Mechanical spring type damping controllable bicycle rear shock absorber based on electrorheological effect

Abstract

This invention discloses a mechanically spring-type damping controllable rear shock absorber for bicycles based on electrorheological effects, belonging to the field of bicycle shock absorber technology. It includes a working cylinder, a piston rod assembly, a mechanical spring, and a secondary cylinder assembly. The working cylinder contains the main cavity. One end of the piston rod of the piston rod assembly extends into the working cylinder and is connected to the piston assembly. The piston assembly has a positive and a negative electrode, forming a working gap through which electrorheological fluid flows. The positive electrode is connected to an external high-voltage power supply via a positive high-voltage line. The mechanical spring is sleeved on the outside of the working cylinder to provide elastic force. The secondary cylinder assembly is located on the side wall of the working cylinder and communicates internally with the main cavity. The secondary cylinder assembly contains an air diaphragm, which divides it into a liquid chamber communicating with the main cavity and an air chamber filled with compressed gas, used to provide pre-pressure and compensate for volume differences through elastic deformation. This invention achieves real-time electronically controlled adjustment of damping force within a compact size through an external secondary cylinder structure, adapting to the limited installation space of bicycles.

Description

Technical Field

[0001] This invention relates to the field of bicycle shock absorption technology, specifically a mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect. Background Technology

[0002] In the bicycle industry, to mitigate the negative impact of road bumps on rider comfort and the bicycle itself, especially for mountain bikes, downhill bikes, and e-bikes, a rear shock absorber is typically installed between the frame and the rear wheel for shock absorption. With increasingly complex riding scenarios and rising performance demands, the market's requirements for rear shock absorbers have moved beyond basic passive cushioning. Instead, there is a desire for rapid and precise adjustment of damping force based on road conditions or riding modes to achieve better handling and comfort. Electrorheological fluid (ERF), a smart material whose rheological properties can be reversibly controlled by an external electric field, provides an ideal technical path for the electronically controlled adjustment of damping force, and related explorations have already been conducted in the field of motor vehicle shock absorbers.

[0003] In existing electrorheological fluid (EMF) damper designs, to compensate for the volume difference caused by the piston rod entering and exiting the cavity during piston reciprocating motion and to maintain the back pressure required for the working fluid to prevent cavitation, a compensating airbag is typically axially positioned at the inner end of the main working cylinder. The airbag's compression and expansion absorb or release excess EMF, thereby balancing the pressure inside and outside the cavity. However, this axial arrangement with an internal airbag directly occupies the effective length within the main cylinder, significantly reducing the damper's usable stroke and resulting in low stroke efficiency. Furthermore, the localized negative pressure caused by piston movement easily generates air bubbles. When these bubbles flow through the high-voltage electrode gap, they induce medium breakdown, causing damping control failure. In addition, the radial dimension of the piston assembly in a bicycle shock absorber is much smaller than that in a motor vehicle shock absorber. The electrode structure and conductivity introduction method of existing EMF dampers are designed based on the relatively ample radial space of motor vehicle shock absorbers. Directly transplanting them to bicycle shock absorbers faces space constraints, making it impossible to achieve an effective arrangement of the electrode structure within the limited radial space of the piston. Summary of the Invention

[0004] The purpose of this invention is to provide a mechanically spring-type damped controllable bicycle rear shock absorber based on electrorheological effect to solve the above-mentioned problems.

[0005] The technical solution of this invention is: A mechanically spring-type damping controllable bicycle rear shock absorber based on electrorheological effect includes: a working cylinder, internally configured as a main cavity for accommodating electrorheological fluid; a piston rod assembly, including: a piston rod, one end of which extends into the working cylinder and is connected to the piston assembly, the piston assembly slidingly fitting against the inner wall of the working cylinder and dividing it into a rod-side cavity and a rodless cavity, the piston assembly having a positive electrode and a negative electrode, a working gap forming between the positive electrode and the negative electrode for the electrorheological fluid to flow through, the positive electrode being connected to an external high-voltage power supply via a positive high-voltage wire passing through the inside of the piston rod; and a mechanical spring sleeved on the working cylinder. The outer side of the cylinder has two ends that abut against the end of the piston rod assembly located outside the working cylinder and the outer side of the working cylinder, respectively, to provide elastic force; the auxiliary cylinder assembly is disposed on the side wall of the working cylinder and communicates internally with the main cavity. The auxiliary cylinder assembly is provided with an air bladder diaphragm, which divides the interior of the auxiliary cylinder assembly into a liquid chamber communicating with the main cavity and an air chamber filled with compressed gas. The compressed gas provides pre-pressure to the electrorheological fluid through the air bladder diaphragm, and the air bladder diaphragm can compensate for the volume difference between the rod chamber and the rodless chamber when the piston assembly slides through elastic deformation.

