Device for connecting mechanical parts to the body of a motor vehicle

Abstract: A device for screwing to the floor (1) from below, a mechanical part (5) which has previously been placed against the underside of the floor (1) of a motor vehicle body, provides for the mechanical part(5)which is to be connected to be arranged so that at least one reference pin (7) projects upwardly to engage a corresponding reference hole (4a) in a wall (4) of the body floor (1) from below. The reference pin (7) has a through-hole (11). A sleeve (12) with an upper end portion of smaller diameter is fixed to the upper side of the wall (4) of the body floor (1), coaxially with the reference hole (4a), and defines a threaded hole (14) for engagement by a screw (15) which can be inserted through the hole (11) in the reference pin (7) from beneath. The sleeve (12) also includes a base portion of larger diameter for receiving the outer surface of the part of the reference pin (7) which projects above the said wall (4) of the floor (1) through the reference hole (4a) so as to allow the centering of the threaded hole (14) which is to be engaged by the screw (15) with the hole (11) in the reference pin (7). When the mechanical part (5) has to be connected to the floor (1) with the interposition of a block of elastomeric material, the reference pin (7) may be an integral part of the metal reinforcement of the block.

Description: The present invention relates to an assembly according to the preamble of enclosed claim 1. An assembly of this kind is disclosed in WO-A-87 05 976, wherein the sleeve is fixed above the floor by means of the threaded connection between the screw and the sleeve. Therefore an anti-rotation tool has to be used in order to avoid the rotation of the screw, when the sleeve is therein threaded. Thus both screw and sleeve must be manipulated during the screwing operation. Recently, a tendency has developed in the art to pre-assemble the mechanical components of a motor vehicle, such as, for example, the suspension members, usually by the assembly of the various parts on auxiliary, pre-assembly frames, and then to mount the auxiliary frames carrying the pre-assembled unit on the motor vehicle body with automatic equipment. One example of an embodiment of this type, which relates to the case of a rear suspension system mounted beneath the floor of the motor vehicle body from below, is illustrated in the earlier European patent application No. EP-A-0 373 125 filed by the same Applicant and designating the same inventor as in the present application. In embodiments of this type, the fixing of the are-assembled system under the floor of the motor vehicle body is effected by screwing from beneath with the aid of automatic screwing devices. The object of the present invention is to provide an assembly which enables the pre-assembled system to be assembled on the body in a particularly simple and easy manner, whether directly or with the interposition of elastic bushes and with the aid of automatic screwing devices. In order to achieve this object, the invention provides an assembly according to claim 1. The said arrangement can also be used when the mechanical part to be connected has to be fixed to the body with the interposition of an elastic block. In this case, the reference pin may be an integral part of the metallic reinforcement of the block. As will become apparent from the description above, a characteristic of the assembly according to the invention is that the reference pins used to centre the mechanical parts on the body also constitute part of the fixing device. The device enables the elements to be assembled and positioned correctly without the need for further reference parts. Further characteristics and advantages of the invention will become apparent from the description which follows with reference to the appended drawings, provided purely by way of non-limiting example, in which: Figure 1 is a cross-section of a first embodiment of a connecting device of the invention, Figure 2 shows part of the device of Figure 1, Figure 3 illustrates a further part of the device of Figure 1, and Figure 4 illustrates a second embodiment of the device of the invention. With reference to Figure 1, part of the floor of a motor vehicle body is indicated 1 and includes a flat panel 2 and a longitudinal member 3 constituted by a profiled section with longitudinal flanges 3a welded to the flat panel 2 and a central longitudinal wall 4. A mechanical part 5, for example, a metal sheet forming part of a pre-assembled frame on which the rear suspension of the motor vehicle has been assembled, is fixed to the wall portion 4 by a device 6 according to the present invention. With reference to Figure 2 as well, the device 6 includes a reference pin 7 having at its lower end a head 8 welded to the sheet 5 and having a shank 9 inserted through a hole 10 in the sheet 5. Naturally, the reference pin 7 may be fixed to the sheet 5 in any other manner, for example by interference. The reference pin 7 has an axial through-hole 11. The device further includes a sleeve 12 having an upper end portion 13 of smaller diameter whose inner surface defines a threaded hole 14 for engagement by a fixing screw 15 intended to be inserted through the hole 11 in the reference pin 7 from below and having a head 16 which bears against the head 8 of the reference pin 7 with the interposition of a washer 17. The sleeve 12 further includes a base portion 18 of larger diameter which is connected to the portion 13 by an intermediate conical portion 19. The inner cylindrical surface 20 of the base portion 18 of the sleeve 12 is arranged to receive the outer surface of the part of the reference pin 7 which projects above the sheet 5. In order to facilitate this reception, the end portion of the pin 7 has an outer frusto-conical surface 7a. The sleeve 12 opens above the reference pin 7 to enable the automatic centering of the threaded hole 14 with the through-hole 11 in the reference pin 7 so as to enable the screw 15 to engage the threaded hole 14 correctly on assembly. Finally, the sleeve 12 has an annular base flange 21 which is welded to the inner surface of the wall portion 4. The fact that the sleeve 13 bears against the wall portion 4 through the annular flange, together with the fact that the reference pin 7 bears against the wall 5 through the head 8, enables the load exerted by the screw 15 to be transferred to a relatively extensive bearing surface once it has been tightened. The traction exerted by the bolt is thus divided satisfactorily between the various parts of the connection. The pull of the bolt thus has good elasticity and hence the fixing is reliable. As already mentioned above, the reference pins 7, as well as fulfilling the function of providing easy centering of the mechanical part on the body, also constitute an integral part of the connecting device. Finally, the fitting of the sleeve 12 onto the reference pin 7 makes the assembly and the fixing by means of the screw 15 quick and easy. Figure 4 relates to the case in which the mechanical part 5 has to be fixed to the wall portion 4 with the interposition of a rubber block 22. The rubber block 22 comprises an annular rubber member 23 the outer surface of which is vulcanised onto an annular appendage 5a of the part 5 and the inner surface of which is vulcanised onto a tubular metal reinforcement 24 having an end ring 25. In this case, the reference pin 7 constitutes an integral part of the reinforcement 24. The screw 15 passes through and is longer than the hole 11 in the reinforcement 24. The head 16 of the screw 15 bears against the end surface of the rubber ring 23 with the interposition of the metal plate 26. Naturally the constructional details of embodiment may be varied with respect to those described and illustrated without thereby departing from the scope of the present invention as defined by claim 1.

