Brake pedal device

Abstract

To provide a brake pedal device which can improve operability by an operator.SOLUTION: A brake pedal device comprises a support part 10, a shaft member 20, a pedal base part 30 and a pedal operation part 40. An axial center CL of the shaft member 20 is positioned on a side opposite to a face 31 of the pedal base part 30 facing an operator side with respect to a center line S in a thickness direction of the pedal base part 30. When the operator wears shoes 70, and depresses and operates the pedal operation part 40, the operator brings a heel 71 of the shoes 70 into contact with a position of a floor 60 or the like separated from the axial center CL to the rear of a vehicle by a prescribed distance, and in the state that both a big toe ball 80 and a big toe belly 81 of the operator contact an insole 73 of the shoes 70, the operator can depress the pedal operation part 40. At that time, a positional relationship between the shaft member 20 and the pedal operation part 40 is regulated so that an angle at which MTP joint 82 of the operator bends toward an extension side according to increase in pedal stroke.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present disclosure relates to a brake pedal device mounted on a vehicle. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a brake pedal device, an accelerator pedal device, and the like are known as pedal devices mounted on a vehicle.

[0003] Patent Document 1 discloses an organ-type accelerator pedal device. The organ type refers to a pedal operating part, which is a part of the pedal that is stepped on by the driver, disposed on the upper side in the vehicle vertical direction (i.e., above the vehicle) with respect to the axis about which the pedal swings. The accelerator pedal device of Patent Document 1 is configured such that, when viewed from the direction in which the axis of the pedal extends (hereinafter referred to as the "axis direction"), the pedal operating part has a convex surface part and a flat surface part. The convex surface part is a curved surface that is convex toward the driver's side (i.e., the rear side of the vehicle), and the flat surface part is a flat surface that is provided continuously with the convex surface part on the upper side of the vehicle. This accelerator pedal device is configured such that, when the driver depresses the pedal, the contact point between the part of the driver's shoe that corresponds to the ball of the driver's foot and the pedal operating part moves smoothly from the flat surface part to the convex surface part as the pedal stroke increases. The pedal stroke is also called the pedal operation amount. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-204193 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the accelerator pedal device described in Patent Document 1, the distance between the flat surface of the pedal operation portion and the sole of the driver's shoe corresponding to the first toe gradually increases as the pedal stroke increases. Therefore, with this accelerator pedal device, as the pedal stroke increases, the driver's first toe gradually rises off the insole of the shoe, and the driver ends up operating the pedal with only the ball of the foot.

[0006] Generally, a brake pedal device mounted on a vehicle is set to generate a larger reaction force against the pedal force applied by the driver than an accelerator pedal device. Therefore, the pedal force required for the driver to operate the brake pedal device is larger than the pedal force required for the accelerator pedal device. Therefore, if the configuration of Patent Document 1 is applied to a brake pedal device, as the pedal stroke increases, the driver will not be able to apply a pedal force from the big toe to the pedal operation part, resulting in a problem of deterioration in operability.

[0007] In view of the above, an object of the present disclosure is to provide a brake pedal device that can improve operability by a driver. [Means for solving the problem]

[0008] According to one aspect of the present disclosure, a brake pedal device mounted on a vehicle includes: A support (10) that is attached to a vehicle; A shaft member (20) provided to the support portion; a pedal base (30) that is rotatable around an axis (CL) of the shaft member relative to the support portion within a predetermined angular range; a pedal operation unit (40) that is provided at the pedal base and is stepped on by the driver; The shaft center is located on the opposite side of the surface (31) of the pedal base that faces the driver with respect to the center line (S) in the thickness direction of the pedal base, When a driver wears a shoe (70) and depresses the pedal operation part, the heel (71) of the shoe can be placed in contact with a position on the vehicle floor (60) or a member placed on the floor that is a predetermined distance rearward from the axis of the vehicle, and the pedal operation part can be depressed with both the ball (80) and the pad (81) of the big toe in contact with the insole (73) of the shoe. The positional relationship between the shaft member and the pedal operation part is specified so that at this time, the angle at which the driver's MTP joint (82) bends toward the extension side increases as the pedal stroke increases.

[0009] According to this, the brake pedal device is configured such that the angle at which the driver's MTP joint is bent toward the extension side gradually increases as the pedal stroke increases. Therefore, as the pedal stroke increases, the contact area between the ball and the pad of the big toe and the insole of the shoe increases, and the foot pressure is distributed to the ball and the pad of the big toe, thereby mitigating an excessive increase in foot pressure. Therefore, this brake pedal device provides a good pedaling feeling by the ball and the pad of the big toe, and improves operability for the driver.

[0010] In addition, the gradual increase in the angle at which the MTP joint bends toward the extension side refers to the gradual increase in the angle at which the MTP joint bends toward the extension side due to design, and does not mean that the driver intentionally bends the MTP joint against the movement of the pedal. Shoes are generally shoes used for driving vehicles, such as sneakers, sneakers, and leather shoes. MTP is an abbreviation for metatarsophalangeal.

[0011] According to another aspect of the present disclosure, a brake pedal device mounted on a vehicle includes: A support (10) that is attached to a vehicle; A shaft member (20) provided to the support portion; a pedal base (30) that is rotatable around an axis (CL) of the shaft member relative to the support portion within a predetermined angular range; a pedal operation unit (40) that is provided at the pedal base and is stepped on by the driver; The axis is located on the opposite side of the pedal base to the surface facing the driver with respect to the center line (S) in the thickness direction of the pedal base, When using a human body model to operate the pedal operation unit by depressing it, the heel (H) of the human body model can be brought into contact with a position on the vehicle floor (60) or a component placed on the floor that is a predetermined distance toward the rear of the vehicle from the axis center, and the pedal operation unit can be depressed with both the ball of the foot (80) and the pad of the foot (81) of the human body model in contact with the pedal operation unit, and the positional relationship between the axis component and the pedal operation unit is specified so that the angle at which the MTP joint (82) of the human body model bends toward the extension side increases as the pedal stroke increases.

[0012] According to this, the behavior of the dummy and the behavior of the driver are similar to each other. Therefore, the brake pedal device according to another aspect of the present disclosure is also configured such that, as in the above-mentioned one aspect of the present disclosure, when the driver operates the pedal, the angle at which the MTP joint of the dummy is bent toward the extension side gradually increases as the pedal stroke increases. Therefore, the brake pedal device according to another aspect of the present disclosure can also improve the operability by the driver.

