Unmanned lengthy object carrying dolly

Abstract

To provide an unmanned lengthy object carrying dolly that can carry a lengthy carrying object in a state stably loaded thereon.SOLUTION: An unmanned lengthy object carrying dolly includes: a running device that includes a pair of wheels each provided at front right and front left, and, rear right and rear left sides of a dolly frame, the wheel being independently turned by each drive motor; a dolly main body supported by the running device; a loading platform 40 that includes a yawing table 41 which has right and left ends alternately moving forward or backward by rotating around the vertical axis relative to the dolly main body; a rotational angular sensor that detects the rotational angle of the loading platform 40; and a drive control device that executes a drive control on the running device based on the detection signal from the rotational angular sensor. Displacement members 62 that restrict the rotation of the yawing table 41 from both of the right and left sides across the rotation center of such a table abut on the loading platform 40. The displacement members 62 are provided with a pair of right and left origin return mechanisms 56 each causing the pushing force of a return spring 66 to act on the rotation of the yawing table 41.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a long-sized unmanned carrier vehicle that stably carries and transports long-sized objects to be transported such as railway car bodies.

Background Art

[0002] In railway vehicle repair factories, manufacturing factories, construction sites, etc., long objects such as railway vehicle bodies and column members made of steel frames are transported. Patent Document 1 below discloses a long-sized unmanned carrier vehicle for transporting such long-sized objects to be transported. This long-sized unmanned carrier vehicle cooperatively transports a long-sized object to be transported, which is a heavy long object, while supporting the front part and the rear part by two carrier vehicles. The two long-sized unmanned carrier vehicles are traveling carrier vehicles composed of independent two-wheel vehicles or omnidirectional moving vehicles, etc. The master-side carrier vehicle performs drive control for movement according to a command sent to the movement command unit, and the slave-side carrier vehicle connected via the object to be transported performs drive control coordinated with the master-side carrier vehicle. And, during cooperative transportation, the position error absorption mechanism is designed to operate when a position error occurs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The places where the long-object unmanned transport cart runs are not necessarily always flat and well-maintained. In places such as railway vehicle maintenance factories, there are steps and gradients. In the transverse transport (see Fig. 10) where a long transport object is laterally moved while being supported by two long-object unmanned transport carts in such places, even if it is coordinated control due to the different running surfaces of each other, the running speed will be affected. And a deviation occurs in the relative positional relationship between the two long-object unmanned transport carts, causing the long transport object to tilt. As a result, stress due to its own weight acts on the long transport object, and deformation or damage may occur in that part. Therefore, it is desirable to stably mount the long transport object on the long-object unmanned transport cart.

[0005] Therefore, an object of the present invention is to provide a long-object unmanned transport cart that stably mounts and transports a long transport object in order to solve such problems.

Means for Solving the Problems

[0006] The long-object unmanned transport cart according to the present invention is a long-object unmanned transport cart that supports and transports a long transport object with a plurality of units, and includes a traveling device having a pair of wheels that independently rotate by respective drive motors on the front, rear, left, and right of a rectangular cart frame, a cart body supported by the traveling device, a mounting table having a yawing table that rotates about a vertical axis so that the left and right ends alternately move back and forth, a rotation angle sensor that detects the rotation angle of the mounting table, and a drive control device that performs drive control on the traveling device based on the detection signal of the rotation angle sensor. The mounting table is provided with displacement members that restrict rotation from both the left and right sides sandwiching the rotation center with respect to the yawing table, and a pair of left and right origin return mechanisms are provided in the displacement members so that the biasing force of a return spring acts on the rotation of the yawing table.

