WO2020203475A1

WO2020203475A1 - Asphalt finisher

Info

Publication number: WO2020203475A1
Application number: PCT/JP2020/013072
Authority: WO
Inventors: 渡邊　哲也; 英紀高山
Original assignee: 住友建機株式会社
Priority date: 2019-03-29
Filing date: 2020-03-24
Publication date: 2020-10-08
Also published as: JPWO2020203475A1; CN113924395A; EP3951061A4; EP3951061A1; JP7410931B2

Abstract

An asphalt finisher (100) comprises: an information acquisition device (51) that acquires information relating to the surface of a pavement material compacted by screeds (3); and a controller (50). The screeds (3) include a front-side screed (30) arranged offset in the vehicle length direction, and a rear-side screed (31). The controller (50) determines, based on the information acquired by the information acquisition device (51), the level difference (LD) formed between the surface of the pavement material compacted by the front-side screed (30) and the surface of the pavement material compacted by the rear-side screed (31).

Description

Asphalt finisher

This disclosure relates to asphalt finishers.

Conventionally, an asphalt finisher having a rear screed that can expand and contract in the left-right direction with respect to the front screed is known (see Patent Document 1). This asphalt finisher can increase the width of the road to be laid by extending the rear screed.

JP-A-2017-160636

However, the above-mentioned asphalt finisher has a surface of the pavement material compacted by the front screed (hereinafter referred to as "central pavement surface") and a surface of the pavement material compacted by the rear screed (hereinafter referred to as "side pavement surface"). ”) And are configured to partially overlap in the direction of travel.

Therefore, the above-mentioned asphalt finisher causes a difference between the height of the central pavement surface and the height of the side pavement surface, and as a result, causes a step on the pavement surface which is the surface of the finally produced pavement body. , There is a risk of degrading the quality of the pavement surface.

Therefore, it is desired to provide an asphalt finisher that can suppress deterioration of the quality of the pavement surface.

The asphalt finisher according to the embodiment of the present invention includes a tractor, a hopper installed on the front side of the tractor to receive the pavement material, a conveyor for feeding the pavement material in the hopper to the rear side of the tractor, and the conveyor. A screw that spreads the pavement material fed by the tractor on the rear side of the tractor, a screed that compacts the pavement material spread by the screw on the rear side of the screw, and a pavement material compacted by the screed. The screed includes an information acquisition device for acquiring information about the surface and a control device, and the screed includes a front side screed and a rear side screed arranged so as to be offset in the vehicle length direction, and the control device is the information acquisition device. Determines the presence or absence of a step formed between the surface of the pavement material compacted by the front screed and the surface of the pavement compacted by the rear screed, based on the information acquired by.

By the above-mentioned means, an asphalt finisher capable of suppressing deterioration of the quality of the pavement surface is provided.

It is a side view of the asphalt finisher which concerns on embodiment of this invention. It is a top view of the asphalt finisher of FIG. It is a block diagram which shows the configuration example of a screed elevating system. It is sectional drawing of a pavement body. It is a figure which shows the display example of the screen which is displayed on the display device. It is a figure which shows the display example of the screen which is displayed on the display device. It is a figure which shows the display example of the screen which is displayed on the display device. It is a flowchart of height adjustment processing. It is a side view of a screed and a pavement body. It is a side view of a screed and a pavement body. It is a side view of a screed and a pavement body. It is a side view of a screed and a pavement body.

FIG. 1 is a side view of an asphalt finisher 100 which is an example of a road machine according to an embodiment of the present invention. FIG. 2 is a top view of the asphalt finisher 100. The asphalt finisher 100 is mainly composed of a tractor 1, a hopper 2, a screed 3, and the like. In the following, the direction of the hopper 2 as seen from the tractor 1 (+ X direction) is the front, and the direction of the screed 3 as seen from the tractor 1 (−X direction) is the rear.

The tractor 1 is a mechanism for running the asphalt finisher 100. In the present embodiment, the tractor 1 uses the rear wheel running hydraulic motor to rotate the rear wheels 5, and uses the front wheel running hydraulic motor to rotate the front wheels 6 to move the asphalt finisher 100. The rear wheel running hydraulic motor and the front wheel running hydraulic motor rotate by receiving the supply of hydraulic oil from the hydraulic pump. The rear wheels 5 and the front wheels 6 may be replaced by crawlers.

The controller 50 is a control device that controls the asphalt finisher 100. In the present embodiment, the controller 50 is composed of a microcomputer including a CPU, a memory, a non-volatile storage device, and the like, and is mounted on the tractor 1. The functional elements that carry out each function of the controller 50 are realized by the CPU executing the program stored in the non-volatile storage device. However, each functional element in the controller 50 may be composed of hardware, firmware, or the like.

Hopper 2 is a mechanism for accepting pavement materials. In the present embodiment, the hopper 2 is installed on the front side of the tractor 1 and is configured to be opened and closed in the Y-axis direction (vehicle width direction) by the hopper cylinder. The asphalt finisher 100 normally receives the pavement material from the loading platform of the dump truck with the hopper 2 fully open. The paving material is, for example, an asphalt mixture. 1 and 2 show that the hopper 2 is in the fully open state. The operator of the asphalt finisher 100 normally closes the hopper 2 when the pavement material in the hopper 2 decreases, and collects the pavement material near the inner wall of the hopper 2 in the central portion of the hopper 2. This is so that the pavement material can be fed to the rear side of the tractor 1 by the conveyor CV in the central portion of the hopper 2. The pavement material fed to the rear side of the tractor 1 is spread in the vehicle width direction by the screw SC on the rear side of the tractor 1 and the front side of the screed 3. In the present embodiment, the screw SC is in a state where the extension screw is connected to the left and right. 1 and 2 show the pavement material PV spread by the screw SC in a rough satin pattern.