[0013] The dummy refers to one that is generally used in vehicle design.

[0014] According to another aspect of the present disclosure, a brake pedal device mounted on a vehicle includes: A support (10) that is attached to a vehicle; A shaft member (20) provided to the support portion; a pedal base (30) that is rotatable around an axis (CL) of the shaft member relative to the support portion within a predetermined angular range; a pedal operation unit (40) that is provided at the pedal base and is stepped on by the driver; The axis is located on the opposite side of the pedal base to the surface facing the driver with respect to the center line (S) in the thickness direction of the pedal base, The shaft member is located on an extension line (EL) of the average plane of the pedal operating portion, which is the average of the entire tread surface (41) facing the driver of the pedal operating portion, over the entire range of the pedal stroke.

[0015] According to this, the brake pedal device according to another aspect of the present disclosure is also configured such that the angle at which the driver's MTP joint is bent toward the extension side gradually increases as the pedal stroke increases, similar to the one and another aspects of the present disclosure. Therefore, the brake pedal device according to another aspect of the present disclosure can also improve the operability by the driver.

[0016] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0017] [Figure 1] 1 is a side view showing a state in which a pedal base portion is in an initial position in the brake pedal device according to a first embodiment. [Diagram 2] 1 is a side view showing a state in which a pedal base portion is in a full stroke position in the brake pedal device according to the first embodiment. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 1 and FIG. 2. [Figure 4] 1 is a side view showing a state in which a pedal base is in an initial position when a driver depresses the brake pedal device according to a first embodiment. FIG. [Diagram 5] 1 is a side view showing a state in which a pedal base is in a full stroke position when a driver depresses the brake pedal device according to a first embodiment. FIG. [Figure 6] FIG. 4 is an explanatory diagram for explaining the behavior of an MTP joint when a driver depresses the brake pedal device according to the first embodiment. [Figure 7] FIG. 4 is an explanatory diagram for explaining the behavior of an MTP joint when a driver depresses the brake pedal device according to the first embodiment. [Figure 8] 4 is a graph showing a relationship between a pedal stroke and a behavior of an MTP joint angle in the brake pedal device according to the first embodiment. [Figure 9]FIG. 2 is a side view showing a brake pedal device of a first comparative example. [Figure 10] FIG. 4 is a diagram showing the results of an experiment in which foot pressure distribution was measured when a driver depressed a pedal operation portion of the brake pedal device of the first comparative example to a full stroke position. [Figure 11] FIG. 4 is a diagram showing the results of an experiment in which foot pressure distribution was measured when a driver depressed a pedal operation portion of the brake pedal device according to the first embodiment to a full stroke position. [Figure 12] FIG. 11 is an explanatory diagram for explaining the behavior of the MTP joint when a driver depresses the brake pedal device in the second comparative example. [Figure 13] FIG. 11 is an explanatory diagram for explaining the behavior of the MTP joint when a driver depresses the brake pedal device in the second comparative example. [Figure 14] 13 is a graph showing the relationship between a pedal stroke and behavior of the MTP joint angle in a second comparative example. [Figure 15] FIG. 11 is a side view of a brake pedal device according to a second embodiment. [Figure 16] FIG. 11 is a side view of a brake pedal device according to a third embodiment. [Figure 17] FIG. 11 is a side view of a brake pedal device according to a fourth embodiment. [Figure 18] FIG. 13 is a side view of a brake pedal device according to a fifth embodiment. [Figure 19] FIG. 13 is a side view of a brake pedal device according to a sixth embodiment. [Figure 20] FIG. 13 is a side view of a brake pedal device according to a seventh embodiment. [Figure 21] FIG. 13 is a side view of the brake pedal device according to the eighth embodiment. [Figure 22] FIG. 13 is a side view of a brake pedal device according to a ninth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals, and the description thereof will be omitted.

[0019] (First embodiment) A first embodiment will be described. As shown in Figs. 1 to 3, the brake pedal device according to the first embodiment is an organ type mounted on a vehicle. The organ type refers to a brake pedal device in which a pedal operation unit 40, which is a part of the brake pedal device that is pressed by the driver, is disposed above the vehicle with respect to the axis of rotation CL when mounted on the vehicle. In the organ type brake pedal device, the pedal operation unit 40 rotates toward the front and bottom of the vehicle in response to an increase in the driver's pressing force applied to the pedal operation unit 40. In each drawing, arrows indicate the top, bottom, front, and rear of the vehicle when the brake pedal device is mounted on the vehicle.

[0020] The brake pedal device according to the first embodiment is used in a brake-by-wire system, in which an electronic control device mounted on a vehicle controls the driving of a brake circuit based on an electrical signal output from a sensor unit 50 provided in the brake pedal device to brake the vehicle.

[0021] As shown in FIGS. 1 to 3, the brake pedal device includes a support portion 10, a shaft member 20, a pedal base portion 30, a pedal operation portion 40, a sensor unit 50, and the like.

[0022] The support part 10 is attached to a floor 60 or a dash panel in the vehicle cabin. The support part 10 is sometimes called a housing. The dash panel is a partition wall that separates the inside of the vehicle cabin from the outside of the vehicle cabin, such as an engine room, and is also called a bulkhead. In the first embodiment, the support part 10 is attached to a recessed part 61 provided in a floor 60 of the vehicle. The recessed part 61 is a part recessed downward from the floor 60 or a member placed on the floor 60 (hereinafter referred to as the "floor 60, etc."). Therefore, the brake pedal device is attached so that the axis center CL of the shaft member 20 is located downward from the floor 60, etc. in the vehicle up-down direction (i.e., below the vehicle). The member placed on the floor 60 is, for example, a floor mat, a floor carpet, etc.

[0023] An initial stopper 11 that determines the initial position of the pedal base 30 and a full stroke stopper 12 that determines the full stroke position of the pedal base 30 are provided on the outer wall of the support portion 10. The initial position refers to a position where the pedal base 30 is in an initial state due to the biasing force generated by the reaction force generating mechanism 13 when the pedal force of the driver is not applied to the pedal operating portion 40, as shown in Fig. 1. The full stroke position refers to a position where the pedal base 30 is depressed to the maximum extent against the biasing force generated by the reaction force generating mechanism 13 when the pedal force of the driver is applied to the pedal operating portion 40, as shown in Fig. 2.

[0024] 3, a bearing portion 14 for rotatably supporting the shaft member 20 is provided inside the support portion 10. The shaft member 20 is rotatably supported by the bearing portion 14 via a bearing 15. Therefore, the shaft member 20 is rotatable about its own axis CL.

