DE9117102U1 - Coupling piece - Google Patents

Description

Coupling piece

The invention relates to a coupling piece which, in order to establish a fluid connection, in particular a hydraulic connection, between a first fluid technology component and a second fluid technology component, can be fastened to the first component and can be releasably anchored again in a receptacle of the second fluid technology component.

Couplings of this type are known in particular for hydraulic connections for use in hydraulic systems in a wide variety of designs. The removable anchoring is usually implemented by a screw connection, which is formed by an external thread of the coupling piece and a matching internal thread of the relevant receptacle, so that the known coupling pieces or the connection made with them can also be referred to as a screw coupling. The first fluid technology components are, for example, hydraulic connecting or connection lines in the form of hoses or pipes. The second fluid technology components are hydraulic components, such as hydraulic cylinders, interlinking blocks, valves or similar elements. A screw coupling basically has the advantage of high reliability and operational safety, also combined with the advantage that this connection can be released again if necessary, for example for repair purposes, using a suitable tool. The disadvantage of a screw coupling or screw connection is essentially the relatively high assembly effort required to create the connection, which in many areas, for example in automobile manufacturing, does not meet the requirements of efficient production.

The object of the invention is to provide a coupling piece which, while retaining the advantages of a coupling piece with removable anchoring, in particular

Screw coupling, the assembly effort required when connecting two fluid technology components, especially those of a hydraulic system, is significantly reduced.

To solve this problem, a coupling piece is designed according to the characterizing part of patent claim 1.

The invention makes it possible to pre-assemble the outer, sleeve-like element in the receptacle during the manufacture of the respective second fluid technology component. This is generally possible without any major effort because the manufacturer of the fluid technology components already has the tools necessary for efficient production and assembly. For the user, i.e. for example the manufacturer of machines or automobiles who purchases the fluid technology components with the pre-assembled elements of the respective coupling piece, the connection between a first and a second fluid technology component can be made by simply inserting or pushing the inner element into the outer element, i.e. by means of a plug-in assembly, which can be carried out very easily, in particular in areas of an automobile, for example, which are difficult to access with a tool.

In the invention, the removable anchoring is implemented by a rotary connection. The term "rotary connection" is preferably understood to mean a screw connection between the coupling piece and the second fluid technology component. However, other connections are also conceivable here that are created by turning or screwing in, such as bayonet-like connections or connections using a union nut provided on the coupling piece, etc.

If necessary, i.e. for repair purposes, for example, the connection made with the coupling piece according to the invention can be reconnected at any time using a suitable tool.

The invention thus combines the advantages of such a screw coupling with the advantage of a simple plug-in assembly.

The resilient locking elements are preferably expansion wings of an expansion sleeve that is arranged on the inner element. These locking wings are preferably evenly distributed around the circumference of the inner element and are provided on a sleeve-shaped or hollow-cylindrical section of the expansion sleeve. This section is then preferably enclosed in a cuff-like manner by a support or fastening sleeve that is held in a suitable manner on the inner element.

To seal the transition between the inner element or a channel formed there and a hydraulic guide formed in the second hydraulic component, a sealing ring is preferably provided on the inner element, which rests against a circular-cylindrical counter surface of the fluid guide that surrounds the sealing ring. This design has the advantage that even after the connection has been made, the inner element can be rotated or swiveled around an axis that is concentrically enclosed by the counter surface without damaging the seal. This makes it easy to align the hoses after assembly.

In a further embodiment, the locking surface is formed by at least one removable locking element. In this embodiment, the two elements of the coupling piece can be released by simply removing the locking element. Otherwise, a tool in the form of a release sleeve is preferably used to release the two elements of the coupling piece from one another.

Further developments of the invention are the subject of the dependent claims.

The invention is explained in more detail below with reference to exemplary embodiments and the figures. They show:

1 9· —·

Fig. 1 shows a simplified representation and in section of a two-part, screwable coupling piece according to the invention;

Fig. 2 shows an enlarged partial view and partly in section of the outer and inner elements as well as the expansion sleeve holding the inner element in the outer element of the two-part coupling piece according to Fig. 1;

Fig. 3 is a section along the line I-I of Fig. 2;

Fig. 4 shows a simplified representation and a section of a second possible embodiment of the coupling piece according to the invention;

Fig. 5 and 6 in side view and in section and in the direction of arrow A a third possible embodiment of the coupling piece according to the invention;

Fig. 7 shows a further improved embodiment of the invention in a similar representation to Fig. 1;

Fig. 8 and 9 show an enlarged detailed view of the expansion sleeve for use with the two-part coupling piece according to Fig. 7 in a front view and in section along the line III-III of Fig. 8;

Fig. 10 a blank made of spring sheet metal for producing the expansion sleeve according to Figures 8 and 9;

Fig. 11 and 12 in a similar representation to Fig. 7 or in section along the line IV-IV, a further embodiment of the coupling piece according to the invention;

Fig. 13 shows a release sleeve together with a partial view of the two-part coupling piece of Fig. 7.

Fig. 14 is a similar view to Fig. 2, in another possible embodiment of the invention.

