Variable damping pedal feeling simulation mechanism and simulation method suitable for brake-by-wire system

Abstract

The invention relates to the technical field of brake-by-wire, and discloses a variable damping pedal feeling simulation mechanism and simulation method suitable for a brake-by-wire system, the simulation mechanism comprises a simulator shell and a push rod, and one end, far away from the simulator shell, of the push rod is used for being connected with a brake pedal; the simulator further comprises a variable damping assembly, and the variable damping assembly comprises a damping piston which is arranged in the simulator shell in a sliding mode; the damping pad is attached to the end face of one side of the closed end of the damping piston; the elastic component is arranged on one side of the closed end of the damping pad or fixed to the damping pad, and the elastic component deforms in the y direction under the action of external force and rebounds in the x direction when the external force is cancelled; the damping piston is provided with a damping through hole which is at least partially covered by the damping pad and a through hole which is not interfered by the damping pad; according to the invention, different sizes of fluid flowing channels in different axial reciprocating directions of the damping piston assembly generate different retarding forces on the brake pedal, so that a real pedal feeling simulation effect of heavy stepping at a high speed and light stepping at a low speed is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of brake-by-wire, in particular to a variable damping pedal feel simulation mechanism and simulation method suitable for brake-by-wire systems. BACKGROUND

[0002] Compared with the traditional vacuum brake booster and hydraulic brake caliper combined system, in the existing brake-by-wire system technology including EHB (electronic hydraulic brake) and ETBS (electric transmission brake system), the brake pedal is completely decoupled from the caliper part, so that the driver cannot obtain similar pedal feel feedback as the hydraulic brake system when stepping on the brake pedal. The brake pedal of the traditional vacuum brake booster has the characteristics of slow stepping light, fast stepping heavy, and slow return, which constitutes a hysteresis pedal feel feature, and the hysteresis feel increases with the increase of pedal displacement, so in the existing brake-by-wire system scheme, a non-linear feedback force simulation unit composed of spring, rubber and other parts is often needed. However, the existing pedal feel simulation scheme cannot simulate the hysteresis feel when the pedal is stepped on quickly in the traditional sense, which results in unsatisfactory pedal feel performance. Therefore, some schemes additionally increase the hysteresis component to approach this effect, for example, the Chinese patent with publication number CN119636660A “Dry-type electronic pedal simulator with hysteresis characteristics” uses the friction between the damping ring and the conical inner wall to provide hysteresis feel, but the hysteresis feel provided by this dry friction method is linear resistance characteristics, which cannot achieve the inconsistent characteristics of slow stepping and fast stepping, and the gradual wear of the friction damping ring during repeated reciprocating friction will change the friction characteristics and generate friction debris to pollute the internal environment. Further, some other schemes additionally introduce a separate power source (motor, electromagnet) to generate an additional reaction force on the brake pedal to produce a non-linear feedback force effect, for example, the Chinese patent with publication number CN117549870A “Brake-by-wire chassis pedal simulator and pedal force control method” and the Chinese patent with publication number CN115675404A “Electric pedal simulator”, which makes the product structure more complex and greatly increases the product cost. Therefore, it is urgent to propose a pedal simulator structure and simulation method that adapts to the existing brake-by-wire environment, has no additional power source, and has the pedal feel of the traditional vacuum booster. SUMMARY

[0003] The present application provides a variable damping pedal feel simulation mechanism and simulation method suitable for brake-by-wire systems to solve the problems in the prior art.

