JPS6293513A - Assembly type connecting rod - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The invention relates to a connecting rod shank which is substantially compressively loaded;
a substantially tensile-loaded loop band, the connecting rod shank extending between a piston pin and a crank pin boss that are components of the swivel bearing, the loop band being wound around the piston pin and the crank pin boss; The present invention relates to an assembled connecting rod, at least in part of which is metal.

[Prior art]

A compressively loaded connecting rod shank and a crank pin boss and a piston pin boss 100 of this connecting rod shank are basically known. This endless loop strip is shrink-fitted onto a connecting rod shank with a boss.

A structure in which a plurality of loop strips of fiber composite material surrounds a connecting rod shank containing a piston pin is known from DE 33 26 467 F16J1/16, in which a plurality of loop strips of fiber composite material surround a connecting rod shank containing a piston pin. does not completely surround the pin, but only forms a pin support.

The piston pin, which is in contact with the piston bottom for a bending-moment-free support, is pulled towards said support by both loop strips. For this loop strip, a recess is provided in the piston bottom in the bottom contact area of the piston pin. This recess is disadvantageous because it places the axis of the piston pin and thus the pivot axis of the connecting rod in a relatively "shallow" position. In order to minimize the transverse forces transmitted from the connecting rod to the piston during operation, said axis must be arranged as high as possible.

[Purpose of the invention]

The problem on which the invention is based is the advantage of an assembled connecting rod of the type mentioned at the outset, namely that the compressive and tensile forces are separated in separate components, the connecting rod shank and the loop strip;
The objective is to improve the assembled connecting rod as follows while maintaining the advantage of being lightweight. That is, the aim is to improve the pivot axis so that it can be moved further "upwards", ie towards the combustion chamber of the internal combustion engine, in order to minimize the lateral forces acting on the piston.

[Structure of the invention]

According to the invention, the outer curved metal surface area of the loop strip forms a component of the slewing bearing which transmits the pressing force, and the piston pin transmits only the inertial force in the opposite direction to the pressing force. It is solved by Preferred embodiments of the invention are set out in claims 2-9.

〔Effect of the invention〕

In the prior art (see above-mentioned European patent application), a crankpin boss closed on all sides is provided on the connecting rod shank and is surrounded by a loop band, so that
The connecting rod has a relatively high material strength in the direction of the piston. In addition, in the case of structures based on cited publications,
The material strength of the piston bottom is increased by the depth of the groove for accommodating the loop strip. The present invention, in contrast to the structures of this prior art and publication, makes use of the surface area of the loop strip to form the pressure-transmitting upper component of the swivel bearing. Therefore, the piston pin need only be designed and constructed to transmit an inertial force opposite the pressing force exerted by the pin.

The curved surface area of the loop strip and the area of the piston pin, which serves to transmit the inertial forces, have a cross-sectional shape along an arc.

Therefore, there is no need for a groove formed in the bottom of the piston to accommodate the loop strip so that it is not subjected to pressing force, so the bottom of the piston can be made relatively thin compared to the cited prior art. At the same time, the axis of the swing bearing can be placed at a high position.

In order to avoid a shrink fit for tightening the loop strip, which is relatively difficult to implement, claim 5
In the embodiments of the invention according to items 1 to 8, a tightening device is provided. Since this tightening device is arranged on the side of the connecting rod shank opposite the piston pin with respect to the crankpin hub, it has the advantage that the center of gravity of the connecting rod shank is shifted in this direction, and the vibrating mass is therefore reduced. The structure according to claims 6 to 9 can also be used in the case of other connecting rod embodiments.

〔Example〕

Hereinafter, a plurality of embodiments of the present invention will be described based on the drawings.

Turning first to FIG. 1, this side view shows in particular a loop strip 1, which in all embodiments is designed as a tensile-resistant metal strip. This loop strip is wrapped around the connecting rod shank and piston pin 3, only the crank pin boss 2 being visible in FIG. The piston is indicated by 4. The piston is provided with an inward bearing projection 5.6 for the lower surface area of the piston pin 3. The lower surface area of the piston pin 3 has a cross section extending along an arc around the pivot axis 7. The support portion functions to transmit the inertia force of the piston 4 when the piston 4 descends. The downward movement of the piston is initiated by the crankshaft passing through the crankpin boss 2.

The piston pin 3 is not supported directly on the piston base 8, but via a region 9 of a correspondingly textured loop strip l. This range 9 is provided along the same arc as the other bearings including ranges 5 and 6, centered on the pivot bearing axis.

This upper region 9 of the loop strip l on the piston pin thereby transmits to the piston body not only the tensile forces originating from the piston pin 3, but also the pressing forces exerted by the piston during operation.

Therefore, in order to reduce weight, the piston pin 3 can have a shape different from a cylindrical shape, for example in the manner shown.

In order to obtain a slender connecting rod, it is expedient to pull the loop strip by means of the shaped part IO towards the correspondingly formed side wall of the connecting rod shank, as will be explained in more detail with reference to FIG. It is.

In FIG. 2, the connecting rod shank is indicated at 20.

