阅读说明：本技术 用于执行工作过程的工作机构和用于运行工作机构的方法 (Working mechanism for carrying out a working process and method for operating a working mechanism ) 是由 W·阿尔贝 M·施特姆勒 W·图尔瑙斯 H-J·普拉赫 于 2021-04-29 设计创作，主要内容包括：本发明涉及一种工作机构,具有机器壳体,所述机器壳体配属有具有能够运动的封闭活门的壳体凹口,具有压缩空气驱动器用于使封闭活门运动并且具有致动控制部用于压缩空气驱动器的至少两个工作腔室的可选的换气或排气,其中,第一阀组件配属有第一压力传感器用于探测在第一工作腔室中的第一流体压力并且其中,第二阀组件配属有第二压力传感器用于探测在第二工作腔室中的第二流体压力,其中,致动控制部包括处理机构,其构造成用于处理压力传感器的传感器信号并且其构造成用于提供操控信号,所述操控信号用于第一阀组件以使工作活塞沿朝着第二终端位置的方向进行加速并且用于第二阀组件以使工作活塞在到达第二终端位置之前进行制动。(The invention relates to a working mechanism having a machine housing, which is assigned a housing recess having a movable closure flap, having a compressed-air drive for moving the closure flap and having an actuation control for optional ventilation or venting of at least two working chambers of the compressed-air drive, wherein a first valve assembly is assigned a first pressure sensor for detecting a first fluid pressure in the first working chamber and wherein a second valve assembly is assigned a second pressure sensor for detecting a second fluid pressure in the second working chamber, wherein the actuation control comprises a processing means which is designed to process a sensor signal of the pressure sensor and which is designed to provide an actuation signal for the first valve assembly for accelerating a working piston in the direction of a second end position and for the second valve assembly for accelerating the working piston before the second end position is reached And (5) braking.)

1. Working mechanism (1) for carrying out a working process, having a machine housing (2) which defines a working space (6) and which is provided with a housing recess (5) to which a closure flap (7) which can be moved between an open position and a closed position is assigned, having a working unit which is accommodated in the working space (6) and which is designed for processing and/or treating a work object, having a compressed-air drive (10) which is designed for moving the closure flap (7) and which has a drive housing (16) with a working recess (17) in which a working piston (18) which is accommodated so as to be movable between a first end position and a second end position is arranged, the working piston divides the working recess (17) into a first working chamber (19) of variable size and a second working chamber (20) of variable size, wherein the compressed air drive (10) is assigned an actuation control unit (30) comprising a first valve assembly (48) for optional ventilation or venting of the first working chamber (19) and a second valve assembly (49) for optional ventilation or venting of the second working chamber (20), wherein the first valve assembly (48) is assigned a first pressure sensor (45) for detecting a first fluid pressure in the first working chamber (19) and wherein the second valve assembly (49) is assigned a second pressure sensor (46) for detecting a second fluid pressure in the second working chamber (20), wherein the actuation control unit (30) comprises a processing means (32), the processing means are designed for processing a first sensor signal of the first pressure sensor (45) and a second sensor signal of the second pressure sensor (46) and for providing a first actuating signal to the first valve arrangement (48) and a second actuating signal to the second valve arrangement (49), wherein the processing means (32) are designed for providing a first actuating signal for the first valve arrangement (48) for accelerating the working piston (18) in the direction of the second end position (14) and for providing a second actuating signal for the second valve arrangement (49) for braking the working piston (18) before reaching the second end position (14).

2. The working mechanism (1) according to claim 1, characterized in that the compressed air drive (10) is configured as a pneumatic cylinder and the working piston (18) is connected to a piston rod (21) which passes through the drive housing (16) on the end side, wherein the drive housing (16) is connected to the machine housing (2) and the piston rod (21) is connected to the closure flap (7) or wherein the drive housing (16) is connected to the closure flap (7) and the piston rod (21) is connected to the machine housing (2).

3. The working mechanism (1) according to claim 2, characterized in that the closure flap (7) is mounted in a linearly movable manner on the machine housing (2).

4. Operating mechanism (1) according to claim 2 or 3, characterized in that a position sensor assembly is assigned to the compressed air drive (10), which is configured to provide a position signal and which comprises a first end position sensor (26) which is arranged in the region of a first end position (13) of the operating piston (18), which comprises a second end position sensor (27) which is arranged in the region of a second end position (14) of the operating piston (18) and which is electrically connected to the processing mechanism (32).

5. Operating mechanism (1) according to claim 2 or 3, characterized in that a position sensor arrangement is assigned to the compressed air drive (10), which is designed to provide a position signal and which comprises a position sensor which extends in a region between a first end position (13) for the operating piston (18) and a second end position (14) for the operating piston (18) and which is designed to detect the position of the operating piston (18) between the first end position (13) and the second end position (14).

