Pedal travel simulator

Abstract

The utility model discloses a pedal travel simulator which comprises a hydraulic unit with a piston cavity and a simulator unit with a piston, a shell, a spring I, a spring II, a rubber spring, a simulator ejector rod and an overflowing hole disc. The shell and the hydraulic unit are fixed to form a closed space in the mode that the shell is opposite to an opening of the piston, the two ends of the spring I act on the shell and one end side of the overflowing hole disc respectively, the two ends of the spring II act on the piston and the other end side of the overflowing hole disc respectively, and the simulator ejector rod is of a T-shaped structure comprising a leg part and a head part. The leg part penetrates through the overflowing hole disc and the spring I from the other end side of the overflowing hole disc to be fixed to the bottom of the shell, the rubber spring is arranged in the piston, one end of the rubber spring acts on the piston, and the other end of the rubber spring can act on the T-shaped head of the simulator ejector rod. Therefore, the force value can be accurately controlled, the overall size and weight are reduced, and the structure is compact and light.

Description

Technical Field

[0001] This utility model relates to vehicle braking technology, and more specifically to a pedal travel simulator. Background Technology

[0002] The emergence of integrated braking systems stems primarily from the development of autonomous driving technology and the technological demands on braking systems. With the advancement of vehicle electrification and intelligentization, traditional braking systems can no longer meet the requirements for high dynamic response characteristics and regenerative braking. In Level 2 and lower intelligent driving systems, the main requirements for braking systems are high dynamic response characteristics and regenerative braking functionality. In this context, traditional separate solutions offer no significant advantages in terms of size and cost. Therefore, integrated solutions that combine basic braking and stability functions and are completely decoupled from the pedal are gaining popularity among OEMs. This solution offers higher integration and better performance while reducing cost and size, adapting to the trend of automotive intelligence. Because the system is completely decoupled, there is no vacuum-assisted pedal force feedback; therefore, a component is needed to simulate the feel of a traditional vacuum-assisted pedal, leading to the development of pedal simulators.

[0003] However, the existing structure is as follows Figure 1 The device includes a piston 11, a simulator chamber 12, a simulator spring housing 13, a simulator cylinder 14, a receiving space 15, a simulator rubber cup 16, a simulator piston bottom surface 17, a rubber cup groove 18, an upper cylinder wall 21, an end cap 22, rubber 23, a spring 24, an intermediate piston 25, a piston 26, a piston wall 27, a spring space 28, a piston protrusion 29, and an intermediate protrusion 30. The spring 24 provides the pre-load for the piston 11 to return to its original position. The simulator's foot feel is provided by the rubber 23. Because rubber is more sensitive to temperature changes, when the temperature drops in winter, the rubber temperature decreases, and the rubber force value changes significantly, resulting in the pedal force value not meeting the requirements. Furthermore, the force value of the rubber material cannot be precisely controlled, leading to poor product consistency. Summary of the Invention

[0004] To address the aforementioned problems, the purpose of this invention is to provide a pedal travel simulator that achieves superior performance through an optimized spring layout.

[0005] According to this utility model, a pedal travel simulator is provided, comprising: a hydraulic unit having a piston chamber, and a simulator unit having a piston, a housing, spring I, spring II, a rubber spring, a simulator push rod, and a flow-through orifice plate. The piston is axially movable and placed in the piston chamber. The housing is fixed to the hydraulic unit in a manner opposite to the piston opening to form a sealed space. Spring I is configured so that its two ends act on the housing and one end of the flow-through orifice plate, respectively. Spring II is configured so that its two ends act on the piston and the other end of the flow-through orifice plate, respectively. The simulator push rod is a T-shaped structure including a leg and a head. The leg passes through the flow-through orifice plate and spring I from the other end of the flow-through orifice plate and is fixed to the bottom of the housing. The rubber spring is disposed inside the piston, with one end acting on the piston and the other end acting on the T-shaped head of the simulator push rod.