Screed 3 is a mechanism for compacting the pavement material PV. In this embodiment, 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, and the rear screed 31 includes a left rear screed 31L and a right rear screed 31R.

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 screed 3 is moved up and down together with the leveling arm 3A by the expansion and contraction of the scree drift cylinder 25.

The leveling cylinder 28 is a hydraulic cylinder that moves the front end portion of the leveling arm 3A up and down in order to adjust the leveling thickness of the pavement material. In this embodiment, the leveling cylinder 28 includes a left leveling cylinder 28L and a right leveling cylinder 28R.

In the present embodiment, the rear screed 31 is configured to be expandable and contractible in the vehicle width direction by a telescopic cylinder (not shown). However, the rear screed 31 may be a fixed (non-expandable) screed that is connected at the time of use using a crane or the like.

A screed lifting device 29 is attached to the connecting portion between the front screed 30 and the rear screed 31. The screed elevating device 29 is configured to be able to move the rear screed 31 up and down with respect to the front screed 30. In the present embodiment, the screed elevating device 29 rotates a screed elevating motor as a hydraulic actuator in response to a control command from the controller 50, and drives a rotation / linear motion conversion mechanism attached to the rear screed 31. The rear screed 31 is moved up and down. The screed lifting device 29 includes a left screed lifting device 29L that moves the left rear screed 31L up and down, and a right screed lifting device 29R that moves the right rear screed 31R up and down. The rotation / linear motion conversion mechanism is, for example, a bolt / nut mechanism. The rotation / linear motion conversion mechanism may be another mechanism such as a ball screw mechanism or a rack and pinion mechanism. The screed elevating motor may be an electric motor. The screed lifting device 29 may be a hydraulic cylinder.

A mold board 43 is attached to the front part of the screed 3. The mold board 43 includes a left mold board 43L and a right mold board 43R. The left mold board 43L is configured so that the amount of pavement material PV staying in front of the left rear screed 31L can be adjusted. The right mold board 43R is configured so that the amount of pavement material PV staying in front of the right rear screed 31R can be adjusted. The pavement material PV passes under the left rear screed 31L through the gap between the lower end of the left mold board 43L and the roadbed RB, and passes through the gap between the lower end of the right moldboard 43R and the roadbed RB to the right. It reaches under the rear screed 31R.

The center crown device 26 is mounted on the front screed 30. The center crown device 26 expands and contracts the turnbuckle attached between the left front screed 30L and the right front screed 30R, and the lower surface of the left front screed 30L (left front screed plate) and the right front screed when viewed from the rear. It is a mechanism for adjusting the angle between the 30R (right front screed plate) and the lower surface. Specifically, the center crown device 26 rotates the hydraulic motor in response to a control command from the controller 50 to rotate the body of the turnbuckle and expand and contract the turnbuckle.

A slope crown device 27 is mounted between the front screed 30 and the rear screed 31. The slope crown device 27 includes a left slope crown device 27L and a right slope crown device 27R. Specifically, the left slope crown device 27L is mounted between the left front screed 30L and the left rear screed 31L, and the right slope crown device 27R is mounted between the right front screed 30R and the right rear screed 31R. ing.

The left slope crown device 27L expands and contracts the turnbuckle attached between the left front screed 30L and the left rear screed 31L, and the lower surface and the left of the left front screed 30L (left front screed plate) when viewed from the rear. It is a mechanism for adjusting the angle between the rear screed 31L (left rear screed plate) and the lower surface. Specifically, the left slope crown device 27L rotates the hydraulic motor in response to a control command from the controller 50 to rotate the body of the turnbuckle and expand and contract the turnbuckle. The same applies to the right slope crown device 27R.

The scaffold step 42 is a member that constitutes a scaffold when an operator works behind the scaffold 3.

A guide rail 1G that can be used as a handrail by the operator of the asphalt finisher 100 is installed on the upper part of the tractor 1. The operator of the asphalt finisher 100 includes an operator who operates the tractor 1, an operator who operates the screed 3, and the like. An information acquisition device 51 is attached to the guide rail 1G. The information acquisition device 51 may be attached to the canopy or may be directly attached to the main body of the tractor 1. Further, the information acquisition device 51 may be attached to the front screed 30 or may be attached to the rear screed 31.

The information acquisition device 51 is configured to be able to acquire information on the surface of the pavement material PV compacted by the screed 3. In the present embodiment, the information acquisition device 51 is a lidar configured to be able to measure the distance to an object existing around the asphalt finisher 100, and includes a space behind the screed 3 as a measurement range.

The measurement range of LIDAR is set so as to reliably detect a step that can be formed between the central pavement surface CP having the width W1 and the side pavement surface SP, for example, as shown in FIG. The side pavement surface SP includes a left side pavement surface LP having a width W2 and a right side pavement surface RP having a width W3. The step LD shown by the solid line in FIG. 2 is an example of a step formed between the central pavement surface CP and the left side pavement surface LP.