[0004] The present application solves the above technical problems through the following technical solutions: The variable damping pedal feeling simulation mechanism suitable for a brake-by-wire system comprises a simulator housing and a push rod, the simulator housing has a closed end and an open end, the push rod is arranged at the open end of the simulator housing, the push rod can slide axially in an x direction towards the closed end or in a y direction towards the open end, and the end of the push rod away from the simulator housing is used for being connected with a brake pedal; characterized in that the variable damping assembly further comprises: a damping piston which is slidingly arranged in the simulator housing, a first chamber between the damping piston and the closed end of the simulator housing, and a second chamber between the damping piston and the cover; a damping pad which is attached to the end face of the closed end of the damping piston; a resilient member which is arranged at the closed end of the damping pad or fixed with the damping pad, and deforms in the y direction under the action of an external force and rebounds in the x direction when the external force is removed; the push rod passes through the resilient member, the damping pad and the damping piston, and the resilient member, the damping pad and the damping piston are axially limited by the push rod; a return component is arranged between the closed end of the simulator housing and the damping piston or the push rod; the damping piston is provided with a fluid passage which communicates the first chamber and the second chamber, the fluid passage comprises a damping through hole which is at least partially covered by the damping pad and a through hole which is not interfered by the damping pad; under the action of an external force, the push rod and the variable damping assembly move in the x direction to build pressure, hydraulic oil flows from the first chamber to the second chamber through the through hole or the hydraulic oil flows from the first chamber to the second chamber through the through hole and the damping through hole; when the external force is removed or smaller than the elastic force accumulated by the return component, the return component pushes the push rod and the variable damping assembly to move in the y direction, the hydraulic pressure of the second chamber presses the damping pad towards the damping through hole to hinder the push rod from retreating, the damping through hole is at least partially covered by the damping pad, and the hydraulic oil flows back to the first chamber through the through hole and the damping through hole which is not covered by the damping pad. By stepping on the pedal at different speeds, the speed of the movement of the damping piston is different, the speed of the compression of the brake fluid is different, different hydraulic pressures are generated to provide feedback force to cause the difference in the deformation of the resilient member, and thus the opening degree of the fluid passage between the damping pad and the damping piston is changed to obtain different resistance feelings, thereby achieving the effect of simulating the traditional pedal feeling that fast stepping is light and slow stepping is heavy, and the simulation is provided by the hydraulic pressure generated by the size of the flow passage of the brake fluid itself, the structure is stable, and the simulation is accurate.

[0005] As preferred, the damping piston is cylindrical, the outer side wall of the damping piston is provided with a through hole in the axial direction for connecting the first chamber and the second chamber, the side wall of the damping piston is further provided with an annular groove in the circumferential direction, so that the axial cross section of the damping piston is in the shape of an I-beam, a plurality of damping through holes are arranged concentrically on the two side end faces of the damping piston and penetrate the damping piston, a through hole is arranged on the groove wall of the annular groove and penetrates the inner cavity of the damping through hole and the space outside the annular groove, and the damping pad covers or partially covers the opening end of the damping through hole. The partial coverage can be that the damping pad is semi-sealed and has pores for fluid to pass through; or the damping pad can be annular, the distance between the outer edge of the damping through hole and the center of the damping piston is greater than the outer edge radius of the damping pad; or other similar positional relationships cause the damping pad to not fully cover the damping through hole.

[0006] As preferred, the opening end of the damping piston is provided with a containing cavity for containing the damping pad, the cavity bottom of the containing cavity is matched with the damping pad, the damping pad is arranged in the containing cavity, and the cavity bottom of the containing cavity prevents the damping pad from being bent in the x direction and keeps the damping pad covering the outside of the damping through hole. When the return component releases the elastic potential energy and moves the push rod in the y direction, the hydraulic oil in the second chamber generates a reverse force in the x direction on the push rod. The cooperation of the damping piston and the variable damping assembly achieves the difference of the two-way flow channel, thereby achieving the effect of slow return.

[0007] As preferred, the return component includes a first spring and a second spring, the first spring and the second spring are arranged in series in the second chamber to provide a feedback elastic force corresponding to the pedal stroke; the closed end of the simulator shell has a boss protruding toward the opening end, the first spring and the second spring are connected in series through a spring washer, the spring washer is arranged outside the boss, one end of the second spring is fixedly connected with the inner cavity wall of the closed end of the simulator shell, and the other end abuts against the spring washer; one end of the first spring abuts against the damping piston, and the other end abuts against the spring washer. A nonlinear spring force is provided, the second spring participates in the initial stroke, the pedal force rises gently due to the small stiffness of the second spring, when reaching the limit step, the second spring is compressed to the maximum stroke, at this time, the elastic force of the second spring is fixed, and a larger pedal force is required to compress the first spring.

[0008] As preferred, the outer surface of the boss is provided with a limit step for limiting the continuous compression of the second spring, the stiffness of the first spring is greater than that of the second spring, and the first spring and the second spring are compressed in the x direction to provide a feedback elastic force corresponding to the pedal stroke.

[0009] Preferably, the boss has an internal cavity on one side of the open end, and a buffer block is fitted inside the cavity. An impact head is threadedly connected to the closed end of the push rod. The extension length of the impact head is locked by an adjusting nut. The buffer block, in conjunction with the impact head, provides a soft limit when the push rod reaches the bottom. The impact head is threaded into a threaded hole on the left end of the push rod, and its position is fixed by an adjusting nut. The extension length of the impact head from the push rod can be adjusted by the adjusting nut to meet different pedal travel requirements.