6. Operating mechanism (1) according to claim 4 or 5, characterized in that the processing means (32) has a communication interface (57) which is designed for communication with a control means (11) of a higher stage and in that the processing means (32) is set up in such a way that, when the operating piston (18) is close to the first end position (13) or close to the second end position (14), an activation signal is provided at the communication interface as a function of the position signal of the position sensor arrangement.

7. Operating mechanism (1) according to one of claims 4 to 6, characterized in that the processing means (32) are set up such that, when the operating piston (18) is close to the first end position (13) or close to the second end position (14), a braking signal is provided to the first valve arrangement (48) and to the second valve arrangement (49) as a function of the position signal of the position sensor arrangement in order to initiate the braking of the closure flap (7) by means of the compressed air drive (10).

8. The working mechanism (1) according to one of the preceding claims, characterized in that an interface (4) for coupling with a tool magazine is formed at a first wall section (3) of the machine housing (2) and the closure flap (7) is associated with the first wall section (3) and is formed for releasing and closing a housing recess (5) formed as a tool exchange opening.

9. Operating mechanism (1) according to one of the preceding claims, characterized in that a setpoint pressure profile for the pressure signal (p 1) of the first pressure sensor (45) during the ventilation of the first working chamber (19) is stored in the processing mechanism (32) and that the processing mechanism (32) is designed for determining a deviation between the setpoint pressure profile and the pressure signal (p 1) of the first pressure sensor (45) during the ventilation of the first working chamber (19) and for outputting a fault signal if a predefinable value for the deviation is exceeded.

10. Operating mechanism (1) according to one of the preceding claims, characterized in that the processing means (32) are designed such that an output of a fault signal is made possible when the pressure signal of the first pressure sensor (45) has a fluctuation with a predefinable frequency and/or a predefinable amplitude during the ventilation of the first working chamber (19) and/or when a deviation between a movement duration for the working piston (18) between the first end position (13) and the second end position (14) and a predefinable movement duration exceeds a predefinable value, in particular when the movement duration falls below a predefinable movement duration limit value.

11. Method for operating a working mechanism (1) configured according to one of the preceding claims, having the following steps: providing a first ventilation signal by the processing means (32) to the first valve arrangement (48) and ventilating the first working chamber (19), providing a first exhaust signal by the processing means (32) to the second valve arrangement (49) and exhausting the second working chamber (20), determining a first pressure profile of the first fluid pressure (p 1) and/or determining a second pressure profile of the second fluid pressure (p 2), and providing a first closing signal by the processing means (32) to the first valve arrangement (48) to end ventilation of the first working chamber (19) and providing a second closing signal by the processing means (32) to the second valve arrangement (49) to end exhaust of the second working chamber (20), wherein at least one from the group of the following is performed in accordance with the first pressure profile and/or in accordance with the second pressure profile during provision of the first ventilation signal One diagnostic function is: linear guide diagnostics, closed valve position diagnostics.

12. Method according to claim 11, characterized in that for the linear guide diagnosis a deviation between the pressure values of the first pressure course and the stored pressure values of the first pressure course is determined and a diagnostic signal is output by the processing means (32) when the value of the deviation exceeds a presettable maximum value.

13. Method according to claim 11, characterized in that for the closure flap diagnosis a first change value for the first pressure profile is compared with a presettable first change limit value and/or a second change value for the second pressure profile is compared with a presettable second change limit value and a diagnostic signal is output by the processing means (32) when the first change value exceeds the first change limit value and/or the second change value exceeds the second change limit value.

14. Method according to claim 11, characterized in that for the closure flap diagnosis an evaluation of the position signal of the position sensor arrangement is carried out for determining a movement duration for the working piston (18) between the first end position (13) and the second end position (14), and a diagnostic signal is output by the processing means (32) when the movement duration exceeds a presettable deviation from a presettable movement duration limit value, in particular when the movement duration falls below a presettable movement duration limit value.

15. Method according to claim 11, characterized in that for the closure flap diagnosis, the first pressure profile is evaluated with respect to fluctuations with a presettable frequency and/or with a presettable amplitude and a diagnostic signal is output by the processing means (32) when fluctuations occur within a presettable frequency range and/or with a presettable minimum amplitude.

Technical Field

The invention relates to a working mechanism for carrying out a working process and to a method for operating such a working mechanism.

Background

According to the prior art known to the applicant and not described in the printed literature, a working mechanism configured as a tool machine, for example a milling machine, is provided with a machine housing having a door at the front side, through which a workpiece can be transported into a working space defined by the machine housing. Typically, the door is opened before the beginning of the machining process in order to feed a new workpiece to be machined into the working space and then remains closed until the end of the machining process, after which the door is opened again in order to remove the finished workpiece. Furthermore, a housing recess can be provided on the machine housing, which housing recess is designed for supplying tools into the working space and for removing tools from the working space and can be closed by means of a closure flap. Typically, a plurality of tool changes occur during the machining process for the workpiece, so that the closure flap also has to be opened and closed again a plurality of times, wherein it is possible to interrupt the machining process when the closure flap is opened, in order to prevent, for example, an undesired discharge of cooling lubricant from the working space into the surroundings, as can occur if the machining process continues despite the opening of the closure flap. The movement for closing the flap is effected, for example, by means of an electric variable-speed motor having a flanged (angel flantscher) spindle, by means of which the rotary movement of the variable-speed motor can be converted into a linear movement for closing the flap.

