transport vehicle

Abstract

A transport vehicle according to the invention for transporting objects comprises a base frame, a plurality of wheels for moving the transport vehicle on a floor, a drive unit for driving the wheels, and a receiving unit (1) for inductively receiving energy. The transport vehicle also comprises a lifting device by means of which the receiving unit (1) can be moved relative to the base frame between a lower end position and an upper end position in a vertical direction (Z). The lifting device has an electric cylinder (2) which comprises a cylinder block (22), a push rod movable relative to the cylinder block (22) in the vertical direction (Z), and an electric motor (21) for driving the push rod relative to the cylinder block (22).

Description

[0001] The invention relates to a transport vehicle for transporting objects, which comprises a base frame, a plurality of wheels for moving the transport vehicle on a floor, a drive unit for driving the wheels and a receiving unit for inductively receiving energy.

[0002] A generic transport vehicle for transporting objects is known from the publication DE 10 2020 002 676 B3. The transport vehicle has a plurality of wheels, a drive unit for driving the wheels, and an electrical energy storage device. The transport vehicle further has a receiving unit to which energy can be inductively transmitted from a charging unit, in particular from a linear conductor. The energy inductively transmitted to the receiving unit serves, for example, to charge an electrical energy storage device of the transport vehicle.

[0003] The charging unit is typically located in the floor over which the transport vehicle moves. For the inductive transmission of energy from the charging unit to the receiving unit, a relatively small distance is required between the charging unit and the receiving unit. If there are obstacles on the floor, such as stones, these can collide with the receiving unit when driving over them. This can damage the receiving unit.

[0004] DE 10 2012 022 479 A1 discloses a transport vehicle with a secondary winding for inductive energy absorption. The secondary winding is arranged on the top side of the vehicle.

[0005] A device for positioning and drilling crossbars is known from CN 1 15 194 473 A. The device comprises an induction plate that is slidably connected to a sliding frame.

[0006] CN 1 04 442 518 A describes an automated guided vehicle that can be automatically attached to work table surfaces of different heights. The autonomous vehicle features a liftable, load-bearing table surface.

[0007] The invention is based on the object of developing a transport vehicle for transporting objects.

[0008] The object is achieved according to the invention by a transport vehicle having the features specified in claim 1. Advantageous embodiments and further developments are the subject of the subclaims.

[0009] A transport vehicle according to the invention for transporting objects comprises a base frame, a plurality of wheels for moving the transport vehicle on a floor, a drive unit for driving the wheels, and a receiving unit for inductively receiving energy. In addition, the transport vehicle comprises a lifting device by means of which the receiving unit can be moved in a vertical direction relative to the base frame between a lower end position and an upper end position. The lifting device has an electric cylinder comprising a cylinder block, a push rod movable in the vertical direction relative to the cylinder block, and an electric motor for driving the push rod relative to the cylinder block.

[0010] If the ground is level and free of obstructions, the receiving unit is moved to its lower end position, where it is located in close proximity to the ground above a loading unit. There, the receiving unit is inductively coupled to the loading unit, and energy can be transferred from the loading unit to the receiving unit. The lifting device allows the receiving unit to be lifted, i.e. moved vertically away from the ground to its upper end position, when an obstacle, such as a stone, is detected. This prevents collisions and damage to the receiving unit. This increases safety during operation of the transport vehicle and reduces failure rates. The electric cylinder allows precise control of the vertical movement of the receiving unit relative to the base frame between its lower and upper end positions.

[0011] According to an advantageous embodiment of the invention, the lifting device comprises an upper frame and a lower frame. The upper frame is rigidly connected to the base frame, and the lower frame is rigidly connected to the receiving unit. A vertical movement of the lower frame relative to the upper frame thus corresponds to a vertical movement of the receiving unit relative to the base frame.

[0012] According to an advantageous embodiment of the invention, the upper frame is rigidly connected to the cylinder block and the electric motor, and the lower frame is rigidly connected to the push rod. When the electric motor drives the push rod vertically relative to the cylinder block, the receiving unit moves vertically relative to the base frame.

[0013] According to an advantageous embodiment of the invention, the lifting device comprises a plurality of guide rods extending in the vertical direction and connected to the lower frame in a displacement-proof manner. The guide rods are movable in the vertical direction relative to the upper frame. The guide rods form a linear guide for the lower frame during vertical movement relative to the upper frame.

[0014] According to an advantageous embodiment of the invention, the lower frame is arranged vertically below the upper frame. The lower frame is thus arranged vertically between the floor and the upper frame.

