Transport carriage for heavy objects

Abstract

To provide a carrying truck for a heavy article capable of improving workability and safety.SOLUTION: A conveyance carriage 1 includes a body 10 having a placement surface on which a heavy object 2 to be conveyed is placed, a plurality of rollers 11 provided below the placement surface and capable of moving up and down in the vertical direction, and a control device 17 for controlling the position and operation of the rollers 11. The control device 17 changes the height of the placement surface by moving the roller 11 up and down, and changes the moving direction by moving the roller 11 up and down to switch the ground contact state.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a self-propelled transport vehicle for transporting heavy objects. [Background technology]

[0002] Conventionally, when transporting a heavy object such as a transformer within the premises of a factory or the like, the heavy object is placed on a transport vehicle such as that described in Patent Document 1, and the transport direction is manually controlled within a certain range. Hereinafter, a transport vehicle with such a configuration will be referred to as a conventional configuration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-211720 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the conventional configuration, changing the conveying direction manually is labor-intensive, and changing the direction of the rollers while the load is applied can damage the floor. Furthermore, with the conventional configuration, removing the transport vehicle after transport requires the labor-intensive task of manually jacking up the heavy object, and there is a risk of hands or feet getting caught. In other words, the conventional transport vehicle has room for improvement in terms of workability and safety.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and an object of the present disclosure is to provide a transport vehicle for heavy loads that can improve workability and safety. [Means for solving the problem]

[0006] A transport cart for heavy objects according to one aspect of the present disclosure comprises a main body having a loading surface on which the heavy object to be transported is placed, a plurality of rollers arranged below the loading surface and capable of being raised and lowered in the vertical direction, and a control device that controls the position and operation of the rollers, and the control device changes the height of the loading surface by raising and lowering the rollers, and changes the direction of movement by raising and lowering the rollers to switch the contact state. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a usage pattern of a transport platform vehicle according to an embodiment. [Figure 2] FIG. 1 is a diagram showing an example of the appearance of a transport vehicle; [Figure 3] FIG. 1 is a diagram illustrating an example of a mechanical configuration of a transport vehicle. [Figure 4] FIG. 1 is a diagram schematically illustrating an example of a roller and an elevator device. [Figure 5] FIG. 10 is a diagram showing an example of a manner in which a motor is moved; [Figure 6] FIG. 1 is a diagram illustrating an example of an electrical configuration of a transport vehicle. [Figure 7] A diagram showing an example of the configuration of a control panel [Figure 8] FIG. 1 is a diagram illustrating an example of the configuration of an operating device. [Figure 9] FIG. 10 is a diagram showing an example of how a roller moves up and down; [Figure 10] FIG. 10 is a diagram showing an example of how a heavy object is lifted from a stand; [Figure 11] FIG. 10 is a diagram schematically illustrating an example of a manner in which a heavy object is placed on a stand. [Figure 12] FIG. 10 is a diagram schematically illustrating an example of a mode in which the conveying direction is changed. DETAILED DESCRIPTION OF THE INVENTION

[0008] As shown in side view, front view, and plan view in Fig. 1, the transport vehicle 1 of this embodiment is assumed to be placed at each of the four corners below a heavy object 2, and these four transport vehicles 1 work together to transport one heavy object 2. The heavy object 2 to be transported is assumed to be up to about 20 tons, and examples include extra-high voltage transformers and large distribution panels. Of course, the transport vehicle 1 can also be used to transport lighter equipment.

[0009] That is, in this embodiment, the transport vehicle 1 is assumed to be used for a task that has conventionally been performed manually, such as transporting a heavy load 2 to a predetermined location on a site. Power is supplied to this transport vehicle 1 from a control panel 3 via a connection cable 4, and the transport vehicle 1 transports the heavy load 2 by self-propelled movement based on instructions from an operation device 5 operated by a worker. These four transport vehicles 1, two control panels 3, and one operation device 5 constitute a transport system 6 that transports the heavy load 2.

[0010] 2, the transporting vehicle 1 includes a main body 10 and a plurality of rollers 11. A connector 12 is provided on one of the sides of the main body 10 for receiving power and settings for the travel direction (described later) from a control panel 3. Hereinafter, the side on which the connector 12 is provided will be referred to as the front when the transporting vehicle 1 is used as a reference, the opposite side will be referred to as the rear, and the direction perpendicular to the front-to-rear direction when the transporting vehicle 1 moves forward will be referred to as the left-to-right direction.

