EP2370241A1

EP2370241A1 - Method for manufacturing hybrid levers and pedals and implementation thereof in automobiles

Info

Publication number: EP2370241A1
Application number: EP09784208A
Authority: EP
Inventors: Eric Denis; Xavier Becue; Olivier Rousseaux; Loïc LEFEBVRE
Original assignee: Trelleborg Reims SAS
Current assignee: Carbody SAS
Priority date: 2009-06-15
Filing date: 2009-06-15
Publication date: 2011-10-05
Also published as: WO2010146246A1; US20120085195A1

Abstract

The invention relates to a method which comprises moulding a metal insert (11) from a casting by injection assisted by a fluid under pressure in the concave space which comprises the insert, restricting said space if necessary, in order to obtain a transverse cavity reducing the mass of the unit.

Description

METHOD FOR MANUFACTURING HYDRID PEDALS AND LEVERS AND ITS AUTOMOTIVE APPLICATION

The invention relates to a method of lightening levers and pedals, while maintaining their original rigidity, and its application to the automotive industry for the realization of pedals and levers including.

The automotive industry has been concerned for some time with mass savings on all components of a motor vehicle by making extensive use of plastics for non-working parties, but this concern is now gaining the extent to which their original mechanical characteristics can be preserved; this, even for highly stressed elements when using vehicles, such as the brake pedals, for example still largely metal, whether of direct transmission pedals, hanging from the control rod ( type brake booster), or pedals with remote transmission, although a hybrid solution has already appeared on the market, because it is necessary, of course, that the rigidity obtained by this solution remains identical to that of the all-metal solution.

This is generally the combination of a metal insert and a plastics material filled with glass fibers, using the well-known overmoulding process of an insert providing rigidity, without the overmoulded plastic material contributing to it. a lot.

French Pat. Nos. 2,791,297 and 2,803,241 disclose a method and a technology for producing mixed articles, comprising a rigid element of generally elongate shape, at least a portion of which has a cross section having a profile defining a concave space, combined with a portion of thermoplastic material positioned in said concave space of the rigid member, having at least one recess in its cross section. The method used consisting in arranging the rigid element in a shape injection mold suitable for injecting the molten thermoplastic into the mold, and simultaneously injecting a liquid or gaseous fluid by a needle into said material present in the concave space of the rigid member, using a method of injection assisted by a fluid or gaseous fluid under pressure, more commonly known by those skilled in the art, by the initials of its English terms WIT (Water Injection Technology) or GIT (Gas Injection Technology). It is understood that, using this method, after solidification of the plastic material, the latter has a transverse hollow reducing its mass, without significantly reducing its transverse modulus of inertia and, consequently, its rigidity. The rigid element and the thermoplastic parts being secured by overflow of the thermoplastic material through holes drilled in the rigid element.

Also known by an Internet publication of PÔTSCH; OP LAAK; SCHWITZER and HOLTERMANN, a method of manufacturing pedals and hybrid levers for the automotive industry using the combination of a metal insert and a plastic material by overmoulding said insert, by injection assisted by a fluid under pressure to obtain a transverse depression reducing the mass of the assembly, but this does not necessarily imply that the injection mold is designed to allow the limitation, if necessary, of the concave space in which the injection is made to compensate for the lack of rigidity of thin metal inserts, used to lighten these parts without loss of rigidity.

The present invention aims to adapt this method to the manufacture of pedals and levers for the automotive industry, including hybrid metal plastic pedals, and especially brake pedals.

This invention, as it is characterized, thus solves the problem of defining a method and methods with which, on the one hand, a substantial weight gain of the pedals or levers can be obtained by using inserts thin metal, the lack of rigidity is offset by its overmolding with a hollow plastic form, and, secondly, a significant economic gain is obtained.

The method of manufacturing pedals and hybrid levers for the automotive industry, using the combination of a metal insert and a plastic material by overmolding said insert by injection assisted by a fluid under pressure, with obtaining a transverse hollow reducing the mass of the assembly, consisting essentially of successively performing the following steps:

a) producing the insert from a metal section previously chosen according to its section, the concave space it offers and the mechanical characteristics to be obtained, in combination with the plastic overmolding, for the pedal or the corresponding lever,

b) producing a mold for injection under pressure of the chosen thermoplastic material, allowing the overmolding of the corresponding metal insert,

c) injection of the plastic material into the mold and injection of the selected fluid, using a needle, through the opening initially provided for this, then demolding after cooling,

is characterized in that the injection mold under pressure is provided to allow injection into the concave space that comprises the insert, with limitation if necessary of this space.

