Lifting platform and work robot

Abstract

The present invention relates to a lifting platform (10) and a work robot (70) with such a lifting platform (10). The lifting platform (10) comprises a base element (20), a platform element (30), a guide system (40) for guiding a lifting movement of the platform element (30) relative to the base element (20), and at least two linear actuators (50) for driving the lifting movement of the platform element (30) relative to the base element (20). Each of the linear actuators (50) is mounted so as to be tiltable on both the base element (20) and the platform element (30).

Description

[0001] The present invention relates to a lifting platform and a work robot with such a lifting platform.

[0002] Lifting platforms are commonly used to lift heavy loads. These platforms typically consist of a platform that is movable relative to a base by means of actuators. Various approaches exist to translate the linear movement of the actuators into a lifting movement of the platform relative to the base.

[0003] One possibility is to directly translate the linear motion of the actuators into the movement of the platform. This approach is used in Fig. Figure 1 shows that four simple worm gears 130 are arranged between the base 110 and the platform 120. These are synchronized via a gear assembly 140 and driven by a common motor 150. The worm gears 130 allow screw rods 160 attached to the platform 120 to be extended and retracted, thus raising or lowering the platform 120.

[0004] Another approach, which is in Fig. As shown in Figure 2, two pneumatically or electrically driven linear actuators 210 actuate a scissor linkage 220 consisting of four support struts 222, which are arranged in pairs in a crossed pattern. Two of the support struts 222 are mounted at one end so that they can tilt, respectively, on the base 230 and the platform 240. The opposite ends of the support struts 222 are movable linearly along the base 230 and the platform 240, respectively, via rollers 250. Extending or retracting the linear actuators 210 causes a scissor movement of the support struts 222 and consequently raises or lowers the platform 240.

[0005] However, such established approaches are often heavy and bulky. They are therefore unsuitable, or only very conditionally suitable, for use in industrial robots, especially mobile industrial robots.

[0006] Against this background, it is an object of the present invention to provide a lifting platform that is compact yet has a large lifting capacity.

[0007] This task is solved by a platform according to claim 1.

[0008] It is also an object of the present invention to provide a working robot with a compact lifting platform which has a large stroke.

[0009] This task is solved by a working robot according to claim 9.

[0010] Preferred embodiments are the subject of the dependent claims and the following description.

[0011] According to a first aspect of the invention, the lifting platform comprises a base element, a platform element, a guide system for guiding a lifting movement of the platform element relative to the base element, and at least two linear actuators for driving the lifting movement of the platform element relative to the base element. Each of the linear actuators is mounted, in particular directly, so as to be tiltable on both the base element and the platform element.

[0012] One aspect of the invention is based on the approach of providing at least two linear actuators for driving a lifting movement of a platform element relative to a base element, which expediently act directly on the platform element and the base element. In other words, it is preferred that one component of each linear actuator, such as a spindle or a thrust tube, is attached directly to the platform element, while another component of each linear actuator, such as a housing, is attached directly to the base element. Extending or retracting the spindle or thrust tube from or into the housing can then directly effect a lifting movement of the platform element relative to the base element.

[0013] To enable this direct interaction with the platform and base elements, the linear actuators are advantageously connected to them in such a way that they can change their orientation relative to these elements. Specifically, the linear actuators can be mounted on the platform and base elements in such a way that, when retracted, they essentially lie between them, i.e., tilted by only a few degrees, approximately 20° or less. This results in a lightweight and compact system where the distance between the base and platform elements is particularly small when retracted. For example, installation heights as low as 255 mm when retracted can be achieved. Such a lifting platform is therefore ideally suited for autonomous mobile robots.AMR applications (AMR = “autonomous mobile robot”).

[0014] The platform element is advantageously designed to lift off the base element under the guidance of a guide system. Unlike conventional scissor lifts, the linear actuators can be provided separately from the guide system. In particular, the guide system can be designed solely to guide the movement of the platform element relative to the base element. Consequently, no force is advantageously exerted on the platform element via the guide system to execute the lifting movement. In other words, the lifting movement of the platform element relative to the base element is advantageously not driven by the guide system, even in combination with the linear actuators as in a scissor lift.

[0015] The linear actuators are advantageously positioned between the base and platform elements. The guide system is also conveniently located between the base and platform elements. This allows for not only a low overall height but also compact lateral dimensions.

[0016] Preferred embodiments of the invention and their further developments are described below. These embodiments can be combined with each other and with the aspects of the invention described below, unless expressly excluded.

