Patent Description:
A conical spring, also called journal box spring, mainly refers to a spring with a shock absorption effect formed by combining metal with rubber on a locomotive. The conical spring is installed between a journal box and a frame of a rail locomotive to achieve the effects of support, shock absorption and noise reduction, is a frequently-used shock-absorption and noise-reduction element formed by combining rubber with metal, is installed on a locomotive body of single-stage suspension and two-stage suspension of the locomotive, and is mainly used for bearing the load of the locomotive body and the frame. Formed by vulcanizing a conical metal piece and rubber into a whole through an adhesive at certain temperature and pressure, the conical spring achieves the effects of shock absorption and noise reduction using the vulcanized rubber, and achieves the effects of support and installation interface using the metal piece.

With the development of technique of locomotives, especially the development of technique of high-speed railway motor train units, urban rail trains, metro vehicles and low-floor vehicles, for the conical spring, in order to preferably meet and guarantee the dynamics requirements and safety of locomotives, it is required that the conical spring should have changeable stiffness in vertical stiffness, and the phenomenon of an inverse S curve should not occur to the vertical stiffness. The fact that the inverse S curve occurs to the vertical stiffness is because that a rubber body of the existing conical spring structure has no strong mutual extrusion and has no extrusion of contact between an externally protruded lug boss and rubber, the vertical changeable stiffness of the conical spring is too small under no load, when the locomotive is under load, especially under the maximum vertical load, when it is required that the rubber part of the conical spring should provide sufficiently large vertical stiffness, but the existing conical spring cannot provide large changeable stiffness, so that ideal changeable stiffness cannot be achieved, and thus the stiffness curve presents inverse "S". The conical spring having an inverse "S" curve has large stiffness under no load, so that the risk of derail of the locomotive may be caused. In addition, when the locomotive accelerates, decelerates or makes a turn, it is required that the conical spring has appropriate transverse changeable stiffness and longitudinal changeable stiffness, so that the locomotive more meets dynamics requirements, thereby having good effects of transverse and longitudinal shock absorption and noise reduction. Therefore, by appropriately increasing the number of transverse changeable stiffness and longitudinal changeable stiffness of the locomotive to achieve multiple changes of stiffness, the locomotive may be made to run more steady and smooth. Because the conical spring is a whole formed by vulcanizing metal and rubber, which cannot be disassembled and cannot be conveniently repaired locally, the conical spring is a lifelong maintenance-free product. With the development of technique of locomotives, the fatigue load thereof becomes harsh more and more, and the requirement for fatigue performance becomes strict more and more. For the structure of the current conical spring, while in use, because profiles of rubber of the existing structure are single-structure profiles, "fold" deformation is easy to occur to upper and lower rubber profiles when the product under vertical load, thereby forming stress concentration, and because the vertical load of the product is completely undertaken by rubber, both stress and strain are large, thereby causing rubber to crack due to rubber fatigue finally. Thus, a conical spring capable of adjusting changeable stiffness and capable of preventing folds from occurring while in use is required to meet the above-mentioned requirements.

It is found that the following patent has the similarities to the invention through domestic retrieval:
According to the invention with the application No. "<NUM>" and the title "journal box for bogie of urban rail train", the invention relates to a journal box spring for a bogie of an urban rail train. An outer ring of a spindle is provided with a spacer sleeve I, a spacer sleeve II and an outer sleeve in sequence from inside to outside. The spindle, the spacer sleeve I, the spacer sleeve II and the outer sleeve are all made of metal materials, and a rubber layer III, a rubber layer II and a rubber layer I are respectively arranged between two adjacent metal materials. The exposed metal surface of each of the spindle, the spacer sleeve I, the spacer sleeve II and the outer sleeve is coated with base paint and surface paint. The invention has the advantage that a journal box spring for a bogie of an urban rail train which has small vertical, transverse and longitudinal static stiffness when train wheels move and can improve the flexibility and quality when the train runs.

