Coil spring stiffness monitoring device, monitoring system and monitoring method

Abstract

The present invention provides a stiffness monitoring device, monitoring system, and monitoring method for a coil spring. The stiffness monitoring device includes a fixing assembly, a pressure detection component, and a distance detection component. The distance detection component includes a first sliding member and a second sliding member that can slide relative to each other along a deformation direction. When the first sliding member slides relative to the second sliding member along the deformation direction, a signal receiver corresponding to the position of the signal transmitter among the signal receivers receives a signal from the signal transmitter and sends the number information of the current signal receiver to a processing component; the processing component calculates the current length of the coil spring based on the number information from the current signal receiver. The device can calculate the stiffness of the coil spring. When the coil spring of a vehicle needs to be replaced, an alarm message is issued in a timely manner to remind the driver to check or replace the coil spring in a timely manner, thereby improving the safety of vehicle driving.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle suspension systems, and in particular to a stiffness monitoring device, a monitoring system and a monitoring method for a coil spring. Background Art

[0002] A vehicle's coil springs bear vertical loads on the vehicle and act as a vibration damper. The stiffness of the coil springs affects the vehicle's frequency deviation, which is an important indicator of the vehicle's ride quality. Over the long term, the stiffness of the coil springs decreases with use. However, the specific loss of each coil spring, and whether the loss rate of the coil springs on the left and right sides of the vehicle is consistent, are not typically monitored. Furthermore, existing vehicles cannot accurately assess the stiffness of the coil springs. However, if the stiffness loss is significant after long-term use, or if the left and right spring stiffness values are significantly inconsistent, the vehicle's handling and ride quality can be significantly impacted, and may even cause the vehicle to roll over, seriously impacting its safety. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem in the prior art that the stiffness value of the coil spring cannot be accurately evaluated, which easily affects the driving safety of the vehicle.

[0004] To address the above-mentioned problems, an embodiment of the present invention discloses a stiffness monitoring device for a coil spring, comprising: a fixing assembly, the fixing assembly comprising a first fixing component and a second fixing component disposed opposite to each other in the deformation direction of the coil spring, with the coil spring fixedly disposed between the first and second fixing components; a pressure detecting component disposed on the fixing assembly and detecting the pressure applied to the coil spring in the deformation direction; a distance detecting component extending along the deformation direction and fixed between the first and second fixing components; and a distance detecting component comprising a first sliding member and a second sliding member that are relatively slidable in the deformation direction. The first sliding member is provided with a signal transmitter, and the second sliding member is provided with a plurality of signal receivers, each of which is evenly spaced along the deformation direction and is communicatively connected to a processing component. When the first sliding member slides relative to the second sliding member in the deformation direction, a signal receiver corresponding to the position of the signal transmitter among the signal receivers receives a signal from the signal transmitter and transmits the number of the current signal receiver to the processing component. The processing component calculates the current length of the coil spring based on the number of the current signal receiver.

[0005] With this solution, the pressure sensing component detects the pressure applied to the coil spring in the direction of deformation. Combined with the current length of the coil spring calculated by the processing component, the coil spring's stiffness can be monitored, allowing for timely understanding of the coil spring's stiffness loss rate. If the stiffness loss rate is significant, or if there's a significant difference in stiffness loss between the left and right sides of the vehicle, an alarm can be issued to alert the driver to promptly inspect or replace the coil spring, improving vehicle safety.

[0006] According to another specific embodiment of the present invention, in the stiffness monitoring device of the coil spring disclosed in the embodiment of the present invention, the first sliding member and the second sliding member are both in the shape of long strips extending along the deformation direction, and one end of the first sliding member is fixedly connected to the first fixed component, and the other end is slidably connected to one end of the second sliding member, and the other end of the second sliding member is fixedly connected to the second fixed component; and the first sliding member and the second sliding member are located on the inner side of the coil spring; the first sliding member is provided with protrusions on both sides in the width direction of the first sliding member, and the second sliding member is provided with limiting portions matching the protrusions on both sides in the width direction of the second sliding member; a plurality of rolling components are also provided between the protrusions and the limiting portions and along the length extension direction of the first sliding member; the signal transmitter is provided at the other end of the first sliding member, and the signal receivers are evenly arranged at intervals along the deformation direction at a preset first distance threshold.

[0007] The above solution, with protrusions on both sides of the first sliding member and stoppers on both sides of the second sliding member, prevents the first and second sliding members from deviating in other directions while still being able to slide against each other, thereby improving the accuracy of the calculated current length of the coil spring. Furthermore, a rolling element is provided between the protrusions and the stoppers, further facilitating smoother sliding between the first and second sliding members.

[0008] According to another specific embodiment of the present invention, in the coil spring stiffness monitoring device disclosed in the embodiment of the present invention, the rolling component is a ball; and the preset first distance threshold ranges from 0.5 mm to 1 mm.

[0009] By adopting the above solution and setting the range of the first distance threshold to 0.5 mm to 1 mm, it is possible to achieve a good balance between cost and measurement accuracy.