Effects of the Invention

[0007] According to the above configuration, when loading and transporting a long conveyance object, for example, on the loading platforms of the front and rear automated guided vehicles (AGVs), even if a relative positional deviation occurs between the AGVs, the loading of the long conveyance object can be stabilized by the yawing table and transported. By performing drive control on the traveling device based on the detection signal of the rotation angle sensor, it is possible to correct the positional deviation by adjusting the rotation and traveling angles of the wheels. For the correction control of the relative positional deviation of such AGVs, it is essential to perform zeroing on the yawing table before loading the long conveyance object. However, accurate zeroing can be achieved by the zero return mechanism, and the long conveyance object can be loaded on the yawing table on which zeroing has been performed.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0009] An embodiment of the long unmanned carrier vehicle according to the present invention will be described below with reference to the drawings. In this embodiment, the body part of a railway vehicle (hereinafter referred to as a railway car body) is taken as an example of a long conveyance object, and a long unmanned carrier vehicle for conveying the railway car body in a railway vehicle inspection and repair factory that performs inspections and repairs on the railway car body in particular will be described. FIG. 1 is a perspective view showing a state during conveyance in which two railway car bodies are mounted on two long unmanned carrier vehicles. The railway car body 3 normally runs on railway rails with its front and rear parts mounted on carriages during normal operation. However, the long unmanned carrier vehicle (hereinafter simply referred to as the "unmanned carrier vehicle") 1 of this embodiment supports the railway car body 3 front and rear instead of such carriages and unmannedly conveys the railway car body within the railway vehicle inspection and repair factory for inspection or repair.

[0010] The railway car body 3 is regularly inspected in a railway vehicle inspection and repair factory. Railway rails are laid in the railway vehicle inspection and repair factory, and facilities such as traversers are provided. Conventionally, in order for the railway car body 3 to move within the railway vehicle inspection and repair factory, the railway car body 3 was transferred to a temporary carriage and traveled along the railway rails. However, in the conveyance of this embodiment, the unmanned carrier vehicle 1 that can freely move within the railway vehicle inspection and repair factory regardless of the railway rails is used.

[0011] FIGS. 2 to 4 are views showing the unmanned carrier vehicle 1. In particular, FIG. 2 is a perspective view shown from above, and FIG. 3 is a perspective view shown from below. FIG. 4 is a plan view. In this embodiment, the X-axis direction shown in each figure is described as the front-rear direction of the unmanned carrier vehicle 1 and also as the front-rear direction when conveying the railway car body 3. And the Y-axis direction shown in each figure is described as the width direction in which the railway car body 3 traverses and also as the width direction of the unmanned carrier vehicle 1. Furthermore, the Z-axis direction shown in each figure is the height direction of the railway car body 3 and the unmanned carrier vehicle 1.

[0012] The unmanned transport cart 1 is composed of a rectangular cart frame 11 formed by joining steel pipes and plates, and four traveling devices 12 are assembled from below in the front, rear, left, and right directions. The four traveling devices 12 have the same structure, and FIG. 5 is an external perspective view of the traveling device 12. The traveling device 12 is configured such that a pair of wheels 21, 22 and drive motors 23, 24 are integrated with the device main body 20. The wheels 21, 22 are arranged in parallel by positioning their respective axles coaxially, and rotation is transmitted to the axles from the drive motors 23, 24 arranged sandwiching the wheels 21, 22 in the front and rear via speed reducers 25, 26. And this unmanned transport cart 1 travels by independent drive control of the wheels 21 and the drive motor 23 and the wheels 22 and the drive motor 24 respectively.

[0013] In the device main body 20, a device rotation axis 27 in a vertical posture protrudes upward and is attached to the cart frame 11 via a fixed ring 28, and is configured to rotate in the direction of arrow A in FIG. 3 around the device rotation axis 27. Therefore, the traveling device 12 is configured such that the drive motors 23, 24 function not only for traveling but also for steering. By drive control of the drive motors 23, 24, for example, if the wheels 21, 22 rotate in the same direction, straight-ahead travel is performed, and if they rotate in opposite directions, steering is performed. Also, by changing the angles of the wheels 21, 22, the railway car body 3 mounted on the unmanned transport cart 1 can be transported by lateral movement perpendicular to the X-axis or diagonal movement at a certain angle.

[0014] In the unmanned transport cart 1, two of the four traveling devices 12 on the front side or two on the rear side are assembled to the traveling swing beam. The traveling swing beam is supported by a front and rear axis provided in the front and rear direction (X-axis direction) with respect to the cart frame 11, and the left and right traveling devices 12 can be displaced in the direction of arrow C (vertical direction) shown in FIG. 2. The unmanned transport cart 1 can thus travel stably even in a railway vehicle inspection factory with steps, gradients, etc.

