CN117168793A

CN117168793A - Spring fatigue detection device and method

Info

Publication number: CN117168793A
Application number: CN202311282861.9A
Authority: CN
Inventors: 张凯生
Original assignee: Shenzhen Zhong Shen Ai Di Bedding Technology Co ltd
Current assignee: Shenzhen Zhong Shen Ai Di Bedding Technology Co ltd
Priority date: 2023-09-27
Filing date: 2023-09-27
Publication date: 2023-12-05

Abstract

The application relates to a spring fatigue detection device and a method, wherein the device comprises a base and a support frame; the clamping assemblies comprise a plurality of clamping pieces which are mutually far away from the base and are elastically arranged in a sliding manner, and the clamping pieces are suitable for being abutted against the inner wall of the spring; the pressing assembly comprises a pressing driving piece, a lifting plate, a plurality of pressing pieces and a plurality of adjusting pieces, wherein the pressing driving piece is arranged on the supporting frame and is connected with the lifting plate in a driving mode to drive the lifting plate to move in a lifting mode, the pressing pieces are connected with the lifting plate through the adjusting pieces respectively, the pressing pieces are opposite to the clamping assemblies in the vertical direction, and the adjusting pieces are used for adjusting the height of the pressing pieces relative to the lifting plate. According to the application, the height of the pressing piece relative to the lifting plate is changed, so that when a plurality of pressing pieces descend, the deformation amounts of all springs are ensured to meet the requirements, the detection consistency is better, and the detected result is more convincing.

Description

Spring fatigue detection device and method

Technical Field

The application relates to the technical field of detection, in particular to a spring fatigue detection device and method.

Background

The fatigue characteristic of the spring is an important index of the spring, and is a fracture phenomenon generated after the spring is extruded and deformed, and cracks are generated after the metal is deformed, which is generally small and even can be ignored sometimes, but the cracks are increased and the crack gap is increased due to frequent deformation, so that the spring is finally fatigued.

In the furniture industry, springs are commonly used in mattresses to function as resilient supports. Because the daily frequency of use of mattress is higher, the spring in the mattress also needs to satisfy after tens of thousands of deformation, still has good elasticity performance to guarantee the life of mattress.

In the related art, the bottom end of the spring is fixed, and the air cylinder is used for driving the pressing plate to move up and down, so that the spring is deformed in a reciprocating manner, and tens of thousands of times of deformation are continuously caused. After the test is finished, the state of the spring is checked to judge whether the spring is qualified or not. Multiple springs of the same type may also be tested simultaneously.

In the fatigue test engineering of the spring, the deformation length of the spring needs to be determined according to the self length and the deformation proportion of the spring. When springs with different lengths are tested simultaneously, the pressing plate descends, so that when the longer spring reaches the deformation length, the deformation size of the shorter spring is still smaller than the required deformation size. Therefore, it is difficult to detect springs of different lengths at the same time in the related art.

Disclosure of Invention

The embodiment of the application provides a device and a method for detecting spring fatigue, which are used for solving the technical problem that springs with different lengths are difficult to detect simultaneously in the related art.

In a first aspect, a spring fatigue detection device is provided, which includes a base and a support frame fixed to the base, and further includes:

the clamping assemblies are arranged on the base and used for fixing the springs, each clamping assembly comprises a plurality of clamping pieces, the clamping pieces are mutually far away from each other and are elastically and slidably arranged on the base, and the clamping pieces are suitable for being abutted against the inner walls of the springs;

the pressing assembly comprises a pressing driving piece, a lifting plate, a plurality of pressing pieces and a plurality of adjusting pieces, wherein the pressing driving piece is arranged on the supporting frame and is in driving connection with the lifting plate so as to drive the lifting plate to move in a lifting mode, the pressing pieces are respectively connected with the lifting plate through the adjusting pieces, the pressing pieces are respectively opposite to the clamping assemblies in the vertical direction one by one so as to be used for pressing down the springs, and the adjusting pieces are used for adjusting the height of the pressing pieces relative to the lifting plate;

the sensing module comprises a plurality of pressure sensing pieces, and the pressure sensing pieces are respectively arranged on the bottom surfaces of the pressing pieces.

In some embodiments, the spring fatigue detection device further comprises a control module, wherein the control module is electrically connected with the sensing module, and the control module is suitable for outputting the stiffness coefficient of each spring pressed and generating a curve of the stiffness coefficient of each spring changing with the number of times of pressing.

