Patent Application
20180009280
This application claims priority from German patent application no. 10 2016 112 307.2 filed on Jul. 5, 2016. The entire content of this priority application is incorporated herein by reference.
The invention relates to a method for manufacturing a pressure vessel for a motor vehicle.
The invention further relates to a pressure vessel of this type.
A pressure vessel according to the present invention can be, in particular, an air suspension pot of an air suspension of a motor vehicle. An air suspension pot of a motor vehicle assumes, apart from the transmission of the generated forces from the suspension strut, also the function of a pressure vessel. Alongside further components, the air suspension pot provides the air volume necessary for the spring rate. In the following description, by a pressure vessel should be understood, in particular, an air suspension pot.
When a new motor vehicle model is developed, the necessary definitive internal volume of the pressure vessel can be defined only at an advanced project stage on the basis of vehicle road tests. At the start of the project, generally on the basis of specifications made by the manufacturer of the motor vehicle or its supplier of the superordinate system, here the suspension system, the pressure vessel is initially designed for a defined internal volume. Based on this definition, the manufacture of the necessary forming tools, the construction of jigs and fixtures, i.e. the necessary operating resources, and, where necessary, the system procurement for the manufacture of the pressure vessel, commences.
Since the target internal volume of the pressure vessel, which is determined within the road tests, frequently differs from the internal volume defined at the start, generally high alteration expenditures in respect of the operating resources, and possibly in respect of the production plant, are incurred, resulting in high costs. Furthermore, project end dates are thereby endangered or have to be deferred, whereby further costs can be incurred.
Conditional on the available installation space in the motor vehicle, for instance, an auxiliary air volume may also become necessary, which auxiliary air volume is provided in the form of an additional component, which is generally screwed separately to the suspension strut via a flange. As a result, costs are disadvantageously incurred through the manufacture and assembly of this component.
In many cases, no auxiliary volume in the form of a separate component, but an asymmetrical structure of the pressure vessel, is necessary in order to achieve the determined target internal volume of the pressure vessel. This dictates that the pressure vessel must often no longer be constructed in one part, but rather in multipart construction using individual parts which are difficult to produce. This entails risks in respect of the leak-tightness of the pressure vessel, as well as higher costs. Furthermore, the assembly processes are complicated by the multipart structure, which additionally impacts negatively on the cost situation.
Since, as previously described, the internal volume of the pressure vessel is generally variable only at high cost, the use of the same pressure vessel on a cross-vehicle basis is in many cases difficult.
The object of the invention is therefore to define a method for manufacturing a pressure vessel for a motor vehicle, with which method it is possible to be able to manufacture a pressure vessel, in particular an air suspension pot, in a cost-effective manner, even when the target internal volume of the pressure vessel, determined on the basis of vehicle road tests, differs from the specifications at the start of a project.
Furthermore, the object of the invention is to provide a pressure vessel which can be manufactured in a cost-effective manner.
According to the invention, a method for manufacturing a pressure vessel for a motor vehicle is provided, comprising the steps:
According to the method according to the invention, the pressure vessel is thus constructed from a basic body and an auxiliary body, wherein the auxiliary body is joined to the basic body. To this end, the wall of the basic body has an opening, in the region of which the auxiliary body is joined with the basic body. The auxiliary body can here provide an auxiliary volume, in that the interior of the hollow auxiliary body communicates with the interior of the basic body via the opening, or the auxiliary body can reduce the internal volume of the basic body, in that the auxiliary body reaches into the opening, without the cavity of the auxiliary body communicating with the interior of the basic body.
It will be evident that the wall of the basic body can also have a plurality of openings, as is provided in a preferred embodiment, and that a corresponding number of auxiliary bodies can be provided, which are than joined with the basic body at the openings.
The method according to the invention enables a maximal internal volume variance of the pressure vessel to be realized with minimal alteration cost, without an additional component or an asymmetrical multipart structure of the pressure vessel being necessary for this purpose. The internal volume variance can here be up to +−50% or more.
In particular, costly alterations to the basic body in the various development stages between the start of the project and the final design of the pressure vessel are not necessary, with the exception of the provision of the at least one opening in the wall of the basic body. The auxiliary volume or reduced volume is achieved by the auxiliary body, so that the pressure vessel can be produced with the desired final internal volume, i.e. the target internal volume.
The shape of the auxiliary body can be optional, though a shape of the kind which is capable of being deep-drawn is preferably chosen. A plurality of auxiliary bodies having different sizes and/or shapes, which provide different increased or reduced volumes, can also be provided.
One possible shape of the hollow auxiliary body is a prismatic, in particular cuboidal shape, in which one side of the cuboid is open. Other shapes than cuboidal shapes are equally possible, however.
