Multi-layer composite suspension for a vehicle

Abstract

Multi-layer composite suspension (100) for a vehicle, the suspension comprising: a first mounting unit (200) attached to a rubber spring (10); a second mounting unit (300) attached to a center bolt receptacle (20); and a plurality of composite springs (100) coupled to the first mounting unit (200) and the second mounting unit (300) at opposite ends and spaced perpendicularly apart from each other, the composite springs (100) comprising an upper spring (110) and a lower spring (120), the first mounting unit (200) comprising: a first upper mount (210) coupled to a first end section of the upper spring (110);and a first lower bracket (220) connected to a lower section of the first upper bracket (210) so that it is coupled to a first end section of the lower spring (120), and the second bracket unit (300) comprising: a second upper bracket (310) coupled to a second end section of the upper spring (110); and a second lower bracket (320) coupled to a second end section of the lower spring (120).

Description

BACKGROUND (a) Technical field The present disclosure relates generally to a multi-layer suspension made of composite material for a vehicle, in particular the multi-layer suspension which can bring about an elastic compensation between a vehicle body and an axle by means of springs made of composite material. (b) Description of the related technique In commercial vehicles, a leaf spring generally connects two axle shafts to create an elastic compensation between a center bolt receptacle and the axle shafts. When a conventional suspension structure with a metal leaf spring is used, a "windup" phenomenon occurs, in which opposing leaf springs mounted in the center bolt receptacle rotate in opposite directions when the vehicle comes to a sudden stop. When a "windup" phenomenon occurs, the vehicle body is violently tilted forward, or the load is concentrated on the spring and vehicle body, leading to breakage. Since then, a technique has been developed in which the conventional metal leaf spring has been replaced by a composite spring with resin-impregnated reinforcing fibers. The composite spring is lightweight, contributing to vehicle weight reduction, and superior in tensile strength and elasticity, thus enabling it to replace the conventional leaf spring. However, due to the material properties of the composite spring, it is difficult to apply the screwing method, and it is difficult to use the screwed multi-layer structure like that of the leaf spring, as the composite spring is easily damaged by friction. Therefore, a composite spring is used to replace a multi-layer leaf spring, and if the composite spring is damaged, it is impossible to continue driving the vehicle. Consequently, a suspension structure is required that uses a multi-layer composite spring which can support the vehicle body through another composite spring even if one composite spring is broken, thus preventing breakage due to bolting or friction. For the state of the art, reference is made to KR 10 2018 0 016 749 A , CN 2 04 506 396 U and US 2012 / 0 211 931 A1. The above description serves only to provide a better understanding of the background of the present disclosure and is not intended to imply that it is contained in the area of ​​related technology known to the skilled person. SUMMARY The invention is defined by claim 1. Advantageous embodiments are the subject of the dependent claims. Accordingly, the present disclosure proposes a multi-layered suspension made of composite material, wherein the suspension has several springs made of composite material which allow a vehicle to continue driving even if one of the several springs made of composite material is broken. To solve the above problem, a multi-layered suspension made of composite material is provided, wherein the suspension comprises: a first mounting unit attached to a rubber spring; a second mounting unit attached to a heart bolt receptacle; and a plurality of springs made of composite material, which are coupled to the first mounting unit and the second mounting unit at opposite ends and spaced perpendicularly apart from each other. The composite springs comprise an upper spring and a lower spring, and the first mounting unit comprises: a first upper mount coupled to a first end section of the upper spring; and a first lower mount connected to a lower section of the first upper mount, so that it is connected to the first end section of the lower spring, and the second mounting unit comprises: a second upper mount coupled to a second end section of the upper spring; and a second lower mount coupled to a second end section of the lower spring. The first upper support may include: a first upper plate arranged to be in contact with an upper surface of the first end section of the upper spring; a first lower plate spaced below the first upper plate so that it is in contact with the lower surface of the first end section of the upper spring; and a first side plate configured to connect the first upper plate and the first lower plate; and the first lower support may include: a second upper plate arranged to be in contact with an upper surface of the first end section of the lower spring; a second lower plate spaced below the second upper plate so that it is in contact with a lower surface of the first end section of the lower spring; and a second side plate configured to connect the second upper plate and the second lower plate. The first mounting unit may further include a connecting element that connects the first upper bracket and the first lower bracket, and