Rigidity testing device for measuring metal rubber with pre-compression amount

Abstract

The invention belongs to the technical field of damping material performance testing devices, and discloses a rigidity testing device for measuring metal rubber with pre-compression amount, which comprises a base, a length direction baffle plate, a width direction baffle plate, a positioning baffle plate, a length direction adjusting bolt, a width direction adjusting bolt, a pressure sensor and a dial indicator, the testing device is technically characterized in that a device for applying the pre-compression amount in the non-stress direction, namely the length direction and the width direction, of the metal rubber is designed, the required pre-compression amount in the non-stress direction can be applied to the metal rubber, and the metal rubber can be tested by adjusting the pre-compression amount. The rigidity-damping characteristics of the metal rubber in the stress direction under different pre-compression amounts are obtained, the optimal pre-compression amount of the metal rubber meeting the actual application space is obtained, and the vibration reduction effect of the vibration reduction structure is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of vibration damping material performance testing devices, and in particular relates to a metal rubber stiffness testing device for measuring a pre-compression amount. Background Art

[0002] Metal rubber is an elastic porous material made by cold stamping spirally wound metal wire. It not only has the high elasticity and high damping characteristics of metal, but also retains the mechanical properties of metal. It can work in extreme environments, is not afraid of high and low temperatures, and can also resist corrosion environments by choosing different metals, and has no possibility of aging. These advantages make metal rubber shock absorbers widely used in aviation and aerospace fields. When the metal rubber shock absorber is working, the wire turns inside the material rub against each other, slip, and squeeze, which will consume a lot of vibration energy and play a damping and vibration reduction role.

[0003] Square metal rubber is widely used in vibration reduction in military and civilian engineering fields due to its many advantages such as simple structure, good preparation processability and easy installation. When metal rubber is installed in its working space, a certain pre-compression amount is usually designed to ensure the stability of the metal rubber's damping performance. The size of the pre-compression amount will also affect the stiffness-damping performance of the metal rubber, and then affect the vibration reduction efficiency and natural frequency of the vibration isolator. Therefore, accurately obtaining the static stiffness parameters of metal rubber under different pre-compression amounts is of great significance for design.

[0004] The current metal rubber static stiffness test process is as follows:

[0005] Place a special metal gasket with high parallelism at the center of the material testing machine table, place a metal vibration damping pad at the center of the gasket, and then place another special gasket on the metal vibration damping pad. Figure 1 As shown, the loading end of the material testing machine is separated from the upper special gasket, and loading is started to the specified force value. The deformation data of the metal rubber is read and recorded as the test result.

[0006] This test method reflects the static stiffness of metal rubber to a certain extent, but it does not conform to the actual working conditions for the following reasons: In actual work, the metal rubber has a certain amount of pre-compression in the non-stress direction, and the pre-compression in the non-stress direction will affect the mechanical properties of the metal rubber in the stress direction. The original measurement method did not constrain the non-stress direction of the metal rubber, and the measurement deviated greatly from the actual working state; the original measurement method could not provide an adjustable pre-compression amount, and could not test the mechanical properties of the metal rubber under different pre-compression amounts, and could not obtain the optimal pre-compression amount of the metal rubber required for the vibration isolator. Summary of the invention

[0007] To solve the above technical problems, the present invention provides a stiffness testing device for measuring metal rubber with a pre-compression amount to solve the problems in the prior art. The technical solution adopted by the present invention is as follows:

[0008] A stiffness testing device for measuring metal rubber with a pre-compression amount, comprising a base, a length-direction baffle, a width-direction baffle, a positioning baffle, a length-direction adjustment bolt, a width-direction adjustment bolt, a pressure sensor and a micrometer;

[0009] The base is provided with a recess, which has a "C" - shaped structure; two of the width-direction baffles are symmetrically arranged in the recess, the length-direction baffle is arranged at the open end of the recess, the length-direction baffle abuts against the positioning baffle, and the positioning baffle is connected to the open end face of the base through the length-direction adjustment bolt; both sides of the base are respectively connected to the width-direction baffles through the width-direction adjustment bolts;

[0010] The metal rubber is placed in the recess, the width-direction baffles are respectively arranged on both sides of the metal rubber in the width direction, and the length-direction baffle is arranged at one end of the metal rubber in the length direction;

[0011] The pressure sensor and the micrometer are used to measure the deformation amount and deformation pressure of the metal rubber.

