JP4036372B2

JP4036372B2 - Compression molding equipment

Info

Publication number: JP4036372B2
Application number: JP2003209581A
Authority: JP
Inventors: 穂伸窪田; 聡常田
Original assignee: Nissei Plastic Industrial Co Ltd
Current assignee: Nissei Plastic Industrial Co Ltd
Priority date: 2003-08-29
Filing date: 2003-08-29
Publication date: 2008-01-23
Anticipated expiration: 2023-08-29
Also published as: JP2005074628A

Description

【０００１】
【発明の属する技術分野】
この発明は、ゴム、合成ゴム、熱可塑性ゴム等の可塑性材料を真空下で加熱して圧縮成形する装置に関するものである。
【０００２】
【従来の技術】
従来のゴムの真空プレス成形機では、下部熱盤と上下熱盤との間に挿入した金型を、両熱盤と共に真空ケースにより気密に包囲して真空に減圧したのち、下型と上型の間のゴム材料を両熱盤により加圧して圧縮成形している（例えば、特許文献１参照）。
【０００３】
【特許文献１】
実公平６−５８５７号公報（第２頁、第１図）。
【０００４】
【発明が解決しようとする課題】
上記従来技術では、キャビティを上面に凹設した下型の上にゴム生地を載せ、その上にコアを突設した上型を重ねた型閉状態で、金型を上下部の熱盤間に挿入しているので、上下型間に生ずるスペースはゴム生地の厚み程度で、上型の重みによりゴム生地が押圧されて、キャビティが生地により塞がれたり、或はキャビティに入り込んだ生地の一部によって空気が封じ込められたりしていると、ケース内を真空に減圧してもキャビティ内の脱気が不完全となり易い。
【０００５】
キャビティ内に封じ込まれた空気は、圧縮成形時に生地とキャビティ面との間に介在して圧縮抵抗となるので、その部分の生地がキャビティ面まで達することができず、成形品の表面に空気の痕跡が窪みとなって残る。この表面の窪みにより成形品は不良品となり、成形ロスとして処分されることになる。
【０００６】
この発明は、上記従来の課題を解決するために考えられたものであって、その目的は、圧縮成形が行われるまで金型を開いておくことで脱気を容易となし、また成形材料の変形による空気の封じ込みも防止されて、表面に空気の痕跡がない成形品を圧縮成形することができる新たな圧縮成形装置を提供することにある。
【０００７】
【課題を解決するための手段】
上記目的によるこの発明は、機台上の昇降自在な下部熱盤と、機台上方の支持盤に固定して下部熱盤に対設した上部熱盤と、両熱盤間に座板上の金型と共に出入自在に設けた台盤と、上部熱盤の上側から下向きに台盤に対して昇降自在に設けた真空カップとからなり、その真空カップの開口縁と接して真空カップ内を気密に維持する受縁を上記座板の周囲に設け、その座板に載置固定した下型と、座板の下型両側に立設した複数の開閉シリンダのピストンロッドにより下型と接離自在に支持した上型とから上記金型を構成し、その金型を上記台盤の両熱盤間に位置する部位に設けた開口部に座板を載置して上下動自在に設け、圧縮成形時に真空カップが上記受縁により座板と共に上昇する構成からなる、というものである。
【０００９】
【発明の実施の形態】
図中１は機台、２は機台上方の支持盤で、機台上面の基盤１ａの中央と側部とに立設した複数本のタイバー３，３に連結して設けてある。４は機台内に上向きに縦設した油圧作動の加圧装置で、機台上に加圧ラム４ａが突出位置している。５は台盤で機台中央のタイバー３を回転中心として回動自在に機台上に水平に設けてある。
【００１０】
上記加圧ラム４ａの上端には下部熱盤６が載置固定してあり、その下部熱盤６の上方には、上部熱盤７が支持盤２の下側に突設した支軸８に取付けて対設してある。また上部熱盤７の外周囲には真空カップ９が支軸８に嵌挿して上部熱盤７の上側から下向きに設けてある。この真空カップ９は支持盤２の上面に設置した昇降装置１０により台盤５に対して昇降自在に支持されている。
【００１１】
昇降装置１０は、支持盤２に貫挿した一対の昇降ロッド１１，１１を左右に有する昇降板１２の中央に油圧シリンダ１３を固着し、ピストンロッド１４を支持盤２に固定して、油圧シリンダ側が油圧により昇降板１２と共に上下動するように構成したものからなり、油圧シリンダ１３の上下動により昇降ロッド１１，１１に連結した上記真空カップ９が、支軸８をガイドとして昇降移動する。
【００１２】
上記台盤５の両熱盤間に位置する部位は、下部熱盤６が出入する開口部１５となっており、その開口部１５に座板１６がガイドピン５ａに挿通して上下動自在に載置してある。この座板１６の上に圧縮成形用の金型１７が設置してある。この金型１７は、複数のキャビティを上面に凹設した下型１７ａと、キャビティと対応する複数のコアを下面に突設した上型１７ｂとからなり、下型１７ａを座板１６に載置固定して台盤５の開口部上に設置してある。
【００１３】
上記座板１６は、開口部１５の開口よりも広面積で厚肉の鋼製板体からなり、その板体の開口内に位置する部分の両側に、複数の開閉シリンダ１８，１８が立設してある。この開閉シリンダ１８，１８は、シリンダ１８ａを板体下面に取付けてピストンロッド１８ｂ，１８ｂを下型１７ａの両側の板体上に突出し、そのピストンロッド１８，１８の上端を下型１７ａの上に重ね設けた上型１７ｂの両側の受縁に当接して、該上型１７ｂを支持すると共に開閉シリンダ１８，１８の油圧作動により上型１７ｂを上方へ離して、下型１７ａとの間に脱気スペースを確保し、また上型１７ｂの荷重による上下型間の成形材料の押圧変形を防止できるようにしてある。また座板１６の周囲には上記真空カップ９の開口縁が当接される受縁１９が突設してある。
【００１４】
次に上記圧縮成形装置によるゴム、合成ゴム、熱可塑性ゴム等の成形材料の圧縮成形方法について説明する。
【００１５】
上記金型１７への材料供給は圧縮成形装置の外で行われ、圧縮成形装置では真空カップ９が上昇位置に、下部熱盤６が台盤５よりも下側の降下位置にそれぞれ待機している。金型１７の上下型間にシート状（または塊状）の成形材料２０が供給されると、台盤５が回動して金型１７が圧縮成形装置へと移送され、所要温度（例えば、ゴムの場合１８０℃）に加熱されている下部熱盤６と上部熱盤７との間に、金型１７が台盤５及び座板１６と共に停止位置する。
