Leaf spring device and installation method thereof

Abstract

The present invention discloses a leaf spring device. The leaf spring device may include: a single leaf spring made of a composite material comprising two or more different materials, with at least one mounting hole extending through the leaf spring in its width direction; and at least one auxiliary spring detachably mounted in the at least one mounting hole. The at least one auxiliary spring may have a different rigidity than the leaf spring. The rigidity of the leaf spring device may be adjusted by the rigidity of the auxiliary spring mounted on the leaf spring.

Description

Technical Field

[0001] The present invention relates to a leaf spring device and an installation method thereof, and more particularly, to a leaf spring device and an installation method thereof that can easily adjust the posture of a vehicle due to simple adjustment of rigidity. Background Art

[0002] A vehicle's suspension connects the axles to the vehicle body to prevent vibrations or shocks from the road surface from being directly transmitted to the vehicle body during driving, thereby preventing damage to the vehicle body or onboard objects and improving ride comfort.

[0003] Leaf spring is a type of suspension, mainly used in the rear suspension of large commercial vehicles or buses. It is an important component that affects ride comfort and driving stability.

[0004] Conventional leaf springs are primarily constructed by stacking multiple metal sheets (steel sheets) of varying lengths. These leaf springs are heavy, and when they become damaged, they typically occur on a single leaf. Therefore, replacing the damaged leaf requires disassembling and reassembling the entire leaf spring. This process reduces ease of use and is time-consuming.

[0005] In recent years, single-leaf springs made of composite materials have become increasingly popular, aiming to achieve the same strength as multi-leaf springs while also being lightweight. Composite materials typically combine plastic resin and glass fiber, and the strength and modulus of the composite material can be adjusted based on the glass fiber content.

[0006] The rigidity of conventional multi-leaf springs can be adjusted by adjusting the number of metal plates, as well as the rigidity and length of each metal plate. Consequently, various combinations of metal plates can be combined to suit the actual vehicle specifications (e.g., load deviation in the vehicle width direction). This allows for easy production and management of multi-leaf springs to suit a wide range of specifications.

[0007] Composite leaf springs are typically manufactured using molds. The rigidity of composite leaf springs can be adjusted by varying the strength and elastic modulus of the composite material, as well as the spring's shape. However, due to limitations in adjusting leaf spring rigidity based on the composite material's strength and elastic modulus, the rigidity of composite leaf springs is primarily adjusted by varying the spring's shape. Consequently, various molds are required to produce leaf springs of varying sizes, making it difficult to tailor leaf springs to varying rigidities to meet vehicle specifications.

[0008] The contents recorded in this background technology section are intended to enhance understanding of the background of the present invention and may include contents beyond the prior art known to those of ordinary skill in the art. Summary of the Invention

[0009] (1) Technical issues to be solved

[0010] Embodiments of the present invention are directed to providing a leaf spring device capable of easily adjusting the posture of a vehicle due to simple adjustment of rigidity, and a method for installing the same.

[0011] (2) Technical solution

[0012] A leaf spring device according to an embodiment of the present invention may include: a single leaf spring made of a composite material comprising two or more different materials, having at least one mounting hole extending therethrough in the width direction; and at least one auxiliary spring detachably mounted in the at least one mounting hole. The at least one auxiliary spring may have a different rigidity than the leaf spring.

[0013] Two or more auxiliary springs may be installed in one mounting hole, and the two or more auxiliary springs may be coupled to each other via a fixing member, wherein the fixing member may include a bolt and a nut coupled to each other.

[0014] The two or more assist springs may include: a first assist spring inserted into the mounting hole from one side in the width direction of the leaf spring; and a second assist spring inserted into the mounting hole from the other side in the width direction of the leaf spring. A step may protrude radially outward on each of an outer circumferential surface on one side in the width direction of the first assist spring and an outer circumferential surface on the other side in the width direction of the second assist spring.

[0015] In one aspect, the auxiliary spring may be made of one of an elastic material and a non-elastic material.

[0016] In another aspect, the auxiliary spring may be made of an elastic material, and an insert may be installed inside the auxiliary spring. The insert may be made of a metal material.

