EP0717199B1 - Flat-type fluid cylinder - Google Patents

Description

The invention relates to a working cylinder in a flat design, with an outside one at least essentially having a rectangular cross-sectional contour Cylinder housing, which is also at least one in essentially rectangular cross-sectional contour Recording space limited, in which a complementary contoured, axially movable piston is arranged, the with one on an open front face of the housing outstanding output rod is connected, whose length section located within the receiving space is contoured complementary to the receiving space and axially movable from the peripheral wall of the receiving space is performed, the opposite on the output rod Longitudinal section lying on the axial side of the piston of the recording space forms a first work space that with a connection opening for the supply and / or discharge of a communicates fluidic pressure medium.

Such, by the applicant under the name EZH distributed working cylinders are characterized by their particularly flat design from the rectangular-like Contouring the cylinder housing, the piston and the output rod results. In this working cylinder are linear guide function and pneumatic drive function compactly combined. Due to the non-rotating The working cylinder can be used in many applications be used where high accuracy is required.

In the known working cylinder, the extension stroke is the Output rod through the one supplied to the first work area caused fluidic fluid, which it expediently is compressed air. Will be the first Vented work space, ensures that one acting on the piston mechanical spring arrangement for resetting in the starting position. This integrated into the working cylinder However, spring arrangement is limited from conceptual Establish the maximum possible stroke and leads to a certain length of the Working cylinder. In addition, the restoring force is not variable, as it is fixed by the spring arrangement.

It is the object of the present invention, one compact working cylinder in flat design of the entrance to create the longer strokes and more variable Actuators enabled.

To solve this problem it is provided that the piston and the output rod with an axial distance from each other arranged and via an intermediate connecting rod are motion-coupled, their cross-section is smaller is that of the piston and the guided longitudinal section the output rod that inside the receiving space, with an axial distance to the open front of the housing, where the output rod protrudes Room divider element is sealed, which is is located axially between the piston and the output rod and sealed axially penetrated by the connecting rod is, and that the space divider between the Piston and the open face of the housing Longitudinal section of the receiving space axially in one on the second working space located on the side facing the piston and one facing the open housing end face Subdivision leadership room, with the second work space with a connection opening for the supply and / or discharge of fluid The pressure medium communicates and the leadership space within of the receiving space lying length section of the output rod records.

This is an extremely flat design enabling working cylinder, the fluidic double acting can be actuated so that it takes up a lot of space mechanical spring arrangement can be omitted. The possible fluid loading of the piston is permitted on both sides the achievement of variable actuating forces by simple Change the applied pressure conditions. Nevertheless remains with this arrangement good leadership and Get cross support of the output rod, which in the a relatively large cross-sectional area Lead room that runs through the room divider element in the Recording space is defined.

Advantageous developments of the invention can be seen in the Sub-claims emerge.

The space divider element expediently serves as a stroke limiting element for that from the piston, the connecting rod and the output rod existing, together movable unit. Depending on the stroke direction, preferably runs either the piston or the output rod at the stroke end on the room divider element, which is therefore a stop function Has. To dampen the impact, the relevant end faces of the room divider element with a Be buffered. However, the two preferably form the front end parts of the room divider element itself relevant buffer by the space divider expediently is designed as a plastic part overall, which has a certain elastic compliance.

In a preferred embodiment, the space divider element forms a combined stop and seal part, preferably made of elastomer material. In this case it seals the second workspace towards the lead room by using the peripheral wall of the receiving space and with the outer circumference the connecting rod is in sealing contact.

The supply and discharge of the print medium in and out of second work space is advantageously carried out via a in the space dividing fluid channel that in particular opens at the front and at least partially formed by a particularly annular longitudinal gap can be, which surrounds the connecting rod.

In favor of a low-wear sliding guide Output rod has also proven to be useful to manufacture this output rod from plastic material, the cylinder housing can be made of metal, for example made of aluminum material.