【００１６】
金型１７の移送は、開閉シリンダ１８，１８のピストンロッド１８ｂ，１８ｂを伸長し、上型１７ｂを下型上方へ離して行う。上型１７ｂがピストンロッド１８ｂ，１８ｂに支えられた状態では、下型１７ａの上に載せた成形材料２０に、上型１７ｂの重みが掛からないので荷重による変形が防止される。しかし、材料形態によっては閉じた状態で移送し、移送後に開放するようにしてもよい。
【００１７】
下部熱盤６と上部熱盤７との間に金型１７が位置したのち、昇降装置１０を降下作動して真空カップ９を、開口縁が座板１６に当接するまで降下して台盤上の金型１７及び上部熱盤７の周囲を閉ざす。真空カップ９の支軸８との嵌合周縁と受縁１９の受面には、Ｏリングなどの密閉部材が設けてあることから、真空カップ内は気密に閉ざされる。この真空カップ９による金型１７の閉鎖は、図２に示すように、開閉シリンダ１８，１８により上型１７ｂを下型１７ａから離して行う。
【００１８】
次に真空カップ内を真空に減圧（−９６ＫＰａ）する。金型１７ではピストンロッド１８ｂ，１８ｂによる上型１７ｂの開放支持により上下型間が脱気スペースとなる。また上型１７ｂの荷重による成形材料２０の変形が防止さることから、下型１７ａに凹設したキャビティと成形材料２０との間に、キャビティ内を真空脱気するのに充分な隙間が確保されるようになり、キャビティ内の真空脱気が効率よく行われる。
【００１９】
真空脱気作業が終了したら、開閉シリンダ１８，１８のシリンダ１８ａ，１８ａの油圧回路をオープンにして上型１７ｂを自由状態となす。この状態で加圧装置４の加圧ラム４ａを伸長作動して下部熱盤６を上昇する。また昇降装置１０のシリンダ１３の圧力を加圧装置４の圧力により真空カップ９が上昇後退する圧力に制御する。
【００２０】
加圧ラム４ａは下部熱盤６を台盤５の開口から受縁１９を介して真空カップ９が当接された座板１６と接する。さらに加圧ラム４ａは座板１６を金型１７と共に押し上げてる。また座板１６は受縁に当接した真空カップ９を閉鎖状態を維持しつつ上昇して、上型１７ｂを上部熱盤７に圧接し、金型温度が成形温度に達したのちに下部熱盤６を強圧して、成形材料２０を上型１７ｂの下面のコアによりキャビティに圧入して、図３に示すように圧縮成形する。このコアによる圧縮成形に際して、キャビティ内は完全に真空脱気されているので、成形材料２０による空気の封じ込みが皆無となり、表面に空気の痕跡がない成形品２１を圧縮成形することができる。
【００２１】
圧縮成形後、真空カップ９は昇降装置１０の上昇作動により元の位置に戻されて台盤上が開放され、また開放作動に並行して加圧装置４が作動し、加圧ラム４ａの縮小による下部熱盤６の降下により、座板１６と共に金型１７が型閉状態で台盤上まで降下して、開口部上に座板１６を介して載置される。成形終了後、台盤５は回動して金型１７を圧縮成形装置に隣接した冷却装置に移動し、成形品２１の冷却と離型とが行われる。
【図面の簡単な説明】
【図１】この発明に係わる圧縮成形装置の一部縦断立面図である。
【図２】圧縮成形前の要部縦断面図である。
【図３】圧縮成形時の要部縦断面図である。
【符号の説明】
１機台
２支持盤
３タイバー
４加圧装置
５台盤
６下部熱盤
７上部熱盤
８支軸
９真空カップ
１０昇降装置
１５開口部
１６座板
１７金型
１７ａ下型
１７ｂ上型
１８開閉シリンダ
１８ａシリンダ
１８ｂピストンロッド
１９受縁
２０成形材料
２１成形品[0001]
BACKGROUND OF THE INVENTION
The present invention rubber, synthetic rubber, about equipment you compression molding by heating under vacuum a plastic material such as a thermoplastic rubber.
[0002]
[Prior art]
In a conventional rubber vacuum press molding machine, a mold inserted between a lower heating plate and an upper and lower heating plate is hermetically surrounded by a vacuum case together with both heating plates and then decompressed to a vacuum. The rubber material between the two is pressed by both hot plates and compression molded (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 6-5857 (2nd page, FIG. 1).
[0004]
[Problems to be solved by the invention]
In the above prior art, the mold is placed between the upper and lower heating plates in a closed state in which a rubber cloth is placed on a lower mold having a cavity recessed on the upper surface, and an upper mold having a core projecting thereon is overlaid. Since the space between the upper and lower molds is about the thickness of the rubber cloth, the rubber cloth is pressed by the weight of the upper mold and the cavity is blocked by the cloth, or one of the cloths entering the cavity. If air is confined by the part, even if the inside of the case is depressurized to a vacuum, the deaeration inside the cavity tends to be incomplete.
