JPH03292426A - Shock absorbing buffer and manufacture of it - Google Patents

Abstract

PURPOSE:To realize performance necessary for a soundproof cushion material by making a lower layer in a cylindrical foaming projecting part which has hollow spaces in contact surface, laying a middle layer in the hollow spaces as middle foaming projecting parts having hollow spaces and laying them below a plane foaming sheet. CONSTITUTION:A lower layer C of elastmer which projects downward in regular arrangement and has a curved surface of cylindrical foaming projecting part 3a provided with a hollow as its under surface, is formed below the upper layer A of a plane foaming sheet 1 made of valcanized and molded elastomer. A middle layer B made of elastomer which has a middle foaming projecting part 2a provided with a hollow space is laid on the inside hollow parts of the cylindrical foaming projecting part 3a, and then double layers of projecting parts are formed. Therefore, its flexibility and soundproof performance can absorbe various kinds of shock rapidly.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a shock absorber that is mainly used as a shock absorber for the lower part of a soundproof floor for an apartment complex, and other applications include precision machinery, etc. It has characteristics that make it suitable for use in distribution materials, protective materials (safety walls, etc.) used in athletic facilities, etc.
The present invention relates to a shock absorber that prevents the phenomenon of bottoming out due to impact and has both extremely suitable support and excellent cushioning properties, and a method for manufacturing the same.

[Prior Art] Conventional rubber-like cushioning bodies have been devised in which uneven patterns such as grooves or waves or various protrusions are formed on the lower part of sheets of various elastomer solids or foams.

In particular, many shock absorbers have been disclosed and used as shock absorbers for the lower part of soundproof floors for apartment buildings, but all of these structures with good shock absorbing properties are made of a single compound rubber. Many of these floors have simple undulating patterns with low support, and these floors have high soundproofing effects.
A floor that does not provide a good walking feel and appropriate cushioning properties, and conversely provides a good walking feeling, forms a structure with poor soundproofing effects.

As an example of the above-mentioned conventionally disclosed technology, a carpet underlay mat disclosed in Japanese Utility Model Application Publication No. 55-144029 is an example of a single cushioning structure made of a single compounded rubber that has relatively good support and cushioning properties. has been done. In summary, the structure of this underlay mat is that the sea cucumber-shaped protrusions are arranged diagonally in parallel, with opposite directions for each row, and that they are inserted between the tips of both the left and right sides of the sea cucumber-shaped protrusions to reinforce the tips. A coarse net woven fabric is adhered onto the sea cucumber-shaped protrusions, and the structure allows adjustment of the waveform's expansion in the lateral direction. In addition, as an example of a floor structure which is insufficient in soundproofing properties but has great supportability, Japanese Utility Model Application Publication No. 63-86248 discloses a floor structure. To summarize, the structure of the flexible base material in the lower part of this floor structure is disclosed in which a large number of granules are filled in a concave groove having a flexible downward protrusion.

[Problems to be Solved by the Invention] As mentioned in the above-mentioned conventional technology, as a conventional shock absorber, a shock absorber with high soundproofing effect has a structure based on a single shock absorbing structure of 5 single compound rubber. The cushioning material with high soundproofing properties used as the lower layer material of the soundproofing floor is too soft and gives a very bad feeling when walking on it. With the conventional technology, it is extremely difficult to obtain the L45 rating specified by JIS with a floor that provides a good walking feel.

Therefore, the present invention satisfies all of the performances necessary for a cushion material for soundproof floors, such as ■ soundproofing performance, ■ vibration damping performance, ■ good walking feel (not too soft for a floor), and ■ sagging resistance. The purpose of this research is to explore the structure and provide a shock absorbing body and its manufacturing method.

[Means for Solving the Problems] In order to achieve the above objectives, through trial and error, we confirmed that it is impossible to combine many performances with the conventional concept of a single shock-absorbing structure made of a single rubber compound. Based on the findings from the results, we explored a solution using a composite protruding structure of elastomer.

As a result, we have created a three-layer structure using three types of foamed elastomers with different properties, and at the same time, we have given it a special shape, making it possible to combine four functions such as soundproofing performance, vibration distribution performance, good walking feel, and fatigue resistance performance. It makes gender effective.

This special shape allows for easy adjustment of the air cushion and foamed elastomer cushion, as well as a double layered structure in which the protruding part is a hollow part and the selection of materials used, and provides great support and excellent cushioning capacity. This has been taken into consideration.

