JP3326227B2 - Double floor vibration suppressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double floor for preventing a data processing device installed on a double floor of a building from being damaged when the building is vibrated by an earthquake or the like. The present invention relates to a vibration suppression device.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open Nos. Sho 62-170658, Hei 1-266335, and Hei 2-190580, various vibration suppressing devices for buildings have been developed. The vibration suppression devices disclosed in these publications use a so-called dynamic damper configured by supporting a weight with motion resistance by a spring, and effectively suppress resonance of a floor slab of a building. It is.

[0003]

However, in recent years, with the widespread use of various information processing devices and semiconductor manufacturing equipment, double floors (generally used for the purpose of facilitating wiring and air conditioning, etc.) have been proposed. , Called the free access floor.)
Has become popular. Double floors are constructed by laying a number of floor panels above the building floor slabs at regular intervals from the floor slabs, so that the top of the floor panels has a normal office floor and a floor floor. Below the panel, a space for use in cable wiring and the like is secured.

[0004] When a vibration isolator is installed on a floor slab having a double floor, the simplest and most effective method for installation is to install it in the space between the double floor and the floor slab. However, if the vibration proof device occupies this space, the vibration proof device may hinder the wiring of the cable and the air conditioning in some cases. Also,
Due to the structure of the double floor, when receiving vibration such as an earthquake, there is a case where a sufficient vibration suppressing effect cannot be obtained only with the vibration suppressing device attached to the building body.

A vibration isolator using an additional vibrating body such as a dynamic damper is different from a vibration isolating method using an elastic supporting method using an anti-vibration rubber or an air spring or an insulating method using an insulating material such as sand or gravel. The vibration of the vibrating body can be positively suppressed by causing the additional vibrating body to resonate substantially with the frequency of the vibration source. This device attaches an additional vibrator made of a small mass and a spring to a machine foundation or structure that is in a steady vibration state where the response magnification may become very large when vibrated at a specific frequency. The vibration of the vibrating body is suppressed by making the body almost equal to the frequency of the vibration generator. However, a two-mass system vibration model, in which an additional vibrating body is coupled to a one-mass system vibration model, is placed below Since the three elements of the mass of the vibrating body, the spring constant of the spring, and the damping coefficient of the damper are important factors for vibration damping, the natural frequency of the object fluctuates even with the vibration isolator once completed. As a result, when the frequency of the forced external force to be damped fluctuates or when it is desired to shift the priority target of the damped object, the weight of the additional vibrator, the spring constant of the spring, the damping coefficient of the damper, etc. Easy variable setting It is necessary that a structure, such as possible.

As is well known, a spring provides a vibration resistance in proportion to the displacement, while a damper provides a viscous resistance in proportion to the vibration speed, and the damping mode changes depending on the size of the damper. That is, for example, when a forced external force is applied in a stepwise manner, the number of vibrations until the vibration is attenuated to a vibration having a constant amplitude depends on the damping coefficient of the damper. However, if the damping coefficient of the damper is set to an extremely large value, the damping will be completed in an excessively short time after the external force is applied due to the overdamping state, so that it is not comfortable to sit on a seat with a hard cushion. And conversely, if the damping coefficient of the damper is set extremely small,
The state becomes insufficiently damped, and the vibration continues for a relatively long time after the forced external force is applied, and the user feels uncomfortable as if he were sitting on a seat with too soft cushion. Therefore, the selection range of damping constants is not wide enough so that the damping constant of the damper can be set appropriately according to the usage environment.However, the damper used for damping the machine foundation or structure itself is not used. Since it is huge and is subject to various restrictions due to the arrangement in a limited space between the floor slab and the double floor, it is difficult to install the damping coefficient so that it can be easily changed. Therefore, many of the conventional vibration dampers have a problem that the adjustment range of the damper is narrow, and the vibration control device cannot sufficiently cope with a wide range of vibration sources.

Accordingly, an object of the present invention is to provide a floor slab having an appropriate damping coefficient by providing a suitable damping resistance to an additional vibrating body and adjusting a response magnification in a frequency range before and after the additional vibrating body. Another object of the present invention is to provide a double floor vibration suppressing device which is excellent in vibration suppressing effect of a double floor, has a simple structure, does not require a large installation space, and is easy to construct.

