Device for exhauster centralizing

Abstract

Device for pre-centering an intake system, primarily for an internal combustion engine, which device comprises a screw sleeve (13) arranged in a bore (11) of the intake system. The device is characterized in that the screw sleeve (13) has a pre-centering section (17) at the sleeve end (15) facing the cylinder head (9). à

Description

The invention relates to a device for pre-centering a suction device, which device comprises a screw sleeve placed in a bore of the suction device. The term intake system refers to any device that is located between the cylinder head and air filter of an internal combustion engine and allows fresh air or mixture to flow into the cylinder chamber. A screw sleeve is an internally threaded sleeve that is used to accommodate a stud bolt fixed in the cylinder head. Pre-centering refers to the mechanical orientation that ensures that the intake system, which is placed on the cylinder head but not yet fixed, is held in the desired position. The fastening of suction devices to cylinder heads, in particular to cylinder heads of motor vehicle engines, is known. Such a solution is shown in the patent specification DE 4221913 Cl. The fastening is usually achieved by means of conventional systems consisting of a stud and nut or a thread and screw. During assembly, it is disadvantageous that the suction device must be held on the cylinder head until it is screwed into place. Utility model patent DE 94 16 059 describes a carburettor housing that can be mounted on studs. External threaded sleeves that can be slid onto the protruding studs are screwed into the carburettor housing in such a way that the end faces of the threaded sleeves, which have holes with the same diameter as the studs, are located in the same plane as or inside the mating surface of the carburettor housing. In the larger diameter holes formed on the same axis in the threaded sleeves, nuts with an internal wrench are installed in a way that they can be displaced in the common axial direction of the studs and the holes. When the carburettor housing is slid onto the studs, the outer, smaller diameter holes of the external threaded sleeves are oriented. The disadvantage of this solution is that a separate component - the nut with an internal keyway - performs the role of fastening and a separate component - the external threaded sleeve - performs the orientation and retention role. The aim of our invention is to provide a simple design of an intake device for an internal combustion engine cylinder equipped with a device that does not need to be held when screwed onto the cylinder head, but rather simply by pushing a pre-centering section onto the stud bolt, the intake device is oriented and held at the same time. This object is achieved according to the invention in that the device comprises a screw sleeve placed in the bore of the suction device, and the screw sleeve is provided with a pre-centering section at the end facing the cylinder head. A preferred embodiment of the invention is a suction device provided with a bore for receiving the screw sleeve. The bore has an annular step or constriction, or separate constrictions arranged in an annular shape, such as eyes, on which the shoulder on the outside of the screw sleeve can preferably rest so that the screw sleeve can be pushed back when pulled onto the stud bolt so that the suction device can rest on the cylinder head while the threaded part of the stud bolt is in the pre-centering section. In addition, the screw sleeve is secured against being pushed out of the bore. In a particularly advantageous embodiment of the invention, the pre-centering section - that is, the section of the screw sleeve at the end of the screw sleeve facing the cylinder head - has an internal diameter larger than the diameter of the internal threaded section of the screw sleeve. The threaded section of the screw sleeve is that part of the screw sleeve which is between the pre-centering section and the central section of the screw sleeve and is provided with an internal thread which serves to receive the stud connecting the suction device to the cylinder head. The invention also relates to embodiments in which the screw sleeves do not have a threaded central section but consist essentially only of the pre-centering section, the threaded section and a screw sleeve head which can be gripped with a wrench. Our invention is described in more detail with reference to its exemplary embodiments with the help of the attached figures, where Fig. la. and lb. are longitudinal sections of a part of the intake device and cylinder head, Fig. Figures 2a and 2b show a longitudinal section of a screw sleeve. Figure la shows a suction device 5 consisting of an upper part 1 and a lower part 3. The suction device 5 is fixed to the cylinder head 9 with a stud bolt 7. The suction device 5 has holes 11 for fixing to the cylinder head 9, into which a screw sleeve 13 is inserted in advance to prevent loss. The end of the sleeve 15 of the screw sleeve 13 facing the cylinder head 9 is provided with a pre-centering section 17. The pre-centering section 17 is not threaded. Between the middle section 21 of the screw sleeve and the pre-centering section 17 there is a threaded section 19. At the sleeve end 23 of the screw sleeve 13 farthest from the cylinder head 9 there is a screw sleeve head 25 which can be designed as an external hexagon. The screw sleeve head 25 has an annular shoulder 27 which rests on the wall of the bore 26 of the upper part 1 of the suction device 5. The screw sleeve head 25 further receives a plastic plug which