Train-type scraper vehicles and towing vehicles

Abstract

In order to reduce excavation time, this train-type scraper vehicle comprises: a first scraper vehicle having a first excavation part, and coupled to a towing vehicle by a first coupling member; a second scraper vehicle having a second excavation part, and coupled to the first scraper vehicle by a second coupling member; and a control device from which the first excavation part and the second excavation part receive an instruction to perform excavation simultaneously in at least a partial period.　

Description

Train-type scraper vehicle

[0001] The present invention relates to a train-type scraper vehicle in which a plurality of scraper vehicles are connected together.

[0002] Conventionally, scraper vehicles equipped with a scraper for excavating the ground, etc., and towed by a towing vehicle have been used at civil engineering sites. The scraper vehicle is provided with a bowl for containing the material excavated by the scraper. Patent Document 1 describes a method for increasing the driving force by using an auxiliary drive device to shorten the excavation time until the bowl is filled with the excavated material.

[0003] JP 2015-91692 A

[0004] There have been few proposals for train-type scraper vehicles in which multiple scraper vehicles are linked together to shorten excavation time.

[0005] Therefore, an object of the present invention is to provide a train-type scraper vehicle that shortens excavation time.

[0006] The train-type scraper vehicle of the present invention comprises a first scraper vehicle having a first excavation section and connected to a towing vehicle by a first connecting member, a second scraper vehicle having a second excavation section and connected to the first scraper vehicle by a second connecting member, and a control device that receives instructions for the first excavation section and the second excavation section to perform excavation in an overlapping manner for at least a portion of the period.

[0007] According to the present invention, the first excavation unit and the second excavation unit are provided with a control device that receives instructions to excavate during at least a partial overlapping period, so that the excavation time can be shortened.

[0008] FIG. 1 is a schematic diagram showing a towing vehicle and a scraper vehicle of the first embodiment. FIG. 2 is a block diagram of the main parts of the scraper vehicle of the first embodiment. FIG. 3 is a diagram showing a load cell provided below the axle of the first embodiment. FIG. 4 is a schematic diagram showing how the towing vehicle and the scraper vehicle of the first embodiment travel. FIG. 5 is a schematic diagram showing the excavation sequence of the first embodiment. FIG. 6 is a diagram showing a flowchart executed by the control device of the towing vehicle of the first embodiment. FIG. 7 is a diagram showing a flowchart executed by the control device of the scraper vehicle of the first embodiment. FIG. 8 is a diagram showing a first modified example. FIG. 9 is a diagram showing a second modified example. FIG. 10 is a diagram showing a third modified example.

[0009] A first embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiment described below.

[0010] (First embodiment) The scraper vehicle 20 according to the first embodiment is a train type in which a first scraper vehicle 20a and a second scraper vehicle 20b, which is the last vehicle in the train, are connected (coupled). The train type scraper vehicle 20 may have three or more vehicles. The construction work performed by the scraper vehicle 20 at a civil engineering site consists of a deadheading process, an excavation process, a transporting process, and a discharge process, which form one cycle. The deadheading process is a process in which the scraper vehicle 20 travels to an excavation area 102 (see FIG. 4 ) described below in a travel area 101 described below. The excavation process is a process in which the scraper vehicle 20 excavates soil and sand in the excavation area 102 described below. The transporting process is a process in which the scraper vehicle 20 transports the soil and sand excavated by the scraper vehicle 20 to a discharge area 103 described below in a travel area 101 described below. The discharge process is a process in which the scraper vehicle 20 discharges the soil and sand that it has transported to a discharge area 103 described below. By adopting a train-type scraper vehicle 20 in this embodiment, the amount of excavation and discharge (amount of discharging) can be increased depending on the number of vehicles, making it possible to shorten the construction period. The train-type scraper vehicle 20 in this embodiment is used as a towed vehicle towed by a large truck or other towing vehicle 1.

[0011] In this embodiment, the first scraper car 20a and the second scraper car 20b have almost the same configuration, so the configuration will be mainly described for the scraper car 20a, and the components of the scraper car 20a will be designated with an a after the reference numeral, and the components of the scraper car 20b will be designated with a b after the reference numeral. Note that when referring to each component collectively, the a or b after the reference numeral will be omitted.

[0012] FIG. 1 is a schematic diagram (side view) showing a towing vehicle 1 and a scraper vehicle 20, which are drive vehicles of this first embodiment. For ease of explanation, in FIG. 1 , the direction perpendicular to the paper surface is designated the Y direction, and two orthogonal axial directions within the paper surface are designated the X and Z directions. In the drawings described below, in the side view, the direction perpendicular to the paper surface is designated the Y direction, and the two orthogonal axial directions within the paper surface are designated the X and Z directions. In the top view, the direction perpendicular to the paper surface is designated the Z direction, and the two orthogonal axial directions within the paper surface are designated the X and Y directions. FIG. 2 is a block diagram of the main components of the towing vehicle 1 and scraper vehicle 20 of this first embodiment. As shown in FIG. 1 , the towing vehicle 1 tows scraper vehicles 20a and 20b and is connected (coupled) to the scraper vehicle 20a by a hitch 21a, which is a coupling device. The hitch 21a is detachable from the towing vehicle 1 and has a flexible ball joint 22a provided at one end on the towing vehicle 1 side.

[0013] In this embodiment, the towing vehicle 1 is disassembled and stored in a maintenance workshop so that its dimensions and weight fall within the limits for transportation on public roads. The scraper vehicles 20a and 20b are disassembled and stored in a maintenance workshop so that their dimensions and weight fall within the limits for transportation on public roads. The disassembled towing vehicle 1, scraper vehicles 20a, and scraper vehicles 20b are loaded onto multiple transport vehicles and transported to the civil engineering site. When the transport vehicles arrive at the civil engineering site, the components of the towing vehicle 1 are assembled into the towing vehicle 1 using a lifting machine such as a crane. Similarly, the scraper vehicles 20a and 20b are assembled. Note that the towing vehicle 1, scraper vehicles 20a, and scraper vehicles 20b do not need to be disassembled as long as their dimensions and weight fall within the limits for transportation on public roads. Note that the towing vehicle 1 may also drive itself to the civil engineering site.

[0014] Next, the ball joint 22a of the towing vehicle 1 is connected to the hitch 21a of the scraper vehicle 20a, thereby coupling the towing vehicle 1 and the scraper vehicle 20a. Furthermore, a flexible ball joint 22b provided at one end of the scraper vehicle 20a is connected to the hitch 21b, which is a coupling device for the scraper vehicle 20b, thereby coupling the scraper vehicle 20a and the scraper vehicle 20b. In this way, the towing vehicle 1, the scraper vehicle 20a, and the scraper vehicle 20b are coupled, and are ready for construction as shown in FIG. 1. When the towing vehicle 1 travels in the -X direction in this state, the scraper vehicles 20a and 20b are towed in the -X direction. Here, the X direction is referred to as the first direction, the Y direction is referred to as the second direction, and the Z direction is referred to as the third direction. In the following description, the X direction and the first direction will be used interchangeably as appropriate. The Y direction and the Z direction will also be used interchangeably in the same manner.

[0015] (Towing Vehicle) As is clear from FIG. 1, the towing vehicle 1 of this embodiment is an autonomous driving type vehicle with no driver's seat. Furthermore, in this embodiment, the towing vehicle 1 is driven (propelled) using a fuel cell 2 and in-wheel motors 3 (see FIG. 2) provided on each of the two front wheels and four rear wheels instead of an internal combustion engine. The in-wheel motors 3 may be provided coaxially connected to the hubs of the front and rear wheels. The towing vehicle 1 may be remotely controlled, may have a driver's seat, or may use an internal combustion engine.