Fig. 1

eine erste Bauform des erfindungsgemäßen Arbeitszylinders, teilweise im Längsschnitt gemäß Schnittlinie I-I aus Fig. 2,

Fig. 2

einen Querschnitt durch den Arbeitszylinder aus Fig. 1 gemäß Schnittlinie II-II,

Fig. 3

einen Querschnitt durch den Arbeitszylinder aus Fig. 1 gemäß Schnittlinie III-III und

Fig. 4

eine weitere Bauform des Arbeitszylinders, wiederum teilweise im Längsschnitt analog der Schnittlinie I-I aus Fig. 2.

The invention is explained in more detail below with reference to the accompanying drawing. In this show:

Fig. 1

2 a first design of the working cylinder according to the invention, partly in longitudinal section according to section line II from FIG. 2,

Fig. 2

2 shows a cross section through the working cylinder from FIG. 1 according to section line II-II,

Fig. 3

a cross section through the working cylinder of FIG. 1 according to section line III-III and

Fig. 4

a further design of the working cylinder, again partly in longitudinal section analogous to section line II from FIG. 2.

The working cylinder shown in Fig. 1 to 3 has about a particularly flat design by making it overall has a cuboid-like outer shape, the rectangular cross section is chosen so that it has a comparison has a large long side to the narrow side, the extent of which in the exemplary embodiment at least twice big as that of the narrow side. It is because of it possible to pack several of these cylinders with to put their long sides together, the Center-to-center distance of cylinders in comparison to round-piston cylinders with the same piston area reduced about 40%.

The working cylinder has a cylinder housing 1, the outside is a rectangular cross-sectional contour with rounded corners. It has one Circumferential wall 2, which the radial limitation of one in the Cylinder housing 1 formed receiving space 3 forms. At the one, in Fig. 1 left end is this recording space 3 by a preferably in one piece with the peripheral wall 2 connected end wall 4 closed. This carries a mounting eye 5 for fixing the working cylinder on a component, not shown.

On the opposite other, on the right in Fig. 1 At the end, the cylinder housing 1 is open. Said end is referred to as the open housing end face 6.

The receiving space 3 has over its entire axial length, starting from the end wall 4 to its opening 7 on the open housing end 6, one continuously constant cross-sectional contour. At least this is the case here held substantially rectangular by two longer straight longitudinal sides 8, 8 'at a distance are parallel and the two narrow sides 9, 9 ' in particular are rounded off in a semicircle. Both Please note that the working cylinder in in practice can have a very small size, the longitudinal dimensions of the cross section e.g. 6.5 mm and the transverse dimensions e.g. 1.5 mm.

Sits inside the receiving space 3, at a greater distance to the open housing end face 6, a room divider element 12. According to the example, it is located approximately in the middle of the whole axial length of the receiving space 3. It divides the Recording space 3 in one of the end wall 4 facing Cylinder chamber 13 and one to the open housing end face 6 merging guide room 14.

In the cylinder space 13 is a complementary contoured, axially movable piston 15 added. This sits firmly on a connecting rod 16, which is coaxial extends to the receiving space 3 and a central, axial continuous opening 17 of the room divider element 12 enforced. Your protruding into the guide room 14 outer end 18 is at one in the embodiment plate-shaped output rod 22 set that is axially displaceably mounted in the guide space 14 and with an operating section 23 at the opening 7 protrudes beyond the cylinder housing 1. On the operating section 23 can be moved, not shown Define component.

While the cylinder housing 1 expediently Metal, for example made of aluminum material, is the exemplary output rod 22 is a plastic part. When fully retracted into the guide space 14 Position (Fig. 1) is the output rod 22 with your inner end at the facing end portion 24 of the room divider element 12. The whole inside of the guide space 14 lying length section of the output rod 22 has a complementary to the guide space 14 Cross-sectional contour. This expediently extends over the entire length of the output rod 22.

The output rod 22 and the connecting rod 16 could be formed in one piece in principle. Especially for Simplification of assembly is a separate one in the present case Design provided, the connecting rod 16 by means of a connecting device 25 on the Output rod 22 is fixed. 1 has the Output rod 22 on the room divider element 12 facing End face via a blind hole-like recess 26, in which the connecting rod with its outer end 18th protrudes. Here is a connecting device 25 transverse pin or bolt 25 'is provided which the end 18 penetrates and ends in two opposite Boundary walls of the recess 26 on the Output rod 22 is set.

