Air springs

Abstract

The present invention provides an air spring, comprising a shell, a diaphragm fixed within the shell, a bladder, and a lower end cover, arranged in sequence; the ends of the bladder are respectively sealed and buckled onto the outer walls of the shell and the lower end cover; the diaphragm comprises, from top to bottom, a diaphragm upper cover, a diaphragm, and a diaphragm lower cover; the shell is a hollow structure with an opening at the lower end, the diaphragm seals the opening, so that the shell and the diaphragm upper cover together form an upper chamber, and the bladder, the diaphragm lower cover, and the lower end cover together form a lower chamber; the diaphragm upper cover is provided with at least one upper vent hole communicating with the upper chamber, and the diaphragm lower cover is provided with at least one lower vent hole communicating with the lower chamber; the diaphragm is an elastomer, and under the action of the pressure difference formed between the upper and lower chambers, the diaphragm undergoes elastic deformation and moves up and down within the diaphragm. The air spring of the present invention can isolate high-frequency, small-amplitude vibrations, reduce the conduction of chassis noise, enhance the vehicle's sense of suspension, provide support for the vehicle, and control large vibrations of the vehicle body under roll and pitch conditions.

Description

Technical Field

[0001] The present invention relates to the field of springs, in particular to an air spring structure utilizing a diaphragm box to control stiffness. Background Art

[0002] The basic principle of existing air springs is that gas pressure increases when compressed and decreases when expanded. This is fundamentally based on the ideal gas equation, pV = nRT. As the gas compresses, the air spring develops elasticity, a process that involves thermodynamics. As the compression rate increases, the air spring transitions from an isothermal to an adiabatic process, resulting in different pressure increases at different compression rates. This is reflected in the spring's external characteristics, where the air spring becomes stiffer as the speed of movement increases.

[0003] From the perspective of vehicle performance, the desired spring rate-frequency characteristics are exactly the opposite. We generally prefer springs that are softer at high frequencies and small amplitudes to better isolate the transmission of high-frequency, small-amplitude vibrations and noise, enhancing the vehicle's suspension feel. We prefer springs that are stiffer at low frequencies to provide better support for the vehicle and control larger body vibrations during roll and pitch conditions. Summary of the Invention

[0004] The present invention is to solve the above problems, and an object of the present invention is to provide an air spring that uses a diaphragm to control stiffness.

[0005] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0006] The air spring comprises a housing, a diaphragm, a bladder skin and a lower end cover which are arranged in sequence;

[0007] The two ends of the bladder skin are respectively sealed and pressed on the outer walls of the shell and the lower end cover;

[0008] The membrane box includes a membrane box upper cover, a membrane sheet and a membrane box lower cover from top to bottom, and the membrane box is fixed in the shell;

[0009] The shell is a hollow structure with an opening at the lower end, and the membrane box seals the opening, so that the shell and the membrane box upper cover together form an upper chamber, and the capsule skin, the membrane box lower cover and the lower end cover together form a lower chamber;

[0010] The upper cover of the membrane box is provided with an upper vent hole communicating with the upper chamber, and the lower cover of the membrane box is provided with a lower vent hole communicating with the lower chamber. The number of the upper vent hole is at least one, and the number of the lower vent hole is at least one;

[0011] The diaphragm is an elastic body. Under the action of the pressure difference formed between the upper chamber and the lower chamber, the diaphragm undergoes elastic deformation and moves up and down inside the diaphragm box.

[0012] Furthermore, the shell includes an upper end and an annular lower end; the outer surface of the upper end of the shell is a stepped shaft structure, the end with a smaller diameter is sleeved on the inside of the lower end of the shell, and the end with a larger diameter is overlapped on the upper end surface of the lower end of the shell.

[0013] Furthermore, the upper end of the shell and the lower end of the shell are fixedly connected by bolts; the upper end of the shell and the lower end of the shell are sealed by an O-ring.

[0014] Furthermore, a step is provided inside the lower end of the shell, and the outer surface of the lower cover of the membrane box is a step structure. The upper end surface of the step is used to abut the step surface of the lower cover of the membrane box; the upper end surface of the membrane box abuts the lower end surface of the upper end of the shell.