[0011] In this embodiment, the front-rear direction based on the transporting vehicle 1 is defined as the first movement direction, and the left-right direction perpendicular to the first movement direction is defined as the second movement direction. Note that the front-rear direction and the left-right direction shown in Fig. 2 indicate the movement directions based on the transporting vehicle 1, and may not necessarily coincide with the transport directions when the heavy object 2 is actually transported.

[0012] The main body 10 is formed in a roughly hollow rectangular parallelepiped shape, with the lower ends of the rollers 11 exposed from the bottom surface. The upper surface of the main body 10 serves as a loading surface on which the heavy load 2 is placed. Therefore, the main body 10 is designed to have enough strength to transport the heavy load 2. A cushioning material 13 made of an elastic material such as rubber is provided on this loading surface.

[0013] 3, four rollers 11, eight lifting devices 14 (two for each roller 11), two motors 15, two actuators 16, and a control device 17 that controls them are arranged inside the main body 10. In other words, by arranging the drive system and control system components inside the outer edges of the four rollers 11, the transport vehicle 1 has a compact design that prevents the external dimensions of the main body 10 from becoming excessively large.

[0014] A total of four rollers 11 are provided below the placement surface and near both ends in the front-rear direction and both ends in the left-right direction of the main body 10. By arranging each roller 11 near the outer edges of the front-rear and left-right directions of the main body 10, the distance between opposing rollers 11 is widened, improving stability when a heavy object 2 is placed on it.

[0015] As shown in Fig. 4(a), the rollers 11 have a structure in which an elastic member 19, such as hard rubber, is arranged on the outer periphery of a shaft member 18. Therefore, the distance between each roller 11 of the transporting cart 1 is wide, improving stability and load-bearing capacity when a heavy load 2 is placed on it. Note that Fig. 4 shows rollers 11A with gears, but rollers without gears basically have the same structure.

[0016] Of the four rollers 11 provided on the transporting vehicle 1, the two rollers 11A and 11B located at both ends in the front-rear direction shown in Fig. 3 correspond to first rollers used when the transporting vehicle 1 moves in the front-rear direction. Of these, roller 11A is provided as a so-called drive wheel, and a so-called gear is formed in its central portion.

[0017] Furthermore, the two rollers 11C and 11D arranged at both ends in the left-right direction correspond to second rollers used when the transporting carriage 1 moves left-right. Of these, roller 11C is provided as a so-called drive wheel, and a gear is formed in its central portion.

[0018] The transport vehicle 1 changes the direction of movement between the front and rear directions or the left and right directions by switching the contact state of the four rollers 11. Specifically, each roller 11 is supported by two elevators 14 so that it can move up and down and rotate. These elevators 14 are formed of, for example, hydraulic cylinders, and move up and down based on commands from a control device 17.

[0019] Specifically, the lifting device 14 supports the shaft member 18 of the roller 11 so that the shaft member 18 can be raised and lowered and rotatable by inserting the rod-shaped members 14a into bearings 20 provided on both ends of the shaft member 18. Note that the configuration of the lifting device 14 is not limited to this, and for example, the lifting device 14 can also be configured as a direct acting hydraulic cylinder, and the hydraulic cylinder can be provided with bearings 20 to rotatably support the shaft member 18.

[0020] In this embodiment, when the rollers 11 are raised to their highest position as shown in FIG. 4(a), their lower ends protrude downward from the bottom surface of the main body 10. In the case of FIG. 4(a), the lower ends of the rollers 11 protrude a predetermined distance (Y1) from the bottom surface. Therefore, even when each roller 11 is raised to its highest position, the main body 10 does not come into contact with the floor surface. This prevents damage to the floor surface. Hereinafter, the position at which the rollers 11 are raised to their highest position will be referred to as the raised position.

[0021] When the roller 11 is lowered to the lowest position as shown in FIG. 4(b), its lower end protrudes a distance (Y2) from the bottom surface of the main body 10. At this time, the amount of elevation (Y2-Y1) from the raised position is approximately 25 mm. Note that this amount of elevation is an example and is not limiting. Hereinafter, the position where the roller 11 is lowered to the lowest position will be referred to as the lowered position.