That is, the upper layer is composed of a foamed elastomer laminate with a three-layer structure, the lower layer is a cylindrical protrusion having a hollow part with the contact surface of the lower surface being a curved surface, and the middle layer has a hollow part inside the hollow part. The method is to form an intermediate protrusion with a layered structure of the lower layer and the double protrusion. A three-stage method using a planar foam sheet made of This three-stage structure allows the above-mentioned four steps to be completed.
It is now possible to solve the problem of both performance and performance.

What are the requirements? Therefore, instead of the vulcanized and foamed planar foam sheet, a low-vulcanization planar foam sheet made of a low-foaming elastomer in a low-vulcanization state in a range close to the solid direction is used. Elastomers that produce such a composite structure need to be assembled from materials with different properties, and each property changes the degree of stacking of the double protrusion, the hardness, and the change in spring constant. Depending on your needs, various performance ranges can be obtained. Therefore, the elastomer may be appropriately selected from natural rubber, synthetic rubber, and other elastic polymeric substances having rubber-like elasticity, and materials with varying compositions, specific gravity, etc. may be used.

For example, the upper layer (layer A) is compounded with SBR-based synthetic rubber,
Middle layer (B layer) using a material with an apparent specific gravity of 0.65
For example, a material containing SBR-based synthetic rubber with an apparent specific gravity of 0.60 is used for the lower layer (C layer), and a CR-based synthetic rubber material with an apparent specific gravity of 0.30 is used for the lower layer (C layer). Formed from a variety of different materials. Therefore, the range of variation in the three-layer structure is determined by various variation factors, such as the amount of compounding, different polymers, changes in vulcanization rate, and changes in blowing agent.

That is, when the lower layer (C layer) material, the middle layer (B layer) material, and the upper layer (A layer) heat-formed planar foam sheet are simultaneously vulcanized, the heat-formed planar foam sheet , acts as a sealing material for foaming gas when the C layer and B layer are foamed, and the C layer and B layer, which have different degrees of foaming, are placed under the A layer of the planar foam sheet from the different protruding parts of the C layer and B layer. A stacked body of double protruding parts having a hollow part is integrally constructed to obtain a shock absorbing body having a three-stage structure of layers A, B, and C.

In particular, when stress resistance is important and a low-height foam protrusion is required, instead of using a flat foam sheet as the upper layer, some of the foam gas from the foam may be used during pressure molding in the manufacturing process. A nonwoven fabric that is easily discharged is used to create an upper layer structure of a flat nonwoven fabric sheet that allows free foaming to be controlled. In addition, the strength can be increased by using a long fiber nonwoven fabric. Further, the nonwoven fabric may be selected from short fiber nonwoven fabric, long fiber nonwoven fabric, and various types of nonwoven fabrics having different thicknesses, strengths, etc., depending on the needs.

Next, a method for manufacturing the above-mentioned impact buffer will be explained.

The arrangement of the concavo-convex pattern on the lower layer is selected by changing the cylindrical diameter and arrangement density in accordance with the desired characteristics, and various required regular arrangements are selected. The method for manufacturing the body is to stack a foamable unvulcanized elastomer sheet for the lower layer and an unvulcanized elastomer sheet for the middle layer, which has a lower foamability than the lower layer, and then layer the vulcanized foamed elastomer sheet for the upper layer on top of that. A planar foam sheet of a vulcanized elastomer consisting of a vulcanized elastomer, or a planar foam sheet of a preheat-formed upper layer of an elastomer, such as a planar foam sheet of a low-expanding, low-vulcanized elastomer kept in a low-expanding, low-vulcanized state. A three-layer laminated sheet made of laminated sheets is placed on a flat mold with cylindrical through holes arranged in the required regular arrangement according to the request, and the thickness on the mold can be adjusted by , Place a spacer of the required thickness around the mold, press the flat mold from above and below with a heating plate, and vulcanize it. Two unvulcanized elastomer sheets with different degrees of foaming are freely foamed to form a hollow part.
A heavy protrusion is formed, and the elastomer is integrally vulcanized with the upper layer of the planar foam sheet which has been heat-formed in advance.

As mentioned in the above shock absorber, a nonwoven fabric sheet is used instead of the flat foamed seal of the upper layer, which has been heat-formed in advance of the elastomer, to form an integrally vulcanized state with the upper nonwoven fabric sheet. In some cases.

