Connection arrangement for two fluid line sections, refrigerant circuit of a motor vehicle with such a connection arrangement

Abstract

A connection arrangement (10) is described which is designed to connect two fluid line sections (12-1, 12-2) together, wherein the connection arrangement (10) comprises: a first connecting element (14-1) with an external threaded section (20) which is materially connected to a first end piece (16) of a first fluid line section (12-1), wherein the first connecting element (14-1) projects beyond the first end piece (16) with respect to an axial direction (AR) of the connection arrangement (10) with a line receiving section (18);a second connecting element (14-2) with an internal threaded section (24) which is rotatably arranged about the axial direction (AR) of the connection arrangement (10) and movably along the axial direction (AR) on a second fluid line section (12-2), wherein the second fluid line section (12-2) has a second end piece (22) which can be covered by the second connecting element (14-2) and which has an insertion section (22e) and a contact section (22a) adjoining the insertion section (22e); wherein the insertion section (22e) of the second fluid line section (14-2) can be inserted in the axial direction (AR) into the line receiving section (18) of the first connecting element (14-1); and wherein the first connecting element (14-1) rests against the contact section (22a) of the second fluid line section (12-2) in a connected state. Furthermore, a refrigerant circuit with at least one such connection arrangement and a motor vehicle are described.

Description

The invention relates to a connection arrangement designed to connect two fluid line sections. The invention further relates to a refrigerant circuit of a refrigeration system of a motor vehicle with at least one such connection arrangement. Various connection arrangements are known from the prior art, for example reference to DE 34 19 999 A1 and US 5 782 500 A. The fluid line sections to be connected using this connection arrangement can be, in particular, refrigerant lines or hydraulic lines operating under high fluid pressure. Specifically, such a connection arrangement can be used in a refrigeration system filled with refrigerant R744, where fluid pressures exceeding 50 bar, and especially over 100 bar, may occur. The object underlying the invention is seen as being to provide a connection concept that enables a simple and safe connection of fluid line sections, in particular of refrigerant line sections under high pressure. This problem is solved by a connection arrangement and a refrigerant circuit with the features of the respective independent patent claim. Advantageous embodiments with expedient further developments are specified in the dependent patent claims. A connection arrangement is therefore proposed which is designed to connect two fluid line sections together, wherein the connection arrangement comprises: a first connecting element which is materially connected to a first end piece of a first fluid line section, wherein the first connecting element projects beyond the first end piece with respect to an axial direction of the connection arrangement with a line receiving section, and wherein the first connecting element has an external thread section;A second connecting element, rotatably arranged about the axial direction of the connection arrangement and movably along the axial direction on a second fluid line section, wherein the second fluid line section has a second end piece that can be covered or is covered by the second connecting element, the end piece having an insertion section and a contact section adjoining the insertion section, and wherein the second connecting element has an internal threaded section. The insertion section of the second fluid line section can be inserted axially into the line receiving section of the first connecting element, and the first connecting element rests against the contact section of the second fluid line section in a connected state, with the internal threaded section of the second connecting element engaging with the external threaded section of the first connecting element. Such a connection arrangement makes the second fluid line section, with its insertion section and / or its installation section, part of a sealing contour, thus enabling an improved and secure connection of the fluid line sections. In the connection arrangement, the second connecting element can be designed as a union nut, which rests against the connecting section in the axial direction in the connected state. In this connection arrangement, a sealing element can be arranged between the insertion section of the second fluid line section and the line receiving section of the first connecting element, and / or a sealing element can be arranged between the connection section of the second fluid line section and the line receiving section of the first connecting element. The sealing element is specifically located in or on the second fluid line section, which, as mentioned above, is itself part of a sealing contour. The sealing element can be formed by a coating of the first connecting element, in particular its pipe receiving section, wherein the coating can in particular be a polymer. In other words, at least one inner circumferential surface of the pipe receiving section can be coated with a sealing material, in particular a polymer. Alternatively, the sealing element can be attached separately to the insertion section and may itself have a coating, which can be a polymer in particular. For example, the sealing element