[0006] Furthermore, the axis of the auxiliary cylinder assembly is set at an angle to the axis of the working cylinder, and the fixed connection angle between the auxiliary cylinder assembly and the working cylinder is configured to be adjustable according to the bicycle frame layout to avoid interference with the vehicle structure.

[0007] Furthermore, the auxiliary cylinder assembly includes: an auxiliary cylinder, an auxiliary cylinder end cap, and an auxiliary cylinder sealing screw. One end of the auxiliary cylinder is fixed to the side wall of the working cylinder, and the auxiliary cylinder end cap is connected to the other end of the auxiliary cylinder. The auxiliary cylinder end cap has an air injection hole for filling the air chamber with compressed gas. The auxiliary cylinder sealing screw is threaded into the air injection hole to seal the air injection hole after inflation is completed.

[0008] Furthermore, the piston assembly also includes: an insulating sleeve fitted on the outside of the negative electrode, and the positive electrode fitted on the outside of the insulating sleeve, for electrically isolating the positive electrode from the negative electrode; a conductive head abutting against the end face of the positive electrode and welded to the positive electrode high-voltage line, for introducing the electrical signal of the positive electrode high-voltage line into the positive electrode and pressing the positive electrode firmly; and an insulating cover plate covering the axially outer end face of the conductive head, for axially isolating the positive electrode.

[0009] Furthermore, it also includes a lower spring seat, which is threadedly fitted onto the outside of the working cylinder. The other end of the mechanical spring abuts against the lower spring seat. The lower spring seat is configured to be able to be manually rotated and moved axially along the working cylinder to adjust the preload of the mechanical spring.

[0010] Furthermore, it also includes a sealing assembly disposed at one end of the working cylinder into which the piston rod extends, the piston rod passing through the sealing assembly and slidingly sealingly engaging with it, the sealing assembly being used to prevent the electrorheological fluid in the main cavity from leaking along the piston rod.

[0011] Furthermore, it also includes a base assembly, which is fixedly connected to the end of the working cylinder away from the piston rod extending into it, for sealing the end of the working cylinder; the base assembly includes a base and a sealing screw, the base having an injection hole for injecting electrorheological fluid into the main cavity, and the sealing screw being threaded into the injection hole for sealing the injection hole after injection is completed.

[0012] Furthermore, it also includes an upper connector assembly, which is fixedly connected to one end of the piston rod located outside the working cylinder, and one end of the mechanical spring indirectly abuts against the piston rod assembly through the upper connector assembly; the upper connector assembly and the base assembly are respectively provided with shaft holes for mounting to corresponding positions on the bicycle frame.

[0013] Furthermore, a locking nut is provided at one end of the piston rod located outside the working cylinder. The upper connector assembly includes an upper connector and an upper spring seat. The upper connector is sleeved on the end of the piston rod and locked and fixed by the locking nut. The upper spring seat is fixed to the upper connector and abuts against one end of the mechanical spring.