[0005]
The air sealed in the cavity is compressed between the dough and the cavity surface during compression molding and becomes a compression resistance, so that portion of the dough cannot reach the cavity surface. The trace of remains as a dent. Due to the depression on the surface, the molded product becomes a defective product and is disposed of as a molding loss.
[0006]
The present invention has been conceived in order to solve the above-described conventional problems. The purpose of the present invention is to facilitate degassing by opening a mold until compression molding is performed. It is an object of the present invention to provide a new compression molding apparatus capable of compression molding a molded product that is prevented from being sealed by air due to deformation and has no trace of air on the surface.
[0007]
[Means for Solving the Problems]
The present invention according to the above-described object includes a lower heating plate that can be raised and lowered on a machine base, an upper heating plate that is fixed to a support plate above the machine table and is disposed on the lower heating plate, and a seat plate between the two heating plates. It consists of a base that can be moved in and out together with the mold and a vacuum cup that can be raised and lowered with respect to the base from the upper side of the upper heating plate. The inside of the vacuum cup is hermetically sealed in contact with the opening edge of the vacuum cup. The lower die is provided around the seat plate and is fixed on the seat plate, and the lower die can be contacted and separated by the piston rods of multiple open / close cylinders standing on both sides of the lower plate of the seat plate. The above mold is composed of an upper mold supported on the base plate, and the mold is placed in an opening provided in a portion located between the two heating plates of the base plate so that the seat plate can be moved up and down and compressed. The vacuum cup is configured to rise together with the seat plate by the receiving edge at the time of molding .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
In the figure, reference numeral 1 denotes a machine base, and 2 a support plate above the machine base, which is connected to a plurality of tie bars 3, 3 erected on the center and side of the base 1 a on the top surface of the machine base. Reference numeral 4 denotes a hydraulically operated pressurizing device which is vertically installed in the machine base, and a pressurizing ram 4a projects from the machine base. Reference numeral 5 denotes a base plate, which is horizontally provided on the base so as to be rotatable about a tie bar 3 at the center of the base.
