JP2018179260A - Manufacturing method of laminated rubber bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an internal rubber of a laminate from being exposed due to rubber flow in vulcanization, without deteriorating productivity.SOLUTION: A manufacturing method of a laminated rubber bearing comprises: a step S1 of coating the whole outer periphery of a raw laminate 4N with an unvulcanized protective rubber 5N, to form a raw laminated rubber bearing 1N; a step S2 of pasting and attaching a corner plate 9 with an L-shaped cross section, to each corner portion P on an outer peripheral side of the raw laminated rubber bearing 1N; a step S3 of vulcanization-molding the raw laminated rubber bearing 1N with the corner plate in a mold 10; and a step S4 of removing the corner plate 9 from the laminated rubber bearing 1 after vulcanization molding.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method of manufacturing a laminated rubber bearing capable of suppressing the exposure of internal rubber caused by rubber flow during vulcanization.

  In order to enhance the durability of the laminated rubber bearing, the one having a structure in which the outer periphery of a laminate composed of a hard plate and a rubber elastic plate is covered with a protective rubber layer having excellent weather resistance is widely used.

  In this laminated rubber bearing, it is important to sufficiently discharge the air in the laminate during vulcanization molding. If the air is not sufficiently discharged, the residual air may reduce the adhesion between the hard plate and the rubber elastic plate, resulting in a decrease in the seismic isolation performance.

  Therefore, when the laminated rubber support has a prismatic shape, as shown in FIG. 5A, when covering the outer periphery of the laminated body a with the protective rubber b, the protective rubber b is interrupted at the corner portion of the laminated body a. d is provided. Thereby, as shown in FIG. 5 (B), at the time of vulcanization, the air e in the laminate a can be released between the laminate a and the protective rubber b to the discontinuous part d. The air e is exhausted to the outside of the mold through the split surface fs of the mold f.

  Further, as shown in FIG. 5C, at the time of vulcanization, a rubber flow is generated in the internal rubber a1 (rubber of the rubber elastic plate) and the protective rubber b of the laminate a with the exhaust of the air e. Is filled. At this time, however, part of the inner rubber a1 may reach the mold surface first and be exposed at the outer surface of the laminated rubber bearing. In this case, the exposed portion of the internal rubber a1 is deteriorated, which may lower the durability.

  The following Patent Documents 1 and 2 disclose that the laminate itself is vulcanized before coating with a protective rubber (see Patent Documents 1 and 2). However, in this case, two vulcanization steps are required, leading to a decrease in productivity.

Unexamined-Japanese-Patent No. 11-344075 Unexamined-Japanese-Patent No. 09-239855 gazette

  Then, this invention makes it a subject to provide the manufacturing method of the laminated rubber bearing which can suppress the exposure of the internal rubber of the laminated body resulting from the rubber flow at the time of vulcanization, without causing the fall of productivity.

The present invention is a method of manufacturing a laminated rubber bearing comprising: a prismatic laminate in which a plurality of hard plates and rubber elastic plates are alternately laminated; and a protective rubber layer covering the outer periphery of the laminate. ,
Forming a green laminated rubber support by covering the entire outer periphery of a green laminate in which hard plates and unvulcanized rubber elastic plates are alternately laminated with unvulcanized protective rubber;
Adhesively attaching a corner plate having an L-shaped cross section to each corner portion on the outer peripheral side of the green laminated rubber support;
Vulcanizing the green laminated rubber bearing with the corner plate in a mold;
And the step of removing the corner plate from the laminated rubber bearing after vulcanization molding.

  In the method of manufacturing a laminated rubber bearing according to the present invention, the corner plate is preferably made of a metal plate.

  In the method of manufacturing a laminated rubber bearing according to the present invention, the corner plate preferably has a thickness of 0.5 to 1.0 mm.

  In the method of manufacturing a laminated rubber bearing according to the present invention, it is preferable that a length La of one side of the corner plate is 6 to 14% of a length L0 of one side of the laminated rubber bearing after vulcanization.

  In the method of manufacturing a laminated rubber bearing according to the present invention, the height Ha of the corner plate is preferably 90 to 100% of the height H0 of the laminated rubber bearing after vulcanization.

  In the present invention, after covering the entire outer periphery of the green laminate with unvulcanized protective rubber as in the case of the above, a corner plate having an L-shaped cross section is adhered to each corner portion on the outer peripheral side.