[0016] The towing vehicle 1 of this embodiment also has a hydrogen tank 4 that supplies hydrogen to the fuel cell 2, a storage battery 5, a GNSS 6 (Global Navigation Satellite System), a speedometer 7, a communication device 8, a memory 9, and a control device 10.

[0017] The fuel cell 2 is a power generation device that generates electricity through an electrochemical reaction between hydrogen and oxygen. The hydrogen tank 4 stores hydrogen compressed to several tens of MPa and supplies hydrogen to the fuel cell 2 via a hydrogen supply flow path (not shown). The storage battery 5 is a secondary battery that stores the electric power generated by the fuel cell 2. The storage battery 5 can supply the stored electric power to the motor 3, a storage battery 33 provided on the scraper vehicle 20, and the like. To supply electric power from the storage battery 5 to the scraper vehicle 20, the towing vehicle 1 is provided with a first connector 11 (e.g., a female connector) connected to the storage battery 5, and the scraper vehicle 20 is provided with a second connector 35 (e.g., a male connector) that engages with the first connector 11.

[0018] As shown in Figure 1, the fuel cell 2 and hydrogen tank 4 are located at the front of the towing vehicle 1. Conventionally, the internal combustion engine and driver's seat have been located at the front of the towing vehicle 1. In this embodiment, the internal combustion engine and driver's seat are omitted, allowing a large space to be provided in front of the towing vehicle 1, making it possible to place many hydrogen tanks 4 and ensuring flexibility in the placement of the fuel cell 2 and other components. Note that although the storage battery 5 is shown near the center of the towing vehicle 1 in Figure 1, it may also be located at the front of the towing vehicle 1.

[0019] The GNSS 6 uses artificial satellites to determine the position of the towing vehicle 1. The speedometer 7 detects the speed of the towing vehicle 1 and is a vehicle speed sensor that detects the number of rotations of the shaft connected to the wheels. Various sensors may be used to detect speed, such as a sensor that uses the output of the GNSS 6. Speed ​​detection using the GNSS 6 may also use the method utilizing the Doppler effect described in JP 2019-221081 A. That is, in this embodiment, the GNSS 6 corresponds to a positioning device.

[0020] The communication device 8 is a wireless communication unit that accesses a communication device 40 (described later) or a wide area network such as the Internet, and in this embodiment, transmits the detection results of the speedometer 7 and various drive and control information by the control device 10 to the communication device 40. In this embodiment, the communication device 8 also receives information stored in a memory 39 (described later) and control information by a control device 41 (described later) from the communication device 40.

[0021] The memory 9 is a non-volatile memory (for example, a flash memory) that stores map information of the civil engineering site, a program for automatically driving the towing vehicle 1, a program for controlling the scraper 25 described below and a hydraulic cylinder (not shown) provided on the scraper vehicle 20, dimensions of the main parts of the towing vehicle 1 (for example, the distance in the X direction from the position of the GNSS 6 inside the towing vehicle 1 to the ball joint 22a), and the like.

[0022] The control device 10 is equipped with a CPU and controls the towing vehicle 1 and the scraper vehicle 20. In this embodiment, the control device 10 automatically drives the towing vehicle 1 at the civil engineering site. It also issues instructions to a control device 41 (described later) and controls the drive of a scraper 25 (described later) and a hydraulic cylinder (not shown) provided on the scraper vehicle 20. Control by the control device 10 will be described later using the flowchart in FIG. 6.

[0023] In this embodiment, the scraper 25 provided on the scraper vehicle 20, the hydraulic cylinder (not shown) provided on the scraper vehicle 20, and the hydraulic unit (not shown) provided on the towing vehicle 1 are collectively referred to as the drive device.

[0024] (Scraper Vehicle) The scraper vehicle 20 has a frame 23, a bowl 24, a scraper 25, an axle 26, wheels 27, a strain gauge 28, an accelerometer 29 (see FIG. 2), and a load cell 30 (see FIG. 3), in addition to the hitch 21 and ball joint 22. The scraper vehicle 20 also has an imaging device 31, a solar panel 32 as a power generation device, a storage battery 33 as a secondary battery, a motor 34 (see FIG. 2), a second connector 35, a third connector 36, a blade 37, and a speedometer 38 (see FIG. 2).

[0025] As shown in the block diagram of FIG. 2, the scraper vehicle 20 has a memory 39 that stores various data, a communication device 40, and a control device 41 that controls the entire scraper vehicle 20.

[0026] The frame 23 is a tapered metal part, and has an imaging device 31 attached to its inner surface facing the bowl 24, and a plurality of solar panels 32 attached to its outer surface. The bowl 24 has an open top and is used to store excavated material such as soil and sand excavated by the scraper 25.

[0027] The scraper 25 is a blade-like or spatula-like member for scraping away earth and sand from a travel surface such as the ground surface, and in this embodiment, is provided integrally with the bowl 24 at the bottom thereof.

[0028] The scraper 25 is provided integrally with the bowl 24 at the bottom of the bowl 24 so that the longitudinal direction (Y direction) of the scraper 25 and the width direction (Y direction) of the scraper vehicle 20 are approximately parallel.

[0029] As described above, when the towing vehicle 1 travels in the first direction, the scraper vehicles 20a and 20b are towed in the first direction. The scraper 25a is integrally formed with the bowl 24a, and the scraper 25b is integrally formed with the bowl 24b. That is, the scrapers 25a and 25b are spaced apart in the first direction, with the scraper 25a being provided on the scraper vehicle 20a, which is the towed vehicle, and the scraper 25b being provided on the scraper vehicle 20b, which is also the towed vehicle. In this embodiment, the scraper 25a corresponds to the first excavation section, and the scraper 25b corresponds to the second excavation section.

[0030] Because the bowl 24 and the scraper 25 are integrally provided, the scraper 25 can dig into the ground and excavate earth and sand by tilting the bowl 24 toward the ground using a hydraulic cylinder (not shown) provided on the scraper vehicle 20. The bowl 24 is also provided with an opening (not shown), and when the bowl 24 is tilted toward the ground, the material excavated by the scraper 25 is received into the bowl 24 through the opening (not shown).

[0031] When excavation by the scraper 25 is completed, the bowl 24 is tilted toward the ground by a hydraulic cylinder (not shown) provided on the scraper vehicle 20, so that the scraper 25 is lifted off the ground. When the scraper 25 is lifted off the ground, the load of the excavated material stored in the bowl 24 acts on the ball joint 22 and the pillow block 42 (see FIG. 3 ), which will be described later and which bears the load of the axle 26.

[0032] The axle 26 rotates due to the tractive force of the towing vehicle 1, and the wheels 27 are connected to both ends of the axle 26 and are a pair of driven wheels that rotate with the rotation of the axle 26. The wheels 27 may be provided at the front and rear of the scraper vehicle 20 to serve as the front and rear wheels.

[0033] The strain gauge 28 is a metal resistor, and is attached, for example, via an electrical insulator, to the lower part of the hitch 21, which is the object to be measured. The strain gauge 28 measures strain by changing its resistance value as the metal expands and contracts in proportion to the force applied to the hitch 21. When the material excavated by the scraper 25 is placed in the bowl 24, a load from the excavated material is applied to the bowl 24. The load of the bowl 24 is applied separately to the flexible ball joint 22 and the wheels 27. Because the flexible ball joint 22 supports part of the load of the bowl 24, a tensile stress acts below the hitch 21. The strain gauge 28 measures the change in resistance value due to the tensile stress of the hitch 21, and the control device 41 can measure the weight of the material excavated in the bowl 24 from the resistance value detected by the strain gauge 28.

