Pressure relief valve, compressor having such a pressure relief valve, and refrigerant circuit having such a pressure relief valve

Abstract

The invention relates to a pressure relief valve (10), comprising a main part (12), which has a substantially hollow cylindrical shape, wherein a valve opening (20) is provided on one side and an insertion opening (22) is provided on the opposite side; a valve body (14); a helical spring (16); and a spring counter holder (18), the valve body (14), the helical spring (16), and the spring counter holder (18) being provided within the main part. In order to be able to produce the pressure relief valve (10) from components which are comparatively simple to produce and which can be simply assembled, it is proposed that the spring counter holder (16) has a conical portion (24) and a pressing portion (26) in a radially outer region, the spring counter holder (18) being pressed into the main part (12) in such a way that the pressing portion (26) is force-fittingly connected to the inner face of the main part (12). Furthermore, the invention relates to a compressor and a refrigerant circuit comprising such a pressure relief valve (10).

Description

[0001] Pressure relief valve, compressor with such a pressure relief valve and refrigerant circuit with such a pressure relief valve

[0002] Description

[0003] The invention relates to a pressure relief valve according to the preamble of claim 1. Such a valve is known, for example, from CN 110 762 263 A. Furthermore, the invention relates to a compressor and a refrigerant circuit with such a valve.

[0004] Valves are used to control the flow of fluids in a system. They enable the precise regulation, opening, and closing of lines to achieve a desired operating state. Valves are used in both simple and complex applications to ensure the safety, efficiency, and reliability of systems.

[0005] Pressure relief valves, also known as overpressure valves or pressure relief valves, represent a special subgroup. These protect system components from excessive pressure by opening when a threshold, called the opening pressure, is reached, releasing the fluid, for example, into the environment. After sufficient fluid has been released and the pressure has fallen below the opening pressure, the overpressure valve closes, returning the system to its normal operating state.

[0006] Spring-loaded pressure relief valves are used in many applications, such as refrigerant circuits. They protect other components of the refrigerant circuit, particularly the condenser and expansion valve, from excessively high pressures. The force required to close the valve body is generated by a spring. Its preload determines the opening pressure of the pressure relief valve. The most common design uses a coil spring. The pressure relief valve is mounted according to the instructions mentioned above.

[0007] CN 110 762 263 A is assembled in stages. First, the valve body and spring retainer are inserted into the base body, followed by the coil spring. The spring retainer is then placed on the spring and, by means of an external thread that engages with an internal thread provided within the base body, is at least partially inserted and secured. The position of the spring retainer defines the installation length of the spring and thus its preload, which in turn determines the opening pressure of the valve.

[0008] This design, with corresponding threads on the base body and spring retainer, has the advantage that the opening pressure can be adjusted even after the assembly process is complete. However, a disadvantage is that each component requires an additional machining step to create the threads. Furthermore, mounting the spring retainer by screwing is technically more complex than using a linear feed.

[0009] The invention therefore aims to describe a pressure relief valve that consists of relatively simple components and is easy to install. Further aspects include the specification of a compressor and a refrigerant circuit with such a pressure relief valve.

[0010] According to the invention, this problem is solved by a pressure relief valve according to claim 1. The further aspects are solved by a compressor in a refrigerant circuit according to claim 9 and a refrigerant circuit according to claim 10.

[0011] A pressure relief valve described in the present application, hereinafter also referred to simply as a pressure valve or valve, comprises at least one base body, which functions as a valve housing. This housing has a substantially hollow cylindrical shape. A valve opening is provided on one side of the base body, and an insertion opening on the opposite side. The other components are inserted into the base body through these insertion openings.

[0012] These include a valve body designed and configured to close the valve opening and allow fluid passage. Adjacent to the valve body is a spring that exerts a force on the valve body, thus defining the opening pressure of the pressure valve. The spring is supported by a spring retainer, which, in the assembled state of the pressure valve, is also located within the base body.

