Accelerator pedal mis-depression prevention device and accelerator pedal unit

Abstract

To provide an accelerator pedal malfunction preventing device in which a sudden stepping-down operation of the accelerator pedal is prevented and the operation feeling conforming to a driver is achieved.SOLUTION: A pedal malfunction preventing device 7 comprises: a piston 21 which has a division wall 30 dividing the inside of a cylinder 20 into a first chamber 31 and a second chamber 32, and a main continuous hole 33 and a sub continuous hole 34 arranged at the division wall 30 to communicate the first chamber 31 with the second chamber 32; a normally open valve body 22 which is arranged in the second chamber 32 and can block the main continuous hole 33 by a pressure rise of hydraulic fluid on the second chamber 32 side; and a pushrod 23 which has a second end side connected to the piston 21 and can transfer a tread force to a first end side protruding to outside of the cylinder 20. The main continuous hole 33 and the sub continuous hole 34 are formed in a manner to have an aperture area on the second chamber 32 side larger than an aperture area on the first chamber 31.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an accelerator pedal erroneous depression prevention device and an accelerator pedal unit for preventing a vehicle from suddenly starting due to a sudden depression of the accelerator pedal. [Background technology]

[0002] Conventionally, for vehicles such as automatic vehicles, an erroneous pedal depression prevention device has been proposed to prevent the vehicle from suddenly starting when the driver erroneously applies a sudden pedal depression operation when stopping or starting the vehicle.

[0003] For example, Patent Document 1 discloses a vehicle emergency stop device equipped with a hydraulic control device connected to the underside of an accelerator pedal. The hydraulic control device of this vehicle emergency stop device has a piston that moves within a cylinder, a valve plate that can open and close an orifice provided in the piston, and a spring that urges the valve plate in a direction away from the orifice.

[0004] When the accelerator pedal is depressed with a pressure at a normal speed, the piston of the hydraulic control device moves within the cylinder with the valve plate opening the orifice due to the biasing force of the spring, allowing the pressurized oil in the cylinder to move the piston appropriately, resulting in appropriate speed control when operating the accelerator lever.

[0005] On the other hand, when the accelerator pedal is depressed with abnormally rapid force, the piston of the hydraulic control device moves within the cylinder against the biasing force of the spring with the valve plate closing the orifice. As a result, the pressurized oil within the cylinder applies resistance to the movement of the piston, preventing depression of the accelerator lever. Furthermore, the hydraulic pressure generated by the hydraulic control device pressurizes the brake pedal and automatically stops the engine drive mechanism. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-146106 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the technology disclosed in Patent Document 1 employs a configuration in which the valve plate closes all orifices when the accelerator pedal is suddenly depressed. Therefore, with the technology disclosed in Patent Document 1, there is a risk that the valve plate will stick to the piston due to the difference in oil pressure between the two sides of the piston in the cylinder. As long as this stuck state of the valve plate remains, there is a risk that the driver will be unable to operate the accelerator properly.

[0008] Furthermore, in vehicles equipped with an electronically controlled throttle valve, it is desirable to provide hysteresis in the characteristics of the depression force and depression stroke when the accelerator pedal is depressed and released in order to achieve accelerator operation that matches the driver's feeling. However, the technology disclosed in the above-mentioned Patent Document 1 does not take into consideration the hysteresis characteristics when the accelerator pedal is depressed and released.

[0009] The present invention aims to provide an accelerator pedal mis-depression prevention device and an accelerator pedal unit that can prevent sudden depression of the accelerator pedal and realize an operation feeling that matches the driver's feeling. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided an accelerator pedal misdepression prevention device comprising: a cylinder filled with fluid; a piston having a partition wall dividing a first end side and a second end side of the interior of the cylinder into a first chamber and a second chamber, each having a variable volume, the piston having a main communication hole and an auxiliary communication hole in the partition wall that communicate the first chamber with the second chamber; a normally open valve body provided in the second chamber that is capable of closing the main communication hole in response to a pressure increase of the fluid on the second chamber side; and a push rod whose second end side is connected to the piston and that is capable of transmitting a depression force to a first end side that penetrates the cylinder and protrudes to the outside of the cylinder; Ren Through holes and the sub Ren At least one of the through holes has an opening area on the second chamber side set larger than an opening area on the first chamber side.