[0006] Preferably, the hydraulic unit has an oil inlet at the bottom of the piston chamber, a cup groove for placing a cup around the piston on the inner wall of the piston chamber, and an oil outlet above the cup.

[0007] Preferably, a stepped portion is formed on the inner wall of the piston to serve as a base for supporting spring II.

[0008] Preferably, in the initial installation state when the piston is installed in the piston chamber, the height of the stepped portion is lower than the height of the cup groove relative to the bottom of the piston.

[0009] Preferably, a hollow cylindrical base for mounting the simulator top rod is formed on the bottom wall of the shell, and spring I is supported on the bottom wall of the shell around the hollow cylindrical base.

[0010] Preferably, the outer diameter of the T-shaped head of the simulator push rod is smaller than the inner diameter of spring II, the flow-through plate is a perforated ring structure, which is confined inside the housing by the simulator push rod, and one end is tightly fitted with spring I.

[0011] Preferably, the flow-through plate is provided with flow-through holes that serve as channels for the vertical flow of liquid in the piston cavity and the housing cavity.

[0012] Preferably, the inner wall of the housing is provided with a stop for limiting the movement of the piston.

[0013] Preferably, when the piston is initially installed, there is a gap between the piston and the flow-through orifice plate.

[0014] Preferably, a stepped end face for fastening the housing is formed on the cylinder end side of the hydraulic unit, and a flange is provided at the fastening end of the housing.

[0015] According to this utility model, in order to address the shortcomings of temperature affecting the force value of rubber and the inability to precisely control the force value of rubber materials, which leads to poor product consistency, a simulator scheme with spring I, spring II, and rubber spring is proposed. This not only allows for precise control of the force value and excellent product consistency, but also reduces the overall volume and weight, making the structure more compact and lightweight. Attached Figure Description

[0016] Figure 1 A cross-sectional view of an existing pedal simulator is shown schematically.

[0017] Figure 2 A cross-sectional view of a pedal travel simulator according to an exemplary embodiment of the present invention is shown schematically.

[0018] Figure 3 A schematic cross-sectional view of the pedal travel simulator is shown. Detailed Implementation

[0019] The exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The exemplary embodiments described below and illustrated in the drawings are intended to teach the principles of the present invention, enabling those skilled in the art to implement and use the present invention in various environments and for various applications. Therefore, the scope of protection of the present invention is defined by the appended claims, and the exemplary embodiments are not intended, and should not be considered, a limiting description of the scope of protection of the present invention. Furthermore, for ease of description, the dimensions of the various parts shown in the drawings are not necessarily drawn to actual scale. Orientation descriptions, such as up, down, left, right, top, bottom, etc., are based on the orientation or positional relationships shown in the drawings and are only for the convenience of describing the present 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 present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or partial structures will be omitted where they may cause confusion or make the understanding of the present disclosure difficult to observe. Unless otherwise specifically stated, the order and numerical values ​​of the components and assembly steps described in the embodiments do not limit the scope of this invention.

[0020] like Figure 2 , 3 The illustrated embodiment provides a pedal travel simulator, comprising a simulator unit 200 and a hydraulic unit 100. Here, to facilitate understanding of the correspondence between the components and avoid confusion in the markings, two identical viewpoints are used. Figure 2 , 3 To label the attached icons.

[0021] The hydraulic unit 100 includes a piston chamber 110, an oil inlet 120, and a piston cup 141.

[0022] The simulator unit 200 includes: a piston 210, a housing 220, an elastic element package 230, a simulator push rod 240, and a flow-through orifice plate 250. The elastic element package 230 includes spring I 232, spring II 231, and a rubber spring 233.

[0023] The hydraulic unit 100 includes a bottomed hollow cylinder. The hollow portion is configured as a piston chamber 110 for housing the piston 210. An oil inlet 120 is provided at the bottom of the piston chamber 110. An annular groove 140 is provided on the inner wall of the piston chamber 110 for housing a cup 141 around the piston 210. A stepped end face is formed at the end of the cylinder for fastening the housing 220. Here, the fastening end of the housing 220 can be provided with a flange to fit the stepped end face, reducing the limitation on the dimensional relationship between the diameter of the housing 220 and the diameter of the piston 210.

