Dry type brake pedal simulator integrating pedal displacement and pedal damping sense

Abstract

The invention discloses a dry type brake pedal simulator integrating pedal displacement and pedal damping sense, which comprises a displacement sensor and a pedal sense simulation structure assembly, the pedal sense simulation structure assembly comprises a flange plate, a shell, a piston and support rubber, the shell is fixedly mounted on the left side of the flange plate, a round hole is formed in the center of the left side of the shell, and the piston is arranged in the round hole. The piston penetrates through the circular hole to be installed on the shell in a sliding mode, a check ring is arranged on the piston and located in the shell, supporting rubber in a circular truncated cone shape is fixedly installed on the flange plate and located in the shell, and the piston and the supporting rubber are located on the same axis. The dry type brake pedal simulator integrating the pedal displacement and the pedal damping feeling does not depend on brake fluid any more, the brake fluid does not need to be replaced in the whole life cycle, and the pedal feeling is similar to the damping feeling of a wet type simulator and is closer to the pedal feeling needed by a driver.

Description

Technical Field

[0001] The present invention relates to the technical field of brake pedal simulators in high-level autonomous driving brake-by-wire systems for automobiles, and specifically to a dry brake pedal simulator that integrates pedal displacement and pedal damping feel. Background Art

[0002] At present, mainstream wire-controlled products include integrated braking systems (one-box) and distributed braking systems (two-box), both of which belong to electronic hydraulic braking systems (EHB), that is, wet braking systems. Their pedal simulators and pressure-building units are integrated on the entire valve block, and hydraulic pressure is also used as the transmission medium. However, with the increasing demand for high-level autonomous driving of automobiles, higher requirements are placed on the system performance and safety redundancy of the brake system. The electronic mechanical braking system (EMB), that is, the dry braking system, will become a mainstream direction to meet the above-mentioned braking system requirements. However, since drivers are currently unable to adapt to high-level autonomous driving that eliminates the brake pedal, the brake pedal and pedal feel simulator need to be retained.

[0003] Based on the above technical background and market demand, the present invention proposes a dry pedal simulator integrating pedal displacement and pedal damping feeling. The invention can be applied not only to current EHB products, but also to subsequent EMB products. Summary of the invention

[0004] The purpose of the present invention is to provide a dry brake pedal simulator integrating pedal displacement and pedal damping feeling in view of the deficiencies of the prior art, so as to solve the problems raised in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a dry brake pedal simulator integrating pedal displacement and pedal damping feeling, comprising a displacement sensor and a pedal feeling simulation structure assembly, wherein the pedal feeling simulation structure assembly comprises a flange, a shell, a piston and a supporting rubber, wherein the shell is fixedly mounted on the left side of the flange, a circular hole is opened at the left center position of the shell, the piston passes through the circular hole and is slidably mounted on the shell, a retaining ring is provided on the piston, the retaining ring is located inside the shell, a truncated cone-shaped supporting rubber is fixedly mounted on the flange and is located inside the shell, and the piston and the supporting rubber are on the same axis.

[0006] Preferably, a magnet fixing ring and a spring fixing ring are provided inside the shell, the magnet fixing ring is fixedly mounted on the piston, and two square permanent magnets are mounted on the magnet fixing ring, the ring hole in the middle of the spring fixing ring is just enough for the piston rod of the piston to pass through, a small spring is provided between the left side of the spring fixing ring and the retaining ring of the piston, and a variable stiffness spring is provided between the right side of the spring fixing ring and the flange.

[0007] Preferably, an O-ring is provided between the left side of the retaining ring of the piston and the housing, and the O-ring is fixed on the housing.

[0008] Preferably, a first sealing ring is provided between the circular hole of the housing and the piston, and the first sealing ring is fixed on the housing.

[0009] Preferably, a second sealing ring is provided at the mounting connection between the flange and the housing.

