JPH0725065B2 - Cutting device for thermoplastic synthetic resin moldings - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for cutting a part of a thermoplastic synthetic resin molded product so as to form a continuous curved end portion, particularly for a vehicle molding. The present invention relates to a cutting device for thermoplastic synthetic resin molded products suitable for manufacturing.

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

In order to improve such a point, a method has been proposed in which a cooled synthetic resin molded product is fused by a cutting blade to which a high frequency voltage is applied (for example, Japanese Patent Laid-Open No. 54-11977).

However, in such a conventional method, since the high frequency voltage is applied to the cutting blade, the resin in the portion in contact with the cutting blade is melted to form a molten cross section having an appearance different from that of the other portions. At the same time, since the cutting blade comes into contact with the melted portion, the melted surface is disturbed and the decorative property is impaired.

[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 portion having an excellent appearance continuous with other parts. SUMMARY OF THE INVENTION It is an object of the present invention to provide a cutting device for a thermoplastic synthetic resin molded product, in which a cut surface is formed, a cut surface is not conspicuous, and cutting can be performed with excellent decorativeness.

[Means for Solving the Problems]

The present invention provides a cradle on which a molded product molded from a thermoplastic synthetic resin is mounted, a clamp for fixing the molded product mounted on the cradle, and a forward movement toward a cutting portion on the outer surface side of the molded product. , The part that is provided so as to be retractable and that is substantially along the cut part of the molded product,
A heating device that softens the inside by heating it to a temperature higher than the other parts and higher than room temperature, and when the heating device is retracted, it can be moved forward and backward toward the outer surface of the molded product, and When the hardness of the outer surface of the product is higher than that of the inner part, it advances from the outer surface side of the molded product and stretches without cutting or breaking the outer surface to form a curved end, And a cutting blade having a predetermined shape configured to cut in a state in which the parts are welded together, and a device for cutting a thermoplastic synthetic resin molded article.

In the present invention, as the synthetic resin, a thermoplastic resin such as styrene resin, vinyl chloride resin or polyolefin resin can be used. Also, as a synthetic resin molded article, a vehicle molding is suitable, but other moldings may be used.
These can be molded by an extrusion molding method, an injection molding method, or the like.

The heating device for the synthetic resin molded product may be any device as long as it is a device that softens the inside by heating a narrow region substantially along the cut portion to a temperature higher than the other parts and higher than normal temperature. An apparatus that heats the entire cut portion by high-frequency dielectric heating while the outer surface of the molded article is cooled by air at room temperature or the like is preferable, but a device that heats by blowing a heating fluid, far infrared rays, or the like may be used.

The cutting blade can advance and cut from the outer surface side in a state where the hardness of the outer surface portion of the heated portion is higher than that of the inner portion. In this case, the cutting blade does not need to be heated, but rather is preferably cooled so as to maintain a low temperature. Further, when a device for spraying a cooling fluid is provided on the outer surface side of the cutting portion, the outer surface of the molded product is cooled to increase the hardness, and the cutting blade is also cooled to improve the cutting property.

The advancing speed of the cutting blade is preferably a speed at which the outer surface portion of the synthetic resin molded product is not cut midway, that is, there is no breakage corresponding to shearing. At the time of cutting, it is desirable that clamps be provided on both sides of the cutting blade so that at least one of them can be moved so that the molded product can be cut under tension.

[Action]

In the cutting device of the thermoplastic synthetic resin molded product of the present invention, the thermoplastic synthetic resin molded product is placed on the pedestal and fixed by a clamp. The heating device is moved forward with the cutting blade retracted, and the portion of the synthetic resin molded product substantially along the cut portion is heated to a temperature higher than that of the other portions and at room temperature or higher to soften the inside.

Next, when the heating device is retracted and the hardness of the outer surface side of the molded product is higher than that of the inner part, and the cutting blade is advanced from the outer surface side while preferably applying tensile stress to the cut portion, the outer surface of the molded product is removed. The surface is stretched without being cut or broken to form a curved end portion, and the outer surface portion and the back surface portion are cut in a welded state.