In some embodiments, the adjusting member includes a screw mechanism, the screw mechanism is mounted on the lifting plate, and the screw mechanism is in driving connection with the pressing member, so as to drive the pressing member to move in a vertical direction relative to the lifting plate.

In some embodiments, the clamping assembly further includes a plurality of clamping elastic members, two ends of the clamping elastic members are respectively connected with the clamping member and the base, and the plurality of clamping elastic members are made to be far away from each other by elastic force of the clamping elastic members.

In some embodiments, the clamping assembly further comprises a clamping member, the clamping member comprises a clamping circular table, the clamping circular table is in lifting motion with the base, the clamping circular table is located in the middle of the clamping members, and the circumferential side surface of the clamping circular table is clamped with the clamping members.

In some embodiments, the spring fatigue detection device further comprises a visual detection member, wherein the detection direction of the visual detection member is set towards the spring on the base and is used for detecting whether the spring deflects.

The technical scheme provided by the application has the beneficial effects that:

the embodiment of the application provides a spring fatigue detection device, which is characterized in that when a plurality of springs are subjected to fatigue detection, the springs are respectively arranged on a base, and are respectively fixed through a plurality of clamping assemblies. And the lifting plate is driven to move up and down by the pushing-down driving piece, and the plurality of pushing-down pieces synchronously lift so as to enable the plurality of springs to deform simultaneously, so that the plurality of springs can be detected simultaneously, and the detection efficiency is improved. In addition, according to the length of the spring, the height of the pressing piece relative to the lifting plate is correspondingly adjusted, so that when the spring is synchronously pressed down, the compression ratios of the springs with different lengths are kept consistent, the deformation amounts of all the springs are ensured to meet the requirements, the detection consistency is better, and the detected result is more convincing.

In addition, due to the arrangement of the pressure sensing piece, when the pressing piece descends, the pressing piece can be determined to touch the spring through the pressure sensing piece, so that the working starting point of the pressing piece is determined, and when the pressing piece descends, the spring is directly compressed, so that idle stroke when the pressing piece moves is eliminated, and the detection efficiency of the spring is improved.

In a second aspect, there is provided a spring fatigue detection method, based on the spring fatigue detection device as described above, comprising the steps of:

acquiring lengths of a plurality of springs;

determining the deformation length of each spring according to the lengths of the springs and a preset compression ratio;

a plurality of springs are arranged on the base and are respectively fixed by a plurality of clamping assemblies;

selecting the longest spring and calculating the height compensation value of the pressing piece corresponding to the rest springs;

according to the height compensation value, the height of the pressing piece is adjusted;

determining the pressing stroke of the whole pressing piece according to the deformation length of the longest spring;

the plurality of pressing pieces are enabled to synchronously lift up and down for preset test times according to preset test speed;

judging whether the spring is qualified or not according to the stiffness coefficient of the spring.

In some embodiments, the selecting the longest spring and calculating the height compensation value of the hold-down corresponding to the remaining springs includes:

calculating the length difference between the longest spring and the rest springs;

and calculating a height compensation value according to the length difference and the compression ratio.

In some embodiments, before the step of synchronously lifting the plurality of pressing members at the preset test speed for a preset number of tests, the method further includes obtaining a working start point of the pressing members, where the step of obtaining the working start point of the pressing members includes:

lowering the plurality of hold-down members;

when the pressure sensing piece on the lower pressing piece corresponding to the longest spring detects the pressure, the height position of the pressing piece is recorded, so that the working starting point of the lower pressing piece is obtained.

In some embodiments, the determining whether the spring is acceptable based on the stiffness coefficient of the spring comprises:

acquiring the stiffness coefficient of the spring when the spring is deformed under pressure each time;

calculating the difference between the stiffness coefficient of the spring in each deformation and the stiffness coefficient of the spring in the first deformation, and enabling the difference to be a detection value;

judging whether the detection value obtained by each deformation of the spring is in a preset standard fluctuation range, if so, the spring is qualified, otherwise, the spring is unqualified.