[0010] According to another specific embodiment of the present invention, in the stiffness monitoring device of the coil spring disclosed in the embodiment of the present invention, the first sliding member is a rod-shaped structure, the second sliding member is a hollow columnar structure, and the first sliding member is sleeved in the second sliding member; the first sliding member and the second sliding member are located on the inner side of the coil spring; wherein, one end of the first sliding member is fixedly connected to the first fixed component, and the other end is slidably connected to one end of the second sliding member, and the other end of the second sliding member is fixedly connected to the second fixed component; the signal transmitter is arranged at the other end of the first sliding member, and the signal receivers are evenly arranged along the deformation direction at a preset second distance threshold.

[0011] According to another specific embodiment of the present invention, in the stiffness monitoring device for a coil spring disclosed in the embodiment of the present invention, the preset second distance threshold value ranges from 0.5 mm to 1 mm.

[0012] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a stiffness monitoring device for a coil spring, wherein the pressure detection component includes a pressure sensor arranged at an end portion of a side where the coil spring is fixed to a first fixed component; and / or the pressure detection component further includes a pressure sensor arranged at an end portion of a side where the coil spring is fixed to a second fixed component; and the signal transmitter is an infrared transmitter and the signal receiver is an infrared receiver.

[0013] An embodiment of the present invention also discloses a stiffness monitoring system for coil springs of a vehicle suspension system, wherein the coil spring corresponding to each wheel in the vehicle suspension system is provided with a stiffness monitoring device for the coil spring as described in any of the above embodiments; wherein, in each stiffness monitoring device, a first fixing component is fixedly connected to the vehicle frame, a second fixing component is fixed to the shock absorber of the suspension system and then connected to the axle of the vehicle, and a processing component is connected to the vehicle controller.

[0014] With this solution, each coil spring in the vehicle suspension system is equipped with a stiffness monitoring device, allowing for monitoring of the coil spring's stiffness, thereby providing timely information on the coil spring's stiffness loss rate. If the stiffness loss rate is significant, or if there is a significant difference in stiffness loss between the left and right coil springs, an alarm is issued to alert the driver to promptly inspect or replace the coil spring, thereby improving vehicle safety.

[0015] The embodiments of the present invention further disclose a method for monitoring the stiffness of a coil spring of a vehicle, which is applicable to the coil spring stiffness monitoring system described in the above embodiments; and the coil spring stiffness monitoring method includes:

[0016] S1: The vehicle controller obtains the vehicle status information at a preset time interval and determines whether the vehicle is started based on the status information;

[0017] If yes, proceed to step S2;

[0018] If not, continue to determine whether the vehicle is started;

[0019] S2: The vehicle controller obtains the vehicle speed information in real time and determines whether the vehicle meets the preset stiffness monitoring conditions based on the speed information;

[0020] If yes, proceed to step S3;

[0021] If not, continue to determine whether the vehicle meets the preset stiffness monitoring conditions;

[0022] S3: The pressure detection component of each stiffness monitoring device obtains the pressure of the corresponding coil spring in the deformation direction, and the processing component calculates the current length of the coil spring and calculates the current stiffness of the coil spring based on the pressure of the coil spring, the current length of the coil spring, and the free length of the coil spring;

[0023] S4: The processing component determines whether the coil spring meets a preset replacement condition based on the current stiffness of the coil spring and the initial stiffness of the coil spring;

[0024] If so, the alarm information is output to the vehicle controller;

[0025] If not, continue to determine whether the coil spring reaches the preset replacement condition.

[0026] According to another specific embodiment of the present invention, in a method for monitoring the stiffness of a coil spring of a vehicle disclosed in an embodiment of the present invention, in step S1, the vehicle status information includes the engine speed and the engine temperature; and in step S2, the preset stiffness monitoring condition is: the current vehicle speed is 0; and in step S4, the preset replacement condition is: the stiffness loss rate of the coil spring is greater than a preset loss rate threshold; or the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is greater than a preset loss rate difference; and the current stiffness of the coil spring is calculated according to the following formula:

[0027]

[0028] Where C1 is the current stiffness of the coil spring, G1 is the pressure on the coil spring, H1 is the current length of the coil spring, and H0 is the free length of the coil spring. The stiffness loss rate of the coil spring is calculated using the following formula:

[0029]

[0030] Where n is the stiffness loss rate of the coil spring, C1 is the current stiffness of the coil spring, and C0 is the initial stiffness of the coil spring. Furthermore, the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is calculated according to the following formula:

[0031] Δn=|nleft-nright|

[0032] Wherein, Δn is the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle, nleft is the stiffness loss rate of any coil spring located on the left side of the vehicle, and nright is the stiffness loss rate of any coil spring located on the right side of the vehicle; and, in step S4, when the preset replacement condition is that the stiffness loss rate of the coil spring is greater than a preset loss rate threshold, after outputting an alarm message to the vehicle controller, the further step S5 is executed;

[0033] S5: The processing component determines whether the stiffness loss rate of the coil spring is greater than a preset limit threshold;

[0034] If yes, output a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset first speed threshold;

[0035] If not, continue to determine whether the stiffness loss rate of the coil spring is greater than a preset limit threshold; and

[0036] In step S4, when the preset replacement condition is that the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is greater than the preset loss rate difference, after outputting an alarm message to the vehicle controller, the process further includes executing step S5':

[0037] S5': The processing component determines whether the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is greater than a preset limit difference;

[0038] If yes, output a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset second speed threshold;

[0039] If not, continue to determine whether the stiffness loss rate of the coil spring is greater than the preset limit difference.