[0034] In this embodiment, how the load Wa applied to bowl 24a is divided between ball joint 22a and pillow block 42a is detected in advance. For example, assume that 40% of the load Wa acts on ball joint 22a and 60% of the load Wa acts on pillow block 42a. In this case, control device 41 converts the resistance value measured by strain gauge 28a, which is 40% of the load Wa, to 100%, and calculates the load Wa applied to bowl 24a.

[0035] In this embodiment, the resistance values ​​of the strain gauges 28a may be measured when the bowl 24a is empty or when a load of 100 kg is applied to the bowl 24a, and the measured values ​​may be stored as a table in the memory 39a. When the bowl 24a is empty, only the load of the scraper vehicle 20a acts on the bowl 24a, and the amount of change from this state represents the weight of the excavated material contained in the bowl 24a.

[0036] The table stored in the memory 39a may also store resistance values ​​of the strain gauge 28a when multiple loads (e.g., 200 kg, 300 kg) are applied to the bowl 24a. Although one strain gauge 28a is shown in FIG. 1, multiple strain gauges may be used, and the number is not limited. Since the amount of strain is greatest at the center of the hitch 21a in the X direction, which is the front-to-rear direction, it is preferable to provide the strain gauge 28a at the center of the hitch 21a in the front-to-rear direction and below the hitch 21a in the Z direction, which is the up-and-down direction.

[0037] The above-described method can also be used to determine how the load Wb applied to the second bowl 24b acts on the ball joint 22b and the pillow block 42b.

[0038] As described above, during excavation, the scraper vehicle 20 continues to travel with the scraper 25 digging into the ground. Because the scraper 25 and bowl 24 are integrally formed, the bowl 24 receives a resistance force in the opposite direction to the traveling direction while traveling. At this time, the hitch 21 is pulled toward the bowl 24 with the ball joint 22 as the reference. In other words, a tensile stress acts on the hitch 21 during excavation. The strain gauge 28 measures changes in resistance value due to the tensile stress of the hitch 21, and the control device 41 can measure the resistance force during excavation from the resistance value detected by the strain gauge 28.

[0039] In this embodiment, the bowl 24a and the scraper 25a are integrally formed. The scraper 25a penetrates the ground by tilting the bowl 24a toward the ground using a hydraulic cylinder (not shown) provided on the scraper vehicle 20. As the stroke of the hydraulic cylinder (not shown) provided on the scraper vehicle 20 increases, the scraper 25a penetrates the ground more deeply, resulting in a higher resistance value detected by the strain gauge 28a attached to the hitch 21. When the resistance value detected by the strain gauge 28a exceeds a certain value, the towing force of the towing vehicle 1 is exceeded, causing the speed to decrease. Therefore, the relationship between the resistance value detected by the strain gauge 28a and the speed indicated by the speedometer 7 is measured in advance through pre-calibration and used for the auxiliary drive control described below. That is, the control device 41 adjusts the auxiliary drive force of the motor 34a (in-wheel motor) based on the measurement information of the strain gauge detecting strain changes in the hitch 21a. For example, while traveling at a speed of 10 km / h, the stroke amount of a hydraulic cylinder (not shown) provided in the scraper vehicle 20 is increased in 50 mm increments from 0 mm to increase the amount of penetration of the scraper 25a into the ground, and the resistance value of the strain gauge 28a and the speed indicated by the speedometer 7 are measured. The measured data may be stored as a table in the memory 39a. For example, if the value of the strain gauge 28a exceeds a certain resistance value, the value indicated by the speedometer will be less than 10 km / h. When traveling at a speed of 10 km / h or higher, the resistance value of the strain gauge 28a at that time can be used as a threshold value to adjust the amount of penetration of the scraper 25a into the ground.

[0040] Furthermore, the table stored in the memory 39a may store the resistance values ​​of the strain gauge 28a and the speeds of the speedometer 7 at a plurality of speeds (for example, 20 km / h, 30 km / h).

[0041] The above-described method can also be used to determine the relationship between the resistance force acting on the second bowl 24b and the running speed.

[0042] In this embodiment, the accelerometer 29 detects acceleration acting on the scraper vehicle 20, and any type of accelerometer can be used, such as mechanical, optical, or semiconductor. In this embodiment, the accelerometer 29 detects acceleration in the Z-axis direction near the strain gauge 28, but this is not limited to this, and the accelerometer 29 may also detect acceleration in the X-axis direction or the Y-axis direction. Furthermore, the number of accelerometers 29 may be one, or at least one accelerometer may be provided at each of multiple locations on the scraper vehicle 20. In this case, the accelerometer 29 may be provided near the load cell 30, or may be provided on the towing vehicle 1. If the accelerometer 29 is provided on the towing vehicle 1, it is preferable to provide it near the ball joint 22.

[0043] In this embodiment, the control device 41 calculates the amount of excavated material, such as soil and sand, stored in the bowl 24 based on the strain detected by the strain gauges 28 when the output of the accelerometer 29 is smaller than the threshold value. Alternatively, the control device 41 may calculate the amount of excavated material, such as soil and sand, stored in the bowl 24 from the outputs of N strain gauges 28 (N is a natural number) that have the smallest output from the accelerometer 29, or may perform a calculation to weight the output of the strain gauges 28 when the output of the accelerometer 29 is small. In this first embodiment, if a correction value for the output of the strain gauges 28 corresponding to the output of the accelerometer 29 is stored in the memory 39, the control device 41 can correct the output of the strain gauges 28 using the correction value stored in the memory 39. In this way, the control device 41 processes or selects the detection results of the strain gauges 28 using the output of the accelerometer 29.

[0044] FIG. 3 is a diagram showing the load cell 30 provided below the axle 26 of this embodiment. For ease of explanation, in FIG. 3 , the direction perpendicular to the paper surface is designated the Y direction, and two orthogonal axial directions within the paper surface are designated the X and Z directions. As shown in FIG. 3 , the axle 26 is rotatably supported by a bearing 43, which is held by a pillow block 42 serving as a bearing base. The load cell 30 is provided below the pillow block 42 so as to detect the load of the excavated material in the bowl 24 acting on the wheel 27. Various types of load cells 30, such as piezoelectric load cells and strain load cells, can be used. Although two load cells 30 are shown in FIG. 3 , the number of load cells 30 may be one, three, or more.

[0045] In this embodiment, as described above, the measurement values ​​of the load cell 30 when the bowl 24 is empty and when a load of 100 kg is applied to the bowl 24 may be stored as a table in the memory 39. In this case, it is desirable to store the resistance values ​​of the load cell 30 at multiple loads (e.g., 200 kg, 300 kg). By performing calibration by measuring with the strain gauges 28 and the load cell 30 while changing the load state of the bowl 24, the ratio of the load applied to the ball joint 22 to the load applied to the pillow block 42 can be calculated, and this ratio is stored in the memory 39. Note that this calibration is preferably performed while the towing vehicle 1 and the scraper vehicle 20 are stationary, but it may also be performed while the scraper vehicle 20 is being towed by the towing vehicle 1, or while stationary and towed.

[0046] Calibration may be performed only once or periodically, or may be performed when the wheels 27 are replaced or after adjusting the air pressure of the wheels 27. Calibration may also be performed when the wheels of the towing vehicle 1 are replaced or after adjusting the air pressure of the wheels. The second and subsequent calibrations may be performed only when the bowl 24 is empty, or may be performed with a load of 100 kg, with fewer measurement items or fewer measurements than the first calibration.

