Non-return valve, in particular for a refrigeration or heat circuit

Abstract

The invention relates to a non-return valve, in particular for a refrigeration or heat circuit, which valve can be inserted into a connection opening of a connection device or of a pipe, wherein the non-return valve comprises a valve closing element (61) having a closing body (65), and, when the valve closing element (61) is in an initial position, a closing surface (108) of the closing body (65) abuts the valve seat and closes a passage opening, wherein the closing body (65) extends from the closing surface (108) in the opposite direction to the displacement movement into the working position of the closing body (65), and the closing body (65) has a convex contour (102) at the free front end (101), which contour is connected to the closing surface (108) by a concave contour (105).

Description

[0001] Check valve, especially for a refrigeration or heating circuit

[0002] The invention relates to a check valve, in particular for a heating or cooling circuit.

[0003] WO 2019 / 219732 A1 discloses a check valve for a refrigeration or heating circuit, which can be inserted into an inlet opening of a connection device or a pipe. This check valve comprises a one-piece or multi-piece housing with at least one base housing, with a supply opening on the inlet side and a discharge opening on the outlet side of the base housing, which are connected to each other by a flow channel.

[0004] The base housing comprises at least one guide element, through which a valve closing member is displaceably guided from a starting or closed position to a working or open position. A force storage element acts in the opposite direction to the opening movement of the valve closing member. The base housing, the guide element, and the force storage element acting on the valve closing member are provided downstream of a valve seat, against which a closing surface of a closing body of the valve closing member rests in the starting position.

[0005] The invention is based on the object of designing a check valve which enables a reduction of a pressure loss in a medium flowing through the check valve.

[0006] This object is achieved by a check valve with a valve closing element, which comprises a closing body with a closing surface, preferably adjacent to the closing surface, in particular downstream of the closing surface of the closing body, and a sealing element, which in an initial position rest against the valve seat and close a flow channel. The closing body extends from the closing surface into the working position in a direction opposite to a travel movement of the closing body. The closing body has a convex contour at a free front end which is connected to the closing surface of the closing body by a concave contour. This shape of the closing body, which extends opposite to the flow direction of a medium, starting from the valve seat or the closing surface which rests in the valve seat, enables flow optimization to be achieved.In particular, this can reduce turbulence in the medium, especially when flowing toward the valve seat. By increasing the laminar flow component in the medium flowing through the open check valve, pressure loss can be reduced. Particularly for check valves used on the low-pressure side of a refrigeration or heating circuit, reducing pressure losses can lead to improved efficiency. This has a positive effect, for example, on heat dissipation, which can be increased as a result.

[0007] Preferably, a smooth transition is formed between the convex contour, starting from the front end of the closing body, and the closing surface of the closing body through the concave contour. Gentle gradients are advantageously provided to achieve calm flow zones.

[0008] Furthermore, it is preferably provided that the convex contour at the free end of the closing body directly transitions into the concave contour, and the concave contour directly transitions into the closing surface. This eliminates any straight sections. The direct transition between the contours and from the convex contour to the closing surface allows for further flow optimization.

[0009] The length L of the closing body, from the closing surface to the front end of the closing body, is preferably greater than the travel of the closing body from the starting position to the working position. This means that, regardless of the opening stroke of the closing body, it is positioned toward or in the inlet opening and promotes flow, particularly to reduce pressure loss.

[0010] Preferably, the length FR of the guide surface on the guide rib is smaller than a guide length FL between a sleeve of the base housing and a guide section of the closing body facing the base housing. This allows the closing body to be guided between the guide ribs and the valve seat or the inlet opening during a first stroke phase, and guided on the base housing during a second stroke phase. This enables the closing body to be guided over the entire opening stroke of the valve closure member. In addition, the passage at the valve seat can be completely opened.

[0011] The convex contour formed at the front end of the closing body can be hemispherical or have a parabolic cross-section. Away from the front end of the closing body, the hemispherical contour or parabolic contour can have an equatorial surface with a radius Ri that is smaller than the cross-sectional area of ​​the closing surface. This can be an optimization parameter for reducing pressure loss.

