Road machinery and road machinery support systems

Abstract

To provide a road machine that can lay and level paving materials so that the thickness of the paving materials differs in the vehicle width direction.SOLUTION: An asphalt finisher 100, which is an example of road machinery, includes a tractor 1 running on the roadbed BC, a hopper 2 that receives paving materials PV, a conveyor CV that feeds the paving materials PV in the hopper 2 to the rear of the tractor 1, a screw SC that spreads the paving materials PV fed by the conveyor CV behind the tractor 1, a screed 3 that levels the paving materials PV spread by the screw SC behind the screw SC, and a controller 50 that derives a first height HL and a second height HR of the screed 3 with respect to the roadbed BC. The first height HL is the height of the first point SPL in the screed 3, the second height HR is the height of the second point SPR in the screed 3, and the first point SPL is located at a different position from the second point SPR in the vehicle width direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to road machines and assistance systems for road machines. [Background technology]

[0002] BACKGROUND ART Conventionally, an asphalt finisher that measures the thickness of a paving material spread and leveled by a screed is known (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2-52042 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned asphalt finisher can only handle cases where the paving material is laid evenly so that the thickness of the paving material is uniform in the vehicle width direction, and cannot handle cases where the paving material is laid evenly so that the thickness of the paving material varies in the vehicle width direction.

[0005] It is therefore desirable to provide a road machine that can lay paving material so that the thickness of the paving material varies across the width of the vehicle. [Means for solving the problem]

[0006] A road machine according to an embodiment of the present disclosure comprises a tractor that travels on a roadbed, a hopper that is installed in front of the tractor and that receives paving material, a conveyor that feeds the paving material in the hopper to the rear of the tractor, a screw that spreads the paving material fed by the conveyor behind the tractor, a screed that spreads the paving material behind the screw and levels it, and a calculation device that derives a first height and a second height of the screed relative to the roadbed, wherein the first height is the height of a first point on the screed, and the second height is the height of a second point on the screed, and the first point is located at a position different from the second point in the vehicle width direction. The calculation device derives a virtual line representing the roadbed based on the dimensions of the traveling member, calculates the distance between the virtual line and the first point as the first height, and calculates the distance between the virtual line and the second point as the second height. do. [Effects of the Invention]

[0007] The above-described road machine is capable of laying paving material evenly so that the thickness of the paving material varies in the vehicle width direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a left side view of the asphalt finisher. [Figure 2] FIG. 2 is a top view of the asphalt finisher. [Figure 3] FIG. 2 is a functional block diagram of a controller. [Figure 4] FIG. 2 is a schematic view of the left side of the asphalt finisher. [Figure 5] FIG. 2 is a schematic view of the rear of the asphalt finisher. [Figure 6] FIG. 2 is a schematic view of the left side of the asphalt finisher. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 and 2 are schematic diagrams of an asphalt finisher 100, which is an example of a road machine according to an embodiment of the present disclosure. Specifically, Fig. 1 is a left side view of the asphalt finisher 100, and Fig. 2 is a top view.

[0010] The asphalt finisher 100 is mainly composed of a tractor 1, a hopper 2, and a screed 3. In the example shown in FIGS. 1 and 2, the asphalt finisher 100 is disposed so that the vehicle length direction corresponds to the X-axis direction and the vehicle width direction corresponds to the Y-axis direction. The Z-axis is disposed so as to be perpendicular to both the X-axis and the Y-axis. Specifically, the front side in the vehicle length direction corresponds to the +X side, the rear side in the vehicle length direction corresponds to the -X side, the left side in the vehicle width direction corresponds to the +Y side, the right side in the vehicle width direction corresponds to the -Y side, the upper side in the vertical direction corresponds to the +Z side, and the lower side in the vertical direction corresponds to the -Z side.

[0011] The tractor 1 is a mechanism for propelling the asphalt finisher 100. In the example shown in FIGS. 1 and 2, the tractor 1 moves the asphalt finisher 100 by rotating the rear wheels 5 using a rear wheel drive motor and by rotating the front wheels 6 using a front wheel drive motor. The rear wheel drive motor and the front wheel drive motor are hydraulic motors that are rotated by receiving a supply of hydraulic oil from a hydraulic pump. The tractor 1 may also be equipped with crawlers instead of wheels.

[0012] The controller 50 is an example of a computing device. In the example shown in FIGS. 1 and 2, the controller 50 is a computer including a CPU, a volatile storage device, and a non-volatile storage device, and is mounted on the tractor 1 and configured to control the asphalt finisher 100 by operating various functions. The various functions of the controller 50 are realized, for example, by the CPU executing programs stored in the non-volatile storage device. The various functions realized by the controller 50 include, for example, a function to control the discharge rate of a hydraulic pump that discharges hydraulic oil for driving a hydraulic actuator, and a function to control the flow of hydraulic oil between the hydraulic actuator and the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder and a hydraulic motor.

