EP3781355A1

EP3781355A1 - Piston-cylinder device with automatic shut-off, vacuum holder and vacuum support table

Info

Publication number: EP3781355A1
Application number: EP19726558.0A
Authority: EP
Inventors: Alexander MINDERLEN; Jan Edler
Original assignee: Aventics GmbH
Current assignee: Aventics GmbH
Priority date: 2018-04-20
Filing date: 2019-04-17
Publication date: 2021-02-24
Anticipated expiration: 2039-04-17
Also published as: PL3781355T3; WO2019201368A1; DE102018003211A1; EP3781355B1; DE102018003211B4

Abstract

The invention relates to a piston-cylinder device with automatic shut-off, a vacuum holder and a vacuum support table. The aim of the invention is to provide a piston-cylinder device (1, 1) having a blow or suction function which can be switched off and which has a simple and compact design, can be produced in a simple and cost-effective manner and can be operated in an energy-efficient manner. The aim is achieved in that a piston-cylinder device (1, 1') having delivery means (7) arranged outside of the cylinder housing, in which a suction or pressure pipe (4) which is fluidically connected to the to a pressure device, is arranged in a static manner in the cylinder chamber and on which an axially movable piston (6) having a hollow piston rod (2) is slidingly mounted. The hollow piston rod (2) is arranged on the head side on the piston (6) and is formed with or connected to the delivery means (7), and wherein the hollow piston rod (2) or a pipe section connected thereto is formed below the delivery means (7) with an inner closure plug (9) which, in the retracted position of the hollow piston rod (2), closes a head-side opening (12) of the suction or pressure pipe (4) in a positive fit and releases the latter when the hollow piston rod moves out (2), wherein a fluidic connection can be established between the delivery means (7) and the suction or pressure pipe (4) simultaneously.

Description

Piston-cylinder device with automatic shut-off,

Vacuum holder and vacuum support table

Technical area

The invention relates to a piston-cylinder device with automatic shutdown, a vacuum holder and a vacuum support table.

State of the art

The prior art generally discloses the use of pneumatic piston-cylinder devices for handling workpieces. These may be formed, for example, with a blowing or suction function to hold workpieces or convey with compressed air. In this case, the overpressure or underpressure provided by an external pressure device is generally controlled via a separate switching valve, which creates a correspondingly high pneumatic and control-technical wiring effort.

Furthermore, in the prior art, the use of vacuum tables for

Temporary stationary holding flat workpieces by means of oppression known. Such devices serve the temporary fixation of the workpieces at individual processing stations in the context of a manufacturing process, such as for machining operations such as grinding, drilling, sawing or milling or, for example, for bonding or joining of components. Such vacuum tables usually consist of a central vacuum source, such as a vacuum pump, and a support surface interspersed with suction or suction holes which are in permanent fluid communication with the vacuum source. Since the suppressor is permanently provided independent of function, the operation is relative energy-intensive. In addition, there is a technical challenge in adapting the active area of the vacuum table to the shape and dimensions of the workpiece to be held. In practice, it is known here to cover remaining holes or suction holes with adapter mats, which, however, must be specially adapted to the shape of the respective workpiece to be machined and the desired machining geometry.

GB 892,771 discloses a work table for handling workpieces in which a plurality of vacuum holders are integrated, each formed of a piston-cylinder device with a suction head. The suction heads are arranged within holes in the plate of the work table and arranged at the upper end of a hollow piston rod which is formed at its lower end in each case with a piston axially movable in a cylinder housing. The suction heads are each extendable via a pressure port opening into the lower cylinder chamber and can be connected to a vacuum pump via a separate pressure connection of the hollow piston rod and acted upon by a vacuum. By simultaneous application of an opening into the upper cylinder chamber pressure port and the hollow piston rod with

Suppressing a holding torque is exerted on a respectively sucked by a suction head workpiece. The device disclosed by GB 892,771 does not disclose means for controlling the pressurization with a vacuum. The caves

Piston rods are constantly subjected to negative pressure during operation, irrespective of their function. Since the hollow piston rod each firmly connected to the piston and therefore can only be moved together with this, the must

Pressure connection of the hollow piston rod to be flexible and subject due to the movable connection a material wear.

DE 10 2004 025 781 B4 discloses a vacuum gripper with one of a

Vacuum source with a suppressible acted mouthpiece, which is connected via a hollow piston rod with a piston of a piston-cylinder device.

In the piston-cylinder device is a control valve for controlling the of

Sub-source of energy provided integrated, which controls a first, the mouthpiece displacing and a second, the mouthpiece with oppressing effect. The disclosed in DE 10 2004 025 781 B4, in the piston-cylinder Device integrated control valve is functional with a variety of

Parts relatively expensive and complex built.

