JP4977562B2 - Manufacturing method of laminated rubber bearing - Google Patents

Description

The present invention relates to a method for manufacturing a laminated rubber bearing used for seismic isolation of a structure.

  Conventionally, a laminated rubber bearing (plug-based seismic isolation device) as shown in FIG. 18 is known for isolating buildings, civil engineering structures, equipment, and the like (see Patent Document 1).

  As shown in FIG. 18, the laminated rubber support is formed by alternately laminating an elastic plate 51 made of rubber or the like constituting an elastic material layer and an annular rigid plate 52 constituting a rigid material layer and fixing them to each other. An annular laminated body 53, a cylindrical lead (plug) 54 disposed in a through hole 62 defined by a cylindrical inner peripheral surface 59 formed in the laminated body 53, and a lower surface of the cylindrical lead 54 And flange plates 68 and 69 attached to the lower surface and the upper surface of the laminated body 53 by bolts or the like (not shown), respectively. For example, one flange plate 68 side has a structure such as a foundation. A structure such as a building is placed on the other flange plate 69 side.

  And this laminated rubber bearing body (plug-type seismic isolation device) exhibits a function of reducing earthquake energy by deforming horizontally in the event of an earthquake while stably supporting a building or the like. That is, this laminated rubber bearing body has both functions of a conventional laminated rubber and a damper. Further, by using this laminated rubber bearing, it is possible to reduce the installation space and to improve the workability.

  By the way, in the laminated rubber support body of the above-mentioned patent document 1, since lead is used as a plug material, as an alternative to lead, tin or a tin alloy, which is a non-lead material, is used as a plug material for environmental protection. A laminated rubber bearing has been proposed (see Patent Document 2).

  However, in the laminated rubber bearing body (plug-type seismic isolation device) using the lead plug of Patent Document 1 or the laminated rubber bearing body of Patent Document 2 using a tin or tin alloy plug, the through hole of the laminated body When the plug is inserted into the plug, if the plug does not satisfy the required dimensional accuracy, a gap is generated between the plug and the surrounding laminated body, and sufficient performance may not be exhibited.

  Therefore, to achieve the intended function, it is necessary to use a plug with high dimensional accuracy, but by general casting in which a molten plug raw material (lead, tin, tin alloy, etc.) is poured into a mold. In the plug manufacturing method, it is difficult to ensure the target dimensional accuracy.

Therefore, conventionally, the required dimensional accuracy is ensured by performing machining after casting, and the fact is that this machining causes a cost increase.
JP-A-9-105441 Japanese Unexamined Patent Publication No. 2006-9852

The present invention solves the above-mentioned problems, and it is possible to produce a plug with high dimensional accuracy made of, for example, lead, tin, tin alloy, etc. by only casting without requiring a finishing process by machining. Then, it aims at providing the manufacturing method of the laminated rubber bearing body which can manufacture a reliable rubber bearing body with high reliability at low cost.

In order to solve the above-described problems, a method for producing a laminated rubber bearing according to the present invention includes a laminated body in which a plurality of rubber plates and a plurality of metal plates are alternately laminated in the vertical direction. In the manufacturing method of the laminated rubber bearing body formed in the direction and fitted with the through hole, the metal columnar plug is disposed in the through hole.
The step of producing the plug includes
(a) a step of forming a die for plug casting by combining a main body cylinder, a bottom plate, and an upper flange having an opening serving as an inlet for molten plug raw material;
(b) a step of casting the molten plug raw material so that the molten metal surface reaches the opening of the upper flange;
(c) cooling the mold stepwise or continuously from the bottom to the top so that the molten plug material in the mold gradually solidifies from the bottom to the top;
(d) When the solidification height of the plug raw material reaches a height within a predetermined range from the molten metal surface, the upper flange is removed, and the excess molten plug raw material exceeding the upper end of the main body cylinder is released. A step of attaching an upper cover provided with a through hole for surplus raw material escape to the upper end of the main body body in a state where the molten plug raw material is heated to a temperature at which the molten plug raw material does not solidify upon contact with the upper cover;
(e) The main body cylinder is cooled while heating the plug material in the excess material escape through hole of the upper lid so that the molten plug material entering the excess material escape through hole of the upper lid does not solidify. And gradually solidifying the molten plug raw material in the main body toward the upper part, so as to solidify a portion to be the plug of the plug raw material in the mold,
(f) After solidifying the plug portion of the plug material, heating of the molten plug material in the surplus material escape through hole of the upper lid is stopped, and the surplus material escape through hole of the upper lid is stopped. A step of solidifying the molten plug material that has entered;
(g) removing the upper lid, and removing a surplus portion of the plug material that has entered the through hole for surplus material escape.

