JP2905134B2 - Sheet heating method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for heating a thermoplastic resin sheet.

[0002]

2. Description of the Related Art Conventionally, as a method for heat-forming a thermoplastic resin sheet material, there is a method in which a material is indirectly heated and molded using a short-wavelength or medium-wavelength heater having a maximum energy wavelength of 1 to 3 μm. (For example, see JP-A-7-27
6490).

[0003]

SUMMARY OF THE INVENTION However, in the above-mentioned method for heat-forming a thermoplastic resin sheet material,
The short or medium wavelength heater for indirect heating is rod-shaped,
Since the temperature difference cannot be set in the longitudinal direction of the heater, the temperature at the center of the material to be heated rises faster than the temperature at the end, and when the entire material is heated to the moldable temperature range, the temperature at the center of the material increases. This causes discoloration due to foaming and oxidation.

[0004] Further, depending on the shape to be shaped, some heating requires local heating. However, in the above-described heating method, the temperature of the whole material also increases, so that an arbitrary shape and characteristics cannot be obtained or the shape after shaping is not obtained. Cooling time is required and molding may take a long time. By the way, (1) a proposal of a configuration in which a temperature distribution of a sheet material is arbitrarily provided is disclosed in
This is also disclosed in the official gazette.

However, in this method, since a cylindrical shielding plate is provided between the heater and the sheet, the difference between the high-temperature region and the low-temperature region of the sheet is large. Therefore, it adversely affects the molded product. (2) A proposal for providing a shielding plate between a heater and a sheet is also disclosed in Japanese Patent Application Laid-Open No. 61-193825.

However, this method does not apply heat to certain parts of the sheet. In other words, a certain portion substantially completely blocks the heat from the heater. As is clear from the above, the conventional method has various problems, and at present, there is no proposal for controlling the heat applied to the sheet in the sheet forming zone.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a sheet heating method and apparatus capable of accurately controlling the heat applied to a sheet in a sheet forming zone.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a thermoplastic resin sheet material or a fiber reinforced composite sheet containing a thermoplastic resin as a main constituent material (hereinafter, referred to as a fiber reinforced composite sheet).
Abbreviated as sheet or material), the maximum energy wavelength is 1 to 3μ
When the sheet is indirectly heated using a short-wavelength or medium-wavelength heater or a long-wavelength heater (far-infrared heater), a reflector is provided on the back side of the indirect heater, and the sheet and the indirect heater A shielding plate is provided between the plates to uniformly heat the sheet.

Alternatively, by setting a shielding plate at an arbitrary position, a rise in sheet temperature at an arbitrary position is suppressed, and local heating is performed at positions other than the arbitrary position. Further, the ambient temperature is lowered by cooling the reflector at the central portion of the indirect heater or at an arbitrary portion (collectively referred to as a predetermined portion) to suppress a rise in the sheet temperature at a predetermined portion of the sheet, thereby enabling uniform heating or uniform heating of the sheet. Local heating other than the cooling unit is performed.

Further, in a method of heat-forming a three-dimensional molded article from a thermoplastic resin sheet material or a fiber-reinforced composite sheet material mainly composed of a thermoplastic resin, the sheet is uniformly heated to foam and oxidize the sheet. Can be avoided. Alternatively, the sheet temperature distribution can be arbitrarily set to improve the formability by improving the shape adding property and the productivity by shortening the cooling time.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an overall configuration diagram showing an outline of a sheet forming machine showing an embodiment of the present invention. In this figure, 1 is a thermoplastic resin sheet material to be molded or a fiber reinforced composite sheet (material) mainly composed of a thermoplastic resin, 2 is a molded product, 3 is an upper mold (female mold), 4 is a lower mold. (Male type), 5 is a lower frame, 6 is a sheet stacking device, 7 is a sheet lifting device, 8 is a cylinder for lifting and lowering the sheet, and 9a and 9b are upper and lower heaters as indirect heating heaters 9. .

Reference numeral 10a denotes a drive rack for the upper heater 9a, 10b denotes a drive pinion for the upper heater 9a, 11 denotes a cylinder for raising and lowering the lower heater 9b, 12 denotes a cylinder for raising and lowering the upper die 3, and 13 denotes a lower frame 5 , A lifting device 14 for removing the molded product 2, a driving belt 15a for removing the molded product, and a pulley 15b for removing the molded product.