[0014] Furthermore, the piston assembly also includes: a wear-resistant ring, installed in a groove on the outer circumference of the negative electrode and slidably fitted to the inner wall of the working cylinder; a sealing ring, disposed between the positive electrode and the conductive head; and a pressure cap, sleeved on the outside of the positive electrode and fixedly connected to the negative electrode, for axially pressing and fixing the positive electrode, the insulating sleeve, and the insulating cover plate relative to the negative electrode.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention fixes the auxiliary cylinder assembly to the side wall of the working cylinder and connects its interior to the main cavity. It replaces the traditional built-in airbag structure with a liquid chamber and an air chamber separated by an airbag diaphragm inside the auxiliary cylinder, thus eliminating the need to occupy the axial length inside the working cylinder and maximizing the retention of effective stroke within a given installation length. At the same time, the compressed gas in the air chamber continuously applies pre-pressure to the electrorheological fluid through the airbag diaphragm, ensuring that the main cavity maintains positive pressure during the piston's reciprocating sliding process. This effectively avoids cavitation bubbles caused by local negative pressure and prevents high-voltage breakdown induced by bubbles flowing through the electrode gap. The airbag diaphragm smoothly compensates for the volume difference between the rod chamber and the rodless chamber through elastic deformation, ensuring the consistency and reliability of the damping force output. Furthermore, this invention features positive and negative electrodes on the piston assembly, forming a working gap through which the electrorheological fluid flows. A high-voltage electrical signal is introduced to the positive electrode via a high-voltage wire passing through the piston rod. The electrode structure and conductive introduction method are compactly integrated into the piston assembly, allowing the viscosity and yield strength of the electrorheological fluid flowing through the working gap to change in real time, continuously, and reversibly with the electric field strength. The damping force of the shock absorber can be precisely adjusted via voltage, and the rider or control system can quickly adjust the damping characteristics according to different road conditions, significantly improving riding comfort and handling stability. With its compact structural design, this invention retains sufficient shock absorption stroke while avoiding stroke loss caused by the axial space occupied by the built-in airbag structure and damping failure caused by air bubble rupture. It also achieves real-time electronic control adjustment of the damping force, making it suitable for various riding scenarios from urban commuting to extreme downhill riding.

[0016] Meanwhile, the mechanical spring fitted on the outside of the working cylinder independently provides elastic force, which does not interfere with the controllable damping force provided by the electrorheological fluid in terms of structure and function. The two can be adjusted independently. The spring preload is manually adjusted by rotating the lower spring seat thread, and the damping force is adjusted in real time by external voltage, making the dynamic characteristics of the shock absorber more flexible. It retains the high reliability and linear support characteristics of traditional mechanical springs, and also gives the damping force a millisecond-level intelligent control capability. Attached Figure Description

[0017] Figure 1 This is a front view of the external structure of the present invention.

[0018] Figure 2 This is a front view of the internal structure of the present invention.

[0019] Figure 3 This is a schematic diagram of the internal structure of the piston assembly of the present invention.

[0020] Figure 4 This is a schematic diagram of the working gap of the electrorheological fluid material during the operation of the present invention.

[0021] Among them, 1. Upper connector assembly, 101. Upper connector, 102. Upper spring seat, 2. Mechanical spring, 3. Piston rod assembly, 301. Locking nut, 302. High voltage positive line, 303. Piston rod, 4. Lower spring seat, 5. Working cylinder, 6. Base assembly, 601. Base, 602. Sealing screw, 7. Secondary cylinder assembly, 701. Secondary cylinder, 702. Airbag diaphragm, 703. Secondary cylinder end cap, 704. Secondary cylinder sealing screw, 8. Sealing assembly, 9. Piston assembly, 901. Wear ring, 902. Negative electrode, 903. Positive electrode, 904. Insulating cover plate, 905. Pressure cap, 906. Sealing ring, 907. Insulating sleeve, 908. Conductive head. Detailed Implementation

[0022] The following is combined with Figures 1 to 4 The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to 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.

[0023] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] Example like Figure 1 and Figure 2 As shown, a mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect includes: a working cylinder 5, a piston rod assembly 3, a mechanical spring 2, and a secondary cylinder assembly 7.

[0025] The working cylinder 5 is internally configured as a main cavity for accommodating electrorheological fluid.

