JP2023151461A - asphalt finisher - Google Patents

Abstract

To enhance safety.SOLUTION: An asphalt finisher includes a tractor, a hopper installed on the front side of the tractor, a conveyor for conveying a pavement material in the hopper to the rear side of the tractor, a screw for spreading the pavement material conveyed by the conveyor and spread on a road surface in a vehicle width direction, and a screed device expansible in the vehicle width direction for evenly leveling on the rear side of the screw the pavement material spread by the screw. Expansion/contraction of the screed device is controlled so that the length in the vehicle width direction of the screed device does not fall below the prescribed length based on the screw.SELECTED DRAWING: Figure 2

Description

The present invention relates to an asphalt finisher.

Conventionally, a tractor, a hopper installed on the front side of the tractor to receive the paving material, a conveyor that feeds the paving material in the hopper to the rear side of the tractor, and a conveyor that feeds the paving material fed by the conveyor to the rear side of the tractor. An asphalt finisher is known that includes a screw that spreads the material and a screed that spreads the paving material spread by the screw on the rear side of the screw.

When an asphalt finisher performs construction, it creates a blueprint and spreads the paving material on the road surface based on the blueprint. Various techniques have been proposed to facilitate the construction. For example, Patent Document 1 proposes a technique for automatically correcting the length of a screed in the vehicle width direction when automatically steering an asphalt finisher.

JP2019-007336A

Incidentally, in an asphalt finisher, a side plate extending forward is provided at the far end of the screed. Therefore, if the length of the screed in the vehicle width direction is changed, the side plate may come into contact with the screw.

This possibility is not limited to cases in which the length of the screed in the vehicle width direction is automatically corrected by automatic steering, but also in cases where the operator is adjusting the length of the screed in the vehicle width direction at an asphalt finisher. also exists.

In view of the above, by controlling the length of the screed of the asphalt finisher in the vehicle width direction not to be less than a predetermined length, the side plate is prevented from coming into contact with the screw.

An asphalt finisher according to one aspect of the present invention includes a tractor, a hopper installed on the front side of the tractor, a conveyor that conveys paving material in the hopper to the rear side of the tractor, and a paving material that is conveyed by the conveyor and spread on a road surface. It has a screw that spreads the paving material in the vehicle width direction, and a screed device that is expandable and retractable in the vehicle width direction and spreads the paving material spread by the screw on the rear side of the screw. It is configured to control expansion and contraction of the screed device so that the length in the direction does not fall below a predetermined length based on the screw.

According to one aspect of the present invention, the length of the screed of an asphalt finisher in the vehicle width direction is controlled so as not to be less than a predetermined length, thereby suppressing contact of the side plate with the screw and improving safety. Achieve improvement.

FIG. 1 is a diagram showing an asphalt finisher that is an example of a road machine according to an embodiment. FIG. 2 is a block diagram showing a configuration example of a controller and devices connected to the controller according to the embodiment. FIG. 3 is a hydraulic circuit diagram showing a configuration example of a hydraulic system installed in the asphalt finisher according to the embodiment. FIG. 4 is an explanatory diagram of a screw included in the asphalt finisher according to the embodiment. FIG. 5 is a diagram showing a moving route based on schedule information of the asphalt finisher according to the embodiment. FIG. 6 is a diagram showing the positional relationship between the left side plate and the screw according to the embodiment. FIG. 7 is a flowchart showing control of the asphalt finisher by the controller according to the embodiment. FIG. 8 is a diagram showing a rear view of an asphalt finisher according to a modification.

Embodiments of the present invention will be described below with reference to the drawings. Note that in each drawing, the same or corresponding configurations are denoted by the same reference numerals, and the description thereof may be omitted.

FIG. 1 is a schematic diagram of an asphalt finisher 100 according to an embodiment of the present invention. Specifically, FIG. 1(A) is a left side view of the asphalt finisher 100, and FIG. 1(B) is a top view of the asphalt finisher 100.

The asphalt finisher 100 mainly includes 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. The Z-axis is arranged to be perpendicular 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, and 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.

The tractor 1 is a mechanism for driving the asphalt finisher 100. In the example shown in FIG. 1, the tractor 1 uses a rear wheel running motor 20 (see FIG. 3) to rotate the rear wheels 5, and a front wheel running motor 22 (see FIG. 3) to rotate the front wheels. 6, the asphalt finisher 100 is moved. Both the rear wheel running motor 20 and the front wheel running motor 22 are hydraulic motors that rotate by receiving hydraulic fluid from a hydraulic pump. However, the tractor 1 may include crawlers instead of wheels.

Hopper 2 is a mechanism for receiving paving material. The paving material is, for example, an asphalt mixture. In the example shown in FIG. 1, the hopper 2 is installed on the front side (+X side) of the tractor 1, and is configured to be opened and closed in the Y-axis direction (vehicle width direction) by a hopper cylinder 24. The asphalt finisher 100 normally receives paving material from the bed of a dump truck with the hopper 2 fully open. Further, even when the asphalt finisher 100 is receiving paving material from the bed of a dump truck, it continues to move while pushing the dump truck forward via the push roller 2b. FIGS. 1(A) and 1(B) show the asphalt finisher 100 when the hopper 2 is fully open. When the amount of paving material in the hopper 2 decreases, the operator of the asphalt finisher 100 closes the hopper 2 and collects the paving material near the inner wall of the hopper 2 in the center of the hopper 2. This is to enable the conveyor CV located at the bottom of the central portion of the hopper 2 to convey the paving material to the rear side of the tractor 1. The paving material conveyed to the rear side (−X side) of the tractor 1 is spread in the vehicle width direction on the rear side of the tractor 1 and the front side of the screed 3 by the screw SC.

The conveyor CV is driven by a hydraulic motor that is rotated by receiving hydraulic oil from a hydraulic pump. In the example shown in FIG. 1, the conveyor CV is configured to send the paving material in the hopper 2 to the rear side of the tractor 1 via the conveyance path CP. The conveyance path CP is a substantially rectangular parallelepiped space formed inside the tractor 1, and has a substantially 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.

The screw SC is driven by a hydraulic motor that is rotated by receiving hydraulic oil from a hydraulic pump. Specifically, the screw SC includes a left main screw SCLM, a right main screw SCRM, a first left extension screw SCLE1, and a first right extension screw SCRE1. The left conveyor is configured to feed paving material toward the left main screw SCLM. The right conveyor is configured to feed paving material toward the right main screw SCRM. The left main screw SCLM and the right main screw SCRM are arranged within the width of the tractor 1. The left extension screw SCLE is connected to the left end of the left main screw SCLM and is arranged to protrude to the left from the width of the tractor 1. The right extension screw SCRE is connected to the right end of the right main screw SCRM and is arranged so as to protrude from the width of the tractor 1 to the right side.

The screed 3 is a mechanism for leveling the paving material. In the example shown in FIG. 1, the screed 3 mainly includes a main screed 30 and a telescopic screed 31. The main screed 30 includes a left main screed and a right main screed. The telescopic screed 31 includes a left telescopic screed 31L and a right telescopic screed 31R. The main screed 30, the left telescopic screed 31L, and the right telescopic screed 31R are arranged so as to be shifted back and forth so as not to overlap in the vehicle length direction. Specifically, the left telescoping screed 31L is arranged behind the main screed 30, and the right telescoping screed 31R is arranged behind the left telescoping screed 31L. The screed 3 is a floating screed that is pulled 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 expansion and contraction of the screed lift cylinder 25. The leveling arm 3A includes a left leveling arm 3AL and a right leveling arm 3AR.

The telescopic screed 31 is configured to be expandable and retractable in the vehicle width direction by a screed telescopic cylinder 27 . The screed telescopic cylinder 27 is supported by a support portion fixed to the rear surface of the casing of the main screed 30, and is configured to be able to expand and contract the telescopic screed 31 in the vehicle width direction (Y-axis direction). Specifically, the screed telescopic cylinder 27 includes a left screed telescopic cylinder 27L and a right screed telescopic cylinder 27R. The left screed telescopic cylinder 27L can extend and retract the left telescopic screed 31L to the left in the vehicle width direction with respect to the main screed 30. The right screed telescopic cylinder 27R can extend and contract the right telescopic screed 31R to the right side in the vehicle width direction with respect to the main screed 30.

