INLOADER WITH GATE LOCKING

Description

[0001] The invention relates to an inloader according to the preamble of claim 1 and a method for closing a door on an inloader.

[0002] An inloader is a special type of semi-trailer that allows particularly tall or wide items of cargo to be transported upright between the wheels. For this purpose, the wheels are not connected to each other by continuous axles, but are spring-mounted on independent wheel swing arms on a longitudinal frame profile. The left and right frame profiles are formed by a steel construction that is connected at the front end and has an opening at the rear end, resulting in a U-shaped construction that, when viewed from above, has the shape of a tuning fork without a handle. The U-shaped construction forms a loading space that is open to the rear and can usually be closed with a gate. This can be used, for example, to transport large panes of glass or prefabricated concrete elements.

[0003] An inloader of the type described in the preamble is known from DE 37 40 491 A1. The inloader comprises a rear door pivoted about door hinges. To facilitate closing the door, the door has a centering device formed by conical notches. When the door is closed, the conical notches engage in corresponding recesses located in the chassis or in the ends of the frame longitudinal members. This ensures centering when the door is closed.

[0004] However, when the gate is open, the U-shaped vehicle frame is relatively unstable and can twist, especially when the vehicle is parked on uneven ground. To a certain extent, the adjustment device can compensate for minor twisting movements in the vehicle frame using its conical notch and corresponding recess.

[0005] However, since the vehicle frame is not sufficiently stabilized when the gate is open, under unfavorable conditions, particularly on very uneven ground, the distortion in the vehicle frame can be so great that the conical notches attached to the gate have such a large difference in height relative to the recesses in the vehicle frame that the tips of the notches do not slide into the recesses when the gate is closed, but instead strike the vehicle frame surrounding the recesses. This means that the gate cannot be locked.

[0006] The object of the invention is to eliminate the disadvantages described and to propose an inloader in which the door can be closed and locked easily and safely even under unfavourable conditions, in particular on uneven ground.

[0007] This object is achieved by an inloader having the features of claim 1.

[0008] The inloader has a U-shaped vehicle frame aligned longitudinally with two legs, on which a support device for a transport frame can be arranged. A loading shaft is arranged between the legs, which can be closed by a gate.

[0009] The gate is pivotally mounted on one of the legs on a first outer side of the vehicle frame by means of a hinge device, which may comprise one or more hinges. On a second outer side, the gate comprises at least one centering device that coincides with a receptacle mounted on the other leg of the vehicle frame and, when the gate is closed, aligns the gate relative to said other leg in a closed position.

[0010] The legs of the vehicle frame, and thus the vehicle frame as a whole, are each supported by at least one, preferably several, wheels. The wheels are coupled to the vehicle frame via a wheel suspension. The wheel suspensions are individually or jointly height-adjustable using a lifting device provided on the legs.

[0011] The gate located at the opening of the U-shaped vehicle frame serves various functions, primarily to close the loading bay and stabilize the U-shaped vehicle frame. In order for the gate to lock, the centering elements on the gate and the vehicle frame must be aligned at least sufficiently so that they can slide into each other when the gate is pivoted.

[0012] The chassis of the inloader features a lifting device that allows the suspensions on the left and right sides of the vehicle to be controlled separately. This allows uneven ground to be compensated for by raising the chassis on one or both sides, and the components of the centering device and the support to be aligned. The lifting devices can be operated manually if necessary.

[0013] The inloader according to the invention further comprises at least one sensor device that detects the position of the centering device relative to the position of the receptacle. The position data detected by the sensor device can be displayed manually or electronically and serve as a guide for an operator when manually operating the lifting device and aligning the centering device with the receptacle. This facilitates closing the door.

[0014] The sensor device can be a mechanical indicator or an electronic device. A suitable mechanical sensor could be, for example, a rod sensor attached to the door, whose deflection indicates the relative position of the centering device and the holder. An electronic sensor could be an electronic distance or angle sensor. Therefore, various types of sensors are suitable. It is essential that the sensor is capable of detecting the relative position difference between the centering device attached to the door and the holder attached to the vehicle frame.