the connecting element may be configured to couple the first side plate to the second side plate, so that the first upper bracket and the first lower bracket are connected. The first side plate can be configured to project downwards from the first lower plate and be in contact with an upper surface of the second side plate, and a connecting element can be configured to couple the first side plate to the second side plate by perpendicularly penetrating the first and second side plates. The rubber spring can be provided at an upper end with a rubber spring holder, wherein the rubber spring holder is in contact with a lower surface of the first lower holder, and a lower end of the connecting element can connect the first lower holder and the rubber spring by penetrating the rubber spring holder. The first mounting unit may further include: a first fastening element configured to successively pass through the first upper plate, the upper spring and the first lower plate to fasten the first end section of the upper spring to the first upper bracket; and a second fastening element configured to successively pass through the second upper plate, the lower spring and the second lower plate to fasten the first end section of the lower spring to the first lower bracket. The second mounting unit may further include a support bracket coupled to the heart bolt receptacle and extending upwards and downwards, wherein the second upper bracket may include: a third upper plate extending from the support bracket in such a way as to contact an upper surface of the second end section of the upper spring; and a third lower plate arranged at a distance below the third upper plate and extending from the support bracket in such a way as to contact an upper surface of the second end section of the upper spring, and the second lower bracket may include: a fourth upper plate arranged at a distance below the third lower plate and extending from the support bracket in such a way as to contact an upper surface of the second end section of the lower spring;and a fourth lower plate, which is arranged at a distance below the fourth upper plate and extends from it in such a way that it is in contact with a lower surface of the second end section of the lower spring. The second mounting unit may further include: a third fastening element configured to successively pass through the third upper plate, the upper spring and the third lower plate to secure the second end section of the upper spring to the second upper bracket; and a fourth fastening element configured to successively pass through the fourth upper plate, the lower spring and the fourth lower plate to secure the second end section of the lower spring to the second lower bracket. The rubber spring can be configured such that a pair of rubber springs is provided on opposite sides of the heart bolt receptacle, the first retaining unit can be configured such that a pair of retaining units is attached to the rubber springs, and the composite springs can be arranged between the first and second retaining units. The composite springs can be divided into opposing end sections coupled to the first and second mounting units respectively, and an intermediate middle section formed between them, and the width of the opposing end sections in the direction of the vehicle width can be smaller than the width of the middle section in the direction of the vehicle width. The springs made of composite material can be manufactured with resin-impregnated reinforcing fibers. The reinforcing fibers in an upper spring and in a lower spring may contain a plurality of first fibers arranged perpendicularly in the direction of the vehicle width. The reinforcing fibers in the lower spring may also contain a plurality of second fibers arranged crosswise to the first fibers. The multi-layered suspension made of composite material according to the present disclosure has the following advantages. Firstly, the spring mounting contains several composite springs, so that the vehicle can still drive even if one of the multiple composite springs is broken. Secondly, the service life can be increased by avoiding friction between springs made of composite material. Thirdly, the durability of the springs can be improved by using shorter lengths of springs made from composite material, thus avoiding the “windup” phenomenon. BRIEF DESCRIPTION OF THE DRAWINGS The above and other problems, features and further advantages of the present disclosure will become apparent from the following detailed description in conjunction with the accompanying drawings; which show: Fig. 1 a side view of a multi-layered suspension made of composite material according to one embodiment of the present disclosure; Fig. 2 a perspective exploded view of the multi-layered suspension made of composite material according to the embodiment of the present disclosure; Fig. 3 a perspective view of the multi-layered suspension made of composite material according to the embodiment of the present disclosure; and Fig. 4 a perspective view of a multi-layered suspension made of composite material according to another embodiment of the present disclosure. It is understood that the term "vehicle" or "vehicle-related" or other similar terms used herein generally refer to motor vehicles, such as passenger cars, including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, personal watercraft including various boats and ships, aircraft, and the like, and also includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles (rechargeable from an electrical outlet), hydrogen-powered vehicles, and other vehicles