In the figures, 1 is a fluid technology component, i.e. for example a hydraulic component or the body of such a component, which can have a wide variety of shapes and/or functions, for example a cylinder, a linking block, a valve, a hydraulic pump or similar fluid technology or hydraulic component. One end of a line, which in the embodiment according to Fig. 1 is a hose 3, is connected to the hydraulic component 1 or to a fluid guide 2 formed in this component, which is e.g. a channel, a chamber or similar fluid guide for the pressurized hydraulic fluid, using a coupling piece 4 to which one end of the hose 3 is permanently attached in a suitable manner, for example using a crimp sleeve.

The coupling piece 4 is designed in two parts and consists first of an outer, sleeve-like element 5, which forms a tool engagement surface on a first, upper section 5' in Fig. 1 on its peripheral surface enclosing the sleeve axis, i.e. in the embodiment shown is designed as a hexagon for standard open-end wrenches. This section 5' also has the upper end face 6 of the sleeve-like element in Fig. 1. Adjoining section 5', the sleeve-like element has section 5'', which forms the lower end face 7 of the sleeve-like element 5 made of metal in Fig. 1 and is provided on the circumference with an external thread 8, the external diameter of which is smaller than the smallest diameter of section 5'.

The sleeve-like element 5, which is screwed with its external thread 8 from the outside of the hydraulic component 1 into an internal thread of the section 2' of the fluid guide 2 with an enlarged cross-section, has a continuous bore 9, i.e., extending from the front side 6 to the front side 7, which has a circular cross-section over its entire length and is coaxial with the axis of the sleeve-like element 5. Starting from the front side 6, the bore 9 first has a section 9' and then a section 9'' extending to the front side 7, which has a larger cross-section than the section 9'. At the transition between the sections 9' and 9'', an annular contact surface 10 is formed, which encloses the axis of the sleeve-like element 5 and lies essentially in a plane perpendicular to this axis. In the embodiment shown, the axial length of the two sections 9' and 9 ^TT is approximately the same. However, this is not absolutely necessary. However, since the section 9' serves, in the manner described in more detail below, for axial guidance and radial fixation of the inner element 11 of the coupling piece 4, which is designed as a plug nipple and is also made of metal, it is necessary that the section 9 ¹ has a length sufficient for this function. In the area of the front side 6 or at the opening there, the bore 9 is bevelled at 9''' in such a way that it widens conically in the area of the opening there.

The element 11 consists essentially of a part 12 designed as a pipe piece or sleeve, which has a circular cylindrical peripheral surface and is provided with a channel 13 which is coaxial with the axis of the part 12 and is open at the upper end and at the lower end 12' of the part 12. At the upper end of the part 12, a head 14, also designed as a hose nozzle, is attached by brazing or in another suitable manner, in such a way that the channel 13 continues in a channel 15 provided in the head 14 in a sealed manner. At the upper end of the head 14 in Fig. 1, which is provided with a partial area 14' as

Handpiece is designed with an outer diameter that is larger than that of part 12, the above-mentioned one end of the hose 3 is attached.

Between the upper and lower ends of part 12, spring-loaded locking elements are provided which extend beyond the circumference and can be moved radially inwards, with which the inner element 11, designed as a plug nipple, is held in place by locking in the outer element 5. In the embodiment shown, these locking elements are formed by a single expansion sleeve 16, which is made from spring steel with all its elements in one piece by rolling and punching. As Figs. 2 and 3 show particularly clearly, the expansion sleeve 16 is divided at 17 and has, among other things, a sleeve-like or hollow cylinder-like section, which, however, is also not completely closed due to the division 17. On a common side of section 18, i.e. in the representation chosen for Fig. 1 and 2 on the upper side of section 18, the expansion sleeve 16 has four expansion wings 19 that protrude beyond this side, which are concave on their inner side relative to the axis of the expansion sleeve 16 and convex on their outer side, each curved in an approximately circular arc shape and bent radially outwards in such a way that the radial distance of the expansion wings 19 from the axis of the expansion sleeve 16 increases with increasing distance from section 18 and the expansion wings enclose an angle with the axis of the expansion sleeve. The expansion wings 19 each have the same width in the circumferential direction of the expansion sleeve 16. The expansion sleeve 16 is provided with a wing 20 on both sides of the division point 17. The two wings 20 extend over the same side of section 18 as the expansion wings, have the same length as the expansion wings 19 and form cylindrical surfaces on their inner and outer sides, which have a constant distance from the axis of the expansion sleeve 16 and merge into the corresponding inner and outer surfaces of section 18. These non-expanded wings 20 serve in the

in the manner described in more detail below for holding or fixing the expansion sleeve 16 to the element 11 or its part 12.

To hold and fix the expansion sleeve 16, the part 12 has an annular recess or recess 21 on its outer surface, which is axially limited, i.e. on both sides, by a shoulder or annular surface 22 or 23, respectively, which lies in a plane running perpendicular to the axis of the part 12. In the area of the upper annular surface 22 in Figs. 1 and 2 and in the area of the lower annular surface 23 in these figures, the recess 21 has a depth that is at least equal to, but preferably greater than, the thickness of the flat material used to produce the expansion sleeve 16. Furthermore, the recess 21 is essentially circular-cylindrical in both the area of the annular surface 22 and the area of the annular surface 23, with a diameter that is slightly larger than the diameter of section 18 of the expansion sleeve 16 in the relaxed state. The overall axial width of the recess 21, i.e. the distance between the ring surfaces 22 and 23, is equal to the axial length that the expansion sleeve 16 has in the area of the wings 20 and thus equal to the distance between the lower edge of the section 18 in Fig. 2 and the free end of the wings 20. The expansion sleeve inserted into the recess 21 is thus supported with the free ends of the two wings 20 on the ring surface 22 and with the lower side or edge facing away from the expansion wings 19 and the wings 20 against the ring surface 23 and is therefore also held in the recess 21 or on the part 12 in an axially non-displaceable manner. The axial width of section 21'' corresponds to the axial width of section 18 of the expansion sleeve 16. Between the two sections 21' and 21'', the recess 21 has another section 21''', where the outer diameter increases in a truncated cone shape with increasing axial distance from section 21"', namely corresponding to the inclination of the expansion wings 19. The section 21''' forms a contact and support surface for the expansion wings 19, which, however, has a free end of this