[0015] In a preferred embodiment, the inloader comprises a control device, preferably a microcontroller, in which the positions of the centering device and the receptacle can be set relative to one another. The control device can be part of a central control device provided for the inloader, but it can also be a separate control device, for example, part of a retrofit kit. Such a retrofit kit comprises all the components required for a centering system and is used to convert an inloader initially equipped with a conventional door closing mechanism.

[0016] The advantage of using a control device lies in the fact that it enables communication with the aforementioned sensor device and can, for example, compare the actual position data transmitted by the sensor device with predefined target data for closing the door stored in the control system. Based on such a comparison, automatic control of the lifting device and overall automated alignment of the door to the vehicle frame are also possible.

[0017] The centering device provided on the door is preferably conical, for example, wedge-shaped, or designed as a cone. The mount provided on the vehicle frame is adapted to the contour of the centering device and can, for example, be designed in the form of a conical pocket. Of course, a reverse arrangement is also possible, i.e., attaching the centering device to the vehicle frame and attaching the mount to the door.

[0018] The parts of the centering system that are related to each other are self-centering within a certain range, so that small positional deviations between the door and the vehicle frame are compensated for when the door is closed.

[0019] Preferably, the inloader further comprises a locking device for the door to be closed, by means of which the door can be fixed in a closed position. This is particularly advantageous when the door is closed using a hydraulic cylinder. While the hydraulic cylinder is generally capable of keeping the door closed, there is a risk that the door will swing open unintentionally in the event of a malfunction in the hydraulic system, particularly in the event of a pressure drop. The locking device thus additionally secures the closed position of the door.

[0020] The inloader can further comprise a mechanical closing device by means of which the locking device of the door can be closed. The mechanical closing device preferably has a hydraulically, pneumatically, or electrically driven lifting cylinder that performs the pivoting movement of the door. The corresponding control commands can be transmitted from the control device to the closing device, in particular to its lifting cylinder. In simple terms, the locking device can thus be closed at the push of a button. For example, a catch hook integrated into the closing device engages a round tube provided on the door when the door is already largely closed and pulls the door towards the rear of the vehicle. The centering device provided on the door is thereby drawn into the receptacle provided on the vehicle frame.

[0021] The gate can generally be pivoted from the open to the closed position manually. However, similar to mechanical or automated locking of the gate, it is also possible to pivot the gate mechanically and / or automatically using a lifting cylinder. In this case, the gate as a whole can also be coupled to the vehicle frame via a lifting cylinder, which can be hydraulically, pneumatically, or electrically driven.

[0022] In a preferred embodiment, a radar device, an ultrasonic device, or a lidar sensor device is provided as the sensor device. Using these sensors, distances and / or separations can be detected optically or acoustically or using electromagnetic waves with millimeter precision. In particular, the sensor device can be used to determine the relative height difference between the centering device, for example a cone, and the receptacle, for example a conical pocket. For this purpose, one sensor can be arranged, for example, on the outside of the door and another sensor on a cover panel provided on the vehicle frame. The relative height difference can then be determined via two measuring sections monitored by the sensors and the difference between them.

[0023] The object of the invention is also achieved by a method for closing a door on an inloader.

[0024] In such a method, the position of the centering device provided on the door relative to the position of the holder attached to the vehicle frame is first detected by suitable sensors with the door open and transmitted to the control device. Based on the transmitted sensor data, the control device determines at least one actual distance value, preferably a vertical actual distance value, between the positions of the centering device and holder and compares it with predefined target values stored in the control device. The determined actual distance value forms the basis for a control signal that is transmitted by the control device to the at least one lifting device of a wheel of the inloader for raising or lowering. As a result, one of the legs of the U-shaped vehicle frame is raised or lowered and the actual distance value between the centering device and holder is reduced.The measurements and adjustment movements can be part of a control loop in which the actual distance value is continuously compared with the setpoint value and a continuous readjustment takes place until the actual value corresponds to the setpoint value or is within a predefined tolerance range.

[0025] The advantage of this method is, among other things, that an operator can swing the gate into the closed position alone without having to worry about the alignment of the gate relative to the vehicle frame.