[0008]

In order to achieve the above object, the apparatus of the present invention has the following configuration. That is, a column for a double floor standing upright on the floor slab, and a spring member arranged so as to surround the column and extendable and contractible in the axial direction of the column, and mounted on the column, and An upper holder to which an upper end of a spring member is locked, a lower holder slidably mounted on the column and connected to a lower end of the spring member, and an additional weight mounted on the lower holder And a vibration damping device provided between the lower holder and the column and attenuating vibration by friction.

[0009]

The vibration suppressing device having such a structure mainly exhibits a vibration suppressing function when a vertical vibration is generated in a building. The vertical vibration of the building is transmitted from the floor slab to the support for the double floor, and transmitted from this support to the double floor such as the floor panel. When the vertical vibration is transmitted to the column, the spring member expands and contracts due to the inertial force of the additional weight, and a vibration is generated which acts in a direction to suppress the vertical vibration of the building. The vibration generated by the vibration suppressing device is transmitted to the floor slab and the double floor, and suppresses the vertical vibration of the floor slab and the double floor. In order for the vibration suppressor to effectively attenuate the vertical vibration of the floor slab and the double floor, the frequency of the inertial force generated by the vibration suppressor must be equal to the natural frequency of the floor slab and the double floor within a certain range. Must be equal to In order to adjust the frequency generated by the vibration suppressing device, one or both of the spring force of the spring member and the weight of the additional weight are changed.

Since the vibration damping device of the present invention has a vibration damping device as one of its constituent elements, the vibration damping device gives an appropriate damping resistance to an additional vibrating body such as an additional weight, and a frequency range before and after this. Can be adjusted.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vibration suppression device 1 of the present invention
It is a longitudinal cross-sectional view of the state installed in the support | pillar 3 of FIG. Post 3
It has a pillar main body 4 formed of a hollow cylindrical body, a support substrate 6 fixed to a floor slab 5 to support a lower end of the pillar main body 4, and a floor panel support member 7 fixed to an upper end of the pillar main body 4. As shown in FIG. 1, an upper holder 8 is fitted on the outer peripheral surface of the column 3, and is fixed to the upper portion of the column 3 by a bolt 9 and a nut 10 so as not to rotate. The upper holder 8 is integrally formed of a material such as a synthetic resin. A single spiral groove 8a is formed on the outer peripheral surface of the upper holder 8, and the upper end of the spring member 11 is slidably engaged with the groove 8a.

As shown in FIG. 4, on the outer peripheral surface of the column 3,
A pair of guide rail holders 12 and 13 are fixed with a phase shift of 180 degrees from each other. These guide rail holders 12, 13 are respectively constituted by guide rail holder halves 12a, 12b, 13a, 13b,
These guide rail holder halves 12a, 12b, 13
a, 13b meanwhile guide rails 14a, 14b, 1
It is fixed by a tightening belt k so as to extend in the axial direction of the column 3 with the 5a and 15b sandwiched therebetween. The tightening belt k is fixed by bolts l and nuts m. The guide rails 14a, 14b, 15a, 15b are made of an aluminum alloy mold, and the guide rail holder 12,
13 are installed at an angle so as to form a valley at the center. These guide rails form a part of friction type vibration damping devices 16 and 17 (described later) as shown in FIG.

The upper end of the spring member 11 is placed on the upper holder 8.
And a lower holder 18 is engaged with the lower end thereof. The lower holder 18 has a cylindrical portion 18a with which the spring member 11 is engaged, and a flange portion 18b formed at the lower end of the cylindrical portion 18a. The cylindrical portion 18a and the flange portion 18b are made of a synthetic resin material. And so on. A spiral groove 18c is formed on the outer peripheral surface of the cylindrical portion 18a, similarly to the upper holder 8, and the lower end of the spring member 11 is slidably engaged with the groove 18c. As a result, the lower holder 18 includes the support 3, the guide rail holders 12, 13, and the guide rails 14a, 14
b, 15a, and 15b are supported by the spring member 11 and movably up and down.