Disclosure of Invention

The object of the present invention is to provide a working mechanism and a method for operating such a working mechanism, by means of which the efficiency of machining a workpiece can be increased.

This object is achieved for a working mechanism of the type mentioned at the outset by the features of claim 1. The working mechanism comprises a machine housing which defines a working space and which is provided with a housing recess assigned with a closure flap which is movable between an open position and a closed position, and a working unit which is accommodated in the working space and which is designed for processing and/or treating a work object, and a compressed air drive which is designed for moving the closure flap and which has a drive housing with a working recess in which a working piston which is accommodated movably between a first end position and a second end position is arranged, which piston divides the working recess into a first working chamber of variable size and a second working chamber of variable size, wherein the compressed air drive is assigned an actuation control unit, which comprises a first valve assembly for selective ventilation or venting of the first working chamber and a second valve assembly for selective ventilation or venting of the second working chamber, wherein the first valve assembly is assigned a first pressure sensor for detecting a first fluid pressure in the first working chamber and wherein the second valve assembly is assigned a second pressure sensor for detecting a second fluid pressure in the second working chamber, wherein the actuation control unit comprises a processing means, which is designed for processing a first sensor signal of the first pressure sensor and a second sensor signal of the second pressure sensor and for providing a first actuating signal to the first valve assembly and a second actuating signal to the second valve assembly, wherein the processing means is designed for providing the first actuating signal for the first valve assembly in order to move the working piston in the direction of the second end point The direction of the position is accelerated and used to provide a second pilot signal for the second valve assembly to brake the working piston before the second end position is reached.

The relative movement of the closure flap with respect to the machine housing with high kinematic dynamics (Bewegungsdynamik) is achieved by the use of a compressed air drive which can optionally be configured to provide an oscillating movement or a linear movement. It is preferably provided that the opening and closing process for closing the flap can be carried out more quickly than with the drive technology used up to now. As a result, the stop time, which is necessary for tool changes and which is significantly determined by the duration of the opening process for closing the flap and the subsequent closing process, is reduced. This leads to a reduction in the overall machining time for the workpiece and thus to an increase in the efficiency for the working mechanism, under the assumption that machining of the workpiece requires a large number of tool replacements.

In order to be able to ensure an advantageous use of the compressed air drive, it is advantageous if the compressed air drive is designed as a double-acting compressed air drive, since a combination of drive and brake forces can thus be provided for use as required. In this case, the compressed air drive has a working piston which is accommodated in a working recess in a movable manner and which, together with the working recess, defines a first working chamber of variable size and a second working chamber of variable size. In this case, both the first working chamber and the second working chamber can be supplied with compressed air, optionally during the course of a ventilation process, via the associated first valve assembly or second valve assembly, or can undergo pressure relief via an exhaust process. Preferably, it is provided that the working piston, during the movement of the closure flap from the open position into the closed position, passes through a movement path which starts in the first end position and ends in the second end position. In this case, the drive housing, the working recess and the working piston are coordinated with one another in such a way that, independently of the position of the working piston along the path of movement, both the first working chamber and the second working chamber are always ventilated and vented.

In order to provide compressed air at least one of the two working chambers of the compressed air drive and to vent at least one of the two working chambers, the compressed air drive is assigned an actuation control which can be designed in particular as a valve platform having a first valve assembly which is designed for the ventilation and venting of the first working chamber and having a second valve assembly which is designed for the ventilation and venting of the second working chamber. Purely exemplarily, each of the valve assemblies comprises a gas exchange valve in the form of an 2/2 directional control valve and an exhaust valve in the form of a 2/2 directional control valve, wherein the gas exchange valve and the exhaust valve can be electrically actuated and are in particular embodied as piezo valves.

In order to be able to carry out precise ventilation and venting of the respective working chamber, a pressure sensor is associated with each of the valve assemblies, by means of which the fluid pressure in the respective working chamber or in the supply line associated with the respective working chamber can be determined.

Furthermore, the actuation control unit comprises a processing means, which is in particular designed as a microcontroller or microprocessor and which is designed for processing the electrical signal levels of the first and second pressure sensors and for providing actuating signals to the respective valve assembly. Furthermore, it can be provided that the processing means comprise a communication interface, in particular a bus interface, which is designed for communication with a higher-level control unit, in particular a machine control unit for the working means. Thus, the communication interface can provide the control commands of the control unit of the higher level to the processing means of the actuation control unit and communicate the status signals and/or diagnostic signals of the processing means to the control unit of the higher level.

