DE102005030914A1 - Combustion engine camshaft wear and functional test procedure views camshaft under stroboscopic lighting through transparent windows in valve cover - Google Patents

Abstract

A combustion engine camshaft wear and functional test procedure views the wear and function under stroboscopic lighting through a transparent region (28a-28d) in the engine wall or cover (10) for optical comparison of preset markers between drive chains(17), drive belts and camshaft (18) toothed wheels (20a, b), camshaft adjusters or bearings. Independent claims are included for an engine valve cover with transparent region allowing functional operation to be observed using a stroboscopic lamp.

Description

Technical area

The The invention relates to a method for testing wear and / or wear the function of functional elements of an internal combustion engine according to the features of claim 1. Furthermore, the invention relates a valve chamber cover for use in the above-mentioned internal combustion engine according to the features of claim 8

Of the Valve chamber cover closes the upper part of an internal combustion engine and usually has an oil filler neck as well as an opening to exit the blow-by gases. Furthermore, they are so far known solutions in the range of the valve chamber cover from a single, firm and not made of transparent material. As materials are currently Metals (aluminum, magnesium, steel sheet) or plastic (thermosets, Thermoplastics) used. The valve chamber covers protect and hide generally the valvetrain consisting of toothed belt or timing chain, Camshafts, camshaft adjusting drives and the valves themselves. Da here for lubrication oil is used and the parts in the operation of the internal combustion engine partly operated at high speeds, it comes here to splashing oil, why the valve chamber cover tight with the cylinder head of the engine connected is. Modern valve trains do not need these days anymore be serviced or adjusted. Only wearing part here is the timing belt or timing chain used regularly at the Service tested or have to be exchanged. The review of a Timing chain therefore always requires a lot of effort, since this is the Valve chamber cover must be dismantled. As this is often called component carrier is used, for example Components like harnesses, Sensors, Saugrohrabstützungen, Design and acoustic cover, ignition cable, spark etc. results in an immense time factor alone for the wear test of Valve train. When worn in the Camshaft bearing catches at high speeds due to wear-dependent bearing clearance of the rear Area of the camshaft, so the area opposite the timing belt or the Timing chain to swing on. This can be up to a tearing of the Cylinder head in this area due to the increased load to lead. Again, it is currently necessary to reduce the valve cover order to check the bearing clearance. Another disadvantage is that certain problem cases preferred must be tested with the internal combustion engine, which is disassembled Valve chamber cover not possible is.

task The invention therefore provides a test method and a valve chamber cover indicate which one exam the function or the wear of functional elements in the assembled state of the internal combustion engine allow. This object is achieved by the features of claims 1 and 8 solved.

Disclosure of the invention

According to the invention the exam of wear and / or the function of functional elements of an internal combustion engine, which in the cover of the same are arranged, by a for the human Eye transparent area within the housing wall or the cover. The cover or housing wall is preferably a valve chamber cover and the functional elements can For example, a timing chain, a belt drive, the camshaft, be an adjustment of the camshaft or the valves themselves. By Integration of one or more transparent areas in the valve chamber cover becomes the view of the components in the cylinder head such as valve train or chain drive released. So now they can visually too on the running engine before and after adjustments to the valve train, For example, an exchange of the timing chain, to be checked. Special advantages offers this control option Internal combustion engines, which integrated a valve chamber cover Camshaft bearings do not have, since these engines in the workshop, not or can be disassembled only with great effort and into the production plant must be returned. In addition to the rigid valve trains, this is a visual check option also especially suitable for testing Variable valve trains, since the function of the servomotor is also checked here can. The mechanical end stops The actuators are currently the boundary points of the variable Valve timing, therefore, need these components with very tight tolerances and high costs getting produced. By a visual visual examination exists the possibility after assembly after the coincidence of all actual component tolerances for Example to approach two reference points and this point in the engine management save. This software adjustment does not only provide for the initial installation Advantages but also in case of service in the workshop. Furthermore can also the vibration behavior of the camshaft in the area of not through the timing belt or timing chain specified bearing visually inspected while the internal combustion engine is running.