[0022] As shown in Fig. 5, the motor 15 that drives the roller 11 has a drive gear 21 attached to its output shaft. The motor 15 is movable between a drive position where the drive gear 21 meshes with the gear of the roller 11A to drive the roller 11, as shown in Figs. 5(a) and (c), and a lift position where the drive gear 21 does not mesh with the gear of the roller 11 and the roller 11 can be raised and lowered, as shown in Figs. 5(b) and (d). The motor 15 that drives the roller 11C has a similar configuration. Note that the sizes and shapes of the components shown in Fig. 5 are merely examples and are not limiting.

[0023] If the position of the rotation axis (Jr) of roller 11 at the drive position is X0 and the position of the rotation axis (Jm) of motor 15 is X1, then at the lifting position, motor 15 moves away from roller 11, causing the position of the rotation axis (Jm) to become X2.

[0024] At this time, in the drive position, drive gear 21 meshes with the gear of roller 11 from above, thereby restricting the lifting and lowering of roller 11. Furthermore, in the lifting and lowering position, the gears do not mesh with each other, thereby restricting unintentional rotation of roller 11 during lifting and lowering. In other words, the mechanism for moving motor 15 also functions as a safety mechanism that restricts roller 11 from lifting and lowering while being driven, and from rotating while being lifted and lowered.

[0025] The position of each motor 15 is changed by a linear actuator 16. Specifically, the tip of a rod 16a of the actuator 16 is fixed to the motor 15, and the motor 15 is moved by moving the rod 16a to the left and right in the figure. Although not shown, a rail structure or the like that allows movement only in the lateral direction is provided below the motor 15. Alternatively, the motor 15 can be moved by other methods, such as by attaching the motor 15 to a movable plate and moving the position of the movable plate.

[0026] The lifting device 14, motor 15, and actuator 16 are controlled by a control device 17. As shown in FIG. 6, the control device 17 includes a control unit 17a configured with a microcomputer or the like, and a wireless communication unit 17b for wireless communication with the operating device 5. The control unit 17a controls each unit by executing a computer program stored in a storage unit (not shown). The lifting device 14, motor 15, actuator 16, and control device 17 operate by receiving power from a control panel 3 connected via a connection cable 4.

[0027] 7, the control panel 3 is provided with a power switch 30, an emergency stop switch 31, and a plurality of setting switches 32A to 32D for setting the rotation direction of the motor 15, i.e., the movement direction of the transport vehicle 1. The power switch 30 is used to input an operation to start power supply, and is an illumination type that lights up when power supply is started. Furthermore, the emergency stop switch 31 forcibly cuts off the power supply when operated.

[0028] Setting switches 32A and 32B set the rotation direction of motor 15 when moving in the forward / backward direction. Setting switches 32C and 32D set the rotation direction of motor 15 when moving in the left / right direction. In other words, each transporting vehicle 1 moves in the direction set by this setting switch 32. At this time, the state of each setting switch 32 is transmitted to the control device 17 of transporting vehicle 1 via the connection cable 4. Then, the control device 17 drives and rotates motor 15 according to the setting.

[0029] Specifically, when the setting switch 32 is set to "forward," the control device 17 drives the motor 15 in a forward direction. When the setting switch 32 is set to "reverse," the control device 17 drives the motor 15 in a reverse direction. In this embodiment, with respect to movement in the front-to-rear direction, the transporting vehicle 1 moves forward when the motor 15 rotates forward, and moves backward when the motor 15 rotates reverse. With respect to movement in the left-to-right direction, the transporting vehicle 1 moves right when the motor 15 rotates forward, and moves left when the motor 15 rotates reverse. Note that the association between the rotation direction of the motor 15 and the movement direction is an example, and is not limited to this.

[0030] Then, the worker sets each setting switch 32 to "forward" or "reverse" based on the orientation of each transport vehicle 1 and the transport direction of the heavy load 2. As a result, when transporting the heavy load 2, it becomes possible to move each transport vehicle 1 in the appropriate movement direction simply by issuing an instruction to start movement. Also, by setting the movement direction in advance on the control panel 3 side, there is no need to worry about the movement direction of the transport vehicle 1 when actually transporting the load, which reduces the burden on the worker.