Although not shown in the figure, the sheet 1 is transferred from the sheet stacking device 6 to the heater 9 for indirect heating → the forming section → the unloading device 1.
4 is used. Hereinafter, the configuration of the indirect heating device from above is shown in FIG. 2, and the configuration of the shielding plate is shown in FIGS.
8 to 11 show the configuration of the reflection plate, and FIGS. 12 to 15 show the arrangement of the indirect heater.

In FIG. 2, reference numeral 21 denotes a shielding plate provided between the central portion of the sheet 1 and the heater 9 for indirect heating, reference numeral 22 denotes a reflecting plate provided on the back side of the heater 9 for indirect heating, and reference numeral 23 denotes a sheet during heating. 1 is a thermometer (radiation thermometer) that measures the temperature at the center and at the end. In FIG. 3, the shielding plate 21 has a plurality of openings. In FIG. 4, reference numeral 24 denotes a slit for a shielding plate.

In FIG. 5, the shielding plate 21 is attached to the reflecting plate 22 via a shielding plate fixing rod 31. The shielding plate slit 24 is operated by a motor 32 via a transmission shaft 33, a sprocket 34, and a chain 35. An end of the chain 35 is connected to the shielding plate slit 24. As shown in FIG. 6, the shielding plate slit 2 is formed in the shielding plate 21.
4 is provided with a slide guide 25.

In FIG. 7, reference numeral 41 denotes an inclined shielding plate.
By operating the operation cylinder 42 of the inclined shielding plate 41, the inclination of the inclined shielding plate 41 can be adjusted via the rack 43 and the pinion 44. In FIG. 8, reference numeral 51 denotes a water or air cooling pipe installed on the back surface of the reflection plate 22,
The heater 9 for indirect heating faces the sheet 1.

FIG. 9 shows a reflection plate 22a having an opening. FIG. 10 shows a reflection plate 22 having an opening.
a and the corresponding reflector slit 61 are shown. In FIG. 11, the reflection plate 70 has a reflection plate slit 7.
1 is formed, and an inclined reflecting plate 72 is provided in the reflecting plate slit 71.

Hereinafter, the method for heating the thermoplastic resin sheet of the present invention will be described. As shown in FIGS. 1 and 2, in the process of heating and forming a three-dimensional molded product from the sheet 1, a heater 9 for indirect heating (here, a short-wavelength heater having a maximum energy wavelength of 1 to 3 μm, or a medium-wavelength heater). When the sheet 1 is indirectly heated by using (1), a reflection plate 22 is provided on the back side of the heater 9 for indirect heating, and a shield is provided between the sheet 1 and the heater 9 for indirect heating at the center of the sheet 1 or at an arbitrary position. By providing the plate 21 and reducing the radiated heat at that position, the temperature rise is suppressed, and uniform heating of the entire sheet 1 or local heating other than the shielding plate 21 is performed.

Hereinafter, description will be made with reference to the drawings. FIG. 3 shows an example in which the shielding plate 21 shown in FIG. 2 has an opening, and the degree of radiated heat can be changed by using one having a different aperture ratio. The shielding plate 21 is provided so as to shield the central portion of the sheet 1. FIG.
6 shows a combination of the shielding plate 21 and the slit 24 for the shielding plate in FIG.
By sliding, a desired aperture ratio can be obtained. In addition, during heating, the temperature rise at the center and the end of the sheet 1 is compared with a radiation thermometer or the like (not shown), and the slit 24 for the shielding plate is used to transmit the rotation of the motor 32 as shown in FIG. It can be opened and closed via a shaft 33, a sprocket 34, and a chain 35.

As another example of driving the chain 35, the tip of the piston of the cylinder and the middle of the chain 35 are connected.
The opening ratio may be changed by expansion and contraction of the cylinder. The combination of the shielding plate slit 24 and the shielding plate 21 can change the aperture ratio, so that the heating temperature of the central portion of the sheet 1 can be adjusted.

FIG. 7 shows a structure in which the shielding plate 21 in FIG. 2 has a tilting function. As in the case of FIG.
3. An arbitrary aperture ratio is obtained by operating the pinion 44 and changing the inclination angle. As another example of changing the inclination angle of the inclined shielding plate 41, a pinion 4
4 may be a sprocket, a chain may be hung on the sprocket, and the chain may be rotationally driven by a motor with a sprocket.