[0011] An accelerator pedal unit according to one aspect of the present invention includes a cylinder filled with fluid, a partition wall dividing a first end side and a second end side of the interior of the cylinder into a first chamber and a second chamber, each having a variable volume, a piston having a main communication hole and a sub-communication hole in the partition wall that communicate between the first chamber and the second chamber, a normally open valve body that is provided in the second chamber and can close the main communication hole when pressure of the fluid on the second chamber side increases, and a valve body that is connected at its second end side to the piston and that penetrates the cylinder and protrudes to the outside of the cylinder. Rup The vehicle is equipped with an accidental depression prevention device in which the opening area of ​​at least one of the main communication hole and the auxiliary communication hole on the second chamber side is set larger than the opening area on the first chamber side, and an accelerator pedal that can transmit depression force to the push rod. [Effects of the Invention]

[0012] According to the present invention, it is possible to prevent the accelerator pedal from being suddenly depressed, and to realize an operation feeling that matches the driver's feeling. [Brief explanation of the drawings]

[0013] [Figure 1] Side view of accelerator pedal unit [Figure 2] Cross-sectional view of the main part of the accelerator pedal unit when the accelerator pedal is released [Figure 3] Cross-sectional view of the main part of the accelerator pedal unit when the accelerator pedal is depressed [Figure 4] Cross-sectional view of the main part of the device for preventing accidental stepping [Figure 5] Exploded perspective view of the accidental stepping prevention device [Figure 6] FIG. 1 is an explanatory diagram showing the behavior of the fluid in the accidental depression prevention device when the accelerator pedal is depressed with a normal depression force. [Figure 7] An explanatory diagram showing the behavior of the fluid in the accidental depression prevention device when the accelerator pedal is depressed with a strong force. [Figure 8] FIG. 1 is an explanatory diagram showing the behavior of the fluid in the accidental depression prevention device when the accelerator pedal is released. [Figure 9] Characteristics diagram showing the relationship between accelerator pedal force and pedal stroke [Figure 10] FIG. 10 is a cross-sectional view of a main part of an accelerator pedal unit according to a first modified example. [Figure 11] 10 is a cross-sectional view of a main part of an accelerator pedal unit according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings, in which: Figure 1 is a side view of an accelerator pedal unit according to one embodiment of the present invention;

[0015] The accelerator pedal unit 1 shown in FIG. 1 is applied to, for example, a vehicle equipped with an electronically controlled throttle engine, or a hybrid vehicle or electric vehicle equipped with a traction motor (neither of which are shown).

[0016] This accelerator pedal unit 1 is composed of a housing 5, an accelerator lever 6 supported by the housing 5, and an accidental depression prevention device 7 connected to the second end side, which is the other end side, of the accelerator lever 6.

[0017] The housing 5 has a generally flat box shape. An accelerator opening sensor 10 is provided on the side of the housing 5. The accelerator opening sensor 10 is connected to, for example, an engine control unit (not shown).

[0018] Inside the housing 5, a rotation shaft 11 for supporting the accelerator lever 6 is provided at a position corresponding to the accelerator opening sensor 10 (see FIGS. 2 and 3). Furthermore, an opening 12 that connects the inside and outside of the housing 5 is provided in a part of the bottom surface of the housing 5.

[0019] The accelerator lever 6 is made of, for example, a metal member that has been bent in a predetermined manner. A rotary bearing 15 is provided midway on the accelerator lever 6. The rotary shaft 11 of the housing 5 is inserted into the rotary bearing 15. This allows the accelerator lever 6 to be supported so as to be able to swing freely relative to the housing 5.