[0026] In a preferred embodiment of the method, the centering device of the gate is first brought into close proximity to the receiver, the locking of the gate is activated by means of a start signal, the determination of the positions of the centering device and receiver is carried out continuously after activation, the control signal for raising or lowering the lifting device is integrated into a control circuit.

[0027] As a result, when the locking device is activated to lock the gate, the centering device is automatically threaded into the holder.

[0028] In a special embodiment, the determination of the positions of the centering device and the holder is only activated when a predefined horizontal distance between the centering device and the holder is exceeded. A correction of the actual vertical distance value is particularly interesting when the centering device is relatively close to the holder and thus only occurs during the final section of the door's pivoting movement. If the vertical distance is too great during this phase of the door's pivoting movement, the centering device cannot slide into the holder. The actual horizontal distance value, below which the position data is determined, is preferably less than twenty centimeters, most preferably less than 10 centimeters.This late activation when the gate is pivoting also increases work safety because it ensures that the lifting device is not activated when the gate is already wide open.

[0029] Further measures improving the invention are presented in more detail below with the description of preferred embodiments of the invention with reference to the figures.

[0030] The figures show: Fig. 1 shows an inloader in a perspective view from the rear with the door open; Fig. 2 shows the inloader according to Fig. 1 in a side view with the gate closed; Fig. 3 shows a section of Fig. 2 in an enlarged view; Fig. 4 shows a partial area of the door and the inloader rear area in an enlarged perspective view diagonally from the rear with the lock open; Fig. 5 shows the partial area of the door and rear area according to Fig. 4with hooked locking mechanism; Fig. 6 shows the section of the gate and rear area according to Fig. 5 with a view of the released locking device of the gate; Fig. 7 shows a section of the vehicle rear with a view of the locking device of the gate.

[0031] Identical or similar elements may be provided with identical or similar reference numerals in the following figures. Furthermore, the figures of the drawing, their description, and the claims contain numerous features in combination. A person skilled in the art will appreciate that these features can also be considered individually or combined to form further combinations not described in detail here. The invention extends only to those embodiments which are given by combinations of features from explicit references to the claims. The exemplary embodiments illustrated in the figures are therefore merely descriptive and are not intended to limit the invention in any way.

[0032] The terms "upper", "top", "lower", "left" or "right" used below refer to the arrangement of the components of an inloader standing on a solid surface as shown in the drawing.

[0033] Fig. 1 shows an inloader 100 in a perspective view obliquely from the rear. The inloader 100 comprises a U-shaped vehicle frame 10 aligned in the vehicle's longitudinal direction R with two legs 11, 12 between which a loading shaft 13 is arranged. The rear end of the inloader, viewed in a direction of travel F, forms an open vehicle rear 42 with a loading opening 43 that can be closed by means of a gate 15. In the illustrated embodiment, a carrying device 13 for receiving a transport frame (not shown) for transporting large-format components is located in the lower region of the legs 11, 12.

[0034] In the illustrated embodiment, the gate 15 is coupled on its first outer side 16 to the leg 11 of the vehicle frame 10 by means of two hinges 18. On a second outer side 17, the gate 15 has a handle 41, which is provided to facilitate the manual opening and closing of the gate 15 by an operator.

[0035] In the illustrated embodiment, the gate 15 is in an open position P2, in which two centering devices 20, formed by two cones 19, are already pointing toward two receptacles 30 but are not yet immersed in them. The receptacles 30 are formed by conical pockets 29, the shape of which is adapted to the shape of the cones 19.

[0036] If the gate 15 is in a closed position P1 (cf. Fig. 2), it can be locked with a locking device 24. In order to close the gate 15, it is first pivoted manually close to the rear end of the leg 12 until it reaches the access area of a locking device 24. The locking device 24 comprises a handle 39, by means of which a holding hook 46 provided on the locking device 24 can be pivoted into a closed position in which it engages around a round tube 50 provided on the gate 15. Once the holding hook 46 is in the closed position, the locking device 24 as a whole, and thus also the gate 15, can be raised or lowered via a lifting cylinder 40 (cf. Fig. 7 ) can also be pulled towards the leg 12 in the closed position.

