JP3364125B2 - Press forming apparatus and press forming method for resin sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press-molding apparatus for press-molding while stretching a central portion of a rectangular resin sheet used for manufacturing a molded ceiling of an automobile with a pair of upper and lower press dies, and this press-molding. The present invention relates to a press molding method using an apparatus.

[0002]

2. Description of the Related Art For example, a molded ceiling of an automobile is manufactured by stacking a base material of a resin sheet and a skin and press-molding them with a pair of upper and lower press dies. The base material is a resin sheet that ensures the rigidity of the molded ceiling of the automobile, and the skin is a resin sheet such as a thin laser-like TPO sheet that determines the appearance of the molded ceiling. An example of manufacturing equipment for press-molding these base material and skin will be described with reference to FIGS. 4 to 6. FIG. 4 is a plan view showing an outline of the manufacturing equipment, in which a rectangular base material 1 is a stock material for each product type. It is transferred from one of the parts 21 and 22 to the base material supply part 23 by a feeder 24 as shown in FIG. 5, and is transferred to the base material setting part 26 at one end of the inter-process sheet conveying conveyor 25. The conveyor 25 is a parallel two-way chain conveyor,
The base material 1 is supported horizontally on the conveyor 25 by piercing the peripheral edges of both ends of the rectangular base material 1 into the pins 27 (see FIG. 9) protruding from the conveyor 25. The base material 1 supported by the conveyor 25 is conveyed to the preheating furnace 28 and the main heating furnace 29 to be subjected to heat treatment for press molding, and then conveyed to the press machine 30. On the other hand, the epidermis 2 is transferred from one of the epidermis stock parts 41 and 42 for each kind to the epidermis supply part 43 as shown in FIG.
When it is taken out by the feeder 44 as shown in FIG.
Further, while being supported by the sheet support frame 13 shown in FIG. 8, the sheet support frame 13 is sent together with the sheet support frame 13 to a heating furnace 45, where it is heated by far infrared rays and then conveyed to the press machine 30.

The seat support frame 13 is a rectangular base 14 such as an iron plate, a vertically openable / closable clamp bar 15 installed on a flat upper surface of four sides of the base 14, and a clamp bar 15 fixed to the base 14 to open / close the clamp bar 15. An opening / closing drive mechanism 16 having a cylinder and a motor as a drive source is provided. When the four peripheral edges of the skin 2 are placed on the base 14 and the clamp bar 15 is closed, the four peripheral edges of the skin 2 are clamped by the flat upper surface of the base 14 and the flat lower surface of the clamp bar 15. It is fixed at 14.

The press machine 30 includes an upper press die 11 and a lower press die 1 which are vertically driven to approach and separate from each other.
2 is provided. As shown in FIG. 7, a base material 1 supported by a conveyor 25 at an intermediate position between the upper and lower press dies 11, 12 separated from each other, and a skin whose peripheral portion is fixed by a sheet support frame 13 directly above the base material 1. When 2 is loaded and positioned and fixed,
As shown in FIG. 9, the lower press die 12 rises and the upper press die 11 descends to gradually press-form while stretching the substrate 1 and the skin 2. At this time, the press-molded central portions of the skin 2 and the base material 1 are adhesively fixed to each other by an adhesive previously applied to the back surface of the skin 2. Top and bottom press mold 1
When the press molding of the sheet supporting frame 13 is completed by continuously pressing the central portions of the base material 1 and the outer skin 2 for a predetermined period of time by the pressing of the base materials 1 and 12, the clamp bar 15 of the sheet support frame 13 is opened, and the upper and lower press dies The support frames 13 are unloaded from the press machine 30 after the molds 11 and 12 are released from the press machine 30 to move to the next set of skins. The press-formed molded product is transferred to the press machine 30 on the conveyor 25.
Is conveyed to the next cooling step and cooled, and then trimming press is performed to remove unnecessary portions on the periphery.