[0047] In addition to being used during the aforementioned calibration, load measurement by the load cell 30 may also be performed when the material excavated by the scraper 25 is placed in the bowl 24. In this case, too, the amount of excavated material, such as soil and sand, placed in the bowl 24 is calculated based on the load detected by the load cell 30 when the output of the accelerometer 29 is smaller than the threshold value. Alternatively, the control device 41 may calculate the amount of excavated material, such as soil and sand, placed in the bowl 24 from the outputs of N load cells 30 with small accelerometer 29 outputs (N is a natural number), or may perform a calculation to weight the outputs of the load cells 30 when the output of the accelerometer 29 is small. In this way, the control device 41 processes or selects the detection results of the load cells 30 using the outputs of the accelerometer 29.

[0048] The imaging device 31 is a digital camera that has a lens, an imaging element, an image processing engine, etc., and captures moving and still images. In this embodiment, the imaging device 31 is used to capture an image of the excavated material stored in the bowl 24 and detect whether the bowl 24 is full. Note that instead of the imaging device 31, a non-contact range finder such as an ultrasonic range finder or a laser range finder may be provided on the frame 23 to detect whether the bowl 24 is full. The control device 41 may start measurement using the strain gauge 28, the accelerometer 29, etc., when the bowl 24 is full.

[0049] The solar panel 32 is a power generation device and is mounted on the frame 23. The side surfaces of the frame 23 are tapered so that the side surfaces of the frame 23 can more easily receive sunlight. Incidentally, if a tilting mechanism is provided on the upper surface of the frame 23, the solar panel 32 mounted on the upper surface of the frame 23 can more easily receive sunlight. Incidentally, the solar panel 32 may be mounted on the towing vehicle 1, and the power generated by the solar panel 32 may be stored in the storage battery 5. Furthermore, the power generated by the solar panel 32 may be used as an auxiliary power source for driving the fuel cell 2.

[0050] The storage battery 33 stores the power generated by the fuel cell 2 via the second connector 35, and stores the power generated by the solar panel 32. The power stored in the storage battery 33 is used to drive the motor 34 that directly drives the wheels 27. The storage battery 33 is preferably provided in front of the scraper vehicle 20 (-X direction), and in this embodiment, it is provided in the hitch 21.

[0051] The motor 34 is an in-wheel motor that is installed inside the wheel 27 or is coaxially connected to the hub of the wheel 27. When the scraper 25 scrapes a large amount of ground surface, the scraper 25 gets stuck in the ground surface, increasing running resistance. In this case, the drive wheels of the towing vehicle 1 may spin, and the scraper vehicle 20 may not be able to be towed by the towing force of the towing vehicle 1 alone, requiring the use of a pusher.

[0052] Therefore, in this embodiment, when it is difficult to tow the scraper vehicle 20 using the towing vehicle 1 alone, the wheels 27 are driven by the motor 34. Driving the wheels 27 with the motor 34 eliminates the need for a pusher and eliminates the need to connect the pusher to the last scraper vehicle 20b, thereby shortening the construction period. In this way, the motor 34 functions as an auxiliary drive device. In this embodiment, the towing vehicle 1 and the motor 34 are driven by power generated by a fuel cell, which reduces emissions of greenhouse gases such as carbon dioxide. Note that power generated by solar panels 32 may be used instead of or in addition to the fuel cell.

[0053] The second connector 35 engages with the first connector 11 to supply the power stored in the storage battery 5 to the storage battery 33. The third connector 36a engages with the second connector 35b to store the power stored in the storage battery 33a of the front scraper vehicle 20a in the storage battery 33b of the rear scraper vehicle 20b. The third connector 36 is preferably provided at the rear (+X direction) of the scraper vehicle 20.

[0054] The blade 37 is a metal mechanical part that discharges the excavated material stored in the bowl 24 to the discharge site during the discharge process. The blade 37 is positioned in the +X direction except during the discharge process, and during the discharge process, the blade 37 is moved in the -X direction by a hydraulic cylinder (not shown) provided on the scraper vehicle 20 to discharge the excavated material.

[0055] The speedometer 38 detects the speed of the scraper vehicle 20, and various sensors can be applied, such as a vehicle speed sensor that detects the number of rotations of the axle 26, or a sensor that uses the output of a GNSS (not shown) to determine the position of the scraper vehicle 20. Note that the speedometer 38 may be omitted, or either the speedometer 38a or the speedometer 38b may be omitted.

[0056] The memory 39 may be of any type, and in this embodiment, a non-volatile semiconductor memory (e.g., flash memory) is used. The memory 39 stores various programs for driving the scraper vehicle 20, measurement results from the strain gauges 28, accelerometers 29, and load cells 30, calculation results from the control device 41, dimensions of the main parts of the scraper vehicle 20 (e.g., the distance in the X direction from the forward tip of the hitch 21 to the scraper 25), and the like. The dimensions of the main parts of the scraper vehicle 20 may also be stored in the memory 9. The communication device 40 communicates with a communication device at a base station, a communication device provided at a dumping site during the dumping process, and the communication device 8 on the towing vehicle 1. The communication device 40 can use any communication method, but in this embodiment, data related to the weight of the bowl 24 is wirelessly communicated using a wireless LAN such as Wi-Fi (registered trademark). If an accelerometer is provided on the towing vehicle 1, the communication device 8 on the towing vehicle 1 side may communicate the acceleration detected by the accelerometer to the communication device 40.

[0057] The control device 41 is equipped with a CPU (Central Processing Unit) and controls the entire scraper vehicle 20. In this embodiment, upon receiving instructions from the control device 10, it measures the weight of the excavated material contained in the bowl 24, controls auxiliary driving by the motor 34, and controls the driving of a hydraulic cylinder (not shown) provided in the scraper vehicle 20.

[0058] The construction status of the towing vehicle 1 and scraper vehicle 20 configured as above will be described with reference to the schematic diagram of FIG. 4 showing the construction status.

[0059] 4 is a schematic diagram showing the towing vehicle 1 and scraper vehicle 20 of this embodiment working in a construction area 100 at a civil engineering site. For ease of explanation, in FIG. 4, the direction perpendicular to the plane of the page is defined as the Z direction, and two orthogonal axial directions within the plane of the page are defined as the X direction and the Y direction. The construction area 100 is composed of a travel area 101, an excavation area 102, and a discharge area 103.

[0060] The construction area 100 is an area where the towing vehicle 1 and scraper vehicle 20 of this embodiment perform the aforementioned forwarding process, excavation process, transport process, and discharge process. The traveling area 101 is an area where the towing vehicle 1 and scraper vehicle 20 of this embodiment perform the forwarding process or the transport process. The excavation area 102 is an area where the towing vehicle 1 and scraper vehicle 20 of this embodiment perform the excavation process. The discharge area 103 is an area where the towing vehicle 1 and scraper vehicle 20 of this embodiment perform the discharge process. In this figure, the towing vehicle 1 and scraper vehicle 20 are shown traveling from the traveling area 101 toward the excavation area 102. In other words, this shows the state where the forwarding process is being performed, which corresponds to the state of FIG. 5(a) described below.

[0061] The control of the towing vehicle 1 and scraper vehicle 20 traveling as described above will be explained using the schematic diagram showing the excavation sequence in Figure 5 and the flowcharts in Figures 6 and 7. Figure 6 is a flowchart executed by the control device 10, and Figure 7 is a flowchart executed by the control device 41.

[0062] Figure 5(a) shows the towing vehicle 1 and scraper vehicle 20 traveling in the traveling area 101. At this time, the flowchart in Figure 6 has not yet started. The flowchart in Figure 6 starts when the towing vehicle 1 enters the excavation area 102 from the traveling area 101. In this embodiment, the scraper 25a of the scraper vehicle 20a starts excavating first, followed by the scraper 25b of the scraper vehicle 20b, with the scrapers 25a and 25b continuing to excavate with some overlapping periods, until the scraper 25a finishes excavating first, followed by the scraper 25b.

