The present application claims priority to German Utility Model Application No. 20 2022 103 142.8, entitled “GASKET AND METHOD FOR PRODUCING A GASKET”, and filed on Jun. 2, 2022. The entire contents of the above-listed application is hereby incorporated by reference for all purposes.
The present disclosure relates to a gasket and to a method for producing a gasket, the gasket serving to at least partially seal a gap in a housing, which gap extends at least partially around an interior of the housing. Such a gap exists, for example, between a housing box and a housing cover. The present disclosure may relate to sealing the gap between an oil pan and the cylinder crankcase, or between a timing case cover and the engine, or between a battery c ase and the battery case cover.
To seal the cover of a housing, use is usually made of frame gaskets which extend around the entire housing between the cover and the housing box. Such gaskets are often designed as rubber-metal gaskets, which comprise a metal carrier layer as a carrier frame with elastic sealing elements injection-molded thereon. When cutting such carrier frames of large rubber-metal gaskets, an enormous amount of die-cutting waste is generated as a result of the production process. To reduce the die-cutting waste, carriers of rubber-metal gaskets are therefore also produced in individual segments, which often are not assembled to form the frame of the carrier frame gasket until after additional steps have taken place, such as washing and coating the metal parts. The individual segments can thus be die-cut almost without waste, can easily be transported for further processing, and then can be assembled and joined together, typically by clinching.
In the case of rubber-metal gaskets, it is desirable for the metal carrier layers of adjacent individual segments to be clinched already in the injection-molding die at the same time as the elastomeric sealing elements are injected, thus saving a die and a processing step. However, the clinching could also be carried out in a separate operating step. When clinching adjacent segments, however, significant warpage occurs in the respective metal carrier layers of the segments. If, for example, the carrier layers have positioning holes for fixing the rubber-metal gasket in a precise position in a die for one or more production steps or in a precise position on or in a housing, this warpage reduces the positional accuracy of the respective positioning hole in the carriers. Very high positional tolerances must therefore be provided. On the other hand, the individual segments are fixed in the correct position in the clinching or injection-molding die by means of positioning pins, which engage in corresponding positioning holes in the metal carrier layers of the individual segments. If the individual segments then warp during clinching, the positioning holes become jammed by the positioning pins and the finished frame gasket can only be removed from the clinching die with difficulty.
This warpage may occur as a result of material being displaced when two segments are clinched, and thus the dimensional accuracy of the respective segment is no longer ensured.
The present disclosure aims to provide a gasket in which no warpage or only very little warpage or very slight displacement of the segments occurs as a result of adjacent segments being joined, such as by clinching, and thus, also in the further gasket assembly process, no jamming between positioning pins and positioning holes occurs either in a die or in a housing, and the dimensional accuracy and thus also the function of the gasket is still ensured. Furthermore, the intention is for the joining region of the gasket according to the present disclosure to have a high retaining strength, a high moment of resistance against buckling, and small positional tolerances of the positioning holes in the metal carrier layer of the rubber-metal gasket. For example, the intention is for the gasket to be able to be produced in a single die, for example a clinching die, directly together with the injection molding of the elastomeric sealing elements onto the metal carrier layer segments in an injection-molding die. For the gasket according to the present disclosure, this requires that removal from the die is also easily possible, without the gasket becoming jammed in the die.
Furthermore, the present disclosure provides a production method for a gasket as described above that is simple, inexpensive, generates little die-cutting waste, and may easily be carried out in conventional tools.
The above problems are addressed by embodiments of gaskets described herein.
The present disclosure therefore relates to a gasket which serves to seal a gap in a housing, such as a battery housing, which gap extends at least partially around an interior of the housing. The gasket comprises at least one sealing layer, for example a metal sealing layer, which comprises of at least two segments. The segments are arranged adjacent to each other in their longitudinal direction and in the longitudinal direction of the sealing layer and are joined to each other at least at one joining region. In this way, it is possible to provide, from individual segments, a gasket that has a long length, for example even a closed frame gasket that extends around a box opening.
According to the present disclosure, the joining region is designed in such a way that the two segments have intermeshing engagement elements which are or can be joined to each other. The segments of such a gasket often exist individually for transport to subsequent production steps or during production and are only joined to each other in the course of the production process.
The segments additionally have positioning holes which, in each segment, in the joined state, are arranged behind the engagement element from the point of view of an adjacent segment.
Here and in the following, a positioning “behind an/the engagement element” may refer to the case in which a positioning hole, as seen from an adjacent segment, e.g. for instance as seen from the line of contact with an adjacent segment—and in this case from the axis of symmetry of the engagement elements—is not merely arranged in the sequence of the engagement element but in a geometrically straight line behind the engagement element.
According to the present disclosure, each segment additionally has, at the joining region, a through-opening which is also arranged behind the engagement element from the point of view of the adjacent segment. The through-opening may be arranged in front of the positioning hole, behind the positioning hole, or to the side of the positioning hole. However, it may be advantageous if the through-opening is arranged in front of the positioning hole, for example in front of the nearest positioning hole, e.g. between the engagement element and the positioning hole, for example the nearest positioned positioning hole.