[0026] The piston rod assembly 3 includes a piston rod 303, one end of which extends into the working cylinder 5 and is connected to a piston assembly 9. The piston assembly 9 slides against the inner wall of the working cylinder 5, dividing it into a rod chamber and a rodless chamber. The piston rod 303 has a channel through which a positive high-voltage wire 302 is connected to the piston assembly 9. The positive high-voltage wire 302 extends from one end of the piston rod assembly 3 for connection to an external high-voltage power controller. Figure 3As shown, the piston assembly 9 and piston rod 303 are connected and fixed as a whole by threads. The piston assembly 9 is provided with a positive electrode 903 and a negative electrode 902. A working gap is formed between the positive electrode 903 and the negative electrode 902 for the electrorheological fluid to flow through. The positive electrode 903 is connected to an external high-voltage power supply through a positive high-voltage wire 302 passing through the inside of the piston rod 303, and the negative electrode 902 is electrically connected to the negative terminal of the external high-voltage power supply through the piston rod 303. The viscosity and yield strength of the electrorheological fluid flowing through the working gap can be changed in real time, continuously and reversibly with the strength of the external electric field. The damping force of the shock absorber can be precisely adjusted by voltage. The rider or control system can quickly adjust the damping characteristics according to different road conditions to improve riding comfort and handling stability.

[0027] The mechanical spring 2 is aligned with the axis of the working cylinder 5 and is sleeved on the outside of the working cylinder 5. One end of the piston rod 303 located outside the working cylinder 5 is connected to an upper connector assembly 1. The upper connector assembly 1 includes an upper connector 101 and an upper spring seat 102. The upper spring seat 102 contacts one end of the mechanical spring 2 and provides support. A lower spring seat 4 is also sleeved on the outside of the working cylinder 5. The lower spring seat 4 is installed on the outside of the working cylinder 5 via a threaded connection, and the other end of the mechanical spring 2 contacts the lower spring seat 4. When the rear shock absorber is compressed, the upper connector assembly 1 moves as a whole, driving the mechanical spring 2 to compress. The mechanical spring 2 provides the elastic force, independently providing the main elastic force required by the shock absorber. Structurally, it does not interfere with the controllable damping force provided by the electrorheological fluid, making the dynamic characteristics of the shock absorber more flexible to adjust.

[0028] like Figure 2 As shown, the auxiliary cylinder assembly 7 is located on the side wall of the working cylinder 5. A channel is machined on the opposite side of the injection hole in the main cavity, connecting to the auxiliary cylinder assembly 7. The interior of the auxiliary cylinder assembly 7 communicates with the main cavity. An airbag diaphragm 702 is installed inside the auxiliary cylinder assembly 7. The airbag diaphragm 702 divides the interior of the auxiliary cylinder assembly 7 into a liquid chamber communicating with the main cavity and an air chamber filled with compressed gas. The electrorheological fluid material in the liquid chamber and the compressed air in the air chamber are separated by the airbag diaphragm 702. The compressed gas provides pre-pressure to the electrorheological fluid material through the airbag diaphragm 702. When compressed or stretched, the volume changes of the rod-side and rodless-side of the main cavity differ. The airbag diaphragm 702 can compensate for the volume difference between the rod-side and rodless-side when the piston assembly 9 slides through elastic deformation. The external layout of the auxiliary cylinder 701 does not occupy the internal axial length of the working cylinder 5, maximizing the retention of effective stroke under a given installation length. At the same time, the airbag diaphragm 702 provides continuous pre-pressure to avoid cavitation bubbles caused by local negative pressure, and prevents high-pressure breakdown induced when bubbles flow through the electrode gap, ensuring the long-term reliability of the damper.

[0029] The auxiliary cylinder assembly 7 includes an auxiliary cylinder 701, an auxiliary cylinder end cap 703, and an auxiliary cylinder sealing screw 704. One end of the auxiliary cylinder 701 is fixed to the side wall of the working cylinder 5, and the auxiliary cylinder end cap 703 is connected to the other end of the auxiliary cylinder 701. The auxiliary cylinder end cap 703 is machined with an air injection hole for filling the air chamber with compressed gas. After the required compressed gas is filled into place, the auxiliary cylinder sealing screw 704 is used to seal it. That is, the auxiliary cylinder sealing screw 704 is threaded into the air injection hole and is used to seal the air injection hole after the inflation is completed. The air injection hole allows the compressed gas of the required pressure to be conveniently filled into the air chamber, and the auxiliary cylinder sealing screw 704 achieves a reliable seal, ensuring the adjustability and long-term maintenance of the pre-pressure.