[0010]
A lower heating plate 6 is placed and fixed on the upper end of the pressurizing ram 4a, and an upper heating plate 7 is provided above the lower heating plate 6 on a support shaft 8 protruding below the support plate 2. It is attached and opposed. Further, a vacuum cup 9 is fitted on the support shaft 8 around the outer periphery of the upper heating plate 7 and is provided downward from the upper side of the upper heating plate 7. The vacuum cup 9 is supported so as to be movable up and down with respect to the base plate 5 by a lifting device 10 installed on the upper surface of the support plate 2.
[0011]
The elevating device 10 has a hydraulic cylinder 13 fixed to the center of an elevating plate 12 having a pair of elevating rods 11, 11 inserted in the support board 2 on the left and right sides, and a piston rod 14 fixed to the support board 2. The vacuum cup 9 connected to the lifting rods 11 and 11 is moved up and down with the support shaft 8 as a guide by the hydraulic cylinder 13 moving up and down.
[0012]
The portion located between the two heating plates of the base 5 is an opening 15 through which the lower heating plate 6 enters and exits, and a seat plate 16 is inserted into the guide pin 5a through the opening 15 so as to be movable up and down. It is placed. A compression molding die 17 is installed on the seat plate 16. The mold 17 is composed of a lower mold 17a having a plurality of cavities recessed on the upper surface and an upper mold 17b having a plurality of cores corresponding to the cavities projecting on the lower surface. The lower mold 17a is placed on the seat plate 16. It is fixed and installed on the opening of the base 5.
[0013]
The seat plate 16 is made of a thick steel plate having a larger area than the opening of the opening 15, and a plurality of open / close cylinders 18, 18 are erected on both sides of a portion located in the opening of the plate. It is. The open / close cylinders 18 and 18 have a cylinder 18a attached to the lower surface of the plate body, projecting piston rods 18b and 18b on the plate bodies on both sides of the lower mold 17a , and upper ends of the piston rods 18 and 18 on the lower mold 17a. The upper mold 17b is in contact with the receiving edges on both sides of the upper mold 17b so as to support the upper mold 17b, and the upper mold 17b is separated upward by the hydraulic operation of the open / close cylinders 18 and 18, so that the upper mold 17b is detached from the lower mold 17a. An air space is secured, and pressing deformation of the molding material between the upper and lower molds due to the load of the upper mold 17b can be prevented. A receiving edge 19 is provided around the seat plate 16 so that the opening edge of the vacuum cup 9 is brought into contact therewith.
[0014]
Next, a compression molding method for molding materials such as rubber, synthetic rubber, and thermoplastic rubber by the compression molding apparatus will be described.
[0015]
The material supply to the mold 17 is performed outside the compression molding apparatus. In the compression molding apparatus, the vacuum cup 9 is in the rising position and the lower heating plate 6 is in the lowering position below the base plate 5. Yes. When the sheet-like (or lump-like) molding material 20 is supplied between the upper and lower molds of the mold 17, the base 5 is rotated and the mold 17 is transferred to the compression molding apparatus, and the required temperature (for example, rubber) In this case, the die 17 is stopped with the base plate 5 and the seat plate 16 between the lower heat plate 6 and the upper heat plate 7 heated to 180 ° C.
[0016]
The mold 17 is transferred by extending the piston rods 18b, 18b of the open / close cylinders 18, 18, and separating the upper mold 17b upward from the lower mold. When the upper die 17b is supported by the piston rods 18b and 18b, the molding material 20 placed on the lower die 17a is not weighted by the upper die 17b, so that deformation due to a load is prevented. However, it may be transferred in a closed state depending on the material form, and may be opened after the transfer.
[0017]
After the mold 17 is positioned between the lower heating platen 6 and the upper heating platen 7, the lifting device 10 is lowered to lower the vacuum cup 9 until the opening edge comes into contact with the seat plate 16. The mold 17 and the upper heating platen 7 are closed. Since a sealing member such as an O-ring is provided on the fitting peripheral edge of the vacuum cup 9 with the support shaft 8 and the receiving surface of the receiving edge 19, the inside of the vacuum cup is hermetically closed. As shown in FIG. 2, the mold 17 is closed by the vacuum cup 9 by separating the upper mold 17b from the lower mold 17a by the open / close cylinders 18 and 18.