An additional weight 19 is placed and fixed on the upper surface of the flange portion 18b of the lower holder 18. The additional weight 19, as shown in FIG.
a, 19b, each semi-cylindrical portion 19a, 19b is formed by stacking a plurality of semicircular plate-shaped weights w and fastening them with bolts 20 and nuts 21. The semi-cylindrical portions 19a, 19b are respectively connected to the flange portions 18b of the lower holder 18 by bolts 22 and nuts 23.
Fixed to The bolt 22 is engaged with a notch 18 d formed in the flange portion 18 b of the lower holder 18 (see FIG. 2), inserted into a hole h formed in each plate-shaped weight w, and fastened by a nut 23. Then, it is fixed to the flange portion 18b.

On the lower surface of the flange portion 18b of the lower holder 18, friction-type vibration dampers 16 and 17 are mounted, and these vibration dampers 16 and 17 are arranged on both sides of the column 3 with the column 3 interposed therebetween. . Each vibration damping device 16, 17
Is the spring case 2 formed on the flange portion 18b.
4, a cylinder 24a formed inside the spring case 24, a friction shoe 25 slidably mounted on the cylinder 24a, and the friction shoe 25 being constantly moved in the corresponding guide rails 14a, 14b, 15a, 15b. Compression spring 26 biasing to the surface, and a surface pressure adjusting screw 27 for adjusting the surface pressure of the compression coil spring 26
And

The friction shoes 25, 25 are pressed against the sliding surfaces of the corresponding guide rails 14a, 14b, 15a, 15b by the compression coil springs 26, respectively, so that the friction shoes 25, 25 are in contact with the corresponding guide rails for vibration damping. Generates frictional force. In this embodiment, the compression coil spring 26, the cylinder 24a and the surface pressure adjusting screw 27 are elastic means for urging the friction shoe 25 against the guide rails 14a, 14b, 15a, 15b forming the sliding contact surface. Is configured. The compression coil spring 26 used has a relatively small spring constant and is largely bent from its natural length to be accommodated in the cylinder 24a. Therefore, the friction shoe 25 or the guide rails 14a, 14b, 15a are used. , 15b can be suppressed to a negligible variation in the spring constant even if the sliding surfaces are worn out by friction, whereby the damping coefficients of the vibration damping devices 16, 17 can be set for a long time. The value can be matched to prevent aging.

A support substrate 6 for supporting the lower end of the column body 4
A board plate 6a adhered to the floor slab 5 of the building with an adhesive or the like, a height adjusting bolt 6b erected on the board plate 6a, a height adjusting nut 6c screwed to the bolt 6b; And a detent screw 6d attached to the adjustment nut 6c. The height adjusting nut 6c is provided with a support surface 6e for supporting the lower end of the column main body 4, and the lower end of the column main body 4 is engaged with the support surface 6e and stands upright on the nut 6c.

As shown in FIG. 5, the column 3 is a floor slab 5
A plurality of columns 3 are arranged at predetermined intervals on the upper side and are adjacent to each other.
A stringer 29 for supporting the floor panel 28 is bridged therebetween. The stringer 29 is the support body 4
The end is supported by the floor panel support member 7 fixed to the upper end of the floor panel 28, and the lower surface of the edge of the floor panel 28 is supported by the upper surface of each stringer 29. And
Four corners of the floor panel 28 are fixed to the floor panel support member 7 from the upper surface side of the floor panel 28 by floor panel retainers 30.

As shown in FIG. 5, the vibration suppressing device 1 of the present invention does not need to be installed on all the columns 3 supporting the double floor 2, and the columns 3 of the required portions of the double floor 2 are required. Need only be installed in As shown in the figure, it is desirable to cover the vibration suppressing device 1 with a protective cover 31. The protective cover 31 is formed by combining a plurality of semi-cylindrical members 32 into a cylindrical shape as shown in the figure, and is installed on the support column 3 so that the protective cover 31 covers the outer periphery of the vibration suppression device 1. By using the protective cover 31, a cable or the like (not shown) laid between the double floor 2 and the floor slab 5 comes into contact with a movable portion such as the additional weight 19 of the vibration suppressing device 1 to suppress vibration. It is possible to prevent the operation of the device 1 from being impaired.

