EP2930374B1 - Storage devices and mounting method for manufacturing such storage devices - Google Patents

Description

The invention relates to storage devices, in particular in the form of hydraulic accumulators, with the features in the preamble of claim 1. The invention further relates to an assembly method for producing such storage devices.

Such storage devices are freely available in the form of hydraulic accumulators on the market. Hydraulic accumulators are used, among other things, in hydraulic systems to take up certain volumes of pressurized fluids and to return these to the system as required. Particularly common are hydraulic systems with hydropneumatic storage with a separator designed as a membrane. In particular, the membrane separates a liquid space as a working space from a gas space as a further working space. The membrane takes over the decoupling of gas and liquid space. Nitrogen is preferably used as the working gas. The liquid space communicates with a hydraulic circuit of the system, so that when the pressure in the hydraulic circuit increases, the hydraulic accumulator receives pressure medium and the gas is compressed. With decreasing pressure, the previously compressed gas expands again, displacing the liquid back into the hydraulic circuit.

Particular attention is paid to the attachment of the separator in the storage enclosure in the design of such storage devices. This attachment must withstand the high pressures in the storage device and permanently separate the working spaces from each other gas-tight. Meanwhile, strong dynamic loads on the separator occur when it is moved back and forth in the storage enclosure.

A solution for fixing a separator in a storage enclosure goes from the DE 10 2009 021 463 A1 out. Here, the separator is cup-shaped and has at its outer edge on a torus. The annular bead is held between housing parts in respective groove-shaped recesses. The preparation of such a separator with a torus requires additional steps. Since such storage devices are devices that are manufactured in large quantities, the aspects of manufacturability and production costs must be considered in the design. Therefore, the aim is to further simplify the production and in particular to dispense with an annular bead on the separator.

Another solution for the production of a memory device is from the DE 103 55 435 B3 out. Here, the separator is also designed shell-shaped and also has a constant wall thickness in the region of an upper end edge. In this hydraulic accumulator engages the upper end edge of the separator in a bead-shaped, the edge of the separator annularly enclosing connecting part. The connecting part is in turn fixed by a clamping ring in the housing. In this solution, the insertion of the separating device in the connecting part designed as relatively expensive. Again, there is a desire to further reduce the manufacturing costs and the production time.

The DE 10 2007 003 724 A1 describes a storage device, in particular in the form of a hydraulic accumulator, comprising a storage housing at least two housing parts which at least partially delimit a working space in the storage housing in which a separating device movably guided two media spaces separated from each other and held stationary by means of a holding device in the storage enclosure at a predetermined fixing point, wherein the holding means by means of a separate, different from the housing parts Anpressteils at least the separating device partly in the region of the fixing point with a defined contact force on at least one of the housing parts in a touching manner, wherein the adjacently arranged housing parts overlap each other with their respective free opening areas and wherein the holding device is received in this overlap region, wherein the holding device in a groove-like groove of a housing part is at least partially received and in a pre-assembly with a predetermined projection in spring elastic compliant manner with the separator at the fixing point is in communication and wherein in the assembled position, the supernatant reset the contact pressure on the separator in the region of the fixing point applies.

The invention is therefore based on the cited prior art, the task of demonstrating improved memory devices, which do not have the disadvantages of the prior art and in particular faster and cheaper to produce. Furthermore, a method for producing such memory devices is to be shown.

This object is achieved on the one hand by a memory device having the features of patent claim 1. Advantageous embodiments of the memory devices will become apparent from the dependent claims 2 to 6.

An inventive method for producing such a memory device is apparent from claim 7.

According to the characterizing part of claim 1, it is provided that the separating device is accommodated in the region of its free opening edge in a groove-like depression of one of the housing parts, the recording length is shorter than the other recording length of the groove in the other housing part, which otherwise congruent adjacent to each other in the adjacent housing parts are arranged in the overlapping region.

It is further provided that the holding device applies the separator in a constant or substantially constant wall thickness in the region of the fixing point with a defined contact pressure on at least one of the housing parts in a touching manner.

The solution according to the invention has the advantage that the holding device and the separating device can be manufactured separately and arranged on the respective housing parts and installed together only during assembly. In the assembled state, the holding device permanently secures the separating device in a sealing manner in the storage device. The term "in a touching manner" in this context means that the separating device rests directly or directly on the respective housing part, without further parts or elements being provided between the separating device and the housing part. Consequently, the storage device is simpler and faster overall and therefore less expensive to produce.

A further solution of the problem is according to the characterizing part of claim 2 is that the holding means by means of a separate, different from the housing parts Anpressteils the separator at least partially in the region of the fixing point with a defined contact force against at least one of the housing parts in a touching manner.