[0015] According to an advantageous embodiment of the invention, the lifting device has a lower sensor for detecting the lower end position of the receiving unit relative to the base frame in the vertical direction and an upper sensor for detecting the upper end position of the receiving unit relative to the base frame in the vertical direction. The end positions of the receiving unit can be detected by means of these two sensors, thereby controlling the electric motor of the electric cylinder.

[0016] According to an advantageous embodiment of the invention, the lifting device comprises a sheet metal part that is rigidly connected to the receiving unit. The lower sensor and the upper sensor are designed as inductive sensors for detecting the sheet metal part, and the lower sensor and the upper sensor are rigidly connected to the base frame. Thus, when the receiving unit moves vertically relative to the base frame, the sheet metal part also moves vertically relative to the sensors.

[0017] According to an advantageous embodiment of the invention, when the receiving unit is in the upper end position, the lower sensor and the upper sensor detect the sheet, and when the receiving unit is in the lower end position, none of the sensors detects the sheet, and when the receiving unit is in an intermediate position, only the lower sensor detects the sheet.

[0018] According to an advantageous embodiment of the invention, the lifting device has an ammeter for measuring the current flowing through the electric motor. Measuring the current flowing through the electric motor enables monitoring of the lifting device for stiffness.

[0019] According to an advantageous embodiment of the invention, the transport vehicle comprises an electrical energy storage device for supplying the drive unit and the lifting device, which can be supplied with electrical energy by the receiving unit.

[0020] According to an advantageous embodiment of the invention, the transport vehicle is designed as an autonomously driving transport vehicle and comprises a control device for controlling the drive unit and the lifting device.

[0021] The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0022] The invention will now be explained in more detail with reference to the accompanying drawings. The invention is not limited to the exemplary embodiments shown in the drawings. The drawings only represent the subject matter of the invention schematically. They show: Fig. 1: a perspective view of a lifting device for a transport vehicle.

[0023] Fig.Figure 1 shows a perspective view of a lifting device for a transport vehicle. The lifting device has an upper frame 5 and a lower frame 6. The lower frame 6 is movable relative to the upper frame 5 in a vertical direction Z. A transverse direction Y runs perpendicular to the vertical direction Z. A longitudinal direction X runs perpendicular to the vertical direction Z and perpendicular to the transverse direction Y.

[0024] A receiving unit 1 is arranged on the lower frame 6. The lower frame 6 is connected to the receiving unit 1 in a displacement-proof manner. The lower frame 6 is arranged below the upper frame 5 in the vertical direction Z. The lower frame 6 is arranged between the receiving unit 1 and the upper frame 5 in the vertical direction Z.

[0025] The lifting device has several, in this case four, guide rods 3, which extend in the vertical direction Z. The guide rods 3 are connected to the lower frame 6 in a displacement-proof manner. The guide rods 3 are thus also connected to the receiving unit 1 in a displacement-proof manner. The guide rods 3 are movable relative to the upper frame 5 in the vertical direction Z. The guide rods 3 extend through the upper frame 5.

[0026] The lifting device comprises an electric cylinder 2. The electric cylinder 2 comprises a cylinder block 22 and a push rod movable relative to the cylinder block 22 in the vertical direction Z. The push rod is located partially within the cylinder block 22 and partially protrudes from the cylinder block 22. The electric cylinder 2 also comprises an electric motor 21 for driving the push rod relative to the cylinder block 22 in the vertical direction Z.

[0027] The upper frame 5 is fixedly connected to the cylinder block 22 and to the electric motor 21. The lower frame 6 is fixedly connected to the push rod. When the electric motor 21 drives the push rod out of the cylinder block 22, the lower frame 6 moves away from the upper frame 5 in the vertical direction Z. When the electric motor 21 drives the push rod into the cylinder block 22, the lower frame 6 moves closer to the upper frame 5 in the vertical direction Z.

[0028] The transport vehicle, not shown here, is used to transport objects. The transport vehicle in this case is an autonomous vehicle. The transport vehicle is located on a level surface.

[0029] The transport vehicle comprises a base frame. The base frame has an approximately rectangular cross-section and extends primarily in the longitudinal direction X and the transverse direction Y. The longitudinal direction X corresponds at least approximately to the usual direction of travel of the transport vehicle.

[0030] The longitudinal direction X and the transverse direction Y represent horizontal directions and run parallel to the ground on which the transport vehicle is located. Any direction perpendicular to the vertical direction Z represents a horizontal direction. The vertical direction Z is perpendicular to the flat ground.