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.

The leveling cylinder 23 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 paving material (paving thickness). In the example shown in FIG. 1, 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. Note that the front end portion of the leveling arm 3A is slidably supported by the tractor 1. When increasing the pavement thickness, the controller 50 causes hydraulic oil discharged by the hydraulic pump to flow into the rod-side oil chamber of the leveling cylinder 23, contracts the leveling cylinder 23, and raises the front end portion of the leveling arm 3A. On the other hand, when reducing the leveling thickness, the controller 50 causes the hydraulic oil in the rod-side oil chamber of the leveling cylinder 23 to flow out, extends the leveling cylinder 23, and lowers the front end portion of the leveling arm 3A.

The screed lift cylinder 25 is a hydraulic cylinder for lifting the screed 3. In the example shown in FIG. 1, the screed lift cylinder 25 has a cylinder portion connected to the tractor 1, and a rod portion connected to the rear end portion of the leveling arm 3A. When lifting the screed 3, the controller 50 causes hydraulic oil 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 portion of the leveling arm 3A is lifted, and the screed 3 is lifted. On the other hand, when lowering the lifted screed 3, the controller 50 allows the hydraulic oil in the rod-side oil chamber of the screed lift cylinder 25 to flow out. As a result, the screed lift cylinder 25 is expanded by the weight of the screed 3, the rear end portion of the leveling arm 3A is lowered, and the screed 3 is lowered.

A side plate 40 is attached to the distal end of the telescoping screed 31. The side plate 40 includes a left side plate 40L and a right side plate 40R. Specifically, a left side plate 40L is attached to the distal end (left end) of the left telescopic screed 31L, and a right side plate 40R is attached to the distal end (right end) of the right telescopic screed 31R. .

As shown in FIG. 1(B), the end of the side plate 40 on the front side in the traveling direction (on the X-axis positive direction side) extends up to the extension of the screw SC in the longitudinal direction (rotation axis direction).

A side plate 40 is also attached to the distal end of the telescoping moldboard 41. The expandable mold board 41 is a member for adjusting the amount of paving material that stays in front of the expandable screed 31 among the paving materials spread by the screw SC, and is designed to be able to expand and contract in the vehicle width direction together with the expandable screed 31. It is composed of

Specifically, the expandable mold board 41 is a plate-shaped member extending in the vehicle width direction, and includes a left expandable mold board 41L and a right expandable mold board 41R. A left side plate 40L (an example of a plate part) is attached to the distal end (left end) of the left telescopic mold board 41L, and a right side plate 40R is attached to the distal end (right end) of the right telescopic mold board 41R. (an example of a plate part) is attached.

The expandable mold board 41 is configured so that its height in the Z-axis direction can be adjusted independently of the expandable screed 31 and the side plates 40. The asphalt finisher 100 moves the expandable mold board 41 up and down to adjust the size of the gap between the lower end of the expandable mold board 41 and the roadbed, thereby adjusting the amount of paving material passing through the gap. can. Therefore, by moving the expandable mold board 41 up and down, the asphalt finisher 100 moves the amount of paving material retained on the rear side (-X side) of the expandable mold board 41 and the front side (+X side) of the expandable screed 31 ( height) and thus the amount of paving material taken under the telescopic screed 31.

The screed step 42 is a member that constitutes a scaffold when an operator works behind the screed 3. Specifically, the screed step 42 includes a left screed step 42L, a center screed step 42C, and a right screed step 42R.

The retaining plate 43 prevents the paving material sent out 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 sent out appropriately in the vehicle width direction by the screw SC. It is a plate-like member for. In the example shown in FIG. 1, the retaining plate 43 includes a left retaining plate 43L and a right retaining plate 43R.

Controller 50 is a control device that controls asphalt finisher 100. In the example shown in FIG. 1, the controller 50 is a computer including a CPU, a volatile storage device, and a nonvolatile storage device, and is mounted on the tractor 1. Various functions of the controller 50 are realized, for example, by the CPU executing programs stored in a nonvolatile storage device. Further, various functions realized by the controller 50 include, for example, a function of controlling the discharge amount of a hydraulic pump that supplies hydraulic oil for driving a hydraulic actuator, and a function of controlling the discharge amount of a hydraulic pump that supplies hydraulic oil for driving a hydraulic actuator, and a function of controlling the flow of hydraulic oil between the hydraulic actuator and the hydraulic pump. Contains functions to control. Note that the hydraulic actuator includes a hydraulic cylinder and a hydraulic motor.

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

The GPS module 54 is an example of a GNSS (Global Navigation Satellite System) module, and receives position information indicating the result of two-dimensional positioning (two-dimensional positioning) by GPS (Global Positioning System). The position information includes information representing the position of the asphalt finisher 100 in terms of latitude and longitude. Note that although this embodiment uses GPS as a location information acquisition method, the location information acquisition method is not limited, and other well-known methods may be used.

A space recognition device 51 is attached to the tractor 1. The space recognition device 51 is configured to acquire information regarding the space around the asphalt finisher 100 and output the acquired information to the controller 50. The space recognition device 51 according to this embodiment includes a front monitoring device 51F and a rear monitoring device 51B.

The front monitoring device 51F is configured to be able to monitor the 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 attached to the center of the front end of the upper surface of the tractor 1. Note that the forward monitoring device 51F may be attached to other parts of the asphalt finisher 100.

The rear monitoring device 51B is configured to be able to monitor the rear of the asphalt finisher 100. In this embodiment, the rear monitoring device 51B is a LIDAR whose monitoring range RB is the space behind the screed 3, and is attached to a guide rail 1G that functions as a handrail for the operator of the asphalt finisher 100. . Note that the rear monitoring device 51B may be attached to the lower part of the driver's seat 1S, or may be attached to other parts of the asphalt finisher 100.

The space recognition device 51 may include a side monitoring device configured to monitor the side of the asphalt finisher 100. In this case, the side monitoring device may be attached to the left end of the upper surface of the tractor 1 in front of the rear wheels 5, for example, as a LIDAR whose monitoring range is the space on the left side of the tractor 1. The side monitoring device may be attached to the right end of the upper surface of the tractor 1 in front of the rear wheels 5, for example, as a LIDAR whose monitoring range is the space on the right side of the tractor 1.

LIDAR, for example, measures the distance between the LIDAR and one million or more points within a monitoring range. However, at least one of the front monitoring device 51F and the rear monitoring device 51B may be a monocular camera, a stereo camera, a millimeter wave radar, a laser radar, a laser scanner, a distance image camera, a laser range finder, or the like. The same applies to the side monitoring device. In the embodiment, an example in which LIDAR is used as an example of the space recognition device 51 will be described. However, in this embodiment, the space recognition device 51 is not limited to LIDAR. In other words, any space recognition device that can recognize a space based on the asphalt finisher 100 may be used.

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 larger than the width of the roadbed BS.

The monitoring range RB of the rear monitoring device 51B includes the newly installed pavement. In this embodiment, the monitoring range RB has a width larger than the width of the newly installed pavement.

Measurement information detected by the spatial recognition device 51 according to this embodiment is transmitted to the controller 50. The controller 50 according to the present embodiment automatically steers the asphalt finisher 100 based on the received measurement information. Further, the controller 50 may notify the driver of a warning or the like based on the received measurement information.

Next, with reference to FIG. 2, the controller 50 installed in the asphalt finisher 100 will be described. FIG. 2 is a block diagram showing a configuration example of the controller 50 and devices connected to the controller 50.

As shown in FIG. 2, the controller 50 includes a traveling speed sensor 47, an auxiliary storage device 48, a GPS module 54, a front monitoring device 51F, a rear monitoring device 51B, a drive system controller 52, and a communication device 53. , a screed control device 55 , a screw control device 56 , and a screed length detection device 57 .