[0024] The piston 210 is configured as a bottomed cylindrical structure with a stepped portion formed on its inner wall, serving as a base to support the spring II 231. The rubber spring 233 can be placed on the bottom of the piston 210, with its upper end extending into the inside of the spring II 231. Preferably, in the initial installation state when the piston 210 is installed in the piston cavity 110, the height of the stepped portion relative to the bottom of the piston 210 is lower than the height of the cup groove 140, thereby allowing the spring II 231 to be positioned below the sealing surface of the cup 141.

[0025] The housing 220 is configured as a bottomed cylindrical body, and a hollow cylindrical base for mounting the simulator top rod 240 is formed on the bottom wall of the cylindrical body. The spring I 232 can be supported on the bottom wall of the cylindrical body around the hollow cylindrical base.

[0026] The simulator mounting rod 240 is a T-shaped structure including legs and a head. The outer diameter of the T-shaped head is smaller than the inner diameter of the spring II 231. The T-shaped legs are fixedly connected to the housing 220 by passing through the flow-through plate 250 and the spring I 232 (including but not limited to interference fit, thread, riveting), thus confining the flow-through plate 250 and the spring I 232 inside the housing 220.

[0027] The flow-through orifice plate 250 is a perforated ring structure, which is confined inside the housing 220 by the simulator push rod 240. One end is tightly fitted with spring I 232, and the other end is tightly fitted with spring II 231 to transmit spring force.

[0028] The housing 220 is riveted to the hydraulic unit 100 to form a sealed space, ensuring that the internal structure is not exposed to air. The elastic element package 230 is located within the sealed space. Both the piston cavity 211 and the housing cavity 222 are formed into cavities filled with brake fluid. The flow orifice 252 is a notch formed on the flow orifice plate 250, which is a channel for the fluid to flow up and down in the piston cavity 211 and the housing cavity 222.

[0029] At this time, rubber spring 233 is placed inside piston 210, with one end acting on piston 210 and the other end acting on the T-head of simulator push rod 240. Spring II 231 is placed inside piston 210, with one end acting on piston 210 and the other end acting on flow-through orifice plate 250. Spring I 232 is placed inside housing 220, with one end acting on housing 220 and the other end interacting with spring II 231 through flow-through orifice plate 250.

[0030] like Figure 3 As shown, the stop portion 221 on the inner wall of the housing 220 is used to limit the movement of the piston 210, preventing it from moving too far and coming out of the piston chamber 110, while ensuring that the spring I 232 is not over-compressed.

[0031] When the piston 210 is initially installed, there is a gap 251 between the piston 210 and the flow-through orifice plate 250. The initial preload of the simulator can be adjusted by adjusting this gap.

[0032] The oil inlet 120 is the high-pressure oil inlet of the system. The piston cup 141 divides the piston chamber 110 into upper and lower parts, with the upper part being the normal pressure chamber and the lower part being the high-pressure chamber. During normal operation, high-pressure oil flows into the piston chamber 110 through the oil inlet 120, creating a pressure difference between the upper and lower parts. Under the action of hydraulic pressure, the piston 210 moves axially inside the piston chamber 110. The piston 210 drives its internal rubber spring 233 to move upward simultaneously. Spring II 231 is compressed first until the piston 210 contacts the flow-through orifice plate 250. Continuing to move upward, it compresses spring I 232 until the flow-through orifice plate 250 contacts the stop part 221. At this point, the piston 210 reaches its maximum stroke. The rubber spring 233 will begin to compress when it contacts the simulator push rod 240 until the piston 210 reaches its maximum stroke.

[0033] The oil outlet 130 is connected to the normal pressure chamber above the piston cup 141, and the annular groove 131 is used to connect the internal cavity and the oil outlet 130. When the piston 210 moves upward, the volume of the normal pressure chamber is compressed, and the brake fluid inside flows through the annular groove 131 and is discharged from the oil outlet 130.