The expansion wings 19 have a length which is approximately equal to the axial width of the section ^21f , protrude beyond the side of the section 21''' facing the annular surface 22 and also protrude radially beyond the circumferential surface of the part 12 at their free ends. The maximum diameter of the section 21''' is in any case at least twice the thickness of the flat material used to manufacture the expansion sleeve 16 smaller than the external diameter that the part 12 has outside the recess 21, so that the element 11 designed as a plug nipple can be anchored in the element 5 by insertion and locking in the manner described in more detail below.

In order to achieve a two-end contact of the expansion sleeve 16 in the area of the wings 20 on the ring surfaces 22 and 23 despite the section 21''' and also to prevent the expansion sleeve 16 from twisting about the axis of the part 12, the recess 21 is provided with a flattening 24 where the wings 20 are arranged when the expansion sleeve 16 is mounted, which flattening extends over the entire axial width of the recess, ie over the entire area between the ring surfaces 22 and 23 in all sections 21'-21' ^!l .

In the area of the end 12', the part 12 is provided with an annular groove 25 which concentrically encloses the axis of this part and which is open both towards the circumference and towards the end 12' in such a way that a sealing or O-ring 26 arranged in this groove 25, when the coupling piece 4 is attached to the hydraulic component 1, not only rests on its radially outer circumferential area, but also on the front side against a sealing surface 27 or 28 which are formed in the fluid guide 2 of the hydraulic component 1. Since the groove 25 is designed in such a way that the O-ring 26 is also partially received in the groove 25 in its lower area in Fig. 1, the O-ring 26 is held captive on the part 12. By selecting a suitable material and by a correspondingly large cross-section, it is ensured that the O-ring has a particularly large spring-back volume.

The sealing surface 27, with which the O-ring 26 interacts with its radially outer region, is formed by the circular-cylindrical inner surface of a section 2'' of the liquid guide 2, which (section) has a smaller diameter than section 2', which is approximately the same as or slightly larger than the outer diameter of the part 12. The surface 27 of section 2 ^!l thus also serves as a support surface for radial support or fixation of the part 12 or the element 11. The sealing surface 28 is formed in that the liquid guide 2 adjoining section 2'' has a section 2''' with a smaller diameter than section 2'', so that the annular sealing surface 28 is formed as a shoulder in the transition region between sections 2'' and 2'''. The diameter of section 2''' corresponds to the diameter of the part at the end 12'.

The coupling piece 4 described above is used in such a way that when producing the components of a hydraulic system that are to be connected later, for example when producing the hydraulic components 1 and the hoses 3 with which these hydraulic components are to be connected, the hydraulic components 1 are each pre-assembled with the elements 5 and the lines 3 are each pre-assembled with the elements 11. This can be done efficiently without any problems when producing the hydraulic components, but also when producing the hoses 3. After installing the hydraulic components 1, for example in a motor vehicle or in a machine, these components 1 can then be connected to the hydraulic lines 3 in a particularly simple and assembly-friendly manner, namely by inserting the respective element 11 into the associated element 5. When this is inserted, the expansion wings 19 of the expansion sleeve 16 of the element 11 are each pressed radially inwards in a resilient manner. After passing the shoulder or ring surface 10, the spreading wings spread apart again and snap with their free ends behind the ring surface 10, so that the respective element 11 is

When it is snapped into place, it is held inseparably on the element 5 and the hose 3 is thus connected to the corresponding hydraulic component 1. With the O-ring 26, which is initially elastically compressed more strongly when the element 11 is inserted into the respective element 5, i.e. until the expansion wings 19 snap into place behind the contact surface 10, and after the expansion wings 19 snap into place on the contact surface 10, is still elastically deformed and tightly rests against the sealing surfaces 27 and 28, not only the transition between the section 2''' of the fluid guide and the channel 13 is sealed to the outside, but also the connection made with the coupling piece 4 to the hydraulic component 1 as a whole. This also means that due to the interaction of the O-ring 26 with the sealing surfaces 27 and 28 on the hydraulic component 1, no further sealing is required between this hydraulic component 1 and the sleeve-like element 5 and/or between the two elements 5 and 11. The entire sealing is therefore achieved with a single O-ring 26.

The above-described fixing of the expansion sleeve 16 by means of the wings 20 and the recess 21 has the advantage that the expansion sleeve 16 is attached to the part 12 with practically no play, even in the axial direction, so that the entire resilience of the O-ring 26 can be used for the engagement of the expansion wings 19 on the surface 10 and the elastic contact of the O-ring 26 against the sealing surfaces 27 and 28.

