CN116902537A - Transport module for transporting workpiece carriers without separators - Google Patents

Abstract

The invention relates to a transport module (20) for use with a workpiece carrier (30), wherein the workpiece carrier (30) can be driven by at least two drive devices (23) extending in a transport direction (11). According to the invention, at least three face sensors (50; 51;52; 53) are arranged in the region of the at least one drive device (23), with which the presence or absence of a face on the workpiece carrier can be detected.

Description

Transport module for transporting workpiece carriers without separators

Technical Field

The invention relates to a transport module according to the preamble of claim 1, and also to a transport section having a plurality of such transport modules, and to a method for operating a transport section.

Background

EP 2,163,97 B1 discloses a transport section which is composed of a plurality of transport modules. The transport module has a drive device which comprises a plurality of transport rollers arranged in rows in the transport direction. Almost all the conveyor rollers of the conveyor module are driven by means of the main shaft of a common electric motor. The entrainer device is usually permanently operated, wherein the workpiece carrier can be stopped in a defined position by means of a separator (vereinzler). Separators are known, for example, from EP 484 B1. In order to prevent the electric motor from being overloaded, a slip clutch is provided at the spindle so that the workpiece carrier held in a positive manner does not cause excessive torque at the spindle.

A limitation of this solution is that very large workpiece carriers carrying very heavy workpieces should be used. Such a workpiece can be a battery module of a battery powered vehicle. Due to the inertial forces during the stopping of the workpiece carrier, the separator is in particular overloaded and destroyed after a short time.

In the processing of electronic printed circuit boards, the transport of the printed circuit boards is typically carried out without the use of separators. Transport modules are used here, which are, for example, in accordance with the "IPC-HERMES-9852" standard (version 1.4; can be found inhttps：//www.the-hermesstandard.info/download/Retrieve down) and exchange of data with each other to organize the transfer of printed circuit boards from a transport module to a directly adjacent transport module. The printed circuit board is braked and accelerated by means of an electric motor alone, which brings about transport of the printed circuit board.

In the framework of the invention, this principle should be transferred to a transport module, which is constructed, for example, according to EP 2 163 497 B1. The problem here arises that the presence of the corresponding workpiece carrier cannot be detected as easily as in the case of printed circuit boards. The printed circuit board is basically a flat plate having a constant thickness. In particular, when the workpiece carrier is very large, it is composed of a plurality of parts, wherein for this purpose reference is made to the following explanation of fig. 3. The undersides of such workpiece carriers are relatively separated (zerkruftet), wherein only the working surfaces which touch the conveyor rollers are arranged in a common first transport surface. The remaining underside is retracted relative to the first transport surface.

Disclosure of Invention

With the present invention, the hemmes principle mentioned should be transferred to a transport module for workpiece carriers. In this case, it should be possible to use proximity switches, which are common in the transport section, as sensors in order to be able to carry out the above-mentioned communication between the transport modules. In this case, the smallest possible number of sensors should be used. Furthermore, the invention allows for a significantly longer braking path of the heavy workpiece carrier relative to the light electronic printed circuit board.

According to claim 1, it is proposed that at least three face sensors are provided, each of which is arranged in the region of the respectively associated drive device in such a way that they can each detect the presence or absence of a face, wherein in the transport direction two face sensors, each of which is directly adjacent to one another in the transport direction, are spaced apart from one another in such a way that in at least one position of the workpiece carrier two directly adjacent face sensors detect the presence of the workpiece carrier, wherein the at least three face sensors comprise a first face sensor and a second face sensor which are arranged at opposite ends of the transport module in the transport direction, wherein the at least three face sensors comprise a third face sensor which is arranged directly adjacent to the second face sensor in the transport direction at a braking distance. The surface sensor is preferably arranged in the region of the drive device in such a way that it is aligned in the transport direction with respect to a position in which a particularly friction-fit drive is achieved between the drive device and the surface. In the simplest case, only three sensors can be used to reliably determine all the information required in the context of the desired transport without a separator.

The working surface preferably has a constant width transverse to the boundaries of the rectangle. A single working surface can be provided which extends continuously along the entire rectangular boundary. Preferably, a plurality of individual working surfaces are provided, wherein two adjacent working surfaces are spaced apart from one another along the rectangular boundary on the separator path. The length of the separator passage along the boundary of the rectangle is, for example, between 50% and 200% of the width of the working face transverse to the boundary of the rectangle. The rectangular boundary of the workpiece carrier can be square.

If more than two drive devices are provided, at least one working surface can also be provided next to the boundary of the rectangle, which working surface extends parallel to the associated rectangle side. Preferably, all the face sensors are assigned to one of the at least two drive devices. A single electric motor can be provided which drives all the drive devices. All the drive devices can each be assigned a separate electric motor in order to transport particularly heavy workpieces. When a plurality of electric motors are provided, all the drive devices of the transport module are preferably moved substantially synchronously.