  Also, in the method for producing a laminated rubber bearing of the present invention, the solidification height of the plug raw material is the time (d) when the upper flange is removed and the upper lid is attached to the upper end of the main body barrel. It is characterized by the point of time when the height is within 20 mm from the surface.

  Further, in the present invention, when the plug has a cylindrical shape, the inner diameter of the main body constituting the mold is 0.1 mm to 1.0 mm from the outer diameter of the plug to be manufactured. It is characterized by using a main body cylinder which is large and whose height dimension is 0.1 mm to 1.0 mm larger than the height dimension of the plug to be manufactured.

  Further, in the step (c) of cooling the mold from the lower part to the upper part, the present invention blows a cooling gas onto the outer peripheral surface of the main body body, and also provides a cooling gas blowing region to the main body. The molten plug material in the mold is gradually solidified from the lower part to the upper part by gradually expanding from the lower part to the upper part of the body.

  Further, according to the present invention, the surplus material escape through hole of the upper lid is formed in a central portion of the upper lid, and the inner diameter of the surplus material escape through hole gradually decreases from the lower side to the upper side. It is characterized by being a through hole having such a tapered shape.

  In addition, the present invention is characterized in that it includes a step for smoothly processing the removed portion after removing the excess portion in the step (g) of removing the excess portion.

  Further, the present invention is characterized in that the metal material constituting the plug is at least one selected from lead, tin, and a tin alloy.

  In the present invention, after casting the molten plug material into the above-described mold, the mold is moved from the bottom to the top so that the molten plug material in the mold gradually solidifies from the bottom to the top. Cooling stepwise or continuously, when the solidification height of the plug material reaches a height within a specified range from the molten metal surface, the upper flange is removed, and the surplus exceeding the upper end of the body drum An upper lid provided with an excess material escape through hole for escaping the molten plug material is attached to the upper end of the main body barrel in a state heated to a temperature at which the molten plug material does not solidify upon contact with the upper lid, The main body cylinder is cooled while the plug material in the through hole for surplus material escape in the upper lid is heated so that the molten plug material that has entered the through hole for surplus material in the top lid does not solidify, and the inside of the main body fuse is melted. Plug material facing upward After solidifying the plug material in the mold, the part that becomes the plug is solidified, and then the heating of the molten plug material in the through hole for surplus material escape is stopped, and the surplus material escape through the top cover is penetrated The molten plug material that has entered the hole is solidified, and then the top cover is removed to remove the excess portion of the plug material that has entered the through hole for surplus material escape, so a finishing process is required by machining. In addition, it becomes possible to produce a plug with high dimensional accuracy only by casting. Therefore, by using this plug, it is possible to efficiently manufacture a laminated rubber bearing body with low cost and high reliability.

  That is, in the case of normal casting, dimensional stability is lost because solidification shrinkage progresses toward a portion that is not solidified, but in the present invention, by cooling from the lower part of the mold, Since the molten plug material is solidified from the lower part to the upper part, solidification proceeds only toward the melted part, that is, the upper part of the mold, and solidification shrinkage also proceeds only toward the upper part. Therefore, the dimensional stability in the radial direction of the plug can be maintained.

  However, if the dimensional stability in the radial direction of the plug is maintained by starting the cooling from the lower part of the casting, the place where the solidification finally occurs is usually the upper end of the plug. Since solidification shrinkage concentrates and the end surface cannot be solidified smoothly, it is difficult to maintain the dimensional stability in the height direction.