[0012] The concave contour on the closing body, which extends between the convex contour and the closing surface of the closing body, preferably has a radius R2. This allows for a continuous transition. Alternatively, instead of the radius R2, the concave contour can also be provided as a curve, which is designed with a varying gradient or a varying radius. In particular, the gradient increases toward the transition to the closing surface of the closing body, or the radius becomes smaller.

[0013] As a result, the closing body expands from its front end toward the closing surface. According to a further advantageous embodiment, the radius 2 of the concave contour is larger than the radius Ri of the convex contour.

[0014] According to a further advantageous embodiment of the closing body, it can be provided that the radius Ri of the equatorial surface or the convex contour is smaller than a radius R3 which determines the cross-sectional area of ​​the closing surface of the closing body.

[0015] Advantageously, it can be provided that a length L of the closing body, starting from the closing surface to the free front end of the closing body, lies in a range between 0.25 and 5 in relation to the radius Ri of the convex contour. Even with such a geometry, a reduction in pressure loss could be achieved.

[0016] It is preferably provided that the free front end of the closing body extends upstream beyond the valve seat after the valve closing member has assumed the working position and preferably the end of the closing body projects into the inlet opening adjacent to the valve seat in the working position of the valve closing member.

[0017] Furthermore, an advantageous embodiment of the closing body can be provided by a ratio between the cross-sectional area of ​​the closing surface and the length of the closing body, starting from the closing surface to the front end of the closing body, in a range of 3 to 0.3.

[0018] In a further preferred embodiment, guide ribs extend from the closing surface of the closing body toward the free end of the closing body or up to the free end of the closing body. This allows the closing body, which extends counter to the flow direction, to be guided centrally relative to the valve seat by the guide ribs even during an opening stroke. This allows uniform flow conditions to be maintained regardless of the size of the opening stroke.

[0019] In particular, two or more guide ribs, preferably aligned at the same circumferential angle to each other, are provided on the closing body of the valve closure member. For example, a star-shaped arrangement or an arrangement in the form of a mathematical plus of the guide ribs can be provided on the closing body.

[0020] The guide ribs on the closing body preferably have a guide surface that extends from the closing surface of the closing body toward the free front end of the closing body and is aligned parallel to one another. In particular, it is provided that the guide surfaces of the guide ribs are guided along an inner wall of the inlet opening or in a transition region between a valve seat surface of the valve seat and the inner wall of the inlet opening.

[0021] An inflow surface can be formed between the guide surface of the guide rib and the free end face of the closing body. This inflow surface can be straight, rounded, or even curved. If the inflow surface is straight, it is preferably inclined at an angle of less than 60° to the longitudinal axis of the valve closure member.

[0022] The guide surface of the guide rib preferably extends from the closing surface of the closing body at least to the equatorial surface of the convex contour.

[0023] Furthermore, it can preferably be provided that the guide surface of the guide rib has a length FR that is less than a maximum travel movement of the closing body or an opening stroke of the closing body from the starting position to the working position. Alternatively, it can be provided that the guide surface of the guide rib has a length FR that is equal to or greater than a maximum travel movement of the closing body from the starting position to the working position. This can additionally provide a guide in the inlet opening of the valve housing at the front end of the closing body, which faces in the direction of flow.

[0024] Furthermore, it can preferably be provided that at least one guide element is provided on the valve closure member, in particular aligned opposite to the closing body of the valve closure member, by means of which the valve closure member is displaceably guided in the base housing, preferably during the entire working stroke of the valve closure member between the working position and the starting position in the base housing. This enables the valve closure member to be continuously guided to the base housing by this at least one guide element during an opening and closing movement of the valve closure member.

[0025] According to a preferred embodiment of the check valve, the valve closing member is guided by the guide ribs in the inlet opening in a first stroke phase from the starting position towards the working position up to an intermediate position, and preferably in a second stroke phase from the intermediate position to the working position the guide ribs are released from the inlet opening and the valve closing member is guided by a guide section of the closing body in the base housing, in particular a sleeve of the base housing. This enables the valve closing member to comprise a double guide during the entire opening stroke or working stroke. During the second stroke phase from the intermediate position to the working position the free flow volume can be increased because the guide ribs are no longer guided in the inlet opening.Preferably, the length FR of the guide surface on the guide rib is smaller than a guide length FL between a sleeve of the base housing and a guide section of the closing body facing the base housing. This allows the closing body to be guided over the entire opening stroke of the valve closure member.