[0063] (Explanation of Flowchart) When the control device 10 recognizes from the output of the GNSS 6 that the towing vehicle 1 has left the travel area 101 and entered the excavation area 102, it calculates the time T until the scraper 25a of the scraper vehicle 20a and the scraper 25b of the scraper vehicle 20b each enter the excavation area 102 based on the position information of the GNSS 6, the dimensional information of the scraper vehicles 20a and 20b stored in memory 39, and the speed detected by the speedometer 7, and stores this in memory 9 (step S1). Note that to calculate the time when each of the scraper vehicles 20a and 20b enters the excavation area 102, it is not necessary to use the speed detected by the speedometer 7, and various sensors, such as a sensor using the output of the GNSS 6, may be used for detection. In other words, the speedometer 7 may not be provided.

[0064] The control device 10 determines whether the scraper vehicle 20a has entered the excavation area 102 (step S2). The control device 10 repeats step S2 until the time calculated in step S1 has elapsed.

[0065] When the time calculated in step S1 has elapsed, the control device 10 recognizes that the scraper vehicle 20a has entered the excavation area 102, and issues an instruction to the control device 41a to control the hydraulic cylinder (not shown) provided on the scraper vehicle 20 to dig the scraper 25a into the ground and begin excavation (step S3).

[0066] In step S1, the control device 10 may calculate the time (e.g., 0.5 seconds before) before each of the scrapers 25a and 25b enters the excavation area 102 and store it in the memory 9. In step S1, the control device 10 may calculate the time (e.g., 0.5 seconds after) after each of the scrapers 25a and 25b enters the excavation area 102 and store it in the memory 9.

[0067] In step S2, the control device 10 may use the time before entering the excavation area 102 stored in the memory 9 to determine that the scraper vehicle 20a has not yet entered the excavation area 102. In step S2, the control device 10 may use the time after entering the excavation area 102 stored in the memory 9 to determine that the scraper vehicle 20a has already entered the excavation area 102.

[0068] In step S3, when a time (e.g., 0.5 seconds) has elapsed before entering the excavation area 102, the control device 10 may instruct the control device 41a to control a hydraulic cylinder (not shown) provided in the scraper vehicle 20 to dig the scraper 25a into the ground and start excavation. Also, when a time (e.g., 0.5 seconds) has elapsed after entering the excavation area 102, the control device 10 may instruct the control device 41a to control a hydraulic cylinder (not shown) provided in the scraper vehicle 20 to dig the scraper 25a into the ground and start excavation.

[0069] As described above, in this embodiment, the timing at which the scraper 25 starts excavating does not necessarily have to be precise, and depending on the timing, the excavation start position may be shifted forward or backward by about 10 cm in the X direction from the boundary position between the excavation area 102 and the traveling area 101 on the design drawing.

[0070] FIG. 5B shows the control device 10 performing step S4 (described later) while the scraper 25a continues excavating. That is, it shows the state where only the scraper 25a is excavating. The excavated area 104a is a schematic representation of the area excavated by the scraper vehicle 20a, and the thickness in the Z direction is not to scale. While the scraper 25a continues excavating, the control device 10 transmits, via the communication device 8, the speed detected by the speedometer 7, the number of rotations of the shaft, and various data indicating that excavation is being performed to the control device 41a (step S4). Upon receiving the various data in step S4, the control device 41a starts the flowchart of FIG. 7 (described later).

[0071] Next, the control device 10 determines whether the scraper vehicle 20b has entered the excavation area 102 (step S5). The control device 10 repeats step S5 until the time T calculated in step S1 has elapsed.

[0072] When the time calculated in step S1 has elapsed, the control device 10 recognizes that the scraper vehicle 20b has entered the excavation area 102, and issues an instruction to the control device 41b to control the hydraulic cylinder (not shown) provided on the scraper vehicle 20b to dig the scraper 25b into the ground and begin excavation (step S6).

[0073] 5C shows the state in which the control device 10 performs step S7 (described later) and the scraper 25b continues excavating in parallel with the scraper 25a continuing excavation. That is, the state in which the control device 10 controls the drive devices so that the scrapers 25a and 25b perform excavation with some overlapping periods. In other words, the state in which the control devices 41a and 41b receive instructions from the control device 10 and the scrapers 25a and 25b perform excavation with some overlapping periods. The excavated area 104b is a schematic representation of the area excavated by the scraper vehicle 20b, and the thickness in the Z direction is not to scale.

[0074] While the scraper 25b continues excavating, the control device 10 transmits, via the communication device 8, the speed detected by the speedometer 7, the number of rotations of the shaft, various data indicating that excavation is being performed, and the like to the control device 41b (step S7). Upon receiving the various data in step S7, the control device 41b starts the flowchart of Fig. 7, which will be described later.

[0075] The control device 10 determines whether the excavation amount by the first scraper vehicle 20a has reached a predetermined amount (e.g., the bowl 24a is fully loaded) (step S8). In this embodiment, the control device 10 determines whether the excavation amount has reached the predetermined amount based on the image captured by the imaging device 31a. Note that the image captured by the imaging device 31a may be transmitted to an office at the civil engineering site or a remote office, and a worker may determine whether the excavation amount has reached the predetermined amount, and the result may be transmitted to the control device 10 via the communication device 8.

[0076] The control device 10 repeats steps S4 to S8 until excavation is completed. Note that, as will be described in detail later, the reason for repeating step S4 is to determine whether or not the control device 41a should perform auxiliary driving by the motor 34a.

[0077] When the amount of excavation by the first scraper vehicle 20a reaches a predetermined amount, the control device 10 instructs the control device 41a to control a hydraulic cylinder (not shown) provided on the scraper vehicle 20a to drive the scraper 25a to a position where it is clear of the ground.

[0078] When the excavation amount by the first scraper car 20a reaches a predetermined amount, the control device 10 determines that the excavation process by the scraper car 20a has ended, and proceeds to step S9, which will be described later. In other words, the scraper 25a has finished excavating, and the scraper 25b is now performing excavation.

[0079] The control device 10 determines whether the excavation amount by the second scraper vehicle 20b has reached a predetermined amount (e.g., the bowl 24b is fully loaded) (step S9). In this embodiment, the control device 10 determines whether the excavation amount has reached the predetermined amount based on the image captured by the imaging device 31b. Note that the image captured by the imaging device 31b may be transmitted to an office at the civil engineering site or a remote office, and a worker may determine whether the excavation amount has reached the predetermined amount, and the result may be transmitted to the control device 10 via the communication device 8.

[0080] The control device 10 repeats steps S7 to S9 until the excavation is completed. Note that, as will be described in detail later, the reason for repeating step S7 is to determine whether the control device 41b should perform auxiliary driving by the motor 34b.

[0081] When the amount of excavation by the second scraper vehicle 20b reaches a predetermined amount, the control device 10 instructs the control device 41b to control a hydraulic cylinder (not shown) provided on the scraper vehicle 20b to drive the scraper 25b to a position where it is clear of the ground.

[0082] When the excavation amount by the second scraper vehicle 20b reaches a predetermined amount, the control device 10 determines that the excavation process by the scraper vehicle 20b has ended, and ends the flowchart of FIG.

[0083] When the excavation process by the scraper vehicles 20a and 20b is completed, the control device 10 controls the transport process. Following the transport process, the control device 10 controls the discharge process and the forwarding process.

[0084] In addition, the control device 10 may be configured to transmit various data to the control device 41b as well in step S4 described above. Similarly, the control device 10 may be configured to transmit various data to the control device 41a as well in step S7 described above.