[0015] Furthermore, the lower end cover is provided with a lower air inlet hole for inputting gas into the lower chamber, and the lower end of the shell is provided with an upper air inlet hole for inputting gas into the upper chamber.

[0016] Furthermore, the diaphragm is installed between the upper cover and the lower cover of the diaphragm box by interference fit.

[0017] Furthermore, a circle of grooves is provided on the upper end surface of the membrane box lower cover, and a circle of protrusions is provided on the radial outer side of the diaphragm. The grooves are used to accommodate the protrusions, and the protrusions are interference-fitted between the grooves and the membrane box upper cover.

[0018] Furthermore, the material of the diaphragm is rubber.

[0019] Furthermore, the diaphragm is a corrugated diaphragm.

[0020] Furthermore, both axial end faces of the membrane box are sealed and fixedly connected to the housing.

[0021] The present invention can achieve the following technical effects:

[0022] The air spring of the present invention can not only better isolate high-frequency small-amplitude vibrations, reduce the conduction of chassis noise, and enhance the vehicle's suspension feel, but also provide good support for the vehicle and can control larger vibrations of the vehicle body under roll and pitch conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the air spring disclosed in the present invention;

[0024] Figure 2 It is a graph showing the change in stiffness of a common spring disclosed in the present invention as the action frequency changes;

[0025] Figure 3 is a graph showing the relationship between the stiffness of the air spring disclosed in the present invention and the vibration amplitude;

[0026] Figure 4The present invention discloses the density distribution of amplitude and frequency when a vehicle is actually traveling on a road;

[0027] Figure 5 is a graph showing how the stiffness of the air spring of the present invention changes with the change of the operating frequency;

[0028] Figure 6 1 is a schematic diagram of the top view of the air spring disclosed in the present invention;

[0029] Figure 7 It is a schematic diagram of the sealing structure of the upper end and the lower end of the shell disclosed in the present invention.

[0030] Reference numerals:

[0031] Shell upper end 1-1, shell lower end 1-2, upper air inlet 1-2-1, membrane box 2, membrane box upper cover 2-1, diaphragm 2-2, protrusion 2-2-1, membrane box lower cover 2-3, groove 2-3-1, bladder skin 3, lower end cover 4, lower air inlet 4-1, O-ring 5, dust cover 9-1, casing 9-2, dust cover gasket 9-4, first stainless steel single earring hoop 9-5, casing buckling ring 9-6, second stainless steel single earring hoop 9-7, limiting rubber 9-8, push ring 9-9, piston buckling ring 9-10, lower end cover buckling ring 9-13, piston 9-15. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0033] like Figure 1 The air spring shown comprises an air spring, comprising a housing, a membrane box 2 fixed in the housing, a bladder skin 3 and a lower end cover 4 arranged in sequence;

[0034] The two ends of the bladder skin 3 are respectively sealed and buckled on the outer wall of the lower end of the shell and the outer wall of the lower end cover 4;

[0035] The membrane box 2 includes a membrane box upper cover 2-1, a membrane sheet 2-2 and a membrane box lower cover 2-3 from top to bottom. The membrane sheet 2-2 is sealed in the membrane box 2.

[0036] The shell is a hollow structure with an opening at the lower end. The membrane box 2 seals the opening so that the shell and the membrane box upper cover 2-1 together form an upper chamber, and the bladder skin 4, the membrane box lower cover 2-2 and the lower end cover 3 together form a lower chamber; preferably, the two axial end faces of the membrane box 2 are sealed and fixedly connected to the shell.

[0037] The membrane box upper cover 2-1 is provided with an upper vent hole communicating with the upper chamber, and the membrane box lower cover 2-3 is provided with a lower vent hole communicating with the lower chamber. The number of upper vent holes and lower vent holes is at least one. The number of upper vent holes and lower vent holes varies with the size of the membrane box 2. Preferably, the diameter of each upper vent hole and lower vent hole is no greater than 1 mm. The membrane box upper cover 2-1 is provided with multiple circles of upper vent holes extending radially outward from its center, and each circle has multiple upper vent holes evenly distributed along the circumference of the membrane box upper cover 2-1. The membrane box lower cover 2-3 is provided with multiple circles of lower vent holes extending radially outward from its center, and each circle has multiple lower vent holes evenly distributed along the circumference of the membrane box lower cover 2-3. The upper and lower vent holes can also be randomly distributed on the end surface.