[0010] Preferably, the push rod includes a concentric shaft portion, and a stepped surface is provided on one side of the open end of the concentric shaft portion. The concentric shaft portion passes through the elastic member, the damping pad, and the damping piston. The variable damping assembly is fixed by the stepped surface in conjunction with a retaining spring or bolts.

[0011] Preferably, the damping pad consists of a flexible part and an insert part. The flexible part is a single or multi-layer fully sealed soft material or a semi-sealed soft material with micro-gaps. The insert part is rigid and has a central hole in the center, which can accommodate the concentric shaft part of the push rod through.

[0012] Preferably, the elastic member has a mounting hole at its center, and elastic arms are arranged around the periphery of the mounting hole, extending radially outward from the mounting hole. This shape makes the inner periphery of the elastic member less prone to deformation, while the outer periphery is more easily deformed, facilitating changes in the opening degree of the damping pad and damping spring.

[0013] Preferably, the closed end of the simulator housing is fitted with a cover, and a sealing damping ring for damping piston shock absorption is installed between the cover and the variable damping assembly. A sealing ring for axial sealing of the push rod is installed between the push rod and the cover. The variable damping pedal feel simulation method employs the aforementioned variable damping pedal feel simulation mechanism suitable for brake-by-wire systems, and the method is as follows: A: When the speed is S x When the brake pedal is depressed, the force exerted by the brake pedal on the push rod in the x-direction is denoted as F. c The axial movement of the push rod linked to the brake pedal, together with the damping assembly, moves in the x direction to build up pressure, and the hydraulic oil flows from the first chamber to the second chamber through the through hole or through the through hole and the damping through hole. The compression of the return component generates a force F in the y-direction on the push rod, which corresponds to the push rod's stroke. y The damping pad and elastic component block the flow of hydraulic oil, and the hydraulic oil generates a reverse force on the push rod in the y direction, denoted as F. X ; The resistance force F fed back to the brake pedal z =F y +F X +a;F z Less than F c; a represents the resisting force caused by other factors such as friction. a can be a variable or a constant.

[0014] The speed S of the push rod x The boundary velocity S not greater than that of hydraulic damping n At that time, hydraulic oil flows from the first chamber to the second chamber through the through hole; the speed S of the push rod x Greater than S n At that time, hydraulic oil flows from the first chamber to the second chamber through the through hole and the damping through hole. The resistance F of the hydraulic oil... X The deformation of the damping pad varies with the push rod speed S. x The resistance force F, which increases with the increase of [something], is fed back to the brake pedal. z Increase; B: When the brake pedal is released, the push rod loses the external force input by the brake pedal. The return component releases the elastic potential energy generated by compression, pushing the push rod and the variable damping assembly back in the y-direction. The y-direction force exerted by the return component on the push rod is F corresponding to the push rod stroke. y The damping through-hole is at least partially covered by a damping pad. Hydraulic oil flows from the second chamber back to the first chamber through the through-hole and the damping through-hole not covered by the damping pad. The hydraulic oil in the second chamber generates a reverse force F in the x-direction on the push rod. T Used to prevent the push rod from retracting in the y direction; Among them, F X F z and F T They are positively correlated with the elastic force of the elastic component.

[0015] This invention, by adopting the above technical solutions, has significant technical effects: 1. The combination of a damping pad made of flexible material and an elastic component can use hydraulic pressure to deform the elastic component according to the speed when the brake pedal is pressed, thereby adjusting the gap between the damping pad and the damping piston to generate different sizes of pedal resistance force and achieve a variable damping effect in the brake pedal feel. 2. By changing the number of layers of the elastic component or selecting elastic components of different thicknesses, the deformation of the elastic component can be adjusted when the brake pedal is pressed at the same speed. This changes the opening size of the gap between the damping pad and the damping piston, allowing the pedal resistance to be adjusted according to the user's needs. 3. The different sizes of the fluid flow channels in the axial reciprocating direction of the damping piston assembly produce different resistance forces on the brake pedal, thereby achieving a realistic pedal feel simulation effect of "heavy pressure when pressing fast and light pressure when pressing slow". 4. When the pedal is released, the elastic component presses the damping pad tightly against the damping piston and provides the damping pad to resist the elastic force of the hydraulic oil generated by compression, thereby achieving the effect of "slow rebound". Attached Figure Description

