AUTOMOBILE GEARBOX WITH REVERSE LOCK, CABLE-OPERATED

Abstract

A motor vehicle gearbox comprising an internal locking system (18) for engaging reverse gear, a sheath (16) containing a cable for releasing this system, and a bracket (10) fixed to the gearbox, having an outer face (12) perpendicularly receiving the end of the sheath (16) for passing the cable through the bracket (10), this gearbox comprising a clamping plate surrounding the sheath (16), which is clamped to the outer face of the bracket (12) with the interposition of a seal surrounding this sheath (16). Figure 1

Description

Description Title of the invention: MOTOR VEHICLE GEARBOX WITH REVERSE GEAR LOCK CABLE CONTROL

[0001] — The present invention relates to a motor vehicle gearbox equipped a cable-operated reverse lock, as well as a vehicle au- automobile comprising this gearbox, and a method of assembling the cable control on this gearbox.

[0002] = A known type of motor vehicle gearbox, presented in particular by document FR-A1-3065048, includes a lever operated by the driver which controls the various forward gears and the reverse gear by two main cables working in both directions. This is done by a de- lateral placement of the lever of the selection movements of a synchro- sleeve nization, then by a longitudinal displacement of the sliding movements of this sleeve to perform a gear change.

[0003] — The gear lever also includes a gear release control. engagement of reverse gear, acting on a metal cable sliding in a sheath whose end enters the gearbox to free the passage of this reverse gear. When operating the gear lever to engage a forward gear, the unlocking control which is not activated avoids prevents engagement of reverse gear following a selection error.

[0004] In particular, the end of the sheath of the unlocking control reaches a support fixed on the gearbox, to be held on this support allowing to the input cable in the box in order to apply an unlocking force.

[0005] The end of the sheath is subjected to alternating forces following the application of the tractions on the cable, in an environment presenting temperatures which can be high temperatures and vibrations. This can cause wear on parts. In addition, manufacturing in large series results in dimensional tolerances on the different components. In some cases, losses are obtained at the level of the sheath entry on this support. of oil contained in the gearbox, These losses pose level problems of oil in the gearbox which decreases, of external pollution, and of obligation of repair requested during the mandatory technical inspection of vehicles.