[0017] To ensure particularly stable guidance of the lifting movement, the guide system preferably comprises at least one telescopic lifting column arranged between the platform element and the base element, with at least two column elements arranged at least partially nested. Advantageously, one of the column elements, for example, the outermost column element, is attached to the base element. Similarly, another column element, for example, the innermost column element, is advantageously attached to the platform element. Such a lifting column can also withstand high transverse loads occurring parallel to the base element and the platform element. Despite this, the telescopic nature of the lifting column allows the guide system to be built compactly.

[0018] Box-like arranged column elements according to the invention are column elements that overlap each other at least partially in a direction of movement or lifting. In other words, one column element engages with the other column element. This nesting of the column elements can enable the telescoping of the lifting column.

[0019] The lifting column preferably has three column elements. The middle column element is advantageously movable relative to both the base element and the platform element. The three column elements allow the lifting height to be significantly increased, by approximately one-third, compared to a lifting column with only two column elements.

[0020] A particularly advantageous configuration with regard to force distribution and stability can be achieved by providing four telescopic lifting columns, each positioned at a corner of the base element and the platform element. The platform element and the base element are expediently designed to be essentially rectangular. This arrangement significantly increases the resistance to tilting of the base and platform elements relative to each other. In other words, it further enhances rigidity.

[0021] A substantially rectangular floor element and / or platform element according to the invention is preferably a floor element or platform element with two parallel sides that are perpendicular to each other. The corners may be rounded or chamfered.

[0022] Preferably, the base and platform elements define two parallel planes. A stroke direction determined by the guide system expediently runs perpendicular to these two planes. For example, the at least one lifting column can be oriented perpendicular to the defined planes to determine the corresponding stroke direction. In this configuration, the at least two linear actuators are preferably mounted on the base and platform elements by means of tilting bearings, wherein, during a stroke movement of the platform element relative to the base element, the tilting bearings on the base element move exclusively in the stroke direction relative to the tilting bearings on the platform element. Thus, expediently, no movement of the tilting bearings parallel to the planes defined by the base and platform elements occurs. In other words, the tilting bearings are limited to movement in the stroke direction. This allows for a simple design of the tilting bearings.In particular, no compensation for movement perpendicular to the lifting direction is necessary. The tilting bearings can therefore be designed with minimal maintenance and are easy to install.

[0023] An advantageous arrangement of the tilting bearings – and thus also of the linear actuators – with regard to force distribution can be achieved by arranging the linear actuators in pairs. In this arrangement, the at least two linear actuators form a pair in which the tilting bearings on the platform element are spaced further apart than the tilting bearings on the base element. As a result, the platform element can be supported more broadly. The lifting force can therefore be distributed over a larger area.

[0024] Due to the tiltable mounting of the linear actuators on the base and platform elements, it is possible for the at least two linear actuators to be arranged between the parallel planes defined by the base and platform elements, in every operating state. In other words, the linear actuators are preferably always angled relative to the planes defined by the base and platform elements. The linear actuators are thus advantageously arranged at an angle to the base and platform elements in both the retracted and extended positions. This allows for an extremely low overall height in the retracted position.

[0025] A tilting or angling of a linear actuator relative to or opposite a plane, as described in the invention, preferably involves aligning a longitudinal axis of the linear actuator at an angle of more than 0° and less than 90° to the plane. A linear actuator tilted relative to a plane is therefore neither parallel nor perpendicular to that plane.

[0026] Preferably, the linear actuators, particularly in this arrangement, are protected by side walls of the base and platform elements. Preferably, the base and platform elements have side walls extending substantially parallel to the stroke direction, which overlap at least partially in the stroke direction, and certainly when the linear actuators are retracted. In other words, the side walls of the platform element are arranged in a box-like manner, at least partially and at least in one operating state of the lifting platform. Advantageously, these side walls define an interior space within the lifting platform in which the guide system and the linear actuators are arranged. Consequently, the base and platform elements can form a housing. This reliably protects the linear actuators and the guide system from external influences.Furthermore, operational safety can also be increased, as the guidance system and linear actuators are less easily accessible.

[0027] To ensure smooth and trouble-free raising and lowering of the platform element, the at least two linear actuators are preferably electrically synchronized. This allows the force acting on the platform element to be generated uniformly. In particular, tilting of the floor and platform elements relative to each other can be prevented.