[0016] Figure 1 is a structural schematic diagram of the present application when the brake pedal is not depressed; Figure 2 is a structural schematic diagram of the present application when the brake pedal is depressed; Figure 3 is an exploded view of the present application; Figure 4 is an exploded view of the push rod and the variable damping assembly; Figure 5 is a structural schematic diagram of the push rod and the variable damping assembly when the brake pedal is depressed; Figure 6 is a structural schematic diagram of the push rod and the variable damping assembly when the brake pedal is released; Figure 7 is a structural schematic diagram of the damping piston located at the closed side; Figure 8 is a structural schematic diagram of the damping piston located at the open side; Figure 9 is a schematic diagram of the same force being applied to the brake pedal after the thickness of the elastic member is changed; Figure 10 is a structural schematic diagram of the damping pad and the elastic member being integrated in Example 3; Figure 11 is a structural schematic diagram of the other side of Figure 10 ; Figure 12 is a partial sectional view of Figure 10 ;

[0017] The names of the parts referred to by the respective reference numerals in the above drawings are as follows: wherein 1, push rod; 11, impact head; 12, adjusting nut; 13, concentric shaft portion; 14, stepped surface; 15, snap spring; 2, cover; 21, sealing shock-absorbing ring; 22, sealing ring; 3, simulator housing; 31, first chamber; 32, second chamber; 33, boss; 331, limiting step; 332, cavity inner hole; 333, buffer block; 4, damping piston; 41, damping through hole; 42, through hole; 43, annular groove; 44, accommodating cavity; 5, damping pad; 51, flexible portion; 52, insert portion; 6, elastic member; 61, elastic arm; 62, mounting hole; 71, first spring; 72, second spring; 8, spring washer. DETAILED DESCRIPTION

[0018] The present application will be further described in detail below in conjunction with the drawings and examples.

[0019] Example 1 As Figures 1-2As shown, the variable damping pedal feel simulation mechanism suitable for a brake-by-wire system comprises a simulator housing 3 and a push rod 1, the simulator housing 3 has a closed end and an open end, the push rod 1 is arranged at the open end of the simulator housing 3, the inner cavity of the simulator housing 3 is filled with fluid providing damping force, which is specifically hydraulic oil in this paper for convenient description. The push rod 1 can slide axially in the x direction towards the closed end or in the y direction towards the open end, and the end of the push rod 1 away from the simulator housing 3 is used to connect with the brake pedal.

[0020] As shown in Figures 1-4 It also comprises a variable damping assembly, which comprises: a damping piston 4 slidingly arranged in the simulator housing 3, the damping piston 4 has a first chamber 31 between the closed end of the simulator housing 3 and the damping piston 4, and a second chamber 32 between the damping piston 4 and the cover 2; a damping pad 5 attached to the end face of the closed end of the damping piston 4; a resilient member 6 arranged at the closed end of the damping pad 5, which deforms in the y direction under external force and rebounds in the x direction when the external force is removed.

[0021] The push rod 1 penetrates the resilient member 6, the damping pad 5 and the damping piston 4, and the resilient member 6, the damping pad 5 and the damping piston 4 are axially limited by the push rod 1; wherein the resilient member 6 is one or more, and the thickness of the resilient member 6 can be adjusted, and the pre-tightening force on the damping pad 5 is changed by replacing the resilient member, so as to adjust the fast stepping resistance force threshold.

[0022] A return component is arranged between the closed end of the simulator housing 3 and the damping piston 4 or the push rod 1; As one of the implementation manners, as shown in Figure 4 The push rod 1 comprises a concentric shaft portion 13, the push rod 1 is provided with a stepped surface 14 at the open end side of the concentric shaft portion 13, the concentric shaft portion 13 penetrates the resilient member 6, the damping pad 5 and the damping piston 4, and the variable damping assembly is fixed by the stepped surface 14 cooperating with a snap spring 15 or a bolt. The end of the concentric shaft portion of the push rod is provided with a snap spring groove, the snap spring groove is provided with a snap spring 15, the snap spring 15 cooperates with the stepped surface 14 to axially clamp the damping piston, the damping pad and the resilient member to realize fixation; the concentric shaft portion 13 is used for circumferential positioning of the damping piston, the damping pad and the resilient member.