can be designed as an annular cone whose inner circumference rests against the insertion section and whose outer circumferential surface is conical. The sealing element can have an external threaded section which, in a connected state, transitions into the external threaded section of the first connecting element, such that the internal threaded section of the second connecting element engages with the external threaded sections of the sealing element and the first connecting element. In this connection arrangement, the system section can be designed as a bead-like radial projection of the second fluid line section. In particular, a pipe forming the second fluid line section can be deformed in such a way that the radially projecting, bead-like projection is formed. In the connection arrangement, the first connecting element can have a sealing section adjoining the pipe receiving section, which has a sealing contour that corresponds to an outer contour of the bead-like projection. Furthermore, in the connected state, the bead-like projection in the axial direction can be accommodated between the sealing contour of the first connecting element and a radially inwardly pointing flange section of the second connecting element, in particular the union nut. In this connection arrangement, an annular contact surface of the first fluid pipe section and an annular contact surface of the second fluid pipe section can be in contact with each other in a contact area when connected, or an axial gap can be formed between the two annular contact surfaces. This gap can be bridged fluidically by a bore section in the first connecting element. In the connection arrangement, the first connecting element can be welded or soldered to the first fluid line section. Furthermore, a refrigerant circuit for a motor vehicle refrigeration system is proposed, wherein the refrigerant circuit comprises at least one connection arrangement as described above. The refrigerant circuit can, for example, be filled with refrigerant R744. Furthermore, a motor vehicle may be equipped with a refrigeration system that has a refrigerant circuit in which at least one of the connection arrangements described above is present or used. The first connecting element can be located on the outside of a component of the refrigeration system, and the associated first fluid line section can be located inside the component in question. The component can be, in particular, a refrigerant compressor, a heat exchanger, or a refrigerant receiver. Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. Figure 1 shows a simplified and schematic sectional view of an example of a connection arrangement in an unconnected state or during the process of establishing a connected state as shown in Figure 2; Figure 2 shows the connection arrangement of Figure 1 in a connected state; Figure 3 shows a simplified and schematic sectional view of another example of a connection arrangement in a connected state; Figure 4 shows a simplified and schematic sectional view of another example of a connection arrangement in a connected state; Figure 5 shows further views of the connection arrangement of Figure 4 in an unconnected state or during the process of establishing a connected state as shown in Figure 4; Figure 5 shows the connection arrangement of Figure 4 in an unconnected state or during the process of establishing a connected state as shown in Figure 4.6 A simplified and schematic view of a refrigerant circuit with multiple connection arrangements in a motor vehicle. Fig. 1 shows a simplified and schematic connection arrangement 10 designed to connect two fluid line sections 12-1, 12-2. The connection arrangement 10 is shown in a simplified sectional view at A) in the unconnected position in Fig. 1. The connection arrangement 10 has a first connecting element 14-1 and a second connecting element 14-2. The first connecting element 14-1 is materially connected to a first end piece 16 of the first fluid line section 12-1, wherein the first connecting element 12-1 projects beyond the first end piece 16 with a line receiving section 18 in relation to an axial direction AR of the connection arrangement 10. The first connecting element 14-1 has an external threaded section 20. The first fluid line section 12-1 has an outer diameter that essentially corresponds to an inner diameter of the line receiving section 18. The first connecting element 14-1 is welded or soldered to the first fluid line section 12-1. The second connecting element 14-2 is rotatably arranged about the axial direction AR of the connection arrangement 10 and movably arranged along the axial direction AR on the second fluid line section 12-2, wherein the second fluid line section 12-2 has a second end piece 22 which can be covered or is covered by the second connecting element 14-2, and which has an insertion section 22e and a contact section 22a adjoining the insertion section 22e. The second connecting element 14-2 has an internal threaded section 24. The second fluid line section 12-2, in particular its insertion section 22e of the second end piece 22, has an outer diameter that is essentially the same as the outer diameter of the first fluid line section 12-1. Accordingly, it can also be said that the outer diameter of the second fluid line section 12-2, in particular of the insertion section 22e, is essentially the same as the inner diameter of the line receiving section 18 of the first connecting element 14-1. The insertion section 22e of the second fluid line section 12-2 can be inserted axially into the line receiving section 18 of the first connecting element 