[0020] One end (first end) of the accelerator lever 6 extends outside the housing 5 through the opening 12. An accelerator pedal 16 is fixed to the first end of the accelerator lever 5. When the driver depresses the accelerator pedal 16, a pedal force can be transmitted to the accelerator pedal unit 1.

[0021] Furthermore, inside the housing 5, a pedal force transmission surface 17 is provided on the second end side (other end side) of the accelerator lever 6. This pedal force transmission surface 17 transmits the pedal force from the accelerator lever 6 to the erroneous pedaling prevention device 7, and also transmits the biasing force from the erroneous pedaling prevention device 7. This pedal force transmission surface 17 is formed, for example, by a flat surface.

[0022] As shown in Figures 4 and 5, the accidental stepping prevention device 7 is configured to include a cylinder 20, a piston 21 provided inside the cylinder 20, a push rod 23 connected to the piston 21, and a piston return spring 24.

[0023] The cylinder 20 is fixed to the housing 5 at a position facing the pedal force transmission surface 17 of the accelerator lever 6. The cylinder 20 is configured to include a cylinder body 25 and a cover body .

[0024] The cylinder body 25 is made of, for example, a metal member having a substantially cylindrical shape. One end (first end) of the cylinder body 25 in the direction of the central axis O is open, and the other end (second end) in the direction of the central axis O is closed. A male thread portion 25a is formed on the outer periphery of the cylinder body 25 on the side of the first end.

[0025] The cover 26 is made of, for example, a substantially disk-shaped metal member. A female screw portion 26a protrudes from the edge of the surface (other end surface) of the cover 26 on the second end side. The female screw portion 26a can be threadedly engaged with the male screw portion 25a of the cylinder body 25. In this way, the cover 26 closes one end of the cylinder body 25 and seals hydraulic oil, which is a fluid, inside the cylinder 20.

[0026] Furthermore, a through hole 26b for inserting the push rod 23 in the thickness direction is provided in the center of the cover 26. An annular seal member 27 is held on the inner periphery of this through hole 26b. The seal member 27 provides a liquid-tight seal between the through hole 26b and the push rod 23.

[0027] The piston 21 has a partition wall 30 made of, for example, metal. The partition wall 30 is formed, for example, in a substantially circular plate shape that is slidable along the inner circumferential surface of the cylinder body 25. As a result, the partition wall 30 divides one end side and the other end side of the interior of the cylinder 20 in the direction of the central axis O into a first chamber 31 and a second chamber 32. The volumes of the first chamber 31 and the second chamber 32 are variable as the partition wall 30 of the piston 21 slides inside the cylinder 20 in the direction of the central axis O.

[0028] Furthermore, for example, a main communication hole 33 that communicates between the first chamber 31 side and the second chamber 32 side is provided in the center of the partition wall 30 of the piston 21. The main communication hole 33 has a first tapered surface 33a that tapers so that the opening area decreases from the second chamber 32 side toward the first chamber 31 side. As a result, the flow rate of fluid passing through the main communication hole 33 when the piston 21 moves from the second chamber 32 side to the first chamber 31 side is relatively reduced compared to the flow rate of fluid passing through the main communication hole 33 when the piston 21 moves from the first chamber 31 side to the second chamber 32 side.

[0029] Furthermore, for example, a plurality of auxiliary communication holes 34 are provided around the main communication hole 33 in the partition wall 30 of the piston 21. The total effective opening area of ​​the auxiliary communication holes 34 is set relatively smaller than the effective opening area of ​​the main communication hole 33. Each auxiliary communication hole 34 has a second tapered surface 34a that tapers so that the opening area decreases from the second chamber 32 side toward the first chamber 31 side. As a result, the flow rate of fluid passing through the auxiliary communication holes 34 when the piston 21 moves from the second chamber 32 side toward the first chamber 31 side is relatively reduced compared to the flow rate of fluid passing through the auxiliary communication holes 34 when the piston 21 moves from the first chamber 31 side toward the second chamber 32 side.