The traveling speed sensor 47 is configured to detect the traveling speed of the asphalt finisher 100. In the example shown in FIG. 2 , the running speed sensor 47 is an encoder that detects the angular velocity of the rotating shaft of the rear wheel running motor 20 that drives the rear wheels 5 . Specifically, the traveling speed sensor 47 includes a left traveling speed sensor and a right traveling speed sensor. The left running speed sensor is an encoder that detects the angular velocity of the rotating shaft of the left rear wheel running motor 20L that drives the left rear wheel. The right running speed sensor is an encoder that detects the angular velocity of the rotating shaft of the right rear wheel running motor 20R that drives the right rear wheel. The traveling speed sensor 47 may be configured with a proximity switch or the like that detects a slit formed in the rotary plate.

The auxiliary storage device 48 is configured to store various information. In the example shown in FIG. 2, the auxiliary storage device 48 is a nonvolatile storage device mounted on the tractor 1, and stores various information. For example, the auxiliary storage device 48 stores a schedule information storage section 48a and a screw length storage section 48b.

The schedule information storage unit 48a stores schedule information for constructing a road surface to be paved by the asphalt finisher 100. The schedule information according to the present embodiment includes, for example, the center line of the route traveled by the asphalt finisher 100 and a target line indicating the end of the road surface to be paved (the boundary between the road surface and the road shoulder). There is. The asphalt finisher 100 according to the present embodiment automatically controls road paving based on schedule information.

The screw length storage unit 48b stores information on the length of the screw SC included in the asphalt finisher 100. The screw length storage unit 48b according to the present embodiment stores, for example, a main screw (left main screw SCLM or right main screw SCRM) in the asphalt finisher 100, an expansion screw (for example, a first left extension screw SCLE1, or a first If the right extension screw SCRE1) is connected, information regarding the length of the screw SC after being connected is stored.

Further, the screw length storage section 48b may have information regarding an expansion screw that can be attached to the asphalt finisher 100. For example, the screw length storage section 48b may store the length of the main screw (left main screw SCLM or right main screw SCRM) provided in the asphalt finisher 100. Further, for each expansion screw connectable to the asphalt finisher 100, the screw length storage unit 48b stores information for identifying the expansion screw (for example, model number, RFID, or two-dimensional barcode), and the length and length of the expansion screw. , may be stored in association with each other.

Therefore, when the expansion screw is connected to the asphalt finisher 100, the controller 50 can recognize the length of the screw SC of the asphalt finisher 100 from the information stored in the screw length storage section 48b. Further, the correspondence relationship is not limited to the method stored by the auxiliary storage device 48, and may be held by a server that can communicate with the asphalt finisher 100.

The GPS module 54 is an example of a GNSS (Global Navigation Satellite System) module, and receives position information indicating the result of two-dimensional positioning (two-dimensional positioning) by GPS (Global Positioning System). The position information includes information representing the position of the asphalt finisher 100 in terms of latitude and longitude. Note that although this embodiment uses GPS as a location information acquisition method, the location information acquisition method is not limited, and other well-known methods may be used.

The screed length detection device 57 detects the length by which the extensible screed 31 expands and contracts in the vehicle width direction. The screed length detection device 57 may use any sensor as long as it can detect the length by which the telescoping screed 31 expands and contracts in the vehicle width direction. For example, an imaging device may be used. When an imaging device is used, the telescopic screed 31 is imaged, and the length of the telescopic screed 31 in the vehicle width direction is specified from the captured image.

The communication device 53 performs wireless communication with devices existing around the asphalt finisher 100, such as a road roller, a mobile communication device, an RFID reader, and the like. In this embodiment, as the wireless communication standard of the communication device 53, for example, one or more of Wi-Fi (registered trademark), wireless LAN, Bluetooth (registered trademark), etc. may be used.

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

The screed control device 55 is configured to control the amount of expansion and contraction of the expansion and contraction screed 31 . In the example shown in FIG. 2 , the screed control device 55 controls the flow rate of hydraulic oil flowing into the screed telescopic cylinder 27 . The screed control device 55 includes a screed expansion/contraction control valve 37 shown in FIG. Switch the cutoff.

Then, the screed control device 55 performs control to contract the screed telescopic cylinder 27 to retract the left telescopic screed 31L, and to extend the screed telescopic cylinder 27 to extend the left telescopic screed 31L, in accordance with control instructions from the controller 50. and do.

The screw control device 56 is configured to control the rotational speed of the screw SC. In the example shown in FIG. 2, the screw control device 56 is a solenoid valve that controls the flow rate of hydraulic oil flowing into the hydraulic motor that drives the screw SC. Specifically, the screw control device 56 increases or decreases the flow area of the conduit connecting the hydraulic pump and the hydraulic motor that drives the screw SC in response to a control command from the controller 50. More specifically, the screw control device 56 increases the flow rate of the hydraulic oil flowing into the hydraulic motor that drives the screw SC by increasing the flow path area, thereby increasing the rotational speed of the screw SC. Alternatively, the screw control device 56 reduces the flow rate of the hydraulic oil flowing into the hydraulic motor that drives the screw SC by reducing the flow path area, thereby reducing the rotational speed of the screw SC.

The controller 50 acquires information from the GPS module 54, the front monitoring device 51F, the rear monitoring device 51, the traveling speed sensor 47, the screed length detection device 57, and the auxiliary storage device 48, performs various calculations, and then Depending on the calculation results, control commands are output to the screed control device 55, screw control device 56, and drive system controller 52. Functional blocks included in the controller 50 according to this embodiment will be described later.

<Explanation of hydraulic system>
Next, with reference to FIG. 3, the hydraulic system installed in the asphalt finisher 100 will be described. FIG. 3 is a hydraulic circuit diagram showing a configuration example of a hydraulic system installed in the asphalt finisher 100.

The hydraulic system mainly includes a hydraulic source 14, a rear wheel drive section F1, a conveyor/screw drive section F2, a front wheel drive section F3, a steering/compaction device drive section F4, a leveling section F5, a hopper drive section F6, and a screed drift section. F7, and a screed expansion/contraction part F8.

The hydraulic power source 14 is configured to supply hydraulic oil for operating various drive units. In this embodiment, the hydraulic power source 14 mainly includes an engine 14E, a rear wheel running pump 14R, a charge pump 14C, a cylinder pump 14M, a conveyor screw pump 14S, and a front wheel running pump 14F.

The engine 14E is a drive source that drives the rear wheel running pump 14R, the charge pump 14C, the cylinder pump 14M, the conveyor screw pump 14S, and the front wheel running pump 14F.

The rear wheel running pump 14R is a variable displacement hydraulic pump that supplies driving hydraulic oil to the rear wheel drive section F1. In this embodiment, the rear wheel running pump 14R is a swash plate type variable displacement bidirectional hydraulic pump used in a closed circuit.

The charge pump 14C is a fixed capacity hydraulic pump that supplies control hydraulic oil to the rear wheel drive unit F1.

The cylinder pump 14M is a variable displacement hydraulic pump that can supply hydraulic oil to each of the steering/compaction device drive section F4, the leveling section F5, the hopper drive section F6, the screed lift section F7, and the screed expansion/contraction section F8. . In this embodiment, the cylinder pump 14M is a swash plate type variable displacement hydraulic pump, and its discharge amount is controlled so that the discharge pressure is constant at a predetermined pressure.

The conveyor screw pump 14S is a variable displacement hydraulic pump that supplies hydraulic oil to the conveyor screw drive section F2. In this embodiment, the conveyor screw pump 14S is a swash plate type variable displacement hydraulic pump.

The front wheel running pump 14F is a variable displacement hydraulic pump that supplies hydraulic oil to the front wheel drive section F3. In this embodiment, the front wheel running pump 14F is a swash plate type variable displacement hydraulic pump.

The rear wheel drive unit F1 is configured to drive the rear wheels 5. In this embodiment, the rear wheel drive unit F1 includes a left rear wheel running motor 20L, a right rear wheel running motor 20R, check valves 20La, 20Ra, relief valves 20Lb, 20Rb, and a reduction gear switching valve V0.

The left rear wheel running motor 20L is a hydraulic motor that drives the left rear wheel. Further, the right rear wheel running motor 20R is a hydraulic motor that drives the right rear wheel. In this embodiment, the left rear wheel running motor 20L and the right rear wheel running motor 20R are continuously variable speed hydraulic motors, and constitute a closed circuit (HST circuit) together with the rear wheel running pump 14R.

