Coupling part for a hydraulic coupling

Abstract

The invention relates to a coupling part, in particular a male coupling piece (2), for coupling to a corresponding second coupling part, in particular a female coupling piece (3), of a coupling (1) for pressure-medium lines, in particular hydraulic lines, comprising: a housing (21, 31) having a continuous flow channel (23, 33) extending in the axial direction; a valve tappet (61) for closing the flow channel (23, 33) when the coupling part (2, 3) is in the non-coupled state, the valve tappet being arranged within the flow channel (23, 33) such that the valve tappet can be moved back and forth in the axial direction, and the valve tappet (61) having a closed valve position in which the valve tappet closes the flow channel and an open valve position in which the valve tappet does not close the flow channel (23, 33); a connecting device for mechanically connecting the coupling part to the second coupling part to be coupled, wherein: the coupling part (2, 3) comprises a base part (4, 4*) and a connection part (5) which are connected to one another and form the flow channel (23, 33); the connection part (5) has a connection portion for the connection of a pressure-medium line; the base part (4, 4*) and the connection part (5) each have at least one connecting portion (43, 56); and at least one connecting portion (43, 56) of the connection part (5) is radially press-fitted to a connecting portion of the base part (4, 4*).

Description

[0001] Lawyer's file 25184

[0002] October 8, 2025

[0003] Coupling part for a hydraulic coupling

[0004] The invention relates to a coupling part with a first spring-loaded valve, in particular a coupling plug, for coupling with a corresponding second coupling part, in particular a coupling sleeve, having a second spring-loaded valve, for a coupling for pressure medium lines, in particular hydraulic lines, in which the valves of the two coupling parts open each other automatically when coupling, thereby connecting their flow channels, and close automatically by means of spring force when uncoupling, according to claim 1.

[0005] Couplings of this type are designed, for example, as quick-connect or screw couplings and ensure the rapid connection and disconnection of two hydraulic lines, particularly hydraulic lines. They are primarily used to connect hydraulic devices to a hydraulic power source, for example, to connect a tool to an agricultural or construction machine. The couplings consist of two pluggable coupling parts: a plug and a socket. Both coupling parts have an axial flow channel for the hydraulic fluid. The plug can be inserted into a receiving opening in the socket and releasably locked to it. If the locking mechanism is a screw connection, such as a locking sleeve, it is a screw coupling. A quick-connect coupling uses, for example, a locking ball mechanism as its locking device.Each coupling component also has a coupling housing containing a spring-loaded valve. In the uncoupled state, the valves are positioned to close the flow channel of the respective coupling component. When the two coupling components are connected, the valves open automatically, thus connecting the two flow channels. When disconnected, the valves automatically close the respective flow channel by spring force. Each coupling component has a housing consisting of a base containing the valve and a connection part with a port for a hydraulic line or a machine. The base and connection parts are typically manufactured as separate components, each with a threaded connection for bolting them together.Couplings with such coupling parts are described, for example, in DE 10 2014 010 570 A1 and EP 4 390 207 A1.

[0006] Couplings of the aforementioned type are subjected to mechanical loads and vibrations during their service life. To prevent the screw connections between the base and coupling parts from loosening unintentionally, it is known to secure the screw connections with adhesives. Although most screw connections today are provided with such chemical threadlockers, it still occurs that the screw connection loosens over its service life due to stress and environmental influences. This can lead to damage to the coupling components, which can impair the coupling function or even render it unusable.

[0007] The invention aims to remedy this problem. The invention is based on the objective of providing a coupling part, in particular a coupling plug, for coupling with a corresponding coupling part, in particular a coupling sleeve, a coupling for pressure medium lines, especially hydraulic lines, as well as such a coupling in which a loosening of the connection between the base part and the connection part is reliably prevented. According to the invention, this objective is achieved by a coupling part with the features of the characterizing part of claim 1.

[0008] The invention provides a coupling element, in particular a coupling plug, for coupling with a corresponding coupling element, in particular a coupling sleeve, a coupling for pressure medium lines, especially hydraulic lines, in which a loosening of the connection between the base element and the connection element is reliably prevented. A reliable connection between the base element and the connection element is achieved because the base element and the connection element each have at least one connecting section, wherein at least one connecting section of the connection element is radially crimped to a connecting section of the base element.

[0009] The coupling part has a first spring-loaded valve for the production of a coupling of the generic type with a corresponding coupling part and is designed in such a way that it opens the second spring-loaded valve of this corresponding coupling part when coupling.

[0010] In this context, the term "pressing" refers to a joining process in which two parts are joined together through a forming process. "Radial pressing" refers to pressing with exclusively or predominantly radial pressing forces.

[0011] In a further development of the invention, at least one connecting section of the base part is provided, at least partially, with a toothing that engages with a toothing present in a connecting section of the connecting part, wherein the toothing of the connecting sections of the base part and the connecting part is radially pressed together. This increases the effective contact area, thereby further improving the connection between the base part and the connecting part.

[0012] In one embodiment of the invention, a forming section is arranged adjacent to the toothing of a connecting section, the deformation of which achieves the compression fit. This results in an improved frictional connection. Advantageously, the toothing has at least one area with a triangular, trapezoidal, and / or rectangular cross-section.

[0013] In a further embodiment of the invention, the toothing has teeth of different heights. This further improves the positive locking force.