[0010] Preferably, a third sealing ring is provided between the magnet fixing ring and the inner wall of the housing, and the third sealing ring is fixed on the magnet fixing ring.

[0011] Preferably, connecting bolts are provided on the flange.

[0012] Preferably, the magnet fixing ring has two air flow openings in the axial direction.

[0013] Preferably, the displacement sensor is arranged on the outer side of the housing near the permanent magnet.

[0014] Compared with the prior art, the present invention provides a dry brake pedal simulator integrating pedal displacement and pedal damping feeling, which has the following beneficial effects:

[0015] 1. The dry brake pedal simulator of the present invention integrates pedal displacement and pedal damping feeling, no longer relies on brake fluid, and the brake fluid does not need to be replaced during the entire life cycle. Moreover, the pedal feel is similar to the damping feel of a wet simulator, and is closer to the pedal feel required by the driver. In this aspect, modular design is fully considered, and by changing the stiffness of different small springs, the distance between the variable stiffness spring and the supporting rubber and the piston, 98% of the pedal feel in the current passenger car market can be met. Therefore, the number of parts (small springs, variable stiffness springs) is limited, and modularization is good.

[0016] 2. The present invention integrates pedal displacement sensing and can be directly used in EHB / EMB systems. In order to meet the requirements of high-level L3 and above advanced autonomous driving for system safety redundancy, the pedal displacement sensor is also designed with dual backup, meeting the functional safety level ASI LD requirements of the automotive electronic control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the working principle model of the pedal simulator of the present invention;

[0019] Figure 3 It is a schematic diagram of the working principle of the pedal simulator of the present invention;

[0020] Figure 4It is a schematic diagram of displacement monitoring of the pedal simulator of the present invention.

[0021] Figure numerals: 1. connecting bolt; 2. flange; 3. displacement sensor; 4. permanent magnet; 5. magnet fixing ring; 6. housing; 7. piston; 8. small spring; 9. O-ring; 10. first sealing ring; 11. second sealing ring; 12. variable stiffness spring; 13. supporting rubber; 14. spring fixing ring; 15. third sealing ring. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1-Figure 4In this embodiment: a dry brake pedal simulator integrating pedal displacement and pedal damping feeling, including a displacement sensor 3 and a pedal feeling simulation structure assembly, the pedal feeling simulation structure assembly including a flange 2, a shell 6, a piston 7 and a supporting rubber 13, a connecting bolt 1 is arranged on the flange 2, when installing with the vehicle, it is only necessary to pass the connecting bolt 1 through the front panel of the vehicle and fix it with a nut to realize the installation of the pedal simulator, the arrangement position and quantity of the connecting bolt 1 can be customized and modified according to the needs of the vehicle, the shell 6 is fixedly installed on the left side of the flange 2 by four bolts, a circular hole is opened in the central position of the left side of the shell 6, and the piston 7 passes through the circular hole and is slidably installed on the On the housing 6, a retaining ring is arranged on the piston 7, and the retaining ring is located inside the housing 6. An O-ring 9 is arranged between the left side of the retaining ring of the piston 7 and the housing 6. The O-ring 9 is fixed on the housing 6. The O-ring 9 can be used as a buffer between the piston 7 and the housing 6 to reduce the impact of the retaining ring on the housing 6 when the piston 7 is reset. The truncated cone-shaped supporting rubber 13 is fixedly installed on the flange 2 and is located inside the housing 6. The piston 7 and the supporting rubber 13 are on the same axis. When the piston 7 moves to the right, it will eventually rest on the supporting rubber 13. A magnet fixing ring 5 and a spring fixing ring 14 are arranged inside the housing 6. The magnet fixing ring 5 is fixedly installed on the piston 7 by bolts. Two grooves, two square permanent magnets 4 are installed in the grooves through interference pressure, the magnet fixing ring 5 has two air flow openings in the axial direction, the ring hole in the middle of the spring fixing ring 14 can just allow the piston rod of the piston 7 to pass through, a small spring 8 is arranged between the left side of the spring fixing ring 14 and the retaining ring of the piston 7, a variable stiffness spring 12 is arranged between the right side of the spring fixing ring 14 and the flange 2, the displacement sensor 3 is arranged on the outer side of the shell 6 near the permanent magnet 4, and the pedal displacement signal can be monitored by cooperating with the displacement sensor 3 and the permanent magnet 4, a first sealing ring 10 is arranged between the circular hole of the shell 6 and the piston 7, the first sealing ring 10 is fixed on the shell 6, and the flange 2 and the shell 6 A second sealing ring 11 is provided at the installation connection, and a third sealing ring 15 is provided between the magnet fixing ring 5 and the inner wall of the shell 6. The third sealing ring 15 is fixed on the magnet fixing ring 5, and cooperates with the first sealing ring 10, the second sealing ring 11 and the third sealing ring 15 through the air flow channel opening on the magnet fixing ring 5 to meet the damping feeling required by customers at different pedal speeds. The magnet fixing ring 5 is made of self-lubricating polymer composite materials, and the material of the shell 6 is a high-strength polymer composite material, which ensures that the two can effectively eliminate potential scratching noise during relative motion, improve the quiet effect, and cooperate with the O-ring 9 to eliminate the impact noise when the pedal returns quickly, thereby improving driving comfort.