[0005]

In the case of press molding of resin sheets made of different materials such as the base material 1 and the skin 2, the base material 1 is a thick resin sheet having higher rigidity than the skin 2, and the press of this is used. Even if the support form at the time of molding uses the conveyor 25, an appropriate material tension is applied to the base material 1 by the pins 27 of the conveyor 25 at the time of press molding, and good press molding is possible. On the other hand, a thin laser-like outer skin 2 such as a TPO sheet easily forms a wrinkle that is easily torn during stretching during press molding by only partially supporting the peripheral edge with pins or the like. The base 14 of the frame 13 and the clamp bar 15 firmly clamp.

However, as a practical matter, when the upper press die 11 pushes down the central portion of the outer skin 2 whose peripheral portion is clamped by the sheet support frame 13 during the press forming of FIG. 9, the outer peripheral portion of the outer skin 2 becomes the base. Since it is firmly fixed to the upper surface of 14, it is difficult to adjust the amount of skin material flowing into the mold side and the material tension necessary for press molding.
When the outer skin 2 is stretched by the upper press die 11, stress concentrates on the portion that contacts the inner peripheral edge of the base 14 and breaks or wrinkles occur, which causes defects such as wrinkles in the press-formed product. There is.

In the case where the back surface of the skin 2 is coated with an adhesive, the base 14 of the sheet support frame 13 is treated with Teflon to prevent the adhesive of the skin 2 from adhering to the base 14. Since the back surface of the skin 2 is strongly rubbed against the upper surface of the base 14 during the press molding of
The adhesive on the back surface of the outer skin 2 may stick to the upper surface of the above, and a part of the peripheral edge of the outer skin 2 may be adhered and left on the base 14 in a torn state after press molding. Such a base 14
The skin remaining on the top partially overlaps with the peripheral edge of the new skin set on the base 14 to easily cause wrinkles on the new skin during press molding, which deteriorates the yield of press-formed products. There is. Further, it is troublesome after removing the epidermis remaining on the base 14.

As another press forming apparatus, FIG.
As shown in FIG. 1, the seat support frame 1 is provided with a plurality of pins 17 projectingly provided on a base 14 ′ having the same shape as the above-mentioned base, and the peripheral edge portion of the outer skin 2 is inserted into the pins 17 for support.
Some use 3 '. A press molding apparatus using this sheet support frame 13 ′ is configured to positively tear off the peripheral edge of the skin 2 from the pin 17 when the skin 2 is pressed and pulled, so that the skin material is moved to the mold side. The amount of material flowing in is adjusted to give the skin 2 a material tension necessary for press molding. However, in this case, there is a portion which is not broken by the pin 17 or a portion which is unnecessarily large broken in the peripheral portion of the skin 2, and the material tension applied to the skin 2 during press molding is partially unstable. Therefore, stable and favorable press molding is difficult. Moreover, the base 14 'has a torn piece of epidermis left, which is troublesome to clean.

An object of the present invention is to provide an apparatus and method for stably and satisfactorily press-molding a resin sheet such as the above-mentioned skin.

[0010]

The device of the present invention comprises a frame-shaped base, an open-close type clamp bar for pressing and fixing the peripheral edge of the resin sheet on the base, and a base fixed on the base. The sheet support frame that has an opening / closing drive mechanism that opens and closes the clamp bar with and the central portion of the resin sheet whose peripheral portion is fixed to the sheet support frame, excluding the peripheral portion, is pressed in the thickness direction of the resin sheet. In a press forming apparatus having a press die that press-forms while stretching the sheet, a rotating roller is rotatably fixed along the inner circumference of the base of the sheet support frame, and the periphery of the resin sheet is on both the rotating roller and the base. While pressing the part with a clamp bar and fixing it, press the central part of the resin sheet with a press die.
The resin sheet slides on the outer circumference of the rotary roller and is press-molded in a direction in which the rotary roller is driven to rotate, thereby achieving the above object.