[0013] The hopper 2 is a mechanism for receiving the paving material PV. The paving material PV is, for example, an asphalt mixture. In the example shown in FIGS. 1 and 2, the hopper 2 is installed on the front (+X side) of the tractor 1 and is configured to be opened and closed in the Y-axis direction (vehicle width direction) by a hopper cylinder 24. The asphalt finisher 100 normally receives the paving material PV from the bed of a dump truck with the hopper 2 fully open. A dump truck is an example of a vehicle (transport vehicle) that transports the paving material PV to be supplied to the asphalt finisher 100. Furthermore, even while receiving the paving material PV from the bed of the dump truck, the asphalt finisher 100 can continue traveling by pushing the dump truck forward via the push rollers 2b. FIGS. 1 and 2 show the hopper 2 in a fully open state. Note that for clarity, the paving material PV received in the hopper 2 is not shown in FIGS. 1 and 2.

[0014] When the amount of paving material PV in the hopper 2 decreases, the operator of the asphalt finisher 100 manually closes the hopper 2, so that the paving material PV that was near the inner wall of the hopper 2 is collected in the center of the hopper 2. This is so that the conveyor CV at the center of the bottom of the hopper 2 can transport the paving material PV to the rear of the tractor 1. The paving material PV transported to the rear of the tractor 1 is spread by the screw SC in the vehicle width direction behind the tractor 1 and in front of the screed 3.

[0015] The conveyor CV is driven by a hydraulic motor that rotates when hydraulic oil is supplied from a hydraulic pump. In the example shown in Figures 1 and 2, the conveyor CV is configured to transport the paving material PV in the hopper 2 to the rear of the tractor 1 via a transport path CP. The transport path CP is a substantially rectangular parallelepiped space formed inside the tractor 1. Specifically, the conveyor CV includes a left conveyor CVL and a right conveyor CVR that operate independently of each other.

[0016] The screw SC is driven by a hydraulic motor that rotates by receiving hydraulic oil from a hydraulic pump. Specifically, the screw SC includes a left screw SCL and a right screw SCR that operate independently of each other. In the illustrated example, the left screw SCL is installed so as to protrude to the left side from the width of the tractor 1. The right screw SCR is installed so as to protrude to the right side from the width of the tractor 1.

[0017] The screed 3 is a mechanism for spreading and leveling the paving material PV. In the example shown in FIGS. 1 and 2, the screed 3 mainly includes a front screed 30 and a rear screed 31. The rear screed 31 includes a left rear screed 31L and a right rear screed 31R. The front screed 30, the left rear screed 31L, and the right rear screed 31R are arranged so as to be offset from one another in the front and rear directions. Specifically, the left rear screed 31L is arranged behind the front screed 30, and the right rear screed 31R is arranged behind the left rear screed 31L. The screed 3 is a floating screed towed by the tractor 1 and is connected to the tractor 1 via a leveling arm AM. The screed 3 is moved up and down together with the leveling arm AM by the extension and retraction of a screed lift cylinder 25.

[0018] The rear screed 31 is configured to be able to extend and retract in the vehicle width direction by a telescopic cylinder 60. The telescopic cylinder 60 is supported by a support fixed to the housing of the front screed 30 and is configured to be able to extend and retract the rear screed 31 in the vehicle width direction. Specifically, the telescopic cylinder 60 includes a left telescopic cylinder 60L and a right telescopic cylinder 60R. The left telescopic cylinder 60L extends and retracts the left rear screed 31L in the space left rear of the front screed 30. The right telescopic cylinder 60R extends and retracts the right rear screed 31R in the space right rear of the front screed 30. Note that in Figures 1 and 2, for clarity, a coarse dot pattern is applied to the paving material PV spread in front of the rear screed 31, and a fine dot pattern is applied to the paving material PV (new pavement NP) laid and leveled by the screed 3.

[0019] The leveling arm AM is configured to be able to connect the screed 3 to the tractor 1. Specifically, the leveling arm AM includes a left leveling arm AML and a right leveling arm AMR. Each of the left leveling arm AML and the right leveling arm AMR has one end (rear end) connected to the screed 3 and the other end (front end) connected to the tractor 1 (leveling cylinder 23).

[0020] The leveling cylinder 23 is a hydraulic cylinder that moves the front ends of the leveling arms AM up and down to adjust the spreading thickness of the paving material PV. In the example shown in FIGS. 1 and 2, the cylinder portion of the leveling cylinder 23 is connected to the tractor 1, and the rod portion is connected to the front ends of the leveling arms AM. The front ends of the leveling arms AM are attached to the tractor 1 so that they can slide up and down. When increasing the spreading thickness, the controller 50 causes hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinder 23, contracting the leveling cylinder 23 and raising the front ends of the leveling arms AM. When decreasing the spreading thickness, the controller 50 causes hydraulic oil to flow out of the rod-side oil chamber of the leveling cylinder 23, extending the leveling cylinder 23 and lowering the front ends of the leveling arms AM.

[0021] Specifically, the leveling cylinder 23 includes a left leveling cylinder 23L that moves the front connection point (left front connection point) of the left leveling arm AML up and down, and a right leveling cylinder 23R that moves the front connection point (right front connection point) of the right leveling arm AMR up and down. The controller 50 can extend and retract the left leveling cylinder 23L and the right leveling cylinder 23R separately.