With the method according to the invention, it is possible, moreover, to manufacture pressure vessels across all vehicle models at low alteration cost, since only the auxiliary body or elements have to be appropriately matched or differently positioned relative to the basic body, while the basic body can be used for a plurality of vehicle models, without alteration. By virtue of the invention, moreover, costly additional components or an asymmetrical multipart structure of the pressure vessel can be avoided.
The joining of the auxiliary body with the basic body has not only a connecting, but also a sealing function, so that the opening in the wall of the basic body, after the joining of the auxiliary body, is sealed off in a leak-tight, in particular gas-tight, in particular pressure-resistant manner.
In a preferred embodiment, the auxiliary body is provided such that a contour and dimensioning of the peripheral wall of the auxiliary body is at least approximately matched to a contour and dimensioning of the opening rim of the opening in the wall of the basic body.
This embodiment yields several advantages, which are manifested in part in the following further, preferred embodiments of the method.
Independently from the further, preferred embodiments to be described below, the aforementioned measure has the advantage that the auxiliary body scarcely influences the painting process. Since the finished pressure vessel, after its production, is painted also on the inside, for which purpose the paint is poured or sprayed into the cavity of the pressure vessel, the mutually matched contours and dimensionings of the peripheral wall of the auxiliary body and of the opening rim of the opening produce no recesses in which paint can collect, which paint is then prevented from flowing out of the pressure vessel.
In another preferred embodiment, which in particular is preferred in combination with the aforementioned embodiment, the auxiliary body, prior to the joining, is inserted partially into the opening with its open side to the fore, so that the desired final internal volume of the pressure vessel is obtained.
This embodiment of the method is particularly advantageous in terms of the cost expenditure. It is namely in this embodiment sufficient to provide, for each desired final internal volume of the pot-shaped pressure vessel, auxiliary bodies in one and the same shape and size. Different final internal volumes of the pressure vessel can be obtained by differently far insertion or plugging of the auxiliary body into the opening in the wall of the basic body. The further the auxiliary body is inserted into the opening, the smaller is the provided auxiliary volume. In this embodiment, a variability of the pressure vessel-internal volume is achieved with a minimum of parts.
In another preferred embodiment, the auxiliary body, prior to the joining, is inserted at least partially into the opening with the base wall to the fore, so that the desired final internal volume of the pressure vessel is obtained.
In this embodiment, the initial internal volume of the basic body can be reduced, so that the pressure vessel has a final internal volume which is smaller than the initial internal volume of the basic body. In this case, the advantage is once again that the reduction of the internal volume of the pressure vessel can be variably adjusted. A further advantage consists in the fact that even an auxiliary body of same shape and size can be used for the reduction of the internal volume of the pressure vessel as for the enlargement of the internal volume. The difference consists merely in the fact that the auxiliary body is in one case inserted into the basic body with the open side to the fore, and in the other case with the closed side to the fore. By virtue of this embodiment, a plurality of vehicle variants, which require different internal volumes of the pressure vessels, are served with the same basic vehicle kits and auxiliary bodies (so-called family concept).
All in all, a maximal internal volume variability of the pressure vessel is thus obtained with a minimum of parts.
In connection with the two aforementioned preferred embodiments, in another preferred embodiment it is provided that the joining of the auxiliary body comprises a joining of the peripheral wall of the auxiliary body with the opening rim of the opening in the wall.
In the case of that embodiment of the method in which the auxiliary body can be inserted with variable insertion depth into the opening in the basic body, this measure has the advantage that the joining of the auxiliary body can be realized from outside and is independent of the insertion depth of the auxiliary body. Thus, no conversions of the joining plant are necessary in order to manufacture pressure vessels having different internal volumes. In connection with one of the aforementioned embodiments, according to which the contour and dimensioning of the peripheral wall of the auxiliary body is at least approximately matched to the contour and dimensioning of the opening rim of the opening in the wall of the basic body, a high leak-tightness is achieved due to a positive-locking engagement of the peripheral wall of the auxiliary body with the opening rim of the opening in the wall of the basic body.
Alternatively to the embodiment of an insertable auxiliary body, in another preferred embodiment it is provided that the auxiliary body has on its open side a rim, the auxiliary body, prior to the joining, is fixed to the basic body with the rim around the opening in the wall of said basic body, and the rim of the open side of the auxiliary body is joined with the wall or the opening rim of the opening.
The advantage of this measure consists in the fact that the auxiliary body, in the joined state, is present only on the outer side of the basic body, and thus no part of the auxiliary body projects into the pressure vessel, as is the case with the plug-in variant of the auxiliary body. The aforementioned measure has the advantage that it impacts still less on the painting and also the joining process, or facilitates these two processes.