[0030] Due to the action of these first and second tapered surfaces 33a, 34a, the movement resistance caused by the hydraulic oil when the piston 21 moves from the second chamber 32 side to the first chamber 31 side is relatively greater than the movement resistance caused by the hydraulic oil when the piston 21 moves from the first chamber 31 side to the second chamber 32 side.

[0031] The opening area of ​​the main communication hole 33, the opening area of ​​the sub-communication hole 34, and the taper angles of the first and second tapered surfaces 33a and 34a are appropriately set by experiments, simulations, etc. based on the movement resistance required of the piston 21, etc.

[0032] Furthermore, on the second chamber 32 side, a plurality of (for example, four) first spring bearing pins 30a are provided on the wall surface of the partition wall 30 of the piston 21. These first spring bearing pins 30a are arranged at equal intervals, for example, at positions surrounding the main communicating hole 33 and closer to the central axis O than the sub-communicating holes 34.

[0033] The valve element 22 has, for example, a valve body 36 that can open and close only the main communication hole 33, and an outward flange 37 provided on the second end side of the valve body 36. The valve body 36 and the outward flange 37 are integrally formed, for example, from the same type of metal as the partition wall 30 of the piston 21.

[0034] The valve body 36 is formed of a generally cylindrical member that can be inserted into the main communicating hole 33. A tapered surface 36a that tapers from the second end side to the first end side is formed on the outer circumferential surface of the first end side of the valve body 36. The taper angle of this tapered surface 36a is set smaller than the taper angle of the first tapered surface 33a formed on the main communicating hole 33.

[0035] The outward flange 37 is configured by a substantially disk-shaped member that protrudes radially outward from the second end side of the valve body 36. Second spring bearing pins 37a are provided on this outward flange 37 at positions corresponding to the first spring bearing pins 30a provided on the partition wall 30.

[0036] Each second spring bearing pin 37a is connected to each first spring bearing pin 30a via a valve body return spring 38. As a result, the valve body 22 is elastically connected to the piston 21.

[0037] The valve element 22 is normally open relative to the main communication hole 33 due to the biasing force of the valve element return spring 38. When a predetermined pressing force is applied from the second end side to the first end side, the valve element 22 moves toward the first end side against the biasing force of the valve element return spring 38 and closes the main communication hole 33.

[0038] The pressing force on the valve body 22 is mainly exerted by the repulsive force of the hydraulic oil that is suddenly compressed in the second chamber 32 when the piston 21 moves at a rapid speed from the first end to the second end inside the cylinder 20.

[0039] On the other hand, when the pressing force from the second end side to the first end side is released, the valve body 22 moves toward the second end side due to the biasing force of the valve body return spring 38, and opens the main communication hole 33.

[0040] The push rod 23 is formed of a substantially cylindrical member whose second end is connected to the partition wall 30 of the piston 21. A hole 40 that communicates with the main communication hole 33 is provided along the central axis O at the second end of the push rod 23. The push rod 23 also has an opening 40a that opens the hole 40 to the side surface of the push rod 23. By virtue of the hole 40 and the opening 40a, communication between the first chamber 31 and the second chamber 32 via the main communication hole 33 is maintained when the valve body 22 is open, even when the push rod 23 is connected to the partition wall 30.

[0041] On the other hand, a contact member 41 for contacting the pedal force transmission surface 17 of the accelerator lever 6 is fixed to a first end of the push rod 23.

[0042] The piston return spring 24 is disposed in the second chamber 32. The piston return spring 24 biases the piston 21 toward the first end of the cylinder 20 with a predetermined biasing force.

[0043] Next, the operation of the erroneous depression prevention device 7 configured as above will be described.

[0044] First, the operation when the driver depresses the accelerator pedal 16 at a relatively slow speed (a speed below a specified speed) will be described.

[0045] In this case, for example, as shown in Figure 6, a pedaling force F transmitted to the piston 21 via the push rod 23 causes the piston 21 to move from the first end side to the second end side of the cylinder 20 against the biasing force of the piston return spring 24.