JP 2004142949 A discloses Dl discloses a piston-cylinder device with a cylinder housing statically arranged intake manifold and a piston axiallybeweglich arranged on this, which is formed with a arranged outside the cylinder housing suction head. The control of the suction function is performed by a separate external control device.

DE 22 49 412 A discloses a piston-cylinder device in which an axially movable in a cylinder suction pipe is formed with a suction nozzle. The device further comprises a cylinder arranged to be axially movable Hubbüchse. The control of the travel of the components of the piston-cylinder device and the provision of the suction air via external connection. The disclosed by DE 22 49 412 A piston-cylinder device with suction function is functionally relatively expensive and complex built with a variety of items.

Disclosure of the invention

The invention is based on the object to avoid the disadvantages shown. In particular, a piston-cylinder device with a turn-off blowing or suction function is to be provided, which is constructed structurally simple and compact and can be easily and inexpensively manufactured and a

energy-efficient operation.

The object is achieved by a piston-cylinder device according to claim 1, advantageous embodiments are described in the subclaims.

The gist of the invention is a piston-cylinder device with a dispensing means arranged outside the cylinder housing, in which a suction or pressure tube, which can be brought into fluid communication with a pressure device, is provided, which in the

Cylinder space is arranged statically and on which an axially movable piston with a hollow piston rod is slidably mounted, wherein the hollow piston rod is arranged on the head side of the piston and formed or connected to the dispensing means, and wherein the hollow piston rod or a pipe section connected to it is formed below the dispensing means with an inner closure plug which positively closes a head-side opening of the suction or pressure tube in the retracted position of the hollow piston rod and releases it with the outward movement of the hollow piston rod, at the same time a fluid connection between the

Dispensing means and the suction or pressure tube can be produced. As a pressure device for use with the piston-cylinder device is depending on the desired function (blowing or sucking) an over- or a suppression providing

Pressure device as either a compressed air source, such as a compressor or compressed air storage, or a vacuum source, such as a vacuum pump. The closure plug is disposed in the hollow piston rod such that the operating fluid within the hollow piston rod surrounds it

Closing plug can flow through in a corresponding channel guide, if there is no positive connection between the plug and the suction or pressure tube. Furthermore, the closure plug may be formed within a separate tube section, which is screwed below the dispensing means onto the hollow piston rod, for example with a threaded connection or screwed into this. In this case, the dispensing means is indirectly connected via the separate tube section to the hollow piston rod which is disposed between the dispensing means and the hollow piston rod. For this purpose, the dispensing means can likewise be screwed onto the pipe section or screwed into it with a threaded projection.

In a structurally particularly simple embodiment, the cross-sectional area of the sealing plug or a lug formed by the stopper plug is smaller than the inner diameter of the hollow piston rod or the pipe section, and the sealing plug closes the head-side opening of the suction or pressure tube in the retracted position of the hollow piston rod form fit in that it is either flush with the end face, or that it engages flush with an extension in this circumference, or by being formed with a hollow-cylindrical projection which surrounds the head-side end of the suction or pressure tube in a flush manner. In these

Embodiment variants, the sealing plug is arranged in the hollow piston rod, that it can flow around the operating fluid within the hollow piston rod. For this purpose, the closure plug is held, for example via one or more web connections in the hollow piston rod or the pipe section, or at least one material connection between the closure plug and the wall of the hollow piston rod or the pipe section penetrating fluid channel is provided.

To improve the sealing seat or to compensate for manufacturing tolerances of the sealing plug is formed with one or more sealing means, via which or the positive connection to the suction or pressure tube can be produced.

A structurally simple drive with a mechanical return mechanism for the piston is provided by a cylinder chamber is formed acted upon by a pressure medium connection and the piston is formed with a direction of the loading direction counteracting spring return. The spring return can be constructively designed simply by a correspondingly arranged pressure or tension spring.

A structurally simple pneumatic return mechanism for the piston is provided by both Zylinderkammem are each formed by a pressure medium connection acted upon.

For the pneumatic control of the piston, at least one pressure medium connection can be controlled via a valve. In a structurally simple control solution, the at least one valve is a 3/2-way valve, in the switching positions of which a cylinder chamber connected to this is alternately acted upon and vented.