[0022] The screed lift cylinder 25 is a hydraulic cylinder for lifting the screed 3. In the example shown in FIGS. 1 and 2, the screed lift cylinder 25 includes a left screed lift cylinder 25L and a right screed lift cylinder 25R. The left screed lift cylinder 25L has a cylinder portion connected to the left rear end of the tractor 1 and a rod portion connected to the rear connection point (left rear connection point) of the left leveling arm AML. The right screed lift cylinder 25R has a cylinder portion connected to the right rear end of the tractor 1 and a rod portion connected to the rear connection point (right rear connection point) of the right leveling arm AMR. When lifting the screed 3, the controller 50 causes hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the screed lift cylinder 25. As a result, the screed lift cylinder 25 contracts, the rear ends of the leveling arms AM are lifted, and the screed 3 is lifted. Furthermore, when the lifted screed 3 is to be lowered, the controller 50 allows the hydraulic oil to flow out of the rod-side oil chamber of the screed lift cylinder 25. As a result, the screed lift cylinder 25 extends due to the weight of the screed 3, the rear end of the leveling arm AM descends, and the screed 3 descends. During construction, the screed lift cylinder 25 is in a state where it can extend and retract in response to the up and down movement of the screed 3.

[0023] A side plate 40 is attached to the distal end of the rear screed 31. The side plate 40 is a plate-shaped member extending in the vehicle length direction, and includes a left side plate 40L and a right side plate 40R. Specifically, the left side plate 40L is attached to the distal end (left end) of the left rear screed 31L, and the right side plate 40R is attached to the distal end (right end) of the right rear screed 31R.

[0024] In the illustrated example, the side plate 40 is also connected to the distal end of the moldboard 41. The moldboard 41 is a member for adjusting the amount of paving material PV that remains in front of the rear screed 31 out of the paving material PV spread by the screw SC, and may be configured to be able to expand and contract in the vehicle width direction together with the rear screed 31.

[0025] Specifically, the mold board 41 is a plate-like member extending in the vehicle width direction, and includes a left mold board 41L and a right mold board 41R. In the illustrated example, the left side plate 40L is connected to the distal end (left end) of the left mold board 41L, and the right side plate 40R is connected to the distal end (right end) of the right mold board 41R.

[0026] The moldboard 41 is configured so that its height in the Z-axis direction can be adjusted independently of the rear screed 31 and the side plate 40. By moving the moldboard 41 up and down, the operator of the asphalt finisher 100 can adjust the size of the gap between the lower end of the moldboard 41 and the roadbed BC, and can adjust the amount of paving material PV that passes through that gap. Therefore, by moving the moldboard 41 up and down, the operator of the asphalt finisher 100 can adjust the amount (height) of paving material PV that remains behind the moldboard 41 (-X side) and in front of the rear screed 31 (+X side), and therefore can adjust the amount of paving material PV that is taken in below the rear screed 31.

[0027] The screed step 42 is a member that forms a foothold for a worker when working behind the screed 3. Specifically, the screed step 42 includes a left screed step 42L, a central screed step 42C, and a right screed step 42R.

[0028] The retaining plates 43 are plate-like members that prevent the paving material PV being spread in the vehicle width direction by the screws SC from scattering in front of the screws SC, so that the paving material PV can be properly spread in the vehicle width direction by the screws SC. In the example shown in Figures 1 and 2, the retaining plates 43 include a left retaining plate 43L and a right retaining plate 43R.

[0029] Next, an example of a support function, which is one of the functions of the controller 50, will be described with reference to FIG. 3. FIG. 3 is a functional block diagram of the controller 50. The support function is a function for supporting the operation of the asphalt finisher 100 by the operator of the asphalt finisher 100. The support function is mainly realized by cooperation between the cylinder stroke sensor S1, distance sensor S2, inclination sensor S3, controller 50, and leveling thickness control device 55. Note that the distance sensor S2 and inclination sensor S3 may be omitted. In FIG. 3, blocks representing the distance sensor S2 and inclination sensor S3, which can be omitted, are drawn with dashed lines.

[0030] The cylinder stroke sensor S1 is a sensor that detects the extension / contraction amount (stroke amount) of the hydraulic cylinder. The cylinder stroke sensor S1 may be a sensor of any type. In the illustrated example, the cylinder stroke sensor S1 is an ultrasonic sensor that is configured to be able to separately detect the stroke amounts of the left leveling cylinder 23L, the right leveling cylinder 23R, the left screed lift cylinder 25L, and the right screed lift cylinder 25R. Specifically, the cylinder stroke sensor S1 includes four independent cylinder stroke sensors.

[0031] The distance sensor S2 is a sensor for detecting the distance between the tractor 1 and the roadbed BC. The distance sensor S2 may be a sensor of any type. In the illustrated example, the distance sensor S2 includes a left distance sensor S2L that uses laser light to detect the distance in the Z-axis direction between the left end of the tractor 1 and the roadbed BC, and a right distance sensor S2R that uses laser light to detect the distance in the Z-axis direction between the right end of the tractor 1 and the roadbed BC. Specifically, the left distance sensor S2L is attached to the front end of the left side of the frame of the tractor 1, and the right distance sensor S2R is attached to the front end of the right side of the frame of the tractor 1.