[0031] The transport vehicle comprises several wheels that are rotatable relative to the base frame. The wheels allow the transport vehicle to move along the ground. In this case, the transport vehicle comprises two front wheels that are offset from each other in the transverse direction Y, and two rear wheels that are offset from each other in the transverse direction Y. The front wheels are offset from the rear wheels in the longitudinal direction X.

[0032] When the transport vehicle travels in the usual direction of travel, i.e., in the longitudinal direction X, the wheels rotate about axes of rotation that run in the transverse direction Y. When the transport vehicle corners, for example, the axes of rotation of the front wheels are pivoted about a pivot axis running in the vertical direction Z. The axes of rotation of the front wheels then run in a horizontal direction that is inclined relative to the longitudinal direction X and relative to the transverse direction Y.

[0033] The transport vehicle comprises a drive unit for driving the wheels. The transport vehicle also includes an electrical energy storage device for supplying the drive unit and a control unit for controlling the drive unit. The drive unit comprises, for example, a traction motor and a transmission and drives some or all of the wheels. The transport vehicle also has a steering device (not shown here) for steering the wheels. The steering device can also be controlled by the control unit.

[0034] The transport vehicle also includes the lifting device shown here. The upper frame 5 of the lifting device is rigidly connected to the base frame of the transport vehicle. For example, the upper frame 5 is bolted to the base frame 12.

[0035] The electrical energy storage device also serves to supply the lifting device, in particular to supply the electric motor 21 of the electric cylinder. The control unit also serves to control the lifting device, in particular to control the electric motor 21 of the electric cylinder.

[0036] The transport vehicle also includes the receiving unit 1, which is attached to the subframe 6 of the lifting device. Energy can be inductively transferred to the receiving unit 1 from a charging unit. The energy inductively transferred from the charging unit to the receiving unit 1 is used, for example, to charge the electrical energy storage device of the transport vehicle. By means of the lifting device, the receiving unit 1 can be moved relative to the base frame in the vertical direction Z.

[0037] The receiving unit 1 comprises a transmitter head having a secondary coil. The charging unit is designed, for example, as a current-carrying primary conductor laid in the ground beneath the transport vehicle. The charging unit is also designed, for example, as a current-carrying primary coil laid in the ground beneath the transport vehicle. The charging unit is arranged close to the ground surface. The secondary coil of the transmitter head of the receiving unit 1 can be inductively coupled to the charging unit.

[0038] When the lower frame 6 moves away from the upper frame 5 in the vertical direction Z, the receiving unit 1 moves downward in the vertical direction Z, i.e., toward the ground. When the lower frame 6 approaches the upper frame 5 in the vertical direction Z, the receiving unit 1 moves upward in the vertical direction Z, i.e., away from the ground.

[0039] When the electric motor 21 drives the push rod out of the cylinder block 22, the receiving unit 1 moves downward in the vertical direction Z, i.e., toward the ground and away from the base frame. When the electric motor 21 drives the push rod into the cylinder block 22, the receiving unit 1 moves upward in the vertical direction Z, i.e., away from the ground and toward the base frame.

[0040] By means of the lifting device, the receiving unit 1 can thus be moved relative to the base frame between a lower end position and an upper end position in the vertical direction Z.

[0041] In the lower end position, the distance between the base frame and the receiving unit 1 in the vertical direction Z is at its maximum. The receiving unit 1 is thus located in the immediate vicinity of the floor, in particular above a charging unit located there. The receiving unit 1 is arranged such that the secondary coil is inductively coupled to the charging unit. Thus, energy can be transferred from the charging unit to the receiving unit 1.

[0042] In the upper end position, the distance between the base frame and the receiving unit 1 in the vertical direction Z is minimal. The receiving unit 1 is thus at its maximum distance from the ground. The transport vehicle thus has maximum ground clearance.

[0043] The lifting device has a lower sensor 41 for detecting the lower end position of the receiving unit 1 relative to the base frame in the vertical direction Z. The lower sensor 41 is designed as an inductive sensor. The lower sensor 41 is fixedly connected to the base frame and to the upper frame 5.

[0044] The lifting device has an upper sensor 42 for detecting the upper end position of the receiving unit 1 relative to the base frame in the vertical direction Z. The upper sensor 42 is designed as an inductive sensor. The upper sensor 42 is fixedly connected to the base frame and to the upper frame 5.

[0045] The lifting device has a plate 45, which is non-displaceably connected to the receiving unit 1 and to the subframe 6. The plate 45 is detectable by the lower sensor 41 and the upper sensor 42.