This solution has the advantage that the separator is held non-positively or clampingly on a housing part. Again, there is no need for further measures to ensure the necessary strength of the connection and the tightness. Another advantage of this solution is that the assembly is also easy and time-saving possible.

The adjacently arranged housing parts preferably overlap one another with their respective free opening areas and the holding device is accommodated in this overlapping area. Due to the overlapping arrangement, the holding device can act between the housing parts, wherein the compression of the housing parts can be advantageously used to generate the necessary holding force for the separator or the necessary contact pressure for the pressing. The holding device is provided in a region of the maximum wall thickness of the storage device, so that sufficient space is available to arrange the holding device in this area in recesses of the housing parts.

The projecting in the mounting position supernatant can advantageously result in a flush termination between the holding device and at least one of the housing parts, so that insofar a kind of self-centering of the parts to be joined is created.

The holding device holds the separator at the fixing point in the storage housing preferably free of adhesive. This requires no additional Adhesive are provided and the time required for the application of the adhesive can be omitted.

The larger dimensioned receiving length of the throat advantageously creates in the same a compensation space into which the holding device, in particular in the assembled state of the storage housing, can escape. In this way, an unnecessary crushing or shearing stress of the holding device is avoided and it follows through the axial extension of the holding device, an enlarged mounting and sealing area for the separator. Thus, the separator is set very safe and good sealing in the storage enclosure.

Particularly advantageously, the independent Anpressteil the holding device is annular and preferably has at least at the point of the outlet of the wall of the separator from the groove-like depression of a housing part a cross-sectional change in such a way that the wall of the separator formed of elastically resilient material, the recess without significant change in wall thickness leaves. By the annular pressing the contact pressure is exerted particularly uniformly on the separator. This has the advantage that the separating device is accommodated particularly good sealing in the storage housing. Due to the special cross-sectional geometry of the pressing member is also ensured that the separator is not excessively burdened or even squeezed in the region of the transition from the groove-like depression in the remaining part of the storage enclosure. This helps to extend the life of the separator and thus the memory device concerned.

The separating device may be formed in the manner of a shell made of elastically yielding material which, during operation of the storage device, enters at least one lifted state of movement releasing a media inlet of the storage housing, in which the separating device transversely to the fixing point takes a course in which it is supported against a plant foot in one of the housing parts, which limits the throat, under relief of the fixing point. If the separating device is displaced sufficiently far into the storage housing, the separating device automatically comes to rest against the plant foot. This entails that movement forces of the separation membrane can be introduced into the plant foot, which then no longer have to be introduced at the fixing point between the holding device and the opposite housing part. In this respect, there is a discharge, which contributes to the life of the separator is significantly extended compared to known comparative solutions.

The mounting method for producing a memory device is characterized in that a free end region of a separating device is inserted into a shell-shaped housing part with a groove-like depression, that a pressing part of the holding device is inserted into a further shell-shaped housing part with a groove with a predeterminable, resiliently resilient projection, which is restored during the collapse of the housing part shells to form the storage enclosure of the housing wall of a housing part and thus exerts the required contact pressure on the separator to be determined at the fixing point in the storage housing with its restoring force in the final final assembly state. The pertinent manufacturing or assembly process can be carried out reliably even with large quantities.

The invention is explained in more detail below with reference to an embodiment shown in the figure.

The single FIGURE shows a longitudinal section of a storage device 1 according to the invention, in particular in the form of a hydraulic accumulator, with a storage housing 3 consisting of two housing parts 5, 7, which delimit a working space 9 in the storage housing 3, in which a separation device 11 movably guided two media spaces 13, 15, namely in the form of a gas space 13 and a liquid space 15, separated from each other and held stationary by means of a holding device 17 in the storage enclosure 3 at a predetermined fixing point 19.

These storage devices 1 can serve, for example, within a hydraulic system to compensate for pressure fluctuations, for energy storage, for capturing Pulsationsstößen a pump, etc. The housing parts 5, 7 are shell-shaped and rotationally symmetrical to a longitudinal axis LA. The housing parts 5, 7 are preferably made of an aluminum alloy in one operation in the context of a conventional Pressumformverfahrens.