In an embodiment in which a pressure medium connection via a valve or a 3/2-way valve is controllable, the purely pneumatic control of the piston is made possible by the differential piston principle by the piston is formed with two different sized Beaufschlagungsflächen, with the controllable acted upon Cylinder chamber cooperating loading surface is greater than the other loading surface. In this case, both pressure medium connections can be operated with the same pressure and the uncontrolled pressure medium connection permanently be charged. When acting on the controllable via a valve actuated cylinder chamber of the piston moves in this case due to the larger, cooperating with this cylinder chamber loading surface of the piston against the simultaneous permanent pressurization of the other cylinder chamber. This allows a considerable simplification of the pneumatic interconnection of the piston-cylinder unit.

In an alternative structurally simple embodiment with a pure

pneumatic control, in which both cylinder chambers through

Pressure medium connections can be acted upon, both pressure medium connections are jointly controlled via a 5/2-way valve, in the switching positions, the two Zylinderkammem alternately bechselsinnig acted upon and are vented.

In the valve-controlled embodiments, a particularly compact design is ensured by the valve or the valves is arranged directly on or in the cylinder housing or are.

The piston-cylinder unit can be used as a vacuum holder or vacuum gripper by the pressure device is designed as a suction device and the suction or pressure pipe via the suction device can be acted upon with a negative pressure. to

To improve the frictional connection to a workpiece or object to be held, the dispensing means is preferably designed as a suction head or suction plate with one or more mammalian openings or suction nozzles.

In the above embodiment, a plurality of vacuum holders are used as a vacuum support table by the vacuum holders are physically connected to each other, wherein the dispensing means or the suction cups or suction cups form a support grid.

Further advantages of the invention are shown below together with the description of preferred exemplary embodiments of the invention with reference to FIGS. 1 to 6 in more detail. Show it: 1 is a schematic sectional view of a piston-cylinder unit with retracted piston rod,

Fig. 2 is a schematic sectional view of the piston-cylinder unit of FIG.

1 with extended piston rod,

3 is a schematic representation of the piston-cylinder unit of FIG. 1 with retracted piston rod in functional relationship with a 3/2-way valve and permanent loading of the upper cylinder chamber,

4 is a schematic representation of the piston-cylinder unit of FIG. 1 with retracted piston rod in functional relationship with a 5/2-way valve,

5 is a perspective view of a plurality of piston-cylinder

Facilities formed battery.

Fig. 6 is a perspective view of a plurality of batteries of FIG. 5 formed vacuum support table.

Figs. 1 and 2 show the piston-cylinder device 1 with the hollow piston rod 2. The hollow piston rod 2 is slidably mounted on the cylinder 3 fixedly connected and arranged in this statically arranged suction or pressure pipe 4. In Fig. 1, the hollow piston rod 2 is in its retracted position. In Fig. 2, the hollow piston rod 2 is in its extended position. The suction or pressure pipe 4 is formed on the bottom side with a Druckeinrichtungs- connection 5, via which the suction or pressure pipe 4 can be connected to a (not shown in FIGS. 1 and 2) pressure device and can be brought into a fluid connection with this. The hollow piston rod 2 is arranged on the head 6 on the piston 6 and together with this on the suction or pressure tube 4 movable. The hollow piston rod 2 is formed on the head side with the dispensing means 7, which serves to deliver a suction or pressure action via the central opening 8, depending on whether an overpressure or a negative pressure is provided by a pressure device connected to the pressure device connection 5. is the pressure device port 5 is connected to a vacuum source such as a vacuum pump (not shown in Figs. 1 and 2), the piston-cylinder device 1 is usable as a vacuum holder. Below the dispensing means 7, the hollow piston rod 2 is formed with the inner plug 9. The closure plug 9 is held firmly in the hollow piston rod 2 via a material connection, which is penetrated by the fluid channels 10 and 10 '. The plug 9 is formed with the lug 11, which has a smaller cross-section than the inner diameter of the hollow piston rod 2. In the retracted position of the hollow piston rod 2 engages the stopper 9 with the cylindrical projection 11 in the head-side tube opening 12 of the suction or Pressure tube 4 circumferentially flush, wherein it closes the suction or pressure tube 4 positively. To improve the sealing seat of the projection 9 in the suction or pressure tube 4, the cylindrical projection 11 may be formed with a circumferential O-ring seal (not shown in FIGS. 1 and 2). With the extension movement of the hollow piston rod 2, the sealing plug 9 releases the head-side tube opening 12 of the suction or pressure tube 4, at the same time establishing a fluid connection between the suction or pressure tube 4 and the delivery means 7. The cylinder 3 is connected to the upper, in the above the piston 6 located cylinder chamber 13 opening

Pressure medium connection 14 and the lower, in the cylinder chamber located below the piston 6 cylinder chamber l3 'opening pressure medium connection l4' formed. The