[0037] In order to hold the gate 15 securely in the closed position P1, a blocking device is provided which can be operated by means of a handle 39 and, when activated, prevents the opening of the locking device 24 - and thus also the opening of the gate 15.

[0038] Fig. 2 shows the inloader according to Fig. 1 in a side view. The vehicle frame 10 is supported by wheels 21. The wheels 21 are coupled to the vehicle frame 10 via wheel suspensions 22 and can be pivoted by means of lifting devices 23. The lifting device 23 comprises lifting cylinders 44, which implement the pivoting movement and selectively raise or lower the vehicle frame 10.

[0039] The internal charger further comprises a control device 26 with a microcontroller 27 (cf. Fig. 3, Detail D). The control device 26, which in the illustrated embodiment is arranged in a central region of the vehicle frame 10, serves to evaluate sensor data and to issue control commands to the lifting device 23 and, if necessary, also to a locking device 28.

[0040] Fig. 4shows a partial area of the door 15 and leg 12 of the inloader 100 in an enlarged perspective view obliquely from the rear with the locking device 24 open. A sensor device 25 is provided to determine the orientation of the cones 19 with respect to the cone pockets 29. The sensor device 25 comprises a transmitter 37 arranged at the rear end of the leg 12 and two receivers 36, 36' arranged in the area of the outer side 17 of the door 15. In the illustrated embodiment, the sensor device operates on the basis of ultrasonic waves that are emitted by the transmitter 37 obliquely upwards and downwards in the direction of the receivers 36, 36'. Of course, it would also be possible to reverse the arrangement by arranging one or more transmitters 37 on the door 15 and one or more receivers 36 at the rear end of the leg 12.

[0041] The distance between transmitter 37 and receiver 36 is referred to as the measuring section. A first measuring section 47 extends diagonally upwards from the transmitter 37 to the receiver 36, and a second measuring section 47' extends diagonally downwards from the transmitter 37 to the receiver 36'. By determining the measuring sections 47, 47' between the sensor 37 and the receiver 36, a position PZ of the centering device 20 relative to a position PA of the holder 30 can be determined. A sensor control ensures that the two measuring sections 47, 47' are switched alternately and that only one receiver 36, 36' can receive the signals emitted by the transmitter 37 at a time. This ensures that there is no overlap of signals and that the measuring sections 47, 47' are clearly defined.

[0042] The measuring distances 47, 47' determined by the sensor device 25 are transmitted to the control device 26 and serve as the basis for calculating an actual distance value A between the cone 19 and the conical pocket 29. For example, it can be provided that the actual distance value A extends from a coordinate center point 34 of the cone 19 to a coordinate center point 35 of the conical pocket 29. The coordinate center point 34 is defined by the intersection point of a central axis 32 of the cone 19 with the plane of the cone base. Analogously, the coordinate center point 35 is defined by the intersection point of a central axis 33 of the conical pocket 29 with the outer opening plane of the conical pocket 29. The actual distance value A can be broken down into a horizontal actual distance value AH and a vertical actual distance value AV.

[0043] The actual distance values AV in the vertical direction and AH in the horizontal direction determined by the control device are compared with predefined target values stored in a data memory of the control device. If the specified actual distance values lie within a likewise predefined tolerance range, it can be concluded that, as the pivoting movement of the gate 15 continues, a cone tip 31 located at the front end of the cone 19 moves into the cone pocket 29 and does not collide with the vehicle frame 10 next to an edge 45 surrounding the cone pocket 29.

[0044] If the actual vertical distance value AV lies outside the predefined tolerance range, the cone tip 31 is on a collision course with the vehicle frame 10. In this case, one of the legs 11, 12 is raised or lowered as needed using the lifting device 23. This changes the actual distance value AV, and the current actual value can then be compared with the predefined target value. If necessary, one of the legs 11, 12 is raised again. This process is repeated until the actual distance value AV lies within the predefined tolerance range and the gate 15 can be closed.

