Pedal supporting type friction device

Abstract

A vehicle pedal assembly includes a pedal housing having a mounting surface on a front side for securing within a vehicle. The rotatable pedal has a proximal end portion located within the pedal housing and a distal end portion including a foot pad spaced from the pedal housing. The pedal is biased relative to the pedal housing to a first limited position, and the distal portion is configured to actuate forward from the first limited position. A friction system is provided for generating a retarding force that prevents the pedal from moving toward and away from the first limit position. The friction system includes a friction lever having a friction pad, the friction lever being carried by the pedal and pivotable on the pedal to establish frictional contact with the frictional contact surface of the pedal housing.

Description

Background Art

[0001] The present invention relates to a pedal assembly, such as in a vehicle where a user controls the accelerator, brake and optionally the clutch with their foot. Such a pedal, particularly an accelerator pedal, may include a variable friction device so that the user need not constantly provide a holding force equal to the spring bias force during continued pedal actuation. To this end, a friction lever may be supported on a housing of the pedal assembly and engage a portion of the pedal to provide a frictional retardation to movement. Summary of the invention

[0002] In one aspect, the present invention provides a vehicle pedal assembly. The pedal housing includes a mounting surface located on the front side for fixing in a vehicle. The rotatable pedal has a proximal portion located in the pedal housing and a distal portion including a foot pad spaced apart 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 actuate forward from the first limit position. A friction system is provided for generating a blocking force to prevent the pedal from moving toward and away from the first limit position. The friction system includes a friction lever having a friction pad, the friction lever being carried by the pedal and being pivotable on the pedal to establish friction 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 fixing within a vehicle, and an accelerator pedal including a foot pad. The accelerator pedal is biased by a spring to a first limit position relative to the mounting surface, and the foot pad is configured to actuate forward from the first limit position. A friction system is provided to generate a retarding force that prevents the accelerator pedal from moving 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 so that the retarding force varies according to the deflection of the spring. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0005] Figure 2 is a perspective view of a pedal assembly including a pedal-supporting friction device according to one embodiment of the present invention.

[0006] Figure 3 yes Figure 2 Side view of a pedal assembly with the housing removed to show the internal components.

[0007] Figure 4 yes Figure 2 A perspective view of a pedal assembly with the housing and pedal removed to show the internal components.

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

[0009] Figure 6 is along Figure 2 Cross-sectional view of the pedal assembly taken along centerline 6-6.

[0010] Figure 7 is along Figure 2 Cross-sectional view of the pedal assembly taken along centerline 7-7.

[0011] Figure 8 is along Figure 7 A cross-sectional view of the pedal assembly taken along the center line 8-8.

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

[0013] Fig.10 It is the force analysis diagram of the friction lever of the friction system. DETAILED DESCRIPTION

[0014] Before explaining any embodiment of the present invention in detail, it should be understood that the application of the present invention is not limited to the details of the construction and component arrangement set forth in the following description or shown in the accompanying drawings. The present invention can have other embodiments and can be practiced or implemented in various ways. It should be understood that the description of specific embodiments is not intended to limit the content of the present invention, so that it cannot cover all modifications, equivalents and alternatives within the spirit and scope of the content of the present invention. In addition, it should be understood that the words and terms used herein are for descriptive purposes and should not be regarded as limiting.

[0015] Figure 1A vehicle is shown including a pedal assembly 20 positioned for use by a driver of the vehicle to control travel of the vehicle. In one construction, the pedal assembly 20 is an accelerator pedal assembly. The pedal assembly 20 may include a housing 24 configured to be mounted to a bulkhead 28 (or "firewall") of the vehicle. A pedal arm or simply "pedal" 32 extends from the housing 24, the pedal arm 32 being supported at a pivot 36 in the housing 24. A distal portion of the pedal 32 may be provided with a foot pad or footrest 40 for contact by the driver's foot. In some constructions, 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 to an electronic control module (ECM) 42 of the vehicle for signal communication 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 to prevent movement of the pedal 32 relative to the housing 24, thereby damping movement of the pedal 32 and reducing driver fatigue. Friction systems are known in the prior art, including, for example, U.S. Patent No. 6,515,473 or, more recently, U.S. Patent No. 11,307,606, both of which are incorporated herein by reference in their entirety. However, due to packaging and weight reduction constraints on mass-produced automobiles, it is increasingly difficult to meet design goals using such prior art arrangements. For example, recently, it has become desirable to set the offset distance X between the bulkhead 28 and the pivot 36 of the pedal 32 to be very small, thereby reducing the available space in the housing 24. Conventional designs may already have a relatively small offset distance (e.g., about 27 mm), and if this is further significantly reduced by more than 5% or 7%, it is simply impossible to meet the design goals by further miniaturizing the conventional layout, so a completely new approach is required.