[0024] Working principle and use process of the present invention: The simulator realizes the size and change of force by intervening different parts under different pedal displacements through the cooperation of the small spring 8, the variable stiffness spring 12 and the supporting rubber 13, thereby realizing the desired pedal feel. The specific working process is as follows: Figure 2 and Figure 3 When the driver steps on the brake pedal, the small spring 8 is the first to intervene. At this time, the preload and stiffness of the simulator spring determine the driver's foot force and the gradient of the force change. When the driver continues to step on the pedal, the push rod moves the piston 7. Since the stiffness of the variable stiffness spring 12 is much greater than the stiffness of the small spring 8, the piston 7 compresses the small spring 8 to the right until the gap L1 between the retaining ring of the piston 7 and the spring fixing ring 14 is closed. The force and displacement curve at this time reflects the pedal curve of the initial stage of the pedal feel. As the driver's pedal force increases, due to the closing of the L1 gap, the piston 7 and the spring fixing ring 14 are stuck together. When the piston continues to move to the right, it will compress the variable stiffness spring 12 until the end of the piston 7 contacts the supporting rubber 13. During the process, since there are two kinds of stiffness, the pedal feel curve will be smoother. The force-displacement relationship (stiffness) at this time will reflect the L2 segment in the pedal feel curve. When the driver's braking force increases again, the piston 7 continues to move to the right. At this time, the spring fixing ring 14 is close to the retaining ring of the piston 7 and continues to compress the variable stiffness spring 12. At the same time, the piston 7 contacts and compresses the supporting rubber 13. At this time, the relationship between force and displacement is jointly determined by the variable stiffness spring 12 and the supporting rubber 13. Since the supporting rubber 13 is a truncated cone design, it can better simulate the arc feeling of the real pedal feel. As the displacement of the piston 7 increases, the spring fixing ring 14 contacts the step of the flange 2 to achieve hard limit to ensure that the variable stiffness spring 12 and the supporting rubber 13 do not exceed their working range. S is the total distance moved;

