Asphalt finisher

Abstract

The width of the retaining plate, positioned in front of the screw that spreads the paving material, can be easily adjusted using a simple configuration. [Solution] The system comprises a tractor, a screw for spreading paving material at the rear of the tractor, a screed for compacting the paving material at the rear of the screw, a retaining plate positioned in front of the screw, and a connecting member connecting the screed and the retaining plate. The screed is configured to be expandable and contractible in the width direction of the vehicle, and the retaining plate is configured to be expandable and contractible in the width direction of the vehicle, in conjunction with the expansion and contraction of the width of the screed in the vehicle width direction via the connecting member.

Description

Technical Field

[0001] The present disclosure relates to an asphalt finisher.

Background Art

[0002] Conventionally, in an asphalt finisher, a configuration is known in which a retaining plate is arranged in front of a screw for spreading a paving material to prevent the paving material from scattering forward. On the other hand, a screed for compacting the paving material is arranged behind the screw, and there is also known a screed whose width in the vehicle width direction is configured to be expandable (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the width of the screed in the vehicle width direction is expanded, for example, if an extension screw is connected according to the expanded width of the screed, unless the width of the retaining plate is also expanded, the paving material is likely to scatter forward, and the paving material cannot be smoothly sent to both ends of the screw. Therefore, if an attempt is made to expand the width of the retaining plate manually, a great deal of labor and time are required for the expansion work of the retaining plate, and the work efficiency is reduced.

[0005] Here, Patent Document 1 discloses a configuration in which the width of a retaining plate is expanded using hydraulic pressure or air pressure by a control unit.

[0006] However, in the configuration disclosed in Patent Document 1, hydraulic cylinders, pneumatic cylinders, and circuits in the control unit are required to expand the width of the retaining plate, resulting in a complex configuration and increased costs. Furthermore, adding the configuration disclosed in Patent Document 1 would require modifying the retaining plate and the control unit itself, which would require a significant amount of manpower.

[0007] Therefore, it is preferable to provide an asphalt finisher that can easily expand or contract the width of the retaining plate positioned in front of the screw that spreads the paving material. [Means for solving the problem]

[0008] The asphalt finisher described in this disclosure is Tractor and, The tractor has a screw for spreading the paving material at its rear, A screed for compacting the paving material is located behind the screw, A retaining plate positioned in front of the screw, It has a connecting member that connects the screed and the retaining plate, The screed is configured to be expandable and contractible in the width direction of the vehicle, The retaining plate is configured such that its width in the vehicle width direction expands and contracts in conjunction with the expansion and contraction of the screed's width in the vehicle width direction via the connecting member. [Effects of the Invention]

[0009] According to this disclosure, the width of the retaining plate, which is positioned in front of the screw that spreads the paving material, can be expanded or contracted with a simple configuration. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic left side view of an asphalt finisher according to an embodiment of the present invention. [Figure 2]It is a top view showing an overview of an asphalt finisher according to an embodiment of the present invention. [Figure 3] It is a block diagram showing a configuration example of a controller and devices connected to the controller according to an embodiment of the present invention. [Figure 4] It is a diagram showing the configuration of a screw and a screed in an asphalt finisher according to the present embodiment. [Figure 5] It is a diagram for explaining the connection between a side plate and a retaining plate by a link member according to the present embodiment. [Figure 6A] It is a view from above of the state where the left link member is attached to the left side plate. [Figure 6B] It is a side view of the state where the left link member is attached to the left side plate L. [Figure 7] It is a diagram for explaining the operation of the link member according to the present embodiment. [Figure 8] It is a diagram for explaining the operation of the link member according to the present embodiment. [Figure 9] It is a diagram for explaining the storage method of the link member according to the present embodiment. [Figure 10] It is a diagram for explaining the storage method of the link member according to the present embodiment. [Figure 11] It is a diagram for explaining the operation when the height of the screed changes. [Figure 12] It is a diagram for explaining the operation when the height of the screed changes.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description may be omitted.

[0012] FIG. 1 is a left side view showing an overview of an asphalt finisher 100 according to an embodiment of the present invention. FIG. 2 is a top view showing an overview of the asphalt finisher 100 according to an embodiment of the present invention.

[0013] The asphalt finisher 100 mainly consists of a tractor 1, a hopper 2, and a screed 3. In the example shown in FIG. 1, the asphalt finisher 100 is arranged such that the vehicle length direction corresponds to the X-axis direction and the vehicle width direction corresponds to the Y-axis direction. And the Z-axis is arranged so as to be orthogonal to each of 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.

[0014] The tractor 1 is a mechanism for driving the asphalt finisher 100. In the examples shown in FIGS. 1 and 2, the tractor 1 rotates the rear wheels 5 using a rear-wheel driving motor and rotates the front wheels 6 using a front-wheel driving motor to move the asphalt finisher 100. Both the rear-wheel driving motor 20 and the front-wheel driving motor 22 are hydraulic motors that rotate by receiving the supply of hydraulic oil from a hydraulic pump. However, the tractor 1 may be provided with crawlers instead of wheels.

[0015] The asphalt finisher 100 according to the present embodiment changes the traveling direction by controlling the steering angle of the front wheels 6. When the asphalt finisher 100 is provided with crawlers instead of wheels, the traveling direction is changed by making the rotational speeds between the drive wheels in the right crawler and the drive wheels in the left crawler different.

[0016] Hopper 2 is a mechanism for receiving paving material. The paving material is, for example, an asphalt mixture. In the example shown in Figures 1 and 2, hopper 2 is installed on the front side (+X side) of tractor 1 and is configured to open and close in the Y-axis direction (vehicle width direction) by hopper cylinder 24. The asphalt finisher 100 usually receives paving material from the dump truck bed with hopper 2 fully open. Also, even when receiving paving material from the dump truck bed, the asphalt finisher 100 continues to travel while pushing the dump truck forward via push rollers 2b. Figures 1 and 2 show the asphalt finisher 100 with hopper 2 fully open. When the amount of paving material in hopper 2 decreases, the operator of the asphalt finisher 100 closes hopper 2, collecting the paving material that was near the inner wall of hopper 2 in the center of hopper 2. This is so that the conveyor CV at the bottom of the center of hopper 2 can transport the paving material to the rear side of tractor 1. The paving material, transported to the rear (-X side) of tractor 1, is spread in the vehicle width direction by screw SC at the rear of tractor 1 and in front of screed 3.

