WO2002021232A1

WO2002021232A1 - Pedal support arrangements

Info

Publication number: WO2002021232A1
Application number: PCT/IB2001/001188
Authority: WO
Inventors: Sylvain Cospin
Original assignee: Trelleborg Ab
Priority date: 2000-09-07
Filing date: 2001-07-03
Publication date: 2002-03-14
Also published as: GB2366608B; GB0021981D0; EP1316007A1; AU2001274427A1; GB2366608A

Abstract

An anti-vibration pedal support arrangement for a vehicle, comprising a pedal platform (4) for supporting a pedal and fixing means (6, 8, 10, 12) for securing the platform (4) to the body (2) of the vehicle. The fixing means (6, 8, 10, 12) normally prevents direct undamped contact between the body (2) and the platform (4) and incorporates resilient material (20) for flexing in response to vibration of the body. The arrangement includes a layer of resilient isolating material (14) between the platform (4) and the body (2), the platform (4) moving into solid contact with the body (2) in response to excessive force applied to a pedal.

Description

PEDAL SUPPORT ARRANGEMENTS

The invention relates to support arrangements for pedals in vehicles. Increasingly,

through the use of thinner sheets for the construction of vehicle flooring and the use of

very high pressures in direct injection engines, vibrations are being generated which are

transmitted through the assembled components to the pedals and to their support

platforms. These vibrations and noise are transmitted to the passenger compartment,

reducing the level of comfort for the driver and passengers.

According to the invention, there is provided an anti-vibration pedal support arrangement

for a vehicle, comprising a pedal platform for supporting a pedal and fixing means for

securing the platform to the body of the vehicle, the fixing means normally preventing

direct undamped contact between the body and the platform and incorporating resilient

material for flexing in response to vibration of the body.

According to the invention, there is further provided a pedal support arrangement for a

vehicle, comprising a pedal platform, resilient isolating material for normally spacing the

platform from the body of the vehicle, and resilient fixing means for securing the platform

to the body normally without direct undamped contact between the body and the platform,

the arrangement being such that the platform moves into solid contact with the body of

the vehicle in response to excessive force applied to a pedal, thereby stiffening the

arrangement. Pedal support arrangements embodying the invention, for use in vehicles, will now be

described, by way of example only, with reference to the accompanying drawings in

which:

Figure 1 is a cross-section of an arrangement known from the prior art;

Figure 2 is a cross-section of one of the pedal support arrangements embodying the

invention; and

Figure 3 is a graph plotting the level of isolation achieved against acoustic frequency,

comparing the results obtained with the embodiment of the invention shown in Figure 2

with those obtained with the prior art.

Figure 1 shows a typical pedal support arrangement, in which a pedal support platform

4 made of plastics material is secured to a portion of the body 2 of a vehicle. The body

portion 2 is in this case the bulkhead between the engine and passenger compartments of

the vehicle. The platform 4 is secured by means of a hollow tubular strut 8, which

extends from the bulkhead 2 for locating the pedal plate 4, and a stud bolt 6 in

combination with a nut 10 and a washer 12, the stud bolt extending from the bulkhead

concentrically within the strut 8 for securing the pedal platform 4 in place. The pedal

platform is isolated from the flooring by an isolating layer 14 of a suitable material.

However, vibrations are still directly transmitted from the floor to the pedal platform because there is a direct, undamped link made through the tube 8 and the stud bolt 6 in

combination with the nut 10 and the washer 12. These vibrations manifest themselves as

noise within the passenger compartment, reducing the level of comfort for the driver and

passengers. Previous attempts to overcome this problem by varying the form and material

of the pedal platform have not produced satisfactory results. It should be understood that

the pedal support platform 4 may be made of materials other than plastics, such as, for

example, steel, but that the benefits of the invention are greatest for the embodiment

where the pedal support platform 4 is made of plastics material because such material

may present greater vibro-acoustic problems.

Figure 2 shows a pedal platform arrangement in accordance to the invention, in which the

direct transmission of vibrations through the strut 8 and the stud bolt 6 is damped as a

result of the inclusion of a tubular elastomeric member 20 between the strut 8 and an

adjacent tubular extension 21 of the platform 4. The tubular elastomeric member 20 is

push-fitted onto the strut 8, so that it is compressed by the adjacent tubular extension 21

of the platform 4. The resultant radial force from the elastomeric member 20 tending

towards its incompressed position increases the fictional forces between the strut 8, the

elastomeric member 20 and the platform 4, tending to prevent relative axial movement

between the platform 4 and the strut 8. This elastomeric member dampens the vibrations

transmitted from the strut 8 to the pedal platform 4 by resiliently flexing in response to

the vibrations. Direct transmission of the vibrations from the stud bolt 6 to the pedal

platform 4 is damped by the same elastomeric member 20, provided that the washer 12 does not extend beyond the edges of the elastomeric member 20. In this way, the pedal

platform 4 is completely isolated from the bulkhead 2 of the vehicle.