[0026] The invention, as well as further advantageous embodiments and developments thereof, are described and explained in more detail below with reference to the examples shown in the drawings. The features shown in the description and the drawings can be used individually or in any combination according to the invention. They show:

[0027] Figure 1 is a schematic representation of a refrigeration circuit,

[0028] Figure 2 is a schematic sectional view of a connection device with a check valve,

[0029] Figure 3 is a perspective view of a first embodiment of the check valve,

[0030] Figure 4 is a schematic sectional view of the check valve according to Figure 3,

[0031] Figure 5 is a schematic sectional view of the check valve according to Figure 3 in an installation situation,

[0032] Figure 6 is a schematic sectional view of an alternative embodiment of the check valve according to Figure 3 in an installation situation,

[0033] Figure 7 is a schematic sectional view of the check valve according to Figure 3 with a valve housing in a further installation situation, Figure 8 is a perspective view of an alternative embodiment of the check valve to Figure 3,

[0034] Figure 9 is a schematic sectional view of the check valve according to Figure 8 in an initial position, and

[0035] Figure 10 is a schematic sectional view of the check valve according to Figure 8 in a working position.

[0036] Figure 1 shows a conventional design of a refrigeration or heating circuit 11, in particular of an air conditioning system, which is preferably used in motor vehicles. A refrigerant is compressed in a compressor 12. This can be, for example, R134A, R1234yf or CO2. The compressed refrigerant is fed to a condenser 13, wherein heat exchange takes place between the compressed refrigerant and the environment in order to cool the refrigerant. An accumulator 17 or collector can be provided downstream of the condenser 13 in order to separate the refrigerant in the gas phase and the liquid phase and simultaneously collect the liquid refrigerant. The refrigerant leaving the condenser 13 or accumulator 17 reaches an internal heat exchanger 14. An expansion valve 15 is provided between the internal heat exchanger 14 and a heat exchanger 16.The expansion valve 15 regulates the mass flow of the refrigeration or heating circuit 11 depending on the prevailing pressure difference. The high-pressure refrigerant expands through the expansion valve 15 and reaches the heat exchanger 16 on the low-pressure side. From the heat exchanger 16, the refrigerant absorbs heat from the environment. From there, the refrigerant is fed back to the compressor 12 via the internal heat exchanger 14.

[0037] When using a connection device 21 described below according to Figure 2 in such a refrigeration circuit, there is a deviation in the structure of the refrigeration circuit 11 according to Figure 2 in that the expansion valve 15 is not arranged separately in a line section between the internal heat exchanger 14 and the heat exchanger 16, but is integrated, for example, in a connection block 22.

[0038] The connection device 21 according to Figure 2 comprises an inlet opening 26 of a first through-bore 24, which leads via a throttle point 31 to an outlet opening 27. This outlet opening 27 is connected to an inlet of the heat exchanger 16. Adjacent thereto, a second through-bore 25 is provided in the connection device 21. An inlet opening 28, which is connected to an outlet of the heat exchanger 16, receives the refrigerant coming from the heat exchanger 14 and feeds it to an outlet opening 29 of the second through-bore 25. The inlet opening 26 of the first through-bore 24 and the outlet opening 29 of the second through-bore 25 are provided in a common connection bore 33. An end section of an internal heat exchanger 14 can be inserted into this common connection bore 33.This inner heat exchanger 14 has an outer tube 36, the outer circumference of which abuts the bore section 35 of the connection bore 33 and extends at least partially into the connection bore 33. An annular collar 37 or a flange or other connection point is preferably provided in the outer tube 36, which abuts the connection block 22 and fixes the inner heat exchanger 14 to the connection block 22.

[0039] The outer tube 36 of the inner heat exchanger 14 extends close to or up to the throttle point 31 without covering it. An inner tube 39 of the inner heat exchanger 14 protrudes from the outer tube 36 and preferably bears against an end face 40 formed in the transition region 34 between the outlet opening 29 and the bore section 35. Such an arrangement forms the inlet opening 26 of the first through-bore 24 by an annular channel between the inner tube 39 and the bore section 35 of the connection bore 33. In this connection device 21, an expansion valve 45, for example, is connected downstream of the throttle point 31 in the flow direction of the refrigerant.

