Double-cylinder type magnetorheological damper

Abstract

The utility model discloses a double-cylinder type magneto-rheological shock absorber. The cylinder barrel assembly comprises an inner barrel, an outer barrel and a base, wherein the outer barrel sleeves the periphery of the inner barrel, a radial interval is formed between the outer barrel and the inner barrel, and the base is installed at the bottom end of the inner barrel; the guider assembly is hermetically mounted at the upper end of the inner cylinder; a piston rod penetrates through the guider assembly and extends out of the upper end of the inner cylinder; the floating piston assembly is arranged in the inner cavity and is closer to the bottom end than the piston assembly, the floating piston assembly divides the inner cavity into a magnetorheological fluid cavity and an inner gas chamber in a sealed mode, the magnetorheological fluid cavity is filled with magnetorheological fluid, and the inner gas chamber is filled with gas; wherein the upper end of the outer cylinder is hermetically welded on the inner cylinder, and the bottom end of the outer cylinder is hermetically welded on the base, so that an outer air chamber hermetically isolated from the outside is formed at a radial interval; and the outer air chamber is in air communication with the inner air chamber.

Description

Technical Field

[0001] The utility model relates to the technical field of magnetorheological technology, specifically to magnetorheological devices. More specifically, the utility model relates to a double-cylinder magnetorheological shock absorber, as well as a welding structure and process for sealing and welding the inner cylinder and the outer cylinder of the double-cylinder magnetorheological shock absorber. Background Art

[0002] Magnetorheological technology and equipment are in a period of large-scale growth in technology and application globally and in China. In the fields of military and civilian vehicles, construction machinery, engineering vehicles, medical devices, seats, industrial processing, and equipment vibration reduction, magnetorheological dampers using magnetorheological fluid as the working medium are increasingly being used to achieve technical effects such as vibration reduction, buffering, and comfort experience.

[0003] Conventional piston-type magnetorheological dampers or magnetorheological shock absorbers in current technology are basically single-cylinder magnetorheological shock absorbers. The main disadvantages of conventional single-cylinder magnetorheological shock absorbers are as follows: due to the floating piston and the built-in air chamber, the axial dimension is too large, resulting in problems with limited installation and layout; for single-cylinder magnetorheological shock absorbers with an auxiliary air cylinder, due to the external placement of the auxiliary air cylinder, the radial dimension is too large, resulting in problems with interference with the dust cover.

[0004] In addition, precisely because the axial and radial dimensions are restricted and limited in multiple aspects, the volume of the air chamber of the single-cylinder magnetorheological shock absorber is also limited. A small air chamber volume (i.e., meaning less damping gas) is disadvantageous for the required damping effect, and it is impossible to achieve a better magnetorheological damping effect, and non-desired spring-like bouncing effects may occur in some extreme cases. Therefore, in order to achieve the required damping effect, conventional single-cylinder magnetorheological shock absorbers are generally designed to have an additional separate auxiliary air cylinder in a manner generally parallel to the single cylinder to provide sufficient gas. As mentioned above, the external design of the additional auxiliary air cylinder will undoubtedly bring a series of problems such as too large radial dimensions, interference with the dust cover of the magnetorheological shock absorber, limited installation and layout in a small space, or inability to install, etc.

[0005] Therefore, in view of the above and other more considerations, it is particularly important to develop a magnetorheological shock absorber that is suitable for industrial practical applications, adapts to a smaller layout space, and has better vibration reduction, buffering, working load-bearing, and sealing effects.

[0006] The information included in this background art section of the utility model specification, including any references cited herein and any descriptions or discussions thereof, is included only for the purpose of technical reference and is not considered to be the subject matter limiting the scope of the utility model. Summary of the Utility Model

[0007] In view of the above and other more concepts, the present utility model is proposed.

[0008] More specifically, according to one aspect of the present utility model, a double-cylinder magnetorheological shock absorber is provided. The double-cylinder magnetorheological shock absorber includes: a cylinder assembly, the cylinder assembly including an inner cylinder, an outer cylinder sleeved on the outer periphery of the inner cylinder and forming a radial gap with the inner cylinder, and a base mounted at the bottom end of the inner cylinder; a guide assembly hermetically mounted at the upper end of the inner cylinder; a piston assembly disposed in the inner cavity of the inner cylinder and capable of reciprocating axially, the piston assembly including a piston rod and a piston assembled together, wherein the piston rod passes through the guide assembly and extends out from the upper end of the inner cylinder; a floating piston assembly disposed in the inner cavity and axially floating closer to the bottom end than the piston assembly, wherein the floating piston assembly divides the inner cavity into a magnetorheological fluid chamber and an inner air chamber and hermetically isolates the two, magnetorheological fluid is filled in the magnetorheological fluid chamber, and gas is filled in the inner air chamber; wherein, the outer cylinder is hermetically welded to the inner cylinder at the upper end and hermetically welded to the base at the bottom end, whereby the radial gap forms an outer air chamber hermetically isolated from the outside (referring to the outside of the cylinder-type magnetorheological shock absorber); wherein, the outer air chamber is in gas communication with the inner air chamber through a gas passage.