If two segments are to be joined to each other at one point, by compression or clinching, the displaced material flows predominantly into the gaps at the joining region. If it is desired to hold the gasket frame in position during this, for example by using positioning holes in the gasket segments and positioning pins on the die that engage therein, the warpage of the segments that occurs relative to the stationary positioning pins causes the segments to become jammed by the positioning pins in their positioning holes.
In one variant, the present disclosure now makes it possible that, by pressing a holding punch in the stamping die onto the carrier layer of the adjacent segments at the location of the through-opening, such as onto the circumferential edge thereof, each two segments to be joined can be held in position on both sides of the joining region and thus no jamming of the segments by the die occurs. This applies even when just one of the adjacent segments is designed in the manner according to the present disclosure.
However, these holding punches could in turn cause material displacements and even more warpage. According to the present disclosure, therefore, a through-opening is provided in the segments as a sacrificial hole. The holding punches can then be placed onto this through-opening and grip, for example, the circumferential edge of the through-opening. The material displaced by the holding punch can then flow into the through-opening beneath the holding punch, while at the same time preventing the material that is displaced in the clinched joint region of a segment from causing warpage at the positioning hole.
Therefore, when two segments are joined to each other, for instance compressed together or clinched together, at a joining region, the through-opening—which is arranged for example between the joining region and the positioning hole—in combination with the holding punch enables the two segments to be held in position during the compression or clinching, almost without any warpage. By fixing the segments by means of the holding punch at a through-opening, any warpage of the metal carrier layer that occurs in the region of the joining region as a result of clinching two adjacent segments has no effect on the dimensional accuracy and position of the positioning hole arranged behind the punch or on the dimensional accuracy of the gasket as a whole. As a result, there is no warpage of the position of the positioning hole and thus no jamming of a positioning pin in the positioning hole. The finished gasket can thus easily be removed from the die and then installed with dimensional accuracy, for example on the rim of a battery box.
Since the through-opening can receive material displaced by the holding punch, no significant warpage occurs at the positioning hole located behind the through-opening from the point of view of the adjacent segment, thereby ensuring the dimensional accuracy of the positioning hole in the respective segment. At the time of insertion into an injection-molding die, the positioning hole in the respective segment can therefore serve to position the segment correctly in relation to adjacent segments and in relation to the elastomer to be injected. Since the through-opening between the joining region and the positioning hole receives material that is displaced when a holding punch is pressed on and pressed in, the positioning hole remains in its position with little or no warpage, so that the finished gasket can then easily be removed from the die. This also makes it possible for the gasket to be positioned, without jamming, on a housing that may likewise be equipped with positioning pins.
To sum up, since the joining region is designed with a through-opening as a fixing point for the respective segment during production of the gasket, for example by means of a holding punch, and as a sacrificial hole for receiving material that is displaced by the holding punch, the displacement of the segments as a result of warpage during the clinching or compression of the segments can be significantly reduced, and thus the layer of the gasket can be prevented from being jammed by the positioning pins in a die, for example in an injection-molding die.
Overall, this results in a gasket that solves all of the problems mentioned above. For example, such a joint exhibits a small amount of warpage compared to the non-joined state and can therefore easily also be produced in an injection-molding die. The segments thus joined can nevertheless easily be removed from the injection-molding die as a whole gasket. Furthermore, the positions of the individual openings, for example the through-opening or the positioning holes in the segments, are ensured with high accuracy, so that installation in a housing can also take place without difficulty. Finally, the joints between individual adjacent segments are very stable and have a high retaining strength and also a high buckling strength.
Since the holes, for instance the positioning holes, are present in the gasket with high positional accuracy, there is no need for additional measures as in conventional systems, such as, for example, providing a flexibility of the positioning pins. As a result, the dies required and also the production process are simpler and less expensive.
The engagement elements of adjacent segments may be formed of complementary protrusions or recesses on the outer edges of the two segments that extend between adjacent segments. For example, recesses and protrusions in the layer plane of the gasket may engage behind each other, so that adjacent segments are fixed to each other with a form fit in the longitudinal direction of the segments and the gasket.
The engagement elements may form dovetail-type joints, which may have a shape as known from jigsaw pieces, for example.
The clinching of the engagement elements of adjacent segments at the joining region may take place transversely to the longitudinal direction of the segments and the gasket, adjacently to each other or with an offset in the longitudinal direction of the segments. This offset of the centroids of the clinching elements in the longitudinal direction of adjacent clinching points may be approx. 1 mm or more. In addition, by virtue of such an offset, the warpage transverse to the longitudinal direction is smaller than when the positions at which the engagement elements are compressed are arranged directly adjacent to each other in the transverse direction.
Furthermore, the outer edge, e.g. the longitudinal edge of the segments, may be stamped when joining two segments. This prevents elastomer from reaching the carrier layer during the injection process.