The connection is preferably such that with respect to the Longitudinal axis of the bolt 25 'a degree of freedom between the output rod 22 and the connecting rod 16 are present, so that no tension can occur.

For reasons of compactness, the connecting rod is 16 1 to 3 a flat component, which is a substantially rectangular cross-sectional contour has, with the narrow edges rounded are. The main axes of all previously mentioned Rectangular components collapse.

The piston 15 of the embodiment sits on the End wall 4 facing inner end 27 of the connecting rod 16. There is expediently a cohesive Connection before. The piston 15 can be a plastic part be that directly by injection molding on the Connecting rod 16 is molded so that there are additional There is no need for fastening devices. In the area the outer circumference of the piston 15 carries a circumferential Sealing ring 28, which is conveniently in a Circumferential groove of the piston 15 is held and inside on the Circumferential wall 2 of the cylinder housing 1 bears sealingly.

The piston 15, the connecting rod 16 and the driven part 22 form an at least axially fixed to each other connected unit, which is axially related to each other Can move cylinder housing 1.

The piston 15 divides the cylinder space 13 into one first and a second working space 32, 33. The front Limitation of the first working space 32 forms the End wall 4, that of the second work room 33 forms the room divider element 12. Each work space 32, 33 communicates with its own connection opening 34, 35, via compressed air or another fluid pressure medium can be added or removed as required. The resulting pressurization of the piston 15 results in an axial movement of the same, whichever Stroke an extension or a retraction the output rod 22 with reference to the guide space 14 evokes.

The extension stroke of the output rod 22 is through the space divider element 12 limited. This forms a stroke limit stop for the piston 15, which at the end of its extension movement on the assigned end section 24 'of the room divider element 12. The arrangement is taken so that the output rod 22 in the maximum extended Always a little way in the lead room 14 protrudes and is supported in the transverse direction.

The axial clear distance between the piston 15 and the Output rod 22, reduced by the axial length of the Room divider element 12, gives the maximum possible stroke the output rod 22. The cross-sectional area of the connecting rod 16 is less than that of the piston 15 or the output rod 22. Your cross-sectional length and their cross-sectional width is smaller than the corresponding ones Dimensions of the receiving space 3, so that all around a space on all sides between the connecting rod 16 and the peripheral wall 2 is present.

The room divider element 12 is in the present case with respect to the Cylinder housing 1 separate component, the kind of a Partition wall with a seal to the peripheral wall 2 inside of the receiving space 3 is set. The fluid tight Sealing prevents pressure medium from escaping the adjacent second work space 33 Sealing contact between the room divider element 12 and the Connecting rod 16 before, so that in the area of Breakthrough 17 a fluid leak is excluded.

In principle, separate sealing elements could be used for sealing be provided. To the one already indicated above However, it is advisable to implement the minimum size corresponding one-piece sealant to be provided directly on the room divider element 12, as is the case with the exemplary embodiment.

Here, the room divider element 12 has on the outer circumference a circumferential outer sealing projection 36, the rests on the inside against the peripheral wall 2. Furthermore is also in the interior of the opening 17 integrally formed on the room divider element 12 all-round inner sealing projection 37, which the connecting rod 16 coaxially encloses under sealing contact. The sealing projections 36, 37 can be in the manner of sealing lips be formed that have a certain inclined course have, with their free end to the second to be sealed Working space 33 points. It is also an advantage if the room divider element 12 on the outer circumference in addition to the outer sealing projection 36 at least one complementary to the receiving space 3 contoured bearing section 38 has that for the transverse fixation of the room divider element 12 serves and over which the room divider element 12 tired in the recording room 3 sits. Said bearing section 38 extends 1 in the exemplary embodiment according to FIG a partial length of the room dividing element 12.