[0009] According to one embodiment, the outer cylinder is hermetically welded to the inner cylinder through a transition ring at the upper end without being directly welded to the inner cylinder, and is hermetically welded to the base at the bottom end without being directly welded to the inner cylinder, wherein, the base is press-fitted and sleeved on the bottom end of the inner cylinder.

[0010] According to one embodiment, a limiting member axially extending towards the floating piston assembly in the inner cavity is mounted on the base.

[0011] According to one embodiment, the gas passage is at least one vent hole formed on the circumferential wall of the inner cylinder near the bottom end of the inner cylinder.

[0012] According to one embodiment, the vent hole is axially located between the end face of the bottom end of the inner cylinder and the upper end face of the limiting member.

[0013] According to one embodiment, the limiting member is in the form of a buffer limiting block or a buffer limiting post.

[0014] According to one embodiment, a mounting member is further equipped on the base.

[0015] According to one embodiment, the piston includes a piston end cover formed of a magnetic isolation material, a piston cylinder body, a guide belt, an excitation coil and an iron core, and a liquid passing channel and a bypass liquid passing channel for the magnetorheological fluid to flow are formed in the piston cylinder body; the floating piston assembly includes a floating piston main body and a guide belt and an O-ring mounted on the floating piston main body.

[0016] According to another aspect of the present utility model, a method for sealing and welding the outer cylinder and the inner cylinder of a sealed and welded double-cylinder magnetorheological damper is also disclosed. The method includes the steps of: S1: providing a transition ring; S2: sealing and welding the transition ring on the inner cylinder; S3: crimping the base of the double-cylinder magnetorheological damper on the bottom end of the inner cylinder to form a crimping portion to close the opening at the bottom end of the inner cylinder; S4: sleeving the outer cylinder on the inner cylinder such that the upper end of the outer cylinder overlaps on the transition ring, and the bottom end of the outer cylinder overlaps on the base at the crimping portion, wherein a radial gap is formed between the outer cylinder and the inner cylinder; and S5: sealing and welding the upper end of the outer cylinder to the transition ring without directly welding to the inner cylinder, and sealing and welding the bottom end of the outer cylinder to the base at the crimping portion without directly welding to the inner cylinder, such that the radial gap forms an air chamber that is hermetically isolated from the outside (referring to the outside of the cylinder-type magnetorheological damper).

[0017] According to one embodiment, step S2 is performed before the nitriding or honing process of the inner cylinder.

[0018] According to one embodiment, each of the weldings in step S2 and step S5 forms a complete sealed weld around the circumference of the inner cylinder.

[0019] According to one embodiment, the double-cylinder magnetorheological damper is the double-cylinder magnetorheological damper as described above.

[0020] According to one embodiment, the mounting member is a lifting ring or a pulling ring.

[0021] According to one embodiment, the outer cylinder and the inner cylinder are arranged substantially coaxially.

[0022] According to one embodiment, the double-cylinder magnetorheological damper is further provided with a dust cover.

[0023] According to one embodiment, the welding is seam welding, for example, completed by a seam welding machine.

[0024] According to one embodiment, the double-cylinder magnetorheological damper is configured to withstand working loads of light, medium, and heavy loads.

[0025] According to one embodiment, the gas in the inner and outer air chambers is an inert gas, such as nitrogen, carbon dioxide, and the like.