Here, the base of the sheet supporting frame is a rectangular frame which is provided with clamp bars on each of the four sides to support the peripheral portions of the four sides of the rectangular resin sheet, or a rectangular frame. Clamp bars are installed only on the two opposite sides to support only the peripheral edges of the two opposite sides of the rectangular resin sheet. In addition, the rotating roller arranged along the inner circumference of the base is a guide roller function that is driven by the pulling force during press molding of the resin sheet and is driven by the resin sheet to the press die side. is there.

Further, according to the method of the present invention, an adjustable braking force is applied to the rotary roller, and the elongation amount of the resin sheet during press molding is adjusted by the braking force. By adjusting the rotational force by the braking force from the outside of the rotating roller, the tension of the resin sheet during the press forming can be manually adjusted, and the appropriate press forming according to the material of the resin sheet can be performed.

Further, according to the method of the present invention, the press molding is performed on the basis of the position detection signal of the press mold in the middle of molding in which the central portion of the resin sheet whose peripheral portion is fixed by the sheet supporting frame is press-molded by the press mold. On the way, the clamp bar of the sheet support frame is detached from the peripheral edge of the resin sheet to free the peripheral edge of the resin sheet. Thus, by releasing the peripheral edge of the resin sheet from the sheet support frame during the press molding, the upper limit of the tension of the resin sheet to be press molded is suppressed, and troubles such as breakage of the resin sheet are prevented.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is shown in FIG.
It will be described with reference to FIGS. Incidentally, this embodiment is shown in FIG.
The sheet support frame 3 for supporting the skin 2 at the time of press molding as shown in FIG. Only the existing manufacturing equipment is different. Manufacturing equipment other than the seat support frame 3 in FIG. 1 is the same as the conventional equipment in FIG. 7, and the same parts are denoted by the same reference numerals.

The seat support frame 3 in the embodiment of the present invention is
The rectangular base 4 is a resin sheet to be press-molded so as to detachably support the peripheral portions of the four sides of the rectangular base 2.
And a drive source such as a clamp bar 5 that opens and closes up and down on each of the four sides of the base 4 and a motor that is fixed to each of the four sides of the base 4 and that opens and closes the clamp bar 5 up and down on the base 4. The opening / closing drive mechanism 6 and the rotating roller 7 fixedly rotatably arranged along the inner circumference of each of the four sides of the base 4.

FIG. 2 shows an enlarged view of a set of the clamp bar 5 and the rotating roller 7. The rotating roller 7 is, for example, a Teflon roller or the like which is rotatably fitted around the core shaft 8 of a metal round bar. It is a Teflon-processed cylindrical metal roller. The core shaft 8 projects from both ends of the rotating roller 7,
The protruding end of the core shaft 8 is attached to the base 4 by a roller holder 9
Fixed through. If necessary, the rotating roller 7 is provided with means for urging the rotating roller 7 to apply a braking force when the rotating roller 7 freely rotates around the outer circumference of the core shaft 8, for example, a manual brake adjusting member 10. The inner periphery of each of the four sides of the base 4 and the axis of the rotating roller 7 are parallel to each other, and the upper end of the outer periphery of the rotating roller 7 and the flat upper surface of the base 4 are set to be flush with each other.

The lower surface of the clamp bar 5 is flat, and when the open / close drive mechanism 6 rotates the clamp bar 5 toward the upper surface of the base 4, the lower surface of the clamp bar 5 causes the lower surface of the rotary roller 7 and the base 4 to rotate. Simultaneously press contact with both upper surfaces. Therefore, when the peripheral portion of the skin 2 is placed on the upper surface of the base 4 and the clamp bar 5 is closed, the front end portion of the clamp bar 5 and the rotating roller 7 clamp the inner portion of the peripheral portion of the skin 2 and at the same time after the clamp bar 5. 2 skins at the end and base 4
The outer portion of the peripheral edge is clamped.

The skin 2 whose peripheral portion is supported by the sheet supporting frame 3 is carried into the intermediate position between the upper and lower press dies 11, 12 together with the sheet supporting frame 3 as shown in FIG.
5 is positioned directly above the substrate 1 supported by
At the same time, it is press-molded by the upper and lower press dies 11 and 12.
The process of this press molding is shown in FIGS. 3 (A) and 3 (B).