In order to avoid wear of the contact surface 10 caused by the spreading wings 19, especially in the case of dynamic or changing loads, the spreading sleeve 19 has slightly rounded edges at least on these spreading wings 19. Furthermore, the spreading wings can be bevelled at their free ends so that they rest against the contact surface 10 over as large an area as possible. In order to make it easier for the spreading wings 19 to snap into place behind the contact surface 10 despite the large area of contact, it can be expedient to produce the spreading wings 19 with a non-bevelled edge at their free ends and instead to slightly round the contact surface 10.

beveled, i.e. designed as a conical surface, in order to achieve the large-area contact of the spreading wings 19 on the contact surface 10. Furthermore, the element 5 consists, at least in the area of the contact surface 10, of a hard, wear-resistant material, i.e. of high-quality steel.

The expansion sleeve 16 can be mounted on the part 12 in a particularly simple manner by sliding the expansion sleeve on from the end 12'. The diameters are of course selected so that the expansion sleeve 16 is not overstretched when slid on, i.e. after sliding on, it tightly encloses the part 12 in the area of the recess 21.

A certain amount of force is required to insert the element 11 into the respective element 5 due to the elastic deformation of the spreading wings 19 that is necessary here. In order to be able to apply this force and in particular to avoid a mechanical force being exerted on the hose 3 connected to the element 11 when the element 11 is inserted into the element 5, which could damage the hose 3 due to excessive bending or kinking, the head 14 is designed as a relatively large-area or large-volume handpiece or engagement element for an assembly tool, as described above.

Fig. 4 shows a coupling piece 4a, which differs from the coupling piece 4 essentially only in that the element 11a corresponding to the element 11 does not have the head, and that instead of the hose 3, one end of a curved pipe section 29 or straight pipe section 30 is firmly connected to the element 11a, for example by brazing.

Fig. 5 and 6 show the coupling piece 4b, which differs from the coupling piece 4 only with regard to the element 11b corresponding to the element 11, i.e. the element 11b has an angle piece 31 with a connecting thread 32 at its upper end, with which a

any hydraulic line can be attached using a normal screw connection. In the coupling piece 4b, the cylindrical angle piece 31 also serves as a handle when inserting the element 11b into the element 5.

Fig. 7 shows, in a representation similar to Fig. 1, a two-part coupling piece 4c, which in many respects is very similar to the coupling piece 4 of Fig. 1, but represents a significant improvement in some aspects.

In Fig. 7, 1 is again the hydraulic component with the fluid guide 2 formed in this component, which, however, differs from Fig. 1, has a substantially constant cross-section (section 2 ¹ ') and only widens in the region of the outside of the hydraulic component 1, on which the coupling piece 4c is provided, to form the section 2' provided with the internal thread.

The coupling piece 4c in turn consists of the element 5, which is designed in the same way as the element 5 of the coupling piece 4 and is fastened in the section 2'. In Fig. 7, the element 5 with all its parts is therefore designated with the same reference numerals as are also used in Figures 1-3.

The coupling piece 4c also consists of the element lic, which is very similar to the element 11 in terms of its design and essentially consists of a part 32 designed as a pipe piece or sleeve, which has a circular cylindrical circumferential surface and is provided with a channel 34 which is coaxial with the axis of the part 33. The channel 34 is open at the lower end. At the upper end, the channel 34 ends in a head 35 designed as an angle piece, which is, for example, made in one piece with the part 33 and has an opening provided with an internal or connecting thread 36 for connecting the hydraulic

hose 3. In the coupling piece 4c, the head 35 also serves as a handle when inserting the element lic into the element 5.

Between the head 35 and the lower end 33' of the part 32, locking elements are provided which protrude over the circumference and can be moved radially inwards in a resilient manner, with which the element lic, which is designed as a plug-in nipple, is held in place by locking in the outer element 5. The locking elements are formed by a single expansion sleeve 37, which is made in one piece from a blank 38 made of spring steel sheet by punching and rolling. The expansion sleeve 37 is divided at 39 and has, among other things, a sleeve-like or hollow cylinder-like section 40. On a common side of the section 40, i.e. in the representation chosen for Fig. 7 on the upper side of this section, six expansion wings 41 are provided which protrude upwards over this side, which are concave on their inner side relative to the axis of the expansion sleeve 37 and convex on their outer side, each curved in an approximately circular arc shape and bent radially outwards in such a way that the radial distance of the expansion wings 41 from the axis of the expansion sleeve 37 increases with increasing distance from the section 40 and the expansion wings 41 enclose an angle with the axis of the expansion sleeve. The expansion wings 41 have approximately the same width in the circumferential direction of the expansion sleeve 37. As Figures 8 and 9 in particular show, in the expansion sleeve 37 (in contrast to the expansion sleeve 16) the expansion wings 41 are evenly distributed over the entire circumference. In particular, in the expansion sleeve 37 there is also an expansion wing 41 on each side immediately adjacent to the division 39. An area free of expansion wings, as is present on the wings 20 of the expansion sleeve 16, is therefore missing in the expansion sleeve 37.