Claims: Assembly comprising a floor (1) and a mechanical part (5) to be connected beneath the floor (1), the mechanical part (5) to be connected carrying at least one reference pin (7) provided with a through-hole (11) and projecting upwardly and arranged for insertion through a hole (4a) in a wall portion (4) of the floor (1) from beneath, and a sleeve (12) being placed above the wall portion (4) of the floor (1), coaxially with the hole (4a) in the wall portion (4), and having an upper end portion (13) of smaller diameter defining a threaded hole (14) for engagement by a screw (15) which can be inserted through the hole (11) in the reference pin (7) from beneath, and a base portion (18) of larger diameter arranged to receive the outer surface of the part of the reference pin (7) which projects above the wall portion (4) of the floor (1) so as to allow the centering of the threaded hole (14) with the hole (11) in the reference pin (7), said assembly being characterised in that the sleeve (12) is non-releasably fixed to the upper side of the wall portion (4), so as to allow the connection of the mechanical part (5) to the floor (1) by screwing from below and in that said floor (1) is part of a motor vehicle body. Assembly according to Claim 1, characterised in that the reference pin (7) comprises a head (8) at its lower end and a shank (9) inserted through a hole (10) formed in the wall portion (4) of the part to be connected, the outer surface of the shank (9) having a conical end portion (7a). Assembly according to Claim 1, characterised in that the sleeve (12) has an annular base flange (21) fixed to the upper side of the wall portion (4) of the floor (1). Assembly according to Claim 1, characterised in that the mechanical part (5) is connected to the floor with the interposition of an elastic block (22) and in that the reference pin (7) is an integral part of the metallic inner reinforcement (24) of the elastic block (22).

Inventors: CAMUFFO SERGIO, CAMUFFO, SERGIO
Applicants: FIAT AUTO SPA, FIAT AUTO S.P.A.
Application year: 1990
Main classification: F16B5
IPC codes: F16B5