[0015] Next, the driverless transport cart 1 is provided with a mounting table 40 for mounting the railway car body 3, which is a long transport object, at an intermediate position of the cart frame 11 when viewed in the front-rear direction (X-axis direction). Here, FIGS. 6 to 8 are views showing the mounting table 40. In particular, FIG. 6 is a perspective view of the mounting table 40 viewed from below, FIG. 7 is a cross-sectional perspective view of the mounting table in the direction of arrow M-M shown in FIG. 6, and FIG. 8 is a side view of the mounting table 40 viewed from the longitudinal direction (the width direction of the driverless transport cart 1). As shown in FIG. 4, the mounting table 40 is based on the posture in which the reference line K parallel to the long side of the rectangular yawing table 41 overlaps the Y-axis as the origin. Hereinafter, regarding the mounting table 40 as well, the X-axis, Y-axis, and Z-axis will be described on the premise of the origin state in the driverless transport cart 1.

[0016] The mounting table 40 has a three-layer structure in which three tables are each pivotally supported by different rotation axes, and is assembled to the cart frame 11 via lifting support rods 45. The mounting table 40 is integrally configured such that a rolling table 42 and a pitching table 43 are vertically overlapped under the yawing table 41 on which the railway car body 3 is mounted. The lowermost pitching table 43 is pivotally supported by a lateral support pin 46 in the Y-axis direction with respect to the lifting support rod 45. As a result, the mounting table 40 is configured such that both its front and rear ends swing alternately in the vertical direction.

[0017] Also, the rolling table 42 is pivotally supported by front and rear support pins 52 in the X-axis direction on the pitching table 43. As a result, the mounting table 40 is configured such that both its left and right ends swing alternately in the vertical direction. And the uppermost yawing table 41 has a cylindrical vertical rotation axis 55 fixed in the Z-axis direction at a positioning hole 551 formed in the central portion thereof, and is pivotally supported with respect to the rolling table 42. The rolling table 42 is also provided with a cylindrical bearing portion 47 in the central portion, and the vertical rotation axis 55 is rotatably assembled thereto. As a result, the mounting table 40 is configured such that both its left and right ends swing alternately in the front-rear direction (direction E shown in FIG. 2) with reference to the vertical center line P (parallel to the Z-axis) shown in FIG. 2.

[0018] The lifting support rod 45 that supports the mounting table 40 is inserted into a guide member (not shown) formed on the side of the cart frame 11. A plurality of receiving grooves 451 for height adjustment are formed along the axial direction (Z-axis direction) on the side surface of the lifting support rod 45, and a positioning mechanism for fitting a stopper into the receiving groove 451 is configured on the side of the cart frame 11. The height adjustment of the mounting table 40 is performed by a pair of lifting hydraulic jacks 51 shown by the dashed line. The piston rod tip of the lifting hydraulic jack 51 is only in contact with the lower surface of the rolling table 42. Therefore, the mounting table 40 is supported by the lifting hydraulic jacks 51 and is released by contracting after positioning during height adjustment.

[0019] By the way, two unmanned transport carts 1 of this embodiment can transport the railway car body 3 in the width direction by traveling side by side or diagonally. However, for stable transportation, it is necessary to travel while maintaining the posture of the mounted railway car body 3. That is, it is required that two unmanned transport carts 1 travel while always maintaining a relative positional relationship. For this, extremely high-precision travel control is required, but it is extremely difficult in traveling on uneven places such as railway vehicle maintenance factories by rails or the like. In this regard, the unmanned transport cart 1 is provided with the above-described mounting table 40 so that a certain degree of relative positional deviation can be tolerated.

[0020] Furthermore, in this embodiment, an unmanned transport cart control system for correcting the relative positional deviation between two unmanned transport carts 1 is constructed. The mounting table 40 is provided with a rotation angle sensor 58 for detecting the angle during swinging with respect to the yawing table 41. The rotation angle sensor 58 is, for example, a potentiometer and is provided straddling the vertical rotation axis 55 and the bearing portion 47. The state where the reference line K of the yawing table 41 overlaps the Y-axis is the origin, and the detection angle of the rotation angle sensor 58 is set to 0 degrees. Therefore, the mounting table 40 is provided with a pair of home position return configurations 56 shown in FIG. 8 so that the posture of the yawing table 41 with respect to the cart frame 11 returns to the origin when not mounted.