[0030] In some embodiments, the axis of the auxiliary tube assembly 7 is angled to the axis of the working cylinder 5, and the fixing angle between the auxiliary tube assembly 7 and the working cylinder 5 is configured to be adjustable according to the bicycle frame layout, avoiding spatial interference between the auxiliary tube and frame components such as the rear triangle and swingarm, thus improving the product's adaptability to different bicycle frames. Regarding the shock absorber itself, the axis angle range is from parallel to perpendicular, i.e., 0°-90°, and the specific adjustable angle depends on the installation position of the shock absorber, ensuring that the shock absorber does not interfere with the bicycle frame. When the connection angle is different, the end face connecting the auxiliary tube 701 and the base 601 needs to be finely adjusted accordingly, which will change the appearance but not affect the functional structure. The adjustment can be achieved by changing the angle of the mating end face of the auxiliary tube 701 and the base 601. During assembly, the end faces are pressed together, naturally forming a geometric angle, which can then be permanently fixed. Permanent fixing is usually achieved by welding, but bonding, threaded connections, etc., can also be used.

[0031] like Figure 3As shown, the piston assembly 9 also includes an insulating sleeve 907, a conductive head 908, and an insulating cover plate 904. Starting from the end of the piston rod 303, the negative electrode 902 is mechanically fixed to the piston rod 303. After the negative electrode 902 is fitted onto the end of the piston rod 303, the insulating sleeve 907 is then fitted onto it, thus isolating the positive and negative electrodes. Specifically, the insulating sleeve 907 is fitted outside the negative electrode 902, and the positive electrode 903 is fitted outside the insulating sleeve 907, used to electrically isolate the positive electrode 903 from the negative electrode 902. The positive high-voltage wire 302 passes through the middle channel of the piston rod 303 and is welded to the conductive head 908. The positive electrode 903 is fitted outside the insulating sleeve 907 and pressed down by the conductive head 908. Specifically, the conductive head 908 abuts against the end face of the positive electrode 903 and is welded to the positive high-voltage wire 302, used to introduce the electrical signal from the positive high-voltage wire 302 into the positive electrode 903 and press the positive electrode 903 down. An insulating cover plate 904 is then fitted onto the outer end face of the conductive head 908. That is, the insulating cover plate 904 is placed on the axial outer end face of the conductive head 908 to isolate the positive electrode 903 in the axial direction. The insulating sleeve 907 completely isolates the positive and negative electrodes in the radial direction, and the insulating cover plate 904 isolates the positive electrode 903 in the axial direction. The conductive head 908 simultaneously realizes the functions of electrical introduction and mechanical clamping, effectively preventing the risk of short circuit under high voltage electric field and improving the safety of the device.

[0032] In some embodiments, a lower spring seat 4 is also included. The lower spring seat 4 is threadedly fitted onto the outside of the working cylinder 5. The other end of the mechanical spring 2 abuts against the lower spring seat 4. The lower spring seat 4 is configured to be able to move along the axial direction of the working cylinder 5 by manual rotation to adjust the preload of the mechanical spring 2. The rider can conveniently adjust the spring preload by rotating the lower spring seat 4 to adapt the elastic force to different weights and riding preferences, and this can be done without the aid of special tools. The adjustment of the spring preload and the adjustment of the damping force are independent of each other and do not interfere with each other.

[0033] In some embodiments, a sealing assembly 8 is also included. The sealing assembly 8 is disposed at one end of the working cylinder 5 into which the piston rod 303 extends. The piston rod 303 passes through the sealing assembly 8 and slides and seals with it to prevent the electrorheological fluid material in the main cavity from leaking along the piston rod 303. The sealing assembly 8 is mechanically fixed to one end of the working cylinder 5. The sealing assembly 8 effectively prevents the electrorheological fluid from leaking while ensuring smooth reciprocating sliding of the piston rod, avoiding material loss and environmental pollution, and ensuring the sealing reliability of the product during long-term use.

