EP0405156A1 - Cup-shaped valve tappet - Google Patents

Abstract

In order to create a cup-shaped tappet body (10) for valve tappets, comprising a cylindrical guide body (12), a tappet top (14) and an element (36) supported by the tappet top and holding a valve rest, which can be manufactured in as simple a manner as possible from wear-resistant materials and is hence favourable in terms of cost whilst having good wear properties, it is proposed that the guide body (12) and the tappet top (14) are manufactured in a joined-together form by casting and that the element (36) holding the valve rest is joined integrally to the tappet top (14) and/or the guide body (12). …<IMAGE>…

Description

The invention relates to a bucket tappet body for valve tappets, comprising a cylindrical guide body, a tappet base and an element that holds a valve support and is carried by the tappet base.

Cup tappet bodies of this type are known, the element holding the valve support either being a guide cylinder for a hydraulic play compensation element or a valve support pin for valve tappets without hydraulic valve play compensation.

Cup tappet bodies of this type have so far mostly been welded together from two semi-finished parts, these semi-finished parts being produced by a large number of shaping steps or machining steps.

Such a production of cup tappet bodies is expensive and complex and also has the disadvantage that the use of very wear-resistant materials with good tribological properties means that forming or machining is difficult. Particularly in the case of bucket tappet bodies for valve tappets with hydraulic valve lash compensation, however, there is an increasing demand for such wear-resistant materials, since in operation there is no longer any play between cams and valve tappets and thus increased wear requirements are placed on them.

The invention is therefore based on the object of providing a tappet body which can be produced in the simplest possible manner from wear-resistant materials and is therefore inexpensive with good wear properties.

This object is achieved in that the guide body and the tappet base are produced in a casting-related manner and in that the element holding the valve support is integrally connected to the tappet base and / or the guide body.

The great advantage of the solution according to the invention is to be seen in the fact that the casting connection between the guide body and the tappet base makes the cup tappet body very simple, in particular, for example, without a welding process and at the same time with excellent stability, and also that the element holding the valve support either in a simple and stable manner either with the pestle bottom and / or connected to the guide body. Furthermore, the use of very wear-resistant and therefore tribologically advantageous materials is possible in the solution according to the invention.

In the context of the solution according to the invention, the term "manufactured using a casting technique" is either to be understood to mean that the entire tappet body is cast in one piece or because at least parts of the tappet body are cast and thereby cast onto already prefabricated parts, so that parts are cast on of the bucket tappet body to the prefabricated parts is finally connected to all the parts forming the bucket tappet body.

According to the basic concept of the invention, the element holding the valve support is either connected in one piece to the tappet base and / or in one piece with the guide body. In all cases in which at least the guide body is cast, it is particularly advantageous if the element holding the valve support is cast in one piece with the guide body. As before, the tappet base can either be prefabricated or also cast.

Alternatively, however, it is also conceivable that the element holding the valve support is cast in one piece together with a part of the tappet base adjoining this. In this case, the plunger base is then also cast in the course of the technical connection of all parts of the cup tappet body, or it is also conceivable that the plunger base is a prefabricated cast part.

As already explained above, the basic idea of the invention is to be seen in the fact that the individual parts of the tappet body are connected to a single part by casting one part onto the other parts. Which part is cast is not specified. For example, it is possible to cast at least the tappet base and, in the course of the casting of the tappet base, to connect the other parts, such as the guide body and, for example, also the element holding the valve support. It is particularly advantageous for reasons of production engineering if the guide body is produced as a casting in the course of the casting connection between the guide body and the tappet base, so that at least the guide body is cast and the casting of the guide body leads to the connection of all parts of the cup tappet body.

An advantageous variant of the bucket tappet body described above is characterized in that the guide body is cast onto the tappet base comprising a semi-finished part.

A further advantageous possibility of creating a firm connection between the semi-finished part and the cast-on parts is to encapsulate the semi-finished part in regions, for example to encapsulate the element holding the valve support at least in sections.

In order to create a particularly strong and durable connection between the semifinished part and the parts cast onto it, it is preferably provided that the semifinished part is designed to be castable in a form-fitting manner on the gate side.

If, according to the invention, the plunger base is prefabricated as a semi-finished part, a preferred variant of the present invention provides that the element holding the valve support is prefabricated with the plunger base as a semi-finished part, so that the guide body is cast onto this semi-finished part.

As an alternative to this, however, it is also advantageous from a manufacturing point of view if the casting of the element holding the valve support takes place in the course of the casting connection between the guide body and the tappet base, i.e. So that the element holding the valve support is cast onto the other parts.

In the simplest case, in which all the casting advantages come into play, in particular also with regard to the selection of the materials, it is preferably provided that the guide body, the tappet base and the element holding the valve support are cast as one piece.