[0026] According to the main idea of one or more embodiments of the double-cylinder magnetorheological damper of the present utility model, the following problems can be effectively solved:

[0027] (1) An annular air chamber formed by an inner cylinder and an outer cylinder, which is hermetically welded and load-bearing, solves the problems of conventional single-cylinder magnetorheological shock absorbers with large axial dimensions and limited installation and layout due to the floating piston and the built-in air chamber, and can also solve the problems of single-cylinder magnetorheological shock absorbers with auxiliary air cylinders having large radial dimensions and interference with the dust covers of the magnetorheological shock absorbers due to the external placement of the auxiliary air cylinders;

[0028] (2) Through the hermetically welded annular air chamber, problems such as insufficient volume of the traditional air chamber, poor sealing performance, low durability and reliability, and limited load-bearing are solved;

[0029] (3) Through the unique sealing and welding process of the annular air chamber, the reliability, firmness, sealing performance and dimensional accuracy of the structure are ensured, thereby ensuring the reliability, durability and load-bearing performance of the double-cylinder magnetorheological shock absorber.

[0030] (4) The sealed welding of the inner cylinder and the outer cylinder, as well as the setting of an additional transition ring, enhance the structural strength of the cylinder barrel of the double-cylinder magnetorheological shock absorber of the present invention, making it possible to apply to working conditions and application scenarios with larger loads (including medium loads, heavy loads, etc.).

[0031] (5) Through the setting of a buffer and limit member in the inner cylinder air chamber, the problem that the floating piston assembly is easily damaged in extreme cases, especially its guide member and sealing ring are scratched by, for example, the vent hole structure, is solved, thereby greatly improving and ensuring the reliability, sealing performance, durability and service life of the double-cylinder magnetorheological shock absorber.

[0032] (6) Through the unique sealing and welding process and step setting between the inner cylinder and the outer cylinder of the double-cylinder magnetorheological shock absorber of the present invention, not only can the structural strength and stiffness of the cylinder barrel be ensured and even enhanced, the strength and sealing performance of the welded part of the cylinder barrel be guaranteed, but also the thermal influence of welding on the strength, stiffness and deformation of the double-cylinder magnetorheological shock absorber can be minimized.

[0033] More embodiments of the present invention can also achieve other beneficial technical effects that are not listed one by one. Some of these other technical effects may be described below, and are predictable and understandable by those skilled in the art after reading the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] By referring to the following description together with the drawings, the above-mentioned features and advantages of these embodiments and other features and advantages, as well as the ways to achieve them, will become more obvious, and the embodiments of the present invention can be better understood. In the drawings:

[0035] Figure 1A is an overall schematic view of a double-cylinder magnetorheological shock absorber assembly cut along its longitudinal center line according to an embodiment of the present invention.

[0036] Figure 1B is Figure 1A An overall schematic view of the piston assembly of the shown double-tube magnetorheological damper cut along its longitudinal centerline.

[0037] Figure 2 is Figure 1A A suitably enlarged schematic longitudinal sectional view of the inner tube and outer tube design of the shown double-tube magnetorheological damper, particularly schematically showing the structure and assembly of the inner tube, outer tube and base of the double-tube magnetorheological damper.

[0038] Figure 3A is Figure 1A A schematic longitudinal sectional view of the inner tube design of the shown double-tube magnetorheological damper, schematically showing Figure 1A The design and structure of arranging a transition ring on the inner tube of the shown double-tube magnetorheological damper and crimping (interference fit) the base at the bottom end of the inner tube.

[0039] Figure 3B A schematic perspective view schematically showing the structure of the inner tube and base assembly of the double-tube magnetorheological damper shown in 3A, particularly schematically showing the (partial) gas passage in the form of a vent hole, for example, connecting the outer tube and the inner tube.

[0040] Figure 4A is Figure 1A A schematic longitudinal sectional view of the combination of the outer tube and inner tube of the shown double-tube magnetorheological damper, schematically showing the design of welding one end of the outer tube to the transition ring arranged on the inner tube and the other end to the base crimped on the bottom end of the inner tube, and schematically showing the gas passage in the form of a vent hole connecting the outer tube and the inner tube.

[0041] Figure 4B A magnified structural schematic view of the circled part A in 4A, schematically showing in the form of a magnified view the design details of the base crimped and assembled on the inner tube being hermetically welded to the outer tube on its outer side, and showing the connection of the outer air chamber and the inner air chamber through the vent hole.

[0042] Figure 5 Schematically shown in the form of a magnified schematic longitudinal sectional view Figure 1A The design of the floating piston assembly of the shown double-tube magnetorheological damper, particularly schematically showing the guide band and O-ring installed on the floating piston body.