When cut in this way, the outer surface of the cut part is stretched without being cut, so there is no unnecessary rise or deformation, and it deforms into a curved surface while maintaining a continuous appearance with other parts. Then, a curved end portion is formed and the outer surface portion and the back surface portion are welded and cut. The cut surface is formed with the outer surface part stretched without shearing or fusing, so that the resin inside is not exposed and is formed with a narrow width on the back surface side, so it is not conspicuous from the outer surface side. A synthetic resin molded product having no edges and an excellent appearance can be obtained without end treatment such as end caps.

〔Example〕

Hereinafter, the present invention will be described with reference to the embodiments of the drawings. The example shows an example of manufacturing a molding for a vehicle by cutting a long thermoplastic synthetic resin molded article. 1 to 3 are front views of a cutting device according to an embodiment, FIG. 4 is a perspective view of a part thereof, FIG. 5 is a view taken in the direction of arrow A in FIG. 1, and FIGS. A plan view of the molded product, 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 sectional view taken along line BB thereof, and FIG. 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, etc., and has a tapered surface 23 on the cutout portion 22 side of the molded product 2 as shown in FIG. 8, and the cutting edge 15a is not very sharp. The tip surface is so large that the outer surface portion 2a of the molded article 2 can be stretched without cutting or breaking at the time of cutting, and can be cut while the outer surface portion 2a and the back surface portion 2c are welded. Has been 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.
It has substantially the same shape as the cutting part (cutting line) 21, and applies a high-frequency voltage between the lower electrode 11 and the lower electrode 11 when moving forward so that the part substantially along the cutting part 21 is heated to a temperature exceeding room temperature. . The upper electrode 24 is attached to the base plate 26 via a mounting member 25 made of silicon or FRP. A clamp 27 made of an elastic material is also attached to the base plate 26.
The base plate 26 is connected to the fluid pressure cylinder by the connecting rod 28.
It is connected to the rod 30 of 29 and can move up and down. The fluid pressure cylinder 29 is attached to a slide plate 33 that moves horizontally by a rod 32 of another fluid pressure cylinder 31,
It is fixed by the support legs 34 and the stand plate 35. The fluid pressure cylinder 31 is fixed to a fixed plate 36, and the slide plate 33 horizontally moves along a guide rod 38 fixed between the fixed 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 side opposite to the clamp 43, and the pin 46 provided at the tip of the clamp 45 is clamped in a state where it is bitten into the two cutouts 22 of the molded product. The clamp 45 is connected to the rod 48a of the fluid pressure cylinder 48 attached to the slide plate 47 by the connecting rod 49.
It is attached by and can be moved 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.
It can be moved horizontally along a guide bar 54 fixed between 50 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.

In the method of cutting the molded product 2, first, the molded product 2 manufactured by extrusion molding, injection molding, or the like of a thermoplastic synthetic resin is placed on the molded product placing portion 4 of the pedestal 1 and cut.

FIG. 1 shows a state in which the molded product 2 (molding 61) has been carried out by the carry-out tool 6 after the cutting of the molded product 2 has been completed. From this state, the rodless fluid pressure cylinder 9 moves the carry-out tool 6 a 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. Forward (down)
Let 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 portion of the resin along the line is heated to a temperature above 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. 56 is a heating part, and the density of each point shows the 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, the hardness of the outer surface portion 2a is higher than that of the inner portion 2b, and the tip surface of the cutting edge 15 is so large that the cutting edge 15a does not shear the outer surface portion 2a of the molded product 2. Since it is smooth, as shown in FIG. 10, the outer surface portion 2a is pressed by the cutting blade 15 so as to be stretched as it is without being sheared or broken.
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. A part of the resin in the interior 2b easily moves to the non-cutting portion 44 side to form a bulge, but by applying tension with the clamp 45, the bulge is prevented.