[0025] Moreover, a space is formed inside the support portion 10 in which the sensor unit 50 and the reaction force generating mechanism 13 are provided. By providing the reaction force generating mechanism 13, the brake pedal device can obtain a reaction force similar to that obtained when connected to the master cylinder (i.e., when a reaction force is obtained by hydraulic pressure) even if the mechanical connection between the master cylinder and the pedal base 30 constituting the conventional brake circuit is eliminated.

[0026] 1 and 2, the shaft member 20 and the pedal base 30 are fixed via a connecting portion 21. That is, one end of the connecting portion 21 is fixed to the shaft member 20, and the other end is fixed to the pedal base 30. Therefore, the pedal base 30 is rotatable within a predetermined angle range around the axis CL relative to the support portion 10. The pedal base 30 is formed in a plate shape. Although not shown in the drawings, the pedal base 30 is not limited to being plate-shaped, and may be rod-shaped or curved.

[0027] 1, a center line S in the thickness direction of the pedal base 30 is indicated by a dashed line. The shaft member 20 is located on the opposite side of the center line S in the thickness direction of the pedal base 30 to a surface 31 of the pedal base 30 that faces the driver side (i.e., the vehicle rear side). In detail, in the first embodiment, the shaft member 20 is provided at a position spaced a predetermined distance from the pedal base 30. By arranging the axis CL of the shaft member 20 and the pedal base 30 at positions spaced apart, it is possible to provide the sensor unit 50 in the space around the axis CL.

[0028] As shown in Fig. 3, the sensor unit 50 is provided on the axis CL of the shaft member 20, and detects the rotation angle of the shaft member 20, the pedal base 30, and the pedal operation unit 40 relative to the support unit 10. The rotation angle corresponds to the pedal stroke. The sensor unit 50 has a rotating unit 51 provided on the shaft member 20, and a signal output unit 52 provided on the support unit 10 for outputting a signal according to the phase of the rotating unit 51. In this embodiment, a non-contact sensor capable of detecting the pedal stroke without contact between the rotating unit 51 and the signal output unit 52 is used as the sensor unit 50.

[0029] The rotating part 51 is a magnetic circuit formed by, for example, a magnet 53 and a yoke, and is fixed to the shaft member 20 by a bolt 54, and rotates together with the shaft member 20. On the other hand, the signal output part 52 is composed of one or more Hall ICs 55, etc. When the rotating part 51 rotates together with the shaft member 20 around the axis CL, the magnetic flux density passing through the magnetic sensing surface of the Hall element of the Hall IC 55 changes. Therefore, the signal output part 52 outputs an electric signal according to the pedal stroke.

[0030] As shown in FIG. 1 and FIG. 2, the pedal operation part 40 is provided at a position of the pedal base part 30 away from the shaft member 20 and above the axis CL of the vehicle. The pedal operation part 40 is a part that is stepped on by the driver, in other words, a part that abuts against the sole of the shoe worn by the driver. In the first embodiment, the tread surface 41 of the pedal operation part 40 facing the driver is formed in a flat shape. In this disclosure, a flat shape includes a completely flat surface as well as an uneven surface such as a slip-resistant surface. As will be described later in the fourth and fifth embodiments with reference to FIG. 17 and FIG. 18, the pedal operation part 40 is not limited to a flat shape, and may be a concave or convex curved shape.

[0031] Here, the average surface of the entire tread surface 41 of the pedal operation unit 40 is referred to as the operation unit average surface, and the average surface of the entire surface 31 of the pedal base 30 facing the driver is referred to as the base average surface. In this case, the angle θ_p between the operation unit average surface and the base average surface is smaller than 180° on the driver's side. In other words, it can be said that the operation unit average surface is a surface that is inclined toward the driver's side (i.e., toward the rear of the vehicle) facing upward with respect to the base average surface.

[0032] In Fig. 1 and Fig. 2, the extension line EL of the operation unit average plane is indicated by a two-dot chain line. As shown in Fig. 1 and Fig. 2, in the brake pedal device of the first embodiment, the shaft member 20 is located on the extension line EL of the operation unit average plane from the initial position to the full stroke position. In other words, the shape of the tread surface 41 of the pedal operation unit 40 is specified so that the shaft member 20 is located on the extension line EL of the operation unit average plane over the entire range of the pedal stroke, preferably so that the axis CL of the shaft member 20 is located. Note that the tread surface 41 of the pedal operation unit 40 may be shaped so that a part of the shaft member 20 is located on the extension line EL of the operation unit average plane, as will be described later with reference to Figs. 15 and 16 in the second and third embodiments.

[0033] 4 and 5 show how the driver operates the brake pedal device of the first embodiment described above while wearing shoes 70. Note that the shoes 70 in this disclosure refer to shoes 70 generally used for driving a vehicle, such as sneakers, athletic shoes, leather shoes, etc.

[0034] As shown in FIG. 4 and FIG. 5, when the driver depresses the brake pedal device, the heel 71 of the shoe 70 is brought into contact with the floor 60 or the like at a position at a predetermined distance rearward from the axis CL of the vehicle, and a part of the sole 72 is brought into contact with the pedal operation unit 40. In the brake pedal device of the first embodiment, the driver can depress and operate the pedal operation unit 40 while keeping both the ball 80 and the pad 81 of the big toe in contact with the insole 73 of the shoe 70 over the entire range of the pedal stroke. As the pedal stroke increases, the center position 74 of the contact point between the sole 72 and the pedal operation unit 40 moves from an upper position to a lower position in the pedal operation unit 40. In addition, the brake pedal device of the first embodiment is configured such that the angle at which the driver's MTP joint 82 is bent toward the extension side gradually increases as the pedal stroke increases. In addition, the angle at which the MTP joint 82 bends toward the extension side means that the angle at which the proximal phalanx of the big toe bends toward the extension side (i.e., toward the instep) with respect to the first metatarsal bone increases. As a result, the contact area between the ball of the big toe 80 and the belly of the big toe 81 and the insole 73 increases with an increase in the pedal stroke, so that the foot pressure is dispersed to the ball of the big toe 80 and the belly of the big toe 81, and an excessive increase in the foot pressure is alleviated. Therefore, a good stepping comfort can be obtained, and the operability by the driver can be improved. In addition, the gradual increase in the angle at which the driver's MTP joint 82 bends toward the extension side with an increase in the pedal stroke is similar to the terminal stance that most activates the triceps surae in walking, and the driver can easily transmit the stepping force to the pedal operation unit 40, leading to an improvement in the stepping comfort. In addition, the fact that there are many mechanoreceptors distributed in the ball 80 and pad 81 of the big toe also contributes to improved comfort when stepping on the foot.