[0031] As shown in Fig. 1, this control panel 3 is attached to the side of the heavy load 2 by a belt 7 so as not to shift position. In this case, the two transporting vehicles 1A and 1B arranged on the right side in the plan view are arranged so that the front side on which the corresponding control panel 3 is attached faces forward. On the other hand, the two transporting vehicles 1C and 1D on the left side in the figure are arranged so that the right side on which the control panel 3 is attached faces forward. By arranging them in this orientation, it becomes possible to easily connect each transporting vehicle 1 and each control panel 3.

[0032] Incidentally, when the four transport vehicles 1 are arranged in the above-mentioned orientation, when the heavy load 2 is to be transported to the right in the illustration, the transport vehicles 1A and 1B will move forward relative to the transport vehicle 1. On the other hand, the transport vehicles 1C and 1D will move backward relative to the transport vehicle 1. When the heavy load 2 is to be transported to the left in the illustration, the front and rear are reversed, and when the heavy load 2 is to be transported upward or downward in the illustration, the left and right are similarly reversed.

[0033] In this way, when the orientation of the transporting vehicle 1 differs from the transport direction of the heavy load 2, there is a risk of mistaking the direction of movement if the orientation of the transporting vehicle 1 and the direction of movement are set during transport. In contrast, by setting the direction of movement on the control panel 3 as in this embodiment, the work procedure makes it possible to set and check the direction of movement at a stage before the heavy load 2 is actually transported, preventing work errors such as the movement direction being incorrect during transport.

[0034] Each transporting vehicle 1 receives instructions to travel and instructions to switch the moving direction from an operating device 5 shown in Fig. 8. That is, the control device 17 of the transporting vehicle 1 controls the position and operation of the rollers 11 in response to an operation from the operating device 5 that operates the multiple transporting vehicles 1 from a remote location. Strictly speaking, the control device 17 controls the operation of the rollers 11 by controlling the rotation direction and drive of the motor 15.

[0035] The operating device 5 has a travel switch 50, a double lowering switch 51, a double raising switch 52, a front-rear movement switch 53, and a left-right movement switch 54. When each switch is operated, the operating device 5 simultaneously issues instructions to all of the transport vehicles 1. The travel switch 50 is a push button type, and only while it is pressed by the operator, the motor 15 is driven and the transport vehicle 1 travels.

[0036] At this time, since the movement direction of the transporting vehicle 1 is set on the control panel 3 as described above, the transport and stop of the heavy load 2 can be controlled simply by pressing the travel switch 50, thereby reducing the burden of the transport work. Furthermore, there is no need to keep an eye on the operation device 5 when transporting the heavy load 2, and the worker can carry out the work while checking for swaying of the heavy load 2 and the presence or absence of obstacles in the transport direction. Furthermore, the worker can lift and lower the heavy load 2 from a position away from the heavy load 2, not just while the vehicle is traveling. This ensures the safety of the worker.

[0037] The double-lowering switch 51 is a switch for raising all the rollers 11 to the above-mentioned raised position, so that all the rollers 11 come into contact with the ground and the height (H1) from the floor surface to the placement surface becomes the lowest, as shown in Fig. 9(a). Hereinafter, this state will be referred to as the double-lowering state.

[0038] The double-raising switch 52 is a switch for lowering all the rollers 11 to the above-mentioned lowered position, so that all the rollers 11 are in contact with the ground and the height (H2) from the floor surface to the placement surface is at its highest, as shown in Fig. 9(b). Hereinafter, this state will be referred to as the double-raising state.

[0039] The forward / backward movement switch 53 is a switch for setting the movement direction of the transporting vehicle 1 to the forward / backward direction. Specifically, when the forward / backward direction switch is pressed, as shown in FIG. 9(c), the first rollers 11A and 11B are in a grounded state, and the second rollers 11C and 11D are in a non-grounded state. This enables the transporting vehicle 1 to move in the forward / backward direction. In this embodiment, the height (H3) from the loading surface when moving forward / backward is the same as the height (H2) in the both-raised state. Note that whether the transporting vehicle 1 moves forward or backward when the travel switch 50 is pressed is set on the control panel 3 side.