14-1. In B) Fig. 1, it can be seen that first the insertion section 22e of the second fluid line section 12-2 is inserted into the line receiving section 18, so that the second connecting element 14-2 (union nut) is then brought into engagement with its internal thread section 24 with the external thread section 20 of the first connecting element 14-1 in order to tighten the connection arrangement 10. In Figure C), it can be seen that the insertion section 22e of the second fluid line section 12-2 has not yet been inserted into the line receiving section 18. Here, the second connecting element 14-2 (union nut) is then brought into engagement with its internal thread section 24 with the external thread section 20 of the first connecting element 14-1, so that the insertion section 22e is continuously inserted into the line receiving section 18 when the second connecting element 14-2 is tightened. Fig. 2 shows a simplified and schematic sectional view of the connection arrangement 10 in a connected state of the first connecting element 14-1 and the second connecting element 14-2. In the connected state, the first connecting element 14-1 rests against the mounting section 22a of the second fluid line section 12-2, with the internal thread section 24 of the second connecting element 14-2 engaging with the external thread section 20 of the first connecting element 14-1. The second connecting element 14-2 is designed in particular as a union nut which, in the connected state, rests against the system section 22a in the axial direction AR. In connection arrangement 10, a sealing element 26, simplified here as a thicker black line, is arranged between the insertion section 22e of the second fluid line section 12-2 and the line receiving section 18 of the first connection element 14-1. Alternatively or additionally, a sealing element 26 is also arranged between the system section 22a of the second fluid line section 12-2 and the line receiving section 18 of the first connection element 14-1. The sealing element 26 can be formed by a coating of the pipe receiving section 18, the coating being in particular a polymer. In connection arrangement 10, the connecting section 22a of the second fluid line section 12-2 is designed as a bead-like radial projection of the second fluid line section 12-2. The sectional view shows that connecting section 22a is formed by shaping a tube, in particular a metal tube, that constitutes the second fluid line section 12-2. Connecting section 22a has a larger outer diameter than the insertion section 22e. The insertion section 22e transitions seamlessly and continuously into the system section 22a, particularly due to the forming process, wherein an outer circumferential surface of the insertion section 22e and an outer circumferential surface of the system section 22a form a sealing contour for the connection arrangement 10. The first connecting element 14-1 has a sealing section 28 (Fig. 1) adjoining the pipe receiving section 18, which has an inner circumferential surface that forms a sealing contour. The sealing contour of the sealing section 28 corresponds to an outer contour, or rather to the sealing contour of the bead-like projection formed by the outer circumferential surface of the installation section 22a. In other words, the first connecting element 14-1 is designed in an end-face area as a counter contour (sealing section 28) to the shape of the bead-like contact section 22a. It can also be said that the first connecting element 14-1, the second connecting element 14-2, the insertion section 22e, and the contact section 22a form a positive-locking connection. The first connecting element 14-1 and the second connecting element 14-2 are clamped against each other by means of the interlocking threaded sections 20 and 24. Fig. 2 also shows that in the connected state the bead-like projection or contact sections 22a is received in the axial direction AR between the sealing contour of the first connecting element 14-1 and a radially inwardly pointing flange section 30 of the second connecting element 14-2, in particular the union nut. From the combined view of Figs. 1 and 2, it is further evident that an annular contact surface 32-1 of the first fluid line section 12-1 and an annular contact surface 32-2 of the second fluid line section 12-2 are arranged at an axial distance from each other when connected. This axial distance is bridged fluidically by a bore section 34 formed in the first connecting element. In other words, the bore section 34 adjoins the line receiving section 18 in the axial direction AR, followed by the welded end piece 16 of the first fluid line section 12-1. Fig. 3 shows a connection arrangement 10 similar to that of Fig. 2 in a simplified and schematic sectional view. The same reference numerals are shown in Fig. 3 as in Fig. 2, for which reference is made to the description above. The connection arrangement 10 of Fig. 3 differs from that of Fig. 2 in that the annular contact surface 32-1 of the first fluid line section 12-1 and the annular contact surface 32-2 of the second fluid line section 12-2 abut each other in a contact area SB when connected. The contact area SB is enclosed circumferentially by the first connecting element 14-1 and by the second connecting element 14-2. Fig. 4 shows a simplified and schematic sectional view of another connection arrangement 10, which has a similar structure to the connection arrangement 10 of Fig. 1 and Fig. 2. Therefore, the same reference numerals are used again in Fig. 4, and for their description, reference is made to the description above for Fig. 1 and Fig. 2. In