[0035] Next, the relationship between the behavior of the driver's MTP joint 82 and the pedal stroke, which has been studied by the present disclosure, will be described with reference to Figs. 6 to 8. In the following description with reference to Figs. 6 to 8, the driver can be read as a phantom body. This also applies to the description with reference to Figs. 12 to 14 in the second comparative example described later. In the present disclosure, the phantom body refers to one that is generally used in vehicle design.

[0036] 6 and 7 are schematic diagrams showing the driver's foot and the brake pedal device. In Fig. 6 and Fig. 7, the heel of the driver is indicated by a circle H, the ankle is indicated by a circle A, the MTP joint 82 and the ball of the foot 80 are collectively indicated by a circle M, and the angle of the MTP joint 82 is indicated by θ_mtp. The ankle joint is also called the talocrural joint. The components of the brake pedal device and the floor 60 are designated by the same reference numerals as those described above.

[0037] As described above, the brake pedal device of the first embodiment is attached so that the axis center CL of the shaft member 20 is located below the vehicle floor 60, etc. In the example shown in Figures 6 and 7, the axis center CL of the shaft member 20 is located 20 mm below the vehicle floor 60, etc.

[0038] Fig. 6 shows a state where the pedal stroke is in the initial position, and Fig. 7 shows a state where the pedal stroke is in the full stroke position. As shown in Fig. 6 and Fig. 7, the driver places the heel H of the foot on the floor 60 or the like at a position a predetermined distance rearward of the vehicle from the axis CL, and places both the ball of the foot 80 and the pad 81 of the foot on the pedal operating unit 40. As the state changes from Fig. 6 to Fig. 7, i.e., as the pedal stroke increases, the ball of the foot 80 (i.e., circle M) moves from an upper position to a lower position within the pedal operating unit 40.

[0039] Fig. 8 is a graph showing the behavior of the angle θ_mtp of the MTP joint 82 accompanying the transition of the pedal stroke from Fig. 6 to Fig. 7. The horizontal axis of Fig. 8 indicates the pedal stroke, and the vertical axis indicates the angle θ_mtp of the MTP joint 82. The initial position of the pedal stroke is 0°, and the full stroke position is 16°.

[0040] 8, when the pedal stroke is in the initial position, the angle of the MTP joint 82 is 25°, and the angle θ_mtp of the MTP joint 82 gradually increases as the pedal stroke increases. When the pedal stroke is in the full stroke position, the angle θ_mtp of the MTP joint 82 is close to 26°. In this way, the brake pedal device of the first embodiment is configured so that the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases.

[0041] Here, two comparative examples will be described for comparison with the brake pedal device of the first embodiment. Note that the two comparative examples were devised by the same disclosers as the present disclosure, and are not prior art.

[0042] (First Comparative Example) As shown in FIG. 9, the brake pedal device of the first comparative example differs from that described in the first embodiment only in the shape of the pedal operating portion 40, and the other configurations are the same as those described in the first embodiment.

[0043] In the brake pedal device of the first comparative example, the tread surface 41 of the pedal operation portion 40 facing the driver and the surface 31 of the pedal base portion 30 facing the driver are formed in parallel. Therefore, in the brake pedal device of the first comparative example, the shaft member 20 does not exist on the extension line EL of the average surface of the operation portion.

[0044] FIGS. 10 and 11 show the results of an experiment in which the foot pressure distribution acting on the insole 73 of the shoe 70 was measured when a driver wearing the shoe 70 depressed the brake pedal device to the full stroke position for the brake pedal device of the first comparative example and the brake pedal device of the first embodiment.

[0045] 10 and 11, the area corresponding to the pad 81 of the big toe is indicated by a dashed line P. As shown in the area of ​​dashed line P in Fig. 10, the brake pedal device of the first comparative example resulted in almost no foot pressure distribution being observed in the pad 81 of the big toe. In contrast, as shown in the area of ​​dashed line P in Fig. 11, the brake pedal device of the first embodiment resulted in ample foot pressure distribution being observed in the pad 81 of the big toe.

[0046] From this experiment result, it was found that in the brake pedal device of the first embodiment, when the driver wears the shoe 70 and depresses the pedal to the full stroke position, the foot pressure is distributed to the ball 80 and the pad 81 of the big toe, and an excessive increase in foot pressure is mitigated, compared to the brake pedal device of the comparative example. This result is due to the configuration of the brake pedal device of the first embodiment in which the angle θ_mtp of the MTP joint 82 gradually increases in the extension side as the pedal stroke increases.

[0047] (Second Comparative Example) Next, a second comparative example will be described with reference to Figures 12 to 14. The configuration of the brake pedal device used in the description of the second comparative example is the same as that described in the first embodiment. In the description of the second comparative example, only the mounting position of the brake pedal device relative to the vehicle floor 60 is different from that described in the first embodiment.

[0048] Figures 12 and 13 are schematic diagrams showing the driver's foot and the brake pedal device. As shown in Figures 12 and 13, in the second comparative example, the brake pedal device is attached so that the axis CL of the shaft member 20 is located on the upper side in the vehicle vertical direction (i.e., above the vehicle) relative to the floor 60, etc. In this example, the axis CL of the shaft member 20 is located 20 mm above the floor 60, etc.

[0049] Fig. 12 shows a state where the pedal stroke is in the initial position, and Fig. 13 shows a state where the pedal stroke is in the full stroke position. As shown in Fig. 12 and Fig. 13, the driver places the heel H of the foot on the floor 60 or the like at a position a predetermined distance rearward of the vehicle from the axis CL, and places both the ball of the foot 80 and the pad 81 of the foot on the pedal operating unit 40. As the state changes from Fig. 12 to Fig. 13, i.e., as the pedal stroke increases, the ball of the foot 80 (i.e., circle M) moves from an upper position to a lower position within the pedal operating unit 40.

[0050] Fig. 14 is a graph showing the behavior of the MTP joint 82 accompanying the transition of the pedal stroke from Fig. 12 to Fig. 13. The horizontal axis of Fig. 14 indicates the pedal stroke, and the vertical axis indicates the angle θ_mtp of the MTP joint 82. The initial position of the pedal stroke is 0°, and the full stroke position is 16°.