The measurement range of LIDAR is set to include, for example, the range of the pavement surface having a width larger than the width of the front side screed 30 (that is, the width W1 of the central pavement surface CP). Then, the LIDAR is configured so that, for example, the distance between each of one or more points within the measurement range and the LIDAR (reference point) can be measured. The range Z0 to Z2 shown by the alternate long and short dash line in FIG. 2 shows three examples of the measurement range of LIDAR. In FIG. 2, for clarity, the range Z0 is shown at a position farther than the range Z1 and the range Z2 when viewed from the asphalt finisher 100 so as not to overlap the ranges Z1 and Z2. However, the positional relationship in the vehicle length direction of the ranges Z0 to Z2 in FIG. 2 does not represent the actual positional relationship. Actually, it is desirable that all the ranges Z0 to Z2 are arranged as close to the asphalt finisher 100 as possible as long as the step can be detected.

The range Z0 is set to include the entire width of the new pavement NP, which is the pavement laid by the asphalt finisher 100. The range Z1 does not include the entire width of the new pavement body NP, but is set to include a width wider than the width of the front screed 30.

The range Z2 is set to include four independent ranges of the range Z2a, the range Z2b, the range Z2c, and the range Z2d. Specifically, the range Z2a and the range Z2b are arranged so as to detect a step that can be formed between the central pavement surface CP and the left side pavement surface LP. The range Z2c and the range Z2d are arranged so that a step that can be formed between the central pavement surface CP and the right side pavement surface RP can be detected. More specifically, the range Z2a is arranged so that a step (hereinafter, referred to as "left outer step") that can be formed by the left end portion of the left front screed 30L is detected. The left outer step is typically formed when the left pavement LP is higher than the central pavement CP. The range Z2b is arranged so that a step that can be formed by the right end portion of the left rear screed 31L (hereinafter, referred to as “left inner step”) is detected. The left medial step is typically formed when the central pavement CP is higher than the left pavement LP. The range Z2c is arranged so that a step that can be formed by the left end portion of the right rear screed 31R (hereinafter, referred to as “right inner step”) is detected. The right medial step is typically formed when the central pavement CP is higher than the right pavement RP. The range Z2d is arranged so that a step that can be formed by the right end portion of the right front screed 30R (hereinafter, referred to as “right outer step”) is detected. The right outer step is typically formed when the right pavement RP is higher than the central pavement CP.

The information acquisition device 51 may be a monocular camera, a stereo camera, a millimeter wave radar, an ultrasonic sensor, a laser radar, a laser scanner, a range image camera, a laser range finder, or the like.

In the present embodiment, one information acquisition device 51 is attached to the asphalt finisher 100, but a plurality of information acquisition devices 51 may be attached to the asphalt finisher 100.

The display device 52 is configured to display information about the asphalt finisher 100. In the present embodiment, the display device 52 is a liquid crystal display installed in front of the driver's seat 1S.

The communication device 53 is configured to control communication between the asphalt finisher 100 and a device outside the asphalt finisher 100. In the present embodiment, the communication device 53 is installed in front of the driver's seat 1S.

Next, the screed elevating system LS mounted on the asphalt finisher 100 will be described with reference to FIGS. 3 and 4. FIG. 3 is a block diagram showing a configuration example of the screed elevating system LS. FIG. 4 is a cross-sectional view of the newly constructed pavement body NP, and shows a state when the vertical plane including the alternate long and short dash line SE in FIG. 2 is viewed from the + X side.

The screed lifting system LS is mainly composed of a center crown device 26, a slope crown device 27, a leveling cylinder 28, a screed lifting device 29, a controller 50, an information acquisition device 51, a display device 52, a communication device 53, and the like. ..

The controller 50 includes an information acquisition unit 50a, a crown device drive unit 50b, a leveling cylinder drive unit 50c, and a screed elevating device drive unit 50d as functional elements. The information acquisition unit 50a, the crown device drive unit 50b, the leveling cylinder drive unit 50c, and the screed elevating device drive unit 50d are shown separately for convenience of explanation, but need to be physically separated. It may be composed of software components or hardware components that are common in whole or in part.

The information acquisition unit 50a is configured to be able to acquire information on the surface of the new pavement body NP. In the present embodiment, the information acquisition unit 50a measures the finished shape of the surface of the new pavement body NP based on the output of the lidar as the information acquisition device 51. Specifically, the information acquisition unit 50a measures the finished shape of the surface of the new pavement body NP using the local coordinate system centered on LIDAR and the reference coordinate system. That is, the information acquisition unit 50a specifies the coordinates in the reference coordinate system corresponding to each point on the surface of the new pavement NP by converting the coordinates in the local coordinate system into the coordinates in the reference coordinate system. The reference coordinate system is, for example, the world geodetic coordinate system. The world geographic coordinate system is a three-dimensional Cartesian coordinate system with the origin at the center of gravity of the earth, the X axis in the direction of the intersection of the Greenwich meridian and the equator, the Y axis in the direction of 90 degrees east longitude, and the Z axis in the direction of the North Pole. It is an XYZ coordinate system.

The information acquisition unit 50a is configured to be able to measure the surface shape of the new pavement NP within the measurement range during construction, that is, while the asphalt finisher 100 is advancing.

In the present embodiment, the information acquisition unit 50a sets a point on the feature AP outside the width direction of the new pavement NP as the reference point R1. The reference point R1 is set at the upper end of the L-shaped curb that separates the new pavement NP. However, the feature AP may be another member such as a wooden frame used to divide the new pavement body NP. Alternatively, the information acquisition unit 50a may set a virtual point that is not on the feature AP, such as a point vertically above the upper end of the curb by a predetermined height, as a reference point R1.

