EP1109992B1 - Control device for camshaft systems - Google Patents

Abstract

The present invention relates to a control device for the camshaft systems of an internal combustion engine comprising n V-shaped cylinder benches. The control device comprises a distribution system with a first distribution gear (14) intermeshing with an output gear (12) mounted on the crankshaft (10) of the internal combustion engine. To this end, the distribution configuration comprises m∫n secondary distribution gears (16, 18) that intermesh with the first distribution gear (14) and transmit a driving force to the n camshaft systems (34) of the n cylinder benches through n endless-chain drives (32).

Description

The invention relates to a control drive for a camshaft arrangement Internal combustion engine with n V-shaped cylinder banks, the Control drive has a distributor wheel arrangement with a first distributor gear, which with an output gear arranged on a crankshaft of the internal combustion engine combs, according to the preamble of claim 1.

A generic center drive is from US 4,671,223 for an internal combustion engine of a motorcycle known. Here, a pure gear drive is realized, each Camshaft arrangement of a cylinder bank assigned its own distributor wheel arrangement is. The gears of the respective distributor wheel arrangement are in a respective frame supported. The pure gear drive has the disadvantage that it generates very strong noises. Furthermore, this arrangement is by a separate drive train for each Mechanically camshaft arrangement and requires a large amount of installation space. On Center output for the control drive of an internal combustion engine for a motor vehicle would be included this arrangement is not practicable because all cylinder banks have at least one Should have division. However, this would result in considerable mechanical Weakening of the engine block lead to what occurs in motor vehicles Torques and forces would not be tolerable.

A central control output is also from the article "The Porsche 4.5I racing car type 917 "by Dipl.-Ing. H. Metzger, published in DE-Z reprint ATZ, Automobiltechnische Zeitschrift, 71st year No. 9/12/1969, pages 313 to 320 for one air-cooled four-stroke engine with two flat-lying cylinder rows known, which is special is designed for racing purposes. Four camshafts are driven by one Center output gear of the crankshaft to both cylinder rows over five needle bearing, straight toothed gears. In other words, each row of cylinders is one own control gear assigned. The respective five between crankshaft and camshafts arranged gears are arranged in a respective gear housing, which on a crankcase is screwable. This is also a pure one Gear drive, which has the aforementioned disadvantage that it is too significant Noise is coming. For a racing car for a brand world championship this may be uncritical for a comfortable motor vehicle for everyday use in the however, this is not acceptable on public roads.

A camshaft drive of a V engine is also off known from EP 0 406 528.

The present invention is therefore based on the object of a simple control drive to provide the above-mentioned type with a small space requirement, the the disadvantages mentioned above are overcome.

This object is achieved by a control drive of the above. Kind of with the in Characteristics characterized claim 1 solved. Advantageous embodiments of the Invention are specified in the dependent claims.

For this purpose, it is provided according to the invention that the distributor wheel arrangement m <n second Has distributor wheels, which mesh with the first distributor gear and one Drive energy via n endless chain drives to the n camshaft arrangements of the n Transfer cylinder banks.

This has the advantage that with a single, for example, from the middle of the Internal combustion engine elevating distributor wheel assembly all camshaft assemblies respective cylinder can be driven. This advantageously simplifies one mechanical construction of the control drive and reduces space requirements and weight.

A particularly space-saving center drive for the timing drive can be achieved by that the driven gear is arranged centrally on the crankshaft.

Expediently, m = n-1 or m = n-2, particularly preferably n = 2, 3 or 4 is.

The first and second distributor wheels are in one for easy assembly arranged common carrier, which is pre-assembled on a crankcase Internal combustion engine is attachable. For example, with a center drive for the The control drive is a result of the support screwed onto the crankcase additional stiffening of the engine block, which by appropriate for the Center drive required recesses is mechanically weakened per se.

A simple assembly of the control drive, for example in a recess in a crankcase for a center drive is achieved by the fact that between each second transfer gear and each camshaft assembly a chain endless drive supporting module is provided, the module in a preassembled manner at one end a frictionally coaxially mountable with the respective second distributor gear Sprocket and at least one camshaft gear on an opposite side carries, the endless chain drive wrapping around the sprocket and the camshaft gear.

A suitable gear ratio is expediently obtained from the crankshaft to the respective camshaft arrangement in that a tooth ratio of two Distribution gear to sprocket is chosen such that there is a gear ratio of the crankshaft to the camshaft arrangement of 2: 1 results.

A safe management of the chain of the chain endless drive is achieved by the fact that Module has a U-shaped guide plate for the endless chain drive on the lost side.

