DE3225324C1 - Connecting rod made of fiber reinforced plastic - Google Patents

Description

a) the belts (7.1) in the area of their outwardly bent - by dividing the loop

(7) free ends with a bearing bracket extending transversely to the longitudinal axis of the rod

(8) of fiber strands in parallel and / or crosswise to the direction of extension of the stirrup Orientation are connected and that

b) in the space between the closed bearing cylinder (9) and the bearing bracket (8) this space filling pressure rod (10) at least made of fiber strands in one orientation is embedded parallel to the longitudinal axis of the rod.

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2. Connecting rod according to claim 1, characterized by in planes perpendicular to the longitudinal direction of the bearing arranged cover layers (15) and parallel thereto, the loop (7), the bearing bracket (8) and the compression rod (10) in the longitudinal direction of the bearing dividing intermediate layers (16), each made of fiber strands in a crosswise orientation.

3. Connecting rod according to claim 1 or 2, characterized in that the from in the longitudinal direction of the bracket extending fiber strands of unidirectional orientation built-up bearing bracket (8) via a Intermediate layer (11) made of fiber strands in a crosswise orientation with the belt ends the loop (7) and the pressure rod (10) is connected.

4. Connecting rod according to claim 1 or 3, characterized in that the bearing bracket (8) on the The side facing the bearing cover (3.2) in the area of the flange bores (5) each has a filler piece (13) Fiber strands is attached in a crosswise orientation.

5. Connecting rod according to claim 1, characterized in that the closed bearing cylinder (9) in the Composite with the loop (7) and the compression rod (10) made of fiber strands in a crosswise orientation is constructed, in particular 0 ° / 90 ° orientation to the longitudinal axis of the bearing.

6. Connecting rod according to one or more of the preceding claims, characterized in that that the bearing cover (3.2) has a fiber structure corresponding to that of the open rod head part (3.1), the cover position corresponding to the loop (7) of the connecting rod (bearing bracket

20) has the shape of the cover bearing bracket (17).

The invention relates to a connecting rod according to the preamble of claim 1.

Such a connecting rod, the crank pin bearing is divided for assembly reasons, has in the by DE-OS 30 04 575 known embodiment with a metal jacket around a plastic core in the Compared to a corresponding all-metal structure, it has a significantly lower mass and leads thus, especially in the case of use in high-speed reciprocating piston engines, to smoother running and improved efficiency. Of course, among such criteria there is an endeavor to find one No metal parts. With a corresponding saving of the metal jacket of the known connecting rod would, however, no longer have the necessary strength against compressive and tensile forces guaranteed: The remaining fiber loop, which can only be subjected to tensile loads, would buckle under pressure. In addition, such a metal jacket has, among other things, a supporting outer shape using the fiber loop - composite of two materials with different modulus of elasticity underneath Loading of the connecting rod means that the stiffer fiber material then predominantly carries, d. H. the supporting one Metal jacket is not being used to full capacity.

The object of the invention is essentially to provide a connecting rod of the type mentioned at the beginning to make it possible to dispense with metal parts without reducing strength.

This object is achieved according to the characterizing part of claim 1. Accordingly, the exhausted Invention not in a union of a fiber loop with one - by DE-OS 29 51 112 for connecting rods known - rod, which with the same fiber structure due to its insertion between the both bearings of the connecting rod ensures their pressure absorption capacity. Rather, for this network "Fiber loop / compression rod" sufficient strength against lateral forces acting under mass acceleration only achieved through the introduction of the bearing bracket. This enables the strap ends of the fiber loop frictionally coupling bearing bracket not only their division or the waiver of one on the open Rod head part otherwise endless formation causing multiple curvatures of the fiber loop (for the according to the aforementioned DE-OS 30 04 575 with the requirement for flat flange surfaces of the open Rod head a sheathing with a corresponding outer contour is indispensable), but also a Space-saving yet effective reinforcement of the open rod head part against the embedment pressure the flange bores, preferably in the manner characterized in dependent claim 3.

Finally, in the layered construction characterized in dependent claim 2, corresponding to that the connecting rod known from DE-OS 29 51112 with an endless loop around two closed Bearing, the transverse tension absorption capacity of the loop belts due to shear-transmitting layers is considerable raise. These and the further developments characterized in the other subclaims are explained in more detail below using an exemplary embodiment of the invention. This shows the Drawing in

F i g. 1 in an end view of a connecting rod made of fiber composite material divided at one of the two rod ends,

F i g. 2 is a perspective view of this connecting rod in a partially exploded view.

For example, as a connecting link between the linearly moving part of a crank mechanism and a Crankshaft, the connecting rod shown consists essentially of a rod shaft 1 with as cylindrical bearings formed rod ends 2 and 3 on the one hand for a piston pin, not shown or on the other hand for a crank pin, also not shown. For mounting on the crank pin, the associated rod head 3 can be divided at a parting line 4 perpendicular to the longitudinal axis of the rod, the Connection of the open, half-shell-shaped rod head part 3.1 with a corresponding half-shell-shaped Bearing cover 3.2 via (expansion) screws fitted into bores 5 (Fig. 2) of their flanges 3.3 and 3.4 6 is made.

In order to create a structure made of fiber composite material in such a conventional configuration of the connecting rod, like carbon fiber in a synthetic resin matrix, dispensing with metal without reducing strength reach, the main or shaft part with an open loop 7 made of fiber strands is more unidirectional Orientation along the loop belts 7.1 provided, when they are divided on the open rod head part 3.1 for the Flange formation, the free belt ends are directed radially outward with respect to the rod shaft 1. Frictional connection in the open rod head part 3.1 between the free strap ends of the loop 7 is through one of End of belt to end of belt extending bearing bracket 8 achieved, also from fiber strands of unidirectional orientation in the direction of extension of the stirrup. Here is in the space between a bearing cylinder 9 around which the loop is wrapped and the bearing bracket 8 a compression rod 10 is embedded which, at least from the unidirectional fiber strands parallel to the longitudinal axis of the rod built up, ensures the necessary pressure absorption capacity of the connecting rod. Through a thrust-transmitting Intermediate layer 11 made of fiber strands with crosswise fiber orientation (fiber fabric or scrim) compared to the bearing bracket 8 is also sufficient Strength with regard to the bearing stress on the flange bores 5 (Fig. 2) is ensured. To this Purpose can just as well in the unidirectional fiber structure of the bearing bracket 8 intermediate layers Fiber fabric or scrim can be embedded with crosswise fiber orientation, as well as the intermediate layer 11 additional intermediate layers of fiber material in a unidirectional orientation from belt end to belt end may have. The crosswise fiber orientation is in particular alternating between ± 45 ° and 0 ° / 90 ° to the Longitudinal axis of the temple. For flush embedding of a metal bearing shell half 12.1, if necessary sit on the bearing bracket 8 in the area of the screws 6 filler pieces 13 made of fiber fabric or scrim, especially in layers of ± 45 ° and 0 ° / 90 ° which alternate with regard to the fiber orientation

ίο based on the longitudinal axis of the bearing. On the closed In contrast, the end of the rod is a bearing shell 14 in the (aforementioned) with the loop 7 and the Pressure rod 10 united bearing cylinder 9 embedded, which is made of fiber material in particular in one orientation 0 ° / 90 ° to the longitudinal axis of the bearing.

Finally, to increase the shear stiffness of this fiber structure, there are two ends of the rod Cover layers 15 and parallel thereto, the loop 7 with the bearing bracket 8, the compression rod 10, the intermediate layer Il and the filler pieces 13 in the longitudinal direction of the bearing dividing intermediate layers 16 each made of fiber material in particular provided with an orientation of ± 45 ° to the longitudinal axis of the rod. It goes without saying, moreover, that appropriate fabric or scrim can be used for all cross-oriented fiber material.

As far as the bearing cover 3.2 is concerned, its fiber structure corresponds to that of the open rod head part 3.1 the connecting rod, d. H. here is a. same bearing bracket 17 with in the area of the screws 6 attached filler pieces 18 (for the bedding of a second bearing shell half 12.2) via an intermediate layer 19 of the type described above (11) combined with a further similar bearing bracket 20, which the Loop 7 of the main part of the connecting rod corresponds.

Corresponding shear-transferring cover layers and intermediate layers 15.1 and 16.1 are also present here.

In addition, by means of the heads or nuts of the screws 6 associated washer blocks 21 and 22 are with Corresponding scarfing, compressive stress peaks on the relevant bearing surfaces are largely excluded. As usual, these blocks can be made of metal to improve power transmission be glued to the flanges 3.3 or 3.4. As illustrated in particular Fig.2, the connecting rod structure described a composite of individual fiber components, which blanks from corresponding preformed extruded profiles, sometimes also stamped parts. Thus, the connecting rod is after Can be produced using a modular principle, so it is particularly suitable for series production.

For this purpose 2 sheets of drawings

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Claims (1)

Patent claims: 1. Connecting rod made of fiber-reinforced plastic, one of which is a rod head, z. B. for a piston pin, as a closed, cylindrical bearing and the other rod head, e.g. B. for a crank pin, is designed as a split, cylindrical bearing with an open, half-shell-shaped one Rod head part and with a corresponding half-shell-shaped bearing cap, being unidirectional Fiber strands to a closed storage cylinder encompassing, in the longitudinal direction of the rod extending open loop are combined, the two straps on the open Rod head part for the cover connection in an essentially perpendicular direction to the longitudinal axis of the rod Curved outward direction and thereby formed into a flange with holes, thereby marked that