[0085] Next, the explanation will continue with the flowchart of Fig. 7. The flowchart of Fig. 7 may be performed by the control device 41a or the control device 41b depending on the implementation of the flowchart of Fig. 6, but since the contents are substantially the same, the explanation will continue with the case where it is performed by the control device 41a. The flowchart of Fig. 7 starts when the control device 10 issues a command to start excavation by the scraper 25a in step S3 of the flowchart of Fig. 6.

[0086] The control device 41a receives an instruction from the control device 10 and starts excavation by the scraper 25a (step S101).

[0087] The control device 41a starts imaging by the imaging device 31a (step S102). Imaging by the imaging device 31a continues until the bowl 24a is filled with excavated material. Because it takes time for the bowl 24a to become filled with excavated material, the control device 41a may initially lower the frame rate of the imaging device 31a to capture video, or may capture still images at intervals of several seconds, and then increase the frame rate over time to capture video or shorten the intervals between still images. This allows for efficient imaging.

[0088] The control device 41a determines whether auxiliary driving by the motor 34a is necessary (step S103). If the speed on the speedometer 7 is slower than a predetermined speed, or if the control device 41a compares the speed on the speedometer 7 with the rotation speed and finds that the speed is slow compared to a high rotation speed, i.e., if the wheels of the towing vehicle 1 are spinning freely, the control device 41a drives the wheels 27a by the motor 34a (step S104). Furthermore, if the wheels of the towing vehicle 1 are spinning freely, the control device 41a instructs the control device 10 via the communication device 40a to reduce the rotation speed of the wheels.

[0089] As described above, the value of the strain gauge 28a represents the resistance force that the bowl 24a receives during excavation. The control device 41a may refer to the pre-calibration results stored in the memory 39a and adjust the auxiliary driving force of the motor 34a to the wheels 27a when the value of the strain gauge 28a exceeds a threshold value.

[0090] The control device 41a may start auxiliary driving before the speed drops based on the value of an ammeter (not shown) of the towing vehicle 1 and the value of the engine speed (not shown) of the towing vehicle 1.

[0091] If the auxiliary drive by the motor 34a does not provide enough driving force, the control device 41a instructs the control device 41b via the communication device 40a to drive the motor 34b. Even in this case, if the control device 41a determines that the wheels of the towing vehicle 1, the wheels 27a, or the wheels 27b are spinning freely, it controls the rotation speed of the corresponding wheels to decrease. If the speed indicated by the speedometer 7 becomes faster than a predetermined speed, the control device 41a terminates the auxiliary drive by the motor 34a.

[0092] The wheels 27a may be of a known crawler travelling device, or may be of a triangular crawler type as disclosed in Japanese Patent Laid-Open Publication No. 9-109947.

[0093] The control device 41a determines whether the excavation amount by the scraper 25a has reached a predetermined amount (step S105). Here, the control device 41a determines whether the excavation amount has reached the predetermined amount based on the determination in step S8 of the flowchart in Fig. 6. The control device 41a repeats step S103 and subsequent steps until the excavation amount by the scraper 25a has reached the predetermined amount.

[0094] When the excavation amount reaches a predetermined amount, the control device 41a receives an instruction from the control device 10 and controls a hydraulic cylinder (not shown) provided on the scraper vehicle 20b to drive the scraper 25b to a position where it leaves the ground, thereby ending excavation (step S106).

[0095] The control device 41a performs measurements using the strain gauge 28a and the accelerometer 29a (step S107). The control device 41a measures the load applied to the ball joint 22a using the strain gauge 28a while the scraper vehicle 20a is moving, along with the acceleration acting in the Z direction of the ball joint 22a. The control device 41a may perform measurements using the load cell 30a and the accelerometer 29a multiple times.

[0096] Following the measurement in step S107, the control device 41a calculates the weight of the excavated material contained in the bowl 24a (step S108). In this embodiment, the control device 41a calculates the amount of excavated material, such as soil and sand, contained in the bowl 24a based on the amount of strain detected by the strain gauge 28a when the output of the accelerometer 29a provided in the ball joint 22a is smaller than the threshold value. In this case, the control device 41a may use the weight detected by the load cell 30a when the output of the accelerometer 29a provided in the pillow block 42a is smaller than the threshold value.

[0097] In addition, the control device 41a may calculate the weight of the excavated material, such as soil and sand, stored in the bowl 24a from the outputs of N (N is a natural number) strain gauges 28a and load cells 30a whose outputs from the accelerometers 29a are small, or may perform calculations to weight the outputs of the strain gauges 28a and load cells 30a when the output from the accelerometers 29a is small.

[0098] The hitch 21a may be distorted due to temperature. For this reason, a correction coefficient corresponding to the temperature during excavation may be stored in the memory 39a. In this case, the correction coefficient may be determined by actual measurement during the calibration or the measurement in step S107 of FIG. 7, or may be determined from the linear expansion coefficient (thermal expansion coefficient) of the material of the hitch 21a. Furthermore, to reduce thermal distortion of the hitch 21a, the strain gauge 28a may be covered with a heat insulating material. A thermal distortion correction coefficient may also be determined for the pillow block 42a on which the load cell 30a is mounted and stored in the memory 39a.

[0099] When the control device 41a has finished calculating the weight of the excavated material stored in the bowl 24a in step S108, the control device 41a transmits the calculation result to the communication device of the base station via the communication device 40a. Note that the control device 41a may also transmit the calculation result to a communication device provided at the soil discharge site in the discharge process.

[0100] As described above, in step S3 of the flowchart in FIG. 6, when the control device 41b of the second vehicle receives an instruction from the control device 10 to start excavation using the scraper 25b, it executes the flowchart in FIG. 7. After the control device 41b finishes calculating the weight of the excavated material stored in the bowl 24b, it transmits the calculation result to the base station or the communication device at the soil unloading site via the communication device 40b. A control device (not shown) provided at the base station or the soil unloading site calculates the weight of the excavated material excavated by the scraper vehicle 20 from the weight of the excavated material stored in the bowl 24a and the weight of the excavated material stored in the bowl 24b. Note that instead of the control device (not shown) provided at the base station or the soil unloading site, any one of the control devices 10, 41a, and 41b may calculate the weight of the excavated material excavated by the scraper vehicle 20.

[0101] 6 and 7, the detection of the weight of the excavated material stored in the bowl 24 is triggered by the bowl 24 being full, but this is not limiting. For example, if the weight of the excavated material to be stored in the bowl 24 is predetermined, the control device 41 may detect the weight of the excavated material stored in the bowl 24 while the scraper 25 is excavating, and may communicate with the control device 10 when the predetermined weight is reached or is about to be reached. After receiving communication from the control device 41, the control device 10 may instruct the control device 41 to tilt the scraper 25 toward the ground using a hydraulic cylinder (not shown) provided in the scraper vehicle 20 to end the excavation process.

[0102] As described above, in the train-type scraper vehicle 20 of this embodiment, the scraper vehicle 20a and the scraper vehicle 20b perform excavation with some overlapping periods. Note that the scraper vehicle 20b may start excavation first, or the scraper vehicle 20a and the scraper vehicle 20b may start excavation at the same time. Also, the scraper vehicle 20b may finish excavation first, or the scraper vehicle 20a and the scraper vehicle 20b may finish excavation at the same time.

[0103] Furthermore, when three or more scraper vehicles 20 are being towed, any scraper vehicle 20 may start excavation, and any scraper vehicle 20 may finish excavation. Furthermore, two or more scraper vehicles 20 may start excavation at the same time, and two or more scraper vehicles 20 may finish excavation at the same time. That is, in this embodiment, it is sufficient if there is a period during which at least two scraper vehicles 20 are excavating with some overlapping period.

[0104] According to this embodiment, the scraper vehicles 20a and 20b perform excavation operations in an overlapping manner for a part of the time, so that the time required to load the bowls 24a and 24b, i.e., the excavation time, can be shortened.