FIG. 8 shows that the central portion of the indirect heating heater 9 or the reflecting plate 22 at an arbitrary position is cooled by water or an empty cooling pipe 51 to lower the ambient temperature at the center of the sheet 1 or at an arbitrary position. By reducing the convective heat transfer, the temperature rise is suppressed, and uniform heating of the entire sheet 1 or local heating other than the cooling unit is performed. FIG. 9 shows an example in which the reflection plate 22 shown in FIG.
It is possible to lower the ambient temperature at the center or at any position, and the structure is simple.

FIG. 10 shows a combination of the reflector 22a having an opening in FIG. 9 and the reflector slit 61.
An arbitrary aperture ratio can be obtained by sliding the slit 61 for the reflection plate. Further, a method of opening and closing the reflecting plate slit 61 with a motor or the like (similar to FIG. 5) while comparing the temperature rise at the center portion and the end portion of the sheet 1 with a radiation thermometer or the like (not shown) during heating is also possible. .

FIG. 11 shows the reflecting plate 22 in FIG. 2 having a tilting function. An arbitrary aperture ratio can be obtained by changing the tilting angle during heating in the same manner as in FIG. 12 and 13, while the indirect heating heater 9 is heating, the temperature rise of the central portion and the end portion of the sheet 1 is compared with a radiation thermometer (not shown), and the portion where the temperature of the sheet 1 is high is indirectly heated. Change the distance to the heater 9 for
By suppressing the radiated heat, the temperature rise at the center of the sheet 1 is suppressed, and the sheet 1 is uniformly heated.

FIG. 13 shows that the indirect heating heater 9 at the center is divided into three parts in the longitudinal direction and the set temperature of the end zones (A, B) is set higher than that of the center zone (C), so that the sheet is heated. 1 suppresses a rise in the sheet temperature at the central portion and uniformly heats the entire sheet. Alternatively, the local heating is performed by setting the temperature at an arbitrary position high. The indirect heating heater 9 is moved up and down by a cylinder 81. The indirect heating heater 9-1 is an indirect heating heater in the end zone (B), the indirect heating heater 9-2 is an indirect heating heater in the end zone (A), and the indirect heating heater 9-3 is This is a heater for indirect heating in the central zone (C).

FIG. 14 shows that a short indirect heating heater 9-4 is installed at the end between the indirect heating heaters 9 to accelerate the temperature rise of the sheet 1 at the end of the sheet 1 so that the entire sheet 1 can be uniformly heated. I do. Alternatively, a short heater 9-4 for indirect heating is installed at an arbitrary position, and the local temperature is increased by increasing the sheet temperature at that portion.

[0027]

EXAMPLE 1 FIG. 15 shows a sheet surface temperature distribution when an ABS sheet having a thickness of 2.5 mm was heated for a predetermined time by a conventional short-wavelength rod heater having a maximum energy wavelength of 1.2 μm. At present, the temperature distribution on the sheet surface is up to 30
° C. Next, according to the sheet heating method in the case where the above-described shielding plate having the opening is used, as shown in FIG.
And the effect of the sheet uniform heating by the shielding plate was obtained.

[0028]

Example 2 The sheet described in Example 1 was heated by using a shielding plate that lowers the temperature at the center of the sheet and increases the temperature at the outer periphery. As a result, as shown in FIG. 17, the temperature at the central portion of the sheet was lower than that at the outer peripheral portion, and a desired effect was obtained.

It is needless to say that the arrangement of the indirect heater, the shielding plate, and the reflecting plate can be variously modified in addition to the above-described embodiment according to the heating mode of the sheet. Further, the present invention is not limited to the above-described embodiments, and various modifications are possible based on the gist of the present invention, and these are not excluded from the scope of the present invention.

[0030]

As described above, according to the present invention, the following effects can be obtained. (A) The entire sheet can be heated to the moldable temperature range without discoloration due to foaming and oxidation, or the sheet temperature distribution can be set arbitrarily to improve formability by improving shape addition and shorten cooling time. Can improve productivity.

(B) In a method of heat-forming a three-dimensional molded product from a thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly composed of a thermoplastic resin, a short wavelength having a maximum energy wavelength of 1 to 3 μm or Using a medium wavelength heater or a long wavelength heater (far infrared heater)
When indirectly heating the sheet, a reflection plate is provided on the back side of the indirect heating heater, and a shielding plate is provided between the sheet and the indirect heating heater at the center of the sheet to uniformly heat the sheet. is there.