closes the screw sleeve 13 against splashing water. In order to create a connection between the suction device 5 and the cylinder head 9 - as shown in Fig. 1a -, the screw sleeve 13 is first inserted into the bore 11 of the suction device 5, preferably made of plastic, in a manner that prevents it from falling out, using the shoulder 27 and a further constriction 31 shown in Fig. 1b. The suction device 5 is then pulled onto the stud bolt 7, in particular its upper parts 8, so that the suction device 5 does not have to be held while being screwed on. In the inner bore 11, an annular constriction 31 or individual constrictions arranged in an annular manner, such as eyes, are arranged in such a way that the screw sleeve 13 can be pushed back onto the stud bolt 7 while being pulled on, but the screw sleeve 13 is prevented from being pushed out, in particular by the shoulder 22 in the transition section between the pre-centering section 17 and the threaded section 19 (Fig. 1b). The suction device 5 can thus be screwed on very quickly. The particularly long screw sleeves 13 ensure good accessibility when screwing on. In Figure 2a, the pre-centering section 17, the threaded section 19, and the central section 21 of the screw sleeve are formed. HU 221 291 Bl, 27 shoulders and 25 screw sleeve head 13. It can also be seen in Fig. 2a that the length Z of the pre-centering section 17 without an internal thread is equal to or less than the length G of the threaded section 19 with an internal thread 20. The outer diameter of the pre-centering section 17 is slightly larger than the outer diameter of the threaded section 19, and the outer diameter of the threaded section 19 is larger than the diameter of the central section 21 of the screw sleeve. The transition between the threaded section 19 and the pre-centering section 17 has an annular step or shoulder 22. The screw sleeve head 25 has an increased inner and outer diameter compared to the central section 21 of the screw sleeve. At the transition between the middle section 21 and the screw sleeve head 25, there is a further annular step 24 (Fig. 2b). The outer surface of the pre-centering section 17 and the section between the annular step 24 and the shoulder 27 guide the screw sleeve 13 in the bore. In these parts, large transverse forces can be reliably transferred to the outer annular surfaces. The shoulder 22 is arranged in such a way that the screw sleeve 13 can slide back in the bore. The screw sleeve 13 is inserted forward into the first bore 11 or 26 of the suction device 5. The slippage in the direction of the cylinder head 9 is prevented by the formation of the shoulder 27. The slippage of the screw sleeve 13 when it is pulled onto the stud bolt 7 is prevented by the formation of the annular step or shoulder 22, which comes into positive contact with the annular constriction 31 of the inner bore 11, clearly visible in Fig. 1b, and supports the screw sleeve 13 in its position. It is also clearly visible in Fig. 1a that when the suction device 5 is placed on the cylinder head 9, the upper part 8 of the stud bolt 7 can first easily penetrate the pre-centering section 17 and thus hold the suction device 5 on the cylinder head 9. The screw sleeve 13 is then tightened, and in the process the threaded section 19 of the screw sleeve 13 is screwed onto the stud bolt 7. The advantage of the suction device according to the invention is that it can be simply pulled onto the stud bolts of the cylinder head, and in the process the pre-centering sections formed on the screw sleeves provide orientation, and the constrictions or eyes machined in the holes prevent the screw sleeves from being pushed out. The suction device therefore does not have to be held when screwed on, but simply pushing the pre-centering sections of the screw sleeves onto the stud bolts holds the suction device in the desired position. The suction device can then be screwed on quickly. This advantageously allows automatic assembly, using only the holes and screw sleeves formed with constrictions or eyes, without any further machining or parts. The invention allows suction devices to be mounted particularly safely and simply on the cylinder head of an internal combustion engine.

Claims

PATENT CLAIMS 1. Device for pre-centering an intake device, primarily for an internal combustion engine, which device comprises a screw sleeve placed in the bore of the intake device, characterized in that the screw sleeve (13) is provided with a pre-centering section (17) at the end (15) of the sleeve facing the cylinder head (9).

2. Device according to claim 1, characterized in that the pre-centering section (17) is designed to receive a set screw (7).

3. Device according to claim 1 or 2, characterized in that a threaded section (19) is provided between the pre-centering section (17) and the central section (21) of the screw sleeve.

4. Device according to any one of claims 1-3, characterized in that the length (G) of the threaded section (19) is greater than or equal to the length (Z) of the pre-centering section (17).

5. Device according to any one of claims 1-4, characterized in that an external shoulder (22) is formed on the screw sleeve (13) between the pre-centering section (17) and the threaded section (19).

6. Device according to claim 5, characterized in that the screw sleeve (13) is designed to be pushed back into the bore (11) when being pulled onto the stud (7), and an annular constriction (31) or individual eyes are formed in the bore (11) to secure the screw sleeve against being pushed out and to support the annular shoulder (22) of the screw sleeve (13).