[0040] A check valve 41 can be inserted into the outlet opening 29 of the second through-bore 25 of the connection block 22. Alternatively, a check valve 41 can also be inserted into one end of the inner tube 39 of the inner heat exchanger 14. In both cases, the check valve 41 borders the end face 40 or is arranged adjacent to it. This does not create an additional interface. The check valve 41 can also be used in other circuits to ensure only one flow direction of the medium. In particular, the check valve 41 is installed on the low-pressure side and / or the suction side.

[0041] Figure 3 shows a first embodiment of a check valve 41.

[0042] Figure 4 shows a schematic sectional view of the check valve 41 according to Figure 3.

[0043] This check valve 41 comprises a base housing 44, which is ring-shaped. A guide element 53 is provided in the central region of the base housing 44. This is received, for example, by at least one longitudinal rib 56, preferably by three longitudinal ribs 56. This guide element 53 can comprise a sleeve 54, which is shown in section in Figure 4. Recesses 52 can be provided between the sleeve 54 and the guide element 53. The guide element 53 comprises at least one opening 57, preferably three openings 57, which are connected to one another. The openings 57 are aligned, for example, in a star shape. The openings 57 are preferably located in the longitudinal extension of the longitudinal ribs 56. The base housing 44 can have a circumferential shoulder 95, through which a radially outwardly directed projection is created.This can serve, for example, as a stop for a defined installation of the check valve 41. The base housing 44 can further have a connecting section 85. This can serve to fasten a valve housing 43 with a connecting section 84 arranged thereon to the base housing 44. This arrangement of the valve housing 43 to the base housing 44 is shown, for example, in Figure 7.

[0044] The sectional view according to Figure 4 shows that at least one guide rod 59 extends within the valve closing member 61. This guide rod 59 extends from the closing body 65 in the direction of the base housing 44. A locking element 60 is provided at the end of the guide rod 59. This locking element 60 is directed radially outward. The guide rod 59 has a cross-sectional dimension such that it is guided in the opening 57. Advantageously, three guide rods 59 are aligned in a star shape with respect to one another. To connect the valve closing member 61 to the base housing 44, the guide rods 59 are moved towards one another so that the locking elements 60 can be guided through the openings 57. The guide rods 59 then return to their starting position.The force storage element 71 acting between the base housing 44 and the valve closing member 61 positions the valve closing member 61 into a starting position 62 relative to the base housing 44. The displacement movement of the valve closing member 61 relative to the base housing 44 is limited by the respective locking element 60 of the at least one guide rod 59. This locking element 60 rests against the guide element 53 on an outer side of the base 55 and limits the displacement movement.

[0045] In this initial position 62, the force storage element 71 can be preloaded between the base housing 44 and the valve closing member 61. This allows the opening force of the valve closing member 61 to be adjusted. A faster closing movement from a working position to the initial position 62 can also be achieved.

[0046] An axial guide is formed between a guide section 66 of the valve closure member 61 and the sleeve 54 of the guide element 53. Preferably, an axially displaceable seal can also be provided between the guide section 66 and the sleeve 54. The valve closure member 61 has a recess 79 adjacent to the valve seat 75, in which a sealing element 81 is arranged.

[0047] The closing body 65 of the valve closure member 61 can extend asymmetrically in a region between the sealing element 81 and the base housing 44. For example, a one-sided flattened portion 96 can be provided, which lies opposite a curved profile 97. The curved profile 97 of the closing body 65 can have a flow-optimized profile. The one-sided flattened portion 96 can achieve an increased flow volume.

[0048] The at least one guide rod 59 can provide additional guidance for the internal force storage element 71. The force storage element 71 is preferably provided within the sleeve 54 of the guide element and the guide section.

