JPS6338709A - Differential thickness vibration-damping composite steel plate screwed by tapping screw - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an improvement in a vibration-damping composite steel plate that is screwed onto an object using a tapping screw.

[Conventional technology]

In recent years, as interest in noise has increased and noise regulations have become stricter, technology for noise prevention has been actively developed.

A vibration-damping composite steel plate has also been developed as a material effective in preventing such noise, and FIG. 5 is a perspective view of it. As shown in the figure, the damping composite steel plate (1) consists of two steel plates (1m).
, (Ib), and a viscoelastic substance (1c) is sandwiched between them. Usually, the thickness of the steel plates (la) and (lb) is equal to 0.15 to 6.0 mm, and the thickness of the viscoelastic material (IC) is 0.03 to 0.2 mm.

Methods of using the vibration-damping composite steel plate (1) for noise prevention measures include forming part or all of the noise source with the steel plate, or using the steel plate as a material for a casing that houses the noise source. There are ways to do this.

An example of a device incorporating the above-mentioned noise generation source is an outdoor unit of a room air conditioner. The casing of this type of outdoor unit is usually made of a single-layer steel plate, but this poses a problem in terms of noise prevention, and as a countermeasure, attempts are being made to install vibration-proofing material inside the casing. .

[Problem that the invention seeks to solve]

By the way, the method of using the above-mentioned vibration-proofing material not only has a problem with the vibration-proofing effect because the space for installing the vibration-proofing material is limited, but also causes an increase in cost due to the use of expensive vibration-proofing material. There are other difficulties. From this point of view, a proposal is being considered to use the vibration-damping composite steel plate as the casing material instead of installing vibration-proofing material. It turned out to be flawed. A detailed explanation will be given below with reference to the drawings.

Figure 6 shows how to tap the component (2) onto the casing of the outdoor unit made of vibration-damping composite steel plate (1).
It is an enlarged sectional view of the screwing part when screwing using. Since the thickness of the single Ff steel plate conventionally used as a casing material is 0.8+na, when using the damping composite steel plate as shown in Fig. 5, the thickness is approximately 0.8 m. In order to make the surface steel plate (la), (lb
) with a thickness of 0.4 m was used. As a result, JIS
When using the standard Nyoro M3 tapping device 3),
The thread (3a) is a skin steel plate (
1a), or even if it does not penetrate, the remaining thickness (11-h) of the skin steel plate (1a) seen from the top of the thread is extremely small, so the tightening torque applied to the screw is 10
Even when the load was relatively small, such as ~20 kg, the skin steel plate (1a) broke and the screws became ineffective.

For this reason, instead of tapping 3), attempts have been made to use machine screws and nuts to screw the parts (2) together, or to join the objects by welding, but this method It has been found that this method is extremely disadvantageous in terms of work efficiency compared to the method using tapping screws (3). Therefore, there has been an urgent need for a vibration-damping composite steel plate that can withstand the use of self-tapping screws.

The present invention was made in response to the above-mentioned demand, and aims to provide a vibration-damping composite steel plate that allows the use of tapping screws.

[Means for solving problems]

In order to achieve the above-mentioned promise, in the Naro vibration-damping composite steel plate, a viscoelastic substance is sandwiched between two steel plates that are joined to the object with tapping screws, and the tapping screws of the vibration-damping composite steel plate are screwed together. The thickness of the skin steel plate on the side is jly, and the thickness of the skin steel plate on the opposite side is t2
．． When the height of the thread of the tapping screw is h, the jlp tl is defined by the following formula.

1, ≧h+0.1ms+ 1/4t, <t, <t.

Above LIpt2. In order to limit the value of , we conducted a series of experiments as described below. First, the difference t, -h between the thickness 11 of the skin steel plate (1a) and the height h of the threads was varied, and the value of the breaking torque at that time was determined. FIG. 3 is a diagram showing the results. In the figure, A indicates the yield strength of the skin steel plate (]a) is 36 kg 17 m'', and B indicates the same strength is 18
kg f/am''.Normal vibration damping composite 'n4
The temporary skin steel plate (LA) has a yield strength of 18 kgf.
/+m2(7)LiN plate usage weight: 36 kg
f/m'' steel plate is sometimes used. Taking this into consideration, and from the above experimental results, the thickness of the skin steel plate (1a) on the screwing side of the tapping screw of the vibration damping composite steel plate is the same as the thread of the tapping screw. It has been found that if the height is 0.1M or more larger than the height h, the surface steel plate of the vibration damping composite steel plate will not break when the tapping screw is screwed in, and the screw will be sufficiently effective.Therefore, t, ≧h+o, 1m. Na.

Next, an experiment was conducted to determine the thickness t8 of the skin steel plate on the side opposite to the screwing side of the screw. Figure 4 shows a loss coefficient of 9 and a ratio of the thickness of two steel plates of 1. /11.From this diagram, 1t/1. It can be seen that when becomes less than -, the loss coefficient rapidly decreases, that is, the damping performance decreases. Therefore, the lower limit of t2 was set as Itl. Note that the loss coefficient wa indicates vibration damping performance and represents the degree of attenuation of applied vibration energy. Also, as the diagram shows, 1. /1. Even if the value exceeds 1, the damping performance deteriorates, so the upper limit of t2 was set to tl in consideration of the light weight and economic efficiency of the damping composite steel plate.