[0017] The hopper cylinder 24 is a hydraulic actuator that opens and closes the hopper 2, contracting when opening the hopper 2 and extending when closing the hopper 2. The hopper cylinder 24 includes a left hopper cylinder 24L and a right hopper cylinder 24R.

[0018] The conveyor CV is driven by a hydraulic motor that rotates on a supply of hydraulic fluid from a hydraulic pump. In the example shown in Figures 1 and 2, the conveyor CV is configured to transport paving material from the hopper 2 to the rear of the tractor 1 via a transport passage. The transport passage is a roughly rectangular space formed inside the tractor 1 and has a roughly rectangular entrance OP that opens into the hopper 2 at the front of the tractor 1. Specifically, the conveyor CV includes a left conveyor and a right conveyor.

[0019] The screw SC spreads the paving material at the rear of the tractor 1. The screw SC is driven by a hydraulic motor that rotates on a supply of hydraulic fluid from a hydraulic pump. Specifically, the screw SC includes a left screw SCL located on the left side of the asphalt finisher 100, and a right screw SCR located on the right side of the asphalt finisher 100.

[0020] Screed 3 is used to compact the paving material behind screw SC. Screed 3 is a mechanism for spreading and leveling the paving material. In the examples shown in Figures 1 and 2, screed 3 mainly includes a main screed 30 and an extendable screed 31. Main screed 30 includes a left main screed and a right main screed. Extendable screed 31 includes a left extendable screed 31L and a right extendable screed 31R. Main screed 30, left extendable screed 31L, and right extendable screed 31R are positioned offset front to back so as not to overlap in the vehicle length direction. Specifically, the left extendable screed 31L is positioned behind the main screed 30, and the right extendable screed 31R is positioned behind the left extendable screed 31L. Screed 3 is a floating screed towed by tractor 1 and is connected to tractor 1 via leveling arm 3A. The screed 3 is moved up and down together with the leveling arm 3A by the extension and retraction of the screed lift cylinder 25. The leveling arm 3A includes the left leveling arm 3AL and the right leveling arm 3AR.

[0021] The retractable screed 31 is configured to be able to expand and contract in the vehicle width direction by a screed retractable cylinder 27. The screed retractable cylinder 27 is supported by a support fixed to the rear surface of the housing of the main screed 30, and is configured to be able to expand and contract the retractable screed 31 in the vehicle width direction (Y-axis direction). Specifically, the screed retractable cylinder 27 includes a left screed retractable cylinder 27L (an example of a left-side screed device) and a right screed retractable cylinder 27R (an example of a right-side screed device). The left screed retractable cylinder 27L can expand and contract the left retractable screed 31L to the left side in the vehicle width direction relative to the main screed 30. The right screed retractable cylinder 27R can expand and contract the right retractable screed 31R to the right side in the vehicle width direction relative to the main screed 30.

[0022] The leveling arm 3A is configured to connect the screed 3 to the tractor 1. Specifically, one end of the leveling arm 3A is connected to the screed 3, and the other end is rotatably connected to the tractor 1.

[0023] The leveling cylinder 23 is a hydraulic cylinder that moves the front end portion of the leveling arm 3A up and down to adjust the paving thickness. In the example shown in Figures 1 and 2, the leveling cylinder 23 has a cylinder portion connected to the tractor 1 and a rod portion connected to the front end portion of the leveling arm 3A. The front end portion of the leveling arm 3A is slidably supported by the tractor 1. To increase the paving thickness, the controller 50 causes the hydraulic fluid discharged by the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinder 23, causing the leveling cylinder 23 to contract and raise the front end portion of the leveling arm 3A. On the other hand, to decrease the paving thickness, the controller 50 causes the hydraulic fluid to flow out of the rod-side oil chamber of the leveling cylinder 23, causing the leveling cylinder 23 to extend and lower the front end portion of the leveling arm 3A. The leveling cylinder 23 includes a left leveling cylinder 23L and a right leveling cylinder 23R.

[0024] The screed lift cylinder 25 is a hydraulic cylinder for lifting the screed 3. In the example shown in Figures 1 and 2, the screed lift cylinder 25 has a cylinder section connected to the tractor 1 and a rod section connected to the rear end of the leveling arm 3A. When lifting the screed 3, the controller 50 allows the hydraulic fluid discharged by 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 end of the leveling arm 3A lifts, and the screed 3 is lifted. On the other hand, when lowering the lifted screed 3, the controller 50 allows the hydraulic fluid in the rod-side oil chamber of the screed lift cylinder 25 to flow out. As a result, the screed lift cylinder 25 extends due to the weight of the screed 3, the rear end of the leveling arm 3A lowers, and the screed 3 is lowered. The screed lift cylinder 25 includes a left screed lift cylinder 25L and a right screed lift cylinder 25R.

[0025] Side plates 40 are attached to the outer ends of the retractable screed 31 in the vehicle width direction. The side plates 40 include a left side plate 40L and a right side plate 40R. Specifically, the left side plate 40L is attached to the outer end (left end) of the left retractable screed 31L, and the right side plate 40R is attached to the outer end (right end) of the right retractable screed 31R.

[0026] As shown in Figure 2, the side plate 40 extends its front end in the direction of travel (positive X-axis direction) to the extension of the longitudinal direction (rotation axis direction) of the screw SC.

[0027] The side plates 40 are also attached to the outer ends of the expandable mold board 41. The expandable mold board 41 is a component for adjusting the amount of paving material that remains in front of the expandable screed 31 among the paving material spread by the screw SC, and is configured to expand and contract in the vehicle width direction together with the expandable screed 31.

[0028] Specifically, the expandable molded board 41 is a plate-shaped member that extends in the vehicle width direction, and includes a left expandable molded board 41L and a right expandable molded board 41R. A left side plate 40L (an example of a plate portion) is attached to the outer end (left end) of the left expandable molded board 41L, and a right side plate 40R (an example of a plate portion) is attached to the outer end (right end) of the right expandable molded board 41R.