[0021] The origin return mechanism 56 is provided in a pair on both side surfaces of the rolling table 42, and has a bilaterally symmetric structure with respect to the center line P of the vertical rotation axis 55. The origin return mechanisms 56 having the same structure on the left and right are fixed with holders 61 on the side surface of the rolling table 42, and displacement rods 62 penetrate through the holders 61 and are slidably held by oil-less bushes. One end of two tie rods 63 parallel to the displacement rod 62 is fixed to the holder 61, and a spring force adjustment plate 65 is fixed to the other end. Male screw portions are formed on the other end sides of the two tie rods 63 and penetrate through two holes formed in the spring force adjustment plate 65. A pair of nuts are screwed onto the male screw portions with the spring force adjustment plate 65 interposed therebetween for each tie rod 63, and the positioning adjustment of the spring force adjustment plate 65 at the other end portion of the tie rod 63 can be performed.

[0022] A shape memory type coil spring 66 is incorporated as a return spring between the holder 61 and the spring force adjustment plate 65 so that the displacement rod 62 passes therethrough. A spring receiver 64 is fixed to the holder 61 side of the displacement rod 62, and two coil springs 66 are arranged in series between the spring receiver 64 and the spring force adjustment plate 65. An action plate 67 is fixed to the forward side surface portion of the carriage (it may also be the rearward side surface portion of the carriage) of the yawing table 41. The action plate 67 is formed so as to protrude downward from the yawing table 41, and the displacement rod 62 is adapted to be applied thereto in the orthogonal direction.

[0023] The displacement rods 62 of a pair of origin return mechanisms 56 are applied to the action plates 67 fixed to both the left and right sides of the yawing table 41 in opposite rotational directions, and the rotation is restricted. That is, the origin return mechanism 56 is adapted to perform origin setting such that the reference line K overlaps the Y axis by restricting the rotation of the yawing table 41 from both the left and right sides. A ball roller 68 of a hexagonal bolt type is screwed to the tip end portion of the displacement rod 62 applied to the action plate 67.

[0024] Next, FIG. 9 is a block diagram simply showing the functional configuration of the automated guided vehicle control system. In this automated guided vehicle control system, information communication such as a travel command is performed between a conveyance management device 8 configured using a computer and a drive control device 7 mounted on the automated guided vehicles 1 (1A, 1B), and the railway car body 3 is conveyed according to a conveyance route.

[0025] Of the two automated guided vehicles 1A and 1B, one serves as the master and the other as the slave for cooperative conveyance. The drive control device 7 has a travel information communication unit 71 for transmitting and receiving travel information between the conveyance management device 8 and the automated guided vehicles 1A and 1B, receives conveyance information for conveying the railway car body 3, and also confirms each other's travel states. Further, the drive control device 7 has a travel information calculation unit 72 for calculating travel information such as the traveling speed, moving direction, and current position coordinates for each of the automated guided vehicles 1A and 1B. If it is the master side, its own position coordinates are calculated, and if it is the slave side, the relative position with respect to the master side is calculated.

[0026] Furthermore, the drive control device 7 has a drive command unit 73 for creating a travel command for the travel device 12. The drive command unit 73 performs travel control according to a predetermined conveyance route based on conveyance information including the conveyance route at the railway vehicle repair factory from the conveyance management device 8, the travel information calculated by the travel information calculation unit 72, and the travel information regarding the other automated guided vehicle 1 acquired via the travel information communication unit 71. At that time, the drive command unit 73 adjusts the travel position based on the detection signal from the rotation angle sensor 58 described above.

[0027] Next, an example of the conveyance of the railway car body 3 in a railway vehicle maintenance shop will be described with reference to FIG. 10. FIG. 10 is a diagram showing the relative positional deviation of the driverless carrier trucks 1(1A, 1B) during the lateral conveyance for moving the railway car body 3 in the vehicle width direction. The two driverless carrier trucks 1A and 1B are subjected to running control for each running device 12, and the drive motors 23 and 24 apply predetermined rotations to the wheels 21 and 22, and running control is performed to convey the coordinated railway car body 3. The railway car body 3 travels back and forth in the X-axis direction shown in FIG. 1, and in addition, the running direction is switched, such as lateral movement in the short side direction of the car body orthogonal to the X-axis or diagonal movement in a predetermined angular direction, and it moves along a predetermined conveyance route.