[0014] In a further embodiment of the invention, the toothing has teeth whose two flanks have different angles to the tooth root. This further improves the positive locking. Advantageously, the respective angle is between 45° and 60°. In this context, the "tooth root" refers to the plane of the cylindrical surface on which the tooth is mounted.

[0015] In a further development of the invention, an annular groove for receiving a sealing ring is provided following the toothing. This achieves an additional seal between the connecting part and the base part.

[0016] In one embodiment of the invention, at least one connecting section of the base part is provided, at least partially, with a thread that engages with a thread present in a connecting section of the connecting part. This achieves a defined axial positioning of the base part and connecting part during assembly via a screwing-in process. Furthermore, the thread engagement provides an additional connection.

[0017] In a further embodiment of the invention, the base part and the connecting part each have an axial stop surface that abuts one another. An interference section is attached to the thread of the base part (or alternatively, the connecting part) on its side facing the stop surface, and an axially narrowing press section is attached to the thread of the connecting part (or alternatively, the base part) on its side facing the stop surface. During the screwing-in process, the interference section is at least partially radially pressed against the press section. This achieves a press fit between the base part and the connecting part via the axial screwing force. The axial movement of the interference section arranged on the base part into the narrowing press section results in a press fit between the base part and the connecting part in this area.

[0018] The oversize section has a defined, preferably conical geometry, with the press-fit section forming a counterpart with a reduced diameter. The difference in diameter should not exceed 0.1 mm to 0.5 mm, depending on the diameter. The geometry itself preferably consists of a surface tapering conically at an angle of between 5° and 85° to the central axis, preferably at an angle of between 5° and 45° to the central axis.

[0019] This compression, achieved through a targeted overlap of the two preferably conical geometries during the screwing process, effectively secures the screw connection, which may also be additionally provided with a chemical locking agent in a known manner, against loosening, thus achieving a reliable connection.

[0020] In a further development of the invention, an annular groove or a shoulder for receiving a sealing ring is arranged in the stop surface of the base part and / or the stop surface of the connecting part. This provides additional sealing of the base part against the connecting part. Alternatively or additionally, an annular groove or a shoulder for receiving a sealing ring can be arranged between the thread and the excess section in the base part and / or the connecting part.

[0021] Due to the hydraulic pressure that builds up in the coupling during operation, the individual components expand to different degrees (dilation). A fluid-tight seal between the connecting part and the base body can be achieved directly via appropriately designed conical surfaces or by installing an additional soft seal, for example, an elastomer O-ring. The positioning of the seal between the connecting part and the base body can influence the expansion of the components. For this proposed solution, positioning a soft seal, preferably axially between the connecting part and the base body, is advantageous.

[0022] This achieves the result that the base body experiences greater elongation than the connecting part. Under the influence of internal pressure, this further increases the surface pressure between the preferably conical bearing surfaces of the interference and compression sections due to the differences in elongation between the two bodies. External moments that promote loosening of the connection act primarily on the pressure-loaded phases. These phases are also those where the surface pressure between the conical surfaces is greatest. Therefore, these phases in particular offer maximum security against unintentional loosening of the connection between the base and connecting parts.

[0023] The present invention further relates to a coupling for a pressure medium line with the features of claim 12. Preferably, the coupling plug and the coupling sleeve each have a valve plunger which, in the course of connecting the coupling plug and coupling sleeve, lie against each other and are each axially displaced against a spring preload into an open valve position, whereby the axial flow channels of the coupling plug and coupling sleeve are opened and connected to each other.

[0024] Other further developments and embodiments of the invention are specified in the remaining dependent claims. Exemplary embodiments of the invention are illustrated in the drawings and are described in detail below. Identical components are designated with the same reference numerals, while components of differing embodiments are marked with a subscript indicating the respective modified embodiment. Components of the coupling sleeve that differ from the coupling plug are marked with an asterisk (*). The drawings show:

[0025] Fig. 1 shows a schematic representation of a coupling in partial section;

[0026] Fig. 2 shows a schematic representation of the coupling plug of the coupling from Figure 1 in partial section;

[0027] Fig. 3 shows a schematic representation of the coupling sleeve of the coupling from Figure 1 in partial section;

[0028] Fig. 4 shows a detailed view of section “Z” of the coupling plug from Fig. 2;

[0029] Fig. 5 shows a schematic representation of a coupling plug of a coupling of a second embodiment;

[0030] Fig. 6 shows a detailed view of section “Z” of the coupling plug from Fig. 5; Fig. 7 shows a schematic partial section view of a coupling of a third embodiment;

[0031] Fig. 8 shows a schematic representation of the coupling plug of the coupling from Figure 7 in partial section;

[0032] Fig. 9 shows a schematic representation of the coupling sleeve of the coupling from Figure 7 in partial section;

[0033] Fig. 10 shows a detailed view of section “Z” of the coupling plug from Fig. 8;

[0034] Fig. 11 shows a schematic representation of a coupling of a fourth embodiment in partial section;

[0035] Fig. 12 shows a schematic representation of the coupling plug of the coupling from Figure 11 in partial section a) before crimping the connection of the base part and the connecting part; b) after crimping the connection of the base part and the connecting part;

[0036] Fig. 13 shows a schematic representation of the coupling sleeve of the coupling from Figure 11 in partial section a) before pressing the connection of the base part and the connecting part; b) after pressing the connection of the base part and the connecting part;

[0037] Fig. 14 shows a schematic representation of a coupling plug of a coupling of a fifth embodiment in partial section a) before crimping the connection of base part and connector part; b) after crimping the connection of base part and connector part;