A safe and force-fitting running of the chain of the chain endless drive with little mechanical wear and low noise are achieved by the fact that Module has a chain tensioning device on the load side.

Fig. 1

eine bevorzugte Ausführungsform eines erfindungsgemäßen Steuertriebes in Vorderansicht,

Fig. 2

in perspektivischer Ansicht,

Fig. 3

einen Träger für eine Verteilerradanordnung eines erfindungsgemäßen Steuertriebes in Vorderansicht,

Fig. 4

in Aufsicht,

Fig. 5

in einer Schnittansicht entlang Linie A-A von Fig. 3,

Fig. 6

in einer Schnittansicht entlang Linie B-B von Fig. 3 und

Fig. 7

ein Modul eines erfindungsgemäßen Steuertriebes in Seitenansicht.

Further features, advantages and advantageous embodiments of the invention result from the dependent claims and from the following description of an embodiment of the invention with reference to the accompanying drawings. These show in

Fig. 1

a preferred embodiment of a control drive according to the invention in front view,

Fig. 2

in perspective view,

Fig. 3

1 shows a carrier for a distributor wheel arrangement of a control drive according to the invention in front view,

Fig. 4

under supervision,

Fig. 5

in a sectional view along line AA of Fig. 3,

Fig. 6

in a sectional view along line BB of Fig. 3 and

Fig. 7

a module of a control drive according to the invention in side view.

The preferred embodiment shown in FIGS. 1 and 2 of an inventive Control drive comprises an output gear 12 arranged on a crankshaft 10 which meshes with a first distributor gear 14. With one with the first Distribution gear 14 frictionally coupled distribution gear 42 mesh two second Distribution gears 16 and 18, which are coaxially non-positively with chain wheels 20, 22 and 24 respective modules 26, 28 and 30 are arranged, only those in FIGS. 1 and 2 Intermediate gears 20 and 24 are visible. The sprocket 22 is hidden behind the Sprocket 20 (see Fig. 5).

Power is transmitted to each of the respective chain endless drives 32 Camshaft gears 34, which with corresponding camshafts, not shown are non-positively connected. The modules 26, 28 and 30 each carry the respective ones Sprockets 20, 22, 24 at one end and camshaft sprockets 34 at one opposite end, the respective chain endless drive 32, the chain wheels 20, 22nd or 24 and the associated camshaft gears 34. About the Chain endless drives 32 are essentially vibration-decoupled or vibration-damped power transmission.

In the embodiment shown in Fig. 1, the output gear 12 meshes Crankshaft 10 additionally with a further distributor gear 35, which has a meshed gear 33 meshes with a first intermediate gear 36, which in turn meshes with a second intermediate gear 38. The second Intermediate gear 38 in turn does not mesh with a drive gear 40 Oil pump shown, so that simultaneously from the crankshaft 10 via the Output gear 12, the oil pump is driven. For example, this includes Transfer gear 35 thirty-seven teeth, the first idler gear 36 eighteen Teeth, the second idler gear 38 eighteen teeth, and the drive gear 40 eighteen teeth.

For the timing drive from the crankshaft 10 to the camshaft sprockets Gear ratio of 2: 1 required. For example, this is thirty-eight Teeth on the output gear 12, sixty-four teeth on a smaller ring gear 42 of intermediate gear 14, fifty-seven teeth on the second Transfer gears 16, 18, eighteen teeth on the sprockets 20, 22, 24 and thirty-two teeth achieved on the camshaft sprockets 32.

The embodiment of a control drive according to the invention shown in FIGS. 1 and 2 is for an internal combustion engine with three rows of cylinders arranged in a V-shape, hereinafter referred to as A, B and C, each module 26, 28 and 30 one Row of cylinders A, B or C or a respective camshaft arrangement of a row of cylinders A, B or C is assigned. It is immediately apparent that with only one transfer gear arrangement 14, 16, 18 actuated all three camshaft arrangements of the three rows of cylinders become. As a result, the arrangement shown as an example is particularly suitable for one Center drive suitable for the control drive, since it leads out of the control drive Crankshaft 10 away, that is from an inner region of a crankcase, not shown, only one of the cylinder rows to the outer camshaft gearwheels 34, namely the middle row of cylinders B must have a central recess or subdivision. The Adjacent rows of cylinders A and C can be undivided as continuous rows of cylinders A, C are trained. The camshaft sprockets 34 of the two neighboring ones Cylinder rows A and C are also from the central row B uplifting modules 26 and 30 actuated.