[0029] The expandable mold board 41 is configured to allow height adjustment in the Z-axis direction independently of the expandable screed 31 and side plates 40. The asphalt finisher 100 can adjust the amount of paving material passing through the gap by moving the expandable mold board 41 up and down, thereby adjusting the size of the gap between the lower end of the expandable mold board 41 and the roadbed. Therefore, the asphalt finisher 100 can adjust the amount (height) of paving material that accumulates on the rear side (-X side) of the expandable mold board 41 and on the front side (+X side) of the expandable screed 31 by moving the expandable mold board 41 up and down, and consequently adjust the amount of paving material taken into the underside of the expandable screed 31.

[0030] The screed step 42 is a component that constitutes a platform for workers when working behind the screed 3. Specifically, the screed step 42 includes the left screed step 42L, the center screed step 42C, and the right screed step 42R.

[0031] The retaining plate 43 is a plate-shaped member that prevents the paving material being fed in the vehicle width direction by the screw SC from scattering in front of the screw SC, in order to ensure that the paving material is properly fed in the vehicle width direction by the screw SC. For this reason, the retaining plate 43 is positioned in front of the screw SC. In the example shown in Figures 1 and 2, the retaining plate 43 includes a left retaining plate 43L and a right retaining plate 43R.

[0032] Furthermore, the asphalt finisher 100 according to this embodiment is equipped with a link member 60. The link member 60 is an example of a connecting member in the present invention and comprises a left link member 60L and a right link member 60R. The left link member 60L is attached to the left side plate 40L and the left retaining plate 43L, thereby connecting the left telescopic screed 31L and the left retaining plate 43L. The right link member 60R is attached to the right side plate 40R and the right retaining plate 43R, thereby connecting the right telescopic screed 31R and the right retaining plate 43R. Details of the link member 60 will be described later.

[0033] The controller 50 is a control device that controls the asphalt finisher 100. In the example shown in Figures 1 and 2, the controller 50 is a computer including a CPU, a volatile memory device, and a non-volatile memory device, and is mounted on the tractor 1. Various functions of the controller 50 are realized, for example, by the CPU executing a program stored in the non-volatile memory device. The various functions realized by the controller 50 also include, for example, a function to control the discharge amount of the hydraulic pump that supplies hydraulic fluid to drive the hydraulic actuator, and a function to control the flow of hydraulic fluid between the hydraulic actuator and the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder and a hydraulic motor.

[0034] The communication device 53 is configured to control communication between the asphalt finisher 100 and equipment located outside the asphalt finisher 100. In this embodiment, the communication device 53 is installed in front of the driver's seat 1S and controls communication via a mobile phone network, a short-range wireless communication network, or a satellite communication network.

[0035] The GPS module 54 is an example of a GNSS (Global Navigation Satellite System) module and receives location information representing the results of two-dimensional positioning (two-dimensional positioning) by GPS (Global Positioning System). The location information includes information representing the position of the asphalt finisher 100 in terms of latitude and longitude. In this embodiment, GPS is used as the method for acquiring location information, but the method for acquiring location information is not limited, and other well-known methods may be used.

[0036] A spatial recognition device 51 is attached to the tractor 1. The spatial recognition device 51 is configured to acquire information about the space around the asphalt finisher 100 and to output the acquired information to the controller 50. The spatial recognition device 51 according to this embodiment includes a forward monitoring device 51F, a rear monitoring device 51B, a right-side monitoring device 51R, and a left-side monitoring device 51L.

[0037] The forward monitoring device 51F is configured to monitor the area in front of the asphalt finisher 100. In this embodiment, the forward monitoring device 51F is a LIDAR whose monitoring range RF is the space in front of the tractor 1, and is mounted on the front center of the upper surface of the tractor 1. The forward monitoring device 51F may also be mounted on other parts of the asphalt finisher 100.

[0038] The rear monitoring device 51B is configured to monitor the area behind the asphalt paver 100. In this embodiment, the rear monitoring device 51B is a LIDAR with a monitoring range RB of the space behind the screed 3, and is mounted on the guide rail 1G, which functions as a handrail for the operator of the asphalt paver 100. The rear monitoring device 51B may also be mounted under the driver's seat 1S, or on other parts of the asphalt paver 100.

[0039] The right-side monitoring device 51R is configured to monitor the right side of the asphalt paver 100. The left-side monitoring device 51L is configured to monitor the left side of the asphalt paver 100. In this embodiment, the right-side monitoring device 51R and the left-side monitoring device 51L are configured to include the edge of the road surface (the boundary between the road surface and the shoulder) and the side plate 40 provided on the outer edge of the telescopic screed 31 as part of their monitoring range. The right-side monitoring device 51R and the left-side monitoring device 51L are, for example, LIDARs and are mounted on the guide rail 1G which functions as a handrail for the operator of the asphalt paver 100. The right-side monitoring device 51R and the left-side monitoring device 51L may be mounted at any position on the side of the asphalt paver 100, provided that they include the monitoring range described above.

[0040] For example, the LIDAR measures the distance between the LIDAR and more than one million points within the monitoring range. However, at least one of the forward monitoring device 51F and the rear monitoring device 51B may be a monocular camera, stereo camera, millimeter-wave radar, laser radar, laser scanner, depth image camera, or laser rangefinder, etc. The same applies to the side monitoring device. This embodiment describes an example in which LIDAR is used as an example of the spatial recognition device 51. However, this embodiment does not limit the spatial recognition device 51 to LIDAR. In other words, any spatial recognition device capable of recognizing space with respect to the asphalt finisher 100 is acceptable.

[0041] The monitoring range RF of the forward monitoring device 51F includes the roadbed. The same applies to the monitoring range of the side monitoring device. In this embodiment, the monitoring range RF has a width greater than the width of the roadbed BS.

[0042] The monitoring range RB of the rearward monitoring device 51B includes the newly constructed pavement. In this embodiment, the monitoring range RB has a width greater than the width of the newly constructed pavement.

[0043] The measurement information detected by the spatial recognition device 51 according to this embodiment is transmitted to the controller 50. Based on the received measurement information, the controller 50 according to this embodiment may perform automatic steering of the asphalt finisher 100. The controller 50 may also provide notifications such as warnings to the driver based on the received measurement information.