In order to be able to ensure an effective execution of the opening and closing process for the closure flap, the processing means are designed to provide actuating signals for the first and second valve assemblies, by means of which a rapid acceleration of the working piston and the closure flap coupled thereto and a subsequent braking of the working piston and the closure flap coupled thereto can be achieved.

In a first step, the processing means provides a first actuating signal to the first valve assembly, by means of which an actuation of the gas exchange valve of the first valve assembly can be initiated in order to thereby bring about a gas exchange of the first working chamber of the compressed air drive. In parallel to this, the processing means can provide a first actuating signal to the second valve arrangement in order to actuate an outlet valve of the second valve arrangement, thereby enabling an outflow of air from the second working chamber which is reduced during the movement of the working piston between the first end position and the second end position.

In a second step, a second actuating signal for the second valve arrangement is provided, wherein the second actuating signal in each case initiates a closing operation for the outlet valve of the second valve arrangement. It can furthermore be provided that the second control signal also causes the opening of the gas exchange valves of the second valve arrangement in order to obtain a supply of compressed air into the second working chamber and thus an increase in the braking action for the working piston. In this case, the processing means can be designed to provide a second actuating signal for the first valve arrangement with the provision of a second actuating signal for the second valve arrangement, which second actuating signal can at least be intended to prevent a further compressed air supply into the first working chamber by closing the first gas exchange valve. In addition, it can also be provided that, by means of an actuation signal to the first valve arrangement, the first exhaust valve is also opened in order to support a braking process for the working piston.

Advantageous developments of the invention are the subject matter of the dependent claims.

Expediently, the compressed air drive is designed as a pneumatic cylinder and the working piston is connected to a piston rod which passes through the drive housing on the end side, wherein the drive housing is connected to the machine housing and the piston rod is connected to the closure flap or wherein the drive housing is connected to the closure flap and the piston rod is connected to the machine housing. This ensures a compact design for the compressed air drive and the possibility of a compact integration of the compressed air drive at the machine housing.

Advantageously, the closure flap is mounted on the machine housing so as to be linearly movable. It is particularly preferably provided that the closure flap moves parallel to a surface of the machine housing, which is also provided with a housing recess, which is to be closed by the closure flap. It is not important here whether a movement of the closure flap in the horizontal direction, in the vertical direction or at an angle to the vertical direction is carried out.

In a further development of the invention, it is provided that the compressed air drive, in particular a compressed air drive designed as a pneumatic cylinder, is assigned a position sensor arrangement which is designed to provide a position signal and which comprises a first end position sensor which is arranged in the region of a first end position of the working piston, and that the position sensor arrangement comprises a second end position sensor which is arranged in the region of a second end position of the working piston and which is electrically connected to the processing means. With a position sensor arrangement of this type, it can be determined from the electrical signals of the respective end position sensors whether the working piston is moved as desired out of one of the end positions in order to reach the other end position and also actually reaches said other end position. With the aid of this information, in particular, further work processes, such as, for example, the execution of a tool change process in the case of an open closure flap or the continuation of a workpiece machining in the case of a closed closure flap, can be initiated at the work machine in order to ensure a desired, efficient working mode of the work machine. In an exemplary embodiment, the first and second end position sensors are embodied as a switching mechanism, which each outputs a switch-on signal when the working piston is arranged in a position that can be preset relative to the respective end position sensor. Alternatively, it can be provided that the first end position sensor and the second end position sensor are configured for position detection of a section of the movement path of the working piston and thus within the respective end position sensor or in the processing means, an evaluation can be carried out as to whether the working piston has reached the respective end position.

In a further embodiment of the invention, it is provided that the compressed air drive, in particular a compressed air drive designed as a pneumatic cylinder, is assigned a position sensor arrangement which is designed to provide a position signal and which comprises a position sensor which extends in a region between a first end position for the working piston and a second end position for the working piston and which is designed to detect the position of the working piston between the first end position and the second end position. By means of such a position sensor, the position of the working piston along the entire movement path between the first end position and the second end position can be determined. Accordingly, at each time point during the operation of the operating device, the position information provided by the position sensor is made available to the processing device and can be used to actuate the first valve assembly and the second valve assembly. The position sensor can also be formed by a plurality of individual sensors which are arranged in rows, possibly partially overlapping, along the movement path.

It is preferably provided that the processing means have a communication interface which is designed to communicate with a control means of a higher level and that the processing means are set up in such a way that, when the working piston is close to the first end position or close to the second end position, an activation signal is provided to the communication interface as a function of the position signal of the position sensor arrangement. By providing the activation signal, further functional components of the operating mechanism, such as, for example, a tool changer or a turning or milling head, can already be prepared for the immediately subsequent action when the closure flap has at least almost reached the respectively sought-after end position.

Advantageously, the processing means are designed such that, when the working piston is close to the first end position or close to the second end position, a braking signal is provided to the first valve arrangement and to the second valve arrangement as a function of the position signal of the position sensor arrangement in order to initiate the braking of the closure flap by means of the compressed air drive. This use of the position signal of the position sensor arrangement results in a high reproducibility with regard to the opening and closing movement for the closure flap, since a very reliable position determination for the working piston can be carried out on the basis of the position signal.