In another embodiment of the present application, a method for detecting fatigue of a spring is provided, and because the method for detecting fatigue of a spring is based on the device for detecting fatigue of a spring, the beneficial effects of the method for detecting fatigue of a spring are consistent with those of the device for detecting fatigue of a spring, and are not described herein.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a spring fatigue detection device according to an embodiment of the present application;

FIG. 2 is a schematic view of a base and clamping assembly provided by an embodiment of the present application;

FIG. 3 is a schematic view of a base, clamping assembly and spring provided in an embodiment of the present application;

FIG. 4 is a front view of a spring fatigue detection device according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a pressing member in a working starting position in a spring fatigue detection device according to an embodiment of the present application;

fig. 6 is a schematic diagram of a spring according to an embodiment of the present application after deformation according to a compression ratio.

In the figure: 1. a base; 2. a support frame; 3. a clamping assembly; 31. a clamping piece; 32. clamping the elastic piece; 33. a tightening member; 331. abutting the round table; 332. tightly supporting the screw rod; 4. pressing down the assembly; 41. pressing down the driving piece; 42. a lifting plate; 43. a pressing piece; 44. an adjusting member; 5. a visual inspection member; a. and (3) a spring.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The embodiment of the application provides a spring fatigue detection device and a spring fatigue detection method, wherein the spring fatigue detection device ensures that the deformation quantity of all springs meets the requirements when a plurality of pressing pieces descend by changing the height of the pressing pieces relative to a lifting plate, so that the detection consistency is better, and the detected result is more convincing. The application solves the technical problem that springs with different lengths are difficult to detect simultaneously in the related art.

Referring to fig. 1, a spring fatigue detection device includes a base 1, a support frame 2, a pressing component 4, and a plurality of chucking components 3. The support frame 2 is portal frame-shaped and is fixed on the base 1. The clamping assemblies 3 are arranged on the base 1, and the clamping assemblies 3 are used for fixing the springs a and keeping the springs a in an upright state. The pressing component 4 is used for pressing the spring a to deform the spring a. The spring a is detected by repeating the process of compressing and recovering the spring a.

Referring to fig. 1, in this embodiment, the clamping assemblies 3 are provided with four groups, and the four groups of clamping assemblies 3 are uniformly arranged on the base 1 along a straight line to allow for simultaneous detection of four springs a.

Referring to fig. 1 to 3, the clamping assembly 3 includes a plurality of clamping members 31 and a plurality of clamping elastic members 32, the clamping members 31 are slidably disposed on the base 1, two ends of the clamping elastic members 32 are respectively connected with the clamping members 31 and the base 1, and the clamping members 31 are mutually separated from each other and slidably disposed on the base 1. The plurality of clamping members 31 are adapted to abut against the inner wall of the spring a under the elastic force of the clamping elastic member 32.

Referring to fig. 1-3, in particular, in this embodiment, four clamping members 31 are provided, and the four clamping members 31 are slidably disposed on the base 1 away from each other, and further, a sliding slot for sliding the clamping members 31 is formed on the base 1. The clamping piece 31 is rod-shaped, and the bottom end of the clamping piece is arranged in the sliding groove in a sliding way. Both ends of the clamping elastic member 32 are respectively connected with the clamping member 31 and the base 1, so that the clamping member 31 is elastically slidably arranged on the base 1, and the clamping member 31 is driven to be far away from each other by the elastic force of the clamping elastic member 32. In this embodiment, the chucking elastic member 32 includes a chucking spring.

Referring to fig. 1 to 3, the spring a is sleeved on the plurality of clamping members 31, and under the action of the plurality of clamping elastic members 32, the plurality of clamping members 31 are far away from each other and all abut against the inner wall of the spring a to fix the spring a and maintain the vertical state of the spring a.

Referring to fig. 1 to 3, since the chucking members 31 are slidably provided, the distance between the chucking members 31 can be adjusted, and the springs a of different inner diameters can be adaptively fixed, so that the springs a of different inner diameters can be conveniently fixed to support the detection of the springs a of different inner diameters.

Referring to fig. 2 and 3, further, the clamping assembly 3 further includes a supporting member 33, where the supporting member 33 includes a supporting round table 331, and the supporting round table 331 moves up and down on the base 1. In this embodiment, the abutting piece 33 further includes an abutting screw 332, the abutting screw 332 is coaxially fixed with the abutting round table 331, and the abutting screw 332 is in threaded connection with the base 1, so as to implement lifting movement of the abutting round table 331 by rotating the abutting screw 332.