The presence of the workpiece carrier entering the transport module can be detected at the earliest possible point in time by means of the first face sensor. With the second working surface sensor, it can be detected that the work piece carrier has left the transport module at a point in time that is as late as possible. The third working surface sensor can be used to identify the position of the workpiece carrier in which the workpiece carrier that is maximally loaded can be braked only with the use of the at least one electric motor until the operation is stopped, so that the workpiece carrier remains completely within the transport module at the end of the braking process. The mentioned braking distance is preferably selected on the basis of the maximum permissible loading of the workpiece carrier.

When the workpiece carrier is placed on the driving device, the first conveying surface and the second conveying surface are overlapped. The second transport surface is preferably oriented perpendicular to the direction of gravity. The drive device can comprise a continuously running pulling means, for example a toothed belt, which runs around the conveyor chain. The drive devices are preferably each configured to be elongated in the transport direction. All workpiece carriers are preferably identically configured on the transport path section with respect to their rectangular boundaries.

Advantageous developments and improvements of the invention are set forth in the dependent claims.

It can be provided that at least one of the face sensors, preferably all of the face sensors, each comprise a slide that can be moved linearly perpendicular to the second transport face and can be brought into direct touching contact with the face, wherein the slide is assigned a proximity switch by means of which the position of the slide can be detected. The slide can be embodied without problems in such a way that its position can be reliably detected with the proximity switch. This is not the case in the preferred workpiece carrier. The slide is preferably equipped with a mechanism known from DE 20312217U1, which prevents the slide from tilting or skewing about its linear operating axis. The proximity switch preferably operates inductively, wherein the proximity switch can also operate optically.

It can be provided that each drive device comprises a plurality of rotatable transport rollers, which are arranged in a row along the transport direction, wherein the transport rollers are spaced apart from one another, wherein each transport roller has a rotational axis oriented perpendicularly to the transport direction, wherein all transport rollers together define a second transport surface, wherein a plurality of transport rollers, preferably all transport rollers, of the transport rollers are in rotary drive connection with a respectively assigned electric motor, wherein either the first or the second working surface sensor is arranged adjacent to a single outermost transport roller, wherein all remaining working surface sensors are each arranged between two directly adjacent transport rollers along the transport direction. The above-mentioned traction means have the disadvantage that the preferred working surface sensor together with the slider cannot be used at the traction means when the traction means have covered the entire width of the working surface. In contrast, sufficient positions exist between the preferred transport rollers for the surface sensor to be located there, so that it can detect the presence or absence of a surface. Furthermore, particularly heavy workpieces can be transported without problems by means of transport rollers.

The transport modules are preferably combined together into a transport path so that a first or second surface sensor, which is arranged completely outside, is also arranged between two immediately adjacent transport rollers. However, they are associated with different transport modules. The rotary drive connection between the transport rollers and the respectively assigned electric motor is preferably realized with a mechanism known from EP 2 163 497 B1, which comprises a so-called spindle. In this case, it can occur that the individual transport rollers are not driven, in particular transport rollers arranged adjacent to the motor. It is sufficient to drive a plurality of the transport rollers in the framework of the invention. When only a single electric motor should be used, two or more transport rollers associated with different drive devices can be fixedly connected to one another, for example by means of a shaft.

At least one rectangular workpiece carrier can be provided, which has an upper side and an opposite lower side, wherein at least one workpiece can be received at the upper side, wherein the lower side has at least one flat working surface at least along the boundary of the rectangle, wherein all working surfaces are arranged in a common first transport surface, wherein at least one working surface defines at least one retraction region which is retracted towards the upper side relative to the first transport surface. Preferably, the at least one workpiece carrier is arranged on the transport module in such a way that the first transport surface and the second transport surface coincide at the same time.

It can be provided that the workpiece carrier comprises at least one ferromagnetic insert which is arranged next to the at least one working surface on the underside of the workpiece carrier, wherein substantially all of the remaining workpiece carriers are not configured ferromagnetically, wherein the transport module comprises at least one position sensor which is arranged in such a way that the presence or absence of an insert can be detected when the relevant workpiece carrier is transported on the transport module. In this connection, the position sensor can be arranged very flexibly between the drive devices, so that every arbitrary desired position can be detected. The position sensor can be used to detect a relatively precisely defined position of the workpiece carrier on the transport module. The accuracy of the position determination is mainly dependent on the switching time of the position sensor. The insert is preferably designed to be so small that the corresponding position can be determined accurately. In this position, the machining is preferably carried out on a workpiece which is received on a workpiece carrier. The workpiece carrier can be substantially entirely composed of aluminum and/or plastic. The workpiece carrier can comprise a ferromagnetic threaded element and further connecting means, wherein the threaded element and the further connecting means are preferably arranged such that they move past the at least one position sensor at such a large distance that the position sensor does not respond. The position sensor is preferably an inductive proximity switch.

Just three working surface sensors, namely a first working surface sensor, a second working surface sensor and a third working surface sensor, can be provided, wherein the length of at least two driving devices in the transport direction is less than or equal to twice the length of the workpiece carrier in the transport direction. With such a small transport module, a very large number of workpiece carriers can be moved independently of one another over the transport path. The transport section can be adapted to the desired transport section only by the number of transport modules used. The transport modules of different lengths do not need to be used, so that the transport modules can be produced cost-effectively with a large number of pieces.