[0040] By adopting the above solution, when the stiffness loss rate of the coil spring is large, the vehicle speed is controlled, which can improve the driving safety of the vehicle.

[0041] According to another specific embodiment of the present invention, in the method for monitoring the stiffness of the coil spring of a vehicle disclosed in the embodiment of the present invention, the preset time interval is 10 minutes to 30 minutes; the preset loss rate threshold range is 60% to 80%; the preset loss rate difference range is 0.3 to 0.5; the preset limit threshold range is 70% to 80%; the preset limit difference range is 0.4 to 0.5; the preset first speed threshold range is 20 km / h to 30 km / h; the preset second speed threshold range is 20 km / h to 30 km / h.

[0042] The beneficial effects of the present invention are:

[0043] The coil spring stiffness monitoring device provided in this solution uses a pressure detection component to detect the pressure applied to the coil spring in the direction of deformation. Combined with the current length of the coil spring calculated by a processing component, the device monitors the coil spring's stiffness, providing timely information on the coil spring's stiffness loss rate. If the stiffness loss rate is significant, or if there's a significant difference in stiffness loss between the left and right sides of the vehicle, an alarm is issued to remind the driver to promptly inspect or replace the coil spring, improving vehicle safety.

[0044] The present invention provides a vehicle suspension system coil spring stiffness monitoring system and a vehicle coil spring stiffness monitoring method. By utilizing the coil spring stiffness monitoring device described above, an alarm message can be promptly issued when the coil spring needs to be replaced, reminding the driver to promptly check or replace the coil spring, thereby improving vehicle driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 1 is a schematic structural diagram of a device for monitoring the stiffness of a coil spring provided in an embodiment of the present invention;

[0046] Figure 2 1 is a schematic structural diagram of a distance detection component provided by an embodiment of the present invention;

[0047] Figure 3 is a structural schematic diagram of a first sliding member provided by an embodiment of the present invention;

[0048] Figure 4 is another structural schematic diagram of a distance detection component provided by an embodiment of the present invention;

[0049] Figure 5 The figure is a flow chart of a method for monitoring the stiffness of a coil spring of a vehicle provided by an embodiment of the present invention.

[0050] Description of reference numerals:

[0051] 1. First fixing component; 2. Second fixing component; 3. Coil spring; 4. First sliding member; 5. Second sliding member; 6. Signal transmitter; 7. Signal receiver; 8. Rolling component. DETAILED DESCRIPTION

[0052] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0053] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0054] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0055] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0056] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0057] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0058] Example 1:

[0059] In order to solve the problem in the prior art that the stiffness value of the coil spring cannot be accurately evaluated, which easily affects the driving safety of the vehicle, an embodiment of the present invention provides a coil spring stiffness monitoring device. Specifically, referring to Figure 1 The coil spring stiffness monitoring device provided in this embodiment includes a fixing component, a pressure detection component, and a distance detection component.

[0060] Further, in the stiffness monitoring device of the coil spring according to the present invention, referring to Figure 1 The fixing assembly includes a first fixing component 1 and a second fixing component 2 that are arranged relative to each other in the deformation direction of the coil spring 3, and the coil spring 3 is fixedly arranged between the first fixing component 1 and the second fixing component 2. Specifically, the deformation direction of the coil spring 3 refers to the compression direction or the tension direction of the coil spring 3. The coil spring 3 of the vehicle suspension system has only one compressed state. Therefore, when the coil spring 3 is the coil spring 3 of the vehicle suspension system, the deformation direction is the compression direction of the coil spring 3. The first fixing component 1 and the second fixing component 2 are plate-like components, and in order to ensure the fixing effect and rigidity, metal materials are generally selected. The coil spring 3 is fixed to the first fixing component 1 and the second fixing component 2 by welding, screwing, or clamping.

[0061] Further, in the stiffness monitoring device of the coil spring according to the present invention, referring to Figure 1 The pressure detection component is arranged on the fixed component to detect the pressure on the coil spring 3 in the deformation direction. In order to ensure the detection effect, the pressure detection component is preferably arranged on the surface of the fixed component, close to the side of the coil spring 3.

[0062] Further, in the stiffness monitoring device of the coil spring according to the present invention, referring to Figure 1 The distance detection component extends along the deformation direction and is fixed between the first fixing component 1 and the second fixing component 2. Figure 2 The distance detection component includes a first sliding member 4 and a second sliding member 5 that can slide relative to each other along the deformation direction. Figure 3 , a signal transmitter 6 is provided on the first sliding member 4, referring to Figure 4 The second sliding member 5 is provided with a plurality of signal receivers 7, each of which is evenly spaced along the deformation direction and is in communication with a processing component. Specifically, the processing component can be an electronic component provided within the first fixed component 1 or the second fixed component 2 and having data transmission and processing functions.