In a further development of the invention, it is provided that an interface for coupling to a tool magazine is formed at the first wall section of the machine housing, and that a closure flap is assigned to the first wall section and is configured for releasing and closing a housing recess formed as a tool exchange opening. The tool magazine can, for example, be a chain magazine (Kettenmagazin) which is installed adjacent to the working mechanism adjacent to the first wall section of the machine housing and which enables the replacement of production tools, such as, for example, milling or turning tools, which are provided at a housing recess for the transfer into or out of the working space of the machine housing, by means of a double-hook gripper.

It is preferably provided that a setpoint pressure profile for the pressure signal of the first pressure sensor during the ventilation of the first working chamber is stored in the processing means and that the processing means are designed to determine a deviation between the setpoint pressure profile and the pressure signal of the first pressure sensor during the ventilation of the first working chamber and to output a fault signal if a predefinable value for the deviation is exceeded. A change in the movement dynamics of the closure flap can be determined, which can be caused, for example, by wear of the compressed air drive or of the guide means for the closure flap or by contamination at the guide means. On the basis of the error signal, the operator of the operating mechanism can indicate a possible imminent error function for the movement of the closure flap and initiate a corresponding countermeasure. For example, the value for the deviation can be selected such that a fault signal is already output in the event of a small change in the actual course of the pressure signal of the first pressure sensor, in order to inform an operator of the working mechanism that preventive maintenance should be carried out before damage to the closure flap or to the guide for the closure flap or to the compressed air drive occurs in the event of further development of changes caused by possible wear.

The processing means is expediently designed such that the output of the error signal takes place when the pressure signal of the first pressure sensor has a fluctuation with a predefinable frequency and/or a predefinable amplitude during the ventilation of the first working chamber and/or when a deviation between a movement duration for the working piston between the first and the second end position and the predefinable movement duration exceeds a predefinable value, in particular when the movement duration falls below a predefinable movement duration limit value. Oscillations of the pressure signal of the first pressure sensor can occur if the connection between the compressed air drive and the closure flap is damaged or fails completely. In order to be able to output a fault signal for this case, the processing means is designed to evaluate the temporal profile of the pressure signal of the first pressure sensor. In particular, a comparison is carried out between the oscillation frequency of the pressure fluctuations that may occur and the frequency spectrum of the permissible and impermissible oscillation frequencies stored in the processing means. In addition or alternatively, the oscillation amplitude of the occurring pressure fluctuations is compared with an extremum value stored in the processing means or a plurality of extremum values stored in the processing means for different oscillation frequencies. In addition or alternatively, provision can be made for a deviation between a movement time period for the working piston between the first end position and the second end position and a presettable movement time period to be determined in the processing means and for a fault signal to be output if the deviation exceeds a presettable value. Preferably, provision is made for a fault signal to be output if the movement duration falls below a movement duration limit value which can be preset.

The object of the invention is achieved by a method for operating a working mechanism according to the invention, comprising the following steps: providing, by the processing means, a first ventilation signal to the first valve arrangement and ventilating the first working chamber, providing, by the processing means, a first exhaust gas signal to the second valve arrangement and exhausting the second working chamber, determining a first pressure profile of the first fluid pressure and/or determining a second pressure profile of the second fluid pressure, and providing, by the processing means, a first closing signal to the first valve arrangement to end the ventilation of the first working chamber, and providing, by the processing means, a second closing signal to the second valve arrangement to end the exhaust of the second working chamber, wherein, during the provision of the first ventilation signal, at least one diagnostic function from the group of: linear guide diagnostics, closed valve position diagnostics.

For the linear guide diagnosis, it is advantageous if a deviation between the pressure values of the first pressure profile and the stored pressure values of the first pressure profile is determined and if the value of the deviation exceeds a predefinable maximum value, a diagnostic signal is output by the processing means.

Preferably, provision is made for a first change value for the first pressure profile to be compared with a presettable first extreme change value and/or for a second change value for the second pressure profile to be compared with a presettable second extreme change value and for a diagnostic signal to be output by the processing means if the first change value exceeds the first extreme change value and/or the second change value exceeds the second extreme change value. In the case of a closure flap diagnosis, the aim is to be able to determine possible damage to the connection between the compressed air drive and the closure flap. In the event of such damage, a relatively rapid movement of the compressed air drive can be used in particular, since the masses of the closure flap do not have to be moved together. Accordingly, for the closing flap diagnosis, it is determined from a change in the first pressure signal, for example the derivative of the first pressure signal with respect to time, whether the first pressure signal has a profile from which a faulty connection between the compressed air drive and the closing flap can be inferred. In the same way, consideration of the second pressure signal can additionally or alternatively be carried out. The output of the fault signal is configured to compare the respective change value with a first or second limit value of change that can be preset and to output a diagnostic signal if the respective limit value of change is exceeded.