  The corner plate closes the mold cut surface, so that it is possible to suppress the lateral rubber flow in the direction in which the rubber escapes from the cut surface during vulcanization. In addition, since the entire outer periphery of the green laminate is covered with the protective rubber, it is possible to suppress the internal rubber of the laminate (rubber of the rubber elastic plate) from flowing to the mold surface side and being exposed.

  Further, air in the laminate can flow up and down through between the laminate and the protective rubber, and can be exhausted from the upper end side or the lower end side of the laminate through the split surface of the mold. Therefore, the decrease in seismic isolation performance due to residual air can be prevented.

It is a perspective view which shows one Example of the laminated rubber bearing formed by the manufacturing method of this invention. (A) is a top view which shows the process of forming a green laminated rubber bearing, (B) is the AA sectional view. (A), (B) is the top view and side view which show the process of adhesively attaching a corner plate. (A) and (B) are the top view and sectional drawing which show the process of vulcanizing and forming the green laminated rubber bearing with a corner plate. (A) is a perspective view showing a conventional green rubber bearing, (B), (C) is a partial sectional view showing air flow and rubber flow at the time of vulcanization.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, a laminated rubber bearing 1 formed by the manufacturing method of the present invention comprises a prismatic laminated body 4 and a protective rubber layer 5 covering the outer periphery of the laminated body 4.

  The laminate 4 includes a plurality of hard plates 2 and a rubber elastic plate 3 stacked alternately, and the hard plate 2 and the rubber elastic plate 3 are firmly joined by vulcanization bonding. Among the plurality of hard plates 2, the lowermost hard plate 2L and the uppermost hard plate 2U are formed to have a larger thickness than the hard plates 2M disposed therebetween.

  A lower fixing plate (not shown) for fixing the laminated rubber bearing 1 to the foundation is attached to the lowermost hard plate 2L. Further, an upper fixing plate (not shown) is attached to the uppermost hard plate 2U for fixing the laminated rubber bearing 1 to the structure. In the present embodiment, in the uppermost hard plate 2U and the lowermost hard plate 2L, fitting recesses 7 for positioning the fixing plate and screw holes 8 for bolting the fixing plate are formed.

  As the hard plate 2, a non-rubber material higher in rigidity than the rubber elastic plate 3, for example, a metal plate such as a steel plate is suitable. However, various materials such as ceramics and synthetic resins can be used as long as they have the same rigidity and strength as the metal plate.

  Although various rubber elastic materials can be used as the rubber elastic plate 3, it is necessary to be excellent in mechanical strength, long-term stability of elastic modulus, long-term stability of deformability, creep resistance, etc. Rubber (NR), chloroprene rubber (CR) and the like can be preferably used. In particular, natural rubber is superior to chloroprene rubber in properties other than weather resistance, so it is more preferable to use a natural rubber material containing 90 phr or more of this natural rubber.

  The hard plate 2 and the rubber elastic plate 3 form rectangular plates having the same shape. The respective thicknesses of the hard plate 2 and the rubber elastic plate 3 are not particularly limited, and the conventional range is suitably adopted. In this example, the thickness of the rubber elastic plate 3 is, for example, about 3 to 7 mm, and the thickness of the hard plate 2M is, for example, about 0.5 to 1.0 times the thickness of the rubber elastic plate 3.

  The protective rubber layer 5 is made of a protective rubber having excellent weather resistance, and protects the laminate 4 from corrosion damage. As this protective rubber, for example, chloroprene rubber (CR), butyl rubber (IIR), halogenated butyl rubber (X-IIR), ethylene propylene rubber (EPM, EPDM), urethane rubber (U), silicone rubber (Q), fluoro rubber Synthetic rubber materials such as (FKM), polysulfide rubber (T), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), ethylene vinyl acetate rubber (EVM), and epichlorohydrin rubber (ECO) can be suitably adopted. In particular, chloroprene rubber (CR), butyl rubber (IIR), halogenated butyl rubber (X-IIR), ethylene propylene rubber (EPM, EPDM) can be suitably adopted from the viewpoint of weather resistance.

  The protective rubber layer 5 and the rubber elastic plate 3 are integrally joined by vulcanization bonding. The thickness of the protective rubber layer 5 is also not particularly limited, and is set to, for example, about 8 to 12 mm in this example.