Zylinderkammem 13 and l3 'are acted upon via the pressure medium connections 14 and l4' with a fluid, whereby the piston 6 is movable up or down. Since the cooperating with the upper cylinder chamber 13 head-side loading surface 15 of the piston 6 due to the head-side arrangement of the hollow piston rod 2 on the piston 6 is smaller than that with the lower cylinder chamber l3 '

together acting bottom-side loading surface l5 ', the piston 6 is operable according to the differential piston principle. In the simultaneous application of both

Beaufschlagungsflächen 15 and 15 'with identical pressure pass the piston 6 due to the larger effective area of the bottom-side loading surface L5' upwards. To enable a Positionsabffage the piston 6 may be formed as a magnetic piston, wherein at the same time one or more inductive sensors are provided on or in the cylinder 3 (in Figs. 1 and 2 not shown. Fig. 3 shows the piston-cylinder device 1 in a schematic functional representation with the 3/2-way valve 16. The hollow piston rod 2 is located in Fig. 3 in its retracted position. The 3/2-way valve 16 is used to control the

Pressure medium connection l4 '. It is located in the illustration according to FIG. 3 in its first switching position, in which the pressure medium connection l4 'is connected via the valve connection 17 to the compressed-air outlet 18. The lower cylinder chamber 13 'is vented in this switching position of the 3/2-way valve 16 via the compressed air outlet 18. The upper pressure medium connection 14 is connected to the compressed air inlet 19. The upper

Cylinder chamber 13 is permanently acted upon via the compressed air inlet 19 with the pressure Pl. In its second switching position, the 3/2-way valve 16 connects the pressure medium connection l4 'via the valve port 17 to the compressed air inlet l9'. In this switching position, the lower cylinder chamber 13 'is also acted upon by the pressure Pl via the compressed air inlet l9'. Due to the larger effective area of the bottom-side loading surface 15 ', the piston 6 moves in the second

Switching position of the 3/2-way valve 16 upwards.

Fig. 4 shows the piston-cylinder device 1 in a schematic functional representation with the 5/2-way valve 20. The hollow piston rod 2 is located in Fig. 4 in its retracted position. The 5/2-way valve 20 serves to control the two pressure medium connections 14 and 14 '. It is located in the illustration according to FIG. 4 in its first switching position, in which the pressure medium connection l4 'is connected via the valve connection 17 * to the compressed air outlet 18'. The lower cylinder chamber 13 'is vented in this switching position of the 5/2-way valve 20 via the compressed air outlet l8'. At the same time, the upper pressure medium connection 14 in this switching position of the 5/2-way valve 20 via the valve port 17 "of the 5/2-way valve 20 with the

Compressed air inlet 19 "connected. The upper cylinder chamber 13 is in this

Switching position of the 5/2-way valve 20 via the compressed air inlet 19 "acted upon. In its second switching position, the 5/2-way valve 20 connects the pressure medium connection l4 'via the valve port 17' to the compressed air inlet 19 ". In this switching position, the lower cylinder chamber 13 'via the compressed air inlet 19 "is acted upon.

At the same time, the upper pressure medium connection 14 in the second switching position of the 5/2-way valve 20 via the valve port 17 "of the 5/2-way valve 20 with the Compressed air outlet 18 "connected. The upper cylinder chamber 13 is vented in the second switching position of the 5/2-way valve 20 via the compressed air inlet 18 ". Since the upper cylinder chamber 13 is vented in the second switching position of the 5/2-way valve 20 and the lower cylinder chamber l3 'is applied simultaneously, the piston 6 in the second switching position of the 3/2-way valve 16 go up.

Fig. 5 shows eight similar piston-cylinder devices G (in Fig. 5 is

For the sake of clarity, only one of the illustrated piston-cylinder devices 1 'quantified), which are physically connected to one another as a battery. The piston-cylinder devices 1 'are each formed on the bottom side with a valve 21 (in FIG. 5, for the sake of clarity, only one of the valves 21 is numbered). The piston-cylinder devices G are each formed at their upper end with a discharge means designed as a suction plate 22 (in FIG. 5, for the sake of clarity, only one of the suction plates 22 is numbered). The suction cups 22 each have a central mammal opening 23.

Fig. 6 shows the vacuum support table 24, which is formed from a plurality of similar, mutually physically connected batteries as shown in FIG. 5 (in FIG. 6, for the sake of clarity, only one of the illustrated piston-cylinder devices 1 'is numbered). The suction cups 22 (in FIG. 6, for reasons of clarity, only one of the suction plates 22 is numbered) form a common support grid for receiving a workpiece.