[0023] The damping piston 4 is provided with a fluid passage communicating the first chamber 31 and the second chamber 32, the fluid passage comprises a damping through hole 41 at least partially covered by the damping pad 5 and a through hole 42 not interfered by the damping pad 5; As shown in Figure 5 Under the action of external force, the push rod 1 and the variable damping assembly move in the x direction to build pressure, and the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42 or the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42 and the damping through hole 41. like Figure 6 As shown, when the external force is canceled or less than the elastic force accumulated by the return component, the return component pushes the push rod 1 and the variable damping assembly to move in the y direction. The hydraulic pressure in the second chamber 32 presses the damping pad 5 against the damping through hole 41, thereby hindering the push rod 1 from retracting. The damping through hole 41 is at least partially covered by the damping pad 5. The hydraulic oil flows from the second chamber 32 back to the first chamber 31 through the through hole 42 and the damping through hole 41 that is not covered by the damping pad 5.

[0024] like Figures 7-8 As shown, the damping piston 4 is cylindrical. A through hole 42 is axially provided on the outer wall of the damping piston 4, connecting the first chamber 31 and the second chamber 32. An annular groove 43 is also circumferentially provided on the side wall of the damping piston 4, making the axial cross-section of the damping piston 4 I-shaped. Several damping through holes 41 are concentrically arranged and penetrating the damping piston 4 on both end faces of the damping piston 4. Through holes 42 are provided on the walls of the annular groove 43, penetrating the inner cavity of the damping through hole 41 and the outer space of the annular groove 43. The damping pad 5 covers or partially covers one side of the opening end of the damping through hole 41. Partial coverage can be achieved by the damping pad 5 being semi-sealed with pores for fluid passage; or by the damping pad 5 being annular, with the distance from the outer edge of the damping through hole 41 to the center of the damping piston 4 being greater than the radius of the outer edge of the damping pad 5; or by other similar positional relationships resulting in the damping pad 5 not fully covering the damping through hole 41.

[0025] The open end of the damping piston 4 is provided with a receiving cavity 44 for accommodating the damping pad 5. The bottom shape of the receiving cavity 44 matches the damping pad 5. The damping pad 5 is placed inside the receiving cavity 44. The bottom of the receiving cavity 44 prevents the damping pad 5 from bending and deforming in the x-direction and keeps it covering the outside of the damping through hole 41. When the return component releases elastic potential energy to move the push rod 1 in the y-direction, the hydraulic oil in the second chamber 32 generates a reverse force in the x-direction on the push rod 1. As one embodiment, the side of the damping pad 5 located at the closed end is flat, so the end face of the damping piston 4 located at the open end is also flat.

[0026] The return component includes a first spring 71 and a second spring 72, which are connected in series in the second chamber 32 to provide feedback force corresponding to the pedal stroke. The closed end of the simulator housing 3 has a boss 33 protruding towards the open end. The first spring 71 and the second spring 72 are connected in series through a spring washer 8, which slides outside the boss 33. One end of the second spring 72 is fixedly connected to the inner wall of the closed end of the simulator housing 3, and the other end abuts against the spring washer 8. One end of the first spring 71 abuts against the damping piston 4, and the other end abuts against the spring washer 8.

[0027] The outer surface of the boss 33 is provided with a limiting step 331 to limit the compression of the second spring 72. The first spring 71 has a greater rigidity than the second spring 72. The first spring 71 and the second spring 72 are compressed along the x direction to provide a feedback elastic force corresponding to the pedal stroke of the push rod 1.

[0028] The boss 33 is provided with a cavity bore 332 on the side of the open end. The cavity bore 332 is fitted with a buffer block 333. The push rod 1 is threadedly connected with a striking head 11 on the side of the closed end. The striking head 11 is locked by an adjusting nut 12 to extend the length. The buffer block 333 cooperates with the striking head 11 to provide soft limiting when the push rod 1 travels to the bottom. The striking head 11 is designed as a contact portion for striking the buffer block 333. The striking head 11 is screwed into the threaded hole at the end of the push rod 1. The thread direction of the inner hole of the adjusting nut 12 is opposite to that of the striking head 11. This makes the striking head 11 fixed in the axial direction to extend the position. The striking head 11 abuts against the buffer block 333 when the push rod 1 reaches the maximum stroke. The extension position of the striking head 11 can be used to adjust the brake pedal stroke.