As shown in FIGS. 1 and 6, when the vibration suppressing device 1 vibrates in the vertical direction together with the floor slab 5 and the double floor 2, the lower portion is caused by the spring force of the spring member 11 and the inertia force of the additional weight 19. The holder 18 vibrates up and down. When the lower holder 18 vibrates in the vertical direction, the vibration damping device 16,
17 friction shoes 25, 25 are guide rails 14a, 1
The sliding surfaces 141a, 141b, 151 of the guide rails are formed from the valleys V formed at the connecting portions of the guide rails 4b, 15a, 15b.
a, 151b, and moves up and down while being pressed against it, and the frequency of vibration generated by the vibration suppressing device 1 is limited to a certain range by the frictional force generated between the friction shoe 25 and the guide rails 14a, 14b, 15a, 15b. . Vibration damping devices 16, 17
Provides a function of imparting an appropriate damping resistance to the additional vibrator such as the additional weight 19 by the generated frictional force, and adjusting the response magnification in the frequency range before and after this.

Here, the frequency generated by the vibration suppressing device 1 refers to the frequency generated when the lower holder 18 moves up and down together with the additional weight 18. Further, the range of the constant frequency generated by the vibration suppression device 1 is defined as a range of the frequency generated by all the vibration suppression devices 1 on the floor slab 5 being equal to the natural frequency of the double floor 2 and the floor slab 5. A certain range including the natural frequency and extending before and after the natural frequency. By setting the vibration frequency generated by the vibration suppressing device 1 in this way, it is possible to effectively suppress the vertical vibration of the floor slab that the building has received due to an earthquake or the like.

Adjustment of the frequency generated by each vibration suppression device 1 is performed by changing the spring constant of the spring member 11 or changing the weight of the additional weight 19. this house,
To change the spring constant of the spring member 11, the spring member 11 is formed by helical grooves 8 a and 18 of the upper holder 8 and the lower holder 18.
This is performed by rotating the spring member 11 along the line c. The weight of the additional weight 19 is changed by changing the number of plate-shaped weights w.
The change of the frequency generated by each vibration suppression device 1 may be performed by changing any one of them, or may be performed by changing both of them.

The vibration dampers 16 and 17 provided between the lower holder 18 and the column 3 provide the additional weight 19 with a vibration resistance equivalent to a viscous resistance in proportion to the displacement of the spring member 11. Provides a viscous drag proportional to the vibration speed. Therefore, the damping mode changes according to the magnitude of the damping coefficient of the vibration damping devices 16 and 17, and, for example, when a forced external force is applied in a stepwise manner, the number of times of the damping vibration and the vibration of the vibration until the vibration is attenuated to a constant amplitude are reduced. The number depends largely on the damping coefficient. In the embodiment, the surface pressure adjusting screw 27 is used.
The maximum screwing amount is secured sufficiently so that the spring force of the compression coil spring 26 can be adjusted over a wide range when the surface pressure adjusting screw 27 is rotated forward and reverse.
For this reason, it is possible to select the optimal damping for the target forced vibration, it is possible to freely select the damping constant according to the use environment, and it is possible to cope with a wide range of vibration sources with a margin.

In the above-described embodiment, the compression coil spring 26 is housed in the spring case 24 integrally formed with the lower holder 18, but the vibration damping device 4 shown in FIG.
As in the case of 0, the compression coil spring 26 can be accommodated in a spring case 41 fixed to the lower holder 18 with screws. In this embodiment, a hook-shaped projection 42 for preventing the friction shoe 25 from coming off is formed along the inner periphery of the opening of the bottomed cylindrical spring case 41. After the friction shoe 25 is stored, the friction shoe 25 is prevented from falling off unless the projection 42 is expanded by a tool or the like. In addition, the spring case 4
1 is screwed into the locking nut 43 to be locked to the bottom surface, and after screwing the surface pressure adjusting screw 27 to an appropriate position, the locking nut 43 is tightened.
The surface pressure adjusting screw 27 can be prevented from loosening.
Also in this embodiment, the friction force of the friction shoe 25 can be varied in an analog manner according to the screwing depth of the surface pressure adjusting screw 27, and fine adjustment of the damping coefficient is possible through fine surface pressure adjustment. It is.

