JP2007253869A - Accelerator pedal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an accelerator pedal device which always performs stable pedal operation without changing hysteresis characteristics in pedaling between an initial use and after an endurance run. <P>SOLUTION: A slide contact part 36 of a friction plate 20 with a rotor 16 has a toric part where the side cross section equipped with a trapezoidal shape having a short side at the rotor side. Thus, the slide contact area of the rotor 16 with the friction plate 20 is gradually increased accompanied by the progress of abrasion of the friction plate 20. Sliding resistance between the rotor 16 and the friction plate 20 is thereby increased by the amount corresponding to a variation of the hysteresis characteristics accompanied by the increase of a set length of the spring 18 after endurance, and as the result, the hysteresis characteristics in pedaling is prevented from being changed between the initial use and after the endurance run. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an accelerator pedal device for a vehicle, and more particularly to an accelerator pedal device having a hysteresis characteristic between an accelerator operation amount and a pedaling force.

  Conventionally, an accelerator pedal device that is depressed by a driver is known. Here, as described in, for example, Patent Document 1, in order to maintain the accelerator operation amount at a desired value even if the depression amount slightly varies, a movement resistance is added to the accelerator pedal, and the accelerator operation amount and its depression force are added. Hysteresis characteristics can be imparted between the two.

  FIG. 14A is a diagram schematically showing each component of a conventional accelerator pedal device. The accelerator pedal device 100 includes an accelerator pedal 102, a rotor 104 that can be rotated in accordance with the operation of the accelerator pedal 102, a spring 106 that urges the rotor 104, and a friction member that is fixed to be non-rotatable, that is, a friction plate. 108. Here, the accelerator pedal 102 includes a swash plate 110 that is inclined at an angle θ with respect to the pedal operation direction D1, while the rotor 104 has a slope 112 that is in surface contact with the swash plate 110. 104 rotates around the axis L and is also urged in the direction of the axis L. Accordingly, a sliding resistance corresponding to the pedal operation amount is generated between the rotor 104 and the friction plate 108. With such a configuration and operation, the accelerator pedal device can have hysteresis characteristics as indicated by the solid line in FIG. A specific example of such a configuration is described in FIGS. 3 and 4 of Patent Document 2, for example. In the example of Patent Document 2, members corresponding to the swash plate 110 and the inclined surface 112 are described as a plurality of helical teeth 34 and 35, respectively.

JP-A-6-299874 JP 2004-108214 A

  In the accelerator pedal device having hysteresis characteristics as described in Patent Documents 1 and 2, the friction plate is worn after use for a certain period, that is, after durability. Specifically, as shown in FIG. 14B, for example, as the friction plate 108 wears, the rotor 104 gradually moves in the direction of the arrow D2, that is, in the friction plate 108 side (upward in FIG. 14B). Displace. Further, since the rotor 104 is in contact with the swash plate 110 of the pedal 102 via a slope 112 like a helical tooth described in FIG. 3 or 4 of Patent Document 2, the axis L is set as compared with the initial use. As a result, the spring 106 rotates in the direction in which the spring 106 extends. Therefore, when compared with the same accelerator operation amount (rotation angle) between the initial use and the endurance of the accelerator pedal device, the latter increases the set length of the spring 106, which causes the rotor 104 to spring. The biasing force received from 106 decreases. From this, the hysteresis characteristic of the accelerator pedal device 100 transitions from the initial use state indicated by the solid line to the post-endurance state indicated by the broken line, as shown in FIG. Therefore, the relationship between the depression force and the accelerator operation amount, which is important in the accelerator pedal device, changes. Specifically, after the endurance, the stepping force for obtaining the same rotor rotation angle, that is, the accelerator operation amount becomes smaller, and the driver feels that the pedal operation is “light”.

  Accordingly, an object of the present invention is to provide an accelerator pedal device in which the hysteresis characteristics at the time of depressing do not change between the initial stage of use and after endurance, and a stable pedal operation is possible in order to eliminate the above-mentioned problems. And

  In order to achieve the above object, the invention according to claim 1 is an accelerator pedal operated by an operator's stepping force, a movable member configured to be displaced according to an operation amount of the accelerator pedal, A return force applying means for applying to the movable member a return force that increases as the amount of operation of the accelerator pedal increases; and a friction member configured to be in sliding contact with the movable member; An accelerator pedal device that generates a sliding resistance between the movable member and the friction member so that a predetermined hysteresis characteristic is obtained between the pedal force and the friction member, and the friction member An accelerator pedal device is provided that is configured to increase sliding resistance with the movable member.