It can be provided that the distance between the first and the third face sensor is selected to be so great that the first and the third face sensor jointly detect the presence of the workpiece carrier only when the workpiece carrier is completely within the transport module. In this way, it can be determined in a simple manner that the workpiece carrier is completely in the current transport module after the transition from the previous transport module.

It can be provided that the workpiece carrier has a plurality of individual working surfaces, wherein two adjacent working surfaces are separated from one another along a rectangular boundary by a separator channel, wherein the separator channel is so wide that, when at least one working surface sensor is arranged in the region of the separator channel, the at least one working surface sensor detects the absence of a working surface. In the framework of the method according to the invention, a separator channel is preferably considered.

Furthermore, a transport section is claimed, which comprises a first transport module and a second transport module according to the invention, wherein the first transport module and the second transport module are arranged directly adjacent to one another in the transport direction, wherein the drive devices assigned to one another are arranged in alignment, so that the workpiece carrier can be transferred from the first transport module to the second transport module by means of the drive devices, wherein the first transport module and the second transport module are connected to one another via a plurality of data channels, which can each only occupy an active state or an inactive state, wherein each data channel is connected to one transport module, namely the first transport module or the second transport module as a transmitter, and the other transport module, namely the second transport module or the first transport module as a receiver. The data channel can be formed by a digital signal line, which can represent, for example, two different direct voltages in order to represent an active state or an inactive state. The first transport module and the second transport module can be connected to each other via a computer network, for example ethernet, in order to realize all data channels. Here, each data channel is assigned a pair of messages, wherein one message indicates a transition from the inactive state to the active state of the data channel and the other message indicates a transition from the active state to the inactive state of the data channel. The status of the data channel is preferably determined and stored in the first transport module and in the second transport module on the basis of the mentioned channel. The messages mentioned are preferably delivered over a computer network using the TCP/IP protocol. It is understood that the transport section can comprise further transport modules, wherein each pair of directly adjacent transport modules is configured there between like the first transport module and the second transport module. All transport modules of the transport section are preferably connected to one another via a common computer network.

A method for operating a transport path according to the invention is also claimed, wherein a mechanical-ready data channel is provided, which is oriented from the second transport module to the first transport module, wherein the mechanical-ready data channel occupies a valid state only if all the face sensors and, if present, all the position sensors of the second transport module indicate the absence of a workpiece carrier. The expression "only when" shall indicate that a situation occurs in which the mentioned conditional mechanical ready data channel cannot be put into effect despite the existence, for example when the finite automaton explained below is in a fault state or when the third working surface sensor is in the region of the separator path. The method aspect and the method aspect below are each assigned a transport module, which serves as a transmitter for the data channel. The transport module preferably autonomously carries out the relevant method aspects, as long as it is not explicitly stated otherwise. For this purpose, the transport module preferably comprises a programmable digital computer which is correspondingly programmed and is connected to the relevant sensors and actuators. The transport path according to the invention is preferably provided in the framework of the first step in time of the method according to the invention.

An on-board available data channel can be provided that is oriented from the first transport module to the second transport module, wherein the on-board available data channel occupies an active state only when at least one of the face sensors indicates the presence of a workpiece carrier. It should be noted here that when the position sensor indicates the presence of a workpiece carrier, then at least one work surface sensor also always indicates the presence of the workpiece carrier. This is caused by the spacing of the face sensors according to claim 1. If no position sensor is present, the on-board available data channel preferably indicates a valid status only when the third work surface sensor indicates the presence of the workpiece carrier. The position sensor is preferably used in conjunction with the finite automaton explained below, wherein the onboard available data channel indicates the active state at the earliest when the position sensor indicates the presence of a workpiece carrier, most preferably when the processing of the workpiece is finished. It is preferred that the on-board available data channel occupies the active state at as early a point in time as possible, in which the mentioned conditions are present. Thereby speeding up the transport of the workpiece carrier.

A start transport data channel can be provided, which is oriented from the second transport module to the first transport module, wherein the start transport data channel occupies the active state only if not only the mechanical-ready data channel but also the vehicle-mounted available data channel also indicates the active state, wherein the entraining device of the second transport module is set in motion at a point in time at which a corresponding state change from the inactive state to the active state takes place at the start transport data channel.

It can be provided that the entraining device of the first transport module is set in motion only when the transport data channel is switched from the inactive state into the active state. In contrast to the principles described above, this method aspect is preferably performed autonomously by the first transport module.