The first and second transfer gears 14, 16 and 18 are as shown in FIGS. 3 and 4 can be seen, arranged in a common carrier 44. This carrier 44 holds the first Transfer gear 14 and the second transfer gears 16 and 18, the carrier For example, pre-assembled in a recess or division of the central cylinder bank B. can be used and screwed to the crankcase. On the carrier 44 are also respective slide-in guides 46, 48 and 50 are each formed for the modules 26, 28 and 30. In these insertion guides 46, 48 and 50 are 44 after the attachment of the carrier the modules 26, 28 and 30 to the crankcase, each with preassembled sprockets 20, 22 and 24 as well as preassembled camshaft sprockets 34 and endless chain drive 32 insertable. As soon as all the gears are in their predetermined location, they are there can be rotatably fixed with the corresponding shaft and bearings.

This results for the chain wheels 20, 22 together with the second distributor gear 16 from Fig. 5. These gears 16, 20 and 22 are in the assembled state on a common shaft 52 frictionally connected to each other, one Central screw 54 fixed this arrangement. The shaft 52 is opposite the carrier 44 mounted rotatably by means of ball bearings 56. The central screw also fastens a gear 58, which serves as a drive for a water pump, not shown.

Fig. 6 illustrates the arrangement of the second transfer gear 18 with the sprocket 24 in assembled condition. Here, a shaft 60 is provided, which of two Central screws 62 and 64 is set. The central screw 64 also holds a gear 66, which serves to drive a further water pump, not shown. The Both of the aforementioned water pumps are, for example, directly adjacent to the carrier 44 in respective V-shaped spaces between the cylinder rows A and B or B and C arranged such that the drive gears directly with the respective gears 58th or 66 comb.

7 illustrates the module 26 for the cylinder bank A by way of example. This module 26 comprises a frame 68 and a run-side, U-shaped guide plate 70 with a Tread 72 for the chain of the chain endless drive, not shown in FIG. 7. In pre-assembled condition, the chain wraps around the sprocket 20 and Camshaft gears 34 and holds them to the frame 68, with no other Attachment for the sprocket 20 and the camshaft sprockets 34 is provided. First after this. Installation or insertion of the modules 26, 28 and 30 are finally done by means of corresponding waves, such as the aforementioned waves 52 and 60 for the Sprockets 20, 22 and 24, rotatably fixed. For example, on the load side is one Chain tensioning device 72 is provided, as can be seen in FIG. 2.

Claims (9)

1. Control device for camshaft systems of an internal combustion engine with n banks of cylinders arranged in a V-shaped configuration, the control device having a distribution system with a first distributor gear (14), which intermeshes with an output gear (12) arranged on a crankshaft (10) of the internal combustion engine, characterized in that the distribution system has m < n secondary distributor gears (16, 18), which intermesh with the first distributor gear (14) and transmit a driving force to the n camshaft systems (34) of the n banks of cylinders through n endless-chain drives (32).
2. Control device according to Claim 1, characterized in that the drive gear (12) is arranged centrally on the crankshaft (10).
3. Control device according to Claim 1 or 2, characterized in that m = n-1 or m = n-2.
4. Control device according to one of the preceding claims, characterized in that n = 2,3 or 4.
5. Control device according to one of the preceding claims, characterized in that the first and the secondary distributor gears (14, 16, 18) are arranged in a common carrier (44), which when pre-assembled can be fixed to a crankcase of the internal combustion engine.
6. Control device according to one of the preceding claims, characterized in that a module (26, 28, 30) that carries the endless-chain drive (32) is provided between each secondary distributor gear (16, 18) and each camshaft system, the module (26, 28, 30) being pre-assembled so that it carries a chain sprocket (20, 22, 24), which can be frictionally and coaxially fitted to the respective secondary distributor gear (16, 18), at one end and at least one camshaft gear (34) on an opposite side, the endless-chain drive (32) passing around the chain sprocket (20, 22, 24) and the camshaft gear (34).
7. Control device according to Claim 6, characterized in that a tooth ratio of secondary distributor gear (16, 18) to chain sprocket (20, 22, 24) is selected such that a crankshaft (10) to camshaft system (34) transmission ratio of 2:1 is obtained.
8. Control device according to Claim 6 or 7, characterized in that the module (26, 28, 30) has a U-shaped guide plate (70) for the endless-chain drive (32) on the idle strand side.
9. Control device according to one of Claims 6 to 8, characterized in that the module (26, 28, 30) has a chain-tensioning fixture (72) on the load strand side.

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