[0105] (Modifications) The above-described embodiment can be modified in various ways and functions can be added, which will be described below. Note that the same components as those in the above-described embodiment will be assigned the same reference numerals, and their description will be omitted or simplified.

[0106] (Modification 1) Fig. 8 shows Modification 1 in which the scraper 25a of the scraper vehicle 20a and the scraper 25b of the scraper vehicle 20b have different shapes. Fig. 8 is a top view of Modification 1.

[0107] The scraper 25a of this modified example 1 has a comb-like shape as shown in Fig. 8. The scraper 25b has a blade-like shape as described above.

[0108] Generally, when the ground in the excavation area 102 is too hard to be excavated with the scraper 25, it is necessary to break up the ground beforehand. For example, the ground is broken up beforehand using a construction machine such as a bulldozer with a ripper, as described in Japanese Patent Laid-Open Publication No. 3-221624. A bulldozer with a ripper has multiple claw-shaped rippers attached to the side of the bulldozer body opposite to the side where the blade is attached. After the ground is broken up with the bulldozer with a ripper, excavation is carried out with the scraper 25.

[0109] In this first modification, the scraper vehicle 20a, which is the first towed vehicle, is equipped with a comb-tooth scraper 25a, which can achieve the same effect as multiple rippers. Furthermore, the scraper vehicle 20b, which is the second towed vehicle, is equipped with a scraper 25b and is coupled to it. As a result, the scraper 25a of the first scraper vehicle 20a digs into the ground to break up hard soil and sand, and the scraper 25b of the second scraper vehicle 20b digs into the ground to excavate the broken up soil and sand.

[0110] The comb teeth of the comb-tooth scraper 25a do not have to have the same shape as that shown in FIG. 8, and the width and number of the comb teeth may be changed depending on the hardness of the ground that has been investigated in advance.

[0111] In this first modified example, there is no need for prior ripper work (work to break up the soil in advance). This eliminates the need for additional machinery (a bulldozer with a ripper), which contributes to reducing machinery costs. In addition, in this embodiment, the first scraper vehicle 20a is equipped with a comb-shaped scraper 25a, and the second scraper vehicle 20b is equipped with a blade-shaped scraper 25b. Since the excavation periods overlap in part, the ripper work and excavation work can be performed simultaneously, thereby shortening the excavation time.

[0112] It is not necessary for the first scraper vehicle 20a to perform the ripper work, and some of the excavation work may be performed by the first scraper vehicle 20a and the second scraper vehicle 20b.

[0113] (Modification 2) Fig. 9 shows Modification 2 in which the longitudinal direction of the scraper 25 intersects with the width direction of the scraper vehicle 20. Fig. 9 is a top view showing the towing vehicle 1 and the scraper vehicle 20 of Modification 2.

[0114] The center line CX is the X-direction reference line between the towing vehicle 1 and the scraper vehicle 20 of this modified example 2. Point Oa represents the longitudinal center point of the scraper 25a. Reference line CYa is the Y-direction reference line that passes through point Oa. Angle θa is the angle between the longitudinal direction of the scraper 25a and the reference line CYa. Point Ob represents the longitudinal center point of the scraper 25b. Reference line CYb is the Y-direction reference line that passes through point Ob. Angle θb is the angle between the longitudinal direction of the scraper 25b and the reference line CYb.

[0115] 9, in this second modification, the longitudinal direction of the scraper 25a extends in a direction rotated counterclockwise around point Oa, and the longitudinal direction of the scraper 25b extends in a direction rotated clockwise by an angle θb around point Ob.

[0116] In this way, in this variant example 2, the longitudinal direction of the scraper 25 is arranged so as to intersect with the width direction of the scraper vehicle 20, so that the excavation resistance force can be distributed in the Y direction, and the excavation resistance force in the X direction, which is the traveling direction, can be reduced.

[0117] The angle θ should be between 5 and 45 degrees, and preferably between 10 and 30 degrees. If the angle θ is less than 5 degrees, the effect of dispersing the excavation resistance force will be reduced. Also, if the angle θ is greater than 45 degrees, the effective area of ​​the bowl 24 in the XY plane will be reduced, and the amount of sediment that can be taken in will be reduced.

[0118] A common method for reducing the excavation resistance is to adjust the amount of penetration of the scraper 25 into the ground, which is adjusted by moving the scraper 25 in the Z direction. However, reducing the amount of penetration of the scraper 25 into the ground reduces the amount of excavation per unit travel distance, which results in a longer excavation time. In this modification 2, the scraper 25 is tilted in the XY plane to reduce the excavation resistance. This allows the scraper 25 to penetrate the ground more deeply, which increases the amount of excavation per unit travel distance and shortens the excavation time.

[0119] The scrapers 25a and 25b may rotate in the same counterclockwise direction or in the same clockwise direction, and the angle θ may be the same or different.

[0120] When scraper 25a is tilted counterclockwise and scraper 25b is tilted clockwise as in this variant example 2, the dispersion force in the Y direction is canceled out, which has the advantage of improving straight-line stability during the period when overlapping excavations are occurring.

[0121] (Variation 3) At conventional civil engineering sites, after the scraper vehicle 20 completes the discharge process in the discharge area 103, the scraper vehicle 20 performs the forwarding process in the travel area 101. While the scraper vehicle 20 is performing the forwarding process, a rolling machine separate from the scraper vehicle 20 performs the rolling process in the discharge area 103. In other words, at conventional civil engineering sites, the machine that performs excavation and the machine that performs compaction are different. Compaction is a process in which a rolling machine equipped with metal rollers applies force from the +Z direction to the -Z direction of the soil and sand discharged by the scraper vehicle 20, reducing the thickness of the soil and hardening the soil. In this variation, the scraper vehicle 20b is equipped with metal rollers and is also able to perform compaction.

[0122] Figure 10 shows a third modification in which a rolling roller 50 is provided at the rear of the scraper vehicle 20b. Figure 10(a) is a top view of the third modification. Figure 10(b) is a side view showing the rolling roller 50 in the third modification in a state where it is lifted off the ground, and Figure 10(c) is a side view showing the rolling roller 50 in the third modification in a state where it is placed on the ground.

[0123] The compaction roller 50 is a component that compacts the soil and sand discharged by at least one of the scraper vehicles 20a and 20b in the discharge area 103. The compaction roller 50 is a cylindrical or cylindrical roller made of metal (e.g., steel) that extends in the Y direction.

[0124] 10(a) and 10(b), a roller shaft member 51 passing through the center of the circular cross section and extending in the Y direction penetrates the rolling roller 50, and the rolling roller 50 is attached so as to be rotatable around the roller shaft member 51 via bearings (not shown). Both ends of the roller shaft member 51 protrude from both ends of the rolling roller 50, and mounting plates 52 (described later) are fixed to both ends of the roller shaft member 51.

[0125] The mounting plate 52 is made of steel material extending in the X direction, with the roller shaft member 51 fixed to the end in the +X direction and the motor shaft member 53 extending in the Y direction (described later) fixed to the end in the -X direction.

[0126] The Y-direction central portion of the motor shaft member 53 and the rear end portion of the scraper vehicle 20b are connected via a bearing (not shown) so as to be freely rotatable around the Y axis, and a motor (not shown) rotates the motor shaft member 53.

[0127] After issuing an instruction for at least one of the scraper vehicles 20a and 20b to discharge soil and sand in the discharge area 103, the control device 10 drives a motor (not shown) provided on the scraper vehicle 20b to rotate the mounting plate 52 clockwise, thereby lowering the compaction roller 50 in the -Z direction and bringing it into contact with the ground. By traveling in this state, the compaction roller 50 can compact the soil and sand. Figure 10(c) shows the state in which the motor (not shown) rotates the motor shaft member 53, causing the compaction roller 50 to travel while installed on the ground.