[0016] Figure 2 The pedal assembly 20 is shown in isolation, wherein only a portion of the pedal arm 32 is shown near the housing 24, and it should be understood that the pedal 32 extends further in the downward direction of the view toward the foot pad 40. The pivot 36 defines an axis of rotation A of the pedal 32, which can be Figure 3 , where the housing 24 is at least partially removed, and can also be seen in Fig. 9. The pivot shaft 36 may be configured with one or more bearings, such as a plain bearing having 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 protrudes outwardly from the main portion 24A of the housing 24 (e.g., generally in the direction opposite to the pedal 32). A cable harness connector (not shown) may be plugged into the electrical connector 46. The electrical connector 46 may form 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 also form a portion of the housing 24. The main housing portion 24A, the closure member 48, and the electrical connector 46 may be combined to form the housing 24, within which is disposed a position sensor module 50 coupled to the electrical connector 46. The position sensor module 50 may include a non-contact sensor (e.g., a Hall effect magnetic sensor) and may be combined with an integrated circuit on a printed circuit board, such as Figure 4 and Figure 5 As shown. In other configurations, any suitable and readily available sensor topology may be used. The position sensor module 50 can track the movement of the pedal 32 within the available range of motion. For use with the Hall effect sensor, a magnet 54 can be affixed to the pedal 32, near the position sensor module 50. When the pedal 32 moves, the magnet 54 passes through the position sensor module 50 and detects changes in the magnetic field to accurately track the position of the pedal 32.

[0017] Figure 2 and Figure 3 The pedal 32 is shown in a first restrained position, which is an unactuated or resting position (also referred to as an "idle" position). The pedal 32 is biased to the first restrained position by at least one spring (e.g., two concentric springs 58, 60). The springs 58, 60 are located within the housing 24. The pedal 32 (at least its distal portion) can be moved in a forward direction F ( Figure 1 and Figure 2 ) moves against the bias. The forward direction F is toward the side of the mounting surface 62 of the housing 24, and the forward direction F can be perpendicular to a reference plane defined by the mounting surface 62 (although the mounting surface 62 itself can be planar). The forward direction F generally points in the direction of forward vehicle travel, with the pedal assembly 20 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 FIG. Figure 6 and Figure 7 As shown, the closure member 48 can provide a spring seat for positioning each spring 58, 60. Only under the force of the springs 58, 60 (without other forces from the user), as shown in FIG. Figure 8As shown, a portion of the pedal 32 provided as a stop or crosspiece 33 is pushed into contact with a stop or buffer 64 of the housing 24. Fig. 9 In the illustrated structure, two buffers 64 are disposed on opposite sides of the main housing portion 24A. The buffers 64 define a first limited position of the pedal 32 relative to the housing 24. The pedal 32 can be inserted through an opening 68 ( Figure 2 and Fig. 9 ) from the first check position to a second check position or a maximum brake (e.g., full throttle) position (not shown). The second check position of the pedal 32 may be defined by contact between the pedal 32 and one or more stop surfaces 70 of the housing 24. Fig. 9 As shown, the main housing portion 24A may provide a stop surface 70 that is divided into two or more spacers with a gap therebetween.

[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 contact one or more friction contact surfaces 82 of the pedal housing 24 to frictionally engage. At least a portion of each surface 82 may be along an arc centered on the pedal axis A. As the pedal 32 moves further away from the first limit position, the biasing force from the springs 58, 60 increases. As the pedal 32 moves further away from the first limit position, the friction system operates to increase the friction force (by increasing the normal force between the friction pad 80 and the friction contact surface 82). In other words, the friction lever 76 is gradually actuated in direct response to the movement of the pedal 32 away from the first limit position and toward the second limit position. On the other hand, when the pedal 32 returns toward the first limit position, the friction lever relieves the frictional resistance. The low friction in the initial region of the pedal stroke ensures that the friction system does not interfere with the ability of the pedal 32 to return to the first limit position. The friction in the initial region of the pedal stroke is also less likely to cause driver fatigue issues because the driver is less likely to maintain the position of the pedal 32 close to the first limit position for a long time.