The check valve 20La controls the pressure of the hydraulic oil in the pipe C1 that connects the first port of the rear wheel running pump 14R and the respective second ports of the left rear wheel running motor 20L and the right rear wheel running motor 20R. Maintain the pressure above the specified level. Specifically, the check valve 20La allows the hydraulic oil discharged by the charge pump 14C to flow into the conduit C1 when the pressure of the hydraulic oil in the conduit C1 is lower than the discharge pressure of the charge pump 14C. Note that the numbers in parentheses in the figure represent port numbers. Similarly, the check valve 20Ra controls the hydraulic oil in the pipe C2 that connects the second port of the rear wheel running pump 14R and the first port of each of the left rear wheel running motor 20L and the right rear wheel running motor 20R. maintain the pressure above the specified pressure. Specifically, the check valve 20Ra allows the hydraulic oil discharged by the charge pump 14C to flow into the conduit C2 when the pressure of the hydraulic oil in the conduit C2 is lower than the discharge pressure of the charge pump 14C.

The relief valve 20Lb maintains the pressure of the hydraulic oil in the conduit C1 below a predetermined relief pressure. Specifically, the relief valve 20Lb causes the hydraulic oil in the conduit C1 to flow out of the closed circuit when the pressure of the hydraulic oil in the conduit C1 exceeds the relief pressure. Similarly, the relief valve 20Rb maintains the pressure of the hydraulic oil in the conduit C2 below a predetermined relief pressure. Specifically, the relief valve 20Rb causes the hydraulic oil in the conduit C2 to flow out of the closed circuit when the pressure of the hydraulic oil in the conduit C2 exceeds the relief pressure.

The reduction gear switching valve V0 is a mechanism that switches the reduction ratio of the left rear wheel running motor 20L and the right rear wheel running motor 20R. In this embodiment, the reduction gear switching valve V0 uses the hydraulic fluid discharged by the charge pump 14C to switch the left rear wheel running motor 20L and the right rear wheel running motor 20R, respectively, in response to a control command from the controller 50. Switch the reduction ratio.

The conveyor/screw drive unit F2 is configured to drive the conveyor CV and screw SC. In this embodiment, the conveyor screw drive unit F2 mainly includes a conveyor motor 21C, a screw motor 21S, a conveyor control valve V1C, and a screw control valve V1S.

Both the conveyor motor 21C and the screw motor 21S are variable displacement hydraulic motors that form an open circuit. The conveyor motor 21C includes a left conveyor motor 21CL and a right conveyor motor 21CR. The screw motor 21S includes a left screw motor 21SL and a right screw motor 21SR. The conveyor control valve V1C includes a left conveyor control valve V1CL and a right conveyor control valve V1CR. The screw control valve V1S includes a left screw control valve V1SL and a right screw control valve V1SR.

The left conveyor control valve V1CL operates in response to a control command from the controller 50, and causes the hydraulic oil discharged by the conveyor screw pump 14S to flow into the suction port of the left conveyor motor 21CL. The hydraulic oil flowing out from the discharge port of 21CL is discharged to the hydraulic oil tank T. The right conveyor control valve V1CR operates in response to a control command from the controller 50, and causes the hydraulic oil discharged by the conveyor screw pump 14S to flow into the suction port of the right conveyor motor 21CR. The hydraulic oil flowing out from the discharge port of 21CR is discharged to the hydraulic oil tank T. Similarly, the left screw control valve V1SL operates in response to a control command from the controller 50, and causes the hydraulic oil discharged by the conveyor screw pump 14S to flow into the suction port of the left screw motor 21SL. The hydraulic oil flowing out from the discharge port of the screw motor 21SL is discharged into the hydraulic oil tank T. The right screw control valve V1SR operates in response to a control command from the controller 50, and causes the hydraulic oil discharged by the conveyor screw pump 14S to flow into the suction port of the right screw motor 21SR. The hydraulic oil flowing out from the discharge port of 21SR is discharged to the hydraulic oil tank T. The hydraulic oil flowing out from the discharge ports of the left conveyor motor 21CL, right conveyor motor 21CR, left screw motor 21SL, and right screw motor 21SR passes through the oil cooler OC and is discharged into the hydraulic oil tank T. .

The front wheel drive unit F3 is configured to drive the front wheels 6. In this embodiment, the front wheel drive unit F3 mainly includes a front wheel running motor 22 and a front wheel running valve V2.

The front wheel running motor 22 is a fixed capacity hydraulic motor that forms an open circuit.
The front wheel running valve V2 operates according to a control command from the controller 50, and causes the hydraulic oil discharged by the front wheel running pump 14F to flow into the suction port of the front wheel running motor 22. In the example shown in FIG. 3, the front wheel running motor 22 includes a left front wheel running motor 22L and a right front wheel running motor 22R. The front wheel running pump 14F supplies hydraulic oil to each of the left front wheel running motor 22L and the right front wheel running motor 22R in parallel.

The steering/compaction device drive section F4 is configured to drive a steering device and a compaction device (both not shown). The steering device is a hydraulic device for steering the front wheels 6. In the present embodiment, the steering device changes the steering angle of the front wheels 6 using hydraulic oil discharged from the cylinder pump 14M, for example, in response to the operation of the steering wheel by the operator. Further, the compaction device is a hydraulic device for compacting the paving material. In this embodiment, the compaction device includes a tamper and a vibrator, and operates the tamper and the vibrator using hydraulic oil discharged by the cylinder pump 14M.

The leveling part F5 is configured to be able to adjust the pavement thickness. In this embodiment, the leveling section F5 mainly includes a leveling cylinder 23, a leveling control valve 33, and a pilot check valve 33P.

The leveling cylinder 23 is a hydraulic cylinder that moves the leveling arm 3A up and down to adjust the pavement thickness. The leveling cylinder 23 is configured to contract when increasing the pavement thickness and expand when decreasing the pavement thickness. In the example shown in FIG. 3, the leveling cylinder 23 includes a left leveling cylinder 23L and a right leveling cylinder 23R.

The leveling control valve 33 is configured to operate in response to a control signal from the controller 50. In the example shown in FIG. 3, the leveling control valve 33 includes a left leveling control valve 33L and a right leveling control valve 33R. When increasing the pavement thickness, the left leveling control valve 33L causes the hydraulic oil discharged by the cylinder pump 14M to flow into the rod side oil chamber of the left leveling cylinder 23L, and from the head side oil chamber of the left leveling cylinder 23L. The leaking hydraulic oil is discharged into the hydraulic oil tank T. In this case, the left leveling cylinder 23L contracts and the left leveling arm 3AL rises. The same applies to the right leveling control valve 33R that contracts the right leveling cylinder 23R. On the other hand, when reducing the pavement thickness, the left leveling control valve 33L causes the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the left leveling cylinder 23L, and also causes the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the left leveling cylinder 23L. The hydraulic oil flowing out from the chamber is discharged into the hydraulic oil tank T. In this case, the left leveling cylinder 23L is extended and the left leveling arm 3AL is lowered. The same applies to the right leveling control valve 33R that extends the right leveling cylinder 23R.

The pilot check valve 33P is configured to prevent the leveling cylinder 23 from moving due to external force. In the example shown in FIG. 3, pilot check valve 33P includes pilot check valves 33PaL, 33PbL, 33PaR, and 33PbR. For example, the pilot check valve 33PaL operates only when the left leveling control valve 33L operates in response to the operator's operation and the hydraulic oil discharged by the cylinder pump 14M flows into the head side oil chamber of the left leveling cylinder 23L. , allows the hydraulic oil in the rod side oil chamber of the left leveling cylinder 23L to flow toward the hydraulic oil tank T. The pilot check valve 33PaL prohibits the hydraulic oil in the rod-side oil chamber of the left leveling cylinder 23L from flowing toward the hydraulic oil tank T in other cases. The same applies to the pilot check valves 33PbL, 33PaR, and 33PbR.

The hopper drive unit F6 is configured to open and close the hopper 2. In this embodiment, the hopper drive unit F6 mainly includes a hopper cylinder 24, a hopper control valve 34, and a pilot check valve 34P.