  According to a second aspect of the present invention, in the accelerator pedal device according to the first aspect, the sliding contact portion with the movable member of the friction member is movable as the wear of the sliding contact portion progresses. An accelerator pedal device is provided that is configured to have a large contact area with a member.

  According to a third aspect of the present invention, in the accelerator pedal device according to the second aspect, the sliding contact portion with the movable member of the friction member has a trapezoidal shape in which a side section has a short side on the movable member side. An accelerator pedal device is provided.

  According to a fourth aspect of the present invention, in the accelerator pedal device according to the second aspect, the sliding contact portion with the movable member included in the friction member has a curved surface with a convex side section on the movable member side. Provided is an accelerator pedal device characterized by being saddle-shaped.

  According to a fifth aspect of the present invention, in the accelerator pedal device according to the third or fourth aspect, the movable member is configured to rotate about an axis in accordance with the operation of the accelerator pedal, and the friction member includes An accelerator pedal device is provided, wherein the sliding contact portion with the movable member has an annular shape.

  According to a sixth aspect of the present invention, in the accelerator pedal device according to the second aspect, the movable member is configured to rotate about an axis in accordance with the operation of the accelerator pedal, and the movable member has the movable member. An accelerator pedal device, wherein the sliding contact portion with the member is configured to move in an outer diameter direction with respect to the axis of the movable member as wear of the sliding contact portion progresses. I will provide a.

  According to a seventh aspect of the present invention, in the accelerator pedal device according to the sixth aspect, the sliding contact portion with the movable member of the friction member has a trapezoidal shape in which a side section has a short side on the movable member side. An accelerator pedal device is provided, characterized in that the inclination of the two oblique sides with respect to the short side of the trapezoidal shape is smaller in the oblique side on the axis side.

  The invention according to claim 8 is the accelerator pedal device according to claim 6, wherein the sliding contact portion with the movable member included in the friction member has a curved surface whose side section is convex toward the movable member. There is provided an accelerator pedal device having a hook-shaped annular portion, wherein the convex curve has different curvatures on the inner diameter side and the outer diameter side with respect to the axis.

  According to the accelerator pedal device of the present invention, the sliding resistance between the movable member and the friction member can be increased as the friction member wears, so that the return force of the return force applying means due to the wear of the friction member is reduced. It is possible to suppress a decrease in the resulting stepping force. Therefore, it is possible to provide an accelerator pedal device whose pedal force characteristics are stable from the initial use to after the endurance. Further, the increase in sliding resistance can be realized by increasing the sliding contact area between the movable member and the friction member as the wear progresses. Alternatively, the increase in the sliding resistance is caused by moving the position of the sliding contact portion relative to the movable member in the outer diameter direction with respect to the axis along with the progress of wear of the friction plate, in other words, the sliding of the sliding contact portion relative to the movable member. It can also be realized by increasing the length in the moving direction.

  Hereinafter, the present invention will be described in detail with reference to the drawings. 1 and 2 are respectively a top view and a side sectional view of an accelerator pedal device 10 according to the present invention, and FIG. 3 is a sectional view taken along line 3-3 in FIG. The accelerator pedal device 10 is mounted on a vehicle and is used to send driving information such as an accelerator operation amount to an engine control device (ECU) (not shown) in order to control the driving state of the vehicle in accordance with a driver's operation. The housing 12, the accelerator pedal 14 accommodated in the housing 12 so as to be rotatable around the axis L, a movable member which can be rotated in accordance with the operation of the accelerator pedal 14, that is, the rotor 16, and the rotor accommodated in the housing 12. A return force applying means for applying a return force for returning 16 to the original position, that is, a spring 18, and a friction member that is provided in a non-rotatable manner and is in sliding contact with the rotor 16, that is, a friction plate 20. As can be seen from the drawing, the spring 18 can give the rotor 16 a restoring force that increases as the operation amount of the accelerator pedal 14, that is, the rotation angle increases. Further, although two coil springs having different diameters are shown as the spring 18, one, three or more coil springs may be used, or another spring may be used. The housing 12, the accelerator pedal 14, the rotor 16, and the friction plate 20 are preferably resin molded products.

  The accelerator pedal 14 can be rotated about the axis L by the operation of the pad 22 by the driver, and the rotation angle can be detected by the rotation angle sensor 24 as an accelerator operation amount. As the rotation angle sensor 24, a non-contact type sensor including magnets 26a, 26b and Hall elements 28 having different polarities provided so as to be integrally rotatable with respect to the axis L in accordance with a pedal operation is possible. A contact type not shown may be used. The accelerator pedal device 10 may have a cover 30 that protects the rotation angle sensor 24.