[0029] As shown in Figure 4 , the damping pad 5 is composed of a flexible portion 51 and an insert portion 52. The flexible portion 51 is a single or multi-layer full-sealing soft material or a semi-sealing soft material with micro gaps. The insert portion 52 is hard. The center of the insert portion 52 has a center hole 53 which can accommodate the concentric shaft portion 13 of the push rod 1. As the material of the flexible portion 51, a sealed material such as rubber can be used, a semi-sealing material can also be used, or a sealed material with small holes can also be used. As long as the flexible portion itself has flexibility and can be deformed by hydraulic pressure, it is acceptable. The smaller the gap on the surface of the material, the greater the damping force generated by the damping pad 5.

[0030] As shown in Figure 4 , the elastic member 6 is provided with a mounting hole 62 in the center. The outer periphery of the mounting hole 62 is provided with elastic arms 61 which extend radially outwardly with the mounting hole 62 as the center.

[0031] As shown in Figure 1 and Figure 3 , the closed end of the simulator housing 3 is provided with a cover 2. The cover 2 is provided with a sealing damping ring 21 between the variable damping assembly and the damping piston 4 for damping and buffering. The push rod 1 is provided with a sealing ring 22 between the push rod 1 and the cover 2 for axial sealing of the push rod 1. The working principle of the pedal feeling simulation is as follows: when the brake pedal is stepped down at different speeds, the reverse force of the hydraulic oil on the damping pad is different, the faster the speed of the push rod, the greater the reverse force of the hydraulic oil on the damping pad, and the greater the gap between the damping pad and the damping piston due to the deformation of the damping pad, thereby realizing the variable damping function of the brake pedal simulator in the patent. In particular, the reverse force of the damping pad 6 can be simply increased by increasing the elastic force of the elastic member 6. Example 2 As Figures 5-6 shown, the variable damping pedal feeling simulation method adopts the variable damping pedal feeling simulation mechanism suitable for the brake-by-wire system in Example 1, and the method is as follows: A: when the brake pedal is stepped down at a speed S x , the x-direction force of the brake pedal on the push rod 1 at this time is denoted as F c ; the axial movement of the push rod 1 linked with the brake pedal moves the pressure building of the damping assembly to the x-direction, and the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42 or the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42 and the damping through hole 41; The return component is compressed to generate a y-direction force on the push rod 1, which is F y corresponding to the stroke of the push rod 1; the damping pad 5 and the elastic member 6 block the flow of hydraulic oil, and the reverse force of the hydraulic oil on the push rod 1 in the y-direction is denoted as F X ; The resistance force F z fed back to the brake pedal is F y +F X +a; F z is less than F c ; a is the resistance force caused by other factors such as friction, and a can be a variable number or a constant. In particular, during the return process of the brake pedal, the reverse force of the hydraulic oil on the damping piston to some extent consumes the reverse force of the elastic potential energy of the return component on the push rod, so the feedback force of the brake pedal on the driver's foot at this time will be less than the applied force when the brake pedal is stepped down, thereby a better pedal feeling can be obtained.

[0032] As Figure 9 shown, when the speed S x of the push rod 1 is not greater than the boundary speed S n of the hydraulic damping, the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42; when the speed S x of the push rod 1 is greater than S n , the hydraulic oil flows from the first chamber 31 to the second chamber 32 through the through hole 42 and the damping through hole 41, and the resistance F X of the hydraulic oil makes the deformation amount of the damping pad 5 change with the speed S xThe resistance force F, which increases with the increase of [something], is fed back to the brake pedal. z Increase; of which, S n It can be a preset value of 0 or higher.

[0033] B: When the brake pedal is released, push rod 1 loses the external force input from the brake pedal. The return component releases the elastic potential energy generated by compression, pushing push rod 1 and the variable damping assembly back in the y-direction. The y-direction force exerted by the return component on push rod 1 is F, which corresponds to the stroke of push rod 1. y The damping through-hole 41 is at least partially covered by the damping pad 5. Hydraulic oil flows from the second chamber 32 back to the first chamber 31 through the through-hole 42 and the damping through-hole 41 not covered by the damping pad 5. The hydraulic oil in the second chamber 32 generates a reverse force F in the x-direction on the push rod 1. T Used to prevent push rod 1 from retracting in the y direction; Among them, F X F z and F T They are positively correlated with the elastic force of elastic member 6.