In the exemplary embodiments described so far, only the design of the indispensable parts of the tappet body has been emphasized. In particular, if the tappet base is to be as light as possible in terms of weight, it is necessary to make all parts as light as possible, ie as thin-walled as possible. In this case it is advantageous, for example, if the guide body has a reinforcing element running in a plane running parallel to the tappet base. This reinforcing element leads to a stiffening of the guide body, so that it can be made thinner overall.

This thinner-walled design of the guide body is expressed, for example, by the fact that the guide body has an undercut between the reinforcing element and the tappet base following the reinforcing element.

The reinforcing element is preferably designed such that it projects inward beyond an inner lateral surface of the guide body.

In connection with the provision of a reinforcing element on the guide body, it is also advantageous if the guide body has an oil groove on its outer lateral surface at the level of the reinforcing element, if necessary, so that preferably the reinforcing element and the oil groove form a bead in the guide body.

In principle, the reinforcing element can be arranged at any point on the tappet body. For example, it is conceivable to arrange the reinforcing element on the lower edge of the guide body in order to stiffen this free edge opposite the tappet base, in particular for the final processing of the tappet body. However, it is particularly advantageous if the reinforcing element is arranged in a central region between the plunger base and a free edge of the guide body opposite the plunger base, since with this arrangement of the reinforcing element there is sufficient stiffening of the guide body and, on the other hand, for example the possibility opens up of the reinforcing element to combine with an oil groove arranged in the same area.

In principle, the reinforcement element could also be connected as a prefabricated part in the course of the casting connection. However, it is particularly advantageous if the reinforcing element is connected in one piece to the guide body and is thus cast in one piece with the guide body in the case of a cast guide body.

Furthermore, in order to increase the stability of the cup tappet body according to the invention, it is advantageous if the guide body has a reinforcing rib cast onto it and extending in a plane parallel to its cylinder axis, preferably several reinforcing ribs being provided which are at equal angular distances from one another.

The reinforcing rib can in principle be arranged in a wide variety of orientations. A simple solution which is advantageous in terms of stability provides that the reinforcing rib runs in the radial direction to the cylinder axis of the guide body.

Alternatively, it is also conceivable within the scope of the invention that the reinforcing rib runs parallel to a tangential direction of the outer surface of the guide body.

In the previously described exemplary embodiments of reinforcing ribs, no consideration has been given to how far the reinforcing rib should extend in the cup tappet body. For example, it is advantageous if the reinforcing rib extends over the tappet base to the element holding the valve support.

Furthermore, it is provided in a preferred embodiment that the reinforcing rib extends from the reinforcing element over the inner circumferential surface of the guide body.

No comments have yet been made regarding the height of the reinforcement rib. For example, it is expedient if the reinforcing rib has a substantially constant height.

Advantageously, the reinforcing rib rises between the element holding the valve support and the inner circumferential surface of the guide body above the tappet base at most approximately up to the height of the element holding the valve support.

It can also be advantageous if the reinforcing rib extends on the inner circumferential surface of the guide body from the tappet bottom to the reinforcing element or beyond the reinforcing element.

A special embodiment of the reinforcing rib provides that it forms a stiffening triangle connected to both the tappet base and the guide body.

In principle, the reinforcing rib could only act selectively on the part to be reinforced, for example on the inner circumferential surface of the guide body or the tappet base. However, it is particularly expedient if the reinforcing rib extends from the entire length

Raised inner surface of the guide body in one piece with the same. Furthermore, it is particularly favorable if the reinforcing rib rises integrally with the tappet base over its entire length.

Another advantageous exemplary embodiment provides for the height of the reinforcing rib that it rises from the tappet base and preferably also from the inner surface of the guide body by approximately the same height as the reinforcing element from the inner surface of the guide body.

As already mentioned at the beginning, the element holding the valve support can be designed in the most varied of forms. An advantageous embodiment provides that the element holding the valve support is a valve support pin rising from the tappet base.

As an alternative to this, it is provided in bucket tappet bodies for valve tappets with hydraulic valve clearance compensation that the element holding the valve support is a guide cylinder for a hydraulic valve clearance compensation element.

No details have yet been given regarding the design of the guide cylinder. Thus, in the case of a bucket tappet body produced within the framework of the technology according to the invention, there is the possibility of radially expanding the guide cylinder on the bottom of the tappet so that it forms an oil space with the play compensation element. As a result, an oil space for the hydraulic valve clearance compensation element is created in a simple manner without additional parts having to be welded in, as is customary, for example, in the prior art.

The supply of the oil space, if necessary, is advantageously carried out in that the oil space is provided with an oil supply line running to the outer jacket side of the guide body, the oil supply line advantageously opening into the oil groove.

In order not to have to create a new part through which the oil supply can be guided, it is particularly expedient if the bucket tappet body according to the invention is to be made as simple as possible from a manufacturing point of view if the oil supply runs through a reinforcing rib, which is advantageously thickened to accommodate the oil supply .