The hopper cylinder 24 is a hydraulic actuator that opens and closes the hopper 2, and contracts when the hopper 2 is opened and expands when the hopper 2 is closed. In the example shown in FIG. 3, the hopper cylinder 24 includes a left hopper cylinder 24L and a right hopper cylinder 24R.

The hopper control valve 34 is configured to operate in response to a control signal from the controller 50. In the example shown in FIG. 3, the hopper control valve 34 includes a left hopper control valve 34L and a right hopper control valve 34R. When opening the hopper 2, the left hopper control valve 34L allows the hydraulic oil discharged by the cylinder pump 14M to flow into the rod side oil chamber of the left hopper cylinder 24L, and flows out from the head side oil chamber of the left hopper cylinder 24L. The hydraulic oil is discharged into the hydraulic oil tank T. In this case, the left hopper cylinder 24L contracts. Further, the right hopper control valve 34R allows the hydraulic oil discharged by the cylinder pump 14M to flow into the rod side oil chamber of the right hopper cylinder 24R, and also controls the hydraulic oil flowing out from the head side oil chamber of the right hopper cylinder 24R. Drain into hydraulic oil tank T. In this case, the right hopper cylinder 24R contracts. On the other hand, when closing the hopper 2, the left hopper control valve 34L causes the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the left hopper cylinder 24L, and also causes the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the left hopper cylinder 24L. The hydraulic oil flowing out from the tank is discharged into the hydraulic oil tank T. In this case, the left hopper cylinder 24L is extended. Further, the right hopper control valve 34R allows the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the right hopper cylinder 24R, and also controls the hydraulic oil flowing out from the rod side oil chamber of the right hopper cylinder 24R. Drain into hydraulic oil tank T. In this case, the right hopper cylinder 24R is extended.

The pilot check valve 34P is configured to prevent the hopper cylinder 24 from contracting due to the weight of the hopper 2 or the weight of the hopper 2 and the paving material in the hopper 2, thereby preventing the hopper 2 from opening. In the example shown in FIG. 3, pilot check valve 34P includes pilot check valve 34PL and pilot check valve 34PR. For example, the pilot check valve 34PL operates only when the left hopper control valve 34L operates in response to an operator's operation, and the hydraulic oil discharged by the cylinder pump 14M flows into the rod side oil chamber of the left hopper cylinder 24L. , allows the hydraulic oil in the head side oil chamber of the left hopper cylinder 24L to flow toward the hydraulic oil tank T. The pilot check valve 34PL prohibits the hydraulic oil in the head side oil chamber of the left hopper cylinder 24L from flowing toward the hydraulic oil tank T in other cases. The same applies to the pilot check valve 34PR.

Note that in the hopper drive unit F6, no pilot check valve is installed between the rod side oil chamber of the hopper cylinder 24 and the hopper control valve 34. This is because the weight of the hopper 2 is large, so there is a low possibility that the hopper cylinder 24 will expand unintentionally due to external force. However, a pilot check valve may be installed between the rod side oil chamber of the hopper cylinder 24 and the hopper control valve 34.

The screed lift part F7 is configured to be able to lift the screed 3. In this embodiment, the screed lift section F7 mainly includes a screed lift cylinder 25, a screed lift control valve 35, a switching valve 35a, a relief valve 35b, and a switching valve 35c.

The screed lift cylinder 25 is a hydraulic actuator that lifts the screed 3, contracts when lifting the screed 3, and expands when lowering the screed 3. In the example shown in FIG. 3, the screed lift cylinder 25 includes a left screed lift cylinder 25L and a right screed lift cylinder 25R.

The screed drift control valve 35 is configured to operate in response to a control signal from the controller 50. When lifting the screed 3, the screed lift control valve 35 causes the hydraulic oil discharged by the cylinder pump 14M to flow into the rod side oil chamber of the screed lift cylinder 25. In this case, the switching valve 35a is switched to the first position including the check valve in response to a control signal from the controller 50. This is to prevent hydraulic oil from flowing backward from the rod-side oil chamber of the screed lift cylinder 25 toward the hydraulic oil tank T. Note that the hydraulic oil flowing out from the head side oil chamber of the screed drift cylinder 25 is discharged into the hydraulic oil tank T without passing through the screed drift control valve 35. In this case, the screed lift cylinder 25 is retracted. On the other hand, when the screed 3 is lowered to the ground, the screed drift control valve 35 is not used (the state shown in FIG. 3 is maintained). In this case, the switching valve 35a is switched to the second position, which does not include a check valve, in response to a control signal from the controller 50. This is to cause the hydraulic oil in the rod side oil chamber of the screed drift cylinder 25 to flow out toward the hydraulic oil tank T. Therefore, the screed lift cylinder 25 expands due to the weight of the screed 3, and the hydraulic oil in the rod-side oil chamber of the screed lift cylinder 25 is discharged into the hydraulic oil tank T through the switching valve 35a and the relief valve 35b.

The switching valve 35a and the relief valve 35b realize vertical movement of the screed 3 in response to changes in the lift force (force of the paving material trying to lift the screed 3) that occurs when paving the road while the asphalt finisher 100 moves. . Specifically, when the screed 3 rises due to an increase in lift, the screed lift cylinder 25 contracts. In this case, the hydraulic oil discharged by the cylinder pump 14M flows into the rod side oil chamber of the screed drift cylinder 25 through the pipe C3, the screed drift control valve 35, and the switching valve 35a. On the other hand, when the screed 3 descends due to a decrease in lift, the screed lift cylinder 25 expands. In this case, the hydraulic oil flowing out from the rod-side oil chamber of the screed lift cylinder 25 is discharged into the hydraulic oil tank T through the switching valve 35a, the screed lift control valve 35, and the relief valve 35b. Note that the switching valve 35c closes the check valve in response to a control signal from the controller 50 when the asphalt finisher 100 is moving and paving the road, that is, when the downstream hydraulic device such as the screed expansion/contraction section F8 is not used. The first position includes the first position. This is to avoid adversely affecting the hydraulic equipment such as the screed expansion/contraction section F8 located downstream. Specifically, this is to prevent the telescopic screed 31, the crown device, the step device, etc. from moving unintentionally.

The screed expansion/contraction part F8 is configured so that the expansion/contraction screed 31 can be expanded/contracted in the vehicle width direction. In this embodiment, the screed expansion/contraction section F8 mainly includes a screed expansion/contraction cylinder 27, a screed expansion/contraction control valve 37, a pilot check valve 37P, and a relief valve 37V. In the example shown in FIG. 3, the screed expansion/contraction control valve 37 includes a left screed expansion/contraction control valve 37L and a right screed expansion/contraction control valve 37R. Pilot check valve 37P includes pilot check valves 37PaL, 37PaR, 37PbL, and 37PbR. The relief valve 37V includes a left relief valve 37VL and a right relief valve 37VR.

The left screed expansion/contraction control valve 37L is configured to operate in response to a control signal from the controller 50. When the left telescopic screed 31L is retracted, the left screed telescopic control valve 37L causes the hydraulic oil discharged by the cylinder pump 14M to flow into the rod side oil chamber of the left screed telescopic cylinder 27L, and also causes the left screed telescopic cylinder 27L to retract. The hydraulic oil flowing out from the head side oil chamber is discharged into the hydraulic oil tank T. In this case, the left screed telescopic cylinder 27L is contracted and the left telescopic screed 31L is retracted. The same applies to the case where the right telescopic screed 31R is retracted. On the other hand, when pushing out the left screed telescopic screed 31L, the left screed telescopic control valve 37L causes the hydraulic oil discharged by the cylinder pump 14M to flow into the head side oil chamber of the left screed telescopic cylinder 27L, and The hydraulic oil flowing out from the 27L rod side oil chamber is discharged to the hydraulic oil tank T. In this case, the left screed telescopic cylinder 27L is expanded and the left telescopic screed 31L is pushed out.

The pilot check valve 37P is configured to prevent the screed telescopic cylinder 27 from moving unintentionally due to external force. For example, the pilot check valve 37PaL operates when the left screed telescopic control valve 37L operates in response to an operator's operation, and the hydraulic oil discharged by the cylinder pump 14M flows into the head side oil chamber of the left screed telescopic cylinder 27L. The hydraulic oil in the rod-side oil chamber of the left screed telescopic cylinder 27L is allowed to flow toward the hydraulic oil tank T only. The pilot check valve 37PaL prohibits the hydraulic oil in the rod side oil chamber of the left screed telescopic cylinder 27L from flowing toward the hydraulic oil tank T in other cases. The same applies to pilot check valves 37PbL, 37PaR, and 37PbR.