[0045] Analogous to a check of the vertical distance actual value AV, a check of the horizontal distance actual value AH is also possible. The horizontal distance actual value AH can be used to control the activation of the lifting device 23. For example, it can be provided that the lifting device 23 can only be activated when the horizontal distance actual value AH falls below a predefined value. Simply put, the lifting device should not operate continuously, but only when the gate 15 has already moved close to its closing position P1.

[0046] The Figures 5 to 7show the functioning of the locking device 28. The locking device 28 comprises a rotary shaft 48, the locking device 24 with the retaining hook 46 and the handle 39, the safety lever 38 and a lifting cylinder 40. The rotary shaft 48 is located on the inside of the leg 12 of the vehicle frame 10. The lifting cylinder 40, in this case a hydraulic cylinder, and the locking device 24 are coupled to the rotary shaft 48. If the lifting cylinder 40 extends, the rotary shaft 48 rotates and the locking device 24 moves towards a cover panel 49 located at the end of the leg 12. In order to lock the gate 15, it is closed manually until the retaining hooks 46 can be placed around the vertical round tube 50 arranged on the gate 15.If the gate locking mechanism is now activated by means of the control device 26, it pulls the gate 15 with its cones 19 into the cone pockets 29 towards the leg 12 and the gate 15 is locked.

[0047] Below is an example of an opening and closing process explained in detail: Opening the gate The locking device 24 is manually unlocked by pivoting the safety lever 38 into a horizontal position. This moves a locking lever resting on the rotary shaft 48 away from the rotary shaft 48 and the rotary shaft 48, which was previously blocked against rotation, is released for rotational movements. The hydraulic locking devices 24 are actuated: o The piston rod of the lifting cylinder 40 retracts. ∘ The piston rod is coupled to the rotary shaft 48 via first levers. ∘ The first levers are coupled, preferably welded, to the rotary shaft 48 at their end facing away from the piston rod. ∘ When the piston rod extends, a torque is transmitted to the rotary shaft 48 via the first levers. ∘ The rotary shaft 48 rotates counterclockwise. ∘ Two further levers are coupled, preferably welded, to the rotary shaft 48.∘ Because the rotating shaft 48 rotates counterclockwise, the second levers are also rotated counterclockwise. ∘ The second levers are coupled to the retaining hook 46. ∘ The retaining hook 46 has a hook-shaped contour on its other side. In the closed position, the hook-shaped contour engages around a round tube 50 attached to the gate 15. ∘ When the rotating shaft 48 is turned counterclockwise, the second levers are also pivoted counterclockwise and the retaining hook 46 is moved away from the round tube 50. ∘ The coupling point at which the second lever is coupled to the retaining hook 46 also forms a rotation axis. To prevent the retaining hook 46 from rotating into an undefined position around the rotation axis of the coupling point, it is also spring-loaded. ∘ When the retaining hook 46 has moved away from the rotating shaft 50, the gate 15 can perform a rotating movement around the hinge 18.For this purpose, the retaining hook 46 must be displaced in a direction R1 so far that the round tube 50 of the gate 15 can be guided past the retaining hook 46 during the pivoting movement of the gate 15 without the retaining hook 46 colliding with the round tube 50. The pivoting movement of the gate 15 is carried out manually by an operator grasping a handle 41 attached to the gate 15 and pivoting the gate 15 open.