Because the invention with the application No. "<NUM>" has no structure capable of substantially increasing the vertical stiffness of the rubber part of the journal box spring under the maximum vertical load, stiffness is mainly increased by metal components under large vertical load, which may affect the shock absorption effect of the journal box spring.

According to the utility model with the application No. "<NUM>" and the title "journal box for bogie of overloaded railway wagon", the utility model discloses a journal box spring for a bogie of an overloaded railway wagon. The object of the utility model is to provide a journal box spring for a bogie of an overloaded railway wagon, to overcome the defects of over large radial stiffness, heavy weight and the like of the existing journal box spring. The utility model comprises an outer sleeve, an inner sleeve, an inner core, a first rubber layer and a second rubber layer, and is characterized in that the first rubber layer and the second rubber layer are vulcanized into a whole together with the outer sleeve, the inner sleeve and the inner core, the outer sleeve is connected to the inner core through a copper conducting wire built in the surface of the first rubber layer and the second rubber layer, and the included angle between the side extension of the first rubber layer and the second rubber layer and the top of the plane journal box spring is <NUM>-<NUM>°. The utility model mainly relates to a journal box spring used on a bogie of an overloaded railway wagon. However, the patent for utility models does not make the journal box spring implement multiple changeable stiffness structure, so that it is difficult to meet multiple changes of stiffness required by a locomotive in different states.

<CIT> discloses a conical spring according to the preamble of claim <NUM> and a method of changing stiffness and preventing folding and cracking of a conical spring according to the preamble of claim <NUM>. <CIT> discloses a further conical spring assembly.

Therefore, so far, there has not been a method and device capable of effectively preventing a rubber body from folding and cracking while preventing a conical spring from changing stiffness and meeting multiple changes of stiffness required by a locomotive in different states, so that there is a need to further improve in this aspect.

The technical problems to be solved by the invention are:.

In view of the above problems, the invention proposes a technical solution with the features of claim1 and claim <NUM>. A method for changing stiffness and preventing folds and cracks of a conical spring is provided. The conical spring comprises an inner conical body, a rubber body and an outer conical body. The rubber body encircles the periphery of the inner conical body. The outer conical body encircles the periphery of the rubber body. The rubber body, the inner conical body and the outer conical body form a conical rubber metal spring together. The method of the invention has the characteristic that an upper rubber profile of the rubber body and a lower rubber profile of the rubber body of the conical spring adopt a multi-segment structural form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure, and the lower rubber profile of the rubber body is of a multi-section upslope structure; for the conical spring, the extent of stiffness change and the position of stiffness change of the conical spring are adjusted by adjusting the shape, slope and length of each section in the multi-section downslope structure of the upper rubber profile of the rubber body and the multi-section upslope structure of the lower rubber profile of the rubber body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.

Further, in the multi-section downslope structure of the upper rubber profile of the rubber body, the shape of each section is a straight line or arc shape, and every two sections are connected through arc section transition, to guarantee that in the process of downwards moving the upper end of the rubber body, the shape of the upper end of the rubber body is always kept as a smooth shape, so that no fold and crack may be generated.

Further, in the multi-section upslope structure of the lower rubber profile of the rubber body, the shape of each section is a straight line or arc shape, every two sections are connected through arc section transition, to guarantee that in the process of downwards moving the rubber body, the shape of the lower end surface of the rubber body is always kept as a smooth shape, so that no fold and crack may be generated.

Further, a lug boss is externally protruded from the bottom of the inner conical body, and after the rubber body downwards moves to the lower end surface of the rubber body and comes into contact with the lug boss, substantial changeable stiffness is generated by the cooperation of double restriction of the lug boss externally protruded from the bottom of the inner conical body and the inner side of the outer conical body; under the action of vertical load, the lower end surface of the rubber body is simultaneously closely fitted with the inner side of the outer conical body and the externally protruded lug boss of the lower part of the inner conical body gradually in a rolling mode, to achieve substantial changeable stiffness.