[0043] The reference numerals are as follows:

[0044] 1 - Piston assembly; 1.1 - Piston rod; 1.2 - Piston end cover; 1.3 - Piston cylinder body; 1.4 - Guide strip; 1.5 - Coil; 1.6 - Iron core; 2 - Guide assembly; 3 - Floating piston assembly; 3.1 - Floating piston; 3.2 - Guide strip; 3.3 - O-ring seal; 4 - Cylinder barrel assembly; 5 - Rod side magnetorheological fluid chamber; 6 - Liquid passage; 7 - By-pass liquid passage; 8 - Non-rod side magnetorheological fluid chamber; 9 - Outer air chamber; 10 - Gas passage; 11 - Inner air chamber; 4.1 - Inner cylinder; 4.2 - Transition ring; 4.2.1 - Weld between inner cylinder and transition ring; 4.3 - Outer cylinder; 4.4 - Limiting part; 4.5 - Base; 4.6 - Lifting ring; 4.7 - Crimping part; 4.8 - Weld between outer cylinder and transition ring; 4.9 - Weld between outer cylinder and base. Detailed implementation manners

[0045] In the following descriptions of the drawings and the detailed implementation manners, details of one or more embodiments of the present utility model will be elaborated. From these descriptions, the drawings, and the claims, other features, objectives, and advantages of the present utility model can be clearly understood.

[0046] It should be understood that the embodiments illustrated and described are not limited to the details of the construction and arrangement of the components set forth in the following descriptions or illustrated in the drawings in their applications. The illustrated embodiments can be other embodiments and can be implemented or executed in various ways. Each example is provided by way of explaining rather than limiting the disclosed embodiments. In fact, it will be obvious to those skilled in the art that various modifications and variations can be made to the embodiments of the present utility model without departing from the scope or essence of the disclosure of the present utility model. For example, the features illustrated or described as part of one embodiment can be used with another embodiment to still produce additional embodiments. Therefore, the disclosure of the present utility model covers such modifications and variations that fall within the scope of the appended claims and their equivalent elements.

[0047] Similarly, it can be understood that the phrases and terms used herein are for the purpose of description and should not be considered restrictive. The use of "including", "comprising", or "having" and their variants herein is intended to open-endedly include the items listed thereafter, their equivalents, and additional items.

[0048] The present utility model will be described in more detail below with reference to specific embodiments of the present utility model.

[0049] Figure 1A is an overall schematic view of a double-cylinder magnetorheological shock absorber assembly according to an embodiment of the present utility model, cut along its longitudinal center line. Figure 1B is Figure 1A an overall schematic view of the piston assembly 1 of the illustrated double-cylinder magnetorheological shock absorber, cut along its longitudinal center line.

[0050] As Figure 1A shown, the double-tube magnetorheological damper assembly may include a generally cylindrical cylinder assembly 4. The inner cylinder 4.1 of the cylinder assembly 4 has a hollow inner cavity. As shown in the figure, in a section of the inner cavity near the upper end of the inner cylinder 4.1, magnetorheological fluid is hermetically filled, that is, the magnetorheological fluid that serves as the working medium of the double-tube magnetorheological damper.

[0051] The piston assembly 1 is disposed in the inner cavity of the inner cylinder 4.1 and can reciprocate axially therein in a sliding manner. For example, the piston assembly 1 may mainly consist of a piston rod 1.1 and a piston fixedly assembled together. An example of the piston may include a piston end cap 1.2 formed of a magnetic isolation material, a piston cylinder body 1.3, a guide strip 1.4, an excitation coil 1.5, and an iron core 1.6, and so on. The piston rod of the piston assembly 1 is connected to the object to be damped (damping / buffering object). The outside of it ( Figure 1A the left side of the shown guide assembly 2) may be connected to a power supply, and the inside of it ( Figure 1A the right side of the shown guide assembly 2) may be connected to the excitation coil 1.5. When an electric current is input to the double-tube magnetorheological damper, the excitation coil 1.5 excites a magnetic field, and a magnetic field circuit is formed between the piston cylinder body 1.3 and the iron core 1.6. The magnetorheological fluid flows through the liquid passage 6 and the bypass liquid passage 7 from the rodless magnetorheological fluid chamber 5, and then flows to the rod magnetorheological fluid chamber 8. Under the magnetic field excitation, the magnetic powder in the magnetorheological fluid forms bridges into chains, thereby changing the damping force during the flow of the magnetorheological fluid. Since the excitation current is controllable, the damping force is electronically controllable.

[0052] The guide assembly 2 is installed in the inner cavity at the upper end of the inner cylinder 4.1 (that is, Figure 1A the left end shown), and guides the piston assembly 1 and seals the upper end of the inner cylinder 4.1 through a (for example, clearance) sealing fit with the piston rod 1.1 of the piston assembly 1.