[0046] During this movement of the piston 21, the hydraulic oil in the second chamber 32 flows into the first chamber 31 via the main communication hole 33 and the sub-communication hole 34. This inflow of hydraulic oil allows the piston 21 to move from the first end side to the second end side inside the cylinder 20 without excessively increasing the internal pressure of the second chamber 32.

[0047] That is, the piston 21 moves inside the cylinder 20 from the first end side to the second end side while receiving a weak reaction force from the hydraulic oil in the first chamber 32.

[0048] As a result, for example, as shown in FIG. 9, the pedal stroke of the accelerator pedal 16 increases substantially linearly with a predetermined gradient a in response to an increase in the pedal force F.

[0049] Next, we will explain what happens when the driver presses the accelerator pedal 16 at a rapid speed (a speed greater than a specified speed). Note that a speed greater than a specified speed here refers to, for example, a speed at which the amount of change (amount of decrease) in the volume of the second chamber 32 caused by the movement of the piston 21 (partition wall 30) within a unit time is sufficiently large compared to the flow rate of hydraulic oil from the second chamber 32 to the first chamber 31 allowed by the main communication hole 33 and the sub-communication hole 34 within a unit time.

[0050] In this case, for example, as shown in Figure 7, the pedal force F transmitted to the piston 21 via the push rod 23 causes the piston 21 to move from the first end side to the second end side of the cylinder 20 against the biasing force of the piston return spring 24.

[0051] When the piston 21 moves, the pressure of the hydraulic oil in the second chamber 32 rises suddenly. Then, the repulsive force of the hydraulic oil whose pressure has risen suddenly acts as a pressing force that presses the valve body 22 from the second end side to the first end side of the cylinder 20.

[0052] This pressing force causes the valve element 22 to move from the second end side to the first end side against the biasing force of the valve element return spring 38 , and the valve body 36 closes the main communication hole 33 .

[0053] As a result, the hydraulic oil in the second chamber 32 moves toward the first chamber 31 only through the auxiliary communication hole 34. Therefore, the state in which the pressure of the hydraulic oil in the second chamber 32 is increased is maintained for a predetermined period of time.

[0054] As a result, the repulsive force of the pressurized hydraulic oil suppresses movement of piston 21 toward the second end. That is, for example, as shown in Fig. 9, with an increase in pedal force F, the pedal stroke increases substantially linearly with a gradient c that is sufficiently larger than gradient a. Therefore, accidental depression prevention device 7 can prevent the vehicle from suddenly starting in response to an accidental depression by the driver, while making the driver aware that an accidental depression of accelerator pedal 16 has occurred.

[0055] Here, even after the accelerator pedal 16 is no longer rapidly depressed, as long as the pressure of the hydraulic oil in the second chamber 32 is relatively higher than the pressure of the hydraulic oil in the first chamber 31, the hydraulic oil in the second chamber 32 moves toward the first chamber 31 via the auxiliary communication hole 34. This equalizes the pressure of the hydraulic oil in the first chamber 31 and the second chamber 32. This equalization of the pressures in the first and second chambers 31, 32 prevents the valve element 22 from sticking to the main communication hole 33, and the biasing force of the valve element return spring 38 moves the valve element 22 to the open position.

[0056] Next, an operation when the driver releases the accelerator pedal 16 will be described.

[0057] In this case, for example, as shown in FIG. 8, when the pedal force starts to be released, the piston 21 starts to move from the second end side to the first end side due to the biasing force of the piston return spring 24.

[0058] When the piston 21 moves, the hydraulic oil in the first chamber 31 flows into the second chamber 32 via the main communication hole 33 and the sub-communication hole .

[0059] As a result, for example, as shown in FIG. 9, the pedal stroke decreases substantially linearly with a predetermined gradient b in response to a decrease in the pedal force F.

[0060] However, due to the action of the first tapered surface 33a and the second tapered surface 34a provided in the main communicating hole 33 and the secondary communicating hole 34, the flow rate of the hydraulic oil moving from the first chamber 31 side to the second chamber 32 side is reduced compared to the flow rate of the hydraulic oil moving from the second chamber 32 side to the first chamber 31 side.