[0051] 14, when the pedal stroke is in the initial position, the angle θ_mtp of the MTP joint 82 is 25°, and as the pedal stroke increases, the angle θ_mtp of the MTP joint 82 gradually decreases. When the pedal stroke is in the full stroke position, the angle θ_mtp of the MTP joint 82 is close to 22°. Thus, in the second comparative example, as the pedal stroke increases, the angle at which the driver's MTP joint 82 bends to the extension side decreases.

[0052] Compared with the first and second comparative examples, the brake pedal device of the first embodiment provides the following advantages.

[0053] (1) The brake pedal device of the first embodiment allows the driver to press the pedal operation unit 40 while placing the heel 71 of the shoe 70 on a position on the floor 60 or the like that is a predetermined distance rearward of the vehicle from the axis CL and while placing both the ball 80 and the pad 81 of the big toe on the insole 73 of the shoe 70. In the brake pedal device, the positional relationship between the shaft member 20 and the pedal operation unit 40 is specified so that when the driver presses the pedal operation unit 40 in this manner, the angle at which the driver's MTP joint 82 bends to the extension side increases as the pedal stroke increases. According to this, the brake pedal device is configured such that the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases. Therefore, as the pedal stroke increases, the contact area between the ball 80 and the pad 81 of the big toe and the insole 73 of the shoe 70 increases, and the foot pressure is distributed to the ball 80 and the pad 81 of the big toe, thereby mitigating an excessive increase in foot pressure. Therefore, this brake pedal device provides a good stepping comfort by the ball 80 and the pad 81 of the big toe, and improves operability by the driver.

[0054] (2) In the first embodiment, the axis CL of the shaft member 20 is disposed on the opposite side to the surface 31 of the pedal base 30 facing the driver with respect to the center line S in the thickness direction of the pedal base 30. The brake pedal device includes a sensor unit 50 on the axis CL of the shaft member 20. According to this, by disposing the axis CL of the shaft member 20 on the opposite side of the face 31 of the pedal base 30 facing the driver with respect to the center line S in the thickness direction of the pedal base 30, a space is formed around the axis CL, and the sensor unit 50 can be provided on the axis CL. The sensor unit 50 can directly detect the rotation angle of the shaft member 20, the pedal base 30, and the pedal operation part 40, and can output a highly accurate electric signal corresponding to the pedal operation amount (i.e., the pedal stroke) by the driver. Therefore, this brake pedal device can improve the detection accuracy of the pedal stroke in a brake-by-wire system, and realize more accurate vehicle driving control.

[0055] (3) The brake pedal device of the first embodiment is an organ type in which the pedal operation portion 40 is disposed above the vehicle with respect to the axis CL. The angle θ_p between the operation portion mean plane and the base mean plane is smaller than 180° on the driver's side (i.e., the rear side of the vehicle). This makes it possible to realize a configuration in the brake pedal device in which the angle at which the driver's MTP joint 82 is bent toward the extension side gradually increases as the pedal stroke increases.

[0056] (4) In the first embodiment, the shaft member 20 is located on the extension line EL of the mean plane of the operation portion over the entire range of the pedal stroke. This makes it possible to realize a configuration in the brake pedal device in which the angle at which the driver's MTP joint 82 is bent toward the extension side gradually increases as the pedal stroke increases. In addition, "the shaft member 20 is located on the extension line EL of the average surface of the operating part" includes not only that the axis center CL of the shaft member 20 is located on the extension line EL of the average surface of the operating part, but also that a part of the shaft member 20 is located on the extension line EL of the average surface of the operating part.

[0057] (5) In the first embodiment, the axis CL of the shaft member 20 is located below the floor 60 and the like of the vehicle. According to this, in the brake pedal device, the tendency for the angle at which the driver's MTP joint 82 bends toward the extension side to gradually increase as the pedal stroke increases can be enhanced.

[0058] (6) The brake pedal device of the first embodiment can also be defined by the movement of the foot of the human model, as described with reference to Figs. 6 to 8. That is, the brake pedal device of the first embodiment can be configured such that the heel H of the human model is brought into contact with a position on the floor 60 or the like that is a predetermined distance rearward of the vehicle from the axis CL, and the pedal operation unit 40 is depressed while both the ball 80 and the pad 81 of the first toe of the human model are in contact with the pedal operation unit 40. In the brake pedal device, the positional relationship between the shaft member 20 and the pedal operation unit 40 is specified such that, when the pedal operation unit 40 is depressed by the human model, the angle at which the MTP joint 82 of the human model is bent toward the extension side gradually increases as the pedal stroke increases. According to this, the behavior of the dummy and the behavior of the driver are similar to each other, and therefore the brake pedal device defined by the movement of the dummy as described above also provides a good feeling of depression by the ball of the foot 80 and the pad of the foot 81 when the driver drives, improving the operability of the driver.

[0059] (Second to Sixth Embodiments) The second to sixth embodiments are different from the first embodiment in the configuration of the pedal operation unit 40, but are otherwise similar to the first embodiment, so only the parts that differ from the first embodiment will be described.

[0060] Second embodiment As shown in FIG. 15, in the brake pedal device of the second embodiment, a portion of the shaft member 20 that is on the vehicle rear side of the axis CL is located on an extension line EL of the operation part mean plane. In other words, the pedal operation part 40 has a shape of a tread surface 41 that is defined so that a part of the shaft member 20 is located on an extension line EL of the operation part mean plane over the entire range of the pedal stroke. The diameter of the shaft member 20 is, for example, about 5 to 10 mm. This configuration also realizes a configuration in which the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases. Therefore, the brake pedal device of the second embodiment can also improve the operability by the driver, similar to the first embodiment.

[0061] Third embodiment As shown in FIG. 16, in the brake pedal device of the third embodiment, a portion of the shaft member 20 located on the vehicle front side of the axis CL is located on an extension line EL of the operation part mean plane. In other words, the pedal operation part 40 has a shape of a tread surface 41 defined so that a part of the shaft member 20 is located on an extension line EL of the operation part mean plane over the entire range of the pedal stroke. The diameter of the shaft member 20 is, for example, about 5 to 10 mm. This configuration also realizes a configuration in which the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases. Therefore, the brake pedal device of the third embodiment can also improve the operability by the driver, similar to the first embodiment.