To fix the expansion sleeve 37 to the part 33, a sleeve 42 (support or fastening sleeve) is also provided, which is also made from a cut piece of sheet steel or spring steel sheet by rolling and which concentrically supports the axis of the part 33.

encloses and with its upper area in Fig. 7 encloses the section 40 of the expansion sleeve 37 like a cuff and presses this section against the peripheral surface of the part 33 or against the bottom surface of a groove-shaped depression provided in the peripheral surface of the part 33 for receiving the section 40. With its lower part in Fig. 7, the sleeve 42 protrudes over the section and rests against the peripheral surface of the part 33 and is secured to this part by a bead 43 engaging in a peripheral groove of the part 33 or in some other way, for example by welding (spot welding) etc. The sleeve 42 and the section 40 of the expansion sleeve 37 are also connected to one another in a suitable manner (e.g. welding).

The sleeve 42 secures the expansion sleeve 37, in particular against axial displacement on part 33. The sleeve 43 also prevents the section 40 of the expansion sleeve 37 from expanding radially outwards when the expansion wings 41 are moved radially inwards in a resilient manner. The sleeve 42 therefore also makes a decisive contribution to improving the functionality and operational reliability of the coupling piece 4c.

The recess or groove-shaped recess 44 for receiving the section 40 has, at its upper edge area in Fig. 7, a truncated cone-shaped section 44', which corresponds to the section 21''' of the element 11 and forms a support surface for the spreading wings 41 in order to support their effect.

As shown in Fig. 7, the tubular part 33 has two sections, namely, starting from the head 35, a section 33'' with a slightly larger outer diameter, which is adapted to the diameter of the bore 9 and, adjoining this downwards, the section 33''', which has a slightly smaller outer diameter and extends to the end 33'. The transition between the sections 33'' and 33''' is located approximately in the area of the free ends of the spreading wings 41. The difference in the diameters of the sections 33 ^tT

and 33''' is at least equal to, but preferably slightly larger than twice the material thickness of the material used for the expansion sleeve 37. Furthermore, the outer diameter of the sleeve 42 is equal to, but preferably smaller than the outer diameter of the section 33''.

In the area of the lower end 33', the part 33 is provided with an annular groove 45 which is only open around the circumference. A sealing ring or O-ring 46 and a support ring 47 are provided in this groove, the latter on the side of the sealing ring 46 facing away from the end 33'.

The coupling piece 4c is used in the same way as described above for the coupling piece 4, i.e. the hydraulic components, for example those fastened in a motor vehicle and pre-assembled with the elements, can be connected to one another in an easy-to-assemble manner by simply inserting the elements lic pre-assembled on the hoses 3. When this is inserted, the spreading wings 41 are pressed radially inwards. After passing the shoulder or ring surface, the spreading wings 41 spread apart again and engage with their free ends behind the ring surface 10 of the respective element 5, so that the elements 5 and lic are permanently connected to one another by engaging, and the hydraulic connection between the hose and the corresponding hydraulic component is thus also established. The O-ring 46 lies sealingly against the inner surface of the liquid guide or section 2'', while the support ring 47 prevents the sealing ring from extruding into the gap to be sealed in a known manner. Since the sealing ring 46 only lies against a circular cylindrical surface concentrically enclosing the axis of the part 33 and not at the same time against a shoulder formed on the liquid guide, as is the case with the sealing ring 26 of the coupling piece 4, the element lic can be rotated or pivoted by 360° or more about the axis of the part 33 even after it has been connected to the element 5, and this without damaging the sealing ring 46. This enables a

Alignment of the hose 3 or the head 35 designed as an angle piece is possible after the elements 5 and lic have been connected, which further simplifies assembly. Since the sealing ring 46 only rests against the cylindrical inner surface of the liquid guide 2, the element lic can also be inserted into the respective element 5 with less effort (in comparison to the coupling piece 4). It is not necessary to compress the sealing ring 46 in the insertion direction.

Since the expansion sleeve 37 of the coupling piece 4c has the expansion wings 41 over its entire circumference, the result is a significantly improved anchoring of the element lic in the element 5 compared to the coupling piece 4, namely with regard to static and dynamic loads. In order to reduce the wear of the contact surface 10 caused by the expansion wings 41, particularly in the case of dynamic or changing loads, the expansion sleeve 37 again has slightly rounded edges on these expansion wings. Furthermore, the expansion wings 41 are preferably bevelled at their free ends so that they rest against the contact surface 10 over as large an area as possible.

Figures 11 and 12 show a coupling piece 4d which differs from the coupling piece 4c essentially only in that instead of the element 5 an element 5a is provided, the bore 9 of which has a constant cross-section. The contact surface corresponding to the shoulder or the contact surface 10 is formed in the coupling piece 4d by two fork arms 48 of a fork-shaped locking element. The locking element 49 is inserted with its fork arms 48 from the side into a recess 50 made in the hexagonal head or section 5' and intersecting the bore 9, in such a way that the two fork arms 48, which form the locking or contact surface for the spreading wings 41 with their areas lying in the bore 9, lie in a plane perpendicular to the axis of the bore and the locking element 49 with an angled end 51 over the circumference of the section

5', i.e. protrudes beyond a hexagonal side of this section. The locking element 49 on this section 5' is secured against accidental slipping out of the recess 50 by spring-loaded engagement on section 5' or in another suitable manner. As shown in Fig. 12, the two fork arms 48 are shaped in a circular arc on their inner sides, particularly in the area of the end 51, so that they act as a contact surface for the spreading wings 41 over the largest possible angular range in relation to the axis of the element 5a.