[0025] In order to better simulate the damping feeling of the current wet pedal, the simulator adds two air flow passages on the magnet fixing ring 5. When the driver steps on the pedal and pushes the piston 7 to move to the right, the air in the right chamber of the shell 6 is compressed and cannot flow out of the shell 6 due to the action of the second sealing ring 11 and the third sealing ring 15. At this time, the air will enter the left side of the piston 7 through the two air flow passages on the magnet fixing ring 5. Since the air flow passage is relatively small, the air will generate damping when passing through the air flow passage, which will be reflected on the pedal and provide the driver with a corresponding damping feeling. At the same time, the size of the damping feeling can be adjusted by changing the size and number of the air flow passages on the magnet fixing ring 5. At the same time, due to the effect of air damping, the pedal feeling of the driver at different speeds can be better simulated. Figure 3 ,The yellow line is the pedal feel when the pedal is pressed quickly, which is closer to the familiar wet pedal feel now;

[0026] The simulator can monitor the magnetic field changes of the two magnets 4 in the magnet fixing ring 5 in real time, and the displacement sensor 3 can convert the real-time piston 7 position and pedal position, and transmit the displacement signal to the brake actuator through the CAN signal to make corresponding braking requests. Figure 4 , the two permanent magnets 4 are arranged at NSNS on the magnet fixing ring 5. At the initial position, the displacement sensor 3 monitors the magnetic field strength at this time and marks the displacement as "0". When the driver steps on the pedal, the piston 7 moves to the right. Since the magnet fixing ring 5 and the piston 7 are a whole, the magnet fixing ring 5 moves to the right with the permanent magnet 4. At this time, the magnetic field at the same position changes with the change of the position of the magnet 4. At this time, the displacement sensor 3 determines the position of the piston 7 at this time, that is, the pedal position, through this change. In addition, in order to meet the requirements of high-level autonomous driving for safety redundancy of the braking system, the displacement sensor 3 and the permanent magnet 4 can be arranged at 90 degrees around the shell 6, so that mutual safety backup can be performed to meet the needs of L3 and above advanced autonomous driving.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dry brake pedal simulator integrating pedal displacement and pedal damping feeling, comprising a displacement sensor (3) and a pedal feeling simulation structure assembly, characterized in that: The pedal feel simulation structure assembly comprises a flange (2), a housing (6), a piston (7) and a supporting rubber (13); the housing (6) is fixedly mounted on the left side of the flange (2); a circular hole is opened at the left central position of the housing (6); the piston (7) passes through the circular hole and is slidably mounted on the housing (6); a retaining ring is arranged on the piston (7), and the retaining ring is located inside the housing (6); the supporting rubber (13) in a truncated cone shape is fixedly mounted on the flange (2) and is located inside the housing (6); the piston (7) and the supporting rubber (13) are on the same axis; A magnet fixing ring (5) and a spring fixing ring (14) are arranged inside the housing (6); the magnet fixing ring (5) is fixedly mounted on the piston (7), and two square permanent magnets (4) are mounted on the magnet fixing ring (5); a ring hole in the middle of the spring fixing ring (14) is just enough for the piston rod of the piston (7) to pass through; a small spring (8) is arranged between the left side of the spring fixing ring (14) and the retaining ring of the piston (7); and a variable stiffness spring (12) is arranged between the right side of the spring fixing ring (14) and the flange (2).

2. A dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: An O-ring (9) is arranged between the left side of the retaining ring of the piston (7) and the housing (6), and the O-ring (9) is fixed on the housing (6).

3. A dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: A first sealing ring (10) is provided between the circular hole of the housing (6) and the piston (7), and the first sealing ring (10) is fixed on the housing (6).

4. A dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: A second sealing ring (11) is provided at the mounting connection between the flange (2) and the housing (6).

5. The dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: A third sealing ring (15) is provided between the magnet fixing ring (5) and the inner wall of the housing (6), and the third sealing ring (15) is fixed on the magnet fixing ring (5).

6. A dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: The flange (2) is provided with connecting bolts (1).

7. The dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: The magnet fixing ring (5) is provided with two air flow openings in the axial direction.

8. The dry brake pedal simulator integrating pedal displacement and pedal damping feeling according to claim 1, characterized in that: The displacement sensor (3) is arranged on the outside of the housing (6) at a position close to the permanent magnet (4).

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