Pedal support friction device

Abstract

The vehicle pedal assembly includes a pedal housing having a forward mounting surface for securing within a vehicle. The rotatable pedal has a proximal portion disposed within the pedal housing and a distal portion including a footpad spaced from the pedal housing. The pedal is biased relative to the pedal housing to a first limit position, and the distal portion is configured to be actuated in a forward direction from the first limit position. A friction system is provided to generate resistance to movement of the pedal toward and away from the first limit position. The friction system includes a friction lever having a friction pad carried by the pedal and pivotable on the pedal to establish frictional contact with a friction contact surface of the pedal housing.

Description

[Background technology]

[0001] <Background> The present invention relates to pedal assemblies, for example in vehicles, where a user controls the throttle, brake, and optionally the clutch with their feet. Such pedals, particularly throttle pedals, may include variable friction devices so that the user does not have to constantly exert a holding force equal to the spring biasing force during sustained pedal actuation. To this end, a friction lever may be supported on the housing of the pedal assembly and engageable with a portion of the pedal to provide frictional resistance to movement. Summary of the Invention [Problem to be solved by the invention]

[0002] <Summary> In one aspect, the present invention provides a vehicle pedal assembly. The pedal housing includes a forward mounting surface for securing the pedal within a vehicle. The rotatable pedal has a proximal portion disposed within the pedal housing and a distal portion including a footpad spaced from the pedal housing. The pedal is biased to a first limit position relative to the pedal housing, and the distal portion is configured to be actuated in a forward direction from the first limit position. A friction system is provided to generate resistance to movement of the pedal toward and away from the first limit position. The friction system includes a friction lever with a friction pad carried by the pedal and pivotable on the pedal to establish frictional contact with a friction contact surface of the pedal housing.

[0003] In another aspect, the present invention provides an accelerator pedal assembly including a mounting surface for securing within a vehicle and an accelerator pedal including a footpad. The accelerator pedal is biased by a spring against the mounting surface to a first limit position, and the footpad is configured for forward movement from the first limit position. A friction system is provided for generating a resistance force against movement of the accelerator pedal toward and away from the first limit position. The friction system includes a friction lever pivotally supported on the accelerator pedal. The spring applies a force to the friction lever such that the resistance force varies according to the deflection of the spring. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 is a schematic diagram of a vehicle pedal assembly mounted to a vehicle bulkhead.

[0005] [Figure 2] FIG. 2 is a perspective view of a pedal assembly according to one embodiment of the present disclosure, including a pedal support friction device.

[0006] [Figure 3] FIG. 3 is a side view of the pedal assembly of FIG. 2 with the housing removed to reveal the internal components.

[0007] [Figure 4] FIG. 4 is a perspective view of the pedal assembly of FIG. 2 with the housing and pedal removed to reveal the internal components.

[0008] [Figure 5] FIG. 5 is a perspective view of the pedal assembly shown in FIG. 4, but with the friction lever also removed.

[0009] [Figure 6] 6 is a cross-sectional view of the pedal assembly taken along line 6-6 of FIG. 2.

[0010] [Figure 7]7 is a cross-sectional view of the pedal assembly taken along line 7-7 of FIG. 2. FIG.

[0011] [Figure 8] 8 is a cross-sectional view of the pedal assembly taken along line 8-8 of FIG.

[0012] [Figure 9] FIG. 9 is a perspective view of the pedal assembly with the pedal removed.

[0013] [Figure 10] FIG. 10 is a free body diagram of the friction lever of the friction system. DETAILED DESCRIPTION OF THE INVENTION