[0044] Next, with reference to Figure 3, the controller 50 mounted on the asphalt finisher 100 will be described. Figure 3 is a block diagram showing an example configuration of the controller 50 and the equipment connected to the controller 50.

[0045] As shown in Figure 3, the controller 50 is connected to a driving speed sensor 47, an auxiliary storage device 48, a GPS module 54, a forward monitoring device 51F, a rear monitoring device 51B, a drive system controller 52, a communication device 53, a screed control device 55, and a screed length detection device 57.

[0046] The travel speed sensor 47 is configured to detect the travel speed of the asphalt finisher 100. In the example shown in Figure 3, the travel speed sensor 47 is an encoder that detects the angular velocity of the rotation shaft of the rear wheel drive motor that drives the rear wheels 5. Specifically, the travel speed sensor 47 includes a left travel speed sensor and a right travel speed sensor. The left travel speed sensor is an encoder that detects the angular velocity of the rotation shaft of the left rear wheel drive motor that drives the left rear wheel. The right travel speed sensor is an encoder that detects the angular velocity of the rotation shaft of the right rear wheel drive motor that drives the right rear wheel. The travel speed sensor 47 may also be configured as a proximity switch or the like that detects a slit formed in the rotating plate.

[0047] The auxiliary storage device 48 is configured to store various types of information. In the example shown in Figure 3, the auxiliary storage device 48 is a non-volatile storage device mounted on the tractor 1 and stores various types of information. For example, the auxiliary storage device 48 stores schedule information storage unit 48a and vehicle width storage unit 48b.

[0048] The schedule information storage unit 48a stores schedule information for the asphalt finisher 100 to construct the road surface to be paved. The schedule information according to this embodiment includes, for example, the center line of the path the asphalt finisher 100 will travel and a target line indicating the edge of the road surface to be paved (the part that forms the boundary between the road surface and the shoulder). The asphalt finisher 100 according to this embodiment performs automatic control of road paving based on the schedule information.

[0049] The vehicle width memory unit 48b stores information on the length from the structural center position of the asphalt finisher 100 (in other words, the length from the left side to the right side of the asphalt finisher 100 in the vehicle width direction) to the side of the asphalt finisher 100.

[0050] Therefore, the controller 50 can calculate the distance from the center position in the vehicle width direction of the asphalt finisher 100 to the side plate 40, according to the length of the retractable screed 31 in the vehicle width direction.

[0051] The GPS module 54 is an example of a GNSS (Global Navigation Satellite System) module and receives location information representing the results of two-dimensional positioning (two-dimensional positioning) by GPS (Global Positioning System). The location information includes information representing the position of the asphalt finisher 100 in terms of latitude and longitude. In this embodiment, GPS is used as the method for acquiring location information, but the method for acquiring location information is not limited, and other well-known methods may be used.

[0052] The screed length detection device 57 (an example of a detection unit) detects the length by which the left retractable screed 31L and the right retractable screed 31R are extended or retracted in the vehicle width direction. The screed length detection device 57 may use any sensor that can detect the length by which the retractable screed 31 is extended or retracted in the vehicle width direction. The screed length detection device 57 may be a laser sensor or the like for detecting the said length, or it may be a GNSS module provided on the side plate 40. For example, the length by which the retractable screed 31 is extended or retracted in the vehicle width direction may be calculated from the distance between the position information detected by the GNSS module and the position information of the GNSS module provided on the main body of the asphalt finisher 100. As another example, instead of the screed length detection device 57, the controller 50 may determine the length of the retractable screed 31 in the vehicle width direction based on the measurement information of the right-side monitoring device 51R and the left-side monitoring device 51L, respectively.

[0053] The communication device 53 communicates wirelessly with devices located around the asphalt finisher 100, or with a server that manages the work site. In this embodiment, one or more of the following wireless communication standards may be used for the communication device 53: for example, Wi-Fi®, wireless LAN, and Bluetooth®.

[0054] The drive system controller 52 controls the tractor 1 according to control commands. For example, the drive system controller 52 controls the speed and steering angle of the tractor 1.

[0055] The screed control device 55 is configured to control the amount of extension and retraction of the retractable screed 31. In the example shown in Figure 3, the screed control device 55 controls the flow rate of hydraulic fluid flowing into the screed extension cylinder 27.

[0056] The screed control device 55 then performs the following actions in accordance with the control commands from the controller 50: contracting the left screed extension cylinder 27L to shorten the left extension screed 31L, and extending the left screed extension cylinder 27L to extend the left extension screed 31L.

[0057] Furthermore, the screed control device 55 performs the following actions in accordance with the control commands from the controller 50: contracting the right screed extension cylinder 27R to shorten the right extension screed 31R, and extending the right screed extension cylinder 27R to extend the right extension screed 31R.

[0058] In this manner, the screed control device 55 controls the lengths of the right retractable screed 31R and the left retractable screed 31L, respectively, according to the control commands from the controller 50.

[0059] The controller 50 acquires information from the GPS module 54, the forward monitoring device 51F, the rear monitoring device 51B, the right-side monitoring device 51R, the left-side monitoring device 51L, the driving speed sensor 47, the screed length detection device 57, and the auxiliary storage device 48, performs various calculations, and then outputs control commands to the screed control device 55 and the drive system controller 52 according to the calculation results.

[0060] Each functional block within the controller 50 is conceptual and does not necessarily need to be physically configured as shown in the diagram. All or part of each functional block can be functionally or physically distributed and integrated in any unit. Each processing function performed by each functional block is implemented, in whole or in any part, by a program executed on the CPU. Alternatively, each functional block may be implemented as wired logic hardware. The program executed by the controller 50 according to this embodiment is not limited to being stored in a non-volatile auxiliary storage device; it may be stored in a distributable storage medium or transmitted and received via a communication line.

[0061] In this embodiment, the controller 50 performs self-position estimation according to the detection results from the GPS module 54, the forward monitoring device 51F, the rear monitoring device 51B, and the driving speed sensor 47, and performs automatic movement control to pave the road surface with asphalt according to the schedule information stored in the auxiliary storage device 48.