[0012] Furthermore, it further includes positioning sliders; positioning sliders are respectively arranged on both inner sides of the base, and the width-direction adjustment bolts are used to push the positioning sliders to extrude the metal rubber.

[0013] Furthermore, the positioning slider includes a square block and a cylinder; the square block is fixedly connected to one end of the cylinder, the other end of the cylinder is inserted into a through hole on the base, the through hole communicates with a width adjustment bolt hole, the width adjustment bolt hole is connected to the width-direction adjustment bolt, and the end of the width-direction adjustment bolt contacts the cylinder.

[0014] Furthermore, a rectangular groove is arranged on the inner side of the base, and the square block is located in the rectangular groove.

[0015] Furthermore, it further includes a pressure head; the pressure head is located between the two width-direction baffles and above the metal rubber; the pressure sensor and the micrometer are connected to the pressure head.

[0016] The present invention has the following beneficial effects:

[0017] The present invention provides a stiffness test device for measuring metal rubber with pre-compression, and the static stiffness-damping characteristics of metal rubber with pre-compression in the length direction or width direction can be measured by this device. The prior art is to place the square metal rubber to be tested in the test plane, and only provide constraints in the force direction and the height direction, and the other directions are in a free state, which cannot simulate the state of the metal rubber actually installed in the workspace, thereby causing errors in the stiffness test results in the height direction. The technical feature adopted by the test device of the present invention is that a device is designed to apply the pre-compression amount of the metal rubber in the non-force direction, that is, the length and width direction, which can apply the required pre-compression amount in the non-force direction to the metal rubber. By adjusting the size of the pre-compression amount, the stiffness-damping characteristics of the metal rubber in the force direction under different pre-compression amounts are obtained, and the optimal pre-compression amount of the metal rubber that meets the actual application space is obtained, thereby improving the vibration reduction effect of the vibration reduction structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Exploded view of the metal rubber stiffness test device with pre-compression;

[0019] Figure 2 A top view of a metal rubber stiffness test device with pre-compression;

[0020] Figure 3 Schematic diagram of the relative position of the pressure head 2 and the metal rubber;

[0021] Figure 4 Schematic diagram of the projection of the width baffle on the base;

[0022] Figure 5 A cross-sectional view of a metal rubber stiffness test device with pre-compression;

[0023] Figure 6 Schematic diagram of positioning slider;

[0024] Figure 7 A schematic diagram of the positional relationship of the test device of the present invention when installed on a testing machine;

[0025] Figure 8 A schematic diagram of test results of metal rubbers with different pre-compression amounts in this embodiment. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention Figure 1-Figure 8 , the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0027] like Figure 1 , Figure 2As shown in the figure, a stiffness testing device for measuring metal rubber with a pre-compression amount includes a base 1, a lengthwise baffle 7, a widthwise baffle 6, a positioning baffle 8, a lengthwise adjustment bolt 9, a widthwise adjustment bolt 4, a pressure sensor 21, and a micrometer 19;

[0028] The base 1 is provided with a recess, which is in a "C" - shaped structure; two of the widthwise baffles 6 are symmetrically arranged in the recess, the lengthwise baffle 7 is arranged at the open end of the recess, the lengthwise baffle 7 abuts against the positioning baffle 8, and the positioning baffle 8 is connected to the open end face of the base 1 through the lengthwise adjustment bolt 9; both sides of the base 1 are respectively connected to the widthwise baffle 6 through the widthwise adjustment bolt 4;

[0029] The metal rubber 3 is placed in the recess. The widthwise baffles 6 are respectively arranged on both sides of the metal rubber 3 in the width direction, and the lengthwise baffle 7 is arranged at one end of the metal rubber 3 in the length direction;

[0030] The pressure sensor 21 and the micrometer 19 are used to measure the deformation amount and deformation pressure of the metal rubber 3.