the connection arrangement 10 of Fig. 4, a separate sealing element 26 is provided. The sealing element 26 is designed, in particular, as a conical ring, which is arranged between the insertion section 22e of the second fluid line section 12-2 and the line receiving section 18 of the first connecting element 14-1 or the second connecting element 14-2. The line receiving section 18 has a shape corresponding to the design of the sealing element 26, in particular a conical inner circumferential surface 18k. With reference to Fig. 5, the connection arrangement 10 of Fig. 4, in particular the creation of a connected state as shown in Fig. 4, is described in more detail. As can be seen from the illustration in A) of Fig. 5, the sealing element 26 is placed on the insertion section 22e of the second fluid line section 12-2. The sealing element 26 rests against the contact section 22 (radial, bead-like projection) in the axial direction AR. The second connecting element 14-2 (union nut) is not shown in this upper illustration. The sealing element 26 has a shape adapted to or corresponding with the system section 22. Furthermore, the sealing element has an external threaded section 26g adjacent to its conical outer surface 26k. The external threaded section 26g has the same dimensions as the external threaded section 20 of the first connecting element 14-1. In the illustration at B) of Fig. 5, it is shown that the insertion section 22e with the sealing element 26 attached to it is inserted or plugged into the line receiving section 18 of the first connecting element 14-1. The second connecting element 14-2 (union nut) can then be moved axially towards and over the mounting section 22a. The internal thread section 24 of the second connecting element 14-2 then engages with the external thread section 26g of the sealing element 26, and, upon further tightening, with the external thread section 20 of the first connecting element 14-1. The second connecting element 14-2 is then tightened so that the connected state of the connection arrangement according to Fig. 4 is established. Referring to the illustrations at C) and D) in Fig. 5, it should be noted that the second connecting element 14-2 (union nut) can also be screwed onto or engaged with the external thread section 26g before the connected state of the connection arrangement 10 has been established. The second connecting element 14-2 has a radial clearance 36 in the axial direction AR between its internal thread section 24 and the clamping section 30 (see also the circled enlargement at C). When the second connecting element 14-2 is tightened, the external thread section 26g of the sealing element 26 is no longer engaged with the internal thread section 24 of the second connecting element 14-2, but is located in the area of ​​the clearance 36. In other words, the engagement between the external thread section 26g and the internal thread section 24 is released before the contact section 22a of the second fluid line section 12-2 comes into contact with the clamping section 30. This provides sufficient axial (AR) and radial clearance, preventing tilting and / or damage to the connecting elements 14-1 and 14-2 during the subsequent assembly process. Furthermore, the loosened engagement between the external thread section 26g and the internal thread section 24 allows tightening torque to be applied to the second connecting element 14-2 (union nut), thus enabling homogeneous compression of the sealing element 26 with the connecting elements 14-1 and 14-2 and the second fluid line section 12-2. The sealing element 26 can be made of a metal. Furthermore, the sealing element 26 can be provided with a coating, in particular a polymer coating. Additionally, the sealing element 26 can be made of a metal that has a lower coefficient of thermal expansion than the metal from which the fluid line sections 12-1, 12-2 are made, so that when the tubular fluid line sections 12-1, 12-2 expand, the sealing element 26 is pressed radially outwards against the first connecting element 14-1 and the second connecting element 14-2. Figure 6 shows a simplified and schematic illustration of a refrigerant circuit 50 of a refrigeration system in a motor vehicle 70. The illustration shows, by way of example, that the refrigerant circuit 50 has at least one connection arrangement 10 as described above. The refrigerant circuit 50 can, for example, be filled with the refrigerant R744. In the example shown in Fig. 6, a refrigerant compressor 52 and a heat exchanger 54 of the refrigerant circuit 50 are illustrated purely by way of example. For both components, i.e., the refrigerant compressor 52 and the heat exchanger 54, the first connecting element 14-1 can be arranged on an outside of the respective component, and the associated first fluid line section 14-1 can be located inside the respective component, which is why it is not visible here. If a component of the refrigerant circuit 50, for example the refrigerant compressor 52 and / or the heat exchanger 54, is provided with a first connecting element 14-1, second fluid line sections 14-2 with corresponding second connecting elements 14-2 (union nut) can be easily connected to or screwed onto the component in question, so that a leak-tight connection under high pressure conditions is established between the component in question and a fluid line section 14-2, which can also be referred to as a refrigerant line section, using a connection arrangement 10 described above (see Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. 5). QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 34 19 999 A1