[0062] At that time, the controller 50 transmits a control command to the screed control device 55 to extend or retract the retractable screed 31, based on measurement information from the right-side monitoring device 51R, the left-side monitoring device 51L, and the screed length detection device 57, so that the paving material does not extend beyond the road surface to be paved.

[0063] More specifically, the controller 50 has, as a functional block composed of software, hardware, or a combination thereof, an acquisition unit 50a, a movement path calculation unit 50b, a movement control unit 50c, and a screed control unit 50d.

[0064] The acquisition unit 50a acquires various types of information. For example, the acquisition unit 50a acquires measurement information from various sensors. For example, the acquisition unit 50a acquires measurement information detected by the forward monitoring device 51F, the rear monitoring device 51B, the right-side monitoring device 51R, and the left-side monitoring device 51L. The acquisition unit 50a also acquires measurement information detected by the driving speed sensor 47 (for example, including the speed of the asphalt finisher 100). The acquisition unit 50a also acquires measurement information from the screed length detection device 57 (the length to which the left telescopic screed 31L and the right telescopic screed 31R are extended in the vehicle width direction). Furthermore, the acquisition unit 50a acquires position information from the GPS module 54. Furthermore, the acquisition unit 50a acquires information from the auxiliary storage device 48 as needed. The acquisition unit 50a may also acquire steering angle information from the tractor 1.

[0065] The movement path calculation unit 50b calculates the target movement path of the asphalt finisher 100 based on the schedule information read from the schedule information storage unit 48a. The target movement path is information that indicates the path along which the structural center position of the asphalt finisher 100 in the vehicle width direction (in other words, in the vehicle width direction between the left side and the right side of the asphalt finisher 100) moves in order for the asphalt finisher 100 to work on the road surface. Note that the target movement path is not limited to a method calculated within the controller 50, but may also be received from an external device via the communication device 53. Furthermore, the target movement path is not limited to the above-mentioned path, but may be any path along which the asphalt finisher 100 can move, for example, the trajectory of the left front wheel of the tractor 1.

[0066] The movement control unit 50c outputs control commands to the drive system controller 52 based on the measurement information and position information acquired by the acquisition unit 50a, so that the asphalt finisher 100 moves along the calculated target movement path. This enables automatic movement control of the asphalt finisher 100.

[0067] The screed control unit 50d outputs a control command to the screed control device 55 to extend or retract the retractable screed 31, based on measurement information (an example of detection results) from the right-side monitoring device 51R, the left-side monitoring device 51L, and the screed length detection device 57, so as to correspond to the width of the road surface on which the paving material is to be spread. This makes it possible to match the length of the screed 3 in the vehicle width direction with the width of the road being constructed, so that the paving material can be spread evenly on the road surface to be paved.

[0068] Figure 4 shows the configuration of the screw SC and screed 3 in the asphalt finisher 100 according to this embodiment. Figure 4 shows an example where the asphalt finisher 100 is moving in the direction of travel 4001. The screw SC provided on the asphalt finisher 100 rotates in direction 4002 according to the control signal from the controller 50. As a result, the paving material is pushed out in direction 4003.

[0069] In the example shown in Figure 4, the edge of the road surface to be paved (the boundary between the road surface and the shoulder) is set as the target line OL (left target line OLL) on the side plate 40 of the asphalt finisher 100.

[0070] Then, as the asphalt finisher 100 moves in the direction of travel 4001, if the road surface changes or the steering angle of the asphalt finisher 100 changes, the target line OL, which is the boundary between the road surface and the shoulder, shifts to the right or left, relative to the center position of the asphalt finisher 100 in the width direction.

[0071] In this embodiment, the acquisition unit 50a of the controller 50 detects the deviation (change) of the target line OL (for example, the left target line OLL) based on measurement information from the right monitoring device 51R and the left monitoring device 51L. Based on the detection result, the screed control unit 50d transmits a control command to the screed control device 55 to extend or retract the retractable screed 31 so that the side plate 40 is aligned with the target line (for example, the left target line OLL).

[0072] This allows the side plate 40 to move to the right 4011 or to the left 4012 so as to follow the target line OL.

[0073] The link member 60 will be described in detail below. In the following description, the relationship between the left retaining plate 43L and the left side plate 40L of the left link member 60L will be explained, but the same applies to the relationship between the right retaining plate 43R and the right side plate 40R of the right link member 60R.

[0074] First, the configuration of the link member 60 and the connection between the side plate 40 and the retaining plate 43 by the link member 60 will be described.

[0075] Figure 5 is a diagram illustrating the connection between the side plate 40 and the retaining plate 43 by the link member 60 according to this embodiment, and is an external perspective view of the vicinity of the left link member 60L. Figure 6A is a view from above of the left link member 60L attached to the left side plate 40L. Figure 6B is a view from the side of the left link member 60L attached to the left side plate 40L.

[0076] As shown in Figure 5, the left link member 60L (link member 60) has an L-shape with two sides 61a and 61b intersecting at a right angle, and one of the two sides 61a, 61b, is positioned to extend in the vehicle width direction (Y-axis direction).

[0077] Two fixing plates 62a and 62b are attached to the tip of the other side portion 61b of the two sides 61a and 61b. As shown in Figure 6A, the two fixing plates 62a and 62b are attached to the side portion 61b by welding or the like, sandwiching the side portion 61b so that a portion of them protrudes from the tip of the side portion 61b. Furthermore, the two fixing plates 62a and 62b are attached to the side portion 61b so that they face each other in the vehicle width direction (Y direction) when the axial direction of the side portion 61b is in the vehicle length direction (X direction). The side portion 61b of the left link member 60L configured in this way is attached to the left side plate 40L.

[0078] A mounting cylinder 63 is attached to the left side plate 40L (side plate 40) near its front edge. The mounting cylinder 63 is an example of a mounting part in the present invention. The mounting cylinder 63 has a cylindrical shape and is mounted so as to pass through the left side plate 40L with its axial direction facing the vehicle width direction (Y-axis direction). The front edge of the left side plate 40L is angled as shown in Figures 5 and 6B. Specifically, the front edge of the left side plate 40L is angled such that its upper end is located behind its lower end.