By integrating the above data, the plate thicknesses 11 and t2 of the two steel plates of the damping double metal steel plate according to the present invention were defined within the above range.

[Effect]

Since the thickness of the vibration-damping composite steel plate used in locations where tapping screws, etc. are used is specified as above, the vibration-damping composite steel plate according to the present invention can sufficiently withstand the use of tapping screws. is what happened.

[Embodiments of the invention]

Fig. 1 shows an example of the use of a damping composite steel plate, which is an embodiment of the present invention, in an outdoor unit. A perspective view of the coupling screw, (C) a cross-sectional view for explaining the state in which the wiring cord restraining plate is screwed into the casing by tapping screws, and FIG. 2 is an enlarged cross-sectional view of the screwing part.

In the figure, (3) is a tapping screw, (3a) is its thread,
(4) is a washer, α [is a damping composite steel plate according to the present invention,
(10a) and (10b) are the skin steel plates, (10e
) is the viscoelastic material layer, aυ is the outdoor unit, ■ is its casing, (12a) is the square hole provided in the casing, (
12b) is a hole for the same clipping screw, f131 is a wiring cord holding plate, (13al is a hole for a clipping screw, tI, L
2 is the thickness of the skin steel plate of the damping composite steel plate, and h is the height of the thread of the tapping screw.

As shown in the figure, insert one end of the part (wiring cord holding round board) 03) into the square hole (12 m) of the casing Oz, and then tap the part αJ through the hole (13a) at the other end.
) to the casing (2). Tapping screw (3
), the thickness t of the skin steel plate (10a) on the threaded side of the thread is 0.1u+ from the height h of the threaded thread (3a) of the tapping thread.
Since it is larger than +++, the clipping screw (3)
The threaded crest (3a) does not reach the layer of the viscoelastic material (10e), and therefore the skin steel plate (10a) is not broken, and the tightening force (3) is sufficient at a predetermined tightening force of 1-lux or more. It is effective. Furthermore, the steel plate on the opposite side to the screwed side (
Since the plate thickness t2 of llb) is larger, thicker, and smaller than t, the damping performance does not deteriorate, and the lightness and economical efficiency of the vibration damping steel plate are not lost.

Note that the above embodiment describes an example of screwing parts, etc. to a vibration-damping composite steel plate using tapping screws, but it is not limited to tapping screws, but in general, it is also possible to screw parts etc. by screwing without using screws. When a screw is used, the damping composite steel plate according to the present invention can be used.

Furthermore, although the above embodiment is an example in which the vibration-damping composite steel sheet according to the present invention is used in the casing of an outdoor unit of a room air conditioner, the vibration-damping composite steel sheet is applicable not only to outdoor units but also to a wide range of general household and commercial uses. Can be used for equipment.

〔Effect of the invention〕

The present invention uses a tapping screw with a thread height h in a vibration-damping composite steel plate for screwing parts, etc., in which the thickness of the steel plate on the screwing side of the tapping screw is Llp and the thickness of the steel plate on the opposite side is 1. Since we defined 1, ≧ h + 0.1 m + a genus it < as goose < 1°, we were able to achieve the following effect.

■ Since vibration-damping composite steel plates can now be used in areas where tapping screws are used, the applications of vibration-damping composite steel plates have expanded.

■ Tapping screws can now be used in areas where objects were previously attached using screws that required nuts.
Productivity has been significantly improved.

[Brief explanation of drawings]

Figure 1 shows an example of the use of a damping composite steel plate, which is an embodiment of the present invention, in an outdoor unit of a room air conditioner.
) is a perspective view of the outdoor unit, 'b) is a perspective view of the wiring cord holding plate and tapping screws, (e) is a cross-sectional view for explaining the state in which the wiring cord holding plate is screwed into the casing by tapping screws, Figure 2 is an enlarged cross-sectional view of the parts screwed together by tapping screws, and Figure 3 is the thickness t of the skin steel plate of the vibration-damping composite steel plate. The difference between 1. Figure 4 is a diagram showing the relationship between loss coefficient and steel plate thickness ratio, Figure 5 is a perspective view of a conventional vibration damping composite steel plate, Figure 6 2. Parts for conventional vibration damping composite steel plate! l! ! It is an enlarged cross-sectional view of a fitting part. In the figure, (3) is a tapping screw, (3a) is its thread,
0 [ is the damping composite steel plate, (''') + (10b) is the skin steel plate, (10c) is the viscoelastic material layer, aυ is the outdoor unit, (2) is its casing, αj is the wiring cord suppressing plate, t ,. t2 is the thickness of the surface steel plate, and h is the height of the thread of the tapping screw. Agent Patent Attorney Masaru Sato Figure 1 (G) (C) IZo 1't!0 Figure 2 t -hmm It's snowing.

Claims (1)

[Scope of Claims] A vibration-damping composite steel plate formed by sandwiching a viscoelastic substance between two steel plates, which is joined to an object by a tapping screw, wherein the skin of the vibration-damping composite steel plate on the side where the tapping screw is screwed. The thickness of the steel plate is t_1, and the thickness of the skin steel plate on the opposite side is t.
_2 A differential thickness vibration damping composite steel plate screwed by a tapping screw, characterized in that when the height of the thread of the tapping screw is h, the above t_1 and t_2 are defined by the following formula. t_1≧h+0.1mm 1/4t_1<t_2<t_1