On the other hand, as in the present invention, when the solidification height of the plug raw material reaches a height within a predetermined range from the molten metal surface, a preheated upper lid having a surplus raw material escape through hole is placed, By gradually solidifying, the molten plug material in the portion that is in contact with the upper lid in a region other than the surplus material escape through-hole solidifies smoothly in a state where it is securely in contact with the upper lid. The molten plug raw material finally solidifies.
As a result, the final solidified portion is in the surplus raw material escape through hole, and the portion that is not smoothly solidified concentrates there. Then, since the portion that has entered the through hole for surplus raw material escape, which is the final solidification site, is removed as a surplus portion, only the portion from which the surplus portion has been removed is processed so as to be smooth. It is possible to easily and reliably form a cast body having excellent dimensional stability in the vertical direction.

  Further, in the conventional casting method, the hot water is supplied in accordance with the amount of shrinkage of the cast body. However, in the case of the present invention, the upper lid has an excess raw material escape through-hole opening, so that the required amount is somewhat. As long as an excessive amount of plug material is supplied first, there is no need for hot water thereafter, and the process can be simplified.

  The cast body has the same dimensions as the inner diameter of the body cylinder constituting the mold immediately after solidification, but shrinks along the linear expansion coefficient specific to the constituent material of the plug as the temperature further decreases after solidification. Therefore, it is possible to reliably remove the mold without making the inner surface of the main body of the mold into a tapered shape.

  Since the cast body shrinks along the linear expansion coefficient inherent to the material, in order to ensure the dimensional stability (dimensional tolerance) of the plug, the inner diameter dimension and height dimension of the main body cylinder should be prepared in advance. It is desirable to determine in consideration of the linear expansion coefficient of the material constituting the plug.

  Further, in the step (d) of claim 1, when the upper flange is removed and the upper lid is attached to the upper end portion of the main body barrel, the solidification height of the plug raw material is within 20 mm from the molten metal surface. When it is time, it becomes possible to smoothly solidify the molten plug raw material of the portion that is in contact with the upper lid in a region other than the surplus raw material escape through-hole in a state of being securely in contact with the upper lid, and also in the height direction. A plug having excellent dimensional stability can be reliably formed, and the present invention can be more effectively realized.

  Since the cast body shrinks along the linear expansion coefficient specific to the material, in order to ensure the dimensional tolerance of the plug, the inner diameter dimension and the height dimension of the main body cylinder are previously measured. As described above, it is desirable to determine in consideration of the material and the constituent material. However, when the plug has a cylindrical shape, the inner diameter dimension of the main body cylinder is larger than the outer diameter dimension of the plug to be manufactured. By using a main body cylinder which is 0.1 mm to 1.0 mm larger and whose height dimension is 0.1 mm to 1.0 mm larger than the height dimension of the plug to be manufactured, a general laminated rubber bearing body can be obtained. When the plug used is manufactured using normal lead, tin, and tin alloys, the difference between the target size due to cooling shrinkage after casting is reduced, and the size of the plug is within the tolerance range. Surely made It becomes possible to.

  Further, in the process of cooling the mold from the lower part to the upper part, the cooling gas is sprayed on the outer peripheral surface of the main body cylinder, and the cooling gas spray region is moved from the lower area of the main body cylinder to the upper area. When it is enlarged, the molten plug material in the mold can be gradually solidified from the lower part to the upper part, and it is possible to achieve high dimensional accuracy at low cost without using special equipment. The plug can be efficiently manufactured, and the present invention can be further effectively realized.

  In addition, by making the through hole for surplus material escape of the upper lid into a through hole having a tapered shape so that the inner diameter becomes smaller from the lower side to the upper side, the surplus portion of the plug material is surely escaped, and the dimensional accuracy Can be manufactured efficiently.

  In addition, after removing the surplus portion of the plug material in the step of removing the surplus portion, it becomes possible to obtain a plug with high dimensional accuracy without taking much trouble by processing the removed portion smoothly, A highly reliable laminated rubber bearing can be efficiently manufactured.

  In addition, by using at least one selected from lead, tin, and a tin alloy as a metal material constituting the plug, the earthquake energy is reduced by deforming in the horizontal direction when an earthquake occurs while stably supporting a building or the like. It becomes possible to reliably manufacture a laminated rubber bearing body that can sufficiently perform its function.

  Hereinafter, examples of the present invention will be shown and features thereof will be described in detail.

FIG. 1 (a) is a view showing a laminated rubber bearing manufactured by the method according to one embodiment of the present invention, and FIG. 1 (b) is a diagram of a plug used in the laminated rubber bearing shown in FIG. 1 (a). It is a perspective view which shows a shape.

