PLUG FOR A CYLINDER HOUSING

[0001] "closure cap for a cylinder case"

[0002] l'a closure cap for a cylinder case, arranging such a closure plug in a cylinder block and a cylinder case having such a closure plug.

[0003] during the production of a cylinder block of an internal combustion engine, holes are generated in the housing wall. A portion of the holes is generated by the passage of prongs to form channels in the oil pan, - and other holes are generated to form vents. - These holes must be unplugged to ensure oil tightness of the housing.

[0004] a first likelihood of clogging consists in the use of plugs screwed.

Another possibility is that of fitting of the balls in the fillings and bond them.

[0005] in one case as in the other, the plugs constitute elements having a significantly large thickness, for example of the order of 10 mm.

[0006] such a thickness of the cap implantation depth also quite significant. It is deposited there a running clearance necessary between the wall and additional elements filling multiple roles in the operation of the engine.

As an example, it is cited the play between the wall and the set timing chain that is greater than 3 mm, or the clearance between the wall and the pulley damper of the timing chain that is about 2 mm, or the clearance between the wall and the tensioning arm of the belt accessory which is of the order of 3 mm.

[0007] il result is that the shutter means for conventional drive design constraints, which are not always acceptable.

[0008] also, the purpose of the invention is to provide means for closing the holes in a cylinder case that overcomes the disadvantages mentioned before.

[0009] le to 1' invention is solved by a sealing plug for sealing a hole in a cylinder case,

which consists of a thin disk.

[0010] advantageously, the disk is provided with a chamfer.

[0011] la embodiment of such a plug for closing holes in a cylinder case so as to avoid portions or parts projecting from the housing wall.

[0012] l'absence of prominent parts or projections results in the running clearance required between the housing wall of the cylinder and other components of the internal combustion engine without impeding 1' oil seal of the housing.

[0013] this arrangement of the invention provides a closure for the least as reliable by the use of a screw-cap or a ball fitted,

or yet other means used before 1' disclosure.

[0014] le closure plug of the invention provides a reliable closure of a bore in a cylinder case merely by its shape which is that of a single disk provided with a chamfer, and thus makes it possible to press the plug into the hole of the housing with an interference fit.

[0015] en variant, a chamfer is formed on the bore of the cylinder block and/or a groove is provided in the bottom of the borehole.

[0016] l ' seal between the plug of the invention and the cylinder block may be enhanced by providing, upon placement of the plug in the hole, a sealant on the inner periphery of the hole.

By populating the housing that represents the hole for the plug to put in place, as indicated, is also operates as holding the plug in the hole by gluing. On fitting of the plug in the hole, the product of [...] is received, for the least mainly, between the chamfer of the shoulder of the bore or into the groove. This arrangement thus ensures sealing is provided.

[0017] le cap 1 'has 1' can be advantageously used in relaxed. In addition, the plug of the invention is, in particular due to its simple form, a piece that can be achieved simply and inexpensively.

It contributes further to the production of compact motors or, for the least, prevents the motors become less compact.

[0018] le aim is further achieved with an arrangement that a closure as described before in a position closing a hole in a cylinder case, as well as by a cylinder case comprising a sealing plug according to the description mentioned before.

[0019] d'other features and advantages of the present invention shall become apparent from the description herein - after a preferred embodiment of the invention.

This description is made with reference to the drawings in which: Figure 1 represents a plug of the invention in a perspective view; Figure 2 represents the plug of the invention, in a side view, in a position just before insertion into a hole in a cylinder case, Figure 3 existing exposures, in a detail of Figure 2, the cap is mounted in a hole of the invention, and Figure 4 shows the arrangement of two holes to plug on a cylinder block of an internal combustion engine. A cap 1 for plugging a hole 2 formed in a cylinder case C., 3 is constituted by a disk having a diameter d and a thickness e.

The diameter d of the disk 3 is determined so as to enable 1' introduction of the plug in the hole 2 1 with an interference fit.

[0020] l ' thickness e of the disk 3 is between 3 mm and 4 mm. This thickness corresponds to about 10% of the diameter of the disk 3.

[0021] to compensate for expansion differences between different materials, the plug 1 is made of the same material as the housing c in which the hole is formed to be closed. Thus, for an aluminum alloy housing, the cap is also made of an aluminum alloy.

In the extent possible, the plug is made of the same aluminum alloy as the casing.

[0022] le choosing the diameter of the plug 1, or disk 3, so that the plug 1 is introduced into the hole 2 of the housing c with an interference fit, already provides only a good oil seal. The coefficient of clamping, [...] to say the ratio between the difference between the two diameters, respectively of the disk 3 and the hole 2, 2 and the hole diameter can vary according to the estimated maximum oil pressure for a given engine type.

It is generally of the order of 0, 05.

[0023] to improve this seal still further, and to provide a holding function by gluing, a sealant, e.g. [...]<(R)> 129078, is deposited in the housing constituting the hole 2 and for reception of the plug 1. on fitting, the sealant is pushed back into the insertion taper, as shown in Figure 3. more particularly, the sealant is received, at least primarily, between the chamfer of the shoulder of the bore and thus ensures 1' seal.