[0053] Figure 5 Schematically shows in the form of an enlarged schematic longitudinal sectional view the Figure 1A design of the floating piston assembly 3 of the shown double-tube magnetorheological damper, especially schematically shows the guide strip 3.2 and the O-ring seal 3.3 installed on the main body of the floating piston 3.1. The floating piston assembly 3 that can move axially "floatably" is used for sealing (by means of the O-ring seal 3.3) to hermetically isolate the magnetorheological fluid from the gas in the outer air chamber 9 and the inner air chamber 11. Those skilled in the art can understand that the floating piston assembly 3 needs to maintain the ability to move "floatably" and also needs to be well-sealed, that is, the rodless magnetorheological fluid chamber 8 (and the magnetorheological fluid therein) at one end of the floating piston assembly 3 and the gas in the outer air chambers 9 and 11 can be hermetically separated from each other.

[0054] The main support of the cylinder barrel assembly 4 encloses the piston assembly 1, magnetorheological fluid, etc. within the inner cylinder 4.1 of the cylinder barrel assembly 4. When the magnetorheological fluid flows from the rodless magnetorheological fluid chamber 5 into the rod magnetorheological fluid chamber 8, the compression damping force is conveniently electronically controllable. When the magnetorheological fluid flows from the rod magnetorheological fluid chamber 8 into the rodless magnetorheological fluid chamber 5, the rebound damping force is also conveniently electronically controllable.

[0055] Figure 2 is Figure 1A A suitably enlarged schematic longitudinal sectional view of the inner cylinder 4.1 and the outer cylinder 4.3 of the shown double-tube magnetorheological shock absorber, particularly schematically showing the structure and assembly of the inner cylinder 4.1, the outer cylinder 4.3 and the base 4.5 of the double-tube magnetorheological shock absorber. As Figure 2 shown, the cylinder barrel assembly 4 includes an inner cylinder 4.1, an outer cylinder 4.3, a base 4.5 and a mounting member 4.6 in the form of a lifting ring or a pull ring (any other suitable form of mounting member is also acceptable). A transition ring 4.2 is provided between the inner cylinder 4.1 and the outer cylinder 4.3. The inner cylinder 4.1 and the transition ring 4.2 are fixedly sealed by butt welding, see the weld 4.2.1 shown in Figure 3A . At the bottom end of the cylinder barrel assembly, that is, the bottom end of the inner cylinder 4.1 (the right end shown in Figure 2 ), a base 4.5 is provided which is sealingly crimped (interference fit) and welded in the radial space between the inner cylinder 4.1 and the outer cylinder 4.3.

[0056] As one of the main concepts of the double-tube magnetorheological shock absorber of the present utility model, on the basis of the traditional single-tube magnetorheological shock absorber, an axially and preferably coaxially extending outer cylinder 4.3 is added by means of sealing welding around the outer periphery of its inner cylinder 4.1. A radial space is formed between the outer cylinder 4.3 and the inner cylinder 4.1 which axially extends and is sealingly welded to the inner cylinder 4.1 at both the upper end (the left end shown in Fig. 1-2) and the bottom end (the right end shown in Fig. 1-2) of the outer cylinder 4.3. In this way, an outer air chamber 9 in the form of an auxiliary annular air chamber is formed between the outer cylinder 4.3 and the inner cylinder 4.1. The outer air chamber 9 and the inner air chamber 11 near the bottom end (the right end shown in Figure 1A ) of the inner cylinder 4.1 are communicated with each other through, for example, a gas passage 10, thus jointly constituting an air chamber with an increased volume capable of accommodating more buffer gas such as high-pressure nitrogen. Such a design releases the axial occupied space of the air chamber design of the single-tube magnetorheological shock absorber and eliminates the radial space of the additionally arranged auxiliary air cylinder, thereby reducing the overall axial and radial dimensions of the shock absorber and the installation space.

[0057] During the use of the double-cylinder magnetorheological shock absorber, the double-cylinder magnetorheological shock absorber can be installed in place by using a threaded fixing or a mounting member in the form of a lifting ring 4.6 (other suitable mounting members can also be used), or any other required mounting method can be adopted. As an example, during operation, only the piston rod 1.1 of the piston assembly 1 at one end needs to be installed on the object to be shock-absorbed (shock-absorbing / buffering object), and the other end is fixed in place through the lifting ring 4.6.

[0058] The following further describes the sealed welding of the outer cylinder 4.3 and the inner cylinder 4.1 of the double-cylinder magnetorheological shock absorber of the present invention in conjunction with the accompanying drawings and other related process steps.