(C) By cooling the reflector at a predetermined portion of the indirect heating heater, the ambient temperature is reduced, the temperature of the sheet is prevented from rising at a predetermined portion of the sheet, and uniform heating of the sheet or local heating other than the cooling unit is performed. Is performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram illustrating an outline of a sheet forming machine according to an embodiment of the present invention.

FIG. 2 shows a configuration of an indirect heating device of a sheet forming machine according to an embodiment of the present invention.

FIG. 3 is a configuration diagram (part 1) of a shielding plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 4 is a configuration diagram (part 2) of a shielding plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 5 is a configuration diagram (part 3) of a shielding plate of a sheet forming machine according to an embodiment of the present invention.

6 is a partial cross-sectional view as viewed from the direction indicated by the arrow A in FIG. 5;

FIG. 7 is a configuration diagram (part 4) of a shielding plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 8 is a configuration diagram (part 1) of a reflection plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 9 is a configuration diagram (part 2) of a reflection plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 10 is a configuration diagram (part 3) of a reflection plate of a sheet forming machine according to an embodiment of the present invention.

FIG. 11 is a configuration diagram (No. 4) of a reflector of a sheet forming machine according to an embodiment of the present invention.

FIG. 12 is a diagram (part 1) illustrating an arrangement of an indirect heater of a sheet forming machine according to an embodiment of the present invention.

FIG. 13 is a view (part 2) illustrating an arrangement of an indirect heater of the sheet forming machine according to the embodiment of the present invention.

FIG. 14 is a diagram (part 3) illustrating an arrangement of an indirect heater of the sheet forming machine according to the embodiment of the present invention.

FIG. 15 is a diagram showing a sheet surface temperature distribution when heated by a conventional short-wavelength rod-shaped heater for a predetermined time.

FIG. 16 is a diagram showing a sheet surface temperature distribution by a sheet heating method when a shielding plate having an opening of the present invention is used.

FIG. 17 is a view showing a sheet surface temperature distribution according to a sheet heating method in the case of using a shielding plate that lowers the temperature of the central part of the sheet and increases the temperature of the outer peripheral part of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet (material) 2 Molded product 3 Upper die (female type) 4 Lower die (male type) 5 Lower frame 6 Sheet loading device 7 Sheet lifting device 8 Sheet lifting / lowering cylinder 9, 9-1, 9-2 , 9-3 Indirect heating heater 9-4 Short indirect heating heater 9a Upper heater 9b Lower heater 10a Upper heater driving rack 10b Upper heater driving pinion 11 Lower heater elevating cylinder 12 Upper die elevating cylinder 13 Cylinder for raising and lowering the lower frame 14 Mold removal device 15a Driving belt 15b for molding removal 15b Pulley 21 for molding removal 21 Shielding plate 22, 70 Reflector 22a Reflector having opening 23 Thermometer (radiation) Thermometer) 24 Slit for shielding plate 25 Slide guide 31 Shield plate fixing rod 32 Motor 33 Transmission shaft 34 Sprocket 35 Chain 41 Tilt Actuating cylinder 43 rack 44 pinion 51 water or slits for air cooling pipes 61, 71 reflector 72 inclined reflecting plate 81 a cylinder of the shielding plate 42 inclined shield

Continuation of the front page (56) References JP-A-8-156083 (JP, A) JP-A-47-22465 (JP, A) JP-A-5-337954 (JP, A) JP-A-60-11132 (JP, A) , A) Japanese Utility Model Showa 57-50323 (JP, U) Japanese Utility Model Showa 59-7814 (JP, U) Japanese Patent Publication 56-39258 (JP, B2) Japanese Patent Publication 62-10819 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 51/00-51/46 B29C 35/02-35/14

Claims (15)