In a further embodiment of the method, it is provided that, for the closure flap diagnosis, an evaluation of the position signal of the position sensor arrangement is carried out in order to determine a displacement time period for the working piston between the first end position and the second end position, and that a diagnostic signal is output by the processing means when the displacement time period exceeds a predeterminable deviation from a predeterminable displacement time period, in particular when the displacement time period falls below a predeterminable displacement time period limit. The execution of the method can be carried out both when the compressed air drive is equipped with the end position sensor and when the compressed air drive is equipped with the position sensor, since in both cases at least the duration of the movement of the closure flap between the first end position and the second end position (or vice versa) can be determined. In the case of the use of a position sensor, a partial section of the movement path for closing the flap can also be taken into account with regard to the movement duration necessary for this. The movement duration (which can also be referred to as the actual duration) is compared in the processing means with a presettable movement duration and the output of the diagnostic signal is carried out if the deviation between the determined movement duration and the presettable movement duration, in particular stored in the processing means, exceeds a presettable deviation. Preferably, provision is made for the movement duration to be compared in the processing means with a movement duration limit value and for a diagnostic signal to be output if the movement duration falls below the movement duration limit value.

In a further development of the method, it is provided that, for the closure flap diagnosis, the first pressure profile is evaluated with respect to fluctuations having a predefinable frequency and/or a predefinable amplitude and that a diagnostic signal is output by the processing means when fluctuations occur within a predefinable frequency range and/or with a predefinable minimum amplitude. Fluctuations occur in the first pressure profile when the pressure regulation is used for ventilating the compressed air drive and the regulator implemented for this purpose attempts to reach the actual value to be pursued for the first pressure at least largely inefficiently due to its regulation properties set for the normal operation of the closure flap when there is a wear or damage situation for the closure flap and/or the compressed air drive. The fluctuations occurring in this case can be checked with respect to their frequency and/or amplitude in order to be able to deduce a wear situation or a failure situation therefrom.

Drawings

Advantageous embodiments of the invention are shown in the figures. Here:

FIG. 1 shows a very schematic side view of a working mechanism with a machine housing, a housing recess with an associated closure flap, a compressed air drive and an actuation control,

figure 2 shows a schematic illustration of the actuation control according to figure 1,

FIG. 3 shows a strictly schematic representation of the signals for different position sensors, an

Fig. 4 shows a very schematic representation of the pressure profile in a compressed air drive.

Detailed Description

The working mechanism 1, which is illustrated purely schematically in fig. 1, is designed purely exemplarily as a milling machine and comprises a square machine housing 2. At a purely exemplary vertically oriented side wall 3 of the machine housing 2, an interface 4, which is only schematically illustrated, is formed and which is provided for coupling a tool magazine, for example a chain magazine, which is not illustrated in greater detail. Furthermore, a housing recess 5, which is formed purely exemplarily at right angles, is provided at the side wall 3, which housing recess penetrates the side wall 3 and thus provides a connection between a (berandeten) working space 6, which is bordered by the machine housing 2, and the surroundings of the working mechanism 1. Provision can be made, for example, for tools, which are not shown in greater detail, to be introduced into the working space 6 or removed from the working space 6 via the housing recess 5, wherein said tools can be used by a milling machine, not shown, accommodated in the working space 6 for machining workpieces, also not shown, and can be accommodated outside the working space 6 in a tool magazine, also not shown.

A closure flap 7 is mounted so as to be linearly movable on the side wall 3, said closure flap being movable along a movement path 15 between an open position, in which the housing recess 5 is released, and a closed position, in which the housing recess 5 is closed. Purely by way of example, two guide rails 8, 9 extending in the horizontal direction are provided for the support of the closure flap 7, said guide rails being fastened to the side walls 3 and being configured, for example, as rod guides, not shown in greater detail, for closing the flap 7. Furthermore, a compressed air drive 10 is associated with the closure flap 7, which is designed to apply a setting force to the closure flap 7. Purely by way of example, the compressed air drive 10 relates to a pneumatic cylinder having a drive housing 16, which extends along the movement path 15 and in which a working recess 17, which is also referred to as a cylinder bore, is formed. A working piston 18 is accommodated in the working recess 17 in a linearly movable, sealed manner, said working piston dividing the working recess 17 into a first working chamber 19 of variable size and a second working chamber 20 of variable size. Furthermore, the working piston 18 is coupled to a piston rod 21 which passes through the drive housing 16 at the end and is connected to a coupling part 22 which is itself fixed to the closure flap 7. Since the drive housing 16 is fixed to the side wall 3 in a manner not shown in greater detail, a linear relative movement of the working piston 18 and the piston rod 21 connected thereto causes a linear relative movement of the closure flap 7 relative to the machine housing 2.