[0059] First, prepare a transition ring 4.2, the inner diameter of which is preferably exactly matched to fit over the outer circumference of the inner cylinder 4.1, and its outer diameter is matched / adapted to the inner diameter of the outer cylinder 4.3. In the welding process of the inner and outer cylinders of the present invention, the transition ring 4.2 is a very important component. On the one hand, it can strengthen and reinforce the double-cylinder magnetorheological shock absorber itself and play a role in minimizing the welding heat influence, reducing the deformation that may occur in the cylinder wall of the double-cylinder magnetorheological shock absorber during welding and when being impacted or struck; and on the other hand, it can ensure the welding and sealing performance between the inner and outer cylinders.

[0060] Second, preferably before performing the processing technology that may change or affect its deformation / dimensions on the cylinder inner cylinder 4.1, such as before its nitriding and honing process treatments, first perform the sealed welding between the inner cylinder 4.1 and the transition ring 4.2, that is, circumferentially weld the transition ring 4.2 to the inner cylinder 4.1, as shown in the complete circumferential sealed and metallurgical bonded weld 4.2.1 between the inner cylinder 4.1 and the transition ring 4.2 in Figure 2 First circumferentially welding the transition ring 4.2 to the inner cylinder 4.1 can not only ensure the cylinder structure strength and sealing performance, but also reduce the influence of welding on the deformation of the inner cylinder 4.1.

[0061] Third, press-fit the base 4.5 onto the inner cylinder 4.1 at the bottom end, for example, sleeved and press-fitted the base 4.5 onto the bottom end of the inner cylinder 4.1 in an interference fit or a tight fit manner by a press, as shown in Figure 3A The press-fitting part 4.7 should have an axial extension distance and form a complete circumferential press-fitting part 4.7 around the inner cylinder 4.1, which is convenient for the subsequent sealed welding process.

[0062] Fourth, sleeved the outer cylinder 4.3 over the inner cylinder 4.1 and form a radial gap between the inner and outer cylinders, which will form an outer air chamber 9 after sealed welding (described below). Among them, one end of the outer cylinder 4.3 ( Figure 4A the left end shown) is sleeved over the transition ring 4.2, and the other end of the outer cylinder 4.3 ( Figure 4AThe right end shown) is nested on the crimping part 4.7. After that, the base 4.5 can be fixedly connected to the lifting ring 4.6 by welding or other suitable means. After that, one end of the outer cylinder 4.3 ( Figure 4A The left end shown) is hermetically welded in a complete circle (for example, seam welding, which can be completed by a seam welding machine) on the transition ring 4.2, forming a weld 4.8 between the outer cylinder and the transition ring as shown in Figure 4A ; and, the other end of the outer cylinder 4.3 ( Figure 4A The right end shown) is hermetically welded in a complete circle (for example, seam welding, which can be completed by a seam welding machine) on the base 4.5 of the crimping part 4.7 (instead of directly welding on the inner cylinder 4.1), forming a weld 4.9 between the outer cylinder and the base as shown in Figure 4A - 4B . Since one end of the outer cylinder 4.3 is welded on the transition ring 4.2 instead of directly welding on the inner cylinder 4.1, and the other end of the outer cylinder 4.3 is welded on the base 4.5 instead of directly welding on the inner cylinder 4.1, therefore, the deformation and other thermal effects of the inner cylinder 4.1 caused by welding can be minimized.

[0063] Fifth, preferably after the above welding, the limiting member 4.4 is pressed into Figure 4A the installation groove of the base 4.5 shown, and can be selectively riveted to prevent loosening. The limiting member 4.4 is used to limit the lowest position of the floating piston assembly 3, avoiding the seal of the floating piston assembly 3 (for example Figure 5 the O-ring 3.3 shown) from being scratched by the gas passage 10 in the form of a vent hole, which will adversely affect its sealing performance, resulting in seal damage or even failure, and ultimately may have an adverse impact on the reliability, service life, and various performance of the device including sealing performance of the double-tube magnetorheological shock absorber. The limiting member 4.4 can selectively have a buffering function. For this purpose, the limiting member 4.4 can be in the form of a buffer limiting block, which can use a material with a certain buffering effect, such as a non-metallic material (such as nylon or hard rubber with good buffering characteristics, reliability, durability, etc.), so that it has both limiting and buffering functions, thereby further avoiding abnormal noise, excessive impact and adverse effects on the overall performance of the device during limiting.