[0063] Furthermore, in the coil spring stiffness monitoring device according to the present invention, when the first sliding member 4 slides relative to the second sliding member 5 in the deformation direction, the signal receiver 7 corresponding to the position of the signal transmitter 6 among the signal receivers 7 receives the signal from the signal transmitter 6 and transmits the number of the current signal receiver 7 to the processing unit. The processing unit calculates the current length of the coil spring 3 based on the number of the current signal receiver 7. Specifically, the second sliding member 5 is evenly spaced along the deformation direction of the coil spring 3. The numbers can be increasing or decreasing from one end of the second sliding member 5 to the other. The processing unit pre-stores the position corresponding to each signal receiver 7, that is, the distance from one end or the other end of the second sliding member 5. This distance is used to calculate the length of the overlapping portion of the first sliding member 4 and the second sliding member 5. Furthermore, the processing unit also pre-stores the lengths of the first sliding member 4 and the second sliding member 5. Based on the lengths of the first sliding member 4 and the second sliding member 5, as well as the length of the overlapping portion of the first sliding member 4 and the second sliding member 5, the processing unit can calculate the current length of the coil spring 3. More specifically, the processing component receives the pressure detected by the pressure detection component on the first fixing component 1 or the second fixing component 2. Furthermore, after calculating the current length of the coil spring 3, the processing component can further determine the stiffness of the coil spring 3 based on the current length of the coil spring 3 and the pressure applied to the coil spring 3 in the deformation direction. With this structure, the stiffness of the coil spring 3 can be monitored by detecting the pressure applied to the coil spring in the deformation direction through the pressure detection component, combined with the current length of the coil spring calculated by the processing component, thereby enabling timely understanding of the stiffness loss rate of the coil spring 3. When the stiffness loss rate is large, or when there is a significant difference in the stiffness loss rate of the coil spring 3 on the left and right sides of the vehicle, an alarm can be issued promptly to remind the driver to promptly inspect or replace the coil spring 3, thereby improving vehicle driving safety.

[0064] Further, in the stiffness monitoring device of the coil spring according to the present invention, referring to Figure 2 The first sliding member 4 and the second sliding member 5 are both in the shape of an elongated strip extending in the deformation direction, with one end of the first sliding member 4 fixedly connected to the first fixing component 1 and the other end slidably connected to one end of the second sliding member 5. The other end of the second sliding member 5 is fixedly connected to the second fixing component 2. Specifically, the methods for fixing one end of the first sliding member 4 and the other end of the second sliding member 5 to the second fixing component 2 include, but are not limited to, bonding, welding, etc.

[0065] Furthermore, in the coil spring stiffness monitoring device according to the present invention, the first sliding member 4 and the second sliding member 5 are located inside the coil spring 3. The first sliding member 4 is provided with protrusions on both sides of its width, and the second sliding member 5 is provided with stoppers that match the protrusions on both sides of its width. Multiple rolling components 8 are also provided between the protrusions and the stoppers, along the length of the first sliding member 4. A signal transmitter 6 is provided at the other end of the first sliding member 4, and the signal receivers 7 are evenly spaced along the deformation direction at a predetermined first distance threshold. Specifically, the rolling components 8 are ball bearings. The predetermined first distance threshold is in the range of 0.5 mm to 1 mm, for example, 0.5 mm, 0.75 mm, 1 mm, or other values within this range. Arranging the signal receivers 7 at the predetermined first distance threshold avoids the high cost associated with continuously arranging the signal receivers 7. Of course, the first distance threshold cannot be too large, otherwise the measurement will be inaccurate, nor too small, otherwise the cost will increase. Setting the first distance threshold in the range of 0.5 mm to 1 mm achieves an optimal balance between cost and measurement accuracy. Furthermore, by providing protrusions on both sides of the first sliding member 4 and limiting portions on both sides of the second sliding member 5, the first sliding member 4 and the second sliding member 5 can be prevented from deflecting in other directions while being able to slide against each other, thereby improving the accuracy of the calculated current length of the coil spring 3. Furthermore, by providing a rolling component 8 between the protrusion and the limiting portion, the sliding between the first sliding member 4 and the second sliding member 5 is smoother and the frictional resistance between the first sliding member 4 and the second sliding member 5 is reduced. It should be noted that the rolling components 8 are also arranged at equal intervals, with the distance between adjacent rolling components 8 being approximately 1 cm to 5 cm. The ball bearing can rotate about its axis relative to the outer wall of the first sliding member 4 and is secured to the inner wall of the second sliding member 5 via a fixing rod.

[0066] Furthermore, in the stiffness monitoring device of the coil spring according to the present invention, the pressure detection component includes a pressure sensor provided at one end portion of the coil spring 3 fixed to the first fixed component 1. The pressure detection component also includes a pressure sensor provided at one end portion of the coil spring 3 fixed to the second fixed component 2. That is, the pressure detection component can be provided on the first fixed component 1, and when the coil spring 3 is compressed downward, the pressure detection component provided on the first fixed component 1 detects the upward thrust of the coil spring 3. The pressure detection component can also be provided on the second fixed component 2, and when the coil spring 3 is compressed downward, the pressure detection component provided on the second fixed component 2 detects the downward pressure of the coil spring 3. Of course, pressure sensors can also be provided on both the first fixed component 1 and the second fixed component 2. With this approach, the pressure of the coil spring 3 can also be monitored when one of the pressure sensors fails.

[0067] Furthermore, in the coil spring stiffness monitoring device according to the present invention, the signal transmitter 6 is an infrared transmitter, and the signal receiver 7 is an infrared receiver. Specifically, the infrared transmitter transmits an infrared signal, and the infrared receiver capable of receiving the infrared signal transmitted by the infrared transmitter is the signal receiver 7 corresponding to the position of the signal transmitter 6.