[0013] The spring retainer has a substantially cylindrical shape. The diameter of the section closest to the insertion opening in the assembled state corresponds approximately to the inner diameter of the base body in a section near the insertion opening. This section of the spring retainer has a conical section, which facilitates its insertion into the base body. Adjoining this is a pressing section, which, in the assembled state, is the part of the spring retainer closest to the insertion opening. In its relaxed state, the pressing section has a slight oversize compared to the corresponding inner diameter of the base body. This oversize causes the pressing section, in the assembled state, to exert a radially outward pressing force on an inner surface of the base body.The spring retainer is thus positively connected to the inside of the base body via its press-fit section and is axially fixed in the base body in this way. The installation length of the spring and the opening pressure of the pressure relief valve are defined by this connection.

[0014] Such a force-fit connection between the press-fit section of the spring retainer and the inside of the base body requires fewer machining steps in the manufacturing process for both components than for pressure relief valves with screw connections known from the prior art, since no threads need to be provided. Furthermore, the design according to the invention allows for simpler assembly, as the spring retainer can be inserted into the base body with a linear feed motion and no screwing motion is necessary.

[0015] According to a preferred embodiment, the spring retainer has at least one relief groove. This groove preferably extends axially from an axial end face of the spring retainer, which, in the assembled state, is closest to the insertion opening of the base body. Its depth corresponds approximately to the height of the pressing section; it is particularly preferably also extended into the conical section. It is preferably circumferential and arranged between a valve axis and a radially outer section of the spring retainer. For manufacturing reasons, the relief groove may have a tapered cross-section starting from the end face of the spring retainer.

[0016] The relief groove simplifies the assembly of the spring counterholder by increasing the radial deformability of the press section. In particular, it reduces the required assembly force needed to overcome the radially outward pressing force in the press section.

[0017] According to a further preferred embodiment, the press section is segmented into at least two press section segments by recesses. The recesses preferably extend from a radially outer side of the press section inwards, up to an optional relief groove. The segmentation of the press section serves the same purpose as the relief groove described above, namely to simplify assembly by increasing the radial deformability of the press section.

[0018] In some embodiments, the radially acting frictional connection between the spring retainer and the base body can be supplemented by an axially acting positive-locking connection. For this purpose, an axial end face can be provided on the inside of the base body in the area of ​​the insertion opening. In the assembly direction, the insertion opening thus represents a narrow section with an adjoining undercut in which the inner diameter of the base body widens. The spring retainer bears against the axial end face of the base body formed by the undercut with its axial end face.During assembly, the radially outward-acting pressing force in the pressing section is used, which, after passing through the insertion opening, causes a deformation in a radially outward direction, resulting in the axial end face of the spring counterholder contacting the axial end face on the inside of the base body, forming a positive-locking connection in the axial direction.

[0019] According to a further preferred embodiment, the spring retainer has at least two support ribs in the conical section, which are preferably evenly distributed along the circumference of the spring retainer. The support ribs preferably extend in the axial direction and ensure that the spring retainer is in contact with the base body not only via the pressing section, but over a larger portion of its axial length. This prevents the spring retainer from tilting within the base body and instead ensures the predetermined position of the spring retainer within the base body.

[0020] According to a further preferred embodiment, the spring retainer has at least one locking lug in a radially outer region of the pressing section, which is at least partially circumferential. Correspondingly, at least two circumferential locking grooves are provided on the corresponding radial inner surface of the base body. During assembly, the at least one locking lug engages in one of the at least two locking grooves, thereby forming a positive-locking connection in the axial direction. The plurality of locking grooves allows for different positions in which the spring retainer can be fixed, and thus for different adjustable opening pressures.

[0021] If at least two locking lugs and at least three locking grooves are provided, they must be arranged at equal axial distances from each other. This is geometrically necessary to ensure that all locking lugs engage simultaneously.

[0022] In practice, an arrangement of three locking lugs and seven locking slots has proven advantageous, as it offers a favorable ratio of assembly force to connection between the spring retainer and the base body. With such an arrangement, all three locking lugs are always engaged, providing five possible positions for fixing the spring retainer.