[0064] Figure 3A is Figure 1A a schematic longitudinal sectional view of the design of the inner cylinder 4.1 of the double-tube magnetorheological shock absorber shown, schematically showing Figure 1A the design and structure of arranging the transition ring 4.2 on the inner cylinder of the double-tube magnetorheological shock absorber shown and crimping (interference fit) the base 4.5 at the bottom end of the inner cylinder 4.1. Figure 3BSchematically shows a schematic perspective view of the inner cylinder and base assembly structure of the double-cylinder magnetorheological damper shown in FIG. 3A, in particular schematically showing a (partial) gas passage 10 in the form of a vent hole, for example, connecting the outer cylinder 4.3 and the inner cylinder 4.1.

[0065] Figure 4A is Figure 1A A schematic longitudinal sectional view of the combination of the outer cylinder 4.3 and the inner cylinder 4.1 of the double-cylinder magnetorheological damper shown, schematically showing the design of welding one end of the outer cylinder 4.3 to the transition ring 4.2 arranged on the inner cylinder 4.1 and the other end to the base 4.5 crimped on the bottom end of the inner cylinder 4.1, and schematically showing the gas passage 10 in the form of a vent hole connecting the outer cylinder 4.3 and the inner cylinder 4.1.

[0066] As Figure 3B and Figure 4B shown, at the bottom of the cylinder assembly 4, for example but not limited to, on the peripheral wall of the inner cylinder 4.1 at the bottom end, a plurality of, for example, 4 gas passages 10 in the form of vent holes can be opened for connecting the outer air chamber 9 and the inner air chamber 11. These gas passages 10 in the form of vent holes can be arranged in a uniformly distributed manner in the circumferential direction, and their shapes can be kidney-shaped or other suitable shapes, so that the gas passing amount can be increased while ensuring the structural strength. Preferably, the position of the gas passage 10 is slightly higher than the base 4.5 and at the same time lower than the Figure 1A left end face shown in FIG. (as Figures 2 - 4A shown, the vent hole 10 is axially located between the end face of the bottom end of the inner cylinder 4.1 and the upper end face / illustrated left end face of the limiting member 4.4), so as to ensure that the gas passage 10 in the form of a vent hole functions normally, and at the same time, it will not cause the leakage of the magnetorheological fluid and be blocked by the structure of the damper itself.

[0067] Figure 4B Schematically shows an enlarged structural schematic view of the circled part A in FIG. 4A, schematically showing in the form of an enlarged view the design details of the base 4.5 press-fitted on the inner cylinder 4.1 on the outside and sealed and welded to the outer cylinder 4.3, and showing that the outer air chamber 9 between the outer cylinder 4.3 and the inner cylinder 4.1 is connected to the inner air chamber 11 at the bottom end of the inner cylinder 4.1 through the vent hole 10, which not only increases the amount of gas and thus improves the buffering and damping effect, but also the gas in the inner air chamber 11 can flow to the outer air chamber 9 through the vent hole 10, which is also beneficial to the heat dissipation of the double-cylinder magnetorheological damper of the present invention during the working process.

[0068] The magnetorheological damper of the present utility model, such as a piston type, adjusts the damping force and damping curve by means of electric control, such as controlling the excitation current. Therefore, an external wire may also be provided and electrically connected and / or signal connected to an external power source and / or a control system. In this regard, the piston rod 1.1 is preferably configured as a hollow rod, and the wire directly or indirectly electrically / signal connected to the excitation coil 1.5 can pass through the hollow rod cavity of the piston rod 1.1 and extend to the outside.

[0069] The present utility model and its main concepts have been discussed above in conjunction with the drawings and embodiments. Those skilled in the art should understand that, without departing from the basic concept of the present utility model, some structures, compositions, and configurations of the double-tube magnetorheological shock absorber can adopt other feasible variations other than those described in the specific implementation manners of this specification. For example, in addition to the outer tube in the double-tube design and the related seal welding, structure, process, and configuration, etc., the double-tube magnetorheological shock absorber of the present utility model can also adopt some designs, components, and structures of the existing single-tube magnetorheological shock absorber / damper, such as those disclosed in the Chinese utility model "Piston-type Magnetorheological Damper Integrated with a Pressure Sensor" with the application number 202223116870.4 filed by the same applicant on November 23, 2022, regarding the piston assembly, floating piston, guide assembly, base, mounting part design, etc., unless it is contradictory to the present utility model. The relevant content in this Chinese utility model "Piston-type Magnetorheological Damper Integrated with a Pressure Sensor" is incorporated into this application by reference as if it were directly described in this application.