In order to provide the setting force by means of the compressed air drive 10, the first working chamber 19 is connected via a first fluid line 23 to an actuation control 30, which is described in more detail later in connection with fig. 2. Furthermore, the second working chamber 20 is connected to the actuation control 30 via a second fluid line 24.

Purely by way of example, the compressed air drive 10 is equipped with a position sensor arrangement 25, which comprises a first end position sensor 26 and a second end position sensor 27, which are each arranged at an end region of the drive housing 16 and are designed to detect the presence (Anwesenheit) or absence (Abwesenheit) of the working piston 18. The first end position sensor 26 is connected to an actuation control unit 30 via a first sensor line 28. The second end position sensor 27 is also connected to the actuation control unit 30 via a second sensor line 29.

According to the illustration of fig. 1, a switching box 11 is arranged laterally adjacent to the machine housing 2, in which a machine control for the working mechanism 1, which is not illustrated in greater detail, is housed, wherein the machine control can comprise, for example, a programmable control (SPS), which is designed to coordinate the entire process that can be performed by the working mechanism. The machine control also coordinates the processing of the workpiece with the tool change necessary for this, which is accompanied by the actuation of the closure flap 7. It is provided as an example that the actuation control 30 is connected to the switching box 11 via a communication line 12.

As can be seen from the purely schematic illustration in fig. 2, the actuation control 30 comprises a valve system 31 and an associated processing means 32. Purely exemplarily, the processing means 32 is configured as a microprocessor and is in electrical connection with a valve 37 of the valve system 31 via control lines 33, 34, 35, 36. Furthermore, a plurality of sensor lines 41, 42, 43, 44 are connected to the processing means 32, wherein the sensor line 41 is connected to the first end position sensor 26 via the sensor line 28 shown in fig. 1 and the sensor line 42 is connected to the second end position sensor 27 via the sensor line 29 shown in fig. 1. Furthermore, a first pressure sensor 45 is connected to the processing means 32 via a sensor line 43, while a second pressure sensor 46 is connected to the processing means 32 via a sensor line 44. The processing means 32 is electrically connected via an internal communication line 56 to a communication interface 57, which is designed for connection to the communication line 12 and thus enables communication between the processing means 32 and the components accommodated in the switching box 11.

The valves 37 and 39 form a first valve assembly 48, which is connected via a first fluid line 50 to a first fluid connection 52, wherein the first fluid connection 52 is connected via a first fluid line 23 to the first working chamber 19 according to the illustration in fig. 1. The valves 38 and 40 form a second valve assembly 49, which is connected via a second fluid line 51 to a second fluid connection 52, wherein the second fluid connection 52 is connected via the second fluid line 24 to the second working chamber 20 according to the illustration in fig. 1.

Furthermore, the valves 37 and 38 are connected to a fluid source 54, which is only schematically illustrated and is typically arranged outside the actuation control 30. The valves 39 and 40 are connected to a fluid outlet which is provided, in particular, with a muffler 55. Purely exemplarily, the valves 37 to 40 are all designed as 2/2 directional valves, wherein the valves 37 to 40 are designed as solenoid valves according to the illustration of fig. 2, but in practice they can also be designed as piezo valves.

As can be gathered from fig. 2, the first pressure sensor 45 is arranged at the first fluid line 50 and thus allows the fluid pressure prevailing in the first working chamber 19 to be determined. The second pressure sensor 46 is arranged at the second fluid line 51 and thus allows a determination of the fluid pressure prevailing in the second working chamber 20.

During operation of the working mechanism 1, it is provided that only one of the respective two valves 37 to 40 of the respective valve arrangement 48 and 49 is opened, while the respective other valve 37 to 40 of the respective valve arrangement 48 and 49 is closed. The two working chambers 19, 20 of the compressed air drive 10 can thus be simultaneously ventilated, for example, by the valves 37 and 38 being opened and the valves 39 and 40 being closed. Furthermore, simultaneous venting of the two working chambers 19, 20 of the compressed air drive 10 can be initiated, for example, in that the valves 39 and 40 are opened and the valves 37 and 38 are closed. Typically, the parallel ventilation of one of the working chambers 19, 20 with the exhaust of the respective other working chamber 19, 20 takes place by opening the associated valves 37 and 39 or 38 and 40, respectively.

In the processing means 32, at least one program, that is to say a sequence of instructions, is stored, by means of which the actuation of the valves 37 to 40 can be carried out as a function of the electrical signals of the two end position sensors 26 and 27 and of the two pressure sensors 45 and 46 in order to carry out the movement for closing the flap 7. The program stored in the processing means 32 enables, in particular, a coordinated actuation of the valves 37 to 40 in order to achieve a high movement dynamics for the movement of the closure flap 7. The high kinetic forces are caused in particular by a strong pressure difference between the first working chamber 19 and the second working chamber 20 and include not only high accelerations for closing the flap 7 but also strong braking, which can be caused by suitable ventilation and venting of the two working chambers 19 and 20.