The abutting round table 331 is located in the middle of the plurality of clamping pieces 31, and the circumferential side surface of the abutting round table 331 abuts against the plurality of clamping pieces 31. After the spring a is sleeved on the plurality of clamping members 31, the abutting screw 332 is rotated to make the abutting round table 331 move up and down, so that the circumferential side surface of the abutting round table 331 abuts against the clamping members 31, and the sliding of the clamping members 31 is limited.

The setting like this, through the slip of supporting tight round platform 331 restriction chucking spare 31, make the spacing of spring a bottom more stable, avoid appearing spring a atress when crooked, drive chucking spare 31 and slide, cause spring a to break away from the condition of constraint. Ensuring that spring a is pressed down steadily.

Referring to fig. 1, the pressing assembly 4 includes a pressing driving member 41, a lifting plate 42, a plurality of pressing members 43, and a plurality of adjusting members 44. The pressing driving member 41 is mounted on the support frame 2, and the pressing driving member 41 is in driving connection with the lifting plate 42 to drive the lifting plate 42 to move up and down. The lifting plate 42 is located above the base 1 and moves up and down above the base 1. The pushing driving member 41 includes a cylinder, an electric cylinder, a screw mechanism or a linear motor, and in this embodiment, the pushing driving member 41 includes an electric cylinder to facilitate changing the movement stroke of the lifting plate 42.

The number of the pressing pieces 43 is set corresponding to the number of the chucking assemblies 3, and the plurality of pressing pieces 43 are respectively connected with the elevation plate 42 through a plurality of adjusting pieces 44. The plurality of pressing pieces 43 are vertically aligned with the plurality of chucking assemblies 3, respectively, one by one for pressing the springs a. Wherein the hold-down 43 is in the form of a block or a disc.

As the lifting plate 42 descends, the plurality of pressing pieces 43 simultaneously descend to respectively press down the plurality of springs a, thereby achieving compression of the springs a. With the lifting plate 42 lifted, the plurality of hold-down pieces 43 are lifted simultaneously, and at this time, the spring a is rebound to the original length due to its own elastic force.

Wherein the adjusting member 44 is used for adjusting the height of the hold-down piece 43 relative to the lifting plate 42 so that the heights of different hold-down pieces 43 are different. When springs a of different lengths are simultaneously detected, the heights of the pressing members 43 are correspondingly adjusted, and after the pressing members 43 descend along with the lifting plate 42, the compression ratios of the springs a of different lengths can be kept consistent. Referring to fig. 6, for example, when the compression ratio is 50%, the plurality of springs a having different lengths are deformed by 50% of their own lengths each time they are pressed down.

By the arrangement, springs a with different lengths can be detected simultaneously, deformation of the springs a with different lengths can be guaranteed to meet detection requirements, detection consistency is better, and detected results are more convincing. In addition, a plurality of springs a with different lengths can be detected together, so that the detection efficiency is improved, and a plurality of groups of clamping assemblies 3 for fixing the springs a on the base 1 can be fully utilized, so that no-load conditions are avoided.

Referring to fig. 1 to 3, in particular, the adjusting member 44 includes a screw mechanism mounted to the lifter plate 42, and the screw mechanism is drivingly connected to the lower pressing member 43 to drive the lower pressing member 43 to move in a vertical direction with respect to the lifter plate 42. The height of the hold-down 43 can be automatically adjusted by a screw mechanism.

The spring fatigue detection device further comprises a sensing module, wherein the sensing module comprises a plurality of pressure sensing pieces, and the pressure sensing pieces are respectively arranged on the bottom surfaces of the pressing pieces 43.

In this embodiment, the pressure sensing member includes a pressure sensor.

So arranged, referring to fig. 5, when the pressing member 43 descends, it can be determined by the pressure sensing member that the pressing member 43 has touched the spring a, so as to determine the working starting point of the pressing member 43, and when the pressing member 43 descends, the spring a is directly compressed, so that the idle stroke of the pressing member 43 in moving is eliminated, and the detection efficiency of the spring a is improved.