Specifically, the information acquisition unit 50a detects the curb based on the output of the rider, and sets the upper end of the curb at a position separated by a predetermined distance in the −X direction from the rear end of the asphalt finisher 100 as a reference point R1. Set as.

After that, the information acquisition unit 50a sets a line that passes through the reference point R1 and is parallel to the width direction (Y-axis direction) of the new pavement NP as a virtual water thread VS. The virtual water thread VS is typically a horizontal line passing through the reference point R1.

After that, the information acquisition unit 50a derives the vertical distance between the virtual water thread VS and the surface of the new pavement body NP. In the present embodiment, the information acquisition unit 50a sets a plurality of points (here, for convenience, 19 points P1 to P19) on the virtual water thread VS at equal intervals. Then, the points Q1 to Q19 on the surface of the new pavement body NP existing directly below each of the points P1 to P19 are specified. Specifically, the information acquisition unit 50a identifies points Q1 to Q19 based on the distance between each point on the surface of the new pavement NP and LIDAR output by LIDAR.

After that, the information acquisition unit 50a calculates the distance D1 between the point P1 and the point Q1. In the present embodiment, the information acquisition unit 50a calculates the distance D1 based on the distance between the point P1 and the lidar and the distance between the point Q1 and the lidar output by the lidar. The same applies to the distances D2 to D19. The information acquisition unit 50a may calculate the thickness of the new pavement NP corresponding to each of the distances D1 to D19 based on the height of the roadbed RB derived from the reference point R1.

The points set on the virtual water thread VS may be arranged at unequal intervals. Further, the number of points may be less than 19 or 20 or more.

After that, the information acquisition unit 50a causes the display device 52 to display the measurement results of the distances D1 to D19. In the present embodiment, the information acquisition unit 50a causes the display device 52 to display the measurement results of the distances D1 to D19 by using a chart. However, the information acquisition unit 50a may display the measurement results of the distances D1 to D19 only as numerical values, or may display as a combination of a chart and numerical values. Alternatively, the information acquisition unit 50a may be configured to display information on the measurement result only when it is determined that the measurement result is abnormal.

The information acquisition unit 50a may determine whether or not there is a step on the pavement surface based on the measurement results of the distances D1 to D19. For example, when the difference in distance between adjacent points (for example, the difference between the distance D8 with respect to the point P8 and the distance D9 with respect to the point P9) is equal to or greater than a predetermined value, the information acquisition unit 50a is located between the points P8 and P9. It is determined that the step LD exists. In this case, the information acquisition unit 50a may display the determination result of the presence / absence of the step on the display device 52. Further, when the information acquisition unit 50a determines that a step exists, the information acquisition unit 50a may display information regarding the position of the step.

The information acquisition unit 50a may determine the presence or absence of a step by performing image processing on the image captured by the image pickup device as the information acquisition device 51. The image pickup apparatus is, for example, a monocular camera, a stereo camera, an infrared camera, a range image camera, a lidar, or the like. The image processing includes, for example, binarization processing, edge detection processing, Hough transform processing, and the like. In this case, the imaging range of the imaging device may include at least the range of the pavement surface shown in the range Z2 of FIG.

The information acquisition unit 50a may transmit calculation results such as measurement results of distances D1 to D19 and determination results of presence / absence of steps to an external device. For example, the information acquisition unit 50a may transmit the calculation result to a management device such as a server installed in an external management center or the like, or a support device such as a smartphone carried by the worker. This is to display the same information as the information displayed on the display device 52 on the display device attached to the management device or the support device.

The information acquisition unit 50a may calculate the difference between the distance D1 and the ideal distance D1T corresponding to the distance D1 as the unevenness of the surface of the new pavement body NP, and output the magnitude of the unevenness as the measurement result. .. The ideal distance D1T is pre-stored in, for example, a non-volatile storage device. If the distance D1 matches the ideal distance D1T, the height of the points on the surface of the new pavement NP corresponding to the distance D1 is equal to the reference height defined by the feature AP. The same applies to the distances D2 to D19. In this case, the information acquisition unit 50a may display the size of the unevenness corresponding to each of the distances D1 to D19 on the display device 52 together with the measurement results of the distances D1 to D19. Alternatively, the information acquisition unit 50a may display the size of the unevenness corresponding to each of the distances D1 to D19 on the display device 52 instead of the measurement results of the distances D1 to D19. The information acquisition unit 50a may display the size of the unevenness on the display device 52 using a chart.

When the size of the unevenness on the surface of the new pavement body NP exceeds a predetermined value, the information acquisition unit 50a may display the fact on the display device 52. In this case, the information acquisition unit 50a may output an alarm from a voice output device (not shown).

The controller 50 may display an image acquired by a camera (not shown) attached to the asphalt finisher 100 that images the rear of the asphalt finisher 100 on the display device 52. Then, the information acquisition unit 50a may superimpose and display information on the measurement results of the distances D1 to D19 on the image acquired by the camera. In this case, the information regarding the measurement results of the distances D1 to D19 may be, for example, a numerical value or a figure representing the size of the unevenness, or a figure or the like representing a step.

When the information acquisition unit 50a continuously measures the finished shape of the surface of the new pavement NP in the traveling direction (X-axis direction) of the asphalt finisher 100, the distribution of the size of the unevenness on the surface and the step on the surface. The display device 52 may display a diagram showing at least one such as the presence or absence of the above. This figure includes, for example, at least one of a figure in which the concave portion is represented in red and the convex portion is represented in blue, and a graphic in which the step is represented by a straight line, etc. ..