[0034] Thus, the spring assembly of the pedal travel simulator consists of spring I 232, spring II 231, and rubber spring 233. Spring II 231 and rubber spring 233 act directly on piston 210 and are both arranged inside piston 210, which has the following advantages: the stiffness of the springs inside piston 210 can be increased, reducing the difference in stiffness with the larger spring and making the force change smoother; the arrangement of spring II 231 inside piston 210 allows spring II 231 to be longer, and spring II 231 can act below the sealing surface of the cup 141, which can effectively prevent the acting position of spring II 231 from being too high, causing piston tilting; the joint arrangement of spring II 231 and rubber spring 233 inside piston 210 can reduce the overall volume and weight, making the structure more compact and lightweight.

[0035] In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. Unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Although the present invention has been described with reference to various specific embodiments, it should be understood that modifications can be made within the spirit and scope of the described inventive concept. Therefore, it is intended that the present invention be limited to the described embodiments but will have the full scope defined by the language of the appended claims.

Claims

1. A pedal travel simulator characterized by, include: A hydraulic unit (100) having a piston chamber (110) and a simulator unit (200) having a piston (210), a housing (220), spring I (232), spring II (231), a rubber spring (233), a simulator push rod (240), and a flow-through orifice plate (250), wherein the piston (210) is axially movable in the piston chamber (110), the housing (220) is fixed between the hydraulic unit (100) and the piston (210) in a manner opposite to the opening of the piston (210) to form a sealed space, and the spring I (232) is configured to act on the housing (220) at both ends respectively. On one end of the flow-through plate (250), spring II (231) is configured to act on the piston (210) and the other end of the flow-through plate (250) respectively. The simulator push rod (240) is a T-shaped structure including legs and head. The legs pass through the flow-through plate (250) and spring I (232) from the other end of the flow-through plate (250) and are fixed to the bottom of the housing (220). The rubber spring (233) is set inside the piston (210), with one end acting on the piston (210) and the other end acting on the T-shaped head of the simulator push rod (240).

2. The pedal travel simulator of claim 1, wherein The hydraulic unit (100) has an oil inlet (120) connected to the bottom of the piston chamber (110), a cup groove (140) for placing a cup (141) around the piston (210) is provided on the inner wall side of the piston chamber (110), and an oil outlet (130) is provided above the cup (141).

3. The pedal stroke simulator of claim 1, wherein, The inner wall of the piston (210) has a stepped portion that serves as a base for supporting the spring II (231).

4. The pedal travel simulator of claim 3, wherein In the initial installation state when the piston (210) is installed in the piston chamber (110), the height of the step portion is lower than the height of the cup groove (140) relative to the bottom of the piston (210).

5. The pedal travel simulator of claim 1, wherein, A hollow cylindrical base for mounting the simulator top rod (240) is formed on the bottom wall of the shell (220), and spring I (232) is supported on the bottom wall of the shell around the hollow cylindrical base.

6. The pedal stroke simulator of claim 1, wherein, The outer diameter of the T-shaped head of the simulator push rod (240) is smaller than the inner diameter of the spring II (231). The flow-through plate (250) is a perforated ring structure, which is restricted inside the housing (220) by the simulator push rod (240), and one end is tightly fitted with the spring I (232).

7. Pedal travel simulator according to claim 6, characterized in that The flow-through plate (250) has a flow-through hole (252) which serves as a channel for the liquid to flow up and down in the piston cavity and the housing cavity.

8. The pedal travel simulator of claim 1, wherein, The inner wall of the housing (220) is provided with a stop (221) for limiting the movement of the piston (210).

9. The pedal travel simulator of claim 1, wherein, When the piston (210) is initially installed, there is a gap (251) between the piston (210) and the flow-through orifice plate (250).

10. The pedal travel simulator of claim 1, wherein, A stepped end face for fastening the housing (220) is formed on the cylindrical end side of the hydraulic unit (100), and a flange is provided at the fastening end of the housing (220).

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