[0028] Electrical synchronization within the meaning of the invention is preferably a measure by which movements of the linear actuators, e.g., the extension or retraction of a spindle or a push rod from an actuator housing, are synchronized. Electrical synchronization can be achieved, for example, by appropriate synchronous motor control and / or by monitoring the actuator position. The linear actuators can, for example, have a position determination system, such as by means of appropriate position encoders, so that the actuator position can be synchronized based on position data provided by the position determination system. Alternatively or additionally, an even distribution of the supplied electrical power to the actuators can be provided, for example by means of one or more power dividers.

[0029] According to a second aspect of the invention, a mobile work robot, in particular, has a lifting platform according to the first aspect of the invention. The compact design and low weight of the platform allow the work robot to be smaller and lighter. This enables the work robot to move under objects with low ground clearance and lift them using the lifting platform. For example, such a work robot could be used in the automotive sector to lift and move vehicles. Alternatively, such a work robot could also be used in production, for example, to transport partially assembled products along an assembly line or to individual assembly stations.

[0030] The invention will now be explained in more detail with reference to the figures. Where expedient, elements with equivalent effects are designated with the same reference numerals. The invention is not limited to the embodiments shown in the figures – not even with regard to functional features. The preceding description, as well as the subsequent description of the figures, contains numerous features, some of which are summarized in the dependent claims. However, those skilled in the art will also be able to consider these features, as well as all other features disclosed above and in the subsequent description of the figures, individually and combine them into meaningful further combinations. In particular, all of the aforementioned features can be combined individually and in any suitable combination with the lifting platform according to the first aspect of the invention and the working robot according to the second aspect of the invention.

[0031] They show, at least partially schematically: Fig. 1. An example of a lifting platform from the state of the art; Fig. 2 an example of a scissor lift from the state of the art; Fig. 3. An example of a hub platform in a side view; Fig. 4 an example of a lifting column in the retracted state; Fig. 5 an example of the lifting column from Fig. 4 in extended position; Fig. 6. An example of a linear actuator; Fig. 7 an example of a tilting bearing; Fig. 8 Example of a lifting column; and Fig. 9 an example of a work robot with a lifting platform.

[0032] Fig. Figure 3 shows an example of a lifting platform 10 with a base element 20 and a platform element 30 in a side view. The lifting platform 10 expediently also includes a guide system for guiding a lifting movement B of the platform element 30 relative to the base element 20, as well as at least two linear actuators for driving the lifting movement. These are shown in Fig. 3, however, is not visible.

[0033] The base element 20 comprises a base 22, which is expediently plate-shaped, and side walls 24 set off from it, namely inwards. The platform element 30 also expediently has side walls 32. The side walls 24, 32 expediently run parallel to a lifting direction R or axis of the lifting platform 10, in or along which the platform element 30 is movable relative to the base element 20. Together with the side walls 24, 32, the base element 20 and the platform element 30 can form a housing 12 for the lifting platform 10. The aforementioned guide system and the at least two linear actuators are then expediently arranged within the housing 12, i.e., within the interior space defined by the side walls 24, 32.

[0034] Advantageously, the side walls 24 of the base element 20 are offset from the edge of the base 22 transversely to the lifting direction R. In other words, the side walls 24 of the platform element 20 are set inwards relative to the edges of the base 22. In contrast, the side walls 32 of the platform element 30 are preferably flush with the edge of the base 22 in the lifting direction R. This allows the side walls 24 of the base element 20 to be arranged, at least partially, within the side walls 32 of the platform element 30, at least when the lifting platform 10 is retracted. In other words, the side walls 24 and 32 are arranged in a nested arrangement, at least partially. The platform element 30 can thus form a "lid" for the base element 20.

[0035] In the example shown, the base element 20, in particular the base 22, has fastening lugs 26. These fastening lugs 26 allow the lifting platform 10 to be attached to a substructure as needed, e.g., secured during transport, or lifted, for example, by crane.

[0036] As will be described in more detail below, the linear actuators within the housing 12 formed by the base element 20 and the platform element 30 are advantageously arranged at an angle, i.e., neither parallel to nor perpendicular to the stroke direction R, and are mounted so as to be tiltable on both the base element 20 and the platform element 30. This allows for a particularly low overall height h when the lifting platform 10 is retracted. For example, the overall height h can be only 255 mm when retracted, while the lifting platform 10 has a stroke of 130 mm.

[0037] Fig. Figure 4 shows an example of a lifting platform 10 in its retracted state. The lifting platform 10 has a base element 20, a guide system 40 with at least one, in this example four, lifting columns 42 and at least two, in this example four, linear actuators 50. A platform element (see Figure 4) Fig. 3) is not shown in the present example for the sake of clarity. The guide system 40 serves to guide a lifting movement of the platform element (not shown) relative to the floor element 20, and the linear actuators 50 serve to drive this movement.