[0040] The left / right movement switch 54 is a switch for setting the movement direction of the transporting vehicle 1 to the left or right direction. Specifically, when the left / right direction switch is pressed, as shown in FIG. 9(d), the first rollers 11A and 11B are not in contact with the ground, and the second rollers 11C and 11D are in contact with the ground. This allows the transporting vehicle 1 to move in the left / right direction. In this embodiment, the height (H4) from the placement surface when moving left or right is the same as the height (H2) when both sides are raised. Note that whether the transporting vehicle 1 moves right or left when the travel switch 50 is pressed is set on the control panel 3 side.

[0041] Next, specific situations assumed when transporting a heavy load 2 will be described with reference to Figs. 10 to 12. As shown in Fig. 10(a), it is assumed that the heavy load 2 to be transported is placed on a platform 60A. In this case, the worker places the transport vehicle 1 in a double-lowered state below the heavy load 2. Then, once all rollers 11 are properly positioned, the worker presses the double-lowering switch 52 of the operating device 5 to raise the loading surface as shown in Fig. 10(b). As a result, the heavy load 2 is lifted from the platform 60A as shown in Fig. 10(c).

[0042] Next, the worker removes the platform 60A and operates, for example, the forward / backward movement switch 53. As a result, as shown in Fig. 10(d), rollers 11A and 11B are brought into a grounded state, and rollers 11C and 11D are raised and no longer in contact with the ground, thereby enabling movement in the forward / backward direction. Then, the worker operates the travel switch 50 to move the transport vehicle 1 in a predetermined direction, here to the left as shown in Fig. 10(e), and begins transporting the heavy load 2.

[0043] Thereafter, the worker transports the heavy load 2 to a predetermined location where another platform 60B is placed, as shown in FIG. 11(a), for example. When transportation is complete, the worker confirms that the heavy load 2 is in an appropriate position relative to the platform 60B, and then operates the double-lift switch 52. As a result, as shown in FIG. 11(b), rollers 11C and D, for example, which were not in contact with the ground during transportation, are now in contact with the ground. As a result, the heavy load 2 is supported by four rollers 11, which improves stability when moving the heavy load 2 up and down.

[0044] Next, the worker operates the double-lowering switch 51 to lower the placement surface. As a result, the heavy load 2 is placed on the platform 60B, and the placement surface is lowered to a position below the heavy load 2, as shown in FIG. 11(c). Then, the worker removes the transport vehicle 1, which has been released from contact with the heavy load 2, from below the heavy load 2. This completes the series of transport operations.

[0045] Incidentally, when transporting heavy load 2, it is not necessarily transported in a straight line, but situations are expected in which the transport direction is changed at right angles along the way. For example, it is expected that the delivery route within a factory site will be well-established and will have right-angle corners. In such cases, if an attempt is made to turn heavy load 2 at a corner to change the transport direction, there is a risk that heavy load 2 will tilt, tip over, or come into contact with a wall or nearby equipment. In addition, a large space may be required to turn heavy load 2.

[0046] Therefore, the transport vehicle 1 can change the transport direction by 90° on the spot. As an example shown in Figure 12, assuming that the right side of the figure is the front and the bottom side of the figure is the right, a heavy object 2 is transported forward from a start location (P1) along a carry-in route (R), and then transported rightward to an end location (P3) via a corner (P2). In this case, the worker places the heavy object 2 on the transport vehicle 1 as shown in Figure 10, operates the forward / backward movement switch 53, and presses the travel button to transport the heavy object 2 to the corner (P2).

[0047] When the transport vehicle 1 reaches the corner (R2), the worker operates the left / right movement switch 54. When the transport vehicle 1 is instructed to change the movement direction, it first puts all of the rollers 11 into a ground contact state, and then switches the ground contact state of the rollers 11 so that the movement direction corresponds to the transport direction. In the example of Figure 12, when moving in the forward / backward direction, rollers 11A and 11B are in a ground contact state, and rollers 11C and 11D are not in a ground contact state.