For axially immobile fixing of the room divider element 12 in the receiving space 3 is used in the embodiment a fastening device 39, which is also a positive Fixation with respect to the cylinder housing 1 causes. This has the advantage that the room divider element 12 despite hard impact of the piston rod 15 and the output rod 22 is not axially displaced. In case of exemplary inexpensive design of the fastening device 39 comprises these two as dowel pins trained cross pins that the space divider element 12 preferably diametrically opposite points across enforce and with their end areas, not shown are fixed in position in the peripheral wall 2. For assembly the room divider element 12 into the receiving space 3rd inserted until corresponding transverse openings of the Room divider element 12 with transverse bores in the peripheral wall 2 align, so that the spring pins only must be pressed in.

In order to achieve a certain impact absorption, there are two end portions 24, 24 'of the room divider element 12 made of material with rubber-elastic properties, preferably made of elastomer material. This face End portions 24, 24 'can be annular in themselves be closed axial projections, which the Surrounding connecting rod 16.

The space divider element 12 preferably consists entirely of Plastic material with the described properties, see above that it is with integrally molded outer and inner sealants 36, 37 can represent a single component, in which the stroke limitation function and the sealing function are combined. Such a room divider element 12 can be manufactured inexpensively by injection molding.

The two first and second connection openings mentioned 34, 35 are in the exemplary embodiment on connecting pieces 42, 43 provided, which is attached to the cylinder housing 1 are. The end wall 4 has one to the first Work space 32 open central recess 44, in the Circumferential area to the outside of the cylinder housing 1 open transverse bore 45 is provided. In the latter is the first connection piece 42 with a pin-like end section 46 used. It can be a press and / or There is an adhesive connection, as well as a screw connection. A penetrating the first connecting piece 42 Channel 47 opens into recess 44 on the inside and ends on the outside with the first connection opening 34.

The first connecting piece 42 is preferred as a plug nipple trained on which a pressure medium line can be plugged via which the fluidic pressure medium is supplied and discharged becomes.

The second connection opening 35 is on the correspondingly designed second connecting piece 43 is provided. Whose inner end section 46 'passes through one in the peripheral region of the room divider element 12 provided transverse bore 45 'of the peripheral wall 2 and protrudes into an alignment subsequent transverse recess 48 of the room divider element 12 inside. The latter is radially inward of the opening 17 open towards. There she communicates with a longitudinal one Fluid channel 52, the face on the face End portion 24 'opens into the second working space 33. The Fluid channel is preferably formed by a longitudinal gap 53, the radially between the connecting rod 16th and the surrounding wall of the opening 17 is located. This longitudinal gap 53 extends in the embodiment over the entire circumference of the connecting rod 16. The mentioned inner sealing projection 37 is located between the mouth of the transverse recess 48 and the front end portion 24 lying area of the Opening 17.

On the end wall 4 there is no need to attach a shock absorbing buffers. The order is made that the output rod 22 on the room dividing element 12th runs up before the piston 15 strikes the end wall 4.

The embodiment of FIG. 4 is essentially identical to that of FIGS. 1 to 3, so that the above Description applies accordingly. differences are only in the design of the Room divider element 12 and the connecting rod 16 and the connecting device 25. To improve the Fluid flow is in the connecting rod 16 surrounding wall of the opening 17 a groove-like Longitudinal recess 54 introduced into the transverse recess 48 empties, and an enlargement of the available standing flow cross section of the associated fluid channel 52 causes.

Furthermore, in this embodiment, the connecting rod 16 via a threaded connection on the output rod 22 fixed. Your outer end 18 is with one External thread 25 '' provided that in a complementary Internal thread of the recess 26 is screwed. In in this case, the connecting rod 16 expediently a circular cross-section over its entire length.