At the lower in the image plane housing part 5, a media inlet 21 is integrally formed. The media inlet 21 comprises a tubular connecting piece 23 which is provided with an external thread 25. The upper housing part 7 has a connection body 27 with an opening 28, through which a working gas, in particular nitrogen, can be introduced into the storage housing 1 in the usual way. The opening 28 is closed by a closure part 29, which is preferably welded to the other housing parts. As additional protection, a cover 31 surrounding the closure part 31 is provided. The cover 31 is positively fixed to the upper housing part 7, for example by means of a welded joint, and may have outer peripheral side surfaces, for example in the form of a hexagon for fixing the memory to third components of a hydraulic system, not shown, by means of a fixing tool, not shown, such as a fork wrench or the like.

A free opening edge 33 of the lower housing part 5 overlaps in an opening portion 35 with its inner side 37 an opening portion 39 of the upper housing part 7 along its outer periphery 41, which in the assembled state shown in about half of the height of the storage enclosure 1 is located. The lower housing part 5 in this case has a reduced in its wall thickness longitudinal edge 43 which extends circumferentially along an associated bearing surface 45 of the upper housing part 7 under the same. At an intermediate point 47, at which the wall thickness of the lower housing part 5 is reduced, an axial stop for the upper housing part 7 is formed. Likewise, the upper housing part 7 is provided with an outwardly projecting shoulder 51, so that in the assembled state, the housing parts 5, 7 come into contact with each other at the respective stops 47, 51. Subsequently, the longitudinal edge 43 is crimped in a conventional manner to connect the housing parts 5, 7 permanently and tightly together.

Between the housing parts 5, 7, the separator 11 is provided. According to the invention, the separating device 11 is at a constant or substantially constant wall thickness in the region of the fixing point 19 with a defined contact pressure on the lower housing part 5 in a touching manner, d. H. directly to. The holding device 17 sets by means of a separate, different from the housing parts 5, 7 pressing part 53, the separator 11 in the region of the fixing point 19 with a defined contact pressure on the lower housing part 5 in a touching manner.

The holding device 17, which is substantially rectangular in cross-section, is received in the groove area 55 in a groove-like groove 55 and is connected in a pre-assembly position with a predeterminable projection in a spring-resilient manner to the separating device 11 at the fixing point 19. In the assembly position shown, the supernatant recovers the contact pressure on the separating device 11 in the region of the fixing point 19. As can be seen in the figure, the supernatant recovered in the mounting position results in a flush closure of the holding device 17 with the upper housing part 7. The holding device 17 holds the separating device 11 at the fixing point 19 in the storage enclosure 1 adhesive-free. The separator 11 is added in the region of its free opening edge 59 in a groove-like recess 61 of the lower housing part 5, whose length LV is shorter than the length of the recording LK 55 of the throat in the upper housing part 7. It is in an embodiment not shown but also possible LK equal to LV. Otherwise, the groove 55 and the depression 61 are arranged congruently adjacent to one another in an overlapping region 54 of the adjacent housing parts 5, 7. The larger sized receiving length LK of the groove 55 creates in the same a compensation chamber 63, in which the holding device 17, in particular in the assembled state of the storage case 1, can escape.

The independent Anpressteil 53 of the holding device 17 is annular and has at least at the point of the outlet 65 of the wall 67 of the separator 11 from the groove-like recess 61 of the lower housing part 5, a cross-sectional change in such a way that the wall formed of elastically resilient material material 67 of the separator 11 can leave the recess 61 without significant change in wall thickness. The change in cross section is formed by a shoulder 69 in Anpressteil 53, the edges are rounded. In particular, in a special steel or aluminum version of the housing parts 5, 7 can be completely dispensed with the groove-like recess 61 so that the opening edge 59 of the separation membrane 11 can invest in a sealingly extending at the top just housing wall of the lower membrane shell 5 ,

The separator 11 is formed in the manner of a shell 71 made of elastically yielding material in the manner of a membrane. The shell 71 passes during operation of the storage device 1 in at least one lifted, the media inlet 21 of the storage housing 1 releasing movement state in which transversely to the fixing point 19, the separator occupies a course in which they are against a Anlagefuß 73 in the upper Housing part 7, which limits the throat 55, can support the relief of the fixing point 19. In the area of the media inlet 21, a disc-shaped valve body 75 is provided, which is arranged on the outside of the separating device 11 or cast or knotted into the separating device 11
can be. In the state shown in the figure of the complete emptying of the liquid space 15 of the valve body 75 comes the media inlet 21 covering the lower housing part 5 with this in Appendix. In particular, in the realization of the memory as aluminum version but can be dispensed with the valve plate 75, since this is not required at the then set low biasing pressure for the fabric insert.