[0038] The diaphragm 2 - 2 is an elastic body. Under the action of the pressure difference formed between the upper chamber and the lower chamber, the diaphragm 2 - 2 undergoes elastic deformation and moves up and down inside the diaphragm box 2 .

[0039] When the air spring moves with high frequency and small amplitude, the gas in the upper and lower vent holes of the diaphragm upper cover 2-1 and the diaphragm lower cover 2-3 with a diameter of no more than 1mm flows quickly, and a pressure difference is generated between the upper and lower chambers of the diaphragm 2-2. The pressure difference drives the diaphragm 2-2 to move up and down with a small amplitude. Since the diaphragm 2-2 can move up and down with the pressure of the gas, the gas pressure difference between the upper and lower chambers is very small. At this time, the diaphragm is relatively soft, and the actual volume of gas that plays an elastic role is the sum of the upper and lower chambers. The spring stiffness is relatively small. The up and down vibration range of the diaphragm is affected by the diaphragm upper cover 2-1 and the lower cover 2-3. 1 and the diaphragm box lower cover 2-3, its maximum fluctuating volume is V1. When the suspension amplitude expands and the gas exchange volume between the upper and lower cavities caused by the vibration of the air spring is greater than V1, the diaphragm is subjected to the impact of the gas and then elastically deforms against the diaphragm box upper cover or the diaphragm box lower cover. At this time, the diaphragm 2-2 blocks the air vents of the diaphragm box upper cover or the diaphragm box lower cover, and the gas in the upper and lower cavities cannot flow quickly. The diaphragm becomes hard, and the gas in the upper cavity is actually isolated. The gas volume that actually plays an elastic role is the lower cavity, the volume is reduced, and the stiffness is increased.

[0040] In a preferred embodiment of the present invention, the housing comprises an upper housing end 1-1 and an annular lower housing end 1-2; the outer surface of the upper housing end 1-1 is a stepped shaft structure. The end with a smaller diameter is sleeved on the interior of the lower housing end 1-2, and the end with a larger diameter is overlapped on the upper end surface of the lower housing end 1-2. Figure 7 As shown, the two are sealed by an O-ring 5. Like this, the two are firmly sealed, and the housing is made into a split structure, which is easy to disassemble and replace the membrane box.

[0041] The upper end 1-1 of the shell and the lower end 1-2 of the shell are fixedly connected by bolts.

[0042] Preferably, a step is provided inside the lower end 1-2 of the housing, and the outer surface of the membrane box lower cover 2-3 is a stepped structure, with the upper end surface of the step being used to abut against the stepped surface of the membrane box lower cover 2-3; and the upper end surface of the membrane box 2 abuts against the lower end surface of the upper end 1-1 of the housing, thereby fixing the axial position of the membrane box.

[0043] In a preferred embodiment of the present invention, lower end cap 4 is provided with a lower air inlet 4-1 for supplying gas to the lower chamber, and lower end 1-2 of the housing is provided with an upper air inlet 1-2-1 for supplying gas to the upper chamber. Gas is simultaneously supplied to both the upper and lower chambers through these two air inlets, and the amount of air entering the upper and lower chambers is controlled by controlling the gas flow rate.

[0044] Preferably, the diaphragm 2-2 is installed between the diaphragm box upper cover 2-1 and the diaphragm box lower cover 2-3 by interference fit.

[0045] Preferably, a circle of grooves 2-3-1 is provided on the upper end surface of the membrane box lower cover 2-3, and a circle of protrusions 2-2-1 is provided on the radial outside of the diaphragm 2-2. The grooves 2-3-1 are used to accommodate the protrusions 2-2-1, and the protrusions 2-2-1 are interference-fitted between the grooves 2-3-1 and the membrane box upper cover 2-1 to achieve sealing between the membrane box upper cover 2-1 and the membrane box lower cover 2-3.

[0046] Preferably, the material of the diaphragm 2-2 is rubber, which has a certain elastic deformation.