Further, as the hold-down piece 43 descends, pressure data detectable by the pressure sensing member when the hold-down piece 43 touches the spring a, to determine that the hold-down piece 43 is in contact with the spring a. Thus, the length of the spring a can be known by the distance the hold-down piece 43 moves and the distance the hold-down piece 43 is away from the base 1. According to the length of the plurality of springs a, the height of the pressing piece 43 relative to the lifting plate 42 can be adjusted in a follow-up adaptive manner, so that the plurality of pressing pieces 43 can be ensured to descend so that the plurality of springs a with different lengths can be deformed according to the consistent compression ratio.

Further, the spring fatigue detection device further comprises a control module, the control module is electrically connected with the sensing module, and the control module is suitable for outputting the stiffness coefficient of each time the spring a is pressed and generating a curve of the stiffness coefficient of each spring a changing along with the pressed times.

Specifically, after the spring a is deformed by a specified compression ratio, the elasticity of the spring a is obtained through the pressure sensing piece, so that the stiffness coefficient of the spring a is calculated. And by summing the stiffness coefficients measured for each compression spring a, a curve is generated that varies with the number of compressions. Generally, the curve is a straight line, reflecting that the stiffness coefficient of the spring a has not changed, and the straight line is a standard line of the spring a, and when the value of the stiffness coefficient is on the standard line, it indicates that the spring a is still in a normal state. When the value of the stiffness coefficient is lower than the standard line, the fatigue of the spring a is reflected at the moment, and the times of the fatigue of the spring a can be rapidly and accurately known through observing the curve, so that whether the spring a is qualified or not is judged.

Further, the plurality of adjusting members 44 are electrically connected with the control module, and after the lengths of all the springs a are measured, the control module controls the plurality of adjusting members 44 to respectively adjust the heights of the plurality of pressing members 43, so that the automatic adjustment of the pressing members 43 for the lengths of the springs a is realized.

Referring to fig. 1, further, the spring fatigue detection device further includes a visual detection member 5, and a detection direction of the visual detection member 5 is set toward the spring a on the base 1 and is used to detect whether the spring a is deflected.

The visual detection piece 5 is arranged on the base 1, and the detection end of the visual detection piece 5 faces to the fixed position of the spring a so as to carry out imaging detection on the spring a in the deformation process and judge whether the spring a is deflected or not. The visual detection piece 5 is electrically connected with the control module, the deflection angle of the spring a is also used as the basis of whether the spring a is qualified or not, and when the deflection angle of the spring a is larger than 5 degrees, the fatigue of the spring a is reflected at the moment. Wherein, visual inspection piece 5 includes a plurality of wide angle cameras, and the quantity of wide angle camera is unanimous with the quantity of chucking subassembly 3.

The embodiment of the application provides a spring fatigue detection device, which is characterized in that when a plurality of springs a are subjected to fatigue detection, the springs a are respectively arranged on a base 1, and are respectively fixed through a plurality of clamping assemblies 3, and due to the elastic movement of clamping pieces 31 of the clamping assemblies 3, the springs a with different inner diameters can be adaptively fixed, so that the springs a with different inner diameters can be conveniently fixed. And then the lifting plate 42 is driven to move up and down by the pushing-down driving piece 41, and the plurality of pushing-down pieces 43 are synchronously lifted up and down so as to simultaneously deform the plurality of springs a, so that the plurality of springs a can be detected simultaneously, and the detection efficiency is improved. In addition, according to the length of the spring a, the height of the pressing piece 43 relative to the lifting plate 42 is correspondingly adjusted, so that when the spring a is synchronously pressed down, the compression ratios of the springs a with different lengths are kept consistent, the deformation amounts of all the springs a are ensured to meet the requirements, the detection consistency is better, and the detected result is more convincing.

In addition, due to the arrangement of the pressure sensing piece, when the pressing piece 43 descends, the pressing piece 43 can be determined to touch the spring a through the pressure sensing piece, so that the working starting point of the pressing piece 43 is determined, and when the pressing piece 43 descends, the spring a is directly compressed, so that idle stroke when the pressing piece 43 moves is eliminated, and the detection efficiency of the spring a is improved.

Another embodiment of the present application provides a spring a fatigue detection method, based on the spring fatigue detection device as described above, comprising the following steps S100-S900.

S100, acquiring lengths of a plurality of springs a.

S200, determining the deformation length of each spring a according to the lengths of the springs a and a preset compression ratio.

S300, a plurality of springs a are arranged on the base 1 and are respectively fixed by a plurality of clamping assemblies 3.