Another advantage, especially today, is to use these transparent areas for styling purposes. This transparent example They allow a view of the inside of the engine and of moving components, allowing technology to be demonstrated and experienced. The visual check for wear or function thus takes place through the transparent area in the valve chamber cover, wherein, for example, comparisons between fixed points and markings of different parts can be made to one another or different tolerance fields can be matched against one another.

According to one advantageous embodiment of the invention, the function and / or the wear between Drive chain or drive belt and the sprocket of the camshaft on a optical comparison of specified markings on the drive chain and drive the belt and sprocket of the camshaft.

According to one advantageous embodiment is in the range of the transparent area the housing wall or the wall cover a light source arranged. This can in the outer environment the housing wall or the cover, or preferably inside or behind be arranged the cover. It is by means of this light source now possible to illuminate the area of interest of the functional element. To activate the light source is provided that this on the opening of a Engine cover, preferably the hood activated becomes. This means So that in the standard driving mode the light source is switched off and only when the vehicle is stationary and opened Hood the light source is turned on automatically.

to exam of rotating parts in operation is according to an embodiment of the invention a stroboscopic lamp in the area of the transparent area of the housing wall or the cover arranged. Especially when it comes to rotating or To test oscillating functional elements, it is advantageous if a stroboscopic lamp with a corresponding to the oscillation or rotation Frequency illuminates the functional element. This can be done then visualize the high-frequency movements. The activation the stroboscopic lamp during operation of the internal combustion engine can in this case via the Engine control unit respectively. Again, the stroboscope lamp inside the housing wall or be arranged behind the cover or outside illuminate the cover and through the transparent area into the interior.

alternative to do so the stroboscopic lamp during operation of the internal combustion engine via a external test device, which is connected, for example, to a diagnostic connector in the engine compartment activate.

The Cover according to the invention for an internal combustion engine, preferably a valve chamber cover, has a housing, which covers certain functional elements. The housing can made of plastic or metal and covers functional elements such as the crank mechanism or certain actuators. A predetermined area within the housing is there for the human eye designed transparent, such that at least one functional element from the outside can be visually checked through the transparent area. The exam can doing so on wear or to function. Partly inside the cover, there may be spattering oil or oil vapor can, it is beneficial the inside of the transparent area by a coating, for example nanocoating, with a lotus effect to provide. This will cause adhesion of, for example, oil or oil mist prevents the transparent area, so that the view in or after the operation of the internal combustion engine is not blocked.

According to one advantageous embodiment of the invention is the transparent area formed of transparent material, which in an opening of the Cover is inserted and connected to this releasably or permanently becomes. The connection can be over a screw or Adhesive bond in metal or thermoset covers done, wherein in certain cases also provided a seal between certain windows and cover must become. The transparent window can be made of glass or Be made of plastic. For thermoplastic covers, the or the window also welded be, for example, over Vibratory, ultrasonic or rotary welding process.

According to one Another embodiment of the invention, the cover in the area the transparent area inside the cover is a light source and / or a stroboscopic lamp. However, it is also possible that Luminous source and / or stroboscopic lamp to be arranged outside the cover, it must be ensured be that to be tested Functional element through the transparent area through the light source and / or the stroboscopic lamp can be illuminated.

Here, it is advantageous that in the arrangement of the light source and / or the stroboscopic lamp inside the cover here at least one protective rib is arranged, such that the protective rib reduces contamination of the light source and / or the stroboscopic lamp during operation of the internal combustion engine. This protective rib can also serve to reinforce the cover, since transparent plastics should not contain glass fibers because of the resulting turbidity, should the rigidity of the cover over the body are provided. Here, increased stiffening measures may be necessary. The stiffening measures can then be designed so that they can be used simultaneously as a splash guard. In this case, the protective ribs should be arranged such that a direct impact of oil splashes on the light source and / or stroboscopic lamp is avoided.

According to one advantageous embodiment of the invention, the cover further a crankcase gas vent on, wherein the light source and / or the stroboscopic lamp inside the Cover disposed in a range of the crankcase gas vent volume flow is. This particular type of arrangement turns out to be advantageous, thus no dirt deposits on the light source and / or the Strobe lamp can adhere. Possible Dirt deposits are entrained by the crankcase ventilation volume flow.