[0068] Example 2:

[0069] This embodiment also provides a stiffness monitoring device for a coil spring. The stiffness monitoring device for a coil spring in this embodiment differs from that in Example 1 only in that the structures of the first sliding member and the second sliding member are different. Specifically, in this embodiment, the first sliding member is a rod-shaped structure, the second sliding member is a hollow cylindrical structure, and the first sliding member is sleeved inside the second sliding member. The first sliding member and the second sliding member are located on the inner side of the coil spring. The inner side of the coil spring refers to the side that is closer to the center of the coil spring when viewed from a vertical direction. In addition, the first sliding member is preferably a rod-shaped structure with a circular cross-section, and the second sliding member is preferably a hollow cylindrical structure, so that even if the first sliding member and the second sliding member are rotated to various angles in their radial direction, they can still slide relative to each other.

[0070] Furthermore, in the coil spring stiffness monitoring device according to the present invention, one end of the first sliding member is fixedly connected to the first fixing component, and the other end is slidably connected to one end of the second sliding member, and the other end of the second sliding member is fixedly connected to the second fixing component. Methods for directly fixing the first sliding member and the second sliding member to the first and second fixing components include, but are not limited to, bonding, welding, and clamping.

[0071] Furthermore, in the stiffness monitoring device for the coil spring according to the present invention, a signal transmitter is provided at the other end of the first sliding member, and the signal receivers are evenly spaced along the deformation direction at a preset second distance threshold. Specifically, the preset second distance threshold ranges from 0.5 mm to 1 mm, such as 0.5 mm, 0.75 mm, 1 mm, or other values within this range. Arranging the signal receivers at the preset second distance threshold can prevent the high cost problem caused by the continuous arrangement of signal receivers. Of course, the second distance threshold cannot be selected too large, otherwise the measurement will be inaccurate; nor can it be selected too small, otherwise the cost will increase. Setting the second distance threshold to a range of 0.5 mm to 1 mm can achieve a good balance between cost and measurement accuracy.

[0072] Furthermore, in the coil spring stiffness monitoring device according to the present invention, a rolling component, such as a roller or pulley, may be disposed between the outer circumferential wall of the first sliding member and the inner circumferential wall of the second sliding member to facilitate smoother relative sliding between the first and second sliding members. The arrangement of the rolling component is similar to that of Example 1 and is not further described here.

[0073] Example 3:

[0074] Based on the aforementioned coil spring stiffness monitoring device, this embodiment provides a coil spring stiffness monitoring system for a vehicle suspension system. Each coil spring corresponding to each wheel in the vehicle suspension system is equipped with a coil spring stiffness monitoring device as described in any of the above embodiments. This embodiment uses a vehicle suspension system equipped with four coil springs: left front, left rear, right front, and right rear. Of course, those skilled in the art can adapt this embodiment to accommodate suspension systems equipped with two, six, or even more coil springs.

[0075] In each stiffness monitoring device, a first fixing component is fixedly connected to the vehicle frame, a second fixing component is fixed to the suspension system's shock absorber, and then connected to the vehicle's axle, and a processing component is connected to the vehicle controller. Specifically, the first fixing component is connected to the frame by screws or welding, and the second fixing component is connected to the shock absorber by snap-fit or welding. The processing component is connected to the vehicle controller via wireless communication, reducing wiring and facilitating data transmission between the processing component and the vehicle controller.

[0076] During the actual installation process, the signal transmitter is first installed on the first sliding member, the signal receiver is installed on the second sliding member, and the first and second sliding members are assembled to form a distance detection component. The pressure detection component is then installed on the fixed assembly. After the fixed assembly and the distance detection component are ready, the first fixed assembly is threadedly connected to the frame, and the distance detection component is welded to the side of the first fixed assembly away from the frame. The coil spring is then sleeved on the outside of the distance detection component, and one end of the coil spring is clamped to the first fixed assembly. The second fixed assembly is then fixed to the other end of the coil spring and the other end of the distance detection component, and the second fixed assembly is welded to the end of the shock absorber away from the axle, thereby providing a stiffness monitoring device for each coil spring in the vehicle suspension system.

[0077] Because each coil spring in the vehicle's suspension system is equipped with a stiffness monitoring device, the stiffness of the coil spring can be monitored, allowing for timely monitoring of the coil spring's stiffness loss rate. If the stiffness loss rate is significant, or if there is a significant difference in stiffness loss between the left and right coil springs, an alarm will be issued to remind the driver to promptly inspect or replace the coil spring, improving vehicle safety.

[0078] Example 4:

[0079] Based on the above-mentioned coil spring stiffness monitoring system, an embodiment of the present invention further provides a method for monitoring the stiffness of a coil spring of a vehicle, which is applicable to the coil spring stiffness monitoring system described in the above embodiment.