[0014] <Detailed explanation> Before describing any embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. It is to be understood that the description of particular embodiments is not intended to limit the disclosure, since it covers all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] FIG. 1 illustrates a vehicle including a pedal assembly 20 arranged for use by a vehicle driver to control vehicle travel. In one configuration, the pedal assembly 20 is an accelerator pedal assembly. The pedal assembly 20 may include a housing 24 configured for mounting to a vehicle bulkhead 28 (or “firewall”). A pedal arm, or simply “pedal” 32, extends from the housing 24, supported at a pivot 36. A distal portion of the pedal 32 may include a footpad or footrest 40 for contact by the driver's foot. In some configurations, the pedal assembly 20 is a pedal and sensor assembly having an integrated position sensor for tracking the position of the pedal 32. The pedal assembly 20 may be connected in signal communication with a vehicle electronic control module (ECM) 42 to control power output from a prime mover 44 (e.g., an internal combustion engine, a hybrid, or an all-electric motor). The pedal assembly 20 includes a friction system, described in more detail below, for generating a variable friction force that resists movement of the pedal 32 relative to the housing 24, thus damping the movement of the pedal 32 and reducing driver fatigue. Friction systems are known in the prior art, including, for example, U.S. Pat. No. 6,515,473 or more recently U.S. Pat. No. 11,307,606, the entire contents of both of which are incorporated herein by reference. However, packaging and weight reduction constraints for mass-produced automobiles have made it increasingly difficult to meet design goals with such prior art devices. For example, more recently, it has been desirable to set the offset distance X between the bulkhead 28 and the pivot 36 of the pedal 32 very low, thereby reducing the available space within the housing 24. Where conventional designs may already have a relatively small offset distance (e.g., approximately 27 mm), a substantial further reduction beyond 5 or 7 percent could make it entirely prohibitive to meet design goals through further compactification of the conventional layout, thus requiring an entirely new approach.

[0016] FIG. 2 depicts the pedal assembly 20 in isolation, showing only the portion of the pedal arm 32 proximal to the housing 24, with the understanding that the pedal 32 extends further downward in the figure toward the footpad 40. The pivot 36, which defines the axis of rotation A of the pedal 32, is also visible in FIGS. 3 and 9, where the housing 24 is at least partially removed. The pivot 36 may comprise one or more bearings, e.g., plain bearings with concentric bearing surfaces. Signal communication with the ECM 42 is provided via an electrical connector 46. The electrical connector 46 may be a plug / socket-type multi-pin connector including an outer shroud that projects outward from the main portion 24A of the housing 24 (e.g., generally away from the pedal 32). A wire harness connector (not shown) may be plugged into the electrical connector 46. The electrical connector 46 may provide a portion of the housing 24 when coupled (e.g., snap-fit) to the main housing portion 24A. Similarly, a plate or closure member 48 may be coupled (e.g., snap-fit) to the main housing portion 24A to form part of the housing 24. The main housing portion 24A, closure member 48, and electrical connector 46 may combine to form the housing 24, within which is provided a position sensor module 50 coupled to the electrical connector 46. The position sensor module 50 may include a contactless sensor (e.g., a Hall-effect magnetic sensor) or, as shown in FIGS. 4 and 5, may incorporate an integrated circuit on a printed circuit board. In other configurations, any suitable and readily available sensor topology may be used. The movement of the pedal 32 may be tracked by the position sensor module 50 throughout the available range of movement. For use with a Hall-effect sensor, a magnet 54 may be affixed to the pedal 32 in a position adjacent to the position sensor module 50. As the pedal 32 is moved, the magnet 54 moves across the position sensor module 50, and magnetic field changes are detected to accurately track the position of the pedal 32.

[0017] 2 and 3 show the pedal 32 in a first limit position, which is an inactivated or rest position (also referred to as an "idle" position). The pedal 32 is biased to the first limit position by at least one spring (e.g., two concentric springs 58, 60). The springs 58, 60 are disposed within the housing 24. At least a distal portion of the pedal 32 is movable in a forward direction F (FIGS. 1 and 2) against a bias by actuation from a user. The forward direction F is toward the side of the housing 24 that provides the mounting surface 62, and the forward direction F may be perpendicular to a reference plane defined by the mounting surface 62 (although the mounting surface 62 itself may or may not be planar). The forward direction F generally faces the direction of forward movement of the vehicle in which the pedal assembly 20 is mounted to the bulkhead 28. The springs 58, 60 that bias the pedal 32 are supported and compressible between the pedal 32 and the closure member 48 of the housing 24. As shown in FIGS. 6 and 7 , the closure member 48 may provide a spring seat for positioning each of the springs 58, 60. Under the force of the springs 58, 60 alone (and no other force from the user), a portion of the pedal 32, provided as a stopper or ledge 33 as shown in FIG. 8 , is biased into contact with a stopper or bumper 64 on the housing 24. In the configuration shown in FIG. 9 , two bumpers 64 are provided on either side of the main housing portion 24A. The bumpers 64 define a first limit position of the pedal 32 relative to the housing 24. The pedal 32 is movable from the first limit position through an opening 68 in the housing 24 ( FIGS. 2 and 9 ) to a second limit position or maximum operating (e.g., full throttle) position, not shown. The second limit position of the pedal 32 may be defined by contact between the pedal 32 and one or more stop surfaces 70 on the housing 24. As shown in FIG. 9, the main housing portion 24A may have a stop surface 70 divided into two or more spaced apart pads.