[0048] Therefore, when the left / right movement switch 54 is operated while the transporting carriage 1 is moving in the forward / backward direction, the rollers 11C and 11D are lowered to a grounded state. In other words, the control device 17 temporarily sets the transporting carriage 1 in a both-up state. After that, the control device 17 raises the rollers 11A and 11B to a non-grounded state, thereby setting the transporting carriage 1 in a state where the rollers 11C and 11D are installed, that is, a state where the transporting carriage 1 can move in the left / right direction.

[0049] This makes it possible to change the conveying direction of the heavy object 2 by 90° on the spot. Similarly, when conveying the heavy object 2 in the left-right direction and then in the front-rear direction, all of the rollers 11 are first brought into contact with the ground, and then the contact state of the rollers 11 is switched to correspond to the conveying direction. Thereafter, the worker conveys the heavy object 2 to the end position of movement by pressing the travel switch 50, and then places the heavy object 2 on the platform 60 or the like as shown in Figure 11 above, and removes the conveying vehicle 1. In this way, the heavy object 2 is conveyed using the conveying vehicle 1.

[0050] According to the embodiment described above, the following effects can be obtained. The transport vehicle 1 according to the embodiment includes a main body 10 having a loading surface on which a heavy object 2 to be transported is placed, a plurality of rollers 11 that are provided below the loading surface and are capable of moving up and down, and a control device 17 that controls the position and operation of the rollers 11. The control device 17 changes the height of the loading surface by raising and lowering the rollers 11, and changes the direction of movement by raising and lowering the rollers 11 to switch the contact state.

[0051] This allows the direction of movement to be changed depending on the state of contact of the rollers 11 with the ground, reducing the effort required to change the direction of movement. Furthermore, when changing the direction of movement, the orientation of the rollers 11 does not need to be changed while the load is applied, so the floor surface is not damaged. Furthermore, the height of the loading surface can be adjusted depending on the direction of the rollers 11, eliminating the need to manually jack up the load. Furthermore, there is no risk of hands or feet getting caught when lifting the heavy load 2 from the platform 60 or placing it on the platform 60.

[0052] Therefore, it is possible to reduce the labor required to transport the heavy object 2, reduce the risk, prevent damage to the floor, and reduce the amount of work required, thereby improving workability and safety. The same effects can also be obtained with the above-mentioned transport system 6.

[0053] In this case, by arranging the drive system and control system members inside each roller 11 as in the embodiment, the size of the transporting carriage 1 is prevented from increasing, and the transporting carriage 1 can be made compact.

[0054] Furthermore, in the transporting carriage 1 according to the embodiment, the rollers 11 include at least two first rollers used when moving in a first movement direction and at least two second rollers used when moving in a second movement direction perpendicular to the first movement direction. When moving in the first movement direction, the control device 17 places the first rollers in a grounded state and the second rollers in an ungrounded state, and when moving in the second movement direction, places the second rollers in a grounded state and the first rollers in an ungrounded state, thereby changing the movement direction.

[0055] This makes it possible to change the transport direction by 90° on the spot without changing the orientation of the heavy object 2, which is extremely useful, for example, when transporting the heavy object 2 through a well-established access route on the premises.

[0056] Furthermore, in the transport vehicle 1 according to the embodiment, when changing the direction of movement, the control device 17 first places all of the rollers 11 in a ground contact state, and then switches the ground contact state of the rollers 11 depending on the direction of movement. As a result, the heavy load 2 is supported by four rollers 11, and the heavy load 2 itself does not move up or down, so the direction of the heavy load 2 can be changed in a stable state. Furthermore, since the orientation of the heavy load 2 itself does not change, the heavy load 2 will not tilt or tip over, and furthermore, the orientation of the rollers 11 does not change when a load is applied, so the floor surface will not be damaged.

[0057] Furthermore, in the transporting platform 1 according to the embodiment, the rollers 11 are provided so as to be capable of ascending or descending simultaneously. As a result, when the heavy object 2 is lifted from the platform 60 or placed on the platform 60, it is supported by four rollers 11, thereby improving stability.

[0058] The transport vehicle 1 according to the embodiment also includes a motor 15 that is movable between a drive position that drives the rollers 11 and a lift position that allows the rollers 11 to be raised and lowered. The control device 17 moves the position of the motor 15 to the drive position when driving the rollers 11, and moves the motor 15 to the lift position when raising and lowering the rollers 11. This prevents the rollers 11 from being raised and lowered unintentionally at the drive position, and also prevents the rollers 11 from being rotated unintentionally when being raised and lowered.