According to the invention, the upper surface of the lug boss is of a multi-section structure, every two sections adopt an arc section for transition, the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss and the opening angle of the inner side of the outer conical body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.

A conical spring for carrying out the above method for changing stiffness and preventing folding and cracking of the conical spring, which comprises an inner conical body, a rubber body and an outer conical body. The rubber body encircles the periphery of the inner conical body. The outer conical body encircles the periphery of the rubber body. The rubber body, the inner conical body and the outer conical body form a conical rubber metal spring together; the
method of the invention has the characteristic that an upper rubber profile of the rubber body of the conical spring and a lower rubber profile of the rubber body adopt a multi-section structure form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure form, and the lower rubber profile of the rubber body is of a multi-section upslope structure.

Further, in the multi-section downslope structure of the upper rubber profile of the rubber body, the shape of each section is a straight line or arc shape, every two sections adopt an arc section for transition, to guarantee that in the process of downwards moving the upper end of the rubber body, the shape of the upper end of the rubber body is always kept as a smooth shape, so that no fold and crack may be generated.

Further, in the multi-section upslope structure of the lower rubber profile of the rubber body, the shape of each section is a straight line or arc shape, every two sections adopt an arc section for transition, to guarantee that in the process of downwards moving the rubber body, the shape of the lower end surface of the rubber body is always kept as a smooth shape, so that no fold and crack may be generated.

Further, a lug boss is externally protruded from the bottom of the inner conical body, after the rubber body downwards moves to the lower end surface of the rubber body and comes into contact with the lug boss, substantial changeable stiffness is generated by the cooperation of double restriction of the lug boss externally protruded from the bottom of the inner conical body and the inner side of the outer conical body; under the action of vertical load, the lower end surface of the rubber body is simultaneously closely fitted with the inner side of the outer conical body and the externally protruded lug boss of the lower part of the inner conical body gradually in a rolling mode, to achieve substantial changeable stiffness.

According to the invention, the upper surface of the lug boss is of a multi-section structure, every two sections adopt an arc section for transition, and the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss and the opening angle of the inner side of the outer conical body; and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.

The invention has the following advantages:.

Legends: <NUM>. inner conical body; <NUM>. inner conical body lug boss; <NUM>. lug boss transition edge; <NUM>. rubber body; <NUM>. annular straight section; <NUM>. first annular straight section; <NUM>. second annular straight section; <NUM>. third annular straight section; <NUM>. fourth annular straight section; <NUM>. fifth annular straight section; <NUM>. annular fillet section; <NUM>. outer conical body.

The invention will be further described as below with reference to embodiments and the drawings.

As shown in <FIG>, a conical spring, comprising an inner conical body <NUM>, a rubber body <NUM> and an outer conical body <NUM>, wherein the lower end of the inner conical body <NUM> extends to the outer side to form an annular inner conical body lug boss <NUM>. As shown in <FIG>, the upper end surface of the rubber body <NUM> is of a multi-section downslope structure of three sections which are a first annular straight section <NUM>, a second annular straight section <NUM> and a third annular straight section <NUM> respectively, and every two annular straight sections adopt the annular fillet section <NUM> for transition. The so-called multi-section downslope structure is a gradually descending trend of the rubber body <NUM> from the joint with the outer conical body <NUM> to the inner conical body <NUM> of the rubber body <NUM>. As shown in <FIG>, the lower end surface of the rubber body <NUM> is of a multi-section upslope structure of two sections which are a fourth annular straight section <NUM> and a fifth annular straight section <NUM> respectively, and the fourth annular straight section <NUM> and the fifth annular straight section <NUM> also adopt the annular fillet section <NUM> for transition. The so-called multi-section upslope structure is a gradually ascending trend of the rubber body <NUM> from the joint with the inner conical body <NUM> to the outer conical body <NUM> of the rubber body <NUM>. In this embodiment, the fillet radius of the annular fillet section <NUM> of the lower end surface of the rubber body <NUM> is <NUM>-<NUM>, and fillet radii of the two annular fillet sections <NUM> of the upper end of the rubber body <NUM> are both <NUM>-<NUM>. The rubber body <NUM> encircles the periphery of the inner conical body <NUM>, and the outer conical body <NUM> encircles the periphery of the rubber body <NUM>. The inner conical body <NUM> and the outer conical body <NUM> are metal components, the inner conical body <NUM> and the outer conical body <NUM>, and the rubber body <NUM> are vulcanized into a whole through an adhesive at certain temperature and pressure. The effects thereof are: the rubber body achieves the effects of shock absorption and noise reduction, and the inner conical body <NUM> and the outer conical body <NUM> achieve the effects of support and installation interface.