The present disclosure also relates to a method for producing a gasket as described above, in which the two segments are compressed together, for instance clinched together, in the region of the joining region.
Furthermore, the regions around the through-openings can be fixed from both sides of the sealing layer, such as by stamping, for instance along the circumferential edge of the through-opening.
Furthermore, the segments may be placed into an injection-molding die, and the two segments may be clinched together by means of the injection-molding die, and an elastomer may be injected onto at least parts of the edge regions of the gasket.
This production method for a gasket as described above is simple, inexpensive, generates little die-cutting waste, and may easily be carried out in conventional dies.
Examples of gaskets according to the present disclosure will be given below. In all the figures, identical or similar elements will be provided with identical or similar reference signs, and therefore there may be no need to repeat the description thereof. A large number of optional features of the present disclosure are implemented in the following examples. However, it is also possible for the present disclosure to be developed with just one, with some, or with all of the optional features of the individual figures. It is also possible for optional features of different exemplary embodiments to be combined with each other.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
When the segments 10 and 20 are joined to each other by the engagement elements, as shown in
The through-opening 13 is arranged between the positioning opening 12 and the end of the segment 10 that is formed by the engagement elements 11a, 11b and 11c. In a manner symmetrical thereto, the through-opening 23 is arranged between the positioning hole 22 and the engagement elements 21a, 21b and 21c.
While
The holding punches prevent significant warpage from occurring at the positioning holes 12 and 22 as a result of the joining region 2 being clinched. The use of holding punches does not for its part produce any additional warpage, or only negligible warpage, at the positioning holes 12 and 22 since the holding punches press against the circumferential edge of the through-opening 13 and 23, but the through-openings 13 and 23 receive most or all of the material that is displaced by the holding punches.
The position of the positioning holes 12 and 22 is therefore not significantly affected, or is not affected at all, by the clinching of the two segments 10 and 20 at the joining region 2 and by the holding punches at the through-openings 13 and 23. The gasket 1 according to the present disclosure is therefore very dimensionally stable even in the joining region and in the region of the positioning holes 12 and 22 and is not jammed by positioning pins in the die or on a housing. It can therefore easily be removed from the die used for the joining process, and can also be applied with dimensional accuracy to a housing, for example a housing of a battery box.
In addition, the segment 10 is also compressed along its outer edge 15 having the edge sections 15a, 15b, so that depressions 17d, 17e are formed on the outer edge 15 in the layer of the segment 10. In a corresponding manner, the segment 20 is also compressed along its outer edge having the edge sections 25a, 25b, so that depressions 27d and 27e are formed on the outer edge in the layer of the segment 20. Elastomeric sealing lips 16a, 16b are injected onto these depressions.
The embossed contours produced during clinching of adjacent gasket segments, whether in the area of the joint, in the region of the sacrificial hole or along the outer edge of the segments, are easy to recognize because in these areas, on the one hand, the thickness of the metallic layer of the respective segment is reduced (see, for example, depressions 17d, 17e or recesses 17c, 27c) and, on the other hand, the microstructure of the metallic layer has been changed by the clinching process.
The upper stamping die plate 3 (in
Furthermore, the upper stamping die plate 3 has two stamping elements 5a′ and 5b′, and the lower stamping die plate 4 has the stamping elements 6a′ and 6b′ at corresponding positions. In the closed state of the stamping die, which is shown in
In a corresponding manner, the stamping elements 5b′ and 6b′ compress the opposite edge 15a of the first element 10 in order likewise to thin the first element 10 for the injection of an elastomer seal (not shown here).
Since both the first segment 10 and the second segment 20 are simultaneously fixed at the through-openings 13 and 23 during the compression of the joining region 2, warpage caused by the stamping of the joining region 2 has no effect or only a minor effect on the regions around the through-openings 13 and 23 and for instance on the regions of the segments 10 and 20 that are located behind the through-openings 13 and 23 from the point of view of the respective other segment. This prevents any warpage of the positioning holes 22 and 12 and any jamming or tilting of the positioning pins 9b, 9a in the positioning holes 22 and 12.
In the present example, the positioning holes 12 and 22 are arranged in each case behind, such as in a straight line behind, the adjacent through-openings 13 and 23 from the point of view of the respective other segment, as seen from the joining region. However, it is also possible for them to be arranged to the side of or in front of the through-openings 13 and 23, without entirely losing the described technical effects.
It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. Moreover, unless explicitly stated to the contrary, the terms “first,” “second,” “third,” and the like are not intended to denote any order, position, quantity, or importance, but rather are used merely as labels to distinguish one element from another. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and/or properties disclosed herein.
As used herein, the term “approximately” or “substantially” is construed to mean plus or minus five percent of the range unless otherwise specified.
The following claims particularly point out certain combinations and sub-combinations regarded as novel and non-obvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.
Number | Date | Country | Kind |
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20 2022 103 142.8 | Jun 2022 | DE | national |