In order to obtain a high final internal volume variance of the pressure vessel within the aforementioned embodiment, the auxiliary body according to another preferred embodiment is provided having a predetermined internal volume of the auxiliary body, which internal volume is dimensioned such that, after the joining of the auxiliary body, the pressure vessel having the desired final internal volume is obtained, wherein the provision of the auxiliary body having the predetermined internal volume can comprise a shortening of the auxiliary body.
As the joining method, in the method according to the invention for joining the auxiliary body to the basic body, all common joining methods can be used, in particular welding, gluing, pressing and/or soldering.
In another preferred embodiment of the method, the auxiliary body is provided as a deep-drawn part.
The advantage of this embodiment consists in a further cost reduction in the manufacture of the pressure vessel. Equally, the basic body can also be produced as a one-piece deep-drawn part or can be composed of a plurality of deep-drawn parts.
As already mentioned above, the basic body can be provided having a plurality of openings distributed in the wall, wherein a plurality of auxiliary bodies are provided, which, in order to obtain the pressure vessel having the desired final internal volume, are joined with the basic body at the openings.
This measure is of advantage in particular when the available installation space for the pressure vessel in the vehicle is restricted around the pressure vessel, wherein, with the aforementioned embodiment, an auxiliary volume can be distributed amongst a plurality of auxiliary bodies, which then protrude less far from the basic body in the radial direction than if the same auxiliary volume must be provided only by a single auxiliary body. This embodiment thus has the advantage that it is particularly space-saving.
The method according to the invention for manufacturing a pressure vessel, which method is here described, can be used both if the basic body is in one piece, and in respect of multipart basic bodies. In the latter case, the opening in the wall of the basic body can be made in or introduced into the wall of the basic body such that it reaches over individual parts. For instance, a part of the opening can be configured on a first basic body part, and the remaining part of the opening on the other basic body part, so that the opening rim, as in the case of a one-piece basic body, extends preferably along a continuous line.
According to the invention, a pressure vessel for a motor vehicle, comprising a basic body, is also provided, wherein the basic body has an internal volume, and wherein the basic body has a wall, which extends fully around a longitudinal axis of the basic body, wherein the wall has an opening, which has an opening rim, and comprising a hollow auxiliary body, which has a base wall and a peripheral wall, wherein the auxiliary body is open on a side lying opposite the base wall, and wherein the auxiliary body is joined with the basic body at the opening in the wall of the basic body, whereby the pressure vessel has an internal volume which is larger or smaller than the internal volume of the basic body.
The advantages stated in connection with the representation of the method according to the invention apply also to the pressure vessel according to the invention and to the below-stated preferred embodiments of the pressure vessel.
Preferably, a contour and dimensioning of the peripheral wall of the auxiliary body is at least approximately matched to a contour and dimensioning of the opening rim of the opening in the wall of the basic body.
Further preferably, the auxiliary body is inserted partially into the opening in the wall of the basic body with the open side to the fore, in particular is plugged-in in positive-locking engagement.
Alternatively hereto, the auxiliary body is inserted at least partially into the opening with the base wall to the fore, in particular is plugged-in in positive-locking engagement.
Further preferably, the auxiliary body has on its open side a rim, and the auxiliary body is fixed to the basic body with the rim around the opening in the wall of said basic body, and the rim of the open side of the auxiliary body is joined with the wall or the opening rim of the opening.
Further preferably, the basic body has a plurality of openings distributed in the wall, wherein a plurality of auxiliary bodies are joined with the basic body at the openings in the wall.
Further preferably, the pressure vessel is a pot-shaped pressure vessel having a pot-shaped basic body. Further preferably, the pressure vessel is an air suspension pot of an air suspension for a motor vehicle.
Further advantages and features emerge from the following description and the appended drawings.
It will be evident that the aforementioned features, which are to be further explained below, are usable not only in the respectively defined combination, but also in other combinations or in isolation, without departing from the scope of the present invention.
Illustrative embodiments of the invention are represented in the drawing and are described in greater detail below with reference to said drawing, wherein:
The pressure vessel 10 has a basic body 12, which is pot-shaped, and an auxiliary body 14, which is joined with the basic body 12, as will be further described.
In the illustrative embodiment of
The basic body 12 has a flange 18, which can serve for the attachment, for instance, of a bellows (not represented). On its side lying opposite the flange 18, the basic body 12 has an opening, which serves for the installation of further parts of the air suspension, such as, for instance, a shock absorber. The basic body 12, and thus the pressure vessel 10, can be secured via fastening means 22 (represented by way of example in
The basic body 12 has a wall 24 extending fully around the longitudinal axis 16, which wall, as the wall extending fully around the longitudinal axis 16, is the side wall of the basic body 12, or which wall, in other words, extends in the direction of the longitudinal axis. In the fitted position of the pressure vessel in a vehicle, the wall 24 runs substantially vertically.