[0049] The closing body 65 of the valve closing member 61 extends from the sealing element 81 opposite the base housing 44. This closing body 65 has a convex contour 102 at a free end 101. Starting from the convex contour 102 and in the direction of the sealing element 81, the convex contour 102 is adjoined by a concave contour 105, which merges into a closing surface 108 of the closing body 65. This closing surface 108 directly borders the sealing element 81 or the recess 79 in the closing body 65. The closing surface 108 can be designed to bear flatly or linearly in the valve seat 75. The convex contour 102 can be semicircular and ends in a fictitious equatorial surface 103 remote from the free front end 101. In a semicircular contour, the equatorial surface 103 corresponds to twice the radius Ri, which determines the curvature of the convex contour 102.Alternatively, the convex contour 102 can be formed by a parabola, viewed in cross-section, which also ends in the equatorial surface 103. Directly adjacent to this equatorial surface 103, the concave contour 105 extends toward the closing surface 108 of the closing body 65. The concave contour 105 can have a constant curvature with a radius R2. The concave contour 105 can also be formed with an increasing gradient toward the closing surface 108.

[0050] Adjacent to the sealing element 81, the closing surface 108 comprises a cross-sectional area 109 with a radius R3. This cross-sectional area 109 corresponds to a cross-sectional area for a through-opening 24 in the valve seat 75, in which the valve closing member 61 rests in an initial position and closes the through-opening 24.

[0051] Figure 5 shows a schematic view of the check valve 41 according to Figures 3 and 4 in a first installation situation. In this embodiment, a connection opening of the connection device 21 or a pipe 39 is shown. The connection opening can be an outlet opening and / or inlet opening 26, 27, 28, 29. The check valve 41 closes the passage opening 24 in one flow direction.

[0052] The base housing 44 rests on a step in the connection opening of the connection device 21 with the shoulder 95. As a result, the check valve 41 assumes a defined position within the connection opening. The check element 41 can be installed with a defined preload force of the force storage element 71. In this case, the force storage element 71 between the valve closing member 61 and the base housing 44 is subjected to a compressive force and preferably corresponds to the closing force of the valve closing member 61. The valve seat 75 is formed by a constriction in the through-opening 24. The closing body 65 and the seal 81 of the valve closing member 61 rest against this valve seat 75. In the initial position 62 of the check valve 41 shown in Figure 5, the through-opening 24 is closed.

[0053] By changing the distance between the valve seat 75 and the base housing 44 of the check valve 11 in the connection opening of the connection device 21, the preload of the force storage element 71 and thus an opening time can be adjusted.

[0054] When pressure is applied to the valve closing member 61 by a medium, the valve closing member 61 is moved toward the base housing 44, preferably after overcoming the set preload force. The valve closing member 61 is moved into a working position 63. As a result, the closing body 65 of the valve closing member 61 lifts off the valve seat 75, and the medium can flow toward the base housing 44. For example, the medium passes through the at least one flow channel 49 through the discharge opening 51.

[0055] The closing body 65 rests with its closing surface 108 in an initial position 62 in the valve seat 64. In this embodiment of the check valve 41, the closing body 65 extends beyond the valve seat 64 opposite to the flow direction.

[0056] The closing body 65 can, for example, have a radius Ri for an equatorial surface 103 that is smaller than a radius R3 of the cross-sectional area in which the closing surface 108 lies. Ri is preferably smaller than 0.5 R3 or 0.25 R3. Furthermore, it can preferably be provided that the radius Ri for the convex contour 102 is smaller than the radius R2 for the concave contour 105. Furthermore, it can preferably be provided that the length L, starting from the sealing element 81 or the closing surface 108 to the free front end of the closing body 101, lies in a range between 0.5 and 5 in relation to the radius Ri. It is preferably provided that the length L is greater than an opening stroke of the valve closing member from the starting position 62 to the working position 63.Furthermore, it can be provided that a ratio between the radius R3 of the cross-sectional area of ​​the closing surface 108 and the length L from the closing surface 108 to the front end 101 of the closing body 65 is in a range of 4 to 0.25.

[0057] Figure 6 shows a schematic sectional view of an alternative embodiment of the check valve 41 according to Figure 3 in an analogous installation situation according to Figure 5. This embodiment of the check valve 41 corresponds to that in Figures 3 to 5. In addition, in the check valve 41 according to Figure 6, guide ribs 82 are provided on the closing body 65. These guide ribs 82 preferably extend from the closing surface 108 in the direction of the free front end 101 of the closing body 65. Advantageously, two or more guide ribs 82 are provided. These guide ribs 82 have guide surfaces 83, which are preferably aligned parallel to one another. The guide surfaces 83 are aligned coaxially to the longitudinal axis of the valve closing member 61 or to its lifting movement.The guide surfaces 83 can have inflow surfaces 111 that, starting from one end of the guide surface 83, transition into the concave contour 105 or the convex contour 102. The inflow surface 111 can also transition directly into the front end 101 of the convex contour 102.