[0028] For example, when the railway car body 3 is moved laterally, by controlling the rotation of the wheels 21 and 22, the apparatus main body 20 rotates 90 degrees in the direction indicated by the arrow A in FIG. 3, and the railway car body 3 moves laterally in the short side direction. At this time, the left and right driverless carrier trucks 1A and 1B are subjected to running control so that the positions in the running direction coincide, but as shown in FIG. 10, a relative positional deviation may occur between the two trucks. This is because, in addition to the generation of a speed difference between the driverless carrier trucks 1A and 1B due to the weight balance of the railway car body 3 to be conveyed, a change may occur in the running speed of one of them due to steps or gradients on the running surface.

[0029] FIG. 10 shows a situation where the left driverless carrier truck 1A is ahead of the right driverless carrier truck 1B. At this time, the longitudinal posture of the railway car body 3 is inclined, and accordingly, the yawing tables 41 of the driverless carrier trucks 1A and 1B swing. Therefore, in the driverless carrier trucks 1A and 1B of the present embodiment, the positional relationship between the placement table 40 in the railway car body 3 is kept constant without being affected by the inclination in the longitudinal direction, and it is possible to avoid the balance being lost and the influence of strains that may occur in the mounting portion with the trucks.

[0030] When a relative positional deviation occurs between the unmanned carrier vehicles 1A and 1B that are connected to each other by the railway car body 3, the rotation angle θ detected by the rotation angle sensor 58 is proportional to the deviation amount S when deviating from the original positional relationship. Such relative positional deviations in the unmanned carrier vehicles 1A and 1B and the accompanying rocking of the yawing table 41 can occur not only in the lateral conveyance of the railway car body 3 shown in FIG. 10 but also in conveyance in any direction such as diagonal conveyance or forward and backward conveyance. Therefore, in any case, by adjusting the relative positional deviation of the unmanned carrier vehicles 1A and 1B so as to return the rotation angle θ to 0 degrees (return the reference line K to the Y-axis), the longitudinal posture of the railway car body 3 can be corrected. And the process for correcting such a posture of the railway car body 3 assists the traveling control for causing the unmanned carrier vehicles 1A and 1B to travel along the conveyance route.

[0031] It is important that the mounting conditions of the railway car body 3 are correctly adjusted for the adjustment of the relative positional deviation of the unmanned carrier vehicles 1A and 1B. For this purpose, it is necessary that the origin setting of the rotation angle sensor 58 in which the reference line K of the yawing table 41 overlaps the Y-axis of the unmanned carrier vehicle 1 is performed in a state where the railway car body 3 is not mounted. The adjustment work for origin setting is performed by a pair of home return mechanisms 56 that restrict the rotation of the yawing table 41 from opposite directions to each other. The home return mechanism 56 has the tip of the displacement rod 62 applied to the yawing table 41 via the action plate 67 from the clockwise direction and the counterclockwise direction, which are opposite directions, about the vertical rotation axis 55. For the left and right home return mechanisms 56, the origin setting is performed by finely adjusting the contact position of the ball roller 68 with the action plate 67 of the mounting table 40.

[0032] When the posture of the yawing table 41 is at the origin, the ball rollers 68 of the origin return mechanism 56 are in contact with the left and right actuator plates 67 so that no load acts on the coil spring 66, and it is stable. By adjusting the screwing amount of the ball roller 68 with respect to the displacement rod 62, the position in contact with the actuator plate 67 is adjusted, and the positioning in the rotation direction of the yawing table 41 is performed. That is, adjustment is performed so that the rotation angle θ of the rotation angle sensor 58 becomes 0 degrees. And when the relative positional deviation of the above-described automated guided vehicles 1A and 1B occurs, the yawing table 41 rotates in one direction, and the coil spring 66 is compressed in the origin return mechanism 56 in the rotation direction.