[0070] Those skilled in the art can understand that although the transition ring 4.2 has a generally consistent ring body thickness as shown in the above figure, its inner and outer diameters are restricted by the designs of the inner tube 4.1 and the outer tube 4.3. However, the transition ring 4.2 can also adopt other shapes and structures. For example, the ring body thickness of the transition ring 4.2 can be gradually changed, or the transition ring 4.2 can have at least two ring bodies with different thicknesses, etc. Additionally, in certain special situations, such as in some application scenarios where the requirements for the dimensional accuracy and strength of the double-tube magnetorheological shock absorber are not particularly high, or in the case where the inner tube or the outer tube has a self-welding setting / part, it is not excluded that the transition ring can be cancelled and the outer tube can be directly welded to the inner tube, etc. The base 4.5 and the inner tube 4.1 can also adopt other assembly / connection methods (such as screw connection, interference fit, instead of crimping), and then the two are welded together, etc. These all fall within the scope of the present utility model.

[0071] The foregoing description of several embodiments of the present utility model has been presented for purposes of illustration. The foregoing description is not intended to be exhaustive nor to limit the present utility model to the precise steps and / or forms disclosed. Obviously, many modifications and variations are possible in light of the above teachings. The scope of the present utility model and all equivalents thereof are intended to be defined by the appended claims.

Claims

1. A double-tube magnetorheological damper, characterized in that: The double-tube magnetorheological damper comprises: A cylinder assembly, the cylinder assembly comprising an inner cylinder, an outer cylinder which is overlapped on the outer periphery of the inner cylinder and forms a radial interval with the inner cylinder, and a base installed at the bottom end of the inner cylinder; a guide assembly sealingly mounted on the upper end of the inner cylinder; A piston assembly disposed in the inner cavity of the inner cylinder and capable of axially reciprocating movement, the piston assembly comprising a piston rod and a piston assembled together, wherein the piston rod passes through the guide assembly and extends from the upper end of the inner cylinder; and A floating piston assembly that can float axially and is disposed in the inner cavity and is closer to the bottom end than the piston assembly, wherein the floating piston assembly divides the inner cavity into a magnetorheological fluid cavity and an inner gas chamber and seals the two apart, the magnetorheological fluid cavity is filled with magnetorheological fluid, and the inner gas chamber is filled with gas; wherein the outer cylinder is sealed and welded to the inner cylinder at the upper end and to the base at the lower end, whereby the radial spacing forms an outer air chamber sealed and isolated from the outside; and Wherein, the outer air chamber is in gas communication with the inner air chamber through a gas channel.

2. The double-tube magnetorheological damper according to claim 1, characterized in that: in, The outer cylinder is seal-welded to the inner cylinder via a transition ring at the upper end without being directly welded to the inner cylinder, and is seal-welded to the base at the lower end without being directly welded to the inner cylinder, wherein the base is press-fitted and overlapped on the lower end of the inner cylinder.

3. The double-tube magnetorheological damper according to claim 1 or 2, characterized in that: A stopper is mounted on the base and extends axially in the inner cavity toward the floating piston assembly.

4. The double-tube magnetorheological damper according to claim 3 is characterized in that: The gas passage is at least one vent hole formed on the circumferential wall of the inner cylinder near the bottom end of the inner cylinder.

5. The double-tube magnetorheological damper according to claim 4, characterized in that: The vent hole is located between the end surface of the bottom end of the inner tube and the upper end surface of the limiting member in the axial direction.

6. The double-tube magnetorheological damper according to claim 3, characterized in that: The limiting member is in the form of a buffer limiting block or a buffer limiting column.

7. The double-tube magnetorheological damper according to claim 1 or 2, characterized in that: The base is further equipped with a mounting member.

8. The double-tube magnetorheological damper according to claim 7, characterized in that: The mounting piece is a lifting ring or a pulling ring.

9. The double-tube magnetorheological damper according to claim 1 or 2, characterized in that: The piston comprises a piston end cover, a piston cylinder, a guide belt, an excitation coil and an iron core formed of a magnetic isolation material, and a through-liquid channel and a bypass through-liquid channel for magnetorheological fluid to flow are formed in the piston cylinder; and The floating piston assembly includes a floating piston body and a guide band and an O-ring mounted on the floating piston body.

10. The double-tube magnetorheological damper according to claim 1 or 2, characterized in that: The double-tube magnetorheological vibration absorber is also provided with a dust cover.

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