  The accelerator pedal 14 and the rotor 16 are engaged in part A in FIG. 3. Specifically, for example, the accelerator pedal 14 and the rotor 16 have a helical structure as shown in FIG. 9 of Patent Document 1 or FIG. Match. Accordingly, the rotor 16 rotates about the axis L as the accelerator pedal 14 rotates about the axis L, and is urged in a direction to be pressed against the friction plate 20. Therefore, as the rotation angle of the accelerator pedal 14 is larger, the pressing force applied to the friction plate 20 is also increased. As a result, the sliding resistance between the rotor 16 and the friction plate 20 is also increased. This is schematically illustrated in FIGS. 4 (a) and 4 (b). 4A shows the initial use of the accelerator pedal device 10, and FIG. 4B shows the state after durability. As shown in the figure, the accelerator pedal 14 has a swash plate 32 having an angle θ with respect to the pedal operation direction, while the rotor 16 has a shape complementary to the swash plate 32, that is, an angle with respect to the pedal operation direction. The slope 34 forms (180 ° −θ).

  When the driver steps on the pad 22 of the accelerator pedal 14, the accelerator pedal 14 rotates about the axis L in the direction indicated by the arrow D3 in FIG. As described above, the accelerator pedal 14 has the swash plate 32 having an angle θ with respect to the pedal operation direction, while the rotor 16 has the inclined surface 34 in surface contact with the swash plate 32, so that the rotor 16 rotates around the axis L. While rotating, it is also urged in a direction (right side in FIG. 3) pressed against the friction plate 20 along the axis L. Accordingly, a sliding resistance corresponding to the pedal operation amount is generated between the rotor 16 and the friction plate 20.

  Since the conventional friction plate 108 has an annular portion, that is, a sliding contact portion 114 having a rectangular side cross section as shown in FIGS. 5 (a) and 5 (b), it can be seen from FIGS. 10 (a) and 10 (b). As described above, the sliding contact area between the rotor and the friction plate does not change even when wear progresses. Therefore, as described above, as wear of the friction plate progresses, the hysteresis characteristic changes by the amount of extension of the spring set length (the graph shifts downward in FIG. 15). However, in the present invention, in the friction plate 20 according to the first embodiment shown in detail in FIGS. 6A and 6B, the sliding contact portion 36 with the rotor 16 has a side cross section (a plane including the axis L). The cross-section cut at) has a trapezoidal annular portion with a short side 38 on the rotor side. Therefore, as the wear progresses, the sliding contact area between the rotor 16 and the friction plate 20 gradually increases. As a result, it is possible to increase the sliding resistance between the rotor 16 and the friction plate 20 by an amount corresponding to the amount of change in hysteresis characteristics (the amount of decrease in pedaling force) that accompanies an increase in the set length of the spring 18 after endurance. As shown in FIG. 7, the hysteresis characteristic when the accelerator is depressed can be substantially unchanged between the initial stage of use and after the endurance. In FIG. 7, the initial use, the endurance (present invention), and the endurance (conventional) are indicated by a two-dot chain line, a solid line, and a broken line, respectively. As can be seen from FIG. 7, in the present invention, the hysteresis characteristic when the accelerator is returned after endurance shifts further downward than in the conventional case, but the pedaling force range at the same rotation angle is expanded, so that the accelerator opening degree It becomes easier to keep the constant. In general, when the accelerator is returned, an operation for holding the accelerator constant at a certain opening is often required, and this is also one of the effects of the present invention.

  In order to substantially match the hysteresis characteristics when the pedal is depressed after the endurance, specifically, an increase amount of the set length of the spring 18 with respect to the wear amount of the friction plate 20, and a decrease in the urging force of the spring 18 thereby. Find the relationship between quantities in advance. Next, the reaction force of the spring 18 at a certain rotation angle, that is, the urging force F1 (see FIG. 4A) coincides with the component force F2 in the expansion / contraction direction of the spring 18 of the pedal depression force (that is, proportional to tan θ) (that is, the accelerator pedal is The sliding contact area, that is, the sliding of the friction plate 20 so that the sliding resistance between the rotor 16 and the friction plate 20 when maintaining a certain rotation angle coincides with the decrease amount of the spring reaction force F1 with the increase in the set length. The dimension of the contact part 36 is defined. Here, the sliding resistance can be obtained as a function of a force F3 (proportional to 1 / tan θ) for pressing the rotor 16 against the friction plate 20, a sliding contact area, and a sliding average diameter described later.