It can be provided that the first transport module only brakes the device until the third working surface sensor is switched from a state in which the third working surface sensor indicates the absence of the workpiece carrier to a state in which the third working surface sensor indicates the presence of the workpiece carrier. It is contemplated that the braking process does not occur when the machine ready data channel and/or the start transport data channel indicates a valid state and/or when the stop transport data channel indicates an invalid state. Whereby transportation can be expedited. It is conceivable that the workpiece carrier is braked from the third working surface sensor to a lower speed, wherein the workpiece carrier is braked until the stop of operation, just when the position sensor indicates the presence of the workpiece carrier. If the workpiece carrier is braked in front of the third face sensor, it may still be partially on the previous transport module when the workpiece carrier is stopped at the end of the braking process. The braking process is preferably effected exclusively by means of at least one electric motor, the rotational speed of which is retarded as a function of a predefined rotational speed profile over time.

A transport completion data channel can be provided, which is oriented from the first transport module to the second transport module, wherein the transport completion data channel occupies an active state only when the drive of the first transport module is deactivated, wherein furthermore all the face sensors and, if present, all the position sensors of the first transport module indicate the absence of the workpiece carrier. This method aspect is performed by the first transport module only according to the principles described above.

It can be provided that a transport-stopping data channel is provided, which is oriented from the second transport module to the first transport module, wherein the transport-stopping data channel takes up an active state only when the drive device of the second transport module is deactivated or braked until deactivated, wherein the first transport module brakes both drive devices until deactivated before the second surface sensor of the first transport module indicates the presence of the workpiece carrier when the state of the transport-stopping data channel is switched from the inactive state to the active state. In particular, it is conceivable for the first transport module to transport the workpiece carrier past the third face sensor to the position sensor and to stop it there, while stopping the transport data channel indicates an active state.

It can be provided that the first transport module and/or the second transport module each implement a finite automaton having a plurality of states, wherein at least a part of the states mentioned each represent a different phase of a transition of the workpiece carrier from the first transport module to the second transport module, wherein each state of the finite automaton is assigned a unique combination of states of the outgoing data channels, wherein a switching of the states of the finite automaton is implemented as a function of the states of the incoming data channels and as a function of the states of the at least three face sensors and, if present, as a function of the states of the at least one position sensor. Finite automata (finite state machine (finite state machine);https：//de.wikipedia.org/wiki/ Endlicher_Automat) With a limited number of fixedly predefined states. A number of conditions can be considered in the framework of flow control with a limited number of robots than can be represented with a digital data channel according to the invention. Can realizeA start state or a corresponding state sequence, which causes the transport section to be transferred from the undefined state into the defined state after the transport section has been switched in. A fault condition can be implemented that occurs when there is a disallowed combination of incoming signals. This fault condition may occur, for example, when the workpiece carrier is removed from the transport section during the ongoing transport of the workpiece carrier.

It can be provided that the plurality of states of the finite automaton comprise at least two zero states, in which all the face sensors indicate the absence of the workpiece carrier, wherein the zero states comprise a first zero state, which brings about the mechanical-ready data channel occupying an active state, wherein the mechanical-ready data channel occupies an inactive state in all the remaining zero states, wherein the further zero states mentioned represent states of the transport section in which the only face sensor respectively assigned to the relevant zero state is located above the separator path, so that the face sensor indicates the absence of the workpiece carrier. The zero state preferably comprises a second zero state, which is associated with the third face sensor. It is conceivable that a zero state is also set for the first face sensor and/or the second face sensor. However, both cases can also be considered by appropriately choosing the transition conditions between the other states of the finite automaton without having to introduce an additional zero state for this.

It goes without saying that the features mentioned above and yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the invention.

Drawings

The invention is explained in more detail below with reference to the drawings. In the figure:

fig. 1 shows a roughly schematic top view of a transport module according to the invention;

fig. 2 shows a rough schematic side view of a transport module according to the invention;

fig. 3 shows a perspective view of the underside of the workpiece carrier; and is also provided with

Fig. 4 shows a graph of a transport section with different data channels.

Detailed Description

Fig. 1 shows a rough schematic top view of a transport module 20 according to the invention. The workpiece carrier 30 shown in fig. 3 should be transported in the transport direction 11 by means of the transport module 20. The respective transport section is composed of a plurality of such transport modules 20, which are arranged next to one another in the transport direction 11. The branched transport section can be realized, for example, by means of a lifting transverse unit.

The transport module 20 comprises two elongated drive devices 23 which are arranged parallel to the transport direction 11 and spaced apart from one another. When using particularly large workpiece carriers 30, three or more parallel drive devices 23 can also be present. It should be noted here that the present transport module 20 envisages a battery module for particularly large and heavy workpieces, in particular for vehicles of battery power.

The drive device 23 is preferably constructed according to EP 2 163 497 B1. The entrainer device comprises a corresponding series of transport rollers 25 which are arranged in a row in the transport direction, wherein the transport rollers are spaced apart from one another. All transport rollers 25 together define a second transport surface (14 in fig. 2) with their preferably cylindrical circumferential surface, which is preferably oriented perpendicularly to the direction of gravity. All transport rollers 25 can rotate about an axis of rotation which is oriented perpendicular to the transport direction 11. Each drive device 23 has its own electric motor 24, which is in rotary drive connection with almost all associated transport rollers 25 via the spindle shown in EP 2 163 497 B1. The workpiece carrier 30 can thus be driven in a friction fit over the entire length of the drive device 23.