[0058] The guide surface 83 preferably has a length FR. The length FR of the guide surface 83 from the guide rib 82 is preferably smaller than a length FL of a guide formed between a sleeve 54 on the base housing 44 and the guide section 66 on the closing body 65. Furthermore, it is preferably provided that the guide surfaces 83 of the guide ribs 82 have an outer circumference that corresponds to an inner diameter of the through-opening 24.

[0059] Figure 7 shows a schematic sectional view of the check valve 41 according to Figures 3 to 5, which additionally comprises a valve housing 43. The valve housing 43 comprises the connection section 84, which engages the connection section 85. The connection section 85 is preferably provided so as to surround the outside of the connection section 84. Alternatively, a reversed arrangement can also be provided. A plug-in, locking, snap-in, press-in, or screw connection can be provided for this connection interface 46. It can be detachable or non-detachable.

[0060] A preload force acting on the force storage element 71 can be determined by the length of the valve housing 43 or the distance of the valve seat 75 to the connection interface 84 or to the base housing 44.

[0061] The valve housing 43 may have an inner wall section extending from the base housing 44, which preferably tapers continuously in cross-section up to the valve seat 75 to form a constriction. Following this, the inner cross-section of the valve housing 43 is again increasingly enlarged.

[0062] On the outer circumference of the valve housing 43, a recessed receptacle for a further sealing element 89 is provided for sealing the connection point in the connection device 21.

[0063] A frontal annular collar 87 of the valve housing 43 rests against a shoulder of the connection device 21. This allows a defined installation situation of the check valve 41 for the connection opening in the connection device 21 or the pipe 39.

[0064] The mode of operation of this check valve 41 corresponds to that in Figures 3 to 5. The check valve 41 according to Figure 7 can, like the embodiment in Figure 6, have guide ribs 82 with guide surfaces 83.

[0065] Figures 8 to 10 show a further alternative embodiment of the check valve 41 to the previously described embodiments. This embodiment of the check valve 41 according to Figures 8 to 10 comprises a base housing 44 for receiving the valve closing member 61 with the guide rods 59, which are guided in the at least one guide element 53, according to Figures 3 to 5. Furthermore, the check valve 41 can comprise a valve housing 43, which can be connected to the base housing 44 via the detachable interface 46.

[0066] In this alternative embodiment shown in Figures 8 to 10, the design of the closing body 65 of the valve closing member 61 differs from the embodiment shown in Figures 3 to 5. However, the shape of the closing body 65, starting from the closing surface 108 up to the free front end 101, corresponds to the previously described embodiments. A sealing element 81 is also provided on the valve closing member 61. The closing surface 108 of the closing body 65 rests against a valve seat surface 76 of the valve seat 75 and absorbs the closing force of the force storage element 71. The sealing element 81 also rests against the valve seat surface 76, but only in a sealing manner. This valve seat 75 is preferably designed in the form of a cone, which widens in the flow direction from the inlet opening 26, 28 to the outlet opening 27, 29. This enlarges the cross-section of the flow channel 49.This has the advantage that the flow velocity of the medium decreases with increasing cross-sectional area and thus the flow pressure losses can be reduced.