[0047] Preferably, the diaphragm 2-2 is a corrugated diaphragm. This ensures that the diaphragm does not undergo rigid deformation even under high air pressure. The membrane box upper cover 2-1 and the membrane box lower cover 2-3 are made of plastic or metal. When air flows through the housing, the diaphragm 2-2 is subjected to a certain amount of air pressure, causing it to elastically deform and move up and down within the membrane box 2.

[0048] Preferably, the height of the diaphragm 2-2 from the diaphragm box upper cover 2-1 and the diaphragm box lower cover 2-3 is equal and needs to be designed within the elastic deformation range of the diaphragm 2-2.

[0049] The spring stiffness of ordinary air springs increases with the increase of the action frequency, such as Figure 2 As shown; the stiffness of the air spring of the present invention changes with the change of vibration amplitude, as shown Figure 3 As shown; in fact, when a vehicle is driving on the road, the amplitude and frequency conform to the road power spectrum density distribution, and the amplitude is inversely proportional to the frequency, that is, as the amplitude increases, the frequency of vibration decreases, as shown Figure 4 As shown; the air spring stiffness of the relevant structure of the present invention is actually installed at a frequency point, that is, under vibrations below this frequency, the air spring shows a higher stiffness K1 to the outside, and under vibrations above this frequency, the air spring shows a lower stiffness K2 to the outside, as shown Figure 5 shown.

[0050] The two ends of the bladder skin 3 are respectively sealed and buckled on the outer wall of the shell and the lower end cover 4, and the shell structure of the air spring in the art can be referred to. Figure 1 The air spring shown includes a dust cover 9-1, a protective tube 9-2, a dust cover gasket 9-4, a first stainless steel single-eared hoop 9-5, a protective tube pressing ring 9-6, a second stainless steel single-eared hoop 9-7, a limiting rubber 9-8, a push ring 9-9, a piston pressing ring 9-10, a lower end cover pressing ring 9-13 and a piston 9-15, wherein the shell 1, the bladder skin 3 and the lower end cover 4 form a sealed chamber, and the membrane box 2 divides the chamber into two upper and lower chambers. The outer wall of the lower end of the shell lower end 1-2 and the bladder skin 3 are sealed by a piston pressing ring 9-10, and the lower end cover 4 and the bladder skin 3 are sealed by a lower end cover pressing ring 9-13; wherein, the piston 9-15 is fixedly sleeved on the outer periphery of the shell; the casing 9-2 is sleeved on the outer periphery of the bladder skin 3, covering the outer wall of the bladder skin 3, protecting the bladder skin 3, and also limiting the expanded outer diameter of the bladder skin 3 to prevent the bladder skin 3 from expanding too much and causing damage. The casing 9-2 and the bladder skin 3 are fixed by a casing pressing ring 9-6; the dust cover 9-1 is sleeved on the outer periphery of the upper end of the casing 9-2, and the upper end of the dust cover 9-1 and the upper end of the shell lower end 1-2 are fixed by a snap connection. The dust cover gasket sleeve 9-4 is sleeved on the casing 9-2, and preferably corresponds to the pressing position of the bladder skin 3. The lower end of the preferred dust cover 9-1 is fixed to the dust cover gasket sleeve 9-4 via a first stainless steel single-ear hoop 9-5. A limiting rubber sleeve is provided on the outer periphery of the lower end cover. One end of the limiting rubber 9-8 is fixed to the lower end cover 4 by a snap connection. The other end of the limiting rubber 9-8 is fixed to the outer periphery of the lower end of the casing 9-2 via a second stainless steel single-ear hoop 9-7. The lower end of the casing 9-2 is provided with a radial protrusion to better fix the limiting rubber 9-8. The limiting rubber 9-8 protects the exposed portion of the bladder skin 3, playing a role in dustproofing and waterproofing. The push ring 9-9 is used to prevent relative movement between the bladder skin 3 and the outer wall of the lower end cover buckling ring; it abuts the lower end cover 4, and the surface in contact with the bladder skin 3 is a curved surface. The push ring 9-9 is sleeved on the outer circumference of the buckling ring of the lower end cover, and the bottom surface of the push ring 9-9 abuts the lower end cover 4; the longitudinal section of the push ring 9-9 is approximately a smooth right triangle. The function of the push ring 9-9 is to prevent the airbag formed by the bag skin from being damaged by friction or extrusion with the buckling ring of the lower end cover due to the up and down movement during operation. The surface of the push ring 9-9 in contact with the airbag is arc-shaped or straight-line-shaped, and has a certain inclination angle, which can alleviate the swinging force on the airbag, etc., and can make the airbag move accordingly on the inclined plane according to the direction of the force.