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 surface while maintaining the appearance continuous with other portions, and a smooth curved end portion 62a is formed.
With the outer surface and back surface welded together, the cutting blade
A molding 61 as shown in FIGS. 12 to 14 is manufactured by cutting between 15 and the lower electrode 11. Lower electrode 11
Adjust the upper surface of the adjustment bolt 14 so that it matches the tip of the cutting blade 15.
The molded product 2 can be completely cut by adjusting the level by.

The cutting surface 63 formed by the cutting blade 15 is formed such that the outer surface portion 2a is stretched without being sheared or broken, and thus the resin of the inner portion 2b is not exposed to the outer surface side, The front surface portion 2a and the rear surface portion 2c are welded to each other, and are formed in the vicinity of the rear surface portion 2c and are inconspicuous from the outer surface 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 d direction and repeat the above operation.

In the above device, since the upper electrode 24 and the cutting blade 15 as a heating device can be selectively driven to heat and cut at the same position, only the resin in a narrow region along the cutting portion 21 is heated and softened and cut. The end 62 can be
The end portion 62 having a continuous curved surface and excellent appearance is formed without sagging. 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. Curved surface cannot be formed,
When only a narrow region is heated, this is not the case, and the continuous curved end portion 62 as described above is formed.

〔The invention's effect〕

According to the present invention, since the heating device and the cutting blade can be selectively driven, the portion substantially along the cut portion of the thermoplastic synthetic resin molded article is kept at a higher temperature and room temperature than the other portions. Edges on a curved surface that are heated to a temperature above the temperature to soften the inside and extend the cutting surface by advancing the cutting blade to cut or break the outside surface while making the hardness of the outside surface higher than the inside. Can be cut in a state where the outer surface portion and the back surface portion are welded to each other, thereby forming a curved end portion having an excellent appearance continuous with other portions, and the cut surface is not conspicuous The resin molded product can be cut so as to have an excellent appearance.

In this case, since the parts other than the cutting part are not softened and remain high in hardness, unnecessary bulging and deformation are prevented from occurring on the molding side during cutting, and only the cutting part is heated so that heating can be performed 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 of the embodiment, and FIG.
FIG. 5 is a perspective view of a part thereof, FIG. 5 is a view in the direction of arrow A in FIG. 1, FIGS. 6 and 7 are plan views of the molded product, and FIGS. 8 to 11 are cross-sectional views showing a cut state. FIG. 12 is a perspective view of a part of the manufactured molding, FIG. 13 is a BB sectional view thereof, and FIG. 14 is a CC sectional view. 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, 15a is a cutting edge, 21 is a cutting part, 22 is a cutting part, 24 is an upper electrode, 27, 43, 45 are clamps, 55 is a nozzle, 56 is a heating part, 61 is a molding, 62
Is an end portion, and 63 is a cut surface.

Claims (4)

[Claims] 1. A cradle on which a molded article molded from a thermoplastic synthetic resin is placed, a clamp for fixing the molded article placed on the cradle, and an outer surface of the molded article facing a cutting portion. A part that is provided so that it can be moved forward and backward and that is substantially along the cut part of the molded product,
A heating device that softens the inside by heating it to a temperature higher than the other parts and higher than room temperature, and when the heating device is retracted, it can be moved forward and backward toward the outer surface of the molded product, and When the hardness of the outer surface of the product is higher than that of the inner part, it advances from the outer surface side of the molded product and stretches without cutting or breaking the outer surface to form a curved end, And a cutting blade having a predetermined shape configured to cut in a state in which the parts are welded, and a cutting device for a thermoplastic synthetic resin molded article. 2. The apparatus according to claim 1, wherein the clamps are provided on both sides of the cutting portion, and at least one of the clamps is movable so that the molded article can be tensioned. 3. The device according to claim 1, wherein the heating device is an electrode for high frequency dielectric heating. 4. The device according to claim 1, wherein the heating device and the cutting blade have substantially the same shape.