powered by alternative fuels (e.g., fuels derived from resources other than petroleum). As used herein, a hybrid vehicle is a vehicle with two or more sources of propulsion, e.g., vehicles powered by both gasoline and electric motors. The terminology used herein is intended to describe only certain embodiments and is not meant to limit the disclosure. As used herein, the singular forms "one" and "the" are to include the plural forms unless the context clearly indicates otherwise. Furthermore, it is understood that the terms "has" and / or "having" as used in this description indicate the presence of specified features, integer quantities, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integer quantities, steps, operations, elements, components, and / or groups thereof. As used herein, the phrase "and / or" includes all combinations of one or more of the listed items.Unless expressly stated otherwise, throughout this description the term "constitute" and forms thereof such as "constitutes" or "constitutes" are to be understood as including the specified elements, but not excluding other elements. Furthermore, the terms "unit," the (English) word endings "-er," "-or," and the term "module" in this description mean units for performing at least one function or operation and may be implemented by hardware or software components and combinations thereof. Furthermore, the control logic of the present disclosure can be implemented as non-volatile, computer-readable media on a computer-readable medium with executable program instructions that are executed by a processor, a controller, and the like. Examples of computer-readable media include, but are not limited to, ROMs, RAMs, Compact Disc (CD)-ROMs, magnetic tapes, floppy disks, USB flash drives, smart cards, and optical data storage devices. The computer-readable recording medium can also be distributed across networked computer systems, so that the computer-readable medium is stored and executed in a distributed manner, e.g., by a telematics server or a Controller Area Network (CAN). All terms used herein, including technical or scientific terms, have the same meanings as those understood by the person skilled in the art to which the present invention is directed, unless otherwise defined. Terms defined in commonly used dictionaries should be understood in the same way as in the context of the relevant technology and must not be interpreted in an ideal or overly formal sense unless clearly defined otherwise. Terms defined in a commonly used dictionary should be understood in the same way as in the context of the relevant technology and must not be interpreted in an ideal or overly formal sense unless defined accordingly in this description. In the following, a multi-layered suspension made of composite material according to exemplary embodiments of the present disclosure is described in more detail with reference to the accompanying drawings. Fig. 1 is a side view of a multi-layered suspension made of composite material according to an embodiment of the present disclosure; Fig. 2 is a perspective exploded view of the multi-layered suspension made of composite material according to the embodiment of the present disclosure; and Fig. 3 is a perspective view of the multi-layered suspension made of composite material according to the embodiment of the present disclosure. As shown in Figs. 1, 2 to 3, an embodiment of a multi-layered suspension made of composite material according to the present disclosure comprises: a first mounting unit 200 attached to a rubber spring 10; a second mounting unit 300 attached to a heart bolt receptacle 20; and a plurality of springs made of composite material 100, which are manufactured with resin-impregnated reinforcing fibers and whose opposite ends are coupled to the first mounting unit 200 and the second mounting unit 300 respectively and are spaced perpendicularly apart from each other. The rubber spring 10 described here is installed on an axle shaft of a commercial vehicle to elastically absorb shocks transmitted from the ground, and the center bolt receptacle 20 is configured to distribute the load of the vehicle body evenly over each axle shaft. The springs made of composite material 100 are manufactured with resin-impregnated reinforcing fibers. The reinforcing fibers are preferably arranged in a predetermined direction, so that they exhibit an anisotropic structure with increased stiffness in a specific direction. The first mounting unit 200 and the second mounting unit 300 are each designed with a groove for receiving opposite ends of the composite material springs 100 and their coupling. The first mounting unit 200 and the second mounting unit 300 are each provided with a plurality of grooves into which each of the composite springs 100 is inserted, so that a plurality of the composite springs 100 can establish a connection between the first mounting unit 200 and the second mounting unit 300, with the springs being spaced apart from one another. The composite springs 100 can, for example, comprise an upper spring 110 and a lower spring 120. The first mounting unit 200 can be roughly divided into a first upper mounting 210 and a first lower mounting 220, and the first upper mounting 210 and the first lower mounting 220 can be formed in one piece by means of a connecting element 230. The first upper bracket 210 is formed with a groove in which a first end section of the upper spring 110 is inserted, and the first lower bracket 220 is formed with a groove in which a first end section of the lower spring 120 is inserted. In particular, the first upper bracket 