[0038] The lifting columns 42, which expediently do not have a drive function themselves but merely serve as guides, are arranged in the area of ​​the corners of the rectangular base element 20. One column element 42a is fixedly mounted on the base element 20. Another column element 42c, on the other hand, is fixedly mounted to the platform element (not shown).

[0039] The linear actuators 50 are arranged in pairs between two lifting columns 42 along a longitudinal direction or longitudinal axis L of the base element 20 or the lifting platform 10. Each linear actuator 50 is mounted at its end on the base element 20 by means of a tilting bearing 60, allowing it to tilt. Equivalently, the linear actuators 50 are mounted at their opposite end on the platform element (not shown) by means of tilting bearings 62, allowing them to tilt. The linear actuators 50 of each pair 52 are tilted relative to the plane defined by the base element 20 (and correspondingly to a plane defined by the platform element (not shown)) such that the distance d between the tilting bearings 60 on the base element 20 is smaller than the distance between the tilting bearings 62 on the platform element (not shown).

[0040] Fig. Figure 5 shows an example of the lifting platform 10. Fig. 4 in an extended state. Here, inner column elements 42b, 42c of the lifting column 42 are extended further than in the Fig. The retracted state shown in Figure 4 is extended. Likewise, the spindles 54 or thrust tubes of the linear actuators 50 are extended further from a corresponding housing 56. As in connection with Fig. As explained in more detail below (6), the position of the tilting bearings 60 on the base element 20 relative to the position of the tilting bearings 62 on the platform element (not shown) has changed only in the direction of travel R, but not perpendicular to it. The resulting stroke of the platform element (not shown) relative to the base element 20 can, for example, be 130 mm.

[0041] Fig. Figure 6 shows an example of a linear actuator 50, which is mounted to a base element 20 of a lifting platform by means of a tilting bearing 60 and to a platform element 30 of the lifting platform by means of a tilting bearing 62. In particular, a housing 56 of the linear actuator 50, which contains a linear unit for converting a rotary motion of a motor 58 into a translational motion of a spindle 54 or a thrust tube, is mounted to the base element 20 in a tilting manner. The spindle 54 or the thrust tube, on the other hand, is mounted to the platform element 30 in a tilting manner.

[0042] Of course, the assembly can also be arranged the other way around, i.e. the spindle 54 can be mounted on the base element 20 by means of the tilting bearing 60 and the housing 56 on the platform element 30 by means of the tilting bearing 62.

[0043] The tilting bearings 60, 62 on the base and platform elements 20, 30 are preferably mounted at a fixed distance D transversely to a stroke direction R. This distance D does not change even during movement of the platform element 30 relative to the base element 20. In other words, when the platform element 30 moves relative to the base element 20, the tilting bearings 60, 62 move relative to each other exclusively in the stroke direction R. Consequently, the linear actuator 50, and in particular its longitudinal axis J defined by the direction of movement of the spindle 54 or the thrust tube, changes its orientation relative to the base element 20 and the platform element 30 during such movement.

[0044] Fig. Figure 7 shows an example of a tilting bearing 62, with which a linear actuator (shown only in part) is mounted to a platform element of a lifting platform in a tilting manner. The tilting bearing 62 comprises a bearing body 64, which can be attached to the platform element, for example, by screwing it in place, and has two bearing arms 64a. The bearing arms 64a each have a through-hole 64b, through which a bushing 66 or bearing sleeve passes. The bushings 66 or bearing sleeves may have an end projection with which they bear against an outer surface of the bearing arms 64a. The bushings 66 or bearing sleeves are in turn penetrated by a bearing bolt 68. The bearing bolt 68 has a threaded bore in each of its two axial ends, into which a screw 68a is screwed for axial fixation of the bearing bolt 68 between the bearing arms 64a. The screws 68a are supported on the bushings 66 via washers 68b.Bearing sleeves, especially their projections.

[0045] The bearing bolt 68 expediently passes through a through-bore 54a of a spindle 54 or of a thrust tube of the linear actuator.

[0046] Advantageously, a tilting bearing for the tilting mounting of the linear actuator to a base element of the lifting platform is designed analogously. Here, the bearing bolt 68 can pass through an eye of a swivel head, which is arranged at the end of a housing of the linear actuator.