[0032] The inclination sensor S3 is a sensor for detecting the inclination of the tractor 1. The inclination sensor S3 may be a sensor of any type. In the illustrated example, the inclination sensor S3 is a capacitance-type inclination sensor, and is configured to be able to detect the inclination of the tractor 1 relative to a horizontal plane. Specifically, the inclination sensor S3 is configured to be able to detect the pitch angle and yaw angle of the tractor 1.

[0033] The leveling thickness control device 55 is configured to control the leveling thickness. In the illustrated example, the leveling thickness control device 55 is a solenoid valve that controls the flow rate of hydraulic oil flowing into or out of the leveling cylinder 23. Specifically, the leveling thickness control device 55 increases or decreases the flow path area, which is the cross-sectional area of ​​the pipe connecting the leveling cylinder 23 and the hydraulic pump, in response to a control command from the controller 50.

[0034] More specifically, the laying thickness control device 55 allows hydraulic oil discharged from the hydraulic pump to flow into the rod-side oil chamber of the left leveling cylinder 23L, and contracts the left leveling cylinder 23L to raise the front end of the left leveling arm AML, thereby increasing the laying thickness (left leveling thickness) of the paving material PV (new pavement NP) to the left (+Y side) of the front-to-rear axis AX of the asphalt finisher 100. In addition, the laying thickness control device 55 can decrease the left leveling thickness by letting out hydraulic oil from the rod-side oil chamber of the left leveling cylinder 23L and extending the left leveling cylinder 23L to lower the front end of the left leveling arm AML. Similarly, the laying thickness control device 55 allows hydraulic oil discharged by the hydraulic pump to flow into the rod-side oil chamber of the right leveling cylinder 23R, contracting the right leveling cylinder 23R and raising the front end of the right leveling arm AMR, thereby increasing the laying thickness (right laying thickness) of the paving material PV (new pavement NP) to the right (-Y side) of the front-to-rear axis AX of the asphalt finisher 100. In addition, the laying thickness control device 55 can decrease the right laying thickness by letting out hydraulic oil from the rod-side oil chamber of the right leveling cylinder 23R and extending the right leveling cylinder 23R to lower the front end of the right leveling arm AMR.

[0035] In the illustrated example, the front and rear axes AX of the asphalt finisher 100 are axes that perpendicularly intersect the axles 5X of the rear wheels 5 and extend along the vehicle length direction, and form the center line of the tractor 1.

[0036] The controller 50 acquires information from the cylinder stroke sensor S1 etc., performs various calculations, and then outputs control commands to the spreading thickness control device 55 etc. according to the calculation results. Specifically, the controller 50 determines whether or not predetermined conditions are met based on the information acquired from the cylinder stroke sensor S1 etc., and outputs control commands to the spreading thickness control device 55 etc. when it determines that the predetermined conditions are met.

[0037] More specifically, the controller 50 has a calculation unit 50A and a spreading thickness control unit 50B as functional blocks configured by software, hardware, or a combination thereof.

[0038] The calculation unit 50A is configured to calculate information necessary for controlling the spreading thickness. In the illustrated example, the calculation unit 50A is configured to calculate the height of the screed 3 relative to the roadbed BC.

[0039] Here, an example of a method by which the controller 50 calculates the height of the screed 3 relative to the roadbed BC will be described with reference to Figures 4 and 5. Figure 4 is a schematic diagram of the left side of the asphalt finisher 100, and Figure 5 is a schematic diagram of the rear of the asphalt finisher 100. Note that in Figures 4 and 5, a dot pattern is added to the front screed 30 for clarity. The same applies to Figure 6 shown below.

[0040] The calculation unit 50A of the controller 50 is configured to calculate a first height HL and a second height HR of the screed 3 relative to the roadbed BC. The first height HL is the height of a first point SPL on the screed 3, and the second height HR is the height of a second point SPR on the screed 3. The first point SPL is located at a different position from the second point SPR in the vehicle width direction. In the illustrated example, the first point SPL is the left rear end point of the screed plate of the front screed 30, and the second point SPR is the right rear end point of the screed plate of the front screed 30. However, the first point SPL and the second point SPR may correspond to other positions on the front screed 30.

[0041] Specifically, the calculation unit 50A derives a left virtual line VTL that passes through the ground contact point of the left rear wheel 5L and the ground contact point of the left front wheel 6L based on the radius RD1 of the left front wheel 6L and the radius RD2 of the left rear wheel 5L. Similarly, the calculation unit 50A derives a right virtual line VTR that passes through the ground contact point of the right rear wheel 5R and the ground contact point of the right front wheel based on the radius RD1 of the right front wheel (not shown) and the radius RD2 of the right rear wheel 5R. Note that the radius RD1 is the length of a line segment connecting the axle 6X of the front wheel 6 and the ground contact point of the front wheel 6, and the radius RD2 is the length of a line segment connecting the axle 5X of the rear wheel 5 and the ground contact point of the rear wheel 5. Note that the radii RD1 and RD2 are values ​​that are pre-registered in a non-volatile storage device or the like of the controller 50.