[0018]
Next, the vacuum cup is depressurized (-96 KPa). In the mold 17, the upper mold 17b is supported by the piston rods 18b and 18b so that the space between the upper and lower molds becomes a deaeration space. Further, since deformation of the molding material 20 due to the load of the upper mold 17b is prevented, a sufficient gap is secured between the cavity recessed in the lower mold 17a and the molding material 20 for vacuum deaeration inside the cavity. Thus, vacuum deaeration inside the cavity is efficiently performed.
[0019]
When the vacuum degassing operation is completed, the hydraulic circuits of the cylinders 18a and 18a of the open / close cylinders 18 and 18 are opened to bring the upper die 17b into a free state. In this state, the pressurizing ram 4a of the pressurizing device 4 is extended and the lower heating plate 6 is raised. Further, the pressure of the cylinder 13 of the elevating device 10 is controlled to a pressure at which the vacuum cup 9 is raised and retracted by the pressure of the pressurizing device 4.
[0020]
The pressurizing ram 4 a contacts the lower heating plate 6 with the seat plate 16 against which the vacuum cup 9 is abutted through the receiving edge 19 from the opening of the platform 5. Further, the pressure ram 4 a pushes up the seat plate 16 together with the mold 17. Further, the seat plate 16 is raised while maintaining the vacuum cup 9 in contact with the receiving edge in a closed state, the upper die 17b is pressed against the upper heating platen 7, and after the mold temperature reaches the molding temperature, the lower heat The board 6 is strongly pressed, and the molding material 20 is press-fitted into the cavity by the core on the lower surface of the upper mold 17b and compression-molded as shown in FIG. Since the cavity is completely evacuated during the compression molding by the core, there is no air sealing by the molding material 20, and the molded product 21 having no trace of air on the surface can be compression molded.
[0021]
After the compression molding, the vacuum cup 9 is returned to its original position by the lifting operation of the lifting device 10, the top of the base plate is opened, and the pressure device 4 is operated in parallel with the opening operation, and the pressure ram 4a is reduced. Due to the lowering of the lower heating plate 6, the mold 17 together with the seat plate 16 is lowered onto the base plate in a mold-closed state, and is placed on the opening via the seat plate 16. After completion of molding, the base 5 is rotated to move the mold 17 to a cooling device adjacent to the compression molding device, and the molded product 21 is cooled and released.
[Brief description of the drawings]
FIG. 1 is a partially vertical elevational view of a compression molding apparatus according to the present invention.
FIG. 2 is a longitudinal sectional view of a main part before compression molding.
FIG. 3 is a longitudinal sectional view of an essential part at the time of compression molding.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Machine base 2 Supporting board 3 Tie bar 4 Pressurization apparatus 5 Base board 6 Lower heating board 7 Upper heating board 8 Shaft 9 Vacuum cup 10 Lifting device 15 Opening part 16 Seat plate 17 Mold 17a Lower mold 17b Upper mold 18 Opening and closing cylinder 18a Cylinder 18b Piston rod 19 Receiving edge 20 Molding material 21 Molded product

Claims

機台上の昇降自在な下部熱盤と、機台上方の支持盤に固定して下部熱盤に対設した上部熱盤と、両熱盤間に座板上の金型と共に出入自在に設けた台盤と、上部熱盤の上側から下向きに台盤に対して昇降自在に設けた真空カップとからなり、
その真空カップの開口縁と接して真空カップ内を気密に維持する受縁を上記座板の周囲に設け、その座板に載置固定した下型と、座板の下型両側に立設した複数の開閉シリンダのピストンロッドにより下型と接離自在に支持した上型とから上記金型を構成し、その金型を上記台盤の両熱盤間に位置する部位に設けた開口部に座板を載置して上下動自在に設け、圧縮成形時に真空カップが上記受縁により座板と共に上昇する構成からなることを特徴とする圧縮成形装置。A lower heating plate that can be moved up and down on the machine base, an upper heating plate that is fixed to the support plate above the machine table and is placed on the lower heating plate, and a mold on the seat plate between the two heating plates. And a vacuum cup provided so as to be movable up and down with respect to the base plate from the upper side of the upper heat plate.
A receiving edge that is in contact with the opening edge of the vacuum cup and keeps the inside of the vacuum cup airtight is provided around the seat plate, and a lower mold that is placed and fixed on the seat plate, and both sides of the lower mold of the seat plate are erected. The mold is composed of an upper mold that is detachably supported by a lower rod by piston rods of a plurality of open / close cylinders, and the mold is provided in an opening provided in a portion located between both heating plates of the platform. A compression molding apparatus, wherein a seat plate is placed so as to be movable up and down, and the vacuum cup is raised together with the seat plate by the receiving edge during compression molding.