[0128] The length of the scraper 25 in the Y direction is the digging width when the scraper 25 digs into the ground to excavate earth and sand, and is the discharge width when the scraper vehicle 20 discharges earth and sand.

[0129] In this modified example, it is desirable that the Y-direction length of the compaction roller 50 be longer than the Y-direction length of the scraper 25. The soil and sand discharged from the scraper vehicle 20 is discharged from the bowl 24 along the Y-direction length of the scraper 25. Because the Y-direction length of the compaction roller 50 is longer than the Y-direction length of the scraper 25, compaction can be performed efficiently.

[0130] 10(c), the control device 10 may further rotate a motor (not shown) clockwise to lift the wheels 27b off the ground and have the load of the scraper vehicle 20b supported only by the compaction roller 50, thereby enhancing the compaction effect of the compaction roller 50. Also, because the compaction effect can be obtained simply by the movement of the wheels 27a and 27b, the compaction may be performed by at least one of the wheels 27a and 27b without the compaction roller 50 coming into contact with the ground. In FIG. 10(c), the wheels 27b are not completely lifted off the ground, so the compaction is performed by both the wheels 27b and the compaction roller 50.

[0131] As described above, at general civil engineering sites, after the scraper vehicle 20 completes the discharge process in the discharge area 103, while the scraper vehicle 20 performs the forwarding process in the travel area 101, a rolling machine separate from the scraper vehicle 20 performs the rolling process in the discharge area 103. In the third modification, the rolling roller 50 is provided at the rear of the scraper vehicle 20b. Therefore, the control device 10 can control the scraper vehicle 20a and / or scraper vehicle 20b to perform the rolling process after completing the discharge process. In other words, when the scraper vehicle moves to the forwarding process, the discharge process and the rolling process are completed.

[0132] In this way, in this variant example 3, a series of processes at a civil engineering site (transport process, excavation process, transportation process, discharge process, and compaction process) can be carried out by a single machine, which not only reduces excavation time but also shortens the entire process at the civil engineering site and reduces machine costs.

[0133] The above-described embodiment is merely an example for explaining the present invention, and various modifications can be made without departing from the spirit and scope of the present invention. For example, in the above-described embodiment, the towing vehicle 1 is used as the driving vehicle, but a push-type driving vehicle that pushes the scraper vehicle 20 from behind the scraper vehicle 20 may also be used. Furthermore, the scraper vehicle 20 may be provided with a gyro sensor that detects angular velocity from the Coriolis force, and when the angular velocity acting on the scraper vehicle 20 is small, measurements may be performed using the strain gauge 28, accelerometer 29, or load cell 30.

[0134] Measurements may also be made using the strain gauges 28, accelerometers 29, and load cells 30 while the scraper vehicle 20 is stationary. Alternatively, the weight of the excavated material contained in the bowl 24 may be detected when the scraper vehicle 20 is stationary and when it is moving, and the weight when it is stationary may be used as a reference to correct the weight when it is moving, and this correction value may be stored in memory 39. Then, when calculating the weight when it is moving from the next time onwards, the calculated weight may be corrected using the correction value stored in memory 39. Alternatively, a gyro sensor may be used instead of or in combination with the acceleration sensor.

[0135] REFERENCE SIGNS LIST 1 towing vehicle 2 fuel cell 3 motor 4 hydrogen tank 7 speedometer 10 control device 12 two-dimensional code section 20 scraper vehicle 21 hitch 22 ball joint 24 bowl 25 scraper 28 strain gauge 29 accelerometer 30 load cell 39 memory 40 communication device 41 control device 50 compaction roller 100 construction area 101 traveling area 102 excavation area 103 discharge area 104 excavated area

Claims

1. a first scraper vehicle having a first excavation section and a first auxiliary drive unit and coupled to the towing vehicle; a second scraper vehicle having a second excavation unit and a second auxiliary drive device and coupled to the first scraper vehicle; A train-type scraper vehicle comprising: a control device that controls at least one of the first auxiliary drive device and the second auxiliary drive device based on distortion information of at least one of the first scraper vehicle and the second scraper vehicle when the first excavation unit and the second excavation unit receive instructions to perform excavation in an overlapping manner for at least a portion of the period and perform the overlapping excavation.

2. A train-type scraper vehicle as described in claim 1, wherein the control device controls at least one of the first auxiliary drive unit and the second auxiliary drive unit based on information on the strain corresponding to the weight of the excavated material excavated by at least one of the first excavation unit and the second excavation unit.

3. 2. The train-type scraper vehicle according to claim 1, wherein the control device includes a first control unit provided in the first scraper vehicle and a second control unit provided in the second scraper vehicle.

4. The train-type scraper vehicle according to any one of claims 1 to 3, wherein the first excavation portion and the second excavation portion have different shapes.

5. The train-type scraper vehicle according to any one of claims 1 to 3, wherein a longitudinal direction of the first excavation section is arranged to intersect with a vehicle width direction of the first scraper vehicle.

6. The train-type scraper vehicle according to any one of claims 1 to 3, wherein a longitudinal direction of the second excavation section is arranged to intersect with a vehicle width direction of the second scraper vehicle.

7. A train-type scraper vehicle as described in any one of claims 1 to 3, wherein a compaction roller for compacting the excavated material discharged from at least one of the first scraper vehicle or the second scraper vehicle is provided behind the second scraper vehicle.

8. The first auxiliary drive device includes a first in-wheel motor that drives a wheel of the first scraper vehicle using electricity, the second auxiliary drive device includes a second in-wheel motor that drives a wheel of the second scraper vehicle using electricity, 4. A train-type scraper vehicle as described in any one of claims 1 to 3, wherein the control device drives at least one of the first in-wheel motor and the second in-wheel motor while the first excavation unit and the second excavation unit are performing excavation simultaneously.

9. The train-type scraper vehicle described in claim 8, wherein the control device detects the distortion information using a first connecting member that connects the towing vehicle and the first scraper vehicle, and adjusts the driving force of the first in-wheel motor based on the distortion information.

10. The train-type scraper vehicle described in claim 8, wherein the control device detects the distortion information using a second connecting member that connects the first scraper vehicle and the second scraper vehicle, and adjusts the driving force of the second in-wheel motor based on the distortion information.

11. a drive unit for driving a first excavation unit and a first auxiliary drive unit provided on a first towed vehicle towed in a first direction, and a second excavation unit and a second auxiliary drive unit provided on a second towed vehicle connected to the first towed vehicle; A towing vehicle comprising: a control device that controls the drive device so that the first excavation unit and the second excavation unit perform excavation in an overlapping manner for at least a portion of the time; and a control device that controls at least one of the first auxiliary drive device and the second auxiliary drive device based on information about strain in at least one of the first towed vehicle and the second towed vehicle during the overlapping excavation.

12. a positioning device for determining the position of the towing vehicle; The towing vehicle according to claim 11 , wherein the control device determines whether to start digging by the first excavator based on the positioning result of the positioning device and the dimensions of the first towed vehicle.

13. A towing vehicle as described in Claim 11, wherein the control device controls at least one of the first auxiliary drive unit and the second auxiliary drive unit based on information on the strain corresponding to the weight of the excavated material excavated by at least one of the first excavation unit and the second excavation unit.

14. A towing vehicle as described in Claim 11, wherein the control device simultaneously starts excavation in the first excavation section and the second excavation section.

15. A towing vehicle as described in Claim 11, wherein the control device starts excavation of the second excavation section after excavation of the first excavation section has started.