[0038] Fig. 15 shows a schematic representation of a coupling plug of a coupling of a sixth embodiment in partial section a) before crimping the connection of the base part and the connection part; b) after crimping the connection of the base part and the connection part; Fig. 16 shows a schematic representation of a coupling plug of a coupling of a seventh embodiment in partial section a) before crimping the connection of the base part and the connection part; b) after crimping the connection of the base part and the connection part;

[0039] Fig. 17 shows a schematic representation of a coupling of an eighth embodiment in partial section a) before pressing the connection of the base part and the connecting part; b) after pressing the connection of the base part and the connecting part;

[0040] Fig. 18 shows a schematic representation of the coupling plug of the coupling from Figure 17 in partial section a) before crimping the connection of the base part and the connecting part; b) after crimping the connection of the base part and the connecting part;

[0041] Fig. 19 shows a schematic representation of the coupling sleeve of the coupling from Figure 17 in partial section a) before pressing the connection of the base part and the connecting part; b) after pressing the connection of the base part and the connecting part;

[0042] Fig. 20 shows a detailed view of section “Z” of the coupling plug from Fig. 18 a) before crimping the connection between the base part and the connector part; b) after crimping the connection between the base part and the connector part;

[0043] Fig. 21 shows a schematic representation of the coupling plug of a coupling of a ninth embodiment in partial section a) before crimping the connection of the base part and the connection part; b) after crimping the connection of the base part and the connection part;

[0044] Fig. 22 shows a detailed view of section “Z” of the coupling plug from Fig. 21 a) before crimping the connection between the base part and the connector part; b) after crimping the connection between the base part and the connector part;

[0045] Fig. 23 shows a schematic representation of a coupling of a tenth embodiment in partial section;

[0046] Fig. 24 shows a schematic representation of the coupling plug of the coupling from Figure 23 in partial section;

[0047] Fig. 25 shows a schematic representation of the coupling sleeve of the coupling from Figure 23 in partial section;

[0048] The hydraulic coupling 1 selected as an embodiment according to Figure 1 is formed from a coupling plug 2 and a coupling sleeve 3.

[0049] The coupling plug 2 has a housing 21 formed by a base part 4, which is connected to a terminal part 5 and on which a locking sleeve 7 is rotatably arranged. The housing 21 is hollow and has a through-passage 22 in which a valve assembly 6 is arranged, through which an axially extending first flow channel 23 is bounded.

[0050] The valve assembly 6 comprises a valve tappet 61, which functions as a valve body and has at its end a diameter-expanded sealing cone 611. The sealing cone 611 is stepped at its wider end, forming two axially and radially concentric shoulders 612 and 613. A sealing ring 62 is arranged on the outer, first shoulder 612, projecting radially beyond the sealing cone 611. In the axial direction, the sealing ring 62 projects slightly beyond the first shoulder 612. A stop ring 63 is arranged on the inner, second shoulder 613. The stop ring 63 has an annular circumferential rib 631 on its outer surface, which engages in an annular recess 621 provided for this purpose in the sealing ring 62. A coil spring 64 is arranged on the valve tappet 61, encompassing the sealing ring 631, by means of which the valve tappet 61 is biased into its sealing position. The stop ring 63 is pressed onto the valve tappet 61.(Alternatively, the stop ring 63 can also be pre-tensioned against the sealing ring 62 by the coil spring 64.) On its side opposite the stop ring 63, the coil spring 64 rests against a flow ring 65, which is inserted into the base part 4 of the housing 21 and rests against the connecting part 5, against which it is pre-tensioned by the coil spring 64. Flow channels 651 are provided around the circumference of the flow ring 65. The inner diameter of the flow ring 65 corresponds approximately to the end-end outer diameter of the valve tappet 61, which projects into the flow ring 65 through which it is guided. The outer diameter of the flow ring 65 corresponds essentially to the inner diameter of the base part 4 against which the flow ring 65 rests.

[0051] The base part 4 of the housing 21 is essentially hollow and cylindrical. At its end facing the sealing cone 61 1 of the valve tappet 61, the base part 4 has an internal cone 41 against which the sealing cone 61 1 of the valve tappet 61 rests, being pre-tensioned by the coil spring 64. The sealing cone 61 1 is sealed against the internal cone 61 1 by the sealing ring 62. A web 42 is provided around the outside of the base part 4 approximately in the center. Spaced apart from the web 42, a connecting section 43 is provided on its side opposite the internal cone 41, into which an external thread 431 is provided.

[0052] In the connecting section 431, an interference section 432 is arranged, which extends to the end face of the base part 4. The interference section

[0053] In the exemplary embodiment, 432 is conically shaped. A recess 44 is provided in the end face of the base part 4, spaced apart from the excess section 432.

[0054] The connecting part 5 is designed in the form of a rotationally symmetrical hollow body. It has a first section 51, which is designed in the form of an external hexagon, to which a second section 52 is connected, which is designed in the form of a pipe connection. An axial stepped bore 53 is guided centrally through the connecting part 5, through which a shoulder 54 is formed.

[0055] A groove 55 is provided around the outside of the first section 51. Inside the first section 51, a connecting section 56 extends to the shoulder 54. An internal thread 561 is arranged in the connecting section 56. Spaced apart from the internal thread 561 is a press-fit section 562, which terminates in the shoulder 54. In the exemplary embodiment, the press-fit section 562 is designed in the form of an internal cone whose inner diameter is larger than the outer diameter of the conical oversize section 432 of the base part 4. The difference between the inner and outer diameters can be between 0.1 mm and 0.5 mm, depending on the size.

[0056] The connecting part 5 is screwed onto the external thread 451 of the base part 4 via its internal thread 561, with the end face of the base part 4 abutting the shoulder 54 of the connecting part 5. During the screwing process, the conical oversize section 432 is forced into the press-fit section 562, thereby radially crimping it to the press-fit section 562 (see Figure 4). An O-ring is inserted into the recess 44 of the base part 4, sealing the base part 4 against the connecting part 5. The flow ring 65, which is held by the base part 4, rests against the shoulder 54 of the connecting part 5.

[0057] The locking sleeve 7 is essentially hollow cylindrical and has a circumferential cording around its outer surface. At its end facing the connecting part 5, a flange 71 with an L-shaped cross-section is arranged, with which the locking sleeve 7 rests on the circumferential web 42 of the base part 4. The locking sleeve 7 is thus rotatably held between the web 42 and the connecting part 5. Inside the locking sleeve 7, an annular groove 72 is formed, which extends axially to the flange 71 that defines its boundaries. At its end opposite the flange 71, the locking sleeve 7 has an internally diameter-enlarged section 73 in which a circumferential groove 74 is formed on the outside.

[0058] The coupling sleeve 3 is essentially identical in design to the coupling plug 2. It has a housing 31 formed by a base part 4* that is modified compared to the coupling plug 2 and is connected to a terminal part 5. The housing 31 is hollow and has a through-hole 32 in which a valve assembly 6 is arranged, through which a second flow channel 33 extending in the axial direction is defined.

[0059] Unlike the base part 4 of the coupling plug 2, the base part 4* of the coupling sleeve 3 has a widened section 421 instead of the web 42. This section is provided on its outer surface with two axially spaced circumferential grooves 422, 423. At its end, the base part 4 has an annular piece 45, which is spaced apart from the outer second groove 423 and has an external thread 451. On the side of the annular piece 45 opposite the external thread 451, a groove 452 is provided to accommodate a sealing ring.

[0060] The coupling sleeve 3 is fitted onto the coupling plug 2, with the annular piece 45 of the base part 4* of the coupling sleeve 3 encompassing the base part 4 of the coupling plug 2 and the annular piece 45 bearing against the rib 42 of the coupling plug 2. The base part 4* is sealed against the base part 4 of the coupling plug 2 by the sealing ring arranged in the groove 452. The locking sleeve 7 is screwed onto the external thread 451 of the annular piece 45 of the base part 4* by its internal thread 75. The locking sleeve 7 is sealed against the base part 4* of the coupling sleeve 3 by the O-ring arranged in the outer second groove 423.

[0061] When the coupling sleeve 3 is placed on the coupling plug 2, the valve tappets 61 of coupling sleeve 3 and coupling plug 2 are each moved backwards against the preload force of the respective coil spring 64 in the direction of the respective connection part 5, thereby releasing the first flow channel 23 of the coupling plug 2 and the second flow channel 33 of the coupling sleeve 3 and combining to form one flow channel.

[0062] In the embodiment shown in Figure 5, a connecting section 43 is provided on the side of the coupling plug 2i opposite the inner cone 41, spaced apart from the web 42 of the base part 4i. An external thread 431 is provided in this connecting section. Here, however, the external thread 431 extends to the end face of the base part 4i. A recess 44 for receiving an O-ring is provided in the end face, to which an axially extending oversize section 432 is attached. In this embodiment, the oversize section 432 is conically shaped.

[0063] The connecting part 5i has a first section 51, designed in the form of an external hexagon, to which a second section 52, designed in the form of a pipe connection, is attached. An axial stepped bore 53 is guided centrally through the connecting part 5i, forming a shoulder 54. Inside the first section 51, there is a connecting section 56 extending to the shoulder 54, in which an internal thread 561 is arranged, also extending to the shoulder 54. A press-fit section 562, designed in the form of an internal cone, is inserted into the shoulder 54. The inner diameter of this cone is larger than the outer diameter of the conical oversize section 432 of the base part 4i. The difference between the inner and outer diameters can be between 0.1 mm and 0.5 mm, depending on the size.

[0064] The connecting part 5i is screwed onto the external thread 431 of the base part 4i via its internal thread 561, with the end face of the base part 4i abutting the shoulder 54 of the connecting part 5i. During the screwing process, the axially extending conical oversize section 432 from the end face is forced into the press-fit section 562 inserted into the shoulder 54, thereby forming a radial surface press fit with the press-fit section 562 (see Figure 6). An O-ring is inserted into the recess 44 of the base part 4i, sealing the base part 4i against the shoulder 54 of the connecting part 5i. Naturally, the connection between the base part and the connecting part of a coupling sleeve that can be coupled to this coupling plug 2i can be implemented in the same manner.

[0065] The hydraulic coupling 12 according to Figure 7 corresponds essentially to the hydraulic coupling 1 according to Figure 1, except that the connecting sections 43, 56 of the base part 42 and the connection part 52 are modified with respect to the arrangement of the O-ring for sealing the base part 42 relative to the connection part 52 in the coupling plug 22 and the coupling sleeve 32. In this embodiment, the O-ring is inserted into a groove 57 provided between the internal thread 561 and the shoulder 54 of the first section of the connection part 52. The external thread 431 of the base part 42 is shortened, thus providing a sealing surface 430 against which the O-ring arranged in the groove 57 of the connection part 52 abuts (see Figure 10).

[0066] The hydraulic coupling I 3 according to figure 1 1 corresponds essentially to the hydraulic coupling 1 according to figure 1, wherein the connecting sections 43, 56 of base part 4a and connection part 5a are designed differently in the coupling plug 23 and the coupling sleeve 33.

[0067] As shown in Figure 1, an internal toothing 433 is provided in the connecting section 43 of the coupling plug 2, which is arranged at a distance from the web 42 of the base part 4a. The valleys of this toothing are of different depths. In the exemplary embodiment, there are two valleys, the depth of which increases in the direction of the web 42. A press-fit recess 434 adjoins the internal toothing 433. A recess 44 for receiving an O-ring is provided at the end of the press-fit recess 434, spaced apart from it.

[0068] In this embodiment, the first section 51 of the connecting part 5a is designed in the form of a narrow open-end wrench engagement. On its side opposite the second section 52, a collar 51 1 extending conically outwards adjoins the first section 51. A connecting section 56 is arranged on the inside of the collar 51 1, in which an external toothing 563 is incorporated. This toothing corresponds to the internal toothing 433 of the connecting section 43 of the base part 4a, and the teeth of this external toothing are of different heights corresponding to the valleys of the internal toothing 433.

[0069] The connecting part 53 is pushed onto the base part 4a, with the end face of the base part 4a abutting the shoulder 54 of the connecting part 53. The O-ring arranged in the recess 44 of the base part 4a seals against the cylindrical inner wall of the first section 51 of the connecting part 53 (see Figure 12a). Subsequently, the collar 51 1 is radially formed by an externally attached pressing tool (not shown) so that the external teeth 563 of the connecting section 56 engage with the internal teeth 433 of the connecting section 43, with a region of the collar 51 1 adjacent to the external teeth 563 being formed into the press-fit recess 434 (see Figure 12b).

[0070] The connecting sections 43, 56 of base part 4a* and connection part 53 of the coupling sleeve 3a are designed in the same way as shown in Figures 13a and 13b.

[0071] In the embodiment shown in Figure 14, the coupling plug 24 is essentially designed in accordance with the coupling plug 2a of the previous embodiment shown in Figure 1, wherein a locking groove 435 is provided in the connecting section 43 of the base part 44 instead of the internal teeth. A press-fit recess 434 is provided spaced apart from the locking groove 435. On the end face of the base part 44, a recess 44 for receiving an O-ring is provided, corresponding to the embodiment shown in Figure 1.

[0072] On the inside of the collar 51 1, the connecting section 56 of the connecting part 54 has a circumferential detent rib 564 at its end, instead of external teeth, for engaging the detent groove 435 of the base part 54. Instead of the hexagonal shape of the first section 51 of the base part 53 in the previous embodiment, a largely cylindrical shape is present here. The connecting part 54 is pushed onto the base part 44, with the end face of the base part 44 sealingly abutting the shoulder 54 of the connecting part 54 via the O-ring arranged in the recess 44 (see Figure 14a). Subsequently, the collar 511 is again radially formed by means of an externally attached press tool (not shown), so that the locking web 564 of the connecting section 56 engages with the locking groove 435 of the connecting section 43, with a region of the collar 511 adjacent to the locking web 564 being formed into the press-fit recess 434 (see Figure 14b).

[0073] The coupling plug 2s according to Figure 15 largely corresponds to the coupling plug 24 of the previous embodiment according to Figure 14, wherein a second locking groove 435 is provided in the connecting section 43 of the base part 4s adjacent to the first locking groove 435.

[0074] On the inside of the collar 511, the connecting section 56 of the connecting part 5s has a second locking rib 564 arranged adjacent to the circumferential first locking rib 564 for engaging the locking grooves 435 of the base part 5s. Instead of the largely cylindrical shape of the first section 51 of the base part 54 of the previous embodiment, a hexagonal shape is again present here.

[0075] The connecting part 5s is in turn pushed onto the base part 4s, with the end face of the base part 4s sealingly abutting the shoulder 54 of the connecting part 5s via the O-ring arranged in the recess 44 (see Figure 15a). Subsequently, the collar 511 is radially formed by an externally attached pressing tool (not shown) so that the locking lugs 564 of the connecting section 56 engage with the locking grooves 435 of the connecting section 43, with a region of the collar 511 adjacent to the locking lugs 564 being formed into the press-fit recess 434 (see Figure 15b).

[0076] The coupling plug 2e according to Figure 16 is largely designed in accordance with the coupling plug of the previous embodiment according to Figure 15, wherein a straight toothing 436 is provided in the connecting section 43 which is arranged at a distance from the web 42 of the base part 4e. A recess 44 for receiving an O-ring is provided in the end face of the base part 4a.

[0077] On the first section 51 of the connecting part 5e, a cylindrical collar 512 is arranged, on the inside of which a connecting section 56 is arranged. A straight toothing 565 is incorporated into the connecting section 56 of the cylindrical collar 512 for engagement with the straight toothing 436 of the base part 4e. A press recess 566 adjoins the straight toothing 565.

[0078] The connecting part 5e is pushed onto the base part 4e, with the end face of the base part 4e sealingly abutting the shoulder 54 of the connecting part 5e via the O-ring arranged in the recess 44. The connecting section 56 of the cylindrical collar 512 is positioned concentrically and spaced apart from the connecting section 43 of the base part 4e (see Figure 16a).

[0079] Subsequently, the cylindrical collar 512 is radially formed by means of an externally attached press tool (not shown), so that the straight toothing 565 of the connecting section 56 engages with the straight toothing 436 of the connecting section 43, whereby the press recess 566 of the connecting section 56 is pressed in, forming a material accumulation in the transition from the first section 51 to the cylindrical collar 512 (see Figure 16b).

[0080] The hydraulic coupling 1 ? according to figure 17 corresponds essentially to the hydraulic coupling according to figure 1 , wherein the connecting sections 43, 56 of the base part 4?, 4?* and of the connecting part 5? of coupling plug 2? and coupling sleeve 3? are designed differently.

[0081] A straight toothing 436 is provided in the connecting section 43, which is arranged at a distance from the circumferential rib 42 of the base part 47 of the coupling plug 27. Also spaced at a distance from the straight toothing 436, an external thread 431 is provided in the connecting section 43, extending to the end face of the base part. A recess 44 for receiving an O-ring is provided in the end face of the base part 4s. A connecting section 56 is provided internally in the first section 51 of the connecting part 5s, extending to the shoulder 54. An internal thread 561 is provided in the connecting section 56, extending to the shoulder 54. On the side opposite the second section 52, a cylindrical collar 512 is arranged on the first section 51, into which a straight toothing 565 is introduced at its free end, spaced apart from the internal thread 561, for engagement with the straight toothing 436 of the base part 4?.

[0082] The connecting part 5? is screwed onto the external thread 431 of the base part 4? with its internal thread 561, the end face of the base part 4? resting against the shoulder 54 of the connecting part 5? The connecting section 56 of the cylindrical collar 512 is positioned concentrically and spaced apart from the connecting section 43 of the base part 4? (see Figures 18a, 20a).

[0083] Subsequently, the cylindrical collar 512 is radially formed by means of an externally attached press tool (not shown), so that the straight toothing 565 of the connecting section 56 engages with the straight toothing 436 of the connecting section 43 (see Figures 18b, 20b).

[0084] The connecting sections 43, 56 of the coupling sleeve 3?, via which the base part 4?* and the connecting part 5? are connected, correspond to the connecting sections 43, 56 of the coupling plug 2e described above (see Figure 19).

[0085] The coupling plug 2s according to Figure 21 essentially corresponds to the previously described coupling plug 2? of the hydraulic coupling according to Figure 18, with the connecting sections 43, 56 of the base part 4s and the connecting part 58 being designed differently. Here, a detent ridge 437 is arranged on the base part 4s instead of the straight teeth, spaced apart from the internal thread 431, with a detent ridge 564 being present at the end of the cylindrical collar 512 of the connecting part 5s instead of the straight teeth. The connecting part 5s is in turn screwed onto the external thread 431 of the base part 4s with its internal thread 561, with the end face of the base part 4s abutting the shoulder 54 of the connecting part 5s. The connecting section 56 of the cylindrical collar 512 is positioned concentrically and spaced apart from the connecting section 43 of the base part 4s (see Figures 21a, 22a).

[0086] Subsequently, the cylindrical collar 512 is radially formed by means of an externally attached press tool (not shown), so that the locking lug 512 of the connecting part 5s engages behind the locking lug 437 of the base part 4s (see Figures 21b, 22b).

[0087] Naturally, the connection between the base part and the connection part of a coupling sleeve that can be coupled with this 2s coupling plug can be carried out in the same way.

[0088] The hydraulic coupling 1 according to the embodiment shown in Figure 23 is formed from a coupling plug 200 and a coupling sleeve 300, which have a different design with a different valve arrangement compared to the embodiments described above.

[0089] The coupling plug 200 has a housing 21 formed by a base part 4 connected to a terminal part 5. The housing 21 is hollow and has a through-passage 22 in which a valve assembly 8 is arranged, through which an axially extending first flow channel 23 is bounded.

[0090] The valve assembly 8 comprises a hollow valve tappet 81, which functions as a valve body and is formed from a tappet sleeve 81 1 provided with a tappet cap 812. A shoulder 813 is arranged in the tappet sleeve 81 1, against which a coil spring 84 rests, biasing the valve tappet 81 into its sealing position. The end of the coil spring 84 opposite the valve tappet 81 rests against a shoulder 54 in the connecting part 5.

[0091] The base part 4 of the housing 21 is essentially designed as a stepped, hollow cylindrical component. At its end facing the tappet cap 812 of the valve tappet 81, the base part 4 has an internal cone 41, to which a cylindrical guide section 46 with a reduced diameter adjoins, forming a shoulder 47. An annular groove 461 for receiving a sealing ring to seal against the tappet cap 812 is provided internally in the guide section 46. The tappet cap 812 is pre-tensioned against the shoulder 47 by the coil spring 84 with a collar 813 arranged on the spring for this purpose. In this position, the tappet cap 812 is in line with the end face of the guide section 46. A connecting section 48 adjoins the internal cone 41 on its side opposite the guide section 46. In the connecting section 48 an internal thread 481 is arranged, which extends to its free end.A press-fit section 482 is located at a distance from the internal thread 481. In this embodiment, it is designed as an internal cone and terminates in a shoulder 483. An annular groove 484 for receiving a sealing ring is provided between the internal thread 481 and the press-fit section 481.

[0092] The connecting part 5 is designed in the form of a rotationally symmetrical hollow body. It has a first section 51, which is designed in the form of an external hexagon, to which a second section 52, designed in the form of a pipe connection, is attached. Opposite the second section 52, a connecting section 58 is attached to the first section 51, into which an external thread 581 is provided. Spaced apart from the external thread 581, an interference section 582 is arranged in the connecting section 58, extending to the end face of the connecting part 5. In the exemplary embodiment, the interference section 582 is conical. Between the interference section 582 and the external thread 581, a relief groove forming a sealing surface is provided in the connecting section. An axial stepped bore 53 is guided centrally through the connecting part 5, forming a shoulder 54 against which the coil spring 84 rests.

[0093] The base part 4 is screwed onto the external thread 581 of the connecting part 5 via its internal thread 481, with the end face of the connecting part 5 abutting the shoulder 483 of the base part 4. During the screwing process, the conical oversize section 582 is forced into the press-fit section 482, thus being radially pressed against it. The base part 4 is sealed against the connecting part 5 by the sealing ring inserted into the annular groove 484.

[0094] The coupling sleeve 30 has a housing 31 formed by a connecting part 5*, which differs from the coupling plug 20, and is connected to a base part 4*, which also differs in design. The housing 31 is hollow and has a passage 32 in which a valve assembly 8* is arranged, by which a second flow channel 33 extending axially is defined. A piston 34 is centrally located in the passage 32 via an annular piece 35 provided with axial passages, which has a diameter-expanded sealing cone 341 at its end, which is provided circumferentially with a sealing ring 342. Opposite the annular piece 35, a connecting section 56 is provided on the connecting part 5*, which extends to a shoulder 54 against which the annular piece 35 rests. An internal thread 561 is arranged in the connecting section 56.Spaced apart from the internal thread 561 is a press section 562, which terminates in the shoulder 54. In the exemplary embodiment, the press section 562 is designed in the form of an internal cone whose inner diameter is larger than the outer diameter of the conical oversize section 432 of the base part 4*.

[0095] A first inner sleeve 36 is mounted on the ring piece 35. The first inner sleeve 36 is essentially hollow and has two spaced-apart webs 361 on the inside of its end facing away from the ring piece 35, between which sealing rings are arranged. At its end opposite the webs 361, the first inner sleeve 36 has a section 362 with an increased inner diameter, against which the ring piece 35 abuts. A two-stage reduction in the outer diameter adjoins the section 362 with an increased inner diameter, formed by a first shoulder 363 and a second shoulder 364.

[0096] A second inner sleeve 37, essentially hollow and cylindrical, is arranged within the first inner sleeve 36. At one end, its outer surface rests against the webs 361, and at the opposite end, its end face rests against the sealing cone 341 of the piston 34. Its inner surface rests against the sealing ring 342. The second inner sleeve 37 is the central component of the valve assembly 8*. At its end opposite the sealing cone 341, the second inner sleeve 37 has an outer circumferential collar 371, which engages behind the inner web 361 of the first inner sleeve. It is biased against this collar by a coil spring 343 surrounding the piston 34. As can be seen in Figure 25, the flow channel 33 is bounded by the piston 34 and the first and second inner sleeves 36 and 37.

[0097] The base part 4* of the housing 31 is essentially hollow and cylindrical. At its end facing the sealing cone 341 of the piston 34, the base part 4* has a reduced-diameter section 49, which forms a shoulder 491. In the reduced-diameter section 49, conically tapered bores 492 are provided in an annular arrangement, accommodating balls 76. At its end opposite the reduced-diameter section 49, a connecting section 43 is arranged on the base part 4*, into which an external thread 431 is provided. Spaced apart from the external thread 431, an interference section 432 is arranged in the connecting section 43, extending to the end face of the base part 4. In the exemplary embodiment, the interference section 432 is conical.

[0098] The base part 4* is screwed into the internal thread 561 of the connecting part 5* via its external thread 431, with the end face of the base part 4* abutting the shoulder 54 of the connecting part 5*. During the screwing process, the conical oversize section 432 is forced into the press section 562, thus radially crimping it to the press section 562. The connecting section 43 of the base part 4* abuts the first inner sleeve 36, with a shoulder 485 located on its inner side abutting the first shoulder 363 of the first inner sleeve 36. The first inner sleeve 36 is thus held firmly between the ring piece 35 and the connecting section 43 of the base part 4*.

[0099] A locking sleeve 7 is slid onto the base part 4*. At its end facing the sealing cone 341 of the piston 4, the locking sleeve has an internal annular groove 77 into which balls 76, inserted into the bores 492 of the base part 4*, engage. The locking sleeve 7 is biased in the direction opposite to that of the connecting part 5* by a coil spring 78 arranged between it and the base part 4*.

[0100] The valve tappet 82 of the coupling sleeve 30 is designed in the form of a cylindrical sleeve, which has an inwardly projecting collar 821 at its end facing the sealing cone 341 of the piston 4, the inner diameter of which corresponds essentially to the maximum outer diameter of the sealing cone 341. At its end opposite the collar 821, the valve tappet 82 has an externally circumferential rib 822 with which it abuts the shoulder 491 of the base part 4*, against which it is biased by a coil spring 83 arranged between the first inner sleeve 36 and the base part 4*.By moving the valve tappet 82 against the preload of the coil spring 83, the bores 492 of the base part 4* are first released, causing the balls 76, which were previously in contact with the valve tappet 82, to move inwards out of the annular groove 77 of the locking sleeve 7, thereby pushing the locking sleeve 7, which was previously held in position by the balls 77, towards the coupling plug 20 by the preload of the coil spring 78.