In the strictly schematic illustration of fig. 3, the signal profiles for the end position sensors 26 and 27 and for position sensors, not shown, which can be used as an alternative to the end position sensors 26 and 27 are shown, wherein the position sensors can extend along the movement path 15 along the drive housing 16 and determine the position of the working piston 18 along the entire movement path 15. Purely by way of example, it is assumed that a permanent magnet, which is not shown in greater detail, is arranged at the working piston 18 and that the two end position sensors 26, 27 and the position sensor, which is not shown, are designed to detect the field strength of the magnetic field provided by the permanent magnet, so that, when the end position sensors 26, 27 are used, a detection of the position of the working piston 18 can be carried out at least for a section of the movement path 15 or, when a position sensor is used, a complete detection of the position of the working piston 18 can be carried out.

As can be derived from fig. 3, the position sensor generates a position signal 60 which is proportional to the distance of the working piston 18 from the first end position 13 shown in fig. 1. Accordingly, the detection range of the position sensor extends over the entire length of the movement path 15. In contrast, the two end position sensors 26 and 27 are only designed to detect a partial section of the movement path 15. In this case, a first end position sensor 26 is arranged at the drive housing 16 in such a way that it can detect the working piston 18 as long as it is in the region of the first end position 13. A second end position sensor 27 is arranged at the drive housing 16 in such a way that it can detect the working piston 18 as long as it is in the region of the second end position 14.

As an example, the first end position sensor 26 provides a constant signal level 61 when the working piston 18 is arranged in the first end position 13 and when the working piston 18 is at a small distance from the first end position 13, which then decreases linearly with increasing distance of the working piston 18 from the first end position 13 and disappears with increasing distance of the working piston 18 from the first end position 13. In contrast, the second end position sensor 26 does not provide the signal level 62, as long as the working piston 18 is arranged in the region of the first end position 13. The signal level 62 rises purely exemplarily linearly to a maximum only when the working piston 18 is close to the second end position 14, which then remains constant until the working piston 18 reaches the second end position 14.

In the illustration of fig. 4, a first pressure profile p1 for the pressure in the first working chamber 19 and a second pressure profile p2 for the pressure in the second working chamber 20 are shown strictly schematically and purely by way of example, which can occur when a closing process for the closure flap 7 according to fig. 1 is carried out. The following description of fig. 4 proceeds from the fact that the closure flap 7 is initially arranged in the open position, with which the working piston 18 is arranged in the first end position 13.

At time t1, a ventilation signal is provided by processing mechanism 32 to first valve assembly 48 and an exhaust signal is provided to second valve assembly 49. The ventilation signal for the first valve assembly 48 causes the opening of the valve 37 shown in fig. 2, thereby establishing a connection for fluid communication between the fluid source 54 and the first working chamber 19. The exhaust signal for the second valve assembly 59 causes the opening of the valve 39 shown in fig. 2, thereby releasing the connection of fluid communication between the second working chamber 20 and the muffler 55. By opening the valve 37, according to the illustration in fig. 4, a pressure increase initially occurs for the first pressure p1 until the pressure on the working piston 18 caused by the pressure increase in the compressed air drive 10 is so great that the working piston 18, with the coupled piston rod 21 and the closure flap 7, begins to move from the first end position 13 in the direction of the second end position 14. The start of the movement takes place at time t2 and is accompanied on the one hand by a pressure drop for the first pressure p1 in the first working chamber 19 and a pressure rise for the pressure p2 due to the reduction in volume of the second working chamber 20.

From time t3, the acceleration phase for the closure flap 7 is complete and the same type of movement of the working piston 18, the piston rod 21 connected thereto and the closure flap 7 takes place up to time t 4. At time t4, the closure flap 7 has almost reached the closed position, so that to avoid a collision of the closure flap 7 in the closed position and to avoid a collision of the working piston 18 in the second end position 14, a brake is applied to the closure flap 7 and the working piston 18. To this end, a closing signal is provided to the valve 37 of the first valve assembly 48 in order to prevent a further supply of compressed air into the first working chamber 19. In addition, a closing signal is provided to valve 39 of second valve assembly 49 to prevent further venting of second working chamber 20. In addition, provision can optionally be made for a ventilation signal to be provided to the valve 38 of the second valve arrangement 49 in order to obtain a pressure increase in the second working chamber 20.

This causes a reduction in the movement speed for the working piston 18, the piston rod 21 connected thereto and the closure flap 7. As a result, a pressure reduction occurs in the first working chamber 19 from time t 4. Furthermore, a pressure increase is caused in the second working chamber 20 from time t4 until time t5, at which time the working piston 18 has reached the second end position 14 and the closure flap 7 thereby completely closes the housing recess 5. From this point in time, there is a force equilibrium of the pressure which acts on the working piston 18. For this force compensation at the working piston 18, it is necessary for the pressure p1 to be greater than the pressure p2, since the effective surface of the working piston 18 is reduced in the first working chamber 19 by the piston rod 21 and is smaller than the effective surface of the working piston 18 in the second working chamber.