[0051] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0052] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0053] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. Air spring, characterized in that, It comprises a shell, a membrane box (2), a bladder skin (3) and a lower end cover (4) arranged in sequence; The two ends of the bladder skin (3) are respectively sealed and pressed against the outer walls of the shell and the lower end cover (4); The membrane box (2) comprises, from top to bottom, a membrane box upper cover (2-1), a membrane sheet (2-2) and a membrane box lower cover (2-3), and the membrane box (2) is fixed in the housing; The shell is a hollow structure with an opening at the lower end, and the membrane box (2) seals the opening, so that the shell and the membrane box upper cover (2-1) together form an upper chamber, and the capsule skin (3), the membrane box lower cover (2-3) and the lower end cover (4) together form a lower chamber; The membrane box upper cover (2-1) is provided with an upper vent hole communicating with the upper chamber, and the membrane box lower cover (2-3) is provided with a lower vent hole communicating with the lower chamber, the number of the upper vent hole is at least one, and the number of the lower vent hole is at least one; The diaphragm (2-2) is an elastic body. Under the action of the pressure difference formed between the upper chamber and the lower chamber, the diaphragm (2-2) undergoes elastic deformation and moves up and down inside the diaphragm box (2); The shell comprises a shell upper end (1-1) and an annular shell lower end (1-2); the outer surface of the shell upper end (1-1) is a stepped shaft structure, the end with a smaller diameter is sleeved on the interior of the shell lower end (1-2), and the end with a larger diameter is overlapped on the upper end surface of the shell lower end (1-2); The upper end (1-1) of the housing and the lower end (1-2) of the housing are fixedly connected by bolts; the upper end (1-1) of the housing and the lower end (1-2) of the housing are sealed by an O-ring (5); The interior of the lower end (1-2) of the shell is provided with a step, the outer surface of the membrane box lower cover (2-3) is a step structure, and the upper end surface of the step is used to abut the step surface of the membrane box lower cover (2-3); the upper end surface of the membrane box (2) abuts the lower end surface of the upper end (1-1) of the shell; The lower end cover (4) is provided with a lower air inlet (4-1) for inputting gas into the lower chamber, and the lower end (1-2) of the shell is provided with an upper air inlet (1-2-1) for inputting gas into the upper chamber; The maximum fluctuating volume of the diaphragm (2-2) is V1. When the gas exchange volume between the upper and lower cavities caused by the vibration of the air spring is greater than V1, the diaphragm (2-2) undergoes elastic deformation and presses against the diaphragm box upper cover (2-1) or the diaphragm box lower cover (2-3), and the diaphragm (2-2) blocks the vent hole of the diaphragm box upper cover (2-1) or the diaphragm box lower cover (2-3).

2. The air spring according to claim 1, wherein: The diaphragm (2-2) is installed between the diaphragm box upper cover (2-1) and the diaphragm box lower cover (2-3) by interference fit.

3. The air spring according to claim 1, wherein: The upper end surface of the membrane box lower cover (2-3) is provided with a circle of grooves (2-3-1), and the radial outer portion of the membrane (2-2) is provided with a circle of protrusions (2-2-1). The grooves (2-3-1) are used to accommodate the protrusions (2-2-1), and the protrusions (2-2-1) are interference-fitted between the grooves (2-3-1) and the membrane box upper cover (2-1).

4. The air spring according to claim 1, wherein: The material of the diaphragm (2-2) is rubber.

5. The air spring according to claim 1, wherein: The diaphragm (2-2) is a corrugated diaphragm.

6. The air spring according to claim 1, wherein: Both axial end faces of the membrane box (2) are sealed and fixedly connected to the housing.

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