The presence of the workpiece carrier 30 is currently detected by three face sensors 50, which are currently arranged at one of the two drive devices 23. In contrast to the illustration in fig. 1, these face sensors are arranged just between two adjacent transport rollers 25, so that they can detect the face of the workpiece carrier 30 (reference numeral 34 in fig. 3). The precise arrangement of the face sensor 50 is explained in more detail below with reference to fig. 2.

A position sensor 60 is further provided, which is preferably implemented as an inductive proximity switch. The presence of the workpiece carrier 30 shown in fig. 3 cannot be detected in its basic form by such a position sensor, since it is largely composed of aluminum and/or plastic. The workpiece carrier 30 is therefore provided with a particularly ferromagnetic insert (reference numeral 36 in fig. 3), which is small relative to the entire workpiece carrier 30. The position sensor 60 can correspondingly detect a precisely defined position of the workpiece carrier 30. In this position, the work piece 12 is preferably processed and transported on a work piece carrier 30. In this position, the workpiece carrier 30 is located entirely on the single transport module 20 and not, for example, at the transition between two immediately adjacent transport modules 20.

Fig. 2 shows a rough schematic side view of a transport module 20 according to the invention. The first transport surface 13 at the underside 32 of the workpiece carrier 30 is shown slightly spaced apart from the second transport surface 14, which is defined by the transport rollers 25, for clarity reasons. During transport, the first transport surface and the second transport surface 13;14 are coincident.

The three face sensors 50 are preferably implemented identically to one another. Each of which comprises a slide 54 which is supported so as to be movable perpendicular to the second transport surface 14. The position of the slider 54 is detected by means of a proximity switch 55, which most preferably works inductively. The slide 54 is preferably preloaded by means of a spring into a position in which its upper side protrudes beyond the second transport surface 14. When the workpiece carrier 30 touches the slide 54 with its working surface (34 in fig. 3), the upper side of the slide 54 is then pressed down to the second transport surface 14, so that the proximity switch 55 responds. With this mechanism, the following is considered: the presence of the workpiece carrier 30 cannot be detected directly or only with a significant uncertainty with the proximity switch 55.

A second face sensor and a third face sensor 52;53 are arranged in the transport direction 11 between two immediately adjacent transport rollers 25 of the transport module 20 shown. The first face sensor 51 is arranged directly adjacent to the single outermost conveyor roller 26, i.e. the first conveyor roller in the transport direction 11. When a further transport module (not shown) is formed there, the first face sensor 51 is also located between the two transport rollers 25. The second face sensor 52 is arranged between the outermost transport roller 26 opposite in the transport direction 11 and the transport roller 25 arranged directly upstream thereof in the transport direction 11. The third face sensor 53 is arranged in front of the second face sensor 52 with a braking distance 61. The braking distance 61 is at least so large that the fully loaded workpiece carrier 30 can be braked solely by means of the electric motor (reference number 24 in fig. 1) in the region of this section. The first face sensor and the third face sensor 51 are selected in this way; 53 such that in at least one position of the workpiece carrier 30 the two mentioned work surface sensors 51;53 to respond. Such a position is shown in fig. 2. At the same time, the distances mentioned are selected such that both the first face sensor and the third face sensor 51;53 also respond, the workpiece carrier 30 is entirely within the transport module 20. The mentioned distance is correspondingly slightly smaller than the length of the workpiece carrier 30 in the transport direction 11. The braking distance 61 can be selected in a relatively more flexible manner. To the maximum extent, this braking distance is slightly smaller than the length of the workpiece carrier 30 in the transport direction. At a predefined loading and driving speed of the workpiece carrier 30, the braking distance 61 is at least as large as the minimum braking path achievable with the electric motor (24 in fig. 1). In this way, the length of the transport module 20 can be flexibly adapted to the specific planned transport route.

Fig. 3 shows a perspective view of the underside 32 of the workpiece carrier 30. Because the workpiece carrier 30 is provided for very large workpieces, it is not embodied as a solid plate. More precisely, a relatively lightweight workpiece carrier 30 is provided, which is formed from a plurality of aluminum extrudates 80. The aluminum extruded profiles are firmly connected to one another, wherein the aluminum extruded profiles are screwed to one another, in particular by means of parallel and angle connectors 81, 82. The aluminum extrusion 80 has a T-shaped recess as seen in cross section, which can be used for this purpose.

Based on this lightweight design, the workpiece carrier 30 is supported at a plurality of positions by the entraining device 23, so that it does not deform under the weight of the heavy workpiece. Such support occurs at the work surface 34; at 34', the running surfaces are formed from plastic strips, which are fixedly connected, in particular screwed, to the associated aluminum extruded profile 80. All flat work surfaces 34; 34' are arranged in a common first transport plane (reference 13 in fig. 2). The working surface 34 extends with a constant width along the rectangular boundary 33 of the workpiece carrier 30. The longer rectangular sides are oriented parallel to the transport direction 11, wherein there are two parallel tracks of the working surface, the distance of which is adapted to the distance of the two drive devices in fig. 2. A total of three working surfaces 34 are arranged perpendicular to the transport direction 11; 34'. The adapted transport module has three parallel drive devices for this purpose, in order to avoid deflection along the long rectangular sides.