If the locking element 49 is provided on the element 5a, the elements 5a and lic are connected in the same way as described above for the coupling piece 4c. Using a suitable tool, for example a screwdriver, the locking element 49 can be removed from the element 5a to release the connection, whereby the element lic can be pulled out of the element 5a after the spreading wings 41 have been released. The advantage of this design is not only the relatively simple re-release of the two elements of the coupling piece Id, but it is also advantageous that the element 5a with the locking element 49 can be provided at practically any point on an outer surface of the hydraulic component 1, since by accommodating the locking element 49 in the section 5' of the element 5a, the re-releaseable connection using the locking element 49 can be provided at practically any point on a surface of the hydraulic component.

The frustoconical sections 21''' and 44' on the coupling pieces 4 to 4d not only act as a support for the expansion wings 19 and 41 of the expansion sleeves 16 and 37, but these frustoconical surfaces also increase operational reliability in that they ensure, after assembly of the respective expansion sleeve 16 and 37, that the expansion fingers 19 and 41 have the required spread, i.e. in the required manner over the circumferential surface of the respective element

11, lla, lib or lic protrude. The truncated cone-shaped sections 21''' and 44 also make it possible to produce the respective expansion sleeve 16 or 37 by simply punching and rolling, for example from the blank 38, without a further work step being necessary for spreading the expansion wings 19 or 41. This is then inevitably carried out by the support surfaces when assembling the respective expansion sleeve 19 or 37. This results in a significant simplification of production.

Fig. 13 shows a release sleeve 52, i.e. a tool which is particularly intended for use with the coupling piece 4c and with which it is possible to easily separate the two elements 5 and lic of this coupling piece in the event of repair, i.e. when the element 5 has been unscrewed from the hydraulic component 1. The release sleeve 52 made of metal, which is formed, for example, from a length of a piece of pipe or is made from a cut piece of sheet metal by rolling, has an inner diameter which is equal to the outer diameter of the sleeve 42 and an outer diameter which is slightly smaller than the diameter of the bore 9 of the element 5.

In order to be able to use the release sleeve 52, the element lic is designed so that the outer diameter of the sleeve 42 is smaller than the diameter of the bore 9 by at least twice the wall thickness of the release sleeve 52. To release the element lic from the element 5 unscrewed from the hydraulic component 1, the release sleeve is pushed onto the part 33 from the end 33', namely into the open end of the element 5 up to the area of the spreading wings 41. These are then pressed radially inwards with the release sleeve 52 so that they are released from the contact surface 10 and the element lic can be pulled off the element 5. Since the spreading wings 41 are evenly distributed around the circumference of the part 33, i.e. the spreading sleeve 37 has no area without spreading wings 41, the exact centering of the releasing sleeve 52 is possible when sliding it onto the spreading arms 41.

in relation to the axis of part 33 and thus a uniform inward pressing of all spreading wings 41 is possible with the unlocking sleeve 52. Unlocking with the unlocking sleeve 52, i.e. the uniform inward pressing of the spreading wings 41, is also supported by the section 44' forming the contact or support surface for the spreading finger 41.

Fig. 14 shows a coupling piece 4e which essentially corresponds to the coupling piece 4, but in which a ring 53 is provided instead of the expansion sleeve 16, which is arranged in a recess 54 of the element 11d corresponding to the recess 21. In the area of the recess 54, the element 11d has a constant outer diameter, i.e. the frustoconical section 21''' is missing there. The ring 53 is slotted, i.e. provided with a continuous slot 55 which is provided in an oblique manner, i.e. the slot 55 lies in an imaginary plane which is intersected by the central axis of the element 11d at an angle of less than 90°. The ring 53, which lies with its axis coaxial or parallel to the axis of the element 11d, can be supported with its upper and lower end faces against an annular surface delimiting the recess 54. On the peripheral surface, the ring 53 is designed in the shape of a truncated cone in such a way that the outer diameter of this ring in the representation chosen for Fig. 14 decreases from the upper end face to the lower end face of the ring 53, i.e. the ring 53 with its end face having the smaller outer diameter is closer to the end 12' of the element 11d than with its end face having the larger outer diameter. At least on the end face having the larger diameter, the outer diameter of the ring 53 is larger than the diameter of the section 9' of the bore 9, so that the element 11d is anchored to the element 5 by the ring 53. Through the slot 55, the ring 53 made of a resilient or elastic material, preferably spring steel, can act as a spring or expansion ring, i.e. when inserting the element 11d into the element 5 or the

When the ring 43 is pushed into the bore 9 there, it is elastically deformed via the frustoconical outer surface 56, which comes into contact with the surface of the bore 9, in order to reduce its outer diameter and then snaps behind the contact surface 10, whereby the element 11d is locked. It is understood that in the locked state the inner diameter of the ring 53 is larger than the outer diameter of the element 11d in the area of the recess 54. The oblique course of the slot 55 ensures that the element 11d is reliably anchored in the element 5, despite a relatively large slot width, even at the high operating pressures in hydraulic applications, for example around 250 bar, because the slot ends in the upper and lower end faces of the ring 53 are not directly opposite one another. Due to the truncated cone-shaped outer surface 56, this design also allows unlocking by means of the unlocking sleeve 52 if necessary.