[0080] Specifically, refer to Figure 5 , the stiffness monitoring methods of coil springs include:

[0081] S1: The vehicle controller obtains the vehicle status information at a preset time interval and determines whether the vehicle is started based on the status information;

[0082] If yes, proceed to step S2;

[0083] If not, continue to determine whether the vehicle is started;

[0084] S2: The vehicle controller obtains the vehicle speed information in real time and determines whether the vehicle meets the preset stiffness monitoring conditions based on the speed information;

[0085] If yes, proceed to step S3;

[0086] If not, continue to determine whether the vehicle meets the preset stiffness monitoring conditions;

[0087] S3: The pressure detection component of each stiffness monitoring device obtains the pressure of the corresponding coil spring in the deformation direction, and the processing component calculates the current length of the coil spring and calculates the current stiffness of the coil spring based on the pressure of the coil spring, the current length of the coil spring, and the free length of the coil spring;

[0088] S4: The processing component determines whether the coil spring meets a preset replacement condition based on the current stiffness of the coil spring and the initial stiffness of the coil spring;

[0089] If so, the alarm information is output to the vehicle controller;

[0090] If not, continue to determine whether the coil spring reaches the preset replacement condition.

[0091] Specifically, in step S1, the preset time interval is 10 to 30 minutes; for example, it can be 10, 20, 30 minutes, or other time periods within this range. Acquiring vehicle status information at preset time intervals can reduce computational complexity compared to real-time acquisition. However, the preset time interval cannot be too long, otherwise it will cause a lag in coil spring stiffness monitoring, affecting driving safety. Therefore, setting the preset time interval to 10 to 30 minutes can minimize computational complexity without compromising driving safety. More specifically, vehicle status information includes engine speed and engine temperature. Engine speed can be measured by an engine speed sensor, and engine temperature can be measured by an engine temperature sensor. When the engine speed exceeds a certain speed, such as 10 rad / s, the vehicle is started; or when the engine temperature exceeds a certain temperature, such as 75°C, the vehicle is started. Determining vehicle start based on engine speed and engine temperature is more accurate because the engine status is directly related to vehicle start. It should be noted that in some new energy vehicles without engines, the vehicle's power-on status can be detected to determine whether the vehicle is started.

[0092] In step S2, the preset stiffness monitoring condition is that the vehicle's current speed is zero. In other words, whenever the vehicle's speed reaches zero, the preset stiffness monitoring condition is met, and the subsequent stiffness monitoring steps can proceed. This step, which monitors stiffness when the vehicle's speed is zero, not only reduces computational costs but also, because the vehicle is relatively stable at zero speed, provides more accurate stiffness calculations.

[0093] In step S4, the preset replacement conditions are: the stiffness loss rate of the coil spring is greater than a preset loss rate threshold; or the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is greater than a preset loss rate difference. Specifically, in this embodiment, the stiffness of each coil spring is monitored using a stiffness monitoring device corresponding to each coil spring. When the stiffness loss rate of any coil spring exceeds the preset loss rate threshold, the corresponding coil spring is replaced. When the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is greater than the preset loss rate difference, the coil spring with the greater loss rate needs to be replaced. More specifically, the preset loss rate threshold ranges from 60% to 80%, for example, 60%, 70%, 80%, or other values within this range. The preset loss rate difference ranges from 0.3 to 0.5, for example, 0.3, 0.35, 0.5, or other values within this range.

[0094] Furthermore, in the method for monitoring the stiffness of the coil spring of the vehicle of the present invention, the current stiffness of the coil spring is calculated according to the following formula:

[0095]

[0096] Among them, C1 is the current stiffness of the coil spring, G1 is the pressure on the coil spring, H1 is the current length of the coil spring, and H0 is the free length of the coil spring.

[0097] Furthermore, in the method for monitoring the stiffness of the coil spring of the vehicle of the present invention, the stiffness loss rate of the coil spring is calculated according to the following formula:

[0098]

[0099] Where n is the stiffness loss rate of the coil spring, C1 is the current stiffness of the coil spring, and C0 is the initial stiffness of the coil spring.

[0100] Furthermore, in the method for monitoring the stiffness of the coil spring of the vehicle of the present invention, the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is calculated according to the following formula:

[0101] Δn=|nleft-nright|

[0102] Among them, Δn is the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle, nleft is the stiffness loss rate of any coil spring located on the left side of the vehicle, and nright is the stiffness loss rate of any coil spring located on the right side of the vehicle.

[0103] Furthermore, in the method for monitoring the stiffness of the coil spring of the vehicle of the present invention, in step S4, when the preset replacement condition is that the stiffness loss rate of the coil spring is greater than a preset loss rate threshold, after outputting an alarm message to the vehicle controller, the method further includes executing step S5;

[0104] S5: The processing component determines whether the stiffness loss rate of the coil spring is greater than a preset limit threshold;

[0105] If yes, output a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset first speed threshold;

[0106] If not, continue to determine whether the stiffness loss rate of the coil spring is greater than a preset limit threshold.

[0107] Specifically, the preset limit threshold ranges from 70% to 80%, for example, it can be 70%, 75%, 80%, or other values within this range. The preset first speed threshold ranges from 20km / h to 30km / h; for example, it can be 20km / h, 25km / h, 30km / h, or other values within this range. In other words, when the stiffness of the coil spring is greater than the preset limit threshold, the vehicle speed needs to be controlled. In actual use, if it is detected that the coil spring needs to be replaced, and the owner does not have a replacement coil spring at the time, the vehicle needs to be driven to an after-sales service or repair center for replacement. During the process of driving to the after-sales service or repair center, the vehicle speed needs to be controlled to prevent the vehicle from rolling over or other hazards. With this method, when the stiffness loss rate of the coil spring is large, controlling the vehicle speed can improve the driving safety of the vehicle.