[0018] As briefly described above, the pedal assembly 20 includes a friction system. The friction system includes a friction lever 76 having one or more friction pads 80 that frictionally engage and contact one or more friction contact surfaces 82 of the pedal housing 24. At least a portion of each surface 82 may trace an arc about the pedal axis A. As the pedal 32 moves further from the first limit position, the biasing force from the springs 58, 60 increases. The friction system operates to apply friction (by increasing the normal force between the friction pads 80 and the friction contact surfaces 82) as the pedal 32 moves further from the first limit position. In other words, the friction lever 76 is directly and gradually actuated in response to the pedal 32 moving away from the first limit position toward the second limit position. Meanwhile, the friction lever reduces frictional resistance as the pedal 32 returns toward the first limit position. The low friction in this initial region of pedal travel ensures that the friction system does not impede the pedal 32's ability to return to the first limit position. Friction in the initial region of pedal travel also reduces driver fatigue concerns, as the driver is less likely to maintain the pedal 32 near the first limit position for an extended period of time.

[0019] The friction lever 76 is supported by and pivots on the pedal 32, as opposed to the housing 24. The connection between the friction lever 76 and the pedal 32 defines a lever axis B about which the friction lever 76 pivots relative to the pedal 32. In the illustrated configuration, the pivot connection is formed by two laterally opposed hinge pins 86 of the friction lever 76 received in complementary receptacles 88 of the pedal 32, as shown in FIGS. 3 and 6. The hinge pins 86 are also visible in FIG. 9, in which the pedal 32 is removed. In other configurations, the hinge pins 86 and receptacles 88 can be reversed, such that the pedal 32 includes the hinge pins. As can be seen in FIGS. 3, 6, and 7, the friction lever 76 is partially or completely nested within the pedal 32, which includes a hollow cavity that accommodates the friction lever 76.

[0020] FIG. 7 is a cross-sectional view through the interface where the friction pad 80 engages the friction contact surface 82 of the pedal housing 24. FIGS. 8 and 9 also provide a clearer view of these interfaces. The friction pads 80 may be formed on opposite laterally-opposed sides of the main body 90 of the friction lever 76. The friction pads 80 may be formed on lateral protrusions 92 of the main body 90. Although not required in all embodiments, the friction pads 80 may be formed of a material separate from the material forming the main body 90 of the friction lever 76. The main body 90 may be glass-filled resin (nylon), and the friction pads 80 may be unfilled lubricated POM (acetal). In some configurations, the friction pads 80 are overmolded onto the main body 90 to form the friction lever 76. As shown, in a configuration with two lateral projections 92, two spaced apart friction pads 80 may be molded into a continuous piece with a central connecting strip spanning the body 90 (FIGS. 4 and 9).

[0021] As described above, the friction lever 76 is nested within the pedal 32. Furthermore, the friction lever 76 may be saddle-shaped ( FIG. 6 ), including a top wall and two side walls. Cavities for partially receiving the springs 58, 60 are provided within the friction lever 76 below the top wall and between the side walls. The side walls establish a pivotal connection to the pedal 32 via a hinge pin 86 formed thereon in the illustrated configuration. A spring cap 96 is located between the top wall of the friction lever 76 and the springs 58, 60. Thus, the springs 58, 60 do not directly contact the friction lever 76. The spring cap 96 establishes a sliding interface with the inside of the top wall of the friction lever, which largely or completely restricts the springs 58, 60 to transmitting forces on-axis rather than off-axis during flexion. The spring caps 96 may have a shape complementary to the ends of the springs 58, 60 to maintain their positioning.

