| Method of manufacturing laminated mold and laminated mold -> Monitor Keywords |
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  Method of manufacturing laminated mold and laminated moldRelated Patent Categories: Abrading, Abrading Process, Utilizing Fluent Abradant, By BlastingThe Patent Description & Claims data below is from USPTO Patent Application 20070155290. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This is a Division of application Ser. No. 10/518,017 filed Dec. 14, 2004, which in turn is a National Stage Application of International Application No. PCT/JP03/08342 filed Jul. 1, 2003. The disclosures of the prior applications are hereby incorporated by reference herein in their entirety. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] Present invention relates to a manufacturing method of a tire mold for molding a tire with vulcanization and specifically related to the laminated mold provided with a laminate consisting of a plurality of thin sheets laminated on each other in a widthwise direction and a manufacturing method thereof. [0004] 2. Description of the Prior Art [0005] As shown by FIG. 8(a) and FIG. 8(b), so far has been used a vulcanization metal mold (50) comprising a plurality of sector molds (53) annularly coupled each of which is formed of a holder (52) by which a crown portion metal mold (51) having a cross sectional shape of the tire crown portion is held and the surface of a raw tire being already molded is press fit to an inner wall of the heated vulcanization mold (50) by pressurizing inner side of the molded tire and such application of heat and pressure to raw rubber has been employed as a method of vulcanization of tire. Usually, the above crown portion metal mold (51) can be manufactured by casting and yet, because such a casting mold not only costs much labour but also material cost is high, recently for meeting purpose of attaining low cost and reduction in delivery date in place of the above crown portion metal mold (51), which is a casting mold, a laminated mold as shown by FIG. 9(a) and FIG. 9(b) has become in use wherein the laminated mold comprises an annular tread pattern molding portion being formed by arranging a plurality of sector molds (63) in a peripheral direction of the tire wherein the crown portion metal mold (61), which consists of the laminate being formed of a plurality of thin sheets laminated, held by the holder (62) constitutes the sector mold (63). In this description (61s) denotes a lamination surface of the thin sheet (61), (61p) denotes an end face of the thin sheet on the side of the holder (62) and (61q) denotes an end face of the thin sheet on the side of contacting with the face of the tire stepping on the road surface (hereinafter, the wording "the face of the tire stepping on the road surface" is shortened to read "the tire stepping face"). [0006] In view of automating and speeding up the manufacturing, the thin sheet (61a) is generally formed by means of a laser machining with 2DCAM. Thus formed thin sheets (61a) are laminated to form the laminate to be used as the crown portion metal mold (61) and by placing the crown portion metal mold (61) in the holder (62), the sector mold (63) having the laminate as the crown portion metal mold can be formed. Concretely speaking, as shown by FIG. 10 the thin sheet materials (61z) are cut at respective both ends by casting a laser beam perpendicularly to those thin sheet materials (61z) to become rectangularly shaped cross section and those thin sheet (61a) having thus formed rectangularly shaped cross section are laminated in a widthwise direction of the tire to form the tread pattern molding portion. [0007] However, as long as relying on the above method, as shown by FIG. 9(a) due to the fact that the cross section of the thin sheet (61a) is rectangularly shaped, the crown portion metal mold (61), which is formed by coupling end faces (61q) of respective thin sheets (61a), inevitably becomes to have a profile stepped by the amount corresponding to the thickness of the thin sheets (61a) having the rectangularly shaped cross section. Accordingly, there have arisen problems such that not only appearance of the vulcanized tire is inferior but also its performance is inferior than that of the vulcanized tire manufactured through the casting mold currently in use. Furthermore, possibility of degradation in durability is anticipated because many protrusions with acute angle appear on the tire stepping face. [0008] Further, in the case where the thin sheets are laminated in a peripheral direction of the tire, though close contact between those thin sheets can be assured on the inner side of radial direction, but on the outer side thereof gaps are inevitably produced therebetween and not only opening and closing operation of the mold becomes unstable but also degradation in its durability will be caused. [0009] The present invention is made to cope with those problems so far have arisen and thus object of the present invention to provide a method for manufacturing the laminated mold capable of suppressing formation of stepped shape appearing on its profile comparing with the one as originally intended. SUMMARY OF THE INVENTION [0010] The invention of the second aspect provides the manufacturing