[0062] (Fourth embodiment) As shown in FIG. 17, the pedal operation unit 40 of the brake pedal device of the fourth embodiment has a tread surface 41 facing the driver, which is formed in a curved shape that is concave toward the front of the vehicle. In the fourth embodiment, a part of the shaft member 20 is located on the extension line EL of the operation unit average plane. In other words, the pedal operation unit 40 has a curved shape of the tread surface 41 so that a part of the shaft member 20 is located on the extension line EL of the operation unit average plane over the entire range of the pedal stroke. This configuration also realizes a configuration in which the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases. Therefore, the brake pedal device of the fourth embodiment can also improve the operability by the driver, as in the first embodiment.

[0063] Fifth embodiment As shown in FIG. 18, the pedal operation unit 40 of the brake pedal device of the fifth embodiment has a tread surface 41 facing the driver, which is formed in a curved shape that is convex toward the rear of the vehicle. In the fifth embodiment, too, a part of the shaft member 20 is located on the extension line EL of the operation unit average plane over the entire range of the pedal stroke. In other words, the pedal operation unit 40 has a curved shape of the tread surface 41 so that a part of the shaft member 20 is located on the extension line EL of the operation unit average plane over the entire range of the pedal stroke. This configuration also makes it possible to realize a configuration in which the angle at which the driver's MTP joint 82 bends toward the extension side gradually increases as the pedal stroke increases. Therefore, the brake pedal device of the fifth embodiment can also improve the operability by the driver, as in the first embodiment.

[0064] Sixth embodiment As shown in Fig. 19, the brake pedal device of the sixth embodiment has a different friction coefficient of the tread surface 41 of the pedal operation unit 40. That is, in this brake pedal device, the friction coefficient when an object moves on the tread surface 41 of the pedal operation unit 40 from above the vehicle to below the vehicle is different from the friction coefficient when an object moves on the tread surface 41 from below the vehicle to above the vehicle. Specifically, in this brake pedal device, the friction coefficient when an object moves on the tread surface 41 of the pedal operation unit 40 from above the vehicle to below the vehicle is greater than the friction coefficient when an object moves on the tread surface 41 of the pedal operation unit 40 from above the vehicle to below the vehicle. The tread surface 41 of the pedal operation unit 40 is configured with a shape similar to that of an inclined pile fabric, for example.

[0065] In FIG. 19, the direction in which the sole 72 moves on the tread surface 41 of the pedal operation unit 40 when the driver depresses the pedal is indicated by an arrow D, and the direction in which the sole 72 moves on the tread surface 41 of the pedal operation unit 40 when the driver depresses the pedal is indicated by an arrow U. In the sixth embodiment, the coefficient of friction when the sole 72 moves on the tread surface 41 of the pedal operation unit 40 when the driver depresses the pedal is greater than the coefficient of friction when the sole 72 moves on the tread surface 41 of the pedal operation unit 40 when the driver depresses the pedal. This allows the driver to maintain the pedal stroke at that time even if the depressing force applied to the pedal operation unit 40 is reduced during the depressing or depressing operation. Therefore, the brake pedal device makes it easier for the driver to maintain the pedal stroke at any position, improving operability.

[0066] (Seventh and Eighth Embodiments) The seventh and eighth embodiments are different from the first embodiment etc. in the configuration of the vehicle floor 60 etc., but are otherwise similar to the first embodiment etc., so only the parts that differ from the first embodiment etc. will be described.

[0067] Seventh embodiment As shown in FIG. 20, the brake pedal device of the seventh embodiment includes a heel abutment portion 62 at a position on the floor 60 or the like where the heel abuts against the heel 71 of the shoe 70 worn by the driver. The heel abutment portion 62 is provided at a position a predetermined distance rearward of the vehicle from the shaft member 20, and is a member capable of suppressing the heel 71 of the shoe 70 from moving forward of the vehicle. The friction coefficient of the surface of the heel abutment portion 62 facing upward of the vehicle is set to be greater than the friction coefficient of the portion of the floor 60 or the like other than the heel abutment portion 62. The heel abutment portion 62 may be integrally formed with the floor 60 or the like, or may be formed as a separate member from the floor 60 or the like. The heel abutment portion 62 is formed, for example, of a high-friction material or has an uneven shape.

[0068] In the seventh embodiment described above, when the driver depresses the pedal operation unit 40, the heel abutment portion 62 provided on the floor 60 or the like allows the driver to easily fix the position of the heel 71 of the shoe 70. Therefore, it is possible to increase the tendency for the angle at which the driver's MTP joint 82 bends toward the extension side to gradually increase as the pedal stroke increases, thereby improving operability by the driver.

[0069] Eighth embodiment As shown in Fig. 21, the brake pedal device of the eighth embodiment has a protruding portion 63 protruding upward from a part of a heel contact portion 62. The protruding portion 63 is provided at a portion of the heel contact portion 62 that is further forward than a portion of the heel contact portion 62 that contacts the heel 71 of the driver's shoe 70. The protruding portion 63 is shaped to protrude upward from the portion of the heel contact portion 62 that contacts the heel 71 of the driver's shoe 70. The protruding portion 63 may be shaped in a staircase as shown in Fig. 21. The protruding portion 63 is not limited to a staircase shape, and may be, for example, an inclined surface shape.

[0070] In the eighth embodiment described above, when the driver depresses the pedal operation unit 40, the position of the heel 71 of the shoe 70 worn by the driver can be easily fixed by the protruding portion 63 provided on the floor 60 or the like. Therefore, the tendency for the angle at which the driver's MTP joint 82 bends to the extension side to gradually increase with an increase in the pedal stroke can be enhanced, improving operability by the driver.

[0071] Ninth embodiment The ninth embodiment is different from the first embodiment etc. in that the mounting position of the brake pedal device relative to the floor 60 etc. and the sizes of the pedal base 30 and the pedal operating unit 40 are changed, but otherwise is similar to the first embodiment etc., so only the parts that differ from the first embodiment etc. will be described.

[0072] As shown in Fig. 22, the brake pedal device of the ninth embodiment is attached so that the axis CL of the shaft member 20 and the upper surface of the floor 60 or the like are located at the same height in the vehicle up-down direction. Moreover, in this brake pedal device, the pedal base 30 and the pedal operating portion 40 are formed to be equal to or larger than the size of the shoe 70 of a typical driver. This ninth embodiment can also achieve the same effects as the above-mentioned first embodiment, etc.