[0022] FIG. 10 is a cross-sectional view of the pedal assembly 20 labeled as a free body diagram of the forces on the friction lever 76. A coordinate system is used in which the x-direction extends parallel to the flat interface between the spring cap 96 and the inside of the friction lever 76. The y-direction is perpendicular to the x-direction as shown. The parts themselves have depth into the page, but the free body diagram resolves to a two-dimensional system because forces acting into and out of the page are negligible. The springs 58, 60 exert a force F S and applies (via spring cap 96) to the underside of friction lever 76. S varies with pedal position and therefore spring deflection, and is parallel to the y direction and perpendicular to the x direction. At this point, the normal friction force f S may be applied, but it is very small or negligible. S , f S are the respective moment arm distances r from the pivot axis B established between the friction lever 76 and the pedal 32. SX and r SY As shown in FIG. 10, the force generated by the springs 58 and 60, i.e., F S applies a clockwise moment about pivot axis B to friction lever 76, which, due to the configuration of surface 82, biases friction pad 80 against housing surface 82 with a force (not shown) toward axis A of pedal pivot 36. Of course, spring force F S An increase in F results in an increase in the force applied by the friction pad 80 to the surface 82. The surface 82 acts on the friction lever 76 with a force F normal to the surface 82. Based on the coefficient of friction, the force F results in a friction force f tangential to the surface 82 (and therefore tangential to a radial line extending from the pedal axis A to the contact point). The friction force f serves to resist the movement of the pedal 32. Depending on the direction of pedal movement, the friction force f may act on the pedal 32 in combination with the spring force (during pedal actuation, as shown) or against the spring force (during pedal release). The forces F and f are determined by the respective moment arm distances r from the pivot axis B established between the friction lever 76 and the pedal 32. 1Xand r 1Y Finally, pedal 32 acts on friction lever 76 with force F3. Force F3 is directed through pivot B (on hinge pin 86) and therefore has no moment arm or a moment arm length of zero.

[0023] 10, various moment arms for the spring force and the resulting friction f1 at the friction pad 80 are shown to be related to the spring force F S That is, the effect of moment arm length r 1X , r 1Y is the moment arm length r SX , r SY This results in a particular lever ratio specific to the physical configuration of the friction lever 76, e.g., the placement of the friction pad 80 and the placement of the wall that receives the spring cap 96 relative to the placement of the pivot B (via the hinge pin 86). The effective lever ratio, and therefore the amount of amplification from spring force to friction force, can be manipulated as part of the design to achieve different goals. Thus, the present invention is not limited to the exact shape and effective ratio of the illustrated embodiment.

[0024] As briefly mentioned above, the pedal assembly 20 with the friction system disclosed herein can provide a very compact and lightweight product for mass-produced passenger cars or other specialized vehicles. In some configurations, the offset distance X between the pedal arm pivot axis A and the mounting surface 62 is less than 26 mm, and in some configurations, it is less than 25 mm. The offset distance X can be 10 mm or greater, and in some configurations, it can be 20 mm or greater or 24 mm or greater.

[0025] Various features and advantages of the invention are set forth in the following claims.

Claims

1. a pedal housing including a forward mounting surface for securing the pedal within a vehicle; a rotatable pedal having a proximal portion disposed within the pedal housing and a distal portion including a footpad spaced from the pedal housing, the pedal being biased to a first limit position relative to the pedal housing, the distal portion being configured to be actuated in a forward direction from the first limit position; a friction system for generating resistance to movement of the pedal toward and away from the first limit position, A vehicle pedal assembly, wherein the friction system includes a friction lever having a friction pad, the friction lever carried by the pedal and pivotable on the pedal to establish frictional contact with a friction contact surface of the pedal housing.