  Next, a method of manufacturing the laminated rubber bearing 1 will be described. In the manufacturing method of the present invention, the step S1 (FIG. 2) of forming the green laminated rubber bearing 1N, the step S2 of adhering the corner plate 9 (FIG. 3), the step S3 of vulcanizing and forming (FIG. 4) A step S4 (not shown) of removing the plate 9 is included.

  Specifically, as shown in FIGS. 2A and 2B, in the step S1, the entire outer periphery of the green laminate 4N in which the hard plate 2 and the non-vulcanized rubber elastic plate 3N are alternately stacked, Cover with unvulcanized protective rubber 5N. Thereby, a raw laminated rubber bearing 1N is formed. In this example, the entire outer periphery is covered without providing a break in the corner portion by adhering the rubber plate material 20 made of the protective rubber 5N to each side surface of the green laminate 4N.

  As shown in FIGS. 3A and 3B, in the step S2, a corner plate 9 having an L-shaped cross section is adhesively attached to each corner portion P on the outer peripheral side of the green laminated rubber support 1N. The angle α between the inner surfaces 9s of the corner plates 9 is substantially equal to the angle β between the outer surfaces Ps of the corner portions P, thereby bringing the inner surfaces 9s and the outer surfaces Ps into close contact. In the present example, the angles α and β are 90 °.

  As shown in FIGS. 4A and 4B, in step S3, the green laminated rubber bearing 1N with a corner plate is vulcanized and formed in the mold 10.

  The mold 10 of this example includes an inner mold 11 whose inner surface is a molding surface, and a peripheral frame 12 surrounding the periphery thereof. The inner mold 11 includes a pair of block-shaped second molds disposed in a direction orthogonal to the pair of block-shaped first mold parts 11A parallel to each other and the first mold part 11A. It comprises the part 11B.

  The first mold portion 11A has substantially the same length as the side surface of the green laminated rubber bearing 1N with a corner plate. The second mold portion 11B is disposed across the outer ends of the first mold portion 11A. Accordingly, the split surface Da of the inner mold 11 is formed between the outer end of the first mold portion 11A and the second mold portion 11B. Further, as shown in FIG. 4B, the mold 10 includes an upper plate 13U and a lower plate 13L, and between the upper end of the inner mold 11 and the upper plate 13U, and the lower end and lower part of the inner mold 11. Upper and lower split surfaces Db, Dc are formed between the plates 13L.

  Therefore, by providing the corner plate 9, it is possible to suppress the lateral rubber flow in the direction in which the rubber escapes from the fractured surface Da at the time of vulcanization. Moreover, since the entire outer periphery of the green laminate 4N is covered with the protective rubber 5N, the inner rubber (rubber of the rubber elastic plate 3N) of the laminate 4B flows toward the inner surface (molding surface) of the inner mold 11 and is exposed. You can suppress it.

  The air e in the laminate 4N flows up and down through the space between the laminate 4N and the protective rubber 5N, and is exhausted to the outside of the mold through the upper and lower split surfaces Db and Dc. Therefore, the fall of the seismic isolation performance by residual air can also be prevented. The excess rubber can escape from the upper and lower split surfaces Db, Dc, as with the air.

  In step S4 (not shown), the corner plate 9 is removed from the laminated rubber support 1 after vulcanization molding. The corner plate 9 needs not to be deformed or damaged by removal from the laminated rubber bearing 1 in order to be used repeatedly. Therefore, the corner plate 9 is preferably formed of a metal plate, in particular, a stainless steel plate.

  As shown in an exaggerated manner in FIG. 1, a step 21 is inevitably formed on the outer surface of the laminated rubber bearing 1 by removing the corner plate 9. Therefore, when the corner plate 9 is too thick, the step 21 becomes large and the stress is concentrated, which may cause damage starting from the step 21. Therefore, the thickness t (shown in FIG. 3) of the corner plate 9 is preferably in the range of 0.5 to 1.0 mm.

  If the length La (shown in FIG. 3A) of one side of the corner plate 9 is too short, the effect of suppressing the rubber flow by the corner plate 9 is not sufficiently exhibited. If the length La (shown in FIG. 3) is too long, the stress at the time of shear deformation tends to be concentrated on the step 21, which is disadvantageous to the durability. Therefore, the length La is preferably in the range of 6 to 14% of the length L0 (shown in FIG. 1) of one side of the laminated rubber bearing 1 after vulcanization.