Claims (17)

1. Working cylinder in flat construction, with a cylinder housing (1) of an at least substantially rectangular external cross-sectional contour bordering a location chamber (3) of a likewise at least substantially rectangular cross-sectional contour, in which an axially movable piston (15) of a complementary contour is arranged and connected to an actuating rod (22) projecting from the location chamber (3) at an open end face (6) of the housing, the section of said actuating rod which lies within the location chamber (3) having a contour complementary to that of the location chamber (3) and being guided for axial movement by the circumferential wall (2) of the location chamber (3), whereby the section of the location chamber (3) lying at the axial end of the piston (15) which is opposite the actuating rod (22) forms a first working chamber (32) communicating with a port (34) for the supply and/or discharge of a pressure fluid, characterized in that the piston (15) and the actuating rod (22) are arranged at an axial distance from one another and dynamically coupled by an intermediate tie rod (16) of a smaller cross-section than that of the piston (15) and the guided section of the actuating rod (22), in that. within the location chamber (3), a chamber divider element (12) is fixed to form a seal at an axial distance from the open end face (6) of the housing where the actuating rod (22) projects, said element lying axially between the piston (15) and the actuating rod (22) and being axially penetrated by the tie rod (16) while forming a seal, and in that the chamber divider element (12) axially divides the section of the location chamber (3) lying between the piston (15) and the open end face (6) of the housing into a second working chamber (33) at the end facing the piston (15) and a guide chamber (14) facing the open end face (6) of the housing, the second working chamber (33) communicating with a port (35) for the supply and/or discharge of pressure fluid, while the guide chamber (14) contains the section of the actuating rod (22) which lies within the location chamber (3).
2. Working cylinder according to claim 1, characterized in that the tie rod (16) has an at least substantially rectangular cross-sectional contour.
3. Working cylinder according to claim 1 or 2, characterized in that the chamber divider element (12) acts as a stroke limiting element against which the piston (15) and/or actuating rod (22) run to limit the retraction or extension stroke.
4. Working cylinder according to any of claims 1 to 3, characterized in that the chamber divider element (13) is a plastic part, preferably an elastomer part.
5. Working cylinder according to claim 4, characterized in that the external circumference of the chamber divider element (12) is provided with at least one integral and circumferentially continuous external sealing projection (36) in contact with the circumferential wall (2) of the location chamber (3).
6. Working cylinder according to claim 4 or 5, characterized in that the opening (17) of the chamber divider element (12) penetrated by the tie rod (16) is assigned at least one internal sealing projection (37) integral with the chamber divider element in circumferentially continuous contact with the external circumference of the tie rod (16).
7. Working cylinder according to claim 6, characterized in that the internal sealing projection (37) lies within the opening (17).
8. Working cylinder according to any of claims 1 to 7, characterized in that the chamber divider element (13) is inserted into the location chamber (3) and fixed in position by at least one cross pin (39) anchored in the cylinder housing (1) at its end.
9. Working cylinder according to any of claims 1 to 8, characterized in that the fluid connection between the second working chamber (33) and the assigned port (35) is provided by a fluid passage (52) in the chamber divider element (12) terminating at the end face of the chamber divider element (12) which faces the second working chamber (33).
10. Working cylinder according to claim 9, characterized in that at least one section of the fluid passage (52) is represented by a longitudinal gap (53) between the tie rod (16) and the surrounding wall of the opening (17).
11. Working cylinder according to any of claims 1 to 10, characterized in that the port (35) assigned to the second working chamber (33) is arranged at a connecting piece (43) passing through the circumferential wall (2) of the location chamber (3), its end section (46) projecting into a lateral recess (48) of the chamber divider element (12).
12. Working cylinder according to any of claims 1 to 11, characterized in that the actuating rod (22) and the tie rod (16) are designed as separate components attached to one another by means of a connecting device (25, 25', 25").
13. Working cylinder according to claim 12, characterized in that the tie rod (16) projects into and is located in an end recess (26) of the actuating rod (22).
14. Working cylinder according to any of claims 1 to 13, characterized in that the actuating rod (22) is an in particular plate-like plastic part.
15. Working cylinder according to any of claims 1 to 14, characterized in that the piston (15) is a plastic part located on the piston rod (16) by a casting process.
16. Working cylinder according to any of claims 1 to 15, characterized in that the narrow sides of at least part of said at least substantially rectangular components are rounded.
17. Working cylinder according to claim 16, characterized in that the at least substantially rectangular components have a cross-section with straight side walls (8, 8') lying parallel to one another and narrow sides (9, 9') of a semicircular contour.

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