[0061] Therefore, the resistance of the hydraulic oil acting on the piston 21 is relatively greater when the piston 21 moves from the second end side to the first end side than when the piston 21 moves from the first end side to the second end side.

[0062] Therefore, the slope b of the pedal stroke relative to the depression force F when the accelerator pedal 16 is released is relatively smaller than the slope a of the pedal stroke relative to the depression force F when the accelerator pedal 16 is depressed. In other words, the relationship between the depression force F and the pedal stroke when the accelerator pedal 16 is depressed and released exhibits a hysteresis characteristic.

[0063] According to this embodiment, the accidental depression prevention device 7 has a partition 30 that divides the first end side and the second end side of the interior of the cylinder 20 into a first chamber 31 and a second chamber 32, each having a variable volume, and is equipped with a piston 21 in which a main communication hole 33 and an auxiliary communication hole 34 that connect the first chamber 31 and the second chamber 32 are provided in the partition 30, a normally open valve body 22 that is provided in the second chamber 32 and can close the main communication hole 33 by an increase in pressure of the fluid (hydraulic oil) on the second chamber 32 side, and a push rod 23 whose second end side is connected to the piston 21 and that can transmit a depression force to the first end side that penetrates the cylinder 20 and protrudes to the outside of the cylinder 20, and a first tapered surface 33a and a second tapered surface 34a are formed in the main communication hole 33 and the auxiliary communication hole 34 so that the opening area on the second chamber 32 side is set larger than the opening area on the first chamber 31 side. This prevents the accelerator pedal 16 from being suddenly depressed, and also makes it possible to realize an operation feeling that matches the driver's feeling.

[0064] That is, when an abrupt depression force F is transmitted to piston 21 due to accidental depression of accelerator pedal 16, a sudden increase in hydraulic oil pressure on the second chamber 32 side causes valve body 22 to close main communication hole 33. This significantly reduces the flow rate of hydraulic oil moving from second chamber 32 side to first chamber 31 side, and the pressure of hydraulic oil on the second chamber 32 side is maintained at a high level for a predetermined period of time. Therefore, even when accelerator pedal 16 is accidentally depressed, it is possible to reliably prevent the vehicle from suddenly starting.

[0065] In addition, the hydraulic oil in the second chamber 32, whose pressure has risen sharply due to an erroneous depression, gradually moves from the second chamber 32 to the first chamber 31 via the sub-communication hole 34, even while the main communication hole 33 is closed. This makes it possible to smooth out the pressure of the hydraulic oil in the first chamber 31 and the second chamber 32, and effectively prevent the valve body 22 from sticking to the main communication hole 33.

[0066] In this case, because the total effective opening area of ​​the auxiliary communication holes 34 is set sufficiently smaller than the effective opening area of ​​the main communication hole 33, the pressure of the hydraulic oil in the second chamber 32 that increases when the main communication hole 33 is closed by the valve element 22 can be maintained for a predetermined period of time. Furthermore, because the taper angle of the tapered surface 36a of the valve body 36 is set smaller than the taper angle of the first tapered surface 33a of the main communication hole 33, the valve element 22 can be accurately removed from the main communication hole 33 when the pressure of the hydraulic oil in the second chamber 32 drops.

[0067] Furthermore, by forming the first tapered surface 33a and the second tapered surface 34a in the main communication hole 33 and the sub-communication hole 34 so that the opening area on the second chamber 32 side is set larger than the opening area on the first chamber 31 side, the movement resistance that the piston 21 receives from the hydraulic oil can be made different when the driver presses and releases the accelerator pedal 16, thereby achieving an operating feel that matches the driver's feeling.

[0068] The invention described in the above embodiments is not limited to these embodiments, and various modifications can be made in the implementation stage without departing from the gist of the invention. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriate combinations of the disclosed multiple constituent elements.