[0079] A stopper 68 is attached to the tip of one of the two sides 61a, 61b, side 61a. The stopper 68 is, for example, plate-shaped and is attached to side 61a such that its plane faces the axial direction of side 61a. The side 61a of the left link member 60L configured in this way is attached to the left retaining plate 43L.

[0080] The left retaining plate 43L (retaining plate 43) has a fixed plate 64 and a sliding plate 65. The sliding plate 65 is slidable in the vehicle width direction (Y-axis direction) by a sliding mechanism 66 provided on the fixed plate 64. The sliding mechanism 66 may have, for example, rollers. As a result, the width of the left retaining plate 43L (retaining plate 43) can be expanded and contracted in the vehicle width direction (Y-axis direction). The sliding plate 65 is provided with a retaining hole 67 at the end on the left side plate 40L side in the vehicle width direction (Y-axis direction). The retaining hole 67 is for holding the left link member 60L by inserting the side portion 61a of the left link member 60L through it. Therefore, it has a size that allows the side portion 61a of the left link member 60L to be inserted, and may be, for example, an elongated hole that is long in the vertical direction (Z-axis direction). A retaining plate 69a is also attached to the sliding plate 65. The retaining plate 69a is attached to the slide plate 65 at a predetermined distance from the retaining hole 67, on the side opposite to the left side plate 40L in the vehicle width direction (Y-axis direction) relative to the retaining hole 67. The retaining plate 69a is attached to the slide plate 65 by welding or the like so that its flat surface faces the axial direction of the edge portion 61a. The retaining plate 69a is provided with a retaining hole 69b. The retaining hole 69b is for holding the left link member 60L by allowing the edge portion 61a of the left link member 60L to pass through it. Therefore, the retaining hole 69b is sized to allow the edge portion 61a of the left link member 60L to pass through. In addition, the stopper 68 provided on the edge portion 61a of the left link member 60L has a shape that prevents it from passing through the retaining hole 69b.

[0081] The left link member 60L is attached to the left retaining plate 43L by inserting its edge portion 61a through the retaining holes 67 and 69b, and is held slidably in the vehicle width direction (Y-axis direction). In this case, the left link member 60L is held on the left retaining plate 43L so as to be rotatable with its edge portion 61a as the axis of rotation.

[0082] Furthermore, as shown in Figure 6A, the left link member 60L is attached to the left side plate 40L by sandwiching it between two fixing plates 62a and 62b. Therefore, the distance between the two fixing plates 62a and 62b is wider than the thickness of the left side plate 40L that is sandwiched between the fixing plates 62a and 62b. Also, as shown in Figure 6B, the two fixing plates 62a and 62b are placed on the side surface of the mounting cylinder 63 provided on the left side plate 40L. Therefore, the length of the edge portion 61b of the left link member 60L is such that, when the edge portion 61a is held by the left retaining plate 43L, the two fixing plates 62a and 62b are placed on the side surface of the mounting cylinder 63, and the edge portion 61a itself does not come into contact with the left side plate 40L, as shown in Figure 6A. Furthermore, instead of simply attaching the two fixing plates 62a and 62b to the edge portion 61b by welding or the like, a portion of the edges of the two fixing plates 62a and 62b that are in contact with the mounting cylinder 63 may be connected via a plate. In that case, the plate connecting the fixing plates 62a and 62b will connect them at a position that is not in contact with the left side plate 40L.

[0083] In this way, the left side plate 40L and the left retaining plate 43L are connected via the left link member 60L. Similarly, the right side plate 40R and the right retaining plate 43R are connected via the right link member 60R.

[0084] Next, the function of the link member 60 will be explained.

[0085] Figures 7 and 8 are diagrams illustrating the operation of the link member 60 according to this embodiment.

[0086] As described above, the side plates 40 are attached to the outer ends of the telescopic screed 31 in the vehicle width direction. Specifically, the left side plate 40L is attached to the outer end of the left telescopic screed 31L in the vehicle width direction, and the right side plate 40R is attached to the outer end of the right telescopic screed 31R in the vehicle width direction. Also, as described above, the link members 60 are attached to the side plates 40 and the retaining plates 43. Specifically, the left link member 60L is attached to the left side plate 40L and the left retaining plate 43L. The right link member 60R is attached to the right side plate 40R and the right retaining plate 43R.

[0087] As a result, the link member 60 connects the telescopic screed 31 and the retaining plate 43. Specifically, as shown in Figure 7, the left link member 60L connects the left telescopic screed 31L and the left retaining plate 43L. The right link member 60R connects the right telescopic screed 31R and the right retaining plate 43R.

[0088] In this state, for example, when the left retractable screed 31L extends from the state shown in Figure 7 in the direction 4013 in Figure 8, and the width of the screed 3 increases, the left side plate 40L moves in the direction 4014 in Figure 8. Here, the left link member 60L is attached to the left side plate 40L. The left link member 60L is attached to the left side plate 40L by two fixing plates 62a and 62b attached to the edge portion 61b, which face each other in the vehicle width direction (Y axis direction) and sandwich the left side plate 40L.

[0089] Furthermore, the left link member 60L is slidably attached to the slide plate 65 of the left retaining plate 43L in the vehicle width direction (Y-axis direction).

[0090] Therefore, when the left side plate 40L moves 4014 in the central direction of Figure 8, the left link member 60L slides 4014 in the central direction of Figure 8 relative to the slide plate 65 of the left retaining plate 43L.

[0091] Subsequently, when the stopper 68 provided on the edge portion 61a of the left link member 60L comes into contact with the retaining plate 69a provided on the slide plate 65, the shape of the stopper 68 prevents it from passing through the retaining hole 69b provided on the retaining plate 69a, thus preventing the left link member 60L from sliding any further in the direction 4014 in Figure 8 relative to the slide plate 65.

[0092] As a result, the slide plate 65, being slidable relative to the fixed plate 64 in the vehicle width direction (Y-axis direction), is pulled outward (+Y side) in the vehicle width direction (Y-axis direction) by the left link member 60L and slides in the direction 4015 in Figure 8. This extends the width of the left retaining plate 43L in the vehicle width direction (Y-axis direction).

