JPH0653390B2 - Molding manufacturing method - Google Patents

Description

The present invention relates to a method for producing a molding by cutting a part of a thermoplastic synthetic resin molded article.

[Conventional technology]

As a method of manufacturing a synthetic resin molding for a vehicle, there is a method of shearing a synthetic resin molded product such as an extrusion molded product or an injection molded product of a thermoplastic synthetic resin to manufacture the molding. However, when the synthetic resin molded product is sheared, the sheared end face is exposed and the decorative property is impaired, and the edge is dangerous. Therefore, it is necessary to perform end treatment such as forming an end cap on the sheared portion.

In order to improve such a point, a method of fusing a cooled synthetic resin molded article with a cutting blade to which a high frequency voltage is applied has been proposed (JP-A-54-11977).

However, in such a conventional method, since a high frequency voltage is applied to the cutting blade, the resin in the portion in contact with the cutting blade is melted and a fusing end surface having an appearance different from that of the other portions is formed. At the same time, there is a problem that the fusing end face is disturbed and the decorativeness is impaired because the cutting blade contacts the molten portion.

[Problems to be Solved by the Invention]

In order to solve the above problems, an object of the present invention is to cut off a part of a molded product by cutting with a principle different from shearing and fusing, thereby forming a curved end having an excellent appearance continuous with other parts. Part is formed, and the cut surface is not conspicuous,
It is to propose a method for manufacturing a molding that can be cut so as to have excellent decorativeness.

[Means for Solving the Problems]

This invention comprises: a) a step of obtaining a molded article having a desired outer surface from a thermoplastic synthetic resin and having a shape larger than the final product shape; b) a portion substantially along the cut portion of the molded article, Other than the part, the process of heating to a temperature higher than room temperature and softening the inside, and c) the cutting edge with the outer surface part of the heated part being harder than the inside By advancing from the outer surface side, stretching the outer surface without cutting or breaking, moving the internal resin to the peripheral part, forming a curved end part, and welding the outer surface part and the back surface part It is a method of manufacturing a molding including a step of cutting a part of a molded product by cutting in a state.

In the present invention, as the thermoplastic synthetic resin, styrene resin, vinyl chloride resin, polyolefin resin and the like can be used. Further, as the synthetic resin molded product, an extrusion molded product,
Examples include injection molded products.

The synthetic resin molded product is heated by heating a narrow region substantially along the cut portion to a temperature higher than the temperature other than that portion and higher than room temperature to soften the inside. At this time, it is preferable to heat the entire cut portion by high frequency dielectric heating while the outer surface of the synthetic resin molded article is cooled by air at room temperature or the like, but it may be heated by spraying a heating fluid or far infrared rays. .

The synthetic resin molded article is cut by advancing the cutting blade from the outer surface side in a state where the outer surface of the heated portion has a higher hardness than the inside. In this case, when cutting is performed while spraying the cooling fluid on the outer surface side of the cutting portion, the outer surface of the molded article is cooled to have higher hardness than the inside, and the cutting blade is also cooled to improve the cutting property.

The speed of advance of the cutting blade is such that the outer surface of the synthetic resin molded product is stretched without being cut or broken in the middle, the resin inside moves to the peripheral part, and a curved end is formed. To do. At the time of cutting, it is desirable to cut with the tension applied to both sides of the cut portion of the molded product as a reference.

[Work]

In the method for producing a molding of the present invention, a narrow region along the cut portion of the thermoplastic synthetic resin molded article is heated to soften the inside, and the outer surface portion has a higher hardness than the inside, and the cutting blade is When it is advanced from the outer surface side, the outer surface portion has a high hardness and is pushed and stretched without being cut or broken by the cutting blade, and therefore the resin in the softened state inside moves to the peripheral portion. When the cutting blade further advances in this state, the outer surface of the cutting portion does not have unnecessary swelling or deformation, and is deformed into a curved surface while maintaining a continuous appearance with other portions, and the curved end portion is It is formed and cut in a state where the outer surface portion and the back surface portion are welded. The cut surface is formed with the outer surface part stretched without shearing or fusing, so it is conspicuous from the outer surface side because it is formed with a narrow width on the back side without exposing the resin inside. No
It is possible to obtain a molding with an excellent appearance without performing a terminal treatment such as an end cap.