[0048] Closing the gate The gate 15 is manually pivoted by an operator towards the rear of the vehicle 42. The gate 15 is manually pivoted until the tips of the centering device 20, for example a conical tip 31, are at a distance of 0 mm to 80 mm, preferably 10 mm to 30 mm, from an outer plane E of the receptacle 30. An automatic closing device coupled to the control device 26 is actuated, thereby starting a control loop: ∘ The transmitter 37 of the sensor device 25 attached to the rear of the vehicle 42 sends at least one signal to one, preferably several, receivers 36, 36' attached to the gate 15. ∘ A distance extending from the transmitter 37 to the receiver 36, 36' is detected as a measuring distance 47, 47' and transmitted to the control device 26 or its microcontroller 27.∘ In the microcontroller, the position PZ of the centering device 20 relative to the position PA of the holder 30 and a current actual distance value A from the centering device 20 to the holder 30 are determined on the basis of the measuring sections 47, 47'. The current actual distance value A is composed of a horizontal actual distance value AH and a vertical actual distance value AV. o A coordinate center point 34 provided on the centering device 20 and a coordinate center point 35 provided on the holder 30 can be used as base values. ∘ At least one predefined target value for the distance between the centering device 20 (for example a cone 19) and the holder 30 (for example a conical pocket 29) is stored in the microcontroller 27. The target distance value relates to a horizontal target distance value and / or a vertical target distance value.∘ If the actual vertical distance value AV is greater than the desired vertical distance value, a control signal is transmitted from the control system to the lifting device 23 of the wheel suspension 22 and the vehicle frame 10 is either raised or lowered slightly on the leg to which the locking device 24 is also attached, depending on the requirements and the resulting control command. ∘ In a simple embodiment, a one-time control signal is transmitted to the lifting device 23 and the leg 11, 12 of the vehicle frame is pivoted once so that the holder 30 and the centering device 20 are in the predefined desired position relative to one another. ∘ In a preferred embodiment, the measurement of the actual distance values A and the raising / lowering of the vehicle frame 10 are integrated into a control loop.It is therefore possible: either after each lifting / lowering movement of the vehicle frame leg 11, 12, a further measurement of one or more actual distance values A is carried out until the measurement data of the current actual distance values AV and / or AH determined by the sensor device 25 have reached the specified target value, or to carry out measurements continuously during the lifting / lowering movement, wherein a corresponding control program is designed in such a way that the current actual distance values A are continuously determined in the smallest time units, for example twenty times per second, until the current actual distance values AV and / or AH have reached the specified target value.∘ After the vehicle frame leg 11, 12 has been raised / lowered or, if a control loop is provided, after an actual distance value AV measured by the sensor device 25 corresponds to the predefined target value, the control device 25 sends a command to the lifting cylinder 40 of the locking device 28 to initiate rotation of the rotary shaft 48. ∘ The rotary shaft 48 is rotated clockwise by the lifting cylinder 40. ∘ By rotating the rotary shaft 48, a movement is transmitted to the locking device 24 and the retaining hook 46. ∘ The kinematics are designed such that the retaining hook 46 of the locking device engages the round tube 50 of the door 15 and pulls it towards the vehicle rear 42 of the inloader 100.∘ Fine adjustment is carried out in that the cone 19 provided on the gate 15 engages in the conical pocket 29 provided on the vehicle rear 42 and the cone tip 31 slides along the outer wall of the conical pocket 29 until the cone 19 is finally received in the conical pocket 29 with a form-fitting fit and the gate 15 is in the closed position P1. ∘ The gate 15 is thus held in the closed position P1 by the lifting cylinder 40. To prevent the gate 15 from opening in the event of a pressure drop, the manual safety lever 38 is also actuated. The manual safety lever 38 is coupled to a safety element that engages in the rotating shaft 48 or on the rotating shaft 48, so that the rotation of the rotating shaft 48 is mechanically blocked. Even in the event of a pressure drop in the lifting cylinder 40, the rotating shaft 48 and thus the gate 15 as a whole are held in the closed position P1. .

[0049] The height adjustment of the vehicle frame is preferably performed in conjunction with the closing of the door. However, it can also be performed independently, for example, to align the vehicle frame in an optimal position for loading when the door is open. List of reference symbols

[0050] 10Vehicle frame 11Leg (of 10) 12Leg (of 10) 13Loading shaft 14Carrying device 15Gate 16First outer side (of 15) 17Second outer side (of 15) 18Hinge 19Cone 20Centering device 21Wheels 22Wheel suspension 23Lifting device 24Locking device 25Sensor device 26Control device 27Microcontroller 28Closing device 29Cone pocket 30Receiver 31Cone tip 32Central axis (of 20) 33Central axis (of 30) 34Coordinate center point (of 20) 35Coordinate center point (of 30) 36, 36'Receiver 37Transmitter 38Safety lever (for 28) 39Handle (on 24) 40Lifting cylinder (of 28) 41Handle (on 15) 42Rear of vehicle 43Loading opening 44Lifting cylinder (of 23) 45Rim (of 29) 46Holding hook 47, 47'Measuring section 48Rotary shaft (of 28) 49End panel 50Round tube 100 inloaders AActual distance value AHhorizontal actual distance value AVvertical actual distance value DDetail EPlane (of 30) FDirection of travel P1Closed position (of 15) P2Open position (of 15) PAPosition (of 30) PZPosition (of 20) RVehicle longitudinal direction R1Direction