[Function] Since the impact buffer of the present invention is configured as described above, the A-layer is a planar foam sheet that has been heat-molded in advance, or the B-layer and C-layer are foamable unvulcanized elastomers. It acts as a sealing material for the foaming gas of the sheet, completely sealing upward leakage of foaming gas generated from layers B and C, and easily stacking double protrusions with good hollow parts. Demonstrates the ability to form. Excellent soundproofing performance is obtained by the contact curved surface of the lower surface of the cylindrical foam protrusion having a hollow part in the lower layer, and the intermediate layer provides an intermediate foam protrusion inside the cylindrical foam protrusion in the lower layer having a hollow part. Appropriate vibration damping performance is obtained by forming stacked double protrusions, and in addition, the three-layer structure of a flat foam sheet of layer A, layer B, and layer 0, which are heat-formed in advance of elastomer, and the double protrusion. Compared to conventional single-layer structures, the structure of the parts eliminates the sudden bottoming out phenomenon due to multi-stage support, provides a good walking feel, and exhibits extremely excellent fatigue resistance. It is. Furthermore, when a nonwoven fabric sheet is used as the upper layer, the height of the cylindrical foam protrusion can be controlled, and in terms of the balance of the four performances of the present invention, a relatively high sag resistance property can be obtained.

[Example] Next, the present invention will be explained based on exemplary drawings.

FIG. 1 is a partial vertical sectional view showing an example of a shock absorber.

In the figure, 1 is a planar foam sheet of the upper layer (A layer) which is pre-vulcanized and formed of elastomer, 2 is the foam sheet of the middle layer (B layer) of elastomer, and 2a is the cylindrical foam sheet with a hollow part of the lower layer. An intermediate foam protrusion having a hollow part for an intermediate layer formed inside the protrusion, 3 is a foam sheet of the lower layer (0 layer) of elastomer, 3a partially protrudes downward, and the contact surface of the lower surface is curved. It is a cylindrical foam protrusion with a hollow lower layer.

That is, as shown in the figure, in the lower part of the planar foam sheet 1 of the upper layer (layer A), in accordance with the request, the lower layer has a hollow part that protrudes downward in a required regular arrangement and has a curved lower surface. This is a shock absorber in which a double protrusion is constructed by stacking an intermediate foam protrusion 2a having a hollow intermediate layer inside a cylindrical foam protrusion 3a.

FIG. 2 is an explanatory diagram of the method for manufacturing the impact buffer of the present invention.

In the figure, 4 is a flat mold, which is shown in a perspective view, and 4a is a spacer for adjusting the thickness of three layers (A, B, C) on the mold. Reference numeral 4b denotes through-holes that are penetrated through the entire surface of the flat mold in a required regular arrangement according to the required conditions. Reference numeral 5 denotes heating plates for pressure-welding vulcanization, which are provided above and below the flat metal mold 4 to sandwich and heat the metal mold 4, and the lower heating plate is omitted from the drawing. 6 is a planar foam sheet for the upper layer which has been heat-molded in advance from a foamable elastomer; 7 is a foamable uncured elastomer sheet for the middle layer which has less foamability than the lower layer; 8 is a foamable unvulcanized elastomer for the lower layer. 3 for filling these molds with sheets
The laminated sheet (6, 7, 8) is placed inside the spacer 4a on the flat mold 4, and the heating plate 5 is placed inside the spacer 4a.
By pressing the foamable unvulcanized elastomer sheet onto the mold and foaming it, a three-layer foamed laminated sheet with a predetermined thickness is formed on the flat mold with a spacer that adjusts the foaming thickness to the desired thickness. On the other hand, a double protrusion having a hollow portion as shown in the figure is formed by free foaming into the through hole. Alternatively, if a planar nonwoven fabric sheet is used as the upper layer, the planar nonwoven fabric sheet is used instead of the planar foam sheet 6.

FIG. 3 is a partially enlarged sectional view showing an example obtained by the method of this example.