[0019] The friction lever 76 is supported by the pedal 32 and pivots on the pedal 32 rather than on 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 construction, the pivot connection is formed by two opposed and laterally opposed hinge pins 86 of the friction lever 76, which are received in complementary sockets 88 of the pedal 32, as shown. Figure 3 and Figure 6 As shown. Fig. 9 In the embodiment shown, the pedal 32 is removed and the hinge pin 86 is also visible. In other constructions, the hinge pin 86 and the socket 88 can be reversed so that the pedal 32 includes the hinge pin. Figure 3 , Figure 6 and Figure 7 As can be seen in FIG. 8 , the friction lever 76 is partially or fully nested in the pedal 32 , and the pedal 32 includes a cavity for accommodating the friction lever 76 .

[0020] Figure 7 is a cross-section of the interface where the friction pad 80 engages the friction contact surface 82 of the pedal housing 24 . Figure 8 and Fig. 9 A clear view of these interfaces is also provided. The friction pads 80 may be formed on opposite lateral sides of the body 90 of the friction lever 76. The friction pads 80 may be formed on lateral projections 92 of the body 90. Although not required in all embodiments, the friction pads 80 may be made of a separate material that is different from the material forming the body 90 of the friction lever 76. The body 90 may be a glass-filled resin (nylon) and the friction pads 80 may be an unfilled self-lubricating POM (polyoxymethylene). In some structures, the friction pads 80 are overmolded onto the body 90 to form the friction lever 76. In structures having two lateral projections 92, as shown, the two spaced apart friction pads 80 may be molded as a continuous piece with a central connecting strip spanning the body 90 ( Figure 4 and Fig. 9 ).

[0021] As described above, the friction lever 76 is embedded in the pedal 32. In addition, the friction lever 76 can be saddle-shaped ( Figure 6 ), including a top wall and two side walls. A cavity for partially accommodating springs 58, 60 is provided in the friction lever 76 below the top wall and between the side walls. The side wall is pivotally connected to the pedal 32 via a hinge pin 86 formed thereon in the illustrated structure. A spring cap 96 is located between the top wall of the friction lever 76 and the springs 58, 60. Therefore, the springs 58, 60 do not directly contact the friction lever 76. The spring cap 96 forms a sliding interface with the inner side of the top wall of the friction lever, which largely or completely limits the springs 58, 60 to transmit force along the axis when bending, rather than transmitting force outside the axis. The spring cap 96 may have a shape complementary to the ends of the springs 58, 60 to maintain their positioning.

[0022] Fig.10 is a cross section of the pedal assembly 20, with the force diagram labeled for the forces on the friction lever 76. A coordinate system is used where the x-direction is parallel to the planar interface between the spring cap 96 and the interior of the friction lever 76. The y-direction is perpendicular to the x-direction as shown. Although the parts themselves have depth in the page, the force diagram is resolved into a two-dimensional system because any forces acting inside / outside the page are negligible. The springs 58, 60 generate and apply a force F S (via spring cap 96) to the underside of friction lever 76. Force F SIt varies according to the pedal position and the spring deflection, parallel to the y direction and perpendicular to the x direction. At the same point, a vertical friction force f can be applied S , although very small or negligible. S 、f S The moment arm distances r acting on the pivot axis B established between the friction lever 76 and the pedal 32 are SX and r SY If Fig.10 As shown, the force generated by springs 58 and 60, namely F S , exerting a clockwise moment on friction lever 76 about pivot axis B. Due to the configuration of surface 82, this causes friction pad 80 to abut against housing surface 82 with a force (not shown) directed toward axis A of pedal pivot 36. Of course, the increased spring force F S The friction pad 80 causes an increase in the force applied to the surface 82 by the friction pad 80. The surface 82 acts on the friction lever 76 with a force F1 perpendicular to the surface 82. Based on the coefficient of friction, the force F1 results in a friction force f1 that is 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 f1 is responsible for resisting the movement of the pedal 32. Depending on the direction of the pedal movement, the friction force f1 can act on the pedal 32 in conjunction with the spring force (as shown, during pedal actuation) or in opposition to the spring force (during pedal release). The forces F1, f1, respectively, act at a moment arm distance r from the pivot axis B established between the friction lever 76 and the pedal 32. 1X and r 1Y Finally, the pedal 32 acts on the friction lever 76 with a force F3. The force F3 is directed through the pivot axis B (on the hinge pin 86), so there is no moment arm, or the length of the moment arm is zero.