The The above-mentioned protective rib can also be arranged in such a way that the protective rib contamination of the transparent area reduced or prevented in the field of internal combustion engine.

Farther it is also possible the transparent area through the arrangement in the crankcase ventilation volume flow to protect against the adhesion of dirt particles.

These and further features of preferred embodiments of the invention go out from the claims also from the description and the drawings, wherein the individual features each for alone or in the form of subcombinations the embodiment of the invention and in other fields be realized and advantageous also for protectable versions can represent for the protection is claimed here.

Short description of drawings

1 shows a schematic view of the housing cover including crank operation,

2 shows schematically the test of the camshaft and

3 Checking the camshaft drive wheel.

Embodiment (s) of the invention

The 1 shows a valve chamber cover 10 , which is a crank mechanism 11 covers. Here is the valve chamber cover 10 with a cylinder head and engine block, not shown here, sealingly connected, since the upper part of the crank mechanism 11 lubricated with oil. The crank mechanism 11 has a flywheel 12 on which with a crankshaft 13 connected is. The crankshaft 13 is about pistons 14 , which over connecting rods 15 with the crankshaft 13 connected are driven. At the opposite end of the crankshaft, this has a chain drive 16 on, which via a timing chain 17 a first camshaft wheel 18 drives. The first camshaft sprocket 18 is via a tooth connection with a second camshaft sprocket 19 connected. These two camshaft gears 18 . 19 drive two camshafts 20a . 20b at. These camshafts are in camshaft bearings 21 stored. The camshafts 20a . 20b act on hydraulic tappets 22 , which then intake or exhaust valves 23 drive. The valve chamber cover has several screw connections all around 24 for tight connection with the cylinder head, not shown. Furthermore, an oil filler neck and an insert for a crankcase gas venting unit 26 on. In the middle of the valve chamber cover are more spark plug openings 27 arranged, wherein the openings substantially between the camshafts 20a . 20b are arranged. Furthermore, the valve chamber cover 10 different transparent areas 28a , b, c, d. The valve chamber cover 10 can consist of different materials. For metal and thermoset hoods, the transparent areas 28a , b, c, d are screwed or glued as glass or plastic windows. For bolted solutions, a seal must be placed between the window and the valve chamber cover. For thermoplastic valve chamber lids, the chambers can also be welded. For example, vibration ultrasound or spin welding methods are available here. Since transparent plastics are not allowed to contain glass fibers because of the haze that results, the stiffness of the valve chamber cover must be provided above the base body. Here, increased stiffening measures may be necessary. These stiffening measures can be designed in the lower area not shown here in such a way that they simultaneously as splash protection for the transparent area 28a , b. c, d can be used. For thermoplastic valve chamber covers 10 The service window can also be introduced through a 2-K process. Since transparent materials are often very different from the valve chamber cover materials, the surface should possibly be prepared by a plasma process before the 2-component process so that a gas-tight connection of the two materials is achieved. Through the transparent areas 28a -d Various points of the crank mechanism can be observed or tested for wear. The window 28a For example, allows the view of a camshaft bearing, which is arranged opposite to the camshaft gears, since here is the largest flutter tendency of the camshaft 20a , b can occur. The window 28b can be used, for example, for styling effects, especially in view of the ever-increasing tuning scene, this would have the effect here, with the engine running, the entire width of the camshaft 20a to see in operation. The window 28c and d allow a look at the connection between the drive chain 17 and camshaft sprocket 18 , in which case the chain wear can be determined in the assembled state.

The 2 shows a detail of the end of the camshaft 20a when driving the hydraulic tappet 22 , By appropriate arrangement of a transparent area 28a , b, c, d can be here by comparing the position of the camshaft 20a to the hydraulic tappet 22 Check a camshaft adjustment during operation of the internal combustion engine. This is done either with a stroboscopic lamp from the outside through the transparent area or through one in the valve chamber cover 10 arranged stroboscopic lamp a comparison between a marker 30 on the camshaft 20a opposite a tolerance field 31 on the hydraulic tappet 22 to be pulled. The mark can 30 aware of a cam 29 the camshaft 20a be aligned or as here, for example, be arranged at a 90 ° angle thereto. The width of the tolerance field 31 Can be designed according to the specifications and specifications of the engine manufacturer, so that in sensitive vehicles quite a very narrow tolerance field 31 is conceivable. In this connection is also good the connection between the valve chamber cover 10 and cylinder head 32 to recognize.