The relief valve 37V is configured to prevent members related to the telescopic screed 31 from being destroyed by excessive external force acting in the direction of retracting the telescopic screed 31. For example, if the pressure of the hydraulic oil in the head side oil chamber of the left screed telescopic cylinder 27L increases excessively due to an excessive external force acting in the direction of contracting the left screed telescopic cylinder 27L, the left relief valve 37VL is activated on the head side. Allows hydraulic oil in the oil chamber to flow into the hydraulic oil tank T. As a result, the left screed telescopic cylinder 27L contracts and absorbs a portion of the external force, thereby preventing the left telescopic screed 31L from being damaged. The same applies to the right relief valve 37VR.

<Controller functional block>
Each functional block within the controller 50 of the asphalt finisher 100 will be explained. Each functional block within the controller 50 is conceptual and does not necessarily need to be physically configured as illustrated. It is possible to configure all or part of each functional block by functionally or physically distributing and integrating it in arbitrary units. All or any part of each processing function performed by each functional block is realized by a program executed by the CPU. Alternatively, each functional block may be realized as hardware using wired logic. The program executed by the controller 50 according to the present embodiment is not limited to being stored in a non-volatile auxiliary storage device, but may be stored in a distributable storage medium, or can be stored in a storage medium that can be distributed via a communication line NW. It may also be sent and received.

The controller 50 according to the present embodiment estimates its own position according to the detection results from the GPS module 54, the front monitoring device 51F, the rear monitoring device 51, and the traveling speed sensor 47, and performs self-position estimation based on the schedule stored in the auxiliary storage device 48. Automatic movement control is performed to asphalt the road surface indicated by the information.

At this time, the controller 50 sends a control command to the screed control device 55 to extend or shorten the telescopic screed 31 based on the measurement information from the screed length detection device 57 so that the paving material does not protrude from the road surface to be paved. Send.

By the way, a side plate 40 is attached to the distal end of the extensible screed 31. Therefore, when the telescopic screed 31 is contracted in the vehicle width direction, the side plate 40 may come into contact with the screw.

Therefore, the controller 50 according to the present embodiment controls the expansion and contraction of the expansion and contraction screed 31 so that the length of the expansion and contraction screed 31 (an example of a screed device) in the vehicle width direction does not become less than a predetermined length based on the screw SC. Control.

The predetermined length based on the screw SC is a length determined so that the side plate 40 does not come into contact with the screw SC, and is, for example, the length of the screw SC in the vehicle width direction plus a predetermined margin. In other words, the length is longer than the length of the screw SC in the vehicle width direction. Thereby, the telescopic screed 31 can be prevented from coming into contact with the screw SC.

More specifically, the controller 50 includes a communication control section 50a, a setting section 50b, an acquisition section 50c, a movement route calculation section 50d, and a movement control section 50e as functional blocks composed of software, hardware, or a combination thereof. , and a screed control section 50f.

The communication control unit 50a sends and receives information to and from external devices.

For example, the communication control unit 50a may receive information regarding the expansion screw connected to the asphalt finisher 100 from an RFID (Radio Frequency Identification) reader or a two-dimensional barcode reader.

The setting unit 50b registers the length of the screw SC of the asphalt finisher 100 in the screw length storage unit 48b based on the information regarding the expansion screw received by the communication control unit 50a. Next, the expansion screw connected to the asphalt finisher 100 will be explained.

The asphalt finisher 100 according to the present embodiment connects different expansion screws depending on the width of the road to be paved.

FIG. 4 is an explanatory diagram of the screw SC included in the asphalt finisher 100 according to the present embodiment. As shown in FIG. 4, the asphalt finisher 100 includes a plurality of types of expansion screws that can be connected to the left main screw SCLM. In the example shown in FIG. 4, there is a first left extension screw SCLE1 and a second left extension screw SCLE2. Each of the first left extension screw SCLE1 and the second left extension screw SCLE2 can be connected to the left main screw SCLM. The length of the first left extension screw SCLE1 is, for example, 1 m, and the length of the second left extension screw SCLE2 is, for example, 50 cm. In this way, the length of the expansion screw differs depending on the type.

Alternatively, the first left extension screw SCLE1, the second left extension screw SCLE2, and the left main screw SCLM may all be connected. Any connection method may be used, such as bolt fastening.

The operator fastens the expansion screw to the main screw according to the width of the road to be paved by the asphalt finisher 100. In this embodiment, as described above, in order for the controller 50 to control the length of the telescopic screed 31 in the vehicle width direction so that it does not become less than a predetermined length based on the screw SC, You need to know the length.

Therefore, the operator performs work to set the length of the expansion screw connected to the asphalt finisher 100.

For example, if the RFID 44L1 is embedded in the first left extension screw SCLE1 and the RFID 44L2 is embedded in the second left extension screw SCLE2, the operator may )'s RFID (for example, RFID44L1) is read by an RFID reader (not shown). The information read by the RFID reader includes information identifying the expansion screw to be connected (for example, the first left extension screw SCLE1) or information indicating the length of the expansion screw.

The RFID reader then transmits the read information to the communication device 53 of the asphalt finisher 100.

Then, the communication control unit 50a receives information identifying the expansion screw to be connected (for example, the first left extension screw SCLE1) or information indicating the length of the expansion screw from the RFID reader via the communication device 53. do.

The setting unit 50b registers the length of the screw SC after the expansion screw is connected to the asphalt finisher 100 in the screw length storage unit 48b based on the received information. For example, when the setting unit 50b has received information identifying an expansion screw, the setting unit 50b includes information for identifying the expansion screw (for example, model number, RFID) stored in the screw length storage unit 48b, and the information for identifying the expansion screw. The length of the connected expansion screw is determined from the correspondence between the length of and the length of the expansion screw. Then, the setting section 50b registers the specified length in the screw length storage section 48b.

Further, the setting unit 50b registers the length of the screw SC, which is the sum of the length of the expansion screw and the length of the main screw, in the screw length storage unit 48b.

Further, the setting unit 50b sets a predetermined length as a reference when controlling the expansion and contraction of the screw based on the length of the screw SC. Control using a predetermined length will be described later.

In this embodiment, the case where the source of the information regarding the expansion screw to be connected is the RFID reader has been described. However, in this embodiment, the transmission source is not limited to an RFID reader, and may be a worker's mobile communication device, for example. For example, if a two-dimensional barcode is pasted on the expansion screw, an imaging device included in the mobile communication device images the two-dimensional barcode, and the mobile communication device transmits the information extracted from the two-dimensional barcode. It may also be transmitted to the device 53. Furthermore, an input device provided in the asphalt finisher 100 may accept input of information regarding the expansion screw (for example, model number) or the length of the expansion screw. In these cases, the setting unit 50b registers the length of the expansion screw and the length of the screw SC in the screw length storage unit 48b based on the information.

Further, if the length of the expansion screw registered by the setting unit 50b does not correspond to the width of the road in the schedule information stored in the schedule information storage unit 48a, the controller 50 issues a warning before starting construction. may be output. Furthermore, the controller 50 may suppress the start of automatic control until the information on the expansion screw corresponding to the width of the road in the schedule information is registered.

Returning to FIG. 2, the acquisition unit 50c acquires various information. For example, the acquisition unit 50c acquires measurement information from various sensors. For example, the acquisition unit 50c acquires measurement information from the front monitoring device 51F, the rear monitoring device 51, the traveling speed sensor 47, and the screed length detection device 57. As another example, the acquisition unit 50c acquires position information from the GPS module 54. Furthermore, the acquisition unit 50c acquires information from the auxiliary storage device 48 as necessary.

The moving route calculation unit 50d calculates the moving route of the asphalt finisher 100 based on the schedule information read from the schedule information storage unit 48a.

The movement control unit 50e outputs a control command based on the measurement information and position information acquired by the acquisition unit 50c to the drive system controller 52 so as to move along the calculated movement route. As a result, automatic movement control of the asphalt finisher 100 is performed.