[0042] In the illustrated example, the calculation unit 50A is configured to derive the position of the left virtual line VTL by calculating the coordinates of the ground contact points of the left rear wheel 5L and the left front wheel 6L in a three-dimensional orthogonal coordinate system having the reference point RP as the origin. Similarly, the calculation unit 50A is configured to derive the position of the right virtual line VTR by calculating the coordinates of the ground contact points of the right rear wheel 5R and the right front wheel in a three-dimensional orthogonal coordinate system having the reference point RP as the origin.

[0043] In the illustrated example, the reference point RP is the intersection of the center line (front-rear axis AX) of the tractor 1 extending along the vehicle length direction (X-axis direction) and the axle 5X of the rear wheel 5.

[0044] The calculation unit 50A is also configured to derive the relative position of the first point SPL with respect to the reference point RP. In the illustrated example, the calculation unit 50A is configured to derive the coordinates of the first point SPL in a three-dimensional orthogonal coordinate system with the reference point RP as the origin.

[0045] More specifically, the calculation unit 50A derives the length ST1 of the left leveling cylinder 23L based on the stroke amount of the left leveling cylinder 23L detected by the cylinder stroke sensor S1, and further calculates the coordinate of the left front connection point P1L of the left leveling arm AML based on the length ST1. The calculation unit 50A also derives the length ST2 of the left screed lift cylinder 25L based on the stroke amount of the left screed lift cylinder 25L detected by the cylinder stroke sensor S1, and further calculates the coordinate of the left rear connection point P2L of the left leveling arm AML based on the length ST1. The calculation unit 50A then calculates the coordinate of the first point SPL based on the coordinate of the left front connection point P1L and the coordinate of the left rear connection point P2L.

[0046] Similarly, the calculation unit 50A derives the length of the right leveling cylinder 23R based on the stroke amount of the right leveling cylinder 23R detected by the cylinder stroke sensor S1, and further calculates the coordinates of the right front connecting point (not shown) of the right leveling arm AMR based on that length. The calculation unit 50A also derives the length of the right screed lift cylinder 25R based on the stroke amount of the right screed lift cylinder 25R detected by the cylinder stroke sensor S1, and further calculates the coordinates of the right rear connecting point (not shown) of the right leveling arm AMR based on that length. The calculation unit 50A then calculates the coordinates of the second point SPR based on the coordinates of the left front connecting point and the coordinates of the left rear connecting point.

[0047] The dimensions of each member, such as the leveling cylinder 23, the screed lift cylinder 25, the leveling arm AM, and the front screed 30, as well as the positions (coordinates) of the connection points of the leveling cylinder 23 and the screed lift cylinder 25 relative to the tractor 1, are pre-registered in a non-volatile memory device or the like of the controller 50. Therefore, the calculation unit 50A can calculate the coordinates of the first point SPL and the second point SPR based on the values ​​pre-registered in the non-volatile memory device or the like and the detection value of the cylinder stroke sensor S1. This is because, in the illustrated example, the leveling arm AM and the screed 3 are rigidly connected.

[0048] The calculation unit 50A then derives the distance between the left virtual line VTL and the first point SPL as the first height HL (left leveled thickness) based on the coordinates of the left virtual line VTL and the first point SPL calculated by the method described above. Similarly, the calculation unit 50A derives the distance between the right virtual line VTR and the second point SPR as the second height HR (right leveled thickness) based on the coordinates of the right virtual line VTR and the second point SPR calculated by the method described above.

[0049] The paving thickness control unit 50B is configured to control the paving thickness of the paving material PV. In the illustrated example, the paving thickness control unit 50B is configured to adjust the paving thickness so that a preset target paving thickness matches the actual paving thickness. The target paving thickness is, for example, the distance between the design surface and the roadbed BC set in the design data. Specifically, the preset target paving thickness includes a left target paving thickness, which is the target value for the thickness of the paving material PV to be laid and leveled in the area to the left of the longitudinal axis AX of the asphalt finisher 100, and a right target paving thickness, which is the target value for the thickness of the paving material PV to be laid and leveled in the area to the right of the longitudinal axis AX of the asphalt finisher 100. For example, the left target leveling thickness is the target value of the thickness of the paving material PV directly below the left end of the screed plate of the front screed 30, and the right target leveling thickness is the target value of the thickness of the paving material PV directly below the right end of the screed plate of the front screed 30.

[0050] More specifically, the spreading thickness control unit 50B generates a control command to the spreading thickness control device 55 so that the first height HL (left spreading thickness) calculated by the calculation unit 50A matches the left target spreading thickness.

[0051] Similarly, the spreading thickness control unit 50B generates a control command to the spreading thickness control device 55 so that the second height HR (right spreading thickness) calculated by the calculation unit 50A matches the right target spreading thickness.