[0034] In some embodiments, a base assembly 6 is also included. The base assembly 6 is fixedly connected to the end of the working cylinder 5 that is away from the piston rod 303 and is used to close the end of the working cylinder 5. The base assembly 6 includes a base 601 and a sealing screw 602. The base 601 has an injection hole for injecting electrorheological fluid into the main cavity. The sealing screw 602 is threaded into the injection hole and is used to seal the injection hole after injection. Electrorheological fluid can be conveniently injected into the main cavity through the injection hole. After injection, the cavity is sealed with the sealing screw 602 to ensure the cavity is airtight. The manufacturing and assembly process is simple and easy.

[0035] In some embodiments, the system further includes an upper connector assembly 1, which is fixedly connected to one end of the piston rod 303 located outside the working cylinder 5. One end of the mechanical spring 2 is indirectly connected to the piston rod assembly 3 through the upper connector assembly 1. The upper connector assembly 1 and the base assembly 6 are respectively provided with shaft holes for installation onto the corresponding positions of the bicycle frame. The shock absorber can be conveniently installed between the bicycle frame and the rear swingarm through the shaft holes on the upper connector assembly 1 and the base assembly 6, which is quick to assemble and reliable to connect.

[0036] A locking nut 301 is provided at one end of the piston rod 303 located outside the working cylinder 5. The upper connector assembly 1 includes an upper connector 101 and an upper spring seat 102. The upper connector 101 is sleeved on the end of the piston rod 303 and locked and fixed by the locking nut 301. The upper spring seat 102 is fixed to the upper connector 101 and abuts against one end of the mechanical spring 2. The locking nut 301 fixes the upper connector 101 and the end of the piston rod 303 into a whole, and the connection is firm and reliable. The upper spring seat 102 moves with the piston rod 303 as a whole and compresses the spring to ensure the effective transmission of elastic force.

[0037] like Figure 3 As shown, the piston assembly 9 also includes: a wear-resistant ring 901, a sealing ring 906, and a pressure cap 905. The wear-resistant ring 901 is installed in a groove on the outer circumference of the negative electrode 902 and slides against the inner wall of the working cylinder 5. The sealing ring 906 is disposed between the positive electrode 903 and the conductive head 908. The pressure cap 905 is sleeved on the outside of the positive electrode 903 and fixedly connected to the negative electrode 902, used to axially press and fix the positive electrode 903, the insulating sleeve 907, and the insulating cover plate 904 relative to the negative electrode 902. The wear-resistant ring 901 reduces the sliding friction between the piston assembly 3 and the inner wall of the working cylinder 5, extending the service life. The sealing ring 906 prevents electrorheological fluid from seeping into the interior from between the positive electrode and the conductive head. The pressure cap 905 axially presses and fixes each part, ensuring that the overall structure of the piston assembly is compact and stable.

[0038] like Figure 4 As shown, the working gap of the electrorheological fluid material, ERF, is displayed during operation. Figure 4The directional arrows indicate the flow direction of the electrorheological fluid material when the shock absorber is compressed. When the shock absorber is stretched, the material flows through the same channel but in the opposite direction. The electric field formed between the negative electrode 902 and the positive electrode 903 within the working gap can change the mechanical properties of the electrorheological fluid material. Furthermore, the strength of this electric field can be controlled by the external power supply voltage. Therefore, the resistance exerted on the negative electrode 902 and the positive electrode 903 by the electrorheological fluid material flowing through this electric field can be adjusted and controlled to a certain extent. The specific force generated depends on factors such as the effective strength of the electric field, the gap width, the relative effective area between the negative electrode 902 and the positive electrode 903, the materials and processing technology of the positive and negative electrodes, and the shear rate of the electrorheological fluid within the electric field.

[0039] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect, characterized in that, include: The working cylinder has an internal main chamber configured to contain the electrorheological fluid. A piston rod assembly includes: a piston rod, one end of which extends into the working cylinder and is connected to a piston assembly; the piston assembly is slidably fitted to the inner wall of the working cylinder and divides it into a rod chamber and a rodless chamber; the piston assembly is provided with a positive electrode and a negative electrode; a working gap is formed between the positive electrode and the negative electrode for electrorheological fluid to flow through; the positive electrode is connected to an external high-voltage power supply through a positive high-voltage wire passing through the inside of the piston rod. A mechanical spring is sleeved on the outside of the working cylinder, with its two ends respectively abutting against the end of the piston rod assembly located outside the working cylinder and the outside of the working cylinder, to provide elastic force; A secondary cylinder assembly is disposed on the side wall of the working cylinder and communicates internally with the main cavity. The secondary cylinder assembly is provided with an air bladder diaphragm, which divides the interior of the secondary cylinder assembly into a liquid chamber communicating with the main cavity and an air chamber filled with compressed gas. The compressed gas provides pre-pressure to the electrorheological fluid through the air bladder diaphragm, and the air bladder diaphragm can compensate for the volume difference between the rod chamber and the rodless chamber when the piston assembly slides through elastic deformation.