  As shown in FIG. 1, this laminated rubber bearing is formed by alternately laminating elastic plates 1 made of rubber or the like constituting an elastic material layer and annular rigid plates 2 constituting a rigid material layer made of metal or the like. An annular laminated body 3 fixed to each other, a Sn alloy columnar plug 4 inserted into a through-hole 12 defined by a cylindrical inner peripheral surface 9 of the laminated body 3, and the laminated body 3 Are provided with flange plates 18 and 19 attached to each of the lower surface and the upper surface by bolts 17 via connecting steel plates 15 and 16.

  The laminated rubber bearing is configured such that, for example, the flange plate 18 side is fixed to a structure such as a foundation, and a structure such as a building is placed on the flange plate 19 side.

Note that the plug 4 used in the laminated rubber bearing body of FIG. 1 has a cylindrical shape, and has a diameter of 159.5 mm and a height of 400 mm.
As a constituent material of the plug 4, a tin-bismuth alloy containing 99.5% by weight of tin and 0.3% by weight of bismuth and having the balance as impurities is used.
In addition, as a plug used for a lamination | stacking rubber bearing body, there are many things of a cylindrical shape normally, a diameter of 50-300 mm, and a height of 200-600 mm.

  Hereinafter, the manufacturing method of the plug 4 used for this laminated rubber support will be described with reference to FIGS.

  (1) First, as shown in FIG. 2, the main body barrel 21, the bottom plate 22, and the upper flange 23 having an opening 23 a serving as an inlet for the melted plug raw material 20 (see FIG. 7) are combined. A die A for plug casting is formed so that the upper end of the main body cylinder 21 is the upper end of the plug 4 (see FIG. 1) to be manufactured.

  As shown in FIGS. 3 (a) and 3 (b), the main body cylinder 21 constituting the mold A has a flange portion (saddle portion) 21b for connecting the bottom plate 22 to the lower end portion of the pipe-like member 21a. It has. The body cylinder 21 has an inner diameter dimension that is 0.1 to 1.0 mm larger than the outer diameter dimension of the plug 4 to be manufactured and a height dimension that is 0.1 to 1.0 mm larger than the height dimension of the plug 4 to be manufactured. It has a height dimension and a plate thickness of 5 mm or more.

  Further, as the bottom plate 22, as shown in FIGS. 4 (a) and 4 (b), a closed flange having no outer hole and having the same outer diameter as the outer diameter of the flange portion 21b constituting the main body barrel 21 is used. It has been.

  Furthermore, as the upper flange 23, as shown in FIGS. 5A and 5B, an opening 23a having a diameter equal to or smaller than the inner diameter of the pipe-shaped member 21a of the main body barrel 21 by about 20 mm is provided at the center. And an opening flange having an outer diameter larger than the outer diameter of the pipe-shaped member 21a is used.

Further, as will be described later, the mold A has an upper end of the main body cylinder 21 after the upper flange 23 is removed when the solidification height of the plug raw material 20 reaches a height within a predetermined range from the molten metal surface. The upper cover 25 provided with the through hole 25a for surplus raw material escape which escapes the surplus molten plug raw material 20 over the upper end part of the main body cylinder 21 attached to a part is provided (refer FIG. 6).
The surplus material escape through-hole 25a of the upper lid 25 has a smoothly machined inner peripheral surface, a lower end diameter of 5 mm or more, and a flared shape with an inclined inner peripheral surface (tapered shape). ) So that the molten plug raw material 20 can easily enter.

(2) Then, the mold A (FIG. 2) in which the main body cylinder 21, the bottom plate 22, and the upper flange 23 are combined is preheated to 100 ° C. to 400 ° C. in a heating furnace.
The upper lid 25 is also preheated to 100 ° C. to 400 ° C. in a heating furnace.
On the other hand, the tin alloy as the plug raw material 20 is heated to a temperature in the range of the melting point to the melting point + 200 ° C. in a predetermined kettle.

  (3) Then, the molten plug material 20 is cast into a preheated mold A. At this time, as shown in FIG. 7, even when solidified, the molten metal surface is positioned higher than the upper end of the main body cylinder 21 constituting the mold A and does not overflow from the opening 23a of the upper flange 23. The plug material 20 is put into the mold A.