The memory device 1 according to the invention can be produced particularly easily and quickly. For this purpose, in the cup-shaped lower housing part 5 with a groove-like recess 61 of the free end portion 59 of the separator 11 is inserted. In the upper shell-shaped housing part 7 with a Kehlung 55 then a Anpressteil 53 of the holding device 17 is inserted with a predetermined, resilient elastic supernatant. The supernatant is reset when moving the housing part shells 5, 7 with the formation of the storage enclosure 1 of the housing wall 77 of the upper housing part 7 and exercises in such a way with its restoring force in the final final assembly state, the required contact pressure on the separator to be determined 11 at the fixing point 19 in the storage enclosure 1.

The solution according to the invention has the advantage that the holding device 17 and the separating device 11 can be manufactured separately and arranged on the respective housing parts 5, 7 and installed together only during assembly. In this case, the holding device 17 is used to set the separator 11 in a sealing manner in the storage device 1. Characterized in that the separator 11 rests against one of the housing parts 5, 7, there is no necessary need for additional parts, to ensure the seal. Consequently, the storage device 1 is generally simpler and faster and thus cheaper to produce and due to the determination of the separator according to the invention long-lasting and reliable use.

Claims (7)

1. A storage device, in particular in the form of a hydraulic accumulator, that has an accumulator housing (3) consisting of at least two housing parts (5, 7) that at least partially delimit a working chamber (9) within the accumulator housing (3) in which a separator (11), guided moveably, separates two medium chambers (13, 15) from one another and is held, fixed, at a pre-specifiable fixing point (19) within the accumulator housing (3) by means of a holding device (17), by means of an independent pressing part (53) different from the housing parts (5, 7) the holding device (17) positioning at least the separator (11) partially in the region of the fixing point (19) with a defined pressing force so that it is in contact with at least one of the housing parts (5, 7), the housing parts (5, 7) arranged adjacent to one another overlapping one another with their respectively free opening regions (35, 39) and the holding device (17) being received in this overlap region (54), the holding device (17) being received at least partially in a groove-like channel (55) of the one housing part (7), and in a pre-assembly position being connected with a pre-specifiable protrusion in a spring-elastically flexible manner to the separator (11) at the fixing point (19), and in the assembly position the protrusion, re-set, applying the pressing force to the separator (11) in the region of the fixing point (19), characterised in that the separator (11) is received in the region of its free opening edge (59) in a groove-like indentation (61) of one of the housing parts (5, 7), the receiving length (LV) of which is shorter than the other receiving length (LK) of the channel (55) in the other housing part (7, 5) which are otherwise arranged congruently and lying opposite one another adjacently in the adjacent housing parts (5, 7) in their overlap region (54).
2. The storage device according to Claim 1 or 2, characterised in that the protrusion that is re-set in the assembly position results in a flush ending between the holding device (17) and at least one of the housing parts (5, 7).
3. The storage device according to any of the preceding claims, characterised in that the holding device (17) holds the separator (11) at the fixing point (19) within the accumulator housing (3) without any adhesive.
4. The storage device according to any of the preceding claims, characterised in that the larger receiving length (LK) of the channel (55) creates within the latter a compensating chamber (63) into which the holding device (17) can divert, in particular in the assembled state of the accumulator housing (1).
5. The storage device according to any of the preceding claims, characterised in that the independent pressing part (53) of the holding device (17) is made annularly and preferably has, at least at the point of the run-out (65) of the wall (67) of the separator (11) from the groove-like indentation (61) of the one housing part (5, 7) a cross-sectional change such that the wall (67) of the separator (11) that is formed of an elastically flexible material leaves the indentation (61) without any substantial change in wall thickness.
6. The storage device according to any of the preceding claims, characterised in that the separator (11) is formed from an elastically flexible material in the manner of a shell (71) that, during operation of the storage device (11), passes into at least a raised movement state that clears a medium inlet (21) of the accumulator housing (3) in which the separator (11) adopts a course transverse to the fixing point (19) in which it is supported against a system foot (73) in one of the housing parts (5, 7) that delimits the channel (55) such as to relieve the fixing point (19).
7. The assembly method for producing a storage device according to any of the preceding claims, characterised in that the free end region (59) of a separator (11) is inserted in a shell-shaped housing part (5, 7) with a groove-like indentation (61), that a pressing part (53) of the holding device (17) is inserted in another shell-shaped housing part (7) with a channel (55) with a pre-specifiable, spring-elastically flexible protrusion which, upon moving together the housing part shells (5, 7), is re-set by the housing wall (77) of the one housing part (7) such as to form the accumulator housing (3), and thus, with its re-set force in the complete final assembled state, applies the required pressing force to the separator (11) to be fixed at the fixing point (19) within the accumulator housing (3).

Images