[0017] In one aspect, an even number of mounting holes may be formed in the leaf spring, and the even number of mounting holes may be formed symmetrically with respect to a load center in a longitudinal direction of the leaf spring.

[0018] According to another embodiment of the present invention, a method for installing a leaf spring device may include the following steps: preparing a leaf spring including a single leaf spring and an auxiliary spring detachably mounted on the leaf spring; installing the leaf spring device on both sides of an axle; judging whether a vehicle height difference in a width direction occurs; determining the rigidity of the auxiliary spring according to the vehicle height difference in the width direction; and installing the auxiliary spring having the determined rigidity on the leaf spring.

[0019] The method may further include the steps of: installing a leaf spring device having an auxiliary spring having a determined rigidity mounted thereon on the axle; and again determining whether a height difference of the vehicle in the width direction occurs.

[0020] The rigidity of the leaf spring device can be adjusted by the rigidity of an auxiliary spring mounted on the leaf spring.

[0021] In one aspect, the auxiliary spring may be made of one of an elastic material and a non-elastic material.

[0022] In another aspect, the auxiliary spring may be made of an elastic material, and an insert made of a metal material may be installed inside the auxiliary spring.

[0023] (3) Beneficial effects

[0024] According to the embodiments of the present invention, the rigidity of the composite leaf spring device can be easily adjusted, and the posture of the vehicle to which the composite leaf spring device is applied can be easily adjusted, thereby improving ride comfort and driving stability.

[0025] In addition, only one mold is required to produce one shape of leaf spring, thus saving development expenses and costs.

[0026] In addition, in the detailed description of the embodiments of the present invention, the effects that can be obtained or predicted by the embodiments of the present invention will be disclosed directly or implicitly. That is, various effects predicted by the embodiments of the present invention will be disclosed in the detailed description to be described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The embodiments of the present specification may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like reference numbers indicate identical or functionally similar components.

[0028] Figure 1 A leaf spring arrangement according to an embodiment of the present invention is schematically shown mounted on an axle.

[0029] Figure 2 is a perspective view of a leaf spring device according to an embodiment of the present invention.

[0030] Figure 3 is a front view of a leaf spring device according to an embodiment of the present invention.

[0031] Figure 4 is an exploded view of a leaf spring device according to an embodiment of the present invention.

[0032] Figure 5 is a perspective view of an auxiliary spring according to an embodiment of the present invention.

[0033] Figure 6is a front view of an auxiliary spring according to an embodiment of the present invention.

[0034] Figure 7 is a schematic diagram illustrating a system for performing a method for installing a leaf spring device according to an embodiment of the present invention.

[0035] Figure 8 is a flowchart illustrating a method of installing a leaf spring device according to an embodiment of the present invention.

[0036] Figure 9 A case where a vehicle height difference occurs in the width direction of the vehicle is schematically shown.

[0037] Figure 10 A case where a leaf spring device according to an embodiment of the present invention is applied to solve a vehicle height difference occurring in the width direction of the vehicle is schematically shown.

[0038] The accompanying drawings referred to above are not necessarily drawn to scale and should be understood as presenting a somewhat simplified representation of various preferred features illustrating the basic principles of the present invention. For example, the specific design features of the present disclosure, including specific dimensions, directions, positions, and shapes, will be determined in part by the specific intended application and use environment. DETAILED DESCRIPTION

[0039] The terms used herein are intended to describe specific embodiments only and are not intended to limit the present invention. Unless otherwise expressly indicated in the context, the singular as used herein includes the plural. As used in this specification, it is understood that the terms "include" and / or "include" specify the presence of the features, integers, steps, operations, components, assemblies mentioned, but do not exclude the presence or addition of more than one of other features, integers, steps, operations, components, assemblies, and / or their combinations. As used herein, the term "and / or" includes any one or all combinations of the items listed in association.

[0040] Terms such as "vehicle" or "vehicular" or other similar terms used in this document will generally be understood to include automobiles including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, marine vessels including various yachts and boats, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels from resources other than petroleum).