The screed control unit 50f issues a control command for expanding and contracting the elastic screed 31 based on the measurement information (an example of a detection result) of the screed length detection device 57 so as to correspond to the width of the road surface on which paving material is to be spread. It is output to the control device 55. Thereby, the length of the screed 3 in the vehicle width direction can be made to match the width of the road to be paved, so that the paving material can be appropriately spread over the road surface to be paved.

However, when performing control to shorten the telescopic screed 31 to correspond to the width of the road surface on which paving material is to be spread, the screed control section 50f controls the Control to shorten the screed 31 is suppressed.

Specifically, when controlling the retractable screed 31 to shorten it, the screed control unit 50f determines that the length of the retractable screed 31 in the vehicle width direction is a predetermined length based on the measurement information of the screed length detection device 57. When detected, even if the side plate 40 protrudes outside the road surface (toward the road shoulder), control to shorten the telescopic screed 31 is suppressed. Next, the suppression of the control of the screed control unit 50f to contract the telescopic screed 31 will be explained.

<Explanation of the movement route of the asphalt finisher>
FIG. 5 is a diagram showing a travel route of the asphalt finisher 100 according to the present embodiment based on schedule information. In the example shown in FIG. 5, a case will be described in which the asphalt finisher 100 moves in a traveling direction 5001.

Then, the movement control unit 50e of the asphalt finisher 100 controls the tractor 1 so that the center of the asphalt finisher 100 coincides with the center line CL1 of the road to be paved in order to move along the road to be paved. .

Further, the screed control unit 50f outputs a control command to the screed control device 55 to extend and contract the left telescopic screed 31L so that the left side plate 40L matches the left target line OLL. Similarly, the screed control unit 50f outputs a control command to the screed control device 55 to extend and contract the right telescopic screed 31R so that the right side plate 40R matches the right target line OLR. Thereby, even if the center of the asphalt finisher 100 is slightly deviated from the center line CL1 of the road to be paved, it is possible to appropriately spread the paving material on the road surface to be paved.

By the way, when the center of the asphalt finisher 100 coincides with the center line CL1, the length from the center line CL1 to the edge of the road in the left direction is L1, and the length from the center line CL1 to the edge of the road in the right direction is L1. The length up to this point is L1. Therefore, the screed control unit 50f may perform expansion/contraction control so that the distance from the center of the asphalt finisher 100 to the right side plate 40R and left side plate 40L is the length L1.

However, in the asphalt finisher 100, when the movement control unit 50e performs automatic control, the center of the asphalt finisher 100 may deviate from the center line CL1. For example, if the road is curved and there is a delay in the timing at which the movement control unit 50e automatically controls the steering angle of the tractor 1 to change the steering angle, the center of the asphalt finisher 100 will shift from the center line CL1. In this case, for example, the center of the asphalt finisher 100 may move along the route CL2.

In this case, the screed control unit 50f controls the expansion and contraction of the left telescopic screed 31L so that the distance from the center of the asphalt finisher 100 to the left side plate 40L is L3.

The screed control unit 50f needs to control the expansion and contraction of the right telescopic screed 31R so that the distance from the center of the asphalt finisher 100 to the right side plate 40R is L2. However, when the right telescopic screed 31R is shortened so that the length from the center of the asphalt finisher 100 to the right side plate 40R becomes length L2, the right side plate 40R may come into contact with the screw SC. .

FIG. 6 is a diagram showing the positional relationship between the left side plate 40L and the screw SC according to the present embodiment. Although FIG. 6 shows the positional relationship between the screw SC in which the first left extension screw SCLE1 is connected to the left main screw SCLM and the left side plate 40L, the positional relationship between the screw SC and the right side plate 40R is also shown. It will be the same.

In the example shown in FIG. 6, the traveling direction is 5001. The left main screw SCLM and the first left extension screw SCLE1 are rotated in the direction of arrow 6001 under the control of the screw control device 56, thereby pushing the paving material toward the road shoulder (the direction where the target line OLL exists).

Then, the screed control unit 50f performs expansion/contraction control using the left screed expansion/contraction cylinder 27L so that the left side plate 40L matches the left target line OLL. Note that the extensible mold board 41 is assumed to expand and contract according to the expansion and contraction control by the left screed expansion and contraction cylinder 27L, and a description thereof will be omitted.

When it is detected that the left side plate 40L has shifted to the right from the left target line OLL, the screed control unit 50f controls the left screed telescopic cylinder 27L to extend, and moves the left side plate 40L in the direction of the left arrow 6002. let

Similarly, when it is detected that the left side plate 40L has shifted to the left from the left target line OLL, the screed control unit 50f performs control to retract the left screed telescopic cylinder 27L, and moves the left side plate 40L in the direction of the right arrow. Move to 6003. However, if the left side plate 40L moves too far in the right arrow direction 6003, the left side plate 40L contacts the end of the first left extension screw SCLE1.

Therefore, the screed control unit 50f according to the present embodiment is configured such that the length of the telescopic screed 31 (an example of a screed device) in the vehicle width direction is set to a predetermined length so that the left side plate 40L does not come into contact with the first left extension screw SCLE1. control so that the temperature does not drop below that level.

Returning to FIG. 5, when performing control to shorten the telescopic screed 31, the screed control unit 50f suppresses the control to shorten the telescopic screed 31 when the length of the telescopic screed 31 in the vehicle width direction is a predetermined length. As a result, the right side plate 40R is moving along a movement line 5011 that protrudes from the right target line OLR to the road shoulder side. As a result, although the paving material protrudes onto the road shoulder, it is possible to suppress the right side plate 40R from coming into contact with the screw SC. Therefore, by the controller 50 performing the above-described control, it is possible to suppress the right side plate 40R from coming into contact with the screw SC, and improve safety.

The controller 50 according to the present embodiment can perform various controls when suppressing the control for contracting the telescopic screed 31.

For example, the movement control unit 50e may perform control to reduce the speed of the tractor 1 of the asphalt finisher 100 when the screed control unit 50f suppresses control to shorten the telescopic screed.

That is, when the screed control unit 50f suppresses the control to shorten the telescopic screed 31, the movement control unit 50e estimates that the center of the asphalt finisher 100 is deviated from the center line of the road. Then, the movement control unit 50e performs control to reduce the speed of the tractor 1 in order to correct the deviation. After reducing the speed, the movement control unit 50e can restart control to extend and contract the telescopic screed 31 so that the side plate 40 matches the target line by correcting the moving direction of the asphalt finisher 100. Therefore, since the moving direction can be corrected twice as much as the speed is reduced, the accuracy of paving the road surface can be improved. Further, after reducing the speed of the tractor 1, the movement control unit 50e may stop the tractor 1 if it is difficult to correct the moving direction or if it recognizes that an abnormality has occurred.

As another example, the communication control unit 50a may transmit information indicating that the screed control unit 50f has suppressed the control to retract the elastic screed 31 to the external device. For example, the communication control unit 50a transmits information indicating that the control to shorten the telescopic screed 31 has been suppressed to a road roller located behind the asphalt finisher 100 in the traveling direction. This allows the road roller to perform control based on this information. Further, the communication control unit 50a may transmit information indicating that the control to retract the telescopic screed 31 has been suppressed to the mobile communication devices of workers present in the surrounding area. By transmitting this information, subsequent road rollers or workers can follow up. For example, a worker can return paving material that has protruded onto the road shoulder to the road surface. Therefore, the communication control unit 50a can improve the accuracy of road surface paving by transmitting the above-mentioned information. Furthermore, the communication control unit 50a may transmit information indicating that the control to shorten the telescopic screed 31 has been suppressed to the management server that manages the work history. Thereby, the present embodiment can manage the work history of the asphalt finisher 100.

<Explanation of control procedure in automatic movement control by asphalt finisher>
FIG. 7 is a flowchart showing control of the asphalt finisher 100 by the controller 50 according to the present embodiment. In the example shown in FIG. 7, the length of the screw SC has already been registered in the screw length storage section 48b.