[0047] Fig. Figure 8 shows an example of a lifting column 42 of a guide system for a lifting platform. In the example shown, the lifting column 42 has three column elements 42a, 42b, 42c that are arranged at least partially nested, i.e., at least partially interlocking. The column elements 42a, 42b, 42c are movably mounted relative to each other in a stroke direction R of the lifting column 42. Guide and / or sliding elements, not visible in the present sectional view, may be arranged between the outermost column element 42a and the middle column element 42b, as well as between the middle column element 42b and the innermost column element 42c. Advantageously, stoppers 44 are also arranged between the outermost column element 42a and the middle column element 42b, as well as between the middle column element 42b and the innermost column element 42c, which limit the stroke of the lifting column 42.The stoppers 44 can run in elongated recesses 46 or be arranged on the outer sides of the column elements 42a, 42b, 42c and run parallel to the stroke direction R.

[0048] Fig. Figure 9 shows an example of a mobile work robot 70. The work robot 70 has a chassis 72 and a lifting platform 10 mounted on it. The chassis 72 has wheels 74 with which the work robot 70 can move. Thus, the work robot 70 can, for example, drive under objects to be lifted, such as vehicles and / or similar items, and then lift a platform element 30 of the lifting platform 10 from a base element 20 of the lifting platform 10. The object lifted in this way can then be moved by means of the work robot 70. Reference symbol list 10 lifting platforms 12 cases 20 floor elements 22 base 24 side wall 26 Mounting eyelet 30 platform elements 32 side wall 40 Management system 42 Lifting column 42a Column element 42b Column element 42c column element 44 stoppers 46 Exclusion 50 Linear Actuator 52 pairs 54 Spindle 54a Through bore 56 cases 60 tilting bearings 62 tilting bearings 64 bearing bodies 64a Bearing arm 64b Through hole 66 socket 68 bearing bolts 68a screw 68b Washer 70 industrial robots 72 chassis 74 wheels 110 base 120 platform 130 worm gears 140 Gear arrangement 150 engine 160 screw rods 210 Linear actuator 220 scissor linkages 222 Support strut 230 base 240 platform 250 rolls R lifting direction B Lifting movement L Longitudinal axis J Longitudinal axis d distance D distance h Construction height

Claims

[1] Lifting platform (10) comprising a base element (20), a platform element (30), a guide system (40) for guiding a lifting movement (B) of the platform element (30) relative to the base element (20) and at least two linear actuators (50) for driving the lifting movement (B) of the platform element (30) relative to the base element (20), wherein each of the linear actuators (50) is mounted so as to be tiltable on both the base element (20) and the platform element (30). [2] Lifting platform (10) according to claim 1, wherein the guide system (40) has at least one telescopic lifting column (42) arranged between the platform element (30) and the base element (20) with at least two column elements (42a, 42b, 42c) arranged at least partially nested and one of the column elements (42a) is attached to the base element (20) and another of the column elements (42c) is attached to the platform element (30). [3] Lifting platform (10) according to claim 2, wherein the base element (20) and the platform element (30) are substantially rectangular and the guide system (40) has four telescopic lifting columns (42) which are each arranged in the region of a corner of the base element (20) and the platform element (30). [4] Lifting platform (10) according to one of the preceding claims, wherein - the base element (20) and the platform element (30) define two parallel planes and a lifting direction (R) defined by the guide system (40) runs perpendicular to these two planes and - the at least two linear actuators (50) are mounted on the base element (20) and on the platform element (30) by means of tilting bearings (60, 62) so as to be tiltable and the tilting bearings (60) on the base element (20) move during a lifting movement (B) of the platform element (30) relative to the base element (20) exclusively in the lifting direction (R) relative to the tilting bearings (62) on the platform element (30). [5] Lifting platform (10) according to one of the preceding claims, wherein the at least two linear actuators (50) are mounted on the base element (20) and on the platform element (30) by means of tilting bearings (60, 62) so as to be tiltable, and the at least two linear actuators (50) form at least one pair (52) in which the tilting bearings (62) on the platform element (30) are spaced further apart from each other than the tilting bearings (60) on the base element (20). [6] Lifting platform (10) according to one of the preceding claims, wherein the floor element (20) and the platform element (30) define two planes parallel to each other and the at least two linear actuators (50) are arranged between and tilted relative to these two planes in every operating state. [7] Lifting platform (10) according to one of the preceding claims, wherein the base element (20) and the platform element (30) have side walls (24, 32) extending substantially parallel to the lifting direction (R) which overlap at least partially in a box-like manner in the lifting direction (R). [8] Lifting platform (10) according to one of the preceding claims, wherein the at least two linear actuators (50) are electrically synchronized with each other. [9] Working robot (70) with a lifting platform (10) according to one of the preceding claims.

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