[0041] In addition, it should be understood that one or more of the following methods or aspects can be performed by at least one controller. The term "controller" can refer to a hardware device including a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute the program instructions to perform one or more processes described in more detail below. As described herein, a controller can control the operation of a unit, module, component, device, or similar device. Furthermore, it should be understood that, as recognized by a person of ordinary skill in the art, the following methods can be performed by a device including a controller and one or more other components.

[0042] Furthermore, the controller of the present invention can be implemented as a non-transitory computer-readable recording medium including executable program instructions executed by a processor. Examples of computer-readable recording media include, but are not limited to, read-only memory (ROM), random access memory (RAM), compact disc (CD) drives, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable recording medium can be distributed throughout a computer network, such as a telematics server or a controller area network (CAN), so that program instructions can be stored and executed in a distributed manner.

[0043] Figure 1 A leaf spring arrangement according to an embodiment of the present invention is schematically shown mounted on an axle.

[0044] like Figure 1 As shown, a leaf spring device 10 according to an embodiment of the present invention includes two ends and a central portion in the longitudinal direction. A first joint member 4 is mounted at one end of the leaf spring device 10, and a second joint member 6 is mounted at the other end. The second joint member 6 is coupled to a shackle link 7. The shackle link 7 allows the span of the leaf spring device 10 to be varied. Thus, one end of the leaf spring device 10 is connected to a side frame (not shown) of the vehicle body via the first joint member 4, while the other end of the leaf spring device 10 is connected to the side frame via the second joint member 6 and the shackle link 7.

[0045] The center of the leaf spring device 10 is secured to one end of the axle 1 via a first securing member 8. The first securing member 8 can be a U-bolt. Wheels 2 are mounted on each end of the axle 1. Therefore, when vibration or impact from the road surface is transmitted to the wheels 2, the vibration or impact is transmitted through the axle 1 to the leaf spring device 10, which then deploys to reduce the vibration or impact transmitted to the vehicle body.

[0046] Figure 2 is a perspective view of a leaf spring device according to an embodiment of the present invention, Figure 3 is a front view of a leaf spring device according to an embodiment of the present invention, Figure 4 is an exploded view of a leaf spring device according to an embodiment of the present invention.

[0047] like Figures 2 to 4 As shown, a leaf spring device 10 according to an embodiment of the present invention includes a leaf spring 12 and an auxiliary spring 14. The rigidity of the auxiliary spring 14 can differ from that of the leaf spring 12. For example, the rigidity of the auxiliary spring 14 can be greater or less than that of the leaf spring 12, allowing the overall rigidity of the leaf spring device 10 to be adjusted by installing an auxiliary spring 14 having an appropriate rigidity on the leaf spring 12. When the rigidity of the leaf spring device 10 needs to be greater than that of the leaf spring 12, an auxiliary spring 14 having a greater rigidity than the leaf spring 12 can be installed on the leaf spring 12. Conversely, when the rigidity of the leaf spring device 10 needs to be less than that of the leaf spring 12, an auxiliary spring 14 having a less rigidity than the leaf spring 12 can be installed on the leaf spring 12. Therefore, instead of making a special mold based on the required rigidity of the leaf spring device 10, the rigidity of the leaf spring device 10 can be adjusted by replacing and installing auxiliary springs 14 having various rigidities on a leaf spring 12 having a single rigidity.

[0048] The leaf spring 12 may be a single leaf spring made of a composite material. A composite material may include two or more different materials. For example, the composite material may be a combination of plastic resin and fiberglass, but is not limited thereto. The leaf spring 12 may be formed into an appropriate shape to achieve the desired rigidity and may be manufactured using a mold.

[0049] At least one mounting hole 16 is formed in the center of the leaf spring 12, extending through the leaf spring 12 in the width direction. The auxiliary spring 14 is mounted in this mounting hole 16. For example, a pair of auxiliary springs 14a and 14b can be mounted in a single mounting hole 16 using a bolt 20 and a nut 22. While the bolt 20 and nut 22 are shown as securing members, these securing members are not limited to bolts 20 and nut 22. Various securing members known to those skilled in the art can be used to secure the pair of auxiliary springs 14a and 14b mounted in the mounting hole 16 to the leaf spring 12. Furthermore, the number of auxiliary springs 14 mounted in a single mounting hole 16 is not limited to two. An appropriate number of auxiliary springs 14 can be used to distribute and support a load applied to the leaf spring device 10 without separating from the leaf spring 12. For example, one or more additional auxiliary springs can be positioned between the pair of auxiliary springs 14a and 14b. The cross-sectional shape of the mounting hole 16 is illustrated as an elliptical shape, but is not limited to this. The cross-sectional shape of the mounting hole 16 may be such that the auxiliary spring 14 mounted therein can disperse and support a load when a load is applied to the leaf spring device 10. The cross-sectional shape of the mounting hole 16 may be elliptical, circular, polygonal, or the like.

[0050] If two or more mounting holes 16 are formed, the mounting holes 16 can be dispersed on both sides with the center of the leaf spring 12 in the longitudinal direction as a reference. In addition, an even number of mounting holes 16 can be formed. When an even number of mounting holes 16 are formed, the mounting holes 16 can be formed symmetrically with respect to the load center in the longitudinal direction of the leaf spring 12. Here, the load center of the leaf spring 12 refers to the center of the load applied from the axle 1 through the first fixing member 8. Since the mounting holes 16 are formed symmetrically with respect to the load center of the leaf spring 12, when a load is applied to the leaf spring device 10, the auxiliary spring 14 installed in the mounting hole 16 can evenly distribute and support the load. Therefore, the rigidity of the leaf spring device 10 using the auxiliary spring 14 can be easily adjusted.

[0051] Below, refer to Figure 5 and Figure 6 , the auxiliary spring 14 will be described in more detail.

[0052] Figure 5 is a perspective view of an auxiliary spring according to an embodiment of the present invention, Figure 6 is a front view of an auxiliary spring according to an embodiment of the present invention.

[0053] like Figure 5 and Figure 6 As shown, the assist spring 14 may include a body 34 , a step 32 , and a fixing hole 36 .

[0054] The body 34 may have a cross-sectional shape corresponding to that of the mounting hole 16 to be inserted into the mounting hole 16 and to distribute and support the load applied to the leaf spring device 10. For example, the cross-sectional shape of the body 34 may be oval, circular, polygonal, or the like.

[0055] A step 32 protrudes radially outward along the outer circumference of one widthwise side of the main body 34. When a pair of auxiliary springs 14a and 14b are installed in a single mounting hole 16, steps 32 are formed on the outer circumference of one widthwise side of the first auxiliary spring 14a and the outer circumference of the other widthwise side of the second auxiliary spring 14b. In this case, the first auxiliary spring 14a is inserted into the mounting hole 16 from one widthwise side of the leaf spring 12, and the second auxiliary spring 14b is inserted into the mounting hole 16 from the other widthwise side of the leaf spring 12. The bolt 20 and nut 22 engage with each other, and the first and second auxiliary springs 14a and 14b are pulled toward each other. At this time, the steps 32 of the first and second auxiliary springs 14a and 14b respectively adhere to the side surfaces of the leaf spring 12, thereby enhancing the coupling force between the first and second auxiliary springs 14a and 14b and the leaf spring 12. Therefore, the load applied to the leaf spring device 10 is dispersed and supported on the leaf spring 12, the first and second assist springs 14a and 14b, and separation of the leaf spring 12 from the first and second assist springs 14a and 14b can be prevented.

[0056] The fixing hole 36 is formed to extend through the auxiliary spring 14 in the width direction. A fixing member, such as a bolt 20, is inserted into the fixing hole 36 to attach the auxiliary spring 14 to the leaf spring 12. For example, a pair of auxiliary springs 14a and 14b may be inserted into the mounting hole 16, the bolt 20 extending through the fixing holes 36 of the pair of auxiliary springs 14a and 14b, and the nut 22 attached to the end of the bolt 20 to attach the pair of auxiliary springs 14a and 14b to the leaf spring 12.

[0057] The auxiliary spring 14 can be made of one material, or Figure 6 As shown, an insert 38 may be installed inside the auxiliary spring 14. When the auxiliary spring 14 is made of a single material, the single material may be an elastic material such as rubber. Alternatively, the auxiliary spring 14 may be made of a non-elastic material such as steel. Alternatively, the auxiliary spring 14 may be made of an elastic material such as rubber, and an insert 38 of a metal material may be installed inside the auxiliary spring 14. The material of the auxiliary spring 14 and whether the insert 38 is installed inside the auxiliary spring 14 may be determined based on the desired rigidity of the auxiliary spring 14. The shape of the insert 38 is not limited thereto, but may be similar in shape to the auxiliary spring 14.

[0058] Figure 7 is a schematic diagram illustrating a system for performing a method for installing a leaf spring device according to an embodiment of the present invention.

[0059] like Figure 7 As shown in FIG, a system according to an embodiment of the present invention may include a sensor 52 , a controller 50 , a display 54 , and a manufacturer 56 .

[0060] The sensor 52 can detect data used to determine whether the stiffness of the leaf spring device 10 needs to be adjusted. In one example, the sensor 52 can be a load sensor mounted on each wheel 2. In this case, the sensor 52 measures the reaction force acting on the wheel 2, allowing the controller 50 to determine whether the stiffness of the leaf spring device 10 needs to be adjusted. In another example, the sensor 52 can be a torque sensor mounted on the axle 1. In this case, the sensor 52 measures the torque of the axle 1, allowing the controller 50 to determine whether the stiffness of the leaf spring device 10 needs to be adjusted.

[0061] The controller 50 is communicatively connected to the sensor 52 to receive data measured by the sensor 52. The controller 50 can determine whether the stiffness of the leaf spring device 10 needs to be adjusted based on the data from the sensor 52. Furthermore, the controller 50 can determine the target stiffness of the assist spring 14 based on the data from the sensor 52. The controller 50 is communicatively connected to the display 54 and the manufacturer 56 to transmit the determination result to the display 54 and the manufacturer 56.

[0062] The display 54 may be installed at an appropriate location to inform the user whether it is necessary to adjust the stiffness of the leaf spring device 10 and the target stiffness of the auxiliary spring 14. A speaker (not shown) may be installed instead of or in addition to the display 54 to audibly inform the user whether it is necessary to adjust the stiffness of the leaf spring device 10 and the target stiffness of the auxiliary spring 14.

[0063] The maker 56 is a device for manufacturing the leaf spring device 10. The maker 56 can separate the auxiliary spring 14 from the leaf spring 12 and assemble the auxiliary spring 14 having a target stiffness onto the leaf spring 12 under the control of the controller 50 or through a user's operation.

[0064] Below, refer to Figure 8 、 Figure 9 as well as Figure 10 , a method for installing the leaf spring device 10 according to an embodiment of the present invention is described.

[0065] Figure 8 is a flow chart illustrating a method for installing a leaf spring device according to an embodiment of the present invention, Figure 9Schematically showing a situation where a vehicle height difference occurs in the width direction of the vehicle, Figure 10 A case where a leaf spring device according to an embodiment of the present invention is applied to solve a vehicle height difference occurring in the width direction of the vehicle is schematically shown.

[0066] like Figure 8 As shown, the method for installing the leaf spring device 10 according to an embodiment of the present invention begins by preparing the leaf spring device 10 (S110). As described above, the leaf spring device 10 may include a leaf spring 12 and an auxiliary spring 14. Here, the auxiliary spring 14 having a predetermined rigidity is installed on the leaf spring 12, so that the leaf spring device 10 has a predetermined rigidity.

[0067] After the leaf spring device 10 is prepared, the leaf spring device 10 is mounted on the vehicle under the control of the controller 50 or the operation of the user ( S120 ).

[0068] Afterwards, the sensor 52 detects data for determining whether the rigidity of the leaf spring device 10 needs to be adjusted, and transmits the detected data to the controller 50. The controller 50 determines whether the rigidity of the leaf spring device 10 needs to be adjusted based on the data. For example, Figure 9 As shown, the controller 50 determines whether a vehicle height difference in the width direction occurs based on the data ( S130 ).

[0069] When a height difference in the vehicle width direction occurs in step S130, the controller 50 determines the stiffness of the auxiliary spring 14 based on the height difference in the vehicle width direction. For example, the controller 50 determines the target stiffness of one leaf spring device 10 and the target stiffness of the other leaf spring device 10 installed on both sides of the axle 1 based on the height difference in the vehicle width direction. Furthermore, based on the target stiffness of the one leaf spring device 10 and the target stiffness of the other leaf spring device 10, the controller 50 determines the stiffness of the auxiliary spring 14 for each leaf spring device 10.

[0070] Thereafter, the controller 50 installs the auxiliary spring 14 having a determined rigidity on the leaf spring 12 ( S150 ), and installs the leaf spring device 10 having the auxiliary spring 14 installed thereon on the vehicle ( S120 ).

[0071] Afterwards, the controller 50 determines whether there is still a height difference in the width direction of the vehicle (S130) through the sensor 52. If there is still a height difference in the width direction of the vehicle, the controller 50 will repeatedly perform steps S140, S150, S120 and S130.

[0072] like Figure 10 As shown, if the vehicle height difference in the width direction does not occur, the controller 50 ends the method according to the embodiment of the present invention.

[0073] The preferred embodiments of the present invention are described above, but the present invention is not limited to the embodiments, and should include all modifications that can be easily modified by ordinary technicians in the field to which the invention belongs and are considered to be equivalent.

Claims

1. A leaf spring device comprising: A single leaf spring made of a composite material comprising two or more different materials and having at least one mounting hole extending therethrough in the width direction; as well as at least one auxiliary spring, detachably mounted in the at least one mounting hole, wherein the stiffness of the at least one auxiliary spring is different from the stiffness of the leaf spring, Two or more assist springs are installed in one mounting hole and are coupled to each other by a fixing member.

2. The leaf spring device according to claim 1, wherein The two or more auxiliary springs include: a first auxiliary spring inserted into the mounting hole from one side in the width direction of the leaf spring; and a second auxiliary spring inserted into the mounting hole from the other side in the width direction of the leaf spring. A step protrudes radially outward on each of an outer peripheral surface on one side in the width direction of the first assist spring and an outer peripheral surface on the other side in the width direction of the second assist spring.

3. The leaf spring device according to claim 1, wherein The auxiliary spring is made of one of an elastic material and a non-elastic material.

4. The leaf spring device according to claim 1, wherein The auxiliary spring is made of elastic material, and an insert is installed inside the auxiliary spring.

5. The leaf spring device according to claim 4, wherein: The insert is made of metal material.

6. The leaf spring device according to claim 1, wherein There are an even number of mounting holes formed in the leaf spring. The even-numbered mounting holes are formed symmetrically with respect to a load center in a longitudinal direction of the leaf spring.

7. A method for installing a leaf spring device, comprising the following steps: preparing a leaf spring device including a single leaf spring and an auxiliary spring detachably mounted on the leaf spring; Installing the leaf spring device on both sides of the axle; Determining whether a vehicle height difference occurs in the width direction; determining the stiffness of the auxiliary spring according to the vehicle height difference in the width direction; and An auxiliary spring having a certain rigidity is installed in at least one installation hole formed through the leaf spring in the width direction. Two or more auxiliary springs are installed in one installation hole, and the two or more auxiliary springs are coupled to each other via a fixing member.

8. The method for installing a leaf spring device according to claim 7, further comprising the following steps: installing a leaf spring device having an auxiliary spring having a predetermined stiffness on the axle; and It is determined whether a height difference of the vehicle in the width direction occurs.

9. The method for installing a leaf spring device according to claim 7, wherein: The rigidity of the leaf spring device is adjusted by the rigidity of an auxiliary spring mounted on the leaf spring.

10. The method for installing a leaf spring device according to claim 7, wherein: The auxiliary spring is made of one of an elastic material and a non-elastic material.

11. The method for installing a leaf spring device according to claim 7, wherein: The auxiliary spring is made of an elastic material, and an insert made of a metal material is installed inside the auxiliary spring.

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