[0052] For example, if the currently calculated first height HL (left laying leveling thickness) is greater than the left target laying leveling thickness, the laying thickness control unit 50B generates a control command to extend the left leveling cylinder 23L and lower the front end of the left leveling arm AML in order to reduce the left laying leveling thickness, and outputs this control command to the laying thickness control device 55. Conversely, if the currently calculated first height HL (left laying leveling thickness) is smaller than the left target laying leveling thickness, the laying thickness control unit 50B generates a control command to contract the left leveling cylinder 23L and raise the front end of the left leveling arm AML in order to increase the left laying leveling thickness, and outputs this control command to the laying thickness control device 55.

[0053] With this configuration, the controller 50 can spread the paving material PV evenly so that the thickness of the paving material PV varies in the vehicle width direction (Y-axis direction).

[0054] Next, another example of a method by which the controller 50 calculates the height of the screed 3 relative to the roadbed BC will be described with reference to Fig. 6. Fig. 6 is a schematic diagram of the left side of the asphalt finisher 100, and corresponds to Fig. 4.

[0055] The method described with reference to FIG. 6 differs from the method described with reference to FIG. 4 mainly in that the left virtual line VTL and the right virtual line VTR are derived using the output of at least one of the distance sensor S2 and the tilt sensor S3, but is otherwise the same as the method described with reference to FIG. 4.

[0056] Specifically, the calculation unit 50A derives the left trajectory BCL, which is a line representing the surface shape of the roadbed BC along which the left front wheel 6L and the left rear wheel 5L pass, based on the output of the left distance sensor S2L obtained each time the asphalt finisher 100 advances a predetermined distance (for example, a few centimeters). Note that the calculation unit 50A may also use the output of the inclination sensor S3 to derive the left trajectory BCL.

[0057] The left trajectory BCL is a line (a line on a virtual plane parallel to the XZ plane) connecting points (measurement points) hit by the laser light emitted by the left distance sensor S2L each time the asphalt finisher 100 advances a predetermined distance. The calculation unit 50A calculates the coordinates of each measurement point on the left trajectory BCL in a three-dimensional orthogonal coordinate system with the reference point RP as the origin.

[0058] Similarly, the calculation unit 50A derives a right trajectory (not shown), which is a line representing the surface shape of the roadbed BC over which the right front wheel and right rear wheel 5R pass, based on the output of the right distance sensor S2R obtained each time the asphalt finisher 100 advances a predetermined distance (for example, a few centimeters). Note that the calculation unit 50A may also use the output of the inclination sensor S3 to derive the right trajectory.

[0059] The right trajectory is a line (a line on a virtual plane parallel to the XZ plane) connecting points (measurement points) hit by the laser light emitted by the right distance sensor S2R each time the asphalt finisher 100 moves a predetermined distance. The calculation unit 50A calculates the coordinates of each measurement point on the right trajectory in a three-dimensional orthogonal coordinate system with the reference point RP as the origin.

[0060] The calculation unit 50A then derives a straight line representing the left trajectory BCL as the left virtual line VTL. In the illustrated example, the left virtual line VTL is an approximate straight line of the left trajectory BCL derived using the least squares method.

[0061] Similarly, the calculation unit 50A derives a straight line representing the right trajectory as a right virtual line VTR. In the illustrated example, the right virtual line VTR is an approximate straight line of the right trajectory derived using the least squares method.

[0062] The calculation unit 50A may use a method other than the least squares method to derive straight lines representing the left locus BCL and the right locus as the left virtual line VTL and the right virtual line VTR, respectively.

[0063] Then, the calculation unit 50A derives the distance between the left virtual line VTL and the first point SPL as the first height HL (left leveled thickness) based on the coordinates of the left virtual line VTL and the first point SPL, in the same manner as the method described with reference to Fig. 4. Similarly, the calculation unit 50A derives the distance between the right virtual line VTR and the second point SPR as the second height HR (right leveled thickness) based on the coordinates of the right virtual line VTR and the second point SPR.

[0064] The spreading thickness control unit 50B then generates a control command for the spreading thickness control device 55 so that the first height HL (left spreading thickness) calculated by the calculation unit 50A matches the left target spreading thickness. The spreading thickness control unit 50B also generates a control command for the spreading thickness control device 55 so that the second height HR (right spreading thickness) calculated by the calculation unit 50A matches the right target spreading thickness.

[0065] With this configuration, the controller 50 can spread the paving material PV evenly so that the thickness of the paving material PV varies in the vehicle width direction (Y-axis direction).

[0066] As described above, asphalt finisher 100, as shown in Figures 1 and 2, includes tractor 1 traveling on roadbed BC, hopper 2 installed in front of tractor 1 to receive paving material PV, conveyor CV that feeds paving material PV in hopper 2 to the rear of tractor 1, screw SC that spreads paving material PV fed by conveyor CV behind tractor 1, screed 3 that spreads and levels paving material PV spread by screw SC behind screw SC, and controller 50 as a calculation device that derives a first height HL (see Figure 5) and a second height HR (see Figure 5) of screed 3 relative to roadbed BC. As shown in Figure 5, first height HL is the height of first point SPL on screed 3, and second height HR is the height of second point SPR on screed 3. First point SPL is located at a different position from second point SPR in the vehicle width direction (Y-axis direction).