The auxiliary body 14 is, like the basic body 12, a hollow body, and has a base wall 26 and a peripheral wall 28.
Further details of the basic body 12 and of the auxiliary body 14 are described below with reference to
The opening 30 is substantially rectangular with rounded corners, wherein the rectangular form of the opening 30 is only exemplary. For instance, the opening 30 can also be circular.
In the initial state shown in
Within the manufacture of the pressure vessel 10 in
In the shown illustrative embodiment, the auxiliary body 14 has the shape of a unilaterally open cuboid, the dimensioning and contour of which is appropriately matched to the shape and dimensioning of the opening 30 in the basic body 12. In other illustrative embodiments, in which the opening is, for instance, circular, the auxiliary body correspondingly has a circular peripheral wall 28.
In order to manufacture the pressure vessel 10, the auxiliary body 14 is joined with the basic body 12 at the opening 30 in the wall 24 of the basic body 12, such that the pressure vessel 10 having the desired final internal volume or target internal volume, which is larger or smaller than the initial internal volume of the basic body 12 according to
In the illustrative embodiment shown in
The joining is preferably realized by welding. Other joining methods such as gluing, pressing, soldering, can, however, likewise be used. Moreover, the joining establishes the final leak-tightness of the bond of auxiliary body 14 and basic body 12 at the opening 30.
While, in the pressure vessel 10 and the pressure vessel 10a, the auxiliary body 14 is inserted into the opening 30 in the basic body 12 with the open side 34 to the fore in order to achieve a final internal volume of the pressure vessel 10 or 10a which is larger than the initial internal volume of the basic body 12,
Once the auxiliary body 14 is inserted, with the insertion depth necessary for the setting of the desired final internal volume of the pressure vessel 10b, in the opening 30 in the basic body 12, the auxiliary body 14 is joined with the basic body at the opening 30, in that the peripheral wall 28 of the auxiliary body 14 is joined with the opening rim 32 of the opening 30 in the wall 24 of the basic body 12.
In the illustrative embodiment in
The advantages of the method according to the invention for manufacturing a pressure vessel, and those of the pressure vessel, are manifested particularly clearly on the basis of
Thus, with same components, various pressure vessels are also able to be manufactured across vehicle models at no additional cost (so-called family concept).
That principle of manufacture of a pressure vessel which has been described with reference to
The two basic body parts 13 and 15 are joined together along a connecting seam 17, for instance by welding or other common joining methods. Both parts 13 and 15 together have a wall 24c, which has an opening 30c spread over both parts 13 and 15. Correspondingly, the opening rim 32c of the opening 30c extends over both parts 13 and 15 of the basic body 12b. Here too, the same auxiliary body 14 as in the pressure vessels 10 and 10a, which, as in
Without this being represented in the drawing, it will be apparent to the person skilled in the art that also the embodiment in
The pressure vessel 10e has the same basic body 12 in
In order to achieve in this embodiment the desired final internal volume or target internal volume of the finished pressure vessel 10e, the auxiliary body 14e is provided having a predetermined length and width, or a predetermined internal volume which is dimensioned such that, after the joining of the auxiliary body 14e, the pressure vessel 10e having the desired final internal volume is obtained.
To this end, starting from the auxiliary body 14 in
The auxiliary body 14e can, of course, also be used with the basic bodies 12c in
The auxiliary bodies 14 and 14e are preferably produced as deep-drawn parts.
From the representations in
While, in the shown and above-described illustrative embodiments, only one auxiliary body 14 or 14e is used for the manufacture of a pressure vessel, it is equally possible, however, within the scope of the invention, to distribute a plurality of such auxiliary bodies on the wall 24 or 24c, in which case a corresponding number of openings can be provided in the wall 24 or 24c. As a result, an auxiliary volume, in particular an added volume, can be distributed amongst a plurality of auxiliary bodies, without the finished pressure vessel being built large in the radial direction with respect to the longitudinal axis 16. A plurality of auxiliary bodies are also suitable, however, where a reduced volume of the pressure vessel must be obtained in relation to the initial internal volume of the basic body.
Moreover, it will be evident that the herein described method for manufacturing a pressure vessel is usable not only with rotationally symmetric basic bodies, but also with basic bodies which are not rotationally symmetric with respect to the longitudinal axis 16.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2016 112 307.2 | Jul 2016 | DE | national |