As shown at E and F in <FIG>, in the current conical spring, both the upper end and the lower end of the rubber body <NUM> adopt a shape of combining a straight section with an arc section. In such structure, when the rubber body <NUM> bears the maximum vertical load, corresponding folds at E and F in <FIG> may occur to the upper end surface and the lower end surface of the rubber body <NUM>, which will cause cracks of the rubber body <NUM> over time; because the conical spring is a whole formed by vulcanizing metal and rubber, which cannot be disassembled and cannot be conveniently repaired locally, the conical spring is a lifelong maintenance-free product, so that the conical spring is replaced if the rubber body <NUM> cracks.

To prevent the upper end of the rubber body <NUM> from folding, the structure used in this embodiment is as shown in <FIG>. The upper end of the rubber body <NUM> is formed into a whole by the first annular straight section <NUM>, the second annular straight section <NUM>, the third annular straight section <NUM> and two annular fillet sections <NUM>. The first annular straight section <NUM> and the second annular straight section <NUM> adopt the annular fillet sections <NUM> for transition, and the second annular straight section <NUM> and the third annular straight section <NUM> also adopt the annular fillet sections <NUM> for transition. In the process of downwards moving the rubber body <NUM> when being subjected to vertical load, because the outer side of the rubber body <NUM> is connected to the inner side of the outer conical body <NUM>, the movement of the upper end and outer side of the rubber body <NUM> may be restricted by the outer conical body <NUM>. Thus, in the process of downwards moving the rubber body <NUM> when being subjected to vertical load, the change of the shape of the upper end of the rubber body <NUM> may be affected by multiple factors such as the slope and length of each annular straight section <NUM>, inside slope of the outer conical body <NUM> and the like.

For example, any one of the first annular straight section <NUM> and the second annular straight section is inwards tilted rather than outwards tilted as in <FIG>. Alternatively, if the length of any one of the first annular straight section <NUM>, the second annular straight section <NUM> and the third annular straight section <NUM> is too large, the shape of the upper end of the rubber body <NUM> may present a fold similar to that at E in <FIG> in the process of downwards moving the rubber body <NUM>. As shown in the following Table, the Table shows the included angle between each annular straight section of the rubber body <NUM> in this embodiment and the vertical direction and the length of each annular straight section.

As shown in <FIG>, when the conical spring is subjected to the downward pressure of the vertical load, the rubber body <NUM> downwards moves, and the shape of the upper end of the rubber body <NUM> may change. Because the slope and length of each of the first annular straight section <NUM>, the second annular straight section <NUM> and the third annular straight section <NUM> and the fillet radius of the annular fillet section <NUM> are designed reasonably, in the process in downwards moving the rubber body <NUM>, the shape of the upper end of the rubber body <NUM> may be always kept as a smooth shape. The upper end of the rubber body <NUM> may be prevented from folding, so that the upper end of the rubber body may be prevented from cracking. When the conical spring is subjected to the downward pressure of the maximum vertical load, the shape of the upper end of the rubber body <NUM> may present a smooth shape as shown at C in <FIG>.