The invention has been described above using exemplary embodiments. It goes without saying that numerous changes and modifications are possible without thereby departing from the inventive concept underlying the invention. Regardless of the specific design, all of the embodiments described combine the advantage that when installing the hydraulic components, for example in a vehicle or in a machine, the connection between the individual components can be made in a simple manner using only a plug-in assembly, with the advantage of a screw connection, with which it is possible to release the connection in question in the event of repairs. In the case of the coupling pieces 4, 4a, 4b, 4c, this is only possible with an appropriate tool. The coupling pieces naturally have dimensions such that they can be used with the usual hydraulic components. In a preferred use for micro-hydraulic components, the length of the elements 5 and 5a (distance between the end faces 6 and 7) is, for example, only 14 mm. The other dimensions are then also correspondingly small.

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List of reference symbols used

1 2'', 2''' I lla, lib, lic, Hydraulic component 2 Fluid flow 2', 4a, 4b, 4c, 4d, Section 3 5a Hose 4, 5'' 4e coupling piece 5, element 5', Section 6 Front side 7 Front side OO 9'' External thread 9 drilling 9', Section 9'' , 21'', 21''' bevel 10 Contact surface 11, lld element 12 Part 12' End 13 channel 14 Head 15 channel 16 Expansion sleeve 17 division 18 Section 19 Spread wings 20 wing 21 Turning 21' Section 22 Ring area 23 Ring area 24 Flattening 25 Groove 26 O-ring 27 Sealing surface 28 Sealing surface 29 Pipe section

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30 pipe pieces

31 Angle piece

32 connection thread

33 Part 33' End

33'' section

33''' Section

34 Channel

35 head

36 connection threads

37 Expansion sleeve

38 Cutting

39 Division

40 Section

41 Spread Wing

42 sleeve

43 bead

44 Recess 44' Section

45 groove

46 O-ring

47 Support ring

48 Fork arm

49 Locking element

50 recess

51 End

52 Release sleeve

53 Rings

54 Turn

55 slot

56 Exterior surface

Claims (31)