S400, selecting the longest spring a, and calculating the height compensation value of the hold-down piece 43 corresponding to the rest springs a.

S500, adjusting the height of the hold-down piece 43 according to the height compensation value.

S600, determining the pressing stroke of the whole pressing piece 43 according to the deformation length of the longest spring a.

S700, the operation start point of the hold-down piece 43 is acquired.

S800, the plurality of pressing pieces 43 are synchronously lifted and lowered in a reciprocating manner according to a preset test speed for a preset test time.

S900, judging whether the spring a is qualified or not according to the stiffness coefficient of the spring a.

Wherein, step S100, the lengths of a plurality of springs a are acquired, specifically:

the length of the spring a is obtained by selecting the parameters of the spring a. In this embodiment, the pressure sensor may also be used to determine that the pressing member 43 touches the spring a as the pressing member 43 descends after the spring a is fixed to the base 1. The length of the spring a can be calculated from the height of the presser 43 relative to the base 1 and the distance the presser 43 moves to touch the spring a.

In step S200, the deformation length of each spring a is determined according to the lengths of the plurality of springs a and the preset compression ratio. Specifically:

the preset compression ratio includes any value from 50% to 90%, in this embodiment, the compression ratio is 50% to simulate the deformation state of the spring a in the mattress.

Let the length of the spring a be L and the compression ratio be a, the deformation length Δl=al of the spring a. The required deformation length of all springs a can thus be known after the compression ratio has been determined.

In step S300, a plurality of springs a are disposed on the base 1 and are respectively fixed by a plurality of clamping assemblies 3. Specifically:

referring to fig. 4, a plurality of springs a are respectively fixed by a plurality of chucking assemblies 3, and are all vertically disposed. The plurality of springs a are each supported by the base 1, and the top surfaces of the plurality of springs a are different in height due to the different lengths of the plurality of springs a.

In step S400, the longest spring a is selected, and the height compensation value of the hold-down 43 corresponding to the remaining springs a is calculated. Specifically:

the length of the springs a is compared firstly to pick out the spring a with the longest length. The calculation of the height compensation value of the hold-down piece 43 corresponding to the remaining springs a specifically includes:

the difference in length between the longest spring a and the remaining springs a is calculated.

Let the length of the longest spring a be Lmax and the lengths of the remaining springs a be Lx (x is 1, 2, 3.), the length difference between the longest spring a and the remaining springs a can be calculated: lmax-Lx.

The height compensation value Hx of the hold-down piece 43 corresponding to each spring a is calculated according to the following formula.

Hx＝(Lmax-Lx)/(1-a)

It will be appreciated that the longest spring a has a corresponding height compensation value of 0.

In step S500, the height of the pressing member 43 is adjusted according to the height compensation value. Specifically:

the height of the entire pushing piece 43 is determined by adjusting the distance of the height compensation value of the remaining pushing pieces 43 downward with respect to the pushing piece 43 corresponding to the longest spring a based on the height of the pushing piece 43 corresponding to the longest spring a.

In step S600, the pressing stroke of the full pressing member 43 is determined according to the deformation length of the longest spring a. Specifically:

after the deformation length of the longest spring a is determined, the descending distance of the pressing pieces 43 corresponding to the longest spring a can be determined, and since the plurality of pressing pieces 43 move uniformly, the descending distances of all the pressing pieces 43 are determined. Since each of the pressing members 43 is height-adjusted according to the length of its corresponding spring a, when the plurality of pressing members 43 are simultaneously lowered by a uniform distance, the plurality of springs a are respectively deformed in accordance with a uniform compression ratio.

In step S700, a working start point of the hold-down member 43 is obtained. Specifically comprising:

lowering the plurality of hold down members 43.

When the pressure is detected by the pressure sensing member on the pressing piece 43 corresponding to the longest spring a, the height position of the pressing piece 43 is recorded to obtain the operation start point of the pressing piece 43.

Referring to fig. 5, the plurality of pressing pieces 43 are simultaneously lowered, and the pressing piece 43 corresponding to the longest spring a first touches the spring a, at which time the pressure sensing piece detects the pressure, and the surface pressing piece 43 has been in contact with the spring a. The height position of the hold-down piece 43 at this time is recorded, and this position is the work start point of the hold-down piece 43. It will be appreciated that this position is the highest level of the hold-down 43, and that the hold-down 43 shortens the idle stroke that is not in contact with the spring a when it is lowered, thereby saving the time for each deformation and recovery of the spring a and improving the detection efficiency.