2. The mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, The axis of the auxiliary cylinder assembly is set at an angle to the axis of the working cylinder, and the fixed angle between the auxiliary cylinder assembly and the working cylinder is configured to be adjustable according to the bicycle frame layout.

3. The mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, The auxiliary cylinder assembly includes: an auxiliary cylinder, an auxiliary cylinder end cap, and an auxiliary cylinder sealing screw. One end of the auxiliary cylinder is fixed to the side wall of the working cylinder, and the auxiliary cylinder end cap is connected to the other end of the auxiliary cylinder. The auxiliary cylinder end cap has an air inlet for filling the air chamber with compressed gas. The auxiliary cylinder sealing screw is threaded into the air inlet and is used to seal the air inlet after filling.

4. The mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, The piston assembly also includes: An insulating sleeve is fitted over the outside of the negative electrode, and the positive electrode is fitted over the outside of the insulating sleeve, for electrically isolating the positive electrode from the negative electrode; A conductive head is abutted against the end face of the positive electrode and welded to the positive high-voltage line, used to introduce the electrical signal of the positive high-voltage line into the positive electrode and press the positive electrode firmly; An insulating cover plate is placed on the axial outer end face of the conductive head to isolate the positive electrode in the axial direction.

5. A mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, It also includes a lower spring seat, which is threadedly fitted onto the outside of the working cylinder. The other end of the mechanical spring abuts against the lower spring seat. The lower spring seat is configured to be able to be manually rotated and moved along the axial direction of the working cylinder to adjust the preload of the mechanical spring.

6. A mechanically spring-type damped controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, It also includes a sealing assembly disposed at one end of the working cylinder into which the piston rod extends, the piston rod passing through the sealing assembly and engaging in a sliding sealing engagement with it.

7. A mechanically spring-type damped controllable bicycle rear shock absorber based on electrorheological effect according to claim 1, characterized in that, It also includes a base assembly, which is fixedly connected to the end of the working cylinder away from the piston rod extending in, for sealing the end of the working cylinder; the base assembly includes a base and a sealing screw, the base having an injection hole for injecting electrorheological fluid into the main cavity, and the sealing screw being threaded into the injection hole for sealing the injection hole after injection is completed.

8. A mechanically spring-type damped controllable bicycle rear shock absorber based on electrorheological effect according to claim 7, characterized in that, It also includes an upper connector assembly, which is fixedly connected to one end of the piston rod located outside the working cylinder, and one end of the mechanical spring indirectly abuts against the piston rod assembly through the upper connector assembly; the upper connector assembly and the base assembly are respectively provided with shaft holes for mounting to corresponding positions on the bicycle frame.

9. A mechanically spring-type damped controllable bicycle rear shock absorber based on electrorheological effect according to claim 8, characterized in that, The piston rod is provided with a locking nut at one end outside the working cylinder. The upper connector assembly includes an upper connector and an upper spring seat. The upper connector is sleeved on the end of the piston rod and locked and fixed by the locking nut. The upper spring seat is fixed to the upper connector and abuts against one end of the mechanical spring.

10. A mechanical spring-type damping controllable bicycle rear shock absorber based on electrorheological effect according to claim 4, characterized in that, The piston assembly also includes: The wear-resistant ring is set in the groove on the outer circumferential surface of the negative electrode and slides in fit with the inner wall of the working cylinder; A sealing ring is disposed between the positive electrode and the conductive head; A pressure cap is fitted onto the outside of the positive electrode and fixedly connected to the negative electrode, used to axially press and fix the positive electrode, the insulating sleeve, and the insulating cover plate relative to the negative electrode.

Images