[0034] Example 3 Its structural embodiment 1, such as Figures 10-12 As shown, the only difference is that the elastic member 6 is fixed to the damping pad 5. In one embodiment, the elastic member 6 and the damping pad 5 are processed as one piece. The end face of the damping pad 5 on the closed side is a flat surface, and a reinforcing frame is provided on the other side. The radially arranged elastic member 6 is embedded in the center of the damping pad 5, and the elastic arm of the elastic member extends into the reinforcing frame for fixation. The working principle is the same as in Embodiments 1 and 2.

[0035] In the description of this invention, it should be understood that the terms "center," "length," "width," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] In summary, the above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the present invention.

Claims

1. A variable damping pedal feel simulation mechanism suitable for a brake-by-wire system, comprising a simulator housing (3) and a push rod (1), the simulator housing (3) having a closed end and an open end, the push rod (1) being disposed at the open end of the simulator housing (3), the push rod (1) being axially sliding towards the closed end in the x-direction or towards the open end in the y-direction, the end of the push rod (1) away from the simulator housing (3) being used for connection with the brake pedal; characterized in that, It also includes a variable damping component, which includes: The damping piston (4) is slidably disposed inside the simulator housing (3). There is a first chamber (31) between the damping piston (4) and the closed end of the simulator housing (3), and a second chamber (32) between the damping piston (4) and the cover (2). The damping pad (5) is attached to the end face of the closed end of the damping piston (4); The elastic member (6) is located on one side of the closed end of the damping pad (5) or fixed to the damping pad (5). Under the action of external force, the elastic member (6) deforms in the y direction and rebounds in the x direction when the external force is removed. The push rod (1) passes through the elastic member (6), the damping pad (5), and the damping piston (4), and the elastic member (6), the damping pad (5), and the damping piston (4) are axially limited by the push rod (1); A return component is provided between the closed end of the simulator housing (3) and the damping piston (4) or push rod (1); The damping piston (4) is provided with a fluid channel connecting the first chamber (31) and the second chamber (32). The fluid channel includes a damping through hole (41) at least partially covered by the damping pad (5) and a through hole (42) that is not interfered with by the damping pad (5). Under the application of external force, the push rod (1) and the variable damping assembly move in the x direction to build up pressure, and the hydraulic oil flows from the first chamber (31) to the second chamber (32) through the through hole (42) or through the through hole (42) and the damping through hole (41). When the external force is canceled or less than the elastic force accumulated by the return component, the return component pushes the push rod (1) and the variable damping component to move in the y direction. The hydraulic pressure in the second chamber (32) presses the damping pad (5) against the damping through hole (41) to prevent the push rod (1) from retracting. The damping through hole (41) is at least partially covered by the damping pad (5). The hydraulic oil flows from the second chamber (32) back to the first chamber (31) through the through hole (42) and the damping through hole (41) not covered by the damping pad (5).

2. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The damping piston (4) is cylindrical. A through hole (42) is provided axially on the outer side wall of the damping piston (4) to connect the first chamber (31) and the second chamber (32). The side wall of the damping piston (4) is also provided with an annular groove (43) in the circumferential direction so that the axial cross section of the damping piston (4) is I-shaped. Several damping through holes (41) are provided on both sides of the damping piston (4) and are arranged concentrically and pass through the damping piston (4). The damping through hole (41) and the groove wall of the annular groove (43) are provided with a through hole (42) that passes through the inner cavity of the damping through hole (41) of the damping piston (4) and the outer space of the annular groove (43). The damping pad (5) covers or partially covers one side of the opening end of the damping through hole (41).

3. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1 or 2, characterized in that: The damping piston (4) has an opening end with a receiving cavity (44) for receiving the damping pad (5). The bottom shape of the receiving cavity (44) matches the damping pad (5). The damping pad (5) is placed in the receiving cavity (44). The bottom of the receiving cavity (44) prevents the damping pad (5) from bending and deforming in the x direction and keeps it covered outside the damping through hole (41). When the return component releases elastic potential energy to move the push rod (1) in the y direction, the hydraulic oil in the second chamber (32) generates a reverse force in the x direction on the push rod (1).

4. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The return component includes a first spring (71) and a second spring (72). The first spring (71) and the second spring (72) are connected in series in the second chamber (32) to provide feedback force corresponding to the pedal stroke. The closed end of the simulator housing (3) has a boss (33) protruding towards the open end. The first spring (71) and the second spring (72) are connected in series through a spring washer (8). The spring washer (8) slides outside the boss (33). One end of the second spring (72) is fixedly connected to the inner wall of the closed end of the simulator housing (3), and the other end abuts against the spring washer (8). One end of the first spring (71) abuts against the damping piston (4), and the other end abuts against the spring washer (8).

5. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 4, characterized in that: The outer surface of the boss (33) is provided with a limiting step (331) to limit the continued compression of the second spring (72). The stiffness of the first spring (71) is greater than that of the second spring (72). The first spring (71) and the second spring (72) are compressed along the x direction to provide feedback force corresponding to the push rod (1) and the pedal stroke.

6. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 4, characterized in that: The boss (33) has a cavity inner hole (332) on one side of the open end. A buffer block (333) is installed in the cavity inner hole (332). The push rod (1) has an impact head (11) threaded on one side of the closed end. The extension length of the impact head (11) is locked by adjusting the nut (12). The buffer block (333) cooperates with the impact head (11) to provide a soft limit when the push rod (1) moves to the bottom.

7. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The push rod (1) includes a concentric shaft part (13). A stepped surface (14) is provided on one side of the open end of the concentric shaft part (13). The concentric shaft part (13) passes through the elastic member (6), the damping pad (5) and the damping piston (4). The variable damping assembly is fixed by the stepped surface (14) in conjunction with the snap ring (15) or bolts.

8. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The damping pad (5) consists of a flexible part (51) and an insert part (52). The flexible part (51) is a single or multi-layer fully sealed soft material or a semi-sealed soft material with micro-gaps. The insert part (52) is rigid. The insert part (52) has a central hole (53) in the center. The central hole (53) can accommodate the concentric shaft part (13) of the push rod (1) through which it passes.

9. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The elastic member (6) has a mounting hole (62) at its center and an elastic arm (61) on its outer periphery. The elastic arm (61) extends outward from the mounting hole (62) in a radial pattern.

10. The variable damping pedal feel simulation mechanism for a brake-by-wire system according to claim 1, characterized in that: The closed end of the simulator housing (3) is fitted with a cover (2), and a sealing damping ring (21) for damping piston (4) is installed between the cover (2) and the variable damping assembly. A sealing ring (22) for axial sealing of push rod (1) is installed between push rod (1) and cover (2).

11. A method for simulating the feel of a variable damping pedal, characterized in that, The variable damping pedal feel simulation mechanism for a brake-by-wire system, as described in any one of claims 1-10, is employed, and the method is as follows: A: When the speed is S x When the brake pedal is pressed, the force exerted by the brake pedal on the push rod (1) in the x direction at this time is denoted as F. c The push rod (1) linked to the brake pedal moves axially and together with the damping assembly moves in the x direction to build up pressure. Hydraulic oil flows from the first chamber (31) to the second chamber (32) through the through hole (42) or through the through hole (42) and the damping through hole (41). The compression of the return component generates a force F in the y-direction on the push rod (1) corresponding to the stroke of the push rod (1). y The damping pad (5) and the elastic member (6) block the flow of hydraulic oil, and the hydraulic oil generates a reverse force on the push rod (1) in the y direction, denoted as F. X ; The resistance force F fed back to the brake pedal z =F y +F X +a;F z Less than F c ; The velocity S of push rod (1) x The boundary velocity S not greater than that of hydraulic damping n At that time, hydraulic oil flows from the first chamber (31) to the second chamber (32) through the through hole (42); the speed S of the push rod (1) x Greater than S n At that time, hydraulic oil flows from the first chamber (31) to the second chamber (32) through the through hole (42) and the damping through hole (41), and the resistance F of the hydraulic oil... X The deformation of the damping pad (5) varies with the velocity S of the push rod (1). x The resistance force F, which increases with the increase of [something], is fed back to the brake pedal. z Increase; B: When the brake pedal is released, the push rod (1) loses the external force input by the brake pedal. The return component releases the elastic potential energy generated by compression and pushes the push rod (1) and the variable damping assembly back in the y direction. The force exerted by the return component on the push rod (1) in the y direction is F corresponding to the stroke of the push rod (1). y The damping through-hole (41) is at least partially covered by the damping pad (5). Hydraulic oil flows from the second chamber (32) back to the first chamber (31) through the through-hole (42) and the damping through-hole (41) not covered by the damping pad (5). The hydraulic oil in the second chamber (32) generates a reverse force F in the x direction on the push rod (1). T Used to prevent the push rod (1) from retracting in the y direction; Among them, F X F z and F T They are positively correlated with the elastic force of the elastic member (6).

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