210 comprises a first upper plate 211, a first lower plate 212, and a first side plate 213, wherein the first upper plate 211 is arranged to be in contact with an upper side surface of the first end section of the upper spring 110, the lower plate 212 is arranged to be in contact with a lower side surface of the first end section of the upper spring 110, and the first side plate 213 connects the end sections of the first upper plate 211 and the first lower plate 212. Thus, the bracket 210 as a whole is formed as a U-shaped groove into which the first end section of the upper spring 110 is inserted. The lower end of the first side plate 213 is configured to extend further downwards than the first lower plate 212, and the first side plate 213 is formed with a through-hole in it. The inside of the through-hole may be threaded. Since the first side plate 213 extends downwards from the first lower plate 212, the first upper support 210 may be F-shaped. The first lower bracket 220 comprises a second upper plate 221, a second lower plate 222, and a second side plate 223, wherein, similar to the first upper bracket 210, the second upper plate 221 is arranged to be in contact with an upper side surface of the first end section of the lower spring 120, the second lower plate 222 is arranged to be in contact with a lower side surface of the first end section of the lower spring 120, and the second side plate 223 connects the end sections of the second upper plate 221 and the second lower plate 222. Thus, the first lower bracket 220 as a whole is formed as a U-shaped groove into which the first end section of the lower spring 120 is inserted. The upper end of the second side plate 223 is in close contact with the lower end of the first side plate 213, and the second side plate 223 is provided with a perpendicularly formed through-opening for communication with the through-opening of the first side plate 213. The connecting element 230 penetrates the through-holes of the first side plate 213 and the second side plate 223 simultaneously to connect the first side plate 213 and the second side plate 223, thus coupling the first upper bracket 210 and the first lower bracket 220 to each other. The connecting element 230 can be a screw or a rivet, and if the connecting element 230 is a screw, it can be fastened by means of the thread on the inside of the through-holes of the first side plate 213 and the second side plate 223. Since the first side plate 213 extends further downwards than the first lower plate 212, the grooves formed in the first upper bracket 210 and in a second lower bracket 320 are spaced apart from each other, whereby the upper spring 110 and the lower spring 120 can be held at a predetermined distance. The upper end of the rubber spring 10 is provided with a rubber spring holder 11 which is in contact with the lower surface of the first lower holder 220, and the rubber spring holder 11 has a through-hole which communicates with the through-hole formed in the first side plate 213, the lower end section of the connecting element 230 passing through the through-hole in the rubber spring holder 11 to integrally fasten the first lower holder 220 and the rubber spring 10. This attaches the first mounting unit 200 to the rubber spring 10, so that the first end section of the upper spring 110 and the lower spring 120 can be coupled to the upper end of the rubber spring 10. Preferably, the first mounting unit 200 further comprises: a first fastening element 214, which successively penetrates the first upper plate 211, the first end section of the upper spring 110 and the first lower plate 212 to fasten the upper spring 110 to the first upper mounting unit 210; and a second fastening element 224, which successively penetrates the second upper plate 221, the first end section of the lower spring 120 and the second lower plate 222 to fasten the lower spring 120 to the first lower mounting unit 220. The first fastening element 214 and the second fastening element 224 are preferably provided as a Huck screw or rivet for fastening the first end section of the upper spring 110 to the first upper bracket 210 and for fastening the first end section of the lower spring 120 to the first lower bracket 220. The second mounting unit 300 can be subdivided into: a second upper mounting 310 coupled to a second end section of the upper spring 110; the second lower mounting 320 coupled to a second end section of the lower spring 120; and a support bracket 330 coupled to the heart bolt receptacle 20 to support the second upper mounting 310 and the second lower mounting 320. The second upper support 310 comprises: a third upper plate 311 extending laterally from the upper end of the support bracket 330 so that it comes into contact with an upper side surface of the second end section of the upper spring 110; and a third lower plate 312 extending from the side surface of the support bracket 330, being spaced below the third upper plate 311 so that it is in contact with a lower side surface of the second end section of the upper spring 110. Similar to the second upper bracket 310, the second lower bracket 320 includes: a fourth upper plate 321 extending from the side face of the support bracket 330, spaced below the third lower plate 312 such that it is in contact with an upper side face of the second end section of the lower spring 120; and a fourth lower plate 322 extending from the side face of the support bracket 330, spaced below the fourth upper plate 321 such that it is in contact with a lower side face of the second end section of the lower spring 120. The support