The crown device drive unit 50b is configured to drive at least one of the center crown device 26 and the slope crown device 27. In the present embodiment, the crown device drive unit 50b operates the center crown device 26 and the slope crown device 27 individually by using a hydraulic pump, a hydraulic motor, a control valve, and the like. Specifically, the crown device drive unit 50b individually operates the center crown device 26 and the slope crown device 27 in response to a command from an operator of the asphalt finisher 100 via an input device (not shown). The crown device drive unit 50b may operate the center crown device 26 and the slope crown device 27 individually and autonomously in response to a control command from the controller 50, in addition to the command from the operator.

The leveling cylinder drive unit 50c is configured to drive the leveling cylinder 28. The leveling cylinder drive unit 50c operates the leveling cylinder 28 by using a hydraulic pump, a control valve, and the like. Specifically, the leveling cylinder drive unit 50c operates the leveling cylinder 28 in response to a command from the operator of the asphalt finisher 100 via the input device. The leveling cylinder drive unit 50c may autonomously operate the leveling cylinder 28 in response to a control command from the controller 50, in addition to a command from the operator.

The screed lifting device drive unit 50d is configured to drive the screed lifting device 29. The screed lifting device 29 is a mechanism for moving the rear screed 31 up and down in order to eliminate a step formed between the pavement surface compacted by the front screed 30 and the pavement surface compacted by the rear screed 31. Is. Eliminating the step means preventing the step detected by the controller 50 from being continuously formed thereafter. The step that has already been formed is removed by using, for example, a rake for leveling work, a road roller, a plate compactor, or the like.

The screed lifting device drive unit 50d operates the screed lifting device 29 by using a hydraulic pump, a hydraulic motor, a control valve, and the like. Specifically, the screed lifting device drive unit 50d operates the screed lifting device 29 in response to a command from the operator of the asphalt finisher 100 via the input device. The screed elevating device drive unit 50d may autonomously operate the screed elevating device 29 in response to a control command from the controller 50, in addition to a command from the operator.

For example, the operator who sees the measurement results of the distances D1 to D19 displayed on the display device 52 may operate the center crown device 26 via the input device and the crown device drive unit 50b. This is to adjust the angle between the lower surface of the left front screed plate and the lower surface of the right front screed plate when viewed from the rear.

When the controller 50 detects that the thickness of the left side portion (+ Y side portion) of the new pavement body NP formed by the left rear screed 31L is increasing toward the outside, the crown device drive unit 50b A control command may be output to. In this case, the crown device drive unit 50b causes the left slope crown device 27L to perform adjustment in response to a control command from the controller 50.

The operator who sees the measurement results of the distances D1 to D19 not only operates the center crown device 26 or the slope crown device 27 in order to adjust the thickness of the new pavement NP, but also via the leveling cylinder drive unit 50c. The leveling cylinder 28 may be operated. This is because when adjusting the thickness of the new pavement NP, the adjustment by the leveling cylinder is more effective than the adjustment by the center crown device 26 and the slope crown device. Further, the operator who sees the information notifying that the step exists may operate the screed elevating device 29 in order to eliminate the step.

When it is detected that a step is generated between the pavement surface formed by the front screed 30 and the pavement surface formed by the rear screed 31, the controller 50 may refer to, for example, the screed lifting device drive unit 50d. You may output a control command. In this case, the screed elevating device drive unit 50d operates the screed elevating device 29 in response to the control command from the controller 50 to eliminate the step. Specifically, the screed elevating device drive unit 50d includes, for example, a pavement surface compacted by the left front screed 30L and a pavement surface compacted by the left rear screed 31L by operating the screed elevating device 29. The left rear side screed 31L is moved up and down in order to eliminate the step formed between the two. More specifically, the screed elevating device drive unit 50d rotates a screed elevating motor as a hydraulic actuator constituting the screed elevating device 29 in response to a control command from the controller 50, and causes the left rear screed 31L to rotate. The attached rotation / linear motion conversion mechanism is driven to move the left rear screed 31L up and down.

As described above, the controller 50 may autonomously control at least one of the center crown device 26, the slope crown device 27, the leveling cylinder 28, and the screed elevating device 29. Alternatively, the operator may manually control at least one of the center crown device 26, the slope crown device 27, the leveling cylinder 28, and the screed elevating device 29 while checking the contents displayed on the display device 52. ..

Next, referring to FIGS. 5A to 5C, the screen GX displayed on the display device 52 by the controller 50 when the controller 50 detects a step formed between the central pavement surface CP and the side pavement surface SP. Will be described. 5A to 5C show three display examples of the screen GX. Specifically, FIG. 5A is a screen GX displayed when a step formed by the right end portion of the left rear screed 31L and a step formed by the right end portion of the right front screed 30R are detected. .. FIG. 5B is a screen GX displayed when a step formed by the left end portion of the left front screed 30L is detected. FIG. 5C is a screen GX displayed when a step formed by the left end portion of the right rear screed 31R is detected.

The screen GX shown in FIGS. 5A to 5C includes an airframe figure GM, a pavement material figure GP, and a road surface figure GR as common figures.

The body figure GM represents the top view of the asphalt finisher 100. In the present embodiment, the airframe figure GM represents a top view of a portion behind the screw SC.