  (4) After casting the plug material 20, as shown in FIG. 8, the cooling jig 26 provided with the lower blower means 26a, the central blower means 26b, and the upper blower means 26c is placed in the predetermined vicinity of the mold A. Install in the position. The cooling means 26 is configured to be able to supply cooling air to the lower part, the central part, and the upper part of the mold A from the lower blowing means 26a, the central blowing means 26b, and the upper blowing means 26c. The melted plug raw material 20 in the mold A can be gradually solidified from the lower part toward the upper part.

In performing the cooling, first, cooling air is supplied from the lower blowing means 26a, and the cooling is started from the lower part of the mold A.
At this time, heating is performed from the opening 23a of the upper flange 23 by the heating means (burner in this embodiment) 27 so that the plug material 20 on the upper part of the mold A in contact with the outside air does not solidify first. (See FIG. 8).

(5) When the solidification position (solidification height) of the plug raw material 20 reaches a height H1 that exceeds the supply position of the cooling air from the lower blowing means 26a, the cooling air is also sent from the central blowing means 26b of the mold A. And the cooling of the central portion of the mold A is started while continuing the cooling of the lower part of the mold A (FIG. 9).
Furthermore, when the solidification position (solidification height) reaches a height H2 that exceeds the supply position of the cooling air from the central blower means 26b, the cooling air is also supplied from the upper blower means 26c, and the mold A Cooling is started also on the upper part of the mold A while continuing cooling of the lower part and the central part (FIG. 10).

(6) Then, when solidification progresses and the solidification position (solidification height) reaches a height H3 of about 5 to 20 mm from the molten metal surface, the excess molten plug raw material 20 is removed as necessary ( The upper flange 23 is removed (FIG. 11), so that the molten plug material is positioned slightly above the upper end of the main body cylinder.
At this time, the molten plug material 20 is in a raised state as shown in FIG. 12 due to surface tension.

(7) Then, the upper lid 25 having a tapered material escape through hole 25a heated to a temperature at which the non-solidified portion of the plug raw material 20 does not solidify upon contact with the upper lid 25, The surplus material escape through-hole 25a is set on the upper end of the main body barrel 21 in such a posture that the skirt spreads.
When the upper lid 25 is set, the molten plug raw material 20 in the portion rising upward from the upper end of the main body cylinder 21 of the mold A due to surface tension quickly moves to the surplus raw material escape through hole 25a (FIG. 13).

  (8) Then, as shown in FIG. 13, the heating means (burner in this embodiment) 27 causes the excess of the upper lid 25 so that the molten plug raw material entering the through hole 25a for surplus raw material escape of the upper lid 25 does not solidify. Cooling of the body cylinder 21 of the mold A is continued while heating the molten plug material 20 in the material escape through hole 25a.

  (9) After that, as shown in FIG. 14, when the solidification position reaches the upper end of the body cylinder 21 of the mold A, the heating of the molten plug material 20 in the surplus material escape through hole 25a by the burner 27 is stopped. Then, as shown in FIG. 15, the solidification of the molten plug raw material 20 in the surplus raw material escape through hole 25a is completed.

  (10) After the solidification of the molten plug material 20 in the surplus material escape through hole 25a is completed, the upper lid 25 is removed (see FIG. 16). At this time, since the surplus material escape through hole 25a has a tapered shape, the upper lid 25 can be easily removed even when the temperature of the solidified plug material is not lower than the melting point and not lower than 100 ° C.

(11) After removing the upper lid 25, as shown in FIG. 17, the solidified part (surplus part) 20a in the surplus material escape through hole 25a is removed. The excess portion 20a can be removed by a cutting method using a cutter or the like.
And the finishing process which grinds | smooths the trace which removed the said excessive part 20a of the solidified plug raw material (casting body) with a paper file etc. is smoothed.

(12) Then, after the surface temperature of the cast body is lowered to near room temperature, the main body cylinder 21 is slowly removed from the solidified plug material, that is, the cast body, and removed from the mold. Then, if necessary, the surface of the removed casting is simply finished with a paper file or the like.
Thereby, the plug 4 (FIG. 1 (b)) with high dimensional accuracy can be obtained by substantially only casting, without requiring a finishing process by high-precision machining.

