EP2921927A2

EP2921927A2 - Control pedal for vehicle and manufacturing method thereof

Info

Publication number: EP2921927A2
Application number: EP15159629.3A
Authority: EP
Inventors: Alessandro Michele Caruso; Renato Antonio Cavaglia'
Original assignee: Plastic Components and Modules Automotive SpA
Current assignee: Plastic Components and Modules Automotive SpA
Priority date: 2014-03-19
Filing date: 2015-03-18
Publication date: 2015-09-23
Anticipated expiration: 2035-03-18
Also published as: BR102015005962B1; EP2921927A3; MX2015003524A; BR102015005962A2; MX356747B; EP2921927B1; CN104960420A; CN104960420B

Abstract

The pedal (10) comprises a pedal arm (12) of plastic material having a tubular structure, with a first arm part (18) having an open cross-section and a second arm part (20) having an open cross-section, which arm parts are produced by moulding separately from each other and are joined to each other by welded joint so as to define the closed cross-section of the pedal arm (12). The pedal (10) further comprises a foot pad (14) that is wholly formed by the first arm part (18).

Description

The present invention relates generally to a control pedal for vehicle, such as for example a brake pedal or a clutch pedal, and more specifically to a pedal comprising a pedal arm of plastic material with a tubular structure. According to another aspect, the present invention relates to a method for manufacturing a control pedal for vehicle as defined above.
Several solutions of vehicle pedals with a pedal arm of plastic material are known.
According to a first known solution, the pedal arm is obtained by moulding and comprises a plurality of ribs having the function of increasing the moment of inertia, and hence the stiffness, of the pedal arm. This solution offers the advantages of the low cost, of the ease of manufacturing and of the reduced weight. On the other hand, it requires a proper arrangement of the ribs, which is not always possible, or at least not always easy, to obtain, in those cases where the forces acting on the pedal arm have different directions of application.
A further known solution consists in adding, by insert moulding, a metal insert (typically an insert of steel or aluminium) to a pedal arm of plastic material provided with stiffening ribs, in order to further increase the stiffness of the pedal. This solution is however affected by the drawbacks of the high cost, since it requires both a mould for moulding the metal insert and a mould for insert-moulding the plastic part of the pedal on the metal insert, as well as of the high weight, due to presence of the metal insert.
According to a third known solution, the required stiffness of the pedal arm is obtained by making the pedal arm as a tubular body. In this case, the pedal arm is produced starting from a solid body and removing material from the inside of that body by gas- or water-assisted moulding technique. A pedal arm is thus obtained which has good characteristics in terms of stiffness and mechanical strength. This solution has however several drawbacks, in particular that it is applicable only to certain geometries and shapes of the pedal and that it involves difficulties in ensuring a uniform wall thickness, which may lead to an increase in the overall weight of the pedal.
A control pedal for vehicle according to the preamble of independent claim 1 is known from WO2014/019793 .
It is an object of the present invention to provide an improved control pedal for vehicle with respect to the above-discussed prior art, in particular in terms of strength, weight, safety and manufacturability.
This and other objects are fully achieved according to the invention by virtue of a control pedal for vehicle as set forth in independent claim 1, as well as by virtue of a method for manufacturing a control pedal for vehicle as set forth in independent claim 7.
Advantageous embodiments of the invention are defined in the dependent claims, the subject-matter of which is to be regarded as an integral and integrating part of the following description.
In short, the invention is based on the idea of providing a control pedal for vehicle wherein the pedal arm is obtained by joining two arm parts having an open cross-section and wherein one of the arm parts forms the whole foot pad of the pedal and, preferably, also the whole hinge bush of the pedal. The manufacturing method of a control pedal for vehicle according to the invention provides, therefore, first for the two arm parts to be obtained by moulding separately from each other, with one of them forming the whole foot pad of the pedal and, preferably, also the whole hinge bush of the pedal, and then for the two arm parts to be joined to each other, preferably by welding.
This solution allows to combine the advantage of the high stiffness and mechanical strength given by the tubular structure of the pedal arm and the advantages of ease of manufacturing and high dimensional precision, in particular in terms of wall thickness, with resulting optimization of the overall weight of the pedal, which are offered by the fact that the two arm parts are obtained by moulding. Moreover, since one of the two arm parts forms the whole foot pad of the pedal, even in case of failure of the welded joint between the two arm parts, with resulting disconnection of these parts, it is ensured the possibility for the driver to operate the pedal.
Further characteristics and advantages of the present invention will clearly result from the following detailed description, given purely by way of non-limiting example with reference to the appended drawings, wherein:

Figure 1 is a perspective view of a control pedal for vehicle according to a preferred embodiment of the present invention;
Figure 2 is an exploded view of the control pedal for vehicle of Figure 1; and
Figure 3 is a perspective view showing in detail the pedal of Figure 1, sectioned through a plane perpendicular to a joint surface between the two arm parts of the pedal.