As shown in <FIG> and <FIG>, the lower end of the inner conical body <NUM> extends to the outer side to form an annular inner conical body lug boss <NUM>, the lower end of the rubber body <NUM> is located above the inner conical body lug boss <NUM>, a fourth annular straight section <NUM> and a fifth annular straight section <NUM> are provided at the lower end of the rubber body <NUM>, and the fourth annular straight section <NUM> and the fifth annular straight section <NUM> adopt the annular fillet section <NUM> for transition. When the conical spring is subjected to the downward pressure of the vertical load, the lower end of the rubber body <NUM> downwards moves and changes in shape, but the change in shape of the lower end of the rubber body <NUM> is restricted by both the inner side of the outer conical body <NUM> and the inner conical body lug boss <NUM>. Therefore, the lower end of the rubber body <NUM> may be fitted with the inner conical body lug boss <NUM> and the inner side of the outer conical body <NUM>, the inner conical body lug boss <NUM> and the lug boss transition edge <NUM> adopt a gentle straight line edge for transition, so that a smooth shape may be formed when the lower end of the rubber body <NUM> is fitted with the inner conical body lug boss <NUM> and the inner side of the outer conical body <NUM>. The lower end of the rubber body <NUM> may be prevented from folding, so that the lower end of the rubber body <NUM> may be prevented from cracking. When the conical spring is subjected to the downward pressure of the maximum vertical load, the shape of the lower end of the rubber body <NUM> may present a smooth shape as shown at D in <FIG>, also see that shown in <FIG>.

As shown in <FIG>, because the first annular straight section <NUM> and the second annular straight section <NUM> of the rubber body <NUM> adopt the annular fillet section <NUM> for transition, and the second annular straight section <NUM> and the third annular straight section <NUM> also adopt the annular fillet section <NUM> for transition, when the conical spring is subjected to the downward pressure of the vertical load to make the upper end of the rubber body <NUM> downwards move, the shape of the upper end surface <NUM> of the rubber body <NUM> is always changed from the annular fillet section <NUM>, thus, the positions of vertical changeable stiffness, transverse changeable stiffness and longitudinal changeable stiffness of the conical spring may be adjusted by changing the length of the annular straight section <NUM>; the number of times of changing vertical stiffness, transverse stiffness and longitudinal stiffness may be increased by increasing the number of the annular straight sections <NUM>; and the vertical changeable stiffness, transverse changeable stiffness and longitudinal changeable stiffness of the conical spring may be adjusted by changing the slope of the annular straight section <NUM>.

Because the requirements of the locomotive for the stiffness of the conical spring are different in different conditions, when the locomotive is under no load, it is required that the conical spring should not have too large stiffness but should have good elasticity, so that good elasticity refers that a good effect of shock absorption may be achieved since the stiffness of conical spring may be not suddenly increased even if the pressure of the load of the locomotive on the conical spring is suddenly increased. However, after the locomotive is under load, especially under the maximum load, it is required that the conical spring should have large stiffness and should have good elasticity, which requires that the conical spring should have good changeable stiffness to meet the stiffness requirements of the locomotive in various cases.

As shown in <FIG>, because of having no structures of annular straight sections and annular fillet sections <NUM>, the conical spring at present cannot achieve multiple changes of stiffness. The vertical stiffness curves of the conical spring at present are as shown in <FIG>, and there are two vertical stiffness curves in the Figure, wherein the curve located on the upper part is a vertical stiffness curve when the locomotive is loaded, and the curve located on the lower part is a vertical stiffness curve when the locomotive is unloaded. At present, under no load, according to different models of locomotives, each conical spring is subjected to a vertical load of about 14KN-18KN, it can be seen from <FIG> that 14KN-18KN is at the inverse S curve of the vertical stiffness of the conical spring. The inverse S curve has the characteristic that the distance of downward movement of the rubber body <NUM> is not large, but the stiffness thereof is increased quickly, and such stiffness increase mode is not beneficial to the shock absorption of the locomotive, which may cause the risk of derail of the locomotive.