[0069] For example, in the above-described embodiment, a configuration was described in which the main communicating hole 33 and the sub-communicating hole 34 are provided with the first tapered surface 33a and the second tapered surface 34a, but depending on the movement resistance required for the piston 21, it is also possible to eliminate the tapered surface of either the main communicating hole 33 or the sub-communicating hole 34 and make it a cylindrical surface.

[0070] In the above embodiment, the function of the return spring for urging the accelerator pedal 16 to its original rest position is realized by the piston return spring 24 provided inside the cylinder 20. However, the function of the return spring can be realized by various other configurations. For example, as shown in FIG. 10, a return spring 24a that acts directly on the accelerator lever 6 can be disposed inside the housing 5. Alternatively, for example, as shown in FIG. 11, a return spring 24b that acts around the rotation axis 11 of the accelerator lever 6 can be disposed inside the housing 5.

[0071] 10 and 11 require a mechanism for transmitting the return force of the return springs 24a and 24b to the piston 21. Such a mechanism can be realized, for example, by providing the pedal force transmission surface 17 in a slit-shaped keyway and using a key that engages with this keyway as the abutment member 41.

[0072] Furthermore, even if some constituent elements are deleted from all the constituent elements shown in the above-mentioned form, if the stated problem can be solved and the stated effect can be obtained, the configuration from which these constituent elements are deleted can be extracted as an invention. [Explanation of symbols]

[0073] 1...Accelerator pedal unit 5... Chassis 6...Accelerator lever 7... Misstep prevention device 10...Accelerator opening sensor 11... Rotating axis 12 … Opening 15... Rotating bearing 16...Accelerator pedal 17 ... Pedal force transmission surface 20...cylinder 21... Piston 22... Valve body 23... Push rod 24...Piston return spring 25... Cylinder body 25a … Male thread part 26... Lid 26a … Female thread 26b … Through hole 27 ... Sealing material 30 … bulkhead 30a ... First spring support pin 33 … Main communication hole 34 … Sub-communication hole 36... Valve body 36a ... Tapered surface 37... Outward flange 37a ... Second spring support pin 38... Valve body return spring 40 … Hole 40a … opening 41 ... Contact member O … Central axis

Claims

1. a cylinder in which a fluid is sealed; a piston having a partition wall that divides a first end side and a second end side of the interior of the cylinder into a first chamber and a second chamber, each having a variable volume, the partition wall being provided with a main communication hole and a sub communication hole that communicate the first chamber with the second chamber; a normally open valve body provided in the second chamber and capable of closing the main communication hole in response to a pressure increase of the fluid on the second chamber side; a push rod having a second end connected to the piston and a first end penetrating the cylinder and projecting to the outside of the cylinder, capable of transmitting a pedal force; An accelerator pedal mis-depression prevention device characterized in that the opening area of ​​at least one of the main communication hole and the auxiliary communication hole on the second chamber side is set larger than the opening area on the first chamber side.

2. 2. The accelerator pedal mis-depression prevention device according to claim 1, wherein the effective opening area of ​​the auxiliary communication hole is relatively smaller than the effective opening area of ​​the main communication hole.

3. the main communication hole has a tapered surface having an inner diameter that decreases from the second chamber side toward the first chamber side, the valve body has a tapered surface whose outer diameter decreases from the second end side toward the first end side, 3. The accelerator pedal mis-depression prevention device according to claim 1, wherein the taper angle of the tapered surface of the valve body is set smaller than the taper angle of the tapered surface of the main communication hole.

4. a piston having a partition wall dividing a first end side and a second end side of the interior of the cylinder into a first chamber and a second chamber, each having a variable volume, the partition wall having a main communication hole and an auxiliary communication hole communicating the first chamber and the second chamber; a normally open valve body provided in the second chamber and capable of closing the main communication hole in response to a pressure increase of the fluid on the second chamber side; and a push rod connected at its second end side to the piston and projecting through the cylinder to the outside, wherein the opening area of ​​at least one of the main communication hole and the auxiliary communication hole on the second chamber side is set larger than the opening area of ​​the first chamber side; an accelerator pedal capable of transmitting a depression force to the push rod;

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