[0059] Furthermore, in the transporting vehicle 1 according to the embodiment, the control device 17 controls the position and operation of the rollers 11 in response to an operation from the operation device 5 that operates the multiple transporting vehicles 1 from a remote location. This allows the worker to work at a location away from the heavy load 2, thereby improving safety.

[0060] In the embodiment, a configuration has been exemplified in which the lower ends of the rollers 11 protrude below the main body 10 even in the raised position, but when moving in the forward / backward or left / right direction, that is, when any of the rollers 11 is in contact with the ground, the unused rollers 11 can be raised to a storage position where they are stored inside the main body 10.

[0061] In the embodiment, an example is shown in which the forward / backward and left / right directions are checked based on the orientation of the transport cart 1, but by providing a lamp or the like on the side of the transport cart 1 to indicate the direction of movement and turning it on to reflect the setting of the control panel 3, it is possible to create a configuration in which the worker can easily and reliably understand the direction of movement when the travel switch 50 is operated.

[0062] The double lowering switch 51, double raising switch 52, front-rear movement switch 53, and left-right movement switch 54 of the operating device 5 can be configured to be illuminated, allowing the worker to grasp their current state. It is also assumed that these switches take a certain amount of time to change state after being operated. Therefore, for example, the double raising switch 52 can be configured to flash when operated and to remain lit continuously when both sides are raised, allowing the worker to grasp whether the state change has been completed.

[0063] In the embodiment, the configuration in which the operation device 5 and the control device 17 of the transporting carriage 1 are connected by wireless communication has been exemplified, but a configuration in which the connection is made by wired communication via the control panel 3 may also be used.

[0064] Although the embodiment illustrates a configuration in which two control panels 3 are used independently, it is also possible to configure the emergency switches of the control panels 3 to be linked together. As a result, even if control panels 3 are arranged, for example, on the front and back of the heavy object 2, the power supply to one control panel 3 can be cut off by operating the emergency stop switch 31 of the other control panel 3.

[0065] In the embodiment, an example of transporting the heavy object 2 with both sides raised is shown, but it is also possible to transport the heavy object 2 with the center of gravity lowered by slightly lowering the loading surface after placing the heavy object 2 on the loading surface.

[0066] The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0067] In the drawings, 1, 1A to 1D indicate a transport vehicle, 2 indicates a heavy load, 5 indicates an operating device, 10 indicates a main body, 11, 11A to 11D indicate rollers, 15 indicates a motor, and 17 indicates a control device.

Claims

1. a main body having a placement surface on which a heavy object to be transported is placed; a plurality of rollers provided below the mounting surface and capable of moving up and down in the vertical direction; a control device for controlling the position and movement of the roller; The control device changes the height of the loading surface by raising and lowering the rollers, and changes the direction of movement of the transport cart for heavy objects by raising and lowering the rollers to switch the contact state.

2. the rollers include at least two first rollers used when moving in a first movement direction and at least two second rollers used when moving in a second movement direction perpendicular to the first movement direction, 2. A transport vehicle for heavy objects as described in claim 1, wherein the control device changes the direction of movement by placing the first roller in a grounded state and the second roller in an ungrounded state when moving in the first movement direction, and by placing the second roller in a grounded state and the first roller in an ungrounded state when moving in the second movement direction.

3. 2. The transport vehicle for heavy loads according to claim 1, wherein, when changing the direction of movement, the control device first places all of the rollers in a ground contact state, and then switches the ground contact state of the rollers depending on the direction of movement.

4. 2. The transport vehicle for heavy loads according to claim 1, wherein the plurality of rollers are provided so as to be capable of ascending or descending simultaneously.

5. a motor provided to be movable between a drive position for driving the roller and a lifting position for lifting and lowering the roller; 2. The transport vehicle for heavy loads according to claim 1, wherein the control device moves the position of the motor to a drive position when driving the roller, and moves the motor to a lift position when lifting or lowering the roller.

6. 2. The transport vehicle for heavy loads according to claim 1, wherein the control device controls the positions and operations of the rollers in response to an operation from an operating device that operates a plurality of transport vehicles from a remote location.

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