The pavement material figure GP represents the top view of the pavement material PV before being compacted by the screed 3. In the present embodiment, the pavement material figure GP is represented by a coarse (thin) satin pattern.

The road surface figure GR represents the top view of the newly constructed pavement body NP. In the present embodiment, the road surface figure GR is represented by a fine (dark) satin pattern.

FIG. 5A includes figures G11, G12, G21, and G22. The figure G11 represents the left inner step formed by the right end portion of the left rear screed 31L. In the present embodiment, the figure G11 is represented by a thick broken line. The step LD shown by the solid line in FIG. 2 is an example of the left inner step. The left inner step is formed when the height of the pavement surface compacted by the left front screed 30L is higher than the height of the pavement compacted by the left rear screed 31L.

The figure G12 represents the right outer step formed by the right end portion of the right front screed 30R. In the present embodiment, the figure G12 is represented by a thick broken line. The right outer step is formed when the height of the pavement surface compacted by the right front screed 30R is lower than the height of the pavement compacted by the right rear screed 31R.

The figure G21 is displayed when a step on the left inner side is detected. In the present embodiment, the figure G21 is a balloon including character information regarding measures that can be taken to eliminate the left inner step, and indicates the position of the figure G11. The figure G21 can inform the operator of the asphalt finisher 100 that the left rear screed 31L is autonomously raised by the controller 50 by displaying text information such as "raise the left", for example.

The figure G22 is displayed when the right outer step is detected. In the present embodiment, the figure G22 is a balloon including character information regarding measures that can be taken to eliminate the right outer step, and indicates the position of the figure G12. The figure G22 can inform the operator of the asphalt finisher 100 that the right rear screed 31R is autonomously lowered by the controller 50 by displaying text information such as "lower right", for example.

FIG. 5B includes figures G13 and G23. Figure G13 represents the left outer step formed by the left end of the left front screed 30L. In the present embodiment, the figure G13 is represented by a thick broken line. The left outer step is formed when the height of the pavement surface compacted by the left front screed 30L is lower than the height of the pavement compacted by the left rear screed 31L.

The figure G23 is displayed when the left outer step is detected. In the present embodiment, the figure G23 is a balloon including character information regarding measures that can be taken to eliminate the left outer step, and indicates the position of the figure G13. The figure G23 can inform the operator of the asphalt finisher 100 that the left rear screed 31L is autonomously lowered by the controller 50 by displaying text information such as "lowering the left", for example.

FIG. 5C includes figures G14 and G24. The figure G14 represents a right inner step formed by the left end portion of the right rear screed 31R. In the present embodiment, the figure G14 is represented by a thick broken line. The right inner step is formed when the height of the pavement surface compacted by the right front screed 30R is higher than the height of the pavement compacted by the right rear screed 31R.

The figure G24 is displayed when a step on the right inner side is detected. In the present embodiment, the figure G24 is a balloon including character information regarding measures that can be taken to eliminate the step on the right inner side, and points to the position of the figure G14. The figure G24 can inform the operator of the asphalt finisher 100 that the right rear screed 31R is autonomously lowered by the controller 50, for example, by displaying text information such as "raise to the right".

Next, referring to FIG. 6, a process in which the controller 50 adjusts the height of the rear screed 31 in order to eliminate the step formed between the central pavement surface CP and the side pavement surface SP (hereinafter, “” "Height adjustment process") will be described. FIG. 6 is a flowchart of the height adjustment process. The controller 50 repeatedly executes this height adjustment process at a predetermined control cycle, for example, when the asphalt finisher 100 is moving forward.

First, the controller 50 determines whether or not there is a high step on the left outer side (step ST1). In the present embodiment, the information acquisition unit 50a of the controller 50 determines the presence or absence of the left outer step based on the output of the lidar as the information acquisition device 51.

When it is determined that the left outer step exists (YES in step ST1), the controller 50 lowers the left rear screed 31L (step ST2). This is to eliminate the left outer step by lowering the left side pavement LP higher than the central pavement CP and adjusting the height of the left side pavement LP to the height of the central pavement CP. In the present embodiment, the information acquisition unit 50a of the controller 50 outputs a control command for lowering the left rear screed 31L to the screed elevating device drive unit 50d. The screed elevating device drive unit 50d operates the left screed elevating device 29L in response to a control command from the information acquisition unit 50a to lower the left rear screed 31L.

When it is determined that there is no high step on the left outer side (NO in step ST1), the controller 50 determines whether or not there is a high step on the left inner side (step ST3). In the present embodiment, the information acquisition unit 50a of the controller 50 determines the presence or absence of the left inner step based on the output of the lidar as the information acquisition device 51.

When it is determined that there is a high step on the left inner side (YES in step ST3), the controller 50 raises the left rear screed 31L (step ST4). This is to eliminate the left inner step by raising the left side pavement LP lower than the central pavement CP and adjusting the height of the left side pavement LP to the height of the central pavement CP. In the present embodiment, the information acquisition unit 50a of the controller 50 outputs a control command for raising the left rear screed 31L to the screed elevating device drive unit 50d. The screed elevating device drive unit 50d operates the left screed elevating device 29L in response to a control command from the information acquisition unit 50a to raise the left rear screed 31L.

The controller 50 may be configured to determine whether or not there is a left outer step after determining whether or not there is a left inner step.

After that, the controller 50 determines whether or not there is a high step on the right outer side (step ST5). In the present embodiment, the information acquisition unit 50a of the controller 50 determines the presence or absence of the right outer step based on the output of the lidar as the information acquisition device 51.