FIG. 3A shows a step in which the upper and lower press dies 11 and 12 move up and down in a direction in which the upper and lower press dies 11 and 12 approach each other and the base material 1 and the skin 2 are overlapped and the pressing is started. The upper press die 11 gradually pushes down and extends. At this time, the inner portion of the peripheral portion of the outer skin 2 is pressed against the outer peripheral surface of the rotating roller 7, and the outer skin 2 is pulled toward the mold side, whereby the rotating roller 7 is driven to rotate so as to send the outer skin 2 toward the mold side. Therefore, the stress concentration at the peripheral portion of the skin 2 is relieved by the rotating roller 7. Therefore, even if the back surface of the skin 2 is coated with the adhesive, it does not reach the edge of the base 4 or the outer periphery of the rotating roller 7, and the occurrence of the trouble due to the adhesive of the skin 2 is avoided. Press molding can be performed by smoothly stretching the skin 2.

Further, when the braking force applied to the rotating roller 7 is adjusted in advance by the brake adjusting member 10 at the initial stage of the press molding shown in FIG. 3A, the skin 2 is driven to rotate by the expansion. The rotating force of the rotating roller 7 is adjusted by the braking force, and the material tension applied to the outer skin 2 during press forming is arbitrarily adjusted. With this tension adjustment, the flow rate of the skin material from the rotating roller 7 to the mold side is arbitrarily adjusted, and the skin 2 is sent to the mold side without tearing or wrinkling, and smooth press molding is performed. It is performed stably.

The functions of the rotating roller 7 for relieving stress concentration and adjusting the tension of the skin material are slightly different depending on the material and outer diameter of the rotating roller 7. For example, when the rotating roller 7 is a Teflon roller, its outer diameter is 12 to
It is recognized that when the thickness is about 15 mm, each function of stress concentration relaxation during press forming of the skin 2 and adjustment of the skin material tension is effectively exhibited. In this case, it has been found that when the outer diameter of the rotating roller 7 is smaller than 12 mm, stress concentration is likely to occur, and when it exceeds 15 mm, it is difficult to adjust the material tension.

At the stage of FIG. 3 (A), the central portions of the skin 2 and the base material 1 are in a state of being temporarily pressed by the upper and lower press dies 11 and 12, and the rotary roller 7 and the upper press die 11 are pressed. The tension in the epidermis 2 in the stretched state between is close to the upper limit. Therefore, as shown in FIG. 3B, the clamp bar 5 of the seat support frame 3 is opened at the timing when the tension of the outer skin 2 approaches the upper limit based on the detection signal of the mold position at the stage of FIG. 3A. , Upper and lower press mold 1
Press molding by 1 and 12 is continued. When the clamp bar 5 is opened, the peripheral edge portion of the outer skin 2 is released to be in a free state, so that the peripheral edge portion flows into the mold side through the rotating roller 7 to reduce the tension, and the outer skin portion which is likely to occur in the latter half of press molding. Breaking is avoided. Further, at the stage of FIG. 3B, the center portions of the base material 1 and the skin 2 are almost press-molded, that is, the skin 2 does not necessarily need to be supported by the seat support frame 3, so this stage There is no problem even if you open the clamp bar 5 with. Further, if the clamp bar 5 is opened during the press molding, only the sheet support frame 3 can be detached from the mold side during the press molding and used for another purpose such as a new skin set.

In the above embodiment, the peripheral edge of the four sides of the rectangular skin 2 is supported by the rectangular sheet support frame 3, but the clamp bar 5 is provided only on the opposite two sides of the rectangular sheet support frame 3. May be installed to support only the peripheral edges of the two opposite sides of the skin 2. Further, the present invention is not limited to a press molding apparatus for a molded ceiling of an automobile, and the point is that a thin resin sheet that is easily broken or wrinkled during stretching of press molding and has a stable material tension can be effectively applied.