[0023] Through observation Fig.10 It can be seen that the various force arms of the spring force and the friction f1 generated at the friction pad 80 cause the spring force F S In other words, the arm length r 1X and r 1Y The value is shorter than the lever arm length r SX and r SY This results in a particular lever ratio that is specific to the physical configuration of the friction lever 76, e.g., the location of the wall that houses the spring cap 96 relative to the location of the friction pad 80 and the location of the pivot axis B (through the hinge pin 86). The effective lever ratio, and therefore the amount of amplification from the spring force to the 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 described above, the pedal assembly 20 having the friction system disclosed herein can provide a very compact, lightweight product for mass-produced passenger cars or other special purpose vehicles. In some constructions, the offset distance X between the pedal arm pivot axis A and the mounting surface 62 is less than 26 mm, and in some constructions is less than 25 mm. The offset distance X can be greater than or equal to 10 mm, and in some constructions is greater than or equal to 20 mm or greater than or equal to 24 mm.

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

Claims

1. A vehicle pedal assembly, comprising: a pedal housing including a front mounting surface for securing within a vehicle; a rotatable pedal having a proximal portion disposed within a pedal housing and a distal portion including a foot pad spaced from the pedal housing, wherein the pedal is biased relative to the pedal housing to a first stop position and the distal portion is configured to be actuated forwardly from the first stop position; as well as a friction system for generating a retardation force preventing the pedal from moving toward and away from the first limit position, The friction system includes a friction lever with a friction pad, the friction lever is carried by the pedal and can pivot on the pedal to form friction contact with the friction contact surface of the pedal housing. 2 . The vehicle pedal assembly of claim 1 , wherein the friction lever is embedded in the pedal.

3. 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 so that 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. The vehicle pedal assembly of claim 1, wherein the friction lever is saddle-shaped and includes a pair of spaced-apart side walls with a spring cavity therebetween, wherein each of the pair of spaced-apart side walls is pivotally connected to the pedal.

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

6. The vehicle pedal assembly of claim 1, wherein a spring for biasing the pedal to the first limit position is pressed against the friction lever about a first contact point, and the friction pad defines a second contact point at which the friction pad contacts the friction contact surface of the pedal housing, and wherein the first contact point is farther from a pivot axis of the friction lever on the pedal than the second contact point, so that when a force is generated from the friction pad to the friction contact surface of the pedal housing, the force from the spring is amplified according to the lever ratio of the friction lever.

7. 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 non-contact sensor configured to track the position of the pedal. 8 . The vehicle pedal assembly of claim 1 , wherein the friction pad is overmolded to a body of the friction lever.

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

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

11. An accelerator pedal assembly, comprising: For securing to a mounting surface within a vehicle; an accelerator pedal including a foot pad, wherein the accelerator pedal is spring biased to a first check position, and the foot pad is configured to actuate forward from the first check position; as well as a friction system for generating a retardation force preventing the accelerator pedal from moving toward and away from the first limit position, wherein the friction system comprises a friction lever pivotally supported on the accelerator pedal, and The spring applies a force to the friction lever such that the blocking force varies according to the deflection of the spring.

12. The accelerator pedal assembly of claim 11, further comprising a pedal housing having a mounting surface, wherein: Opposite to the foot pad, the accelerator pedal includes a proximal end portion located in the pedal housing and supported to rotate about a pedal axis. 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 a force of the spring.

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

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

16. 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 non-contact sensor configured to track the accelerator pedal position. 17 . The accelerator pedal assembly of claim 11 , wherein the friction lever includes at least one friction pad overmolded to the friction lever body.

18. The accelerator pedal assembly of claim 11, wherein the friction lever is embedded in the accelerator pedal.

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

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

21. 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 millimeters.

22. 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 millimeters.

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