[0093] In this way, the width of the left retaining plate 43L in the vehicle width direction (Y-axis direction) expands in conjunction with the expansion of the width of the left telescopic screed 31L in the vehicle width direction via the left link member 60L. Similarly, the width of the right retaining plate 43R in the vehicle width direction (Y-axis direction) expands in conjunction with the expansion of the width of the right telescopic screed 31R in the vehicle width direction via the right link member 60R. Furthermore, a stopper 68 provided on the edge portion 61a of the left link member 60L may be provided such that when the stopper 68 contacts the retaining plate 69a of the slide plate 65, the left link member 60L cannot slide relative to the slide plate 65 in the direction opposite to the direction 4014 in Figure 8. This allows the width of the left retaining plate 43L in the vehicle width direction (Y-axis direction) to be reduced in conjunction with the reduction of the width of the left telescopic screed 31L in the vehicle width direction via the left link member 60L. A similar configuration can be applied to the right link member 60R.

[0094] In this way, the width of the left retaining plate 43L in the vehicle width direction (Y-axis direction) can be expanded and contracted in conjunction with the expansion and contraction of the width of the left telescopic screed 31L in the vehicle width direction via the left link member 60L. Similarly, the width of the right retaining plate 43R in the vehicle width direction (Y-axis direction) can be expanded and contracted in conjunction with the expansion and contraction of the width of the right telescopic screed 31R in the vehicle width direction via the right link member 60R.

[0095] In this embodiment, the retaining plate 43 is configured so that its width in the vehicle width direction is expandable and contractible in conjunction with the expansion and contraction of the width of the expandable screed 31 in the vehicle width direction via the link member 60. This allows the width of the retaining plate 43 to be expanded with a simple configuration.

[0096] Furthermore, in this embodiment, the link member 60 is attached to the side plate 40 and the retaining plate 43, thereby connecting the telescopic screed 31 and the retaining plate 43. This allows the telescopic screed 31 and the retaining plate 43 to be connected with a simple configuration.

[0097] Furthermore, in this embodiment, when the width of the telescopic screed 31 in the vehicle width direction is extended, the retaining plate 43 is pulled outward in the vehicle width direction by the link member 60, thereby extending its width in the vehicle width direction. This also allows the telescopic screed 31 and the retaining plate 43 to be connected with a simple configuration.

[0098] Next, we will explain how to store the link member 60.

[0099] Figures 9 and 10 are diagrams illustrating the method of housing the link member 60 according to this embodiment.

[0100] As described above, the left link member 60L is held by the left retaining plate 43L so as to be rotatable with its edge portion 61a as the axis of rotation. Furthermore, when the left link member 60L is attached to the left side plate 40L, the two fixing plates 62a and 62b provided on the edge portion 61a are placed on the side surface of the mounting cylinder 63 so as to sandwich the left side plate 40L.

[0101] Therefore, as shown in Figure 9, the left link member 60L can be rotated in the direction 4016 in Figure 9, with its edge 61a as the axis of rotation. This allows the left side plate 40L to be free from being sandwiched between the two fixing plates 62a and 62b. As a result, the left link member 60L can be removed from the left side plate 40L by simply rotating the left link member 60L in the direction 4016 in Figure 9, with its edge 61a as the axis of rotation.

[0102] In this embodiment, the link member 60 is detachably attached to the side plate 40. This makes it possible to prevent the width of the retaining plate 43 from being linked to the width of the telescopic screed 31, as needed for work or other purposes.

[0103] Furthermore, as described above, the left link member 60L is attached to the left retaining plate 43L by inserting its edge portion 61a through the retaining holes 67 and 69b, and is held in a slidable manner in the vehicle width direction (Y-axis direction).

[0104] Therefore, as shown in Figure 10, after removing the left link member 60L from the left side plate 40L as shown in Figure 9, the left link member 60L can be slid in the direction 4017 in Figure 10. However, if a stopper is provided that prevents the left link member 60L from sliding relative to the slide plate 65 in the opposite direction to the direction 4014 in Figure 8, then the stopper should be removed or otherwise removed.

[0105] In this way, the left link member 60L can be housed in the left retaining plate 43L. Thus, in this embodiment, the link member 60 can be housed in the retaining plate 43. This prevents the link member 60 from getting in the way when working behind the retaining plate 43, such as when expanding the screw SC.

[0106] Alternatively, the link member 60 could be housed in the retaining plate 43 by folding, for example, instead of sliding it. However, if the link member 60 can be housed in the retaining plate 43 by sliding it inward in the vehicle width direction (Y-axis direction), the workspace required to house the link member 60 in the retaining plate 43 can also be reduced.

[0107] Furthermore, in this embodiment, the link member 60 is L-shaped, with one side of the L-shape slidably attached to the retaining plate 43 and the other side of the L-shape detachably attached to the side plate 40. This allows the link member 60 to be easily configured according to the distance between the retaining plate 43 and the side plate 40 in the vehicle width direction (Y-axis direction) and the distance between the retaining plate 43 and the side plate 40 in the vehicle length direction (X-axis direction).

[0108] To attach the link member 60 housed in the retaining plate 43 to the side plate 40, simply reverse the above procedure.

[0109] Specifically, first, the link member 60 is slid in the vehicle width direction (Y-axis direction) to pull it out from the retaining plate 43. Then, the link member 60 is rotated with its side portion 61a as the axis of rotation, and the two fixing plates 62a and 62b are placed on the mounting cylinder 63 from above so that the side plate 40 is sandwiched between the two fixing plates 62a and 62b.

[0110] This allows the link member 60 housed in the retaining plate 43 to be attached to the side plate 40.

[0111] Next, we will explain the effects of changes in the height and inclination of screed 3.

[0112] In this embodiment, as described above, the screed 3 of the asphalt finisher 100 is moved up and down together with the leveling arm 3A by the extension and retraction of the screed lift cylinder 25. In addition, the inclination of the screed 3 may also change by the extension and retraction of the leveling cylinder 23.

[0113] Figures 11 and 12 illustrate the effects of changing the height of the screed 3.

[0114] When the left link member 60L is attached to the left side plate 40L, the left side plate 40L is sandwiched between the two fixing plates 62a and 62b, and as shown in Figure 11, the two fixing plates 62a and 62b are placed on the side surface of the mounting cylinder 63 provided on the left side plate 40L.