As shown in <FIG> and <FIG>, in this embodiment, three annular straight sections <NUM> and two annular fillet sections <NUM> of the upper end of rubber body <NUM> enable the conical spring to achieve two vertical, transverse and longitudinal stiffness changes. The vertical stiffness curves of the conical spring in this embodiment are as shown in <FIG>, and there are two vertical stiffness curves in the Figure, wherein the curve located on the upper part is a vertical stiffness curve when the locomotive is loaded, and the curve located on the lower part is a vertical stiffness curve when the locomotive is unloaded. Because of the structure of two vertical stiffness changes in this embodiment, when the conical spring is subjected to the downward pressure of the vertical load suddenly increased, the distance of downward movement of the rubber body <NUM> is also large, thereby achieving good effects of buffering and shock absorption. It can be seen from <FIG> that the inverse S curve of the vertical stiffness of the conical spring is already eliminated in this embodiment. Similarly, when the locomotive accelerates, decelerates or makes a turn, because of the structure of the three annular straight sections <NUM> and two annular fillet sections <NUM> of the upper end of the rubber body <NUM>, the conical spring has two stiffness changes in the transverse direction and the longitudinal direction, and achieves good effects of buffering and shock absorption in the transverse direction and the longitudinal direction. Thus, the locomotive is more steady and smooth while the locomotive accelerates, decelerates or makes a turn, thereby increasing the comfortableness of passengers in the locomotive.

As shown in <FIG>, <FIG>, when the conical spring bears the maximum vertical load, the change in shape when the lower end of the rubber body <NUM> downwards moves may be restricted by the inner side of the outer conical body <NUM> and the inner conical body lug boss <NUM>, so that the lower end of the rubber body <NUM> enables the stiffness of the conical spring to be substantially increased. When the conical spring bears the maximum vertical load, the change in shape of the upper end of the rubber body <NUM> may also be restricted by the inner side of the outer conical body <NUM> and the shape of the lower end of the rubber body <NUM>, so that the upper end of the rubber body <NUM> may bear the maximum vertical load, and a smooth shape is formed under the maximum vertical load. Just because the conical spring still can bear the load using the rubber body <NUM> under the maximum vertical load, the conical spring still can have good effects of buffering, shock absorption and noise reduction under the maximum vertical load.

It can be seen in this embodiment that for the five annular straight sections <NUM> and three annular fillet sections <NUM> of the upper end surface of the rubber body <NUM> of the conical spring and the lower end surface of the rubber body <NUM>, three stiffness changes are formed. Moreover, the changeable stiffness of the conical spring may be changed by changing the length or slope of any one of the five annular straight sections <NUM> during manufacture, that is to say, the changeable stiffness of the conical spring may be changed by adjusting the length or slope of the annular straight section. When the vertical load is not large, for the conical spring, because of the above-mentioned three stiffness changes, the conical spring may have good effects of buffering and shock absorption; when the vertical load is large and even reaches the maximum vertical load, as shown in <FIG>, both the upper end of the rubber body <NUM> of the conical spring and the lower end of the rubber body <NUM> are in a smooth shape without stiffness change. Therefore, it can be seen from <FIG> that the stiffness change thereof is not as gentle as that under small load. However, because under the maximum vertical load, the conical spring can still bear load using the rubber body <NUM>, the conical spring can still have good effects of buffering, shock absorption and noise reduction at this moment. The design of the five annular straight sections <NUM> and three annular fillet sections <NUM> in this embodiment enables the shapes of both the upper end and the lower end of the rubber body <NUM> to have no fold in the process that the conical spring bears no load to bears the maximum vertical load, thereby preventing the rubber body <NUM> from cracking.