The tubular extension .21 of the platform 4 has an elongated shank 30 extending through

the layer 14 but normally stopping short of the pedal plate 4. In the event of an unusually

large force being applied to one of the pedals, the free end of the shank 30 comes into

solid contact with the bulkhead 2 to block the slight movement normally provided by the

elastomeric member 20, this contact making the assembly very stiff and giving the desired

driving feel. In the arrangement shown in Figure 1, in contrast, the assembly is always

very stiff but the driving feel is consequently reduced. Thus, the arrangement shown in

Figure 2 provides a pedal plate with the required driving feel, including the damping of

vibrations and the associated noise, under normal conditions, and which functions in a

rigid state under excessive pedal forces. When the pedal plate functions under the

excessive pedal forces, and there is a solid contact between the pedal platform 4 and the

bulkhead 2, the vibrations which would produce noise in the passenger compartment are

damped by the foot on the pedal.

The same effect may be achieved if the pedal platform 4 is biassed to be separate from

the bulkhead 2, in a manner which allows relative movements between the pedal platform

4 and the bulkhead 2 dependent on the force applied to the pedal. The characteristics of

the or each elastomeric member 20 define the instant when the pedal platform makes

contact with the bulkhead. The graph of Figure 3 illustrates the improvement in the level of noise damping achieved

through the arrangement shown in Figure 2 in comparison with the prior art arrangement

shown in Figure 1. Over a broad range of frequencies, the level of isolation achieved by

the arrangement of Figure 1 is very close to that of a vehicle bulkhead without any pedal

platform. This demonstrates that the noise levels in the passenger compartment are

significantly lower with the arrangement of Figure 2 than have been achieved to date in

the prior art.

The pedal support arrangement shown in Figure 2 is particularly applicable for suspended

pedals where the pedal platform 4 is not part of the structure of the body of the vehicle

but is mounted. However, the support arrangement can be adapted for use in the case

where the pedal platform is joined to the bulkhead.

Claims

1. An anti-vibration pedal support arrangement for a vehicle, comprising a pedal

platform (4) for supporting apedal and fixing means (6,8,10,12) for securing the platform

(4) to the body (2) of the vehicle, the fixing means (6,8,10,12) normally preventing direct

undamped contact between the body (2) and the platform (4) and incorporating resilient

material (20) for flexing in response to vibration of the body (2).

2. An arrangement according to claim 1, including a layer of isolating material (14)

for positioning between the pedal platform (4) and the body (2) of the vehicle and through

which the fixing means passes (6,8,10,12).

3. An arrangement according to claim 1 or 2, in which the fixing means comprises

a rigid tubular strut (8) extending through the pedal platform (4), and a rigid stud (6)

extending through the tubular strut (8) and securing the platform (4) to the strut (8), and

in which the resilient material (20) extends around the strut (8) and is resiliently

positioned between the strut (8) and the platform (4).

4. An arrangement according to claim 3, in which the stud (6) is resiliently clamped

to the strut (8).

5. An arrangement according to claim 4, in which the stud (6) is resiliently clamped

to the strut (8) by means of a nut (10) engaging the stud (6) and a resilient washer (12)

acting between the nut (10) and an end of the strut (8).

6. An arrangement according to claim 5, in which the resilient washer (10) overlies

the resilient material (20) but does not overlie the platform (4).

7. An arrangement according to any preceding claim, in which the platform (4)

includes at least one extension (21) having a free end adjacent to but normally spaced

from the body (2) of the vehicle but so as to be forced into contact with the body (2) of

the vehicle when excessive force is applied to a pedal thereby providing stiffening of the

arrangement.

8. A pedal support arrangement for a vehicle, comprising a pedal platform (4),

resilient isolating material (14) for normally spacing the platform (4) from a body (2) of

the vehicle, and resilient fixing means (6,8,10,12) for securing the platform (4) to the

body (2) normally without direct undamped contact between the body (2) and the

platform (4), the arrangement being such that the platform (4) moves into solid contact

with the body (2) of the vehicle in response to excessive force applied to a pedal, thereby

stiffening the arrangement.

9. An arrangement according to claim 8, in which the resilient isolating material (14)

is in the form of a layer of the material and in which the fixing means (6,8,10,12) passes

through this layer.

10. An arrangement according to claim 9, in which the fixing means comprises a rigid

tubular strut (8) extending through the pedal platform (4) and the layer of isolating

material (14), and a rigid stud (6) extending through the tubular strut (8) and securing the

platform (4) to the strut (8), and including resilient material (20) extending around the

strut (8) and resiliently positioned between the strut (8) and the platform (4).

11. An arrangement according to claim 10, in which the stud (6) is resiliently clamped

to the strut (8).

12. An arrangement according to claim 10 or 11, in which the platform (4) includes

at least one extension (21) passing through the layer of isolating material (14) adjacent

to the strut (8), the extension (21) having a free end adjacent to but normally spaced from

the body (2) of the vehicle but so as to be forced into the solid contact with the body (2)

of the vehicle when the excessive force is applied.