With reference to the drawings, a control pedal for vehicle according to an embodiment of the present invention is generally indicated 10 and basically comprises a pedal arm 12, a foot pad 14 attached to an end (bottom end) of the pedal arm 12 and a hinge bush 16 attached to the opposite end (top end) of the pedal arm 12 to allow mounting of the pedal 10 for rotation about a substantially horizontal axis of rotation x. The above-mentioned components of the pedal 10, namely the pedal arm 12, the foot pad 14 and the hinge bush 16, are all made of plastic material, and more in particular of the same plastic material, such as for example polypropylene o polyamide reinforced with glass fibres up to 50%.
According to a first aspect of the present invention, the pedal arm 12 has a tubular structure, that is to say, it has an inner cavity extending substantially throughout the longitudinal extension of the arm, so as to benefit from the advantages of the reduced weight and of the high stiffness and mechanical strength given by a structure of this kind. More specifically, the tubular structure of the pedal arm 12 is obtained according to the invention by joining, preferably by means of welding, two separate arm parts, indicated 18 and 20, respectively. According to the embodiment shown in the drawings, the arm part 18 has a substantially C-shaped cross-section, which is preferably oriented so as to open laterally, i.e. in the direction of the axis of rotation x. According to the embodiment shown in the drawings, the arm part 20 is a substantially plate-like element, which extends preferably in a plane perpendicular to the axis of rotation x, i.e. in a vertical plane, and acts as a cover that closes the open side of the arm part 18. Alternatively, both the arm parts 18 and 20 might have a substantially C-shaped cross-section. The arm part (or the arm parts) having the substantially C-shaped cross-section may be provided with stiffening ribs (not shown). The foot pad 14 is wholly formed, preferably in one piece, by one of the two arm parts 18 and 20, namely by the arm part 18. In the proposed embodiment, the hinge bush 16 is also wholly formed, preferably in one piece, by one of the two arm parts 18 and 20, in particular by the arm part 18, i.e. by the same arm part forming the foot pad 14.
By virtue of their open cross-sections, the two arm parts 18 and 20 can be produced by moulding, which allows to obtain a high dimensional precision, in particular in terms of thickness of those parts. It is thus possible to optimize, at the design stage, the thicknesses, and hence the weight, of the two arm parts 18 and 20.
The method for manufacturing a control pedal for vehicle according to the invention basically provides for the following steps:

a) producing, separately from each other, the two arm parts 18 and 20, preferably by moulding, with one of the two arm parts forming the whole foot pad 14 and, preferably, also the whole hinge bush 16; and
b) joining, preferably by welding, the two arm parts 18 and 20 thus obtained so as to form a pedal arm 12 having a tubular structure.

As will clearly result from the above description, a control pedal according to the present invention combines the advantages of high stiffness and mechanical strength of a tubular structure with the advantages of high dimensional precision and resulting possibility of optimizing the thicknesses, and hence the weight, of the pedal arm given by the moulding technique. Moreover, the control pedal according to the invention is easy to manufacture, since it is obtained by simple moulding and welding steps. A control pedal is thus obtained, which is at the same time strong, light and not expensive.
Naturally, the principle of the invention remaining unchanged, the embodiments and the constructional details may be greatly modified with respect to those described and illustrated purely by way of a non-limiting example, without thereby departing from the scope of protection as defined in the appended claims.

Claims

Control pedal (10) for vehicle, comprising a pedal arm (12), a foot pad (14) arranged at an end of the pedal arm (12) and a hinge bush (16) arranged at the opposite end of the pedal arm (12) and defining an axis of rotation (x) for the pedal arm (12), wherein the pedal arm (12), the foot pad (14) and the hinge bush (16) are made of plastic material, wherein the pedal arm (12) has a tubular structure with a closed cross-section and comprises a first arm part (18) with an open cross-section and a second arm part (20) with an open cross-section which are joined to each other so as to define the closed cross-section of the pedal arm (12),
characterized in that the foot pad (14) is wholly formed by the first arm part (18).
Control pedal according to claim 1, wherein the hinge bush (16) is also wholly formed by the first arm part (18).
Control pedal according to claim 1 or claim 2, wherein the first and second arm parts (18, 20) are joined to each other by welded joint.
Control pedal according to any of the preceding claims, wherein the first arm part (18) has a C-shaped cross-section and wherein the second arm part (20) is made as a plate-like element acting as a cover that closes the open side of the first arm part (18).
Control pedal according to claim 4, wherein the second arm part (20) extends in a plane perpendicular to the axis of rotation (x) of the pedal arm (12).
Control pedal according to claim 4 or claim 5, wherein the first arm part (18) is provided with stiffening ribs.
Method for manufacturing a control pedal (10) for vehicle according to any of the preceding claims, comprising the steps of:
- producing the first and second arm parts (18, 20) by moulding process, and

- joining to each other the first and second arm parts (18, 20) thus obtained.
Method according to claim 7, wherein the step of joining to each other the first and second arm parts (18, 20) is performed by welding.