-m nclaims: 1. Coupling piece which can be fastened to the first component for establishing a fluid connection, in particular a hydraulic connection between a first fluid technology component and a second fluid technology component, and can be anchored again in a receptacle formed on the second component in a receptacle, characterized in that the coupling piece (4, 4a, 4b, 4b, 4c) is designed in at least two parts with an outer element (5, 5a) and an inner element (11, 11a, 11b, lic), that the outer element (5, 5a) is designed in the manner of a sleeve with a through-opening (9), has on its outer surface the means (8) for the releasable anchoring and also forms a tool engagement surface, and that the inner element (11, 11a, 11b, lic) at least in a partial area forming one end (12', 33') of this element (12, 33) is also designed in a sleeve-like manner with a channel (13, 34u) open at one end (12', 33'), that the channel (13, 34) of the inner element (11, 11a, 11b, lic) is also open at another end of this element (11, 11a, 11b, lic) and means (14, 31, 32, 35) for fastening the first fluid technology component (3, 29, 30) are provided there, and that the inner element (11, 11a, 11b, lic) with its sleeve-like section (12, 33) can be inserted from one end face (6) of the outer element (5, 5a) into its recess (9) and there by engaging at least one resilient locking element (19, 41) behind at least one locking surface (10, 48) can be locked. 2. Coupling piece according to claim 1, characterized in that a rotary connection, preferably a screw connection, is provided for anchoring the outer element (5, 5a) in the receptacle of the second fluid technology component (1). 3. Coupling piece according to claim 1 or 2, characterized in that the outer element (5, 5a) is provided with a peripheral surface forming a square or a hexagon in a partial area (5') to form the tool engagement surface. 4. Coupling piece according to one of claims 1 to 3, characterized in that the inner element (11, 11a, 11b, 11c) has at its other end means for connecting a hose (3) or a pipe piece (29, 30). 5. Coupling piece according to one of claims 1 to 4, characterized in that the inner element (11, 11a, 11b, 11c) after being connected to the outer element (5, 5a) protrudes with its one end (12', 33') within the receptacle (2) of the second fluid technology component (1) from the outer element (5, 5a). 6. Coupling piece according to claim 5, characterized in that, using at least one seal (26, 46), an outwardly sealed transition is formed between one end ( ^12f , 33') of the inner element (11, 11a, 11b, lic) or the channel (13, 34) of the inner element (11, 11a, 11b, lic) open there and a liquid guide (2) formed in the second fluid technology component (1). 7. Coupling piece according to claim 6, characterized in that the seal is a sealing or O-ring (26) made of elastic material with a particularly large spring-back volume provided on one end (12') of the inner element (11, 11a, lib), and that when the elements (5; 11, 11a, lib) are connected to one another, the sealing ring (26) rests against at least one sealing surface (27, 28) formed in the receptacle (2', 2''). 8. Coupling piece according to one of claims 1 to 7, characterized in that the receptacle is formed by a recess or by at least one section (2', 2'') of a liquid guide (2) in the second fluid technology component. 9. Coupling piece according to one of claims 1 to 8, characterized in that the locking elements are formed by expansion wings (19, 41) of an expansion sleeve (16, 37) which is manufactured in one piece with these and fastened to the inner element (11, 11a, 11b, 11c) or to its sleeve-like section (12, 33), that the expansion wings (19, 41) are inclined relative to the axis of the expansion sleeve (16, 37), and that the expansion sleeve (16, 37) is preferably divided. 10. Coupling piece according to claim 9, characterized in that the expansion sleeve (16, 37) has a sleeve-like or hollow cylinder-like section (18, 40), that the expansion wings (19, 41) protrude beyond one end of the sleeve-like section (18, 40). 11. Coupling piece according to claim 10, characterized in that the expansion sleeve (16, 37) forms at least one contact surface at each of its two ends, which are offset from one another in the direction of the axis of the expansion sleeve, which contact surface rests against one of at least two counter surfaces (22, 23) formed on this element (11, 11a, lib) for axially securing the expansion sleeve (16), and that the distance between the counter surfaces (22, 23) is equal to the distance between the two contact surfaces. 12. Coupling piece according to claim 11, characterized in that the expansion sleeve (16) has, in addition to the expansion wings (19) inclined relative to the axis of the expansion sleeve (16), at least one further wing (20) which preferably extends together with the expansion wings (19) over a common side of the sleeve-like section (18) · ca· protrudes, but lies substantially parallel to the axis of the expansion sleeve (16) and forms at its free end one of the at least two contact surfaces of the expansion sleeve (16). 13. Coupling piece according to claim 12, characterized in that at least two further wings (20) are provided, and preferably one such further wing (20) on each side of the dividing point (17) of the divided expansion sleeve (16). 14. Coupling piece according to one of claims 11 to 13, characterized in that the inner element (11, 11a, lib) has a recess (21) on the sleeve-like section (12), the edge or boundary surfaces (22, 23) of which form the counter surfaces. 15. Coupling piece according to one of claims 9 to 14, characterized in that a contact surface (21 ¹ '', 44'), preferably designed as a conical surface, is formed on the inner element (11, 11a, 11b, 11c), namely for supporting the spreading wings (19, 41) in the region of a partial length adjoining the sleeve-like section (18). 16. Coupling piece according to one of claims 1 to 15, characterized in that the at least one locking surface (10) is formed by a shoulder in the recess (9) of the outer element (5). 17. Coupling piece according to one of claims 1 to 16, characterized in that the recess (9) of the outer element (5, 5a) has a bevel (9' ¹ ') on that end face (6) from which the inner element (11, 11a, 11b, lic) is introduced into the outer element (5, 5a). 18. Coupling piece according to one of claims 1 to 17, characterized in that the inner element (11, 11b, lic) is formed with a head piece (14, 31, 35) with a wider cross section on a partial length which projects beyond the one end face (6) of the outer element (5, 5a) after the inner element (11, 11b, lic) has been inserted, this head piece preferably being provided in the region of the other end of the inner element (11, 11b, lic). 19. Coupling piece according to one of claims 1 to 18, characterized in that the inner element (11) has at its other end a hose nipple or a connecting piece (31) with a connecting thread (32). 20. Coupling piece according to one of claims 1 to 19, characterized in that the inner element (Ha) is designed at the other end for a connection of a pipe piece (29, 30). 21. Coupling piece according to one of claims 6-20, characterized in that the seal is a sealing or O-ring (46) provided at one end (33') of the inner element (lic), which concentrically encloses an axis of the inner element (lic), and that when elements (5, 5a; lic) are connected to one another, the sealing ring (46) rests against a cylindrical sealing surface formed in the receptacle (2', 2'') and concentrically enclosing the axis of the inner element (lic). 22. Coupling piece according to one of the preceding claims, characterized in that the sleeve-shaped section (40) of the expansion sleeve (37) is enclosed by a sleeve (42), and that the sleeve (42) is fastened or secured to the inner element (lic). 23. Coupling piece according to one of the preceding claims, characterized in that the spreading wings (41) are evenly distributed around the entire circumference of the inner element (lic). 24. Coupling piece according to one of claims 1-23, characterized in that the locking surface (48) is formed by at least one locking element (49) which is detachably provided on the element of the coupling piece having this locking surface, preferably on the outer element (5a) of the coupling piece. 25. Coupling piece according to claim 24, characterized in that the at least one locking element (49) is provided so as to be insertable on the element (5a) having the locking surface (48), and specifically in an axial direction which runs transversely or perpendicularly to the axial direction in which the inner element (lic) can be inserted into the outer element (5a). 26. Coupling piece according to claim 24 or 25, characterized in that the at least one locking element (49) is provided on a partial section of the element (5a) of the coupling piece (4d) having the locking surface (48), which (partial section) protrudes beyond the second hydraulic component (1). 27. Coupling piece according to one of claims 24 - 26, characterized in that the locking element (49) is fork-shaped with two fork arms (48) forming the locking surface. 28. Coupling piece according to one of the preceding claims, characterized in that the resilient locking element is a slotted ring (53) made of a resilient or elastic material, preferably spring steel. 29. Coupling piece according to claim 28, characterized in that the ring (53) has a slot (55) running obliquely to the axis of the ring. 30. Coupling piece according to claim 28 or 29, characterized in that the ring (53) is frustoconical on its outer surface (56). 31. Disassembly tool for use with a coupling piece according to one of claims 1-30, characterized by its design as a release sleeve (52).