2. The vehicle pedal assembly of claim 1 , wherein the friction lever is nested within the pedal.

3. 2. The vehicle pedal assembly of claim 1, wherein a portion of the friction contact surface is an arcuate surface centered on the pivot axis of the pedal, and the friction lever is configured to apply a force to the friction contact surface of the pedal housing in a direction toward the pivot axis of the pedal.

4. 2. The vehicle pedal assembly of claim 1, wherein the friction lever is saddle-shaped and includes a pair of spaced-apart side walls having a spring cavity therebetween, each of the pair of spaced-apart side walls pivotally coupled to the pedal.

5. 2. The vehicle pedal assembly of claim 1, further comprising a spring cap, the spring cap having a first side that engages with at least one spring to maintain its position, and the spring cap having a second side that forms a sliding interface with the friction lever.

6. 2. The vehicle pedal assembly of claim 1, wherein a spring acting to bias the pedal to the first limit position urges the friction lever about a first contact point and defines a second contact point where the friction pad touches the friction contact surface of the pedal housing, the first contact point being farther from a pivot axis of the friction lever on the pedal than the second contact point, and the force from the spring is amplified according to a lever ratio of the friction lever in generating a force from the friction pad to the friction contact surface of the pedal housing.

7. 10. The vehicle pedal assembly of claim 1, wherein the pedal housing is a multi-piece housing including an electrical connector connected to a position sensor module including a contactless sensor configured to track the position of the pedal.

8. The vehicle pedal assembly of claim 1 , wherein the friction pad is overmolded onto the body of the friction lever.

9. 2. The vehicle pedal assembly of claim 1, wherein the offset distance between the mounting surface and the pedal pivot axis is less than 26 mm.

10. 2. The vehicle pedal assembly of claim 1, wherein the offset distance between the mounting surface and the pedal pivot axis is less than 25 mm.

11. a mounting surface for securing the device within the vehicle; an accelerator pedal including a footpad, the accelerator pedal being biased to a first limit position by a spring, the footpad being configured to be actuated in a forward direction from the first limit position; a friction system for generating resistance to movement of the accelerator pedal toward and away from the first limit position, the friction system includes a friction lever pivotally supported on the accelerator pedal; The spring applies a force to the friction lever such that the resistance force varies according to the deflection of the spring.

12. 12. The accelerator pedal assembly of claim 11, further comprising a pedal housing including the mounting surface, and opposite the foot pad, the accelerator pedal including a proximal portion disposed within the pedal housing and supported for rotation about a pedal axis.

13. 13. The accelerator pedal assembly of claim 12, wherein the friction lever contacts the friction contact surface of the pedal housing with a force proportional to the force from the spring.

14. 14. The accelerator pedal assembly of claim 13, wherein the friction lever is configured to amplify the force from the spring when applying a force to the friction contact surface of the pedal housing.

15. 14. The accelerator pedal assembly of claim 13, wherein a portion of the friction contact surface is an arcuate surface centered on the pedal shaft, and the friction lever is configured to apply a force to the friction contact surface of the pedal housing in a direction toward the pedal shaft.

16. 13. The accelerator pedal assembly of claim 12, wherein the pedal housing is a multi-piece housing including an electrical connector connected to a position sensor module including a contactless sensor configured to track the position of the accelerator pedal.

17. 12. The accelerator pedal assembly of claim 11, wherein the friction lever includes at least one friction pad overmolded onto a body of the friction lever.

18. 12. The accelerator pedal assembly of claim 11, wherein the friction lever is nested within the accelerator pedal.

19. 12. The accelerator pedal assembly of claim 11, wherein the friction lever is saddle-shaped and includes a pair of spaced-apart side walls having a spring cavity therebetween, each of the pair of spaced-apart side walls pivotally coupled to the accelerator pedal.

20. 12. The accelerator pedal assembly of claim 11, further comprising a spring cap, the spring cap having a first side that engages the spring to maintain its position, and the spring cap having a second side that forms a sliding interface with the friction lever.

21. 12. The accelerator pedal assembly of claim 11, wherein the offset distance between the mounting surface and the pivot axis of the accelerator pedal is less than 26 mm.

22. 12. The accelerator pedal assembly of claim 11, wherein the offset distance between the mounting surface and the pivot axis of the accelerator pedal is less than 25 mm.

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