DE2350384A1 - TUNNEL FRAME FOR INTERNAL COMBUSTION ENGINES - Google Patents

Description

Dipl.-Ing. M. Schröter

~ Patent attorney

5S6O iserlohn

Pioj-enetockstr. !

5ο October 1973 N.Vo Appingedammer Bronsraotorenfabrik

Appinqedanffi Netherlands * Farmsumweg 43

Tunnel frames for internal combustion engines

The invention relates to a tunnel frame for a multi-cylinder internal combustion engine or for a multi-cylinder internal combustion engine, in line or with two, or more, rows of cylinders, with a tunnel opening in the transverse walls, the size of which is sufficient to a crankshaft in the axial direction through the tunnel opening through in and out of the frame with the center line of the main bearings near or at the edge of the Tunnels, with the immovable half of the main bearing housing is integral with the reinforced edge of the tunnel opening, with half the main bearing housing is closed with a separate main bearing cap.

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Except for very small internal combustion engines, in which the crankshaft is in certain cases in the frame itself is assembled, it is common in the majority of engine types, the crankshaft either from above, from on the side or from below in the frame and then in a bedding with the help of main bearing caps to locate on the upper side, or the crankshaft to hang in main bearing caps. In all these cases, the engine frame is open in the crankshaft direction to the Insert or remove the crankshaft. This opening it must be concluded for what purpose different solutions are used.

A rather different procedure, which is seldom used, is what is called a. Tunnel frame or tunnel frame use, in this case a tunnel-like Opening, generally near the localization of the Crankshaft, while running, runs through the engine frame. This tunnel is generally shaped like this tet that it is possible to use an assembled crankshaft, e.g. B. with attached swing weights or balance weights, to bring in and out of the frame without any disassembly is necessary. There are in general two methods suitable by which the crankshaft is supported in the tunnel frame. The one procedure makes use of rolling bearings that are approximately the same diameter as the tunnel, with the main journal with the adjacent crank arms in a circular main bearing disc passes, which also serves as the inner race of the bearing. In the other method, the crankshaft passes from the normal main bearing journals with a crank arm on each side, with the main bearing shells in one stationary, split disc, with a tight fit in the tunnel bore. There will also be half Discs are used, in which case the main bearing is closed with a normal bearing cap, the half disk is often cranked on the side of the tunnel bore which is closest to the cylinders.

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Characteristic for most of the known machines with a tunnel frame is the fact that the center line of the crankshaft coincides with the center line of the tunnel. · All of these · types are relatively expensive because they consist of different parts with tight tolerances, which in terms of the barrel tolerances and strength as a result the changing loads are very critical · This tunnel design can be simplified if the main bearings of the Crankshaft are in the edge of the tunnel opening and are closed by the usual or * common, separate main bearing caps · If this is provided, forms the fixed half of the main bearing housing is an integral part with the tunnel frame, with the advantages and The advantages of the latter are retained and, in return, mainly the great rigidity of the closed, monolithic one Tunnel frame · The main bearing can be closed with a separate main bearing cap of conventional design.

Since in practice there is a majority of multi-cylinder machines occur, each design should primarily be suitable for this · If this is followed, the multi-cylinder crankshaft, possibly equipped with counterbalancing weights and forged flanges at one or both ends, will in practice have a circular casing.

There are therefore good reasons that the tunnel should be cylindrical, or nearly cylindrical, as it has been heretofore the practice is.

Such a design is known from the German publication 19195831. This writing refers to a very small machine of the small number type of cylinders, which are generally air-cooled, and in the power range of approximately 10 HP or PS per cylinder. The tunnel is located under the crankshaft, with any oil sump or oil pan being even deeper lies. In order to still achieve a stiff, monolithic design, one is forced to use the motor housing or the

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To extend the crankcase very deeply below the center line of the crankshaft.

For larger machines with 100 or more horsepower per cylinder, it is unrealistic to increase the size accordingly to achieve a similar, simple design. Indeed, a machine with such a deep housing could in many cases not be installed in the engine room of a ship to keep the housing or in the oil sump, but in one separate lower tank between the machine foundations and the transverse components of the ship's hull. A less extensive one Housing would then be possible. But this would conflict with necessity, an approximate one to provide constant section modulus of the transverse section around the tunnel opening.