A variant that is particularly advantageous from the point of view of the material mass is characterized in that the guide cylinder forms a guide ring for the valve clearance compensation element on its side facing away from the tappet base and, between this and the tappet base, a base ring that carries the guide ring and has a larger inner and outer diameter than the guide ring has, so that the oil space is formed between this and the valve clearance compensation element. With this construction, an oil space is created in a simple manner, it advantageously being possible for the wall thicknesses of the guide ring and the base ring to be substantially the same.

In all of the exemplary embodiments described so far, only the structural features of the tappet body have been used. In the context of the invention, however, the features relating to the material have proven to be important in the same way.

An advantageous embodiment of the tappet body according to the invention therefore provides that the cast part of the tappet body is made of cast iron.

The cast iron expediently has a partially or completely metastably solidified structure, at least in the region of the ram base. A cup tappet body of this type is manufactured, for example, from hard chilled cast iron or partially carbide cast iron. This embodiment is particularly useful in order to optimize the tribological properties of the tappet base on which the cam of a camshaft rests, i.e. as wear-resistant as possible and adapted to the material of the camshaft.

The cast iron can be thermally uncured. However, it is even more expedient if the cast iron is thermally or thermochemically hardened.

One possibility for hardening the cast iron is for it to be hardened by heat treatment with phase change. Alternatively or in addition, it is also possible to harden the cast iron by thermochemical edge zone hardening, e.g. a nitriding, nitrocarburizing or case hardening. Another alternative or additive measure involves the cast iron being hardened by remelting.

As an alternative to the provision of cast iron, the inventive concept of a cup tappet body, in particular the technical connection of the parts of the same, also offers the possibility that the cast part Part of the tappet body is cast from steel. For example, case hardening steel can be used as steel, but it can also be tempered steel, nitriding steel, tool steel or high-speed steel. As a rule, all these types of steel cannot be processed, or can only be processed with great difficulty, and also involve difficulties in machining. However, the inventive design of the casting connection and the near-net-shape production of these parts creates the possibility of also producing the tappet body according to the invention from these materials.

Another alternative for producing the tappet body according to the invention from cast iron or steel is that the cast part of the tappet body is cast from a light metal alloy. This light metal alloy is preferably an aluminum alloy or a titanium alloy.

In order to further improve the mechanical properties, it is furthermore expedient if the light metal alloy is reinforced with fiber or wiskers.

If the tappet body according to the invention is not completely cast, but rather comprises a semi-finished part, it is particularly expedient according to the invention if the semi-finished part is made of steel. These steel materials can be selected according to the required tribological properties, in particular of the tappet base, and thus create the possibility, with respect to those parts of the tappet body, that are less so Wear is subject to using simpler and cheaper materials. All steels already described above can be considered as steel materials.

As an alternative to the steel materials, it is conceivable that the semi-finished part is made of ceramic material. The ceramic material also offers tribologically advantageous properties and also opens up the possibility of designing the remaining parts of the tappet body with cheaper or simpler materials.

As a third alternative, in addition to the provision of steel materials and ceramic materials for the semi-finished part, a further advantageous embodiment can be seen in the fact that the semi-finished part is made of hard metal, which also offers advantages due to its properties, in particular for the plunger base.

With regard to the method for using the materials described above for casting the bucket tappet body according to the invention in connection with the casting connection of all parts of the same, it is expediently provided that the cast part of the bucket tappet body is produced by casting, which is preferably a near-net shape casting that the tappet body only has to be subjected to grinding operations.

Various casting techniques are conceivable within the implementation of near-net shape casting. For example, it is advantageous to use the cast part of the Cup tappet body by sand casting or by fine material or by precision casting in ceramic molds, by die casting or also by die casting, the die casting being used in particular in light metal alloys and preferably in aluminum.

As an alternative to molding, it would also be advantageous if the cast part of the tappet body was produced by powder metal injection molding.

In addition to the features of the tappet body itself described above, the object of the invention is also achieved by a method for producing a tappet body for valve tappets with the features mentioned above in that the entire tappet body is cast largely close to the final shape.

As an alternative to this, the object according to the invention is also achieved by a method for producing a tappet body for valve tappets if a part of the tappet body is produced as a semi-finished part and is produced by casting the other parts of the cup tappet body onto the semi-finished part of the cup tappet body as a casting-related composite part to a close to the final shape.

In both of the methods described above as alternatives, it is easiest if the tappet body is cast close to the final shape, which is the simplest and most cost-effective procedure on the part of the casting technique.

Alternatively, however, if particularly high material requirements are placed on parts of the cup tappet body, it can be advantageous if the cup tappet body is perfected by reshaping following the largely near-net shape casting.

In all of the methods described above, it is also expedient if the bucket tappet body is subjected to a final grinding process to size, not to produce the contour, but only for reasons of dimensional accuracy.