A separator passage 35 should also be indicated, which interrupts the working surface 34 at different positions at the border of the rectangle. The respectively associated separator stop 38 is arranged in exactly aligned relation to the associated separator channel 35. A corresponding separator is known for example from EP 484648b 1. When the movable stop member of the separator comes into touching contact with the separator stop 38, the workpiece carrier 30 is held. Such a separator should then be dispensed with according to the invention. It is nevertheless advantageous if the workpiece carrier 30 is suitable for conventional operation with a separator. The transport section can thus be implemented cost-effectively, for example, with separators at locations where no workpiece carrier 30 is loaded or where it is loaded only lightly, wherein the transport module according to the invention, which is relatively expensive, is used only at locations where the workpiece carrier 30 is loaded heavily. The separator passage 35 is particularly important for the present invention because it interferes with the function of the face sensor. When the face sensor is just below the separator passage 35, the face sensor indicates that the work piece carrier 30 is not present, although it is actually present. This problem is taken into account by the method according to claim 18.

In each of the four corners of the workpiece carrier 30, a rotatable roller 83 is arranged, the axis of rotation of which is oriented perpendicularly to the first transport surface 13. This achieves a low friction transport on curves (see EP 2189399b 1).

Fig. 4 shows a graph of a transport section 10 with different data channels. Data communication between two immediately adjacent transport modules 20 of a transport section 10 is shown. Similar communication is preferably achieved between all immediately adjacent transport modules 20 of the transport section.

The second transport module 22 is arranged behind the first transport module 21 with respect to the transport direction (reference numeral 11 in fig. 1). Five data channels 70 are shown; 71;72;73;74 are in the simplest case constructed as wires whose dc voltage potential just compiles two states, namely an active state and an inactive state. Just two users and data channels 70, respectively; 71;72;73;74, wherein one is a transmitter and the other is a receiver. The directed point-to-point communication is then conducted.

Since the corresponding communication only places an appropriate requirement for the time delay, it is possible and for cost reasons preferable that the two transport modules are connected by means of a computer network, for example ethernet. Here, each data channel 70;71;72;73;74 are assigned a pair of network messages, wherein one message indicates the data channel 70;71;72;73;74 from an inactive state into an active state, wherein another message indicates the data channel 70;71;72;73;74 from an active state to an inactive state. A data channel 70;71;72;73; the status of 74 is preferably determined and stored in the first transport module and in the second transport module based on the mentioned messages. The messages mentioned are preferably delivered via a computer network using the TCP/IP protocol.

The machine-ready data channel 70 is oriented from the second transport module to the first transport module 22;21. the active state indicates that the second transport module 22 is ready to receive the workpiece carrier (reference numeral 30 in fig. 1) of the first transport module 21. For this purpose, no workpiece carrier must be present on the second transport module 22.

The vehicle-mounted available data channel 71 is oriented from the first transport module to the second transport module 21;22. the active state indicates that there is a workpiece carrier on the first transport module 21 that is ready to be transferred to the second transport module 22. When the first transport module 21 achieves pure transport, then the following is the case: the workpiece carrier is located entirely on the first transport module 21. If the machining of the workpiece on the workpiece carrier takes place within the first transport module 21, the onboard data channel 71 is available when the machining is completed.

The start transport data channel 72 is oriented from the second transport module to the first transport module 21. The second transport module 22, which is determined by the status of the machine-ready data channel 70 and the vehicle-mounted available data channel 71, should transfer the workpiece carrier from the first transport module to the second transport module 21;22 and in response thereto put its entraining device (reference numeral 23 in fig. 1) into motion, wherein the start transport data channel 72 is put into active state. When the start transport data channel 72 occupies an active state, the first transport module 21 places its bringing device in motion. In a protective sense this can depend on the fact that the mechanically ready data channel has previously taken up a valid state. This protection is preferably achieved by means of the above-mentioned finite automaton.

The transport completion data channel 73 is oriented from the first transport module to the second transport module 21;22. the active state indicates that the workpiece carrier has been transferred from the first transport module to the second transport module 21; after 22 the workpiece carrier has completely left the first transport module 21. The second transport module 22 determines when to end the transport of the workpiece carrier. This is the case when the second transport module recognizes by means of its working surface sensor (50 in fig. 1) that the work piece carrier is completely located on the second transport module 22. The stop transport data channel 74 is set active by the second transport module 22 which causes the first transport module 21 to stop its operation with the equipment (reference numeral 23 in fig. 1). This can be omitted for the purpose of accelerating the transport, when the first transport module is able to receive the workpiece carrier immediately from the transport module situated before in the transport direction.