[0067] The closing body 65 is preferably designed with a length such that a front end 101 is positioned within the inlet opening 28 independently of an opening stroke of the valve closing member 61. The front end 101 of the closing body 65 can extend up to a transition between the valve seat surface 76 and an inner wall 74 of the inlet opening 26 or beyond in the direction of the inlet opening 26. This embodiment can also apply to the previously described embodiments. The guide ribs 82 are provided on the closing body 65 pointing towards the inlet opening 26, 28. The closing body 65 and the guide ribs 82 arranged thereon with their guide surfaces 83 advantageously correspond to the embodiment according to Figure 6. During a stroke movement of the valve closing member 61 from the starting position 62 into the working position 63, the guide surfaces 83 of the guide ribs 82 can rest on the valve seat 75 orthe through-opening 24 of the valve housing 43. This provides axial guidance for the valve closing member 61. The guide surface 83 of the guide rib 82 can also be shortened, so that guidance is only provided until the guide section 66 of the closing body 65 is guided through the sleeve 54. Thus, the guidance by the guide ribs 82 only acts during a first opening phase of the valve closing member relative to the valve seat up to an intermediate position. During a further travel path or opening stroke from the intermediate position into the working position 63, the guidance acts between the guide section 66 of the closing body 65 and the base body 44 or the sleeve 54 of the base body 44. The further guidance formed by the guide rods 59 and the opening 57 in the base housing 44 acts continuously over the entire stroke path or the travel movement between the working position 63 and the starting position 62.The same applies to the movement of the valve closing element 61 from the working position 63 to the starting position 62.

[0068] In this alternative embodiment, the guide section 66 and the sleeve 54 do not engage with one another in a starting position 62 of the valve closing member 61. Rather, they are arranged separately from one another. As soon as the guide surfaces 83 of the guide ribs 82 on the closing body 65 detach from the valve seat 75 during the transition from a first opening phase to a second opening phase of the valve closing member 61, the guide section 66 and the sleeve 54 engage with one another and form an axial guide for the valve closing member 61. In a working position of the valve closing member 61 according to Figure 10, the guide section 66 and the sleeve 54 engage with one another in such a way that the force storage element 71 is completely enclosed. The flow channel 49 extends outside the valve closing member 61, the guide section 66 and the sleeve 54, so that the flow medium does not come into contact with the force storage element 71.

[0069] The guide ribs 82 provided on the closing body 65 can furthermore have the advantage that they act as so-called rectifiers, i.e. that the flow of the medium can be calmed, which in turn enables a reduced flow pressure loss.

Claims

Claims Check valve, in particular for a refrigeration or heating circuit, which can be inserted into a connection opening (26, 27, 28, 29) of a connection device (21) or a pipe (39), - with a one-piece or multi-piece housing (42) which comprises at least one base housing (44), wherein a feed opening (48) is provided on the inlet side and a discharge opening (51) is provided on the outlet side of the base housing (44), which are connected to one another by a flow channel (49), - with a guide element (53) provided on the base housing (44), through which a valve closing member (61) is displaceably guided, wherein the valve closing member (61) is arranged in an initial position (42) by a force storage element (71) and the valve closing member (61) is displaceable against a force of the force storage element (71) into a working position (63) in the direction of the discharge opening (51), - with a closing body (65) arranged on the valve closing member (61), which has a closing surface (108) which, in an initial position (62) of the valve closing member (61), rests against a valve seat (75) of the connecting device (21) or of the tube (39) or of a valve housing (43) of the housing (42), and closes a through opening (24), - with a sealing element (81) arranged adjacent to the closing body (65), which rests against the valve seat (75) and - wherein the base housing (44), the guide element (53) and the force storage element (71) acting on the valve closing member (61) are provided downstream of the valve seat (75), characterized in that - that the closing body (65) extends from the closing surface (108) opposite to a movement of the valve closing member (61) from the starting position (62) into the working position (63), and - that the closing body (65) has a convex contour (102) at its free end face (101), which is connected to the closing surface (108) by a concave contour (105). Check valve according to claim 1, characterized in that a smooth transition is formed between the convex contour (102) and the closing surface (108) by the concave contour (105). Check valve according to claim 1 or 2, characterized in that the convex contour (102) transitions directly into the concave contour (105), and the concave contour (105) transitions directly into the closing surface (108) of the closing body (65). Check valve according to one of the preceding claims, characterized in that a length L of the closing body (65) starting from the closing surface (108) to the free front end (101) of the closing body (65) is greater than a displacement movement of the valve closing member (61) from the starting position (62) into the working position (63).Check valve according to one of the preceding claims, characterized in that the closing body (65) is hemispherical or has a parabolic cross-section at its free front end (101), and that remote from the free front end (101) an equatorial surface (103) is formed by the convex contour (102) with a radius Ri which is smaller than a radius R3 of a cross-sectional area (109) of the closing surface (108). Check valve according to one of the preceding claims, characterized in that the concave contour (105) between the convex contour (101) and the closing surface (108) is formed by a radius R2 or by a curved profile with a changing gradient or a changing radius, in particular an increasing gradient or a decreasing radius in the direction of the closing surface (108) for widening the concave contour (102), and preferably the radius R2 of the concave contour (105) is greater than the radius Ri of the convex contour (102). Check valve according to claims 4 to 6, characterized in that a length L of the closing body (65), starting from the closing surface (108) to the free front end (101) of the closing body (65), in relation to the radius Ri of the equatorial surface (103), lies in a range between 0.25 and 5.Check valve according to one of the preceding claims, characterized in that the free frontal end (101) of the closing body (65) extends upstream beyond the valve seat (75) after the valve closing member (61) has assumed the working position (63), and preferably the end (101) of the closing body (65) in the working position (65) of the valve closing member (61) projects into the inlet opening (26) adjacent to the valve seat (75). Check valve according to one of claims 4 to 8, characterized in that a ratio between the radius R3 of the cross-sectional area of ​​the closing surface (108) and the length L of the closing body (65), starting from the closing surface (108) to the free frontal end (101) of the closing body (65), is in a range of 3 to 0.