  Moreover, according to the accelerator pedal apparatus which concerns on this invention, the lifetime of the rotor 16 can be improved. That is, the actual sliding contact area between the rotor 16 and the friction plate 20 increases with the progress of wear of the friction plate 20, so that even if the pressing force applied to the friction plate 20 by the rotor 16 is the same. The force (surface pressure) per unit area is reduced compared to the conventional case. Therefore, the tendency that only a specific part of the rotor 16 is worn is weakened. As a result, the life of the rotor can be extended and the replacement frequency can be reduced.

  FIG. 8 is a side sectional view of a friction plate 20 ′ according to the second embodiment, similar to FIG. 6B, and FIGS. 9A and 9B are FIGS. 4A and 4B. 5 is a schematic view in which the friction plate 20 is replaced with a friction plate 20 ′. The sliding contact portion 36 ′ of the friction plate 20 ′ has a semicircular or bowl-shaped annular shape with a convex arc or curve on the rotor 16 side, instead of the trapezoidal shape shown in FIG. Part. Even with such a shape, the sliding contact area with the rotor 16 can be increased as the sliding contact portion wears, and the same effect as in the first embodiment can be obtained.

  FIG. 10 is a perspective view and a side sectional view of the friction plate 20 ″ according to the third embodiment. FIGS. 11 (a) and 11 (b) show the friction plate 20 in FIG. 4 (a) and FIG. 4 (b). It is the schematic diagram substituted by board 20 ''. The sliding contact portion 36 ″ of the friction plate 20 ″ is a trapezoidal ring-shaped portion whose side cross section has a short side on the rotor 16 side, so that the friction plate 20 ″ shown in FIGS. As in the sliding contact portion 36, the slopes of the two hypotenuses 40 "and 42" with respect to the trapezoidal short side 38 "are different from each other as shown in FIG. It is smaller (in the illustrated example, the hypotenuse 40 "and the short side 38" form a substantially right angle, and the hypotenuse 42 "and the short side 38" form an obtuse angle). According to such a configuration, the position of the sliding contact portion 36 ″ with respect to the rotor 16 moves in the outer diameter direction with respect to the axis L as the friction plate 20 ″ wears. In other words, the sliding average diameter increases as the wear progresses. Here, the sliding average diameter means an average value of the maximum diameter and the minimum diameter on the substantially annular sliding contact surface, and is represented by a symbol d in FIGS. 4 and 9. In the friction plates 20 and 20 'according to the first and second embodiments described above, the sliding average diameter d does not substantially change even when wear progresses. After the endurance, the sliding average diameter d becomes d 'larger than d. The larger the sliding average diameter, the higher the sliding speed in the sliding direction at the sliding contact portion. As the sliding resistance increases, the sliding resistance can be increased to a desired value without changing the sliding contact area, and the change in the sliding average diameter is combined with the change in the sliding contact area. In this case, although not shown, it is conceivable that the sliding average diameter becomes smaller as the wear progresses.

  FIG. 12 is a perspective view and a side sectional view of the friction plate 20 ″ ″ according to the fourth embodiment. FIGS. 13 (a) and 13 (b) show the friction plate 20 in FIGS. 4 (a) and 4 (b). FIG. 6 is a schematic view replaced with a friction plate 20 ″ ′. The sliding contact portion 36 ″ of the friction plate 20 ″ ′ is a hook-shaped annular portion whose side section is convex toward the rotor 16, so that the sliding contact portion 36 ′ of the friction plate 20 ′ shown in FIG. However, the curvature of the bowl-shaped curve is different between the inner diameter side and the outer diameter side with respect to the axis L, and more specifically, the curvature is smaller on the inner diameter side. Even with such a configuration, the position of the sliding contact portion 36 ″ ″ with respect to the rotor 16 can be moved in the outer diameter direction with respect to the axis L as the friction plate 20 ″ wears, that is, the sliding average diameter. Can be increased as the wear progresses.