  By using this plug 4 to construct a laminated rubber bearing as shown in FIG. 1A, it is possible to provide a laminated rubber bearing having high reliability at low cost.

  In the above embodiment, the mold A is cooled stepwise (from the bottom to the top) using the cooling jig 26 provided with the lower blower 26a, the central blower 26b, and the upper blower 26c. Although the case of the case described above has been described as an example, the number of stages of cooling is not limited to three, and the number of stages can be determined in consideration of conditions such as plug dimensions and constituent materials.

Further, the cooling from the lower part to the upper part of the mold A may not be performed stepwise, but may be continuously performed from the lower part to the upper part.
In the above embodiment, the case where a tin alloy is used as a constituent material of the plug has been described as an example. However, lead or a lead alloy can be used as the constituent material of the plug, and other materials can also be used. Is possible.

  The present invention is not limited to the above-described embodiment in other respects as well. The specific structure of the mold, the specific structure of the upper cover, the shape of the through hole for surplus raw material escape of the upper cover, the shape of the plug And the relationship between the dimensions of the plugs to be manufactured and the dimensions of the mold, the number of plugs provided in one laminated rubber support, and a plurality of rubber plates and a plurality of metal plates are alternately laminated in the vertical direction. Specific structure of laminated body, casting conditions of plug raw material into mold, removal method of surplus part that has entered through hole for surplus raw material, specific structure of cooling jig for cooling mold, etc. However, various applications and modifications can be made within the scope of the invention.

According to the present invention, it is possible to manufacture a plug with high dimensional accuracy only by casting without substantially requiring a finishing process by machining, and the use of the plug makes it possible to reduce the cost and reliability. It becomes possible to provide a highly laminated rubber bearing.
Therefore, the present invention can be widely applied to the field of laminated rubber bearings and manufacturing technology thereof.

(a) is a figure which shows the laminated rubber bearing manufactured by the method concerning one Example of this invention, (b) is a perspective view which shows the shape of the plug used in the laminated rubber bearing of (a). is there. It is a figure which shows the structure of the metal mold | die used in casting the plug in the Example of this invention. It is a figure which shows the structure of the main body cylinder which comprises the metal mold | die used in the Example of this invention, (a) is a top view, (b) is front sectional drawing. It is a figure which shows the structure of the baseplate which comprises the metal mold | die used in the Example of this invention, (a) is front sectional drawing, (b) is a top view. It is a figure which shows the structure of the upper flange which comprises the metal mold | die used in the Example of this invention, (a) is front sectional drawing, (b) is a top view. It is a figure which shows the structure of the upper cover used in the Example of this invention, (a) is front sectional drawing, (b) is a top view. In the Example of this invention, it is a figure which shows the state which cast the molten plug raw material into the metal mold | die. In the Example of this invention, it is a figure which shows the state which is cooling the lower part of the metal mold | die which cast the molten plug raw material. In the Example of this invention, it is a figure which shows the state which is cooling the lower part and center part of the metal mold | die which cast the molten plug raw material. In the Example of this invention, it is a figure which shows the state which is cooling the lower part, center part, and upper part of the metal mold | die which cast the molten plug raw material. In the Example of this invention, it is a figure which shows the state which removed the upper flange when the solidification position (solidification height) of the plug raw material in a metal mold | die becomes about 5-20 mm from a molten metal surface. In the Example of this invention, when the solidification position (solidification height) of the plug raw material in a metal mold | die becomes about 5-20 mm from a molten metal surface, the state of the molten metal surface when removing an upper flange is modeled. FIG. In the Example of this invention, it is a figure which shows the state which attached the upper cover after removing the upper flange of a metal mold | die. In the Example of this invention, it is a figure which shows the state which the solidification position (solidification height) of the plug raw material in a metal mold | die reached even the upper end of the main body cylinder of a metal mold | die. In the Example of this invention, it is a figure which shows the state which all the plug raw materials in a metal mold solidified. In the Example of this invention, it is a figure which shows the state which removed the upper cover from the main body cylinder which comprises a metal mold | die. In the Example of this invention, it is a figure which shows the state which removed the solidified part (excess part) in the through-hole for surplus raw material escape of the upper cover of plug raw material (casting body). It is a figure which shows the structure of the conventional laminated rubber support body.