[0024]

According to the resin sheet press molding apparatus of the first aspect, the stress concentration at the peripheral portion of the resin sheet which is stretched by press molding of the rotary roller arranged along the inner periphery of the base of the sheet support frame. Is alleviated, and the flow of the resin sheet into the mold is made smooth, so that the quality of the press-molded product of the resin sheet and the yield can be improved. In addition, since the rotating roller is driven to rotate by pulling the resin sheet, the adhesive does not stick to the rotating roller or the base even if the resin sheet has the adhesive,
This type of adhesive reduces the yield of press-formed products,
There is no need to clean resin sheet pieces that have been torn into pieces on the sheet support frame.

According to the method of press-molding a resin sheet of claim 2, when the resin sheet is press-molded, the rotation amount of the rotary roller is driven to rotate and is fed to the mold side.
Since it can be adjusted appropriately by adjusting the braking force applied to the rotating roller, more stable and favorable press molding of the resin sheet becomes possible.

According to the resin sheet press-molding method of the third aspect, the peripheral edge portion of the resin sheet is released from the sheet support frame before the resin sheet starts to be pressed by the mold and the material tension becomes unnecessarily large. By setting the free state by pressing, the material tension can be suppressed and adjusted during the press forming, and the press forming can be always performed in a good state without breaking the resin sheet until the final stage of the press forming.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a press molding apparatus showing an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of the seat support frame in FIG.

3A and 3B are cross-sectional views of the resin sheet supported by the sheet support frame shown in FIG. 2 at various stages during press molding, in which (A) is the initial stage of press molding and (B) is a stage in the middle of press molding. Is.

FIG. 4 is a plan view showing an outline of press molding equipment for two resin sheets.

5 is a side view showing an outline of a resin sheet (base material) conveyance path in the equipment shown in FIG. 4;

FIG. 6 is a side view showing an outline of a resin sheet (skin) conveying path in the equipment shown in FIG. 4;

FIG. 7 is a sectional view of a main part of a conventional resin sheet press molding apparatus.

FIG. 8 is a plan view of the seat support frame in FIG.

FIG. 9 is a partial enlarged cross-sectional view when a resin sheet is press-molded by the apparatus shown in FIG.

FIG. 10 is a cross-sectional view of a main part of another conventional press-forming apparatus for resin sheets.

[Explanation of symbols]

2 Resin sheet (skin) 3 seat support frame 4 base 5 Clamp bar 6 Open / close drive mechanism 7 rotating rollers 11 Upper press die 12 Lower press die

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Claims (3)

(57) [Claims] 1. A frame-shaped base, an opening / closing clamp bar for pressing and fixing a peripheral portion of a resin sheet on the base, and an opening / closing for opening and closing the clamp bar up and down on the base fixed to the base. A press that presses the sheet supporting frame having a drive mechanism and the central portion of the resin sheet whose peripheral portion is fixed to the sheet supporting frame, excluding the peripheral portion, in the thickness direction of the resin sheet while stretching the resin sheet. In a press molding apparatus having a mold, a rotating roller is rotatably fixed along the inner circumference of the base of the sheet support frame, and a peripheral edge of the resin sheet is pressed by a clamp bar on both the rotating roller and the base. In the fixed state, press the central part of the resin sheet with a press die in such a direction that the resin sheet slides on the outer periphery of the rotating roller and is driven to rotate the rotating roller. Press forming apparatus of the resin sheet, characterized in that it has. 2. The press forming apparatus according to claim 1, wherein an adjustable braking force is applied to the rotary roller, and the elongation amount of the resin sheet during press forming is adjusted by the braking force. And a method of press molding a resin sheet. 3. The position of the press die during press forming, wherein the press forming apparatus according to claim 1 is used, and the center portion of the resin sheet whose peripheral portion is fixed by the sheet support frame is press formed with a press die. A method for press-molding a resin sheet, characterized in that a clamp bar of a sheet support frame is detached from a peripheral edge portion of a resin sheet during the press-molding so that the peripheral edge portion of the resin sheet is freed based on a detection signal.