〔Example〕

Hereinafter, the present invention will be described with reference to the embodiments of the drawings. 1 to 3 are front views of the cutting device, FIG. 4 is a perspective view of a part thereof, FIG. 5 is a view in the direction of arrow A in FIG. 1, and FIGS. 6 and 7 show molded products. A plan view, FIGS. 8 to 11 are sectional views showing a cut state, FIG. 12 is a perspective view of a part of the manufactured molding, FIG. 13 is its BB sectional view, and FIG. 14 is C-
It is C sectional drawing.

In the figure, 1 is a pedestal, on which a molded product 2 is placed, and side guides 3 are formed on both sides so as to be movable in the longitudinal direction. An opening 5 is provided in the longitudinal center of the molded product placement portion 4 (right side in FIGS. 1 to 3) of the cradle 1.
A bracket 8 connected to the carry-out tool 6 that reciprocates above by a mounting bolt 7 extends downward through the opening 5 and is connected to the moving body 10 of the rodless fluid pressure cylinder 9. On the lower side of the pedestal 1, a lower electrode 11 is provided at a portion corresponding to the cut portion of the molded product 2 to be placed, and the lower electrode 11 is pulled by the spring 12 to the fixed base 13. With 14, the level of the electrode surface can be adjusted.

A cutting blade 15 is provided above the pedestal 1 at a position facing the lower electrode 11.
Is provided so as to be movable up and down, and is moved forward and backward toward the outer surface of the molded product 2 by the rod 18 of the fluid pressure cylinder 17 fixed to the fixed plate 16 to move the molded product 2 between the lower electrode 11 and the lower electrode 11. It is designed to be cut. In FIG. 6, 21 indicates a cutting line, and the cutting blade 15 has the same shape as the cutting line 21. The cutting blade (15) is made of ceramic, a material obtained by vapor-depositing ceramic on a non-magnetic metal, or the like, has a tapered surface 23 on the side of the cut portion 22 of the molded product 2, and the cutting edge is not very sharp, but its tip is It is preferably smoothed.

Above the pedestal 1, the upper electrode 24 serving as a heating device is arranged so as to move up and down along the same trajectory as the cutting blade 15 when the cutting blade 15 moves backward.
Is provided. The upper electrode 24, as shown in FIG.
The shape is substantially the same as that of the cutting portion (cutting line) 21, and a high frequency voltage is applied between the cutting electrode and the lower electrode 11 at the time of forward movement to heat a portion substantially along the cutting portion 21. The upper electrode 24 is attached to the base plate 26 via a mounting member 25 made of silicon FRP. A clamp 27 made of an elastic material is also attached to the base plate 26. Also base plate 26
Is connected to a rod 30 of a fluid pressure cylinder 29 by a connecting rod 28 so as to move up and down. Fluid pressure cylinder 29
Is fixed by a support leg 34 and a stand plate 35 to a slide plate 33 that moves horizontally by a rod 32 of another fluid pressure cylinder 31. Fluid pressure cylinder 31
Is fixed to the fixed plate 36, and the slide plate
The reference numeral 33 is adapted to horizontally move along a guide rod 38 fixed between the fixing plates 36 and 37. 39 and 40 are guide holes.

A fluid pressure cylinder 41 is fixed to the fixing plate 36, and a clamp 43 is provided on a rod 42 of the fluid pressure cylinder 41 to move up and down to press the non-cutting portion 44 of the molded product 2 against the pedestal 1 for clamping. ing. Another clamp 45 is arranged on the opposite side of the clamp 43, and the pin 46 provided at the tip of the clamp 45 is clamped in a state in which the pin 46 bites into the cutout portion 22 of the molded product 2. The clamp 45 is attached by a connecting rod 49 to a rod 48a of a fluid pressure cylinder 48 attached to a slide plate 47 so as to move up and down. The slide plate 47 is attached to the rod 52 of the fluid pressure cylinder 51 fixed to the fixed plate 50, and
It can move in the horizontal direction along a guide rod 54 fixed between 0 and 53.

A nozzle 55 blows cooling air from the non-cutting portion 44 side toward the outer surface of the cutting portion 21 when the cutting blade 15 is advanced. 61 is a manufactured molding, 62 is an end portion, and 63 is a cut surface.