Further, in the above embodiment, the spring force of the compression coil spring 26 is adjusted by the surface pressure adjusting screw 27. However, as in the vibration damping device 45 shown in FIG.
Between the compression coil spring 2 and the compression coil spring 2 according to the number of the surface pressure adjustment shims 26 to be used.
The spring force of No. 6 may be adjusted. In this case, the attenuation coefficient can be switched discretely in accordance with the number of the surface pressure adjusting shims 46 used, and the surface pressure can be accurately grasped.

Further, in each of the above embodiments, the case where a pair of vibration damping devices 16, 17 or 40 or 46 are disposed opposite to each other around the column 3 is taken as an example, but as shown in FIG. For example, three vibration damping devices 46 may be arranged around the column 3 at a distance of 120 ° from each other, and as shown in FIG. They may be arranged 90 degrees apart from each other. In addition, the vibration damping device 46 or 40, or 1
6 and 17 can be used in a number of five or more. By arranging a plurality of vibration damping devices in parallel, when the additional weight 19 vibrates up and down, the lower holder 18 is prevented from swaying and stable damping Can be promised.

[0027]

As described above, since the vibration suppressing device of the present invention is installed on a column for supporting a double floor,
It becomes possible to arrange this vibration suppressing device concentrated on the local part of the double floor. Therefore, vibration can be effectively prevented in accordance with the vibration characteristics of the floor slab.

Further, the vibration suppressing device of the present invention is installed around a column for supporting a double floor,
In addition, since the components of the apparatus are dispersedly arranged in the longitudinal direction of the column along the axis of the column, it is possible to reduce the size of the entire apparatus and not occupy a large space when installing the apparatus. Therefore, when laying a cable or the like in the space between the double floor and the floor slab, the vibration suppressing device does not interfere. In addition, since the device is small, each component is also small, and there is an effect that its manufacture and assembly are easy.

Further, since the vibration suppressing devices are installed in a distributed manner on a plurality of columns, the respective vibration suppressing devices are relatively lightweight and easy to handle. Moreover, when the double floor is constructed, the vibration suppressing device is also constructed at the same time, so that there is no influence on the construction process.

Further, since a vibration damping device for damping vibration by friction is provided between the lower holder and the column, the frequency band in which vibration can be suppressed is widened, and the viscous resistance proportional to the vibration speed with respect to the additional weight is increased. By changing the damping mode according to the magnitude of the damping coefficient, for example, by setting the damping coefficient large, the damping after the forced external force is applied can be completed in a short time, or vice versa. Can be set to a small value, and the damping constant can be freely selected in accordance with the use environment, for example, when a forced external force is applied, so that the damping constant can be freely selected.

Further, the vibration damping device can prevent the response magnification of the vibrating body from increasing in the vibration band around the natural frequency.

The damping force of the vibration damping device is basically adjusted by changing the inclination angle of the guide rail and the spring constant of the spring pressing the friction shoe. As a result, a stable damping characteristic is obtained in which the energy consumption per cycle is proportional to the speed proportional type damping (for example, damping using fluid) in proportion to the displacement and the pressing force of the friction shoe.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state in which a vibration suppressing device of the present invention is installed on a column having a double floor.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a main part of the vibration suppressing device of the present invention.

FIG. 4 is an exploded perspective view illustrating a mounting state of a guide rail holder and a guide rail.

FIG. 5 is a perspective view of a state in which a double floor is supported using the vibration suppression device of the present invention.

FIG. 6 is a longitudinal sectional view illustrating a schematic configuration of a vibration damping device.

FIG. 7 is a longitudinal sectional view showing a modified example of the vibration damping device shown in FIG.

8 is a longitudinal sectional view showing a modified example of the vibration damping device shown in FIG.

FIG. 9 is a longitudinal sectional view showing a modification of the vibration suppressing device shown in FIG.