[0023] According to a further preferred embodiment, each of the at least two detent grooves corresponds to a defined opening pressure of the pressure relief valve. Each detent groove has a specific spring installation length, which corresponds to a defined opening pressure. This offers the advantage that the same valve, consisting of the same components, can be used for applications with different predefined opening pressures. When inserting the spring retainer into the base body, the spring retainer, with its at least one detent lug, simply needs to be positioned in the detent groove that corresponds to the desired opening pressure in the specific application.

[0024] In a further preferred embodiment, four recesses as described above are provided, which segment the press section into four equally sized press section segments. These segments have at least one locking lug as described above on their radially outer side, with the locking lugs of two opposing press section segments arranged at the same axial height. The locking lugs of the other two opposing press section segments are axially offset by half the axial distance between the at least two locking grooves of the base body. This ensures that the locking lugs of all four press section segments never engage in a locking groove simultaneously, but only the locking lugs of the opposing press section segments do.

[0025] When the spring-loaded retainer is inserted, the locking lugs of the directly adjacent press-fit segments alternately engage in the locking grooves of the base body. This design allows for even finer gradation when selecting the opening pressure, since, compared to the previous embodiment, engagement does not occur at the distance between at least two locking grooves, but rather at half that distance. This means the corresponding pressure relief valve can also be used where very precise requirements are placed on the opening pressure, and where this opening pressure could not be adjusted in the previous embodiment.

[0026] A pressure relief valve in one of the embodiments described above can be used in a compressor within a refrigerant circuit. It can be arranged on either the low-pressure or high-pressure side to protect the other components of the refrigerant circuit from excessively high pressures.

[0027] Alternatively or additionally, a pressure relief valve can be used in a refrigerant circuit in one of the embodiments described above. There, it is arranged upstream or downstream of the refrigerant compressor, thereby protecting the other components of the refrigerant circuit, in particular the condenser and the expansion valve, from excessively high pressures.

[0028] The invention is explained in more detail below with reference to the accompanying drawings. The embodiments shown therein represent examples of how the pressure relief valve according to the invention can be designed. Identical reference numerals always denote identical elements.

[0029] The drawings show

[0030] Fig. 1 shows a first embodiment of the pressure relief valve according to the invention in a sectional view;

[0031] Fig. 2 shows a spring counterhold according to the pressure relief valve of Fig. 1 in a detailed view;

[0032] Fig. 3 shows an alternatively designed spring counterholder in a detailed view;

[0033] Fig. 4 shows a second embodiment of the pressure relief valve according to the invention in a sectional view;

[0034] Fig. 5 shows a section of Fig. 4 in a detailed view;

[0035] Fig. 6 shows a spring counterholder according to the pressure relief valve of the embodiment of Fig. 4 in a detailed view;

[0036] Fig. 7 shows a first embodiment of a compressor according to the invention in a sectional view;

[0037] Fig. 8 shows a second embodiment of a compressor according to the invention in a sectional view; and

[0038] Fig. 9 shows a schematic view of an embodiment of a refrigerant circuit according to the invention. Fig. 1 shows a pressure relief valve 10 according to the invention in a first embodiment. The pressure relief valve 10 comprises a base body 12 with a substantially hollow cylindrical shape, which, in the illustration according to Fig. 1, has a valve opening 20 at its lower end and an inlet opening 22 at its opposite, upper end.

[0039] Within the base body 12, a valve body 14, a coil spring 16, and a spring retainer 18 are arranged in this order for assembly purposes. The coil spring 18 exerts a force on the valve body 14 that corresponds to the opening pressure of the valve 10. The coil spring 16 is supported by the spring retainer 18. The installation length of the spring 16, which depends on the position of the spring retainer 18, thus determines the opening pressure of the valve 10.

[0040] The spring retainer 18 can essentially be divided into two sections, the lower section of which, as shown in Fig. 1, comprises only a guide pin that is not an essential part of the present invention. The upper section of the spring retainer 18, which has a greater radial extent, has a conical section 24 and a pressing section 26. The conical section 24 is shaped as described and serves to facilitate the insertion of the spring retainer 18 into the base body 12 during assembly. In the assembled state, the pressing section 26 exerts a radially outward force on an inner surface of the base body 12. This pressing action results in a force-fit connection between the spring retainer 18 and the base body 12, thereby fixing the spring retainer 18 axially in the base body 12.