List of reference numerals:

10 transport section

11 transport direction

12 work piece

13 first transport surface

14 second transport surface

20 transport module

21 first transport module

22 second transport module

23 drive device

24 electric motor

25 transport roller

26 outermost transport roller

30 workpiece carrier

31 upper side

32 underside of

33 rectangle boundary

34 working face

34' optional working face

35 separator passage

36 ferromagnetic insert

37 retraction area

38 separator stop

50 working face sensor

51 first working surface sensor

52 second face sensor

53 third face sensor

54 slide

55 proximity switch

60 position sensor

61 brake distance

70 mechanical ready data channel

71 vehicle-mounted available data channel

72 start to transport data channel

73 transport completion data channel

74 stop transport data channel

80 aluminium extrusion section bar

81 parallel connector

82 angle connector

83 rollers.

Claims (18)

1. A transport module (20) for use with a rectangular workpiece carrier (30), having an upper side (31) and an opposite lower side (32), wherein at least one workpiece (12) can be received at the upper side (31), wherein the lower side (32) has at least one flat working surface (34; 34') at least along a rectangular boundary (33), wherein all working surfaces (34) are arranged in a common first transport surface (13), wherein the at least one working surface (34) defines at least one retraction region (37) which is retracted with respect to the first transport surface (13) toward the upper side (31), wherein the transport module (20) comprises at least two straight drive devices (23) which extend parallel to one another in a transport direction (11), wherein the drive devices define a common second transport surface (14), wherein the drive devices are spaced apart from one another in such a way that the drive devices can be coupled to the workpiece carrier (30) with each other by way of the motor drive devices (24) in such a way that the motor drive devices (24) are engaged in each other in the transport direction, the mentioned friction-fit entrainment can be achieved over the entire length of the entrainment device (23),

Characterized in that at least three face sensors (50) are provided, each of which is arranged in the region of a respective associated drive device (23) such that they can each detect the presence or absence of a face (34), wherein in each case two face sensors (50) which are directly adjacent in the transport direction (11) are spaced apart from one another in the transport direction (11) such that two face sensors (50) which are directly adjacent in the transport direction (11) detect the presence of a workpiece carrier (30) in at least one position of the workpiece carrier (30), wherein the at least three face sensors (50) comprise a first face sensor and a second face sensor (51; 52) which are arranged at opposite ends of the transport module (20) in the transport direction (11), wherein the at least three face sensors (50) comprise a third face sensor (53) which is arranged in the transport direction (11) adjacent to the second face sensor (52) with a distance of the brake face (61).

2. The transport module (50) according to claim 1,

wherein at least one of the face sensors (50), preferably all of the face sensors (50), each comprises a slide (54) which can be moved linearly perpendicular to the second transport face and which can be brought into direct touching contact with the face (34), wherein the slide (54) is assigned a proximity switch (55) by means of which the position of the slide (54) can be detected.

3. The transport module (20) according to any of the preceding claims,

wherein each drive device (23) comprises a plurality of rotatable transport rollers (25) which are arranged in a row along a transport direction (11), wherein the transport rollers are spaced apart from one another, wherein each transport roller (25) has an axis of rotation which is oriented perpendicularly to the transport direction (11), wherein all transport rollers (25) together define the second transport surface (14), wherein a plurality of the transport rollers (25), preferably all transport rollers (25), are in rotary drive connection with a respectively assigned electric motor (24), wherein either the first or the second surface sensor (51; 52) is arranged adjacent to a single outermost transport roller (26), wherein all remaining surface sensors (50) are each arranged between two directly adjacent transport rollers (25) along the transport direction (11).

4. The transport module (20) according to any of the preceding claims,

wherein at least one rectangular workpiece carrier (30) is provided, which has an upper side (31) and an opposite lower side (32), wherein at least one workpiece (12) can be received at the upper side (31), wherein the lower side (32) has at least one flat working surface (34; 34 ') at least along the boundary of the rectangle, wherein all working surfaces (34; 34 ') are arranged in a common first transport surface, wherein the at least one working surface (34; 34 ') defines at least one retraction region (37) which is retracted relative to the first transport surface (13) toward the upper side (31).

5. The transport module (20) of claim 4,

wherein the workpiece carrier (30) comprises at least one ferromagnetic insert (36) which is arranged next to the at least one working surface (34; 34') on the underside (32) of the workpiece carrier (30), wherein substantially all remaining workpiece carriers (30) are not configured ferromagnetically, wherein the transport module (20) comprises at least one position sensor (60) which is arranged in such a way that the presence or absence of an insert (36) can be detected when the relevant workpiece carrier (30) is transported on the transport module (20).

6. The transport module (20) according to claim 4 or 5,

wherein exactly three face sensors (50), namely a first face sensor, a second face sensor and a third face sensor (51; 52; 53), are provided, wherein the length of the at least two drive devices (23) in the transport direction (11) is less than or equal to twice the length of the workpiece carrier (30) in the transport direction (11).

7. The transport module (20) of claim 6,

wherein the distance between the first and third face sensors (51; 53) is selected to be so great that the first and third face sensors (51; 53) jointly detect the presence of the workpiece carrier only when the workpiece carrier (30) is completely within the transport module (20).