[0073] (Other embodiments) (1) In each of the above embodiments, the brake pedal device has been described as being used in a brake-by-wire system, but is not limited thereto. For example, the brake pedal device may not be used in a brake-by-wire system and may be mechanically connected to a conventional master cylinder. Also, the brake pedal device may be used in a brake-by-wire system and may be mechanically connected to a master cylinder. In this case, the reaction force generating mechanism 13 may be eliminated.

[0074] (2) In each of the above embodiments, the sensor unit 50 included in the brake pedal device has been described as being provided on the axis CL of the shaft member 20, but this is not limited thereto. The sensor unit 50 may be provided, for example, at a position away from the axis CL of the shaft member 20. In addition, the sensor unit 50 may detect the angle, position, stroke, etc. of the shaft member 20, the pedal base 30, the pedal operating unit 40, or a member that moves in synchronization therewith.

[0075] (3) In each of the above embodiments, the sensor unit 50 of the brake pedal device is described as being composed of a magnetic circuit, a Hall IC 55, etc. However, this is not limited thereto. The sensor unit 50 may be composed of, for example, a magnetic resistance element, an inductive sensor, etc.

[0076] (4) In each of the above embodiments, the brake pedal device is configured such that the shaft member 20 is rotatably provided relative to the support portion 10. However, the present invention is not limited to this. For example, the brake pedal device may be configured such that the support portion 10 and the shaft member 20 are fixed, and the pedal base portion 30 is rotatably provided relative to the shaft member 20.

[0077] (5) In each of the above embodiments, the support portion 10 of the brake pedal device is described as a housing having an internal space therein. However, the present invention is not limited to this and may have any configuration as long as it is capable of supporting the shaft member 20.

[0078] The present disclosure is not limited to the above-mentioned embodiments, and can be appropriately modified within the scope of the claims. In addition, the above-mentioned embodiments and parts thereof are not unrelated to each other, and can be appropriately combined except when the combination is clearly impossible. In addition, in each of the above-mentioned embodiments, it goes without saying that the elements constituting the embodiment are not necessarily essential, except when it is specifically stated that they are essential or when it is clearly considered to be essential in principle. In addition, in each of the above-mentioned embodiments, when the numbers, values, amounts, ranges, etc. of the components of the embodiment are mentioned, they are not limited to the specific numbers, except when it is specifically stated that they are essential or when it is clearly limited to a specific number in principle. In addition, in each of the above-mentioned embodiments, when the shape, positional relationship, etc. of the components are mentioned, they are not limited to the shape, positional relationship, etc., except when it is specifically stated that they are essential or when it is clearly limited to a specific shape, positional relationship, etc. in principle.

[0079] (In view of the present disclosure) The present disclosure described above can be understood from the following viewpoints, for example. [First viewpoint] A brake pedal device mounted on a vehicle, A support (10) that is attached to the vehicle; A shaft member (20) provided on the support portion; a pedal base portion (30) provided on the support portion so as to be rotatable within a predetermined angular range around an axis center (CL) of the shaft member; a pedal operation unit (40) that is provided at the pedal base and is stepped on by a driver, The axis is located on the opposite side of the surface (31) of the pedal base facing the driver with respect to a center line (S) in a thickness direction of the pedal base, a brake pedal device in which, when the driver wears a shoe (70) and depresses the pedal operation portion, the heel (71) of the shoe can be in contact with a position on the floor (60) of the vehicle or a member placed on the floor that is a predetermined distance rearward of the vehicle from the axis center, and the pedal operation portion can be depressed with both the ball (80) and the pad (81) of the big toe of the driver in contact with the insole (73) of the shoe, and the positional relationship between the axis member and the pedal operation portion is specified so that the angle at which the driver's MTP joint (82) bends toward the extension side increases as the pedal stroke increases. [Second viewpoint] The brake pedal device according to a first aspect, further comprising a sensor unit (50) provided on the axis and configured to detect rotation angles of the shaft member, the pedal base, and the pedal operating portion relative to the support portion. [Third Perspective] the brake pedal device is of an organ type in which the pedal operation portion is disposed above the vehicle with respect to the axis, The brake pedal device according to the first or second aspect, wherein an angle (θ_p) between an operation portion average plane, which is the average of an entire tread surface (41) of the pedal operation portion that faces the driver side, and a base average plane, which is the average of an entire surface of the pedal base that faces the driver side, is smaller than 180° on the driver side. [Fourth viewpoint] A brake pedal device as described in any one of the first to third aspects, wherein the shaft member is located on an extension line (EL) of the average plane of the operation portion, which is the average of the entire tread surface of the pedal operation portion that faces the driver, throughout the entire range of the pedal stroke. [Fifth viewpoint] A brake pedal device as described in any one of the first to fourth aspects, wherein the axis is located lower in the vehicle vertical direction than the floor or a member placed on the floor, or is at the same height in the vehicle vertical direction as the floor or a member placed on the floor. [Sixth viewpoint] A brake pedal device as described in any one of the first to fifth aspects, wherein a friction coefficient when an object moves from above the vehicle to below the vehicle on a tread surface of the pedal operation portion facing the driver is different from a friction coefficient when the object moves from below the vehicle to above the vehicle on the tread surface. [Seventh viewpoint] A brake pedal device as described in any one of the first to sixth aspects, wherein the coefficient of friction when an object moves from below the vehicle to above the vehicle on the tread surface of the pedal operation portion facing the driver's side is greater than the coefficient of friction when the object moves from above the vehicle to below the vehicle on the tread surface. [Eighth viewpoint] The brake pedal device according to any one of the first to seventh aspects, further comprising a heel abutment portion (62) on the floor or on a member placed on the floor, the heel abutting against the heel of the shoe worn by the driver at a position a predetermined distance rearward of the vehicle from the shaft member, and capable of preventing the heel of the shoe from moving forward of the vehicle. [Ninth viewpoint] A brake pedal device as described in an eighth aspect, wherein the friction coefficient of the surface of the heel contact portion facing upward toward the vehicle is greater than the friction coefficient of the portion of the floor or a member placed on the floor excluding the heel contact portion. [10th viewpoint] The brake pedal device according to the eighth or ninth aspect, wherein the heel contact portion has a protruding portion (63) that protrudes upward from the vehicle at a position forward of the vehicle from a point where the heel of the shoe worn by the driver contacts the heel. [Eleventh viewpoint] A brake pedal device mounted on a vehicle, A support (10) that is attached to the vehicle; A shaft member (20) provided on the support portion; a pedal base portion (30) provided on the support portion so as to be rotatable within a predetermined angular range around an axis center (CL) of the shaft member; a pedal operation unit (40) that is provided at the pedal base and is stepped on by a driver, The axis is located on the opposite side of the pedal base from the surface of the pedal base facing the driver with respect to a center line (S) in a thickness direction of the pedal base, a brake pedal device in which, when a human body model is used to depress and operate the pedal operation unit, the heel (H) of the human body model can be abutted against a position on the floor (60) of the vehicle or a member placed on the floor that is a predetermined distance rearward of the vehicle from the axis center, and the pedal operation unit can be depressed with both the ball (80) of the first foot and the pad (81) of the first foot of the human body model abutting against the pedal operation unit, and a positional relationship between the axis member and the pedal operation unit is specified so that an angle at which the MTP joint (82) of the human body model bends toward the extension side increases as the pedal stroke increases. [12th viewpoint] A brake pedal device mounted on a vehicle, A support (10) that is attached to the vehicle; A shaft member (20) provided on the support portion; a pedal base portion (30) provided on the support portion so as to be rotatable within a predetermined angular range around an axis center (CL) of the shaft member; a pedal operation unit (40) that is provided at the pedal base and is stepped on by a driver, The axis is located on the opposite side of the pedal base from the surface of the pedal base facing the driver with respect to a center line (S) in a thickness direction of the pedal base, A brake pedal device, wherein the shaft member is located on an extension line (EL) of the average plane of the operation portion, which is the average of the entire tread surface (41) of the pedal operation portion that faces the driver, throughout the entire range of the pedal stroke.