[0031] The base 1 has a symmetrical structure, and is designed with width adjustment bolt holes 10 that extend out of the side wall, and mounting edges 13 for positioning the widthwise baffle 6. The recess of the base 1 is used to place the widthwise baffle 6, the metal rubber 3, the lengthwise baffle 7, and the pressure head 22.

[0032] As the lengthwise adjustment bolt 9 is turned, the lengthwise baffle 7 and the positioning baffle 8 are pushed to move in the length direction of the metal rubber, thereby changing the pre - compression amount of the metal rubber 3 in the length direction.

[0033] As Figure 4 shown, there are four width adjustment bolt holes 10, two on each side. Their centers are located at the projection of the center line of the widthwise baffle 6 on the side wall of the base, and are evenly distributed on the center line. Such a design is more conducive to the movement of the widthwise baffle 6.

[0034] Furthermore, it also includes positioning sliders 5; positioning sliders 5 are respectively arranged on both inner sides of the base 1, and the widthwise adjustment bolt 4 is used to push the positioning sliders 5 to squeeze the metal rubber 3.

[0035] Furthermore, the positioning slider 5 includes a square block 17 and a cylinder 18; the square block 17 is fixedly connected to one end of the cylinder 18, and the other end of the cylinder 18 is inserted into a through - hole 16 on the base 1. The through - hole 16 communicates with the width adjustment bolt hole 10, the width adjustment bolt hole 10 is connected to the widthwise adjustment bolt 4, and the end of the widthwise adjustment bolt 4 contacts the cylinder 18.

[0036] As the width-direction adjusting bolt 4 is turned, the block 17 is pushed to move in the width direction of the metal rubber, thereby changing the pre-compression amount of the metal rubber 3 in the width direction.

[0037] Furthermore, a rectangular groove 15 is provided inside the base 1, and the block 17 is located inside the rectangular groove 15. The length direction of the rectangular groove 15 is parallel to the length direction of the base 1.

[0038] Furthermore, it also includes a pressure head 2 ; the pressure head 2 is located between the two width-direction baffles 6 and above the metal rubber 3 ; the pressure sensor 21 and the micrometer 19 are connected to the pressure head 2 .

[0039] The positioning slide block 5 is processed in coordination with the base, and the tolerance value is less than 0.05.

[0040] like Figure 2 , Figure 6 As shown, the thickness D10 of the positioning slider 5 should be greater than the initial gap value e3p in the width direction.

[0041] The length D11 of the cylinder 18 should be greater than the sum of the length D6 of the through hole 16 assembled therewith and the initial gap value e3p in the width direction.

[0042] like Figure 5 As shown, the distance D8 between the end surface of the width adjustment bolt hole 10 and the outer end surface of the cylinder 18 should be greater than the initial gap value e3p in the width direction.

[0043] The baffle plate 6 in the width direction is placed in the corresponding mounting edge 13 in the base 1, and the four surfaces of the baffle plate 6 in the width direction are in contact with the base 1. The two baffle plates 6 in the width direction are distributed in the base 1 in a mirror image, and can uniformly apply a pre-compression amount in the width direction to the metal rubber 3.

[0044] The side end surface 23 of the width direction baffle 6 should be aligned with the side end surface 24 of the base 1 .

[0045] The positioning baffle 8 includes two overhanging baffles 11, a lengthwise pre-compression adjustment bolt hole 25, and a groove 26 that matches the lengthwise baffle 7. Two lengthwise adjustment bolts 9 are connected through the lengthwise pre-compression adjustment bolt hole 25 on the positioning baffle 8.

[0046] The positioning baffle 8 is used to relatively fix the position of the length direction baffle 7 to prevent the length direction baffle 7 from tilting when the adjustment bolt 9 is screwed into the base, thereby preventing the metal rubber 3 from being uniformly loaded with the pre-compression amount.

[0047] The length direction baffle 7 is installed in cooperation with the positioning baffle 8, and the length direction baffle 7 is in contact with the metal rubber 3. When the length direction adjusting bolt 9 is adjusted, the length direction baffle 7 compresses the metal rubber to provide a pre-compression amount in the length direction.

[0048] The metal rubber 3 is placed on the two width direction baffles 6 , the inner surface 28 of the base groove, and the length direction baffle 7 .

[0049] The pressure head 2 is placed on the upper surface of the metal rubber 3, and in order to make the metal rubber bear force evenly, as shown in FIG. Figure 3 As shown, the centroid of the pressure head 2 and the centroid of the metal rubber 3 are located on the same vertical line.

[0050] The width D1 of the pressure head 2 is consistent with the width D2 of the longitudinal baffle 7 .

[0051] Since the diameter of the metal rubber wire is generally greater than 0.12 mm, the two width direction baffles 6 are matched with the mounting surfaces corresponding to the base 1, and the tolerance value is less than 0.05. This design is to make the width direction baffle 6 have better mobility while ensuring that no wire clamping occurs during the movement process.

[0052] The extended side plate 11 of the positioning baffle 8 is processed in coordination with the contact surface of the base 1 to ensure its slidability and positioning function.

[0053] Preferably, the distance e1 between the base 1 and the positioning baffle 8 should be greater than the maximum value of the designed pre-compression amount L in the length direction.

[0054] Preferably, the distance D3 between the end surface of the extended plate of the positioning baffle 8 and the extended hole of the base should be greater than the maximum value of the design value L of the pre-compression amount in the length direction.

[0055] Preferably, a distance D10 between the end surface of the base 1 and the end surface of the metal rubber is greater than 10 mm.

[0056] The gaps e3 and e2 between the pressure head 2 and the width direction baffle 6 and the length direction baffle 7 are determined by the designed pre-compression amounts W and L of the metal rubber. For example, the width of the metal rubber in the figure is 20 mm, the height is 10 mm, and the length is 50 mm. The planned experiment obtains a pre-compression amount W in the width direction of 1 and 2 mm, and a pre-compression amount L in the length direction of 1, 3, and 5 mm. At this time, the initial gap value in the width direction e3 = the maximum value of the pre-compression amount in the width direction / 2 = 1 mm, and the initial gap value in the length direction e2 = the maximum value of the pre-compression amount in the length direction / 2 = 2.5 mm.

[0057] Pre-compression setting:

[0058] The length of the extension plate of the positioning baffle exceeds the length D4 of the end face of the base, which should be greater than the designed pre-compression in the length direction. The pre-compression in the width direction is designed to be 1 or 2 mm, and the pre-compression in the length direction is designed to be 1, 3 or 5 mm. At this time, the initial gap value e3p in the width direction is 1 mm, and the initial gap value e2p in the length direction is 2.5 mm. Taking the measurement of the stiffness-damping characteristics of the metal rubber under the pre-compression of 1 mm in the length direction and 1 mm in the width direction as an example, because the M6 ​​fine-thread bolts with a pitch of 0.5 mm are used, the bolts for adjusting the length pre-compression on one side are first turned 2 turns at the same time, and then the bolts for adjusting the length pre-compression on the other side are turned 2 turns at the same time, so that the metal rubber is subjected to uniform pre-compression on both sides of the width. Similarly, the two bolts for adjusting the length pre-compression are turned at the same time, and turned 2 turns to apply 1 mm pre-compression in the length direction.

[0059] like Figure 7 As shown, after the pre-compression amount is adjusted, the position of the pressure head 22 is adjusted, and the electronic micrometer 19 is placed on the upper surface of the pressure head 2, and the electronic micrometer 19 is not in contact with the force sensor 21.

[0060] sensor:

[0061] like Figure 7 As shown, the sensor includes a force sensor 21 and a micrometer 19 .

[0062] The force sensor 21 is an STC type tension and pressure sensor with a measuring range of 250kg and an accuracy of 4‰. It is connected to the computer through a data transmission port. The upper and lower end faces of the pressure sensor 9 are provided with M12 threads. The lower end face is connected to the connecting piece 22, and the upper end face is connected to the connecting rod 20. To ensure the uniformity of pressure, the center of the lower end face coincides with the centroid of the upper surface of the pressure head 2.

[0063] The micrometer 11 is a B531 type electronic digital micrometer with a measuring range of 25mm and an accuracy of 0.001mm. It is connected to the computer through a data transmission port and is used to measure the deformation of the measured part in the force direction. The needle of the micrometer 11 hits the upper surface of the pressure head 2 and should not contact the force sensor.

[0064] Quasi-static radial stiffness test process:

[0065] First, the moving crossbeam of the testing machine is controlled by a computer to move downward at a low speed to compress the tested piece, and the speed range is 0.1 to 1 mm / min. The compression force is controlled to 1 KN. Then, the moving crossbeam of the testing machine is controlled to move upward at a low speed to restore the tested piece to its original state, and the speed range is 0.1 to 1 mm / min, until the point contact between the connecting member 22 and the pressure head 22 is completely separated. In the process of compression and restoration of the tested piece, the test force data is measured by the pressure sensor 9, and the radial deformation data is measured by the micrometer 19.

[0066] Data processing of test results:

[0067] like Figure 8 As shown, in the embodiment of the present invention, the test force data and radial deformation data obtained by the test are first plotted into a test force-radial deformation curve of the tested piece, the test force-radial deformation curve includes a compression loading section P1(x) and a compression unloading section P2(x), the 400N-600N section in the compression loading section P1(x) of the test force-radial deformation curve is intercepted, and the linear equation y=kx+b is used for minimum quadratic fitting, and the linear slope k is 5894.96, and the linear pitch b is 325. The linear slope k is the quasi-static stiffness test value of the tested metal rubber 3, 5894.96N / mm.

[0068] The embodiments described above are only descriptions of the preferred modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, modifications, and substitutions made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A test device for measuring the stiffness of metal rubber with pre-compression, characterized in that: It includes a base (1), a lengthwise baffle (7), a widthwise baffle (6), a positioning baffle (8), a lengthwise adjustment bolt (9), a widthwise adjustment bolt (4), a pressure sensor (21) and a micrometer (19); The base (1) is provided with a recess, which is in a "C" - shaped structure; two of the widthwise baffles (6) are symmetrically arranged in the recess, the lengthwise baffle (7) is arranged at the open end of the recess, the lengthwise baffle (7) abuts against the positioning baffle (8), and the positioning baffle (8) is connected to the open end face of the base (1) through the lengthwise adjustment bolt (9); the two sides of the base (1) are respectively connected to the widthwise baffles (6) through the widthwise adjustment bolts (4); The recess is used for placing the metal rubber (3), the two widthwise sides of the metal rubber (3) are respectively provided with the widthwise baffles (6), and one end of the metal rubber (3) in the length direction is provided with the lengthwise baffle (7); The pressure sensor (21) and the micrometer (19) are used to measure the deformation amount and deformation pressure of the metal rubber (3).

2. A metal rubber stiffness test device for measuring pre-compression according to claim 1, characterized in that: It further includes a positioning slider (5); The positioning sliders (5) are respectively arranged on the two inner sides of the base (1), and the widthwise adjustment bolts (4) are used to push the positioning sliders (5) to extrude the metal rubber (3).

3. A metal rubber stiffness testing device for measuring pre-compression according to claim 2, characterized in that: The positioning slider (5) includes a square block (17) and a cylinder (18); the square block (17) is fixedly connected to one end of the cylinder (18), the other end of the cylinder (18) is inserted into a through - hole (16) on the base (1), the through - hole (16) communicates with a width - adjustment bolt hole (10), the width - adjustment bolt hole (10) is connected to the widthwise adjustment bolt (4), and the end of the widthwise adjustment bolt (4) contacts the cylinder (18).

4. A metal rubber stiffness test device for measuring pre-compression according to claim 3, characterized in that: A rectangular groove (15) is arranged on the inner side of the base (1), and the square block (17) is located in the rectangular groove (15).

5. A testing device for measuring the stiffness of metal rubber with pre-compression according to claim 1, characterized in that: It further includes a pressure head (2); the pressure head (2) is located between the two widthwise baffles (6) and above the metal rubber (3); the pressure sensor (21) and the micrometer (19) are connected to the pressure head (2).

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