[0067] As shown in Figure 5, the controller 50 may derive virtual lines VT (left virtual line VTL and right virtual line VTR) representing the roadbed BC based on the dimensions of the running members, calculate the distance between the left virtual line VTL and the first point SPL as the first height HL (left leveling thickness), and calculate the distance between the right virtual line VTR and the second point SPR as the second height HR (right leveling thickness).

[0068] The dimensions of the traveling members are, for example, the radius RD1 of the front wheels 6 and the radius RD2 of the rear wheels 5. If the tractor 1 is a crawler type rather than a wheeled type, the dimensions of the traveling members are, for example, the distance between the rotation axis of the traveling hydraulic motor that rotates the crawler and the outer surface of the crawler link located vertically below it.

[0069] The tractor 1 may be equipped with at least one of a distance sensor S2 that detects the distance to the roadbed BC and an inclination sensor S3 that detects the inclination of the tractor 1. In this case, as shown in Fig. 6, the controller 50 may derive a virtual line VT (a left virtual line VTL and a right virtual line VTR) that represents the roadbed BC based on the output of at least one of the distance sensor S2 and the inclination sensor S3, and may calculate the distance between the left virtual line VTL and the first point SPL as a first height HL, and the distance between the right virtual line VTR and the second point SPR as a second height HR.

[0070] The asphalt finisher 100 may be equipped with an actuator that adjusts the spreading and leveling thickness. In the example shown in Figures 1 and 2, the asphalt finisher 100 is equipped with a leveling cylinder 23 as an actuator that adjusts the spreading and leveling thickness. In this case, the controller 50 may control the extension and contraction amount (stroke amount) of the leveling cylinder 23 so that each of the first height HL and the second height HR matches the height of the design surface.

[0071] The controller 50 may recognize the respective positions of the first point SPL and the second point SPR using coordinates in a predetermined coordinate system. In the example shown in Figures 4 to 6, the controller 50 recognizes the respective positions of the first point SPL and the second point SPR using coordinates in a three-dimensional orthogonal coordinate system with a reference point RP as the origin. The reference point RP is the intersection of the center line of the tractor 1 extending along the vehicle length direction (X-axis direction) of the asphalt finisher 100 and the axle 5X of the rear wheel 5.

[0072] The screed 3 may include a front screed 30 and a left rear screed 31L and a right rear screed 31R that are extendable and retractable in the vehicle width direction (Y-axis direction). In this case, as shown in Figure 5, the first point SPL may be the left rear end point of the screed plate of the front screed 30, and the second point SPR may be the right rear end point of the screed plate of the front screed 30.

[0073] As shown in Figures 5 and 6, the controller 50 may detect unevenness in the roadbed BC based on the output of at least one of the distance sensor S2 and the inclination sensor S3, derive straight lines (left virtual line VTL and right virtual line VTR) representing the roadbed BC including such unevenness, calculate the distance between the straight line (left virtual line VTL) and the first point SPL as the first height HL, and calculate the distance between the straight line (right virtual line VTR) and the second point SPR as the second height HR.

[0074] The straight lines (left virtual line VTL and right virtual line VTR) derived by the controller 50 may be approximated straight lines. In the example shown in Fig. 6, the left virtual line VTL is an approximated straight line of the left trajectory BCL derived based on the output of the distance sensor S2. The straight lines (left virtual line VTL and right virtual line VTR) derived by the controller 50 may be approximated straight lines derived using the least squares method.

[0075] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise.

[0076] For example, in the above-described embodiment, the controller 50 is mounted on the edge side (tractor 1 of the asphalt finisher 100), but it may also be mounted on the cloud side (outside the asphalt finisher 100). In this case, the controller 50 may be configured to acquire information output by various devices attached to the asphalt finisher 100 through a communication device mounted on the tractor 1, and to transmit control commands to the leveling thickness control device 55 and the like through the communication device mounted on the tractor 1. The communication device is configured to control communication with external devices, for example, via a communication network.

[0077] The communication network is configured to mainly interconnect the asphalt finisher 100, the management device, and the support device. The communication network includes, for example, at least one of a satellite communication network, a mobile phone communication network, and the Internet network.

[0078] The support device is, for example, a computer equipped with a CPU, ROM, RAM, an input / output interface, an input device, a display, etc. Specifically, the support device includes a mobile communication terminal and a fixed communication terminal, etc. The mobile communication terminal is, for example, a laptop computer, a tablet PC, a mobile phone, a smartphone, a smart watch, or smart glasses.

[0079] The management device is a device installed in an external facility such as a management center, and stores and manages information transmitted by the asphalt finisher 100. The management device is, for example, a computer equipped with a CPU, ROM, RAM, input / output interface, input device, display, etc. Specifically, the management device acquires and stores information received via a communication network, and manages the stored information so that an operator (administrator) can refer to it as needed.

[0080] The asphalt finisher 100, the management device, and the support device are connected to each other using a communication protocol such as the Internet Protocol. There may be one or more asphalt finishers 100, management devices, and support devices connected via a communication network.