3. Check valve according to one of the preceding claims, characterized in that the free frontal end (101) of the closing body (65) extends upstream of the valve seat (75) after the valve closing member (61) has assumed the working position (63). Guide ribs (82) extend from the end face (108) of the closing body (65) toward the free end face (101) of the closing body (65) or up to the free end face (101) of the closing body. A check valve according to claim 10, characterized in that two or more guide ribs (82), preferably aligned at the same circumferential angle to one another, are provided on the closing body (85). Check valve according to claim 10 or 11, characterized in that the guide ribs (82) have a guide surface (83) which extends from the closing surface (108) of the closing body (65) in the direction of the free front end (101) of the closing body (65) and is aligned parallel to one another, and is preferably guided along an inner wall (74) of the inlet opening (28) or in a transition region between a valve seat surface (76) of the valve seat (75) and the inner wall (74) of the inlet opening (26).Check valve according to claim 12, characterized in that an inflow surface (111) is formed between the guide surface (83) of the guide rib (82) and the free front end (101) of the closing body (65), which inflow surface is designed to be straight, curved, or rounded. Check valve according to one of claims 12 or 13, characterized in that the guide surface (83) of the guide rib (82) extends at least from the closing surface (108) of the closing body (65) to the equatorial surface (103) on the closing body (65). Check valve according to one of claims 12 to 14, characterized in that the guide surface (83) of the guide rib (82). has a length FR that is less than a maximum travel movement of the closing body (65) from the starting position (62) into the working position (63). Check valve according to one of claims 12 to 14, characterized in that the guide surface (83) of the guide rib (82) has a length FR that is equal to or greater than a maximum travel movement of the closing body (65) from the starting position (62) into the working position (63).Check valve according to one of claims 10 to 15, characterized in that the valve closing member (61) is guided in a first stroke phase from the starting position (42) in the direction of the working position (63) up to an intermediate position by the guide ribs (82) in the inlet opening (26) and preferably in a second stroke phase from the intermediate position up to the working position (63) the guide ribs (82) are released from the inlet opening (26) and the valve closing member (61) is guided by a guide section (66) of the closing body (65) and a guide section (66) of the base housing (44), in particular a sleeve (54) of the base housing (44). Check valve according to claim 17, characterized in that the length FR of the guide surface (83) on the guide rib (82) is smaller than a guide length FL between the sleeve (54) of the base housing (44) and a guide section (66) of the closing body (65) which points towards the base housing (44).Check valve according to one of the preceding claims, characterized in that the sealing element (81) is arranged downstream of the closing surface (108) of the closing body (85) and the closing force of the force storage element (71) is transferred to the valve seat (75) via the closing surface (108) of the closing body (85) and / or the sealing element (81) only bears against the valve seat (75) in a sealing manner. Check valve according to one of the preceding claims, characterized in that at least one guide element (53), in particular aligned opposite to the closing body (65), is provided on the valve closing member (61), by means of which guide element the valve closing member (61) is displaceably guided in the base housing (44), preferably during the entire working stroke of the valve closing member (61) between the working position (63) and the starting position (62) in the base housing (44).

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