According to the invention, the solution to this problem is a construction in which the bore for the Main bearing shells of the crankshaft in the edge of the tunnel opening located, remote from the cylinders · Furthermore, the frame according to the invention should have a high degree of rigidity around the tunnel opening, especially at the point with the greatest stress concentrations, i.e. near the edges of the tunnel on the side of the cylinder bank or banks. It's from the Dutch Patent application 71 07528, among others, known the transverse walls in the direction of the crankshaft on this side, looking at the cylinders, with the help of two plates to connect "A stiff, double-walled, closed at the base, tubular carrier results, which runs from one side of the machine to the other and perpendicular to the plane through the center lines of the cylinders and - in the case of a machine with two or more rows of cylinders - in the middle one or more sharp kinks above at least that part of the frame where the cylinders are located. Each tubular support therefore consists of an inner and an outer

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End plate, which can show a sharp curve in the middle and which is always enclosed between two transverse walls is * Over the length of the machine, the connecting tubular supports together form a long, flat box Internal transverse walls · By having the edge of the tunnel opening closest to the cylinders with the underside of the tubular support, i.e. coincident with the inner end plate, the frame according to the invention corresponds to the Requirements to have a section modulus of the transverse walls of approximately constant value around the tunnel opening, where the forces exerted by the cylinder head bolts or Cylinder head rods originate from, are transmitted via logical and shortest "paths to the main bearings, without unacceptable or inadmissible stress accumulations

If the tubular supports have well-rounded openings that are connected to one another, can it as a purge air receiver in the case of two-stroke engines to serve.

In case the cylinder head rods from the cylinder heads extending through the tubular support into the inner end plate, the tubular support is of Tensile forces infoige der.Verbrigung made free. By passing over the reinforced edge of the tunnel opening into the inner end plate can create local stress concentrations be avoided. The reinforced edge of the tunnel also merges into the integral main bearing housing, with the gas forces from the cylinder head through the cylinder head rods that inner end plate and the reinforced transverse walls are passed through the shortest route to the main bearings.

Thanks to the size of the machine, the joint in the main bearing housing can be flat as opposed to circular with tunnel frames of small dimensions

With reference to the following description of the accompanying drawings, the invention is particularly explained,

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a two-stroke V-shaped hollow piston engine is selected as an example, but it should be noted that the The invention can be applied equally to other machine types and designs without further ado.

Fig. 1 shows an ordinary tunnel frame as it is, for. B. with the machine according to the Dutch Patent 125,193 is used;

Fig. 2 shows a cross-section and partly a front view of a tunnel frame according to the invention, applied to a two-stroke hollow piston V-type engine.

For informational purposes, FIG. 1 shows a known tunnel frame as used in a V-type engine, in which the tunnel opening 1 is visible. The center of the tunnel opening coincides with the center line 2 of the crankshaft. The diameter of the opening is designed so that an assembled crankshaft can be brought into and out of the frame through the opening. The tunnel openings are in the transverse walls 3 of the frame and at least in one of the end walls. The crankshaft is either carried more or less directly in the tunnel opening by means of rollers or rollers, or is carried with the help of auxiliary structures, with their main journal or main running surfaces in the tunnel opening. Reaction forces of the rotating masses and combustion forces must be conducted from the crankshaft through the main bearings and the transverse walls. In order to guarantee that the crankshaft has a reliable bearing system, the transverse walls should not only be sufficiently strong and stable, but also sufficiently rigid. For this purpose there should be a cross-section of sufficient resistance all around the tunnel opening. This applies to points k, 5 and 6 “The integral half 8 of the main bearing housing is located in the transverse wall 3 and no longer needs to be a separate part. A very stiff or strong construction results from the main bearing housing

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comes with a well-known separate main bearing cap 9. (Figure 2) closed; in the main bearing bore the normal bearing shells 10 and 11 placed. Sufficient rigidity in the plane of the transverse walls and on all sides of the edge the tunnel opening is achieved by reinforcing and stiffening this edge by means of a reinforcement component 12, which merges at 13 on the crankshaft side in the part l4, which is the integral main bearing housing half forms, and on the opposite side at 15 merges into the inner end plates 17 and 18 of the frame · The Plates 19 and 20 serve as outer end plates. If the tunnel is moved towards the cylinders, as in Figure 1 is shown schematically until the center line of the crankshaft 2 comes to lie approximately on the edge 7 of the tunnel 1, it is clear that near point 6 there is insufficient rigidity of the transverse section, due to too small Moment of resistance