bracket 330 is provided on the upper section of the heart bolt receptacle 20 and has a block shape with a predetermined height, and the support bracket 330 and the heart bolt receptacle 20 can be welded together, attached to each other by a coupling element such as a screw or integrally formed and provided as a single body. The second mounting unit 300 preferably further comprises: a third fastening element 313 configured to successively penetrate the third upper plate 311, the upper spring 110 and the third lower plate 312 to fasten the second end section of the upper spring 110 to the second upper mounting unit 310; and a fourth fastening element 323 configured to successively penetrate the fourth upper plate 321, the lower spring 120 and the fourth lower plate 322 to fasten the second end section of the lower spring 120 to the second lower mounting unit 320. The third fastening element 313 and the fourth fastening element 323 are preferably provided as a Huck screw or rivet. The position where each of the first fastening element 214, second fastening element 224, third fastening element 313, and fourth fastening element 323 described above penetrates each bracket and spring can, for example, in the case of the first fastening element 214, be located at a predetermined distance, e.g., 5 mm, inside the ends of the first upper plate 211 and the first lower plate 212. In other words, the first upper plate 211 and the first lower plate 212 are in close contact with the upper and lower side surfaces of the upper spring 110, respectively, and are attached to it outside the position where the first fastening element 214 passes through, thus preventing the problem of the upper spring 110 breaking due to cracking in the opening of the upper spring 110 caused by the first fastening element 214. Similarly, the second fastening element 224, the third fastening element 313 and the fourth fastening element 323 can be designed with the same structure to prevent cracking at the opposite end of the upper spring 110 and the lower spring 120. The rubber spring 10 can each be installed in opposite directions to the center bolt receptacle 20, i.e., in the forward and reverse directions of the vehicle, and an axle shaft can be coupled to the lower end of each rubber spring 10. In this case, the upper spring 110 and the lower spring 120 are provided in pairs. For example, one upper spring 110 can be coupled to a rubber spring 10 installed in the forward direction of the vehicle based on the center bolt receptacle 20, and the other upper spring 110 can be coupled to a rubber spring 10 installed in the reverse direction of the vehicle based on the center bolt receptacle 20. This eliminates the problem that arises in the prior art with a vehicle, because it cannot be moved if a conventional composite spring is damaged. In contrast, according to the claimed invention, it is possible to drive the vehicle even if any one of the composite springs 100 is damaged. As shown in Fig. 4 in another embodiment of the multi-layered suspension made of composite material according to the present disclosure, the shape of the springs made of composite material 100 may differ from that of the first embodiment. The springs made of composite material 100 can be divided into: opposing end sections 101, which are coupled to both the first mounting unit 200 and the second mounting unit 300; and an intermediate middle section 102 formed between them, wherein the width of the opposing end sections 101 in the direction of the vehicle width may be smaller than that of the middle section 102 in the direction of the vehicle width. This serves to compensate for the problem that the lateral modulus of elasticity decreases under lateral load due to the properties of the composite material springs 100. As the width of the central section 102 increases towards the vehicle width, the resistance to lateral and torsional loads increases. These loads occur when cornering and due to the rolling behavior of the vehicle body, which sways from side to side. Reinforcing fibers 103 are incorporated into the springs made of composite material 100, wherein the reinforcing fibers 103 preferably include first fibers 103a which are arranged essentially perpendicular to the forward-backward direction of the vehicle, i.e. in the direction of the vehicle width. The reason for this is that the direction in which the main load acts on the composite springs 100 is the forward-backward direction, so that the stiffness in the longitudinal direction, i.e. in the forward-backward direction and in the perpendicular direction, can be increased by the first fibers 103a. In addition to the first fibers 103a, the lower spring 120 of the springs made of composite material 100 preferably also contains second fibers 103b, which are arranged crosswise to the first fibers 103a. The reason for this is that its higher load acts on the lower spring 120 compared to the upper spring 110 when lateral and torsional loads are effective, and therefore it is necessary to improve the lateral stiffness of the lower spring 120. Accordingly, the second fibers 103b are arranged in an oblique line at an angle of, for example, 45° relative to the arrangement direction of the first fibers 103a, so that the lateral stiffness of the lower spring 120 can be improved. Although a preferred embodiment of the present disclosure has been described for illustrative purposes, it is understood by the person skilled in the art that additions and substitutions are possible without deviating from the scope and spirit of the disclosure as defined in the attached claims.