First, before performing automatic control, the acquisition unit 50c of the controller 50 acquires a predetermined length based on the length of the screw SC from the screw length storage unit 48b of the auxiliary storage device 48 (S7001).

Next, the acquisition unit 50c acquires schedule information from the schedule information storage unit 48a of the auxiliary storage device 48 before performing automatic control (S7002).

The moving route calculation unit 50d calculates the moving route of the asphalt finisher 100 according to the schedule information (S7003).

Then, the movement control unit 50e starts movement control to move according to the calculated movement route (S7004).

The acquisition unit 50c acquires position information from the GPS module 54, and also acquires measurement information from each of the front monitoring device 51F, the rear monitoring device 51, the traveling speed sensor 47, and the screed length detection device 57 (S7005).

The movement control unit 50e performs movement control to move according to the movement route based on the position information and the measurement information of the front monitoring device 51F, the rear monitoring device 51, and the traveling speed sensor 47 (S7006).

The screed control unit 50f determines whether the side plate 40 is deviated from the target line based on the measurement information of the screed length detection device 57 and the position of the target line indicated by the schedule information (S7007). . If it is determined that the side plate 40 has not deviated from the target line (S7007: No), the expansion/contraction control is not performed and the process moves to S7011.

When it is determined that the side plate 40 has deviated from the target line (S7007: Yes), the screed control unit 50f controls the length of the telescopic screed 31 in the vehicle width direction to a predetermined length. It is determined whether there is no control to shorten the length to be less than the length of (S7008).

If it is determined that the control is not to shorten the length of the telescopic screed 31 in the vehicle width direction below a predetermined length (S7008: No), the screed control unit 50f performs the telescopic control to correct the deviation. Execute (S7009).

On the other hand, if it is determined that the control is to shorten the length of the telescopic screed 31 in the vehicle width direction below a predetermined length (S7008: Yes), the shortening control is stopped (S7010).

Thereafter, the movement control unit 50e determines whether movement along the movement route has ended (S7011). If it is determined that the process has not been completed (S7011: No), the process starts from S7005 again.

On the other hand, if the movement control unit 50e determines that the movement along the movement route has ended (S7011: Yes), the process ends.

When performing movement control, the controller 50 according to the present embodiment can perform expansion and contraction control of the expansion and contraction screed 31 in accordance with the width of the road. At this time, if it is necessary to reduce the length of the telescopic screed 31 in the vehicle width direction below a predetermined length, the side plate 40 can be attached to the screw SC by stopping the reduction control. Contact can be suppressed.

(Modified example)
In the embodiment described above, a case has been described in which the controller 50 controls the expansion and contraction of the expansion and contraction screed 31 when automatically controlling the movement of the asphalt finisher 100. However, the control to shorten the telescopic screed 31 is not limited to the case where automatic movement control is performed as in the embodiment described above, and may be performed when an operation to shorten the telescopic screed 31 is received from the operator. . Therefore, in a modified example, a case will be described in which an operation for contracting the telescopic screed 31 is received from the operator.

The asphalt finisher 100 according to this modification moves according to the steering by the operator sitting in the driver's seat 1S. Further, the asphalt finisher 100 according to the present modification controls the expansion and contraction of the expansion and contraction screed 31 in accordance with an operation from an operator.

FIG. 8 is a diagram showing a rear view of the asphalt finisher 100. In the example shown in FIG. 8, the input unit 55L receives an operation from the operator for extending and contracting the left telescopic screed 31L to the left side in the vehicle width direction with respect to the main screed 30. The input unit 55R receives an operation from an operator to extend and contract the right telescopic screed 31R to the right side in the vehicle width direction with respect to the main screed 30. The input unit 55L and the input unit 55R output information on the received operation to the controller 50.

Thereby, the screed control unit 50f of the controller 50 performs expansion/contraction control of the expansion/contraction screed 31 according to the received operation information.

In addition, when the screed control unit 50f controls the telescopic screed 31 to contract based on the operation input from the input unit 55L or the input unit 55R, when the length of the telescopic screed 31 in the vehicle width direction is a predetermined length. In addition, the control to retract the telescopic screed 31 is suppressed.

In this modification, the screed control unit 50f performs the above-described control, so that even when the operator controls the expansion and contraction of the expansion and contraction screed 31, it is possible to suppress the screw SC from coming into contact with the side plate 40. Therefore, the asphalt finisher 100 according to this modification can improve safety.

In this modification, the case where the input devices that accept operations from the operator are the input section 55L and the input section 55R has been described. However, this modification is not limited to an example including the input section 55L and the input section 55R. For example, one input device may be used to control the expansion and contraction of the left telescopic screed 31L and the right telescopic screed 31R. The input device is not limited to being installed near the rear surface of the asphalt finisher 100, but may be installed in the driver's seat 1S, or may be a detachable device that performs wireless communication.

<Effect>
Since the controller 50 of the asphalt finisher 100 according to the above-described embodiments and modifications has the above-described configuration, when controlling the expansion and contraction of the expansion and contraction screed 31 in accordance with the width of the road surface, The expansion and contraction of the extensible screed 31 is controlled so that the length of the screed 31 does not fall below a predetermined length based on the screw SC. This makes it possible to prevent the side plate 40 provided at the far end of the telescopic screed 31 from coming into contact with the screw SC, thereby improving safety.

Further, when connecting an expansion screw, the predetermined length is set based on the total length of the main screw and the expansion screw. For example, when the asphalt finisher 100 changes the length of the screw SC according to the width of the road during construction, control is performed so that the side plate 40 does not come into contact with the screw SC after the length has been changed. Therefore, even if the length of the screw SC is changed, contact with the side plate 40 is suppressed, so that safety can be improved.

Although the embodiments have been described in detail above, the present disclosure is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist described in the claims.

Although the embodiments of the asphalt finisher have been described above, the present invention is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present invention.

100 Asphalt finisher SCLM Left main screw SCRM Right main screw SCLE1 1st left extension screw SCRE1 1st right extension screw 27L Left screed telescopic cylinder 27R Right screed telescopic cylinder 30 Main screed 31L Left telescopic screed 31R Right telescopic screed 47 Travel speed sensor 48 Auxiliary Storage device 48a Schedule information storage section 48b Screw length storage section 50 Controller 50a Communication control section 50b Setting section 50c Acquisition section 50d Movement route calculation section 50e Movement control section 50f Screed control section 51F Front monitoring device 51B Rear monitoring device 52 Drive system controller 53 Communication device 54 GPS module 55 Screed control device 56 Screw control device

Claims (7)

tractor and
a hopper installed on the front side of the tractor;
a conveyor that conveys the paving material in the hopper to the rear side of the tractor;
a screw that spreads the paving material conveyed by the conveyor and spread on the road surface in the vehicle width direction;
a screed device that is expandable and retractable in the vehicle width direction and spreads the paving material spread by the screw on the rear side of the screw;
The screed device is configured to control expansion and contraction of the screed device so that the length of the screed device in the vehicle width direction does not fall below a predetermined length based on the screw;
asphalt finisher. When controlling the screed device to shorten it so as to correspond to the width of the road surface on which the paving material is to be spread, the screed device is controlled to shorten when the length of the screed device in the vehicle width direction is the predetermined length. configured to suppress
The asphalt finisher according to claim 1. When the screed device is controlled to shorten based on the detection result of the length of the screed device in the vehicle width direction so as to correspond to the width of the road surface on which the paving material is to be spread, the length of the screed device in the vehicle width direction is configured to suppress control to shorten the screed device when the length is the predetermined length;
The asphalt finisher according to claim 2. further comprising an input device for inputting expansion/contraction operations of the screed device,
When the screed device is controlled to shorten based on an operation input from the input device, the control to shorten the screed device is suppressed when the length of the screed device in the vehicle width direction is the predetermined length. is configured to
The asphalt finisher according to claim 2. configured to perform control to reduce the speed of the asphalt finisher when the control to shorten the screed device is suppressed;
The asphalt finisher according to any one of claims 2 to 4. configured to transmit information indicating that control for retracting the screed device has been suppressed to an external device;
The asphalt finisher according to any one of claims 2 to 5. The predetermined length is configured to be set based on the length of the screw in the vehicle width direction.
The asphalt finisher according to any one of claims 1 to 6.

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