A direct transmission brake pedal hooked from the control rod, made by applying the method according to the invention, made by overmolding to from a U-shaped insert, of a shape corresponding to that sought, comprising, in its wings, the passage orifices of the hinge pin and the transmission axis of the pedal, and, in its base, the orifices for securing the plastic body with the U-shaped insert during overmoulding, is characterized in that it is made from a U-shaped insert, with lateral return by a part made of

L, comprising, for the U-shaped part, several orifices for securing said insert with the plastic body during overmoulding, and, at its end opposite the pad of the pedal, as well as in the L-shaped part, the orifices of passage of the axis of articulation of the pedal, said plastic body having the brake pad and the remote transmission device; the plastic pad, overmolded during the injection phase, comprising an orifice for the passage of fluid. The portion located at the L-shaped metal pin return, having the brake rod ball cage holder, is overmoulded and reinforced by plastic ribs.

The hollow part obtained by the injection of the fluid, located in the upper part of the pedal, is reinforced by ribs.

A remote transmission brake pedal hung from the control rod, made by applying the method according to the invention, is characterized in that it is made by overmolding from a double U-shaped insert made in two parts , each comprising, at their upper end, on the hinge pin side, an L-shaped part intended for embedding these parts one inside the other, in order to obtain a common profile of greater width, intended to receive during overmoulding, a hinge housing extending toward the free end of the U-shaped portion to form the brake rod ball cage carrier. The parts, consisting of the metal insert, being stiffened by plastic ribs. The advantages obtained, thanks to this invention, consist, in addition to the large mass gain achieved, in that all the functional elements of the assembly is obtained in a single operation: foot support sole, support contactors pedal, passage of the pedal shaft, hooked area of the control rod, etc.

Other features and advantages will become apparent in the following description of various embodiments of hybrid automobile brake pedals by overmolding a metal insert by injection of a plastic material assisted by pressurized water according to the invention. , given as non-limiting examples, with reference to the appended drawings, in which:

FIG. 1 represents an overall side view, in perspective, of a direct transmission brake pedal suspended from the control rod, with "grayed" indication of the visible portions of the overmoulding,

FIG. 2 represents an overall side view, in perspective, of a remote transmission brake pedal suspended from the control rod;

FIG. 3 represents a perspective side view of the metal insert of the pedal according to FIG. 2;

FIG. 4 represents a perspective side view of the plastic body of the pedal according to FIG. 2;

FIG. 5 represents a partial side view, in perspective and by transparency, of the L-shaped part of the metal insert according to FIG. 2;

FIG. 6 represents a partial bottom view, in perspective and by transparency, of the L-shaped part of the metal insert according to FIG. 2; FIG. 7 represents a partial top view, in perspective and through transparency, of the plastic pad of the pedal according to FIG. 2;

FIG. 8 represents an overall partial bottom view, in perspective, of the pedal according to FIG. 2;

FIG. 9 represents a view in transparency of the inside of the injection channel of a single-channel pedal and an overmolded L-shaped reference according to FIGS. 3, 5, 6, 7 and 8,

FIG. 10 represents an overall side view, in perspective, of a double insert pedal molded with injection of water,

FIG. 11 represents an overall view of the double insert pedal according to FIG. 10,

FIG. 12 represents an overall view of the plastic part of the pedal according to FIG. 10,

FIG. 13 represents a partial side view of the function of the two inserts according to FIG. 10,

FIG. 14 shows a partial side view of the molding area of the brake rod ball joint holder of the double insert pedal according to FIG. 10;

FIG. 15 represents a partial bottom view, by transparency, of the pedal according to FIG. 10, showing the water injection orifice and the limitation, according to AA, of the water injection zone. Now examining in more detail all the figures, we note:

- In Figure 1, this pedal direct transmission 10 comprises a U-shaped insert 11 of appropriate shape, having in its wings, the passage holes of the axis of articulation and transmission of the pedal 10, and in its base, the fastening orifices of the plastic body 12 with the insert 11 during overmolding,

in FIGS. 2 to 9, corresponding to the hybrid pedal with remote transmission

20 hooked from the control rod, that said pedal 20 comprises a U-shaped insert 21, with lateral return by an L-shaped portion 22, having, in the U-shaped portion 21 and at the base of the U, a plurality of orifices 211 securing said insert 21 with the plastic body 23 during its overmolding, and at its end opposite the shoe 231 of the pedal 20, as well as in the L-shaped portion 22, the holes 221 for the passage of the axis The plastic body 23 comprising, as shown in Figure 4, the shoe 231 and the remote transmission device 232.