Claims

1. Internal loader (100) with a U-shaped vehicle frame (10) directed in the longitudinal direction (R) of the vehicle and having two limbs (11, 12) and a loading shaft (13) arranged between the limbs (11, 12), which can be closed by a gate (15), wherein the gate (15) - is pivotably attached to one of the limbs (11, 12) on a first outer side (16) by means of a hinge (18), - on a second outer side (17) comprises at least one centring device (20), which coincides with a receptacle (30) attached to the other of the limbs (11, 12) and, when the gate (15) is closed, aligns the gate (15) with respect to the said other limb (11, 12) in a closed position (P1), and wherein the limbs (11, 12) are each carried by at least one, preferably several, running wheels (21) with a wheel suspension (22), characterised in that the wheel suspensions (22) are individually or jointly height-adjustable by means of a lifting device (23) on the limbs (11, 12) and at least one sensor device (25) is provided which detects a position (PZ) of the centring device (20) relative to a position (PA) of the receptacle (30).

2. Internal loader (100) according to claim 1, characterised in that a control device (26), preferably a microcontroller (27), is provided, in which the positions (PZ) of the centring device (20) and (PA) of the receptacle (30) can be set in relation to one another.

3. Internal loader (100) according to one of claims 1 or 2, characterised in that the centring device (20) is a cone (19) and the receptacle (30) is a conical pocket (29).

4. Internal loader (100) according to one of claims 1 to 3, characterised in that a locking device (24) is provided, by means of which the gate (15) can be fixed in the closing position (P1).

5. Internal loader (100) according to one of claims 1 to 4, characterised in that the locking device (24) can be closed by means of a mechanical closing device (28), wherein the closing device (28) preferably comprises a hydraulically, pneumatically or electrically driven lifting cylinder (40).

6. Internal loader (100) according to one of claims 1 to 5, characterised in that the gate (15) can be closed by means of a mechanical closing device, the closing device preferably comprising a hydraulically, pneumatically or electrically driven lifting cylinder.

7. Internal loader (100) according to one of claims 1 to 6, characterised in that a radar device, an ultrasonic device or a lidar sensor device is provided as the sensor device (25).

8. Method for closing a gate (15) on an internal loader (100) according to one of claims 1 to 7, characterised in that: - when the gate (15) is open, the position (PZ) of the centring device (20) relative to the position (PA) of the receptacle (30) is detected and transmitted to a control device (26), - at least one actual distance value (A), preferably an actual vertical distance value (AV), between the positions (PZ) and (PA) is determined by the control device (26), - the actual distance value (A, AV) is compared with predefined setpoint values stored in the control device (26), - the control device (26) transmits a control signal for raising or lowering to the at least one lifting device (23) of a running wheel (21), so that one of the limbs (11, 12) is raised or lowered and the actual distance (A, AV) between the centring device (20) and the receptacle (30) is reduced.

9. Method according to claim 8, characterised in that - the centring device (20) of the gate (15) is brought into close proximity to the receptacle (30), - the locking of the door (15) can be activated by means of a start signal, - the positions (PZ, PA) of the centring device (20) and the receptacle (30) are determined continuously after activation, and - the control signal is part of a control loop, so that when the closing device (28) for locking the gate (15) is activated, the centring device (20) is automatically threaded into the receptacle (30).

10. Method according to claim 9, characterised in that the determination of the positions (PZ, PA) of the centring device (20) and the receptacle (30) is only activated when a predefined horizontal distance (AH) between the centring device (20) and the receptacle (30) is undershot, so that a correction of the actual vertical distance value (AV) only takes place on a final section of the pivoting movement of the gate (15).