[0033] Therefore, according to the present embodiment, when the yawing table 41 of the mounting table 40 rotates in the direction of arrow E, it is not necessary to rigidly connect the automated guided vehicles 1A and 1B. Even if a relative positional deviation occurs between the automated guided vehicles 1A and 1B during transportation, the risk of damage to the railway vehicle 3 due to torsion or the like is avoided. And the relative positional deviation of the automated guided vehicles 1A and 1B generated during transportation can be detected by the rotation angle sensor 58 provided on the mounting table 40, and the positional deviation is corrected by the traveling control on the transport vehicle side.

[0034] In the correction control of the relative positional deviation of the automated guided vehicles 1A and 1B, zeroing on the mounting table 40 is essential. However, in this embodiment, accurate zeroing can be performed by the origin return mechanism 56, and the railway vehicle 3 can be mounted on the mounting table 40 where the zeroing has been performed. Further, if the railway vehicle 3 or the like mounted on the mounting table 40 is removed, the compressed coil spring 66 returns to its original state, and the yawing table 41 automatically returns to the origin. By doing so, even if a relative positional deviation occurs in the transport vehicles 1A and 1B, the positional deviation can be correctly corrected.

[0035] As described above, one embodiment of the present invention has been described. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit thereof. In the above embodiment, a potentiometer was exemplified as an example of the rotation angle sensor 58, but a VR resolver, an encoder, or the like may also be used. Also, in the above embodiment, a shape memory alloy is applied to the coil spring 66, but general steel or another type of alloy may be used.

Explanation of Reference Numerals

[0036] 1(1A, 1B)…Automated guided vehicle 3…Railway car body 7…Drive control device 8…Transport management device 11…Trolley frame 12…Travel device 20…Device main body 21, 22…Wheels 23, 24…Drive motors 40…Mounting table 41…Yawing table 42…Rolling table 43…Pitching table 55…Rotation axis 56…Home return mechanism 58…Rotation angle sensor 61…Holder 62…Displacement rod 63…Tie rod 64…Spring receiver 65…Spring force adjustment plate 66…Coil spring 67…Actuating plate 71…Travel information communication section 72…Travel information calculation section 73…Drive command section K…Reference line θ…Rotation angle

Claims

1. An unmanned carrier vehicle for long objects that supports and conveys a plurality of long objects to be conveyed, a traveling device having a pair of wheels that rotate independently by respective drive motors on the front, rear, left, and right of a rectangular vehicle frame, a vehicle body supported by the traveling device, a mounting table having a yawing table that rotates about a vertical axis so that the left and right ends alternate front and rear, a rotation angle sensor that detects the rotation angle of the mounting table, a drive control device that performs drive control on the traveling device based on a detection signal of the rotation angle sensor, and having, on the mounting table, displacement members that restrict rotation are applied from both left and right sides sandwiching the rotation center with respect to the yawing table, and a pair of left and right home return mechanisms are provided in which a biasing force of a return spring acts on each of the displacement members with respect to the rotation of the yawing table. An unmanned carrier vehicle for long objects.

2. The home return mechanism according to claim 1, wherein the displacement member is a displacement rod whose tip is applied to the yawing table, and the biasing force of the return spring acts on the displacement rod. The unmanned carrier vehicle for long objects described.

3. The unmanned carrier vehicle for long objects according to claim 2, wherein a ball roller is screwed to the tip of the displacement rod.

4. The home return mechanism includes a holder fixed to the support portion side that rotatably supports the yawing table, the displacement rod slidably held with respect to the holder, two tie rods fixed to the holder sandwiching the displacement rod, a spring force adjustment plate that can be fixed by changing its position with respect to the tie rod, a spring receiver fixed to the displacement rod, and a coil spring incorporated as the return spring between the spring force adjustment plate and the spring receiver. The unmanned carrier vehicle for long objects described in claim 3.

5. The mounting table is configured integrally so that a pitching table whose front and rear ends swing up and down about a horizontal axis in the width direction, a rolling table whose left and right ends swing up and down about a front and rear axis in the front and rear direction with respect to the pitching table, and the yawing table whose left and right ends alternate front and rear about a vertical axis in the up and down direction with respect to the rolling table overlap vertically. The unmanned carrier vehicle for long objects described in claim 1.

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