8. The transport module (20) according to any one of claims 4 to 7,

wherein the workpiece carrier (30) has a plurality of individual working surfaces (34; 34 '), wherein two adjacent working surfaces (34) are separated from each other along the rectangular boundary (33) by a separator channel (35), wherein the separator channel (35) is so wide that, when at least one working surface sensor (50) is arranged in the region of the separator channel (35), it detects the absence of the working surfaces (34; 34').

9. Transport section (10) comprising a first transport module and a second transport module (21; 22), which are each configured according to one of the preceding claims, wherein the first transport module and the second transport module (21; 22) are arranged directly adjacent to one another in a transport direction (11), wherein a drive device (23) associated with one another is arranged in alignment, such that a workpiece carrier (30) can be transferred by means of the drive device (23) from the first transport module to the second transport module (21; 22), wherein the first transport module and the second transport module (21; 22) are connected to one another by a plurality of data channels (70; 71;72;73; 74), which can each only occupy an active or inactive state, wherein each data channel (70; 71;72;73; 74) is connected to one transport module, i.e. the first transport module or the second transport module (21; 22) as a transmitter, and the second transport module, i.e. the first transport module (21; 22) as a receiver, respectively.

10. Method for operating a transport section (10) according to claim 9, wherein a mechanical ready data channel (70) is provided, which is oriented from the second transport module to the first transport module (22; 21), wherein the mechanical ready data channel (70) occupies an active state only if all working surface sensors (50) and if present all position sensors (60) of the second transport module (22) indicate the absence of a workpiece carrier (30).

11. The method according to claim 10,

wherein a vehicle-mounted data channel (71) is provided, which is oriented from the first transport module to the second transport module (21; 22), wherein the vehicle-mounted data channel (71) occupies an active state only when at least one of the face sensors (50) indicates the presence of a workpiece carrier (30).

12. The method according to claim 11,

wherein a start transport data channel (72) is provided, which is oriented from the second transport module to the first transport module (22; 21), wherein the start transport data channel (72) occupies an active state only when not only the machine-ready data channel (70) but also the vehicle-mounted data channel (71) indicates an active state, wherein the entraining device (23) of the second transport module (22) is put into motion at a point in time at which a corresponding state change from an inactive state to an active state takes place at the start transport data channel (72).

13. The method according to claim 12,

wherein the entraining device (23) of the first transport module (21) is set in motion only when the start transport data channel (72) changes from an inactive state into an active state.

14. The method according to any one of claims 10 to 13, wherein the first transport module (21) is preferably implemented as in any one of claims 6 to 8,

wherein the first transport module (21) only brakes the drive device (23) until the first transport module stops operating if the third working surface sensor (53) transitions from a state in which the third working surface sensor indicates the absence of the workpiece carrier (30) to a state in which the third working surface sensor indicates the presence of the workpiece carrier.

15. The method according to any one of claim 10 to 14,

wherein a transport completion data channel (73) is provided, which is oriented from the first transport module to the second transport module (21; 22), wherein the transport completion data channel (73) assumes an active state only when the drive device (23) of the first transport module (21) is deactivated, wherein furthermore all working surface sensors (50) and, if present, all position sensors of the first transport module (21) indicate the absence of a workpiece carrier (30).

16. The method according to any one of claim 10 to 15,

wherein a transport stopping data channel (74) is provided, which is oriented from the second transport module to the first transport module (22; 21), wherein the transport stopping data channel (74) occupies an active state only when the drive device (23) of the second transport module (22) is deactivated or braked until deactivated, wherein when the state of the transport stopping data channel (74) is transferred from an inactive state to an active state, the first transport module (21) brakes both drive devices until deactivated before the second face sensor (52) of the first transport module indicates the presence of a workpiece carrier (30).

17. The method according to any one of claim 10 to 16,

wherein the first transport module and/or the second transport module (21; 22) each execute a finite automaton having a plurality of states, wherein at least a part of the states mentioned each represent a different phase of a transition of the workpiece carrier (30) from the first transport module to the second transport module (21; 22), wherein each state of the finite automaton is assigned a unique combination of states of the outgoing data channels, wherein the transition of the state of the finite automaton is effected as a function of the state of the incoming data channels and as a function of the state of the at least three working surface sensors (50) and, if present, of the state of the at least one position sensor (60).

18. The method of claim 17, referring back to claim 8,

wherein the states of the finite automaton comprise at least two zero states in which all face sensors (50; 51;52; 53) indicate the absence of the workpiece carrier (30), wherein the zero states comprise a first zero state which causes the mechanical ready data channel (70) to occupy the active state, wherein the mechanical ready data channel (70) occupies the inactive state in all remaining zero states, wherein the remaining zero states mentioned represent the following states of the transport section (10) in which the only face sensor (50; 51;52; 53) respectively assigned to the relevant zero state is above a separator path (35) so that the face sensor indicates the absence of the workpiece carrier (30).