The frame, see the dotted lines in Figure 1, must be considerably reinforced and stiffened according to the invention as shown in FIG. The same tunnel design from Figure 1 is also shown here, the inner end plates 17 and 18 being provided, respectively. The outer end plates 19 and 20 (Figure 1), which the Boxes 21 and 22 in the crankshaft direction of the frame are connected to one another by plates 23 and 24, to form a tubular beam 25 with the transverse walls extending into the outer end panels. in the In the case of a V-engine, the end plates 19t form 23 and 20, a sharp curve 35 at its intersection. This tubular The carrier runs from one side 26 of the motor to the other side 27 and is closed at both extremities. Due to a sufficient distance between the inner and outer end plates 17 and 19 or 18 and 20, in turn great rigidity can be achieved on all sides of the tunnel. In this tubular carrier openings 28, 29 and 30 can be provided without impairing the rigidity, where ·! through these openings the interior of all

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tubular support parts come into connection with one another over the entire length and width of the frame while they Form a one-piece flat box · If you follow this, you can the tubular carrier 25 is provided as a purge air receiver if the engine is a two-stroke engine.

Near 15, the reinforcement strip of the tunnel opening merges into the inner end plates 17 and 18. These heavy end plates 17 and 18, which extend the entire length of the engine, thus form an integral part with the edges 12, 13 and lk of the tunnel. In order to direct the large combustion forces from the cylinder heads to the crankshaft main bearings via the shortest route with maximum rigidity, the cylinder head bolts are extended into the rigid inner end plates 17 and 18 as tie rods or connecting rods. At 31 a cylinder head is indicated, at 32 a cylinder liner surrounded by a cooling jacket, at 33 the cylinder head bolts or tie rods, a quantity of at least four per cylinder generally being fitted and being screwed into the inner end plate at 3 ^.

It should be noted that the above-mentioned and other types, which form the essence and scope of the invention can be used for welded, cast and also combined weld-cast constructions. The invention can be used on machines in line, V-machines, as shown in the example, and also on machines or motors with more than two rows of cylinders can be used · In addition, the invention can also be applied to machines other than the ordinary vertical type can be applied.

Claims

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Claims (3)

Claims . JTunnel frame for a multi-cylinder internal combustion engine, in line or with two or more rows of cylinders, with a tunnel opening in the transverse walls, the size of which is sufficient to move a crankshaft in the axial direction bring the frame in and out of it with the centerline of the main bearings near or at the edge of the Tunnel is provided, with the non-removable half of the main bearing housing is provided integrally with the reinforced edge of the tunnel opening, with half the main bearing housing is closed with a separate main bearing cap, characterized in -that the bore for the main bearing shells (10) of the crankshaft, in the edge (lA) of the tunnel opening (1) located away from the cylinders. 2. Tunnel frame according to claim 1, characterized in that the cross-sections, as is known per se, through the transverse walls show an approximately constant moment of resistance through all sides of the tunnel opening, with a tubular Support is located on the cylinder side to reinforce the lower part of the cylinder and the combustion forces to head towards the main camps, the tubular β beam extends over the entire length of the part of the frame which supports the cylinders and of one Side by side, and perpendicular to the plane provided through the cylinder centerlines, and that in the case of machines with one or more V-angles between the cylinder rows the same number of lengthways sharp curves is provided, this tubular support extending in the direction of the center line of the Cylinder extends from the edge of the tunnel opening towards the end of the transverse walls on the cylinder side. 409817/0337 3. Tunnel frame according to claim 2, characterized in that the tubular carrier produces a rounded connection Openings in the intersecting transverse walls and other internal reinforcement parts or reinforcement components having* k, tunnel frame for a two-stroke engine according to claim 3 ι characterized in that the tubular carrier functions as a scavenging air receiver. 5 tunnel frame according to one of the preceding claims, characterized in that the joints in the main bearing housing are flat, the plane passing through the joint runs through approximately the center line of the main bearing bore. 409817/0337 Blank page