LIST OF REFERENCE NUMBERS

1, 1 piston-cylinder device

2 Hollow piston rod

3 cylinders

4 suction or pressure tube

5 printer port

6 pistons

7 delivery means

8 opening

9 plug

10, 10 fluid channel

11 approach

12 pipe opening

13, 13 ^* cylinder chamber

14, 14 ⁴ Pressure medium connection

15, 15 ^* loading area

16 3/2-way valve

17, 17% 17 "valve connection

18, 18 ^* , 18 "compressed air outlet

19, 19 ^* , 19 "compressed air inlet

20 5/2-way valve

21 valve

22 suction cups

23 mammal opening

24 V acuum support table

Claims

claims

1. piston-cylinder device with a disposed outside the cylinder housing dispensing means, characterized in that a pressure device in fluid communication with a suction or pressure tube (4) is provided, which is arranged statically in the cylinder chamber and on which an axially movable piston ( 6) is slidably mounted with a hollow piston rod (2) wherein the hollow

Piston rod (2) arranged on the head side of the piston (6) and formed or connected to the dispensing means (7), and wherein the hollow piston rod (2) or a pipe section connected to it below the dispensing means (7) with an inner

Closure plug (9) is formed, which in the retracted position of the hollow piston rod (2) a head-side opening (12) of the suction or pressure tube (4) positively closes and this with the extension movement of the hollow

Piston rod (2) releases, wherein at the same time a fluid connection between the delivery means (7) and the suction or pressure tube (4) can be produced.

2. Piston-cylinder device according to claim 1, characterized in that the cross-sectional area of the sealing plug (9) or of the closure plug (9) formed neck (11) is smaller than the inner diameter of the hollow piston rod (2) or of the pipe section , And the closure plug (9), the head-side opening (12) of the suction or pressure tube (4) in the retracted position of the hollow piston rod (2) positively closes by engaging these end face flush, with a lug (11) in this engages flush with the circumference, or is formed with a hollow cylindrical projection, which surrounds the head-side end of the suction or pressure tube (4) flush.

3. Piston-cylinder device according to claim 1, characterized in that the closure plug (9) via one or more web connections in the hollow

Piston rod (2) or the pipe section is held or in a material connection between the closure plug and the wall of the hollow piston rod or the pipe section at least one of these penetrating fluid channel (10, l0 ') is provided.

4. piston-cylinder device according to one of claims 1 to 3, characterized

characterized in that the closure plug is formed with one or more sealing means, via which or the positive connection to the suction or pressure pipe (4) can be produced.

5. piston-cylinder device according to one of claims 1 to 4, characterized

characterized in that a cylinder chamber (13, l3 ') by a

Pressure medium connection (14, l4 ') is formed acted upon and the piston (6) is formed with a the biasing direction counteracting spring return.

6. piston-cylinder device according to one of claims 1 to 4, characterized

characterized in that both Zylinderkammem (13, 13 ') each by a

Pressure medium connection (14, l4 ') are formed acted upon.

7. piston-cylinder device according to claim 6, characterized in that

at least one pressure medium connection (14, l4 ') via a valve (21) is controllable.

8. piston-cylinder device according to claim 7, characterized in that the at least one valve (21) is a 3/2-way valve (16), in its switching positions connected to this cylinder chamber (l3 ') is alternately acted upon and vented ,

9. piston-cylinder device according to one of claims 6 to 8, wherein a

Pressure medium connection via a valve or a 3/2-way valve is controllable, characterized in that the piston (6) with two different sizes

Beaufschlagungsflächen (15, 15 ') is formed, wherein the controllably acted upon cylinder chamber (l3') cooperating loading surface (l5 ') is greater than the other loading surface (15).

10. piston-cylinder device according to claim 6, characterized in that both pressure medium connections (14, l4 ') together via a 5/2-way valve (20) controllable are, in whose switching positions, the two Zylinderkammem (14, l4 ') alternately beechelsinnig acted upon and can be vented.

11. piston-cylinder device according to one of claims 7 to 10, characterized

in that the valve (21) or the valves are located directly on or in the

Cylinder housing is or are arranged.

12. Vacuum holder with a piston-cylinder device according to one of claims 1 to 11, characterized in that the pressure device is designed as a suction device and the suction or pressure tube (4) can be acted upon by the suction device with a negative pressure.

13. Vacuum holder according to claim 12, characterized in that the dispensing means (7) as a suction head or suction cup (22) with one or more mammalian openings (23) or suction nozzles is formed.

14. Vacuum support table with a plurality of vacuum holders according to claim 12 or 13, characterized in that the vacuum holders are physically connected to each other, wherein the dispensing means (7) or the suction cups or suction cups (22) a

Form support grid.