At 21 this connecting rod forms a curved support surface for a piston pin 22 and at its end, which is lower in the figure, forms a split crankpin boss 24 with a bearing bridge or cap 23. are doing. In this case as well, the piston pin 22 is supported by the piston 25 in its lower range in the figure in order to transmit inertial force, similar to the structure shown in FIG. In FIG. 2, only the piston bottom 26 of the piston is shown.

Similar to the embodiment of FIG. 1, the transmission of the pressing force exerted by the piston 25 to the connecting rod is via a bearing or rotary part 27 provided in the piston bottom 26 and an upper region of the loop strip 29. to the connecting rod shank. The outer surface 28 of this area and the outer circumference of the bearing area 27 are arranged along an arc centered on the axis 30 of the piston pin 22, which forms the pivot bearing axis.

In the embodiment shown in FIG. 2, a molded member 31 is also provided. This shaping element serves to pull the lateral areas of the loop strip 29 towards the side walls of the articulating shank 20 in order to obtain a slim connecting rod. This side wall is recessed relative to the crank pin boss 24. In this embodiment, two "open" loop strips are used. The loop strips a, '+ji1< 32, 33 are fixed to a burr-like part 35 forming a stamp material of the tightening device 34. Adjustment or tightening bolt 3
6° 37 supports the part 35 in the gap 23 and thus in the connecting rod shank. By means of this adjusting or tightening bolt, the stress in the loop strip 29 can therefore be adjusted to a predetermined value. Thereby, this construction allows assembly of the connecting rod by means of a loose loop strip and subsequent adjustment to a predetermined stress and, if necessary, adjustment or adaptation during operation. Complex shrink fits, which are particularly inconvenient for mass production, are avoided.

This advantage lies in the endless loop strip 4 shown in Figure 3.4.
It can also be obtained by a structure with 0.

In this case too, a tightening device 41 with a bridge-shaped part 42 is provided. In this embodiment, a loop strip 40 is wrapped around the outside of the surface part. Part 42
is supported on the cap 45 of the crank pin boss via adjustment or tightening poles 43, 44. Other parts of this crank pin boss are not shown.

Tightening bolts used as pressure bolts 43.44
has planned failure points of 46 and 47.

This predetermined failure point causes the bolt head to break when the loop strip 40 reaches a predetermined stress value, thus determining the stress value.

The provision of such a tightening device 37 or 41 has advantages not only with regard to assembly, but also with respect to the operating condition of the connecting rod. This is because the mass of the clamping device moves the center of gravity of the connecting rod downwards in the figure, thereby reducing the vibrating mass part. This is in addition to the basic advantage of the structure according to the invention, namely that it is possible to arrange the pivot axis 7 or 3o in a "high" position in the region of the piston bottom.

[Brief explanation of drawings]

Fig. 1 is a side view of the first embodiment, Fig. 2 is a side view of the second embodiment, Fig. 3 is a partial view of the third embodiment, and Fig. 4 is a section IV-IV of Fig. 3. It is a sectional view along the line. 22... Piston pin 20... Connecting rod shank 24... Crank pin boss 28... Surface area 29... Loop strip 34... Tightening device 40... Loop strip

Claims (1)

[Claims] 1. A connecting rod shank that is substantially compressively loaded and a loop strip that is substantially tensilely loaded, the connecting rod shank having a piston pin and a crank pin boss that are constituent members of a slewing bearing. In an assembled connecting rod extending between the loop strips (29), the loop strips are wound around the piston pin and the crankpin boss, and the loop strips (29) are made of metal, at least in part, the outer curved metal surface area ( 28) forms a component of a slewing bearing which transmits a pressing force, and the piston pin (22) transmits only an inertial force in the opposite direction to the pressing force. 2. Connecting rod according to claim 1, characterized in that the surface area (28) is precisely machined. 3. The connecting rod according to claim 1 or 2, characterized in that the loop strip (29) is a metal strip. 4. Claim 1 or 2, characterized in that the loop strip (29) consists of a fiber composite material, which fiber composite material is reinforced with metal in the surface area (28). Connecting rod as described. 5. Crank pin boss opposite to piston pin (22) (
24) is provided with a tightening device (34) for the loop strip (29). connecting rod. 6. A connecting rod shank that is substantially compressively loaded and a loop strip that is substantially tensilely loaded, the connecting rod shank extending between a piston pin and a crank pin boss that are components of the slewing bearing. In the assembled connecting rod, in which the loop strip is wound around the piston pin and the crankpin boss, and at least a portion of the loop strip is made of metal, the loop strip ( 29) Tightening device for (34)
is provided, and this tightening device is characterized in that it includes a component (35) which is connected in a complementary manner to the loop strip and is supported on the actual connecting rod via adjustment bolts (36, 37). A connecting rod according to any one of claims 1 to 4. 7. Connecting rod according to claim 6, characterized in that the loop strip (40) is endless and surrounds one side of the component (42). 8. Connecting rod according to claim 6, characterized in that the ends (32, 33) of the loop strip (29) are fixed to the component (35). 9. The adjustment bolts (43, 47) are at the planned failure point (46,
47), and the predetermined breaking point breaks the adjusting bolt when the loop strip (40) reaches a predetermined stress value. Connecting rod listed in any one.