FIG. 10 is a longitudinal sectional view showing another modification of the vibration damping device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 51 ... Vibration suppression device 2 ... Double floor 3 ... Strut 4 ... Strut main body 5 ... Floor slab 6 ... Support substrate 7 ... Floor panel support member 8 ... Upper holder 8a ... Spiral groove 9 ... Bolt 11 ... Spring member 14a, 14b, 15a, 15b ... guide rails 141a, 141b, 151a, 151b ... sliding contact surfaces 16, 17, 40, 45 ... vibration damping device 18 ... lower holder 18c ... spiral groove 19 ... additional weight 24 ... spring case 25: Friction shoe 27: Surface pressure adjusting screw 41: Spring case 42: Projection 46: Surface pressure adjusting shim

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hitoshi Okita 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Toshifumi Ninomiya 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Inside Telegraph and Telephone Corporation (72) Inventor Yukio Sawabe 5-8 Akihabara, Taito-ku, Tokyo Inside NTT Building Research Institute (72) Inventor Takao Okumura 1-1-1 Uchisaiwaicho, Chiyoda-ku, Tokyo No. 1 Inside Naka Technical Research Institute Co., Ltd. (72) Tatsuo Shoji 1-1-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo Tokyo, Japan Inside (72) Inventor Seiji Shimura 1-1-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo, Japan (56) References JP-A-2-129428 (JP, A) JP 7-6300 (JP, B2) Flat 8-3262 (JP, B2) Tokuoyake flat 4-19344 (JP, B2) patent 3092097 (JP, B2) utility model registration 2560383 (JP, Y2) (58 ) investigated the field (Int.Cl. ^7, DB Name) E04F 15/18 601 E04F 15/024 605 F16F 15/04

Claims (7)

(57) [Claims] 1. A strut for a double floor standing upright on a floor slab, a spring member arranged to surround the strut and expandable and contractable in the axial direction of the strut, and mounted on the strut. And an upper holder to which an upper end of the spring member is locked, a lower holder slidably mounted on the column and connected to a lower end of the spring member, and mounted on the lower holder. And a vibration damping device provided between the lower holder and the column and attenuating vibration by friction. 2. The vibration damping device according to claim 1, further comprising: a sliding contact surface formed on the support, a friction shoe supported by the lower holder and sliding in contact with the sliding contact surface; The double-floor vibration suppressing device according to claim 1, comprising an elastic means for pressing against the contact surface. 3. The vibration damping device according to claim 1, wherein said vibration damping device is supported by said lower holder and provided with a plurality of sliding contact surfaces provided at substantially equal distances from each other around said support column, and is in contact with said corresponding sliding contact surface. The double-floor vibration suppression device according to claim 1, comprising: a plurality of sliding friction sliding members; and a plurality of elastic means for pressing the friction sliding members against the sliding surfaces. 4. The sliding contact surface comprises a pair of inclined surfaces extending in a direction along the axis of the column and continuous, and the connecting portions of the pair of inclined surfaces are respectively formed by a pair of inclined surfaces. The double-floor vibration suppression device according to claim 2 or 3, wherein the two floors are inclined in opposite directions so as to form a valley. 5. The sliding contact surface is formed on a guide rail, and a guide rail holder is attached to an outer peripheral surface of the support, wherein the sliding contact surface of the guide rail extends in an axial direction of the support, and The double floor vibration suppression device according to claim 2, wherein the support is attached to the guide rail holder such that a central portion of the support in the axial direction forms a valley. 6. The elastic means includes: a spring having one end engaged with the friction shoe to bias the friction shoe in a direction to press the friction shoe against the sliding surface; and a spring case formed in the lower holder. 3. The screw according to claim 2, further comprising a surface pressure adjusting screw which is screwed to the spring case so as to be able to advance and retreat, and a tip of which locks the other end of the spring.
Or the double floor vibration suppressor according to 3. And a spring case formed on the lower holder, wherein the elastic means includes a spring having one end locked to the friction shoe and urging the friction shoe in a direction of pressing the friction shoe against the sliding contact surface. The double floor vibration according to claim 2, further comprising a surface pressure adjusting shim inserted between the spring case and the other end of the spring to adjust a surface pressure of the spring. Suppression device.