[0080] It should be noted that the eleventh aspect may be arbitrarily combined with any of the configurations described in the first to tenth aspects above. Also, the twelfth aspect may be arbitrarily combined with any of the configurations described in the first to third and fifth to eleventh aspects above. [Explanation of symbols]

[0081] 10 Support part 20 Shaft member 30 Pedal base 40 Pedal operation section 70 Shoes 71 Heel of shoe 73 Shoe insoles 80 Ball of the foot 81 Belly of the Big Toe 82 MTP joint

Claims

1. A brake pedal device mounted on a vehicle, comprising: a support portion (10) attached to the vehicle; a shaft member (20) provided on the support portion; a pedal base portion (30) rotatably provided around the axis (CL) of the shaft member with respect to the support portion within a predetermined angular range; a pedal operation portion (40) provided on the pedal base portion and being a portion stepped on by a driver; wherein the axis is located on the side opposite to the surface (31) of the pedal base portion facing the driver side with respect to the center line (S) in the thickness direction of the pedal base portion; the brake pedal device is an organ type in which the pedal operation portion is disposed above the vehicle with respect to the axis; a brake pedal device, wherein an angle (θ_p) formed between an operation portion average plane obtained by averaging the entire tread surface (41) of the pedal operation portion facing the driver side and a base portion average plane obtained by averaging the entire surface of the pedal base portion facing the driver side is less than 180° on the driver side.

2. A brake pedal device mounted on a vehicle, comprising: a support portion (10) attached to the vehicle; a shaft member (20) provided on the support portion; a pedal base portion (30) rotatably provided around the axis (CL) of the shaft member with respect to the support portion within a predetermined angular range; a pedal operation portion (40) provided on the pedal base portion and being a portion stepped on by a driver; wherein the axis is located on the side opposite to the surface (31) of the pedal base portion facing the driver side with respect to the center line (S) in the thickness direction of the pedal base portion; a brake pedal device, wherein the shaft member is located on an extension line (EL) of an operation portion average plane obtained by averaging the entire tread surface of the pedal operation portion facing the driver side within the entire range of the pedal stroke.

3. The brake pedal device according to claim 1 or 2, wherein the axis is located below the vehicle in the vehicle vertical direction with respect to the floor or a member placed on the floor, or is at the same height as the floor or a member placed on the floor in the vehicle vertical direction.

4. The brake pedal device according to claim 1 or 2, wherein a friction coefficient when an object moves from above the vehicle to below the vehicle on the tread surface of the pedal operation portion facing the driver side is different from a friction coefficient when the object moves from below the vehicle to above the vehicle on the tread surface.

5. The brake pedal device according to claim 1 or 2, wherein the coefficient of friction when an object moves from above the vehicle to below the vehicle on the tread surface of the pedal operation portion facing the driver side is smaller than the coefficient of friction when the object moves from below the vehicle to above the vehicle on the tread surface.

6. The brake pedal device according to claim 1 or 2, further comprising a heel contact portion (62) provided at a position a predetermined distance behind the vehicle from the shaft member in the floor or a member placed on the floor, which contacts the heel of the shoe worn by the driver and can suppress the movement of the heel of the shoe forward of the vehicle.

7. The brake pedal device according to claim 6, wherein the coefficient of friction of the surface of the heel contact portion facing above the vehicle is larger than the coefficient of friction of the portion of the floor or the member placed on the floor excluding the heel contact portion.

8. The brake pedal device according to claim 6, wherein the heel contact portion has a protruding portion (63) protruding upward from a portion on the front side of the vehicle of the position where the heel of the shoe worn by the driver contacts.

9. When the driver wears shoes (70) and steps on the pedal operation portion, the heel (71) of the shoe contacts a position a predetermined distance behind the vehicle from the axis center of the floor (60) of the vehicle or a member placed on the floor, and the pedal operation portion can be stepped on with both the ball of the big toe (80) and the belly of the big toe (81) of the driver contacting the insole (73) of the shoe. And the positional relationship between the shaft member and the pedal operation portion is defined such that as the pedal stroke increases, the angle at which the MTP joint (82) of the driver bends toward the extended side increases. The brake pedal device according to claim 1 or 2.

10. The brake pedal device according to claim 1 or 2, further comprising a sensor unit (50) provided on the axis center for detecting the rotation angles of the shaft member, the pedal base portion, and the pedal operation portion with respect to the support portion.

11. When the pedal operation part is depressed using a mannequin, the heel (H) of the mannequin is brought into contact with a position that is a predetermined distance behind the vehicle rearward from the axial center among the floor (60) of the vehicle or the members placed on the floor, and the pedal operation part can be depressed with both the ball of the big toe (80) and the belly of the big toe (81) of the mannequin in contact with the pedal operation part, and at that time, the positional relationship between the shaft member and the pedal operation part is defined such that the angle by which the MTP joint (82) of the mannequin bends toward the extended side increases as the pedal stroke increases. The brake pedal device according to claim 1 or 2.

Images