The method of manufacturing the molding 61 is as follows. First, a molded product 2 having a desired outer surface is manufactured from a thermoplastic synthetic resin by extrusion molding, injection molding, or the like, and the molded product 2 is mounted on the molded product mounting portion 4 of the pedestal 1. To disconnect.

FIG. 1 shows a state in which the molded product 2 (molding 61) is carried out by the carry-out tool 6 after the cutting of the molded product 2 is completed, and the carry-out tool 6 is moved by the rodless fluid pressure cylinder 9 from this state. After retracting in the direction, the molded product placement unit 4
Position the new molded product 2 on the
Drive the clamp 43 and move the clamp 43 forward,
Clamp 44. At the same time, with the fluid pressure cylinder 51 advancing the slide plate 47 in the a direction, the fluid pressure cylinder 48 causes the clamp 45 to advance (lower) in the c direction to clamp the cutout portion 22 of the molded product 2, and the pin 46 Pressed on the outer surface.

At this time, with the cutting blade 15 retracted (raised) in the d direction by the fluid pressure cylinder 17, the slide plate 33 is advanced in the b direction by the fluid pressure cylinder 31, and the base plate 26 is moved in the c direction by the fluid pressure cylinder 29. Move forward (down). As a result, the clamp 27 is pressed against the molded product 2 to clamp the vicinity of the cut portion 21, and the upper electrode 24 is set at a position facing the cut portion 21 of the molded product 2. 2 and 8 show this state.

In this state, a high frequency voltage is applied between the upper electrode 24 and the lower electrode 11, and high frequency dielectric heating is performed to cut the cut portion 21 of the molded product 2.
The resin in a narrow area along the line is heated to a temperature higher than room temperature. Due to the high frequency dielectric heating, the resin near the cut portion 21 of the molded product 2 is uniformly heated to a temperature equal to or higher than room temperature due to self-heating, but the outer surface 2a is exposed to the air at room temperature. Since it is always cooled, the temperature becomes lower than the internal 2b. Then, when the inner surface 2b is heated to such an extent that it softens, the outer surface portion 2a has a higher hardness than the inner surface 2b. Reference numeral 56 denotes a heating portion, where the density of each point indicates the high temperature, the low density portion indicates a relatively low temperature, and the high density portion indicates a relatively high temperature.

In this state, in reverse operation to the above, the fluid pressure cylinders 29 and 31 retract the upper electrode 24 in the directions d and a to return it to the position shown in FIG.
Is advanced in the c direction to perform cutting. This state is shown in FIGS. 3 and 9-11.

At this time, while the clamp 45 is pulled in the b direction by the fluid pressure cylinder 51 to apply tension to the molded product 2, while the fluid pressure cylinder 17 blows cooling air from the nozzle 55 as shown in FIG. When the cutting blade 15 is advanced from the outer surface side, since the outer surface portion 2a has high hardness, as shown in FIG. 10, the cutting blade 15 is pushed so as to be stretched without being cut or broken by the cutting blade 15. Then, the resin in the inside 2b moves to the peripheral portion. At this time, since the tapered surface 23 is formed on the cutting portion 15 side of the cutting blade 15, the resin is extruded along the tapered surface 23. Although a part of the resin in the inside 2b easily moves to the non-cutting portion 44 side to form a bulge, the bulge is prevented by applying tension in a direction away from the cutting portion 21 by the clamp 45.

When the cutting blade 15 is further advanced in this state, as shown in FIG. 11, the non-cutting portion 44 to be the molding 61 and the outer surface portion.
2a is further stretched and deformed into a curved shape while maintaining a continuous appearance with other portions, and is cut between the cutting blade 15 and the lower electrode 11 in a state where the curved end portion 62 is formed. Is the 12th
A molding 61 as shown in FIGS. 1 to 14 is manufactured. By adjusting the level with the adjusting bolt 14 so that the upper surface of the lower electrode 11 coincides with the tip of the cutting blade 15,
The molded product 2 can be cut completely.

The cutting surface 63 formed by the cutting blade 15 is formed in the vicinity of the back surface portion 2c in a state where the resin of the inside 2b is not exposed to the outer surface side and the outer surface portion 2a and the back surface portion 2c are welded, and the outer surface Not noticeable from the side. Therefore, the molding 61 having an excellent appearance can be obtained without using the end cap or the like to end-process the cut surface 63, and the molding 61 can be used as it is.

