vehicle width direction to adjust an amount of the paving material (PV) staying in front of the screed (3), wherein the side plate front end portion (41a) is pivotably connected to a distal end of the moldboard (42).

4. The road paving machine (100) according to claim 1, wherein the side plate front end portion (41a) is provided to pivot outward in the vehicle width direction.

5. The road paving machine (100) according to any one of claims 1 to 4, further comprising: a side plate pivoting mechanism (55) that pivots the side plate front end portion (41a); and a control device (50) that controls the side plate pivoting mechanism (55) so that a direction of the side plate front end portion (41a) is aligned with a boundary (GD, GDR, GDL) of a construction range (BS) where the paving material (PV) is to be laid.

Images