When it is determined that there is a high step on the right outer side (YES in step ST5), the controller 50 lowers the right rear screed 31R (step ST6). This is to eliminate the right outer step by lowering the right side pavement RP higher than the central pavement CP and adjusting the height of the right side pavement RP to the height of the central pavement CP. In the present embodiment, the information acquisition unit 50a of the controller 50 outputs a control command for lowering the right rear screed 31R to the screed elevating device drive unit 50d. The screed elevating device drive unit 50d operates the right screed elevating device 29R in response to a control command from the information acquisition unit 50a to lower the right rear screed 31R.

When it is determined that there is no high step on the right outer side (NO in step ST5), the controller 50 determines whether or not there is a high step on the right inner side (step ST7). In the present embodiment, the information acquisition unit 50a of the controller 50 determines the presence or absence of the right inner step based on the output of the lidar as the information acquisition device 51.

When it is determined that there is a high step on the right inside (YES in step ST7), the controller 50 raises the right rear screed 31R (step ST8). This is to eliminate the right inner step by raising the right side pavement RP lower than the central pavement CP and adjusting the height of the right side pavement RP to the height of the central pavement CP. In the present embodiment, the information acquisition unit 50a of the controller 50 outputs a control command for raising the right rear screed 31R to the screed elevating device drive unit 50d. The screed elevating device drive unit 50d operates the right screed elevating device 29R in response to a control command from the information acquisition unit 50a to raise the right rear screed 31R.

The controller 50 may be configured to determine whether or not there is a left outer step after determining whether or not there is a right inner step.

The controller 50 may determine the existence or nonexistence of each of the right inner step and the right outer step, and then determine the existence or nonexistence of each of the left inner step and the left outer step, and the left inner step, the left outer step, and the right inner step may be determined. , And the presence or absence of each of the right outer step may be determined separately in any order.

With the above configuration, the controller 50 can prevent the step formed between the central pavement surface CP and the side pavement surface SP from continuing for a long distance.

Next, with reference to FIGS. 7A to 7D, the movement of the screed 3 when eliminating the step LD (see FIG. 2), which is an example of the left inner step, will be described. 7A to 7D are side views of the screed 3 and the new pavement NP when the new pavement NP of FIG. 2 is viewed from the + Y side. However, in FIGS. 7A to 7D, for the sake of clarity, most of the screed 3 except for the left front screed plate 30LP of the left front screed 30L and the left rear screed plate 31LP of the left rear screed 31L is omitted. ing. The following description relates to the case where the left rear screed 31L is raised, the case where the left rear screed 31L is lowered, the case where the right rear screed 31R is raised, and the case where the right rear screed 31R is lowered. The same applies to.

Specifically, FIG. 7A is a diagram when the controller 50 detects the step LD and starts ascending the left rear screed 31L. FIG. 7B is a diagram when the controller 50 raises the left rear screed 31L. FIG. 7C is a diagram when the controller 50 finishes ascending the left rear screed 31L. FIG. 7D is a view when a pavement surface without a step is formed.

As shown in FIG. 7A, when the controller 50 detects the step LD having the length L0 in the X-axis direction as the left inner step, it operates the left screed elevating device 29L and operates the left rear screed in the direction indicated by the arrow AR1. Start the rise of 31L. At the time of FIG. 7A, the size of the step LD corresponding to the difference between the height of the rear end portion of the left front screed plate 30LP and the height of the rear end portion of the left rear screed plate 31LP is the value DP1. Further, the swallowing angle β of the left rear screed plate 31LP is larger than the swallowing angle α of the left front screed plate 30LP.

After that, as shown in FIG. 7B, the controller 50 moves in the direction indicated by the arrow AR2 until the height of the rear end of the left front screed plate 30LP and the height of the rear end of the left rear screed plate 31LP match. Continue to rise the left rear screed 31L. In the present embodiment, the controller 50 raises the left rear screed 31L at a predetermined ascending speed regardless of the value DP1 which is the size of the step LD when the left rear screed 31L starts to rise. There is. However, the controller 50 may determine the target ascending speed and the target ascending width based on the value DP1. At the time of FIG. 7B, the size of the step LD is a value DP2 smaller than the value DP1.

After that, when the ascending width of the left rear screed 31L reaches the target ascending width, the controller 50 stops the ascending of the left rear screed 31L as shown in FIG. 7C. The step LD is eliminated when the length in the X-axis direction reaches the value L1. At the time of FIG. 7C, the size of the step LD is zero.

After that, the controller 50 maintains the height of the left rear screed 31L when the ascent of the left rear screed 31L is stopped. As a result, as shown in FIG. 7D, the asphalt finisher 100 can form a paved surface without steps.

With the above configuration, the asphalt finisher 100 automatically detects the step formed between the central pavement surface CP and the side pavement surface SP, and then the rear screed 31 so as to eliminate the step. Can be moved up and down autonomously. Therefore, it is possible to prevent the length of the step in the traveling direction from becoming excessive. As a result, the asphalt finisher 100 can improve the work efficiency by reducing the work for removing the step that has already been formed.

Further, the asphalt finisher 100 can form a pavement with few steps without being influenced by the skill level of the operator regarding the manual operation of the screed lifting device 29. Therefore, the asphalt finisher 100 can maintain the quality of the pavement formed at a certain level or higher.