After cutting, the cutting blade 15 is retracted in the d direction by the fluid pressure cylinder 17, and the carry-out tool 6 is driven by the rodless fluid pressure cylinder 9 as shown in FIG. 1 to remove the cut cutting portion 22 and the manufactured molding 61. Carry out in the b direction and repeat the above operation.

In the above method, the upper electrode 24 and the cutting blade 15 as a heating device are selectively driven to heat and cut at the same position, so that only the resin in a narrow region along the cutting portion 21 is heated and softened and cut. Therefore, the end 62 does not sag, and the end 62 having a continuous curved surface and having an excellent appearance is formed. Arranging the upper electrode 24 and the cutting blade 15 side by side, in order to move the cutting blade 15 in parallel with the upper electrode 24, it is necessary to heat a wide area near the cutting portion, so that the end portion 62 is continuous. Although a curved surface cannot be formed, if only a narrow area is heated, this does not occur, and the continuous curved end portion 62 as described above is formed.

〔The invention's effect〕

According to the present invention, a portion substantially along the cut portion of the thermoplastic synthetic resin molded article is heated to a temperature higher than room temperature to soften the inside, and the outer surface portion has a higher hardness than the inside, Move the cutting blade forward, stretch the outer surface without cutting or breaking it, move the resin inside to the periphery,
By forming a curved end and cutting it with the outer surface portion and the back surface being welded, a curved end portion having an excellent appearance continuous with other parts is formed, and the cut surface It is possible to manufacture a molding having an excellent appearance that is inconspicuous by a simple operation.

In this case, since the parts other than the cutting part are not softened and remain high in hardness, unnecessary swelling and deformation are prevented from occurring on the molding side during cutting, and only the cutting part is heated so that it can be cut in a short time. As a result, the energy consumption can be reduced while improving the property.

[Brief description of drawings]

1 to 3 are front views of the cutting device, FIG. 4 is a perspective view of a part thereof, FIG. 5 is a view in the direction of arrow A in FIG. 1, and FIGS. 6 and 7 show molded products. A plan view, FIGS. 8 to 11 are sectional views showing a cut state, FIG. 12 is a perspective view of a part of the manufactured molding, and FIG. 13 is a BB sectional view thereof, and FIG.
The figure is a sectional view taken along line CC. In each drawing, the same reference numerals indicate the same parts, 1 is a pedestal, 2 is a molded product, 6 is a carry-out tool, 9, 17, 29, 31, 41, 48, 51 are fluid pressure cylinders, 11 is a lower electrode, 15 is a cutting blade, 21 is a cutting portion, 22 is a cutting portion, 24 is an upper electrode, 27, 43 and 45 are clamps, 55 is a nozzle, 56 is a heating portion, 61 is a molding, 62 is an end portion, 63 is a cutting surface. Is.

Claims (4)

[Claims] 1. A step of obtaining a molded article having a desired outer surface from a thermoplastic synthetic resin and having a shape larger than the final product shape, b) a portion substantially along a cut portion of the molded article, A step of softening the inside by heating to a temperature higher than the temperature other than the portion other than the portion and higher than room temperature, and c) the cutting blade in a state where the hardness of the outer surface of the heated portion is higher than that of the inside. From the outer surface side, stretch the outer surface without cutting or breaking it, move the resin inside to the peripheral part, form a curved end part, and weld the outer surface part and the back surface part. A method of manufacturing a molding, including a step of cutting a part of a molded product by cutting the molded product. 2. An electrode having substantially the same shape as the cutting blade is arranged on the outer surface side of the molded product, and a high frequency voltage is applied between the electrode and another electrode arranged on the opposite side of the molded product to heat the molded product. The method according to claim 1. 3. The method according to claim 1, wherein the heating fluid is blown toward the molded product from the tip of a plate-shaped heating tool having substantially the same shape as the cutting blade. 4. The cutting method according to claim 1, wherein the cutting blade is cut while spraying a cooling fluid toward the outer surface of the molded product while the cutting blade is moving forward.
Item 4. The method according to any one of Items 3 to 3.