As approximately the same as the structure in embodiment <NUM>, the upper end surface of the upper rubber body <NUM> and the lower end surface of the rubber body <NUM>, and the lug boss transition edge <NUM> adopt gentle curve edge for transition rather than non-gentle straight line edge for transition. The upper end of the rubber body <NUM> is divided into four annular straight sections <NUM> and three annular fillet sections <NUM>, while the lower end of the rubber body <NUM> is divided into three annular straight sections <NUM> and two annular fillet sections <NUM>. In this way, the number of times of stiffness changes of the conical spring may be changed by changing the number of annular straight sections <NUM>, that is to say, the number of times of stiffness changes of the conical spring may be changed by adjusting the number of annular straight sections <NUM>. Increasing or reducing the number of annular straight sections <NUM> still enables the shapes of both the upper end and the lower end of the rubber body <NUM> to have no fold in the process that the conical spring bears no load to bears the maximum vertical load and to be kept as smooth shapes always.

It can be seen through the above-mentioned embodiment that the invention relates to a method for changing stiffness and preventing folds and cracks of a conical spring. The conical spring comprises an inner conical body, a rubber body and an outer conical body. The rubber body encircles the periphery of the inner conical body. The outer conical body encircles the periphery of the rubber body. The rubber body, the inner conical body and the outer conical body form a conical rubber metal spring together. The method of the invention has the characteristic that an upper rubber profile of the rubber body and a lower rubber profile of the rubber body of the conical spring adopt a multi-segment structural form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure, and the lower rubber profile of the rubber body is of a multi-section upslope structure; for the conical spring, the extent of stiffness change and the position of stiffness change of the conical spring are adjusted by adjusting the shape, slope and length of each section in the multi-section downslope structure of the upper rubber profile of the rubber body and the multi-section upslope structure of the lower rubber profile of the rubber body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.

Further, in the multi-section downslope structure of the upper rubber profile of the rubber body, the shape of each section is a straight line or arc shape, every two sections are connected through an arc section transition, to guarantee that in the process of downwards moving the upper end of the rubber body, the shape of the upper end of the rubber body is always kept as a smooth shape, so that no fold and crack may be generated.

Further, the upper surface of the lug boss is of a multi-section structure, every two sections adopt an arc section for transition, the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss and the opening angle of the inner side of the outer conical body, and the adjustment multiple of stiffness changes is achieved by controlling the number of multiple sections.

Claim 1:
A method for changing stiffness and preventing folding and cracking of a conical spring,
wherein the conical spring comprises an inner conical body (<NUM>), a rubber body (<NUM>) and an outer conical body (<NUM>), wherein the rubber body (<NUM>) encircles the periphery of the inner conical body (<NUM>), the outer conical body (<NUM>) encircles the periphery of the rubber body (<NUM>), the rubber body (<NUM>), the inner conical body (<NUM>) and the outer conical body (<NUM>) form a conical rubber metal spring together,
wherein an upper rubber profile of the rubber body and a lower rubber profile of the rubber body (<NUM>) of the conical spring adopt a multi-segment structural form, wherein the upper rubber profile of the rubber body is of a multi-section downslope structure, and the lower rubber profile of the rubber body (<NUM>) is of a multi-section upslope structure; for the conical spring, the extent of stiffness change and the position of stiffness change of the conical spring are adjusted by adjusting the shape, slope and length of each section in the multi-section downslope structure of the upper rubber profile of the rubber body (<NUM>) and the multi-section upslope structure of the lower rubber profile of the rubber body, and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections,
wherein the inner conical body (<NUM>) extends to the outer side to form an annular inner conical body lug boss (<NUM>) such that when rubber body (<NUM>) moves downwards under large vertical load, at this moment the lower end of the rubber body (<NUM>) is fitted with the inner conical body lug boss (<NUM>),
the method being characterized in that the upper surface of the lug boss (<NUM>) is of a multi-section structure, every two sections adopt an arc section for transition, the extent of stiffness change and the position of stiffness change are adjusted by adjusting the shape, slope and length of each section of the lug boss (<NUM>) and the opening angle of the inner side of the outer conical body (<NUM>), and the adjustment of multiple stiffness changes is achieved by controlling the number of multiple sections.