[0108] Furthermore, in the vehicle coil spring stiffness monitoring method of the present invention, in step S4, when the preset replacement condition is that the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is greater than a preset loss rate difference, after outputting an alarm message to the vehicle controller, the method further includes executing step S5':

[0109] S5': The processing component determines whether the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is greater than a preset limit difference;

[0110] If yes, output a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset second speed threshold;

[0111] If not, continue to determine whether the stiffness loss rate of the coil spring is greater than the preset limit difference.

[0112] Specifically, the preset limit difference ranges from 0.4 to 0.5; for example, it can be 0.4, 0.45, 0.5, or other values within this range. The preset second speed threshold ranges from 20 km / h to 30 km / h, for example, it can be 20 km / h, 25 km / h, 30 km / h, or other values within this range. In other words, when the stiffness loss rate of the coil spring is greater than the preset limit difference, the vehicle speed needs to be controlled. In actual use, if it is detected that the coil spring needs to be replaced and the owner does not have a replacement coil spring at the time, the vehicle needs to be driven to an after-sales service or repair center for replacement. During the journey to the after-sales service or repair center, the vehicle speed needs to be controlled to prevent the vehicle from rolling over or other hazards. With this method, when the stiffness loss rate of the coil spring is large, controlling the vehicle speed can improve vehicle driving safety.

[0113] Example 5:

[0114] Based on the above-mentioned method for monitoring the stiffness of a coil spring, this embodiment provides a specific method for monitoring the stiffness of a coil spring.

[0115] Specifically, the vehicle controller (VCU) obtains the vehicle's engine speed at 30-minute intervals. When the speed exceeds 10 rad / s, the vehicle is started, and the VCU begins executing the step of acquiring vehicle speed information in real time. When the vehicle speed reaches zero, the VCU sends a command to the stiffness monitoring device, which begins monitoring the stiffness of all coil springs in the vehicle's suspension system. The processing unit of the stiffness monitoring device stores a preset loss rate threshold, a preset loss rate difference, a preset limit threshold, and a preset limit difference. When the processing unit of the stiffness monitoring device calculates the current stiffness of the coil spring, it compares the current stiffness with the pre-stored data. If the coil spring stiffness loss rate exceeds the preset loss rate threshold, or if the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle exceeds the preset loss rate difference, an alarm is output to the VCU, which then generates an alarm prompt message to the instrument panel or central control screen, prompting the driver to replace the coil spring. If the coil spring loss rate exceeds a preset threshold, or the difference between the loss rate of either coil spring on the left side of the vehicle and the loss rate of either coil spring on the right side exceeds a preset threshold, the coil springs are insufficient to support the vehicle, posing a high driving risk. If the coil springs cannot be replaced promptly, the vehicle's speed should be controlled to reduce the risk of a dangerous situation.

[0116] Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood by those skilled in the art that the above description is provided as a further detailed description of the present invention in conjunction with specific embodiments thereof, and that the specific implementation of the present invention is not limited to these descriptions. Those skilled in the art may make various changes in form and details, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A device for monitoring the stiffness of a coil spring, characterized in that: include: a fixing assembly comprising a first fixing member and a second fixing member disposed opposite to each other in a deformation direction of the coil spring, wherein the coil spring is fixedly disposed between the first fixing member and the second fixing member; a pressure detection component, the pressure detection component being provided on the fixing assembly and detecting the pressure exerted on the coil spring in the deformation direction; a distance detecting component extending along the deformation direction and fixed between the first fixing component and the second fixing component; and The distance detecting component includes a first sliding member and a second sliding member that can slide relatively along the deformation direction; in A signal transmitter is provided on the first sliding member, and a plurality of signal receivers are provided on the second sliding member, wherein the signal receivers are evenly spaced along the deformation direction and are all in communication connection with the processing component; One end of the first sliding member is fixedly connected to the first fixing component, and the other end is slidably connected to one end of the second sliding member, and the other end of the second sliding member is fixedly connected to the second fixing component; and the signal transmitter is arranged at the other end of the first sliding member; When the first sliding member slides relative to the second sliding member along the deformation direction, the signal receiver corresponding to the position of the signal transmitter among the signal receivers receives the signal from the signal transmitter and sends the number information of the current signal receiver to the processing component; The processing component calculates the current length of the coil spring based on the number information from the current signal receiver. The processing component pre-stores the distance between each signal receiver and one end or the other end of the second sliding member. The length of the overlapping part of the first sliding member and the second sliding member can be calculated using the distance. The processing component also pre-stores the lengths of the first sliding member and the second sliding member.

2. The coil spring stiffness monitoring device according to claim 1, wherein: The first sliding member and the second sliding member are both in the shape of long strips extending along the deformation direction, and The first sliding member and the second sliding member are located inside the coil spring; The first sliding member is provided with protruding portions on both sides in the width direction thereof, and the second sliding member is provided with limiting portions matching the protruding portions on both sides in the width direction thereof; A plurality of rolling components are further provided between the protruding portion and the limiting portion and along the length extension direction of the first sliding member; The signal receivers are evenly spaced along the deformation direction at a preset first distance threshold.

3. The coil spring stiffness monitoring device according to claim 2, wherein: The rolling component is a ball; The preset first distance threshold ranges from 0.5 mm to 1 mm.