In step S800, the plurality of pressing members 43 are synchronously lifted and lowered for a preset number of times according to a preset test speed. Specifically:

the preset test speed comprises 0.1-0.5m/s, and under the test speed, the spring a is slowly pressed down so as to simulate the state that a person sits to the mattress to cause the deformation of the spring a, so that the detection result of the spring a is more convincing.

The preset number of tests includes 1 to 10 tens of thousands, and in this embodiment, the number of tests is preferably 3 tens of thousands.

And step S900, judging whether the spring a is qualified or not according to the stiffness coefficient of the spring a. Specifically comprising:

the stiffness coefficient of the spring a at each compression deformation is obtained.

And calculating the difference between the stiffness coefficient of the spring a during each deformation and the stiffness coefficient of the spring a during the first deformation, and enabling the difference to be a detection value.

Judging whether the detection value obtained by each deformation of the spring a is in a preset standard fluctuation range, if so, judging that the spring a is qualified, otherwise, judging that the spring a is unqualified.

When the spring a is pressed each time, the deformation amount of the spring a pressed each time is consistent, and the pressure sensor is used for measuring the pressure of the spring a when the spring a is subjected to preset deformation, so that the stiffness coefficient of the spring a when the spring a is deformed each time can be calculated.

Specifically, the stiffness coefficient measured when the spring a is pressed for the first time is taken as a standard value, and the stiffness coefficient measured when the spring a is deformed for each time is subtracted from the standard value to obtain a detection value.

And judging whether the detection value is in a preset standard fluctuation range, wherein the preset standard fluctuation range is +/-15N/mm. If the detection value obtained by each deformation of the spring a is within the standard fluctuation range in the test times, the spring a is qualified. Otherwise, the spring a fails.

By means of the arrangement, the performance of the spring a can be quantified by detecting the state of the spring a after each deformation in real time, the state of the spring a is intuitively reflected through data, and whether the spring a is tired or not is accurately reflected.

In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of describing the present application and simplifying the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be constructed and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

It should be noted that in the present application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the application to enable those skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The utility model provides a spring fatigue detection device, its characterized in that includes base and with the support frame that the base is fixed still includes:

2. The spring fatigue detection device of claim 1, further comprising a control module electrically connected to the sensing module, the control module adapted to output the stiffness coefficient of each compression of the spring and generate a profile of the stiffness coefficient of each spring as a function of the number of compressions.

3. The spring fatigue detection device according to claim 1, wherein the adjusting member comprises a screw mechanism mounted to the lifter plate, the screw mechanism being drivingly connected to the hold-down member to drive the hold-down member to move in a vertical direction relative to the lifter plate.

4. The spring fatigue testing device of claim 1, wherein the clamping assembly further comprises a plurality of clamping elastic members, two ends of the clamping elastic members are respectively connected with the clamping member and the base, and the plurality of clamping elastic members have elastic forces that keep the plurality of clamping members away from each other.

5. The spring fatigue detection device of claim 4, wherein the clamping assembly further comprises a clamping member, the clamping member comprises a clamping circular table, the clamping circular table moves up and down in the base, the clamping circular table is positioned in the middle of the clamping members, and the circumferential side surfaces of the clamping circular table are clamped against the clamping members.

6. The spring fatigue detection device according to claim 1, further comprising a visual detection member, a detection direction of the visual detection member being provided toward the spring on the base and for detecting whether the spring is deflected.

7. A spring fatigue detection method, characterized by being based on the spring fatigue detection device according to any one of claims 1 to 6, comprising the steps of:

acquiring lengths of a plurality of springs;

8. The method for detecting fatigue of springs according to claim 7, wherein selecting the longest spring and calculating the height compensation value of the hold-down piece corresponding to the remaining springs comprises:

9. The method of claim 7, further comprising obtaining a working start point of the hold-down piece before the plurality of hold-down pieces are reciprocally lifted up and down for a predetermined number of times at a predetermined test speed, the obtaining the working start point of the hold-down piece comprising:

lowering the plurality of hold-down members;

10. The method for detecting fatigue of a spring according to claim 7, wherein the step of judging whether the spring is acceptable or not based on the stiffness coefficient of the spring comprises: