Adjustable inertia amplification type noise reduction device for low-frequency noise

Abstract

The invention belongs to the technical field of noise reduction devices, and discloses a low-frequency noise adjustable inertia amplification type noise reduction device which comprises an inertia amplification super-structure plate upper plate, noise reduction structures are installed at the top end of the inertia amplification super-structure plate upper plate in a staggered mode, and a support structure is installed at the bottom end of the inertia amplification super-structure plate upper plate. A micro-perforated plate is fixedly installed at the bottom end of the support structure, porous sound absorption materials are fixedly installed at the positions, located in the support structure, of the top end of the micro-perforated plate and the bottom end of the upper plate of the inertia amplification super-structure plate, and an installation structure is fixedly installed at the position, located at the bottom end of the noise reduction structure, of the interior of the upper plate of the inertia amplification super-structure plate; by adjusting the angles of the multiple noise reduction structures, the multiple noise reduction structures are combined into different line type noise reduction schemes, the most effective noise reduction mode can be performed on noise by adjusting the angles, meanwhile, different line combinations are suitable for different types of noise environments and scenes, and the universality and adaptability of the noise reduction algorithm are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction devices, and particularly to an adjustable inertial amplification type noise reduction device for low-frequency noise. Background Art

[0002] In current noise processing technologies, the suppression of low-frequency noise is particularly important because it often has a serious impact on people's work, life, and health. To reduce low-frequency noise, researchers have tried various methods, including filters, sound-absorbing materials, sound insulation, etc. However, traditional low-frequency noise suppression methods have some deficiencies. For example, filters may filter out useful signals, sound-absorbing materials are costly and have limited effects, and the sound insulation effect may also be restricted.

[0003] The existing noise reduction devices mainly include the following types:

[0004] Active noise reduction: By generating reverse sound waves with the noise source to cancel the noise generated by the noise source, the effect of noise reduction is achieved.

[0005] Passive noise reduction: Mainly through sound-absorbing materials and sound-insulating materials to absorb or block the propagation of noise.

[0006] Inertial noise reduction: By performing inertial impacts on the noise source to change the frequency characteristics of the noise, thereby achieving the purpose of noise reduction.

[0007] The inertial noise reduction device uses an inertial amplification metamaterial plate for noise reduction, and a grooved noise reduction structure is installed on the surface of the upper plate in the inertial amplification metamaterial plate. The grooved noise reduction structure is not convenient for installation with the upper plate in the inertial amplification metamaterial plate, and the angle is not convenient to adjust after installation, resulting in the angle and direction of the grooves being inconvenient to adjust, further affecting its noise reduction effect. Summary of the Invention

[0008] In view of the problem in the prior art that the inertial noise reduction device uses an inertial amplification metamaterial plate for noise reduction, and a grooved noise reduction structure is installed on the surface of the upper plate in the inertial amplification metamaterial plate. The grooved noise reduction structure is not convenient for installation with the upper plate in the inertial amplification metamaterial plate, and the angle is not convenient to adjust after installation, resulting in the angle and direction of the grooves being inconvenient to adjust, further affecting its noise reduction effect, the present invention proposes the following technical solutions:

[0009] An adjustable inertial amplification type noise reduction device for low-frequency noise comprises an upper plate of an inertial amplification superstructure plate, a noise reduction structure is staggeredly installed on the top of the upper plate of the inertial amplification superstructure plate, a bracket structure is installed on the bottom of the upper plate of the inertial amplification superstructure plate, a micro-perforated plate is fixedly installed on the bottom of the bracket structure, a porous sound-absorbing material is fixedly installed at the top of the micro-perforated plate and the bottom of the upper plate of the inertial amplification superstructure plate located at an inner position of the bracket structure, a mounting structure is fixedly installed at the inner position of the upper plate of the inertial amplification superstructure plate at the bottom end of the noise reduction structure, the mounting structure is used to install the noise reduction structure and can facilitate the adjustment of the angle of the noise reduction structure;

[0010] The mounting structure includes a column fixedly mounted on the bottom end of the noise reduction structure, a mounting ring is mounted inside the upper plate of the inertia amplification superstructure plate by screws, a rotating ring is movably connected to the top of the mounting ring, a fixed ring is rotatably connected to the top of the rotating ring, a plug-in rod is welded to the bottom end of the fixed ring and the plug-in rod passes through and is connected to the inside of the mounting ring, a spring rod is embedded and mounted on the bottom of the inner wall of the fixed ring, a clip strip is clamped and mounted on one end of the spring rod, and an inclination angle is provided at the position of the clip strip near one end of the column, a spring column is clamped and mounted between the opposite surfaces of the mounting ring and the rotating ring, a fitting groove is provided on the outer surface of the column, and the inner wall of the fitting groove and the outer side of the clip strip fit together.

[0011] As a preferred embodiment of the above technical solution, the noise reduction structure includes a horizontal bar movably mounted on the top of the upper plate of the inertial amplification superstructure plate, a rectangular rod is mounted on the top of the horizontal bar, and a mass block is clamped and mounted on one end of the rectangular rod.

[0012] As a preferred embodiment of the above technical solution, the size of the clamping strip near one end of the column is smaller than that of the other end, the shape of the fitting groove is conical, the size of the fitting groove near one end of the column center line is smaller than that of the other end, and the outer diameter of the clamping strip near one end of the column and the inner wall of the fitting groove fit each other.

[0013] As a preferred embodiment of the above technical solution, the support structure includes a top frame fixedly installed on the bottom edge of the upper plate of the inertia amplification superstructure plate, an outer frame is fixedly installed at the top of the micro-perforated plate corresponding to the bottom edge of the top frame, an inner frame is fixedly installed at the bottom end of the inner wall of the outer frame at the top position of the micro-perforated plate, threaded rods passing through the outer frame are fixedly installed at the four corners of the bottom end of the upper plate of the inertia amplification superstructure plate, and nuts are connected by threads on the outer side of the threaded rods at a position inside the outer frame.

[0014] As a preferred embodiment of the above technical solution, the outer sides of the porous sound absorbing material are respectively in contact with the inner walls of the top frame and the inner frame, and the inner frame and the top frame have the same shape.

[0015] As a preferred embodiment of the above technical solution, the bottom end of the horizontal bar and the top end of the column are fixedly connected.

[0016] Preferably, as the above technical solution, a concave block is fixedly installed at the top of the horizontal bar, and the rectangular rod is clamped and installed inside the concave block.

[0017] Preferably, as the above technical solution, a plurality of positioning holes are arranged in a circumferential array with the center point as the reference at the position corresponding to the bottom end of the insertion rod at the top of the installation ring, and a chamfer is provided at the edge of the bottom end of the insertion rod.

[0018] Preferably, as the above technical solution, positioning grooves adapted to the installation ring are equidistantly arranged at the top of the upper plate of the inertial amplification metamaterial plate, and the inner wall of the positioning groove and the outer side of the installation ring are mutually attached.

[0019] Preferably, as the above technical solution, the spring rod and the spring column have the same shape, and both the spring rod and the spring column are composed of a sleeve, a movable rod and a spring.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) By adjusting the angles of multiple noise reduction structures, multiple noise reduction structures are combined into different pattern-type noise reduction schemes. By adjusting the angles, the most effective noise reduction mode for noise can be achieved, and noise can be effectively suppressed while retaining the original texture of the image. At the same time, different pattern combinations are suitable for different types of noise environments and scenarios, improving the versatility and adaptability of the noise reduction algorithm;

[0022] (2) By adjusting the size of the mass block in the noise reduction structure and adjusting the thickness of the porous sound-absorbing material through the support structure, the position and width of the acting frequency band are further adjusted, so as to play a role in absorbing and isolating noise, thereby ensuring effective absorption of noise, enhancing the noise reduction effect, and at the same time, customized design can be carried out according to the actual environment or the needs of the noise source to adapt to different usage scenarios;

[0023] (3) It is convenient to install and fix the upright column, and thus it is convenient to install the noise reduction structure, thereby saving installation time and cost, improving work efficiency, and reducing errors or damages caused by improper operation during installation. It can also quickly adjust the position under different environments or requirements. Description of the Drawings

[0024] Figure 1 Shows the structural schematic diagram of an adjustable inertial amplification type noise reduction device for a low-frequency noise in Embodiment 1;

[0025] Figure 2 Shows the installation structural schematic diagram of the micro-perforated plate in Embodiment 1;

[0026] Figure 3 Shows the installation structural schematic diagram of the micro-perforated plate in Embodiment 1;

[0027] Figure 4 Shown is in Embodiment 1 Figure 3 An enlarged schematic view of area A in

[0028] Figure 5 Shown is a schematic structural view of the bracket structure in Embodiment 1;

[0029] Figure 6 Shown is a schematic structural view of the noise reduction structure in Embodiment 1;

[0030] Figure 7 Shown is a schematic structural view of the installation structure in Embodiment 1.

[0031] In the figure: 1. Upper plate of the inertial amplification metamaterial plate; 2. Noise reduction structure; 21. Horizontal bar; 22. Concave block; 23. Rectangular rod; 24. Mass block; 3. Bracket structure; 31. Top frame; 32. Outer frame; 33. Inner frame; 34. Threaded rod; 35. Nut; 4. Microperforated plate; 5. Porous sound-absorbing material; 6. Installation structure; 61. Column; 62. Clamping strip; 63. Spring rod; 64. Fixed ring; 65. Insertion rod; 66. Installation ring; 67. Spring column; 68. Rotating ring. Detailed implementation manners

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0033] Embodiment 1: The present invention provides an adjustable inertial amplification type noise reduction device for low-frequency noise. As Figures 1-7 shown, an adjustable inertial amplification type noise reduction device for low-frequency noise includes an upper plate 1 of an inertial amplification metamaterial plate. Noise reduction structures 2 are alternately installed at the top end of the upper plate 1 of the inertial amplification metamaterial plate. A bracket structure 3 is installed at the bottom end of the upper plate 1 of the inertial amplification metamaterial plate. A microperforated plate 4 is fixedly installed at the bottom end of the bracket structure 3. Porous sound-absorbing materials 5 are fixedly installed at positions inside the bracket structure 3 between the top end of the microperforated plate 4 and the bottom end of the upper plate 1 of the inertial amplification metamaterial plate. An installation structure 6 is fixedly installed inside the upper plate 1 of the inertial amplification metamaterial plate at a position below the noise reduction structure 2. The installation structure 6 is used for installing the noise reduction structure 2 and can facilitate the adjustment of the angle of the noise reduction structure 2.

[0034] As Figure 1 , Figure 2 and Figure 6 shown, the noise reduction structure 2 includes a horizontal bar 21 movably installed at the top end of the upper plate 1 of the inertial amplification metamaterial plate. A concave block 22 is fixedly installed at the top end of the horizontal bar 21. A rectangular rod 23 is clamped and installed inside the concave block 22. A mass block 24 is clamped and installed at one end of the rectangular rod 23;

[0035] Under the action of the concave block 22, the installation of the rectangular rod 23 is facilitated, and the installation difficulty of the rectangular rod 23 is changed. At the same time, under the action of the rectangular rod 23, the installation of the mass block 24 is facilitated, and the installation difficulty of the mass block 24 is changed. The noise reduction structure 2 composed of the mass block 24, the concave block 22, the rectangular rod 23 and the mass block 24 constructs the energy functional of the coupling system in the way of "building blocks". The low-level energy functional is directly used by the high-level, greatly simplifying the complexity of the coupling system modeling.

[0036] As Figure 3 and Figure 5 shown, the bracket structure 3 includes a top frame 31 fixedly installed at the bottom edge of the upper plate 1 of the inertial amplification metamaterial plate. An outer frame 32 is fixedly installed at the position corresponding to the bottom edge of the top frame 31 at the top of the micro-perforated plate 4. An inner frame 33 is fixedly installed at the position of the bottom end of the inner wall of the outer frame 32 at the top of the micro-perforated plate 4. Threaded rods 34 penetrating the outer frame 32 are fixedly installed at the four corners of the bottom end of the upper plate 1 of the inertial amplification metamaterial plate. Nuts 35 are threadedly connected to the outer sides of the threaded rods 34 inside the outer frame 32. The outer sides of the porous sound-absorbing material 5 are respectively attached to the inner walls of the top frame 31 and the inner frame 33. The inner frame 33 and the top frame 31 have the same shape.

[0037] Through the cooperation between the inner frame 33 and the top frame 31, the porous sound-absorbing material 5 is limited to prevent the displacement of the porous sound-absorbing material 5. And under the action of the outer frame 32, the outer frame 32 and the top frame 31 are made to coincide. Then, under the action of the threaded rod 34 and the nut 35, the upper plate 1 of the inertial amplification metamaterial plate and the micro-perforated plate 4 are fixed, so as to achieve the purpose of adjusting and fixing the distance between the upper plate 1 of the inertial amplification metamaterial plate and the micro-perforated plate 4. Furthermore, the porous sound-absorbing material 5 is clamped and fixed, and the distance between the upper plate 1 of the inertial amplification metamaterial plate and the micro-perforated plate 4 can be adjusted, so as to be applicable to porous sound-absorbing materials 5 with different thicknesses.

[0038] As Figure 4 and Figure 7As shown in the figure, the mounting structure 6 includes a column 61 fixedly mounted at the bottom end of the noise reduction structure 2. A fixed connection is made between the bottom end of the horizontal bar 21 and the top end of the column 61. An installation ring 66 is installed inside the upper plate 1 of the inertial amplification metamaterial plate by screws. The top end of the installation ring 66 is connected to a rotating ring 68 in a vertically movable manner. The top end of the rotating ring 68 is rotatably connected to a fixed ring 64. A clamping bar 62 is movably connected inside the fixed ring 64. The bottom end of the fixed ring 64 is welded with plugging rods 65 at equal intervals, and the plugging rods 65 penetrate and are connected to the inside of the installation ring 66. Four spring columns 67 are clamped and installed between the opposite surfaces of the installation ring 66 and the rotating ring 68, which is convenient for the reset of the rotating ring 68 and changes the reset difficulty of the rotating ring 68. Spring rods 63 are symmetrically clamped and installed between the clamping bar 62 and the fixed ring 64. The spring rods 63 and the spring columns 67 have the same shape. Both the spring rods 63 and the spring columns 67 are composed of a sleeve, a movable rod and a spring. The movable rod is movably connected inside the sleeve, and a spring is installed between one end of the movable rod and the inner wall of the sleeve. The spring is used to drive the back-and-forth movement of the movable rod, which is convenient for the reset of the clamping bar 62 and changes the reset difficulty of the clamping bar 62. A fitting groove is opened on the outer surface of the column 61. The inner wall of the fitting groove and the outer side of the clamping bar 62 are mutually attached. An inclination angle is opened at one edge of the clamping bar 62. The dimension of the clamping bar 62 near the column 61 is smaller than that of the other end. The shape of the fitting groove is conical. The dimension of the fitting groove near the center line of the column 61 is smaller than that of the other end. The outer diameter between the clamping bar 62 near the column 61 and the inner wall of the fitting groove is mutually attached. This is convenient for the connection between the clamping bar 62 and the column 61 and changes the connection difficulty between the clamping bar 62 and the column 61. A number of positioning holes are opened in a circumferential array with the center point as the reference at the position corresponding to the bottom end of the plugging rod 65 at the top end of the installation ring 66 for the connection between the plugging rod 65 and the installation ring 66, so as to fix the rotating ring 68 and change the fixing difficulty of the rotating ring 68. A chamfer is opened at the edge of the bottom end of the plugging rod 65. Positioning grooves for fitting the installation ring 66 are opened at equal intervals at the top end of the upper plate 1 of the inertial amplification metamaterial plate. The inner wall of the positioning groove and the outer side of the installation ring 66 are mutually attached, which is convenient for the installation of the installation ring 66 and changes the installation difficulty of the installation ring 66;

[0039] The operator inserts the column 61 at the bottom end of the horizontal bar 21 into the upper plate 1 of the inertial amplification metamaterial plate. At this time, the column 61 first pushes the latch 62, and the latch 62 drives the spring rod 63 to compress. When the fitting groove of the column 61 corresponds to the latch 62, the tension of the spring rod 63 drives the latch 62 into the column 61, thus achieving the purpose of facilitating the installation and fixation of the column 61, and further achieving the purpose of facilitating the installation of the noise reduction structure 2. Then, when it is necessary to adjust the angle of the noise reduction structure 2, the operator pulls the noise reduction structure 2. When the noise reduction structure 2 moves, it drives the latch 62 to rise through the column 61. When the latch 62 rises, it drives the fixed ring 64 to rise through the spring rod 63. When the fixed ring 64 rises, it drives the insertion rod 65 to rise. When the insertion rod 65 rises, it separates from the mounting ring 66 and drives the rotating ring 68 to rise. When the rotating ring 68 rises, it drives the spring column 67 to stretch. Then, the operator rotates the noise reduction structure 2, and the noise reduction structure 2 drives the fixed ring 64 to rotate inside the rotating ring 68, and then relaxes it. At this time, the insertion rod 65 enters different holes of the mounting ring 66, thus achieving the purpose of adjusting the angle of the noise reduction structure 2 and changing the adjustment difficulty of the angle of the noise reduction structure 2.

[0040] Working principle: During the actual use of the device, the horizontal bar 21, the concave block 22, the rectangular rod 23 and the mass block 24 are combined to form the noise reduction structure 2. Then, the operator puts the porous sound-absorbing material 5 into the micro-perforated panel 4. Next, the micro-perforated panel 4 and the upper plate 1 of the inertial amplification metamaterial plate are installed through the support structure 3, so that the micro-perforated panel 4 and the upper plate 1 of the inertial amplification metamaterial plate squeeze and fix the porous sound-absorbing material 5. The device adopts a detachable structure form. By adjusting the size of the mass block 24 in the noise reduction structure 2 and adjusting the thickness of the porous sound-absorbing material 5 through the support structure 3, the position and width of the effective frequency band are further adjusted, so as to play a role in absorbing and isolating noise, thus ensuring the effective absorption of noise, enhancing the noise reduction effect, and at the same time, it can be customized according to the actual environment or the requirements of the noise source to adapt to different usage scenarios;

[0041] Then, the operator inserts the column 61 at the bottom end of the horizontal bar 21 into the upper plate 1 of the inertial amplification metamaterial plate. At this time, the column 61 first pushes the latch 62, and the latch 62 drives the spring rod 63 to compress. When the fitting groove of the column 61 corresponds to the latch 62, the tension of the spring rod 63 drives the latch 62 into the column 61, thus achieving the purpose of facilitating the installation and fixation of the column 61, and further achieving the purpose of facilitating the installation of the noise reduction structure 2, thereby saving installation time and cost, improving work efficiency, and reducing errors or damages caused by improper operation during installation. It can also quickly adjust the position under different environments or requirements;

[0042] Next, when it is necessary to adjust the angle of the noise reduction structure 2, at this time, the operator pulls the noise reduction structure 2. When the noise reduction structure 2 moves, it drives the clamping strip 62 to rise through the column 61. When the clamping strip 62 rises, it drives the fixed ring 64 to rise through the spring rod 63. When the fixed ring 64 rises, it drives the insertion rod 65 to rise. When the insertion rod 65 rises, it separates from the mounting ring 66 and drives the rotating ring 68 to rise. When the rotating ring 68 rises, it drives the spring column 67 to stretch. Then, the operator rotates the noise reduction structure 2, so that the noise reduction structure 2 drives the fixed ring 64 to rotate inside the rotating ring 68, thereby changing the overall angle of the noise reduction structure 2. When the insertion rod 65 enters different holes of the mounting ring 66, the purpose of fixing the noise reduction structure 2 after adjusting the angle is achieved, and the difficulty of adjusting the angle of the noise reduction structure 2 is changed. By adjusting the angles of multiple noise reduction structures 2, multiple noise reduction structures 2 are combined into different pattern-type noise reduction schemes. By adjusting the angle, the most effective noise reduction mode for noise can be achieved. At the same time, different pattern combinations are suitable for different types of noise environments and scenarios, improving the versatility and adaptability of the noise reduction algorithm.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them.

Claims

1. An adjustable inertial amplification type noise reduction device for low-frequency noise, characterized in that: The invention comprises an inertia amplifying superstructure upper plate (1), wherein a noise reduction structure (2) is staggeredly installed at the top of the inertia amplifying superstructure upper plate (1), a support structure (3) is installed at the bottom of the inertia amplifying superstructure upper plate (1), a micro-perforated plate (4) is fixedly installed at the bottom of the support structure (3), a porous sound absorbing material (5) is fixedly installed at the top of the micro-perforated plate (4) and the bottom of the inertia amplifying superstructure upper plate (1) at a position inside the support structure (3), and a mounting structure (6) is fixedly installed at a position inside the inertia amplifying superstructure upper plate (1) at the bottom of the noise reduction structure (2), and the mounting structure (6) is used to mount the noise reduction structure (2) and can facilitate the adjustment of the angle of the noise reduction structure (2).

2. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 1, characterized in that: The mounting structure (6) comprises a column (61) fixedly mounted on the bottom end of the noise reduction structure (2); a mounting ring (66) is mounted inside the upper plate (1) of the inertia amplification superstructure plate by means of screws; a rotating ring (68) is movably connected to the top of the mounting ring (66) in an upper and lower manner; a fixed ring (64) is rotatably connected to the top of the rotating ring (68); a plug-in rod (65) is welded to the bottom end of the fixed ring (64) and the plug-in rod (65) is connected to the inside of the mounting ring (66); a spring rod (63) is embedded and mounted at the bottom of the inner wall of the fixed ring (64); a clamping strip (62) is clamped and mounted at one end of the spring rod (63); a spring column (67) is clamped and mounted between the opposite surfaces of the mounting ring (66) and the rotating ring (68); a fitting groove is provided on the outer surface of the column (61); the inner wall of the fitting groove and the outer side of the clamping strip (62) are in contact with each other.

3. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 1, characterized in that: The noise reduction structure (2) comprises a horizontal bar (21) movably mounted on the top of the inertia amplification superstructure plate upper plate (1), a rectangular rod (23) being mounted on the top of the horizontal bar (21), and a mass block (24) being clamped and mounted at one end of the rectangular rod (23).

4. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 1, characterized in that: The support structure (3) comprises a top frame (31) fixedly mounted on the bottom edge of the upper plate (1) of the inertia amplification superstructure plate; an outer frame (32) is fixedly mounted at the top of the micro-perforated plate (4) corresponding to the bottom edge of the top frame (31); an inner frame (33) is fixedly mounted at the bottom of the inner wall of the outer frame (32) at the top position of the micro-perforated plate (4); threaded rods (34) penetrating the outer frame (32) are fixedly mounted at the four corners of the bottom end of the upper plate (1) of the inertia amplification superstructure plate; and nuts (35) are connected to the outer side of the threaded rods (34) at a position inside the outer frame (32) through threads.

5. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 4, characterized in that: The outer sides of the porous sound-absorbing material (5) are respectively fitted to the inner walls of the top frame (31) and the inner frame (33), and the inner frame (33) and the top frame (31) have the same shape.

6. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 3, characterized in that: The bottom end of the horizontal bar (21) and the top end of the column (61) are fixedly connected.

7. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 3, characterized in that: A concave block (22) is fixedly mounted on the top of the horizontal bar (21), and the rectangular rod (23) is clamped and mounted inside the concave block (22).

8. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 2, characterized in that: The top of the mounting ring (66) is provided with a plurality of positioning holes in a circular array with the center point as a reference at a position corresponding to the bottom of the plug-in rod (65); the bottom edge of the plug-in rod (65) is provided with a chamfer; and the clamping strip (62) is provided with an inclined angle at a position close to one end of the column (61).

9. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 2, characterized in that: The top of the upper plate (1) of the inertia amplification super structure plate is provided with equidistant positioning grooves which fit the mounting ring (66), and the inner wall of the positioning groove and the outer side of the mounting ring (66) fit each other.

10. The adjustable inertial amplification type noise reduction device for low-frequency noise according to claim 2, characterized in that: The spring rod (63) and the spring column (67) have the same shape, and are both formed by combining a sleeve, a movable rod and a spring.

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