4. The coil spring stiffness monitoring device according to claim 1, wherein: The first sliding member is a rod-shaped structure, and the second sliding member is a hollow columnar structure. The first sliding member is sleeved inside the second sliding member. The first sliding member and the second sliding member are located inside the coil spring. The signal receivers are evenly spaced along the deformation direction at a preset second distance threshold.

5. The coil spring stiffness monitoring device according to claim 4, characterized in that: The preset second distance threshold ranges from 0.5 mm to 1 mm.

6. The coil spring stiffness monitoring device according to claim 1, wherein: in The pressure detection component includes a pressure sensor provided at an end portion of one side of the coil spring fixed to the first fixing component; and / or The pressure detection component further includes a pressure sensor provided at one end portion of the coil spring fixed to the second fixing component; and The signal transmitter is an infrared transmitter, and the signal receiver is an infrared receiver.

7. A stiffness monitoring system for a coil spring of a vehicle suspension system, characterized in that: The coil spring corresponding to each wheel in the vehicle suspension system is provided with a coil spring stiffness monitoring device according to any one of claims 1 to 6; wherein In each of the stiffness monitoring devices, the first fixing component is fixedly connected to the vehicle frame, the second fixing component is fixed to the shock absorber of the suspension system and then connected to the axle of the vehicle, and the processing component is connected to the vehicle controller of the vehicle.

8. A method for monitoring the stiffness of a coil spring of a vehicle, characterized in that: A stiffness monitoring system for a coil spring according to claim 7; and The method for monitoring the stiffness of the coil spring comprises: S1: The vehicle controller obtains vehicle status information at preset time intervals and determines whether the vehicle is started based on the status information; If yes, proceed to step S2; If not, continue to determine whether the vehicle is started; S2: The vehicle controller obtains the vehicle speed information in real time and determines whether the vehicle meets the preset stiffness monitoring condition based on the vehicle speed information; If yes, proceed to step S3; If not, continue to determine whether the vehicle meets the preset stiffness monitoring conditions; S3: the pressure detection component of each stiffness monitoring device obtains the pressure exerted on the corresponding coil spring in the deformation direction, the processing component calculates the current length of the coil spring, and calculates the current stiffness of the coil spring based on the pressure exerted on the coil spring, the current length of the coil spring, and the free length of the coil spring; S4: the processing component determines whether the coil spring meets a preset replacement condition based on the current stiffness of the coil spring and the initial stiffness of the coil spring; If so, output an alarm message to the vehicle controller; If not, continue to determine whether the coil spring meets the preset replacement condition.

9. The method for monitoring the stiffness of a coil spring of a vehicle according to claim 8, wherein: In step S1, the vehicle status information includes engine speed and engine temperature; and In step S2, the preset stiffness monitoring conditions are: The vehicle's current speed is 0; and In step S4, the preset replacement condition is: The stiffness loss rate of the coil spring is greater than a preset loss rate threshold; or The difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is greater than a preset loss rate difference; and The current stiffness of the coil spring is calculated according to the following formula: Wherein, C1 is the current stiffness of the coil spring, G1 is the pressure on the coil spring, H1 is the current length of the coil spring, and H0 is the free length of the coil spring; and The stiffness loss rate of the coil spring is calculated according to the following formula: Wherein, n is the stiffness loss rate of the coil spring, C1 is the current stiffness of the coil spring, and C0 is the initial stiffness of the coil spring; and Calculate the difference between the rate of spring loss of any coil spring located on the left side of the vehicle and the rate of spring loss of any coil spring located on the right side of the vehicle using the following formula: Δn=|nleft-nright| wherein Δn is the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle, nleft is the stiffness loss rate of any coil spring located on the left side of the vehicle, and nright is the stiffness loss rate of any coil spring located on the right side of the vehicle; and In the step S4, when the preset replacement condition is that the stiffness loss rate of the coil spring is greater than a preset loss rate threshold, after outputting an alarm message to the vehicle controller, the process further includes executing step S5; S5: The processing component determines whether the stiffness loss rate of the coil spring is greater than a preset limit threshold; If yes, outputting a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset first speed threshold; If not, continue to determine whether the stiffness loss rate of the coil spring is greater than a preset limit threshold; and In step S4, when the preset replacement condition is that the difference between the stiffness loss rate of any coil spring located on the left side of the vehicle and the stiffness loss rate of any coil spring located on the right side of the vehicle is greater than the preset loss rate difference, after outputting the alarm information to the vehicle controller, the process further includes executing step S5': S5': the processing component determines whether the difference between the stiffness loss rate of any coil spring on the left side of the vehicle and the stiffness loss rate of any coil spring on the right side of the vehicle is greater than a preset limit difference; If yes, outputting a prompt message to the vehicle controller to control the vehicle to travel at a speed lower than a preset second speed threshold; If not, continue to determine whether the stiffness loss rate of the coil spring is greater than a preset limit difference.

10. The method for monitoring the stiffness of a coil spring of a vehicle according to claim 9, wherein: The preset time interval is 10 minutes to 30 minutes; The preset loss rate threshold ranges from 60% to 80%; The preset loss rate difference ranges from 0.3 to 0.5; The preset limit threshold ranges from 70% to 80%; The preset limit difference ranges from 0.4 to 0.5; The preset first speed threshold range is 20km / h to 30km / h; The preset second speed threshold ranges from 20 km / h to 30 km / h.

Images