[0101] As the valve tappet 82 moves further, its collar 821 abuts a shoulder 372 located on the outside of the second inner sleeve 37, causing the second inner sleeve 37 to move away from the sealing cone 341 of the piston 34 against the preload of the coil spring 343. This opens the second flow channel 33 of the coupling sleeve 30. The valve tappet 82 is therefore part of the valve assembly 8* and interacts with the second inner sleeve 37, which here functions as the valve body.

Claims

Patent claims 1. Coupling part with a first spring-loaded valve, in particular a coupling plug (2), for coupling with a corresponding second coupling part, in particular a coupling sleeve (3), which has a second spring-loaded valve, a coupling (1) for pressure medium lines, in particular hydraulic lines, in which the valves of the two coupling parts open each other automatically when coupling, thereby connecting their flow channels, and close automatically by means of spring force when uncoupling, comprising a housing (21, 31) with a continuous flow channel (23, 33) extending in the axial direction, a valve body (61, 37, 81) arranged to be axially displaceable back and forth within the flow channel (23, 33) for closing the flow channel (23, 33) in the uncoupled state of the coupling part (2, 3), wherein the valve body (61, 37, 81) ) a closed,The coupling part (2, 3) has a valve position that closes the flow channel and an open position that does not close the flow channel (23, 33), a connecting device for mechanically connecting the coupling part to the second coupling part to be coupled, wherein the coupling part (2, 3) comprises a base part (4, 4*) and a connection part (5, 5*) which are connected to each other and form the flow channel (23, 33), wherein the connection part (5, 5*) has a connection section for connecting a pressure medium line, characterized in that the base part (4, 4*) and connection part (5, 5*) each have at least one connection section (43, 56), wherein at least one connection section (43, 56) of the connection part (5, 5*) is radially crimped to a connection section of the base part (4, 4*).

2. Coupling part according to claim 1, characterized in that at least one connecting section (43) of the base part (4, 4*) is provided at least partially with a toothing (433, 436) which engages in a connecting section (56) of the connecting part (5, 5*). The toothing (563, 565) engages, with the toothing (433, 436, 563, 565) of the connecting sections (43, 56) of the base part (4, 4*) and the connecting part (5, 5*) being radially pressed together.

3. Coupling part according to claim 2, characterized in that a forming section is arranged adjacent to the toothing (433, 436, 563, 565) of a connecting section (43, 56), the deformation of which achieves the compression.

4. Coupling part according to claim 2 or 3, characterized in that the toothing (433, 436, 563, 565) has at least one area with a toothing having a triangular cross-section and / or a trapezoidal cross-section and / or a rectangular cross-section.

5. Coupling part according to one of claims 2 to 4, characterized in that the toothing (433, 563) has teeth of different heights.

6. Coupling part according to one of claims 1 to 5, characterized in that the toothing (433, 563) has teeth whose two flanks have a different angle to the tooth root, wherein the respective angle is preferably between 45° and 60°.

7. Coupling part according to one of claims 2 to 6, characterized in that an annular groove (44, 57) for receiving a sealing ring is connected to the toothing (433, 436, 563, 565).

8. Coupling part according to one of the preceding claims, characterized in that at least one connecting section (43) of the base part (4, 4*) is provided at least partially with a thread (431 ) which engages with a thread (561 ) in a connecting section (56) of the connecting part (5, 5*).

9. Coupling part according to claim 8, characterized in that the base part (4, 4*) and the connecting part (5, 5*) each have an axial stop surface which abut each other, wherein an interference section (432) is attached to the thread (431, 561) of the base part (4, 4*) or of the connecting part (5, 5*) on its side facing the stop surface and an axially narrowing press section (562) is attached to the thread of the connecting part (5, 5*) or of the base part (4, 4*) on its side facing the stop surface, wherein the interference section (432) is at least partially radially pressed with the press section (562) during the screwing process.

10. Coupling part according to claim 9, characterized in that the oversize section (432) is conical at least in some areas.

11. Coupling part according to claim 9 or 10, characterized in that an annular groove (55) or a recess (44) for receiving a sealing ring is arranged in the stop surface of the base part and / or the stop surface of the connecting part.

12. Coupling part according to claim 9 or 10, characterized in that an annular groove (55) or a shoulder (44) for receiving a sealing ring is arranged between the thread (431 , 561 ) and the oversize section (432) in the base part (4, 4*) and / or the connecting part (5, 5*).

13. Coupling (1 ) for a pressure medium line, in particular a hydraulic line, with a coupling plug (2) which is detachably connected to a coupling sleeve (3), characterized in that the coupling plug (2) and / or the coupling sleeve (3) is designed according to one of the preceding claims.

14. Coupling according to claim 13, characterized in that the coupling plug (2) and the coupling sleeve (3) each have a valve tappet (61), which valve tappets (61) lie against each other during the connection of the coupling plug (2) and the coupling sleeve (3) and each- because they are axially displaced into an open valve position against a spring preload, thereby opening and connecting the axial flow channels (23, 33) of coupling plug (2) and coupling sleeve (3).

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