• Fig. 1 Einen Schnitt längs Linie 1-1 in Fig. 2 durch ein erstes Ausführungsbeispiel eines erfindungs­gemäßen Tassenstößelkörpers;
• Fig. 2 eine Draufsicht von unten auf das erste Aus­führungsbeispiels;
• Fig. 3 einen teilweisen Schnitt ähnlich Fig. 1 durch ein zweites Ausführungsbeispiel;
• Fig. 4 einen Schnitt ähnlich Fig. 3 durch ein drittes Ausführungsbeispiel;
• Fig. 5 einen Schnitt längs Linie 5-5 in Fig. 6 durch ein viertes Ausführungsbeispiel;
• Fig. 6 eine Draufsicht von unten auf das sechste Aus­führungsbeispiel;
• Fig. 7 einen Schnitt ähnlich Fig. 1 durch ein fünftes Ausführungsbeispiel;
• Fig. 8 einen Schnitt ähnlich Fig. 1 durch ein sechstes Ausführungsbeispiel;
• Fig. 9 einen Schnitt ähnlich Fig. 1 durch ein siebtes Ausführungsbeispiel.

Further features of the invention are the subject of the following description and the drawing of some exemplary embodiments: The drawings show:

• 1 shows a section along line 1-1 in FIG. 2 through a first embodiment of a tappet body according to the invention;
• Figure 2 is a bottom plan view of the first embodiment;
• Fig. 3 is a partial section similar to Figure 1 through a second embodiment.
• 4 shows a section similar to FIG. 3 through a third embodiment;
• 5 shows a section along line 5-5 in FIG. 6 through a fourth embodiment;
• 6 is a bottom plan view of the sixth embodiment;
• 7 shows a section similar to FIG. 1 through a fifth exemplary embodiment;
• 8 shows a section similar to FIG. 1 through a sixth embodiment;
• Fig. 9 shows a section similar to Fig. 1 through a seventh embodiment.

A first exemplary embodiment (FIG. 1) of a cup tappet body 10 according to the invention for valve tappets comprises a cylindrical guide body 12 which is closed at the top by a tappet base 14 and which has a lower opening 18 delimited by a lower edge 16 opposite the tappet base 14.

The guide body 12 preferably has a circular cylindrical shape, so that its wall 20 has an outer lateral surface 22 as the outer cylindrical surface and an inner lateral surface 24 as the inner cylindrical surface.

In the area of an upper edge 26, the wall merges in one piece into the tappet base 14, which preferably has a cam contact surface 28 which is perpendicular to a cylinder axis 30 of the guide body 12.

In a central region between the plunger base 14 and the lower edge 16, the guide body 12 is provided with a reinforcing element 32 shaped like a bead, which is approximately parallel to the plunger base 14 Plane, preferably in a plane perpendicular to the cylinder axis 30 and stands out as a bead from the inner surface 24 in the direction of the cylinder axis 30, and at the same time creates an oil groove 34 on the outer surface 22, which is also in a plane parallel to the reinforcing element 32, preferably within the scope of the invention, the thickness of the wall 20 is also substantially constant in the area of the reinforcing element 32. In the preferred exemplary embodiments shown in FIG. 1, on the one hand the reinforcing element 32 with a trapezoidal cross section rises from the inner lateral surface 24 and also the oil groove 34 also has a trapezoidal cross section, both cross sections being such that the thickness of the wall 20 is approximately constant remains.

A guide cylinder 36 rises from the tappet base 14 on its side opposite the cam support surface 28 in the direction of the lower edge 16 and coaxially to the cylinder axis 30 for a hydraulic valve lash adjuster element 38, which is only indicated by dash-dotted lines. This guide cylinder 36 comprises a base ring 40 directly adjoining the tappet base 14 and a guide ring 42 carried by the base ring 40, which is the actual guide for the hydraulic valve clearance compensation element 38. In the preferred embodiment according to the present invention, the base ring 40 has a larger inner diameter than the guide ring 42, so that an undercut creates an oil space 44 between the base ring 40 and the hydraulic valve clearance compensation element 38 between the guide ring 42 and the tappet base 14.

In order to allow an overflow of the oil from the oil space 44 into the hydraulic valve lash compensation element 38, an overflow 48 in the form of a depression in this base surface 46 is provided in a base surface 46 of the guide cylinder 36 which is parallel to the cam support surface 28 and is arranged opposite this on the tappet base 14 creates a connection between the oil space 44 and an interior of the hydraulic valve lash compensation element 38. In the simplest case, the overflow 48 can be a depression with a round outer edge. As can be seen in FIG. 2, the overflow 48 is preferably provided with an essentially quadrangular outer edge.

In order to supply oil to the oil space 44 in the case of the external oil supply, an oil supply channel 50 is provided between the oil groove 34 and the oil space 44. This oil supply channel 50 preferably runs in a rib 52 which is pulled up from the tappet base 14 and connects the wall 20 to the guide cylinder 36 and which is pulled up so far that it extends from the oil groove 34 and into the guide cylinder 36 in the transition region between the base ring 40 and the guide ring 42 is able to completely accommodate the opening oil supply channel 50. This rib 52 also serves as a reinforcing rib for stiffening the entire tappet body 10 and in particular for stiffening the wall 20 and the guide cylinder 36 together with the tappet base 14.

As can be seen in particular from FIG. 2, two further reinforcing ribs 54 are provided in the simplest preferred exemplary embodiment, which, however, in contrast to the rib 52, differ from the tappet base 14 and the Raise wall 20 between the reinforcing element 32 and the plunger base 14 in one piece over its entire length, namely by a height which, based on the inner lateral surface 24, corresponds approximately to a height of the reinforcing element 32 designed as a bead. The reinforcing ribs 54 extend into a foot region 56 of the base ring 40.

As can be seen in particular from FIG. 2, the reinforcing ribs 54 and also the rib 52 run in the radial direction to the cylinder axis 30, in the simplest case the rib 52 forming a total of three reinforcements with the reinforcing ribs 54. Preferably, as also indicated in dash-dot lines in FIG. 2, a plurality of reinforcements can be provided, so that, for example, a total of six reinforcements are also conceivable.

In order to make the cup tappet body 10 according to the invention as light as possible, undercuts are provided between the reinforcing element 32 and the tappet base 14 and between the reinforcing ribs, be it as reinforcing ribs 54 or as rib 52, that is to say that the wall 20 of the guide body 12 to substantially the same thickness as that between the reinforcing member 32 and the lower edge 16. This also ensures that the tappet body has a mass that is as small as possible.

In a second exemplary embodiment (FIG. 3) of a cup tappet body according to the invention, designated as a whole by 60, the parts identical to the first exemplary embodiment are provided with the same reference numerals, so that reference can be made to the explanations for the description of the first exemplary embodiment with regard to their description.

The second embodiment differs from the first only in that the reinforcing ribs 54a form a reinforcing triangle between the plunger base 14 and the wall 20 of the guide body 12, which is pulled up from the plunger base 14 to the reinforcing element 32 with a cathete and extends from the other with the other cathete Inner circumferential surface 24 of the wall 20 extends approximately centrally between the latter and the guide cylinder 36, the reinforcing rib 54a continuing over the remaining part up to the foot region 56 of the guide cylinder 36 at a height which corresponds approximately to a height of the reinforcing element 32.

In a third exemplary embodiment of the cup tappet body according to the invention, designated as a whole by 70, shown in FIG. 4, the parts identical to the first exemplary embodiment are provided with the same reference numerals, so that with regard to their description, reference can also be made to the explanations for the first exemplary embodiment.

In contrast to the first exemplary embodiment, the reinforcing rib 54b is pulled up as far from the plunger base 14 as the rib 52, that is to say it extends on the one hand from the plunger base 14 to the reinforcing element 32 and on the other hand from the plunger base 14 to almost the lower edge 72 of the guide cylinder 36 and thus fills almost the entire free space between the inner circumferential surface 24 and the guide cylinder 36.

In a fourth embodiment of the bucket tappet body according to the invention, designated as a whole by 80 and shown in FIGS. 5 and 6, the parts that are identical to the first embodiment are provided with the same reference numerals, so that with regard to their description, again refer to the explanations for can refer to the first embodiment.

In contrast to the first exemplary embodiment, the reinforcing ribs 54c are no longer arranged to run radially to the cylinder axis 30, but instead run parallel to one another and parallel to a tangent to the outer circumferential surface 22 or the base ring 40. The reinforcing ribs 54c run as secants to the circular-cylindrical guide body 12, so that are offset far inward in the direction of the cylinder axis 30 so that they cut the base ring.

Preferably, two such reinforcing ribs 54c running parallel to one another are provided, which rise from the tappet base 14 to approximately the height of the base ring 40 and extend at this height between opposite sides of the inner lateral surface 24. Only the part of the reinforcing rib 54c, which surrounds the oil supply channel 50, is made thickened and raised from the base ring 40 starting from an inner circumferential surface to the reinforcing element 32, so that the oil supply channel 50 can branch off from the oil groove 34 as in the exemplary embodiments described above.

All of the exemplary embodiments of the bucket tappet bodies 10, 60, 70, 80 described above are designed as a one-piece casting, which can preferably be produced directly by molding, which may be sand casting, fine material, precision casting in ceramic molds, mold casting, die casting or powder metal injection molding and the method chosen primarily depends on the material selected. In particular, cast iron based on GGL, GGG or malleable cast iron, which can be alloyed or unalloyed, comes into consideration as materials for such a one-piece casting. A particularly preferred embodiment provides that the tappet body is made of cast iron, which has a partially or completely metastable structure in the area of the tappet base, i.e. e.g. is made partially carbide or hard shell cast, since the tappet base 14 with the cam bearing surface 28 is subject to the greatest wear stresses, which applies in particular to a bucket tappet body for valve tappets with a hydraulic valve lash compensation element, since in these the cam bearing surface 28 is always in contact with the cam and thus causes lubrication problems between the cam surfaces 28 and the cam occur.

Chilled cast iron is particularly advantageous for the production of a cup tappet body, since it allows the tribological properties of the cam contact surface to be easily adapted to cams also produced by casting, for example.

In addition, as is generally known, a hardening treatment of the cup tappet body can take place after the casting, in which, for example, the cast iron passes through Heat treatment with phase change is hardened. In addition, thermochemical hardening of the edge zone of the cast iron or remelt hardening is also conceivable.

In other exemplary embodiments of the cup tappet body 10, 60, 70, 80 according to the invention, however, it is also conceivable to cast them from steel materials, such as case-hardening steels, preferably GS-15 Cr 3, GS-16 Mn Cr 5, GS-21 Ni Cr Mo 2, GS -16 Cr Mo 4 or tempered steels, such as preferably GS-53 Mn Si 4, GS-42 Cr V 6, GS-42 Cr Mo 4, or nitriding steels, such as preferably GX 38 Cr Mo V 5 1, GS-31 Cr Mo V 9, GS-34 Cr Al Ni 7, or tool steels, such as preferably 105 W Cr 6, X 210 Cr W 12 or high-speed steels, such as preferably S-6-5-2.

Finally, it is also possible to produce a one-piece tappet body 10, 60, 70, 80 from light metal alloys, for example aluminum-based alloys, such as Al Si 7 Mg, Al Si 17, Al Mg 9 Zn 1, Al Cu 4 Ti Mg or titanium Base alloys, such as preferably Ti Al 6 V 4, where the light metal alloys can still be fiber or wisker reinforced.

In a further embodiment of the tappet body according to the invention, designated as a whole by 90 and shown in Fig. 7, those parts, insofar as they are identical to those of the first embodiment, are provided with the same reference numerals and additionally with a ', so that also with respect the description of which can be referred to the explanations for the first exemplary embodiment.

In contrast to the first embodiment, the tappet base 14 'is exemplarily thicker than in the first embodiment and comprises a semi-finished part, designated as a whole with 92, which has a tappet base plate 94 which extends over the entire guide body 12', covers it and thereby the cam contact surface 28 ' wearing.

At this plunger base plate 94 is then also the guide cylinder 36 'integrally formed with the base ring 40' and the guide ring 40 '. Furthermore, the tappet base plate 94 carries on its cam support surface 28 'opposite sprue elements 96, which are, for example, dovetail-shaped and allow a positive connection with a lower part 98 of the tappet base 14'. Similarly, the base ring 40 'and the guide ring 42' can be provided with sprue elements for the rib 52 or the reinforcing ribs 54. The lower part 98 of the plunger base 14 'is in turn made by this in one piece with the guide body 12' and the reinforcing ribs 54 and the rib 52 as a cast part, this cast part being cast onto the prefabricated semi-finished part 92 and thus technically connected to it to form a unit is.

Alternatively, it would also be advantageous according to the invention if the base ring 40 'and the guide ring 42' are cast in a ring shape and the ribs or the reinforcing ribs extend from this ring.

Preferably, the manufacture of the tappet body 90 takes place in such a way that the semi-finished part 92 in turn is prefabricated by casting or also by machining, is produced from the corresponding material and then a casting of the semi-finished part 92 together with the guide body 12 'and the reinforcing ribs 54' and the Rib 52 'takes place.

The semi-finished part 92 can in principle be a semi-finished part that is produced from the same materials that have already been specified in connection with other exemplary embodiments. This semi-finished part 92 is preferably made of very wear-resistant materials in order to ensure the necessary tribological properties of the cam contact surface 28 '. In addition, it is also possible to manufacture the semi-finished part 92 from hard metal or from ceramic materials, such as pure and mixed ceramics made of ZrO₂, AL₂O₃ and Si₃N₄.

In a further embodiment (100) (FIG. 8) of the tappet body according to the invention, parts identical to the first embodiment are also provided with the same reference numerals and additionally with ", so that reference can be made to the above explanations regarding their description.

In contrast to the first embodiment, the plunger base 14˝ also has a two-part shape, that is to say that the plunger base 14˝ comprises a plunger base plate 102 which carries the cam contact surface 28˝ and is produced as a semi-finished part, the Ram base plate does not extend in the radial direction to the cylinder axis 30˝ to the outer circumferential surface 22˝, but has a smaller extent and is embedded in a support base 104, which is cast-molded with the guide body 12˝ and which engages around the stem base plate 102 at its lateral edges 106 and is flush with it this concludes. For this purpose, the lateral edges of the tappet base plate 102 are preferably also beveled in a dovetail-like manner, so that they enable the tappet base plate 102 to be positively anchored in the support base 104.

The tappet base plate 102 can be produced in the same way as the semi-finished part 92 from the same materials that were mentioned in connection with the one-piece tappet body 10, 60, 70, 80 and additionally also from hard metal or ceramic materials.

For the manufacture of the cup tappet body 100, the tappet base plate 102 is also produced as a semi-finished part, and the support base 104 together with the guide body 12˝ and also the guide cylinder 36˝ is then integrally cast onto it in a casting process.

In all of the exemplary embodiments 10, 60, 70, 80, 90, 100 of the tappet body according to the invention, it has always been assumed that after casting, no subsequent shaping process takes place except for the final mechanical machining of the tappet body to size. As an alternative, however, it is conceivable, for example, to produce the reinforcing element 32 by means of a forming process following the casting, for example by rolling in a bead.

A further example of a cup tappet body according to the invention, shown in FIG. 9 and designated 110, is insofar as it is identical to the first exemplary embodiment, provided with the same reference numerals and additionally with ‴, so that the description of these parts refers to the explanations for the first Embodiment can be referenced.

In contrast to the first exemplary embodiment, no guide cylinder 36 is provided as the valve support element, but only a valve support pin 112 rising from the tappet base 14, so that the tappet body 110 is not used to accommodate a hydraulic valve play compensation element, but is used as a mechanical tappet.

In addition, the reinforcing element 32 ‴ is not arranged approximately centrally between the tappet base 14 ‴ and the lower edge 16 ‴, but in the region of the lower edge 16 ‴, and serves to stiffen the latter, in particular to facilitate subsequent processing of the tappet body 110 after casting .

In addition, the rib 52 has been dispensed with in the cup tappet body 110 and the oil groove 34 has also been eliminated.

If the valve support pin 112 exceeds a certain height, it is advantageous to provide the tappet body with a rib 54.

The cup tappet body 110, like the exemplary embodiments 10, 60, 70, 80 of the cup tappet body according to the invention, is produced in one piece from the same materials and according to the same methods as the cup tappet bodies 10, 60, 70, 80.

In addition, however, it is also conceivable to design the tappet base similar to that of the cup tappet body 100 or to form the valve support pin 112 in one piece on a semi-finished part similar to the cup tappet body 90.

In these cases, the same materials are used for the semi-finished parts as for the tappet bodies 90 and 100.

Claims (47)

1. cup tappet body for valve tappets, comprising a cylindrical guide body, a tappet base and an element that holds a valve support and is carried by the tappet base,
characterized,
that the guide body (12) and the tappet base (14) are produced in a casting-related manner and that the element (36, 112) holding the valve support is integrally connected to the tappet base (14) and / or the guide body (12). 2. tappet body according to claim 1, characterized in that the valve support element (36, 112) is integrally cast together with the guide body (12). 3. Cup tappet body according to claim 1, characterized in that the element (36, 112) holding the valve support is integrally cast together with a part of the tappet base (14) adjoining this. 4. tappet body according to one of the preceding claims, characterized in that the guide body (12) is made as a casting in the course of the casting connection of the guide body (12) and tappet base (14). 5. bucket tappet body according to claim 4, characterized in that the guide body (12) on the a semi-finished part (92, 102) comprising tappet base (14 ', 14˝) is cast. 6. bucket tappet body according to claim 5, characterized in that the semi-finished part (92, 102) is formed cast on the gate side. 7. tappet body according to one of claims 5 or 6, characterized in that the valve support element (36 ') is prefabricated with the semi-finished part (92). 8. tappet body according to one of claims 1 to 6, characterized in that the casting of the valve support element (36, 112) takes place in the course of the casting connection of the guide body and tappet bottom. 9. cup tappet body according to one of claims 1 to 3, characterized in that the guide body (12), the tappet base (14) and the valve support element (36, 112) are cast as an integral part. 10. Cup tappet body according to one of the preceding claims, characterized in that the guide body (12) has a reinforcing element (32) running in a plane running parallel to the tappet bottom. 11. bucket tappet body according to claim 10, characterized in that the guide body (12) between the reinforcing element (32) and the tappet bottom (14) following the reinforcing element (32) has an undercut. 12. tappet body according to one of claims 10 or 11, characterized in that the guide body (12) on its outer lateral surface (22) at the level of the reinforcing element (32) has an oil groove (34). 13. Cup tappet body according to one of claims 10 to 12, characterized in that the reinforcing element (32) is arranged in a central region between the tappet base (14) and a free edge (16) of the guide body opposite the tappet base (14). 14. tappet body according to one of claims 10 to 13, characterized in that the reinforcing element (32) is integrally connected to the guide body (12). 15. bucket tappet body according to one of the preceding claims, characterized in that the guide body (12) has a cast on this and in a parallel plane to the cylinder axis (30) extending reinforcing rib (52, 54, 54a, b, c). 16. cup tappet body according to claim 15, characterized in that the reinforcing rib (52, 54) extends in the radial direction to the cylinder axis of the guide body. 17. tappet body according to claim 15, characterized in that the reinforcing rib (54c) extends parallel to a tangential direction of the outer surface (22) of the guide body. 18. Cup tappet body according to one of claims 15 to 17, characterized in that the reinforcing rib (54, 54a, b, c) extends over the tappet base (14) to the element (36, 112) holding the valve support. 19. Cup tappet body according to one of claims 15 to 18, characterized in that the reinforcing rib (52, 54, 54a, b) extends from the reinforcing element (32) over the inner lateral surface (24) of the guide body (12). 20. tappet body according to claim 18 or 19, characterized in that the reinforcing rib (52, 54) has a substantially constant height. 21. Cup tappet body according to one of claims 15 to 19, characterized in that the reinforcing rib (54c) between the valve support element (36) and the inner circumferential surface (24) of the guide body (12) on the tappet base (14) at most approximately to to the height of the element (36) holding the valve support. 22. Cup tappet body according to one of claims 15 to 21, characterized in that the reinforcing rib (52, 54, 54a, b) extends on the inner lateral surface of the guide body from the tappet base to at least the reinforcing element (32). 23. Cup tappet body according to one of claims 15 to 22, characterized in that the reinforcing rib (54a, 54b, 54c) forms a stiffening triangle connected to both the tappet base (14) and the guide body (12). 24. tappet body according to one of claims 15 to 23, characterized in that the reinforcing rib (52, 54, 54a, b, c) rises integrally with the same over its entire length from the inner lateral surface (24) of the guide body (12). 25. tappet body according to one of claims 18 to 23, characterized in that the reinforcing rib (52, 54, 54a, b, c) rises integrally with the tappet base (14) over its entire length. 26. tappet body according to one of claims 15 to 25, characterized in that the reinforcing rib (52, 54) rises from the tappet base (14) by approximately the same height as the reinforcing element (32) from the inner circumferential surface (24) of the guide body (12) . 27. Cup tappet body according to one of the preceding claims, characterized in that the element holding the valve support is a valve support pin (12) rising from the tappet base (14). 28. Cup tappet body according to one of claims 1 to 27, characterized in that the element holding the valve support is a guide cylinder (36) for a hydraulic valve clearance compensation element (38). 29. Cup tappet body according to claim 28, characterized in that the guide cylinder (36) is extended radially on the tappet base side and forms an oil space (44). 30. tappet body according to claim 29, characterized in that the oil space (44) with an outer jacket side (22) of the guide body (12) extending oil supply (50) is provided. 31. tappet body according to claim 30, characterized in that the oil supply (50) through a reinforcing rib (52) passes through. 32. cup tappet body according to one of claims 29 to 31, characterized in that the guide cylinder (36) on its side facing away from the tappet base (14) forms a guide ring (42) for the valve clearance compensation element (38) and between it and the tappet base (14) has a base ring (40) which carries the guide ring (42) and has a larger inner and outer diameter than the guide ring (42), so that the oil space (44) is formed between the latter and the valve clearance compensation element (38). 33. tappet body according to one of the preceding claims, characterized in that the cast part of the tappet body is made of cast iron. 34. tappet body according to claim 30, characterized in that the cast iron has a partially or completely metastable solidified structure at least in the region of the tappet base (14). 35. tappet body according to claim 34, characterized in that the cast iron is thermally or thermochemically hardened. 36. cup tappet body according to one of claims 1 to 32, characterized in that the cast part of the cup tappet body is cast from steel material. 37. cup tappet body according to one of claims 1 to 32, characterized in that the cast part of the cup tappet body is cast from a light metal alloy. 38. tappet body according to claim 37, characterized in that the light metal alloy is fiber or wisker reinforced. 39. tappet body according to one of the preceding claims, characterized in that the semi-finished part (92, 102) is made of steel material. 40. tappet body according to one of claims 1 to 38, characterized in that the semi-finished part (92, 102) is made of ceramic material. 41. tappet body according to one of claims 1 to 38, characterized in that the semi-finished part (92, 102) is made of hard metal. 42. cup tappet body according to one of the preceding claims, characterized in that the cast part of the cup tappet body is made by molding. 43. cup tappet body according to claim 41, characterized in that the cast part of the cup tappet body is made by powder metal injection molding. 44. A method for producing a cup tappet body for valve tappets according to one of the preceding claims, characterized in that the entire cup tappet body is cast largely close to the final shape. 45. A method for producing a cup tappet body for valve tappets according to one of claims 1 to 43, characterized in that a part of the cup tappet body is produced as a semi-finished part close to the final shape and is produced by casting the other parts of the cup tappet body onto the semi-finished part of the cup tappet body as a composite casting part . 46. The method according to any one of claims 44 or 45, characterized in that the tappet body is made close to the final contour. 47. The method according to any one of claims 44 or 45, characterized in that the tappet body is produced close to the final contour by a subsequent molding.

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