[0081] The controller 50 may be provided in the management device or in the support device. The calculation unit 50A and the spreading thickness control unit 50B of the controller 50 may be distributed between the management device and the support device.

[0082] In this way, the asphalt finisher 100 and at least one of the management device and the support device may constitute a support system that supports the movement of the asphalt finisher 100. [Explanation of symbols]

[0083] 1 Tractor 2 Hopper 2b Push roller 3 Screed 5 Rear wheel 6 Front wheel 23 Leveling cylinder 24 Hopper cylinder 25 Screed lift cylinder 30 Front screed 31 Rear screed 40 Side plate 41 Moldboard 42 Screed step 43 Retaining plate 50 Controller 50A Calculation unit 50B Leveling thickness control unit 55 Leveling thickness control device 60 Telescopic cylinder 100 Asphalt finisher AM Leveling arm CP Transfer path CV Conveyor PV Paving material SC Screw

Claims

1. A tractor that travels on a roadbed; a hopper installed in front of the tractor to receive paving material; a conveyor that feeds the paving material in the hopper to the rear of the tractor; a screw that spreads the paving material fed by the conveyor behind the tractor; a screed that spreads the paving material spread by the screw behind the screw; A calculation device that derives a first height and a second height of the screed relative to the roadbed, the first height is the height of a first point on the screed; the second height is the height of a second point on the screed; the first point is at a position different from the second point in the vehicle width direction, The calculation device derives a virtual line representing the roadbed based on the dimensions of a traveling member, calculates the distance between the virtual line and the first point as the first height, and calculates the distance between the virtual line and the second point as the second height. Road machinery.

2. A tractor that travels on a roadbed; a hopper installed in front of the tractor to receive paving material; a conveyor that feeds the paving material in the hopper to the rear of the tractor; a screw that spreads the paving material fed by the conveyor behind the tractor; a screed that spreads the paving material spread by the screw behind the screw; A calculation device that derives a first height and a second height of the screed relative to the roadbed, the first height is the height of a first point on the screed; the second height is the height of a second point on the screed; the first point is at a position different from the second point in the vehicle width direction, At least one of a distance sensor that detects the distance to the roadbed and an inclination sensor that detects the inclination of the tractor is attached to the tractor, The calculation device derives a virtual line representing the roadbed based on the output of at least one of the distance sensor and the inclination sensor and the dimensions of the traveling member, calculates the distance between the virtual line and the first point as the first height, and calculates the distance between the virtual line and the second point as the second height. Road machinery.

3. Equipped with an actuator to adjust the thickness of the paving, the computing device controls the actuator so that each of the first height and the second height coincides with a height of a design surface.

3. A road machine according to claim 1 or 2.

4. the computing device recognizes the positions of the first point and the second point using coordinates in a predetermined coordinate system; 3. A road machine according to claim 1 or 2.

5. The screed includes a front screed and left and right rear screeds that are extendable and retractable in the vehicle width direction, The first point is the left rear end point of the screed plate of the front screed, The second point is the right rear end point of the screed plate of the front screed, 3. A road machine according to claim 1 or 2.

6. The calculation device detects unevenness of the roadbed based on the output of at least one of the distance sensor and the inclination sensor and the dimensions of the traveling member, derives a straight line representing the roadbed including the unevenness, calculates the distance between the straight line and the first point as the first height, and calculates the distance between the straight line and the second point as the second height.

3. A road machine according to claim 2.

7. The straight line is an approximate straight line.

7. A road machine according to claim 6.

8. A road machine support system comprising: a tractor that travels on a roadbed; a hopper that is installed in front of the tractor and that receives paving material; a conveyor that feeds the paving material in the hopper to the rear of the tractor; a screw that spreads the paving material fed by the conveyor behind the tractor; and a screed that spreads the paving material behind the screw and levels it, A calculation device is provided to derive a first height and a second height of the screed relative to the roadbed, the first height is the height of a first point on the screed; the second height is the height of a second point on the screed; the first point is at a position different from the second point in the vehicle width direction, The calculation device derives a virtual line representing the roadbed based on the dimensions of a traveling member, calculates the distance between the virtual line and the first point as the first height, and calculates the distance between the virtual line and the second point as the second height. Road machinery assistance systems.

9. A road machinery support system comprising: a tractor that travels on a roadbed; a hopper installed in front of the tractor to receive paving material; a conveyor that feeds the paving material in the hopper to the rear of the tractor; a screw that spreads the paving material fed by the conveyor behind the tractor; and a screed that evens out the paving material spread by the screw behind the screw, A calculation device is provided to derive a first height and a second height of the screed relative to the roadbed, the first height is the height of a first point on the screed; the second height is the height of a second point on the screed; the first point is at a position different from the second point in the vehicle width direction, At least one of a distance sensor that detects the distance to the roadbed and an inclination sensor that detects the inclination of the tractor is attached to the tractor, The calculation device derives a virtual line representing the roadbed based on the output of at least one of the distance sensor and the inclination sensor and the dimensions of the traveling member, calculates the distance between the virtual line and the first point as the first height, and calculates the distance between the virtual line and the second point as the second height. Road machinery assistance systems.

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