As shown in FIGS. 2 to 9, holes made in the U-shaped insert

21 ensure the maintenance of the plastic body 23 in the soul of the U; the plastic pad 231, molded during the injection phase, has an orifice 233 allowing the passage of water, which flushes, by injection, the plastic material against the wings of the U. As shown in particular in FIGS. , 6 and 8, the portion located at the L-shaped return 22 of the metal insert 21 may be overmolded and also reinforced by plastic ribs 234, inwardly as well as outwardly of the L-shaped portion 22 The brake rod ball cage holder is also overmoulded on the L-shaped portion 22 of the metal insert 21. As shown in FIG. 8, it is quite possible to terminate the hollow portion. , due to the injection of water in the upper part of the pedal 20, and to strengthen this same upper part by the addition of ribs 235. In FIGS. 10 to 15, corresponding to the hybrid pedal with remote transmission 30 of hanging from the control rod, with a double U-shaped insert, it is noted that the insert consists of two U-shaped parts 31 and 32, each comprising , at their upper end, on the hinge pin side, an L-shaped portion 311, 321 intended for embedding these parts one inside the other, to obtain a U-profile by welding at their overlapping zone. , intended to receive, during overmolding, a hinge housing 33 extending towards the free end of the small U-shaped portion 32 to form the brake rod ball cage support 34, as shown in FIG. 12. As shown in Figures 14 and 15, the U-shaped portions 31 and 32 constituting the metal insert may be stiffened by plastic ribs, outside as well as inside these parts.

As for the simple pedal 10 of Figure 1, the metal insert 31, 32 is provided with holes 310, 320 whose role is to secure the metal portion to the overmolded portion.

As shown in Figure 15, the injection of water, to push the plastic within the space that is left to him, is by a single point 330, common to both channels.

It is noted, again in FIG. 15, that it is possible to terminate the water injection zone at the junction plane AA of the two U-shaped portions 31 and 32 of the insert, thereby reinforcing the piece by addition of ribs 331 after the AA limit of the water injection zone.

In the given examples only U-shaped and L-shaped inserts have been used, but it is obvious that inserts of other profiles, such as T-shaped for example, can also be used, subject only to that they have a lateral concavity sufficient to lend themselves to overmolding with injection of water, by providing a sufficient transverse hollow in the plastic material to reduce its mass without compromising the rigidity of the assembly.

Claims

claims

1. A method of manufacturing pedals and hybrid levers for the automotive industry, using the combination of a metal insert and a plastic material by overmolding said insert by injection assisted by a fluid under pressure, with obtaining a transverse hollow reducing the mass of the assembly, consisting essentially of successively performing the following steps:

a) realization of the insert from a metal section previously selected according to its section, the concave space it offers and the mechanical characteristics to be obtained, in combination with the plastic overmolding, for the pedal or the corresponding lever,

characterized in that the pressurized injection mold is provided to allow injection into the concave space of the insert, with limitation, if necessary, of this space.

2. Direct transmission brake pedal (10) hooked from the control rod, carried out by applying the method according to claim 1, made by overmolding from a U-shaped insert (11), of a shape corresponding to that sought, including in its wings, the orifices of passage of the axis of articulation and the transmission axis of the pedal (10), and in its base, the fastening orifices of the plastic body

(12) with the U-shaped insert (11) during overmolding, characterized in that it is made from a U-shaped insert (21), with lateral return by an L-shaped portion (22), comprising, for the U-shaped portion (21), a plurality of orifices (211) for securing said insert (21) to the plastic body (23) during overmolding, and at its end opposite to the pad (231) of the pedal ( 20), as well as in the L-shaped portion (22), the holes (221) for passage of the pivot axis of the pedal (20), the said plastic body (23) comprising the brake pad ( 231) and the remote transmission device

(232); said plastic pad (231), overmolded during the injection phase, having an orifice (233) allowing the passage of the fluid.

3. Brake pedal according to claim 2, characterized in that the portion located at the L-shaped return (22) of the metal insert (21), comprising the brake rod ball joint holder, is overmolded and reinforced by ribs (234) of plastics material.

4. Brake pedal according to claim 2, characterized in that the hollow portion obtained by the injection of the fluid, located in the upper part of the pedal (20), is reinforced by ribs (235).

5. Pedal brake transmission remote (30) hooked from the control rod, made by applying the method according to claim 1, characterized in that it is performed by overmolding from a double U-shaped insert made in two parts (31) and (32), each having, at their upper end, hinge axis side, an L-shaped part (311, 321) intended for the fitting of these parts into one another , to obtain a common profile of greater width, intended to receive, during overmolding, a hinge housing (33) extending towards the end free of the U-shaped portion (32) to form the brake rod ball cage support (34).

6. Brake pedal according to claim 5, characterized in that the parts (31, 32), consisting of the metal insert, are stiffened by plastic ribs.