The 3 shows an example for realizing the check of the chain wear by one of the transparent areas 28c or d. The camshaft wheel 18 has several openings distributed over the circumference 35 which serves mainly for weight saving. The timing chain 17 has a special chain link 33 on. This has deviating from the other chain links a down-facing cam 34 on, which at new timing chain 17 concentric inside one of the openings 35 of the camshaft wheel 18 located. Should it during operation of the internal combustion engine to a wear-related elongation of the timing chain 17 come, so the cam moves 34 of the chain link 33 from the previously concentric arrangement to the opening 35 out, so that easily and quickly chain wear can be detected in the assembled state of the internal combustion engine.

Claims (14)

Method for testing wear and / or the function of functional elements of an internal combustion engine, wherein the functional elements are arranged within housing walls or behind covers of the internal combustion engine, characterized in that the wear and / or the function by a transparent to the human eye area within the housing wall or the cover is made. Method according to claim 1, characterized in that that the functional element is a drive chain or a drive belt a camshaft of the internal combustion engine, wherein the function and / or the wear over one optical comparison of predetermined markings between drive chain or the drive belt and sprocket of the camshaft is checked. Method according to claim 1, characterized in that that the functional part is an actuating element, in particular a camshaft actuating element, is, where the function over an optical comparison of predetermined marks between the to be adjusted element, preferably a camshaft and a this fixed element, preferably a valve is tested. Method according to claim 1, characterized in that that the functional part is a camshaft bearing, wherein the function and / or the wear over one optical test during operation of the camshaft through the optically transparent Area in the area of the non-driven end of the camshaft checked becomes. Method according to one of the preceding claims, characterized characterized in that a light source in the region of the transparent Area, in particular in the interior of the housing or behind the Cover, is arranged, the lighting when opening a Engine cover, in particular the hood activated becomes. Method according to one of the preceding claims, characterized marked for testing of rotating parts in operation a stroboscopic lamp in the area the transparent area is arranged, wherein the stroboscopic lamp activated during operation of the internal combustion engine via an engine control unit becomes. Method according to one of Claims 1 to 5, characterized in that a stroboscopic lamp is arranged in the region of the transparent region for testing parts which rotate during operation, the stroboscopic lamp being operated during operation of the focal engine is activated via an external test device. Cover for an internal combustion engine, preferably valve chamber cover, comprising a housing, which covers certain functional elements, characterized that a given range for the human eye is transparent, such that at least one Functional element from outside can be visually checked through the transparent area. Cover according to claim 8, characterized in that that the transparent area through a window of transparent Material is formed, this being inserted into an opening of the cover is and with this solvable or unsolvable connected is. Cover according to one of claims 8 to 9, characterized that in the region of the transparent region, preferably in the interior of the Cover, a light source and / or a stroboscopic lamp arranged is. Cover according to claim 10, characterized in that that inside the cover in the area of the light source and / or the stroboscopic lamp is arranged at least one protective rib, such that the protective rib pollution of the light source and / or the stroboscopic lamp is reduced during operation of the internal combustion engine. Cover according to one of claims 10 to 11, characterized that the cover further comprises a crankcase gas vent, wherein the light source and / or the strobe lamp inside the cover in an area the crankcase gas vent volume flow is arranged. Cover according to one of claims 8 to 12, characterized that inside the cover in the region of the transparent area at least a protective rib is arranged, such that the protective rib a Contamination of the transparent area during operation of the internal combustion engine reduced. Cover according to one of claims 8 to 13, characterized in that the cover further comprises a crankcase gas vent, wherein the transparent Area inside the cover in a range of crankcase gas ventilation volume flow is arranged.