[0046] When receiving unit 1 is in the upper end position, the lower sensor 41 and the upper sensor 42 detect the sheet 45. When receiving unit 1 is in the lower end position, none of the sensors 41, 42 detect the sheet 45. When receiving unit 1 is in an intermediate position, only the lower sensor 41 detects the sheet 45.

[0047] When the electric motor 21 drives the push rod in the direction out of the cylinder block 22 and the receiving unit 1 moves downwards in the vertical direction Z, a lower target current flows through the electric motor 21 if the lifting device is intact.

[0048] When the electric motor 21 drives the push rod in the direction into the cylinder block 22 and the receiving unit 1 moves upwards in the vertical direction Z, an upper target current flows through the electric motor 21 if the lifting device is intact.

[0049] The lifting device has an ammeter for measuring the current flowing through the electric motor 21. Measuring the current flowing through the electric motor enables monitoring of the lifting device, particularly for stiffness.

[0050] If the ammeter measures a current flowing through the electric motor 21 which is greater than the respective target current, the lifting device is difficult to move, for example, one of the guide rods 3 is bent.

[0051] If the ammeter measures a current flowing through the electric motor 21 which is smaller than the respective target current, the receiving unit 1 is not present, for example. List of reference symbols 1 receiving unit 2 electric cylinders 3 guide rod 5 upper frame 6 subframes 21 Electric motor 22 cylinder block 41 lower sensor 42 upper sensor 45 sheet metal X Longitudinal direction Y transverse direction Z vertical direction

Claims

[1] Transport vehicle for transporting objects, comprising a basic frame, a plurality of wheels for moving the transport vehicle on a floor, a drive unit to drive the wheels and a receiving unit (1) for inductive absorption of energy, characterized by , that the transport vehicle includes a lifting device, by means of which the receiving unit (1) is movable relative to the base frame between a lower end position and an upper end position in a vertical direction (Z), and that the lifting device has an electric cylinder (2) which a cylinder block (22), a push rod movable relative to the cylinder block (22) in the vertical direction (Z) and an electric motor (21) for driving the push rod relative to the cylinder block (22). [2] Transport vehicle according to claim 1, characterized bythat the lifting device (10) has an upper frame (5) and a lower frame (6), and that the upper frame (5) is connected to the base frame in a displaceable manner, and that the lower frame (6) is connected to the receiving unit (1) in a displaceable manner. [3] Transport vehicle according to claim 2, characterized by , that the upper frame (5) is connected to the cylinder block (22) and to the electric motor (21) in a displacement-proof manner, and that the subframe (6) is connected to the push rod in a displacement-proof manner. [4] Transport vehicle according to one of claims 2 to 3, characterized by that the lifting device has a plurality of guide rods (3) which extend in the vertical direction (Z) and which are connected to the lower frame (6) in a displacement-proof manner, and that the guide rods (3) are movable relative to the upper frame (5) in the vertical direction (Z). [5] Transport vehicle according to one of claims 2 to 4, characterized bythat the lower frame (6) is arranged in the vertical direction (Z) below the upper frame (5). [6] Transport vehicle according to one of the preceding claims, characterized by , that the lifting device has a lower sensor (41) for detecting the lower end position of the receiving unit (1) relative to the base frame in the vertical direction (Z) and an upper sensor (42) for detecting the upper end position of the receiving unit (1) relative to the base frame in the vertical direction (Z). [7] Transport vehicle according to claim 6, characterized by , that the lifting device has a plate (45) which is connected to the receiving unit (1) in a displacement-proof manner, and that the lower sensor (41) and the upper sensor (42) are designed as inductive sensors for detecting the sheet (45), and that the lower sensor (41) and the upper sensor (42) are connected to the base frame in a displacement-proof manner. [8] Transport vehicle according to claim 7, characterized by , that when the receiving unit (1) is in the upper end position, the lower sensor (41) and the upper sensor (42) detect the sheet (45), and that when the receiving unit (1) is in the lower end position, none of the sensors (41, 42) detects the sheet (45), and that When the receiving unit (1) is in an intermediate position, only the lower sensor (41) detects the sheet (45). [9] Transport vehicle according to one of the preceding claims, characterized by that the lifting device has an ammeter for measuring a current flowing through the electric motor (21). [10] Transport vehicle according to one of the preceding claims, characterized by , that the transport vehicle comprises an electrical energy storage device for supplying the drive unit and the lifting device, which can be supplied with electrical energy by the receiving unit (1). [11] Transport vehicle according to one of the preceding claims, characterized by , that the transport vehicle is designed as an autonomously driving transport vehicle and a control device for controlling the drive unit and the lifting device.

Images