Claims

Multi-layer composite suspension (100) for a vehicle, the suspension comprising: a first mounting unit (200) attached to a rubber spring (10); a second mounting unit (300) attached to a center bolt receptacle (20); and a plurality of composite springs (100) coupled to the first mounting unit (200) and the second mounting unit (300) at opposite ends and spaced perpendicularly apart from each other, the composite springs (100) comprising an upper spring (110) and a lower spring (120), the first mounting unit (200) comprising: a first upper mount (210) coupled to a first end section of the upper spring (110);and a first lower bracket (220) connected to a lower section of the first upper bracket (210) so that it is coupled to a first end section of the lower spring (120), and the second bracket unit (300) comprising: a second upper bracket (310) coupled to a second end section of the upper spring (110); and a second lower bracket (320) coupled to a second end section of the lower spring (120). Multi-layer suspension according to claim 1, wherein: the first upper support (210) comprises: a first upper plate (211) arranged to be in contact with an upper surface of the first end section of the upper spring (110); a first lower plate (212) arranged at a distance below the first upper plate (211) in contact with a lower surface of the first end section of the upper spring (110); and a first side plate (213) configured to connect the first upper plate (211) to the first lower plate (212); and the first lower support (220) comprises: a second upper plate (221) arranged to be in contact with an upper surface of the first end section of the lower spring (120); a second lower plate (222) arranged at a distance below the second upper plate (221) in contact with a lower surface of the first end section of the lower spring (120);and a second side plate (223) configured to connect the second upper plate (221) to the second lower plate (222). Multi-layer suspension according to claim 2, wherein: the first mounting unit (200) further comprises a connecting element (230) that connects the first upper mounting (210) and the first lower mounting (220) together, and the connecting element (230) is configured to couple the first side plate (213) and the second side plate (223) so that the first upper mounting (210) and the first lower mounting (220) are connected together. Multi-layer suspension according to claim 2, wherein: the first side plate (213) is configured to project downwards from the first lower plate (212) and is in contact with an upper surface of the second side plate (223), and a connecting element (230) is configured to couple the first side plate (213) and the second side plate (223) by perpendicularly penetrating the first side plate (213) and the second side plate (223). Multi-layer suspension according to claim 4, wherein: the rubber spring (10) is provided at an upper end with a rubber spring holder (11) which is in contact with a lower surface of the first lower holder (220), and a lower end of the connecting element (230) connects the first lower holder (220) and the rubber spring (10) by penetrating the rubber spring holder (11). Multi-layer suspension according to claim 2, wherein the first mounting unit (200) further comprises: a first fastening element (214) configured to pass successively through the first upper plate (211), the upper spring (110) and the first lower plate (212) to fasten the first end section of the upper spring (110) to the first upper mounting (210); and a second fastening element (224) configured to pass successively through the second upper plate (221), the lower spring (120) and the second lower plate (222) to fasten the first end section of the lower spring (120) to the first lower mounting (220). Multi-layer suspension according to claim 1, wherein: the second mounting unit (300) further comprises a support bracket (330) coupled to the center bolt receptacle (20) and extending upwards and downwards, the second upper mounting (310) comprises: a third upper plate (311) extending from the support bracket (330) so that it comes into contact with an upper surface of the second end section of the upper spring (110); and a third lower plate (312) arranged at a distance below the third upper plate (311) and extending from the support angle (330) so that it is in contact with a lower surface of the second end section of the upper spring (110), and the second lower support (320) includes: a fourth upper plate (321) arranged at a distance below the third lower plate (312) and extending from the support angle (330) so that it is in contact with an upper surface of the second end section of the lower spring (120);and a fourth lower plate (322) arranged at a distance below the fourth upper plate (321) and extending from the support angle (330) so that it is in contact with a lower surface of the second end section of the lower spring (120). Multi-layer suspension according to claim 7, wherein the second mounting unit (300) further comprises: a third fastening element (313) configured to pass successively through the third upper plate (311), the upper spring (110) and the third lower plate (312) to fasten the second end section of the upper spring (110) to the second upper mounting (310); and a fourth fastening element (323) configured to pass successively through the fourth upper plate (321), the lower spring (120) and the fourth lower plate (322) to fasten the second end section of the lower spring (120) to the second lower mounting (320). Multi-layer suspension according to claim 1, wherein: the rubber spring (10) is configured such that a pair of rubber springs (10) is arranged on opposite sides of the heart bolt receptacle (20), the first mounting unit (200) is configured such that a pair of the first mounting units (200) is attached to the rubber springs (10), and the composite springs (100) are arranged between the first mounting unit (200) and the second mounting unit (300). Multi-layer suspension according to claim 1, wherein: the springs made of composite material (100) are divided into opposite end sections (101), each coupled to the first mounting unit (200) and the second mounting unit (300), and a middle section (102) formed between them, and wherein a width of the opposite end sections (101) in the direction of the vehicle width is smaller than a width of the middle section (102) in the direction of the vehicle width. Multi-layer suspension according to claim 1, wherein the springs are made of composite material (100) with resin-impregnated reinforcing fibers (103). Multi-layer suspension according to claim 11, wherein the reinforcing fibers (103) in an upper spring (110) and in a lower spring (120) contain a plurality of first fibers (103a) arranged perpendicular to the direction of the vehicle width. Multi-layer suspension according to claim 12, wherein the reinforcing fibers (103) in the lower spring (120) further comprise a plurality of second fibers (103b) arranged crosswise to the first fibers (103a).

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