[0006] In the case of a fleet of vehicles in circulation, the repair of these leaks requires simplicity of repair which must be able to be carried out on the complete vehicle, without dismantle existing parts in order to limit labor time, however a guarantee that this solution will last over time for all interventions. The present invention aims in particular to avoid these problems of the prior art. To this end, it proposes a motor vehicle gearbox comprising an internal system for locking the engagement of the reverse gear, a sheath containing a cable for unlocking this system, and a support fixed to the gearbox, having an outer face receiving perpendicularly the end of the sheath to pass the cable through the support, this gearbox being remarkable in that it comprises a clamping plate surrounding the sheath, which is clamped on the outer face of the support with the interposition of a seal surrounding this sheath. An advantage of this gearbox is that simply by adding the seal and then a plate on vehicles already in circulation, coming on the external face of the support, we obtain a mechanical hold under this plate of the seal which is compressed by enclosing the end of the sheath. The seal can remain flexible to ensure its function, and is thus maintained in position despite vibrations and expansions without the risk of deforming or detaching. This provides a guaranteed seal over time between the outlet of the sheath and the support, which prevents any leaks. The motor vehicle gearbox according to the invention may further comprise one or more of the following features, which may be combined with each other. Advantageously, the clamping plate has two parts which come together around the sheath. In this case, one part can form a half-collar which is assembled on the other part forming a base to close a hole receiving the sheath. Furthermore, advantageously the half-collar slides radially in guides formed on each side on the base comprising ribs fitted into grooves. Advantageously, the half-collar is held on the base by a clipping device. Advantageously, the same fixing screw tightens the clamping plate and the support on the gearbox. In this case, advantageously the outer face of the support has a surface receiving the support of the clamping plate which is flat. Advantageously, the support or the clamping plate has a groove around the sheath receiving a paste forming the seal. The invention also relates to a motor vehicle equipped with a gearbox comprising any one of the preceding characteristics, remarkable in that it comprises a gear lever actuating cables for controlling the forward gear ratios and unlocking the reverse gear. The invention also relates to a method of intervention on this vehicle, remarkable in that it comprises a step of depositing a sealing paste on the support around the sheath, of placing the clamping plate around the sheath, then of sliding this plate towards the support and clamping it thereon. The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description below given by way of example, with reference to the appended drawings in which: [Fig.1] is a view of the end of the control cables and the reverse gear release cable arriving at a gearbox according to the invention, before mounting the clamping plate; [Fig.2] is a view of a clamping plate comprising two assembled parts added to the support of the unlocking sheath of this gearbox; [Fig.3] is a view of the two parts of this plate; [Fig.4] shows the assembly of the two parts of the plate around the sheath; and [Fig.5] shows the tightening of this plate assembled on the support. [Fig.1] shows two control cables 2 of a gearbox sliding in sheaths 4 held by a fixing 6 on the gearbox, each having a connecting end 8 with levers coming out of this box. A support 10 made by molding a plastic material, has a flat part resting on the gearbox casing, receiving on its flat outer face 12 a fixing screw 14 passing through this part to tighten it on the gearbox casing while ensuring a seal. A sheath 16 receiving a release cable actuated by the gear lever is guided by the support 10 to present its end fixed to this support perpendicular to its flat face 12. The sheath 16 is then curved by guides of the support 10. The end of the cable actuates the release system 18. Figures 2 and 3 show a clamping plate 30 comprising a base 32 and a half-collar 34, having a flat lower face 36 provided to bear on the flat face of the support 12. The assembled clamping plate 30 has an elongated shape comprising at one end a first bore 40 for receiving the fixing screw 14, at the other end a second bore 42 surrounding the end of the sheath 16, and between the two on one side a hollow 38 leaving a passage for a reinforcing rib of the support 10. The half-collar 34 comprises two parallel flanks each having a rib 44, these ribs fitting into corresponding grooves of the base 32 by forming a sliding guide following a radial direction of the second bore 42 in order to close its complete contour. An end-of-travel clip ensures the holding of the half-collar 34 in final position. The base 32 comprising on one side a thick contour 46 perpendicular to the clamping plate 30, connected by ribs 48 to the second drilling 42, with the half-collar 34 fitted by its ribs 44 on the base 32 to close this second drilling, provide this assembled plate with significant rigidity. [Fig.4] shows the support 10 with the sheath 16 shown straight, which has come out of its guides from the support giving it a curvature. The method of installing the seal first comprises the depositing of a sealing paste 50 on the flat face 12 of the support 10, around the end of the sheath 16. Then the clamping plate 32 is positioned around the sheath 16, by adjusting the base 32 and the half-collar 34 on each side of this sheath with clipping of the half-collar in order to form the second hole 42 surrounding the sheath. [Fig.5] shows, after the clamping plate 30 has been lowered onto the flat face of the support 12, by sliding it along the sheath 16, the removal of the fixing screw 14 and then its screwing, which tightens this plate onto the support 10 and the support onto the gearbox casing. Pressure is obtained on the sealing paste 50 which is compressed between the clamping plate 30 and the top of the support 10, around the end of the sheath 16, which ensures that it remains in position over time despite temperature increases and vibrations. It is advantageous to provide on one of the two opposite faces of the support 10 or the clamping plate 30, around the sheath 16, a circular groove making it possible to retain a quantity of sealing paste 50 surrounding this sheath. In this way the paste 50 forms a solid bead which ensures effective holding. The installation of the sealing paste 50 and then of the clamping plate 30 is done by first removing the fixing screw 14 from the support 10, without any other disassembly on the vehicle. In particular, the clamping plate 30 in two parts allowing its second hole 42 to be opened, allows it to be installed around the sheath 16 without disassembling this sheath. This sealing can be done quickly and economically. With the invention, a complete change of the support 10 with the cable and the sheath 16 is avoided, which could be done as an alternative to mount parts having better sealing, but resulting in the recycling of these parts, the purchase of new parts, and requiring more labor time.

Claims

Claims

1. Gearbox of a motor vehicle comprising an internal system locking mechanism (18) for engaging the reverse gear, a sheath (16) containing a cable for unlocking this system, and a support (10) fixed on the gearbox, having an external face (12) receiving perpendicularly the end of the sheath (16) to pass the cable through the support (10), characterized in that it comprises a clamping plate (30) surrounding the sheath (16), which is clamped on the outer face of the support (12) with the interposition of a seal (50) surrounding this sheath (16).

2. Gearbox according to claim 1, characterized in that the clamping plate (30) has two parts which come together around of the sheath (16).

3. Gearbox according to claim 2, characterized in that a part forms a half-collar (34) which is assembled on the other part forming a base (32) to close a hole (42) receiving the sheath (16).

4. Gearbox according to claim 3, characterized in that the half-collar (34) slides radially in guides formed of each side on the base (32) comprising fitted ribs (44) in grooves.

5. Gearbox according to claim 3 or 4, characterized in that the half-collar (34) is held on the base (32) by a device of clipping.

6. A gearbox according to any one of the preceding claims. preceding, characterized in that the same fixing screw (14) tightens the A gearbox according to claim 6, characterized in that the face outer surface of the support (12) has a surface receiving the support of the clamping plate (30) which is flat.

8. A gearbox according to any one of the preceding claims. preceding, characterized in that the support (10) or the clamping plate (30) has around the sheath (14) a groove receiving a paste forming the seal (50).

9. Motor vehicle equipped with a gearbox according to one of any of the preceding claims, characterized in that it has a gear lever operating control cables forward gear ratios (2) and gear release reverse gear.

10. Method of intervening on a vehicle according to claim 9, ca- characterized in that it includes a step of depositing a paste sealing (50) on the support (10) around the sheath (16), for putting in place the clamping plate (30) around the sheath (16), then cou- smoothing of this plate (30) towards the support (10) and its tightening above.