It is a top view which shows the whole accelerator pedal apparatus which concerns on this invention. It is sectional drawing in the 2-2 line of FIG. It is sectional drawing in the 3-3 line of FIG. (A) It is a schematic diagram of the principal part of the accelerator pedal apparatus which concerns on the 1st Embodiment of this invention, Comprising: It is a figure showing the use initial stage, (b) It is a figure showing after durability. (A) It is a top view of the friction board of the conventional accelerator pedal apparatus, (b) It is a sectional side view which follows the 5b-5b line of (a). (A) It is a top view of the friction board of the accelerator pedal apparatus which concerns on the 1st Embodiment of this invention, (b) It is a sectional side view which follows the 6b-6b line | wire of (a). It is a graph explaining the hysteresis characteristic of the accelerator pedal apparatus of this invention compared with a conventional one. It is a sectional side view of the friction board of the accelerator pedal apparatus which concerns on the 2nd Embodiment of this invention. (A) It is a schematic diagram of the principal part of the accelerator pedal apparatus which concerns on the 2nd Embodiment of this invention, Comprising: It is a figure showing the use initial stage, (b) It is a figure showing after durability. It is a sectional side view of the friction board of the accelerator pedal apparatus which concerns on the 3rd Embodiment of this invention. (A) It is a schematic diagram of the principal part of the accelerator pedal apparatus which concerns on the 3rd Embodiment of this invention, Comprising: It is a figure showing the use initial stage, (b) It is a figure showing after durability. It is a sectional side view of the friction board of the accelerator pedal apparatus which concerns on the 4th Embodiment of this invention. (A) It is a schematic diagram of the principal part of the accelerator pedal apparatus which concerns on the 4th Embodiment of this invention, Comprising: It is a figure showing the use initial stage, (b) It is a figure showing after durability. (A) It is a schematic diagram of the principal part of the conventional accelerator pedal apparatus, Comprising: It is a figure showing the use initial stage, (b) It is a figure showing durability. It is a graph explaining the hysteresis characteristic of the conventional accelerator pedal apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Accel pedal apparatus 12 Housing 14 Accel pedal 16 Rotor 18 Spring 20, 20 ', 20 ", 20"' Friction plate 32 Swash plate 34 Slope 36, 36 ', 36 ", 36"' Sliding contact part

Claims (8)

An accelerator pedal (14) operated by the pedaling force of the operator;
A movable member (16) configured to be displaced according to an operation amount of the accelerator pedal (14);
Return force applying means (18) for applying a return force that increases with an increase in the operation amount of the accelerator pedal to the movable member (16);
A friction member (20, 20 ', 20 ", 20"') configured to slidably contact the movable member (16);
A sliding resistance is provided between the movable member (16) and the friction member (20, 20 ', 20 ", 20"') so that a predetermined hysteresis characteristic is obtained between the accelerator operation amount and the pedal effort. An accelerator pedal device (10) for generating,
As the friction member (20, 20 ′, 20 ″, 20 ″ ′) wears, the sliding resistance between the friction member (20, 20 ′, 20 ″, 20 ″ ′) and the movable member (16) increases. An accelerator pedal device, characterized by being configured as follows.   The sliding contact portion (36, 36 ', 36 ", 36"') of the friction member (20, 20 ', 20 ", 20"') with the movable member (16) is the sliding contact portion. The contact area with the movable member (16) increases as the wear of (36, 36 ', 36 ", 36"') progresses. Accelerator pedal device.   The sliding contact portion (36, 36 ″) with the movable member (16) of the friction member (20, 20 ″) has a trapezoidal shape in which the side section has a short side (38, 38 ″) on the movable member side. The accelerator pedal device according to claim 2, wherein the accelerator pedal device has a shape.   The sliding contact portion (36, 36 ″) with the movable member (16) of the friction member (20 ′, 20 ″) has a bowl shape with a side section having a convex curve on the movable member side. The accelerator pedal device according to claim 2, wherein the accelerator pedal device is provided.   The movable member (16) is configured to rotate about the axis (L) in accordance with the operation of the accelerator pedal (14), and the friction member (20, 20 ′, 20 ″, 20 ″ ′) has. The accelerator pedal device according to claim 3 or 4, characterized in that the sliding contact portions (36, 36 ', 36 ", 36"') with the movable member (16) have an annular shape.   The movable member (16) is configured to rotate about the axis (L) in accordance with the operation of the accelerator pedal (14), and the movable member (16) included in the friction member (20 ″, 20 ″ ′). ) With the axis (L) of the movable member (16) as wear of the sliding contact portions (36 ″, 36 ″ ′) progresses. The accelerator pedal device according to claim 2, wherein the accelerator pedal device is configured to move in an outer diameter direction.   The sliding contact portion (36 ″) of the friction member (20 ″) with the movable member (16) is a trapezoidal annular portion whose side section has a short side (38 ″) on the movable member side. The inclination of the two hypotenuses (40 ", 42") with respect to the short side (38 ") of the trapezoidal shape is smaller in the hypotenuse (40") on the axis (L) side. The accelerator pedal device according to claim 6.   The sliding contact portion (36 ″ ′) with the movable member (16) of the friction member (20 ″ ′) is a bowl-shaped annular portion having a convex side curve on the side of the movable member. The accelerator pedal device according to claim 6, wherein the convex curve has different curvatures on an inner diameter side and an outer diameter side with respect to the axis (L).

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