As described above, the asphalt finisher 100 according to the embodiment of the present invention has the tractor 1, the hopper 2 installed on the front side of the tractor 1 and accepting the pavement material, and the pavement material in the hopper 2 to the rear side of the tractor 1. A conveyor CV to be fed, a screw SC that spreads the pavement material fed by the conveyor CV on the rear side of the tractor 1, and a screed 3 that compacts the pavement material spread by the screw SC on the rear side of the screw SC. The information acquisition device 51 for acquiring information on the surface of the pavement material compacted by the screed 3 and the controller 50 as a control device are provided. The screed 3 includes a front screed 30 and a rear screed 31 that are arranged so as to be offset in the vehicle length direction. Then, the controller 50 is a step formed between the surface of the pavement material compacted by the front screed 30 and the surface of the pavement material compacted by the rear screed 31 based on the information acquired by the information acquisition device 51. It is configured to determine the presence or absence of.

With this configuration, the asphalt finisher 100 can detect that a step has been formed at an early stage, so that deterioration of the quality of the formed pavement surface can be suppressed.

The information acquisition device 51 is preferably attached to the canopy or the tractor 1. With this configuration, the asphalt finisher 100 can improve the measurement accuracy of the finished shape of the surface of the newly constructed pavement NP. This is because both the canopy and the tractor 1 have less vibration than the screed 3. However, the information acquisition device 51 may be attached to the screed 3. In this case, the information acquisition device 51 can acquire information on the surface of the pavement material at a position close to the surface of the pavement material compacted by the screed 3.

The asphalt finisher 100 preferably includes a controller 50 as a control device that calculates the unevenness of the road surface with respect to the reference height determined by the feature AP based on the output of the information acquisition device 51, or determines the presence or absence of a step. ing. With this configuration, the asphalt finisher 100 can easily measure the shape of the surface of the new pavement NP by itself without being connected to other devices, or the presence or absence of a step on the surface of the new pavement NP can be determined. It can be easily determined. The information acquisition device 51 can also be used to realize other functions such as backward monitoring. Further, the operator of the asphalt finisher 100 can intuitively grasp the state of the finished shape of the surface of the new pavement NP by looking at the information on the unevenness with respect to the reference height on the surface of the new pavement NP.

The asphalt finisher 100 preferably has a display function for displaying the result of calculation by the controller 50. The display function can be applied to a display device 52 mounted on the asphalt finisher 100, a display device attached to a management device such as a computer installed in an external management center, or a support device such as a smartphone carried by an operator. It is realized by the attached display device and the like. With this configuration, the asphalt finisher 100 can convey information about the new pavement NP to the operator of the asphalt finisher 100 or the workers working around the asphalt finisher 100.

The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions can be applied to the above-described embodiments without departing from the scope of the present invention. In addition, each of the features described with reference to the above-described embodiments may be appropriately combined as long as there is no technical conflict.

For example, the asphalt finisher 100 may include a front screed lifting device that moves the front screed 30 up and down, in addition to the screed lifting device 29 that moves the rear screed 31 up and down. In this case, the asphalt finisher 100 may be configured so that the left front screed 30L and the right front screed 30R can be moved up and down separately.

Further, in the above-described embodiment, the controller 50 is configured to automatically detect the step and then move the rear screed 31 up and down to autonomously eliminate the step. However, the controller 50 may be configured to notify the operator that a step has been detected and then prompt the operator to move the rear screed 31 up and down. In this case, the controller 50 may use at least one of sound, light, vibration, and the like to assist the operator in manually operating the screed lifting device 29.

This application claims priority based on Japanese Patent Application No. 2019-066680 filed on March 29, 2019, and the entire contents of this Japanese patent application are incorporated herein by reference.

1 ... tractor 1G ... guide rail 1S ... driver's seat 2 ... hopper 3 ... screed 3A ... leveling arm 5 ... rear wheel 6 ... front wheel 25 ... scree drift Cylinder 26 ... Center crown device 27 ... Slope crown device 28 ... Leveling cylinder 29 ... Screed lifting device 30 ... Front side screed 31 ... Rear screed 43 ... Mold board 50 ...・ Controller 50a ・・・ Information acquisition unit 50b ・・・ Crown device drive unit 50c ・・・ Leveling cylinder drive unit 50d ・・・ Pavement elevating device drive unit 51 ・・・ Information acquisition device 52 ・・・ Display device 53 ・・・ Communication device 100 ・・・ Asphalt finisher AP ・・・ Feature CV ・・・ Conveyor NP ・・・ New pavement PV ・・・ Pavement material RB ・・・ Roadbed SC ・・・ Cylinder

Claims

With a tractor
A hopper installed on the front side of the tractor to receive pavement material,
A conveyor that feeds the pavement material in the hopper to the rear side of the tractor,
A screw that spreads the pavement material fed by the conveyor behind the tractor, and
A screed that compacts the pavement material spread by the screw on the rear side of the screw,
An information acquisition device that acquires information on the surface of the pavement material compacted by the screed, and
Equipped with a control device,
The screed includes a front screed and a rear screed that are staggered in the vehicle length direction.
The control device is a step formed between the surface of the pavement material compacted by the front screed and the surface of the pavement compacted by the rear screed based on the information acquired by the information acquisition device. Judging the existence,
Asphalt finisher.
It is equipped with an actuator that moves the rear screed up and down.
The control device determines whether to raise or lower the rear screed by the actuator according to the position of the step in the vehicle width direction.
The asphalt finisher according to claim 1.
The information acquisition device is attached to the canopy, the tractor or the screed.
The asphalt finisher according to claim 1.