(57) [Claims] 1. A method for heat-forming a three-dimensional molded product from a thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly composed of a thermoplastic resin, wherein the sheet is indirectly heated using an indirect heater. ,
An opening is formed between the sheet and the indirect heater.
Shielding plate provided Rutotomoni, adjusting the opening degree of the opening
Adjusting means for opening the shielding plate.
Adjusting a degree of opening of a mouth to adjust heat transmission from the indirect heater, suppressing a rise in temperature of a predetermined portion of the sheet, and adjusting heat applied to the sheet. . 2. The sheet heating method according to claim 1, wherein the adjusting means for adjusting the degree of opening of the opening is formed by a switch.
The slit for the shielding plate with the lit formed is opposed to the shielding plate.
Slidably and slide the slit for the shielding plate
By adjusting the opening degree of the shield plate by de, reduce the temperature rise of a predetermined portion of the sheet, the sheet heating method, characterized by adjusting the heat applied to the sheet. 3. The method for heating a sheet according to claim 1 , wherein an inclined plate is provided at an opening of the shielding plate, and an opening angle of the opening of the shielding plate is adjusted by adjusting an inclination angle of the inclined plate.
Adjusting the heat applied to the sheet by controlling the temperature rise of a predetermined portion of the sheet. 4. A method for heat-forming a three-dimensional molded article from a thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly composed of a thermoplastic resin, wherein the sheet is indirectly heated using an indirect heater. ,
A reflection plate is provided on the back side of the indirect heater, and the back surface of the reflection plate is cooled to suppress an ambient temperature of a predetermined portion of the sheet, suppress a temperature rise of the sheet, and adjust heat applied to the sheet. A method for heating a sheet, comprising: 5. A method for heat-forming a three-dimensional molded article from a thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly containing a thermoplastic resin, wherein the sheet is indirectly heated using an indirect heater. ,
Heating the sheet, wherein a reflecting plate is provided on the back side of the indirect heater, and an opening is provided in the reflecting plate to suppress a temperature rise of a predetermined portion of the sheet and adjust heat applied to the sheet. Method. 6. The sheet heating method according to claim 5 , wherein the slit for the reflection plate having the slit is formed by the reflection.
Provided slidable with respect to the plate, and the slit for the reflection plate
A method for heating a sheet, comprising: adjusting a degree of opening of the reflection plate by sliding, thereby suppressing a temperature rise of a predetermined portion of the sheet and adjusting heat applied to the sheet. 7. The method for heating a sheet according to claim 5 , wherein an inclined plate is provided in an opening of the reflector, and an angle of the inclined plate is adjusted to adjust an opening degree of the opening of the reflector. A method for heating a sheet, comprising suppressing a rise in temperature of a predetermined portion of the sheet and adjusting heat applied to the sheet. 8. An apparatus for thermoforming a three-dimensional molded article from a thermoplastic resin sheet material or a fiber reinforced composite sheet mainly composed of a thermoplastic resin, comprising: (a) an indirect heater for heating the sheet; (B) placed between the sheet and the indirect heater and opened;
A shielding plate which mouth is formed, adjusting the hands to adjust the opening degree of the opening of (c) the shielding plate
And (d) driving means for driving the adjusting means.
The degree of opening of the opening of the shielding plate is adjusted by the adjusting means.
The sheet heating apparatus according to claim 1, wherein the temperature of the sheet is suppressed by increasing the temperature of the sheet, and the heat applied to the sheet is adjusted. 9. The heating device for a seat according to claim 8, before Sulfur butterfly integer means slits are formed, the shielding plate
Equipped with a slit for shielding plate provided to be slidable
Then, the slit for the shielding plate is slid by the driving means.
Te, be characterized by adjusting the opening degree of the shield plate
That the seat of the heating device. 10. A heating device for a seat according to claim 8, before Sulfur butterfly integer means comprises a tilting plate arranged in the opening of the shielding plate, thereby operating the tilting plate by the driving means
Adjusting the degree of opening of the opening of the shielding plate.
Characteristic sheet heating device. 11. A thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly composed of a thermoplastic resin,
An apparatus for heating and forming a three-dimensional molded article, comprising: (a) an indirect heater for heating the sheet; (b) a reflector disposed behind the indirect heater; and (c) a predetermined portion of the reflector. A sheet heating device, comprising: means for cooling the back surface of the sheet. 12. A thermoplastic resin sheet material or a fiber-reinforced composite sheet mainly composed of a thermoplastic resin,
An apparatus for heat-forming a three-dimensional molded article, comprising: (a) an indirect heater for heating the sheet; (b) a reflector disposed behind the indirect heater; and (c) a reflector provided on the reflector. An apparatus for heating a sheet, comprising: an opening. 13. A heating device for a seat according to claim 12, the heating device for a seat, characterized by comprising means for adjusting the opening degree of the reflecting plate. 14. The sheet heating apparatus according to claim 12 , wherein the means for adjusting the degree of opening of the reflector is an inclined plate provided at the opening of the reflector .
That the seat of the heating device. 15. A heating device for a seat according to claim 11, 12, 13 or 14, wherein, shea <br/> over preparative characterized by comprising a shielding plate between said sheet and said indirect heater Heating equipment.