[0041] Below the insertion opening 22, the base body 12 has a circumferential undercut 32, which forms an axial end face 38 of the base body 12. Once the spring retainer 18 has completely passed through the insertion opening 22 during assembly, the radially outward force in the pressing section 26 causes a portion of the pressing section 26 to enter the undercut 32. In this process, an axial end face 36 of the spring retainer 18 comes into contact with the axial end face 38 of the base body 12. In addition to the frictional connection described above, the position of the spring retainer 18 is thus also secured in the axial direction by this positive locking connection.

[0042] Figures 2 and 3 show possible designs of the spring retainer 18. The spring retainer 18 according to Figure 2 has three recesses 30 that segment the press section 26 into three press section segments 34. Furthermore, the spring retainer 18 has a circumferential relief groove 28. Both of these features, the segmentation of the press section 26 into press section segments 34 as well as the relief groove 28, serve to simplify assembly by increasing the radial deformability of the press section 26. This reduces the force required to insert the spring retainer 18 into the base body 12.

[0043] The spring retainer 18 according to Fig. 3 also has a relief groove 28 for the same purpose. Compared to the variant according to Fig. 2, this design differs on the one hand by the absence of the recesses 30, and on the other hand by the significantly narrower pressing section 26 and the correspondingly wider conical section 24. The resulting risk of the spring retainer 18 tilting in the base body 12 is eliminated by the arrangement of several support ribs 40 in the conical section 24. These ensure that the spring retainer 18 rests in the base body 12 over a sufficient axial length.

[0044] Fig. 4 shows a second embodiment of the pressure relief valve 10 according to the invention, with the positioning and fixing of the spring retainer 18 being explained in more detail with reference to Figs. 5 and 6. The pressure relief valve 10 according to Fig. 4 contains the same components as the embodiment according to Fig. 1. The differences lie in the design of the pressing section 26 and in the absence of the undercut 32 and thus the axial end face 38 of the base body 12.

[0045] The detailed view in Fig. 5 shows in particular that several detent grooves 44 are provided on the inside of the base body 12. Several detent lugs 42 are arranged in the pressing section 26 of the spring retainer 18, the shape of which corresponds to that of the detent grooves 44. The engagement of the detent lugs 42 in the detent grooves 44 creates a positive-locking connection in the axial direction, which, in addition to the frictional connection provided by the pressing section 26, fixes the axial position of the spring retainer 18 in the base body 12.

[0046] The number of detent slots 44 should be at least one greater than the number of detent lugs 42, so that, on the one hand, all detent lugs 42 are always engaged with a detent slot 44, and on the other hand, an adjustment option is provided. Figure 5 shows a design with three detent lugs 42 and seven detent slots 44. Assuming that all detent lugs 42 are always engaged with a detent slot 44, this results in five possible positions. Each of these positions defines a specific installation length of the spring 16 and thus a specific opening pressure of the pressure relief valve 10.

[0047] Fig. 6 shows a detailed view of the spring retainer 18 according to Figs. 4 and 5. The wider pressing section 26, compared to the spring retainer 18 according to Fig. 3, in combination with the circumferential locking lugs 42, ensures sufficiently stable mounting of the spring retainer 18 in the base body 12, which is why this design does not require support ribs 40.

[0048] Fig. 7 shows a first embodiment of a compressor 46 according to the invention with a low-pressure side 48 and a high-pressure side 50. In the illustrated embodiment, the pressure relief valve 10 is arranged on the low-pressure side 48 of the compressor 46.

[0049] In contrast, Fig. 8 shows a second embodiment of an otherwise identical compressor 10, which differs from the embodiment shown in Fig. 7 in that the pressure relief valve 10 is arranged on the high-pressure side 50.