[0115] Furthermore, the left link member 60L is held by the left retaining plate 43L so as to be rotatable with its side portion 61a as the axis of rotation.

[0116] Here, with the left link member 60L attached to the left side plate 40L, the side surface of the mounting cylinder 63 on which the two fixing plates 62a and 62b are placed is cylindrical. Therefore, as the height of the screed 3 increases, if the left side plate 40L moves in the direction of arrow 4021 in Figure 12, the two fixing plates 62a and 62b can move along the side surface of the mounting cylinder 63 while changing the contact area with the side surface, provided that the left link member 60L can rotate around its edge 61a as the axis of rotation.

[0117] As a result, when the height of the screed 3 increases and the left side plate 40L moves in the direction of arrow 4021 in Figure 12, the left link member 60L rotates around its edge 61a as its axis of rotation, allowing the two fixing plates 62a and 62b to move along the side surface of the mounting cylinder 63 while changing the contact area with the side surface. In this case, because the left link member 60L rotates around its edge 61a as its axis of rotation, and the two fixing plates 62a and 62b move along the side surface of the mounting cylinder 63 while changing the contact area with the side surface, the left retaining plate 43L does not move along with the left side plate 40L in the direction of arrow 4021 in Figure 12.

[0118] Similarly, even if the height of the screed 3 is reduced, the left link member 60L rotates around the edge portion 61a as the axis of rotation, and the left retaining plate 43L does not move in the same direction as the left side plate 40L.

[0119] Similarly, even if the inclination of the screed 3 changes, the left link member 60L rotates around the edge portion 61a as the axis of rotation, and the height of the left retaining plate 43L does not change.

[0120] In this embodiment, the mounting cylinder 63, which is an example of a mounting part to which the link member 60 is attached, has a cylindrical surface on the side on which the two fixing plates 62a and 62b of the link member 60 are placed. As a result, the mounting cylinder 63 has a structure that allows the left link member 60L to be held rotatably with its side portion 61a as the axis of rotation. With this configuration, even if the height or inclination of the screed 3 changes, it is possible to avoid a change in the height of the left side plate 40L.

[0121] Furthermore, some asphalt finishers 100 allow the height of the screed 3 to be set higher in the central part in the vehicle width direction (Y-axis direction) and lower at both ends in the vehicle width direction (Y-axis direction). This is done to create a slight mountain-like slope on the road surface, for example, to allow water to flow more easily to both sides of the road during rainfall. When the height of the screed 3 is set in this way, the side plate 40, which is sandwiched between the two fixing plates 62a and 62b, is not parallel to the two fixing plates 62a and 62b, but is tilted at an angle.

[0122] Therefore, the distance between the two fixing plates 62a and 62b can be made wider to allow for a certain margin relative to the thickness of the side plate 40 sandwiched between the fixing plates 62a and 62b. In that case, the two fixing plates 62a and 62b may be attached to the edge portion 61b by welding via spacers. Alternatively, a portion of the edges of the two fixing plates 62a and 62b that are in contact with the mounting cylinder 63 may be connected via a plate. As a result, even if the side plate 40 is tilted at an angle relative to the two fixing plates 62a and 62b, the side plate 40 can still be sandwiched between the two fixing plates 62a and 62b.

[0123] Although embodiments have been described in detail above, this disclosure is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist described in the claims. [Explanation of symbols]

[0124] 1 tractor 1G guide rail 1S Driver's seat 2 Hoppers 2b Push roller 3 Screede 3A Leveling Arm 5 Rear wheels 6 Front wheels 23 Leveling Cylinder 24 Hopper Cylinder 25 Screed lift cylinder 27 Screed stretchable cylinder 30 Main Scred 31 Extendable Screed 40 Side Plates 41 Expandable Molded Board 42 Screed Step 43 Retaining Plate 47. Driving speed sensor 48 Auxiliary storage device 48a Schedule Information Storage Unit 48b Vehicle width memory section 50 controllers 50a Acquisition Department 50b Movement path calculation unit 50c Mobile Control Unit 50d Screed Control Unit 51 Spatial recognition device 52 Drive System Controller 53 Communication equipment 54 GPS modules 55 Scred control device 57 Scred length detection device 60 Link members 61a,61b Side part 62a,62b Fixed plate 63 Mounting cylinder 64 Fixing plate 65 Slide Plate 66. Slide mechanism 67,69b Retaining hole 68 Stopper 69a Holding plate 100 Asphalt Finisher CV Conveyor OP Entrance SC Screw

Claims

1. Tractor and, The tractor has a screw for spreading the paving material at its rear, A screed for compacting the paving material is located behind the screw, A retaining plate positioned in front of the screw, It has a connecting member that connects the screed and the retaining plate, The screed is configured to be expandable and contractible in the width direction of the vehicle, An asphalt finisher in which the retaining plate is configured so that its width in the vehicle width direction is expandable and contractible in conjunction with the expansion and contraction of the screed in the vehicle width direction via the connecting member.

2. The screed has side plates attached to the outer end in the vehicle width direction, The asphalt finisher according to claim 1, wherein the connecting member is attached to the side plate and the retaining plate, thereby connecting the screed and the retaining plate.

3. The asphalt finisher according to claim 2, wherein the retaining plate is pulled outward in the vehicle width direction by the connecting member when the width of the screed in the vehicle width direction is extended, thereby extending the width of the retaining plate in the vehicle width direction.

4. The asphalt finisher according to claim 3, wherein the connecting member is detachably attached to the side plate.

5. The asphalt finisher according to claim 4, wherein the connecting member is housed in the retaining plate.

6. The asphalt finisher according to claim 5, wherein the connecting member can be housed in the retaining plate by sliding toward the inside in the vehicle width direction.

7. The asphalt finisher according to claim 6, wherein the connecting member is L-shaped, one side of the L-shape is slidably attached to the retaining plate, and the other side of the L-shape is detachably attached to the side plate.

8. The side plate has a mounting portion to which the connecting member is attached, The asphalt finisher according to claim 7, wherein the mounting portion has a structure that holds the connecting member so that it can rotate with the one side portion as the axis of rotation.

Images