[0002] US 5 782 500 A

[0002]

Claims

Connection arrangement (10) configured to connect two fluid line sections (12-1, 12-2) together, the connection arrangement (10) comprising: a first connecting element (14-1) which is materially connected to a first end piece (16) of a first fluid line section (12-1), wherein the first connecting element (14-1) projects beyond the first end piece (16) with respect to an axial direction (AR) of the connection arrangement (10) with a line receiving section (18), and wherein the first connecting element (14-1) has an external threaded section (20);a second connecting element (14-2) rotatably arranged about the axial direction (AR) of the connection arrangement (10) and movably along the axial direction (AR) on a second fluid line section (12-2), wherein the second fluid line section (12-2) has a second end piece (22) that can be covered or is covered by the second connecting element (14-2), the end piece having an insertion section (22e) and a fitting section (22a) adjoining the insertion section (22e), and wherein the second connecting element (14-2) has an internal threaded section (24); wherein the insertion section (22e) of the second fluid line section (12-2) can be inserted in the axial direction (AR) into the line receiving section (18) of the first connecting element (14-1);and wherein the first connecting element (14-1) is in a connected state against the installation section (22a) of the second fluid line section (12-2), wherein the internal thread section (24) of the second connecting element (14-2) is engaged with the external thread section (20) of the first connecting element (14-1). Connection arrangement (10) according to claim 1, wherein the second connecting element (14-2) is designed as a union nut which, in the connected state, rests against the installation section (22a) in the axial direction (AR). Connection arrangement (10) according to claim 1 or 2, wherein a sealing element (26) is arranged between the insertion section (22e) of the second fluid line section (12-2) and the line receiving section (18) of the first connection element (14-1) and / or a sealing element (26) is arranged between the installation section (22a) of the second fluid line section (12-2) and the line receiving section (18) of the first connection element (14-1). Connection arrangement (10) according to claim 3, wherein the sealing element (26) is formed by a coating of the first connection element (14-1), in particular of its cable receiving section (18), wherein the coating may in particular be a polymer. Connection arrangement (10) according to claim 3, wherein the sealing element (26) can be attached separately to the insertion section (22e) and in particular has a coating itself, wherein the coating can in particular be a polymer. Connection arrangement (10) according to claim 5, wherein the sealing element (26) has an external threaded section (26g) which, in a connected state, transitions into the external threaded section (20) of the first connecting element (14-1) such that the internal threaded section (24) of the second connecting element (14-2) engages with the external threaded sections (20, 26g) of the sealing element (26) and the first connecting element (14-1). Connection arrangement (10) according to one of the preceding claims, wherein the system section (22a) is designed as a bead-like radial projection of the second fluid line section (12-2), wherein in particular the first connecting element (14-1) has a sealing section (28) adjoining the line receiving section (18), which has a sealing contour that corresponds to an outer contour of the bead-like projection. Connection arrangement (10) according to claim 7, wherein in the connected state the bead-like projection in axial direction (AR) is received between the sealing contour (28) of the first connecting element (14-1) and a radially inwardly extending flange section (30) of the second connecting element (14-2), in particular the union nut. Connection arrangement (10) according to one of the preceding claims, wherein the first connecting element (14-1) is welded or soldered to the first fluid line section (12-1). Refrigerant circuit (50) of a refrigeration system of a motor vehicle (70), wherein the refrigerant circuit (50) has at least one connection arrangement (10) according to one of the preceding claims.

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