In addition, the three-layer laminated sheet (6, 7, 8) for mold filling is
The foaming degree is appropriately selected depending on the selection of the material, but in this example, the upper layer planar foam sheet 6
The thickness of the foamable uncured elastomer sheet 7 for the middle layer is 0.5 mm, and the thickness of the foamable unvulcanized elastomer sheet 8 for the lower layer is 0.5 mm. By heating and foaming, the flat thickness of the unfoamed intermediate layer (0.5 mm) is formed into the foamed sheet 2 of the intermediate layer of 1 mm, and the flat thickness of the unfoamed lower layer (0.5 mm) is used. )
was molded into a foam sheet 3 with a 1.5 mm lower layer. Therefore, the total thickness of the 3-layer laminated sheet for filling before heating is 2
．． 0+m, the total thickness of the 3-layer foam laminate sheet after heating and foaming is 3. It is 5mm.

Further, as shown in the partially enlarged sectional view of FIG. 3, the state of the double protrusion into the through hole is an intermediate foam protrusion having a hollow part of the intermediate layer protruding from the lower part of the upper layer planar foam sheet 1. The height of 2a is about 4. The height of the cylindrical foam protrusion 3a having a hollow portion in the lower layer from the bottom of the flat foam sheet in the upper layer is 7.0Il111, and the cylinder diameter in the lower layer is 6.0mm. 2
mm, distance between cylinders is 4. An example in which the thickness is 0 mm is shown.

[Effects of the Invention] As mentioned in the operation section above, the present invention is a structure that has the function of absorbing shock in multiple stages, so while it is flexible and exhibits suitable soundproofing properties, it also has a structure that is flexible and exhibits suitable soundproofing properties. Appropriate responsive absorption is exhibited against various shocks such as fluctuations, without losing the buffering function such as the conventional bottoming out phenomenon. The proportion of combined balance properties can also be easily varied, and the desired shock absorber can be freely and easily obtained.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view showing an example of the impact buffer of the present invention, and FIG. 2 is an explanatory diagram of the manufacturing method (lower part of a flat mold The heating plate 5 is omitted from the illustration). FIG. 3 is a partially enlarged sectional view of the impact buffer obtained by this example. A...Upper layer B...Middle layer C...Lower layer 1...Upper layer planar foam sheet 2...Middle layer foam sheet 2a...Intermediate foam protrusion having a hollow part in the middle layer Part 3...lower layer foam sheet 3a...lower layer cylindrical foam protrusion 4 having a hollow part
...Flat-shaped mold 4a...Spacer 4b...
・Through holes (pierced through the entire surface of the mold in a required regular arrangement) 5... Heating plate (a similar heating plate is set at the bottom of the flat mold) 6... Foaming Upper layer planar foam sheet 7, which is preheat-molded with a polyester elastomer...A foamable unvulcanized elastomer sheet for the middle layer, which has a lower foamability than the lower layer.

Claims (4)

[Claims] (1) In a laminated sheet consisting of three layers: an upper layer, an intermediate layer, and a lower layer, the lower layer partially protrudes downward to form a cylindrical foam protrusion having a hollow portion with a curved contact surface on the lower surface,
2. The intermediate layer is stacked as an intermediate foam protrusion having a hollow part inside the cylindrical foam protrusion of the lower layer, and has the above-mentioned hollow part at the bottom of the flat foam sheet without the protrusion of the upper layer. A shock absorber characterized by having a heavy protrusion. (2) The shock absorber according to claim 1, wherein the planar foam sheet having no upper layer protrusions is a flat nonwoven fabric sheet having no upper layer protrusions. (3) Layer the foamable uncured elastomer sheet for the lower layer and the unvulcanized elastomer sheet for the middle layer, which has a smaller foamability than the lower layer, and then place the planar upper layer of elastomer pre-heat-formed on top of that. Foam sheets are laminated to form a three-layer laminated sheet, and the above three layers are placed on a flat mold with cylindrical through holes provided in a regular arrangement as desired.
Place the laminated sheet and adjust the foaming thickness on the mold by placing a spacer of the required thickness around the mold, pressing it with a heating plate from above and below to vulcanize it, and forming the cylindrical shape of the mold. Inside the through hole,
Freely foaming two unvulcanized elastomer sheets with different foaming degrees for the lower layer and the middle layer to form a double protrusion having a hollow part inside a cylindrical foamed protrusion having a hollow part in the lower layer, A method for producing a shock absorber, characterized by forming an integrally vulcanized state with a planar foam sheet as an upper layer. (4) The method for producing a shock absorber according to claim 3, wherein the upper layer of the planar foam sheet, which has been heat-molded in advance, is a nonwoven fabric sheet.