  If the height Ha (shown in FIG. 3B) of the corner plate 9 is too small, the area between the upper end of the corner plate 9 and the upper end of the green laminated rubber support 1N and / or the lower end of the corner plate 9 The inner rubber of the laminate 4B (rubber of the rubber elastic plate 3N) may flow to the inner surface (the molding surface) of the inner mold 11 through the region between the lower end of the green laminated rubber bearing 1N and the green rubber bearing 1N. Therefore, the height Ha is preferably in the range of 90 to 100% of the height H0 (shown in FIG. 1) of the laminated rubber bearing 1 after vulcanization.

  As mentioned above, although the especially preferable embodiment of this invention was explained in full detail, this invention can be deform | transformed into a various aspect, and can be implemented, without being limited to embodiment of illustration.

  The laminated rubber bearing with the structure shown in Fig. 1 was made as an experiment according to the specifications in Table 1, and the presence or absence of exposure of the internal rubber to the outer surface of the laminated rubber bearing and the presence or absence of deterioration in seismic isolation performance due to insufficient exhaust of air. Tested.

  In the conventional example, as shown in FIG. 5A, in the corner portion of the green laminate in the step S1, a non-vulcanized protective rubber is provided with a discontinuous portion. In the comparative example and the example, as shown in FIG. 3, the entire outer periphery of the green laminate is covered with unvulcanized protective rubber in step S1. Further, in Comparative Example 1, no corner plate is used, and therefore steps S2 and S4 are not performed. In the conventional example, the comparative example, and the example, the same mold is used in step S3.

The common specifications of the laminated rubber bearing to be manufactured are as follows.
Shape; square pole (one piece length L0 = 420 mm, height H0 = 134 mm)
Protective rubber thickness: 10 mm

(1) Existence of internal rubber exposure:
14 laminated rubber bearings were made by trial and judged by visually inspecting the outer surface.

(2) Seismic isolation performance:
The shear stiffness and the amount of shear deformation at break were measured for each of the 14 laminated rubber bearings made on trial, and their average values were compared. The higher the shear rigidity and the amount of shear deformation at the time of breakage, the more exhaust of the air in the laminate is considered, and it is considered that the reduction in the adhesion between the hard plate and the rubber elastic plate due to the residual air is suppressed. .

  As shown in the table, in the example, it can be confirmed that the exposure of the internal rubber due to the rubber flow at the time of vulcanization can be suppressed while securing the exhaust of the air in the laminate.

DESCRIPTION OF SYMBOLS 1 Laminated rubber bearing 1N Raw laminated rubber bearing 2 Hard plate 3 Rubber elastic plate 3N Unvulcanized rubber elastic plate 4 Laminated body 4N Raw laminated body 5 Protective rubber layer 5N Unvulcanized protective rubber 9 Corner plate 10 Mold P corner portion S1 to S4 process

Claims (5)

A method of manufacturing a laminated rubber bearing comprising: a prismatic laminated body in which a plurality of hard plates and a rubber elastic plate are alternately laminated; and a protective rubber layer covering the outer periphery of the laminated body,
Forming a green laminated rubber support by covering the entire outer periphery of a green laminate in which hard plates and unvulcanized rubber elastic plates are alternately laminated with unvulcanized protective rubber;
Adhesively attaching a corner plate having an L-shaped cross section to each corner portion on the outer peripheral side of the green laminated rubber support;
Vulcanizing the green laminated rubber bearing with the corner plate in a mold;
And a step of removing the corner plate from the laminated rubber support after vulcanization molding.   The method for producing a laminated rubber bearing according to claim 1, wherein the corner plate is made of a metal plate.   The thickness of the said corner plate is 0.5-1.0 mm, The manufacturing method of the laminated rubber bearing of Claim 1 or 2 characterized by the above-mentioned.   The laminated rubber support according to any one of claims 1 to 3, wherein a length La of one side of the corner plate is 6 to 14% of a length L0 of one side of the laminated rubber support after vulcanization. Manufacturing method.   The method for manufacturing a laminated rubber bearing according to any one of claims 1 to 4, wherein the height Ha of the corner plate is 90 to 100% of the height H0 of the laminated rubber bearing after vulcanization.

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