method of the laminated mold comprising the laminate being formed of a plurality of thin sheets laminated in a widthwise direction or in a peripheral direction of the tire, and the manufacturing method is characterized in comprising the steps of laminating those thin sheets under the condition that the excess portions of them, which exceed the shape of the tire crown portion, are left on the side contacting with the tire stepping face, and after proceeding the lamination step removal of the excess portions is carried out by means of a shot blast. By virtue of such a process, the profile of the laminated mold on the side of the tire stepping side can be formed quite the same with that of the tire as originally intended, and as a result the tire, which has both of the profile and the performance equivalent to those obtained through the casting mold currently in use, can become to be realizable easily. It is noted that, though the profile of the tire crown portion as given above is generally meant by that which is taken in a widthwise direction but nevertheless the present invention also includes the profile taken in a peripheral direction of the tire crown portion such as change in depth of grooves in a peripheral direction of the tire. [0011] The manufacturing method of the laminated mold according to the invention of the second aspect characterized in that the removal of the excess portions according to the invention of the first aspect is carried out by means of the shot blast. [0012] The manufacturing method of the laminated mold according to the invention of the third aspect is characterized in that the material to be injected (hereinafter "the material to be injected" shortened to read "injection material") according to the invention of the second aspect is limited to aluminum powder. [0013] The manufacturing method of the laminated mold according to the invention of the fourth aspect characterized in that removal of the excess portions according to the second aspect or the third aspect is carried out after masking boundary portions of respective thin sheets. [0014] The invention of the fifth aspect provides the manufacturing method of the laminated mold comprising the laminate being formed of a plurality of thin sheets laminated in a widthwise direction or in a peripheral direction of the tire, wherein those thin sheets on the side of the tire stepping face are tapered in advance so as to bring those tapered portion thereof to have the taper angle approximately equal to the angle corresponding to that of the profile of the crown portion and after tapering them those tapered thin sheets are laminated. Through this process of manufacturing method, by a simple machining the profile of the laminated mold on the side of the tire stepping face can be approximated to the one as originally intended. [0015] The manufacturing method of the laminated mold according to the invention of the sixth aspect, the tapering work according to the fifth aspect is carried out by a laser machining. [0016] The manufacturing method of the laminated mold according to the invention of the seventh aspect, the tapering work according to the fifth aspect is carried out by means of a shot blast. [0017] The manufacturing method of the laminated mold according to the invention of the eighth aspect is characterized in that when laminating a plurality of thin sheets in a peripheral direction of the tire according either one of the first through seventh aspect, bumps are provided on respective lamination surfaces of thin sheets in a thicknesswise direction thereof, those thin sheets are caused to mutually abut therebetween in a lamination direction through those bumps so as to secure those thin sheets with a fixed spacing, enabling to secure them in a close contact therebetween, thereby stabilizing opening and closing operation of the mold and also improving the durability of the mold further. [0018] The invention of the ninth aspect provides the laminated mold comprising the laminate being formed of a plurality of thin sheets laminated in a widthwise direction of the tire characterized in that bumps are provided on the lamination surfaces of respective thin sheets protruding in a thicknesswise thereof so that those thin sheets are caused to mutually abut in a laminationwise direction, there by securing those thin sheets with a fixed spacing. [0019] The laminated mold according to the invention of the tenth aspect characterized in that the bumps provided on respective thin sheets according to the ninth aspect are formed by a press work. [0020] The laminated mold according to the eleventh aspect characterized in that the thickness of the thin sheets according to the ninth or tenth aspect is limited to fall in the arrange of 0.1.about.3 mm. BRIEF DESCRIPTION OF THE DRAWINGS [0021] FIG. 1 shows a constitution of the sector mold used for the laminated mold presented in the most preferable Embodiment 1 of the present invention. Continue reading... Full patent description for Method of manufacturing laminated mold and laminated mold Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Method of manufacturing laminated mold and laminated mold patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. 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