DESCRIPTION OF SYMBOLS 1 Elastic board 2 Rigid board 3 Laminated body 4 Plug 15, 16 Connection steel plate 17 Bolt 18, 19 Flange plate 20 Plug raw material 21 Body trunk 21a Pipe-shaped member 21b Flange part (saddle part)
22 bottom plate 23 upper flange 23a opening 25 upper lid 25a surplus material escape through hole 26 cooling jig 26a lower air blowing means 26b central air blowing means 26c upper air blowing means 27 heating means (burner)
A Mold H1, H2, H3 Solidification position (solidification height)

Claims (7)

A columnar plug made of metal, in which at least one through hole is formed in a vertical direction in a laminate formed by alternately laminating a plurality of rubber plates and a plurality of metal plates in the vertical direction, and is fitted to the through hole. In the manufacturing method of the laminated rubber bearing body formed by arranging in the through hole,
The step of producing the plug includes
(a) a step of forming a die for plug casting by combining a main body cylinder, a bottom plate, and an upper flange having an opening serving as an inlet for molten plug raw material;
(b) a step of casting the molten plug raw material so that the molten metal surface reaches the opening of the upper flange;
(c) cooling the mold stepwise or continuously from the bottom to the top so that the molten plug material in the mold gradually solidifies from the bottom to the top;
(d) When the solidification height of the plug raw material reaches a height within a predetermined range from the molten metal surface, the upper flange is removed, and the excess molten plug raw material exceeding the upper end of the main body cylinder is released. A step of attaching an upper cover provided with a through hole for surplus raw material escape to the upper end of the main body body in a state where the molten plug raw material is heated to a temperature at which the molten plug raw material does not solidify upon contact with the upper cover;
(e) The main body cylinder is cooled while heating the plug material in the excess material escape through hole of the upper lid so that the molten plug material entering the excess material escape through hole of the upper lid does not solidify. And gradually solidifying the molten plug raw material in the main body toward the upper part, so as to solidify a portion to be the plug of the plug raw material in the mold,
(f) After solidifying the plug portion of the plug material, heating of the molten plug material in the surplus material escape through hole of the upper lid is stopped, and the surplus material escape through hole of the upper lid is stopped. A step of solidifying the molten plug material that has entered;
(g) removing the upper lid, and removing a surplus portion of the plug material that has entered the through hole for surplus material escape, and a method for producing a laminated rubber bearing body.   In (d), when the upper flange is removed and the upper lid is attached to the upper end portion of the main body barrel, the solidification height of the plug raw material is a height within 20 mm from the molten metal surface. The method for producing a laminated rubber bearing body according to claim 1.   In the case where the plug has a cylindrical shape, the inner diameter of the main body cylinder constituting the mold is 0.1 mm to 1.0 mm larger than the outer diameter of the plug to be manufactured, and the height is high. The method for manufacturing a laminated rubber bearing according to claim 1 or 2, wherein a main body cylinder having a dimension 0.1 mm to 1.0 mm larger than a height dimension of a plug to be manufactured is used.   In the step (c) of cooling the mold from the lower part toward the upper part, the cooling gas is blown onto the outer peripheral surface of the main body cylinder, and the blowing area of the cooling gas is changed from the lower area of the main body cylinder. The lamination according to any one of claims 1 to 3, wherein the molten plug material in the mold is gradually solidified from the lower part toward the upper part by gradually expanding toward the upper region. Manufacturing method for rubber bearings.   The surplus material escape through-hole of the upper lid is formed in the center of the upper lid, and the surplus material escape through-hole has a tapered shape such that the inner diameter gradually decreases from the lower side to the upper side. It is a through-hole, The manufacturing method of the laminated rubber bearing body in any one of Claims 1-4 characterized by the above-mentioned.   6. The method according to any one of claims 1 to 5, further comprising a step of processing the removed portion smoothly after removing the excess portion in the step of removing the excess portion of (g). Manufacturing method of laminated rubber bearing.   The method for producing a laminated rubber bearing body according to any one of claims 1 to 6, wherein the metal material constituting the plug is at least one selected from lead, tin, and a tin alloy.

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