[0050] Fig. 9 shows a schematic representation of a refrigerant circuit 52 according to the invention. Besides the compressor 46, the refrigerant circuit 52 comprises a condenser 54, an expansion valve 56, and an evaporator 58. A refrigerant flows through the refrigerant circuit 52 in a flow direction 60 indicated by arrows. In the illustrated embodiment, the pressure relief valve 10 is arranged downstream of the compressor 46 and upstream of the condenser 54 in the flow direction 60. However, embodiments are also conceivable in which the pressure relief valve 10 is arranged at other positions within the refrigerant circuit 52, e.g., downstream of the evaporator 58 and upstream of the compressor 46.

[0051] List of reference signs

[0052] Overpressure valve

[0053] basic body

[0054] Valve body

[0055] coil spring

[0056] Spring counter holder

[0057] Valve opening

[0058] insertion opening

[0059] Conical section

[0060] Press section

[0061] Relief groove

[0062] Exclusion

[0063] Undercut

[0064] Press section segment

[0065] Axial end face of the spring retainer

[0066] Axial end face of the base body

[0067] Support bridge

[0068] Rastnose

[0069] Locking groove

[0070] compressor

[0071] Low-pressure side

[0072] High pressure side

[0073] Refrigerant circuit

[0074] capacitor

[0075] Expansion valve

[0076] Evaporator

[0077] Flow direction

Claims

Claims 1. Pressure relief valve (10), with - a base body (12) having a substantially hollow cylindrical shape, wherein a valve opening (20) is provided on one side and an insertion opening (22) is provided on an opposite side, - a valve body (14), - a coil spring (16) and - a spring retainer (18), wherein the valve body (14), the coil spring (16) and the spring retainer (18) are arranged within the base body (12), characterized by the fact that the spring retainer (16) has a conical section (24) and a press section (26) in a radially outer area, wherein the spring retainer (16) is pressed into the base body (12) such that the press section (26) is positively connected to an inner surface of the base body (12).

2. Pressure relief valve (10) according to claim 1, characterized by the fact that the spring retainer (16) has at least one relief groove (28) which increases the radial deformability of the press section (26).

3. Pressure relief valve (10) according to claim 1 or 2, characterized by the fact that the press section (26) is segmented into at least two press section segments (34) by radially arranged recesses (30) to increase the radial deformability of the press section (26).

4. Overpressure valve (10) according to one of the preceding claims, characterized by the fact that between an axial end face (36) of the spring retainer (16) and a positive locking connection in the axial direction exists between an axial end face (38) and the inside of the base body (12).

5. Pressure relief valve (10) according to one of the preceding claims, characterized by the fact that the spring retainer (16) in the conical section (24) has at least two support webs (40) which prevent the spring retainer (16) from tilting within the base body (12).

6. Overpressure valve (10) according to one of the preceding claims, characterized by the fact that at least one at least partially circumferential locking lug (42) is provided in a radially outer area of ​​the pressing section (26) of the spring counterholder (16) and at least two circumferential locking grooves (44) are provided on a radial inner side of the base body (12), wherein a positive locking connection in the axial direction exists between the at least one locking lug (42) and at least one of the locking grooves (44).

7. Overpressure valve (10) according to claim 6, which is characterized by the fact that each of the at least two detent grooves (44) corresponds to a defined opening pressure of the overpressure valve (10).

8. Overpressure valve (10) according to claim 6 or 7, characterized by the fact that the press section (26) is segmented into four press section segments (34), wherein the at least one locking lug (42) of each pair of opposing press section segments (36) is arranged at a first axial position and the at least one locking lug (42) of each pair of opposing press section segments (36) is arranged at a second axial position, wherein the axial distance between the first position and the second position is half the axial distance of the at least two locking grooves (44). 15 9. Compressor (46) in a refrigerant circuit (52) with a pressure relief valve (10) according to one of claims 1 to 8, wherein the pressure relief valve (10) is arranged on the high pressure side (50) or on the low pressure side (48) of the compressor (46).

10. Refrigerant circuit (52) with a pressure relief valve (10) according to one of claims 1 to 8, wherein the pressure relief valve (10) is arranged in a flow direction (60) of the refrigerant circuit (52) upstream or downstream of a compressor (46).

Images